Environment

Permanent URI for this collection

https://datad1.aau.org/handle/123456789/1385

Browse

Browsing Environment by Issue Date

Filter results by year or month
Now showing 1 - 20 of 74
  • Thumbnail Image
    Item
    The Tropical Atlantic Observing System
    (Frontiers in Marine Science, 2019-05-10) Foltz, G.R.; Brandt, P.; Richter, I.
    The tropical Atlantic is home to multiple coupled climate variations covering a wide range of timescales and impacting societally relevant phenomena such as continental rainfall, Atlantic hurricane activity, oceanic biological productivity, and atmospheric circulation in the equatorial Pacific. The tropical Atlantic also connects the southernand northern branches of the Atlantic meridional overturning circulation and receives freshwater input from some of the world’s largest rivers. To address these diverse, unique, and interconnected research challenges, a rich network of ocean observations has developed, building on the backbone of the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA). This network has evolved naturally over time and out of necessity in order to address the most important outstanding scientific questions and to improve predictions of tropical Atlantic severe weather and global climate variability and change. The tropical Atlantic observing system is motivated by goals to understand and better predict phenomena such as tropical Atlantic interannual to decadal variability and climate change; multidecadal variability and its links to the meridional overturning circulation; air-sea fluxes of CO2 and their implications for the fate of anthropogenic CO2; the Amazon River plume and its interactions with biogeochemistry, vertical mixing, and hurricanes; the highly productive eastern boundary and equatorial upwelling systems; and oceanic oxygen minimum zones, their impacts on biogeochemical cycles and marine ecosystems, and their feedbacks to climate.
  • Thumbnail Image
    Item
    Detection and spatio-temporal variation of marine heatwaves in the Gulf of Guinea, Nigeria
    (Academic Journals (Journal of Oceanography and Marine Science), 2019-09-04) Asuquo, Francis Emile; Oghenechovwen, Oghenekevwe Christopher
    Time series analyses spanning 30 years (1988 - 2017) on spatial and temporal variations in sea surface temperatures reveal the occurrence of marine heatwaves (MHWs) within the Nigerian segment of the Gulf of Guinea. For specific focus, three locations were also chosen along Nigeria’s coastal zone, namely Lagos lagoon (western region), the Niger Delta (Forcados/Central region) and outer Cross River estuary (eastern region). Daily SST data was subjected to MHW detection algorithm, and then examined using Gaussian and Poisson distribution models to delineate the distribution of maximum intensities and frequency of occurrence of these extreme events, respectively. Determining the likelihood difference of maximum intensities of MHWs and the association between MHW count and occurrence year during the period was done using Kruskal-Wallis and Kendall rank correlation tests, respectively. Results show that the entire study area has been experiencing MHWs more frequently in recent decades, with the northwest region having higher counts. Strong seasonality exists, as more MHWs occurred in winter months (October to May). Peak month for MHW occurrence over the entire study area was May. November is shared as a peak month for the three focus coastal locations, although MHWs in Cross River and Niger Delta locations exhibited multi-modal patterns. None of the MHWs in Lagos location was categorized as severe. This study contributes to the World Climate Research Programme Grand Challenge on Weather and Climate Extremes.
  • Thumbnail Image
    Item
    Entre la rue et l’internet : pratiques revendicatives et stratégies de mobilisation de Y’en a marre, du Balai citoyen, Filimbi et de la Lucha, Afrique et développement
    (Afrique et développement, 2020) Dimé, Mamadou; Kapagama, Pascal; Soré, Zakaria
    Cet article analyse les pratiques de mobilisation des mouvements citoyens Y’en a marre au Sénégal, le Balai citoyen au Burkina Faso et Filimbi et la Lucha en République démocratique du Congo. Il propose un éclairage qui insiste sur les innovations en matière de militantisme sur le terrain, la part dévolue aux technologies de l’information et de la communication, les pratiques idiomatiques et les canaux et moyens d’expression. L’accent est mis sur les systèmes langagiers structurant les discours, les modes opératoires de la lutte sur le terrain avant de jeter un regard sur les réactions des pouvoirs politiques qui oscillent souvent entre répression, cooptation, corruption subordination, intimidation, instrumentalisation, infiltration, récupération politique, etc.
