检索结果-南通市图书馆

Neutral stochastic delay partial functional integro-differential equations driven by a fractional Brownian motion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2013年第4期8卷 745-760页

作者： Tomas CARABALLO mamadou abdoul diop Dpto. Ecuaciones Diferenciales y Analisis Numerico Universidad de Sevilla Apdo. de Correos 1160 41080-Sevilla Spain Universite Gaston Berger de Saint-Louis UFR SAT Departement de Mathematiques 234 Saint-Louis Senegal

This paper deals with the existence and uniqueness of mild solutions to neutral stochastic delay functional integro-differential equations perturbed by a fractional Brownian motion BH, with Hurst parameter H E （1/2, 1）. We use the theory of resolvent operators developed by R. Grimmer to show the existence of mild solutions. An example is provided to illustrate the results of this work.

关键词： Resolvent operator C0-semigroup Wiener process mild solution fractional Brownian motion

Restoration or Rehabilitation of the Faleme River Affected by Mining Activities: What Methods?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2024年第4期16卷 233-263页

作者： Mor diop Ibrahima Mall Elhadji mamadou Sonko Tidiane diop Birane Niane Cheikh Mbow Environmental Sciences Institute (ISE) Cheikh Anta Diop university of Dakar Dakar Senegal Higher School of Mines Geology and Environment Amadou Mahtar Mbow University of Diamniadio (UAM) Dakar Senegal Department of Chemical Cheikh Anta Diop university of Dakar Dakar Senegal Departmentof Engineering Sciences Iba Der Thiam University of Thi&#232s Thi&#232s Senegal

The Faleme River, a West Africa long transboundary stream (625 km) and abundant flow (>1100 million m3) is affected by severe erosion because of mining activities that takes place throughout the riverbed. To preserve this important watercourse and ensure the sustainability of its services, selecting and implementing appropriates restorations techniques is vital. In this context, the purpose of this paper was to present an overview of the actions and techniques that can be implemented for the restoration/rehabilitation of the Faleme. The methodological approach includes field investigation, water sampling, literature review with cases studies and SWOT analysis of the four methods presented: river dredging, constructed wetlands, floating treatment wetlands and chemical precipitation (coagulation and flocculation). The study confirmed the pollution of the river by suspended solids (TSS > 1100 mg/L) and heavy metals such as iron, zinc, aluminium, and arsenic. For the restoration methods, it was illustrated through description of their mode of operation and through some case studies presented, that all the four methods have proven their effectiveness in treating rivers but have differences in their costs, their sustainability (detrimental to living organisms or causing a second pollution) and social acceptance. They also have weaknesses and issues that must be addressed to ensure success of rehabilitation. For the case of the Faleme river, after analysis, floating treatment wetlands are highly recommended for their low cost, good removal efficiency if the vulnerability of the raft and buoyancy to strong waves and flow is under control.

关键词： Faleme River River Restoration Constructed Wetlands Dredging Floating Treatment Wetlands Coagulation-Flocculation

Influence of the Nature of the Incoming Sludge on the Performance of a Vertical Flow Reed Beds in Dakar-Senegal

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2024年第6期16卷 429-449页

作者： Elhadji mamadou Sonko Diomaye Dieng Maïmouna Lo Cheikh diop Laboratoire dEtude Environnemental des Milieux Urbains (LEEMUR) Institut des Sciences de lEnvironnement (ISE) Facult des Sciences et Technique (FST) Universit Cheikh Anta Diop de Dakar (UCAD) Dakar-Fann Sngal

This work investigates the influence of the type sludge on drainage, plant development, purification performances and biosolids quality. Drainage properties were measured through the frequency of clogging, the percentage of leachate recovered and the dryness of accumulated sludge. Plant development was measured through the density, the height and the stem diameter. Purification performance was evaluated from the reduction rate. Biosolids quality was measured after 3 months of maturation. The results show that the clogging frequencies were 9.5%;0% and 3.7%;the volume of leachate recovered was 42.2%;20.4% and 24.7% and, the dryness was 33.4%;61.1% and 52.4% for FS-ST, FS-STT and SS respectively. Plants densities were about, with densities 197.1, 171.3 and 178.3 plants/m2 in beds fed respectively with FS-ST, FS-STT and SS. Despite the high removal rates, the concentrations of pollutants in the leachates are above the Senegalese standard NS 05-061 for discharge into the environment. The biosolids are all mature with C/N and NH4+/NO3?ratios lower than 12 and 1 respectively. The biosolids are also rich in organic and mineral elements. The concentrations of Ascaris eggs are higher than the WHO recommendations. These biosolids should be stored for additional time or composted.

