237 research outputs found

    Caractérisation des peuplements ligneux de la zone Cayor Baol (Thiès-Sénégal)

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    Cette étude se propose de déterminer la composition floristique et la structure des peuplements ligneux dans trois localités de la région de Thiès (Fandène, Mont Rolland et Sessène). Sur un transect orienté Nord/Sud, partant de Mont Rolland à Sessène, un inventaire floristique et des relevés dendrométriques ont été effectués en fonction des unités morphopédologiques. Le traitement statistique des données recueillies a montré que la flore ligneuse, dans ces 3 sites, est riche de 35 espèces réparties en 30 genres appartenant à 20 familles. La famille des  Mimosaceae est la mieux représentée, suivie des Caesalpiniaceae, des Combretaceae et des Anacardiaceae. La richesse floristique varie suivant les sites. La surface terrière est plus élevée au Mont Rolland, le  recouvrement et la densité sont plus importants à Fandène. La distribution du peuplement selon la circonférence est homogène à Fandène,  contrairement à Sessène et à Mont Rolland. Quant à la distribution selon la hauteur des individus, elle montre une prédominance de la strate arbustive dans les 3 sites. Les analyses de régression ont montré une corrélation entre la circonférence et la hauteur. La pression anthropiquesur la strate ligneuse est plus importante à Sessène, moyenne au Mont Rolland et faible à Fandène. L’AFC montre une forte hétérogénéité des peuplements ligneux. Elle a révélé l’existence de 3 groupements en  étroite relation avec les facteurs édaphologiques.© 2013 International Formulae Group. All rights reserved.Mot clés : Thiès, ligneux, flore, structure, groupement

    Phase II study of paclitaxel combined with capecitabine as second-line treatment for advanced gastric carcinoma after failure of cisplatin-based regimens

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    Purpose To determine the safety and the efficacy of paclitaxel and capecitabine as second-line combination chemotherapy after failure of platinum regimens in advanced gastric cancer. Methods Patients with histologically proven gastric cancer and measurable metastatic disease received capecitabine 825 mg/m2 twice daily (1,650 mg/m2 per day) on days 1–14 and paclitaxel 175 mg/m2 by intravenous infusion on day 1 every 3 weeks until disease progression or unacceptable toxicities. Results Between June 2003 and October 2005, 26 patients, of median age 59 years (range 41–84 years) were included in the study and were treated by paclitaxel/capecitabine combination. Overall response rate was 34.6% (95%CI = 17.2–55.7%) with one complete response and 42.3% (95%CI = 17.2–55.7%) of patients achieved a stable disease. Median progression-free survival was 4.5 months (95%CI = 4–4.5 months). Median overall survival was 7.5 months (95%CI = 6–10 months). Cumulated overall survival including cisplatin regimens was 15.5 months (95%CI = 11–18 months). Grade 3/4 adverse events included alopecia (30.8%), neutropenia (11.5%), hand foot skin reaction (11.5%), neuropathy (11.5%), arthralgias (7.5%), and anemia (3.8%). Conclusions Paclitaxel and capecitabine combination was safe and effective in advanced gastric cancer after failure of cisplatin regimens. The cumulated overall survival of 15.5 months suggests a particular interest of taxanes in second-line treatment after failure of platinum salts

    Existence and asymptotic behavior of solutions for neutral stochastic partial integrodifferential equations with infinite delays

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    In this work we study the existence, uniqueness and asymptotic behavior of mild solutions for neutral stochastic partial integrodifferential equations with infinite delays. To prove the results, we use the theory of resolvent operators as developed by R. Grimmer [12] R. Grimmer. Resolvent operators for integral equations in a banach space. Transactions of the American Mathematical Society, 273(1): 333-349, 1982, as well as a version of the fixed point principle. We establish sufficient conditions ensuring that the mild solutions are exponentially stable in pth-moment. An example is provided to illustrate the abstract results.Fondo Europeo de Desarrollo RegionalMinisterio de Economía y CompetitividadConsejería de Innovación, Ciencia y Empresa (Junta de Andalucía

