One of the most common types of risk faced by SMEs of the hotel sector in Cameroon is the operational risk as there exist uncertainty related to personnel, clients, processes and systems that motivated this study. Today, organizations are investing a lot on business activities which requires risk management practices to mitigate the negative outcomes of operational risks. In line with this, the study focuses on the effect of operational risk management on the profitability of Small and Medium Size Enterprises (SMEs) of the hotel sector in Cameroon. The data used was collected through questionnaires and limited to SMEs of the target sector, imputed through SPSS and analyzed by multiple correlations with ANOVA tables. The findings reveals that there exist strong positive relationship between operational risk management and profitability. Hence, By managing enterprise-wide risk, the management will develop a unified picture of risk for decision-making and improve the organization’s ability to manage risk effectively which can enhance its profitability. This present research will give new insight to the researchers and will help them to consider the proposed model to implement and generalize in different settings.
Soil erosion by precipitation, rainfall and runoff is a widespread phenomenon in different countries of the world. It becomes disastrous in particular on the slopes because of the torrentiality of the flow, of the strong vulnerability of the grounds (soft rocks, fragile grounds, steep slopes). The present study has for objective: The analysis of the data of concentrations of sediments in suspension are measured at the station of the rivers highlights relations, linking the concentration (or the solid flow) of the sediments in suspension to the liquid flow and to quantify the seasonal, monthly and interannual and intra annual variation of the surface degradation. Annual tonnage estimates of solids loads to the Mé were derived from the power law for all seasons. From this deduction, the annual quantities of sediment transported by the Mé from 2015/2017 is 7.06.106 t/year, or a specific degradation of 1.79.103 t/km2/year. On the other hand, in 2017, the value of this solid input is 3.06.106 t/year. However, the annual solid input is estimated at 7063.03.103 t/year with a specific degradation of 1784.47 t/km2/year at the Mé from 2015 to 2017.
The comparative study of cocoa-based agroforests, fallow lands, and forests in the Akoupé department reveals promising results in combating climate change. Cocoa-based agroforests (SAFs) stand out with a higher average nitrogen content (0.22) compared to fallow lands (0.14) and forests (0.08), promoting carbon sequestration and reducing greenhouse gas emissions. Correlation analysis shows a moderate positive relationship between nitrogen and potassium, enhancing nutrient utilization and strengthening crop resilience against climate variations. While SAFs sometimes exceed sustainable agriculture thresholds for nitrogen, phosphorus, and potassium, and to a lesser extent, fallow lands for nitrogen, sustainable management practices (crop rotation, organic fertilization) can mitigate these exceedances. Overall, SAFs prove to be powerful allies against climate change. Their carbon sequestration capacity, resilience, and agricultural potential make them essential systems for sustainable agriculture. These findings can guide farmers and policymakers towards environmentally friendly practices and contribute to a greener and more sustainable future.
Since 2015, the stink locust (Zonocerus variegatus) population has been proliferating in the Mawanga sector, in the territory of Kasongo Lunda, an administrative entity in the province of Kwango in the Democratic Republic of Congo. This insect ravages food crops and fruit trees, devouring their leaves and bark and causing the host plant to wither. To assess the insecticidal action of four total extracts based on Nicotiana tabacum, Tephrosia vogelii, Zingiber officinale and Capsicum frutescens on the stink locust, a field trial involving a cassava crop was set up between November 2020 and December 2021 in the Emmaüs village in the Mawanga sector, Kasongo Lunda territory, in the Democratic Republic of Congo. Tobacco and ginger showed the lowest incidence and severity of locust damage. For the latter parameter, their performance was equal to that of deltamethrin. These two plant species showed potential for use in the manufacture of biopesticides to help farmers control the locust.
The elders ate and treated themselves with native plant species, some of which have not been domesticated and others are now experiencing the beginning of domestication. To avoid their extinction on the one hand and to enrich the range of cultivable plant species on the other, we have opted to conduct a preliminary trial of domestication of leafy vegetables and fruits. The retained parameters for the experiment were the emergence of the seedlings, the growth in both thickness and length, the plant movements, the effect of illumination on the species, the flowering and the developmental cycles as well as the setting in place of the tested species in agroforestry. From this study it appears that the seedling emergence differs between species, the growth in thickness correlates positively with the final species size, and the twining and tendril plants excel in terms of growth in length. The study of the illumination effect has made possible to categorize these species into heliophilous, sciaphilous and indifferent plants. As far as flowering is concerned, a distinction is made between annual and perennial plants in this batch. Finally, sciaphilous plants have integrated the agroforestry system by making them evolve under woody species with multiple uses.
