517 research outputs found

    “Now I understand what you were trying to do, I see that this was the best module I had at University”: Student Learning Expectations Reviewed Eight Years Later"

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    The article reflects on a small longitudinal case study of a large compulsory module in a pre-1992 red-brick law school, using a narrative discursive method. It suggests that "alternative" methods of university law school teaching, such as Problem Based Learning, are experienced by students at the time as unsatisfactory. After being in graduate employment for several years, the students' experience has entirely changed. At that stage in their development and careers, students understand the relationships between the skills being fostered in such modules, and employment in the legal or other graduate professions. Processes, such as the Teaching Excellence Framework, that rely too strongly on contemporaneous assessments of the quality of student learning, such as the National Student Survey, create strong individual and institutional incentives to avoid such "risky" teaching. This undermines the stated aim of enhancing "employability" through university education

    The natural furanone (5<i>Z</i>)-4-bromo-5-(bromomethylene)-3-butyl-2(5<i>H</i>)-furanone disrupts quorum sensing-regulated gene expression in <i>Vibrio harveyi</i> by decreasing the DNA-binding activity of the transcriptional regulator protein luxR

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    This study aimed at getting a deeper insight in the molecular mechanism by which the natural furanone (5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)- furanone disrupts quorum sensing in Vibrio harveyi. Bioluminescence experiments with signal molecule receptor double mutants revealed that the furanone blocks all three channels of the V. harveyi quorum sensing system. In further experiments using mutants with mutations in the quorum sensing signal transduction pathway, the compound was found to block quorum sensing-regulated bioluminescence by interacting with a component located downstream of the Hfq protein. Furthermore, reverse transcriptase real-time polymerase chain reaction with specific primers showed that there was no effect of the furanone on luxRVh mRNA levels in wild-type V. harveyi cells. In contrast, mobility shift assays showed that in the presence of the furanone, significantly lower levels of the LuxRVh response regulator protein were able to bind to its target promoter sequences in wild-type V. harveyi. Finally, tests with purified LuxRVh protein also showed less shifts with furanone-treated LuxRVh, whereas the LuxRVh concentration was found not to be altered by the furanone (as determined by SDS-PAGE). Therefore, our data indicate that the furanone blocks quorum sensing in V. harveyi by rendering the quorum sensing master regulator protein LuxRVh unable to bind to the promoter sequences of quorum sensing-regulated genes

    Competition between local and nonlocal dissipation effects in two-dimensional quantum Josephson junction arrays

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    We discuss the local and nonlocal dissipation effects on the existence of the global phase coherence transitions in two dimensional Josephson-coupled junctions. The quantum phase transitions are also examined for various lattice geometries: square, triangular and honeycomb. The T=0 superconductor-insulator phase transition is analyzed as a function of several control parameters which include self-capacitance and junction capacitance and both local and nonlocal dissipation effects. We found the critical value of the nonlocal dissipation parameter \alpha_{1} depends on a geometry of the lattice. The critical value of the normal state conductance seems to be difficult to obtain experimentally if we take into consideration different damping mechanisms which are presented in real physical systems.Comment: accepted to Physica C Ref. No.: PHYSC-D-06-00244R

    Atmospheric Heating and Wind Acceleration: Results for Cool Evolved Stars based on Proposed Processes

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    A chromosphere is a universal attribute of stars of spectral type later than ~F5. Evolved (K and M) giants and supergiants (including the zeta Aurigae binaries) show extended and highly turbulent chromospheres, which develop into slow massive winds. The associated continuous mass loss has a significant impact on stellar evolution, and thence on the chemical evolution of galaxies. Yet despite the fundamental importance of those winds in astrophysics, the question of their origin(s) remains unsolved. What sources heat a chromosphere? What is the role of the chromosphere in the formation of stellar winds? This chapter provides a review of the observational requirements and theoretical approaches for modeling chromospheric heating and the acceleration of winds in single cool, evolved stars and in eclipsing binary stars, including physical models that have recently been proposed. It describes the successes that have been achieved so far by invoking acoustic and MHD waves to provide a physical description of plasma heating and wind acceleration, and discusses the challenges that still remain.Comment: 46 pages, 9 figures, 1 table; modified and unedited manuscript; accepted version to appear in: Giants of Eclipse, eds. E. Griffin and T. Ake (Berlin: Springer

