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The toolbox for imaging molecules is well-equipped today. Some techniques visualize the geometrical structure, others the electron density or electron orbitals. Molecules are many-body systems for which the correlation between the constituents is decisive and the spatial and the momentum distribution of one electron depends on those of the other electrons and the nuclei. Such correlations have escaped direct observation by imaging techniques so far. Here, we implement an imaging scheme which visualizes correlations between electrons by coincident detection of the reaction fragments after high energy photofragmentation. With this technique, we examine the H2 two-electron wave function in which electron–electron correlation beyond the mean-field level is prominent. We visualize the dependence of the wave function on the internuclear distance. High energy photoelectrons are shown to be a powerful tool for molecular imaging. Our study paves the way for future time resolved correlation imaging at FELs and laser based X-ray sources.
Secretins form multimeric channels across the outer membrane of Gram-negative bacteria that mediate the import or export of substrates and/or extrusion of type IV pili. The secretin complex of Thermus thermophilus is an oligomer of the 757-residue PilQ protein, essential for DNA uptake and pilus extrusion. Here, we present the cryo-EM structure of this bifunctional complex at a resolution of ~7 Å using a new reconstruction protocol. Thirteen protomers form a large periplasmic domain of six stacked rings and a secretin domain in the outer membrane. A homology model of the PilQ protein was fitted into the cryo-EM map. A crown-like structure outside the outer membrane capping the secretin was found not to be part of PilQ. Mutations in the secretin domain disrupted the crown and abolished DNA uptake, suggesting a central role of the crown in natural transformation.
Patients who undergo endovascular repair of aortic aneurysms (EVAR) require life-long surveillance because complications including, in particular, endoleaks, aneurysm rupture, and graft dislocation are diagnosed in a certain share of the patient population and may occur at any time after the original procedure. Radiation exposure in patients undergoing EVAR and post-EVAR surveillance has been investigated by previous authors. Arriving at realistic exposure data is essential because radiation doses resulting from CT were shown to be not irrelevant. Efforts directed at identification of factors impacting the level of radiation exposure in both the course of the EVAR procedure and post-EVAR endovascular interventions and CTAs are warranted as potentially modifiable factors may offer opportunities to reduce the radiation. In the light of the risks found to be associated with radiation exposure and considering the findings above, those involved in EVAR and post-EVAR surveillance should aim at optimal dose management.
We have determined the crystal structures of two decachlorocyclopentasilanes, namely bis(tetra-n-butylammonium) dichloride decachlorocyclopentasilane dichloromethane disolvate, 2C16H36N+·2Cl−·Si5Cl10·2CH2Cl2, (I), and bis(tetraethylammonium) dichloride decachlorocyclopentasilane dichloromethane disolvate, 2C8H20N+·2Cl−·Si5Cl10·2CH2Cl2, (II), both of which crystallize with discrete cations, anions, and solvent molecules. In (I), the complete decachlorocyclopentasilane ring is generated by a crystallographic twofold rotation axis. In (II), one cation is located on a general position and the other two are disordered about centres of inversion. These are the first structures featuring the structural motif of a five-membered cyclopentasilane ring coordinated from both sides by a chloride ion. The extended structures of (I) and (II) feature numerous C—H⋯Cl interactions. In (II), the N atoms are located on centres of inversion and as a result, the ethylene chains are disordered over equally occupied orientations.
Status and restoration potential of heathlands and sand grasslands in the southwest of Luxembourg
(2017)
In Europe, semi-natural nutrient-poor ecosystems such as sand grasslands and heathlands have shown extreme declines in surface area and species richness within the last century. The remaining sites are hence of high conservation value. This study analysed the vascular plant species inventory of established and recently restored heathlands and sand grasslands in the southwest of Luxembourg. Analyses to explain differences in vegetation composition between “old” (remnant sites or sites restored a long time ago) and “new” (recently restored) sites in relation to environmental variables were carried out with DCAs and ANOVA/Mann-Whitney-U tests, respectively. The vegetation of old heathlands had few character species of typical heathland communities (Calluno-Ulicetea, Nardetalia), whereas new heathland sites were preponderantly marked by taxa of meso- or eutrophic grasslands and ruderal communities. New heathland sites mainly differed from old sites by higher soil phosphorus contents. Sand grassland vegetation was species-rich and composed by species of the Sedo-Scleranthetea and Festuco-Brometea. With increasing age of the sites, vegetation composition shifted to grass dominance with species of the Molinio-Arrhenateretea. New sand grasslands differed from old sand grasslands by higher soil pH, higher soil potassium content and lower graminoid cover. The differences between new and old sites of both habitat types could mainly be explained by successional processes or were a result of topsoil removal. In some cases, former anthropogenic impact at or in close proximity of restored sites resulted in unsuitable conditions, such as alkaline soil on former landfill sites or highly eutrophic soil due to intensive agriculture. Future management options for the study sites are discussed.
This study describes the vascular flora and community structure of grasslands occurring on heaps of waste rock left by former Zn-Pb mining in relation to the metal content in the soil and other environmental factors. The study was performed on 65 heaps scattered in agricultural land in southern Poland. The sites were described in terms of plant community characteristics, soil physicochemical properties, distance from woodland, altitude and local climate. The number of plant species and proportion of species of the Festuco-Brometea class decreased with increasing heavy metal (Cd, Pb, Zn) content in the soil, and increased with Ca content and pH of the soil. There was a negative relationship between the proportion of the later successional species and heavy metal content in the soil and a positive relationship between plants connected with the earlier stages of succession and metals. Floristic composition was also affected by distance from woodland and height above sea level. The investigated heaps were primarily colonised by native species dispersed by wind, characterised as competitive stresstolerant, ruderal and competitive strategy species. Three types of Carlino acaulis-Brometum erecti (CB) communities were distinguished: CB typicum – dominated by Brachypodium pinnatum, with the highest proportion of calcareous grassland species, CB festucetosum ovinae subass. nova – loose grassland with abundant facultative metallophytes, and the CB rubietosum caesi subass. nova with nutrientdemanding ruderal and woody plants invading from the nearby forest communities. The three subassociations represent different successional stages of Carlino acaulis-Brometum erecti, strongly dependent on both the substrate and spatial relations. The proportions of species traits, especially a high occurrence of endangered species and a very low proportion of alien species show that the post-mining habitats studied have a similar degree of ‘naturalness’ as valuable xerothermic grasslands on nonmetalliferous habitats. They thus may be considered as valuable objects for the protection of plant diversity.
This paper provides a comprehensive survey of the results of phytocoenological research into Alnus incana forests from the alliance Alnion incanae in the Dinarides. Stands from the south-eastern Dinarides (Alnetum incanae = Oxali-Alnetum incanae) were analyzed and compared with those from the north-western Dinarides (Lamio orvalae-Alnetum incanae). The comparison reveals significant differences in the floristic composition and in the degree of differentiation – and particularly in the presence of the species of the Illyrian floristic geoelement. Focus was placed on the area of western Croatia where a geographic variant of Helleborus dumetorum had previously been defined within the association Lamio orvalae-Alnetum incanae. Two of its subtypes, Salix alba and Alnus glutinosa, were determined in our research. The former subtype thrives on occasionally flooded, moist sites, where the floristic composition is dominated by hygrophytes. The latter subtype grows on elevated and drier terraces and is richer in mesophilous species from the surrounding zonal forests. A floristic-sociological comparison of the Lamio orvalae-Alnetum incanae with the related syntaxa indicates the presence of about fourty diagnostic species which accentuate its independence and the need to assess it at the level of an independent, regional association within the alliance Alnion incanae.
The aim of our study was to reveal the differences in the species composition and soil properties of open sandy grasslands dominated by different Festuca species, Festuca vaginata and F. pseudovaginata. Due to the arid conditions, sandy grasslands are generally covered by xerothermic vegetation in which F. vaginata is a typical dominant species. Festuca pseudovaginata, a species newly described by the authors, can also gain dominance in sandy grasslands. However, species composition and soil properties of grasslands dominated by this recently discovered species are still undiscovered. Based on previous coenological studies, we hypothesised that the grasslands characterised by the endemic F. vaginata are more species-rich than those with F.pseudovaginata.
Coenological sampling was carried out in May 2009 at two study sites using the Braun-Blanquet method in quadrats of 2 m × 2 m. Five relevés were sampled in stands dominated by F. vaginata and F. pseudovaginata respectively at two study sites in Central Hungary, resulting in a total of twenty relevés. Analyses were based on the cover scores of vascular plant species and cryptogam crust and values of seven soil properties (pH [KCl], pH [H2O], humus, total N, Ca, P2O5 and K2O) measured in the 0–15 and 15–30 cm soil layers. Soil properties of the grasslands dominated by F. pseudovaginata and F. vaginata (dependent variables) were compared by linear mixed models, where ‘grassland type’ was the fixed factor and ‘site nested in grassland type’ was considered as random factor. Data were analysed by cluster analysis, fusion algorithm was a combinatorial method (minimising increase of variance), and the correlation was used as comparative function. We compared the cover of subordinate species by Mann-Whitney U test. We found that F. pseudovaginata and F. vaginata samples were well separated, and grasslands dominated by F. pseudovaginata had nearly two times more species than those dominated by F. vaginata. Based on the cluster analyses using plant cover and upper 0–15 cm soil layer data, F. pseudovaginata and F. vaginata groups could be well separated. Linear mixed models revealed that F. vaginata grasslands were typical on soils with higher pH, nitrogen, phosphorous and potassium contents compared to F. pseudovaginata grasslands, which indicates a tight connection between the properties of the upper soil layer and the vegetation in sandy grasslands.
Bromus racemosus L. is a rather rare grass species of moist meadows. It has strongly decreased in the course of the 20th century due to intensification of agricultural grassland management, and is therefore included in Red Lists of several European countries. Its winter annual life-cycle is remarkable for a species of permanent grasslands.
The aim of this study is to determine the habitat preference and optimal management of B. racemosus in the Netherlands and surrounding countries. Vegetation, soil and hydrological data from 28 sites in the Netherlands have been compared with B. racemosus cover, and with vegetation data from surrounding countries. The results indicate that B. racemosus is characteristic of Molinio-Arrhenatheretea meadows with good mineralisation and aftermath grazing. The optimum lies in grasslands of the alliance Alopecurion pratensis (Deschampsion cespitosae), but the species ranges from wetter Calthion palustris meadows to drier Arrhenatherion elatioris and Cynosurion cristati grasslands. It prefers intermediate nutrient levels and hydrological conditions (mesic sites), but within this range the highest cover is found in relatively nutrient rich and dry sites. Because of the absence of a seedbank and a low dispersal capability, B. racemosus is vulnerable to changes in grassland management. A management of mowing after 15 June and aftermath grazing is most suitable, since it enables fruit ripening and the maintenance of an open sward, needed for germination and development. The risk of extinction is likely to be higher in flat polders than in floodplain sites with natural relief, where the species may shift between belts in different years.
Vegetation patterns of floodplain forests are highly variable across different habitats in European regions. Their plant communities have been well described from the phytosociological point of view, but plant species richness and composition patterns and their underlying environmental factors are still insufficiently known. Sixty-one vegetation plots of black alder-dominated floodplain forests were sampled in central Slovakia in order to find main environmental predictors affecting floristic diversity of their vegetation. For each vegetation plot with a constant size (400m2), vascular plant species and a set of topographic, climatic, soil physical and chemical characteristics were recorded. A generalized linear model was applied to explain relevance of environmental factors on changes of species richness, whereas the relationship between species composition and explanatory variables was tested using ordination methods. Main gradients of species compositional variation were soil moisture, light, elevation and soil chemistry-related variables. Vascular species richness of plots varied between 19 and 59 (mean 38). Herb-layer species richness was positively related to the soil pH, stream power index and negatively to the concentration of soil iron. These linear trends were accompanied by a hump-shaped response to sand content and a U-shaped response to elevation.
Background: Isolated transient vertigo can be the only symptom of posterior circulation ischemia. Thus, it is important to differentiate isolated vertigo of a cerebrovascular origin from that of more benign origins, as patients with cerebral ischemia have a much higher risk for future stroke than do those with "peripheral" vertigo. The current study aims to identify risk factors for cerebrovascular origin of isolated transient vertigo, and for future cerebrovascular events.
Methods: From the files of 339 outpatients with isolated transient vertigo we extracted history, clinical and technical findings, diagnosis, and follow-up information on subsequent stroke or transient ischemic attack (TIA). Risk factors were analyzed using multivariate regression models (logistic or Cox) and reconfirmed in univariate analyses.
Results: On first presentation, 48 (14.2%) patients received the diagnosis "probable or definite cerebrovascular vertigo". During follow-up, 41 patients suffered stroke or TIA (event rate 7.9 per 100 person years, 95% confidence interval (CI) 5.5–10.4), 26 in the posterior circulation (event rate 4.8 per 100 person years, 95% CI 3.0–6.7). The diagnosis was not associated with follow-up cerebrovascular events. In multivariate models testing multiple potential determinants, only the presentation mode was consistently associated with the diagnosis and stroke risk: patients who presented because of vertigo (rather than reporting vertigo when they presented for other reasons) had a significantly higher risk for future stroke or TIA (p = 0.028, event rate 13.4 vs. 5.4 per 100 person years) and for future posterior circulation stroke or TIA (p = 0.044, event rate 7.8 vs. 3.5 per 100 person years).
Conclusions: We here report for the first time follow-up stroke rates in patients with transient isolated vertigo. In such patients, the identification of those with cerebrovascular origin remains difficult, and presentation mode was found to be the only consistent risk factor. Confirmation in an independent prospective sample is needed.
Functional imaging studies using BOLD contrasts have consistently reported activation of the supplementary motor area (SMA) both during motor and internal timing tasks. Opposing findings, however, have been shown for the modulation of beta oscillations in the SMA. While movement suppresses beta oscillations in the SMA, motor and non-motor tasks that rely on internal timing increase the amplitude of beta oscillations in the SMA. These independent observations suggest that the relationship between beta oscillations and BOLD activation is more complex than previously thought. Here we set out to investigate this rapport by examining beta oscillations in the SMA during movement with varying degrees of internal timing demands. In a simultaneous EEG-fMRI experiment, 20 healthy right-handed subjects performed an auditory-paced finger-tapping task. Internal timing was operationalized by including conditions with taps on every fourth auditory beat, which necessitates generation of a slow internal rhythm, while tapping to every auditory beat reflected simple auditory-motor synchronization. In the SMA, BOLD activity increased and power in both the low and the high beta band decreased expectedly during each condition compared to baseline. Internal timing was associated with a reduced desynchronization of low beta oscillations compared to conditions without internal timing demands. In parallel with this relative beta power increase, internal timing activated the SMA more strongly in terms of BOLD. This documents a task-dependent non-linear relationship between BOLD and beta-oscillations in the SMA. We discuss different roles of beta synchronization and desynchronization in active processing within the same cortical region.
