3,169 research outputs found

    Isotropic, Nematic and Smectic A Phase Behaviour in a Fictitious Field

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    Phase behaviours of liquid crystals under external fields, conjugate to the nematic order and smectic order, are studied within the framework of mean field approximation developed by McMillan. It is found that phase diagrams, of temperature vs interaction parameter of smectic A order, show several topologically different types caused by the external fields. The influences of the field conjugate to the smectic A phase, which is fictitious field, are precisely discussed.Comment: To be published in J. Phys. Soc. Jpn. vol.73 No.

    Analysis of a Four-Layer Series-Coupled Perceptron. II

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    On the convergence to statistical equilibrium for harmonic crystals

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    We consider the dynamics of a harmonic crystal in dd dimensions with nn components, d,nd,n arbitrary, d,nā‰„1d,n\ge 1, and study the distribution Ī¼t\mu_t of the solution at time tāˆˆRt\in\R. The initial measure Ī¼0\mu_0 has a translation-invariant correlation matrix, zero mean, and finite mean energy density. It also satisfies a Rosenblatt- resp. Ibragimov-Linnik type mixing condition. The main result is the convergence of Ī¼t\mu_t to a Gaussian measure as tā†’āˆžt\to\infty. The proof is based on the long time asymptotics of the Green's function and on Bernstein's ``room-corridors'' method

    The role of endogenous and exogenous RasGAP-derived fragment N in protecting cardiomyocytes from peroxynitrite-induced apoptosis.

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    Peroxynitrite (PN) is a potent nitrating and oxidizing agent generated during various pathological situations affecting the heart. The negative effects of PN result, at least in part, from its ability to activate caspases and apoptosis. RasGAP is a ubiquitously expressed protein that is cleaved sequentially by caspase-3. At low caspase-3 activity, RasGAP is cleaved into an N-terminal fragment, called fragment N, that protects cells by activating the Ras/PI3K/Akt pathway. At high caspase-3 activity, fragment N is further cleaved and this abrogates its capacity to stimulate the antiapoptotic Akt kinase. Fragment N formation is crucial for the survival of cells exposed to a variety of stresses. Here we investigate the pattern of RasGAP cleavage upon PN stimulation and the capacity of fragment N to protect cardiomyocytes. PN did not lead to sequential cleavage of RasGAP. Indeed, PN did not allow accumulation of fragment N because it induced its rapid cleavage into smaller fragments. No situations were found in cells treated with PN in which the presence of fragment N was associated with survival. However, expression of a caspase-resistant form of fragment N in cardiomyocytes protected them from PN-induced apoptosis. Our results indicate that the antiapoptotic pathway activated by fragment N is effective at inhibiting PN-induced apoptosis (as seen when cardiomyocytes express a capase-3-resistant form of fragment N) but because fragment N is too transiently generated in response to PN, no survival response is effectively produced. This may explain the marked deleterious consequences of PN generation in various organs, including the heart

    Vertebrate Air Breathing Arose In Fresh Waters And Not In The Oceans

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137418/1/evo00662.pd

    Unsung heroes: who supports social work students on placement?

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    Since the introduction of the three year degree programme in 2003, social work education has undergone a number of significant changes. The time students spend on placement has been increased to two hundred days, and the range of placement opportunities and the way in which these placements have been configured has significantly diversified. A consistent feature over the years, however, has been the presence of a Practice Educator (PE) who has guided, assessed and taught the student whilst on placement. Unsurprisingly, the role of the PE and the pivotal relationship they have with the student has been explored in the past and features in social work literature. This paper, however, concentrates on a range of other relationships which are of significance in providing support to students on placement. In particular it draws on research to discuss the role of the university contact tutor, the place of the wider team in which the student is sited, and the support offered by family, friends and others. Placements and the work undertaken by PEā€™s will continue to be integral to the delivery of social work education. It is, however, essential to recognise and value the often over looked role of others in providing support to students on placement

    Female mice respond to male ultrasonic ā€˜songsā€™ with approach behaviour

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    The ultrasonic vocalizations of mice are attracting increasing attention, because they have been recognized as an informative readout in genetically modified strains. In addition, the observation that male mice produce elaborate sequences of ultrasonic vocalizations (ā€˜songā€™) when exposed to female mice or their scents has sparked a debate as to whether these sounds areā€”in terms of their structure and functionā€”analogous to bird song. We conducted playback experiments with cycling female mice to explore the function of male mouse songs. Using a place preference design, we show that these vocalizations elicited approach behaviour in females. In contrast, the playback of pup isolation calls or whistle-like artificial control sounds did not evoke approach responses. Surprisingly, the females also did not respond to pup isolation calls. In addition, female responses did not vary in relation to reproductive cycle, i.e. whether they were in oestrus or not. Furthermore, our data revealed a rapid habituation of subjects to the experimental situation, which stands in stark contrast to other species' responses to courtship vocalizations. Nevertheless, our results clearly demonstrate that male mouse songs elicit females' interest

    The Teaching of Maths to Students with Dyslexia: A Teachers' Perspective

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    This case study explores the perceptions of teachers who teach maths to students with dyslexia at the Dyslexia Association of Singapore (DAS). The authors examined the challenges participants faced when teaching students with dyslexia maths, the processes that were used to help their learners understand maths concepts, and supports that were provided to minimise student anxiety and boost selfā€esteem. Four distinct challenges emerged including inadequate training, content area language barriers, cognitive style implications and their impact on maths learning, and addressing and remediating studentsā€™ anxiety towards learning maths and the impact on their selfā€esteem. Results indicated that teachers enjoy teaching maths to students with dyslexia but find that adequate training, teaching experience, and exposure to multiple teaching strategies are required for success. As DAS is a unique organisation that helps students with dyslexia improve their literacy and numeracy skills, teacher professional development and teacher training are important aspects that need to be in place so that teachers are wellā€supported and guided to coach these students. Suggestions to meet these challenges are provided
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