Shear flow-interchange instability in nightside magnetotail causes auroral beads as a signature of substorm onset

A geometric wedge model of the near-earth nightside plasma sheet is used to derive a wave equation for low frequency shear flow-interchange waves which transmit $\vec{E} \times \vec{B}$ sheared zonal flows along magnetic flux tubes towards the ionosphere. Discrepancies with the wave equation result used in Kalmoni et al. (2015) for shear flow-ballooning instability are discussed. The shear flow-interchange instability appears to be responsible for substorm onset. The wedge wave equation is used to compute rough expressions for dispersion relations and local growth rates in the midnight region of the nightside magnetotail where the instability develops, forming the auroral beads characteristic of geomagnetic substorm onset. Stability analysis for the shear flow-interchange modes demonstrates that nonlinear analysis is necessary for quantitatively accurate results and determines the spatial scale on which the instability varies

Exploring women’s experiences: embodied pathways and influences for exercise participation

It has been well-documented that women face pressures to conform to a slim, toned, and athletic body, becoming “tyrannised” by beauty ideals. Under these contemporary ideologies of perfectionism, women are placed under constant surveillance, evaluation and, objectification and are thus reduced to “being” their bodies. However, there is little known about the potential relationships between different types of exercise, body image, and exercise motivation. With this in mind, this paper contributes towards a small but developing body of research that utilises feminist phenomenology to reveal twelve women’s early embodied motivations for exercising and draws upon material gathered from a three-year ethnography into the embodied experiences of women in fitness cultures. This paper delves into the influences on their continued participation over time and explores how these experiences shape their understandings of the embodied self and the broader constructions of the gendered body. The discussion provided illuminates how early influences on exercise participation and how pressures on women to conform to dominant notions of the “feminine” body are imposed by structural, cultural, historical, and localised forces in ways that affect and shape future physical activity participation, and the physical cultures where these tensions are played out

Catching Element Formation In The Act

Gamma-ray astronomy explores the most energetic photons in nature to address some of the most pressing puzzles in contemporary astrophysics. It encompasses a wide range of objects and phenomena: stars, supernovae, novae, neutron stars, stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays and relativistic-particle acceleration, and the evolution of galaxies. MeV gamma-rays provide a unique probe of nuclear processes in astronomy, directly measuring radioactive decay, nuclear de-excitation, and positron annihilation. The substantial information carried by gamma-ray photons allows us to see deeper into these objects, the bulk of the power is often emitted at gamma-ray energies, and radioactivity provides a natural physical clock that adds unique information. New science will be driven by time-domain population studies at gamma-ray energies. This science is enabled by next-generation gamma-ray instruments with one to two orders of magnitude better sensitivity, larger sky coverage, and faster cadence than all previous gamma-ray instruments. This transformative capability permits: (a) the accurate identification of the gamma-ray emitting objects and correlations with observations taken at other wavelengths and with other messengers; (b) construction of new gamma-ray maps of the Milky Way and other nearby galaxies where extended regions are distinguished from point sources; and (c) considerable serendipitous science of scarce events -- nearby neutron star mergers, for example. Advances in technology push the performance of new gamma-ray instruments to address a wide set of astrophysical questions.Comment: 14 pages including 3 figure

Whose knowledge, whose voices? Power, agency and resistance in disability studies for the global south

Meekosha (2011) maintains that research and theories about disability derive mainly from the global North. Disability Studies rarely include non-metropolitan thinkers. Even when they do, these studies tend to be seen as context specific, and the social theories which emanate from these studies are rarely refered to in research theorizing disability in the North. This chapter sets out to investigate how this one way transfer of knowledge affects the way Disability Studies is conceptualised - whose experiences are incorporated within these studies; and whose are left out. Multilateral debate and dialogue between Disability Studies academics and activists in different locations around the world would help add on to the knowledge already available in the field, while keeping others informed about what is taking place in 'similar' situations elsewhere.peer-reviewe

Herd prevalence of Salmonella spp. in Danish pig herds after implementation of the Danish Salmonella Control Program with reference to a pre-implementation study

The problems addressed are: (1) comparison of prevalences of Salmonella spp. in different herd types in the Danish pig population after implementation of the Danish Salmonella Control Program (DSCP), and (2) to make a reference to a study from 1993/1994 (pre-implementation) with a discussion of possible biases when diagnostic methods differ slightly. The objectives were to present the prevalences of Salmonella spp., Salmonella Typhimurium, and multiresistant S. Typhimurium DT104 in Danish pig herds in 1998. Further, to discuss how herd prevalences may be compared to a previous study.A bacteriological study in 1998 comprised: (a) a random sample of slaughter pig producing herds (N=1962); (b) a random sample of farrow-to-grower (sow) herds (N=305); and (c) all breeding and multiplying (genetic) herds (N=366). A previous bacteriological study on Salmonella presence in 1993/1994 served as a model for the present study. The results of the study were that multiresistant S. Typhimurium DT104 was detected in one herd producing slaughter pigs. The herd apparent prevalences (HAPs) of Salmonella spp. were 11.7, 16.7 and 11.4% in genetic, sow, and slaughter pig herds, respectively. The conclusion of the study was that prevalence of multiresistant S. Typhimurium DT104 was low in the examined slaughter pig herds. The herd true prevalence (HTP) of Salmonella spp. in pigs had declined from before the start of the DSCP in 1993/1994 to 4 years later (1998).LR: 20061115; PUBM: Print; JID: 7705469; 0 (Anti-Bacterial Agents); ppublishSource type: Electronic(1