69 research outputs found
Effects of mountain gorilla foraging activities on the productivity of their food plant species
Mountain gorillas subsist principally on foliage from the dense herbaceous understorey that is found throughout most of their habitat in the Virunga Volcanoes region. Their foraging activities cause considerable structural damage to this vegetation. Those plant species that are quantitatively most important in the gorillas' diet respond to this damage by increasing primary productivity. At a sample of spots at which gorillas had fed, these species showed significantly higher growth rates over a 6-month interval than they did at nearby spots that had not been touched by the gorillas. Stem densities of herbaceous food species at feeding spots increased markedly both in comparison to their original values and to values for the same species at untouched spots. As a result, spots at which gorillas have fed are likely to become very attractive as future feeding spots. It is unlikely that gorillas âmanageâ their habitat in any specific fashion, largely because they do not have exclusive use of their home ranges. Their activities appear to maintain habitat productivity over the short term, on a time scale relevant to patterns of area revisits by social groups, and may contribute to long term beneficial alterations of regularly used areas, however. Effects of the type reported here may have been an important aspect of the adaptation by gorillas to terrestrial folivory. RĂSUMEĂ Les gorilles de montagne s'alimentent principalement de feuillages dans le sous-bois herbacĂ dense prĂsent presque partout dans leur habitat de la rĂgion des volcans Virunga. Leurs activitĂs alimentaires causent des dommages structurels considĂrables Ă cette vĂgĂtation. Les plantes des espĂces qui sont quantitativement les plus importants dans le rĂgime du gorille rĂagissent Ă ces dĂgats en augmentant leur productivitĂ primaire. Aux postes Ăchantillons oĂ les gorilles se sont nourris, ces espĂces prĂsentent des taux de croissance significantivement supĂrieurs sur un intervalle de six mois, par rapport aux postes voisins qui n'ont pas ĂtĂ touchĂs par les gorilles. Les densitĂs de tiges des espĂces herbacĂes appĂtĂes aux postes de nourrissage augmentent nettement aussi bien en comparaison avec leurs valeurs antĂrieures qu'avec celles de ces mÄmes espĂces dans des stations non touchĂes. En consĂquence, les postes oĂ les gorilles se sont nourris ont plus de chance de devenir des futurs postes de nourrissage trĂs attractifs. Il est peu probable que les gorilles âgĂrentâ leur habitat d'une quelconque faĂon, surtout parce qu'ils n'ont pas l'utilisation exclusive de leur domaine vital. Leurs activitĂs semblent maintenir Ă court terme la productivitĂ de leur habitat, sur une Ăchelle de temps comprenant les visites successives de groupes sociaux, et peuvent contribuer Ă long terme Ă des altĂrations bĂnĂfiques pour ces zones rĂguliĂrement frĂquentĂes. Des effets du type rapportĂ ici peuvent avoir ĂtĂ un ĂlĂment important de l'adaptation des gorilles Ă la folivorie terrestre.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75171/1/j.1365-2028.1987.tb01102.x.pd
The challenges of long-term invasive mammal management: lessons from the UK
We consider the motivations, strategies, and costs involved in invasive mammal management undertaken in the UK. Widespread established invasive mammals require longâterm management to limit damage or spread, but ongoing management is costly and complex. Longâterm management is most effective where it is applied at a landscape scale, but this requires overarching coâordination between multiple stakeholders. Five challenges for successful longâterm management of invasive mammal species are identified as follows: defining landscapeâscale strategies, management coâordination, stakeholder and community engagement, sustainable funding, and evidence requirements. We make recommendations on the supportive infrastructure needed for effective landscapeâscale management of invasive mammals to fulfil longâterm conservation aims, as follows. 1. There is a need for evidenceâbased Invasive Species Action Plans to provide strategy for the longâterm ongoing management of prioritised species at appropriate scales. 2. Where possible, multispecies approaches to invasive species management should be adopted. 3. Trusted leadership should be identified to take ownership of Action Plans and provide an overarching coâordination to bring individuals, organisations, and funders together. 4. Support for a centralised hub for training, data, and knowledge flows will greatly improve scientific outcomes through a searchable evidence base, and via best practice and knowledge sharing
Evaluation of Commercial Probiotic Products
Although there is a vast number of probiotic products commercially available due to their acceptability and increasing usage, their quality control has continuously been a major concern. This study aimed to assess some commercially available probiotics on the UK market for content in relation to their label claim. Seven products were used for the study. The bacteria content were isolated, identified and enumerated on selective media. The results revealed that all products evaluated contained viable probiotic bacteria but only three out of the seven products (43%) contained the claimed culture concentration or more. None of the multispecies product contained all the labelled probiotic bacteria. Misidentification of some species occurred. The results concurred with previous studies and showed that quality issues with commercial probiotics remain. Since probiotic activity is linked with probiotic concentration and is strain specific, the need exist for a global comprehensive legislation to control the quality of probiotics whose market is gaining huge momentum
The âmosaic habitatâ concept in human evolution: past and present
The habitats preferred by hominins and other species are an important theme in palaeoanthropology, and the âmosaic habitatâ (also referred to as habitat heterogeneity) has been a central concept in this regard for the last four decades. Here we explore the development of this concept â loosely defined as a range of different habitat types, such as woodlands, riverine forest and savannah within a limited spatial areaâ in studies of human evolution in the last sixty years or so. We outline the key developments that took place before and around the time when the term âmosaicâ came to wider palaeoanthropological attention. To achieve this we used an analysis of the published literature, a study of illustrations of hominin evolution from 1925 onwards and an email survey of senior researchers in palaeoanthropology and related fields. We found that the term mosaic starts to be applied in palaeoanthropological thinking during the 1970âs due to the work of a number of researchers, including Karl Butzer and Glynn Isaac , with the earliest usage we have found of âmosaicâ in specific reference to hominin habitats being by Adriaan Kortlandt (1972). While we observe a steady increase in the numbers of publications reporting mosaic palaeohabitats, in keeping with the growing interest and specialisation in various methods of palaeoenvironmental reconstruction, we also note that there is a lack of critical studies that define this habitat, or examine the temporal and spatial scales associated with it. The general consensus within the field is that the concept now requires more detailed definition and study to evaluate its role in human evolution
Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans
Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have
fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in
25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16
regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of
correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP,
while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in
Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium
(LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region.
Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant
enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the
refined data for existing association signals, we estimate that these loci now explain âź38.9% of the familial relative risk of PrCa,
an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of
PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent
signals within the same regio
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