    Understanding Similarities and Differences in CKD and Dialysis Care in Children and Adults

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    In lower-income settings there is often a dearth of resources and nephrologists, especially pediatric nephrologists, and individual physicians often find themselves caring for patients with chronic kidney diseases and end-stage kidney failure across the age spectrum. The management of such patients in high-income settings is relatively protocolized and permits high-volume services to run efficiently. The basic principles of managing chronic kidney disease and providing dialysis are similar for adults and children, however, given the differences in body size, causes of kidney failure, nutrition, and growth between children and adults with kidney diseases, nephrologists must understand the relevance of these differences, and have an approach to providing quality and safe dialysis to each group. Prevention, early diagnosis, and early intervention with simple therapeutic and lifestyle interventions are achievable goals to manage symptoms, complications, and reduce progression, or avoid kidney failure in children and adults. These strategies currently are easier to implement in higher-resource settings with robust health systems. In many low-resource settings, kidney diseases are only first diagnosed at end stage, and resources to pay out of pocket for appropriate care are lacking. Many barriers therefore exist in these settings, where specialist nephrology personnel may be least accessible. To improve management of patients at all ages, we highlight differences and similarities, and provide practical guidance on the management of children and adults with chronic kidney disease and kidney failure. It is important that children are managed with a view to optimizing growth and well-being and maximizing future options (eg, maintaining vein health and optimizing cardiovascular risk), and that adults are managed with attention paid to quality of life and optimization of physical health

    CHARACTERIZATION OF RF SIGNAL BEHAVIOR FOR THE USE IN INDOOR HUMAN PRESENCE DETECTION

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    ABSTRACT This paper presents a method or technique that identifies physical intrusion detection in an indoor environment that is based on received signal strength indicator (RSSI) on radio frequency identification. The objective of this paper is two folds. Firstly, is to characterize the signal behavior in an indoor environment using statistical measures. Secondly, is to identify the existence of a human presence inside a contained environment (e.g., room). The objective is to use simple means like the recorded readings of the received signal strength indicator (RSSI). The characterization was observed during three distinctive time intervals, namely; empty room, with human presence, and transitional period during link crossings. The experiment was repeatedly conducted for 5 minutes to validate the averaged results. In order to emulate real-life environment, experiments were conducted using Zigbee-compliant iris mote XM2110 and MIB510 programming boards with transmitter and receiver antennas, and interfaced using TinyOS software on Linux. Our results show that there are distinctive statistical features that can utilized as flags to classify the three cases stated above, empty room, occupied and link being crossed. These results motivate the design of alarm system to detect human presence using RSSI statistics only

    Mechanical and structural properties of termite soil as a partial replacement to cement for different applications

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    This paper presents the results of the experimental and theoretical study of the mechanical and structural properties of termite soil as a partial replacement to cement for different applications, especially in the building/construction industry. Different volume fractions of termite soil are mixed with Portland cement and their compressive and flexural strengths as well as fracture toughness values are determined. The mechanical properties of the composites are also elucidated after curing the samples for 7 days, 14 days and 28 days. The study shows that the 28 days Compressive strength decreases with increasing volume percentage of termite soil for volume percentages up to 60%. The 28 day strength was also greater than the requirement of (NIS 87: 2000) for non-bearing load walls (δmin=2.8N/mm²› 2.5 N/mm²). The flexural strength for 20% replacement (at all curing days) was greater than 7 N/mm². The fracture toughness was also observed to decrease with increasing volume percentage of termite soil up to 20 vol. %. This resulted in a maximum fracture toughness of 4.24  for the materials with 20 vol. % of termite soil stabilization. The samples are then characterized via X-ray Diffraction (XRD) and Energy Dispersive Spectroscopy (EDX). The implications of the results are discussed for the development of sustainable termite-stabilized building materials

    Unraveling the hydrological budget of isolated and seasonally contrasted subtropical lakes

