This study addresses the pressing need to evaluate the quality of water resources in the Oued Guir watershed,highlighting the importance of monitoring both surface water and groundwater in the context of environmental...This study addresses the pressing need to evaluate the quality of water resources in the Oued Guir watershed,highlighting the importance of monitoring both surface water and groundwater in the context of environmental and public health.It focuses on the evaluation of physicochemical and bacteriological water quality downstream of the Kaddoussa Dam,as well as the characterization of wastewater from the Boudnib treatment plant discharged into Oued Guir.The goal is to assess the health of aquatic ecosystems and understand the impact of anthropogenic activities on these sensitive environments.A comprehensive analysis was conducted at 15 selected stations during a sampling campaign in November 2023.Groundwater and surface water were assessed using 10 physicochemical parameters,while bacteriological quality was evaluated based on fecal coliforms and Escherichia coli.In addition,38 parameters were studied to characterize the wastewater discharge.All analyses followed standard procedures and the results were compared to Moroccan and World Health Organization(WHO)standards.The study revealed that surface water and groundwater in the study area exhibited strong mineralization,with Electrical Conductivity(EC)exceeding 1400µS/cm at all stations.Nitrogen quality,in terms of Nitrates(NO₃⁻),was moderate across stations,while Ammonium(NH₄⁺)quality was consistently excellent.Physicochemical parameters of surface waters indicated overall excellent quality.Bacteriological analysis showed minimal contamination by fecal coliforms and Escherichia coli,with levels deemed negligible.However,wastewater from the Boudnib treatment plant exceeded Moroccan standards for organic load,presenting a potential environmental risk.展开更多
In this paper, the qualitative properties of general nonautonomous Lotka-Volterran-species competitive systems with impulsive e？ects are studied. Some new criteria on thepermanence, extinction and global attractivity...In this paper, the qualitative properties of general nonautonomous Lotka-Volterran-species competitive systems with impulsive e？ects are studied. Some new criteria on thepermanence, extinction and global attractivity of partial species are established by used themethods of inequalities estimate and Liapunov functions. As applications, nonautonomous twospecies Lotka-Volterra systems with impulses are discussed.展开更多
In this paper, the existence of strictly positive solutions for N-species nonau- tonom ous Kolm ogorov com petition system s is studied. By applying the Schauder's fixed point theorem som e new sufficient condit...In this paper, the existence of strictly positive solutions for N-species nonau- tonom ous Kolm ogorov com petition system s is studied. By applying the Schauder's fixed point theorem som e new sufficient conditions are established. In particular, for the alm ost periodic system , the existence of strictly positive alm ostperiodic solutions is obtained. Som e previous results are im proved and generalized.展开更多
Introduction: In Burkina Faso, as in most developing countries, limited access to biological tests forces practitioners to resort very often to probabilistic antibiotic therapy. The objective of this study is to deter...Introduction: In Burkina Faso, as in most developing countries, limited access to biological tests forces practitioners to resort very often to probabilistic antibiotic therapy. The objective of this study is to determine the extent of this prescription. Patients and Methods: This was a cross-sectional study with retrospective data collection of patients hospitalized in the infectious diseases department in the period from January 1, 2005 to December 31, 2020. The records of patients who received probabilistic antibiotic therapy were included. Results: During the study period, 330 patients had received probabilistic antibiotic therapy. The majority of patients were male (53%), with a sex ratio of 1.12. The mean age of the patients was 33 years ± 14. The age range of 20 to 40 years was the most represented (42%). Fifteen percent (15%) of patients were living with HIV. The majority of patients were from urban areas (56.4%). Forty-nine percent (49%) of the patients worked in the informal sector. Clinically, the reasons for consultation were dominated by fever, alteration of general condition, neurological disorders, digestive disorders, respiratory signs, urinary signs and diffuse pain. The physical examination showed that 48.1% of the patients had meningeal irritation syndrome, 10% had convulsions and 10% had focal signs, trismus was present in 4% of the patients and facial paralysis in 3%. In the digestive system, hepatomegaly was present in 29% of patients and digestive candidiasis in 31%. Respiratory examination showed crepitus and fluid effusion syndrome in 26.83% and 20.62% of patients respectively. The presumptive diagnosis was dominated by bacterial meningitis, salmonellosis and bronchopneumonia with banal germs. In terms of treatment, the beta-lactam family of drugs was the most prescribed. They were followed by aminoglycosides and fluoroquinolones. The evolution was marked by the death of 50 patients (15%). Conclusion: The most prescribed molecules belong to the family of Beta-lactam. And this prescription improved the outcome of patients. Bacterial susceptibility studies will allow better orientation of probabilistic antibiotic therapy in order to limit the emergence of multi-resistant bacteria.展开更多