Reactive oxygen species are produced transiently in response to cell stimuli, and function as second messengers that oxidize target proteins. Protein-tyrosine phosphatases are important reactive oxygen species targets, whose oxidation results in rapid, reversible, catalytic inactivation. Despite increasing evidence for the importance of protein-tyrosine phosphatase oxidation in signal transduction, the cell biological details of reactive oxygen species-catalyzed protein-tyrosine phosphatase inactivation have remained largely unclear, due to our inability to visualize protein-tyrosine phosphatase oxidation in cells. By combining proximity ligation assay with chemical labeling of cysteine residues in the sulfenic acid state, we visualize oxidized Src homology 2 domain-containing protein-tyrosine phosphatase 2 (SHP2). We find that platelet-derived growth factor evokes transient oxidation on or close to RAB5+/ early endosome antigen 1− endosomes. SHP2 oxidation requires NADPH oxidases (NOXs), and oxidized SHP2 co-localizes with platelet-derived growth factor receptor and NOX1/4. Our data demonstrate spatially and temporally limited protein oxidation within cells, and suggest that platelet-derived growth factor-dependent “redoxosomes,” contribute to proper signal transduction.
Steilhänge der Mittelgebirge weisen eine kleinräumige standörtliche Vielfalt auf und wurden aufgrund ihrer exponierten Lage bereits frühzeitig durch den Menschen u. a. als Befestigungsanlage genutzt. Daraus resultierte häufig eine hohe floristische und vegetationskundliche Diversität mit hohem Naturschutzwert. Durch Umwelt- und Nutzungsveränderungen hat sich aber auch an diesen Standorten in den letzten Jahrzehnten ein starker Wandel vollzogen. Durch Auswertung alter Florenlisten und Vegetationsaufnahmen und durch aktuelle Erhebungen wollen wir die Vegetationszusammensetzung der Lengder Burg, eines Steilhangs auf Unterem Muschelkalk im südlichen Göttinger Wald (Süd-Niedersachsen, Deutschland), und ihre Veränderung aufzeigen und Rückschlüsse für die zukünftige Behandlung ziehen. Dazu wurden Angaben zur Gefäßpflanzenflora aus dem Zeitraum 1950 bis 1995 mit einer aktuellen floristischen Kartierung des Gesamtgebiets von 2016 verglichen. Die Vegetationszusammensetzung wurde anhand von 37 Vegetationsaufnahmen aus dem früheren Zeitraum harakterisiert. 29 dieser Flächen wurden 2009 bis 2016 erneut aufgenommen. Räumliche und zeitliche Unterschiede in der Diversität und Artenzusammensetzung wurden hinsichtlich verschiedener standörtlicher Parameter und ökologischer Artengruppen analysiert.
Die Vegetation lässt sich zwei Gruppen zuordnen: 1. Das Carici-Fagetum und seine Kontaktgesellschaften an südlich und westlich exponierten Steilhängen. 2. Das Hordelymo-Fagetum mit verschiedenen Ausbildungen auf dem Plateau und an flacheren Süd- und Nordhangbereichen. Im Carici-Fagetum ist ein deutlicher Diversitätsverlust und eine Zunahme in der Dominanzstruktur der Krautschicht zu erkennen, der im Vergleich der Aufnahmezeiträume auf eine zunehmende Homogenisierung der Vegetation hinweist. Zurückgegangen sind dabei besonders die typischen Kenn- und Trennarten dieser Waldgesellschaft bei gleichzeitiger Zunahme der Buche in der Verjüngung. Im Hordelymo-Fagetum bewirkt neben Gehölzen in der Strauch- und Krautschicht vor allem die Zunahme von Allium ursinum eine homogenere Artenzusammensetzung, jedoch ohne Diversitätsverlust. Neben Stickstoffeinträgen, dem Klimawandel sowie einem reduzierten Rehwild-Verbiss bedingt besonders der Nutzungswandel diese Veränderungen. Vor allem im Carici-Fagetum wirkte sich der Übergang zwischen früherer Nieder- und Mittelwald-Nutzung mit Waldweide über eine fast 100jährige Hochwald-Nutzung bis zum jetzigen Schutzwald stark aus. Gleichwohl weisen die steilen Hänge weiterhin einen hohen Anteil an Rote-Liste-Arten auf und tragen wesentlich zur hohen Biodiversität des Gebiets bei. Veränderungen in der Vegetation der Lengder Burg spiegeln die Veränderungen im Göttinger Wald insgesamt wider. Kleinflächige Offenhaltungsmaßnahmen zur Erhaltung wertvoller floristischer Elemente sind teilweise erfolgreich. Kleinwüchsige, lichtbedürftige Magerkeitszeiger verschwinden jedoch zunehmend aus den sich entwickelnden, hochwüchsigen Stauden-Säumen. In den benachbarten, unbewirtschafteten Hangbuchenwäldern sorgt die fehlende Nutzung nach Jahrhunderten der Auflichtung und Aushagerung für eine Sukzession in Richtung mesophilen Kalkbuchenwalds.
In Borstgrasrasen (Nardetalia) des Werra-Meißner-Gebietes (Nordhessen, Südniedersachsen) wurden 2012 nach 25 Jahren auf möglichst gleichen Untersuchungsflächen (quasi-Dauerflächen) Wiederholungsaufnahmen angefertigt, um den gegenwärtigen Zustand bzw. Veränderungen in diesem prioritären FFH-Lebensraumtyp zu erfassen. Es wurden insgesamt 61 Flächen untersucht. Neben der Artenzusammensetzung wurden auch Bodenparameter (pH, C/N-Verhältnis, Mächtigkeit der organischen Auflage) und die Nutzung erfasst.
Bei der Wiederholungsaufnahme 2012 waren, abgesehen von einer Aufforstungsfläche, noch auf allen Flächen Arten der Borstgrasrasen vorhanden. Die Flächen wurden 2012 überwiegend genutzt oder gepflegt, während 1986/87 Brachflächen noch bei weitem dominierten. Eine Düngung der Flächen erfolgte nicht. Trotz dieser generell günstigen Nutzungssituation lässt sich ein genereller Trend zur Eutrophierung feststellen, der sich hinsichtlich Artenzahl und Deckung in einer Zunahme von Arten des Wirtschaftsgrünlandes (Molinio-Arrhenatheretea) bei gleichzeitiger Abnahme der Borstgrasrasen-Kennarten äußert. Auch die Artenzahlen der übrigen Magerkeitszeiger nahmen im Mittel ab, während Verbrachungszeiger im Allgemeinen zunahmen. Eine Veränderung der Gesamtartenzahl war nicht festzustellen. Die mittleren Zeigerwerte spiegeln die Verschiebungen im Arteninventar durch erhöhte mittlere Reaktions- und Stickstoffzahlen wider. Strukturell hat in den vergangenen 25 Jahren vor allem eine generelle Zunahme der Moosschichtdeckung und eine Ausbreitung der Sträucher auf Brachflächen stattgefunden. Bei den Bodenparametern waren 2012 eine signifikante Erhöhung der pH-Werte, eine Einengung der C/N-Verhältnisse und eine Abnahme der Mächtigkeit der organischen Auflage (Of) feststellbar. Regressionsmodelle zeigen, dass dabei die Zunahme von Arten des Wirtschaftsgrünlandes direkt mit den ansteigenden pH-Werten zusammen hing, während die Veränderungen bei den Kennarten eher vom Ausgangs-C/N-Verhältnis, teilweise auch von der Entwicklung der organischen Auflage und der Nutzung abhängig waren. Die vorgefundenen Veränderungen werden vor dem Hintergrund möglicher Gefährdungsszenarien (Brache, Eutrophierung, Bodenversauerung, Klimawandel) diskutiert. Angesichts des unerwarteten Befundes einer Eutrophierung bei gleichzeitig nachlassender Bodenversauerung, wird die Hypothese aufgestellt, dass der seit den 1990er-Jahren erfolgte Rückgang der Schwefeldepositionen mit nachfolgender Erholung der Boden-pH-Werte und nachlassender Stressbelastung, z. B. durch Ammonium-Toxizität, die Veränderungen ausgelöst haben könnte. Außerdem deuten die Ergebnisse auf eine zumindest teilweise zu geringe Nutzungs- bzw. Pflegeintensität bzw. zu späte Nutzungstermine. Möglicherweise führt der erhöhte Eutrophierungsdruck hier auch zu verstärkten Anforderungen an das Management der Flächen. Eindeutige Indizien für klimabedingte Veränderungen im Arteninventar ließen sich nicht finden. Indirekte Effekte über eine erwärmungsbedingte Förderung der Mineralisationsraten oder ein ursächlicher Zusammenhang zwischen höheren Wintertemperaturen und der Zunahme der Moosdeckung lassen sich jedoch nicht ausschließen.
Transitional between the Pannonian Basin and the Eastern Carpathians the Transcarpathian Ukraine (Transcarpathia) has a diverse geology including Quaternary sediments, volcanites, limestones and flysch, and its climate at low altitudes is relatively warm and humid. We conducted a field survey in June 2016 focusing on mesophilous forest vegetation along a transect covering almost the whole lowaltitudinal part of Transcarpathia. We recorded 54 relevés in the field and further digitized 22 relevés from literature. Using classification analysis, we distinguished three clusters of oak-hornbeam forests (alliance Carpinion betuli; 1–3) and three clusters of scree and ravine forests (alliance Tilio platyphylli-Acerion; 4–6): (1) Slightly wet Pannonian oak-hornbeam forests occurring in the lowland part of the region (Circaeo-Carpinetum); (2) Mesophilous oak-hornbeam forests (Carici pilosae-Carpinetum); (3) Xero-mesophilous oak-hornbeam forests (a drier subtype of the Carici pilosae-Carpinetum and the association Primulo veris-Carpinetum); (4) Mesophilous scree forests (Phyllitido-Aceretum); (5) Forests of steep slopes (Aceri-Tilietum) and transitions to mesophilous oak-hornbeam forests (Carici pilosae-Carpinetum); (6) Cool and wet scree and ravine forests (Arunco dioici-Aceretum pseudoplatani). Using indirect ordination analysis, three environmental variables (altitude, heat load index and slope) were identified as factors of significant influence on the species composition. These factors well distinguish oak-hornbeam forests from scree and ravine forests.
Understanding plant-plant interactions is essential in planning and implementing effective grassland management strategies. Positive and negative interactions generally co-occur in plant communities and the net effect of these interactions may depend on the disturbance regime, including grazing. Shrubs can act as biotic refuges by physically protecting neighbouring plants from herbivores. As a result, we would expect that in pastures the diversity and flowering success of plants is higher in the close vicinity of shrubs compared to the open vegetation. Nevertheless, we can also assume a competitive trade-off cost for plants that grow together with shrubs. In this study, we assessed the small-scale effects of dwarf shrubs (30–40 cm in diameter) on species density and flowering success. Specifically, we considered three types of microsites: (i) shrub interior, (ii) edge of shrub, and (iii) open pasture (more than 2 meters away from the shrub). We surveyed these three types of microsites using 10 × 10 cm sized plots both in grazed and ungrazed meadow steppe, in central Hungary. The highest species density was found at the edge of shrubs, both in grazed and ungrazed vegetation. Meanwhile, species density did not differ significantly between shrub interiors and the open pasture. However, in grazed vegetation, species flowering success was significantly higher in shrub interiors and edges than in the open pasture; no significant trend was observed for this measure in ungrazed vegetation. In contrast to previous studies, we did not detect a competitive effect of small-sized shrubs on plants in ungrazed vegetation. Our results indicate that small-sized shrubs protect other plants from herbivores and that the edge effect plays an important role for the maintenance of small-scale species diversity in pastures. Overall, our results underline the beneficial effect of biotic refuges in pastures and we suggest that retaining a sparse population of small-sized native shrubs is advantageous from a conservation point of view.
The influence of the Eastern migration route on the Slovak flora – a comparison after 40 years
(2017)
Transport is an important source of introduction and spread of alien plants into new areas and countries. This study provides comprehensive research of selected railway localities in South-Eastern Slovakia to determine the influence of the Eastern Migration Route on the Slovak flora. Railway transshipment yards in Čierna nad Tisou, Dobrá, Velké Kapušany and Matovce were studied from 1964 to 2013; with historic data sampled 1964–1998 and recent data sampled 2012–2013. These data sets were compared to determine differences in species structure following the decreased use of the transshipment yards.
A total of 657 vascular plant taxa were recorded in all localities (566 taxa in the historic and 431 taxa in the recent data set). Native species prevailed over aliens and archaeophytes over neophytes in both time periods. The most frequent aliens were naturalised taxa, where Asiatic and European species prevailed. The most frequent families were Poaceae, Asteraceae and Brassicaceae, and while many species introduced with Russian wheat were recorded only in the past, several taxa are also recorded only recently. Hemicryptophytes were the most abundant life form. Most recorded species were competitors, reproducing by seed and pollinated by insects. Zoochory and hemerochory were the most frequent dispersal types. The proportion of species traits has not changed over time. We identified 49 threatened taxa (38 in the historic and 27 in the recent data set). The Eastern migration route significantly increases the species number of alien vascular plants in the Slovak flora. Although this route had much greater importance in the past, when the role of the Eastern Slovak trans-shipment railway yards was much higher, the studied yards remain an important gateway to Eastern Central Europe and they continue to support agestochory migration of adventive plants.
Wet grasslands once covered a large area in the lowlands of northern Germany, but have declined since several decades as a result of land use intensification. Permanent plot data from such grasslands in the region that would allow to assess the extent of changes in species composition and richness are still rare. Here, we present a re-visitation study of 52 quasi-permanent plots from the Stedinger Land area in the basin of the river Weser near Bremen, comparing quadrat data between 1948 and 2015. In 1948, the grasslands were characterized by species typical of wet, moderately fertile grasslands belonging to the Bromo-Senecionetum aquatici (Bromion racemosi), including 15 species currently classified as threatened. Until 2015, the vegetation had changed strongly: almost all indicators of wet grasslands had either declined or completely vanished, whereas more nutrient-demanding species of less wet soils had increased, especially grasses. The cumulative number of species had declined by 50%, while mean plot species richness had decreased by 64.6%, mainly resulting from the pronounced loss of many herbs. A comparison of mean Ellenberg indicator values suggested that the plots had become drier, but also more base- and nutrient-rich, most likely triggered by the intensification of land use with drainage and fertilization as well as more frequent and earlier cutting. Our study reflects the dramatic loss of plant species diversity in wet grasslands over the past 60−70 years in areas not preserved and properly managed, and it documents the need for protecting remnants of these grasslands and for restoring wet grassland areas by re-wetting, nutrient removal and the transition to a less intensive land use.
Marginal associations, i.e. floristically impoverished associations at the margin of the distribution area of a higher syntaxon, form a problem in vegetation classification, because true character species are lacking. We propose a new approach for the classification of such marginal associations, making use of the notion of 'chorological tension zones'. In the absence of true character species, the species from other syntaxa of the same formation can be used as such. Our proposal is to use the species group from every formation-true class only once within every marginal alliance, to limit the number of possible marginal associations. This approach is illustrated in a classification of the retamoid thickets in the Netherlands. On the basis of a numerical-subjective classification of the relevant species in the scrub layer and the evaluation of relevant literature, we conclude that the broom and gorse thickets in the Netherlands can be assigned to the Cytisetea scopario-striati Rivas-Mart. 1974, which is represented by four associations, each of which is characterised by the species of other scrub classes. The Ulici europaei-Sarothamnion scoparii Doing ex Weber 1997 is represented by the Rubo plicati-Sarothamnetum scoparii Weber 1987 and the Crataego monogynae-Cytisetum scoparii R. Haveman, I. de Ronde & J.H.J. Schaminée ass. nov., the Ulici europaei-Cytision striati Rivas-Mart., Báscones, Díaz, Fern. Gonz. & Loidi 1991 by the Frangulo alni-Ulicetum europaei De Foucault 1988 and the Rubo ulmifolii-Ulicetum europaei J.-M. Géhu ex R. Haveman, I. de Ronde & J.H.J. Schaminée ass. nov. This classification is based on a restricted dataset though, and a revision, based on a larger dataset from a wider region has to prove the tenability of the classification.
