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Thought structures of modelling task solutions and their connection to the level of difficulty
(2015)
Although efforts have been made to integrate the concept of mathematical modelling in school, among others PISA and TIMSS revealed weaknesses of not only German students in the field of mathematical modelling. There may be various reasons starting from educational policy via curricular issues to practical instructional concerns. Studies show that mathematical modelling has not been arrived yet in everyday school class (Blum &BorromeoFerri, 2009, p. 47). Thus, the proportion of mathematical modelling in everyday school classes is low (Jordan et al., 2006). When focusing on the teachers’ point of view there are difficulties which may contribute to avoid modelling tasks in class. The development of reasonable modelling tasks, estimating the task space, valuating the task difficulty and assessing the student solutions are difficulties which occur to an increasing degree compared to ordinary mathematics tasks.The project MokiMaS (transl.: modeling competency in math classes of secondary education) aims at providing inter-year modelling tasks, whose task space and level of difficulty is known, together with an evaluation scheme. In particular a theory based method has been developed to determine the level of difficulty of modelling tasks on the basis of thought structures, representing the cognitive load of solution approaches. The current question is whether this method leads to a realistic rating. To go further into that question an evaluation scheme has been developed which is guided by the daily assessment work of teachers, to investigate the relation of task difficulty and student performance.
Cyclic GMP (cGMP) signalling regulates multiple biological functions through activation of protein kinase G and cyclic nucleotide-gated (CNG) channels. In sensory neurons, cGMP permits signal modulation, amplification and encoding, before depolarization. Here we implement a guanylyl cyclase rhodopsin from Blastocladiella emersonii as a new optogenetic tool (BeCyclOp), enabling rapid light-triggered cGMP increase in heterologous cells (Xenopus oocytes, HEK293T cells) and in Caenorhabditis elegans. Among five different fungal CyclOps, exhibiting unusual eight transmembrane topologies and cytosolic N-termini, BeCyclOp is the superior optogenetic tool (light/dark activity ratio: 5,000; no cAMP production; turnover (20 °C) ∼17 cGMP s−1). Via co-expressed CNG channels (OLF in oocytes, TAX-2/4 in C. elegans muscle), BeCyclOp photoactivation induces a rapid conductance increase and depolarization at very low light intensities. In O2/CO2 sensory neurons of C. elegans, BeCyclOp activation evokes behavioural responses consistent with their normal sensory function. BeCyclOp therefore enables precise and rapid optogenetic manipulation of cGMP levels in cells and animals.
Mitochondrial respiratory supercomplexes (mtRSCs) are stoichiometric assemblies of electron transport chain (ETC) complexes in the inner mitochondrial membrane. They are hypothesized to regulate electron flow, the generation of reactive oxygen species (ROS) and to stabilize ETC complexes. Using the fungal ageing model Podospora anserina, we investigated the impact of homologues of the Saccharomyces cerevisiae respiratory supercomplex factors 1 and 2 (termed PaRCF1 and PaRCF2) on mtRSC formation, fitness and lifespan. Whereas PaRCF2’s role seems negligible, ablation of PaRCF1 alters size of monomeric complex IV, reduces the abundance of complex IV-containing supercomplexes, negatively affects vital functions and shortens lifespan. PaRcf1 overexpression slightly prolongs lifespan, though without appreciably influencing ETC organization. Overall, our results identify PaRCF1 as necessary yet not sufficient for mtRSC formation and demonstrate that PaRCF1-dependent stability of complex IV and associated supercomplexes is highly relevant for maintenance of the healthy lifespan in a eukaryotic model organism.
Filamentous, heterocyst-forming cyanobacteria exchange nutrients and regulators between cells for diazotrophic growth. Two alternative modes of exchange have been discussed involving transport either through the periplasm or through septal junctions linking adjacent cells. Septal junctions and channels in the septal peptidoglycan are likely filled with septal junction complexes. While possible proteinaceous factors involved in septal junction formation, SepJ (FraG), FraC, and FraD, have been identified, little is known about peptidoglycan channel formation and septal junction complex anchoring to the peptidoglycan. We describe a factor, SjcF1, involved in regulation of septal junction channel formation in the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120. SjcF1 interacts with the peptidoglycan layer through two peptidoglycan-binding domains and is localized throughout the cell periphery but at higher levels in the intercellular septa. A strain with an insertion in sjcF1 was not affected in peptidoglycan synthesis but showed an altered morphology of the septal peptidoglycan channels, which were significantly wider in the mutant than in the wild type. The mutant was impaired in intercellular exchange of a fluorescent probe to a similar extent as a sepJ deletion mutant. SjcF1 additionally bears an SH3 domain for protein-protein interactions. SH3 binding domains were identified in SepJ and FraC, and evidence for interaction of SjcF1 with both SepJ and FraC was obtained. SjcF1 represents a novel protein involved in structuring the peptidoglycan layer, which links peptidoglycan channel formation to septal junction complex function in multicellular cyanobacteria. Nonetheless, based on its subcellular distribution, this might not be the only function of SjcF1.
Previous research on working memory (WM) in children with poor mathematical skills has yielded heterogeneous results, possibly due to inconsistent consideration of the IQ-achievement discrepancy and additional reading and spelling difficulties. To examine the impact of both, the WM of 68 average-achieving and 68 low-achieving third-graders in mathematics was assessed. Preliminary analyses showed that poor mathematical skills were associated with poor WM. Afterwards, children with isolated mathematical difficulties were separated from those with additional reading and spelling difficulties. Half of each group fulfilled the IQ-achievement discrepancy, resulting in a 2 (additional reading and spelling difficulties: yes/no) by 2 (IQ-achievement discrepancy: yes/no) factorial design. Analyses revealed that not fulfilling the IQ achievement discrepancy was associated with poor visual WM, whereas additional reading and spelling difficulties were associated with poor central executive functioning in children fulfilling the IQ-achievement discrepancy. Therefore, WM in children with poor mathematical skills differs according to the IQ-achievement discrepancy and additional reading and spelling difficulties.
Proton-pumping complex I of the mitochondrial respiratory chain is among the largest and most complex membrane protein complexes. The enzyme contributes substantially to oxidative energy-conversion in eukaryotic cells. Its malfunctions are implicated in many hereditary and degenerative disorders. Here, we report the X-ray structure of mitochondrial complex I at 3.6- 3.9 Å resolution describing in detail the central subunits that execute the bioenergetic function. A continuous axis of basic and acidic residues running centrally through the membrane arm connects the ubiquinone reduction site in the hydrophilic arm to four putative proton-pumping units. The binding position for a substrate analogous inhibitor and blockage of the predicted ubiquinone binding site provide a model for the ‘deactive’ form of the enzyme. The proposed transition into the active form is based on a concerted structural rearrangement at the ubiquinone reduction site rendering support for a two-state stabilization-change mechanism of protonpumping.
