913 research outputs found
StoĂwellenuntersuchungen zum Zerfall stickstoffhaltiger Verbindungen mit spektroskopischen Methoden
In dieser Arbeit wurden Geschwindigkeitskonstanten fĂŒr den thermischen Zerfall von NCN und Allylamin unter verbrennungsrelevanten Bedingungen untersucht. Zerfallsreaktionen stickstoffhaltiger Verbindungen spielen zum Beispiel bei der Stickoxidbildung in Verbrennungsprozessen eine Rolle. Die Experimente wurden an einem StoĂrohr durchgefĂŒhrt, an das ein ARAS-Aufbau oder ein FM-Spektrometer gekoppelt wurde. Die erhaltenen Ergebnisse wurden mit Hilfe der statistischen Reaktionstheorie analysiert
Supporting second language acquisition of bilingual preschool children through professionalization of caregivers in specialized preschool programs
The aim of the present study was to investigate the effectiveness of a training program on language support strategies and dialogic reading for caregivers working in specialized preschool programs. These programs serve children without a regular childcare place who grow up with one or more languages other than German as the environmental language. Recent studies investigating the development of children attending these programs found only moderate improvements in German receptive language skills, while language support quality of the programs was rated as average. We assessed receptive second language competencies in vocabulary and grammar of nâ=â48 children and language support competencies of nâ=â15 caregivers using an interventional pre-posttest design. Receptive vocabulary skills of children supported by trained caregivers (intervention group) were compared to children supported by untrained caregivers (control group, nâ=â43). We found that both childrenâs and caregiversâ competencies increased from pre- to posttest, whereas the control groupâs receptive vocabulary skills did not increase noticeably. The caregiversâ language support competencies influenced the increase of childrenâs receptive grammar but not vocabulary skills. The comparison between the intervention group and control group consistently showed no effect of group membership on childrenâs receptive vocabulary acquisition over time. Since the control group data came from a secondary analysis, only receptive vocabulary skills could be compared. The preliminary results of our study suggest that a caregiversâ training on language support strategies and dialogic reading in everyday educational situations support bilingual childrenâs grammar acquisition
Vernetzung - ErzÀhlung - Kollation: Digitale Methoden in der Biographieforschung
Vor dem Hintergrund sich verĂ€ndernder ForschungsansĂ€tze in den Geisteswissenschaften, dem Aufschwung digitaler, algorithmenbasierter Analyse- und Auswertungsverfahren in vornehmlich textgeprĂ€gten Wissenschaftsbereichen sowie den zentralen Auswirkungen, die das auf lebensgeschichtliche Quellen im digitalen Raum haben muss, soll die Wechselbeziehung zwischen den Digital Humanities und biographischer Forschung beleuchtet werden. Anhand dreier Schlagworte, die als Gliederungsabschnitte fungieren, beleuchtet der vorliegende Artikel Einzelaspekte dieses Zusammenhangs. Unter den Ăberschriften Vernetzung, ErzĂ€hlung und Kollation soll exemplarisch gezeigt werden, wie geisteswissenschaftliche Fragestellungen anhand digitaler biographischer Daten beantwortet werden können. Zuvörderst werden biographische Metadaten auf ihr Potential fĂŒr eine zukunftsweisende Vernetzungsstrategie hin ĂŒberprĂŒft. Im Anschluss werden Fragen der Entwicklung von biographischen Narrativen aufgeworfen. In einem dritten Schritt werden Kollationstools, wie sie bei der Analyse von Biographien verwendet werden, dargestellt, um das Potential aufzudecken, das auch in diesem Ansatz fĂŒr biographische Forschung zu finden ist
2D layered transport properties from topological insulator BiSe single crystals and micro flakes
Low-field magnetotransport measurements of topological insulators such as
BiSe are important for revealing the nature of topological surface
states by quantum corrections to the conductivity, such as
weak-antilocalization. Recently, a rich variety of high-field magnetotransport
properties in the regime of high electron densities ( cm)
were reported, which can be related to additional two-dimensional layered
conductivity, hampering the identification of the topological surface states.
