587 research outputs found

    Early Holocene fauna from a new subfossil site: A first assessment from Christmas River, south central Madagascar

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    We report on faunal remains recovered during recent explorations at ‘Christmas River’, the only subfossil locality known from Madagascar’s south central plateau. Recovered remains of several extinct taxa date to approximately 10,000 14C years before present (BP), including crocodiles, tortoises, the elephant bird Aepyornis, the carnivoran Cryptoprocta spelea, the lemurs Archaeolemur majori, Pachylemur insignis, and Megaladapis edwardsi, and abundant remains of the dwarf hippopotamus, Hippopotamus lemerlei. The presence of southern - limited, forest - dependent species at Christmas River supports the hypothesis that forest once extended, perhaps discontinuously, across the central highlands towards the west. One theory is that sites in the north central highlands, which are higher in elevation, maintained more mesic conditions during Plio - Quaternary climate shifts than those of the lower elevation sites of the south central highlands. Thus, elevation above sea level may have acted as a filter that limited species dispersal across the island in the past. Such a scenario would explain the distinction between more humid, higher elevation, northern highland subfossil communities versus more arid, lower elevation, southern subfossil communities. Continued exploration at Christmas River thus provides a remarkable opportunity for deciphering ecological changes that have taken place in south central Madagascar during the Holocene.RÉSUMÉMadagascar est reconnue comme l’une des régions les plus sensibles du monde en ce qui concerne les menaces pesant sur sa biodiversité, et cela à cause de niveaux d’endémisme inégalés, d’une diversité variée et d’un impact humain important sur l’environnement. Suite à la colonisation par l’Homme il y a plus de 2000 ans, des extinctions de masse de la faune et un important recul forestier ont eu lieu en laissant des marques sur les écosystèmes modernes qui sont dans un état de bouleversement écologique. Certaines plantes endémiques, par exemple, ont perdu d’importantes espèces mutualistes, des animaux ont été obligés d’exploiter d’autres ressources ou habiter des endroits auxquels ils sont mal adaptés. La diversité des plantes et des animaux a diminué, est menacée ou a même complètement disparue de certaines routes de dissémination. Bien que l’Homme soit largement incriminé dans son rôle de déclencheur de ces extinctions massives, les transformations anthropiques qui ont contribué au changement du climat sont controversées. Les hautes - terres de Madagascar sont actuellement dominées par des zones herbeuses étendues qui agissent comme des barrières empêchant les mouvements de la faune de part et d’autre de l’île. Nous suggérons qu’une forêt humide plus ou moins continue devait s’étendre sur les hautes-terres. Des informations paléoécologiques des hautes - terres du Centre sud sontènécessaires pour évaluer cette hypothèse afin de démêler la contribution relative des facteurs climatiques et anthropiques dans les changements paléoécologiques de la région. Cependant, les stations de subfossiles étaient jusqu’alors inconnues dans cette région. Nous présentons ici les résultats de recherches réalisées sur les restes fauniques découverts au cours de fouilles récentes à Christmas River, la seule station de subfossiles connue des hautes - terres du Centre sud de Madagascar. Des restes de plusieurs espèces datant approximativement de 10,000 14C B.P. ont été identifiés dont des restes appartenant à des espèces de crocodile, de tortue, de l’Aepyornis, du carnivore Cryptoprocta spelea, des lémuriens Archaeolemur majori, Pachylemur insignis et Megaladapis edwardsi ainsi que de nombreux restes de l’hippopotame nain Hippopotamus lemerlei. La présence à Christmas River d’espèces sylvicoles endémiques du Sud appuie l’hypothèse de l’existence d’une forêt, certainement discontinue, mais qui s’étendait sur les hautes - terres centrales en se poursuivant vers l’ouest. Une théorie a proposé que les sites septentrionaux des hautes - terres centrales, à des altitudes plus élevées, maintenaient des conditions plus humides au cours des changements du Plio - quaternaire que les sites méridionaux de ces hautes - terres centrales. Ainsi, dans le passé, l’altitude a du agir comme un filtre qui empêchait la dispersion des espèces d’un endroit à l’autre de l’île. Un tel scénario expliquerait la distinction entre les communautés subfossiles du nord des hautes - terres qui étaient plus humides à haute altitude et les communautés subfossiles du sud aride à basse altitude. La poursuite de l’exploration à Christmas River constitue une occasion unique pour décoder les changements écologiques qui sont intervenus dans le Sud de cette région centrale de Madagascar au cours de l’Holocène

    Acceptability of novel lifelogging technology to determine context of sedentary behaviour in older adults