Models propose an auditory-motor mapping via a left-hemispheric dorsal speech-processing stream, yet its detailed contributions to speech perception and production are unclear. Using fMRI-navigated repetitive transcranial magnetic stimulation (rTMS), we virtually lesioned left dorsal stream components in healthy human subjects and probed the consequences on speech-related facilitation of articulatory motor cortex (M1) excitability, as indexed by increases in motor-evoked potential (MEP) amplitude of a lip muscle, and on speech processing performance in phonological tests. Speech-related MEP facilitation was disrupted by rTMS of the posterior superior temporal sulcus (pSTS), the sylvian parieto-temporal region (SPT), and by double-knock-out but not individual lesioning of pars opercularis of the inferior frontal gyrus (pIFG) and the dorsal premotor cortex (dPMC), and not by rTMS of the ventral speech-processing stream or an occipital control site. RTMS of the dorsal stream but not of the ventral stream or the occipital control site caused deficits specifically in the processing of fast transients of the acoustic speech signal. Performance of syllable and pseudoword repetition correlated with speech-related MEP facilitation, and this relation was abolished with rTMS of pSTS, SPT, and pIFG. Findings provide direct evidence that auditory-motor mapping in the left dorsal stream causes reliable and specific speech-related MEP facilitation in left articulatory M1. The left dorsal stream targets the articulatory M1 through pSTS and SPT constituting essential posterior input regions and parallel via frontal pathways through pIFG and dPMC. Finally, engagement of the left dorsal stream is necessary for processing of fast transients in the auditory signal.
The dopamine β-hydroxylase (DβH) enzyme transforms dopamine into noradrenaline. We hypothesized that individuals with low activity DBH genotypes (rs1611115 CT/TT) are more sensitive to the influence of cannabis and cocaine on cognitive impulse control and functional connectivity in the limbic ‘reward’ circuit because they experience a drug induced hyperdopaminergic state compared to individuals with high activity DBH genotypes (rs1611115 CC). Regular drug users (N = 122) received acute doses of cannabis (450 μg/kg THC), cocaine HCl 300 mg and placebo. Cognitive impulse control was assessed by means of the Matching Familiar Figures Test (MFFT). Resting state fMRI was measured in a subset of participants to determine functional connectivity between the nucleus accumbens (NAc) and (sub)cortical areas. The influence of cannabis and cocaine on impulsivity and functional connectivity significantly interacted with DBH genotype. Both drugs increased cognitive impulsivity in participants with CT/TT genotypes but not in CC participants. Both drugs also reduced functional connectivity between the NAc and the limbic lobe, prefrontal cortex, striatum and thalamus and primarily in individuals with CT/TT genotypes. Correlational analysis indicated a significant negative association between cognitive impulsivity and functional connectivity in subcortical areas of the brain. It is concluded that interference of cannabis and cocaine with cognitive impulse control and functional corticostriatal connectivity depends on DBH genotype. The present data provide a neural substrate and behavioral mechanism by which drug users can progress to drug seeking and may also offer a rationale for targeted pharmacotherapy in chronic drug users with high risk DBH genotypes.
Das Folgende ist eine Auseinandersetzung mit dem Zeitungsartikel von Patrick Bahners (FAZ 5. 9. 2015) und zugleich mit seiner wichtigsten Autorität, Gerd Althoff (FmSt 48, 2014, S. 261-76: "Das Amtsverständnis Gregors VII. und die neue These vom Friedenspakt in Canossa"). Zu beiden Texten sind einige Bemerkungen vonnöten. Der vorliegenden Fassung meiner Darlegung gingen Versionen voraus, die an Jürgen Petersohn u.a., sowie jeweils erweitert an Nikolas Jaspert und zuletzt an Folker Reichert geschickt wurden. Ich stelle hiermit diese erweiterte Version (entgegen meiner ursprünglichen Absicht) auf Drängen von Kollegen und Freunden ins "Netz".
Aims: We sought to describe perfusion dyssynchrony analysis specifically to exploit the high temporal resolution of stress perfusion CMR. This novel approach detects differences in the temporal distribution of the wash-in of contrast agent across the left ventricular wall.
Methods and results: Ninety-eight patients with suspected coronary artery disease (CAD) were retrospectively identified. All patients had undergone perfusion CMR at 3T and invasive angiography with fractional flow reserve (FFR) of lesions visually judged >50% stenosis. Stress images were analysed using four different perfusion dyssynchrony indices: the variance and coefficient of variation of the time to maximum signal upslope (V-TTMU and C-TTMU) and the variance and coefficient of variation of the time to peak myocardial signal enhancement (V-TTP and C-TTP). Patients were classified according to the number of vessels with haemodynamically significant CAD indicated by FFR <0.8. All indices of perfusion dyssynchrony were capable of identifying the presence of significant CAD. C-TTP >10% identified CAD with sensitivity 0.889, specificity 0.857 (P < 0.0001). All indices correlated with the number of diseased vessels. C-TTP >12% identified multi-vessel disease with sensitivity 0.806, specificity 0.657 (P < 0.0001). C-TTP was also the dyssynchrony index with the best inter- and intra-observer reproducibility. Perfusion dyssynchrony indices showed weak correlation with other invasive and non-invasive measurements of the severity of ischaemia, including FFR, visual ischaemic burden, and MPR.
Conclusion: These findings suggest that perfusion dyssynchrony analysis is a robust novel approach to the analysis of first-pass perfusion and has the potential to add complementary information to aid assessment of CAD.
The presented work inside this thesis aims to raise the degree of automation in analog circuit design. Therefore, a framework was developed to provide the necessary mechanisms in order to carry out a fully automated analog circuit synthesis, i.e., the construction of an analog circuit fulfilling all previously defined (electrical) specifications. Nowadays, analog circuit design in general is a very time consuming process compared to a digital design flow. Due to its discrete nature, the digital design process is highly automated and thus very efficient compared to analog circuit design. In modern Very-Large-Scale integration (VLSI) circuits the analog parts are mostly just a small portion of the overall chip area. Although this small portion is known to consume a major part of the needed workforce. Paired with product cycles which constantly get shorter, the time needed to develop the analog parts of an integrated circuit (IC) becomes a determinant factor. Apart from this, the ongoing progress in semiconductor processing technologies promises more speed with less power consumption on smaller areas, forcing the IC developers to keep track with the technology nodes in order to maintain competitiveness. Analog circuitry exhibits the inherent property of being hard to reuse, as porting from one technology node to another imposes critical changes for operating conditions (e.g., supply voltage) - mostly leading to a full redesign for most of the analog modules. This productivity gap between digital and analog design resembles the primary motivation for this thesis. Due to the availability of commercial sizing tools, this work deliberately focuses on the construction of circuit topologies in distinction to parameter synthesis, which can be obtained with a dedicated sizing tool. The focus on circuit construction allows the development of a framework which allows a full design space exploration. This thesis describes the needed concepts and methods to realize a deterministic, explorative analog synthesis framework. Despite this, a reference implementation is presented, which demonstrates the applicability in current analog design flows.
This study examines the urban heat island (UHI) of Brussels, for both current (2000–2009) and projected future (2060–2069) climate conditions, by employing very high resolution (250 m) modelling experiments, using the urban boundary layer climate model UrbClim. Meteorological parameters that are related to the intensity of the UHI are identified and it is investigated how these parameters and the magnitude of the UHI evolve for two plausible trajectories for future climate conditions. UHI intensity is found to be strongly correlated to the inversion strength in the lowest 100 m of the atmosphere. The results for the future scenarios indicate that the magnitude of the UHI is expected to decrease slightly due to global warming. This can be attributed to the increased incoming longwave radiation, caused by higher air temperature and humidity values. The presence of the UHI also has a significant impact on the frequency of extreme temperature events in the city area, both in present and future climates, and exacerbates the impact of climate change on the urban population as the amount of heat wave days in the city increases twice as fast as in the rural surroundings.