Extensively managed pastures harbour rare and endangered species and have a decisive role in maintaining grassland biodiversity. Traditional herding of local robust cattle breeds is considered as a feasible tool for preserving these habitats. We studied the scale-dependent effects of grazing on the species richness and composition of three dry grassland types in the Great Hungarian Plain: Achilleo setaceae-Festucetum pseudovinae and Artemisio santonici-Festucetum pseudovinae alkaline grasslands, and Potentillo arenariae-Festucetum pseudovinae sand grassland. We asked the following questions: (1) Does extensive grazing have a scale-dependent effect on plant species richness of alkaline and sand grasslands? (2) How does grazing affect the proportion of specialists, generalists and weeds in the three grassland types? We sampled ten sites of each grassland type, including five extensively grazed and five non-grazed sites (altogether we had 30 sites). We used a series of nested plots each consisting of 10 plots from the size of 0.01 m² to 16 m². We revealed that grazing has contrasting effects in the three grassland types, and had a considerable effect on their species richness even at small scales. In both alkaline grassland types, total species richness was overall higher in grazed plots but it increased in a similar manner for both ungrazed and grazed habitats across plot sizes. Small-scale heterogeneity likely due to the uneven distribution of grazing, trampling and defecation together with mitigated rate of competition allowed more species to co-exist even at small scales in grazed alkaline grasslands. Grazing increased the richness of specialists, but likely due to the salt stress, establishment of weeds was hampered. Open gaps formed by trampling likely supported the establishment of several specialist species such as Plantago tenuiflora and Puccinellia limosa which are typical to open alkali grasslands. Contrary, in sand grasslands, we did not detect any effect of grazing on total species richness, likely due to the adverse effect of grazing on the species richness of specialists and weeds. In contrast with the former findings we detected significantly higher species richness in 0.01 m² and 0.0625 m² plots in the grazed sand grasslands, but found no differences at larger scales. Whilst species richness of specialists was significantly decreased, richness of weeds was increased by grazing. Decrease in the specialist species richness was likely due to the lack of their evolutionary adaptation to grazing. Degradation caused by grazing and trampling together with the propagule pressure from the neighbouring anthropogenic habitats resulted in an increased richness of weeds in the grazed sites.
The vast majority of European grasslands strongly depend on the regular removal of aboveground biomass by agricultural land use, mostly grazing or mowing or a combination of both. These specific management schemes have strong influence on plant diversity and vegetation composition, depending on their particular characteristics and their intensity. For example, the presence or absence of fertilization will favour some species over others, changing plant communities accordingly. Additionally, the farmer’s choice of a specific management scheme will also depend on the abiotic site conditions. This leads to a complex set of associated factors potentially affecting the structure and diversity of grasslands.
In this study, we compiled a unique dataset of 169 differently managed grasslands (in total 202 plots), which were sampled in five regions across Germany. For each plot, we documented management characteristics, measured plant diversity and functional group composition, recorded endangered species according to red lists, and calculated Ellenberg indicator values. We assessed patterns in vegetation composition and diversity in relation to the particular management scheme, which was categorized as meadow, meadow with autumn or winter grazing (with mowing as predominant management), mown pasture (where mowing and grazing are used at roughly equal intensity), seasonal pasture (with grazing as predominant management) and year-round pasture.
Our study showed that grasslands of different management schemes significantly differed in diversity, structure and functional composition. However, it also became obvious that vegetation composition was not strictly distinguished by management alone. Local and regional characteristics such as soil conditions, size of the grassland species pool or land-use history, often played a more prominent role than land use alone. Assumingly, the interplay of those local and regional characteristics with the proportion of grazing and mowing at a particular site inhibit clear differences among our predefined management schemes. Nevertheless, species richness was the lowest in year-round pastures, moderate in meadows and highest in seasonal pastures. In contrast, year-round pastures harboured the highest mean numbers of endangered species. The dependency of a certain management scheme on site-specific environmental factors such as soil fertility, further complicated the clear separation of management effects from those of the environmental background. In summary, modern grassland management strongly shaped grassland vegetation, but today’s combination of different management practices complicated the assessment of specific land-use effects on plant diversity. Thus, neither mowing nor grazing turned out to be “the one and only” management for nature conservation. Although our results challenge long-term prognoses for future vegetation development under modern grassland management, we clearly showed that low-intensity management and the absence of fertilization promoted plant diversity, with higher values in pastures compared to meadows and mown pastures.
Die in Amerika heimische Kolumbianische Zwergwasserlinse (Wolffia columbiana) tritt neuerdings in Europa als Neophyt auf und konnte in Niedersachsen zum ersten Mal im Jahr 2016 nachgewiesen werden. Im Hintergrund stehen die für den Naturschutz relevanten Fragen, wie viele vermeintliche Vorkommen von Wolffia arrhiza in Wirklichkeit Wolffia columbiana repräsentieren und ob dieser Neophyt die heimische und gefährdete Art Wolffia arrhiza verdrängen kann.
Die Floristisch-soziologische Arbeitsgemeinschaft wurde am 13. August 1927 in Göttingen gegründet und besteht nun, mit einer Unterbrechung zwischen 1941 und 1948, seit 90 Jahren. In diesem Rückblick wird vor allem die Entwicklung nach dem 2. Weltkrieg näher dargestellt. Hauptkapitel sind Verein, Satzung und Vorstände, Mitgliederentwicklung, Jahrestagungen, Arbeitskurse und Workshops, die Publikation der Mitteilungen und von Tuexenia mit ihren Beiheften sowie der Synopsis der Pflanzengesellschaften Deutschlands. Insgesamt wird eine sehr erfolgreiche Entwicklung mit Konstanz wesentlicher, schon zu Beginn formulierter Ziele und dynamischen Anpassungen an neue Gegebenheiten festgestellt.
GrassVeg.DE – die neue kollaborative Vegetationsdatenbank für alle Offenlandhabitate Deutschlands
(2017)
Der Bericht stellt die neue kollaborative Vegetationsdatenbank GrassVeg.DE (EU-DE-020; http://bit.ly/2qgX208) vor, die Vegetationsaufnahmen von Grasländern und anderen nicht-aquatischen Offenlandhabitaten Deutschlands sammelt, um sie national und international für die vegetationsökologische Forschung zur Verfügung zu stellen. GrassVeg.DE trägt die Daten zum European Vegetation Archive (EVA) und künftig auch zur globalen Vegetationsdatenbank „sPlot“ bei. Datenlieferanten von GrassVeg.DE behalten volle Verfügungsgewalt über ihre Daten und werden Mitglied des GrassVeg.DE-Konsortiums. Dadurch profitieren sie durch Co-Autorenschaften und Zitate von ihren Beiträgen und erlangen zugleich die Möglichkeit, selbst Projekte zu beantragen, die GrassVeg.DE- oder EVA-Daten nutzen. Die schnell wachsende GrassVeg.DE-Datenbank umfasste im Juli 2017 3.181 Vegetationsaufnahmen aus acht deutschen Bundesländern. Perspektivisch kann GrassVeg.DE dazu beitragen, eine konsistente Neuklassifikation der Graslandvegetationstypen Deutschlands im Rahmen der Synopsis der Pflanzengesellschaften Deutschlands zu ermöglichen. Wir schließen den Beitrag mit einem Aufruf, eigene und aus der Literatur digitalisierte Vegetationsaufnahmen zu GrassVeg.DE beizutragen.
Seit 12 Jahren werden von Mitgliedern der Eurasian Dry Grassland Group (EDGG) und deren Vorgängerorganisationen Grasland-Sonderteile in Tuexenia herausgegeben. Der diesjährige Sonderteil enthält fünf Artikel, die das Grasland verschiedener mitteleuropäischer Länder mit unterschiedlichen Zielen untersuchen. Der erste Artikel untersucht Auswirkungen von Weide und Mahd auf die Diversität des Graslands in Deutschland in Abhängigkeit von verschiedenen Umweltfaktoren, der zweite die Auswirkung kleiner Büsche auf den Artenreichtum von Gefäßpflanzen in beweideten Wiesensteppen in Ungarn. Der dritte Artikel fragt, ob sich ungarische Sandtrockenrasen mit Festuca vaginata von solchen mit F. pseudovaginata in ihrer Vegetation und ihren Standortsbedingungen unterscheiden; die letztere war erst kürzlich beschrieben worden. Der vierte Artikel modelliert Auswirkungen des Klimawandels auf geschützte Graslandbestände in Serbien und deren Arten während schließlich der fünfte Artikel die Initiative einer neuen Datenbank des deutschen Graslands (GrassVeg.DE) vorstellt und dazu aufruft, sich daran zu beteiligen. Insgesamt haben zu diesem 12. Grasland-Sonderteil 41 Autoren aus fünf Ländern (Dänemark, Deutschland, Italien, Schweiz, Serbien und Ungarn) beigetragen.
Ants were shown to be significant pollinators of two orchid species in the alpine zone of the Alps. Repeated observations from several localities confirm the ant Formica lemani as pollinator of Chamorchis alpina whereas Formica exsecta is reported here for the first time as pollinator of Dactylorhiza viridis. These findings appear of great interest, as significant ant pollination of orchids is unknown so far from any other region or habitat type in the Holarctic. This raises the question if there are specific adaptations. The observations do not provide suggestions to adaptations of the Formica ants for pollinating orchids – they simply followed their normal foraging behavior shown in any type of habitat. Yet, special adaptations are given by the two orchid species in developing pollination mechanisms more strongly involving ground-moving insects which are not inactivated by increased wind velocity and lower temperatures in the alpine zone. These are mainly beetles and ants. The pollination mechanisms and interactions with ants of both orchid species are described. Dactylorhiza viridis is outstanding among orchids in needing 20 to 30 minutes for the 90-degree forward bending of the pollinium after attachment to the insect’s forehead whereas the same process takes place between 15 seconds and 3 to 5 minutes in other orchids. Forward bending of pollinia is required for precise placement of the pollen at the stigmatic surface of another flower. The very long bending time is an adaptation to the longer presence time of ground-moving insects at the same plant and aims to reduce the frequency of geitonogamy (self-fertilization). The high frequency of ant pollination in these orchids is a consequence of the high activity density of aggressive, predatory worker ants leading to a displacement of other pollinators. Attempts of ants to remove the fresh, strongly adhesive pollinia from their foreheads failed and a single ant head could carry up to eight pollinia.
Intense direct and indirect human pressure has been imposed on grasslands throughout their range. Mostly due to the constant need for more food production or due to changes in environmental conditions, grasslands as habitats are expected to become highly endangered. The aim of this study was to estimate the grasslands’ ecological response to future climate and environmental changes. The study took place in three ecologically different grassland communities in three protected natural areas of Serbia (Southeastern Europe), following the same methodology. The study sites were: 1) Peštersko polje Special Nature Reserve (SNR), 2) Deliblato sands SNR (its southern part: Labudovo okno) and 3) Zasavica SNR.
Climate change was simulated for mean temperatures and precipitations using the Eta Belgrade University-Princeton Ocean Model (EBU-POM) climate model, for the A1B Intergovernmental Panel on Climate Change (IPCC) emission scenario covering the 1951–2100 period and insolation and volumetric soil moisture content for the 1979–2100 period. Grassland vegetation was analysed at all three sites. One representative plant community per site was selected for further analysis and simulation of ecological changes. One plot was positioned inside each of the above-mentioned communities, all vascular plant species inside the plot were recorded, and soil samples were taken. Ecological Optima (EO) for moisture and temperature were calculated from modified Ellenberg’s plant indicator values of recorded species. The plants’ response to climate and environmental changes was simulated using the VSD+ model for the 2010–2100 period. The data obtained from the model were further analysed with Canonical Correspondence Analysis (CCA).
Overall results show that the temperature rise, along with the irregular precipitation at all three sites, will lead to a drop of the relative abundance of many native species in the period between 2040 and 2060. The low obtained Habitat Suitability Index for the future means that there will be either unfavourable environmental conditions for the development of grasslands, or the species we analysed were untypical. Cosmopolitans and xerothermic species will be more accustomed to the new conditions. Grasses will be the most resilient functional group according to our study. It may be concluded that the functional group of grasses will also play the leading role in future
grasslands at the studied sites.
Central European temperate forests are – with the exception of floodplain forests – relatively little invaded by alien plants. However, despite substantial recent progress, there is still a lack of using vege-tation plot data for analyzing spatio-temporal patterns of alien tree species invasions.
We calculated relevé-based metrics of tree species’ ecological preferences using 19,413 phytosociological forest relevés of the Austrian vegetation database. We focused on the five most widely distributed alien trees, i.e. two archaeophytes (Castanea sativa, Juglans regia) and three neophytes (Acer negundo, Ailanthus altissima, Robinia pseudoacacia). For each of these species we analyzed the mean cover in the tree layer and the occurrence in the herb and shrub layers in relevés colonized by adult trees as a measure for persistence. Further, we evaluated the intergenerational ecological plasticity (= the ability of young trees to grow under different site conditions than adults) for the tree species, and the mean relevé indicator values for light, nutrients, moisture and hemeroby. We then compared these alien and native tree species metrics.
We found that A. altissima and R. pseudoacacia build up high mean cover values in invaded forests, but this was not the case for the other alien trees. Thus, both species strongly affected forest communities of invaded sites. Similarly, the two species were common in the lower vegetation layers indicating recruitment under the canopy of adult conspecifics; this was facilitated by their ability to produce root suckers. Highest values of inter-generational ecological plasticity occurred in native pioneer trees and species of softwood floodplain forests, while alien trees had moderately high (A. negundo, A. altissima, J. regia) to low values (C. sativa, R. pseudoacacia). With the exception of C. sativa, all alien species showed high mean Ellenberg indicator values for light and nutrients, and were more common in sites with high hemeroby and high mean Ellenberg indicator values for temperature. Distinct from the ecological preferences of alien trees, and thus rarely invaded, were montane beech forests, coniferous mountain forests and forests at extremely dry sites, as well as swamp and bog forests dominated by willows and ash.
We conclude that relevé-based metrics of the behavior of alien tree species allow new insights into the spatio-temporal dynamics of invasion of woody species in forests. Future work should expand this approach, e.g., by considering the role of life history traits and actual site conditions.
The flora in the Caucasus Ecoregion is rich in economically important plants. While its value in terms of food crops and medicinal plants has recently been subject to scientific research, the ornamental value of many Caucasian plant species has not yet been fully recognized. In order to assess the ornamental value of the Caucasian flora, vegetation data from two mountainous study regions in Georgia (n = 958 species, mostly grassland vegetation) was compared with the product range of ornamental plants in Germany using an online plant shopping guide. Characterization of the 150 plant species listed in both databases revealed that 121 species are present in central Europe and 117 species are natives or archaeophytes in Germany. Thus, only few species are Caucasian endemics. Furthermore, a list of 79 potential ornamentals endemic to the Caucasus was compiled from the literature. In order to place them in context of the horticultural market, the species characteristics were examined. Following this, a critical discussion of the potentials and risks arising from trade with ornamental plants was carried out with regard to nature conservation, biological invasion control, genetic resource maintenance and socioeconomic significance.
