36,846 research outputs found

    An economical vent cover

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    Inexpensive formed-plastic vent cover has been developed that allows controlled purge of vent systems and also provides blowout protection. Cover can also be used in relief mode to allow normal system relief flows without disengaging from vent system. Cover consists of two parts made of plastics with varying densities to fit media used and desired pressures

    Coupling Non-Gravitational Fields with Simplicial Spacetimes

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    The inclusion of source terms in discrete gravity is a long-standing problem. Providing a consistent coupling of source to the lattice in Regge Calculus (RC) yields a robust unstructured spacetime mesh applicable to both numerical relativity and quantum gravity. RC provides a particularly insightful approach to this problem with its purely geometric representation of spacetime. The simplicial building blocks of RC enable us to represent all matter and fields in a coordinate-free manner. We provide an interpretation of RC as a discrete exterior calculus framework into which non-gravitational fields naturally couple with the simplicial lattice. Using this approach we obtain a consistent mapping of the continuum action for non-gravitational fields to the Regge lattice. In this paper we apply this framework to scalar, vector and tensor fields. In particular we reconstruct the lattice action for (1) the scalar field, (2) Maxwell field tensor and (3) Dirac particles. The straightforward application of our discretization techniques to these three fields demonstrates a universal implementation of coupling source to the lattice in Regge calculus.Comment: 10 pages, no figures, Latex, fixed typos and minor corrections

    Collide and Conquer: Constraints on Simplified Dark Matter Models using Mono-X Collider Searches

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    The use of simplified models as a tool for interpreting dark matter collider searches has become increasingly prevalent, and while early Run II results are beginning to appear, we look to see what further information can be extracted from the Run I dataset. We consider three `standard' simplified models that couple quarks to fermionic singlet dark matter: an ss-channel vector mediator with vector or axial-vector couplings, and a tt-channel scalar mediator. Upper limits on the couplings are calculated and compared across three alternate channels, namely mono-jet, mono-ZZ (leptonic) and mono-W/ZW/Z (hadronic). The strongest limits are observed in the mono-jet channel, however the computational simplicity and absence of significant tt-channel model width effects in the mono-boson channels make these a straightforward and competitive alternative. We also include a comparison with relic density and direct detection constraints.Comment: 32 pages, 8 figures; v2: minor changes, conclusion unchanged, matches published versio

    Time relaxation of microwave second order response of superconductors in the critical state

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    Relaxation of the microwave second order response of YBa2Cu3O7 and Ba0.6K0.4BiO3 crystals in the critical state is studied. The samples are exposed to static and pulsed microwave magnetic fields. The second harmonic signals decay during the time in which the microwave pulse endures. The decay times depend on the supercon-ductor investigated and on the way the value of the static field has been reached.Comment: 2 pages, 1 figur

    A catalogue of solar cosmic ray events: IMPS 4 and 5, May 1967 - December 1972

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    This catalogue of solar cosmic ray events has been prepared for the use of solar physicists and other interested scientists. It contains some 185 solar particle events detected by the Goddard Space Flight Center Cosmic Ray Experiments on IMP's IV and V (Explorer 34 and 41) for the period May 1967 - December 1972. The data is presented in the form of hourly averages for three proton energy intervals - 0.9 - 1.6 MeV; 6 - 20 MeV and 20 - 80 MeV. In addition the time histories of .5 - 1.1 MeV electrons are shown on a separate scale. To assist in the identification of related solar events, the onset time of the electron event is indicated. The details of the instrumentation and detector techniques are described. Further descriptions of data reduction procedure and on the time-history plots are given

    Enhancement of Recombinant Protein Production in Transgenic Nicotiana benthamiana Plant Cell Suspension Cultures with Co-Cultivation of Agrobacterium Containing Silencing Suppressors.

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    We have previously demonstrated that the inducible plant viral vector (CMViva) in transgenic plant cell cultures can significantly improve the productivity of extracellular functional recombinant human alpha-1-antiryspin (rAAT) compared with either a common plant constitutive promoter (Cauliflower mosaic virus (CaMV) 35S) or a chemically inducible promoter (estrogen receptor-based XVE) system. For a transgenic plant host system, however, viral or transgene-induced post-transcriptional gene silencing (PTGS) has been identified as a host response mechanism that may dramatically reduce the expression of a foreign gene. Previous studies have suggested that viral gene silencing suppressors encoded by a virus can block or interfere with the pathways of transgene-induced PTGS in plant cells. In this study, the capability of nine different viral gene silencing suppressors were evaluated for improving the production of rAAT protein in transgenic plant cell cultures (CMViva, XVE or 35S system) using an Agrobacterium-mediated transient expression co-cultivation process in which transgenic plant cells and recombinant Agrobacterium carrying the viral gene silencing suppressor were grown together in suspension cultures. Through the co-cultivation process, the impacts of gene silencing suppressors on the rAAT production were elucidated, and promising gene silencing suppressors were identified. Furthermore, the combinations of gene silencing suppressors were optimized using design of experiments methodology. The results have shown that in transgenic CMViva cell cultures, the functional rAAT as a percentage of total soluble protein is increased 5.7 fold with the expression of P19, and 17.2 fold with the co-expression of CP, P19 and P24

    Living with Phenylketonuria: lessons from the PKU community

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    Introduction: We report the practical, social and psychological issues of living with phenylketonuria (PKU) from one of the largest surveys that has been completed by both adults with PKU and parents/caregivers of children. Methods: In the UK, parents/caregivers of children and adults with PKU were invited to complete an online survey between November 2017 to January 2018 by the NSPKU (National Society for Phenylketonuria). Results: 631 participants (adults, n=338; parents/caregivers of children, n=293) with PKU completed the questionnaire. Problems experienced by children with PKU were: difficulty with maintaining focus (48%,n=114/236), educational difficulties (28%, n=67/236), anxiety or depression (29%, n=68/236), and gastrointestinal symptoms (34%, n=97/282). Fifty one per cent (n=120/236) described social exclusion; 17% (n=41/236) had relationship issues with friends or family. Problems experienced by adults were: depression or anxiety (52%, n=148/286), difficulty maintaining focus (54%, n=154/286), and low mood (54%, n=180/334). Difficulties were experienced with relationships (34%, n=96/286); social exclusion (44%, n=126/286); and gastrointestinal issues (n=34%, n=112/334). Common medications used included antidepressants (40%, n=131/331) and anxiolytics (18%, n=60/334). Discussions: Adults with PKU or caregivers/parents of children identified significant neurocognitive, mental health and general health issues. Limits on socialisation, perception of social isolation and dietary stigma are major obstacles which are difficult to overcome with conventional dietary management

    "More than a game": the impact of sport-based youth mentoring schemes on developing resilience toward violent extremism

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    This paper draws upon the findings of an evaluation of “More than a Game”, a sport-focused youth mentoring program in Melbourne, Australia that aimed to develop a community-based resilience model using team-based sports to address issues of identity, belonging, and cultural isolation amongst young Muslim men in order to counter forms of violent extremism. In this essay we focus specifically on whether the intense embodied encounters and emotions experienced in team sports can help break down barriers of cultural and religious difference between young people and facilitate experiences of resilience, mutual respect, trust, social inclusion and belonging. Whilst the project findings are directly relevant to the domain of countering violent extremism, they also contribute to a growing body of literature which considers the relationship between team-based sport, cross-cultural engagement and the development of social resilience, inclusion and belonging in other domains of youth engagement and community-building
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