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Groundwater resources are the main sources of water used to supply drinking water to the population of the Ouémé Delta via the Continental Terminal aquifer. Urbanization, population growth, and agricultural ...Groundwater resources are the main sources of water used to supply drinking water to the population of the Ouémé Delta via the Continental Terminal aquifer. Urbanization, population growth, and agricultural and industrial activities have resulted in a deterioration in the quality of these resources. To assess the quality of the delta’s groundwater and its suitability for human consumption and irrigation, a total of fourteen (14) physico-chemical parameters were analyzed in some forty existing water points between September 2020 and March 2021, using standard water analysis techniques. The values obtained were compared with the potability standards recommended by the World Health Organization (WHO) and the Republic of Benin and were subjected to statistical analysis (principal component analysis (PCA)). In addition, methods for determining the suitability of water for irrigation were used. The results showed that the waters are acidic to slightly neutral and influenced by ambient temperature. In addition, the waters are moderately mineralized, with conductivities (24 - 1205 μS/cm) in line with WHO standards. A comparison of the analytical results of the WHO (2017) and Benin (2001) standards indicates that the majority of the waters studied are of good quality for all the chemical parameters considered. Nevertheless, some samples show levels of nitrates (21%), potassium (14% to 16%), calcium (13%), ammonium (12%), nitrites (8%) and bicarbonates (10%) over their respective standards. The Wilcox and Riverside diagrams indicate that the majority of waters (90%) have excellent suitability for irrigation and no negative effect on soil fertilization.展开更多
Hydrological models are very useful tools for evaluating water resources, and the hydroclimatic hazards associated with the water cycle. However, their calibration and validation require the use of performance criteri...Hydrological models are very useful tools for evaluating water resources, and the hydroclimatic hazards associated with the water cycle. However, their calibration and validation require the use of performance criteria which choice is not straightforward. This paper aims to evaluate the influence of the performance criteria on water balance components and water extremes using two global rainfall-runoff models (HBV and GR4J) over the Ouémé watershed at the Bonou and Savè outlets. Three (3) Efficacy criteria (Nash, coefficient of determination, and KGE) were considered for calibration and validation. The results show that the Nash criterion provides a good assessment of the simulation of the different parts of the hydrograph. KGE is better for simulating peak flows and water balance elements than other efficiency criteria. This study could serve as a basis for the choice of performance criteria in hydrological modelling.展开更多
In response to the increased frequency of flood events in recent years, it has become crucial to enhance preparedness and anticipation through precise flood risk assessments. To this end, this study aims to produce up...In response to the increased frequency of flood events in recent years, it has become crucial to enhance preparedness and anticipation through precise flood risk assessments. To this end, this study aims to produce updated and precise flood risk maps for the Lower Valley of Ouémé River Basin, located in the South of Benin. The methodology used consisted of a combination of geographical information systems (GIS) and multi-criteria analysis, including Analytical Hierarchy Process (AHP) methods to define and quantify criteria for flood risk assessment. Seven hydro-geomorphological indicators (elevation, rainfall, slope, distance from rivers, flow accumulation, soil type, and drainage density), four socio-economic vulnerability indicators (female population density, literacy rate, poverty index, and road network density), and two exposure indicators (population density and land use) were integrated to generate risk maps. The results indicate that approximately 21.5% of the Lower