  • Thumbnail Image
    Item
    Diversité floristique et caractéristiques démographiques des juvéniles des parcs à Faidherbia suivant un gradient climatique au Burkina Faso
    (Science et technique, Sciences naturelles et appliquées, 2020-01) TRAORE, Innocent Charles Emmanuel; TINDANO, Elycée; OUEDRAOGO, Oumarou
    Les parcs agroforestiers constituent le socle du système de production et fournissent des biens et services aux populations rurales. Cependant, leur exploitation ne garantit pas une conservation durable des populations juvéniles ligneuses. Cette étude se propose de caractériser le potentiel de régénération dont disposent les parcs à Faidherbia albida (delile) A. chev. qui sont des espaces à haut intérêt socio-économique. La diversité floristique et la structure démographique de la végétation juvénile des parcs ainsi que les mécanismes de régénération de l’arbre dominant F. albida ont été caractérisées dans les trois secteurs climatiques du Burkina Faso. Au total 43 espèces ont été recensées avec une flore ligneuse juvénile des parcs à F. albida typique à chaque secteur climatique. La plupart des 11 espèces juvéniles dominantes de ces parcs ont une dynamique régressive de leurs populations même si le secteur soudanien semble être propice à un bon recrutement de F. albida et de Piliostigma thonningii (Schumach.) Milne-Redh. Le drageonnage reste le mécanisme de régénération le plus adapté aux conditions écologiques de F. albida. Les résultats de cette étude contribuent à consolider les bases des activités de développement sur les parcs à F. albida afin de garantir leur gestion durable.
  • Thumbnail Image
    Item
    Mycetoma epidemiology, diagnosis management, andoutcome in three hospital centres in Senegal from 2008 to2018
    (Sow et al., 2020-04-24) Sow, Doudou; Ndiaye, Maodo; Sarr, Lamine
    Mycetoma is a neglected tropical disease caused by various actinomycetes or fungi. The disease is characterized by the formationof tumor like-swellings and grains. Senegal is an endemic country where mycetoma cases are under-or misdiagnosed due to thelack of capacities and knowledge among health workers and the community; and where the management of eumycetoma,burdened by a high amputation rate, is currently inadequate. This study aimed to update data on the epidemiology of mycetomacases diagnosed in three hospital centres in Senegal over a 10 years-period. A total of 193 patients, diagnosed from 2008 to 2018,were included in the study. The most frequent presentation was eumycetoma (47.2%); followed by actinomycetoma (36.8%); itremained undetermined in 16.1% of the patients. The mean age was 38.3 years (68.4% of the patients were between 15 and 45years-old); the male: female ratio was a 2.94; and most were farmers. One hundred fifty-six (80.8%) patients had usedphytotherapy before attending the hospital. Mycetoma was mainly located to the lower limbs (91.2%). Grains were observed in 85%of the patients; including white (25.6%) and yellow (4.3%) grains. The etiological diagnosis was complex, resulting in negative directmicroscopy, culture and/or histopathology findings, which explains that 16.1% remained uncharacterized. In most of cases,actinomycetoma were treated with a combination of cotrimoxazole, amoxicillin/clavulanic acid, and streptomycin; whereaseumycetoma cases were treated with terbinafine. The surgery was done in 100 (51.8%) of the patients including 9 inactinomycetoma, 78 in eumycetoma and 13 in undetermined form. The high number of uncharacterized mycetoma in this study, thedelay in attending a qualified health-care facility, and the lack of available adequate antifungal drug, point out the need tostrengthen mycetoma management capacities in Senegal.
  • Thumbnail Image
    Item
    Multihost Transmission of Schistosoma mansoni in Senegal, 2015–2018
    (PubMed Central, 2020-06) Catalano, Stefano; Léger, Elsa; Fall, Cheikh B.
    In West Africa, Schistosoma spp. are capable of infecting multiple definitive hosts, a lifecycle feature that may complicate schistosomiasis control. We characterized the evolutionary relationships among multiple Schistosoma mansoni isolates collected from snails (intermediate hosts), humans (definitive hosts), and rodents (definitive hosts) in Senegal. On a local scale, diagnosis of S. mansoni infection ranged 3.8%–44.8% in school-aged children, 1.7%–52.6% in Mastomys huberti mice, and 1.8%–7.1% in Biomphalaria pfeifferi snails. Our phylogenetic framework confirmed the presence of multiple S. mansoni lineages that could infect both humans and rodents; divergence times of these lineages varied (0.13–0.02 million years ago). We propose that extensive movement of persons across West Africa might have contributed to the establishment of these various multihost S. mansoni clades. High S. mansoni prevalence in rodents at transmission sites frequented by humans further highlights the implications that alternative hosts could have on future public health interventions.
