215 research outputs found
The price of protection:a defensive endosymbiont impairs nymph growth in the bird cherryâoat aphid, <i>Rhopalosiphum padi</i>
Strong divergent selection at multiple loci in two closely related species of ragworts adapted to high and low elevations on Mount Etna
ADĂNOPATHIES CERVICO-FACIALES EN ODONTO STOMATOLOGIE: ĂTUDE DE 82 OBSERVATIONS.
Objectif : étudier les adénopathies cervico-faciales en rapport avec la tuberculose dans notre
pratique Odonto-stomatologique.
Matériels et Méthodes : Nous avons réalisé une étude rétrospective sur une période de quatre
ans (janvier 2007 Ă dĂ©cembre 2010), au Centre Hospitalier Universitaire dâOdontostomatologie (CHU OS) de Bamako, sur des cas successifs dâadĂ©nopathies cervico-faciales.
LâIDRT et lâanatomopathologie de la piĂšce biopsique ont servi pour le diagnostic Ă©tiologique
de la tuberculose. Les données ont été recueillies à partir des dossiers médicaux et saisies
puis analysées avec le logiciel Epiinfo.fr 6.0.
Résultats : Les lésions ont concerné 82 patients dont 37 hommes (45,1%) avec un sex ratio de
0,82. La tranche dâĂąge la plus reprĂ©sentĂ©e a Ă©tĂ© celle de 20 et 29 ans (28%). Le siĂšge
anatomique privilĂ©giĂ© Ă©tait la rĂ©gion cervicale avec 34,14%.Nos patients ont bĂ©nĂ©ficiĂ© dâune
radiographie thoracique dans 90,20% des cas. LâIDRT a Ă©tĂ© effectuĂ©e chez 72% des patients
et lâadĂ©nite tuberculeuse casĂ©o- folliculaire a Ă©tĂ© retrouvĂ©e dans 8,50% des cas.
Conclusion : Notre Ă©tude a rĂ©vĂ©lĂ© une prĂ©valence de 0,31% dâadĂ©nopathies cervico-faciales
dont 80,50% Ă©tait dâorigine tuberculeuse. Devant toute adĂ©nopathie cervico-faciale dans une
zone dâendĂ©mie tuberculeuse, une IDRT et un examen anatomopathologique de la biopsie
ganglionnaire devrait ĂȘtre systĂ©matique pour la prise en charge prĂ©coce de la tuberculose
Effects of the soil microbiome on the demography of two annual prairie plants
This work is licensed under a Creative Commons Attribution 4.0 International License.1. Both mutualistic and pathogenic soil microbes are known to play important roles in shaping the fitness of plants, likely affecting plants at different life cycle stages.
2. In order to investigate the differential effects of native soil mutualists and pathogens on plant fitness, we compared survival and reproduction of two annual tallgrass prairie plant species (Chamaecrista fasciculata and Coreopsis tinctoria) in a field study using 3 soil inocula treatments containing different compositions of microbes. The soil inocula types included fresh native whole soil taken from a remnant prairie containing both native mutualists and pathogens, soil enhanced with arbuscular mycorrhizal (AM) fungi derived from remnant prairies, and uninoculated controls.
3. For both species, plants inoculated with native prairie AM fungi performed much better than those in uninoculated soil for all parts of the life cycle. Plants in the native whole prairie soil were either generally similar to plants in the uninoculated soil or had slightly higher survival or reproduction.
4. Overall, these results suggest that native prairie AM fungi can have important positive effects on the fitness of early successional plants. As inclusion of prairie AM fungi and pathogens decreased plant fitness relative to prairie AM fungi alone, we expect that native pathogens also can have large effects on fitness of these annuals. Our findings support the use of AM fungi to enhance plant establishment in prairie restorations.National Science Foundation (NSF DEBâ1556664)National Science Foundation (DEBâ1738041)National Science Foundation (OIA 1656006
Effects of microplastics and drought on soil ecosystem functions and multifunctionality
1. Microplastics in soils have become an important threat for terrestrial systems as they may potentially alter the geochemical/biophysical soil environment and can interact with drought. As microplastics may affect soil water content, this could exacerbate the well-known negative effects of drought on ecosystem functionality. Thus, functions including litter decomposition, soil aggregation or those related with nutrient cycling can be altered. Despite this potential interaction, we know relatively little about how microplastics, under different soil water conditions, affect ecosystem functions and multifunctionality.