Valley is under high and very high flood risk, mainly in the south between Dangbo, So-Ava, and Aguégués. The study findings align with the historical flood pattern in the region, which confirms the suitability of the used method. The novelty of this work lies in its comprehensive approach, the incorporation of AHP for weighting factors, and the use of remote sensing data, GIS technology, and spatial analysis techniques which adds precision to the mapping process. This work advances the scientific understanding of flood risk assessment and offers practical insights and solutions for flood-prone regions. The detailed flood risk indicator maps obtained stand out from previous studies and provide valuable information for effective flood risk management and mitigation efforts in the Lower Valley of Ouémé.展开更多
This study assessed sediment contamination by heavy metals and pesticide active ingredients linked to chemical inputs used in agricultural activities in the lower Ouémé. Pesticide residues from the organochl...This study assessed sediment contamination by heavy metals and pesticide active ingredients linked to chemical inputs used in agricultural activities in the lower Ouémé. Pesticide residues from the organochlorine, pyrethroid and organophosphorus families were investigated by gas chromatography, and heavy metals (Cd, Pb, As, Ni, Zn, Fe, Mg, Cr and Hg) by atomic absorption spectrophotometry. The metallic pollution indices, the contamination factor (CF) and the ecological risk index were calculated. The results revealed 8 active ingredients in the rainy season and 9 in the dry season. Glyphosate was the active ingredient with the highest concentration at all stations, 9.65 ± 0.84 mg/kg recorded in the dry season at the Aguigadji station. All glyphosate values were above the EQS. DDT, Atrazine and Endosulfan also showed high concentrations in the dry and rainy seasons. Emamectin, Abamectin and Lambda Cyhalothrin also showed high concentrations in the dry season at Aguigadji, Ahlan and Sele. Only glyphosate was recorded at the control station (Toho), but in very low concentrations. Lead showed the highest concentrations at all the stations, 265.96 ± 21.02 mg/Kg in the rainy season and 255.38 ± 79.09 mg/Kg in the dry season, all detected at the Aguigadji station and above the EQS. Zn, Ni, Fe, Cu and Cr were all representative in both the dry and rainy seasons at the contaminated stations. Manganese showed high concentrations in the rainy season. Pb showed very high contamination (FC ≥ 6) at the Aguigadji and Ahlan stations and significant contamination (3 ≤ FC 6) at the Sele station in both the rainy and dry seasons. Ni, Hg and Cd, showed either moderate or significant contamination at the contaminated stations. The risk values showed a considerable ecological Ri (190 ≤ Ri < 380) in the rainy season and a moderate ecological Ri (95 ≤ Ri < 190) in the dry season at these contaminated stations.展开更多
Based on 2022 and 2023 hydrometric data and satellite images (Sentinel 2022, SPOT 2010), this study aims to present the Nokoué Lake and its channels’ re-cent hydromorphological characteristics. Integrating flow,...Based on 2022 and 2023 hydrometric data and satellite images (Sentinel 2022, SPOT 2010), this study aims to present the Nokoué Lake and its channels’ re-cent hydromorphological characteristics. Integrating flow, tributary morphology, and topography data determined specific power values along the axes studied. The values obtained range from 2.69 to 12.92 W/m2 for Ouémé River and 2.46 to 10.99 W/m2 for Sô River. The resulting water erosion on banks and bottoms is of linear, areolar, or gully and claw types. Lake bathymetry varies from -0.5 to -2.6 m (low flow period) and -1 to -4 m;in the Ouémé, Sô, and Totchè rivers, it varies from -5 m to -7 m, reaching -10 m at the Cotonou channel entrance (flood period). Bathymetric profiles reveal varied “U”, “V” and “Intermediate” bottom morphologies, influenced by erosion/sedimentation processes and human activities. The flow facies identified are lentic in the northern tributaries and lotic in the Cotonou and Totchè canals. Spatial analysis identified nine (09) thematic classes. In 2022, the surface area of the water body has increased from 274 km2 at low water to 280 km2 at high water, whereas in 2010 (a recent year of exceptional flooding), the surface area was 270 km2 at low water and 277 km2 at high water. Significant changes in land use are observed between 2010 and 2022. The floodplain area decreased slightly, from 421 km2 in 2010 (year of exceptional flooding) to 419 km2 in 2022. The evolution of land use shows a progressive expansion of the urban environment to the detriment of the natural environment. In the medium to long term, this trend could threaten the hydromorphological balance and even the existence of this important lagoon ecosystem.展开更多