  • Thumbnail Image
    Item
    DETERRENCE OF THEFT IN A SITUATION OF COMPETITION BETWEEN FORMAL AND INFORMAL INSTITUTIONS
    (L'Actualité économique, 2020-06) Yerbanga, Antoine
    The aim of this article is to highlight important factors neglected in modelling the effects of deterrent policies on thieves' activities in the real world. The methodology adopted consists of defining a world with three continuous spaces. Space in the centre has no institutions and no production. Only the other two spaces have institutions and are places for production. The study uses the Tullock contest fonction for n-players developed by Jia (2012) to identify thieves' efforts and the institutions' endowments at equilibrium. In contrast to the existing literature, our results indicate a perverse, indirect effect of institutions' deterrence strategies on thieves' activities and a negative effect of an increase in institutional deterrence on the total proportion of production stolen. This outcome therefore supports deterrence policies. Symmetric equilibrium becomes unstable when institutions have different production levels. However, we note that asymmetric equilibrium remains optimal, even in situations of differences in production across institutions. A confrontation between thieves from different areas can be a way for an institution to provide less deterrence in an asymmetric balance while guaranteeing a higher level of consumption than that under the opposing institution.
  • Thumbnail Image
    Item
    Multihost Transmission of Schistosoma mansoni in Senegal, 2015–2018
    (RESEARCH, 2020-06-06) Catalano, Stefano; Léger, Elsa; Fall, Cheikh B.
    In West Africa, Schistosoma spp. are capable of infecting multiple definitive hosts, a lifecycle feature that may complicate schistosomiasis control. We characterized the evolutionary relationships among multiple Schistosoma mansoni isolates collected from snails (intermediate hosts), humans (definitive hosts), and rodents (definitive hosts) in Senegal. On a local scale, diagnosis of S. mansoni infection ranged 3.8%–44.8% in school-aged children, 1.7%–52.6% in Mastomys huberti mice, and 1.8%– 7.1% in Biomphalaria pfeifferi snails. Our phylogenetic framework confirmed the presence of multiple S. mansoni lineages that could infect both humans and rodents; divergence times of these lineages varied (0.13–0.02 million years ago). We propose that extensive movement of persons across West Africa might have contributed to the establishment of these various multihost S. mansoni clades. High S. mansoni prevalence in rodents at transmission sites frequented by humans further highlights the implications that alternative hosts could have on future public health interventions.
  • Thumbnail Image
    Item
    Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2): What Can Africa Learn from Ongoing Research in Epidemiology, Clinical Manifestations, Chemotherapy and Prevention?
    (Asian Journal of Medicine and Health, 2020-06-25) Sevidzem, Silas Lendzele; Koumba, Aubin Armel; Zinga-Koumba, Christophe Roland
    The world is experiencing an outbreak due to the new and mysterious SARS-CoV-2. Information regarding its source and transmission dynamics in different environments as well as medications for its prevention and cure is weak. This review seeks to document on the epidemiology, clinical signs, control, prevention, and present some perspectives for SARS-CoV-2 research in Africa. There are geographical differences in morbidity and mortality rates of this disease all over the world. The scientific community strongly reject claims regarding the fact that the virus has been genetically manipulated, but supports the theory that it has a natural origin from animal host as any other emerging viral disease. Although animals are thought to be the original source of global spill over, person-to-person transmission is well comprehended. Transmission could be enhanced by symptomatic and asymptomatic individuals with high contaminations reported in dense urban environments. Scientific evidences from the Center for Disease Control (CDC) and other publications reported that contaminated surfaces and air could possibly be the underlying mechanism through which SARS-CoV-2 spreads. Cohort studies reveal that children as well as adults could be vulnerable to the disease, but others attribute it to health care workers, some risky habits (drinking and smoking) and comorbid individuals due to their immune suppressed status. There is no drug of choice for SARS-CoV-2, but clinical studies including several antiviral drugs are underway. Similarly, vaccine studies and clinical trial studies are ongoing. Because there is no medication, preventive measures such as Personal Protective Equipments (PPEs), ventilators, sanitation, social distancing, and quarantine are the gears globally used to curb the spread of this virus. The African continent does not have high morbidity and mortality compared to other continents that are highly affected. The following lessons could be learned by Africans from ongoing research: that the SARS-CoV-2 originated from an animal host, individuals could be infected irrespective of their age, sex, race, and origin, there is a broad spectrum of clinical signs and confirmatory diagnosis is required, there is no approved drug of choice, vaccine trials are ongoing and community-based prevention is required, the recommendations put in place by the Government and the WHO to curb the spread of this virus should be strictly followed. From the above lessons, a research project to study the ecological epidemiology of SARS-CoV-2 in tropical African settings by including the following aspects: socio-cultural, economic, and political characteristics as well as the evaluation of measures taken by the different countries to combat the disease is required.