2. To address this gap, we performed an experiment using grassland plant communities growing in microcosms. Microplastic fibres (absent, present) and soil water conditions (well-watered, drought) were applied in a fully factorial design. At harvest, we measured soil ecosystem functions related to nutrient cycling (beta-glucosaminidase, beta-D-cellobiosidase, phosphatase, beta-glucosidase enzymes), respiration, nutrient retention, pH, litter decomposition and soil aggregation (water stable aggregates). As terrestrial systems provide these functions simultaneously, we also assessed ecosystem multifunctionality, an index that encompasses the array of ecosystem functions measured here.
3. We found that the interaction between microplastic fibres and drought affected ecosystem functions and multifunctionality. Drought had negatively affected nutrient cycling by decreasing enzymatic activities by up to similar to 39%, while microplastics increased soil aggregation by similar to 18%, soil pH by similar to 4% and nutrient retention by up to similar to 70% by diminishing nutrient leaching. Microplastic fibres also impacted soil enzymes, respiration and ecosystem multifunctionality, but importantly, the direction of these effects depended on soil water status. That is, under well-watered conditions, these functions decreased with microplastic fibres by up to similar to 34% while under drought they had similar values irrespective of the microplastic presence, or tended to increase with microplastics. Litter decomposition had a contrary pattern increasing with microplastics by similar to 6% under well-watered conditions while decreasing to a similar percentage under drought.
4. Synthesis and applications. Single ecosystem functions can be positively or negatively affected by microplastics fibres depending on soil water status. However, our results suggest that microplastic fibres may cause negative effects on ecosystem soil multifunctionality of a similar magnitude as drought. Thus, strategies to counteract this new global change factor are necessary
Ocean-scale footprint of a highly mobile fishing fleet: Social-ecological drivers of fleet behaviour and evidence of illegal fishing.
Managing the footprint of highly mobile fishing fleets is increasingly important due to continuing declines in fish populations. However, social-ecological drivers for fisher behaviour remain poorly understood for many fleets globally. Using the Sri Lankan fleet as a case study, we explored the role of social, environmental and policy drivers of effort distribution and illegal fishing. We used semi-structured interviews and participatory mapping with 95 fishers, combined with explanatory modelling (GLM) and multivariate statistics, including principal component analysis (PCA). Our findings highlighted the broad footprint (~3,800,000 km2) of this fleet, with fishing effort expended in high seas (53.9%), domestic (40.9%) and, illegally, in foreign waters (5.2%). Twenty-six per cent of fishers directly admitted to fishing illegally in foreign waters during interviews, whereas 62% of fishers indicated doing so during participatory mapping. GLMs explained underlying decisions of where to fish (36% of the total deviance in effort distribution) as a function of social variables (14%), notably distance from landing sites (13%), and environmental variables (11%), notably sea surface temperature (10%). Multivariate analysis revealed that individual fisher characteristics associated with illegal fishing, such as a level of reliance on sharks, vary across the fleet. The analysis of qualitative data suggested that the influence of interpersonal and community social networks and perceptions of higher catch value, particularly of sharks, may be important. Our approach demonstrated the utility of mixed methods research, including the collection of qualitative data, for creating a detailed understanding of spatial behaviour, including decisions of whether to fish illegally. Results highlighted the importance of adopting a social-ecological lens to investigate drivers for human behaviour and non-compliance with rules. We advocate for a nuanced approach to monitoring and managing of fleets, including investigating localised social drivers for illegal fishing and enhancing regional transparency in fleet monitoring
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