文摘This study addresses the pressing need to evaluate the quality of water resources in the Oued Guir watershed,highlighting the importance of monitoring both surface water and groundwater in the context of environmental and public health.It focuses on the evaluation of physicochemical and bacteriological water quality downstream of the Kaddoussa Dam,as well as the characterization of wastewater from the Boudnib treatment plant discharged into Oued Guir.The goal is to assess the health of aquatic ecosystems and understand the impact of anthropogenic activities on these sensitive environments.A comprehensive analysis was conducted at 15 selected stations during a sampling campaign in November 2023.Groundwater and surface water were assessed using 10 physicochemical parameters,while bacteriological quality was evaluated based on fecal coliforms and Escherichia coli.In addition,38 parameters were studied to characterize the wastewater discharge.All analyses followed standard procedures and the results were compared to Moroccan and World Health Organization(WHO)standards.The study revealed that surface water and groundwater in the study area exhibited strong mineralization,with Electrical Conductivity(EC)exceeding 1400µS/cm at all stations.Nitrogen quality,in terms of Nitrates(NO₃⁻),was moderate across stations,while Ammonium(NH₄⁺)quality was consistently excellent.Physicochemical parameters of surface waters indicated overall excellent quality.Bacteriological analysis showed minimal contamination by fecal coliforms and Escherichia coli,with levels deemed negligible.However,wastewater from the Boudnib treatment plant exceeded Moroccan standards for organic load,presenting a potential environmental risk.
基金Supported by The National Natural Science Foundation of P.R. China [60764003]The Scientific Research Programmes of Colleges in Xinjiang [XJEDU2007G01, XJEDU2006I05]+1 种基金The National Key Technologies R & D Program of China [2008BAI68B01]The Natural Science Foundation of Jiangxi Province [2008GZS0027]
文摘In this paper, the qualitative properties of general nonautonomous Lotka-Volterran-species competitive systems with impulsive e？ects are studied. Some new criteria on thepermanence, extinction and global attractivity of partial species are established by used themethods of inequalities estimate and Liapunov functions. As applications, nonautonomous twospecies Lotka-Volterra systems with impulses are discussed.
文摘In this paper, the existence of strictly positive solutions for N-species nonau- tonom ous Kolm ogorov com petition system s is studied. By applying the Schauder's fixed point theorem som e new sufficient conditions are established. In particular, for the alm ost periodic system , the existence of strictly positive alm ostperiodic solutions is obtained. Som e previous results are im proved and generalized.
文摘Introduction: In Burkina Faso, as in most developing countries, limited access to biological tests forces practitioners to resort very often to probabilistic antibiotic therapy. The objective of this study is to determine the extent of this prescription. Patients and Methods: This was a cross-sectional study with retrospective data collection of patients hospitalized in the infectious diseases department in the period from January 1, 2005 to December 31, 2020. The records of patients who received probabilistic antibiotic therapy were included. Results: During the study period, 330 patients had received probabilistic antibiotic therapy. The majority of patients were male (53%), with a sex ratio of 1.12. The mean age of the patients was 33 years ± 14. The age range of 20 to 40 years was the most represented (42%). Fifteen percent (15%) of patients were living with HIV. The majority of patients were from urban areas (56.4%). Forty-nine percent (49%) of the patients worked in the informal sector. Clinically, the reasons for consultation were dominated by fever, alteration of general condition, neurological disorders, digestive disorders, respiratory signs, urinary signs and diffuse pain. The physical examination showed that 48.1% of the patients had meningeal irritation syndrome, 10% had convulsions and 10% had focal signs, trismus was present in 4% of the patients and facial paralysis in 3%. In the digestive system, hepatomegaly was present in 29% of patients and digestive candidiasis in 31%. Respiratory examination showed crepitus and fluid effusion syndrome in 26.83% and 20.62% of patients respectively. The presumptive diagnosis was dominated by bacterial meningitis, salmonellosis and bronchopneumonia with banal germs. In terms of treatment, the beta-lactam family of drugs was the most prescribed. They were followed by aminoglycosides and fluoroquinolones. The evolution was marked by the death of 50 patients (15%). Conclusion: The most prescribed molecules belong to the family of Beta-lactam. And this prescription improved the outcome of patients. Bacterial susceptibility studies will allow better orientation of probabilistic antibiotic therapy in order to limit the emergence of multi-resistant bacteria.