In tropical environments, parasitosis is a public health problem. This study aims to describe the evolution of the prevalence of intestinal parasitosis diagnosed at the laboratory of the University Hospital of Abomey-Calavi/So-Ava in the Atlantic Department of southern Benin in West Africa from 2010 to 2020. Each stool sample was examined directly with physiological water and stained with Lugol’s stain. From 2010 to 2020, 2348 patients benefited from a parasitological examination of stools at the laboratory of the University Hospital of Abomey-Calavi/So-Ava. 181 samples were positive (8%). 53% of the patients with parasitic disease were female. Children aged 0 to 5 years represent 51% of the parasitized patients. 97.90% of the parasites identified during the parasitological examination of stools belong to the group of protozoa. Entamoeba histolytica is the most observed parasite species (64.64%), followed by Entamoeba coli (27.76%), Trichomonas intestinalis (3.30%), Giardia lamblia (2.20%), Ascaris lumbricoides (1.6%) and Trichuris trichiura (0.5%). An effective control of intestinal parasitosis in Benin will require the eradication of intestinal protozoosis.
The Yaouré gold district is located in the central-western part of Ivory Coast. The lithostratigraphy of this district is characterized from bottom to top as follows: (a) a series of metamorphic rocks, consisting of biotite gneiss and granodiorite gneiss; (b) a series of metasedimentary rocks, composed of medium to fine-grained sandstones and graphitic schists with elongated linear quartz-feldspar crystals and a north-south oriented schistosity.; (c) a series of volcanic rocks, consisting of pillow basalt flows associated with late-stage intrusive rocks (granodiorite, diorite, gabbro, tonalite, microgranodiorite, microdiorite, microgabbro), marking the end of magmatism; (d) a series of volcanoclastic rocks, composed of polygenic conglomerates. The petrographic study of the geological formations in the Yaouré gold district has allowed us to identify three main groups of rocks: (i) magmatic rocks (plutonic, subvolcanic, and volcanic); (ii) metamorphic rocks; (iii) volcano-sedimentary rocks (volcanoclastic and metasedimentary). Most of the lithologies in our study area are affected by greenschist metamorphism, characterized by minerals such as chlorite, sericite, epidote, as well as hydrothermal activity with carbonate fillings (calcite), quartz, potassium feldspar, sulfides, and varying amounts of gold.
In Côte d’Ivoire, the problem of forest sustainability has led to studies on their dynamics being undertaken in recent years. The Dahliafleur Nature Reserve, located in the commune of Bingerville is part of the Ivorian urban forests. Unfortunately, it is very little known in its floristic diversity, let alone its vegetation. The surface surveys supplemented by the mobile survey made it possible to identify 135 species throughout the forest. These species are divided into 110 genera and 53 families. The most represented families in these three zones are respectively for the North, South and East zones, the Fabaceae, the Apocynaceae and the Araceae. The analysis of the chorological spectrum of all the species identified highlights five types of chorological affinities. The species with the strongest I.V.I. are (in descending order) Tabernaemontana crassa, Ceiba pentandra, Senna siamea, Acacia mangium, and Nesogordonia papaverifera. A comparison of the different plots in two by two reveals a rather weak similarity.
The objective of this work is to examine the way in which newly hired assistants are welcomed, to know the level of appreciation that these assistants have of their welcome and integration and to determine what major psychological effects result from this.
To carry out this study, we used the survey method for data collection. It is supported by questionnaire, interview, observation, documentation techniques for data collection, statistics and content analysis for data processing and analysis.
The study population consists of 384 assistants appointed on April 13, 2018. We extracted an occasional sample of 102 subjects.
After analyzing and processing the data; it turned out that there is no reception and integration policy at the University of Kinshasa. The comments reported by the respondents describe a minimal reception and integration system instead of a real reception and integration policy, generally taking place at the level of faculties or departments. It is only through interaction with their colleagues that certain essential knowledge is transmitted to the newly hired assistant.