  • Thumbnail Image
    Item
    Prevalence and distribution of schistosomiasis in human, livestock, and snail populations in northern Senegal: a One Health epidemiological study of a multi-host system
    (Elsevier, 2020-08) Léger, Elsa; Borlase, Anna; Fall, Cheikh B
    Background Schistosomiasis is a neglected tropical disease of global medical and veterinary importance. As efforts to eliminate schistosomiasis as a public health problem and interrupt transmission gather momentum, the potential zoonotic risk posed by livestock Schistosoma species via viable hybridisation in sub-Saharan Africa have been largely overlooked. We aimed to investigate the prevalence, distribution, and multi-host, multiparasite transmission cycle of Haematobium group schistosomiasis in Senegal, West Africa. Methods In this epidemiological study, we carried out systematic surveys in definitive hosts (humans, cattle, sheep, and goats) and snail intermediate hosts, in 2016–18, in two areas of Northern Senegal: Richard Toll and Lac de Guiers, where transmission is perennial; and Barkedji and Linguère, where transmission is seasonal. The occurrence and distribution of Schistosoma species and hybrids were assessed by molecular analyses of parasitological specimens obtained from the different hosts. Children in the study villages aged 5–17 years and enrolled in school were selected from school registers. Adults (aged 18–78 years) were self-selecting volunteers. Livestock from the study villages in both areas were also randomly sampled, as were post-mortem samples from local abattoirs. Additionally, five malacological surveys of snail intermediate hosts were carried out at each site in open water sources used by the communities and their animals. Findings In May to August, 2016, we surveyed 375 children and 20 adults from Richard Toll and Lac de Guiers, and 201 children and 107 adults from Barkedji and Linguère; in October, 2017, to January, 2018, we surveyed 386 children and 88 adults from Richard Toll and Lac de Guiers, and 323 children and 85 adults from Barkedji and Linguère. In Richard Toll and Lac de Guiers the prevalence of urogenital schistosomiasis in children was estimated to be 87% (95% CI 80–95) in 2016 and 88% (82–95) in 2017–18. An estimated 63% (in 2016) and 72% (in 2017–18) of infected children were shedding Schistosoma haematobium–Schistosoma bovis hybrids. In adults in Richard Toll and Lac de Guiers, the prevalence of urogenital schistosomiasis was estimated to be 79% (52–97) in 2016 and 41% (30–54) in 2017–18, with 88% of infected samples containing S haematobium–S bovis hybrids. In Barkedji and Linguère the prevalence of urogenital schistosomiasis in children was estimated to be 30% (23–38) in 2016 and 42% (35–49) in 2017–18, with the proportion of infected children found to be shedding S haematobium–S bovis hybrid miracidia much lower than in Richard Toll and Lac de Guiers (11% in 2016 and 9% in 2017–18). In adults in Barkedji and Linguère, the prevalence of urogenital schistosomiasis was estimated to be 26% (17–36) in 2016 and 47% (34–60) in 2017–18, with 10% of infected samples containing S haematobium–S bovis hybrids. The prevalence of S bovis in the sympatric cattle population of Richard Toll and the Lac de Guiers was 92% (80–99), with S bovis also found in sheep (estimated prevalence 14% [5–31]) and goats (15% [5–33]). In Barkedji and Linguère the main schistosome species in livestock was Schistosoma curassoni, with an estimated prevalence of 73% (48–93) in sheep, 84% (61–98) in goats and 8% (2–24) in cattle. S haematobium–S bovis hybrids were not found in livestock. In Richard Toll and Lac de Guiers 35% of infected Bulinus spp snail intermediate hosts were found to be shedding S haematobium–S bovis hybrids (68% shedding S haematobium; 17% shedding S bovis); however, no snails were found to be shedding S haematobium hybrids in Barkedji and Linguère (29% shedding S haematobium; 71% shedding S curassoni). Interpretation Our findings suggest that hybrids originate in humans via zoonotic spillover from livestock populations, where schistosomiasis is co-endemic. Introgressive hybridisation, evolving host ranges, and wider ecosystem contexts could affect the transmission dynamics of schistosomiasis and other pathogens, demonstrating the need to consider control measures within a One Health framework. Funding Zoonoses and Emerging Livestock Systems programme (UK Biotechnology and Biological Sciences Research Council, UK Department for International Development, UK Economic and Social Research Council, UK Medical Research Council, UK Natural Environment Research Council, and UK Defence Science and Technology Laboratory).
