9 research outputs found

    Divergent trends of large carnivore populations within the Bénoué Complex, North Cameroon, shown by long-term fine-scale monitoring

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    Large carnivore populations have suffered declines worldwide. For the African continent, these have been particularlystrong in West and Central Africa. The Bénoué Complex in North Cameroon, located in Central Africa, is a keylandscape for their conservation. We determined spatiotemporal trends in lion (Panthera leo), leopard (Panthera pardus)and spotted hyaena (Crocuta crocuta) abundance, using repeated spoor counts on transects from 2007 to 2015. Resultsof the temporal analysis indicate that lion and spotted hyaena abundance reduced over time across the complex, whereasleopards only declined in the last 2 years and primarily in the Faro Block. From the spatial analysis, it became clearspoor abundances differ between areas within the Bénoué Complex and between management types: Spoor densitieswere especially higher in Bouba Ndjida National Park and the hunting zones around Faro. This effect is most probablyrelated to a more effective management strategy in these areas. Our fine-scale long-term monitoring technique provides alow-cost, easy to implement, multi-scale and effective tool for the identification of both regional and range-widecarnivore conservation hotspots.Environmental Biolog

    Changes in lion (Panthera leo) home range size in Waza National Park, Cameroon

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    The spatial ecology of Africa lions (Panthera leo) was studied from 2007 to 2009 in Waza National Park, Cameroon, by equipping individual lions with GPS/VHF radio-collars. Mean home range estimates using 100% minimum convex polygons (MCP) and 95% kernel-density estimation (KDE) were respectively 1015 km2 and 641 km2. The lions spent a considerable amount of time out of the park during the study period (21%), resulting in significantly larger wet season home ranges than in the hot dry season when they were largely within the park. Time spent outside of the park coincided with increased livestock predation, especially by males. The seasonal variation observed in home range appeared to be mainly due to prey dispersal, flooding and migrating livestock. Mean home range size was observed to have increased by 58.6% within the last decade. This observed increase in home range could possibly be attributed to recent declines in wild prey abundance and also, may be indicative of a trend of general degradation of the park due to intense human pressure. The change observed in lions’ ranging behaviour was remarkable, with lions crossing the highway parallel to the park to the Cameroon-Nigerian borders. Measures to restore the integrity of the park are urgently needed, which could include the construction of a partial fence along the western boundary of the park to prevent lions moving across the parallel highway

    JARID2 haploinsufficiency is associated with a clinically distinct neurodevelopmental syndrome

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    Item does not contain fulltextPURPOSE: JARID2, located on chromosome 6p22.3, is a regulator of histone methyltransferase complexes that is expressed in human neurons. So far, 13 individuals sharing clinical features including intellectual disability (ID) were reported with de novo heterozygous deletions in 6p22-p24 encompassing the full length JARID2 gene (OMIM 601594). However, all published individuals to date have a deletion of at least one other adjoining gene, making it difficult to determine if JARID2 is the critical gene responsible for the shared features. We aim to confirm JARID2 as a human disease gene and further elucidate the associated clinical phenotype. METHODS: Chromosome microarray analysis, exome sequencing, and an online matching platform (GeneMatcher) were used to identify individuals with single-nucleotide variants or deletions involving JARID2. RESULTS: We report 16 individuals in 15 families with a deletion or single-nucleotide variant in JARID2. Several of these variants are likely to result in haploinsufficiency due to nonsense-mediated messenger RNA (mRNA) decay. All individuals have developmental delay and/or ID and share some overlapping clinical characteristics such as facial features with those who have larger deletions involving JARID2. CONCLUSION: We report that JARID2 haploinsufficiency leads to a clinically distinct neurodevelopmental syndrome, thus establishing gene-disease validity for the purpose of diagnostic reporting
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