The frequency of intensional and non-first-order definable operators in natural languages constitutes a challenge for automated reasoning with the kind of logical translations that are deemed adequate by formal semanticists. Whereas linguists employ expressive higher-order logics in their theories of meaning, the most successful logical reasoning strategies with natural language to date rely on sophisticated first-order theorem provers and model builders. In order to bridge the fundamental mathematical gap between linguistic theory and computational practice, we present a general translation from a higher-order logic frequently employed in the linguistics literature, two-sorted Type Theory, to first-order logic under Henkin semantics. We investigate alternative formulations of the translation, discuss their properties, and evaluate the availability of linguistically relevant inferences with standard theorem provers in a test suite of inference problems stated in English. The results of the experiment indicate that translation from higher-order logic to first-order logic under Henkin semantics is a promising strategy for automated reasoning with natural languages.
El siguiente trabajo se propone como objetivo la reconstrucción de la estructura interna que constituye a las acciones con sentido (o intencionales) de los hombres tal como puede ser hecha desde la pragmática trascendental del lenguaje de Karl-Otto Apel. Resaltando (I) el papel decisivo que juega el lenguaje y el discurso en la constitución como tal de las acciones intencionales, se procede a la explicitación de una estructura interna de pretensiones de validez similar a la que es posible encontrar en el discurso explícito, tal como lo hicieron los planteos clásicos de Karl-Otto Apel. Luego de la discusión de algunas críticas que pueden hacerse a esta reconstrucción (II), se arriban finalmente a algunas conclusiones referidas a los presupuestos de las acciones no lingüísticas (III).
Dieser Leitfaden ist im Rahmen des Projektes "IndUK – Individuelles Umwelthandeln und Klimaschutz – Ergebnisintegration und transdisziplinäre Verwertung von Erkenntnissen aus der SÖF-Forschung zu den sozialen Dimensionen von Klimaschutz und Klimawandel" entstanden. Das Projekt IndUK wurde vom Bundesministerium für Bildung und Forschung (BMBF) im Förderschwerpunkt Sozial-ökologische Forschung gefördert.
Im Kontext der Diskussion zur „Globalisierung des Managements“ und der daraus entstandenen These einer transnationalen Klasse untersuchen wir in diesem Beitrag den Stellenwert internationaler Berufserfahrung bei Bankvorständen in Deutschland und weltweit. Bisherige Forschungen (etwa Pohlmann 2009) argumentieren, dass bei den Top-100- Industrieunternehmen in den USA, Ostasien und Deutschland Karriereverläufe im mittleren und Spitzenmanagement kaum internationalisiert sind und Hauskarrieren die Regel seien. Unsere eigene explorative Untersuchung legt die Vermutung nahe, dass die Situation im deutschen sowie im globalen Bankensektor anders aussieht. Vor allem in Deutschland verlaufen die Top-Karrieren im Unterschied zu Industrieunternehmen deutlich internationaler, was auf andere personelle Konstellation im Feld des global vernetzten Finanzsektors hinweist. Im deutschen wie im globalen Finanzsektor könnten wir es hierbei mit dem Phänomen einer „Transnationalisierung ohne Migration“ zu tun haben.
In methodischer Hinsicht macht unsere Studie auf die Grenzen quantitativer Forschungsdesigns bei der Untersuchung internationaler Berufserfahrung und internationalen Arbeitspraxen aufmerksam. Daher plädieren wir für ein an die Kategorien der Bourdieu‘schen Sozialtheorie angelehntes qualitatives Forschungsdesign für die Untersuchung der Herausbildung einer globalen Klasse auf den globalisierten Finanzmärkten.
Globale Finanzplätze im Vergleich : Frankfurt und Sydney zwischen Global City und lokaler Variation
(2015)
Frankfurt und Sydney sind international bedeutende Knotenpunkte des Global- Cities-Netzwerks. Als transnationale Finanzzentren erreichen sie im Global Financial Centres Index (GFCI) ähnliche Platzierungen. Populäre Rankings wie der GFCI entfalten ihre Wirkungsmacht in einem politischen Diskurs, der die Konkurrenz von Finanzzentren in einem hierarchischen Städtenetzwerk betont und so die Orientierung an den Champions der Finanzmetropolen forciert. Der hier vorgenommene kontrastive Vergleich Frankfurts und Sydneys zeigt hingegen, dass die stark von Globalisierungs- und Finanzialisierungstendenzen beeinflussten Städte sich nicht einfach einem Idealtypus von Global Cities angleichen. Vielmehr sorgt die Einbettung in unterschiedliche Entwicklungslinien – im Falle Frankfurts in die Tradition einer koordinierten Marktwirtschaft, im Falle Sydneys in die Tradition einer liberalen Marktwirtschaft – für die Ausbildung von Finanzsystemen mit unterschiedlichem Charakter und unterschiedlicher Reichweite. So weist der Finanzplatz Frankfurt im Vergleich mit Sydney eine starke globale Vernetzung auf, wenngleich die Merkmale der koordinierten Marktwirtschaft - geringere Börsenkapitalisierung der Unternehmen, einer primär kreditbasierten Unternehmensfinanzierung und geringere Finanzmarktorientierung der Bevölkerung nachwirken. Demgegenüber profitiert der Finanzstandort Sydney von einer durchwegs finanzialisierten Ökonomie, was sich in der Finanzmarktorientierung von Unternehmen und jener der allgemeinen Bevölkerung ausdrückt, weist aber eine stärkere Binnenorientierung, also die Fokussierung auf den nationalen Markt auf.
National Model United Nations New York 2015 : Delegation der Goethe-Universität Frankfurt am Main
(2015)
Seit ihrer Gründung im Jahr 1945 sind die Vereinten Nationen zur bedeutendsten und einflussreichsten internationalen Organisation geworden. Als völkerrechtlicher Zusammenschluss verschiedenster Staaten haben die Vereinten Nationen eine generelle Zuständigkeit in Fragen von Frieden, Sicherheit und internationalem Zusammenleben. Unter den sechs Hauptorganen der Vereinten Nationen sind besonders der Sicherheitsrat und die Generalversammlung hervorzuheben. Letztere ist mit Vertretern aus allen 193 Mitgliedsstaaten die weltweit größte, regelmäßige Zusammenkunft von offiziellen Staatsvertretern. ...
Background: Alzheimer’s Disease (AD) is the most common form of dementia and one of the major diseases of old age, causing the impairment of cognitive functions. This disease does not only confront society with financial issues, but also puts severe stress on individuals suffering from AD and their relatives alike. One of the possible symptoms, commonly described in AD, is the impairment of learning as well as the recognition of face-name associations. Beginning at age 60, the chance to develop AD grows exponentially with increasing age, making age a major risk factor. Additionally, the e4 allele of the apolipoprotein E (APOE) polymorphism has been associated with the risk of developing AD when compared to the more common e3 allele. While strong evidence shows a stronger decline in cognitive function with rising age for e4 carriers, some studies demonstrated better cognitive function in e4 carriers at a young age.
This led to the postulation of the hypothesis of antagonistic pleiotropy of the APOE gene, wherein the e4 allele may benefit cognitive function in young carriers, yet leads to a faster decline at a later point in life, encouraging the development of cognitive dysfunction such as AD. Several functional magnetic resonance imaging (fMRI) studies, examining functional activation patterns, found APOE-related differences in key areas of episodic memory, such as the hippocampus, where e4 carriers show aberrant activation similar to AD patients. However, associative memory (encoding and retrieval of face name pairs) has not been well examined for APOE-related differences. Interaction effects of age and the APOE genotype, such as those postulated by the hypothesis of antagonistic pleiotropy, have not been addressed in face-name association tasks either.
