5,156 research outputs found
Hybrid dialog: Dialogic learning in large lecture classes
Attendance at classical lectures usually leads to rather poor learning success. A wide variety of studies show that while lectures are as effective as any other method for transmitting information, they are inferior in many other dimensions. Lectures are not as effective as discussion methods in promoting thought and they are ineffective at teaching behavioral skills and subject-related values as well as at awakening interest in a subject. Still ex-cathedra teaching is a favored way to cope with a high student-to-teacher ratio. To solve this conflict between organizational and pedagogical requirements, a group of researchers at the Institute of Teacher Education at the University of Zurich has developed a hybrid course setting using an online learning platform. Their setting incorporates a dialog among students within a large lecture class. Furthermore a feedback loop enables the lecturer to continuously adjust the content of the lecture to the learning process of the students. In this article, the authors first present the structure of this setting and then illustrate how to implement it by the web-based open source learning management system OLAT (Online Learning and Training). Based on their research, they focus on key components for the success of their hybrid dialog. They show how individual and group learning can be fostered with corresponding assignments, assessments, and assigned roles such as moderators. Thus, the authors will define their position that the challenge of a large lecture class can be met while successfully implementing social learning and process-oriented assessments of academic achievement
The epidemiological type identification of Serratia marcescens from outbreaks of infection in hospitals
A study of serological, bacteriocine and phage typing of Serratia marcescens was made. Specific O-antisera of adequate titre were relatively simple to prepare but H-antisera exhibited many heterologous agglutination reactions amongst the type strains. Most of these cross-reactions were not reproduced when immobilization tests with H-sera were performed. Direct haemagglutination tests were used to establish the presence of fimbriae amongst the H-type strains and the results of agglutination tests with non-fimbriate variants of strains indicated that fimbrial antibody in high titre was present in some sera. Replicate typing of 100 pairs of cultures by the phage-typing method indicated that small variations in pattern were common and that larger variations occurred occasionally. Therefore differences in pattern of less than two strong reactions should not be taken as evidence that strains can be distinguished. Cultures of S. marcescens, 273 in total, from six outbreaks of infection in British and European hospitals were typed by O-serology, H agglutination and immobilization tests, phage typing and bacteriocine susceptibility by a cross-streaking method. The typability of strains by each method was high but the results suggested that no single method was sufficiently discriminating to be used alone for typing. Comparison of the H-type and typing patterns of members of the same O serogroup from incidents of infection showed that reliable results were obtained by H-typing or by phage and bacteriocine typing after the application of the appropriate ‘difference' rule. The greatest discrimination between strains of the same 0-group was obtained by the use of H-typing or phage typin
Development of microsatellite loci in the European Dipper, Cinclus cinclus
Eighteen polymorphic microsatellite DNA loci were isolated in the Central European subspecies of the European Dipper (Cinclus cinclus aquaticus). The loci were tested for polymorphism using a test panel of 24 breeding birds. Numbers of alleles ranged from 2 to 21 per locus and expected heterozygosities varied between 0.47 and 0.83. Two loci (Cici10 and Cici12) proved to be Z-linked. Some pairs of loci exhibited significant linkage disequilibrium but not the two loci that are located on the Z-chromosome. This pattern suggests that demographic effects rather than physical linkage are likely responsible for the observed levels of linkage disequilibrium. These loci will be useful for applied conservation projects and for investigations of the dispersal and mating patterns of European and other dipper
VEGF188 promotes corneal reinnervation after injury
Vascular endothelial growth factor A (VEGF) induces angiogenesis and vascular hyperpermeability in ocular tissues and is therefore a key therapeutic target for eye conditions in which these processes are dysregulated. In contrast, the therapeutic potential of VEGF's neurotrophic roles in the eye has remained unexploited. In particular, it is not known whether modulating levels of any of the 3 major alternatively spliced VEGF isoforms might provide a therapeutic approach to promote neural health in the eye without inducing vascular pathology. Here, we have used a variety of mouse models to demonstrate differences in overall VEGF levels and VEGF isoform ratios across tissues in the healthy eye. We further show that VEGF isoform expression was differentially regulated in retinal versus corneal disease models. Among the 3 major isoforms - termed VEGF120, VEGF164, and VEGF188 - VEGF188 was upregulated to the greatest extent in injured cornea, where it was both necessary and sufficient for corneal nerve regeneration. Moreover, topical VEGF188 application further promoted corneal nerve regeneration without inducing pathological neovascularization. VEGF isoform modulation should therefore be explored further for its potential in promoting neural health in the eye
Upper Limit on the molecular resonance strengths in the C+C fusion reaction
Carbon burning is a crucial process for a number of important astrophysical
scenarios. The lowest measured energy is around E=2.1 MeV, only
partially overlapping with the energy range of astrophysical interest. The
currently adopted reaction rates are based on an extrapolation which is highly
uncertain because of potential resonances existing in the unmeasured energy
range and the complication of the effective nuclear potential. By comparing the
cross sections of the three carbon isotope fusion reactions,
C+C, C+C and C+C, we have
established an upper limit on the molecular resonance strengths in
C+C fusion reaction. The preliminary results are presented
and the impact on nuclear astrophysics is discussed.Comment: 4 pages, 3 figures, FUSION11 conference proceedin
Inflation and the cosmic microwave background
I give a status report and outlook concerning the use of the cosmic microwave
background anisotropies to constrain the inflationary cosmology, and stress its
crucial role as an underlying paradigm for the estimation of cosmological
parameters.Comment: 8 pages LaTeX file, with two figures incorporated using epsf. To
appear, proceedings of `The non-sleeping universe', Porto (Astrophysics and
Space Science
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