Der Zwerg-Rohrkolben (Typha minima Funck ex Hoppe) ist eine charakteristische Pionierpflanze von alpinen Wildflusslandschaften. Seit den siebziger Jahren ist diese Kennart jedoch in Deutschland vollständig und in Österreich nahezu ausgestorben. Die anhaltenden Populationsrückgänge der Art sind wahrscheinlich das Ergebnis der weitverbreiteten Flussregulierung und des Kraftwerksbaus in Kombination mit den sehr speziellen Standortsansprüchen der Art. Dank den Anstrengungen von Wiederansiedlungsprogrammen befindet sich T. minima wieder an der Oberen Drau in Österreich. In dieser Publikation wird über die Keimung, das Wachstum, die Reproduktion und die Umweltpräferenzen von T. minima berichtet.
Die Keimungsexperimente von 2014 zeigten eine sehr niedrige mittlere Keimungsrate von 15,6% bei einem Schwankungsbereich von 0–90 %. Die Keimungsraten stiegen mit höheren Temperaturen, erhöhter Saatgutreife und kürzeren Saatgutlagerungszeiten. Nach der Saatgutlagerung von 480 Stunden wurde keine Keimung mehr beobachtet.
Beim FFH-Monitoring 2014 an der Oberen Drau wurden Zwerg-Rohrkolben-Keimlinge (Höhe < 5 cm) generell nur selten gefunden. Die vegetative Jungphase (Höhe > 15 cm, ausschließlich sterile Triebe) wies zumeist den höchsten Flächenanteil im Mittel von 62% auf. Typha minima bildete bis zu einem Alter von ca. 3 Jahren ausschließlich sterile Triebe aus. Ab einem Alter von ca. 9 Jahren wurden auch fertile Triebe mit Blütenständen ausgebildet, wobei deren Anzahl mit zunehmendem Alter sich tendenziell erhöhte. Die Analyse der Standortsfaktoren zeigte, dass T. minima auf eine hohe Bodenfeuchte im Mittel von 39 Vol-% angewiesen ist. Darüber hinaus war der Faktor Beschattung entscheidend. Erst ab einem Beschattungsgrad von 50% durch Weidengebüsche war eine Abnahme der Triebdichte von T. minima zu verzeichnen. Wir schließen daraus, dass T. minima-Populationen während der Keimungsphase extrem empfindlich sind und dass massive Habitatverluste überwiegend das Ergebnis der Flussregulation und der reduzierten Morphodynamik sind, die normalerweise geeignete offene Siedlungsräume für die Keimung des Zwerg-Rohrkolbens schaffen würde.
The view that tumors consist of a homogenous mass of clonal derived cells has dramatically changed in recent years. Tumors harbor an enormous heterogeneity of cells with distinct capabilities and functions. The heterogeneity originates from a differentiation hierarchy of tumor cells, similar to normal tissue organization of stem-cell driven organs, but also from clonal succession of subpopulations by randomly acquired genetic mutations and epigenetic changes. Both scenarios are certainly not mutually exclusive, and also stem and progenitor cells underlie mutational selection. Intratumoral heterogeneity is a major challenge for cancer treatment and disease monitoring. Functional studies revealed that not all tumor cells have the same ability to initiate tumor growth upon transplantation in receptive animal models. The tumorinitiating cells (TICs) were called cancer stem cells due to their similarities to normal tissue stem cells in their molecular and functional properties. They can renew themselves long-term and give rise to tumor cells lacking cancer stem cell properties. However, it is worth stressing here that TICs do not necessarily originate from stem cells, but may have regained stem cell properties. TICs caught major attention since they may provide important steps in the progression of malignant diseases, such as epithelial-to-mesenchymal transition, dissemination, long-term persistence, therapy resistance, and relapse of the disease. The prospective identification of TICs using distinct surface markers would allow their molecular and functional characterization, the design of detection methods for diagnosis and prognosis, and the development of targeted therapies against these detrimental cells. While functional evidence for the existence of TICs were provided for many tumor entities, their marker profile still remains largely undefined and controversial. ...
Purpose: To evaluate long-term outcome of three years and treatment patterns of patients suffering from severely drug-refractory epilepsy (SDRE).
Methods: This analysis was population-based and retrospective, with data collected from four million individuals insured by statutory German health insurance. ICD-10 codes for epilepsy (G40*) and intake of anticonvulsants were used to identify prevalent cases, which were then compared with a matched cohort drawn from the population at large. Insurance data were available from 2008 to 2013. Any patient who had been prescribed with at least four different antiepileptic drugs (AEDs) in an 18-month period was defined as an SDRE case.
Results: A total of 769 patients with SDRE were identified. Of these, 19% were children and adolescents; the overall mean age was 42.3 years, 45.4% were female and 54.6% male. An average of 2.7 AEDs per patient was prescribed during the first follow-up year. The AEDs most commonly prescribed were: levetiracetam (53.5%), lamotrigine (41.4%), valproate (41.3%), lacosamide (20.4%), and topiramate (17.8%). During 3-year follow-up, there was an annual rate of hospitalization in the range 42.7 to 55%, which was significantly higher than the 11.6–12.8% (p < 0.001) for the matched controls. Admissions to hospital because of epilepsy ranged between 1.7 and 1.9 per year, with an average duration for each epilepsy-caused hospitalization of 10–11.1 days. The number of comorbidities for SDRE patients was significantly increased compared with the matched controls: depression (28% against 10%), vascular disorders (22% against 5%), and injury rates were also higher (head 16% against 3%, trunk and limbs 16% against 8%). The 3-year mortality rate for SDRE patients was 14% against 2.1% in the matched cohort.
Conclusion: SDRE patients are treated with AED polytherapy for all of the 3-year follow-up period. They are hospitalized more frequently than the general population and show increased morbidity levels and a sevenfold increase in mortality rate over 3 years. Further examination is required of ways in which new approaches to treatment could lead to better outcomes in severely affected patients.
Background: CML presenting with a variant Philadelphia translocation, atypical BCR-ABL transcript, additional chromosomal aberrations, and evolving MDS is uncommon and therapeutically challenging. The prognostic significance of these genetic findings is uncertain, even as singular aberrations, with nearly no data on management and outcome when they coexist. MDS evolving during the course of CML may be either treatment-associated or an independently coexisting disease, and is generally considered to have an inferior prognosis. Tyrosine kinase inhibitors (TKI) directed against BCR-ABL are the mainstay of treatment for CML, whereas treatment modalities that may be utilized for MDS and CML include allogeneic stem cell transplant and – at least conceptually – hypomethylating agents.
Case report: Here, we describe the clinical course of such a patient, demonstrating that long-term combined treatment with dasatinib and azacitidine for coexisting CML and MDS is feasible and well tolerated, and may be capable of slowing disease progression. This combination therapy had no deleterious effect on subsequent potentially curative haploidentical bone marrow transplantation.
Conclusions: The different prognostic implications of this unusual case and new therapeutic options in CML are discussed, together with a review of the current literature on CML presenting with different types of genomic aberrations and the coincident development of MDS. Additionally, this case gives an example of long-term combined treatment of tyrosine kinase inhibitors and hypomethylating agents, which could be pioneering in CML treatment.
Cellular attachment plays a vital role in the differentiation of pheochromocytoma (PC12) cells. PC12 cells are noradrenergic clonal cells isolated from the adrenal medulla of Rattus norvegicus and studied extensively as they have the ability to differentiate into sympathetic neuron-like cells. The effect of several experimental parameters including (i) the concentration of nerve growth factor (NGF); (ii) substratum coatings, such as poly-L-lysine (PLL), fibronectin (Fn), and laminin (Lam); and (iii) double coatings composed of PLL/Lam and PLL/Fn on the differentiation process of PC12 cells were studied. Cell morphology was visualised using brightfield phase contrast microscopy, cellular metabolism and proliferation were quantified using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, and the neurite outgrowth and axonal generation of the PC12 cells were evaluated using wide field fluorescence microscopy. It was found that double coatings of PLL/Lam and PLL/Fn supported robust adhesion and a two-fold enhanced neurite outgrowth of PC12 cells when treated with 100 ng/mL of NGF while exhibiting stable metabolic activity, leading to the accelerated generation of axons.
We present a dataset of free-viewing eye-movement recordings that contains more than 2.7 million fixation locations from 949 observers on more than 1000 images from different categories. This dataset aggregates and harmonizes data from 23 different studies conducted at the Institute of Cognitive Science at Osnabrück University and the University Medical Center in Hamburg-Eppendorf. Trained personnel recorded all studies under standard conditions with homogeneous equipment and parameter settings. All studies allowed for free eye-movements, and differed in the age range of participants (~7–80 years), stimulus sizes, stimulus modifications (phase scrambled, spatial filtering, mirrored), and stimuli categories (natural and urban scenes, web sites, fractal, pink-noise, and ambiguous artistic figures). The size and variability of viewing behavior within this dataset presents a strong opportunity for evaluating and comparing computational models of overt attention, and furthermore, for thoroughly quantifying strategies of viewing behavior. This also makes the dataset a good starting point for investigating whether viewing strategies change in patient groups.
Background: The Aedes (Stegomyia) albopictus subgroup includes 11 cryptic species of which Ae. albopictus is the most widely distributed. Its global expansion associated with a documented vector competence for several emerging arboviruses raise obvious concerns in the recently colonized regions. While several studies have provided important insights regarding medical importance of Ae. albopicus, the investigations of the other sibling species are scarce. In Asia, indigenous populations within the Ae. albopictus subgroup can be found in sympatry. In the present study, we aimed to describe and compare molecular, morphological and bacterial symbionts composition among sympatric individuals from the Ae. albopictus subgroup inhabiting a Vietnamese protected area.
Results: Based on morphological structure of the cibarial armarture, we identified a cryptic species in the forest park at Bù Gia Mập in the south-eastern region of Vietnam. Analysis of nuclear (ITS1-5.8S-ITS2) and mitochondrial (cox1, nad5) markers confirmed the divergence between the cryptic species and Ae. albopictus. Analysis of midgut bacterial microbiota revealed a strong similarity among the two species with a notable difference; contrary to Ae. albopictus, the cryptic species did not harbour any Wolbachia infection.
Conclusions: These results could reflect either a recent invasion of Wolbachia in Ae. albopictus or alternatively a loss of this symbiont in the cryptic species. We argue that neglected species of the Ae. albopictus subgroup are of main importance in order to estimate variation of host-symbionts interactions across evolution.
Ion channel gating is essential for cellular homeostasis and is tightly controlled. In some eukaryotic and most bacterial ligand-gated K+ channels, RCK domains regulate ion fluxes. Until now, a single regulatory mechanism has been proposed for all RCK-regulated channels, involving signal transduction from the RCK domain to the gating area. Here, we present an inactive ADP-bound structure of KtrAB from Vibrio alginolyticus, determined by cryo-electron microscopy, which, combined with EPR spectroscopy and molecular dynamics simulations, uncovers a novel regulatory mechanism for ligand-induced action at a distance. Exchange of activating ATP to inactivating ADP triggers short helical segments in the K+-translocating KtrB dimer to organize into two long helices that penetrate deeply into the regulatory RCK domains, thus connecting nucleotide-binding sites and ion gates. As KtrAB and its homolog TrkAH have been implicated as bacterial pathogenicity factors, the discovery of this functionally relevant inactive conformation may advance structure-guided drug development.
SR proteins function in nuclear pre-mRNA processing, mRNA export, and translation. To investigate their cellular dynamics, we developed a quantitative assay, which detects differences in nucleocytoplasmic shuttling among seven canonical SR protein family members. As expected, SRSF2 and SRSF5 shuttle poorly in HeLa cells but surprisingly display considerable shuttling in pluripotent murine P19 cells. Combining individual-resolution cross-linking and immunoprecipitation (iCLIP) and mass spectrometry, we show that elevated arginine methylation of SRSF5 and lower phosphorylation levels of cobound SRSF2 enhance shuttling of SRSF5 in P19 cells by modulating protein-protein and protein-RNA interactions. Moreover, SRSF5 is bound to pluripotency-specific transcripts such as Lin28a and Pou5f1/Oct4 in the cytoplasm. SRSF5 depletion reduces and overexpression increases their cytoplasmic mRNA levels, suggesting that enhanced mRNA export by SRSF5 is required for the expression of pluripotency factors. Remarkably, neural differentiation of P19 cells leads to dramatically reduced SRSF5 shuttling. Our findings indicate that posttranslational modification of SR proteins underlies the regulation of their mRNA export activities and distinguishes pluripotent from differentiated cells.
Recently the Universal Linear Accelerator (UNILAC) serves as a powerful high duty factor (25%) heavy ion beam accelerator for the ambitious experiment program at GSI. Beam time availability for SHE (Super Heavy Element)-research will be decreased due to the limitation of the UNILAC providing Uranium beams with an extremely high peak current for FAIR simultaneously. To keep the GSI-SHE program competitive on a high level and even beyond, a standalone superconducting continuous wave (100% duty factor) LINAC in combination with the upgraded GSI High Charge State injector is envisaged. In preparation for this, the first LINAC section (financed by HIM and GSI) will be tested with beam in 2017, demonstrating the future experimental capabilities. Further on the construction of an extended cryo module comprising two shorter Crossbar-H cavities is foreseen to test until end of 2017. As a final R&D step towards an entire LINAC three advanced cryo modules, each comprising two CH cavities, should be built until 2019, serving for first user experiments at the Coulomb barrier.
Die aus Amerika stammende, neophytische Kolumbianische Zwergwasserlinse Wolffia columbiana wurde in Europa erstmals im Jahr 2013 in Deutschland und den Niederlanden nachgewiesen. Daraufhin wurden weitere 11 Freilandvorkommen von Wolffia aus Deutschland (Nordrhein-Westfalen, Hessen und Rheinland-Pfalz), den Niederlanden und Polen überprüft. Bei 10 der insgesamt 13 untersuchten Proben handelte es sich um Wolffia columbiana, darunter alle 8 bislang untersuchten Vorkommen aus Deutschland. Lediglich bei 3 Freilandproben aus den Niederlanden und Polen handelte es sich um die einheimische Wolffia arrhiza. Der Neophyt scheint also durchaus weiter verbreitet zu sein als gedacht. Die Unterscheidung beider Arten ist nicht ganz leicht, die Unterscheidungsmerkmale werden vorgestellt. Die Vorkommen von Wolffia in Europa sollten überprüft werden, um zu klären, wie viele Vorkommen von Wolffia arrhiza es überhaupt noch gibt, und bei wie vielen Vorkommen es sich tatsächlich um die neophytische Wolffia columbiana oder andere neophytische Wolffia-Arten handelt.
Im NSG Emsdettener Venn im Kreis Steinfurt/NRW wächst seit mindestens 2011 Frasers Auenhartheu (Triade-num fraseri), eine Art, die an sumpfigen Standorten in Nord-Amerika heimisch ist. Das Vorkommen breitet sich im Emsdettener Venn weiter aus und ist hier offensichtlich bereits eingebürgert. Da es sich wahrscheinlich um die erste Verwilderung der Art in Deutschland handelt, wird Frasers Auenhartheu mit Fotos vorgestellt und das Vorkommen näher beschrieben.