关键词： Biosolid Quality Dewatering Performance Planted Drying Beds Purification Performance Sludge Type

Long-Term Impact of Acute Retinoic Acid Supplementation at the Young Age on Testicular Architecture of Wistar Albino Rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Reproductive Sciences 2024年第1期12卷 1-13页

作者： Mama Sy Racha Kamenda Ibondou Fatoumata Bah Robert Foko Ndiaga diop Mame Vénus abdoulaye Séga Cheikh diop mamadou Fall Oumar Faye Laboratory of Histology Embryology and Cytogenetics Faculty of Medecine Cheikh Anta Diop University Dakar Senegal

Introduction: Inappropriate and excess vitamin supplementation, particularly for vitamin A, is increasingly recognized as a public health problem in developed countries. On the other hand, blind supplementation of vitamin A, for children in developing countries is a subject of controversy in the literature. The crucial role of vitamin A in the process of spermatogenesis in adult rodents is well established, but only a few publications are consecrated to the long-term effect of vitamin A intake at a young age on testicular development and differentiation. Objectives: Our study aimed to evaluate the long-term effects of acute supplementation at an early age, in the post-natal period, on spermatogenesis and testicular trophicity at adult age. Material and Methods: Young Wistar Albinos rats of 22 days received an acute high dose of supplementation of vitamin A (retinyl palmitate). The control group, group 1, received only extra virgin olive oil, Group 2 a dose of 7000 IU/kg of retinyl palmitate, group 3, 14,000 IU/kg, and Group 4 a dose of 28,000 IU/kg. At 10 weeks of age, the testes’ testosterone levels were measured by ELISA. For histological assessment, sections were stained with Hematoxylin eosin, and the Johnsen score was used to evaluate spermatogenesis in the seminiferous tubules. Results: The average testicular weights of rats were significantly lower in group 4 (p < 0.05), and so was the testosterone level in the testis compared to the control group (p .01). Most of the seminiferous tubules were concerned by an arrest of spermatogenesis and the Johnsen score was decreased with a mean score of 5.96 ± 1.60 (p .001) in that Group. In Group 3, Johnsen’s score was significantly better than the one obtained with the control. Conclusion: We observed a negative effect in the long term with a high acute dose of supplementation of retinyl palmitate at a young age, on testicular development and differentiation. Despite a return to normal diet after that supplementation, d

关键词： Vitamin A Retinyl Palmitate Spermatogenesis Testis-Wistar Albino Rats

Seasonal Performance of Solar Power Plants in the Sahel Region: A Study in Senegal, West Africa

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Smart Grid and Renewable Energy 2024年第2期15卷 79-97页

作者： Serigne abdoul Aziz Niang mamadou Simina Drame Astou Sarr Mame Diarra Toure Ahmed Gueye Seydina Oumar Ndiaye Kharouna Talla FST D&#233partement de Physique Universit&#233 Cheikh Anta Diop de Dakar Dakar S&#233n&#233gal Laboratoire de Physique de l’Atmosphère et de l’Océan Siméon Fongang Université Cheikh Anta Diop Dakar Sénégal

The main objective of this study is to evaluate the seasonal performance of 20 MW solar power plants in Senegal. The analysis revealed notable seasonal variations in the performance of all stations. The most significant yields are recorded in spring, autumn and winter, with values ranging from 5 to 7.51 kWh/kWp/day for the reference yield and 4.02 to 7.58 kWh/kWp/day for the final yield. These fluctuations are associated with intense solar activity during the dry season and clear skies, indicating peak production. Conversely, minimum values are recorded during the rainy season from June to September, with a final yield of 3.86 kWh/kW/day due to dust, clouds and high temperatures. The performance ratio analysis shows seasonal dynamics throughout the year with rates ranging from 77.40% to 95.79%, reinforcing reliability and optimal utilization of installed capacity. The results of the capacity factor vary significantly, with March, April, May, and sometimes October standing out as periods of optimal performance, with 16% for Kahone, 16% for Bokhol, 18% for Malicounda and 23% for Sakal. Total losses from solar power plants show similar seasonal trends standing out for high loss levels from June to July, reaching up to 3.35 kWh/kWp/day in June. However, using solar trackers at Sakal has increased production by up to 25%, demonstrating the operational stability of this innovative technology compared with the plants fixed panel. Finally, comparing these results with international studies confirms the outstanding efficiency of Senegalese solar power plants, other installations around the world.