Leading Question: Is it possible to detect interaction effects between age and APOE genotype on cognitive performance or neuronal activation patterns in healthy young and old participants during an fMRI face-name association task, supporting the hypothesis of antagonistic pleiotropy of the APOE genotype?
Methods: Participants were stratied by age, and APOE e4 carriers were randomly matched with homozygous e3 carriers. Neuropsychological examination (CVLT and CERAD) was administered. Participants underwent structural MRI analysis via voxelbased morphometry (VBM) as well as fMRI imaging during a face-name association task.
Results: Apart from strong age-related effects in cognitive function detected during neuropsychological testing, the behavioral data from the face-name association task as well as the structural MRI analysis did not show an association with the APOE genotype. Nevertheless, analysis of functional MRI data showed age- as well as APOE-dependent effects on activation patterns for the encoding and retrieval of face-name pairs, in absence of differences in cognitive performance. Further analysis showed eight clusters of significant age X APOE genotype interactions in areas previously associated with working and visual associative memory, including the fusiform gyri bilaterally. These interactions show different patterns, whereas a relative hypoactivation of young e4 carriers together with a hyperactivation of old e4 carriers is the most prominent.
Conclusions: With regard to the leading question, this study successfully found age X APOE interactions in a face-name pair retrieval task, although no interaction effects were present in the encoding task, structural analysis, or cognitive performance. The agemediated effect of the APOE e4 allele on functional activation patterns may be explained by the compensatory hypothesis, describing a relative hyperactivation of old e4 carriers as compensatory, and interpreting a relative hypoactivation of younger e4 participants as reduced effort to achieve the same cognitive performance as non carriers.
These findings present further evidence of an antagonistic pleiotropy of the APOE genotype, showing age-dependent effects of the e4 allele even in healthy carriers. Nevertheless, previously described differences in cognitive performance and brain structure, even in young participants, were not found. On the contrary, functional MRI analysis showed APOE-related differences in young and old participants, suggesting that this modality may be more sensitive in detecting APOE-mediated changes. Among the clusters, demonstrating an interaction effect, the fusiform gyri were most prominent, which might be due to its important role in visual associative memory. As previous studies indicate an early and strong involvement of this area due to AD pathology, this interaction effect of age and APOE genotype in healthy participants underlines the importance of this region in the development of AD, and should be the focus of further research. However, this research is also required to determine, how exactly the APOE genotype influences brain function in healthy humans, and to clarify its relationship to pathological processes facilitating the development of AD.
Die aktuelle Debatte um Pornographie stellt sich andere Fragen als in den kämpferischen 70er Jahren. In den interdisziplinären Beiträgen des Sammelbandes wird Pornographie als kulturelles Artefakt behandelt, als Begriff, der in Diskurse über Sexualität und Moderne, über Identität und Jugend verwoben ist. Die Autor_innen arbeiten mit empirisch-sozialwissenschaftlichen Methoden Fragen nach dem Nutzer_innenverhalten von Onlinepornographie und jugendlichem Pornokonsum auf, bieten theoriegeleitete Zugänge zur Unbestimmbarkeit von Pornographie, zu ihrer notwendigen Einbettung in andere gesellschaftliche Kontexte sowie künstlerische Interventionen zu ihrem emanzipatorischen Potential. Die Beiträge bieten einen gelungenen Einblick in den aktuellen Stand der Debatte dieses noch jungen Feldes.
Recent STAR data for the directed flow of protons, antiprotons and charged pions obtained within the beam energy scan program are analyzed within the Parton-Hadron-String-Dynamics (PHSD/HSD) transport models. Both versions of the kinetic approach are used to clarify the role of partonic degrees of freedom. The PHSD results, simulating a partonic phase and its coexistence with a hadronic one, are roughly consistent with the STAR data. Generally, the semi-qualitative agreement between the measured data and model results supports the idea of a crossover type of quark-hadron transition which softens the nuclear EoS but shows no indication of a first-order phase transition. Furthermore, the directed flow of kaons and antikaons is evaluated in the PHSD/HSD approachesfrom √sNN ≈ 3 - 200 GeV which shows a high sensitivity to hadronic potentials in the FAIR/NICA energy regime √sNN ≤ 8 GeV.
Die vorliegende Arbeit, die im Rahmen des zwischen 2011 und 2013 durchgeführten Forschungsprojektes „Förderung von Modellbildungs- und Falsifikationsprozessen im Elementar- und Primarbereich“ entstanden ist, untersuchte auf Grundlage neuerer entwicklungspsychologischer Forschungsbefunde die Möglichkeiten der Förderung im naturwissenschaftlichen Denken bei Kindern im Elementarbereich. Nach der theoretischen Einordnung des Themas und der Darstellung der Forschungslage wurden im empirischen Teil in einem ersten Schritt die Kompetenzen beim Schlussfolgern im Themengebiet Elastizität und Plastizität und beim Wissenschaftsverständnis von Kindern im Alter von vier bis zehn Jahren, eingeteilt in vier Altersstufen, ermittelt; weiterhin wurden die Verknüpfungen beider Kompetenzbereiche untersucht. Als Instrumente dienten ein bereits erprobter Schlussfolgerungstest sowie ein neu entwickelter Test zur Kompetenzmessung von Wissenschaftsverständnis. In der Grundschule wurden die Tests jeweils als Gruppentests und im Kindergarten als Einzeltests durchgeführt. Die Stichprobe um-fasste 142 Kinder, 82 Kinder aus dem Primarbereich und 60 Kinder aus dem Elementarbereich. Beim Schlussfolgern zeigte sich, dass es für Kinder aller einbezogenen Altersgruppen deutlich leichter war, mit Ereignissen umzugehen, die eine Vermutung bestätigen, als mit solchen, die eine Vermutung widerlegen. Zudem stellte sich heraus, dass der Umgang mit Ereignissen, die im Hinblick auf eine Vermutung irrelevant sind, noch schwieriger war. Mit zunehmendem Alter war eine Kompetenzsteigerung erkennbar. Die Analyse der Tests ergab außerdem einen Zusammenhang zwischen Wissenschaftsverständnis und Schlussfolgern sowie einen deutlichen Einfluss exekutiver Funktionen. Im zweiten Schritt wurden zwei ausgewählte Trainingsmaß-nahmen zur Förderung der Koordination von Theorie und Evidenz bei Kindern im Alter von fünf bis sechs Jahren auf ihre Wirksamkeit hin geprüft, und zwar einerseits durch die Unter-stützung mit adaptivem Nachfragen bei fehlerhaften Antworten sowie andererseits durch eine intensive Förderung mit Modellierung. Die an einer Stichprobe von 63 Kindern durchgeführte Trainingsstudie war als Prä-Post-Studie angelegt und umfasste die Überprüfung des erworbenen Wissens. Die Studie ergab, dass die intensiv geförderten Kinder deutlich höhere Kompetenzen erworben hatten als die durch adaptive Unterstützung unterstützten Probanden. Außer-dem wurde ein Transfer-Test im Inhaltsgebiet Schwimmen und Sinken durchgeführt; hierbei wurden beide Trainingsgruppen in gleicher Weise mit adaptivem Nachfragen unterstützt. Dabei zeigten Kinder beider Trainingsgruppen deutlich höhere Kompetenzen beim Schlussfolgern als im Post-Test, dennoch zeigten Kinder mit vorheriger intensiver Förderung durch Modellierung wiederum höhere Kompetenzen im Transfer-Test als Kinder aus der Gruppe mit adaptiver Unterstützung. Abschließend wurde noch ein Argumentationstest durchgeführt, bei dem Kinder aller drei Experimentalgruppen (Trainingsgruppe 1, Trainingsgruppe 2, Kontrollgruppe) über-greifende Kompetenzen beim Schlussfolgern zeigen konnten. In diesem Test zeigte sich zwischen den drei Gruppen kein Unterschied im Hinblick auf angemessene Antworten beim Schlussfolgern.