This study was carried out to evaluate the acute and subacute toxicity of aqueous extracts of Rhynchospora corymbosa (DRC) and Olax subscorpioidea (DOSA) in Wistar rats. For the study of acute toxicity, the rats divided into 3 batches of 6 subjects (3 males and 3 females) and the aqueous extracts DRC and DOSA were administered once, orally at 2000 mg/kg/bw respectively. for batches 2 and 3. The rats were monitored for 14 days. In the subacute toxicity study, DRC and DOSA aqueous extracts were administered orally to rats at doses 400, 800 and 1600 mg/kg/bw daily for 28 days. Their body weight was monitored during the experimental period, while the hematological and biochemical parameters of the blood and the histo-pathological study of the kidney and liver were evaluated at the end of the experiment. Oral administration of DRC and DOSA aqueous extracts at doses of 2000 mg/kg bw did not result in the death of rats in all treated batches. The subacute toxicity study in rats did not show any toxicity of Rhynchospora corymbosa and Olax subscorpioidea extracts at the doses administered. It appears from all of these results that the aqueous extracts of DRC and DOSA at doses 400; 800 and 1600 mg/kg/bw administered orally to rats is well tolerated and its activity does not cause any harm to the organs, biochemical and hematological parameters as well as to the mass of the animals compared to those of normal rats. The study of the toxicity of DRC and DOSA aqueous extracts did not show signs of acute or subacute toxicity at the doses studied.
In reference to the psychoanalytical theory on the drives, the birth of a child in poor health leads to drive dissatisfaction preventing the support of the ego in the father which could inflict symbolic wounds on the latter. Research on intellectual disability has focused more on analyzing the experiences of mothers of children with intellectual disabilities and the experiences of siblings. However, the experiences of fathers of children with intellectual disabilities and their symbolic wounds are not documented. However, fathers and mothers of children with disabilities experience it differently. The study aims to fill this gap by linking this handicap to the symbolic wounds of fathers. A semi-structured clinical interview was carried out in the city of Douala with the father (aged 37) of an 11-year-old male child. The results of the thematic content analysis highlight a painful transmission, a depreciation of the ego, a narcissistic attack, a feeling of humiliation and a feeling of injustice in the latter. It can be concluded that these observed symbolic injuries are related to intellectual disability.
The aim of this study was to determine the diversity and structure of aquatic macroinvertebrates in the middle course of the Comoé River. Sampling of macroinvertebrates was carried out at four stations in this course. A total of 3921 individuals of aquatic macroinvertebrates were identified in this part of the river. These macroinvertebrates are divided into 137 taxa, 72 families, 17 orders and 6 classes. Insects with 64% numerically dominate this population of aquatic invertebrates. They are followed by gastropods (21%). Ephemeroptera (27%), Mesogastropoda (21%) and Coleoptera (13%) are the most abundant orders. The most diverse orders are Coleoptera (27 taxa) followed by Ephemeroptera (19 taxa). The Dytiscidae (8 taxa) constitute the most diversified family in this part of the river. According to the number of individuals per species, Melanoides tuberculata (8%) dominates in the middle course. In the middle course, the Shannon-Weaver index varies from 2.85 to 3.56 and the fairness from 0.83 to 0.95. The abundance coupled with the various indices of diversity studied reveal that the waters of the stations of the middle course are well populated in aquatic macroinvertebrates and well diversified.
Parameters of the weight-length relationship and the condition factor are very important in the knowledge of several aspects of biology and in the management of fisheries. Unfortunately, there are few studies relating to the ichthyofauna of Lake Tanganyika in general and cichlids in particular. This study was conducted with the aim of contributing to enrich the existing database and the rational management of the lake. Total lengths and weights were obtained based on T. unimaculatum and O. niloticus fish samples collected over 8 months (January to August 2021). The correlations between the length and the weight of the specimens are very strong with coefficients of determination ranging from 0.95 to 0.99. In both stations, positive allometry was recorded in T. unimaculatum (b>3) while isometric growth was recorded in O. niloticus. Mean K is greater than 1 in O. niloticus while mean K <1 in T. unimaculatum. In the latter species, the average K varies significantly depending on the sites (p<0.5) whereas the variation in the average K is not significant in the two sites in O. niloiticus (p>0.). This shows that the two species of cichlid fish adapt differently to the two stations with different environmental characteristics: O. niloticus seems indifferent to the degree of pollution while T. unimaculatum displays an average K in a station known to be less polluted compared to the ‘other.
