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This paper examines the applicability of the combination of data types in a study of German idioms of life with the tools of cognitive metaphor theory. The data sources for conceptual metaphors were mainly metaphors found in the relevant literature. These metaphors are of introspective nature to a great extent. The primary data sources for metaphorical expressions were dictionaries that represent introspective data, too. These data have been complemented by corpus data. The paper discusses the problems of introspective and corpus data raised by the study of German idioms of life. Two case studies demonstrate the advantages of the combination of data and methods.
This article investigates the function and reality of language in Niklas Luhmann's systems theory. How can one interpret the systems-theoretical assumption that language is based on communication? Luhmann describes language as a dynamic media/form relationship, which is able to couple the social and psychological system. This structural coupling, which constructs consciousness and language as two autonomous systems, raises problems if one defines language from a cognitive point of view. This article discusses these problems and aims to develop assumptions and questions within the systems-theoretical approach.
Neuronal activity in the brain is often investigated in the presence of stimuli, termed externally driven activity. This stimulus-response-perspective has long been focussed on in order to find out how the nervous system responds to different stimuli. The neuronal response consists of baseline activity, so called spontaneous activity1, and activity which is caused by the stimulus. The baseline activity is often considered as constant over time which allows the identification of the stimulus-evoked part of the neuronal response by averaging over a set of trials.
However, during the last years it has been recognized that own dynamics of the nervous system plays an important role in information processing. As a consequence, spontaneous activity is no longer regarded only as background ’noise’ and its role in cortical processing is reconsidered. Therefore, the study of spontaneous firing pattern gains more importance as these patterns may shape neuronal responses to a larger extent as previously thought. For example, recent findings suggest that prestimulus activity can predict a person’s visual perception performance on a single trial basis (Hanslmayr et al., 2007). In this context, Ringach (2009) remarks that one can learn much about even the quiescent state of the brain which “underlies the importance of understanding cortical responses as the fusion of ongoing activity and sensory input”.
Taking into account that spontaneous activity reflects anything else but noise, new challenges arise when analysing neuronal data. In this thesis one of these problems related to the analysis of neuronal activity will be adressed, namely the nonstationarity of firing rates.
The present work consists of four chapters. First of all the introduction gives neurophysiological background information to get an idea of neuronal information processing. Afterwords the theory of point processes is provided which forms the basis for modeling neuronal spiking data. In the last section of the introduction a statement of the problem is given. Chapter 2 proposes an easily applicable statistical method for the detection of nonstationarity. It is applied to simulations and to real data in order to show its capabilities. Thereafter, four other approaches are presented which provide useful illustrations concerning the nonstationarity of the firing rate but share the problem that one cannot make objective statements on the basis of their results. They were developed in the course of establishing a suitable method. In chapter 4 the results are discussed and suggestions for further study are given.
One of the unresolved questions in studies on population dynamics of forest Lepidoptera is why some populations at times reach outbreak densities, whereas others never do. Resolving this question is especially challenging if populations of the same species in different areas or of closely-related species in the same area are considered. The present study focused on three closely-related geometrid moth species, autumnal Epirrita autumnata, winter Operophtera brumata and northern winter moths Operophtera fagata, in southern Finland. There, winter and northern winter moth populations can reach outbreak densities, whereas autumnal moth densities stay relatively low. We tested the hypothesis that a lower vulnerability to pupal predation may explain the observed differences in population dynamics. The results obtained do not support this hypothesis because pupal predation probabilities were not significantly different between the two genera within or without the Operophtera outbreak area or in years with or without a current Operophtera outbreak. Overall, pupal predation was even higher in winter and northern winter moths than in autumnal moths. Differences in larval predation and parasitism, as well as in the reproductive capacities of the species, might be other candidates.
1. Both direct and indirect competition can have profound effects on species abundance and expansion rates, especially for a species trying to strengthen a foothold in new areas, such as the winter moth (Operophtera brumata) currently in northernmost Finland. There, winter moths have overlapping outbreak ranges with autumnal moths (Epirrita autumnata), who also share the same host, the mountain birch (Betula pubescens ssp. czerepanovii). Competitive interactions are also possible, but so far unstudied, are explanations for the observed 1–3 years phase lag between the population cycles of the two moth species. 2. In two field experiments, we studied host plant-mediated indirect inter-specific competition and direct interference/exploitation competition between autumnal and winter moths. The experimental larvae were grown either with the competing species or with the same number of conspecifics until pupation. Inter-specific competition was judged from differences in pupal mass (reflecting lifespan fecundity), larval development time and larval survival. 3. Larval performance measurements suggested that neither direct nor indirect interspecific competition with the autumnal moth reduce the growth rate of winter moth populations. Winter moths even had a higher probability of survival when reared together with autumnal moths. 4. Thus, we conclude that neither direct nor indirect inter-specific competition is capable of suppressing the spread of the winter moth outbreak range and that both are also an unlikely cause for the phase lag between the phase-locked population cycles of the two moth species.
Integer point sets minimizing average pairwise L1 distance: What is the optimal shape of a town?
(2010)
An n-town, n[is an element of]N , is a group of n buildings, each occupying a distinct position on a 2-dimensional integer grid. If we measure the distance between two buildings along the axis-parallel street grid, then an n-town has optimal shape if the sum of all pairwise Manhattan distances is minimized. This problem has been studied for cities, i.e., the limiting case of very large n. For cities, it is known that the optimal shape can be described by a differential equation, for which no closed-form solution is known. We show that optimal n-towns can be computed in O(n[superscript 7.5]) time. This is also practically useful, as it allows us to compute optimal solutions up to n=80.
The current study tested the assumption that floristic and functional diversity patterns are negatively related to soil nitrogen content. We analyzed 20 plots with soil N-contents ranging from 0.63% to 1.06% in a deciduous forest near Munich (Germany). To describe species adaptation strategies to different nitrogen availabilities, we used a plant functional type (PFT) approach. Each identified PFT represents one realized adaptation strategy to the current environment. These were correlated, next to plant species richness and evenness, to soil nitrogen contents. We found that N-efficient species were typical for low soil nitrogen contents, while N-requiring species occur at high N-contents. In contrast to our initial hypotheses, floristic and functional diversity measures (number of PFTs) were positively related to nitrogen content in the soil. Every functional group has its own adaptation to the prevailing environmental conditions; in consequence, these functional groups can co-exist but do not out-compete one another. The increased number of functional groups at high N-contents leads to increased species richness. Hence, for explaining diversity patterns we need to consider species groups representing different adaptations to the current environmental conditions. Such co-existing ecological strategies may even overcome the importance of competition in their effect on biodiversity.
Background: Early inner ear development requires the strict regulation of cell proliferation, survival, migration and differentiation, coordinated by the concerted action of extrinsic and intrinsic factors. Deregulation of these processes is associated with embryonic malformations and deafness. We have shown that insulin-like growth factor I (IGF-I) plays a key role in embryonic and postnatal otic development by triggering the activation of intracellular lipid and protein kinases. RAF kinases are serine/threonine kinases that regulate the highly conserved RAS-RAF-MEK-ERK signaling cascade involved in transducing the signals from extracellular growth factors to the nucleus. However, the regulation of RAF kinase activity by growth factors during development is complex and still not fully understood.
Methodology/Principal Findings: By using a combination of qRT-PCR, Western blotting, immunohistochemistry and in situ hybridization, we show that C-RAF and B-RAF are expressed during the early development of the chicken inner ear in specific spatiotemporal patterns. Moreover, later in development B-RAF expression is associated to hair cells in the sensory patches. Experiments in ex vivo cultures of otic vesicle explants demonstrate that the influence of IGF-I on proliferation but not survival depends on RAF kinase activating the MEK-ERK phosphorylation cascade. With the specific RAF inhibitor Sorafenib, we show that blocking RAF activity in organotypic cultures increases apoptosis and diminishes the rate of cell proliferation in the otic epithelia, as well as severely impairing neurogenesis of the acoustic-vestibular ganglion (AVG) and neuron maturation.
Conclusions/Significance: We conclude that RAF kinase activity is essential to establish the balance between cell proliferation and death in neuroepithelial otic precursors, and for otic neuron differentiation and axonal growth at the AVG.
Understanding causal relationships, or effective connectivity, between parts of the brain is of utmost importance because a large part of the brain’s activity is thought to be internally generated and, hence, quantifying stimulus response relationships alone does not fully describe brain dynamics. Past efforts to determine effective connectivity mostly relied on model based approaches such as Granger causality or dynamic causal modeling. Transfer entropy (TE) is an alternative measure of effective connectivity based on information theory. TE does not require a model of the interaction and is inherently non-linear. We investigated the applicability of TE as a metric in a test for effective connectivity to electrophysiological data based on simulations and magnetoencephalography (MEG) recordings in a simple motor task. In particular, we demonstrate that TE improved the detectability of effective connectivity for non-linear interactions, and for sensor level MEG signals where linear methods are hampered by signal-cross-talk due to volume conduction.
Meeting Abstract : Gesellschaft für Arzneimittelanwendungsforschung und Arzneimittelepidemiologie e.V. (GAA). 17. Jahrestagung der Gesellschaft für Arzneimittelanwendungsforschung und Arzneimittelepidemiologie. Osnabrück, 25.-26.11.2010.
ntroduction: Several drugs require dose adjustment in patients with impaired renal function, which however, often goes undetected. Serum creatinine may be normal in patients while renal function is already reduced. The estimated GFR (eGFR) allows a more precise evaluation of the renal function. This study was carried out in a group practice for family medicine, in Frankfurt/ Main, Germany. The exploration aimed at investigating if patients with renal insufficiency were recognised and if their prescriptions were appropriate in terms of dose adjustment or contra-indications.
Methods: In patients (>65yrs) with renal insufficiency (creatinine clearance <60 ml/min), their prescribed medication was retrospectively explored (Observation period 1.1.2008 to 1.4.2009). The Cockroft-Gault formula was used as estimate for the eGFR, using a creatinine value from the patient’s charts. In 90 patients, a second eGFR could be estimated from a second creatinine value obtained within 3-6 months. The recommended dose of each prescription in the SmPC (Fachinformation“) was compared to the dose that had been actually prescribed.
Results: Out of 232 consecutively patients >65 yrs, 102 had an eGFR <60 ml/min, 16 of these had an eGFR <30 ml/min. The eGFR was closely correlated (r2=0.81) with an independent second eGFR. Out of these 102 patients, 48 had a serum creatinine level within the normal range. Renal adjustment was required in 263 of a total of 613 prescriptions. 72 prescriptions in a total of 45 patients were not appropriately adjusted (32) or prescribed despite a contraindication (40). For chronic prescriptions, metformin, ramipril, enalapril, HCTZ, and spironolactone accounted for 70% of inappropriate dosing; the magnitude of misdosing was 1.5 to 4 fold (median 2). 9 temporary prescriptions (of a total of 60 prescriptions) in 8 patients were not adjusted (cefuroxim, cefpodoxim, levofloxacin). We could not prove that patients with normal serum creatinine had a higher rate of inappropriate dosing than those with already elevated creatinine.
Discussion and conclusion: In this GP practice, we have demonstrated a considerable prevalence of inappropriate dosing in patients with impaired renal function. It remains to be elucidated whether surveillance of appropriate dosing in renal impairment can be optimized e.g. with CPOE.
Observations on the longevity and ecology of Isopogon prostratus McGill. (Proteaceae) based on 1985 and 2009 field measures on Newnes Plateau, near Lithgow, and a seed germination trial are provided. Its survival strategy appears to be that of a stress-tolerator with long-term persistence at (relatively few) suitable sites, and it remains a relatively rare plant. It is conjectured that it is likely to have been a species of greater abundance in the drier, colder and generally treeless conditions of the Newnes Plateau 15–20 000 years ago, but, as conditions became warmer and wetter it has become reduced to isolated populations as taller shrubs outcompeted it for light.
Whipcord plant is a term used for some dicot angiosperms with small, scale-like leaves closely appressed to the stem. So far, the term has mostly been used in this sense for plants from New Zealand. Here, I summarize the incidence and habitat relations of New Zealand whipcord plants and then use the literature to show that whipcord plants also occur in south-eastern Australia. New Zealand whipcord plants comprise nine species of Hebe, four of Leonohebe and six of Helichrysum, while in south-eastern Australia there are six species of Ozothamnus and one of Leucophyta. In both areas, some species are alpine to subalpine, while some are from lowland habitats with significant summer water deficits.