Es wird über Vorkommen des Rauen Straußgrases Agrostis scabra WILLD. (Poaceae) in Essen und in Nordrhein-Westfalen berichtet. Die Art stammt ursprünglich aus Nordamerika und Ostasien. Sie ist im Ruhrgebiet mindestens seit 1992 eingebürgert und besiedelt offene Standorte auf Zechenbrachen und an Talsperren.
Zwei Funde des Arabischen Schneckenklees (Medicago arabica) in Geseke/Kreis Soest und Köln gaben Anlass, weitere Funde aus NRW zusammenzustellen und den Status der Art im Bundesland zu diskutieren. Angaben von Botanikern des 20. Jahrhunderts legen nahe, dass die Art schon damals an Wegrändern, auf Bahngeländen, auf Geländen von Wollspinnereien und in Gärten eingebürgert war. Zwei aktuelle Vorkommen in Köln und Königs-winter werden hier als eingebürgert betrachtet. Funde im Aachener Raum schließen sich an das niederländische Areal an, wo die Art als indigen betrachtet wird, sodass sogar ein Indigenat der Art in Nordrhein-Westfalen nicht auszuschließen ist.
Im Gemeindegebiet von Holzwickede (Kreis Unna, Nordrhein-Westfalen) wachsen derzeit fünf verschiedene Orchideen-Sippen. Die bei weitem Häufigste ist die Breitblättrige Stendelwurz (Epipactis helleborine), von der mehr als 1300 Pflanzen gefunden wurden und die als typische Orchidee des Siedlungsraums bezeichnet werden kann. Das Fuchs' Knabenkraut (Dactylorhiza fuchsii) wächst heute nicht mehr in der Naturlandschaft, sondern nur noch an zwei Orten in Zierrasen in Privatgärten im Siedlungsraum. Das Hybrid-Knabenkraut (Dactylorhiza maculata agg. x majalis) konnte an drei verschiedenen Stellen in Wiesen gefunden werden und ist offenbar konkurrenzkräftiger als ihre Elternarten. Die Vogelnestwurz (Neottia nidus-avis) war bisher im Gebiet noch nicht gefunden worden, bei dem neu entdeckten Wuchsort handelt es sich möglicherweise um eine Neuansiedlung. Ein Erstfund für Nordrhein-Westfalen gelang mit einer Hybride der Schnepfen-Ragwurz (Ophrys scolopax-Hybride), deren mögliche Herkunft diskutiert wird.
Aktuelle Entwicklungen der Verbreitung und Häufigkeit epiphytischer Moose und Flechten im Stadtgebiet Aachen und in angrenzenden Regionen werden vorgestellt. Speziell besprochen werden die folgenden Arten: Lebermoose: Cololejeunea minutissima, Lejeunea ulicina (= Microlejeunea u.), Metzgeria consanguinea (= M. temperata), M. violacea (= M. fruticulosa); Flechten: Diploicia canescens, Normandina pulchella, Melanohalea exasperata (= Melanelia e.), M. laciniatula (= Melanelia l.), Parmotrema pseudoreticulatum (= Rimelia olivaria), P. reticulatum (= Rimelia r.), Physcia clementei.
Über das Vorkommen stabilisierter Zwischenformen zwischen Geranium purpureum und G. robertianum in Aachen wird berichtet. Sie entsprechen im Habitus, in der Pollengröße sowie in der Farbe der Staubbeutel G. purpureum, unterscheiden sich aber in Kronblattfarbe und -maßen, Kelchfarbe und -behaarung sowie der Fruchtoberfläche. Es handelt sich offenbar um durch introgressive Hybridisation von G. robertianum in G. purpureum entstandene Sippen, die als G. urbanum und G. alboroseum neu beschrieben werden. Aufgrund der Pollengröße ist eine (annähernd) diploide Chromosomenzahl zu erwarten. Selten konnten intermediäre Hybriden G. purpureum × G. robertianum und G. urbanum × G. robertianum beobachtet werden, die heterogen große Pollenkörner ausbilden, keine reifen Früchte bilden und vermutlich triploid sind.
Der erste Teil einer Darstellung der Gattung Echinochloa im Stadtgebiet Aachen und nahe gelegenen Gebieten von Belgien, den Niederlanden und der Städteregion Aachen beschäftigt sich mit der E. muricata-Gruppe. In dieser Gruppe wird neben E. muricata s. str. eine weitere Art, E. wiegandii, unterschieden. Sie vermittelt vom Aussehen der Rispen und Ährchen zu E. crus-galli s. l., gehört aber aufgrund charakteristischer Merkmale der fertilen Deck- und Vorspelzen in die E. muricata-Gruppe. Diagnostische Merkmale von E. wiegandii gegenüber E. muricata s. str. sind ein früherer Blühbeginn, schlankere, schwächer bestachelte, dunkler gefärbte Ährchen sowie eine tendenziell längere Begrannung der Ährchen.
Persicaria x condensata, die Hybride zwischen P. maculosa und P. mitis, konnte an einigen Stellen im Stadtgebiet von Aachen sowie in angrenzenden Gebieten der Städteregion Aachen, Belgien und den Niederlanden an gemeinsamen Wuchsorten der Eltern beobachtet werden, insgesamt in etwa vierhundert Pflanzen. Fast alle sind nahezu steril, morphologisch einheitlich und dürften Primärhybriden sein. Sie vermitteln habituell und in den Merk-malen zwischen den Eltern. Auffallend sind neben der weitgehenden Sterilität die weißen bis hell rosa gefärbten Blütenstände. An einem Fundort in Deutschland konnten deutlich stärker fertile Rückkreuzungen von P. x condensata mit P. maculosa nachgewiesen werden. Sie ähneln P. maculosa. Die Entstehung mehrerer abweichender, recht einheitlicher, wenig fertiler Pflanzen von P. x condensata, die P. mitis stärker ähneln, ist ungeklärt. Sie wuchsen an zwei Stellen in den Niederlanden. An zwei Wuchsorten in Belgien und den Niederlanden konnten sechs Pflanzen von Persicaria x subglandulosa, der Hybride zwischen P. hydropiper und P. minor, und 13 Pflanzen von P. x wilmsii, der Hybride zwischen P. minor und P. mitis, beobachtet werden. P. x subglandulosa bildete keine reifen Früchte und zeigte ebenfalls weißliche Blütenstände. Die Pflanzen vermitteln zwischen den Eltern, ähneln insgesamt eher P. minor, vergrünen im Blütenbereich stärker und sind hier deutlich drüsig. P. x wilmsii ist partiell steril, bildet aber mehr gut ausgebildete Früchte als die anderen Hybriden (außer Rückkreuzungen) aus. Auch bei dieser Hybride sind die Blütenstände weißlich. Sie bildet zwischen den Eltern ansonsten vermittelnde Merkmale aus. Dies betrifft den Habitus sowie die Blüten, Früchte und Blätter. Andere Hybriden zwischen Persicaria hydropiper, P. maculosa, P. minor und P. mitis konnten nicht nachgewiesen werden. Das herausragende Merkmal der beobachteten Hybriden, das auch auf weitere fast sterile Persicaria-Hybriden zutreffen dürfte, sind auffallend helle Blütenstände, die eine einfache Identifizierung von Hybridpflanzen innerhalb von Persicaria-Populationen erlauben.
Hier werden bemerkenswerte floristische Funde aus Nordrhein-Westfalen aus dem Jahr 2016 und einige Nachträge aus 2015 zusammengestellt, die aus Sicht der Schriftleitung von landesweiter Bedeutung sind. Die Funde werden im Laufe des Jahres zunächst chronologisch auf die Homepage des Bochumer Botanischen Vereins gestellt und am Ende des Jahres zu einem Artikel zusammengefasst. Bei der Auswahl der Arten für diese Liste ist nicht an Bestätigung bereits lange bekannter Vorkommen gedacht, die an Ort und Stelle durchgehend vorkommen, sondern z. B. an Neufunde seltener Arten, Wiederfunde seltener Arten, die zwischendurch verschwunden schienen (wie z. B. Ackerunkräuter) oder auch an bekannte Vorkommen, die erloschen sind oder kurz vor dem Erlöschen stehen. Außerdem nehmen Beobachtungen von neophytischen Arten einen großen Raum ein, die entweder auf dem Wege der Einbürgerung sind, deren Einbürgerung noch nicht allgemein bekannt bzw. anerkannt ist oder deren Vorkommen bisher erst selten für Nordrhein-Westfalen veröffentlicht wurden. Ein wichtiges Kriterium für aufgeführte Arten ist die Seltenheit im Bundesland oder der betreffenden Großlandschaft bzw. Region. Die Zuordnung der Arten zu Pflanzenfamilien richtet sich nach Parolly & Rohwer 2016.
Im Folgenden werden für das östliche Ruhrgebiet bemerkenswerte Funde aufgeführt. Das Gebiet umfasst die Städte Gelsenkirchen, Essen, Herne, Bochum, Dortmund, Hagen und Hamm sowie die Kreise Recklinghausen, Unna und den Ennepe-Ruhr-Kreis. Zur besseren Auswertung wurden hinter den Fundorten die MTB-Angaben (Topographische Karte 1:25000) angegeben und ggf. eine Bewertung des Fundes für den hiesigen Raum und der floristische Status hinzugefügt. Funde aus dem östlichen Ruhrgebiet, die von nordrhein-westfälischer Bedeutung sind, sind im Beitrag Bochumer Botanischer Verein 2017 aufgeführt. Die Zuordnung der Arten zu Pflanzenfamilien richtet sich nach Parolly & Rohwer 2016.
Size-resolved measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations and hygroscopicity were conducted at the remote Amazon Tall Tower Observatory (ATTO) in the central Amazon Basin over a full seasonal cycle (Mar 2014–Feb 2015). In a companion part 1 paper, we presented an in-depth CCN characterization based on annually as well as seasonally averaged time intervals and discuss different parametrization strategies to represent the Amazonian CCN cycling in modelling studies (M. Pöhlker et al., 2016b). The present part 2 study analyzes the aerosol and CCN variability in original time resolution and, thus, resolves aerosol advection and transformation for the following case studies, which represent the most characteristic states of the Amazonian atmosphere:
1. Near-pristine (NP) conditions, defined as the absence of detectable black carbon (< 0.01 µg m−3), showed their highest occurrence (up to 30 %) in the wet season (i.e., Mar–May). On average, the NP episodes are characterized by a bimodal aerosol size distribution (strong Aitken mode: DAit = 70 nm, NAit = ~ 200 cm−3 vs. weaker accumulation mode: Dacc = 170 nm, Nacc = ~ 60 cm−3), a mostly organic particle composition, and relatively low hygroscopicity levels (κAit = 0.12 vs. κacc = 0.18). The NP CCN efficiency spectrum shows that the CCN population is sensitive to changes in supersaturation (S) over a wide S range.
2. Long-range transport (LRT) conditions frequently mix Saharan dust, African combustion smoke, and sea spray aerosols into the Amazonian wet season atmosphere. The LRT episodes (i.e., Feb–Apr) are characterized by an accumulation mode dominated size distribution (DAit = 80 nm, NAit = 120 cm−3 vs. Dacc = 180 nm, Nacc = 300 cm−3), a clearly increased abundance of dust and salt compounds, and relatively high hygroscopicity levels (κAit = 0.18, κacc = 0.34). The LRT CCN efficiency spectrum shows that the CCN population is highly sensitive to changes in S in the low S regime.
3. Biomass burning (BB) conditions dominate the Amazonian dry season. A selected characteristic BB episode shows a very strong accumulation mode (DAit = 70 nm, NAit = ~ 140 cm−3 vs. Dacc = 170 nm, Nacc = ~ 3400 cm−3), particles with very high organic fractions (> 90 %), and correspondingly low hygroscopicity levels (κAit = 0.14, κacc = 0.17). The BB CCN efficiency spectrum shows that the CCN population is highly sensitive to changes in S in the low S regime.
4. Mixed pollution conditions show the superposition of African (i.e., volcanic) and Amazonian (i.e., biomass burning) aerosol emissions during the dry season. The African aerosols showed a broad monomodal distribution (D = 130 nm, N = ~ 1300 cm−3), with very high sulfate fractions (20 %), and correspondingly high hygroscopicity (κAit = 0.14, κacc = 0.22). This was superimposed by fresh smoke from nearby fires with one strong mode (D = 113 nm, Nacc = ~ 2800 cm−3), an organic-dominated aerosol, and sharply decreased hygroscopicity (κAit = 0.10, κacc = 0.20). These conditions underline the rapidly changing pollution regimes with clear impacts on the aerosol and CCN properties.
Overall, this study provides detailed insights into the CCN cycling in relation to aerosol-cloud interaction in the vulnerable and climate-relevant Amazon region. The detailed analysis of aerosol and CCN key properties and particularly the extracted CCN efficiency spectra with the associated fit parameters provide a basis for an in-depth analysis of aerosol-cloud interaction in the Amazon and beyond.
The physical housing environment is important to facilitate activities of daily living (ADL) for older people. A hindering environment may lead to ADL dependence and thus increase the need for home services, which is individually restricting and a growing societal burden. This study presents simulations of policy changes with regard to housing accessibility that estimates the potential impact specifically on instrumental activities of daily living (I-ADL), usage of home services, and related costs. The models integrate empirical data to test the hypothesis that a policy providing funding to remove the five most severe environmental barriers in the homes of older people who are at risk of developing dependence in I-ADL, can maintain independence and reduce the need for home services. In addition to official statistics from state agencies in Sweden and Germany, we utilized published results from the ENABLE-AGE and other scientific studies to generate the simulations. The simulations predicted that new policies that remove potentially hindering housing features would improve I-ADL performance among older people and reduce the need for home services. Our findings suggest that a policy change can contribute to positive effects with regard to I-ADL independence among older people and to a reduction of societal burden.
We developed a coupled regional climate system model based on the CCLM regional climate model. Within this model system, using OASIS3-MCT as a coupler, CCLM can be coupled to two land surface models (the Community Land Model (CLM) and VEG3D), the NEMO-MED12 regional ocean model for the Mediterranean Sea, two ocean models for the North and Baltic seas (NEMO-NORDIC and TRIMNP+CICE) and the MPI-ESM Earth system model.
We first present the different model components and the unified OASIS3-MCT interface which handles all couplings in a consistent way, minimising the model source code modifications and defining the physical and numerical aspects of the couplings. We also address specific coupling issues like the handling of different domains, multiple usage of the MCT library and exchange of 3-D fields.
We analyse and compare the computational performance of the different couplings based on real-case simulations over Europe. The usage of the LUCIA tool implemented in OASIS3-MCT enables the quantification of the contributions of the coupled components to the overall coupling cost. These individual contributions are (1) cost of the model(s) coupled, (2) direct cost of coupling including horizontal interpolation and communication between the components, (3) load imbalance, (4) cost of different usage of processors by CCLM in coupled and stand-alone mode and (5) residual cost including i.a. CCLM additional computations.
Finally a procedure for finding an optimum processor configuration for each of the couplings was developed considering the time to solution, computing cost and parallel efficiency of the simulation. The optimum configurations are presented for sequential, concurrent and mixed (sequential+concurrent) coupling layouts. The procedure applied can be regarded as independent of the specific coupling layout and coupling details.