  • Thumbnail Image
    Item
    Prevalence and distribution of schistosomiasis in human, livestock, and snail populations in northern Senegal: a One Health epidemiological study of a multi-host system
    (ELSEVIER, 2020-08-08) Léger, Elsa; Borlase, Anna; Fall, Cheikh B
    Background Schistosomiasis is a neglected tropical disease of global medical and veterinary importance. As efforts to eliminate schistosomiasis as a public health problem and interrupt transmission gather momentum, the potential zoonotic risk posed by livestock Schistosoma species via viable hybridisation in sub-Saharan Africa have been largely overlooked. We aimed to investigate the prevalence, distribution, and multi-host, multiparasite transmission cycle of Haematobium group schistosomiasis in Senegal, West Africa. Methods In this epidemiological study, we carried out systematic surveys in definitive hosts (humans, cattle, sheep, and goats) and snail intermediate hosts, in 2016–18, in two areas of Northern Senegal: Richard Toll and Lac de Guiers, where transmission is perennial; and Barkedji and Linguère, where transmission is seasonal. The occurrence and distribution of Schistosoma species and hybrids were assessed by molecular analyses of parasitological specimens obtained from the different hosts. Children in the study villages aged 5–17 years and enrolled in school were selected from school registers. Adults (aged 18–78 years) were self-selecting volunteers. Livestock from the study villages in both areas were also randomly sampled, as were post-mortem samples from local abattoirs. Additionally, five malacological surveys of snail intermediate hosts were carried out at each site in open water sources used by the communities and their animals. Findings In May to August, 2016, we surveyed 375 children and 20 adults from Richard Toll and Lac de Guiers, and 201 children and 107 adults from Barkedji and Linguère; in October, 2017, to January, 2018, we surveyed 386 children and 88 adults from Richard Toll and Lac de Guiers, and 323 children and 85 adults from Barkedji and Linguère. In Richard Toll and Lac de Guiers the prevalence of urogenital schistosomiasis in children was estimated to be 87% (95% CI 80–95) in 2016 and 88% (82–95) in 2017–18. An estimated 63% (in 2016) and 72% (in 2017–18) of infected children were shedding Schistosoma haematobium–Schistosoma bovis hybrids. In adults in Richard Toll and Lac de Guiers, the prevalence of urogenital schistosomiasis was estimated to be 79% (52–97) in 2016 and 41% (30–54) in 2017–18, with 88% of infected samples containing S haematobium–S bovis hybrids. In Barkedji and Linguère the prevalence of urogenital schistosomiasis in children was estimated to be 30% (23–38) in 2016 and 42% (35–49) in 2017–18, with the proportion of infected children found to be shedding S haematobium–S bovis hybrid miracidia much lower than in Richard Toll and Lac de Guiers (11% in 2016 and 9% in 2017–18). In adults in Barkedji and Linguère, the prevalence of urogenital schistosomiasis was estimated to be 26% (17–36) in 2016 and 47% (34–60) in 2017–18, with 10% of infected samples containing S haematobium–S bovis hybrids. The prevalence of S bovis in the sympatric cattle population of Richard Toll and the Lac de Guiers was 92% (80–99), with S bovis also found in sheep (estimated prevalence 14% [5–31]) and goats (15% [5–33]). In Barkedji and Linguère the main schistosome species in livestock was Schistosoma curassoni, with an estimated prevalence of 73% (48–93) in sheep, 84% (61–98) in goats and 8% (2–24) in cattle. S haematobium–S bovis hybrids were not found in livestock. In Richard Toll and Lac de Guiers 35% of infected Bulinus spp snail intermediate hosts were found to be shedding S haematobium–S bovis hybrids (68% shedding S haematobium; 17% shedding S bovis); however, no snails were found to be shedding S haematobium hybrids in Barkedji and Linguère (29% shedding S haematobium; 71% shedding S curassoni). Interpretation Our findings suggest that hybrids originate in humans via zoonotic spillover from livestock populations, where schistosomiasis is co-endemic. Introgressive hybridisation, evolving host ranges, and wider ecosystem contexts could affect the transmission dynamics of schistosomiasis and other pathogens, demonstrating the need to consider control measures within a One Health framework. Funding Zoonoses and Emerging Livestock Systems programme (UK Biotechnology and Biological Sciences Research Council, UK Department for International Development, UK Economic and Social Research Council, UK Medical Research Council, UK Natural Environment Research Council, and UK Defence Science and Technology Laboratory).