文摘基于数据序列的保密运算可以解决保密的数据查询、保密的数据外包、保密投票、隐私数据的安全共享等多种实际问题,是安全多方计算领域的重要研究方向.两方的序列保密计算已有很多解决方案,但多方序列的保密计算相关的问题和解决方案仍然较少.本文主要研究多方序列相同位置元素和的保密计算和排序问题,其在保密投票、保密选择、保密推荐系统、匿名评价等实际应用中有极其重要的意义.本文首先提出此问题,并给出安全高效的计算协议.协议基于OU公钥密码系统的加法同态性质,在密文上进行多方协同计算,能够在不泄露具体元素与真实和值的情况下给出排序结果.用模拟范例证明了协议在半诚实模型下能够抵抗任意合谋攻击,并通过理论分析和实验证明协议是高效的.当协议参与者有50位、序列元素个数是80时,协议执行时间仅为10.024413 s.
文摘Groundwater resources are the main sources of water used to supply drinking water to the population of the Ouémé Delta via the Continental Terminal aquifer. Urbanization, population growth, and agricultural and industrial activities have resulted in a deterioration in the quality of these resources. To assess the quality of the delta’s groundwater and its suitability for human consumption and irrigation, a total of fourteen (14) physico-chemical parameters were analyzed in some forty existing water points between September 2020 and March 2021, using standard water analysis techniques. The values obtained were compared with the potability standards recommended by the World Health Organization (WHO) and the Republic of Benin and were subjected to statistical analysis (principal component analysis (PCA)). In addition, methods for determining the suitability of water for irrigation were used. The results showed that the waters are acidic to slightly neutral and influenced by ambient temperature. In addition, the waters are moderately mineralized, with conductivities (24 - 1205 μS/cm) in line with WHO standards. A comparison of the analytical results of the WHO (2017) and Benin (2001) standards indicates that the majority of the waters studied are of good quality for all the chemical parameters considered. Nevertheless, some samples show levels of nitrates (21%), potassium (14% to 16%), calcium (13%), ammonium (12%), nitrites (8%) and bicarbonates (10%) over their respective standards. The Wilcox and Riverside diagrams indicate that the majority of waters (90%) have excellent suitability for irrigation and no negative effect on soil fertilization.
文摘Hydrological models are very useful tools for evaluating water resources, and the hydroclimatic hazards associated with the water cycle. However, their calibration and validation require the use of performance criteria which choice is not straightforward. This paper aims to evaluate the influence of the performance criteria on water balance components and water extremes using two global rainfall-runoff models (HBV and GR4J) over the Ouémé watershed at the Bonou and Savè outlets. Three (3) Efficacy criteria (Nash, coefficient of determination, and KGE) were considered for calibration and validation. The results show that the Nash criterion provides a good assessment of the simulation of the different parts of the hydrograph. KGE is better for simulating peak flows and water balance elements than other efficiency criteria. This study could serve as a basis for the choice of performance criteria in hydrological modelling.
文摘In response to the increased frequency of flood events in recent years, it has become crucial to enhance preparedness and anticipation through precise flood risk assessments. To this end, this study aims to produce updated and precise flood risk maps for the Lower Valley of Ouémé River Basin, located in the South of Benin. The methodology used consisted of a combination of geographical information systems (GIS) and multi-criteria analysis, including Analytical Hierarchy Process (AHP) methods to define and quantify criteria for flood risk assessment. Seven hydro-geomorphological indicators (elevation, rainfall, slope, distance from rivers, flow accumulation, soil type, and drainage density), four socio-economic vulnerability indicators (female population density, literacy rate, poverty index, and road network density), and two exposure indicators (population density and land use) were integrated to generate risk maps. The results indicate that approximately 21.5% of the Lower Valley is under high and very high flood risk, mainly in the south between Dangbo, So-Ava, and Aguégués. The study findings align with the historical flood pattern in the region, which confirms the suitability of the used method. The novelty of this work lies in its comprehensive approach, the incorporation of AHP for weighting factors, and the use of remote sensing data, GIS technology, and spatial analysis techniques which adds precision to the mapping process. This work advances the scientific understanding of flood risk assessment and offers practical insights and solutions for flood-prone regions. The detailed flood risk indicator maps obtained stand out from previous studies and provide valuable information for effective flood risk management and mitigation efforts in the Lower Valley of Ouémé.