We found that the direct cost of coupling, i.e. communications and horizontal interpolation, in OASIS3-MCT remains below 7 % of the CCLM stand-alone cost for all couplings investigated. This is in particular true for the exchange of 450 2-D fields between CCLM and MPI-ESM. We identified remaining limitations in the coupling strategies and discuss possible future improvements of the computational efficiency.
Background: As members of the Notothenioidei - the dominant fish taxon in Antarctic waters - the family Bathydraconidae includes 12 genera and 17 species. The knowledge of these species inhabiting an isolated environment is rather fragmentary, including their parasite fauna. Studies on fish hosts and their associated parasites can help gain insights into even remote ecosystems and be used to infer ecological roles in food webs; however, ecological studies on the Bathydraconidae are scarce.
Results: In this study, stomach contents and parasite fauna of the Antarctic dragonfish species Parachaenichthys charcoti (n = 47 specimens) as well as of Gerlachea australis (n = 5), Gymnodraco acuticeps (n = 9) and Racovitzia glacialis (n = 6) were examined. The parasite fauna of P. charcoti consisted of eight genera represented by 11 species, with three of them being new host records. Overall, 24 parasite genera and 26 species were found in the sampled fish, including eleven new host records.
Conclusion: Analyses revealed that the majority of the parasite species found in the different fish hosts are endemic to Antarctic waters and are characterized by a broad host range. These findings are evidence for the current lack of knowledge and the need for further parasitological studies of fish species in this unique habitat.
Background: Treatment of asthma does not always comply with asthma guidelines (AG). This may be rooted in direct or indirect resistance on the doctors’ and/or patients’ side or be caused by the healthcare system. To assess whether patients’ concepts and attitudes are really an implementation barrier for AG, we analysed the patients’ perspective of a “good asthma therapy” and contrasted their wishes with current recommendations.
Methods: Using a qualitative exploratory design, topic centred focus group (FG) discussions were performed until theoretical saturation was reached. Inclusion criteria were an asthma diagnosis and age above 18. FG sessions were recorded audio-visually and analysed via a mapping technique and content analysis performed according to Mayring (supported by MAXQDA®). Participants’ speech times and the proportion of time devoted to different themes were calculated using the Videograph System® and related to the content analysis.
Results: Thirteen men and 24 women aged between 20 and 77 from rural and urban areas attended five FG. Some patients had been recently diagnosed with asthma, others years previously or in childhood. The following topics were addressed: (a) concern about or rejection of therapy components, particularly corticosteroids, which sometimes resulted in autonomous uncommunicated medication changes, (b) lack of time or money for optimal treatment, (c) insufficient involvement in therapy choices and (d) a desire for greater empowerment, (e) suboptimal communication between healthcare professionals and (f) difficulties with recommendations conflicting with daily life. Primarily, (g) participants wanted more time with doctors to discuss difficulties and (h) all aspects of living with an impairing condition.
Conclusions: We identified some important patient driven barriers to implementing AG recommendations. In order to advance AG implementation and improve asthma treatment, the patients’ perspective needs to be considered before drafting new versions of AG. These issues should be addressed at the planning stage.
Trial registration: DRKS00000562 (German Clinical Trials Registry).
To assess the scope of infection control measures for multidrug-resistant bacteria in high-risk settings, a survey among university hospitals was conducted. Fourteen professionals from 8 sites participated. Reported policies varied largely with respect to the types of wards conducting screening, sample types used for screening and implementation of contact precautions. This variability among sites highlights the need for an evidence-based consensus of current infection control policies.
The yeast bc1 complex (complex III) and cytochrome oxidase (complex IV) are mosaics of core subunits encoded by the mitochondrial genome and additional nuclear-encoded proteins imported from the cytosol. Both complexes build in the mitochondrial inner membrane various supramolecular assemblies. The formation of the individual complexes and their supercomplexes depends on the activity of dedicated assembly factors. We identified a so far uncharacterized mitochondrial protein (open reading frame YDR381C-A) as an important assembly factor for complex III, complex IV, and their supercomplexes. Therefore, we named this protein Cox interacting (Coi) 1. Deletion of COI1 results in decreased respiratory growth, reduced membrane potential, and hampered respiration, as well as slow fermentative growth at low temperature. In addition, coi1Δ cells harbour reduced steady-state levels of subunits of complexes III and IV as well as of the assembled complexes and supercomplexes. Interaction of Coi1 with respiratory chain subunits seems transient, as it appears to be a stoichiometric subunit neither of complex III nor of complex IV. Collectively, this work identifies a novel protein that plays a role in the assembly of the mitochondrial respiratory chain.
The mouse bitter taste receptors Tas2r143, Tas2r135, and Tas2r126 are encoded by genes that cluster on chromosome 6 and have been suggested to be expressed under common regulatory elements. Previous studies indicated that the Tas2r143/Tas2r135/Tas2r126 cluster is expressed in the heart, but other organs had not been systematically analyzed. In order to investigate the expression of this bitter taste receptor gene cluster in non-gustatory tissues, we generated a BAC (bacterial artificial chromosome) based transgenic mouse line, expressing CreERT2 under the control of the Tas2r143 promoter. After crossing this line with a mouse line expressing EGFP after Cre-mediated recombination, we were able to validate the Tas2r143-CreERT2 transgenic mouse line and monitor the expression of Tas2r143. EGFP-positive cells, indicating expression of members of the cluster, were found in about 47% of taste buds, and could also be found in several other organs. A population of EGFP-positive cells was identified in thymic epithelial cells, in the lamina propria of the intestine and in vascular smooth muscle cells of cardiac blood vessels. EGFP-positive cells were also identified in the epithelium of organs readily exposed to pathogens including lower airways, the gastrointestinal tract, urethra, vagina, and cervix. With respect to the function of cells expressing this bitter taste receptor cluster, RNA-seq analysis in EGFP-positive cells isolated from the epithelium of trachea and stomach showed expression of genes related to innate immunity. These data further support the concept that bitter taste receptors serve functions outside the gustatory system.
The mTOR (mechanistic target of rapamycin) inhibitor rapamycin has long been known for its immune suppressive properties, but it has shown limited therapeutic success when given systemically to patients with psoriasis. Recent data have shown that the mTOR pathway is hyperactivated in lesional psoriatic skin, which probably contributes to the disease by interfering with maturation of keratinocytes. This study investigated the effect of topical rapamycin treatment in an imiquimod-induced psoriatic mouse model. The disease was less severe if the mice had received rapamycin treatment. Immunohistological analysis revealed that rapamycin not only prevented the activation of mTOR signalling (P-mTOR and P-S6 levels), but almost normalized the expression of epidermal differentiation markers. In addition, the influx of innate immune cells into the draining lymph nodes was partially reduced by rapamycin treatment. These data emphasize the role of mTOR signalling in the pathogenesis of psoriasis, and support the investigation of topical mTOR inhibition as a novel anti-psoriatic strategy.
Brain-derived neurotrophic factor (BDNF), an important neural growth factor, has gained growing interest in neuroscience, but many influencing physiological and analytical aspects still remain unclear. In this study we assessed the impact of storage time at room temperature, repeated freeze/thaw cycles, and storage at −80 °C up to 6 months on serum and ethylenediaminetetraacetic acid (EDTA)-plasma BDNF. Furthermore, we assessed correlations of serum and plasma BDNF concentrations in two independent sets of samples. Coefficients of variations (CVs) for serum BDNF concentrations were significantly lower than CVs of plasma concentrations (n = 245, p = 0.006). Mean serum and plasma concentrations at all analyzed time points remained within the acceptable change limit of the inter-assay precision as declared by the manufacturer. Serum and plasma BDNF concentrations correlated positively in both sets of samples and at all analyzed time points of the stability assessment (r = 0.455 to rs = 0.596; p < 0.004). In summary, when considering the acceptable change limit, BDNF was stable in serum and in EDTA-plasma up to 6 months. Due to a higher reliability, we suggest favoring serum over EDTA-plasma for future experiments assessing peripheral BDNF concentrations.
Treatment of refractory ascites with an automated low-flow ascites pump in patients with cirrhosis
(2017)
Background: Refractory ascites (RA) is a frequent complication of cirrhosis, requiring large volume paracentesis or placement of a transjugular intrahepatic portosystemic shunt (TIPSS). The automated low-flow ascites pump (alfapump, Sequana Medical AG, Zurich, Switzerland) is an innovative treatment option for patients with RA.
Aim: To assess safety and efficacy of this treatment in patients with a contraindication to TIPSS.
Methods: Fifty-six patients (43 males; mean age 62 years) from centres in Germany, Switzerland, UK and Spain were included and followed for up to 24 months. Complications, device deficiencies, paracentesis frequency and patient survival were recorded.
Results: At the time of this analysis, 3 patients completed the 24-month observation period, monitoring of 3 was ongoing, 9 underwent liver transplantation, 17 patients were withdrawn due to serious adverse events and 23 patients died. Most frequently observed technical complication was blocking of the peritoneal catheter. Twenty-three pump-related reinterventions (17 patients) and 12 pump exchanges (11 patients) were required during follow-up. The pump system was explanted in 48% of patients (in 17 patients due to serious adverse events, in 9 at the time of liver transplantation and in 1 due to recovery from RA). Median frequency of paracentesis dropped from 2.17 to 0.17 per month.
Conclusions: The alfapump can expand therapeutic options for cirrhotic patients with RA. Continuous drainage of ascites in a closed loop automated system led to significant reduction in paracentesis frequency. Technical and procedural improvements are required to reduce the rate of adverse events and reinterventions.
The histopathological and molecular heterogeneity of glioblastomas represents a major obstacle for effective therapies. Glioblastomas do not develop autonomously, but evolve in a unique environment that adapts to the growing tumour mass and contributes to the malignancy of these neoplasms. Here, we show that patient-derived glioblastoma xenografts generated in the mouse brain from organotypic spheroids reproducibly give rise to three different histological phenotypes: (i) a highly invasive phenotype with an apparent normal brain vasculature, (ii) a highly angiogenic phenotype displaying microvascular proliferation and necrosis and (iii) an intermediate phenotype combining features of invasion and vessel abnormalities. These phenotypic differences were visible during early phases of tumour development suggesting an early instructive role of tumour cells on the brain parenchyma. Conversely, we found that tumour-instructed stromal cells differentially influenced tumour cell proliferation and migration in vitro, indicating a reciprocal crosstalk between neoplastic and non-neoplastic cells. We did not detect any transdifferentiation of tumour cells into endothelial cells. Cell type-specific transcriptomic analysis of tumour and endothelial cells revealed a strong phenotype-specific molecular conversion between the two cell types, suggesting co-evolution of tumour and endothelial cells. Integrative bioinformatic analysis confirmed the reciprocal crosstalk between tumour and microenvironment and suggested a key role for TGFβ1 and extracellular matrix proteins as major interaction modules that shape glioblastoma progression. These data provide novel insight into tumour-host interactions and identify novel stroma-specific targets that may play a role in combinatorial treatment strategies against glioblastoma.
In Benin, people have a rich ethnobotanical knowledge of plant species, reflecting the cultural and ecological diversity of their environment. Several studies were focused on the question of how valuable are plant species for local communities. However, there has been very little research interest in the orchid species in spite of the importance of orchids in the livelihood of the local people. This study examined the use and differences in knowledge of local people of orchids in the Sudanian zone of Benin. An ethnobotanical study was conducted amongst the four main socio-economic and ethnic groups from six villages around the Pendjari Biosphere Reserve in Benin. One hundred and sixty people participated in this study. Data were gathered using semi-structured individual interviews and analysed using quantitative ethnobotanical methods. 29 different types of use were recorded and can be grouped into four main use categories: medicinal, veterinary, spiritual and food. There were differences in orchid utilization among the ethnic groups, gender and age. The knowledge of orchid uses was significantly affected by the ethnic group and the age of the respondent. Unlike young educated generations, most adults and elders, especially women, had a more comprehensive knowledge of orchid uses. Calyptrochilum christianum, the most used orchid, was mentioned in more than 50% of the types of orchid use. The Gourmantché and Waama tribe had more knowledge on orchid use whereas the Berba tribe had less knowledge. Three orchid species (Habenaria cirrhata, Eulophia horsfallii and Nervilia bicarinata) were reported as food. Orchids had low use value ranging from 0.01 (Eulophia spp) to 0.2 (C. christianum). The controlled access to the biosphere reserve and rural exodus can explain the lack of indigenous knowledge transfer of orchid use and value from elders to the young generation.
Cette étude analyse les stratégies locales de dénomination des espèces végétales par les Mossé des régions du nord, du centre nord, du centre et du Plateau Central du Burkina Faso et leurs perceptions des plantes. A travers des interviews semi directes auprès de 1437 personnes âgées d’au moins 60 ans et des jeunes de moins de 40 ans des différentes localités, l’étude a pu montrer les critères de dénomination, les conceptions que les populations ont des espèces végétales ainsi que l‘impact de ces connaissances dans la conservation de la phytodiversité. 72 espèces au total ont été décrites. Elles sont réparties en 51 genres et 29 familles. Les familles dominantes sont les Commelinaceae et les Fabaceae-Mimosoideae. Dans la taxonomie locale faite sur les plantes en milieu rural Mossé, 16 critères sont utilisés. Les critères les plus cités par la population sont l’usage fait de la plante (94 %), le mysticisme lié à l’espèce (86 %), l’écologie ou le milieu de vie de l’espèce (83 %), la dualité mâle/femelle (83 %), la couleur des organes ou parties de la plante (81 %), l’origine de la plante (80 %), la morphologie foliaire (76 %), la présence d’organes saillants sur la plante (75 %) et le mode de dissémination des fruits ou des graines (74 %). Les noms botaniques attribués aux plantes varient d’une région à une autre. Les populations ont des perceptions vis-à-vis de nombreuses espèces. Ainsi, les espèces comme Stereospermum kunthianum, Calotropis procera, Ozoroa insignis, Faidherbia albida, Maytenus senegalensis et Biophytum umbraculum sont frappées de mysticisme. Elles sont toutes craintes par les populations et sont dans certaines localités à l’abri d’exploitations multiformes humaines. Cela contribue à une meilleure conservation de la biodiversité.
La connaissance du potentiel et de la productivité d'une ressource est une donnée nécessaire à l'élaboration d'une bonne politique de sa gestion. La structure et la productivité des peuplements à Acacia seyal Del. et à Acacia senegal (L) Willd.ont été étudiées dans les formations naturelles de Massenya au Tchad. Sur la base de 32 placeaux de 900 m2 , le diamètre et la hauteur de tous les individus d’espèces ligneuses ont été mesurés. Pour des espèces adultes à port arbustif, le diamètre est mesuré à 50 cm du sol. Les individus juvéniles sont simplement comptés et rangés en classe de hauteur. L’étude de la structure des peuplements et de deux espèces d’Acacia a été réalisée à travers le nombre de tiges à l’hectare et les classes de diamètre. L’Indice de Valeur d’Importance (IVI) a été utilisée pour apprécier la prédominance des espèces sur le site. La productivité des peuplements en gomme a été évaluée en fonction de la production moyenne d’un arbre qui était de 250 g. Les peuplements à Acacia de Massenya sont très denses (619 ± 269 tiges/ha), mais à surface terrière faible (7,10 ± 1,20 m²/ ha) due à un grand nombre d’individus de petit diamètre (11,1 ± 2,2 cm). Ce sont des peuplements généralement arbustif (hauteur de 5,2 ± 0,9 m) avec un bon potentiel de juvéniles (408 ± 267 tiges/ha) pouvant se régénérer naturellement. Toutefois, Acacia seyal semble plus apte à coloniser d’autres milieux qu’Acacia senegal. Sur les sept espèces qui prédominent sur le site, Acacia seyal et Acacia senegal réalisent des IVI plus élevés (respectivement 79 et 54). Les espèces à bon potentiel de régénération sont Acacia seyal (65 ± 8 juv./ha), Acacia senegal (58 ± 10 juv./ha) et Guiera senegalensis (51 ± 8 juv./ha). La production annuelle de gomme est estimée à 56 ± 6 kg/ha de gomme friable (à Acacia seyal) et 41 ± 5 kg/ha de gomme dure (à A. senegal).