  • Thumbnail Image
    Item
    Cost of pediatric hospitalizations in Burkina Faso: A cross-sectional study of children aged <5 years enrolled through an acute gastroenteritis surveillance program
    (Elsevier, 2020-09) Aliabadi, Negar; Bonkoungou, Isidore Juste O.; Pindyck, Talia
    Introduction Diarrheal illness is a leading cause of hospitalizations among children <5 years. We estimated the costs of inpatient care for rotavirus and all-cause acute gastroenteritis (AGE) in two Burkina Faso hospitals. Methods We conducted a cross-sectional study among children <5 years from December 2017 to June 2018 in one urban and one rural pediatric hospital. Costs were ascertained through caregiver interview and chart abstraction. Direct medical, non-medical, and indirect costs per child incurred are reported. Costs were stratified by rotavirus results. Results 211 children <5 years were included. AGE hospitalizations cost 161USD (IQR 117–239); 180USD (IQR 121–242) at the urban and 154USD (IQR 116–235) at the rural site. Direct medical costs were higher in the urban compared to the rural site (140USD (IQR 102–182) vs. 90USD (IQR 71–108), respectively). Direct non-medical costs were higher at the rural versus urban site (15USD (IQR 10, 15) vs. 11USD (IQR 5–20), respectively). Indirect costs were higher at the rural versus urban site (35USD (IQR 8–91) vs. 0USD (IQR 0–26), respectively). Rotavirus hospitalizations incurred less direct medical costs as compared to non-rotavirus hospitalizations at the rural site (79USD (IQR 64–103) vs. 95USD (IQR 80–118)). No other differences by rotavirus testing status were observed. The total median cost of a hospitalization incurred by households was 24USD (IQR 12–49) compared to 75USD for government (IQR 59–97). Direct medical costs for households were higher in the urban site (median 49USD (IQR 31–81) versus rural (median 14USD (IQR 8–25)). Households in the lowest wealth quintiles at the urban site expended 149% of their monthly income on the child’s hospitalization, compared to 96% at the rural site. Conclusions AGE hospitalization costs differed between the urban and rural hospitals and were most burdensome to the lowest income households. Rotavirus positivity was not associated with greater household costs.
  • Thumbnail Image
    Item
    Norovirus and rotavirus in children hospitalised with diarrhoea after rotavirus vaccine introduction in Burkina Faso
    (Cambridge University Press, 2020-10-01) Rönnelid, Y; Bonkoungou, I. J. O.; Ouedraogo, N.
  • Thumbnail Image
    Item
    Toxicity studies on the leaves of senna alata, a medicinal plant from Burkina Fas, in mice and rats
    (2020-11) Léonard, Da Filkpièrè; Youssoufou, Ouedraogo; Abel, Somé Andouormwine
    The aim of the work is to study the acute and subacute toxicity of the aqueous extract of the leaves of Senna alata (ED-SA). Extracts doses of 500, 1000 and 2000 mg/kg of body weight (bw) were administered to the mice for acute toxicity study. The administration volume was 1 ml/100g. A limit test has been carried out to determine the DL50. For subacute toxicity, rats received Senna alata extracts orally for 28 days. The first group to constitute the control received distilled water (solvent for diluting the extracts). Groups 2, 3 and 4 received extracts of S. alata at the respective doses of 500, 1000 and 2000 mg/kg of body weight; satellite groups 5 and 6 received, respectively, distilled water (satellite control) and extract at the maximum dose of 2000 mg/kg (satellite). The satellite groups were observed 14 days after stopping treatment to assess reversibility to toxicity. The collected serum was used for biochemical assays (ALAT, ASAT, creatinine, total cholesterol, and triglycerides). Plasma has been used to assess the effects of the extract on hematological parameters such as blood cells, red blood cells, hematocrit, hemoglobin. The acute toxicity assessment of the aqueous extract of Senna alata has shown that the lethal dose 50 (DL50) is greater than 2000 mg/kg, suggesting that the extract would be practically non-toxic at this dose. In subacute toxicity, no major lesion was observed after histological analysis of the liver and kidneys. These results suggest that the aqueous extract of Senna alata does not affect liver and kidney. In conclusion, this study shows that ED-SA is of low toxicity.
