2,841 research outputs found

    Birds of Mount Kisingiri, Nyanza Province, including a preliminary survey of the Gwassi Hills Forest Reserve and a species new to Kenya

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    Mount Kisingiri comprises a much overlooked highland massif in southern Nyanza Province with a hitherto completely unknown avifauna. Here we detail our findings from three brief exploratory visits undertaken between 2011 and 2014, with a focus on forested habitats above 1800 m in the Gwassi Hills Forest Reserve (GHFR). We confirm the presence of 34 forest-dependent species, including a globally near threatened forest raptor, the Crowned Eagle Stephanoaetus coronatus, as well as the first known occurrence of the Western Citril Crithagra frontalis in Kenya. Including noteworthy species recorded from other, non-forested areas at lower elevations on the volcano, we provide 46 new or updated (post-1970) distributional records for these two quarter degree atlas squares (60A and 60C). Estimates of species detection probability and abundance, a comparison of forest-dependent species between logged and unlogged sites, and a coarse assessment of overall forest integrity, reveal a highly threatened forest bird community with apparently dwindling numbers of forest specialists. Lastly, we confirm continuing and rapid deforestation in the GHFR and highlight the pressing need for improved forest management and more thorough biodiversity surveys of extant forest

    Transcriptome-wide analysis reveals different categories of response to a standardised immune challenge in a wild rodent

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    Individuals vary in their immune response and, as a result, some are more susceptible to infectious disease than others. Little is known about the nature of this individual variation in natural populations, or which components of immune pathways are most responsible, but defining this underlying landscape of variation is an essential first step to understanding the drivers of this variation and, ultimately, predicting the outcome of infection. We describe transcriptome-wide variation in response to a standardised immune challenge in wild field voles. We find that markers can be categorised into a limited number of types. For the majority of markers, the response of an individual is dependent on its baseline expression level, with significant enrichment in this category for conventional immune pathways. Another, moderately sized, category contains markers for which the responses of different individuals are also variable but independent of their baseline expression levels. This category lacks any enrichment for conventional immune pathways. We further identify markers which display particularly high individual variability in response, and could be used as markers of immune response in larger studies. Our work shows how a standardised challenge performed on a natural population can reveal the patterns of natural variation in immune response

    Multiyear social stability and social information use in reef sharks with diel fission–fusion dynamics

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    Animals across vertebrate taxa form social communities and often exist as fission–fusion groups. Central place foragers (CPF) may form groups from which they will predictably disperse to forage, either individually or in smaller groups, before returning to fuse with the larger group. However, the function and stability of social associations in predatory fish acting as CPFs is unknown, as individuals do not need to return to a shelter yet show fidelity to core areas. Using dynamic social networks generated from acoustic tracking data, we document spatially structured sociality in CPF grey reef sharks at a Pacific Ocean atoll. We show that sharks form stable social groups over multiyear periods, with some dyadic associations consistent for up to 4 years. Groups primarily formed during the day, increasing in size throughout the morning before sharks dispersed from the reef at night. Our simulations suggest that multiple individuals sharing a central place and using social information while foraging (i.e. local enhancement) will outperform non-CPF social foragers. We show multiyear social stability in sharks and suggest that social foraging with information transfer could provide a generalizable mechanism for the emergence of sociality with group central place foraging

    No persistent behavioural effects of SCUBA diving on reef sharks

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    A candidate tolerance gene identified in a natural population of field voles (Microtus agrestis)

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    The animal immune response has hitherto been viewed primarily in the context of resistance only. However, individuals, can also employ a tolerance strategy to maintain good health in the face of on-going infection. To shed light on the genetic and physiological basis of tolerance, we use a natural population of field voles, Microtus agrestis, to search for an association between the expression of the transcription factor Gata3, previously identified as a marker of tolerance in this system, and polymorphism in 84 immune and non-immune genes. Our results show clear evidence for an association between Gata3 expression and polymorphism in the Fcer1a gene, with the explanatory power of this polymorphism being comparable to that of other non-genetic variables previously identified as important predictors of Gata3 expression. We also uncover the possible mechanism behind this association using an existing protein-protein interaction network for the mouse model rodent, Mus musculus, which we validate using our own expression network for M. agrestis. Our results suggest that the polymorphism in question may be working at the transcriptional level, leading to changes in the expression of the Th2-related genes, Tyrosine-protein kinase BTK and Tyrosine-protein kinase TXK, and hence potentially altering the strength of the Th2 response, of which Gata3 is a mediator. We believe our work has implications for both treatment and control of infectious disease

    Glue ear, hearing loss and IQ:an association moderated by the child's home environment