Cancer is characterized by a remarkable intertumoral, intratumoral, and cellular heterogeneity that might be explained by the cancer stem cell (CSC) and/or the clonal evolution models. CSCs have the ability to generate all different cells of a tumor and to reinitiate the disease after remission. In the clonal evolution model, a consecutive accumulation of mutations starting in a single cell results in competitive growth of subclones with divergent fitness in either a linear or a branching succession. Acute lymphoblastic leukemia (ALL) is a highly malignant cancer of the lymphoid system in the bone marrow with a dismal prognosis after relapse. However, stabile phenotypes and functional data of CSCs in ALL, the so-called leukemia-initiating cells (LICs), are highly controversial and the question remains whether there is evidence for their existence. This review discusses the concepts of CSCs and clonal evolution in respect to LICs mainly in B-ALL and sheds light onto the technical controversies in LIC isolation and evaluation. These aspects are important for the development of strategies to eradicate cells with LIC capacity. Common properties of LICs within different subclones need to be defined for future ALL diagnostics, treatment, and disease monitoring to improve the patients’ outcome in ALL.
We investigate the properties of the QCD matter across the deconfinement phase transition in the scope of the parton-hadron string dynamics (PHSD) transport approach. We present here in particular the results on the electromagnetic radiation, i.e. photon and dilepton production, in relativistic heavy-ion collisions. By comparing our calculations for the heavy-ion collisions to the available data, we determine the relative importance of the various production sources and address the possible origin of the observed strong elliptic flow v2 of direct photons. We argue that the different centrality dependence of the hadronic and partonic sources for direct photon production in nucleusnucleus collisions can be employed to shed some more light on the origin of the photon v2 “puzzle”. While the dilepton spectra at low invariant mass show in-medium effects like an enhancement from multiple baryonic resonance formation or a collisional broadening of the vector meson spectral functions, the dilepton yield at high invariant masses (above 1.1 GeV) is dominated by QGP contributions for central heavy-ion collisions at ultra-relativistic energies. This allows to have an independent view on the parton dynamics via their electromagnetic massive radiation.
The high collision energies reached at the LHC lead to significant production yields of light (anti-)nuclei and (hyper-)nuclei in proton–proton, proton–lead and, in particular, lead–lead collisions. The excellent particle identification capabilities of the ALICE apparatus, based on the specific energy loss in the Time Projection Chamber and the velocity information in the Time-Of-Flight detector, allow for the detection of these rarely produced particles. Further, the Inner Tracking System gives the possibility to separate primary nuclei from those coming from weak decay of heavier systems. One example of such a weak decay is the measurement of the (anti-)hypertriton decay to 3He + π− (3H̅e̅ + π+). The aforementioned capabilities of the ALICE apparatus offer the unique opportunity to search for exotica, like the bound state of a Λ and a neutron which would decay into a deuteron and a pion, or the bound state of two Λ’s. Results on the production of stable nuclei in Pb–Pb collisions at √sNN = 2.76 TeV are presented, and compared with thermal model predictions. We further present the current status of the searches, by their upper limits on the production yields, and compare the results to thermal and coalescence model expectations.
The pA system is typically regarded in heavy ion collisions as a “cold” nuclear matter environment and thought to isolate and identify initial state effects due to the presence of multiple nucleons in the incoming nucleus. Moreover, pA collisions bridge the gap between peripheral AA collisions and the pp baseline to create a more complete understanding of underlying production mechanisms and how they evolve with multiplicity. Recent measurements at both RHIC and the LHC provide an indication, however, that the “cold” nuclear matter picture may be somewhat naïve.
Recent LHC results from the 2013 p–Pb run at √sNN = 5.02 TeV will be discussed.
Das Feld der interdisziplinäre Diskursforschung hat in den letzten Jahren zunehmend an Bedeutung gewonnen und sich zu einer etablierten Forschungsperspektive am Schnittpunkt von Sprache und Gesellschaft, von Wissen und Macht entwickelt. Die theoretische und methodische Vielgestaltigkeit dieser Forschungsperspektive führt allerdings insbesondere bei der Konzeption und Durchführung von Forschungsarbeiten solchen Zuschnitts immer wieder zu Unsicherheiten und Schwierigkeiten. Drei Werke, die – in unterschiedlicher Weise – auf das sich aus der Vielgestaltigkeit dieses Feldes ergebende Bedürfnis nach Systematisierung und Orientierung antworten, werden im Folgenden vorgestellt. Dabei gilt es deutlich herauszustellen, dass die vorgestellten Werke nicht als Methodenbücher oder Anleitungen zur "korrekten" Durchführung von diskursorientierten Forschungsarbeiten misszuverstehen, sondern vielmehr als Anregung und Verständigung über Fragen, Probleme und Richtungen der Diskursforschung auch über nationale und disziplinäre Grenzen hinweg zu lesen sind.
In this review, I argue that this textbook edited by BENNETT and CHECKEL is exceptionally valuable in at least four aspects. First, with regards to form, the editors provide a paragon of how an edited volume should look: well-connected articles "speak to" and build on each other. The contributors refer to and grapple with the theoretical framework of the editors who, in turn, give heed to the conclusions of the contributors. Second, the book is packed with examples from research practice. These are not only named but thoroughly discussed and evaluated for their methodological potential in all chapters. Third, the book aims at improving and popularizing process tracing, but does not shy away from systematically considering the potential weaknesses of the approach. Fourth, the book combines and bridges various approaches to (mostly) qualitative methods and still manages to provide abstract and easily accessible standards for making "good" process tracing. As such, it is a must-read for scholars working with qualitative methods. However, BENNETT and CHECKEL struggle with fulfilling their promise of bridging positivist and interpretive approaches, for while they do indeed take the latter into account, their general research framework remains largely unchanged by these considerations. On these grounds, I argue that, especially for scholars in the positivist camp, the book can function as a "how-to" guide for designing and implementing research. Although this may not apply equally to interpretive researchers, the book is still a treasure chest for them, providing countless conceptual clarifications and potential pitfalls of process tracing practice.
Die Entwicklungen in der Medizinischen Ausbildung der letzten Jahre konfrontieren Lehrende zunehmend mit neuen didaktischen Herausforderungen. An zahlreichen Standorten im deutschsprachigen Raum werden bereits Qualifizierungsangebote für Lehrende angeboten, jedoch fehlt bisher ein Orientierungsrahmen für medizindidaktische Kompetenzen, der ein Qualifikationsprofil für Lehrende darstellt.