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    Complete understanding of the hydrological functioning of large-scale intertropical watersheds such as the Lake Chad basin is becoming a high priority in the context of climate change in the near future and increasing demographic pressure. This requires integrated studies of all surface water and groundwater bodies and of their quite-complex interconnections. We present here a simple method for estimating the annual mean water balance of sub-Sahelian lakes subject to high seasonal contrast and located in isolated regions with no road access during the rainy season, a situation which precludes continuous monitoring of in situ hydrological data. Our study focuses for the first time on two lakes, Iro and Fitri, located in the eastern basin of Lake Chad. We also test the approach on Lake Ihotry in Madagascar, used as a benchmark site that has previously been extensively studied by our group. We combine the δ18O and δ2H data that we measured during the dry season with altimetry data from the SARAL satellite mission in order to model the seasonal variation of lake volume and isotopic composition. The annual water budget is then estimated from mass balance equations using the Craig–Gordon model for evaporation. We first show that the closed-system behavior of Lake Ihotry (i.e., precipitation equal to evaporation) is well simulated by the model. For lakes Iro and Fitri, we calculate evaporation to influx ratios (E∕I) of 0.6±0.3 and 0.4±0.2, respectively. In the case of the endorheic Lake Fitri, the estimated output flux corresponds to the infiltration of surface water toward the surface aquifer that regulates the chemistry of the lake. These results constitute a first-order assessment of the water budget of these lakes, in regions where direct hydrological and meteorological observations are very scarce or altogether lacking. Finally, we discuss the implications of our data on the hydro-climatic budget at the scale of the catchment basins. We observe that the local evaporation lines (LELs) obtained on both lake and aquifer systems are slightly offset from the average rainfall isotopic composition monitored by IAEA at N'Djamena (Chad), and we show that this difference may reflect the impact of vegetation transpiration on the basin water budget. Based on the discussion of the mass balance budget we conclude that, while being broadly consistent with the idea that transpiration is on the same order of magnitude as evaporation in those basins, we cannot derive a more precise estimate of the partition between these two fluxes, owing to the large uncertainties of the different end-members in the budget equations.</p

    Unraveling the hydrological budget of isolated and seasonally contrasted subtropical lakes

    Get PDF
    Complete understanding of the hydrological functioning of large-scale intertropical watersheds such as the Lake Chad basin is becoming a high priority in the context of climate change in the near future and increasing demographic pressure. This requires integrated studies of all surface water and groundwater bodies and of their quite-complex interconnections. We present here a simple method for estimating the annual mean water balance of sub-Sahelian lakes subject to high seasonal contrast and located in isolated regions with no road access during the rainy season, a situation which precludes continuous monitoring of in situ hydrological data. Our study focuses for the first time on two lakes, Iro and Fitri, located in the eastern basin of Lake Chad. We also test the approach on Lake Ihotry in Madagascar, used as a benchmark site that has previously been extensively studied by our group. We combine the δ18O and δ2H data that we measured during the dry season with altimetry data from the SARAL satellite mission in order to model the seasonal variation of lake volume and isotopic composition. The annual water budget is then estimated from mass balance equations using the Craig–Gordon model for evaporation. We first show that the closed-system behavior of Lake Ihotry (i.e., precipitation equal to evaporation) is well simulated by the model. For lakes Iro and Fitri, we calculate evaporation to influx ratios (E∕I) of 0.6±0.3 and 0.4±0.2, respectively. In the case of the endorheic Lake Fitri, the estimated output flux corresponds to the infiltration of surface water toward the surface aquifer that regulates the chemistry of the lake. These results constitute a first-order assessment of the water budget of these lakes, in regions where direct hydrological and meteorological observations are very scarce or altogether lacking. Finally, we discuss the implications of our data on the hydro-climatic budget at the scale of the catchment basins. We observe that the local evaporation lines (LELs) obtained on both lake and aquifer systems are slightly offset from the average rainfall isotopic composition monitored by IAEA at N'Djamena (Chad), and we show that this difference may reflect the impact of vegetation transpiration on the basin water budget. Based on the discussion of the mass balance budget we conclude that, while being broadly consistent with the idea that transpiration is on the same order of magnitude as evaporation in those basins, we cannot derive a more precise estimate of the partition between these two fluxes, owing to the large uncertainties of the different end-members in the budget equations.</p
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