76 research outputs found

    Synchronization hypothesis in the Winfree model

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    We consider NN oscillators coupled by a mean field as in the Winfree model. The model is governed by two parameters: the coupling strength κ\kappa and the spectrum width γ\gamma of the frequencies of each oscillator. In the uncoupled regime, κ=0\kappa=0, each oscillator possesses its own natural frequency, and the difference between the phases of any two oscillators grows linearly in time. We say that NN oscillators are synchronized if the difference between any two phases is uniformly bounded in time. We identify a new hypothesis for the existence of synchronization. The domain in (γ,κ)(\gamma,\kappa) of synchronization contains coupling values that are both weak and strong. Moreover the domain is independent of the number of oscillators and the distribution of the frequencies. We give a numerical counter-example which shows that this hypothesis is necessary for the existence of synchronization

    Third order differential equations with fixed critical points

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    Cataloged from PDF version of article.The singular point analysis of third order ordinary differential equations which are algebraic in y and y′ is presented. Some new third order ordinary differential equations that pass the Painlevé test as well as the known ones are found. © 2008 Elsevier Inc. All rights reserved

    Introduction of a learning management system at the Kilimanjaro Christian Medical University College

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    Background. Medical schools in Africa face daunting challenges including faculty shortages, growing class sizes, and inadequate resources. Learningmanagement systems (LMS) may be powerful tools for organising and presenting curricular learning materials, with the potential for monitoring and evaluation functions.Objective. To introduce a LMS for the first-year medical student curriculum at the Kilimanjaro Christian Medical University College (KCMU Co), inMoshi, Tanzania, in partnership with the Duke University School of Medicine (Durham, North Carolina, USA).Methods. Observations were made on the requisite information technology (IT) infrastructure and human resource needs, and participation in trainingexercises. LMS utilisation was recorded, and two (student and faculty) surveys were done.Results. The KCMU Co IT infrastructure was upgraded, and an expert team trained for LMS implementation. An introductory LMS workshop forfaculty had 7 out of 25 invitees, but attendance improved to more than 50% in subsequent workshops. Student attendance at workshops was mandatory. Use of the LMS by students rapidly expanded, and growing faculty utilisation followed later. By the end of the second semester, online examinations were offered, resulting in greater student and faculty  satisfaction owing to rapid availability of results. A year after LMS   introduction, 90% of students were accessing the LMS at least 4 days/week. A student survey identified high levels of satisfaction with the LMS software, quality of content, and learning enhancement.Conclusion. LMS can be a useful and efficient tool for curriculum  organisation, administration of online examinations, and continuous monitoring. The lessons learned from KCMU Co may be useful for similar academic settings

    Painlev\'e structure of a multi-ion electrodiffusion system

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    A nonlinear coupled system descriptive of multi-ion electrodiffusion is investigated and all parameters for which the system admits a single-valued general solution are isolated. This is achieved \textit{via} a method initiated by Painleve' with the application of a test due to Kowalevski and Gambier. The solutions can be obtained explicitly in terms of Painleve' transcendents or elliptic functions.Comment: 9 p, Latex, to appear, J Phys A FT

    Social representations and the politics of participation

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    Recent work has called for the integration of different perspectives into the field of political psychology (Haste, 2012). This chapter suggests that one possible direction that such efforts can take is studying the role that social representations theory (SRT) can play in understanding political participation and social change. Social representations are systems of common-sense knowledge and social practice; they provide the lens through which to view and create social and political realities, mediate people's relations with these sociopolitical worlds and defend cultural and political identities. Social representations are therefore key for conceptualising participation as the activity that locates individuals and social groups in their sociopolitical world. Political participation is generally seen as conditional to membership of sociopolitical groups and therefore is often linked to citizenship. To be a citizen of a society or a member of any social group one has to participate as such. Often political participation is defined as the ability to communicate one's views to the political elite or to the political establishment (Uhlaner, 2001), or simply explicit involvement in politics and electoral processes (Milbrath, 1965). However, following scholars on ideology (Eagleton, 1991; Thompson, 1990) and social knowledge (Jovchelovitch, 2007), we extend our understanding of political participation to all social relations and also develop a more agentic model where individuals and groups construct, develop and resist their own views, ideas and beliefs. We thus adopt a broader approach to participation in comparison to other political-psychological approaches, such as personality approaches (e.g. Mondak and Halperin, 2008) and cognitive approaches or, more recently, neuropsychological approaches (Hatemi and McDermott, 2012). We move away from a focus on the individual's political behaviour and its antecedents and outline an approach that focuses on the interaction between psychological and political phenomena (Deutsch and Kinnvall, 2002) through examining the politics of social knowledge