Here, we report that quantum corrections to the electronic conduction are
dominated by the surface states for a semiconducting case, which can be
analyzed by the Hikami-Larkin-Nagaoka model for two coupled surfaces in the
case of strong spin-orbit interaction. However, in the metallic-like case this
analysis fails and additional two-dimensional contributions need to be
accounted for. Shubnikov-de Haas oscillations and quantized Hall resistance
prove as strong indications for the two-dimensional layered metallic behavior.
Temperature-dependent magnetotransport properties of high-quality BiSe
single crystalline exfoliated macro and micro flakes are combined with high
resolution transmission electron microscopy and energy-dispersive x-ray
spectroscopy, confirming the structure and stoichiometry. Angle-resolved
photoemission spectroscopy proves a single-Dirac-cone surface state and a
well-defined bulk band gap in topological insulating state. Spatially resolved
core-level photoelectron microscopy demonstrates the surface stability.Comment: Sci. Rep. (2016
Telling the truth from lie in individual subjects with fast event-related fMRI
Deception is a clinically important behavior with poorly understood neurobiological correlates. Published functional MRI (fMRI) data on the brain activity during deception indicates that, on a multisubject group level, lie is distinguished from truth by increased prefrontal and parietal activity. These findings are theoretically important; however, their applied value will be determined by the accuracy of the discrimination between single deceptive and truthful responses in individual subjects. This study presents the first quantitative estimate of the accuracy of fMRI in conjunction with a formal forced-choice paradigm in detecting deception in individual subjects. We used a paradigm balancing the salience of the target cues to elicit deceptive and truthful responses and determined the accuracy of this model in the classification of single lie and truth events. The relative salience of the task cues affected the net activation associated with lie in the superior medial and inferolateral prefrontal cortices. Lie was discriminated from truth on a single-event level with an accuracy of 78%, while the predictive ability expressed as the area under the curve (AUC) of the receiver operator characteristic curve (ROC) was 85%. Our findings confirm that fMRI, in conjunction with a carefully controlled query procedure, could be used to detect deception in individual subjects. Salience of the task cues is a potential confounding factor in the fMRI pattern attributed to deception in forced choice deception paradigms
Correction: The Endocytic Adaptor Eps15 Controls Marginal Zone B Cell Numbers.
Eps15 is an endocytic adaptor protein involved in clathrin and non-clathrin mediated endocytosis. In Caenorhabditis elegans and Drosophila melanogaster lack of Eps15 leads to defects in synaptic vesicle recycling and synapse formation. We generated Eps15-KO mice to investigate its function in mammals. Eps15-KO mice are born at the expected Mendelian ratio and are fertile. Using a large-scale phenotype screen covering more than 300 parameters correlated to human disease, we found that Eps15-KO mice did not show any sign of disease or neural deficits. Instead, altered blood parameters pointed to an immunological defect. By competitive bone marrow transplantation we demonstrated that Eps15-KO hematopoietic precursor cells were more efficient than the WT counterparts in repopulating B220âș bone marrow cells, CD19â» thymocytes and splenic marginal zone (MZ) B cells. Eps15-KO mice showed a 2-fold increase in MZ B cell numbers when compared with controls. Using reverse bone marrow transplantation, we found that Eps15 regulates MZ B cell numbers in a cell autonomous manner. FACS analysis showed that although MZ B cells were increased in Eps15-KO mice, transitional and pre-MZ B cell numbers were unaffected. The increase in MZ B cell numbers in Eps15 KO mice was not dependent on altered BCR signaling or Notch activity. In conclusion, in mammals, the endocytic adaptor protein Eps15 is a regulator of B-cell lymphopoiesis
Supporting second language acquisition of bilingual preschool children through professionalization of caregivers in specialized preschool programs
