281 research outputs found
Relation entre densité absolue et indice de densité dans l’inventaire des populations de Cobe defassa (kobus ellypsiprimnus defassa, Ruppell) dans la réserve de biosphère de la Pendjari au Bénin
Au nombre des facteurs démographiques caractérisant une population donnée, figure en priorité la connaissance de son effectif dans le temps et de sa distribution spatiale. La présente étude est conduite dans le but d’évaluer la pertinence de deux méthodes de recensement des populations de Cobe defassa dans le Parc National de la Pendjari au Nord Bénin. Il s’agit de la méthode du transect linéaire et celle de la méthode indicielle le long des pistes. Après l’exécution de ces deux types de dénombrement sur le terrain et le traitement des données par des logiciels appropriés, le principal défi a consisté à établir une relation entre les résultats qui en ont découlé pour vérifier l’hypothèse selon laquelle les indices de densité pourraient suppléer valablement les densités absolues pour estimer l’effectif des populations de Cobe defassa dans le contexte écologique de la Réserve de Biosphère de la Pendjari. Les résultats indiquent que le Cobe defassa est une espèce inféodée à la plaine d’inondation de la rivière Pendjari. Sa densité absolue a été estimée à 2,546 individus/Km2, soit 875 individus en utilisant la méthode du transect linéaire, et son indice moyen de densité est de 1,8 cobes defassa/Km. Des résultats obtenus, on note une similitude tendancielle entre la densité absolue (D) et l’indice de densité (I), ce qui a permis l’établissement d’une courbe de régression de formule D = 100,4513 .I0,2701.Mots-clés : Cobe defassa, inventaire, densité, parc National de la Pendjari, Bénin.Relation between the absolute density and the density index in the count of Cobe defassa (kobus ellypsiprimnus defassa, Ruppell) population in Pendjari's biosphere park in BeninAmong the demographic factors that characterize a given population figure priority knowledge of its workforce over time and its distribution in space. This study is conducted in order to assess the relevance of two methods of population census waterbuck, in National Park Pendjari in northern Benin. This is the line transect method, and the method index. After performing these two types of numberings on the field and data processing by suitable softwares, the main challenge of this thesis consisted in establishing a relationship between the results, so as to check up the hypothesis stating that the signs of abundance could stand in for the absolute densities to estimate the number of waterbuck in the ecological context of the Pendjari's biosphere park. The results show that waterbuck is a species submitted to water. The absolute density has been estimated to 2.546 /Km2, that is 875 animals if we use the line transect method, and it’s medium density index is 1.8 waterbuck / Km. These results present a similarity between the trend in absolute density and the density index, which allowed the establishment of a regression formula signs of abundance D = 100.4513 .I0.2701.Keywords : waterbuck, count, density, national park of Pendjari, Benin
Evaluating wind datasets for wave hindcasting in the NW Iberian Peninsula coast
The available wind datasets can be exploited to support the setup of accurate wave models, able to reproduce and forecast extreme event scenarios. It is of utmost importance in the actual context of climate change. This study focuses on evaluating the performance of a numerical wave model, using different wind datasets, helping to create a tool to assess coastal risks, and further on to support the future implementation of reliable warning systems based on numerical models. The numerical model SWAN was implemented, configured and validated for the NW Iberian Peninsula coast, as a test case region. A period of two months, from December 2013 to January 2014, was simulated due to the winter storms that crossed the area. Six distinct wind datasets were selected to test their suitability in regional wave modelling. The results were validated against several sets of wave buoy data, considering wave parameters such as significant wave height, mean wave period and peak direction. The implemented wave model configuration allowed the representation of the wave evolution with relatively good accuracy. All the wind datasets were able to produce reasonably good wave condition estimates. The dataset that best represented the wave properties varied from one wave parameter to another, but the most reliable for the selected region was the reanalysis product generated at the European Centre for Medium-Range Weather Forecasts
Analysis of the dietary practices of the national team of the Republic of Benin during the qualifying round of the 2015 under-17 soccer African Cup of Nations
