1,412 research outputs found

    Spatial behavior of domestic cats and the effects of outdoor access restrictions and interventions to reduce predation of wildlife

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    This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: All data used in this study are available via the Dryad data repository at https://doi.org/10.5061/dryad.vx0k6djsxDomestic cats (Felis catus) that roam outdoors have increased exposure to hazards to their health and welfare. Outdoor cats can themselves present a hazard to biodiversity conservation and wild animal welfare. Approaches to reducing predation of wildlife by cats might also bring benefits to cats by reducing their roaming and associated risks. We investigated ranging behaviors of domestic cats that regularly captured wild prey, and that had restricted or unrestricted outdoor access. We tested whether interventions aimed at reducing predation also affected their spatial behavior. We evaluated cat bells, Birdsbesafe collar covers, using a “puzzle feeder”, provision of meat-rich food, object play, and a control group. Seventy-two cats in 48 households in England completed the 12-week trial in spring 2019. Home ranges were small (median AKDE95 = 1.51 ha). Cats with unrestricted outdoor access had 75% larger home ranges, 31% greater daily distances traveled, and reached 46% greater maximum distances from home, than cats with restricted outdoor access. None of the treatments intended to reduce predation affected cat ranges or distances traveled. While owners might use interventions to reduce predation, the only effective means of reducing cat roaming and associated exposure to outdoor hazards was restriction of outdoor access.SongBird SurvivalUniversity of Exeter College of Life and Environmental Science

    Protective CD8+ T lymphocytes in Primates Immunized with Malaria Sporozoites

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    Live attenuated malaria vaccines are more potent than the recombinant protein, bacterial or viral platform vaccines that have been tested, and an attenuated sporozoite vaccine against falciparum malaria is being developed for humans. In mice, attenuated malaria sporozoite vaccines induce CD8+ T cells that kill parasites developing in the liver. We were curious to know if CD8+ T cells were also important in protecting primates against malaria. We immunized 9 rhesus monkeys with radiation attenuated Plasmodium knowlesi sporozoites, and found that 5 did not develop blood stage infections after challenge with live sporozoites. We then injected 4 of these protected monkeys with cM-T807, a monoclonal antibody to the CD8 molecule which depletes T cells. The fifth monkey received equivalent doses of normal IgG. In 3 of the 4 monkeys receiving cM-T807 circulating CD8+ T cells were profoundly depleted. When re-challenged with live sporozoites all 3 of these depleted animals developed blood stage malaria. The fourth monkey receiving cM-T807 retained many circulating CD8+ T cells. This monkey, and the vaccinated monkey receiving normal IgG, did not develop blood stage malaria at re-challenge with live sporozoites. Animals were treated with antimalarial drugs and rested for 4 months. During this interval CD8+ T cells re-appeared in the circulation of the depleted monkeys. When all vaccinated animals received a third challenge with live sporozoites, all 5 monkeys were once again protected and did not develop blood stage malaria infections. These data indicate that CD8+ T cells are important effector cells protecting monkeys against malaria sporozoite infection. We believe that malaria vaccines which induce effector CD8+ T cells in humans will have the best chance of protecting against malaria

    First case of childhood Takayasu arteritis with renal artery aneurysms

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    Takayasu arteritis is a large vessel systemic granulomatous vasculitis characterized by stenosis or obliteration of large and medium sized arteries. It commonly involves elastic arteries such as the aorta and its main branches. Renal artery involvement is rare and has not been reported in a child. We report a 12-year-old boy with Takayasu arteritis who developed severe hypertension, proteinuria, microscopic hematuria and renal dysfunction. Conventional angiography demonstrated aneurysms of both renal arteries and multiple microaneurysms of the superior mesenteric artery. This case report illustrates that the children with Takayasu arteritis can develop renal involvement resulting in hematuria, proteinuria and even renal failure
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