427 research outputs found
Probing beyond-Horndeski gravity on ultra-large scales
The beyond-Horndeski gravity has recently been reformulated in the dark energy paradigmâwhich has been dubbed, Unified Dark Energy (UDE). The evolution equations for the given UDE appear to correspond to a non-conservative dark energy scenario, in which the total energy-momentum tensor is not conserved. We investigate both the background cosmology and, the large-scale imprint of the UDE by probing the angular power spectrum of galaxy number counts, on ultra-large scales; taking care to include the full relativistic corrections in the observed overdensity. The background evolution shows that only an effective mass smaller than the Planck mass is needed in the early universe in order for predictions in the given theory to match current observational constraints. We found that the effective mass-evolution-rate parameter, which drives the evolution of the UDE, acts to enhance the observed power spectrum and, hence, relativistic effects (on ultra-large scales) by enlarging the UDE sound horizon. Conversely, both the (beyond) Horndeski parameter and the kineticity act to diminish the observed power spectrum, by decreasing the UDE sound horizon. Our results show that, in a universe with UDE, a multi-tracer analysis will be needed to detect the relativistic effects in the large-scale structure. In the light of a multi-tracer analysis, the various relativistic effects hold the potential to distinguish different gravity models. Moreover, while the Doppler effect will remain significant at all epochs and, thus can not be ignored, the integrated Sachs-Wolfe, the time-delay and the potential (difference) effects, respectively, will only become significant at epochs near z = 3 and beyond, and may be neglected at late epochs. In the same vein, the Doppler effect alone can serve as an effective cosmological probe for the large-scale structure or gravity models, in the angular power spectrumâat all z
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Impacts of household sources on air pollution at village and regional scales in India
Approximately 3 billion people worldwide cook with solid fuels, such as wood, charcoal, and agricultural residues. These fuels, also used for residential heating, are often combusted in inefficient devices, producing carbonaceous emissions. Between 2.6 and 3.8 million premature deaths occur as a result of exposure to fine particulate matter from the resulting household air pollution (Health Effects Institute, 2018a; World Health Organization, 2018). Household air pollution also contributes to ambient air pollution; the magnitude of this contribution is uncertain. Here, we simulate the distribution of the two major health-damaging outdoor air pollutants (PM2:5 and O3) using state-of-thescience emissions databases and atmospheric chemical transport models to estimate the impact of household combustion on ambient air quality in India. The present study focuses on New Delhi and the SOMAARTH Demographic, Development, and Environmental Surveillance Site (DDESS) in the Palwal District of Haryana, located about 80 km south of New Delhi. The DDESS covers an approximate population of 200 000 within 52 villages. The emissions inventory used in the present study was prepared based on a national inventory in India (Sharma et al., 2015, 2016), an updated residential sector inventory prepared at the University of Illinois, updated cookstove emissions factors from Fleming et al. (2018b), and PM2:5 speciation from cooking fires from Jayarathne et al. (2018). Simulation of regional air quality was carried out using the US Environmental Protection Agency Community Multiscale Air Quality modeling system (CMAQ) in conjunction with the Weather Research and Forecasting modeling system (WRF) to simulate the meteorological inputs for CMAQ, and the global chemical transport model GEOS-Chem to generate concentrations on the boundary of the computational domain. Comparisons between observed and simulated O3 and PM2:5 levels are carried out to assess overall airborne levels and to estimate the contribution of household cooking emissions
âI don't think I can catch itâ: women, confidence and responsibility in football coach education
Whilst womenâs participation in sport continues to increase, their presence remains ideologically challenging given the significance of sport for the construction of gendered identities. As a hegmonically masculine institution, leadership roles across sport remain male-dominated and the entry of women into positions of authority (such as coaching) routinely contested. But in powerful male-typed sports, like football, womenâs participation remains particularly challenging. Consequently, constructions of gender inequity in coaching were explored at a regional division of the English Football Association through unstructured interviews and coaching course observation. Using critical discourse
analysis we identified the consistent re/production of women as unconfident in their own skills and abilities, and the framing of women themselves as responsible for the gendered inequities in football coaching. Women were thereby
strategically positioned as deservedly on the periphery of the football category,whilst the organization was positioned as progressive and liberal
Genetic polymorphism among Cryptosporidium parvum isolates: evidence of two distinct human transmission cycles.
We report the results of molecular analysis of 39 isolates of Cryptosporidium parvum from human and bovine sources in nine human outbreaks and from bovine sources from a wide geographic distribution. All 39 isolates could be divided into either of two genotypes, on the basis of genetic polymorphism observed at the thrombospondin-related adhesion protein (TRAP-C2) locus. Genotype 1 was observed only in isolates from humans. Genotype 2, however, was seen in calf isolates and in isolates from a subset of human patients who reported direct exposure to infected cattle or consumed items thought to be contaminated with cattle faces. Furthermore, experimental infection studies showed that genotype 2 isolates were infective to mice or calves under routine laboratory conditions, whereas genotype 1 isolates were not. These results support the occurrence of two distinct transmission cycles of C. parvum in humans
Women training to coach a male sport : managing gendered identities and masculinist discourses
Despite increasing female participation in English football (aka soccer), the sport remains rooted in the values and discursive practices of orthodox masculinity. This is
exemplified by the English Football Association (FA), which has been criticized for its ineffective responses to addressing the inclusion and progression of women as
players and workers within the organization. Female membership in male-dominated organizations is not readily achieved, given the dominance of masculinist discourses
and the risks of overtly challenging these. In this study, we explored the discursive management of gendered and/or footballing identities from interviews with participants
in an English regional FAâs women-only football coach education program. All of the participants described the peripheral positioning of women in English football. Analysis identified evidence of both collaboration with and resistance to the dominant masculinist discourses in the accounts of their experiences in football, while also reproducing the most valued footballing identities and knowledge as male. We connect this to the complexities of negotiating and managing gendered identities
for women in male-dominated organizations. All of the participants described the value and benefits of women-only coach education and the majority noted they would prefer women-only coach education in future
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