关键词： Performance Study Photovoltaic Power Plant Season Variations Senegal

Risk Factors for Neonatal Mortality at the Institute of Nutrition and Child Health of the Donka/Guinea-Conakry National Hospital

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Pediatrics 2024年第2期14卷 327-337页

作者： Bangoura Mmah Aminata Kolié Ouo Ouo Camara Salématou Hassimiou Baldé Mariama Bangoura Kaba diop mamadou Moustapha Camara Emmanuel Diallo Fatoumata Binta Doukouré mamadou Aliou mamadou Mouctar Sow Bémy Pé Néabey Institut de Nutrition et de Santé de l’Enfant Conakry Guinea Service de Pédiatrie Hô pital National Donka Conakry Guinea Service de Pédiatrie Hô pital National d’Ignace Deen Conakry Guinea

Introduction: The birth of a baby is a moment of joy and celebration. However, the neonatal period is a very delicate phase of life. Neonatal mortality rates remain high in low-income countries. In Guinea, after 20 years, this rate has fallen from 34.2% in 1998 to 32% in 2018. Objective: To identify the main risk factors for neonatal mortality. Methods: This was an observational, analytical case-control study, lasting 6 months from January 1 to June 30, 2019, conducted at the Institut de Nutrition et de la Santé de l’Enfant (INSE) at Donka National Hospital. Results: We collected 242 cases and 242 controls, i.e. a total of 484 records. 748 patients were registered, with 32.35% deaths. 82.86% of deaths occurred in the early neonatal period. Statistical analysis revealed the main risk factors: prematurity (RQ 7.39 95% CI 3.27 - 16.61 p = 0.0000003), hypothermia (RQ 2.29 95% CI 1.51 - 3.46 p = 0.0001), acute fetal distress (RQ 2.13 95% CI 1.33 - 3.43 p = 0.0016), low birth weight (QR 1.91 95% CI 1.12 - 3.24 p = 0.016), home birth (QR 3.26 95% CI 1.25 - 8.46 p = 0.015). Conclusion: Neonatal mortality is a health problem in the INSE neonatology department. To reduce the mortality rate in this referral facility, it is essential to equip it and provide ongoing training for staff.

关键词： Neonatal Mortality INSE Guinea-Conakry

Preventive Effect of an Extract of Terminalia avicennioides on Acetylcholine-Induced Tracheoconstriction in Wistar Strain Rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Respiratory Diseases 2024年第2期14卷 60-68页

作者： Awa Ba-diop Ndèye Absa Diaw Ibrahima Diouf Mbaye Sène Ouafae Kechaba mamadou Sarr Modou Oumy Kane Physiology Laboratory Department of Medicine Alioune Diop University of Bambey Bambey Senegal IRL3189 Environment Health Societies CNRS-UCAD Dakar Senegal Department of Physiology Laboratory Faculty of Medicine Cheikh Anta Diop University of Dakar Dakar Senegal Department of Physiology Laboratory Faculty of Medicine UFR Sante Assane SECK University of Ziguinchor Ziguinchor Senegal

Asthma is one of the most common chronic respiratory pathologies worldwide. The cost of its treatment, particularly for populations in developing countries like Senegal, requires an alternative which consists of developing research into new therapeutic approaches with the use of plants from traditional pharmacopoeia. The objective of this study was to determine whether the hydroalcoholic extract of Terminalia avicennioides leaves has a preventive effect on the constriction of tracheal smooth muscle induced by Acetylcholine in Wistar strain rats. Methods: The species used in our experiments were male Wistar rats aged between 12 and 14 weeks. Rings of rat trachea were suspended in isolated organ chambers connected to tension sensors. Two pharmacological agents were used: acetylcholine, for its constrictor effect and adrenaline, for its dilating effect on the pulmonary trachea. Our plant material consisted of a hydroalcoholic extract of Terminalia avicennioides leaves. The experimental protocol was that of the preventive model which consisted of impregnating these rings with the extract at a defined concentration then testing its contractility in the presence of Acetylcholine which was the contractile agonist used in this study. The preventive effect of the extract was studied with an Acetylcholine contraction range on rings pre-incubated with Terminalia avicennioides extract. Results: The results showed that Acetylcholine contracts the trachea and the increase in its contractility was dependent on the dose of Ach added cumulatively (10−5 to 4 × 10−5 mol/l). The administration of the hydroalcoholic extract of Terminalia avicennioides leaves led to a modification of the contractile response to Acetylcholine. Indeed, this extract induced a significant attenuation of the contractile responses of the treated tracheal rings compared to those untreated. Conclusion: Terminalia avicennioides had a relaxing effect on tracheal smooth muscle and this effect