Most cellular stresses induce protein translation inhibition and stress granule formation. Here, using Drosophila S2 cells, we investigate the role of G3BP/Rasputin in this process. In contrast to arsenite treatment, where dephosphorylated Ser142 Rasputin is recruited to stress granules, we find that, upon amino acid starvation, only the phosphorylated Ser142 form is recruited. Furthermore, we identify Sec16, a component of the endoplasmic reticulum exit site, as a Rasputin interactor and stabilizer. Sec16 depletion results in Rasputin degradation and inhibition of stress granule formation. However, in the absence of Sec16, pharmacological stabilization of Rasputin is not enough to rescue the assembly of stress granules. This is because Sec16 specifically interacts with phosphorylated Ser142 Rasputin, the form required for stress granule formation upon amino acid starvation. Taken together, these results demonstrate that stress granule formation is fine-tuned by specific signaling cues that are unique to each stress. These results also expand the role of Sec16 as a stress response protein.
Self-extracellular RNA (eRNA), released from stressed or injured cells upon various pathological situations such as ischemia-reperfusion-injury, has been shown to act as an alarmin by inducing procoagulatory and proinflammatory responses. In particular, M1-polarization of macrophages by eRNA resulted in the expression and release of a variety of cytokines, including tumor necrosis factor (TNF)-α or interleukin-6 (IL-6). The present study now investigates in which way self-eRNA may influence the response of macrophages towards various Toll-like receptor (TLR)-agonists. Isolated agonists of TLR2 (Pam2CSK4), TLR3 (PolyIC), TLR4 (LPS), or TLR7 (R848) induced the release of TNF-α in a concentration-dependent manner in murine macrophages, differentiated from bone marrow-derived stem cells by mouse colony stimulating factor. Here, the presence of eRNA shifted the dose-response curve for Pam2CSK4 (Pam) considerably to the left, indicating that eRNA synergistically enhanced the cytokine liberation from macrophages even at very low Pam-levels. The synergistic activation of TLR2 by eRNA/Pam was duplicated by other TLR2-agonists such as FSL-1 or Pam3CSK4. In contrast, for TLR4-agonists such as LPS a synergistic effect of eRNA was much weaker, and was not existent for TLR3-, or TLR7-agonists. The synergistic eRNA/Pam action was dependent on the NFκB-signaling pathway as well as on p38MAP- and MEK1/ERK-kinases and was prevented by predigestion of eRNA with RNase1 or by antibodies against TLR2. Thus, the presence of self-eRNA as alarming molecule sensitizes innate immune responses towards pathogen-associated molecular patterns (PAMPs) in a synergistic way and may thereby contribute to the differentiated outcome of inflammatory responses.
Characterization of a novel KCNJ2 sequence variant detected in Andersen-Tawil syndrome patients
(2017)
Background: Mutations in the KCNJ2 gene encoding the ion channel Kir2.1 have been linked to the Andersen-Tawil syndrome (ATS). Molecular genetic screening performed in a family exhibiting clinical ATS phenotypes unmasked a novel sequence variant (c.434A > G, p.Y145C) in this gene. The aim of this study was to investigate the effect of this variant on Kir2.1 ion channel functionality.
Methods: Mutant as well as wild type GFP tagged Kir2.1 channels were expressed in HEK293 cells. In order to examine the effect of the new variant, electrophysiological measurements were performed using patch clamp technique. Cellular localization of the mutant in comparison to the wild type ion channel was analyzed by confocal laser scanning microscopy.
Results: The currents of cells expressing only mutant channels or a mixture of wild type and mutant were significantly reduced compared to those expressing wild type (WT) channels (p < 0.01). Whereas WT expressing cells exhibited at −120 mV an averaged current of −4.5 ± 1.9 nA, the mutant generates only a current of −0.17 ± 0.07 nA. A co-expression of mutant and WT channel generates only a partial rescue of the WT current. Confocal laser scanning microscopy indicated that the novel variant is not interfering with synthesis and/or protein trafficking.
Conclusions: The detected sequence variant causes loss-of-function of the Kir2.1 channel and explains the clinical phenotypes observed in Andersen-Tawil syndrome patients.
Over recent decades, the global population has been rapidly increasing and human activities have altered terrestrial water fluxes to an unprecedented extent. The phenomenal growth of the human footprint has significantly modified hydrological processes in various ways (e.g. irrigation, artificial dams, and water diversion) and at various scales (from a watershed to the globe). During the early 1990s, awareness of the potential for increased water scarcity led to the first detailed global water resource assessments. Shortly thereafter, in order to analyse the human perturbation on terrestrial water resources, the first generation of large-scale hydrological models (LHMs) was produced. However, at this early stage few models considered the interaction between terrestrial water fluxes and human activities, including water use and reservoir regulation, and even fewer models distinguished water use from surface water and groundwater resources. Since the early 2000s, a growing number of LHMs have incorporated human impacts on the hydrological cycle, yet the representation of human activities in hydrological models remains challenging. In this paper we provide a synthesis of progress in the development and application of human impact modelling in LHMs. We highlight a number of key challenges and discuss possible improvements in order to better represent the human–water interface in hydrological models.
Protein disulfide isomerases (PDIs) support endoplasmic reticulum redox protein folding and cell-surface thiol-redox control of thrombosis and vascular remodeling. The family prototype PDIA1 regulates NADPH oxidase signaling and cytoskeleton organization, however the related underlying mechanisms are unclear. Here we show that genes encoding human PDIA1 and its two paralogs PDIA8 and PDIA2 are each flanked by genes encoding Rho guanine-dissociation inhibitors (GDI), known regulators of RhoGTPases/cytoskeleton. Evolutionary histories of these three microsyntenic regions reveal their emergence by two successive duplication events of a primordial gene pair in the last common vertebrate ancestor. The arrangement, however, is substantially older, detectable in echinoderms, nematodes, and cnidarians. Thus, PDI/RhoGDI pairing in the same transcription orientation emerged early in animal evolution and has been largely maintained. PDI/RhoGDI pairs are embedded into conserved genomic regions displaying common cis-regulatory elements. Analysis of gene expression datasets supports evidence for PDI/RhoGDI coexpression in developmental/inflammatory contexts. PDIA1/RhoGDIα were co-induced in endothelial cells upon CRISP-R-promoted transcription activation of each pair component, and also in mouse arterial intima during flow-induced remodeling. We provide evidence for physical interaction between both proteins. These data support strong functional links between PDI and RhoGDI families, which likely maintained PDI/RhoGDI microsynteny along > 800-million years of evolution.
The soluble loop BC region guides, but not dictates, the assembly of the transmembrane cytochrome b6
(2017)
Studying folding and assembly of naturally occurring α-helical transmembrane proteins can inspire the design of membrane proteins with defined functions. Thus far, most studies have focused on the role of membrane-integrated protein regions. However, to fully understand folding pathways and stabilization of α–helical membrane proteins, it is vital to also include the role of soluble loops. We have analyzed the impact of interhelical loops on folding, assembly and stability of the heme-containing four-helix bundle transmembrane protein cytochrome b6 that is involved in charge transfer across biomembranes. Cytochrome b6 consists of two transmembrane helical hairpins that sandwich two heme molecules. Our analyses strongly suggest that the loop connecting the helical hairpins is not crucial for positioning the two protein “halves” for proper folding and assembly of the holo-protein. Furthermore, proteolytic removal of any of the remaining two loops, which connect the two transmembrane helices of a hairpin structure, appears to also not crucially effect folding and assembly. Overall, the transmembrane four-helix bundle appears to be mainly stabilized via interhelical interactions in the transmembrane regions, while the soluble loop regions guide assembly and stabilize the holo-protein. The results of this study might steer future strategies aiming at designing heme-binding four-helix bundle structures, involved in transmembrane charge transfer reactions.
Cells respond to protein misfolding and aggregation in the cytosol by adjusting gene transcription and a number of post-transcriptional processes. In parallel to functional reactions, cellular structure changes as well; however, the mechanisms underlying the early adaptation of cellular compartments to cytosolic protein misfolding are less clear. Here we show that the mammalian ubiquitin ligase C-terminal Hsp70-interacting protein (CHIP), if freed from chaperones during acute stress, can dock on cellular membranes thus performing a proteostasis sensor function. We reconstituted this process in vitro and found that mainly phosphatidic acid and phosphatidylinositol-4-phosphate enhance association of chaperone-free CHIP with liposomes. HSP70 and membranes compete for mutually exclusive binding to the tetratricopeptide repeat domain of CHIP. At new cellular locations, access to compartment-specific substrates would enable CHIP to participate in the reorganization of the respective organelles, as exemplified by the fragmentation of the Golgi apparatus (effector function).
The formation of secondary particles in the atmosphere accounts for more than half of global cloud condensation nuclei. Experiments at the CERN CLOUD (Cosmics Leaving OUtdoor Droplets) chamber have underlined the importance of ions for new particle formation, but quantifying their effect in the atmosphere remains challenging. By using a novel instrument setup consisting of two nano-particle counters, one of them equipped with an ion filter, we were able to further investigate the ion-related mechanisms of new particle formation. In autumn 2015, we carried out experiments at CLOUD on four systems of different chemical compositions involving monoterpenes, sulfuric acid, nitrogen oxides, and ammonia. We measured the influence of ions on the nucleation rates under precisely controlled and atmospherically relevant conditions. Our results indicate that ions enhance the nucleation process when the charge is necessary to stabilize newly formed clusters, i.e. in conditions where neutral clusters are unstable. For charged clusters that were formed by ion-induced nucleation, we were able to measure, for the first time, their progressive neutralization due to recombination with oppositely charged ions. A large fraction of the clusters carried a charge at 1.2 nm diameter. However, depending on particle growth rates and ion concentrations, charged clusters were largely neutralized by ion–ion recombination before they grew to 2.2 nm. At this size, more than 90 % of particles were neutral. In other words, particles may originate from ion-induced nucleation, although they are neutral upon detection at diameters larger than 2.2 nm. Observations at Hyytiälä, Finland, showed lower ion concentrations and a lower contribution of ion-induced nucleation than measured at CLOUD under similar conditions. Although this can be partly explained by the observation that ion-induced fractions decrease towards lower ion concentrations, further investigations are needed to resolve the origin of the discrepancy.
The degradation of nonfunctional mitochondrial proteins is of fundamental relevance for maintenance of cellular homeostasis. The heteromeric CLPXP protein complex in the mitochondrial matrix is part of this process. In the fungal aging model Podospora anserina, ablation of CLPXP leads to an increase in healthy lifespan. Here, we report that this counterintuitive increase depends on a functional autophagy machinery. In PaClpXP mutants, autophagy is involved in energy conservation and the compensation of impairments in respiration. Strikingly, despite the impact on mitochondrial function, it is not mitophagy but general autophagy that is constitutively induced and required for longevity. In contrast, in another long-lived mutant ablated for the mitochondrial PaIAP protease, autophagy is neither induced nor required for lifespan extension. Our data provide novel mechanistic insights into the capacity of different forms of autophagy to compensate impairments of specific components of the complex mitochondrial quality control network and about the biological role of mitochondrial CLPXP in the control of cellular energy metabolism.
The study of lattice gauge theories with Monte Carlo simulations is hindered by the infamous sign problem that appears under certain circumstances, in particular at non-zero chemical potential. So far, there is no universal method to overcome this problem. However, recent years brought a new class of non-perturbative Hamiltonian techniques named tensor networks, where the sign problem is absent. In previous work, we have demonstrated that this approach, in particular matrix product states in 1+1 dimensions, can be used to perform precise calculations in a lattice gauge theory, the massless and massive Schwinger model. We have computed the mass spectrum of this theory, its thermal properties and real-time dynamics. In this work, we review these results and we extend our calculations to the case of two flavours and non-zero chemical potential. We are able to reliably reproduce known analytical results for this model, thus demonstrating that tensor networks can tackle the sign problem of a lattice gauge theory at finite density
The widespread application of human stem-cell-derived neurons for functional studies is impeded by complicated differentiation protocols, immaturity, and deficient optogene expression as stem cells frequently lose transgene expression over time. Here we report a simple but precise Cre-loxP-based strategy for generating conditional, and thereby stable, optogenetic human stem-cell lines. These cells can be easily and efficiently differentiated into functional neurons, and optogene expression can be triggered by administering Cre protein to the cultures. This conditional expression system may be applied to stem-cell-derived neurons whenever timed transgene expression could help to overcome silencing at the stem-cell level.
Introduction: DACCORD is an observational, non-interventional study being conducted in German primary and secondary care centres. The study aims to describe the impact of disease (including exacerbations) and treatments over 2 years on ‘real-life’ patients with chronic obstructive pulmonary disease (COPD).
Materials and methods: Patients had a clinical and spirometry diagnosis of COPD, were aged ≥40 years and, on recruitment, were initiating or changing COPD maintenance medication. The only exclusion criteria were asthma and randomised clinical trial participation. Exacerbations data were collected every 3 months. COPD medication, COPD Assessment Test (CAT) and forced expiratory volume in 1 s (FEV1) were recorded at baseline and after 1 and 2 years.
Results: A total of 6122 patients were recruited, 3137 (51.2%) of whom completed the 2-year visit. The mean age of these patients was 65.6 years, 59% were male, 69% had mild or moderate airflow limitation, and their mean COPD Assessment Test (CAT) total score was 20.3. Overall, there was a trend towards decreasing COPD exacerbation rates over the 2-year follow-up period, with rates of 0.390 during Year 1 and 0.347 during Year 2. Rates were lower in patients with no exacerbation during the 6 months prior to entry (0.263 and 0.251 during Years 1 and 2, respectively), with 51.6% of patients having no exacerbation during the 6 months prior to entry and over the 2-year follow-up. Approximately 50% of the overall population experienced a clinically relevant improvement from baseline in CAT total score at Year 1 and 2. When assessed by treatment class (or classes), persistence to medication was high (77.8% in Year 1 and 71.4% in Year 2).
Conclusions: Overall, the 2-year follow-up data from DACCORD suggest that for most patients with COPD exacerbations are a rare event. For the majority of patients, the focus should be on managing symptoms, and the impact that these symptoms have on their daily lives. Even for those patients who do exacerbate, although prevention of exacerbations is an important factor, management of symptoms should be a key consideration. DACCORD also suggests that COPD disease progression is not inevitable – providing patients are receiving pharmacological treatment.
