1,461 research outputs found

    Altered functional connectivity within the central reward network in overweight and obese women.

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    Background/objectivesNeuroimaging studies in obese subjects have identified abnormal activation of key regions of central reward circuits, including the nucleus accumbens (NAcc), in response to food-related stimuli. We aimed to examine whether women with elevated body mass index (BMI) show structural and resting state (RS) functional connectivity alterations within regions of the reward network.Subjects/methodsFifty healthy, premenopausal women, 19 overweight and obese (high BMI=26-38 kg m(-2)) and 31 lean (BMI=19-25 kg m(-2)) were selected from the University of California Los Angeles' Oppenheimer Center for Neurobiology of Stress database. Structural and RS functional scans were collected. Group differences in grey matter volume (GMV) of the NAcc, oscillation dynamics of intrinsic brain activity and functional connectivity of the NAcc to regions within the reward network were examined.ResultsGMV of the left NAcc was significantly greater in the high BMI group than in the lean group (P=0.031). Altered frequency distributions were observed in women with high BMI compared with lean group in the left NAcc (P=0.009) in a medium-frequency (MF) band, and in bilateral anterior cingulate cortex (ACC) (P=0.014, <0.001) and ventro-medial prefrontal cortex (vmPFC) (P=0.034, <0.001) in a high-frequency band. Subjects with high BMI had greater connectivity of the left NAcc with bilateral ACC (P=0.024) and right vmPFC (P=0.032) in a MF band and with the left ACC (P=0.03) in a high frequency band.ConclusionsOverweight and obese women in the absence of food-related stimuli show significant structural and functional alterations within regions of reward-related brain networks, which may have a role in altered ingestive behaviors

    An Ontology Engineering Approach to User Profiling for Virtual Tours of Museums and Galleries

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    This paper describes a study of the development of a hierarchical ontology for producing and maintaining personalized profiles to improve the experience of visitors to virtual art galleries and museums. The paper begins by describing some of the features of virtual exhibitions and offers examples of virtual tours that the reader may wish to examine in more detail. The paper then discusses the ontology engineering (OE) approach and domain modelling languages (e.g. KACTUS, SENSUS and METHONTOLOGY). It then follows a basic OE approach to define classes for a cultural heritage virtual tour and to produce a Visitor Profile Ontology that is hierarchical and has static and dynamic elements. It concludes by suggesting ways in which the ontology may be automated to provide a richer, more immersive personalized visitor experience

    Interacting Adaptive Processes with Different Timescales Underlie Short-Term Motor Learning

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    Multiple processes may contribute to motor skill acquisition, but it is thought that many of these processes require sleep or the passage of long periods of time ranging from several hours to many days or weeks. Here we demonstrate that within a timescale of minutes, two distinct fast-acting processes drive motor adaptation. One process responds weakly to error but retains information well, whereas the other responds strongly but has poor retention. This two-state learning system makes the surprising prediction of spontaneous recovery (or adaptation rebound) if error feedback is clamped at zero following an adaptation-extinction training episode. We used a novel paradigm to experimentally confirm this prediction in human motor learning of reaching, and we show that the interaction between the learning processes in this simple two-state system provides a unifying explanation for several different, apparently unrelated, phenomena in motor adaptation including savings, anterograde interference, spontaneous recovery, and rapid unlearning. Our results suggest that motor adaptation depends on at least two distinct neural systems that have different sensitivity to error and retain information at different rates

    Leading Departments with Contingent and Tenure-Eligible Faculty: Strategies and Solutions

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    Leadership and communication strategies for leading departments that include both contingent and tenure-eligible faculty through three case studies, dealing with 1) voting rights and other claims upon resources; 2) a lack of career milestones, making contingent faculty feel “stuck”; and 3) ways to value contributions of contingent faculty

    Are You Ready for a Crisis? Communication and Continuity in the Aftermath

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    Institutions of higher education face numerous crises from natural disasters to mass shootings to sexual abuse scandals. Our interactive workshop will engage participants in planning, negotiating, and recovering from a variety of institutional crises. Participants will develop concrete plans for crisis preparation and recovery, including retrospective sensemaking

    Good Teaching Starts Here: Applied Learning at the Graduate Teaching Assistant Institute