Native vegetation of the NSW south coast, escarpment and southeast tablelands was classified into 191 floristic assemblages at a level of detail appropriate for the discrimination of Threatened Ecological Communities and other vegetation units referred to in government legislation. Assemblages were derived by a numerical analysis of 10832 field sample quadrats including 8523 compiled from 63 previous vegetation surveys. Past bias in the distribution of field data towards land under public tenure was corrected by extensive surveys carried out on private land. The classification revises and integrates the units described in recent vegetation studies of Eden, Cumberland Plain and Sydney-south coast into a single, consistent classification. Relationships between floristic assemblages and climate, terrain, substrate and vegetation structure were used to map the distribution of communities prior to clearing at 1:100 000 scale. The extent of clearing was mapped using interpretations of remote imagery (1991–2001) from previous work, standardised and merged into a single coverage and supplemented with additional work. Profiles for each assemblage, which we term ‘communities’ or ‘map units’, describe their species composition, vegetation structure, environmental habitat, the extent of clearing and conservation status. Lists of diagnostic species were defined using a statistical fidelity measure and a procedure for using these for community identification is described. Approximately 66% of the study area retains a cover of native vegetation, primarily in areas with low fertility soils and dissected topography. Communities subject to over-clearing (>70%) are concentrated in a few large areas characterised by clay/loam soils and flat to undulating terrain. These include the Sydney metropolis, Wingecarribee Plateau, Illawarra Plain, Shoalhaven floodplain, Araluen Valley and Bega Valley, and various smaller river valleys. Forty-one percent of remaining native vegetation is protected within conservation reserves while 31% occurs on private land, 20% in State Forests and 8% on other Crown lands. Forty-five Threatened Ecological Communities (TECs) were recorded in the study area. The majority of TECs are represented by a single map unit, although in some cases a TEC is included within a broader map unit. Twelve TECs are represented by combinations of two or more map units.
The vegetation and floristics of the coastal sandplains on the Umina-Woy Woy Peninsula on the northern foreshores of Broken Bay (lat 33° 30’ S, long 151° 15’ E), 40 km north of Sydney, are described from historical records, sampling of remnants and analysis of regional scale vegetation. Of the seven vegetation communities described, Umina Coastal Sandplain Woodland (UCSW) was originally the most extensive type of vegetation over the Umina-Woy Woy sandplain and on the seaward side of the Pearl Beach sandplain, and possibly on the sandplains at Patonga and Little Patonga. Characteristic tree species are Angophora floribunda and Eucalyptus botryoides; the latter appears to be more common at foreshore sites. Close to the sea and in swales at the base of hillslopes, littoral rainforest elements can be present. Patonga may have had significant inclusions of this vegetation. As a result of clearing for suburban development and its reduction to small remnants, UCSW and Freshwater Wetlands have been listed as an Endangered Ecological Communities under the NSW Threatened Species Conservation Act. A form of the closely-related Sydney Red Gum (SRG) complex occurs on a different SLU on the south-west side of Pearl Beach. A characteristic tree is Angophora costata. Site environmental differences between UCSW and the Sydney Red Gum Complex include their occurrence on iron podsols and humus podsols respectively. Regional vegetation classification and analysis shows that these vegetation units are distinctly different from each other. This is supported by historical evidence from surveyor notation on Crown Survey and land subdivision plans. Originally the Bangalay – Rough-barked Apple Woodland vegetation component of the Umina Woy Woy sandplain was defined by the NSW Scientific Committee for Umina Coastal Sandplain Woodland. Regional analysis now reveals the Red Gum-Red Bloodwood (RGBW) component now merges with this former community. The Pearl Beach vegetation remains separate. A re-definition of UCSW is now required. Management, particularly of UCSW, currently involves revegetation and regeneration works in the vicinity of existing reserves. However, because the depletion has been so extensive there is further opportunity to decrease the loss by utilising the wide riparian reserves and laneways where mature trees still exist. A major conservation concern is the modification and loss of the sandplain vegetation, particularly the wetlands. The historical Crown Survey plans highlight the extent of wetlands as an important ecological feature of the original sandplain landscape. The current study estimated that 83% of wetlands and 79% of riparian vegetation has been lost on the Umina-Woy Woy sandplain since European settlement.
We establish a methodology and present baseline data for a long-term grassy woodland restoration study that commenced in 2007 in two nature reserves (Mulligans Flat, Goorooyarroo (35° 9–13’ S; 149° 9–12’ E)) totalling 1386 ha on the northern boundary of Canberra, in the Australian Capital Territory in south eastern Australia. The experimental infrastructure comprises 96 × 1 ha sites established in Eucalyptus blakelyi / Eucalyptus melliodora dominated woodland. These are being subjected to varying kangaroo grazing pressure and augmentation with logs, while burning treatments are planned. One reserve (Mulligans Flat) has been fenced for feral predator control and contains half the sites, forming a companion experiment to Goorooyarroo. Our baseline floristic study comprised estimates, at the site level, of ground layer biomass, species biomass, ground cover types and soil (0–10 cm) properties. From these data we conclude that the groundlayer vegetation is dominated by Joycea pallida, Austrodanthonia spp., Themeda australis and Aristida ramosa. These grasses varied in abundance according to differences in soil pH, phosphorus and to a lesser extent nitrates. Forb frequencies were highly sensitive to nitrate levels with annual exotic forbs dominating at high nitrate sites. More generally, soil nutrient levels and exotic species in some sites indicated areas of previous pasture improvement activities. Biomass estimates indicated extremely high grazing pressure, sufficient to negatively affect the habitat quality for ground-dependent fauna and some soil processes. These data will provide an important basis for examining rates of ecosystem recovery under different restoration strategies.
The flowers of Waratahs, Telopea speciosissima (family Proteaceae) are regularly harvested illegally from natural bushland, particularly close to urban areas such as the New South Wales Central Coast. The removal of Waratah blooms from the wild may have implications for the long-term survival of local populations because of the interaction between wildfire events, subsequent flowering and limited seedling recruitment opportunities. To reduce the incidence of theft, blue acrylic paint was applied to blooms to reduce their commercial value. The painting of blooms in 2004 did not significantly reduce the incidence of wildflower theft when compared to unpainted blooms, but overall losses were lower (27%) than in 2003 (33%). However, painting of blooms had a deleterious affect on fruit production on plants with multiple heads with painted blooms having significantly reduced fruit set compared to unpainted blooms. Painting of blooms had no significant effect on seed quality (seed production per fruit, seed germination or seedling vigour) when compared to unpainted blooms. The painting of Waratah blooms to reduce theft was relatively ineffective and decreased fruit production. Alternative strategies should be considered to reduce wildflower theft in the area.
This fourth paper in the NSW Vegetation Classification and Assessment series covers the Brigalow Belt South-/1(BBS) and Nandewar (NAN) Bioregions and the western half of the New England Bioregion (NET), an area of 9.3 million hectares being 11.6% of NSW. It completes the NSWVCA coverage for the Border Rivers-Gwydir and Namoi CMA areas and records plant communities in the Central West and Hunter–Central Rivers CMA areas. In total, 585 plant communities are now classified in the NSWVCA covering 11.5 of the 18 Bioregions in NSW (78% of the State). Of these 226 communities are in the NSW Western Plains and 416 are in the NSW Western Slopes. 315 plant communities are classified in the BBS, NAN and west-NET Bioregions including 267 new descriptions since Version 2 was published in 2008. Descriptions of the 315 communities are provided in a 919 page report on the DVD accompanying this paper along with updated reports on other inland NSW bioregions and nine Catchment Management Authority areas fully or partly classified in the NSWVCA to date. A read-only version of Version 3 of the NSWVCA database is on the DVD for use on personal computers. A feature of the BBS and NAN Bioregions is the array of ironbark and bloodwood Eucalyptusdominated shrubby woodlands on sandstone and acid volcanic substrates extending from Dubbo to Queensland. This includes iconic natural areas such as Warrumbungle and Mount Kaputar National Parks and the 500,000 ha Pilliga Scrub forests. Large expanses of basalt-derived soils support grassy box woodland and native grasslands including those on the Liverpool Plains; near Moree; and around Inverell, most of which are cleared and threatened. Wetlands occur on sodic soils near Yetman and in large clay gilgais in the Pilliga region. Sedgelands are rare but occupy impeded creeks. Aeolian lunettes occur at Narran Lake and near Gilgandra. Areas of deep sand contain Allocasuarina, eucalypt mallee and Melaleuca uncinata heath. Tall grassy or ferny open forests occur on mountain ranges above 1000m elevation in the New England Bioregion and on the Liverpool Range while grassy box woodlands occupy lower elevations with lower rainfall and higher temperatures. The vegetation classification and assessment is based on over 100 published and unpublished vegetation surveys and map unit descriptions, expert advice, extra plot sampling and data analysis and over 25 000 km of road traverse with field checking at 805 sites. Key sources of data included floristic analyses produced in western regional forest assessments in the BBS and NAN Bioregions, floristic analyses in over 60 surveys of conservation reserves and analysis of plot data in the western NET Bioregion and covering parts of the Namoi and Border Rivers- Gwydir CMA areas. Approximately 60% of the woody native vegetation in the study area has been cleared resulting in large areas of “derived” native grasslands. As of June 2010, 7% of the area was in 136 protected areas and 127 of the 315 plant communities were assessed to be adequately protected in reserves. Using the NSWVCA database threat criteria, 15 plant communities were assessed as being Critically Endangered, 59 Endangered, 60 Vulnerable, 99 Near Threatened and 82 Least Concern. 61 of these communities are assessed as part of NSW or Commonwealth-listed Threatened Ecological Communities. Current threats include expanding dryland and irrigated cropping on alluvial plains, floodplains and gently undulating topography at lower elevations; over-grazing of steep hills; altered water tables and flooding regimes; localized mining; and the spread of exotic species, notably Coolatai Grass (Hyparrhenia hirta).
Changes in vegetation structure and composition over a 28 year period (1978–2006) following removal of human-induced disturbances, were examined in a calcareous coastal dune system in Point Nepean National Park (380 19’S, 1440 41’E) in south-eastern Victoria, Australia. In the early 1980s human habitation of Point Nepean was abandoned and disturbance regimes such as burning, slashing and land clearing were altered or removed, providing an opportunity to study the recovery of disturbed coastal vegetation. Broad-scale and community-level vegetation changes were assessed by comparing quadrat and GIS mapping data from 1978 with data collected in 2006. Results indicate a change in broad vegetation patterns; shrubland vegetation has replaced hind dune grasslands and disturbed areas and there has been a decrease in exposed coastal areas (such as blowouts, dunes and cliffs), and an increase in woody native species and highly invasive woody weeds. The changes highlight the importance of incorporating vegetation states in planning management actions in dynamic coastal vegetation.
Defining indigenous species may at first appear straight forward; most botanical texts provide similar definitions. The consistent requirement of such definitions is the lack of human intervention in the occurrence of the species within the area under consideration. Islands around the world have been invaded by plant species brought to their shores by humans. They are also places where self-introduced species can be continually arriving, as they have done for millennia. Scrutiny of the situation on Norfolk Island (1200 km east of Australia) finds that the distinction between indigenous and introduced taxa is sometimes unclear. There is also inconsistency regarding the acceptance of self-introduced species as indigenous. This paper explores these issues and notes that they are more important than idle botanical curiosity, because control of introduced (weed) species is a major area of activity in managing protected natural areas.