    A systematic approach to the interrogation and sharing of standardised biofilm signatures

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    Publicado em "6th International Conference on Practical Applications of Computational Biology & Bioinformatics", ISBN 978-3-642-28838-8The study of microorganism consortia, also known as biofilms, is associated to a number of applications in biotechnology, ecotechnology and clinical domains. A public repository on existing biofilm studies would aid in the design of new studies as well as promote collaborative and incremental work. However, bioinformatics approaches are hampered by the limited access to existing data. Scientific publications summarise the studies whilst results are kept in researchers’ private ad hoc files. Since the collection and ability to compare existing data is imperative to move forward in biofilm analysis, the present work has addressed the development of a systematic computer-amenable approach to biofilm data organisation and standardisation. A set of in-house studies involving pathogens and employing different state-of-the-art devices and methods of analysis was used to validate the approach. The approach is now supporting the activities of BiofOmics, a public repository on biofilm signatures (http://biofomics.org).The authors thank, among others, Rosario Oliveira, Maria Joao Vieira, Idalina Machado, Nuno Cerca, Mariana Henriques, Pilar Teixeira, Douglas Monteiro, Melissa Negri, Susana Lopes, Carina Almeida and Helder Lopes, for submitting their data. The financial support from IBB-CEB, Fundacao para a Ciencia e Tecnologia (FCT) and European Community fund FEDER (Program COMPETE), project PTDC/SAU-ESA/646091/2006/FCOMP-01-0124-FEDER-007480, are also gratefully acknowledged

    Notes on a paper of Mess

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    These notes are a companion to the article "Lorentz spacetimes of constant curvature" by Geoffrey Mess, which was first written in 1990 but never published. Mess' paper will appear together with these notes in a forthcoming issue of Geometriae Dedicata.Comment: 26 page

    Incidence Simplicial Matrices Formalized in Coq/SSReflect

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    International audienceSimplicial complexes are at the heart of Computational Algebraic Topology, since they give a concrete, combinatorial description of otherwise rather abstract objects which makes many important topological computations possible. The whole theory has many applications such as coding theory, robotics or digital image analysis. In this paper we present a formalization in the COQ theorem prover of simplicial complexes and their incidence matrices as well as the main theorem that gives meaning to the definition of homology groups and is a first step towards their computation

    Production and Decay of D_1(2420)^0 and D_2^*(2460)^0

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    We have investigated D+π−D^{+}\pi^{-} and D∗+π−D^{*+}\pi^{-} final states and observed the two established L=1L=1 charmed mesons, the D1(2420)0D_1(2420)^0 with mass 2421−2−2+1+22421^{+1+2}_{-2-2} MeV/c2^{2} and width 20−5−3+6+320^{+6+3}_{-5-3} MeV/c2^{2} and the D2∗(2460)0D_2^*(2460)^0 with mass 2465±3±32465 \pm 3 \pm 3 MeV/c2^{2} and width 28−7−6+8+628^{+8+6}_{-7-6} MeV/c2^{2}. Properties of these final states, including their decay angular distributions and spin-parity assignments, have been studied. We identify these two mesons as the jlight=3/2j_{light}=3/2 doublet predicted by HQET. We also obtain constraints on {\footnotesize ΓS/(ΓS+ΓD)\Gamma_S/(\Gamma_S + \Gamma_D)} as a function of the cosine of the relative phase of the two amplitudes in the D1(2420)0D_1(2420)^0 decay.Comment: 15 pages in REVTEX format. hardcopies with figures can be obtained by sending mail to: [email protected]
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