关键词： Bronchial Hyperreactivity Extract Hydroalcoholic of Terminalia Avicennioides Asthma

Evaluation of the Living Conditions and Health Perceptions of Waste Electrical and Electronic Equipment Handlers in the Informal Sector in Dakar

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Occupational Diseases and Environmental Medicine 2024年第2期12卷 115-129页

作者： Robert Faomowe Foko Awa Ndong Marius Kedote Fatoumata Bah Absa Lam Cheikh diop Aminata Toure Mathilde Cabral mamadou Fall Laboratoire de Toxicologie et d’ Hydrologie Facult&#233 de M&#233decine Pharmacie et Odontostomalogie Universit&#233 Cheikh Anta Diop de Dakar Dakar S&#233n&#233gal Unité Mixte de Recherche d&#8217Exploration et de Diagnostic Unit&#233 de Formation et de Recherche des Sciences de la Sant&#233 Universit&#233 Iba Der Thiam de Thi&#232s Thi&#232s S&#233n&#233gal Institut Ré gional de Sant&#233 Publique Universit&#233 d&#8217Abomey-Calavi Ouidah B&#233nin

Electrical and electronic devices are becoming an increasingly important part of our society. In Africa, and in Senegal in particular, the handling and management of electronic and electrical equipment (EEE) that has reached the end of its life is mainly informal. This professional environment is characterized by the disintegration of the sector and the social heterogeneity that can be found there. The objective of this study is to assess the standard of living of electrical and electronic equipment waste handlers in the Dakar region, as well as their perception of their health. A survey was used to obtain information on sociodemographic background, living arrangements, perception of health status, and good practices to be implemented in case of work-related health problems. Life style, perception of general health and health problems were ranged as excellent, very good, good, average and poor. Informal recyclers in the Dakar region lived mainly in rooms and buildings as tenants (49.1%), or in family homes (48.4%) before starting this activity, and 51.2% continue to live in rooms and buildings as tenants compared to 41.4% who still live in a family home. The perception of health status ranged from poor to excellent, and 4.9% believe that they are limited in work due to a disability or health problem. Informal work is a heterogeneous phenomenon that makes research and policymaking particularly complex. There are several external factors within informal WEEE re-cyclers that can cause health problems or functional disability. However, the living conditions and the perception they have of their state of health are contradictory to the working conditions and the social environment to which they belong. A biomedical approach would consolidate these achievements by confirming or invalidating them.

关键词： E-Waste Informal Work Living Arrangements Health Perception Occupational Exposure

Nutritional Profile of Children with Major Sickle Cell Syndrome at the Centre of Medical and Health Advice of Kipé, Conakry, 2018

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Case Reports in Clinical Medicine 2024年第3期13卷 73-84页

作者： mamadou Aliou Doukoure Ibrahima Sory Diallo M’mah Aminata Bangoura Amadou Oury Toure mamadou Moustapha diop Fatoumata Binta Diallo Mohamed Sama Cherif Thierno Saidou Diallo Saidouba Cherif Camara abdoulaye Toure Faculty of Health Science and Technology Gamal Abdel Nasser University Conakry Guinea National AIDS Control Programme Ministry of Health Gamal Abdel Nasser University Conakry Guinea

Introduction: Growth is a reflection of a child’s health and nutritional status. Children with sickle cell disease often have slower statural and weight development. The aim of this study was to evaluate the nutritional profile of children with sickle cell disease (SCD) registered in the CEMECO centre database. Methodology: This was a cross-sectional study with simple random sampling of children aged 1 to 16 years registered in the clinic database. Results: We collected information on 208 children, 121 of whom had sickle cell disease and 87 of whom were normal, with a sex ratio of 1.02. The mean age of the sickle cell patients was 8.7 ± 4.4 years, while that of the non-sickle cell patients was 9.5 ± 4 years. Haemoglobin electrophoresis revealed 103 homozygous (SS), 18 double heterozygous (SC, SBetaThal, SE) and 87 normal (AA) and/or sickle cell trait (AS) sickle cell cases. We observed a significant difference in the height/age ratio (P ¥). Conclusion: The results of our study revealed stunted growth in children with sickle cell disease.

关键词： Sickle Cell Disease Nutrition Growth Puberty Guinea