Eucalyptus largiflorens (Black Box) is the most common tree in the Chowilla anabranch system on the Murray River floodplain. It typically has dull, glaucous, grey-green leaves. Occasional trees with smaller, glossy green leaves (Green Box) occur scattered amongst the Black Box. In areas with increasing salinity, they usually appear much healthier than adjacent, normal Black Box trees. Green Box plants are intermediate between normal Eucalyptus largiflorens plants and Eucalyptus gracilis plants in many morphological and allozyme characters, strongly suggesting that they are hybrids between those species. Green Box plants tolerate salinity better and use water more conservatively than normal Black Box plants, traits that they have probably inherited from Eucalyptus gracilis. In 1994, the Botanic Gardens of Adelaide used tissue culture and micropropagation to produce nearly 9,000 cloned Green Box plants which were planted out on Riverland floodplains. Since the 1990s, the high cost of producing clonal plants has meant that no further such plantings have occurred. Because Green Box plants can be a considerable distance from the nearest plants of one putative parent (Eucalyptus gracilis), more detailed studies could contribute to the existing work on such phantom hybrids.
The arid and semi-arid southwest of New South Wales has received disproportionately less attention from botanists than other similar-sized geographic regions of the state. Recent work has extended our knowledge of three extremely rare plant taxa from this part of the state. Zygophyllum compressum (Zygophyllaceae) and Elachanthus glaber (Asteraceae) are restricted to gypseous rises within active saline groundwater discharge complexes with limited distribution in southwest New South Wales and occur within the plant community “Gypseous shrubland on rises and semi-arid plains” (ID253) which is listed as threatened (vulnerable) within the state. Eremophila crassifolia (Myoporaceae) is restricted to a few plants on a roadside and adjacent mallee vegetation approximately 35 km east of Wentworth. Based on IUCN criteria it is suggested that Eremophila crassifolia is critically endangered and Zygophyllum compressum and Elachanthus glaber endangered in New South Wales and all should be listed under the NSW Threatened Species Conservation Act 1995.
The Greater Blue Mountains World Heritage Area (GBMWHA), immediately west of Sydney (33° 53’S; 151° 13’E), on the east coast of Australia was listed as World Heritage for its outstanding natural values, a major component of which is the high number of eucalypt species and eucalypt-dominated communities present, some 13 per cent of all eucalypt species in the world. They grow in a great variety of plant communities, from tall closed forests, through open forests and woodlands, to stunted mallee shrublands. This paper provides a definitive list of the 96 eucalypts (species of the genera Eucalyptus, Angophora and Corymbia in the family Myrtaceae), that have been recorded there (55 widespread, 41 restricted), together with the distribution of the eucalypts in the eight reserves that make up the GBMWHA, and information on the classification and habitat of the different species. The information is based on records held at the National Herbarium of New South Wales and the results of surveys by the NSW Department of Environment, Climate Change and Water (DECCW) over the past 20 years. The majority of species have components of both stress-tolerator and competitor ecological strategies and this has probably been a main contributor to their success. However details of the ecology of the majority of taxa are poorly-known and more research is needed to provide guidance for conservation management in the face of changing climate conditions.
In folk theories of art reception, readers and cinema audiences are said to experience fictional worlds vicariously 'through' characters, i.e. they 'identify' themselves with them, they partake in their experiences 'empathetically'. In the first section of my essay, I will argue that it is not character but focalization (point of view) which, on a fundamental level, guides our fictional experience, and I will exemplify several ways that characters (or similar ideas) can then in addition come into play. In the next two sections, I will discuss possible cognitive correlates of both the textual device of focalization and textual clues indicating ›persons‹. The aim is to show that what I call ›psycho-poetic effects‹ (that is, the mental representation of anthropomorphic instances) are best described as byproducts of various cognitive programs involved in the reception of narrative fiction. 'Empathy', as it is understood in the above mentioned folk theory of art reception, can then be analysed into individual algorithms of social cognition. And it can be differentiated, as is done in the last section, from other phenomena often confused with it, like emotional experience proper and emotional contagion. Also, I refer to the idea that mirror neurons provide the means to empathize with others, literary characters included. My general proposition is to revise and refine those concepts with the help of evolutionary theory and, thus, to hypothesize as cognitive correlates for textual features only programs specific enough to be correlated with a specific adaptive function which they may have performed in the process of human evolution.
A new, two-channel instrument for simultaneous NO3 and N2O5 monitoring was used to make the first comprehensive set of nocturnal NOx measurements (NO, NO2, NO3 and N2O5) at the Taunus Observatory, a rural mountain site (Kleiner Feldberg) in South-western Germany. In May 2008, NO3 and N2O5 mixing ratios were well above the instrumental detection limit (a few ppt) on all nights of the campaign and were characterised by large variability resulting from inhomogeneously distributed sinks. The concentrations of NO3, N2O5 and NO2 were consistent with the equilibrium constant, K2, defining the rates of formation and thermal dissociation of N2O5. A steady-state lifetime analysis showed that nocturnal NOx losses were generally dominated by reaction of NO3 with volatile organic compounds in this forested region, with N2O5 uptake to aerosols of secondary importance. Analysis of a limited dataset obtained at high relative humidity indicated that the loss of N2O5 by reaction with water vapour is less efficient (> factor 3) than derived using laboratory kinetic data. The fraction of NOx present as NO3 and N2O5 reached ≈20% on some nights, with night-time losses of NOx competing with daytime losses.
A comprehensive evaluation of seasonal backward trajectories initialized in the Northern Hemisphere lowermost stratosphere (LMS) has been performed to investigate the origin of air parcels and the main mechanisms determining characteristic structures in H2O and CO within the LMS. In particular we explain the fundamental role of the transit time since last tropopause crossing (tTST) for the chemical structure of the LMS as well as the feature of the extra-tropical tropopause transition layer (ExTL) as identified from CO profiles. The distribution of H2O in the background LMS above Θ=320 K and 340 K in northern winter and summer, respectively, is found to be governed mainly by the saturation mixing ratio, which in turn is determined by the Lagrangian Cold Point (LCP) encountered by each trajectory. Most of the backward trajectories from this region in the LMS experienced their LCP in the tropics and sub-tropics. The transit time since crossing the tropopause from the troposphere to the stratosphere (tTST) is independent of the H2O value of the air parcel. TST often occurs 20 days after trajectories have encountered their LCP. CO, on the other hand, depends strongly on tTST due to its finite lifetime. The ExTL as identified from CO measurements is then explained as a layer of air just above the tropopause, which on average encountered TST fairly recently.
We present the analysis of the impact of convection on the composition of the tropical tropopause layer region (TTL) in West-Africa during the AMMA-SCOUT campaign. Geophysica M55 aircraft observations of water vapor, ozone, aerosol and CO2 show perturbed values at altitudes ranging from 14 km to 17 km (above the main convective outflow) and satellite data indicates that air detrainment is likely originated from convective cloud east of the flight. Simulations of the BOLAM mesoscale model, nudged with infrared radiance temperatures, are used to estimate the convective impact in the upper troposphere and to assess the fraction of air processed by convection. The analysis shows that BOLAM correctly reproduces the location and the vertical structure of convective outflow. Model-aided analysis indicates that in the outflow of a large convective system, deep convection can largely modify chemical composition and aerosol distribution up to the tropical tropopause. Model analysis also shows that, on average, deep convection occurring in the entire Sahelian transect (up to 2000 km E of the measurement area) has a non negligible role in determining TTL composition.
ucleation experiments starting from the reaction of OH radicals with SO2 have been performed in the IfT-LFT flow tube under atmospheric conditions at 293±0.5 K for a relative humidity of 13–61%. The presence of different additives (H2, CO, 1,3,5-trimethylbenzene) for adjusting the OH radical concentration and resulting OH levels in the range (4–300)·105 molecule cm−3 did not influence the nucleation process itself. The number of detected particles as well as the threshold H2SO4 concentration needed for nucleation was found to be strongly dependent on the counting efficiency of the used counting devices. High-sensitivity particle counters allowed the measurement of freshly nucleated particles with diameters down to about 1.5 nm. A parameterization of the experimental data was developed using power law equations for H2SO4 and H2O vapour. The exponent for H2SO4 from different measurement series was in the range of 1.7–2.1 being in good agreement with those arising from analysis of nucleation events in the atmosphere. For increasing relative humidity, an increase of the particle number was observed. The exponent for H2O vapour was found to be 3.1 representing a first estimate. Addition of 1.2·1011 molecule cm−3 or 1.2·1012 molecule cm−3 of NH3 (range of atmospheric NH3 peak concentrations) revealed that NH3 has a measureable, promoting effect on the nucleation rate under these conditions. The promoting effect was found to be more pronounced for relatively dry conditions. NH3 showed a contribution to particle growth. Adding the amine tert-butylamine instead of NH3, the enhancing impact for nucleation and particle growth appears to be stronger.
River flow regimes, including long-term average flows, seasonality, low flows, high flows and other types of flow variability, play an important role for freshwater ecosystems. Thus, climate change affects freshwater ecosystems not only by increased temperatures but also by altered river flow regimes. However, with one exception, transferable quantitative relations between flow alterations and ecosystem responses have not yet been derived. While discharge decreases are generally considered to be detrimental for ecosystems, the effect of future discharge increases is unclear. As a first step towards a global-scale analysis of climate change impacts on freshwater ecosystems, we quantified the impact of climate change on five ecologically relevant river flow indicators, using the global water model WaterGAP 2.1g to simulate monthly time series of river discharge with a spatial resolution of 0.5 degrees. Four climate change scenarios based on two global climate modelsand two greenhouse gas emissions scenarios were evaluated.
We compared the impact of climate change by the 2050s to the impact of water withdrawals and dams on natural flow regimes that had occurred by 2002. Climate change was computed to alter seasonal flow regimes significantly (i.e. by more than 10%) on 90% of the global land area (excluding Greenland and Antarctica), as compared to only one quarter of the land area that had suffered from significant seasonal flow regime alterations due to dams and water withdrawals. Due to climate change, the timing of the maximum mean monthly river discharge will be shifted by at least one month on one third on the global land area, more often towards earlier months (mainly due to earlier snowmelt). Dams and withdrawals had caused comparable shifts on less than 5% of the land area only. Long-term average annual river discharge is predicted to significantly increase on one half of the land area, and to significantly decrease on one quarter. Dams and withdrawals had led to significant decreases on one sixth of the land area, and nowhere to increases.
Thus, by the 2050s, climate change will have impacted ecologically relevant river flow characteristics much more strongly than dams and water withdrawals have up to now. The only exception refers to the decrease of the statistical low flow Q90, with significant decreases both by past water withdrawals and future climate change on one quarter of the land area. Considering long-term average river discharge, only a few regions, including Spain, Italy, Iraq, Southern India, Western China, the Australian Murray Darling Basin and the High Plains Aquifer in the USA, all of them with extensive irrigation, are expected to be less affected by climate change than by past anthropogenic flow alterations. In some of these regions, climate change will exacerbate the discharge reduction. Emissions scenario B2 leads to only slightly reduced alterations of river flow regimes as compared to scenario A2 even though emissions are much smaller. The differences in alterations resulting from the two applied climate models are larger than those resulting from the two emissions scenarios. Based on general knowledge about ecosystem responses to flow alterations and data related to flow alterations by dams and water withdrawals, we expect that the computed climate change induced river flow alterations will impact freshwater ecosystems more strongly than past anthropogenic alterations.
The Master’s program in Money and Finance (MMF) is an innovative joint venture of the Department of Money and Macroeconomics and of the Department of Finance, both located in the new House of Finance. The program offers promising students from all over the world an intellectually stimulating and challenging setting in which to prepare for their professional careers in central banking, commercial banking, insurance and other financial services. By being located in Frankfurt, one of the world's leading financial centers and the only city in the world with two central banks (the ECB and the German Bundesbank), it offers unique opportunities for interaction with practitioners. The program is taught exclusively in English; knowledge of German is not required for admission to, or completion of the program. It has been designed with a view to establishing itself as a leading Masters program integrating studies in monetary economics, macroeconomics and finance and a major gateway to high-profile jobs in the banking and financial sector.
