33 research outputs found
Perceptions of local populations on the state of phytodiversity in the subwatershed of Kossi river in the municipalities of Dassa-Zoumé and Glazoué in the Center of Benin
In Africa, since several decades a rarefaction of many plant species because of their daily use by people can be observed. This study which was conducted in the subwatershed of the Kossi River aims to collect peasant perceptions about the state of phytodiversity. The data were collected through an individual survey in 10 villages with 492 households. The software CAP version 2.15. and R version 3.3.3. were used for the statistical analysis. In total, 94 species belonging to 83 genera and 38 families were identified. The dominant genera are Ficus, Ocimum, Acacia and Blighia. Forty-six (46) species of the listed species (48.94%) are currently rare and 9 species (19.57%) of those rare species are threatened in Benin. Value of importance (IV) of activity and the consensus value (UCs) of the choice of activity show that logging, agriculture and breeding have greatest influence on species loss. This study gives information on the most used species by the populations and those we can select for reforestation campaigns. As a perspective, a work on the temporal dynamics of the land use units of this sub-basin will be done to better appreciate their evolution over time.
En Afrique, on assiste depuis plusieurs décennies à la raréfaction de plusieurs espèces végétales du fait de leur utilisation quotidienne par les populations. La présente étude conduite dans le sous-bassin versant de la rivière Kossi vise à recueillir les perceptions des populations locales sur l’état de la phytodiversité. Les données ont été collectées à travers une enquête individuelle dans 10 villages auprès de 492 ménages. Les logiciels CAP version 2.15. et R version 3.3.3. ont été utilisés pour les analyses statistiques. Au total, 94 espèces reparties en 83 genres et 38 familles ont été recensées. Les genres dominants sont Ficus, Ocimum, Acacia et Blighia et les familles les mieux représentées sont les Caesalpiniaceae, les Papilionaceae et les Combretaceae. Quarante-six des espèces recensées (48,94%) sont actuellement rares et 9 de ces espèces rares (19,57%) sont menacées au Bénin. La Valeur d’Importance (IV) de l’activité et la valeur consensuelle (UCs) du choix de l’activité ont révélé que l’exploitation forestière, l’agriculture et la transhumance sont les principaux facteurs responsables de cette raréfaction. Cette étude renseigne sur les espèces les plus utiles pour les populations et celles à apporter en cas d’enrichissement. Comme perspective, la dynamique temporelle des unités d’occupation du sol de ce sous-bassin sera abordée pour mieux apprécier leur évolution dans le temps
Trade in vulture parts in West Africa:Burkina Faso may be one of the main sources of vulture carcasses
The current catastrophic decline in African vultures is caused mainly by poisoning, and killing for consumption and belief-based use (traditional medicine). To find out more about the key threats to vultures in West Africa, we assessed the main anthropogenic causes of vulture mortality in Burkina Faso. We analysed incidents of mass vulture mortality, based on interviews conducted in 2016 with local butchers, veterinarians, foresters, and abattoir watchmen at 44 sites across the country. A total of 730 interviews revealed that poisoning was the main cause of mortality of vultures in Burkina Faso (20 of the 23 mass mortality incidents described by respondents were caused by poisoning). Poisoning was also the most lethal threat to vultures (779 out of 879 known vulture deaths were due to poisoning). According to the survey, intentional poisoning of vultures with poisoned baits (which comprised 15 out of 23 mass mortality incidents) produced the highest number of victims (577 out of 879 dead vultures). The number of vultures killed by poisoned baits was higher closer to the borders than elsewhere in Burkina Faso and we believe these recent intentional vulture poisoning events in Burkina Faso were intended to meet the growing demand for vulture body parts in West Africa. The survey showed that unintentional poisoning was the second main cause of vulture mass mortality (5 out of 23 mass mortality incidents comprising 202 of 879 dead vultures). Other important anthropogenic causes of vulture mortality included electrocution at electricity poles and motor vehicle collisions. Our results highlight the need for awareness campaigns, improved policy and legislation, and stronger commitment from governments in West Africa, to halt the trade in vultures and prevent their extirpation.</p
Clinical integration of fast Raman spectroscopy for Mohs micrographic surgery of basal cell carcinoma
We present the first clinical integration of a prototype device based on integrated auto-fluorescence imaging and Raman spectroscopy (Fast Raman device) for intra-operative assessment of surgical margins during Mohs micrographic surgery of basal cell carcinoma (BCC). Fresh skin specimens from 112 patients were used to optimise the tissue pre-processing and the Fast Raman algorithms to enable an analysis of complete Mohs layers within 30 minutes. The optimisation allowed >95% of the resection surface area to be investigated (including the deep and epidermal margins). The Fast Raman device was then used to analyse skin layers excised from the most relevant anatomical sites (nose, temple, eyelid, cheek, forehead, eyebrow and lip) and to detect the three main types of BCC (nodular, superficial and infiltrative). These results suggest that the Fast Raman technique is a promising tool to provide an objective diagnosis “tumour clear yes/no” during Mohs surgery of BCC. This clinical integration study is a key step towards a larger scale diagnosis test accuracy study to reliably determine the sensitivity and specificity in a clinical setting
Fixed Effects and Random Effects Estimation of Higher-Order Spatial Autoregressive Models with Spatial Autoregressive and Heteroskedastic Disturbances
This paper develops a unified framework for fixed and random effects estimation of higher-order spatial autoregressive panel data models with spatial autoregressive
disturbances and heteroskedasticity of unknown form in the idiosyncratic error component. We derive the moment conditions and optimal weighting matrix without distributional assumptions for a generalized moments (GM) estimation procedure of the spatial autoregressive parameters of the disturbance process and define both a random effects and a fixed effects spatial generalized two-stage least squares estimator for the regression parameters of the model. We prove consistency of the proposed estimators and derive their joint asymptotic distribution, which is robust to heteroskedasticity of unknown form in the idiosyncratic error component. Finally, we derive a robust Hausman-test of the spatial random against the spatial fixed effects model. (authors' abstract)Series: Department of Economics Working Paper Serie
Preliminary report on the Pleistocene birds from Crete
A concise account is presented of the Middle-Upper Pleistocene birds from Crete. The elaborate description of this fossil avifauna is in preparation and will be published subsequently.Un bref compte-rendu est donné ici sur les oiseaux du Pléistocène moyen et supérieur de Crète. La description détaillée de cette avifaune est en cours d'élaboration et sera publiée ultérieurement.Weesie Peter D.M. Preliminary report on the Pleistocene birds from Crete. In: Documents des Laboratoires de Géologie, Lyon, n°99, 1987. L'évolution des oiseaux d'après le témoignage des fossiles. Table ronde internationale du CNRS, Lyon-Villeurbanne, 18-21 septembre 1985. pp. 197-200
An integrated framework for the instrumental valuation of nature
Nature is most often valued in terms of its provision of ecosystem goods and services to meet human needs. However, such instrumental valuations, informed by ecological economics, are limited by the mainly anthropocentric orientation. We present a framework to assess anthropocentric and nonanthropocentric instrumental values of nature in a balanced way, in association with sustainability science. Particular attention is Paid to ecosystem functions, to be valued both for their benefits to human beings and for their importance to the ecological and evolutionary functioning of the global ecosystem