Vor dem Hintergrund der Diskussion um die Kompetenzorientierung des Medizinstudiums und auf Grundlage aktueller internationaler Literatur wurde durch den GMA Ausschuss für Personal- und Organisationsentwicklung in der Lehre ein Kernkompetenzmodell für Lehrende in der Medizin entwickelt. Das Modell soll nicht nur den Lehrenden Orientierung zu ihrem Qualifikationsprofil geben, sondern auch die inhaltliche Ausrichtung hochschuldidaktischer (Aus-) Weiter- und Fortbildungen sowie die Evaluation von Fakultätsentwicklungsprozessen erleichtern und nicht zuletzt einheitliche Kriterien für die Beurteilung der Lehrqualifikation in deutschsprachigen Raum definieren.
Das Modell besteht aus sechs Kompetenzfeldern, für die jeweils Teilkompetenzen definiert und Lernziele beschrieben wurden. Anwendungsbeispiele sollen die jeweiligen Kompetenzen verdeutlichen.
Das Modell ist für die praktische Anwendung konzipiert und soll in einem nächsten Schritt durch spezifische Kompetenzen für Lehrende mit besonderen Aufgaben ergänzt werden.
Recent developments in medical education have created increasing challenges for medical teachers which is why the majority of German medical schools already offer educational and instructional skills trainings for their teaching staff. However, to date no framework for educational core competencies for medical teachers exists that might serve as guidance for the qualification of the teaching faculty. Against the background of the discussion about competency based medical education and based upon the international literature, the GMA Committee for Faculty and Organizational Development in Teaching developed a model of core teaching competencies for medical teachers. This framework is designed not only to provide guidance with regard to individual qualification profiles but also to support further advancement of the content, training formats and evaluation of faculty development initiatives and thus, to establish uniform quality criteria for such initiatives in German-speaking medical schools. The model comprises a framework of six competency fields, subdivided into competency components and learning objectives. Additional examples of their use in medical teaching scenarios illustrate and clarify each specific teaching competency. The model has been designed for routine application in medical schools and is thought to be complemented consecutively by additional competencies for teachers with special duties and responsibilities in a future step.
Membrane proteins are biological macromolecules that are located in a cell’s membrane and are responsible for essential functions within an organism, which makes them to prominent drug targets. The extraction of membrane proteins from the hydrophobic membrane bilayer to determine high-resolution crystal structures is a difficult task and only 2% of all solved proteins structures are membrane proteins. Computational methods may help to gain deeper insights into membrane protein structures and their functions. This study will give an overview of such computational methods on a representative set of membrane proteins and will provide ideas for future computational and experimental research on membrane proteins.
In a first step (chapter 2), I updated an earlier, manually-curated data set of homologous membrane proteins (HOMEP) to more recent versions in 2010 (HOMEP2) and 2013 (HOMEP3) using an automated clustering approach. High-resolution structures of membrane proteins listed in the PDB_TM database were structurally aligned and subsequently clustered using structural similarity scores. Both data sets were used as a standard gold reference set for subsequent work.
Subsequently, I have updated and applied the sequence alignment program AlignMe to determine protein descriptors that are suitable for detecting evolutionary relationship between homologous a-helical membrane proteins. Single input descriptors were tested alone and in combination with each other in different modes of AlignMe by optimizing gap penalties on the HOMEP2 data set. Most accurate alignments and homology models on the HOMEP2 data set were observed when using position-specific substitution information (P), secondary structure propensities (S) and transmembrane propensities (T) in the AlignMe PST mode. An evaluation on an independent reference set of membrane protein sequence alignments from the BAliBASE collection showed that different modes of AlignMe are suitable for different sequence similarity levels. The AlignMe PST mode improved the alignment accuracy significantly for distantly related proteins, whereas for closely-related proteins from the BAliBASE set the AlignMe PS mode was more suitable. This work was published in March 2013 in PLOS ONE. In order to allow also an easier usage of the AlignMe program, I have implemented a web server of AlignMe (chapter 4) that provides the optimized settings and gap penalties for the AlignMe P, PS and PST modes. A comparison to other recent alignment web server shows that the alignments of AlignMe are similar or even more accurate than those of other methods, especially for very distantly related proteins for which the inclusion of membrane protein information has been shown to be suitable. This work was published in the NAR web server issue in July 2014.
Although membrane-specific information has been shown to be suitable for aligning distantly related membrane proteins on a sequence level, such information was not incorporated into structural alignment programs making it unclear which method is the most suitable for aligning membrane proteins. Thus, I compared 13 widely-used pairwise structural alignment methods on an updated reference set of homologous membrane protein structures (HOMEP3) and evaluated their accuracy by building models based on the underlying sequence alignments and used scoring functions (e.g., AL4 or CAD-score) to rate the model accuracy (chapter 5). The analysis showed that fragment-based approaches such as FR-TM-align are the most useful for aligning structures of membrane proteins that have undergone large conformational changes whereas rigid approaches were more suitable for proteins that were solved in the same or a similar state. However, no method showed a significant higher accuracy than any other. Additionally, all methods lack a measure to rate the reliability of the accuracy for a specific position within a structure alignment. In order to solve these problems, I propose a consensus-type approach that combines alignments from four different methods, namely FR-TM-align, DaliLite, MATT and FATCAT and assigns a confidence value to each position of the alignment that describes the agreement between the methods. This work has been published 2015 in the journal “PROTEINS: structure, function and bioinformatics”.
Consensus alignments were then generated for each pair of proteins of the HOMEP3 data set and subsequently analyzed for single evolutionary events within membrane spanning segments and for irregular structures (e.g., 310- and p-helices) (chapter 6). Interestingly, single insertions and deletions could be observed with the help of consensus alignments in the conserved membrane-spanning segments of membrane proteins in four protein families. The detection of such single InDels might help to identify crucial residues for a proteins function.
Introduction: In 2008, the German Council of Science had advised universities to establish a quality management system (QMS) that conforms to international standards. The system was to be implemented within 5 years, i.e., until 2014 at the latest. The aim of the present study was to determine whether a QMS suitable for electronic learning (eLearning) domain of medical education to be used across Germany has meanwhile been identified.
Methods: We approached all medical universities in Germany (n=35), using an anonymous questionnaire (8 domains, 50 items).
Results: Our results (response rate 46.3%) indicated very reluctant application of QMS in eLearning and a major information deficit at the various institutions.
Conclusions: Authors conclude that under the limitations of this study there seems to be a considerable need to improve the current knowledge on QMS for eLearning, and that clear guidelines and standards for their implementation should be further defined.
Einleitung: Der Wissenschaftsrat empfahl 2008 den Universitäten innerhalb der nächsten 5 Jahre, d. h. bis spätestens 2014, ein Qualitätsmanagementsystem (QMS), das internationalen Maßstäben entspricht, zu etablieren. Ziel der vorliegenden Studie war es, zu evaluieren, ob es derzeit ein geeignetes QMS für das elektronische Lernen (eLearning) gibt, das speziell im Fach Humanmedizin deutschlandweit eingesetzt werden kann.
Methoden: Im Rahmen einer Umfrage wurden mittels eines anonymisierten Fragebogens (8 Domänen, 50 Items) alle Universitäten (n=35) des Fachbereichs Medizin in Deutschland evaluiert.
Ergebnisse: Die Ergebnisse (46,3% Rücklaufquote) zeigen einen nur zögerlichen Einsatz von QMS für eLearning und dass vor Ort ein großes Informationsdefizit herrscht.