Contributions to Natural History 12: Band 1: 1-516, Band 2: 517-1048, Band 3: 1049-1574. In englischer und z.T. in
deutscher Sprache. ISSN 1660-9972. Bestellung: Naturhistorisches Museum der Burgergemeinde Bern, Bibliothek,
Bernastraße 15, CH-3005 Bern, Schweiz, Internet: http://www.nmbe.unibe.ch
Improvements in water infrastructure in developing countries are of major importance for achieving access to clean water. CuveWaters, a research based IWRM project, currently underway in Namibia, is testing different technical options to de-centralise water supply and upgrade sanitation. The Cuvelai Basin is affected by highly variable precipitation, mostly saline groundwater and a lack of perennial rivers. Water management is characterised by strong dependency on a water pipeline. Finding ways to improve the situation calls for a good grasp of the local situation regarding water utilisation patterns. Technologically sophisticated concepts can easily clash with users’ socio-cultural needs and everyday behaviour as well as their understanding of planning and maintenance. A demand-responsive approach has therefore been developed. It combines a qualitative socio-empirical perspective with participatory planning. This paper discusses method development, empirical application and results. The approaches aim is to support mutual learning as a basis for a sustainable change process.
The basic physics of nonrelativistic and electromagnetic ion stopping in hot and ionized plasma targets is thoroughly updated. Corresponding projectile-target interactions involve enhanced projectile ionization and coupling with target free electrons leading to significantly larger energy losses in hot targets when contrasted to their cold homologues. Standard stoppping formalism is framed around the most economical extrapolation of high velocity stopping in cold matter. Further elaborations pay attention to target electron coupling and nonlinearities due to enhanced projectile charge state, as well. Scaling rules are then used to optimize the enhanced stopping of MeV/amu ions in plasmas with electron linear densities nel ~ 10 18 -10 20 cm -2 . The synchronous firing of dense and strongly ionized plasmas with the time structure of bunched and energetic multicharged ion beam then allow to probe, for the first time, the long searched enhanced plasma stopping and projectile charge at target exit. Laser ablated plasmas (SPQR1) and dense linear plasma columns (SPQR2) show up as targets of choice in providing accurate and on line measurements of plasma parameters. Corresponding stopping results are of a central significance in asserting the validity of intense ion beam scenarios for driving thermonuclear pellets. Other applications of note feature thorium induced fission, novel ion sources and specific material processing through low energy ion beams. Last but not least, the given ion beam-plasma target interaction physics is likely to pave a way to the production and diagnostics of warm dense matter (WDM).
In the scientific literature, the use of a surfactant is recommended for both designing quality control tests for water insoluble or sparingly water soluble drugs and for predicting the bioavailability of drugs from various types of formulations. Since the number of poorly soluble drugs is increasing, the selection of adequate dissolution test for these becomes more and more important. The aim of the present study was to develop predictive and discriminatory test methods based on surfactants that are recommended in the literature. Particular respect was given to the use of sodium lauryl sulfate and Tween 80, the two most commonly used surfactants for this purpose. Tamoxifen was used as a model drug. Dissolution experiments were performed using various concentrations of the two surfactants in buffer media typically used to prepare biorelevant test media. Results were then compared with those deriving from the same test formulations in biorelevant and simplified “biorelevant” media. Results from this study indicate that the concentration of surfactant has a huge impact on both the rate and extent of drug release from the formulation and also on the discriminatory power of the test. However, they also indicate that a well designed and validated test medium containing SLS or Tween 80 can be useful in terms of establishing a discriminatory test medium that possibly could also be used to assure batch to batch bioequivalence. Therefore, the approach described in the present paper might be very helpful for developing predictive and discriminatory methods in early formulation development for poorly soluble drugs and which could also be adopted for QC.
The C-type lectin-like receptor CLEC-2 signals via phosphorylation of a single cytoplasmic YXXL sequence known as a hem-immunoreceptor tyrosine-based activation motif (hemITAM). In this study, we show that phosphorylation of CLEC-2 by the snake toxin rhodocytin is abolished in the absence of the tyrosine kinase Syk but is not altered in the absence of the major platelet Src family kinases, Fyn, Lyn, and Src, or the tyrosine phosphatase CD148, which regulates the basal activity of Src family kinases. Further, phosphorylation of CLEC-2 by rhodocytin is not altered in the presence of the Src family kinase inhibitor PP2, even though PLCγ2 phosphorylation and platelet activation are abolished. A similar dependence of phosphorylation of CLEC-2 on Syk is also seen in response to stimulation by an IgG mAb to CLEC-2, although interestingly CLEC-2 phosphorylation is also reduced in the absence of Lyn. These results provide the first definitive evidence that Syk mediates phosphorylation of the CLEC-2 hemITAM receptor with Src family kinases playing a critical role further downstream through the regulation of Syk and other effector proteins, providing a new paradigm in signaling by YXXL-containing receptors.
Naturally, the floodplains of Central Asian rivers harbour riparian, so-called ‘Tugai’ forests, reeds with Phragmites australis, and shrub communities which form a mosaic depending on the variety of available ground water. In recent decades, these natural ecosystems have been strongly altered anthropogenically or even completely destroyed. In order to restore those ecosystems, knowledge on vegetation, ecosystem dynamics, and natural regeneration processes is essential. In our study, we present results of ecological investigations at the Tarim River. We gathered comprehensive data on soil, vegetation, forest stand age, tree vitality, river course dynamics, and land use and brought it to the landscape level. Thus, recommendations are derived for the maintenance of these floodplain ecosystems, in particular with regard to their biological diversity.
The Ucayali River originates in the high Andean Mountains near the city of Cusco in Peru. After about 1,600 km, it joins with the Marañón River. Both the Ucayali River and the Marañón River are sources of the Amazon. From 2001 to 2005, the Ministry of Transport and Communication of Peru funded a study to determine the navigability of the Ucayali River. In the process, an extensive data set was acquired including hydrological and sedimentological data as well as a comprehensive topographical survey of the riverbed. Since the Ucayali River has experienced no stream channel modification in the past, the available data provide information about the flow pattern for a natural stream and insight into a reference ecosystem. This paper offers the first analysis of the available data and a sediment transport calculation for the Ucayali River.
In recent decades, the number of streams on the Canary Islands has decreased dramatically due to the non-sustainable consumption of water for agriculture and tourism. Natural reaches of streams with an endemic macroinvertebrate fauna do, however, still exist in protected areas of Tenerife and La Gomera. Those reaches serve as a reference to develop an assessment method for streams on islands. This method takes into account common parameters such as water quality and hydromorphology, while emphasizing biodiversity and endemism. The latter concepts as they relate to stream conservation are important in both nature conservation and protection of species as many endemic aquatic organisms are endangered.
This study represents the first comprehensive biological and hydrochemical investigation of small coastal ponds in the saltmarsh dominated Tijuana Estuary, southern California (U.S.). Special attention is given to the brackish water biotopes.
Different salinities and considerable fluctuations in water level characterized these shallow ponds and restrict the biological settlement. Fluctuations of salinities ranged from brackish water to hyperhaline water conditions. Due to different salinity levels, the ponds vary in hydrochemistry, macroinvertebrate species composition and plant communities. The macroinvertebrate community of the brackish waters were dominated by Gastropoda, Odonata, and Coleoptera containing a mixture of freshwater/brackish water species and marine macroinvertebrates. Typical plants of the brackish habitat were Typha domingensis (Southern cattail), and Scirpus californicus (California bulrush) associated with Juncus acutus (Siny rush). These brackish habitats with a wide range of salinity fluctuations are sparsely colonized but represent a niche for typical highly adaptable species. Especially, it is a biotope for species with a wide range of salt tolerance. Therefore, endangered species occurred besides introduced or invasive species in the ponds of the Tijuana Estuary. This fact has to be taken into account in case of wetland restoration. Due to the freshwater influence, the restoration of brackish habitats focuses on the problem of invasive species.
As a part of the interdisciplinary research project ”Integration of nature protection goals with organic farming: an the example from the Hessian ”state domain” [Staatsdomäne] area Frankenhausen”, different restoration measures have been carried out within this site, 15 km north of Kassel. Since 1998, intensive conventional agricultural practices have been substituted with organic farming here. One intention of the agricultural restructuring was to realise nature protection goals in cooperation with sustainable organic agricultural production.
The hydrologic portion of the project addresses both the implementation of restoration measures in rivers and streams and their scientific monitoring. Starting in July 2007, several restoration measures were carried out in the hydrologic systems of the Jungfernbach and Esse streams within the Frankenhausen site. Both systems are formed by typical loess streams (catchment size about 9 km2) which had been heavily degraded for several hundred years by intensive agriculture. The most important restoration measures were removal of a piped section of a tributary of the Jungfernbach at Totenhof, restoration of biological passability by removal of weirs and substitution of narrow pipes under farm paths, relocation of a section of the Jungfernbach from the edge of the floodplain to its original location in the centre, widening of narrow sections and partial raising of the deepened stream bed by means of rough ramps (stone bars) and racks made of oak wood or iron.
These physical restoration measures were accompanied by a scientific monitoring programme comprising morphological, hydrochemical and biological (aquatic macrophytes, aquatic macroinvertebrates, fish and amphibians) aspects.
The aim of this study was to document the original ecological conditions, the restoration measures and the early ecological effects on the stream sections for the first six months following restoration as a basis for further ecological monitoring.
The restoration measures effected clear morphological changes in cross-section and passability. The chemical condition of the streams showed slight changes in some aspects following the restoration, e. g. a reduction of phosphorus, magnesium and potassium concentration. Other than macrophytic algae in the newly shaped sections, aquatic macrophytes did not develop over the winter season before the end of the monitoring phase in April 2008. Within the newly shaped stream sections of a small tributary and of the Jungfernbach, up to 14 aquatic macroinvertebrate taxa started to colonise the new habitats 6 months after restoration.
Fish fauna were very poorly represented in the streams and included only a few specimens of brown trout (Salmo trutta). This did not change markedly after restoration, possibly due to the isolation of the population caused by impassable weirs downstream of the investigation area.
The survival of the approximately 1,000 artificial ponds in the Pfälzerwald (Palatinate Forest) biosphere reserve is endangered as they continue to be abandoned, but a large number of them have conservation and historical value. An overall management concept is needed as the high costs for restoration and the requirements of the EU Water Framework Directive regarding river continuity will make it impossible to maintain all of the ponds. Most of the ponds are migration barriers for fish and aquatic invertebrates. The assessment methods presented here are based on readily available data for the evaluation of the ecological and cultural-historical importance of the ponds, their implications within the landscape, and their (often negative) impact on stream ecology. The assessment of the condition of the ponds’ manmade structures leads to conclusions about the urgency for action. The assessment classes are linked with recommendations for action. In the synopsis of all assessments, management concepts emerge for the individual ponds, and priority lists of ponds can be generated that point out where actions are preferential.
The use of water buffalos for landscape maintenance started ten years ago in Germany. Now, more than 2,100 buffalos are kept by about 90 breeders, and first results concerning their usefulness for landscape management are available. Buffalos are mainly used on particularly wet sites which cannot be grazed by cattle or other domestic animals. Although grazing of wetlands, river banks and water bodies is still controversial, early results from literature and our own research clearly indicate the beneficial impact of moderate grazing on such sites for birds, amphibians, vegetation and insects. This paper presents a short literature review and the first results of the BUBALUS project at Brandenburg University of Technology (BTU) and general experience from other projects.
Species-rich wet grasslands in floodplains are on focus of European nature conservation policy. However, since the seventies of the last century large areas with grasslands in floodplains have been meliorated, ploughed and used for intensive cropping in Germany. Therefore, restoration strategies for large-scale conversion of former arable land into species-rich grasslands and integration into a long-term sustainable land use regime are needed. Dealing with large areas in restoration projects causes high costs which often exceed the possibilities of NGO’s or other stakeholders. Aiming to develop and implement new cost-efficient strategies for restoration and long-term management of wetlands on former arable land local NGO’s and the Anhalt University of Applied Sciences started a co-operation within a project in a heavily degraded floodplain in the Elbe river valley. Up to now, more than 40 ha former arable land was successively bought and immediately grazed by large herbivores (Heck-cattle and Przewalski-horses). The local farmers apply a year-round grazing regime without additional feeding and low stocking density. Scientific evaluation of the project progress and experiments with different re-vegetation variants (natural recovery, hay transfer, seeding of commercial seed mixture) revealed the following results: (1) on former arable land immediate grazing with large herbivores without additional feeding is possible and leads to a successive development of typical grassland communities with low nutrient status, (2) integration of old pastures into the grazing system enhances colonization of native grassland species alongside animal tracks, (3) seeding of a commercial seed mixture impedes the colonization of native grassland species, (4) transfer of species-rich hay accelerates the colonization rate of several grassland species, and (5) highest cover of target species was found on regularly wet sites. Therefore, we conclude that grazing with large herbivores proved to be successful in converting former arable land into species-rich grasslands. Nevertheless, rising of the groundwater table is most important for further development of species-rich wet grasslands in the Wulfener Bruch.