Two practices characterize the diet of elite African soccer players. The first practice consists of the period just before and during competitions, when the players are grouped together in training camps (TC) and supported by sports federations, and the second practice consists of the period when the players are out of training camp (OTC), that is, when they live and eat with their families. This study aims to describe the two characteristic contexts of the diet of Benin's elite soccer players during the 2015 under-17 Soccer African Cup of Nations (U-17 ACN) qualifiers. This is a qualitative and comparative study conducted using an approach that focuses on food consumption practices. The 24-hour recall and food logbook techniques were used to collect food data from the 24 cadet soccer players, during the OTC and TC periods within the three and eight days prior to an U-17 ACN qualifying match. In both contexts, the players' diets were spread over three meals, except for four players in the OTC period. The players claimed that they ate to satiety and with appetite, meals which were mostlylocal and monotonous in the OTC period, but Western and made with seven out of eight food groups in the TC period. In OTC conditions, meals were presented as a single dish and were often consumed alone in 15 to 17 minutes at variable times. In the TC period, meals were consumed in groups at the tables and at fixed times for 22 to 41 minutes. The number of food groups served and the conditions under which meals were consumed during the training camp period make this context the best match for the players' benchmark goals as well as help identify the benchmark eating behaviours of the Beninese soccer players in this study. The results suggest that the trainers of the studied soccer players promote good food hygiene and a longer time devoted to meals by good chewing. Benin Soccer Federation and the Ministry of Sports must worktogether to daily provide these soccer players with three meals, prepared with local food and containing all eight food groups when they are outside of the training camps as well as during training camp periods
Near Infrared Reflectance Spectroscopy: Accelerating sweetpotato breeding at the sweetpotato support platform for West African in Ghana.
Ossifying fibroma of the maxillary sinus at the Kara (Togo) Teaching Hospital
SummaryIntroductionOssifying fibroma of the jaw is a benign tumorous disease, somewhat rare and aggressive. It frequently targets the mandible, but seldom the maxillary.Case studyThe present study reports the first case of left maxillary sinus fibroma treated at the Kara Teaching Hospital in North Togo. It occurred in a 29-year-old patient who experienced slow-growing tumefaction of the left maxillary sinus, resulting in deformation of the left side of the face in the maxillary region and ipsilateral nasal obstruction. Orthopantomography showed a displacement of teeth 21, 22, and 23 with an abnormal degree of opacity at the dental roots. The CT scan of the nose and sinuses revealed a tumorous lesion of expanding bony density increasing in volume at the outer wall of the left maxillary sinus, of regular shape that contained microscopic calcifications, extending into the ipsilateral orbital floor and pushing the surrounding soft tissues forward without invading them. The histopathological examination of the tumor confirmed the diagnosis of ossifying fibroma.DiscussionOssifying fibroma or fibrous osteoma is a rare and benign lesion developing insidiously with a polymorphous aspect. Of unknown etiology, most frequently located in the mandible, it is differentiated from other types of fibroma in its clinical, radiological, and histological aspects. However, only examination of the gross specimen can provide the final diagnosis. Treatment requires surgery.ConclusionSurgical treatment entailed the complete macroscopic enucleoresection. Recovery has been favorable at 2 years of follow-up
Evaluation De La Performance Des Pratiques De Gestion De La Fertilite Des Sols Dans Le Bassin De La Riviere Okpara Au Benin
