7,507 research outputs found

    Numeric and fluid dynamic representation of tornadic double vortex thunderstorms

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    Current understanding of a double vortex thunderstorm involves a pair of contra-rotating vortices that exists in the dynamic updraft. The pair is believed to be a result of a blocking effect which occurs when a cylindrical thermal updraft of a thunderstorm protrudes into the upper level air and there is a large amount of vertical wind shear between the low level and upper level air layers. A numerical tornado prediction scheme based on the double vortex thunderstorm was developed. The Energy-Shear Index (ESI) is part of the scheme and is calculated from radiosonde measurements. The ESI incorporates parameters representative of thermal instability and blocking effect, and indicates appropriate environments for which the development of double vortex thunderstorms is likely

    Bevalac calibration of the SOFIE range and hodoscope detectors

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    The scintillating optical fiber isotope experiment (SOFIE) is a Cerenkov-dE/dx-Range experiment which was developed initially for balloon flight to study the isotopic composition of cosmic rays in the iron region. The electronic range and hodoscope detectors use scintillating optical fibers to image the tracks of stopping charged particles and to determine their trajectory. The particle range is determined and used together with a Cerenkov measurement to determine the mass of the stopping particle. Preliminary results of a Bevalac calibration performed in August, 1984 with a prototype of the balloon flight instrument, to study the measurement precision in range and trajectory which could be attained with this detector are described

    Decoherence at zero temperature

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    Most discussions of decoherence in the literature consider the high-temperature regime but it is also known that, in the presence of dissipation, decoherence can occur even at zero temperature. Whereas most previous investigations all assumed initial decoupling of the quantum system and bath, we consider that the system and environment are entangled at all times. Here, we discuss decoherence for a free particle in an initial Schr\"{o}dinger cat state. Memory effects are incorporated by use of the single relaxation time model (since the oft-used Ohmic model does not give physically correct results)

    It's OK not to be OK: Shared Reflections from two PhD Parents in a Time of Pandemic

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    Adopting an intersectional feminist lens, we explore our identities as single and co‐parents thrust into the new reality of the UK COVID‐19 lockdown. As two PhD students, we present shared reflections on our intersectional and divergent experiences of parenting and our attempts to protect our work and families during a pandemic. We reflect on the social constructions of ‘masculinities’ and ‘emphasized femininities’ as complicated influence on our roles as parents. Finally, we highlight the importance of time and self‐care as ways of managing our shared realities during this uncertain period. Through sharing reflections, we became closer friends in mutual appreciation and solidarity as we learned about each other’s struggles and vulnerabilities

    Learning masculinities in a Japanese high school rugby club

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    This paper draws on research conducted on a Tokyo high school rugby club to explore diversity in the masculinities formed through membership in the club. Based on the premise that particular forms of masculinity are expressed and learnt through ways of playing (game style) and the attendant regimes of training, it examines the expression and learning of masculinities at three analytic levels. It identifies a hegemonic, culture-specific form of masculinity operating in Japanese high school rugby, a class-influenced variation of it at the institutional level of the school and, by further tightening its analytic focus, further variation at an individual level. In doing so this paper highlights the ways in which diversity in the masculinities constructed through contact sports can be obfuscated by a reductionist view of there being only one, universal hegemonic patterns of masculinity

    The appropriation of hegemonic masculinity within selected research on men's health

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    Connell's hegemonic masculinity thesis (HMT) has occupied a relatively dominant position within contemporary research exploring the lives of men. Messerschmidt has conducted a review of recent literature that purports to use HMT, he describes in detail some of the ways Connell's work has been appropriated. Taking Messerschmidt's lead, this paper explores a small selection of men's health research that employ HMT as a central organising theme. Such a narrow focus and limited sample enables the theoretical, conceptual and empirical contributions of engagements with Connell's work to be critically explored in detail. This paper provides colleagues with clear examples of ways in which reified and reductive account of masculinity, are still being reproduced in contemporary analyses of men's lives. In calling for researchers to critically reflect upon their usage of Connell's thesis in more detail, my aim is to increase the subtlety and sophistication of such works. A further hope is that by highlighting specific examples of the need to appraise the relevance and adequacy of HMT as a conceptual frame of lived experiences, we might encourage researchers to access the multitude of different theoretical positions that speak to the lives of men

    Foliar damage beyond species distributions is partly explained by distance dependent interactions with natural enemies

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    Plant distributions are expected to shift in response to climate change, and range expansion dynamics will be shaped by the performance of individuals at the colonizing front. These plants will encounter new biotic communities beyond their range edges, and the net outcome of these encounters could profoundly affect colonization success. However, little is known about how biotic interactions vary across range edges and this has hindered efforts to predict changes in species distributions in response to climate change. In contrast, a rich literature documents how biotic interactions within species ranges vary according to distance to and density of conspecific individuals. Here, we test whether this framework can be extended to explain how biotic interactions differ beyond range edges, where conspecific adults are basically absent. To do so, we planted seven species of trees along a 450‐km latitudinal gradient that crossed the current distributional range of five of these species and monitored foliar disease and invertebrate herbivory over 5 yr. Foliar disease and herbivory were analyzed as a function of distance to and density of conspecific and congeneric trees at several spatial scales. We found that within species ranges foliar disease was lower for seedlings that were farther from conspecific adults for Acer rubrum, Carya glabra, Quercus alba, and Robinia pseudoacacia. Beyond range edges, there was even less foliar disease for C. glabra, Q. alba, and R. pseudoacacia (A. rubrum was not planted outside its range). Liriodendron tulipifera did not experience reduced disease within or beyond its range. In contrast, Quercus velutina displayed significant but idiosyncratic patterns in disease at varying distances from conspecifics. Patterns of distance dependent herbivory across spatial scales was generally weak and in some cases negative (i.e., seedlings farther from conspecific adults had more herbivory). Overall, we conclude that differences in biotic interactions across range edges can be thought of as a spatial extension to the concept of distance dependent biotic interactions. This framework also provides the basis for general predictions of how distance dependent biotic interactions will change across range edges in other systems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134258/1/ecy1468.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134258/2/ecy1468_am.pd

    Masculine femininities/feminine masculinities: power, identities and gender

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    This paper is basically about terminology. In it I discuss the terms 'masculinity' and 'femininity' and how they relate to being male and being female. My theme arises from an increasing difficulty that I am finding in understanding how individual identities relate to dominant constructions of masculinity and femininity. Christine Skelton and Becky Francis argue that we should not be afraid to name certain behaviours as masculine even when they are performed by girls. After a discussion of the problems of defining both 'masculinity' and 'femininity', and a consideration of the power relations between these terms, I go on to consider the concept of 'female masculinity' (Halberstam). I argue that this formulation is problematic, due to its dependence on a main term whose definition is unclear. Finally, I argue that we need to distinguish 'masculinity' and 'femininity' from 'masculinities' and 'femininities'
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