The restoration of ecosystems has become a major challenge throughout the world in the 21st century (see comprehensive surveys from, e. g. Temperton et al. 2004, van Andel & Aronson 2006, Walker et al. 2007, and Zerbe & Wiegleb 2009). Due to non-sustainable land use and inefficient use of natural resources, many ecosystems have been degraded or completely destroyed. Consequently, the functioning of ecosystems has been severely affected and many ecosystem services have been lost.
SIVIM (Sistema de Información de la Vegetación Ibérica y Macaronésica) is an information system designed for capturing, hosting, editing, analyzing and outputting georeferenced plot data of Iberian and Macaronesian vegetation. It currently hosts 86,000 relevés, mainly from the northern half of the Iberian Peninsula and the Balearic Islands, and will grow to 100,000 relevés in the near future. SIVIM has been conceived to offer direct and free on-line access to relevés, tables, as well as to floristic, syntaxonomical and bibliographical records. The system also offers on-line software for edition and analysis of vegetation data. The main characteristics of SIVIM are presented, and its particular technical solutions to typical data banking problems as well as its future objectives are briefly commented.
While many different RNA aptamers have been identified that bind to a plethora of small molecules only very few are capable of acting as engineered riboswitches. Even for aptamers binding the same ligand large differences in their regulatory potential were observed. We address here the molecular basis for these differences by using a set of unrelated neomycin-binding aptamers. UV melting analyses showed that regulating aptamers are thermally stabilized to a significantly higher degree upon ligand binding than inactive ones. Regulating aptamers show high ligand-binding affinity in the low nanomolar range which is necessary but not sufficient for regulation. NMR data showed that a destabilized, open ground state accompanied by extensive structural changes upon ligand binding is important for regulation. In contrast, inactive aptamers are already pre-formed in the absence of the ligand. By a combination of genetic, biochemical and structural analyses, we identified a switching element responsible for destabilizing the ligand free state without compromising the bound form. Our results explain for the first time the molecular mechanism of an engineered riboswitch.
Along three transects of medium voltage power lines in the steppe of Central Kazakhstan, surveys for bird casualties were carried out in summer 2006 in order to estimate the quantitative and qualitative impact of power lines on bird mortality in this area. In total, 409 dead birds of 34 different species were found. Raptors represented 44 % of the total (179 individuals, 10 species). Most of them died due to electrocution. The proportion of raptors strongly varied between early and late summer, the increase in August suggests that especially young birds are prone to electrocution. The density of raptor casualties varied from 0.1 to 7.6 birds per line km and month. Adverse effects of power lines on bird life could be avoided by changing the pole construction (use of suspended insulators) or protective measures (e. g. caps).
Irrigation is the most important water use sector accounting for about 70% of the global freshwater withdrawals and 90% of consumptive water uses. While the extent of irrigation and related water uses are reported in statistical databases or estimated by model simulations, information on the source of irrigation water is scarce and very scattered. Here we present a new global inventory on the extent of areas irrigated with groundwater, surface water or non-conventional sources, and we determine the related consumptive water uses. The inventory provides data for 15 038 national and sub-national administrative units. Irrigated area was provided by census-based statistics from international and national organizations. A global model was then applied to simulate consumptive water uses for irrigation by water source. Globally, area equipped for irrigation is currently about 301 million ha of which 38% are equipped for irrigation with groundwater. Total consumptive groundwater use for irrigation is estimated as 545 km3 yr−1, or 43% of the total consumptive irrigation water use of 1277 km3 yr−1. The countries with the largest extent of areas equipped for irrigation with groundwater, in absolute terms, are India (39 million ha), China (19 million ha) and the USA (17 million ha). Groundwater use in irrigation is increasing both in absolute terms and in percentage of total irrigation, leading in places to concentrations of users exploiting groundwater storage at rates above groundwater recharge. Despite the uncertainties associated with statistical data available to track patterns and growth of groundwater use for irrigation, the inventory presented here is a major step towards a more informed assessment of agricultural water use and its consequences for the global water cycle.
Irrigation is the most important water use sector accounting for about 70% of the global freshwater withdrawals and 90% of consumptive water uses. While the extent of irrigation and related water uses are reported in statistical databases or estimated by model simulations, information on the source of irrigation water is scarce and very scattered. Here we present a new global inventory on the extent of areas irrigated with groundwater, surface water or non-conventional sources, and we determine the related consumptive water uses. The inventory provides data for 15 038 national and sub-national administrative units. Irrigated area was provided by census-based statistics from international and national organizations. A global model was then applied to simulate consumptive water uses for irrigation by water source. Globally, area equipped for irrigation is currently about 301 million ha of which 38% are equipped for irrigation with groundwater. Total consumptive groundwater use for irrigation is estimated as 545 km3 yr−1, or 43% of the total consumptive irrigation water use of 1 277 km3 yr−1. The countries with the largest extent of areas equipped for irrigation with groundwater, in absolute terms, are India (39 million ha), China (19 million ha) and the United States of America (17 million ha). Groundwater use in irrigation is increasing both in absolute terms and in percentage of total irrigation, leading in places to concentrations of users exploiting groundwater storage at rates above groundwater recharge. Despite the uncertainties associated with statistical data available to track patterns and growth of groundwater use for irrigation, the inventory presented here is a major step towards a more informed assessment of agricultural water use and its consequences for the global water cycle.
Direct photon emission in heavy-ion collisions is calculated within a relativistic micro+macro
hybrid model and compared to the microscopic transport model UrQMD. In the hybrid approach,
the high-density part of the collision is calculated by an ideal 3+1-dimensional hydrodynamic
calculation, while the early (pre-equilibrium-) and late (rescattering-) phase are calculated with
the transport model. Different scenarios of the transition from the macroscopic description to
the transport model description and their effects are studied. The calculations are compared to
measurements by the WA98-collaboration and predictions for the future CBM-experiment are
made.
A lot of effort in lattice simulations over the last years has been devoted to studies of the QCD deconfinement transition. Most state-of-the-art simulations use rooted staggered fermions, while Wilson fermions are affected by large systematic uncertainties, such as coarse lattices or heavy sea quarks. Here we report on an ongoing study of the transition, using two degenerate flavours of nonperturbatively O(a) improved Wilson fermions. We start with Nt = 12 and 16 lattices and pion masses of 600 to 450 MeV, aiming at chiral and continuum limits with light quarks.
We compute the static-light baryon spectrum with Nf = 2 flavors of sea quarks using Wilson twisted mass lattice QCD. As light valence quarks we consider quarks, which have the same mass as the sea quarks with corresponding pion masses in the range 340MeV<∼ mPS<∼ 525MeV, as well as partially quenched quarks, which have the mass of the physical s quark. We extract masses of states with isospin I = 0,1/2,1, with strangeness S = 0,−1,−2, with angular momentum of the light degrees of freedom j = 0,1 and with parity P = +,−. We present a preliminary extrapolation in the light u/d and an interpolation in the heavy b quark mass to the physical point and compare with available experimental results.
We present unambiguous evidence from lattice simulations of Nf = 3 QCD for two tricritical points in the (T;m) phase diagram at fixed imaginary m=T = ip=3 mod. 2p=3, one in the light and one in the heavy quark regime. Together with similar results in the literature for Nf = 2 this implies the existence of a chiral and of a deconfinement tricritical line at those values of imaginary chemical potentials. These tricritical lines represent the boundaries of the analytically continued chiral and deconfinement critical surfaces, respectively, which delimit the parameter space with first order phase transitions. It is demonstrated that the shape of the deconfinement critical surface is dictated by tricritical scaling and implies the weakening of the deconfinement transition with real chemical potential. A qualitatively similar effect holds for the chiral critical surface.
We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (Nf = 2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark masses is performed at three values of the lattice spacing a ~ 0:06 fm, a ~ 0:08 fm and a ~ 0:09 fm with lattice sizes ranging from L ~ 1:9 fm to L ~ 3:9 fm. We perform a preliminary study of SU(2) chiral perturbation theory by combining our lattice data from these three values of the lattice spacing.
The isospin, spin and parity dependent potential of a pair of static-light mesons is computed using Wilson twisted mass lattice QCD with two flavors of degenerate dynamical quarks. From the results a simple rule can be deduced stating, which isospin, spin and parity combinations correspond to attractive and which to repulsive forces.
The QCD phase diagram as a function of temperature, T, and chemical potential for baryon
number, mB, is still unknown today, due to the sign problem, which prohibits direct Monte Carlo
simulations for non-vanishing baryon density. Investigations in models sharing chiral symmetry
with QCD predict a phase diagram, in which the transition corresponds to a smooth crossover at
zero density, but which is strengthened by chemical potential to turn into a first order transition
beyond some second order critical point. This contribution reviews the lattice evidence in favour
and against the existence of a critical point.
FIAS Scientific Report 2009
(2010)
In this Annual Report we present some of the ongoing activities of FIAS and of the associated graduate
school, the “Frankfurt International Graduate School for Science” (FIGSS) in the year 2009. The main part of the Report consists of a collection of short reports describing the research projects of scientists working at or associated with FIAS.
Miombo woodland is found throughout the Zambezian regional centre of endemism where most of the rural population make use of its wild plant species. This article presents the results of a study on the composition of the woody vegetation and its anthropogenous alteration in northern Malawi with particular respect to the impact caused by the collection of wild plants. The main vegetation type in this area is miombo woodland which is composed of 80 woody species. The collection of wild plants does not show an effect on the plant diversity but effects are visible in the decreasing number of tall trees.
Background: Rhabdomyosarcoma is the most common soft tissue sarcoma in childhood and has a poor prognosis. Here we assessed the capability of ex vivo expanded cytokine-induced killer cells to lyse both alveolar and embryonic rhabdomyosarcoma cell lines and investigated the mechanisms involved.
Design and Methods: Peripheral blood mononuclear cells from six healthy donors were used to generate and expand cytokine-induced killer cells. The phenotype and composition of these cells were determined by multiparameter flow cytometry, while their cytotoxic effect against rhabdomyosarcoma cells was evaluated by a europium release assay.
Results: Cytokine-induced killer cells efficiently lysed cells from both rhabdomyosarcoma cell lines. Antibody-mediated masking of either NKG2D molecule on cytokine-induced killer cells or its ligands on rhabdomyosarcoma cells (major histocompatibility antigen related chain A and B and UL16 binding protein 2) diminished this effect by 50%, suggesting a major role for the NKG2D molecule in rhabdomyosarcoma cell killing. No effect was observed after blocking CD11a, CD3 or TCRαβ molecules on cytokine-induced killer cells or CD1d on rhabdomyosar-coma cells. Remarkably, cytokine-induced killer cells used tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to activate caspase-3, as the main caspase responsible for the execution of apoptosis. Accordingly, blocking TRAIL receptors on embryonic rhabdomyosarcoma cell lines significantly reduced the anti-tumor effect of cytokine-induced killer cells. About 50% of T cells within the cytokine-induced killer population had an effector memory phenotype, 20% had a naïve phenotype and approximately 30% of the cells had a central memory phenotype. In addition, cytokine-induced killer cells expressed low levels of activation-induced markers CD69 and CD137 and demonstrated a low alloreactive potential.
Conclusions: Our data suggest that cytokine-induced killer cells may be used as a novel adoptive immunotherapy for the treatment of patients with rhabdomyosarcoma after allogeneic stem cell transplantation.