A good management of agricultural land based on scientific knowledge and farmer indigenuous knowledge is necessary to ensure sustainable agricultural production. Our research aims to evaluate the performance of farmers' strategies and improved soil fertility management practices in improving level of crop yields in the basin of the Okpara River in Benin. Surveys using semi-structured questionnaire were conducted from October 11 to November 30, 2015 on a sample of 1048 farmers belonging to socio-cultural groups Tchabè, Mahi, Ditamari, Lokpa, Bariba and Fulani. Informations collected concerned farmers' soil fertility management practices and soil fertility improvement strategies introduced by the extension services. Crop rotation, long term natural fallow, fallow with perennial crops especially cashew trees, cassava "fallow" and cereal and leguminuous intercropping (respectively 91.11; 41.66; 48.53; 54.61 and 86.25% of respondents) are endogenous soil fertility management practices. However, mineral and organic fertilizers (respectively 25.45 and 20.38% of respondents) are improved soil fertility management practices introduced. Generally 42% of respondent mentioned that indigenuous soil fertility management practices could improve only by 25% crop (especially maize) yield level against 98.5% of respondents who mentioned that improved soil fertility management practices could improve by 50% of the crop yield level. Considering the efficiency of these soil fertility management practices our study suggests some issues to be taken into account for better land management in the study area
The regime of climate-related disturbance and nutrient enrichment modulate macroalgal invasions in rockpools
Patterns of invasion by the seaweeds Grateloupia turuturu Yamada and Sargassum muticum (Yendo) Fensholt under crossed combinations of the regime (mean intensity and temporal variability) of climate-related mechanical disturbance and constant nutrient enrichment were experimentally examined in rockpools in north Portugal. The cover of both species was larger under high compared to low intensity of disturbance, but this effect was enhanced by events more heterogeneously distributed over a period of 19 months. The invasion by G. turuturu was also larger in enriched pools, but only when disturbance was applied at high intensity. The richness of native taxa was increased by high intensity events of disturbance evenly distributed over time and by low intensity events heterogeneously distributed, while no differences were documented for other treatments. Temporal variability of disturbance and nutrients interactively affected the total cover of native taxa and the availability of bare rock in different directions. Enriched conditions increased the space occupancy by natives and reduced substratum availability only when associated to heterogeneous events of disturbance. At the same time, relatively more variable disturbances caused a reduced cover by native taxa and an increased availability of free space, but only under natural nutrient levels. Present findings contribute to understand the conditions that would be more likely to facilitate the spread of G. turuturu and S. muticum under current and predicted scenarios of compounded environmental changes and in relation to traits of recipient systems that are considered relevant for the success of invasions, including the native richness and the degree of usage of resources, i.e. primarily space
Assessment of a Sand Spit Morphodynamics Under Extreme Flood Events
<p>Spits are landforms that present a complex morphology, which depends on currents, waves, sediment transport, tidal range and anthropic-induced changes. Their position and shape is subject to extreme events like flood river discharges and storms. They can also respond to processes that take place at larger time scales, as plate tectonics, sea level rise or even climatological patterns with teleconnections all over the world, as the well know North Atlantic Oscillation (NAO) or El Ni&#241;o-Southern Oscillation (ENSO). This is the case of the Douro river mouth sand spit located on the northern coast of Portugal. This naturally dynamic sand spit, which has moved landwards over the past decades, has caused frequent nuisance to navigation, affecting width and depth of the navigation channel. Therefore, a breakwater was constructed in an attempt to stabilise the sand spit and the estuary inlet.</p><p>Validated hydrodynamic numerical models (openTELEMAC-MASCARET and Delft3D) of the Douro river estuary have demonstrated ability to accurately describe the estuarine hydrodynamic patterns and water elevation under extreme flood conditions. Model results showed that for higher river flow discharges the sand spit is partially inundated.</p><p>In this work a morphodynamic model (Delft3D) of the estuary was implemented to assess both the morphodynamics of the sand spit under extreme events, including the effect of sea level rise due to climate change, and the variation of extreme water levels along the estuary due to spit erosional processes that can occur during flood events.</p><p>Preliminary results show that the sand spit will be locally eroded for the higher river flood discharges, forming a two-secondary-channels system, with one channel located near the breakwater&#8217;s southern extremity and the other, narrower, near the south bank. Associated with these two channels, two depositional bars will be formed in front of the channels at the coastal platform. However, the inner immersed sand spit will be suffering a sedimentation process for all of the simulated scenarios. This way, neither the river mouth discharge conditions nor the water levels inside the estuary will suffer significant changes according to the simulated scenarios.