  • Thumbnail Image
    Item
    Multiple Antibiotic Resistance-Coliform Bacteria inSomeSelected Fish Farms of the Central Region of Ghana
    (Hindawi, 2020-12-08) Adinortey, Cynthia Ayefoumi; Aheto, Denis Worlanyo; Boateng, Alex Asomeni
    &is study aimed at assessing the quality of water and fishery products as well as the antibiotic resistance status of some selected fish farms of the Central Region of Ghana. Interview guides were administered to farmers to get data on farming practices and antibiotic use. Total coliform loads of catfish (Clarias gariepinus), tilapia (Oreochromis niloticus), and water samples were determined. Coliforms were identified through various biochemical assays, and their antibiotic resistance patterns were determined. Generally, the total coliform loads of water samples significantly surpassed those of fish samples (p < 0.05). &e maximum and minimum antibiotic resistance percentages were recorded for ampicillin (96.83%) and gentamicin (6.35%), respectively. Although farmers stated that antibiotics were sparingly used, coliform bacteria isolated exhibited various antibiotic resistance patterns. Four out of six fish farms harboured some coliforms with multiple antibiotic resistance (MAR) indices above 0.2, an indication that these bacteria originated from potentially dangerous sources where antibiotics are regularly used.
  • Thumbnail Image
    Item
    Detection, identification and characterization of extended-spectrum beta-lactamases producing Enterobacteriaceae in wastewater and salads marketed in Ouagadougou, Burkina Faso
    (African Journal Online, 2020-12-08) Soré, Souleymane; Sawadogo, Yacouba; Bonkoungou, Juste Isidore
    Extended spectrum beta-lactamase producing Enterobacteriaceae (ESBL-PE) represent a threat for failure of empirical antibiotic therapy and are associated with high mortality, morbidity and expenses. The aims of this study was to determine the prevalence of ESBL-PE and multidrug resistant enterobacteria (MDR), enterobacteria profil, investigate the associated resistance in wastewater and salads. After wastewater and salad sampling, enterobacteria was isoled on (EMB + 4μg / L cefotaxim). The stains of Enterobacteriaceae were identified by using biochemical methods and confirmed as ESBL by double-disc synergy test (amoxicillin/clavulanic acid with cefotaxime 30 μg, ceftazidime 30 μg and ceftriaxone 30 μg). Finally, the associated resistance was investigated by testing the susceptibility of the strains by the disc diffusion method. Global prevalence of ESBL-PE was 53.92% (95% CI: 48,2-59,5) (153/293), 61.11% from wastewater and 42.47% from salads. Major ESBL-E was Escherichia coli (73.44%), followed by Klebsiella pneumoniae (21.88%). Resistance to the aminoglycoside , fluroquinolonones and sulfonamides classes were dominant, observed in 53,83%, 93,86% and 98,95% of the isolates, respectively. The frequence of MDR was hight to channel1 (32,40%) and channel2 (26,26%). This study reports very worrying results. There is an urgent need to develop measures to monitor the spread of these multidrug-resistant strains.
  • Thumbnail Image
    Item
    MYCORRHIZAL STATUS OF CULTIVATED AND WILD PEARL MILLET (PENNISETUMGLAUCUM (L.) R. BR) IN THREE AGRO-ECOLOGICAL ZONES OF SENEGAL
    (International Journal of Development Research, 2020-12-10) Mofini, Marie-Thérèse; Diedhiou, Abdala G.; Niaye, Cheikh
    Pearl millet (Pennisetumglaucum (L.) R. Br) is a cereal grown in the driest tropical and subtropical regions of Africa and Asia. Thanks to its strong capacity to adapt to the dry tropical climate and low fertility soils, millet plays an important role in the food security of local populations in these regions. It is able to establish a mycorrhizal symbiosis with arbuscular mycorrhizal fungi (AMF), which play a key role in the absorption of nutrients and the mitigation of abiotic and biotic stress in their host. We first evaluated the mycorrhizal status of cultivated and wild millet in three agro-ecological zones of Senegal by following a rainfall gradient and then the effect of inoculation with AMF on the growth of cultivated millet. We found that wild and cultivated millet establishedarbuscular mycorrhizal symbiosis but a low rate of mycorrhizationwas observed. The frequency of mycorhization was significantly higher in cultivated than in wild plants. We then evaluated the impact of AMF inoculation on plant growth and found very limited impact. These results suggest that millet is not very dependent on mycorrhizae although AMF may stimulate its growth.
  • Thumbnail Image
    Item
    Modelling and forecasting reservoir sedimentation of irrigation dams in the Guinea Savannah Ecological Zone of Ghana
    (IWA Publishing, 2021) Adongo, Thomas Apusiga; Abagale, Felix K.; Agyare, Wilson A.