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    BACKGROUND: Glue ear or otitis media with effusion (OME) is common in children and may be associated with hearing loss (HL). For most children it has no long lasting effects on cognitive development but it is unclear whether there are subgroups at higher risk of sequelae. OBJECTIVES: To examine the association between a score comprising the number of times a child had OME and HL (OME/HL score) in the first four/five years of life and IQ at age 4 and 8. To examine whether any association between OME/HL and IQ is moderated by socioeconomic, child or family factors. METHODS: Prospective, longitudinal cohort study: the Avon Longitudinal Study of Parents and Children (ALSPAC). 1155 children tested using tympanometry on up to nine occasions and hearing for speech (word recognition) on up to three occasions between age 8 months and 5 years. An OME/HL score was created and associations with IQ at ages 4 and 8 were examined. Potential moderators included a measure of the child's cognitive stimulation at home (HOME score). RESULTS: For the whole sample at age 4 the group with the highest 10% OME/HL scores had performance IQ 5 points lower [95% CI -9, -1] and verbal IQ 6 points lower [95% CI -10, -3] than the unaffected group. By age 8 the evidence for group differences was weak. There were significant interactions between OME/HL and the HOME score: those with high OME/HL scores and low 18 month HOME scores had lower IQ at age 4 and 8 than those with high OME/HL scores and high HOME scores. Adjusted mean differences ranged from 5 to 8 IQ points at age 4 and 8. CONCLUSIONS: The cognitive development of children from homes with lower levels of cognitive stimulation is susceptible to the effects of glue ear and hearing loss

    Geographical location influences the composition of the gut microbiota in wild house mice (Mus musculus domesticus) at a fine spatial scale.

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    The composition of the mammalian gut microbiota can be influenced by a multitude of environmental variables such as diet and infections. Studies investigating the effect of these variables on gut microbiota composition often sample across multiple separate populations and habitat types. In this study we explore how variation in the gut microbiota of the house mouse (Mus musculus domesticus) on the Isle of May, a small island off the east coast of Scotland, is associated with environmental and biological factors. Our study focuses on the effects of environmental variables, specifically trapping location and surrounding vegetation, as well as the host variables sex, age, body weight and endoparasite infection, on the gut microbiota composition across a fine spatial scale in a freely interbreeding population. We found that differences in gut microbiota composition were significantly associated with the trapping location of the host, even across this small spatial scale. Sex of the host showed a weak association with microbiota composition. Whilst sex and location could be identified as playing an important role in the compositional variation of the gut microbiota, 75% of the variation remains unexplained. Whereas other rodent studies have found associations between gut microbiota composition and age of the host or parasite infections, the present study could not clearly establish these associations. We conclude that fine spatial scales are important when considering gut microbiota composition and investigating differences among individuals

    A Four-Antigen Mixture for Rapid Assessment of Onchocerca volvulus Infection

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    Caused by the filarial parasite Onchocerca volvulus, onchocerciasis is a neglected tropical disease associated with blindness and severe dermatitis. Available diagnostic methods are either invasive, require hours or days to perform, and/or need sophisticated equipment to be conducted. Thus, there is an urgent need for simple and rapid technologies for the specific diagnosis of Onchocerca volvulus infection. Here we investigated whether luciferase immunoprecipitation systems (LIPS) can produce a more rapid and specific test for diagnosis of O. volvulus infection. Using modified versions of previously identified Onchocerca-specific antigens, LIPS tests detected antibodies to all four O. volvulus antigens and easily distinguished the O. volvulus-infected samples from uninfected samples. We also tested these four different antigens in a simpler format as a combined mixture and distinguished 100% of the confirmed cases from the uninfected controls. A rapid 15-minute version of this mixture test (QLIPS) also allowed distinction of 100% of the cases from those uninfected and performed even better in identifying Onchocerca from other cross-reactive parasitic infections. This study suggests that this rapid LIPS test (QLIPS) has the potential to be used in point-of-care detection of onchocerciasis and thereby may provide a new tool for diagnosis and the monitoring of transmission control measures

    Supplier-induced demand for psychiatric admissions in Northern New England

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    The development of hospital service areas (HSAs) using small area analysis has been useful in examining variation in medical and surgical care; however, the techniques of small area analysis are underdeveloped in understanding psychiatric admission rates. We sought to develop these techniques in order to understand the relationship between psychiatric bed supply and admission rates in Northern New England. Our primary hypotheses were that there would be substantial variation in psychiatric admission across geographic settings and that bed availability would be positively correlated with admission rates, reflecting a supplier-induced demand phenomenon. Our secondary hypothesis was that the construction of psychiatric HSAs (PHSAs) would yield more meaningful results than the use of existing general medical hospital service areas
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