</p><p>These results will be complemented with further analyses considering the sediment size influence, tidal level, storm surge, sea level rise and river flood discharges.</p><p>Acknowledgements: To the Strategic Funding UIDB/04423/2020 and UIDP/04423/2020 (FCT and ERDF) and to the project EsCo-Ensembles (PTDC/ECI-EGC/30877/2017, NORTE 2020, Portugal 2020, ERDF and FCT). The authors also want to acknowledge the data provided by EDP and IH.</p></jats:p
Future estuarine circulation patterns characterization based on a hydrodynamic models ensemble
<p>Estuarine regions are strategically important from an environmental, economic, and social point of view. To reduce vulnerability and increase resilience, it is crucial to know their dynamics that usually are poorly understood. Numerical models have proven to be an appropriate tool to improve this knowledge and simulate scenarios for future conditions. However, as the modelling results may be inaccurate, the application of the ensembles technique can be very useful in reducing possible uncertainties. In the EsCo-Ensembles project, this technique is proposed to improve hydrodynamic predictions for two Portuguese estuaries: Douro and Minho.</p><p>Two already validated numerical models (openTELEMAC-MASCARET and Delft3D), which have demonstrated their ability to accurately describe estuarine hydrodynamic patterns and water elevation for river flow in normal and extreme conditions, were applied. Several scenarios for climate change effects were defined including river flood peak flows for the 100 and 1000 year return periods and sea level extreme values for RCPs 4.5 and 8.5 in 2100.</p><p>The results demonstrated a clear difference between the hydrodynamic behaviour of the two estuaries. Model outcomes for the Minho estuary, which is dominated by the tide and therefore by oceanographic conditions, show a pronounced effect of rising sea levels on estuarine hydrodynamics. Whereas, for the Douro estuary, which is heavily dominated by the river flow, the effect of the sea level rise is hardly noticeable during flood events.</p><p>These and further results of this ongoing project are expected to (i) provide a complete hydrodynamic characterization of the two estuaries; (ii) evaluate future trends; (iii) estimate the flood risks associated with extreme events and (iv) demonstrate that the combined use of different models reduces their uncertainty and increases the confidence and consistency of the forecasts.</p><p><strong>Acknowledgements: </strong>To the Strategic Funding UIDB/04423/2020 and UIDP/04423/2020 (FCT and ERDF) and to the project EsCo-Ensembles (PTDC/ECI-EGC/30877/2017, NORTE 2020, Portugal 2020, ERDF and FCT). The authors also want to acknowledge the data provided by EDP, IH and Confederaci&#243;n Hidrogr&#225;fica Mi&#241;o-Sil.</p></jats:p
Multi-locational assessment of some physicochemical attributes and amylase activity of sweetpotato varieties and elite materials in Ghana.
As part of the breeding objectives to select sweetpotato materials with acceptable quality attributes for adaptation and subsequent utilisation in Ghana, the total amylase activity and physicochemical attributes (flesh colour, Beta-carotene, dry matter, starch and sugars) of 13 sweetpotato genotypes across five locations were evaluated. Near Infrared Reflectance Spectrometry (NIRS), was mainly employed in the study. The flesh colour of the materials ranged from white to deep orange while thedry matter content ranged from 20% to 44%. Starch, fructose, glucose and sucrose contents were 46– 74, 0.3 - 5, 2 – 8 and 9 – 22% respectively. Apomuden, a deep orange type, recorded the highesttotal sugar content of 36% and the lowest dry matter and starch content of 20% and 46% respectively. Hi-starch variety had the highest dry matter (45%), starch (74%) and the lowest sugar (11%). Dry matter content correlated positively with starch content whilst orange colour intensity was inversely proportional to dry matter content. The outcome of the study supports the fact that sweet potato contains high extractable amylases. Amylase activity of the materials was fairly stable across locations. Okomkum, Faara, Santom Pona, Kemb, and Cemsa 74-228 recorded the highest activity while Hi-starch, Apomuden, Mohc, and 199062.1 were low. There was no correlation between raw sugars and amylase activity. The potential of individual cultivars for food industry will be discussed in relation to starch content and extractable amylases
- …