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    <strong>Objective:</strong> Lifelogging, using body worn sensors (activity monitors and time lapse photography) has the potential to shed light on the context of sedentary behaviour. The objectives of this study were to examine the acceptability, to older adults, of using lifelogging technology and indicate its usefulness for understanding behaviour.<strong> </strong><strong>Method:</strong> 6 older adults (4 males, mean age: 68yrs) wore the equipment (ActivPAL<sup>TM</sup> and Vicon Revue<sup>TM</sup>/SenseCam<sup>TM</sup>) for 7 consecutive days during free-living activity. The older adults’ perception of the lifelogging technology was assessed through semi-structured interviews, including a brief questionnaire (Likert scale), and reference to the researcher&#39;s diary. <strong>Results:</strong> Older adults in this study found the equipment acceptable to wear and it did not interfere with privacy, safety or create reactivity, but they reported problems with the actual technical functioning of the camera. <strong>Conclusion:</strong> This combination of sensors has good potential to provide lifelogging information on the context of sedentary behaviour

    Improved eradication of Clostridium difficile spores from toilets of hospitalized patients using an accelerated hydrogen peroxide as the cleaning agent

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    <p>Abstract</p> <p>Background</p> <p><it>C. difficle </it>spores in the environment of patients with <it>C. difficile </it>associated disease (CDAD) are difficult to eliminate. Bleach (5000 ppm) has been advocated as an effective disinfectant for the environmental surfaces of patients with CDAD. Few alternatives to bleach for non-outbreak conditions have been evaluated in controlled healthcare studies.</p> <p>Methods</p> <p>This study was a prospective clinical comparison during non-outbreak conditions of the efficacy of an accelerated hydrogen peroxide cleaner (0.5% AHP) to the currently used stabilized hydrogen peroxide cleaner (0.05% SHP at manufacturer recommended use-dilution) with respect to spore removal from toilets in a tertiary care facility. The toilets used by patients who had diarrhea with and without <it>C. difficile </it>associated disease (CDAD) were cultured for <it>C. difficile </it>and were monitored using an ultraviolet mark (UVM) to assess cleaning compliance on a daily basis 5 days per week. A total of 243 patients and 714 samples were analysed. The culture results were included in the analysis only if the UVM audit from the same day confirmed that the toilet had been cleaned.</p> <p>Results</p> <p>Our data demonstrated that the efficacy of spore killing is formulation specific and cannot be generalized. The Oxivir<sub>TB</sub><sup>® </sup>AHP formulation resulted in statistically significantly (p = 0.0023) lower levels of toxigenic <it>C. difficile </it>spores in toilets of patients with CDAD compared to the SHP formulation that was routinely being used (28% vs 45% culture positive). The background level of toxigenic <it>C. difficile </it>spores was 10% in toilets of patients with diarrhea not due to CDAD. The UVM audit indicated that despite the enhanced twice-daily cleaning protocol for CDAD patients cleaning was not achieved on approximately 30 - 40% of the days tested.</p> <p>Conclusion</p> <p>Our data indicate that the AHP formulation evaluated that has some sporicidal activity was significantly better than the currently used SHP formulation. This AHP formulation provides a one-step process that significantly lowers the <it>C. difficile </it>spore level in toilets during non-outbreak conditions without the workplace safety concerns associated with 5000 ppm bleach.</p

    Informal Employment

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    The myth surrounding negative connotation of informal employment / informal economy work engagement is one that needs to be revisited as research ventures must be pursued in the direction of encouraging those engaged in it to feel quite elated about their boldness in becoming actively involved in economic development activities. Equally, sensitive approaches should be pursued in pursuance of government statutory obligations in addressing core services like expenditures connected with education and health for example, which can only be achieved through revenue raised from genuine contributions made by the workforce, be it through formal or informal work engagement

    Assessing newborn body composition using principal components analysis: differences in the determinants of fat and skeletal size

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    BACKGROUND: Birth weight is a composite of skeletal size and soft tissue. These components are likely to have different growth patterns. The aim of this paper is to investigate the association between established determinants of birth weight and these separate components. METHODS: Weight, length, crown-rump, knee-heel, head circumference, arm circumference, and skinfold thicknesses were measured at birth in 699 healthy, term, UK babies recruited as part of the Exeter Family Study of Childhood Health. Corresponding measurements were taken on both parents. Principal components analysis with varimax rotation was used to reduce these measurements to two independent components each for mother, father and baby: one highly correlated with measures of fat, the other with skeletal size. RESULTS: Gestational age was significantly related to skeletal size, in both boys and girls (r = 0.41 and 0.52), but not fat. Skeletal size at birth was also associated with parental skeletal size (maternal: r = 0.24 (boys), r = 0.39 (girls) ; paternal: r = 0.16 (boys), r = 0.25 (girls)), and maternal smoking (0.4 SD reduction in boys, 0.6 SD reduction in girls). Fat was associated with parity (first borns smaller by 0.45 SD in boys; 0.31 SD in girls), maternal glucose (r = 0.18 (boys); r = 0.27 (girls)) and maternal fat (r = 0.16 (boys); r = 0.36 (girls)). CONCLUSION: Principal components analysis with varimax rotation provides a useful method for reducing birth weight to two more meaningful components: skeletal size and fat. These components have different associations with known determinants of birth weight, suggesting fat and skeletal size may have different regulatory mechanisms, which would be important to consider when studying the associations of birth weight with later adult disease

