129 research outputs found

    Social Stress and Welfare Problems in Agricultural Animals

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    Disruptions of an animal\u27s social behaviour can, in some respects at least, mimic the effects of such classical stressors as infection and exposure to low temperatures. For example, Barnett (1958) found enlarged adrenals among wild rats which were subjected to attack by other rats in the laboratory. However, the experience of being attacked was not necessary for this physiological response, as the aggressors showed much the same changes as the victims. In fact Archer (1969) reported heightened adrenocortical activity among individually caged mice simply as a result of their being housed next to other mice, without actual physical contact. If adrenocortical activity is increased by social interaction, it seems reasonable that it should be reduced by solitary confinement. Up to a point this appears to be true for male mice (Brain & Nowell, 1970), but prolonged social isolation, lasting a month or more, may have the opposite effect (Sigg et al., 1966)

    Modelling the potential of rainwater harvesting to improve the sustainability of landscape and public garden irrigation

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    Access to water for irrigating amenity landscape and public gardens is under intense pressure due to the rising competition for water between different sectors, exacerbated by increased drought risk and climate change. Rainwater harvesting (RWH) has the potential to reduce the economic impacts of restrictions on irrigation abstraction in dry years and to build resilience to future water shortages. This study investigated the hydrological viability of RWH for the landscape and public garden sector based on an analysis of five Royal Horticultural Society gardens. A RWH model was developed and combined with on-site observations, key informant interviews and GIS analyses, to estimate irrigation demands and the volumes of harvested rainfall for contrasting agroclimatic years. The results showed that gardens located in wetter regions and with low irrigation water demand to harvestable area ratio had a higher RWH potential and could almost exclusively rely on rainwater to meet irrigation demand, even in dry years. RWH potential is more limited for gardens in drier regions where they would require larger areas to harvest rainwater and for storage. Appropriately designed rainwater harvesting systems offer the potential to remove most of the risk of irrigation abstraction restrictions during dry years and associated impacts on amenity planting quality and visitor experience

    Slow Light Propagation in a Thin Optical Fiber via Electromagnetically Induced Transparency

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    We propose a novel configuration that utilizes electromagnetically induced transparency (EIT) to tailor a fiber mode propagating inside a thin optical fiber and coherently control its dispersion properties to drastically reduce the group velocity of the fiber mode. The key to this proposal is: the evanescent-like field of the thin fiber strongly couples with the surrounding active medium, so that the EIT condition is met by the medium. We show how the properties of the fiber mode is modified due to the EIT medium, both numerically and analytically. We demonstrate that the group velocity of the new modified fiber mode can be drastically reduced (approximately 44 m/sec) using the coherently prepared orthohydrogen doped in a matrix of parahydrogen crystal as the EIT medium.Comment: 10 pages in two column RevTex4, 6 Figure

    Equilibrium configurations of two charged masses in General Relativity

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    An asymptotically flat static solution of Einstein-Maxwell equations which describes the field of two non-extreme Reissner - Nordstr\"om sources in equilibrium is presented. It is expressed in terms of physical parameters of the sources (their masses, charges and separating distance). Very simple analytical forms were found for the solution as well as for the equilibrium condition which guarantees the absence of any struts on the symmetry axis. This condition shows that the equilibrium is not possible for two black holes or for two naked singularities. However, in the case when one of the sources is a black hole and another one is a naked singularity, the equilibrium is possible at some distance separating the sources. It is interesting that for appropriately chosen parameters even a Schwarzschild black hole together with a naked singularity can be "suspended" freely in the superposition of their fields.Comment: 4 pages; accepted for publication in Phys. Rev.

    Intergenerational Community-Based Research and Creative Practice: Promoting Environmental Sustainability in Jinja, Uganda

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    This article critically reflects on the methodological approach developed for a recent project based in Jinja, Uganda, that sought to generate new forms of environmental knowledge and action utilizing diverse forms of creative intergenerational practice embedded within a broader framework of community-based participatory research. This approach provided new opportunities for intergenerational dialogue in Jinja, generated increased civic environmental engagement, and resulted in a participant-led campaign to share knowledge regarding sustainable biomass consumption. We term this approach intergenerational community-based research and creative practice. We discuss the advantages of this model while also reflecting throughout on the challenges of the approach
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