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    Increasingly, graduate teaching assistants serve as the primary instructors in undergraduate courses, yet research has shown that training and development for these teaching assistants is often lacking in programs throughout the United States and Canada. Providing mentoring and skill development opportunities for graduate teaching assistants is vital, as many will become the next generation of faculty. This paper discusses the literature on effective training programs, which underscores the importance of consistent feedback from mentors, intrinsic motivation, and practical applications. Afterwards, we examine an existing training program at the University of North Carolina Wilmington. Specifically, we focus on an institute for teaching assistants that helps graduate students understand applied learning as an effective pedagogical modality and helps them implement applied learning lesson plans tailored to their disciplines. Suggestions for strengthening training programs are discussed.   Il est de plus en plus courant que des assistants Ă  l’enseignement soient chargĂ©s de donner des cours de premier cycle universitaire. Cependant, des Ă©tudes ont dĂ©montrĂ© le manque de formation et de progrĂšs de ces assistants Ă  l’enseignement, aux États-Unis comme au Canada. Il est donc indispensable d’offrir des occasions de mentorat et de perfectionnement Ă  ces assistants, puisqu’un grand nombre d’entre eux deviendront la prochaine cohorte de professeurs. Cet article traite des recherches effectuĂ©es sur les programmes de formation efficaces, ce qui souligne l’importance des commentaires des mentors, de la motivation et de la mise en pratique. Ensuite, nous Ă©tudions l’évolution d’un programme de formation Ă  l’UniversitĂ© de Wilmington de la Caroline du Nord. Notre Ă©tude se concentre sur un institut pour les assistants Ă  l’enseignement, qui leur montre que l’apprentissage appliquĂ© est un outil pĂ©dagogique efficace. Par la suite, cet institut les aide Ă  mettre en Ɠuvre un plan de leçon d’apprentissage adaptĂ© Ă  leur discipline. L’article s’achĂšve par des suggestions d’amĂ©lioration des programmes de formation. &nbsp

    Antiviral RNA Interference against Orsay Virus Is neither Systemic nor Transgenerational in Caenorhabditis elegans.

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    UNLABELLED: Antiviral RNA-mediated silencing (RNA interference [RNAi]) acts as a powerful innate immunity defense in plants, invertebrates, and mammals. In Caenorhabditis elegans, RNAi is systemic; i.e., RNAi silencing signals can move between cells and tissues. Furthermore, RNAi effects can be inherited transgenerationally and may last for many generations. Neither the biological relevance of systemic RNAi nor transgenerational RNAi is currently understood. Here we examined the role of both pathways in the protection of C. elegans from viral infection. We studied the Orsay virus, a positive-strand RNA virus related to Nodaviridae and the first and only virus known to infect C. elegans. Immunity to Orsay virus infection requires the RNAi pathway. Surprisingly, we found that genes required for systemic or transgenerational RNAi did not have a role in antiviral defense. Furthermore, we found that Orsay virus infection did not elicit a systemic RNAi response even when a target for RNAi was provided by using transgenes. Finally, we show that viral siRNAs, the effectors of RNAi, are not inherited to a level that provides any significant resistance to viral infection in the next generation. We conclude that systemic or transgenerational RNAi does not play a role in the defense against natural Orsay virus infection. Furthermore, our data suggest that there is a qualitative difference between experimental RNAi and antiviral RNAi. Our data are consistent with a model of systemic and transgenerational RNAi that requires a nuclear or germ line component that is lacking in almost all RNA virus infections. IMPORTANCE: Since its discovery in Caenorhabditis elegans, RNAi has proven a valuable scientific tool in many organisms. In C. elegans, exogenous RNAi spreads throughout the organism and can be passed between generations; however, there has been controversy as to the endogenous role(s) that the RNAi pathway plays. One endogenous role for which spreading both within the infected organism and between generations would be advantageous is a role in viral defense. In plants, antiviral RNAi is systemic and the spread of RNAi between cells provides protection against subsequent viral infection. Here we investigated this by using the only naturally occurring virus known to infect C. elegans, Orsay virus, and surprisingly found that, in contrast to the exogenous RNAi pathway, the antiviral RNAi response targeted against this virus does not spread systemically throughout the organism and cannot be passed between generations. These results suggest that there are differences between the two pathways that remain to be discovered.This work was supported by Cancer Research UK, the Wellcome Trust and an ERC Starting Grant to E.A.M. A.A. was supported by a Herchel-Smith postdoctoral fellowship. P.S. was supported by a Gonville and Caius College fellowship. M.T. was supported by Cancer Research UK. JLP was supported by a Wellcome Trust/University of Cambridge 4-year PhD programme in Developmental Biology. Some strains were provided by the CGC, which is funded by NIH Office of Research Infrastructure Programs (P40 OD010440)This is the author accepted manuscript. The final version is available from the American Society for Microbiology via http://dx.doi.org/10.1128/JVI.03664-1

    e-Tourism and Culture through Virtual Art Galleries: A pilot study of the usability of an interface

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    Virtual tours of museums and galleries are becoming an increasingly common aspect of e-Tourism marketing. This paper reports on a usability pilot study that analyses the design of icons in a German 3-D virtual art gallery interface. It evaluates the extent to which a sample of typical computer users can interpret the meaning of icons from the interface taken ‘out of context’. This was done by assessing a sample of twenty-one icons representing the ‘action’, ‘information’ and ‘navigation’ functions. An Icon Intuitiveness Test (IIT) was used to measure their Icon Recognition Rate (IRR) and to classify them as ‘identifiable’, ‘mediocre’ or ‘vague’ according to an adapted stereotypy. The IIT results show that the meaning of almost 30% of the icons was misinterpreted or confused, which can seriously compromise the usability of an interface. Based on these findings, recommendations are made for icon redesign and replacement and it is concluded that further research is needed into the ‘learnability’ of icons and users’ understanding of icons in context. It is contended that increased usability leading to an improved user experience can have an economic impact on e-Tourism
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