The aim of the present study was to investigate the effectiveness of a training program on language support strategies and dialogic reading for caregivers working in specialized preschool programs. These programs serve children without a regular childcare place who grow up with one or more languages other than German as the environmental language. Recent studies investigating the development of children attending these programs found only moderate improvements in German receptive language skills, while language support quality of the programs was rated as average. We assessed receptive second language competencies in vocabulary and grammar of nâ=â48 children and language support competencies of nâ=â15 caregivers using an interventional pre-posttest design. Receptive vocabulary skills of children supported by trained caregivers (intervention group) were compared to children supported by untrained caregivers (control group, nâ=â43). We found that both childrenâs and caregiversâ competencies increased from pre- to posttest, whereas the control groupâs receptive vocabulary skills did not increase noticeably. The caregiversâ language support competencies influenced the increase of childrenâs receptive grammar but not vocabulary skills. The comparison between the intervention group and control group consistently showed no effect of group membership on childrenâs receptive vocabulary acquisition over time. Since the control group data came from a secondary analysis, only receptive vocabulary skills could be compared. The preliminary results of our study suggest that a caregiversâ training on language support strategies and dialogic reading in everyday educational situations support bilingual childrenâs grammar acquisition
Autenticitet i spil: gymnasieelevers mĂžde med naturvidenskabelig forskning
Danske universiteter udbyder undervisningsforlĂžb til gymnasieelever for at Ăžge viden om oginteresse for naturvidenskab og teknologi. Der er begrĂŠnset evidens for effekten af de forskellige tilbud.Artiklen beskriver resultaterne fra et casestudie af tre undervisningsforlĂžb ved Aarhus Universitet Foulum.Analysen af data fra gymnasielĂŠrere og forskere synliggjorde tre dimensioner med betydning forelevernes faglige lĂŠring og deres indsigt i naturvidenskabelige metoder. Disse dimensioner er: autentiskforskningsmiljĂž, autentiske forskningsmetoder og autentisk forsker. Yderligere undersĂžgelser er dognĂždvendige for en mere indgĂ„ende forstĂ„else af betydningen af elevernes mĂžde med en autentiskforskningsverden samt effekten af de tre dimensioner. Danish universities offer teaching modules to upper secondary school students to increase theirknowledge of and interest in science and tech nology. This article presents findings from a case studyat Aarhus University in Foulum. Three dimensions of authentic science context emerged from dataanalysis of interviews and a survey of involved teachers and scientists: authentic research environment,authentic research methods, and the authentic scientist. The findings indicate that authenticscience context affected studentsâ learning about science and the nature of science. Further studiesare needed to investigate dimensions and effects of science culture in this context
Dispersal within a spatially structured population of lesser kestrels: The role of spatial isolation and conspecific attraction
1. Factors governing dispersal rates have seldom been examined in spatially structured populations of vertebrates. We gathered information during 8 years on transfer rates between subpopulations in a spatially structured, growing population of colonial lesser kestrels Falco naumanni, and analysed the contribution of several variables related to spatial isolation and characteristics of both subpopulation of origin and destination on probabilities of dispersal. 2. Lesser kestrels were highly philopatric to their subpopulations, but first-breeders dispersed more often than adults (26% vs. 4%, n = 1706) because adults were reluctant to move from familiar areas. Frequency of subpopulation change was higher in females than in males (first-recruiters: 30% vs. 22%, n = 987; adults 5% vs. 1%, n = 719), according to their different breeding roles. However, all populational factors had an equal effect on individuals of different sex and dispersal status. 3. Movement rates decreased with inter-subpopulation distance - indicating that travelling to distant subpopulations may impose costs in terms of breeding prospects -and with the number of subpopulations, which increased during our study period. 4. Conspecific attraction strongly influenced the probability of dispersal: it was relatively higher in largely populated subpopulations, and individuals of large subpopulations were reluctant to change to others. These results were neither influenced by the size and breeding density of the subpopulations nor by habitat quality in terms of food availability or risk of predation, as indicated by breeding success of kestrels at each subpopulation. The number of conspecifics could be used by the kestrels as a cue of patch quality in terms of settlement options, and large subpopulations could be more easily detected by prospecting birds. 5. Our study highlights the fact that several assumptions of theoretical metapopulation modelling are often not fulfilled in nature. Both theoretical models and management strategies on spatially structured populations or metapopulations should thus consider the number, population size, and spatial distribution of local populations, as well as their relationships with the dispersal ability of the species.Peer Reviewe
- âŠ