    Global Array-Based Transcriptomics from Minimal Input RNA Utilising an Optimal RNA Isolation Process Combined with SPIA cDNA Probes

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    Technical advances in the collection of clinical material, such as laser capture microdissection and cell sorting, provide the advantage of yielding more refined and homogenous populations of cells. However, these attractive advantages are counter balanced by the significant difficultly in obtaining adequate nucleic acid yields to allow transcriptomic analyses. Established technologies are available to carry out global transcriptomics using nanograms of input RNA, however, many clinical samples of low cell content would be expected to yield RNA within the picogram range. To fully exploit these clinical samples the challenge of isolating adequate RNA yield directly and generating sufficient microarray probes for global transcriptional profiling from this low level RNA input has been addressed in the current report. We have established an optimised RNA isolation workflow specifically designed to yield maximal RNA from minimal cell numbers. This procedure obtained RNA yield sufficient for carrying out global transcriptional profiling from vascular endothelial cell biopsies, clinical material not previously amenable to global transcriptomic approaches. In addition, by assessing the performance of two linear isothermal probe generation methods at decreasing input levels of good quality RNA we demonstrated robust detection of a class of low abundance transcripts (GPCRs) at input levels within the picogram range, a lower level of RNA input (50 pg) than previously reported for global transcriptional profiling and report the ability to interrogate the transcriptome from only 10 pg of input RNA. By exploiting an optimal RNA isolation workflow specifically for samples of low cell content, and linear isothermal RNA amplification methods for low level RNA input we were able to perform global transcriptomics on valuable and potentially informative clinically derived vascular endothelial biopsies here for the first time. These workflows provide the ability to robustly exploit ever more common clinical samples yielding extremely low cell numbers and RNA yields for global transcriptomics

    Do multiple outcome measures require p-value adjustment?

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    BACKGROUND: Readers may question the interpretation of findings in clinical trials when multiple outcome measures are used without adjustment of the p-value. This question arises because of the increased risk of Type I errors (findings of false "significance") when multiple simultaneous hypotheses are tested at set p-values. The primary aim of this study was to estimate the need to make appropriate p-value adjustments in clinical trials to compensate for a possible increased risk in committing Type I errors when multiple outcome measures are used. DISCUSSION: The classicists believe that the chance of finding at least one test statistically significant due to chance and incorrectly declaring a difference increases as the number of comparisons increases. The rationalists have the following objections to that theory: 1) P-value adjustments are calculated based on how many tests are to be considered, and that number has been defined arbitrarily and variably; 2) P-value adjustments reduce the chance of making type I errors, but they increase the chance of making type II errors or needing to increase the sample size. SUMMARY: Readers should balance a study's statistical significance with the magnitude of effect, the quality of the study and with findings from other studies. Researchers facing multiple outcome measures might want to either select a primary outcome measure or use a global assessment measure, rather than adjusting the p-value

    A Common Polymorphism in the Promoter Region of the TNFSF4 Gene Is Associated with Lower Allele-Specific Expression and Risk of Myocardial Infarction

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    BACKGROUND: The TNFSF4/TNFRSF4 system, along with several other receptor-ligand pairs, is involved in the recruitment and activation of T-cells and is therefore tentatively implicated in atherosclerosis and acute coronary syndromes. We have previously shown that genetic variants in TNFSF4 are associated with myocardial infarction (MI) in women. This prompted functional studies of TNFSF4 expression. METHODS AND RESULTS: Based on a screening of the TNFSF4 genomic region, a promoter polymorphism (rs45454293) and a haplotype were identified, conceivably involved in gene regulation. The rs45454293T-allele, in agreement with the linked rs3850641G-allele, proved to be associated with increased risk of MI in women. Haplotype-specific chromatin immunoprecipitation of activated polymerase II, as a measure of transcriptional activity in vivo, suggested that the haplotype including the rs45454293 and rs3850641 polymorphisms is functionally important, the rs45454293T- and rs3850641G-alleles being associated with lower transcriptional activity in cells heterozygous for both polymorphisms. The functional role of rs45454293 on transcriptional levels of TNFSF4 was clarified by luciferase reporter assays, where the rs45454293T-allele decreased gene expression when compared with the rs45454293C-allele, while the rs3850641 SNP did not have any effect on TNFSF4 promoter activity. Electromobility shift assay showed that the rs45454293 polymorphism, but not rs3850641, affects the binding of nuclear factors, thus suggesting that the lower transcriptional activity is attributed to binding of one or more transcriptional repressor(s) to the T-allele. CONCLUSIONS: Our data indicate that the TNFSF4 rs45454293T-allele is associated with lower TNFSF4 expression and increased risk of MI
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