    Building Clinical Clerkships Capacity in a Resource-limited Setting: The Case of the Kilimanjaro Christian Medical University College in Tanzania

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    Background: The shortage of medical doctors in sub-Saharan Africa (SSA) has resulted in increased enrolment in medical schools, which has not been matched with increased faculty size or physical infrastructure. This process has led to overcrowding and possibly reduced quality of training. To reduce overcrowding at its teaching hospital, the Kilimanjaro Christian Medical University College introduced eight-week peripheral clerkship rotations in 2012. We explore students’ perceptions and attitudes towards peripheral hospital placements. Method: The clerkship rotations were conducted in eight hospitals operating in the northern Tanzania, after evaluating each hospitals’ capabilities and establishing the optimum number of students per hospital. Paper-based surveys were conducted after student rotations from 2014 to 2016. Results: Overall student satisfaction was moderate (strength of consensus measure (sCns), 77%). The three cohorts exhibited improving trends over three years with respect to satisfaction with clinical skills and attitude towards placements. student-preceptor interaction was rated highly (sCns 81–84%). The first cohort students expressed concerns about limited laboratory support, and poor access to Internet and learning resources. Specific interventions were undertaken to address these concerns. Conclusions: Student experiences in peripheral rotations were positive with adequate satisfaction levels. Opportunities exist for medical schools in SSA to enhance clinical training and relieve overcrowding through peripheral clerkship rotations.<p

    Synchronization in Winfree model with N oscillators

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    We consider NN oscillators coupled by a mean field as in the Winfree model. The model is governed by two parameters: the coupling strength κ\kappa and the spectrum width γ\gamma of the frequencies of each oscillator. In the uncoupled regime, κ=0\kappa=0, each oscillator possesses its own natural frequency, and the difference between the phases of any two oscillators grows linearly in time. We say that NN oscillators are synchronized if the difference between any two phases is uniformly bounded in time. We identify a new hypothesis for the existence of synchronization. The domain in (γ,κ)(\gamma,\kappa) of synchronization contains coupling values that are both weak and strong. Moreover the domain is independent of the number of oscillators and the distribution of the frequencies. We give a numerical counter-example which shows that this hypothesis is necessary for the existence of synchronization

    Invariant cone and synchronization state stability of the mean field models

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    In this article we prove the stability of mean field systems as the Winfree model in the synchronized state. The model is governed by the coupling strength parameter κ and the natural frequency of each oscillator. The stability is proved independently of the number of os-cillators and the distribution of the natural frequencies. In order to prove the main result, we introduce the positive invariant cone and we start by studying the linearized system. The method can be applied to others mean field models as the Kuramoto model

    MarineFisheries Advisory (2006-02-10; 600-Lb. Spiny Dogfish Possession Limit Set For 2006 Fishing Year)

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    In this article we prove the stability of mean field systems as the Winfree model in the synchronized state. The model is governed by the coupling strength parameter κ\kappa and the natural frequency of each oscillator. The stability is proved independently of the number of os-cillators and the distribution of the natural frequencies. In order to prove the main result, we introduce the positive invariant cone and we start by studying the linearized system. The method can be applied to others mean field models as the Kuramoto model
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