49 research outputs found

    Expanding the scope of ligand substitution from [M(S2C2Ph2] (M = Ni2+, Pd2+, Pt2+) to afford new heteroleptic dithiolene complexes

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    The scope of direct substitution of the dithiolene ligand from [M(S2C2Ph2)2] [M = Ni2+ (1), Pd2+ (2), Pt2+ (3)] to produce heteroleptic species [M(S2C2Ph2)2Ln] (n = 1, 2) has been broadened to include isonitriles and dithiooxamides in addition to phosphines and diimines. Collective observations regarding ligands that cleanly produce [M(S2C2Ph2)Ln], do not react at all, or lead to ill-defined decomposition identify soft σ donors as the ligand type capable of dithiolene substitution. Substitution of MeNC from [Ni(S2C2Ph2)(CNMe)2] by L provides access to a variety of heteroleptic dithiolene complexes not accessible from 1. Substitution of a dithiolene ligand from 1 involves net redox disproportionation of the ligands from radical monoanions, –S•SC2Ph2, to enedithiolate and dithione, the latter of which is an enhanced leaving group that is subject to further irreversible reactions

    First reported case of fatal tuberculosis in a wild African elephant with past human-wildlife contact

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    Tuberculosis is emerging/re-emerging in captive elephant populations, where it causes morbidity and deaths, although no case of TB in wild African elephants has been reported. In this paper we report the first case of fatal TB in an African elephant in the wild. The infection with Mycobacterium tuberculosis was confirmed by post-mortem and histological examinations of a female sub-adult elephant aged >12 years that died in Tsavo East National Park, Kenya, while under treatment. This case is unique in that during its lifetime the elephant had contact with both humans and wild elephants. The source of the infection was unclear because the elephant could have acquired the infection in the orphanage or in the wild. However, our results show that wild elephants can maintain human TB in the wild and that the infection can be fata

    The Influence of Life History Milestones and Association Networks on Crop-Raiding Behavior in Male African Elephants

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    Factors that influence learning and the spread of behavior in wild animal populations are important for understanding species responses to changing environments and for species conservation. In populations of wildlife species that come into conflict with humans by raiding cultivated crops, simple models of exposure of individual animals to crops do not entirely explain the prevalence of crop raiding behavior. We investigated the influence of life history milestones using age and association patterns on the probability of being a crop raider among wild free ranging male African elephants; we focused on males because female elephants are not known to raid crops in our study population. We examined several features of an elephant association network; network density, community structure and association based on age similarity since they are known to influence the spread of behaviors in a population. We found that older males were more likely to be raiders than younger males, that males were more likely to be raiders when their closest associates were also raiders, and that males were more likely to be raiders when their second closest associates were raiders older than them. The male association network had sparse associations, a tendency for individuals similar in age and raiding status to associate, and a strong community structure. However, raiders were randomly distributed between communities. These features of the elephant association network may limit the spread of raiding behavior and likely determine the prevalence of raiding behavior in elephant populations. Our results suggest that social learning has a major influence on the acquisition of raiding behavior in younger males whereas life history factors are important drivers of raiding behavior in older males. Further, both life-history and network patterns may influence the acquisition and spread of complex behaviors in animal populations and provide insight on managing human-wildlife conflict

    Large meta-analysis of genome-wide association studies identifies five loci for lean body mass

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    Lean body mass, consisting mostly of skeletal muscle, is important for healthy aging. We performed a genome-wide association study for whole body (20 cohorts of European ancestry with n = 38,292) and appendicular (arms and legs) lean body mass (n = 28,330) measured using dual energy X-ray absorptiometry or bioelectrical impedance analysis, adjusted for sex, age, height, and fat mass. Twenty-one single-nucleotide polymorphisms were significantly associated with lean body mass either genome wide (p < 5 x 10(-8)) or suggestively genome wide (p < 2.3 x 10(-6)). Replication in 63,475 (47,227 of European ancestry) individuals from 33 cohorts for whole body lean body mass and in 45,090 (42,360 of European ancestry) subjects from 25 cohorts for appendicular lean body mass was successful for five single-nucleotide polymorphisms in/ near HSD17B11, VCAN, ADAMTSL3, IRS1, and FTO for total lean body mass and for three single-nucleotide polymorphisms in/ near VCAN, ADAMTSL3, and IRS1 for appendicular lean body mass. Our findings provide new insight into the genetics of lean body mass

    Parasites in Captive Carnivores at the Animal Orphanage in Kenya

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    This study assessed endoparasitic diversity before and after anthelmintic treatment in captive lions, cheetahs, jackals, serval and sokoke cats, and hyenas at the Nairobi Animal Orphanage. The animals were treated with a broad-spectrum anthelmintic, Canex 4®. Faecal and /or vomitus samples were macroscopically examined for adult parasites. Faecal sedimentation and floatation techniques were used to assess the presence of eggs and oocysts. Of the 27 animals in this study, 23 (85%) were positive for Spirometra spp. eggs, while 21 animals (77.7%) positive for Isospora spp. eggs. Toxocara spp. and Toxascaris spp. eggs were both 66.6% prevalent. Ancylostoma spp. eggs were 62.9% prevalent. Jackals had the highest parasite egg diversity with six genera. Adult parasites were recovered from lion vomitus, which included Aelurostrongylus sp. Toxocara canis, Toxocara cati and Taenia spp. Adult parasites recovered from faecal material were Toxascaris leonina and Toxocara canis. Deworming is an essential component in good management of captive carnivores but need to be accompanied with regular assessments to determine parasite diversity and the efficacy of the drug in use. Sampling for enteric parasites should include vomitus as some parasite propagules may not be found in faecal samples. Keywords: Parasites, Carnivores, Wildlife, Captivity, Anthelmintic, KenyaKenya Veterinarian Vol. 31 (2) 2007: pp. 59-6

    Crimean Congo Haemorrhagic fever virus in humans, animals and ticks in Kenya

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    Presented by Bernard Agwanda at the Kenya One Health conference, 6-8 December 2021 Read more: https://www.ilri.org/kenya-one-health...
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