The TATA Box Binding Protein (TBP) is a 20 kD protein that is essential and universally conserved in eucarya and archaea. Especially among archaea, organisms can be found that live below 0°C as well as organisms that grow above 100°C. The archaeal TBPs show a high sequence identity and a similar structure consisting of α-helices and β-sheets that are arranged in a saddle-shape 2-symmetric fold. In previous studies, we have characterized the thermal stability of thermophilic and mesophilic archaeal TBPs by infrared spectroscopy and showed the correlation between the transition temperature (Tm) and the optimal growth temperature (OGT) of the respective donor organism. In this study, a “new” mutant TBP has been constructed, produced, purified and analyzed for a deeper understanding of the molecular mechanisms of thermoadaptation. The β-sheet part of the mutant consists of the TBP from Methanothermobacter thermoautotrophicus (OGT 65°C, MtTBP65) whose α-helices have been exchanged by those of Methanosarcina mazei (OGT 37°C, MmTBP37). The Hybrid-TBP irreversibly aggregates after thermal unfolding just like MmTBP37 and MtTBP65, but the Tm lies between that of MmTBP37 and MtTBP65 indicating that the interaction between the α-helical and β-sheet part of the TBP is crucial for the thermal stability. The temperature stability is probably encoded in the variable α-helices that interact with the highly conserved and DNA binding β-sheets.
The estimation model PhytoCalc allows a non-destructive quantification of dry weight and nutrient pools of understorey plants in forests by using the relationship between species biomass, cover and mean shoot length. The model has been validated with independent samples in several German forest types and can be a useful tool in forest monitoring. However, in open areas within forests (e.g. clearcuts), the current model version underestimates biomass and produces unreliable nutrient pool estimations. Thus, tissue density, as approximated by leaf dry matter content (LDMC), is systematically higher under high light compared to low light conditions. We demonstrate that the ratio of LDMC under clearcut conditions to LDMC under forest conditions can be used to adjust the PhytoCalc model to clearcut conditions. We investigated the LDMC ratio of five exemplary species commonly occurring on clearcuts. Integrating the square of the ratio as a correction factor improved estimates of biomass to more than 70% fit between observations and predictions. Results also suggest this ratio can be used to correct nutrient concentrations modelled in PhytoCalc, which tend to be overestimated in clearcuts. As morphological groups of plant species exhibit significantly different ratios, we advise using group-specific correction factors for clearcut adjustments in the future.
The CBM experiment will investigate heavy-ion collisions at beam energies from 8 to 45 AGeV at the future accelerator facility FAIR. The goal of the experiment is to study the QCD phase diagram in the vincinity of the QCD critical point. To do so, CBM aims at measuring rare probes among them open charm. In order to identify those rare and short lived particles despite the rich combinatorial background generated in heavy ion collisions, a micro vertex detector (MVD) providing an unprecedented combination of high rate capability and radiation hardness, very light material budget and excellent granularity is required. In this work, we will discuss the concept of this detector and summarize the status of the R&D.
CMOS sensors are the most promising candidates for the Micro-Vertex-Detector (MVD) of the CBM experiment at GSI, as they provide an unprecedented compromise between spatial resolution, low material budget, adequate radiation tolerance and readout speed. To study the integration of these sensors into a detector module, a so-called MVD-demonstrator has been developed. The demonstrator and its in-beam performance will be presented and discussed in this work.
We have developed a versatile software package for the simulation of di-electron production in pp and dp collisions at moderate beam kinetic energies (1-2GeV). Particular attention has been paid to incorporate different descriptions of the Dalitz decay Δ rightarrow Ne + e - via a common interface. In addition, suitable parameterizations for the virtual bremsstrahlung process NN rightarrow NNe + e - based on one-boson exchange models have been implemented. Such simulation tools with high flexibility of the framework are important for the interpretation of the di-electron data taken with the HADES spectrometer and demonstrates the wide applicability within the field of nuclear and hadronic physics.
The aim of this study was to investigate the frequency and effects of peer-victimization on mental health problems among adolescents. Parental and school support were assumed as protective factors that might interact with one another in acting as buffers for adolescents against the risk of peer-victimization. Besides these protective factors, age and gender were additionally considered as moderating factors. The Social and Health Assessment survey was conducted among 986 students aged 11-18 years in order to assess peer-victimization, risk and protective factors and mental health problems. For mental health problems, the Strengths and Difficulties Questionnaire (SDQ) was used. Effects of peer-victimization on mental health problems were additionally compared with normative SDQ data in order to obtain information about clinically relevant psychopathology in our study sample. Results of this study show that peer-victimization carries a serious risk for mental health problems in adolescents. School support is effective in both male and female adolescents by acting as a buffer against the effect of victimization, and school support gains increasing importance in more senior students. Parental support seems to be protective against maladjustment, especially in peer-victimized girls entering secondary school. Since the effect of peer-victimization can be reduced by parental and school support, educational interventions are of great importance in cases of peer-victimization.
Research indicates that autism is the extreme end of a continuously distributed trait. The Social Responsiveness Scale (SRS) and the Social and Communication Disorders Checklist (SCDC) aim to assess autistic traits. The objective of this study was to compare their clinical validity. The SRS showed sensitivities of .74 to .80 and specificities of .69 to 1.00 for autism. Sensitivities were .85 to .90 and specificities .28 to.82 for the SCDC. Correlations with the ADI-R, ADOS and SCQ were higher for the SRS than for the SCDC. The SCDC seems superior to the SRS to screen for unspecific social and communicative deficits including autism. The SRS appears more suitable than the SCDC in clinical settings and for specific autism screening.
A hygroscopicity tandem differential mobility analyzer (HTDMA) was used to measure the water uptake (hygroscopicity) of secondary organic aerosol (SOA) formed during the chemical and photochemical oxidation of several organic precursors in a smog chamber. Electron ionization mass spectra of the non-refractory submicron aerosol were simultaneously determined with an aerosol mass spectrometer (AMS), and correlations between the two different signals were investigated. SOA hygroscopicity was found to strongly correlate with the relative abundance of the ion signal m/z 44 expressed as a fraction of total organic signal (f44). m/z 44 is due mostly to the ion fragment CO2+ for all types of SOA systems studied, and has been previously shown to strongly correlate with organic O/C for ambient and chamber OA. The analysis was also performed on ambient OA from two field experiments at the remote site Jungfraujoch, and the megacity Mexico City, where similar results were found. A simple empirical linear relation between the hygroscopicity of OA at subsaturated RH, as given by the hygroscopic growth factor (GF) or "κorg" parameter, and f44 was determined and is given by κorg=2.2×f44−0.13. This approximation can be further verified and refined as the database for AMS and HTDMA measurements is constantly being expanded around the world. The use of this approximation could introduce an important simplification in the parameterization of hygroscopicity of OA in atmospheric models, since f44 is correlated with the photochemical age of an air mass.
The intrinsic complexity of the brain can lead one to set aside issues related to its relationships with the body, but the field of embodied cognition emphasizes that understanding brain function at the system level requires one to address the role of the brain-body interface. It has only recently been appreciated that this interface performs huge amounts of computation that does not have to be repeated by the brain, and thus affords the brain great simplifications in its representations. In effect the brain’s abstract states can refer to coded representations of the world created by the body. But even if the brain can communicate with the world through abstractions, the severe speed limitations in its neural circuitry mean that vast amounts of indexing must be performed during development so that appropriate behavioral responses can be rapidly accessed. One way this could happen would be if the brain used a decomposition whereby behavioral primitives could be quickly accessed and combined. This realization motivates our study of independent sensorimotor task solvers, which we call modules, in directing behavior. The issue we focus on herein is how an embodied agent can learn to calibrate such individual visuomotor modules while pursuing multiple goals. The biologically plausible standard for module programming is that of reinforcement given during exploration of the environment. However this formulation contains a substantial issue when sensorimotor modules are used in combination: The credit for their overall performance must be divided amongst them. We show that this problem can be solved and that diverse task combinations are beneficial in learning and not a complication, as usually assumed. Our simulations show that fast algorithms are available that allot credit correctly and are insensitive to measurement noise.
The canopy spiders of the floodplain forest in Leipzig have become a focus of ecological studies in recent years. In 2006 we sampled 30 tree canopies in the ‘Burgaue’ nature reserve with pyrethrum knock-down fogging, recording 502 adult spiders belonging to 48 species and 11 families. Based on these data and the results of a previous fogging study, the studied spider community was dominated by forest and forest-edge species with a preference for the shrub and canopy strata as well as by spiders of the web spider feeding guild. The community structure was typical for arboreal spider communities from northern temperate forests but very different from communities in the tropics. Species richness and evenness were similar to the old growth near-primary Białowieża Forest in Poland. The checklist of 96 canopy spider species of the floodplain forest of Leipzig includes 54 additions to the spider fauna of Leipzig and vicinity by recent canopy studies and eight first canopy records for Leipzig from our field work. The theridiid Dipoena torva (Thorell, 1875) was recorded for the first time in Saxony. The floodplain forest of Leipzig sustains a large and species-rich arboreal spider community and is thus a valuable habitat for a large proportion of endangered species (12%).
The display of foreign polypeptides and proteins on the surface of viruses or cells provides an important tool for the engineering of biomolecules and the analysis of their interactions with binding partners. The most extensively used display platform is the coat protein of the filamentous bacteriophage (Smith, 1985). Phage display libraries have often been selected for polypeptides, e.g. single chain (sc) antibodies that bind to a protein of interest, but in vivo selection could only be demonstrated for peptides so far. An alternative display platform is the retrovirus murine leukemia virus (MLV). Here, polypeptides are displayed at the N-terminus of the viral envelope glycoprotein. Proof of principle for this platform was demonstrated for protease substrate libraries, which can be selected through coupling proteolytic activation with viral infectivity (Buchholz et al., 1998). Selection of the library CX4A on living cells resulted in viruses with more than three orders of magnitude improved spreading efficiency through tumor cells (Hartl et al., 2005). Also scAb libraries have recently been displayed and selected using retroviruses (Urban et al., 2005). The library scFvlibxMo displays the repertoire of phage display preselected sc antibodies for laminin-1 binding. The retrovirus based selection process resulted in laminin-specific sc antibodies with improved expression levels in mammalian cells.
This thesis describes the in vivo (i.e. in mouse tumor models) selection of the C-X4-A and scFvlibxMo for tumor homing upon systemic delivery.
For selection of the protease substrate library C-X4-A a subcutaneous tumor was induced in SCID mice followed by three systemic injections of the library. The selection process was monitored over a period of 34 days. After the incubation period mice were sacrificed and virus load in organs and tumor determined. PCR analysis after 34 days showed that virus from the library had preferentially infected the tumor. Sequence analysis showed the selection of protease substrates with the most prominent one with a frequency of over 65%. The four most prominent protease substrate variants where reconstituted into the original viral backbone for further investigation (C-SK-A, C-HI-A, C-HM-A and C-HS-A). Interestingly, these viruses exhibited a reduced spreading capacity in vitro on HT1080 cells as compared to the C-AK-A virus, which had previously been selected on HT1080 cells. When assayed for tumor homing, however, viruses C-HI-A and C-HS-A had clearly improved in comparison to C-AK-A. Tumor tissue had been infected at rates of over 55% while virus load of extratumoral organs was very low (infection rates <0.7 for C-HS-A and <0.02 for C-HI-A). Tumor targeting capacity had thus been improved over 10-fold by the in vivo selection of the C-X4-A library.
The experimental set up for the in vivo selection of the scFvlibxMo library was performed according to that of the C-X4-A library. Fingerprint analysis of the selected viruses that infected tumor tissue resulted in the identification of seven antibody variants showing unique CDR3 sequences. Two prominent clones (M49T-A and M49T-B) were cloned back into the MoMLV genome for further analysis of the reconstituted viruses. While variant B bound laminin-1 efficiently, variant A was unable to do so, although it was selected at highest frequency (76%). Both reconstituted viruses were equally well infectious and spread through HT1080rec1 cells at a similar efficiency as MoMLV. In an in vivo competition experiment the selected viruses clearly out-competed a laminin-1 binding reference virus L36xMo for tumor homing. To understand the molecular driving forces behind the in vivo selection process the epitope of the selected scFv M49T-A was identified using a phage peptide library approach. In silico analysis led to the identification of a small group of possible antigens, including tenascin, fibronectin and collagen.