N-Allyltetramethylpiperidine is readily isomerized to the corresponding enamine by treatment with catalytic amounts of B(C6F5)3. It adds HB(C6F5)2 at the nucleophilic enamine carbon atom to form a C/B Lewis adduct. This reacts with two molar equivalents of carbon monoxide by selective head to tail coupling to give a five-membered C2O2B heterocycle. In contrast the enamine/HB(C6F5)2 Lewis pair reacts with two molar equiv. of nitric oxide by head to head coupling. This reaction probably proceeds via equilibrium with the corresponding vicinal N/B Lewis pair. Most products were characterized by X-ray diffraction.
Impact of human mesenchymal stromal cells on antifungal host response against Aspergillus fumigatus
(2017)
Mesenchymal stromal cells (MSCs) are increasingly given as immunotherapy to hematopoietic stem cell transplant (HSCT) recipients with refractory graft-versus-host disease (GvHD). Whereas the immunosuppressive properties of MSCs seem to be beneficial in GvHD, there is, at the same time, major concern that MSCs increase the risk for infection. We therefore investigated the interplay of human MSCs with Aspergillus fumigatus and the impact of MSCs on different arms of the anti-Aspergillus host response in vitro. Although A. fumigatus hyphae increase mRNA levels of IL6 in MSCs, the extracellular availability of IL-6 and other pro-inflammatory cytokines remains unaffected. Human MSCs are able to phagocyte Aspergillus conidia, but phagocytosis of conidia is not associated with an alteration of the cytokine production by MSCs. In addition, human MSCs do not affect activation and function of A. fumigatus specific CD4+ T cells, and MSCs do not negatively impact the oxidative burst activity of phagocytes. Our in vitro data indicate that administration of human MSCs is not associated with a negative impact on the host response against A. fumigatus and that the fungus does not stimulate MSCs to increase the release of those cytokines which play a central role in the pathophysiology of GvHD.
This paper considers the trend towards megaregionalism (TTIP, TPP) that became prominent in the trade domain in the last years of the Obama administration. While megaregionalism has fallen by the wayside since Trump’s inauguration, the underlying rationale for such treaties will most likely reassert itself rather soon. So there are structural issues that need to be discussed from a standpoint of global justice. In all likelihood, megaregionalism is detrimental to global justice. TTIP in particular, or anything like it, might derail any possibility for a trade organization to aid the pursuit of justice at the global level, and any possibility that trade will be used to that end. From the standpoint of global justice one must hope that megaregionalism does not replace WTO multilateralism. The global-justice framework used here is the grounds-of-justice approach offered in the author’s 2012 On Global Justice.
Megaregional trade negotiations have become the subject of heated debate, above all in the context of the Transatlantic Trade and Investment Partnership (TTIP) and the Trans-Pacific Partnership (TPP). In this article, I argue that the justice of the global order suffers from its institutional fragmentation into regime complexes. From a republican perspective, which aspires to non-domination as a guiding principles and idea of global justice, regime complexes raise specific and important challenges in that they open the door to specific forms of domination. I thereby challenge a more optimistic outlook in regime complexes, which paints a positive normative picture of regime complexes, arguing that they enable the enhancement of democracy beyond the state and, consequently, have the potential to reduce the democratic deficit in global governance. By drawing attention to how regime complexes reinforce domination-related injustice, this article contributes an original perspective on megaregionals and to exploring the implications of global justice as non-domination.
Recent trade negotiations such as TTIP include investor protection clauses. Against the background of an analysis of the case for trade, the paper asks whether such clauses can be justified from a normative perspective. More specifically, what is the impact of investor protection on the domestic distribution of the gains from trade between labour and capital, and how should we assess this impact from the perspective of justice? In order to answer this question, the paper develops a series of ideal-type scenarios that reflect the consequences of investor protection on employment on the one hand, and on the distributive conflict between labour and capital on the other. While no claim is made which of these scenarios corresponds to TTIP or other trade agreements, they provide a useful normative framework to analyse such agreements.
nvestor-state-dispute-settlement (ISDS) is an arbitration mechanism to settle disputes between foreign investors and host-states. Seemingly a technical issue in private international law, ISDS procedures have recently become a matter of public concern and the target of political resistance, due to the power they grant to foreign investors in matters of public policies in the countries they invest in. This article examines the practice of ISDS through the lenses of liberal-statist theories of international justice, which value self-determination. It argues that the investor-state arbitration system illustrates how liberal-statist theories of international distributive justice ought to care about relative socioeconomic disadvantage, contra the sufficiency principle that they typically defend. The sufficiency principle draws on a questionable conception of the freedom that self-determination consists in.
Readers of Hannah Arendt’s now classic formulation of the statelessness problem in her 1951 book The Origins of Totalitarianism abound at a moment when the number of stateless peoples worldwide continues to rise exponentially. Along with statelessness, few concepts in Arendt scholarship have spawned such a volume of literature, and perhaps none have provoked as much interest outside of the field of philosophy, as ‘the right to have rights.’ Interpreting this enigmatic term exposes the heart of our beliefs about the nature of the political and has important consequences for how we practice politics on a global scale because it implicitly takes plural human beings, and not the citizen, as its subjects. Arendt’s conceptualization of this problem remains unsurpassed in its diagnosis of the political situation of statelessness, as well as its intimate description of the human cost of what she refers to as ‘world loss,’ a phenomenon that the prevailing human rights and global justice discourse does not take into account. And yet, as an alternative framework for thinking about global politics, the right to have rights resists easy interpretation, let alone practical application.
The CLOUD (Cosmics Leaving OUtdoor Droplets) experiment at CERN is studying the nucleation and growth of aerosol particles under atmospheric conditions, and their activation into cloud droplets. A key feature of the CLOUD experiment is precise control of the experimental parameters. Temperature uniformity and stability in the chamber are important since many of the processes under study are sensitive to temperature and also to contaminants that can be released from the stainless steel walls by upward temperature fluctuations. The air enclosed within the 3 m CLOUD chamber is equipped with several arrays (strings) of high precision, fast-response thermometers to measure its temperature. Here we present a study of the air temperature uniformity inside the CLOUD chamber under various experimental conditions. Measurements were performed under calibration conditions and run conditions, which are distinguished by the flow rate of fresh air and trace gases entering the chamber: 20 l/min and up to 210 l/min, respectively. During steady-state calibration runs between −70 °C and +20 °C, the air temperature uniformity is better than +/−0.06 °C in the radial direction and +/−0.1 °C in the vertical direction. Larger non-uniformities are present during experimental runs, depending on the temperature control of the make-up air and trace gases (since some trace gases require elevated temperatures until injection into the chamber). The temperature stability is a few times 0.01 °C over periods of several hours during either calibration or steady-state run conditions. During rapid adiabatic expansions to activate cloud droplets and ice particles, the chamber walls are up to 10 °C warmer than the enclosed air. This results in larger non-uniformities while the air returns to its equilibrium temperature with time constant of about 200 s.
Information theory provides a formal framework within which information processing and its disorders can be described. However, information theory has rarely been applied to modeling aspects of the cognitive neuroscience of schizophrenia. The goal of this article is to highlight the benefits of an approach based on information theory, including its recent extensions, for understanding several disrupted neural goal functions as well as related cognitive and symptomatic phenomena in schizophrenia. We begin by demonstrating that foundational concepts from information theory—such as Shannon information, entropy, data compression, block coding, and strategies to increase the signal-to-noise ratio—can be used to provide novel understandings of cognitive impairments in schizophrenia and metrics to evaluate their integrity. We then describe more recent developments in information theory, including the concepts of infomax, coherent infomax, and coding with synergy, to demonstrate how these can be used to develop computational models of schizophrenia-related failures in the tuning of sensory neurons, gain control, perceptual organization, thought organization, selective attention, context processing, predictive coding, and cognitive control. Throughout, we demonstrate how disordered mechanisms may explain both perceptual/cognitive changes and symptom emergence in schizophrenia. Finally, we demonstrate that there is consistency between some information-theoretic concepts and recent discoveries in neurobiology, especially involving the existence of distinct sites for the accumulation of driving input and contextual information prior to their interaction. This convergence can be used to guide future theory, experiment, and treatment development.
Auf Grundlage einer interviewbasierten Studie zu heterosexuellen Paaren, in denen die Frau das Haupteinkommen verdient, beschäftigt sich der Beitrag mit milieuspezifischen Bewältigungsmustern prekärer Beschäftigungsverhältnisse. Vor dem Hintergrund der Erosion des Ernährermodells werden dabei Transformationen von Männlichkeit in den Blick genommen. Es wird die These entwickelt, dass sich mit dem Selbstverständnis als "Künstler" im hochqualifizierten individualisierten Milieu des urbanen Raums ein spezifisches Bewältigungsmuster von Prekarität herausgebildet hat.
The inner boundary and the cristae membrane are connected by pore-like structures termed crista junctions (CJs). The MICOS complex is required for CJ formation and enriched at CJs. Here, we address the roles of the MICOS subunits Mic27 and Mic10. We observe a positive genetic interaction between Mic27 and Mic60 and deletion of Mic27 results in impaired formation of CJs and altered cristae membrane curvature. Mic27 acts in an antagonistic manner to Mic60 as it promotes oligomerization of the F1FO-ATP synthase and partially restores CJ formation in cells lacking Mic60. Mic10 impairs oligomerization of the F1FO-ATP synthase similar to Mic60. Applying complexome profiling, we observed that deletion of Mic27 destabilizes the MICOS complex but does not impair formation of a high molecular weight Mic10 subcomplex. Moreover, this Mic10 subcomplex comigrates with the dimeric F1FO-ATP synthase in a Mic27-independent manner. Further, we observed a chemical crosslink of Mic10 to Mic27 and of Mic10 to the F1FO-ATP synthase subunit e. We corroborate the physical interaction of the MICOS complex and the F1FO-ATP synthase. We propose a model in which part of the F1FO-ATP synthase is linked to the MICOS complex via Mic10 and Mic27 and by that is regulating CJ formation.
Background: Computed-tomography-guided interventions are attractive for tissue sampling of paediatric tumor lesions; however, it comes with exposure to ionizing radiation. The aim of this study was to analyse the radiation dose, accuracy and speed of CT-guided interventions in paediatric patient cohort.
Methods: We retrospectively reviewed CT-guided interventions over a 10 -year period in 65 children. The intervention site consisted of bones in 38, chest (lung) in 15 and abdomen (liver, lymph nodes) in 12 cases. Radiation dose and duration of the procedures were analysed. The statistical analysis was performed using dedicated statistical software (BiAS 8.3.6 software, Epsilon Verlag, North Hasted).
Results: All interventions were performed successfully. Mean target access path to lesion within the patients was 6.0 cm (min 3.5 cm, max 11.2 cm). Time duration to complete intervention was 25:15 min (min 17:03 min, max 43:00 min). The dose-length product (DLP) of intervention scan was 29.5 mGy · cm (min 6 mGy · cm, max 85 mGy · cm) with the lowest dose for biopsies in the region of the chest (p = 0.04).
Conclusions: With justified indications, CT-guided paediatric interventions are safe, effective and can be performed both, with short intervention times and low radiation exposure.
Background: To meet the requirements imposed by the time-dependency of acute stroke therapies, it is necessary 1) to initiate structural and cultural changes in the breadth of stroke-ready hospitals and 2) to find new ways to train the personnel treating patients with acute stroke. We aimed to implement and validate a composite intervention of a stroke team algorithm and simulation-based stroke team training as an effective quality initiative in our regional interdisciplinary neurovascular network consisting of 7 stroke units.
Methods: We recorded door-to-needle times of all consecutive stroke patients receiving thrombolysis at seven stroke units for 3 months before and after a 2 month intervention which included setting up a team-based stroke workflow at each stroke unit, a train-the-trainer seminar for stroke team simulation training and a stroke team simulation training session at each hospital as well as a recommendation to take up regular stroke team trainings.
Results: The intervention reduced the network-wide median door-to-needle time by 12 minutes from 43,0 (IQR 29,8–60,0, n = 122) to 31,0 (IQR 24,0–42,0, n = 112) minutes (p < 0.001) and substantially increased the share of patients receiving thrombolysis within 30 minutes of hospital arrival from 41.5% to 59.6% (p < 0.001). Stroke team training participants stated a significant increase in knowledge on the topic of acute stroke care and in the perception of patient safety. The overall course concept was regarded as highly useful by most participants from different professional backgrounds.
Conclusions: The composite intervention of a binding team-based algorithm and stroke team simulation training showed to be well-transferable in our regional stroke network. We provide suggestions and materials for similar campaigns in other stroke networks.
"Ihr sollt euch nicht zu den Götzen wenden, und gegossene Götter sollt ihr euch nicht machen [...](Lev 19,4) [...] sollen wir nicht meinen, daß das Göttliche dem Gold und Silber oder Stein, einem Gebilde der Kunst und der Erfindung des Menschen gleich sei. (Acta 17,29) Pfui über euch und über das, was ihr an Gottes Statt verehrt! [...] (Q 21,67)"
Diese drei Sätze stammen nacheinander aus der hebräischen Bibel, dem Neuen Testament und dem Koran. Man kann sie beinahe wie einen Text lesen, an dem sich die These des Ägyptologen Jan Assmann belegen ließe, dass mit der Herausbildung monotheistischer Religionen wie Judentum, Christentum und Islam im Allgemeinen und dem Bilderverbot im Besonderen die Unterscheidung zwischen wahr und falsch in die Götterwelt gekommen sei (Assmann 1998, S. 17). ...
Es wäre eine bessere Welt, würde es diese Bilder nicht geben: Die Rede ist von Darstellungen, die sexuellen Missbrauch von und sexualisierte Gewalt an Kindern und Jugendlichen zeigen. Die physischen und psychischen Verletzungen, die durch den Missbrauch, aber auch durch dessen Perpetuierung in Bildern verursacht werden, sind unermesslich. Daher greift die Gesellschaft zu einem ihrer schärfsten Schwerter – dem Strafrecht.
Mit flexiblen Video-Endoskopen gelingen heute hochaufgelöste Bilder des Magen-Darm-Traktes. Bösartige Tumoren werden früher erkannt und oft auch entfernt, ohne die Bauchdecke aufzuschneiden. Sogar Verengungen der Gallenwege lassen sich mit hochpräziser Endoskopietechnik darstellen und behandeln. Die Medizinische Klinik 1 der Universitätsklinik unter der Leitung von Prof. Dr. Stefan Zeuzem gehört zu den Pionieren auf diesem Gebiet.
Lieblingsbild
(2017)
In lebende Körper zu sehen, ohne das Messer anzusetzen, das war lange ein Traum von Wissenschaftlern und Ärzten. Was vor mehr als 120 Jahren mit Conrad Röntgens Entdeckung der X-Strahlen begann, hat sich mit Magnetenzephalographie und Magnetresonanztomographie zu gängigen Instrumenten der Hightech-Medizin entwickelt.
Lieblingsbild
(2017)
Dieses Bild ist wichtig, weil wir daran verstanden haben, wie in der Zelle fehlerhaftes Spleißen verhindert wird. Dazu muss man wissen, dass unsere Gene sich aus Exons und dazwischenliegenden Introns zusammensetzen. Während des Spleißens werden die Introns entfernt und die Exons in ein reifes Transkript zusammengefügt, das dann für ein Protein kodiert. Allerdings gibt es innerhalb der Introns viele Bereiche, die einem Exon sehr ähnlich sehen. Werden diese sogenannten "PseudoExons" fälschlicherweise während des Spleißprozesses erkannt und in das reife Transkript eingebaut, kann das fatale Folgen für das kodierte Protein und oft die gesamte Zelle haben. ...