1,323 research outputs found

    CodeVA Elementary Coaches Academy : Impact of Computer Science Implementation in K-5

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    Abstract This study investigated the impact of CodeVA’s elementary coach’s academy (ECA) on computer science implementation in elementary schools across the state of Virginia. The research took a multimethod qualitative and quantitative approach through surveys, focus groups, interviews and observations of ECA coaches and participants, along with the analysis of historical data provided by CodeVA. The capstone research questions were: “What is the impact of the elementary coaches academy?” and “What impacts the effectiveness of CodeVA’s elementary coaches academy?” In general, the data collected suggested that CodeVA has been effective in reaching its intended audience and meeting the needs of cohort participants, but there is still room for improvement. The review of the data resulted in five overarching anchors being identified that produced the following recommendations: “ use evidenced based coaching models to increase impact”; “utilize adult learning principles to create specific professional development”; “create a more structured professional learning community for ECA”; “improve advanced communication of ECA professional development opportunities” and “create a cache of resources to improve outside access to information for facilitators and coaches of the ECA” Keywords: CodeVA, computer science, elementary coaches academ

    Organic food and farming research needs in the UK:A report on a stakeholder participatory consultation process

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    During 2005 Defra commissioned a study to identify and analyse issues and aspirations that organic stakeholders felt should be addressed by publicly funded organic food and farming research in the UK. How this was undertaken is presented in this paper. A series of 12 workshops were undertaken with stakeholders throughout the UK. Nearly 300 stakeholders attended the workshops. These workshops used participatory approaches to identify and record the most important issues and aspirations from those attending. The use of a highly participatory style was greatly appreciated by stakeholders. In most cases the interaction between stakeholders worked well and resulted in lively discussions. The workshops have served to open up a useful dialogue between groups of stakeholders who do not normally communicate directly. They have produced a significant number of interesting and challenging issues and aspirations

    Book Reviews

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    Astrophysical S-factor of 4He12C radiative capture at low energies

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    The possibility to describe the astrophysical S-factor of the 4He12C radiative capture is considered in the potential cluster model at the energy range 0.1-4.0 MeV. It is shown that the approach used, which takes into account E2 transitions only, gives a good description of the new experimental data for adjusted parameters of potentials and leads to the value S(300) = 16.0⋅\cdotpkeV b.Comment: 8 Pag

    Diarylethene moiety as an enthalpy-entropy switch: photoisomerizable stapled peptides for modulating p53/MDM2 interaction

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    Analogs of the known inhibitor (peptide pDI) of the p53/MDM2 protein–protein interaction are reported, which are stapled by linkers bearing a photoisomerizable diarylethene moiety. The corresponding photoisomers possess significantly different affinities to the p53-interacting domain of the human MDM2. Apparent dissociation constants are in the picomolar-to-low nanomolar range for those isomers with diarylethene in the “open” configuration, but up to eight times larger for the corresponding “closed” isomers. Spectroscopic, structural, and computational studies showed that the stapling linkers of the peptides contribute to their binding. Calorimetry revealed that the binding of the “closed” isomers is mostly enthalpy-driven, whereas the “open” photoforms bind to the protein stronger due to their increased binding entropy. The results suggest that conformational dynamics of the protein-peptide complexes may explain the differences in the thermodynamic profiles of the binding

    Do Null-Type Mutation Operators Help Prevent Null-Type Faults?

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    The null-type is a major source of faults in Java programs, and its overuse has a severe impact on software maintenance. Unfortunately traditional mutation testing operators do not cover null-type faults by default, hence cannot be used as a preventive measure. We address this problem by designing four new mutation operators which model null-type faults explicitly. We show how these mutation operators are capable of revealing the missing tests, and we demonstrate that these mutation operators are useful in practice. For the latter, we analyze the test suites of 15 open-source projects to describe the trade-offs related to the adoption of these operators to strengthen the test suite

    If cooperation is likely punish mildly: Insights from economic experiments based on the snowdrift game

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    Punishment may deter antisocial behavior. Yet to punish is costly, and the costs often do not offset the gains that are due to elevated levels of cooperation. However, the effectiveness of punishment depends not only on how costly it is, but also on the circumstances defining the social dilemma. Using the snowdrift game as the basis, we have conducted a series of economic experiments to determine whether severe punishment is more effective than mild punishment. We have observed that severe punishment is not necessarily more effective, even if the cost of punishment is identical in both cases. The benefits of severe punishment become evident only under extremely adverse conditions, when to cooperate is highly improbable in the absence of sanctions. If cooperation is likely, mild punishment is not less effective and leads to higher average payoffs, and is thus the much preferred alternative. Presented results suggest that the positive effects of punishment stem not only from imposed fines, but may also have a psychological background. Small fines can do wonders in motivating us to chose cooperation over defection, but without the paralyzing effect that may be brought about by large fines. The later should be utilized only when absolutely necessary.Comment: 15 pages, 6 figures; accepted for publication in PLoS ON

    Discovery of mating in the major African livestock pathogen Trypanosoma congolense

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    The protozoan parasite, Trypanosoma congolense, is one of the most economically important pathogens of livestock in Africa and, through its impact on cattle health and productivity, has a significant effect on human health and well being. Despite the importance of this parasite our knowledge of some of the fundamental biological processes is limited. For example, it is unknown whether mating takes place. In this paper we have taken a population genetics based approach to address this question. The availability of genome sequence of the parasite allowed us to identify polymorphic microsatellite markers, which were used to genotype T. congolense isolates from livestock in a discrete geographical area of The Gambia. The data showed a high level of diversity with a large number of distinct genotypes, but a deficit in heterozygotes. Further analysis identified cryptic genetic subdivision into four sub-populations. In one of these, parasite genotypic diversity could only be explained by the occurrence of frequent mating in T. congolense. These data are completely inconsistent with previous suggestions that the parasite expands asexually in the absence of mating. The discovery of mating in this species of trypanosome has significant consequences for the spread of critical traits, such as drug resistance, as well as for fundamental aspects of the biology and epidemiology of this neglected but economically important pathogen

    Environment Orientation : a structured simulation approach for agent-based complex systems

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    Complex systems are collections of independent agents interacting with each other and with their environment to produce emergent behaviour. Agent-based computer simulation is one of the main ways of studying complex systems. A naive approach to such simulation can fare poorly, due to large communication overhead, and due to the scope for deadlock between the interacting agents sharing a computational platform. Agent interaction can instead be considered entirely from the point of view of the environment(s) within which the agents interact. Structuring a simulation using such Environment Orientation leads to a simulation that reduces communication overhead, that is effectively deadlock-free, and yet still behaves in the manner required. Additionally the Environment Orientation architecture eases the development of more sophisticated large-scale simulations, with multiple kinds of complex agents, situated in and interacting with multiple kinds of environments. We describe the Environment Orientation simulation architecture. We report on a number of experiments that demonstrate the effectiveness of the Environment Orientation approach: a simple flocking system, a flocking system with multiple sensory environments, and a flocking system in an external environment
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