The data described in this thesis demonstrate that the retrovirus display platform is capable of allowing the in vivo selection of protease substrates and scFvs. Notably, the replication competence of the system introduced an additional level of complexity to the library. The performed in vivo selections significantly enhanced tumor tropism. Selective infection of tumor cells combined with transfer of anti-tumoral genes is an attractive strategy for cancer therapy being in focus of current research. The viruses selected in this thesis build prime candidates for targeted retrovirus based tumor therapy.
Drug toxicity and viral resistance limit long-term efficacy of antiviral drug treatment for HIV
infection. Thus, alternative therapies need to be explored. Previously, group of “Prof. von Laer”
tested the infusion of T lymphocytes transduced with a retroviral vector (M87o) that expresses an
HIV entry inhibitory peptide (maC46). Gene-modified autologous T cells were infused into 10
HIV-infected patients with advanced disease and multidrug resistant virus during antiretroviral
combination therapy. T cell infusions were tolerated well with no severe side effects. A
significant increase of CD4 counts was observed post infusion. At the end of the one-year
follow-up, the CD4 counts of all patients were still around or above baseline. Gene-modified
cells could be detected in peripheral blood, lymph nodes and bone marrow throughout the oneyear
follow-up, whereby marking levels correlated with the cell dose. No significant changes of
viral load were observed during the first four months. Four of the seven patients that changed
their antiviral drug regimen thereafter responded with a significant decline in plasma viral load.
In conclusion, the transfer of gene-modified cells was safe, led to sustained levels of gene
marking and may improve immune competence in HIV-infected patients with advanced disease
and multidrug resistant virus. However, the low level of gene marking and the lack of substantial
long-term in vivo accumulation of gene-protected cells observed in this trial clearly demonstrate
the requirement for new vectors with new strategy.
In this thesis self‐inactivating lentiviral vectors harboring internal promoters and RNA elements
were therefore evaluated for their potential use in a clinical gene‐therapy trial. The results from
this work provide the basis for the selection of a suitable candidate vector for extensive
preclinical testing. Apart from being capable of transducing non‐dividing cells, lentiviral vectors
incorporate a number of additional features that are of potential value for gene therapeutic
applications. These include a larger packaging capacity, higher titers than γ‐retroviral vectors
and, most importantly, a reduced risk of deregulating cellular genes due to its natural integration
profile. The use of internal promoters to drive expression of the therapeutic transgene maC46
should further improve the safety profile of these new‐generation vectors, while an additional
artificial splice acceptor (SA) into the 5‟UTR of the transgene over all elevate transgene
expression. The rationale for this is that hematopoietic stem and progenitor cells will be
Summary
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protected from enhancer‐mediated transactivation effects and also from potential side effects due
to the aberrant expression of maC46 while at the same time the full clinical benefit for the
patients is maintained.
In order to find a suitable candidate for preclinical studies, two candidate therapeutic vectors
harboring different regulatory elements were selected based on results from pilot experiments.
The internal promoters used to drive expression of codon optimized maC46 were the PGK
promoter and MPSV promoter. This work focuses on the transgene expression levels in
lymphoid cells and antiviral activity. The issues of long term expression, propensity to
methylation mediated silencing of the promoters, and genotoxicity were also touched. In a first
step the performance of different vectors was evaluated in the human T cell lines. Based on
promising data from ex vivo human peripheral blood mononuclear cells, the vector carrying the
MPSV promoter along with intron were selected for in vivo transplantation experiments.
In summary, the ex vivo data suggested the long term survival of lentiviral gene modified cells,
along with maintained expression of introduced genes. It was observed that the expression of
these constructs depends strongly on the activation and differentiation status of the targeted T
cells. This regulation was not linked to any specific promotor. In vivo study shows that maC46
can be introduced into murine multiple hematopoietic lineages via lentiviral vector and expressed
at high levels in their mulilineage progeny, without altering the hematopoiesis. There was no
sign of any kind of hematopoietic or lymphoid malignancies. Although gene-modified
lymphocytes persisted in-vivo, the downregulation of transgene expression was consistent with
the ex-vivo observation. In contrast to that the T cells transplanted group showed delayed
engraftment of donor cells and there was no expression of C46 in blood and lymphatic organs. .
In conclusion, when considering HIV gene therapy focusing CD4+ T cells, potential problems of
T cell activation status as related to the desired clinical effect must be addressed. These results
might open the way for a gene therapy targeting mainly or exclusively activated T cells and
could be exploited for immunostimulatory as well as suppressive approaches.
A study on the impact of mobile telecommunication on the welfare of sub saharan african countries
(2010)
Africa: A continent is waking up. Not through aid or wealth from the exploitation of natural resources, but through a technological revolution. The access to affordable mobile telecommunication. Inspired by deregulation and pioneered by local champions who have taken a lead in what is today's fastest growing mobile market in the world. There is money to be made in these markets, attracting more and more operators from the northern hemisphere.
However positive the short term impact of this revolution may be, governments should try hard to assure a market of continued competition among network operators, as this competition is the source of a self propelled creation of welfare and new opportunities, motivated from within Africa.
Chapter 1 of this thesis highlights the positive impact of mobile telecommunication on the social and economic life in Sub Saharan Africa. Chapter 2 builds on the static as well as the dynamic version of the Network Pricing Game, a model developed by Dr. Carolyn Gideon, to stress the immanent threat of network markets turning into a monopoly. This theses ends in Chapter 3 with an brief outlook on further drivers of economic growth and opportunities awaiting Sub Saharan Africa in the coming decade.
This study presents the development and mapping of simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers in chickpea. The mapping population is based on an inter-specific cross between domesticated and non-domesticated genotypes of chickpea (Cicer arietinum ICC 4958 × C. reticulatum PI 489777). This same population has been the focus of previous studies, permitting integration of new and legacy genetic markers into a single genetic map. We report a set of 311 novel SSR markers (designated ICCM—ICRISAT chickpea microsatellite), obtained from an SSR-enriched genomic library of ICC 4958. Screening of these SSR markers on a diverse panel of 48 chickpea accessions provided 147 polymorphic markers with 2–21 alleles and polymorphic information content value 0.04–0.92. Fifty-two of these markers were polymorphic between parental genotypes of the inter-specific population. We also analyzed 233 previously published (H-series) SSR markers that provided another set of 52 polymorphic markers. An additional 71 gene-based SNP markers were developed from transcript sequences that are highly conserved between chickpea and its near relative Medicago truncatula. By using these three approaches, 175 new marker loci along with 407 previously reported marker loci were integrated to yield an improved genetic map of chickpea. The integrated map contains 521 loci organized into eight linkage groups that span 2,602 cM, with an average inter-marker distance of 4.99 cM. Gene-based markers provide anchor points for comparing the genomes of Medicago and chickpea, and reveal extended synteny between these two species. The combined set of genetic markers and their integration into an improved genetic map should facilitate chickpea genetics and breeding, as well as translational studies between chickpea and Medicago.
EGFL7 regulates adult neural stem cell maintenance and differentiation by inhibition of Notch1
(2010)
In neurobiology the preexisting dogma on the unchangeability of the adult mammalian brain and its inability to give rise to new neurons has been challenged since the early nineties. Generally, it is now accepted that neurogenesis persists in adults. Progress in developmental and stem cell biology in recent years led to an increasing interest in regeneration-based treatment strategies for damaged tissue of the central nervous system. Thus, the enhancement of the endogenous potential of the brain to repair itself is potentially a feasible therapeutic strategy to treat various types of brain damage. Therefore, it is of great interest to understand the molecular mechanism that regulate adult neurogenesis. One of the prominent pathways suggested to be involved here is the Notch signaling cascade. Previously, it has been shown that various components of Notch signaling are expressed in the stem cell niche of the adult subventricular zone (SVZ) in vivo. Interestingly, a recent study demonstrated that the self-renewal potential of adult neural stem cells (NSCs) isolated from the SVZ depend on Notch signaling in vitro.
Recently, we identified a novel non-canonical Notch ligand termed epidermal growth factor-like domain 7 (EGFL7), which was originally described as a protein secreted by endothelial cells and functionally implicated in cellular responses of the vascular system such as cell migration and blood vessel formation. We were able to show that secreted EGFL7 binds to a region in Notch that is involved in ligand-mediated receptor activation, thus acting as an antagonist of Notch signaling.
The present study identifies neurons of the human and murine brain as a novel source of EGFL7, which suggests functions of EGFL7 in the neural system. Expression analyses by quantitative RT-PCR (qRT-PCR) revealed EGFL7 is down regulated in the adult SVZ, which suggests that endogenous EGFL7 may act as a Notch modulator of NSCs. We assessed the expression of Notch pathway components in adult NSCs isolated from the SVZ of adult mice and demonstrated that inhibition of Notch activity by the γ-secretase inhibitor DAPT reduced the self-renewal potential of NSCs. Accordingly, adenoviral-mediated expression of EGFL7 in vitro decreased Notch-specific signaling and reduced proliferation and self-renewal of NSCs. Conversely, activation of Notch by a constitutive active form of Notch (NICD) rescued the EGFL7-mediated reduction of NSC self-renewal verifying that this effect was directly linked to Notch signaling. Congruent to the reduced proliferation rate measured in vitro, induced expression of EGFL7 in vivo significantly reduced the number of Ki-67 positive cells within the SVZ upon cerebroventricular injection of EGFL7 adenovirus.
Expression analyses in the developing brain showed single EGFL7-positive cells within the marginal zone of the neocortex as measured by in situ hybridization. These cells might be Cajal-Retzius cells, specialized neurons, which specifically express Reelin, which is a protein of the extracellular matrix known to control neuronal migration and differentiation. Interstingly, we could show that Reelin and EGFL7 are expressed in a subtype of neurons of the adult mouse cortex. This implied an interaction of both proteins and was verified by co-immunoprecipitation assays, suggesting an additional role for EGFL7 in neuronal maintenance. QRT-PCR based expression analyses in vitro comparing differentiated and non-differentiated NSCs displayed an increase in EGFL7 expression during the differentiation process, which was paralled by reduced Notch signaling. NSCs differentiated on coverslips coated with EGFL7 differentiated into all three cell types - neurons, oligodendrocytes and astrocytes. EGFL7 favored the formation of neurons as compared to control comparable to the effect of the Notch-inhibitor DAPT. Furthermore, additional oligodendrocytes were formed. These cells displayed a mature morphology with distinct sprouts and branches in contrast to the small and round oligodendrocytes that formed on control coverslips, which resembled us of precursor cells. Neurons and oligodendrocytes were formed at the expense of astrocytes. Congruently to the effect observed in vitro, adenoviral-based expression of EGFL7 in the SVZ yielded a slight induction of neuronal differentiation in vivo. Taken together, these results show for the first time a previously unrecognized role for EGFL7 in the brain by modulation of the Notch pathway in adult NSCs, which changes the proliferation and differentiation potential of adult NSCs in vitro and in vivo.
The impact of shift work induced chronic circadian disruption on IL-6 and TNF-α immune responses
(2010)
Aim: Sleep disturbances induce proinflammatory immune responses, which might increase cardiovascular disease risk. So far the effects of acute sleep deprivation and chronic sleep illnesses on the immune system have been investigated. The particular impact of shift work induced chronic circadian disruption on specific immune responses has not been addressed so far.
Methods: Pittsburgh-Sleep-Quality-Index (PSQI) questionnaire and blood sampling was performed by 225 shift workers and 137 daytime workers. As possible markers the proinflammatory cytokines IL-6 and TNF-alpha and lymphocyte cell count were investigated. A medical examination was performed and biometrical data including age, gender, height, weight, waist and hip circumference and smoking habits were collected by a structured interview.
Results: Shift workers had a significantly higher mean PSQI score than day workers (6.73 vs. 4.66; p < 0.001). Day workers and shift workers had similar serum levels of IL-6 (2.30 vs. 2.67 resp.; p = 0.276), TNF-alpha (5.58 vs. 5.68, resp.; p = 0.841) or lymphocytes count (33.68 vs. 32.99, resp.; p = 0.404). Furthermore there were no differences in cytokine levels (IL-6 p = 0.761; TNF-alpha p = 0.759) or lymphocyte count (p = 0.593) comparing the sleep quality within the cohorts. When this calculation of sleep quality was stratified by shift and day workers irrespective of their sleep quality day workers and shift workers had similar serum levels of IL-6, TNF-alpha or lymphocytes count. Multiple linear regression analysis showed a significant correlation of lymphocytes count and smoking habits.
