Characterization of Monsoonal Rainfall in the Sudano-Sahelian Zone of Northwestern Nigeria

Wavelet transform has been underutilized in characterization of rainfall (Real Onset Dates and Real Cessation Dates) in the study area. This study aims at the characterization of monsoonal rainfall. Daily rainfall data of four stations for the period 1981-2018 were collected from Nigerian Meteorological Agency. The Intra-seasonal Rainfall Monitoring Index (IRMI) was generated and used in determining the RODs and RCDs. The Mann–Kendall test was used to detect trends of the rainfall characteristics. Wavelet transform was used in modelling RODs and RCDs. Findings revealed that RODs vary between stations. There is low (0.3 Spearman’s Rank r) correlation between latitudes and Early Cessations (ECs) of rains. The Morlet wavelet analysis revealed that from 1999 to 2018, there were more of EOs and NOs especially in Kano station. We conclude that from 1981 to 2018 there has been a minimal increase in the retreat dates of rainfall in the study area.

Habitat Cooling by a Canadian Well in Ouagadougou (Burkina Faso): Numerical Approach

In the Sahelian zone, air cooling in house by air-soil heat exchanger is an alternative in the context of insufficient of electrical energy. This work is about cooling of a habitat in Ouagadougou by numerical approach. Numerical results provided a better understanding of the influence of parameters such as tube length, air velocity and soil temperature on the thermal efficiency of this system. We analyze the effects of parameters such as renewal air flow rate, soil temperature and number of tubes. The results show that during the hot periods of the day, the Canadian well cool air in habitat.

Heatwaves and Health Risks in the Northern Part of Senegal: Analysing the Distribution of Temperature Related Diseases and Associated Risk Factors

Backgrond: The Sahelian zone of Senegal is marked by heatwave events due to temperatures increase especially in 2013 exceeding 45 ° C with an impact on morbidity and mortality rise. In order to document health impacts of recurrent extreme temperatures in this part of the country, a study was carried out combining heatwaves detection, occurrence of climate-sensitive diseases and risk factors for exposure. Methods To do this, a set of climatic (temperatures) and health (morbidity, mortality) data were collected for April, May and June season from 2009 to 2019. These data were complemented by surveys on exposure risk factors of 1246 households. Statistical methods were used to carry out univariate and bivariate analyzes while cartographic techniques allowed visualization of the main climatic and health indicators. Results The results show an increase in temperatures compared to seasonal normal for the 1971-2000 reference period with threshold exceedances of the 90th percentiles (42°C) for the maxima and (27°C) the minima and higher temperatures during the months of May and June. From health perspective, it was noted an increase in cases of consultation on health facilities as well as a rise in declared morbidity by households especially in the departments of Kanel (17.7%), Ranérou (16.1%), Matam (13.7%) and Bakel (13.7%). The heatwaves of May 2013 were also associated with cases of death with a reported mortality (observed by medical staff) of 12.4% unevenly distributed according to the departments with a higher number of deaths in Matam (25, 2%) and in Bakel (23.5%) than in Podor (8.4%) and Kanel (0.8%). The morbidity and mortality distribution according to gender shows that women (57%) were more affected than men (43%). These health risks have been associated with a number of factors including age, access to drinkable water, type of fuel, type of housing and construction materials, existence of fan, an air conditioner, health antecedents, etc. Conclusion The heatwaves recurrence has led to an upsurge in certain diseases sensitive to rising temperatures, which is increasingly a public health issue in the Sahelian zone of Senegal.