Schlussfolgerung: Unter Berücksichtigung der Limitationen dieser Studie kann zusammenfassend festgehalten werden, dass erheblicher Bedarf zu bestehen scheint, das existierende Informationsdefizit für QMS eLearning zu mindern, sowie zukünftig genaue Richtlinien und Standards zur Umsetzung zu definieren.
Background: The West African country of Burkina Faso (BFA) is an example for the enduring importance of traditional plant use today. A large proportion of its 17 million inhabitants lives in rural communities and strongly depends on local plant products for their livelihood. However, literature on traditional plant use is still scarce and a comprehensive analysis for the country is still missing.
Methods: In this study we combine the information of a recently published plant checklist with information from ethnobotanical literature for a comprehensive, national scale analysis of plant use in Burkina Faso. We quantify the application of plant species in 10 different use categories, evaluate plant use on a plant family level and use the relative importance index to rank all species in the country according to their usefulness. We focus on traditional medicine and quantify the use of plants as remedy against 22 classes of health disorders, evaluate plant use in traditional medicine on the level of plant families and rank all species used in traditional medicine according to their respective usefulness.
Results: A total of 1033 species (50%) in Burkina Faso had a documented use. Traditional medicine, human nutrition and animal fodder were the most important use categories. The 12 most common plant families in BFA differed considerably in their usefulness and application. Fabaceae, Poaceae and Malvaceae were the plant families with the most used species. In this study Khaya senegalensis, Adansonia digitata and Diospyros mespiliformis were ranked the top useful plants in BFA. Infections/Infestations, digestive system disorders and genitourinary disorders are the health problems most commonly addressed with medicinal plants. Fabaceae, Poaceae, Asteraceae, Apocynaceae, Malvaceae and Rubiaceae were the most important plant families in traditional medicine. Tamarindus indica, Vitellaria paradoxa and Adansonia digitata were ranked the most important medicinal plants.
Conclusions: The national-scale analysis revealed systematic patterns of traditional plant use throughout BFA. These results are of interest for applied research, as a detailed knowledge of traditional plant use can a) help to communicate conservation needs and b) facilitate future research on drug screening.
Proteins of the secretin family form large macromolecular complexes, which assemble in the outer membrane of Gram-negative bacteria. Secretins are major components of type II and III secretion systems and are linked to extrusion of type IV pili (T4P) and to DNA uptake. By electron cryo-tomography of whole Thermus thermophilus cells, we determined the in situ structure of a T4P molecular machine in the open and the closed state. Comparison reveals a major conformational change whereby the N-terminal domains of the central secretin PilQ shift by ∼30 Å, and two periplasmic gates open to make way for pilus extrusion. Furthermore, we determine the structure of the assembled pilus.
Background: Second hand smoke (ETS)-associated particulate matter (PM) contributes considerably to indoor air contamination and constitutes a health risk for passive smokers. Easy to measure, PM is a useful parameter to estimate the dosage of ETS that passive smokers are exposed to. Apart from its suitability as a surrogate parameter for ETS-exposure, PM itself affects human morbidity and mortality in a dose-dependent manner. We think that ETS-associated PM should be considered an independent hazard factor, separately from the many other known harmful compounds of ETS. We believe that brand-specific and tobacco-product-specific differences in the release of PM matter and that these differences are of public interest. Methods: To generate ETS of cigarettes and cigarillos as standardized and reproducible as possible, an automatic second hand smoke emitter (AETSE) was developed and placed in a glass chamber. L&M cigarettes ("without additives", "red label", "blue label"), L&M filtered cigarillos ("red") and 3R4F standard research cigarettes (as reference) were smoked automatically according to a self-developed, standardized protocol until the tobacco product was smoked down to 8 mm distance from the tipping paper of the filter. Results: Mean concentration (Cmean) and area under the curve (AUC) in a plot of PM2.5 against time were measured, and compared. CmeanPM2.5 were found to be 518 μg/m3 for 3R4F cigarettes, 576 μg/m3 for L&M "without additives" ("red"), 448 μg/m3 for L&M "blue label", 547 μg/m3 for L&M "red label", and 755 μg/m3 for L&M filtered cigarillos ("red"). AUCPM2.5-values were 208,214 μg/m3·s for 3R4F reference cigarettes, 204,629 μg/m3·s for L&M "without additives" ("red"), 152,718 μg/m3·s for L&M "blue label", 238,098 μg/m3·s for L&M "red label" and 796,909 μg/m3·s for L&M filtered cigarillos ("red"). Conclusion: Considering the large and significant differences in particulate matter emissions between cigarettes and cigarillos, we think that a favorable taxation of cigarillos is not justifiable.
Background: Measurement of prostate-specific antigen (PSA) advanced the diagnostic and prognostic potential for prostate cancer (PCa). However, due to PSA’s lack of specificity, novel biomarkers are needed to improve risk assessment and ensure optimal personalized therapy. A set of protein molecules as potential biomarkers was therefore evaluated in serum of PCa patients.
Methods: Serum samples from patients undergoing radical prostatectomy (RPE) for biopsy-proven PCa without neoadjuvant treatment were compared to serum samples from healthy subjects. Preliminary screening of 119 proteins in 10 PCa patients and 10 controls was carried out by the Proteome Profiler Antibody Array. Those markers showing distinct differences between patients and controls were then further evaluated by ELISA in the serum of 165 PCa patients and 19 controls. Uni- and multivariate as well as correlation analysis were performed to test the capability of these molecules to detect disease and predict pathological outcome.
Results: Screening showed that soluble (s)E-cadherin, E-selectin, MMP2, MMP9, TIMP1, TIMP2, Galectin and Clusterin warranted further evaluation. sE-Cadherin, TIMP1, Galectin and Clusterin were significantly over- and MMP9 under-expressed in PCa compared to controls. The concentration of sE-cadherin, MMP2 and Clusterin correlated negatively and that of MMP9 and TIMP1 positively with the Gleason Sum at prostatectomy. Only sE-cadherin significantly correlated with the highest Gleason pattern. Compared to serum PSA, sE-cadherin provided an independent and better matching predictive ability for discriminating PCas with an upgrade at RPE and aggressive tumors with a Gleason Sum ≥7.
Conclusions: sE-cadherin performed most favorably from a large panel of serum proteins in terms of diagnostic and predictive potential in curatively treatable PCa. sE-cadherin merits further investigation as a biomarker for PCa.
Hintergrund: Die Interaktion zwischen β-HCG und TSH in der Schwangerschaft stellt ein differentialdiagnostisches Problem dar, weil die Wertung von supprimierten TSH-Spiegeln erschwert wird. Dies kann im schlimmsten Fall zu Fehlinterpretationen führen. Ziel der vorliegenden Arbeit war, diese Interaktion an einem großen Kollektiv in einen zeitlichen Kontext mit dem Verlauf der Schwangerschaft zu bringen, da der Zeitpunkt des Screenings entscheidenden Einfluss auf die Höhe des TSH-Spiegels hat. Zusätzlich wurden anhand der vorliegenden Daten Referenzbereiche für Schwangere berechnet und der Einfluss einer Jodmedikation untersucht.