Conclusion: Shift work induces chronic sleep debt. Our data reveals that chronic sleep debt might not always lead to an activation of the immune system, as we did not observe differences in lymphocyte count or level of IL-6 or TNF-alpha serum concentration between shift workers and day workers. Therefore chronic sleep restriction might be eased by a long-term compensating immune regulation which (in healthy) protects against an overstimulation of proinflammatory immune mechanisms and moderates metabolic changes, as they are known from short-term sleep deprivation or sleep related breathing disorders.
Background: Diseases associated with smoking are a foremost cause of premature death in the world, both in developed and developing countries. Eliminating smoking can do more to improve health and prolong life than any other measure in the field of preventive medicine. Today's medical students will play a prominent role in future efforts to prevent and control tobacco use.
Methods: A cross-sectional, self-administered, anonymous survey of fifth-year medical students in Berlin, Germany was conducted in November 2007. The study explored the prevalence of smoking among medical students. We assessed their current knowledge regarding tobacco dependence and the effectiveness of smoking cessation methods. Students' perceived competence to counsel smokers and promote smoking cessation treatments was also explored. Analyses were based on responses from 258 students (86.6% response rate).
Results: One quarter of the medical students surveyed were current smokers. The smoking rate was 22.1% among women, 32.4% among men. Students underestimated smoking-related mortality and the negative effect of smoking on longevity. A considerable number of subjects erroneously assumed that nicotine causes coronary artery disease. Students' overall knowledge of the effectiveness of smoking cessation methods was inadequate. Only one third of the students indicated that they felt qualified to counsel patients about tobacco dependence.
Conclusions: This study reveals serious deficiencies in knowledge and counseling skills among medical students in our sample. The curriculum of every medical school should include a tobacco module. Thus, by providing comprehensive training in nicotine dependence interventions to medical students, smokers will have access to the professional expertise they need to quit smoking.
Family members provide most of the patient care and administer most of the treatments to patients with Alzheimer’s disease (AD). Family caregivers have an important impact on clinical outcomes, such as quality of life (QoL). As a consequence of this service, family caregivers suffer high rates of psychological and physical illness as well as social and financial burdens. Hence, it is important to involve family caregivers in multimodal treatment settings and provide interventions that are both suitable and specifically tailored to their needs. In recent years, several clinical guidelines have been presented worldwide for evidence-based treatment of AD and other forms of dementia. Most of these guidelines have considered family advice as integral to the optimal clinical management of AD. This article reviews current and internationally relevant guidelines with emphasis on recommendations concerning family advice.
Gene therapy is a promising therapeutic strategy that emerged from the attractive idea of targeting therapy at the molecular level. For many patients who suffer from genetic and acquired diseases that cannot be effectively treated by conventional treatment approaches gene therapy remains a huge hope of cure in spite of the hurdles regarding efficacy and safety that need to be overcome. The development of efficient gene transfer vehicles, mainly retroviral vectors, led to the first successful gene therapy trial, to treat patients suffering from X-linked severe combined immunodeficiency syndrome (X-SCID) using gene modified stem cells (Hacein-Bey-Abina, Le Deist et al. 2002). Despite the success of this trial, it revealed the danger of retroviral insertional mutagenesis as a major adverse event of gene therapy using gene-modified stem cells (Hacein-Bey-Abina, von Kalle et al. 2003). In contrast to stem cells, T cells are relatively resistant to insertional mutagenesis and transformation even after transduction with potent oncogenes using retroviral vectors (Newrzela, Cornils et al. 2008). However, mature T cells can self-renew, proliferate and survive for long periods. These criteria are supposed to render T cells prone to transformation. Therefore, the questions of mature T cells transformability and the control mechanism limiting their transformation are still elusive.
Hallin and Mancini’s seminal work Comparing Media Systems: Three Models of Media and
Politics has generated great interest and enthusiasm among media scholars to advance comparative
studies by applying the four dimensions to analyze media performance in different countries. Media
scholars agree that the four variables suggested by the two authors, i.e. the structure of media
markets, political parallelism, role of the state, and professionalization of journalism, provide a
good theoretical framework for the analysis of relationship between political and media system.
Their models for comparing media systems are based on a ‘most similar’ strategy,
analysing media and journalism only in stable Western democracies (i.e. Western European and
North American nations), and the purpose of the research presented in this paper was to develop
the model to include other parts of the world as well.
The most recent attempts to integrate East Central European media systems into the Hallin
and Mancini model, the conclusion being that the East Central European media share most
similarities with the Polarized Pluralist model. This conclusion follows not only Hallin and
Mancini, but also Splichal. The researcher in his earlier works argued that the changes in post-
Soviet media systems could be best explained by referring to the concept of Italianization - the
media are under strong state control, the degree of mass media partisanship is strong, low level of
journalistic professionalism, commercialization.
In fact, out of the three models only two (the Liberal and the Democratic Corporatist
model) are models in any strict sense, whereas the third - Polarized Pluralism - is better defined
as the lack of a model: the Liberal and Democratic Corporatist model are both built on a
consensus around core values, whereas the key feature of the Polarized Pluralism model is that
there is no consensus and no core values. De Albuquerque introduced other variables that also
would be highly relevant to the comparative analysis of media systems, but that have no place in
the Hallin & Mancini framework, the most important one being whether the political system is
presidential or parliamentary. For example, it has been demonstrated that media in presidential systems are more likely to focus on individual politicians and the administrative aspects of
government, as well as acting as an intermediary between different branches of government, than
are media in parliamentary systems.
Scholars dealing with the East Central Europe (and elsewhere) are too interested in fitting
their respective nations to one of the three models, rather than focusing on the variables and on the
comparative dimension. The scholars focus on the variables and on the comparative dimension: it
is strucking that their conclusions are precisely that a strict modeling approach (i.e. trying to fit
any given nation into the three-system model) is not enough if we want to understand media
system differences properly.
Hallin and Mancini (2004: 305) write that “The Democratic Corporatist Model, we suspect,
will have particularly strong relevance for the analysis of those parts of Eastern and Central
Europe that share much of the same historical development, like Poland, Hungary, the Czech
Republic, and the Baltic States”. At the same time, however, they suspect that scholars working on
the East Central European media will find much that is relevant in their analysis of the
Mediterranean region.
The recent attempts integrate East Central European media systems into the Hallin and
Mancini model, the conclusion being that the East Central European media share most similarities
with the Polarized Pluralist model. This conclusion follows not only Hallin and Mancini, but also
Splichal. The researcher in his earlier works argued that the changes in post-Soviet media systems
could be best explaind by referring to the concept of Italianization - including the role of
clientelism, the strong role of the state, the role of the media as an instrument of political struggle,
and a low level of journalistic professionalism.
The Polarized Pluralist model all too often seems to be the default model – what is really
gained, analytically, by saying that post-Communist countries are all basically Polarized Pluralist
media system when they are different in many ways. This question needs further elaboration.
Instead of fitting the Italianization model into East Central Europe, scholars should start working on their own model, introducing other variables, that would allow them to investigate the
media in the region adequately.
Walter Salles is probably the most widely known Brazilian director and producer. This article offers a portrait of his work over the last two decades as part of the cinematic and cultural changes that took place in Brazil. It starts with a historical overview of Brazilian film history and will then take a closer look at the films directed by Salles and his activities as producer. By looking at the evolution of the Brazilian film industry in the last ten to fifteen years in terms of market structures as well as aesthetic qualities, two major references become apparent: the more (but not only) commercial oriented productions of Globo Filmes, which often meet public taste and rely on a well-proven television language; second, the movies of Walter Salles as well as the films produced by Videofilmes, a company run and founded in 1987 by him and his brother, the documentarist João Moreira Salles. Videofilmes not only fosters many of the somewhat marginal, smaller film projects, but also serves as support for more artistically orientated movies.
This study presents a global scale analysis of cropping intensity, crop duration and fallow land extent computed by using the global dataset on monthly irrigated and rainfed crop areas MIRCA2000. MIRCA2000 was mainly derived from census data and crop calendars from literature. Global cropland extent was 16 million km2 around the year 2000 of which 4.4 million km2 (28%) was fallow, resulting in an average cropping intensity of 0.82 for total cropland extent and of 1.13 when excluding fallow land. The lowest cropping intensities related to total cropland extent were found for Southern Africa (0.45), Central America (0.49) and Middle Africa (0.54), while highest cropping intensities were computed for Eastern Asia (1.04) and Southern Asia (1.0). In remote or arid regions where shifting cultivation is practiced, fallow periods last 3–10 years or even longer. In contrast, crops are harvested two or more times per year in highly populated, often irrigated tropical or subtropical lowlands where multi-cropping systems are common. This indicates that intensification of agricultural land use is a strategy that may be able to significantly improve global food security. There exist large uncertainties regarding extent of cropland, harvested crop area and therefore cropping intensity at larger scales. Satellite imagery and remote sensing techniques provide opportunities for decreasing these uncertainties and to improve the MIRCA2000 inventory.
We report on screening tests of 66 extracts obtained from 35 marine sponge species from the Caribbean Sea (Curaçao) and from eight species from the Great Barrier Reef (Lizard Island). Extracts were prepared in aqueous and organic solvents and were tested for hemolytic, hemagglutinating, antibacterial and anti-acetylcholinesterase (AChE) activities, as well as their ability to inhibit or activate cell protein phosphatase 1 (PP1). The most interesting activities were obtained from extracts of Ircinia felix, Pandaros acanthifolium, Topsentia ophiraphidites, Verongula rigida and Neofibularia nolitangere. Aqueous and organic extracts of I. felix and V. rigida showed strong antibacterial activity. Topsentia aqueous and some organic extracts were strongly hemolytic, as were all organic extracts from I. felix. The strongest hemolytic activity was observed in aqueous extracts from P. acanthifolium. Organic extracts of N. nolitangere and I. felix inhibited PP1. The aqueous extract from Myrmekioderma styx possessed the strongest hemagglutinating activity, whilst AChE inhibiting activity was found only in a few sponges and was generally weak, except in the methanolic extract of T. ophiraphidites.
Spontaneous symmetry breaking is a general principle that constitutes the underlying concept of a vast number of physical phenomena ranging from ferromagnetism and superconductivity in condensed matter physics to the Higgs mechanism in the standard model of elementary particles. I focus on manifestations of spontaneously broken symmetries in systems that are not Lorentz invariant, which include both nonrelativistic systems as well as relativistic systems at nonzero density, providing a self-contained review of the properties of spontaneously broken symmetries specific to such theories. Topics covered include: (i) Introduction to the mathematics of spontaneous symmetry breaking and the Goldstone theorem. (ii) Minimization of Higgs-type potentials for higher-dimensional representations. (iii) Counting rules for Nambu–Goldstone bosons and their dispersion relations. (iv) Construction of effective Lagrangians. Specific examples in both relativistic and nonrelativistic physics are worked out in detail.
Surface measurements of aerosol and ice nuclei (IN) at a Central European mountain site during an episode of dust transport from the Sahara are presented. Transport is simulated by the Eulerian regional dust model DREAM. Ice nuclei and mineral dust are significantly correlated. The highest correlation is found between IN concentration and aerosol surface area. The ice nucleating characteristics of the aerosol with respect to temperature and supersaturation are similar during the dust episode than during the course of the year. This suggests that dust is always a dominant constituent of ice nucleating aerosols in Central Europe.
Surface measurements of aerosol and ice nuclei (IN) at a Central European mountain site during an episode of dust transport from the Sahara are presented. Ice nuclei were sampled by electrostatic precipitation on silicon wafers and were analyzed in an isothermal static vapor diffusion chamber. The transport of mineral dust is simulated by the Eulerian regional dust model DREAM. Ice nuclei and mineral dust are significantly correlated, in particular IN number concentration and aerosol surface area. The ice nucleating characteristics of the aerosol as analyzed with respect to temperature and supersaturation are similar during the dust episode than during the course of the year. This suggests that dust may be a main constituent of ice nucleating aerosols in Central Europe.