文摘This study assessed sediment contamination by heavy metals and pesticide active ingredients linked to chemical inputs used in agricultural activities in the lower Ouémé. Pesticide residues from the organochlorine, pyrethroid and organophosphorus families were investigated by gas chromatography, and heavy metals (Cd, Pb, As, Ni, Zn, Fe, Mg, Cr and Hg) by atomic absorption spectrophotometry. The metallic pollution indices, the contamination factor (CF) and the ecological risk index were calculated. The results revealed 8 active ingredients in the rainy season and 9 in the dry season. Glyphosate was the active ingredient with the highest concentration at all stations, 9.65 ± 0.84 mg/kg recorded in the dry season at the Aguigadji station. All glyphosate values were above the EQS. DDT, Atrazine and Endosulfan also showed high concentrations in the dry and rainy seasons. Emamectin, Abamectin and Lambda Cyhalothrin also showed high concentrations in the dry season at Aguigadji, Ahlan and Sele. Only glyphosate was recorded at the control station (Toho), but in very low concentrations. Lead showed the highest concentrations at all the stations, 265.96 ± 21.02 mg/Kg in the rainy season and 255.38 ± 79.09 mg/Kg in the dry season, all detected at the Aguigadji station and above the EQS. Zn, Ni, Fe, Cu and Cr were all representative in both the dry and rainy seasons at the contaminated stations. Manganese showed high concentrations in the rainy season. Pb showed very high contamination (FC ≥ 6) at the Aguigadji and Ahlan stations and significant contamination (3 ≤ FC 6) at the Sele station in both the rainy and dry seasons. Ni, Hg and Cd, showed either moderate or significant contamination at the contaminated stations. The risk values showed a considerable ecological Ri (190 ≤ Ri < 380) in the rainy season and a moderate ecological Ri (95 ≤ Ri < 190) in the dry season at these contaminated stations.
文摘Based on 2022 and 2023 hydrometric data and satellite images (Sentinel 2022, SPOT 2010), this study aims to present the Nokoué Lake and its channels’ re-cent hydromorphological characteristics. Integrating flow, tributary morphology, and topography data determined specific power values along the axes studied. The values obtained range from 2.69 to 12.92 W/m2 for Ouémé River and 2.46 to 10.99 W/m2 for Sô River. The resulting water erosion on banks and bottoms is of linear, areolar, or gully and claw types. Lake bathymetry varies from -0.5 to -2.6 m (low flow period) and -1 to -4 m;in the Ouémé, Sô, and Totchè rivers, it varies from -5 m to -7 m, reaching -10 m at the Cotonou channel entrance (flood period). Bathymetric profiles reveal varied “U”, “V” and “Intermediate” bottom morphologies, influenced by erosion/sedimentation processes and human activities. The flow facies identified are lentic in the northern tributaries and lotic in the Cotonou and Totchè canals. Spatial analysis identified nine (09) thematic classes. In 2022, the surface area of the water body has increased from 274 km2 at low water to 280 km2 at high water, whereas in 2010 (a recent year of exceptional flooding), the surface area was 270 km2 at low water and 277 km2 at high water. Significant changes in land use are observed between 2010 and 2022. The floodplain area decreased slightly, from 421 km2 in 2010 (year of exceptional flooding) to 419 km2 in 2022. The evolution of land use shows a progressive expansion of the urban environment to the detriment of the natural environment. In the medium to long term, this trend could threaten the hydromorphological balance and even the existence of this important lagoon ecosystem.