Prevalence and Diversity of Hepatitis Virus Markers among Patients with Acute Febrile Jaundice in Chad

Only a minority of the patients with acute febrile jaundice evaluated through the Yellow Fever surveillance program were found positive for antibodies against Yellow Fever Virus (YFV). In order to characterize patients with acute febrile jaundice negative for YFV, we collected 255 sera between January to December 2019. We screened for HBV antigens, and antibodies against HCV and HEV. The seroprevalences observed were 10.6% (27/255) for HBV, 2% (5/255) for HCV, 17.3% (44/255) for HEV IgG, 4.3% (11/255) for HEV IgM, and 12.5% (32/255) for both IgG and IgM HEV. Prevalence of HEV was significantly higher in females than males (p < 0.01). HEV IgG prevalence was highest in those 20–29 years old, but the highest incidence rate (IgM positive) was in children 0–9 years old. Exposure to HEV was higher in the Sahelian zone (55.8%, 95% CI: 40.97–70.66) than in the Sudanese zone (30.2%, 95% CI: 24.01–36.37, p = 0.003). The high prevalence rates and hepatitis virus diversity underline the challenge of routine clinical diagnosis in Chad’s Yellow Fever surveillance program.

Analysis of Dairy Farming Systems in the Sahelian Zone of Burkina Faso

The insufficiency and variability of pasture production is a determining factor in milk production, particularly in the Sahelian zone. The objective of this study was to characterize dairy production systems and their relationship with crops to meet livestock needs. It consisted of surveys of 120 farmers in four communes in the Séno province. The results show three groups of dairy farmers that are essentially differentiated by the main activity and the sex of the farmers as well as the size of the cattle herd on the farm. The first group is made of male agropastoralists, with herds averaging 12 cattle. Group 2 consists of male agropastoralists with an average of 22 cattle. Group 3 consists of female pastoralists (96.15%), with a herd size of about 19 head. The cows are fed on pasture and supplemented with crop residues with cotton cake, which is more important in group 2, where more farmers have hayloft for fodder conservation and manure pits compared to the other two groups. Crop residues are used primarily as feed in all groups from January to May. This supplementation allows the maintenance of milk production in the dry season and group 2, with more dairy cows, records more milk milked (6.5 and 3.8 l) and consumed in wet and dry seasons compared to the other two groups. The results suggest that the farmers in the area have low technical level and need capacity building in agropastoral fields to improve their production.

Numerical and Experimental Study of the Thermal Efficiency of an Air-Soil Heat Exchanger in the Sahelian Zone

In the Sahelian zone, air conditioning in house by air-soil heat exchangers is an alternative in the context of insufficient of electrical energy. In this work, we carried out a numerical and experimental study of thermal efficiency of an air-soil heat exchanger. This study provided an estimation of thermal efficiency of an experimental air-soil heat exchanger during June, July and August 2016. Numerical results provided a better understanding of the influence of parameters such as tube length, air velocity and soil temperature on the thermal efficiency of this system.

INFLUENCE OF ASH ON THE MORTALITY OF ADULTS OF BRUCHIDIUS ATROLINEATUS PIC. (COLEOPTERA-BRUCHINAE), IMPORTANT PEST OF COWPEA (VIGNA UNGUICULATA WALP.) IN SAHELIAN ZONE

Bruchidius atrolineatus (pic) (Ba) is one of the most dangerous pests seeds of cowpea (Vigna unguiculata L. Walp). The infestation begins in the fields of crops and continues in stocks where damage can be considerable in the absence of any protective measure. The importance of these damage justifies the development of appropriate, less expensive and easily applicable peasant struggles. A recommended ash test for the traditional cowpea storage was evaluated on the mortality of Bruchidius atrolineatus (PIC) in the laboratory. During this study, several experiments relating to the influence of Ash on adults of B. atrolineatus were carried out. A negative witness has been made for each case. The treatments have been made according to gender and adults. Ash is a substance that seems to be very effective with respect to B. atrolineatus because has significantly reduced its population. Treatment due to the effect of ash has recorded a mortality rate of 85% on the first day. Then treatments with variations due to the increase in the amount of ash, insects and seeds have induced a respective mortality rate of 31.5%, 43.5%, 93.75% and 100% 62.5%, 33.16%, 30%, 24% and 17.04% and 62.5%, 43.75%, 52.5% and 50% on the 1st after treatment. It is apparent from our study that the female seems to be more resistant than males in almost all treatments. This study showed that the ash could constitute an alternative to the use of chemical insecticides in the conservation of cowpea seeds in the Sahelian zone.