Patienten und Methoden: Aus einem unselektionierten Pool von Patientinnen eines nuklearmedizinischen Praxisverbundes wurden die Daten von 1283 schilddrüsengesunden Schwangeren zwischen 16 und 48 Jahren ausgewertet. Neben der TSH-Bestimmung lag ein Schwerpunkt auf dem zeitlichen Verlauf, so dass die Schwangeren in Untergruppen von je 2 Wochen analysiert wurden. Untersucht wurde der Einfluss der Jodmedikation auf die TSH-Werte. Am Ende erfolgte mit Hilfe der logarithmischen Transformation unter Verwendung der 2-Sigma-Grenzen die Bestimmung neuer TSH-Referenzbereiche für Schwangere.
Ergebnisse: Es zeigt sich zu Beginn der Schwangerschaft ein Anstieg der mittleren TSH-Werte von 1,22 mU/l in der 2. SSW bis auf 1,7 mU/l um die 7. SSW mit einem konsekutiven Abfall der TSH-Werte bis auf 0,9 mU/l bis zur 16. SSW (entsprechend 52,9%). Der größte Abfall findet sich in der 12. bis 14. SSW, also zum Zeitpunkt des ersten Screenings. Die Jodmedikation hat keinen maßgeblichen Einfluss auf den TSH-Wert. Die Berechnung schwangerschaftskorrigierter Referenzbereiche zeigt im ersten Drittel TSH-Werte von 0,08 – 3,67 mU/l, im 2. Drittel 0,04 – 2,88 mU/l und im 3. Trimenon 0,17 – 3,19 mU/l.
Schlussfolgerungen: Die Arbeit zeigt, dass die niedrigsten TSH-Werte zum Zeitpunkt des ersten Screenings zu erwarten sind und deswegen möglicherweise zu Fehlentscheidungen führen können. Ein relevanter Zusammenhang der Jodmedikation mit dem TSH-Wert lässt sich nicht nachweisen. Neue Referenzbereiche für Schwangere könnten hilfreich sein, dieses diagnostische Dilemma zu vermeiden.
Diffusion tensor imaging (DTI) is amongst the simplest mathematical models available for diffusion magnetic resonance imaging, yet still by far the most used one. Despite the success of DTI as an imaging tool for white matter fibers, its anatomical underpinnings on a microstructural basis remain unclear. In this study, we used 65 myelin-stained sections of human premotor cortex to validate modeled fiber orientations and oft used microstructure-sensitive scalar measures of DTI on the level of individual voxels. We performed this validation on high spatial resolution diffusion MRI acquisitions investigating both white and gray matter. We found a very good agreement between DTI and myelin orientations with the majority of voxels showing angular differences less than 10°. The agreement was strongest in white matter, particularly in unidirectional fiber pathways. In gray matter, the agreement was good in the deeper layers highlighting radial fiber directions even at lower fractional anisotropy (FA) compared to white matter. This result has potentially important implications for tractography algorithms applied to high resolution diffusion MRI data if the aim is to move across the gray/white matter boundary. We found strong relationships between myelin microstructure and DTI-based microstructure-sensitive measures. High FA values were linked to high myelin density and a sharply tuned histological orientation profile. Conversely, high values of mean diffusivity (MD) were linked to bimodal or diffuse orientation distributions and low myelin density. At high spatial resolution, DTI-based measures can be highly sensitive to white and gray matter microstructure despite being relatively unspecific to concrete microarchitectural aspects.
Aim: We investigated the long-term impact of adjunctive systemic antibiotics on periodontal disease progression. Periodontal therapy is frequently supplemented by systemic antibiotics, although its impact on the course of disease is still unclear.
Material & Methods: This prospective, randomized, double-blind, placebo-controlled multi-centre trial comprising patients suffering from moderate to severe periodontitis evaluated the impact of rational adjunctive use of systemic amoxicillin 500 mg plus metronidazole 400 mg (3x/day, 7 days) on attachment loss. The primary outcome was the percentage of sites showing further attachment loss (PSAL) ≥1.3 mm after the 27.5 months observation period. Standardized therapy comprised mechanical debridement in conjunction with antibiotics or placebo administration, and maintenance therapy at 3 months intervals.
Results: From 506 participating patients, 406 were included in the intention to treat analysis. Median PSAL observed in placebo group was 7.8% compared to 5.3% in antibiotics group (Q25 4.7%/Q75 14.1%; Q25 3.1%/Q75 9.9%; p < 0.001 respectively).
Conclusions: Both treatments were effective in preventing disease progression. Compared to placebo, the prescription of empiric adjunctive systemic antibiotics showed a small absolute, although statistically significant, additional reduction in further attachment loss. Therapists should consider the patient's overall risk for periodontal disease when deciding for or against adjunctive antibiotics prescription.
Background: Detailed injury data are not available for international tournaments in field hockey. We investigated the epidemiology of field hockey injuries during major International Hockey Federation (Fédération Internationale de Hockey, FIH) tournaments in 2013.
Materials: and methods FIH injury reports were used for data collection. All major FIH tournaments for women (n=5) and men (n=11) in 2013 were included. The main focus of this study was to assess the pattern, time, site on the pitch, body site and mechanism of each of the injuries. We calculated the average number of injuries per match and the number of injuries per 1000 player match hours.
Results: The average number of injuries was 0.7 (95% CI 0.5 to 1.0) per match in women's tournaments and 1.2 (95% CI 0.8 to 1.7) per match in men's tournaments. The number of injuries per 1000 player match hours ranged from 23.4 to 44.2 (average 29.1; 95% CI 18.6 to 39.7) in women and 20.8 to 90.9 (average 48.3; 95% CI 30.9 to 65.8) in men. Most injuries occurred in the circle (n=25, 50%, in women, n=95, 51%, in men). The rate of injuries increased after the first quarter. Injuries to the head and face (n=20, 40%) were most common in women. The head/face (n=51, 27%) and the thigh/knee (n=52, 28%) were equally affected in men. The ball caused the most injuries, followed by the stick, collisions and tripping/falling. There were no deaths or injuries that required hospital treatment in the entire cohort.
Summary: Field hockey has a low incidence of acute injuries during competition.
Quantification of spatially and temporally resolved water flows and water storage variations for all land areas of the globe is required to assess water resources, water scarcity and flood hazards, and to understand the Earth system. This quantification is done with the help of global hydrological models (GHMs). What are the challenges and prospects in the development and application of GHMs? Seven important challenges are presented. (1) Data scarcity makes quantification of human water use difficult even though significant progress has been achieved in the last decade. (2) Uncertainty of meteorological input data strongly affects model outputs. (3) The reaction of vegetation to changing climate and CO2 concentrations is uncertain and not taken into account in most GHMs that serve to estimate climate change impacts. (4) Reasons for discrepant responses of GHMs to changing climate have yet to be identified. (5) More accurate estimates of monthly time series of water availability and use are needed to provide good indicators of water scarcity. (6) Integration of gradient-based groundwater modelling into GHMs is necessary for a better simulation of groundwater–surface water interactions and capillary rise. (7) Detection and attribution of human interference with freshwater systems by using GHMs are constrained by data of insufficient quality but also GHM uncertainty itself. Regarding prospects for progress, we propose to decrease the uncertainty of GHM output by making better use of in situ and remotely sensed observations of output variables such as river discharge or total water storage variations by multi-criteria validation, calibration or data assimilation. Finally, we present an initiative that works towards the vision of hyperresolution global hydrological modelling where GHM outputs would be provided at a 1-km resolution with reasonable accuracy.