    Effective management of reservoir sedimentation requires models that can predict sedimentation of the reservoirs. In this study, linear regression, non-linear exponential regression and artificial neural network models have been developed for the forecasting of annual storage capacity loss of reservoirs in the Guinea Savannah Ecological Zone (GSEZ) of Ghana. Annual rainfall, inflows, trap efficiency and reservoir age were input parameters for the models whilst the output parameter was the annual sediment volume in the reservoirs. Twenty (20) years of reservoirs data with 70% data used for model training and 30% used for validation. The ANN model, the feed-forward, back-propagation algorithm Multi-Layer Perceptron model structure which best captured the pattern in the annual sediment volumes retained in the reservoirs ranged from 4-6-1 at Karni to 4-12-1 at Tono. The linear and nonlinear exponential regression models revealed that annual sediment volume retention increased with all four (4) input parameters whilst the rate of sedimentation in the reservoirs is a decreasing function of time. All the three (3) models developed were noted to be efficient and suitable for forecasting annual sedimentation of the studied reservoirs with accuracies above 76%. Forecasted sedimentation up to year 2038 (2019–2038) using the developed models revealed the total storage capacities of the reservoirs to be lost ranged from 13.83 to 50.07%, with 50% of the small and medium reservoirs filled with sediment deposits if no sedimentation control measures are taken to curb the phenomenon.
  • Thumbnail Image
    Item
    L’alimentation des Peuls du Sénégal Comparaison entre contextes rural et urbain autour d’éléments emblématiques
    (Open Edition Journals, 2021) Macia, Enguerran; Tibère, Laurence; Ka, Abdou
    Cet article porte sur l’alimentation des populations peules du Sénégal, plus précisément sur deux groupes de femmes : l’un vivant dans la zone sylvo-pastorale du Ferlo (Nord Est du Sénégal) et l’autre issu du Ferlo et installé dans la capitale du pays, Dakar, depuis au moins dix ans. L’analyse porte sur les différences mais aussi les éléments communs dans l’alimentation de ces populations et sur la pluralité des influences mais aussi, des processus de changements. L’attention a été portée sur les formes de sociabilité et les contenus des repas, et notamment sur la présence d’éléments considérés comme des marqueurs emblématiques de la culture peule par les participants eux-mêmes. L’objectif était de repérer d’éventuelles transformations et continuités dans les pratiques culinaires et alimentaires mais aussi les perceptions qu’ont les femmes en particulier sur le statut de certains marqueurs culturels, dans ce contexte.
  • Thumbnail Image
    Item
    Péril terroriste et reconfiguration des relations forces de défense et de sécurité (FDS) et groupes de vigilantism au Burkina Faso
    (L'Harmattan, 2021) Soré, Zakaria; Côte, Muriel
    Face à une certaine perception de la défaillance de l’État dans le domaine de la sécurité, des initiatives communautaires ont favorisé la résurgence de pratiques locales de défense et de sécurisation des territoires. Les groupes de vigilantisme émergent dans ce contexte avec des modes opératoires souvent décriés. La particularité de leurs actions, ne respectant pas souvent les droits humains, avait limité leurs rapports officiels avec les forces de défense et de sécurité (FDS). La réticence des responsables de ces groupes à accepter certaines dispositions des textes réglementaires de l’État a amené les FDS à restreindre la collaboration avec eux. Cependant, la montée des attaques qualifiées officiellement de « terroristes » pose une nouvelle menace sur la sécurité humaine, et va contribuer à reconfigurer leur relation. La recherche présentée ici vise à saisir cette dynamique socio-sécuritaire à travers l’émergence des Volontaires pour la Défense de la Patrie (VDP) à partir de 2020 au Burkina Faso, qui semblait a priori résoudre la question des opérations de sécurisation des groupes d’auto-défense, et qui, a plutôt conduit au rapprochement entre ces groupes et les FDS. Une approche anthropologique a été utilisée dans ce travail afin de saisir les représentations et pratiques des acteurs autour de leur collaboration. Des entretiens semi-directs ont notamment été réalisés à cet effet auprès des acteurs de la sécurité (police, gendarmerie et armée) et les dozos, les volontaires pour la défense de la patrie et les koglweogo. L’article conclue que, loin de résoudre la question du monopole légitime de l’État sur la violence, les mesures de collaboration entre citoyens et FDS dans un contexte de « menace terroriste » la posent plus que jamais