The objective of this study was to evaluate, in a semi-controlled environment, the resistance of twelve (12) new rice genotypes (KBR2, KBR4, KBR6, KBR8, KBR9, KBR11, KBR12, KBR13, KBR15, KBR17, KBR28, KBR42) to rice blast caused by Magnaporthe oryzae in Burkina Faso. The experimental design used was a randomised block with three (03) replications. The parameters assessed were leaf and panicle severity, leaf and panicle incidence, yield per pot and percentage yield loss. The results showed that genotypes KBR11, KBR15 and KBR42 were resistant to medium resistance to blast, with values ranging from 7.7% to 15% of leaf area diseased and from 14% to 24.07% of panicles diseased. These genotypes recorded the best yields per pot of 60.32g/pot, 65.97g/pot and 60.43g/pot respectively, with relatively low yield losses. Genotypes KBR11, KBR15 and KBR42 were resistant to medium resistance to leaf and panicle blast with high yield performance and relatively low yield loss rates. These genotypes can be used to control rice blast in rice fields in Burkina Faso. They therefore need to be improved and made more widely available. This will require the support of agricultural research, extension services and farm advisory services.
Generally, the technological development has made a great advance in the teaching/learning act even in life. The inclusion of information and communication technology (ICT) in education, as an initiation of a technical process and educational innovation, can lead to changes in teaching/learning practices.
In order to carry out this current study, we adapted the scientific method most recommended in the literature; deductive method, which makes it possible to follow the ICT use by the Life and Earth Sciences (LES) subject teacher at qualification secondary schools. Thus, the used questionnaire was produced and validated by experts, and it was published in Google drive and Facebook groups (LES- teachers), and it was completed by seventy-five (75) LES teachers during the school year 2019-2020. This process comprised more than twenty questions and divided into five sections. It is obtained that the majority of LES teachers have a computer and a personal internet connection, where55% of them integrate ICT in their classes for the lessons form, 23% in the tutorials form, and 35 % in the training exercises. In addition, it is noticed that 54 %of LES teachers use a projector (data show) as a classic method of the ICT use in the learning construction, a portion of 37% use interactive videos, and 9% use the interactive whiteboard.
On the other hand, the teachers questioned believed that the main obstacles to their educational practices relate to the ICT infrastructure, and that 61% of them during the teaching training did not follow courses relating to specifically on the educational use of the computer, with an insufficient number of computers connected to the Internet (10%), the absence of educational software (73%). For educational content adapted to school programs, the results obtained (13%), as well as the absence of educational meetings between teachers, inspectors and stakeholders around the digital resources use (67%), and lack of professional training for the realization of the educational scenarios. According to these results, the Moroccan education system must be based on a timely and thoughtful approach through the development of organizational and technological infrastructure, and to provide a training plan, support for teachers for the production and the integration of digital resources in learning situations in order to improve our education system quality.
The present study aimed to improve the solar water disinfection by the photosensitization of coumarin extracts of some plants of the Rutaceae family (Citrus reticulata, Citrus aurantium and Citrus maxima). The results found in this work show an inhibition of around 7% of faecal coliforms after 15 minutes of exposure for solar disinfection. An inhibition of 17 % is noticed after 30 minutes of exposure. On the other hand, for water treated and exposed to the sun, an inhibition of around 90% is noticed for all the extracts after 30 minutes of exposure. Complete inhibition is recorded after 60 minutes of exposure. These results show that the plant extracts used improve significantly the solar disinfection of water. The photosensitizing activity observed in these extracts is due to the presence of coumarins. These molecules, in the presence of light, absorb energy and pass from the ground state to the excited state. Returning to the ground state, the stored energy is transferred to the oxygen, which then passes from the ground state, triplet, to the excited state, singlet, and inhibits the microorganisms present in the water.
The aim of this study is to gain a better understanding of the variables determining farmers’ willingness to pay for SNK hybrid cocoa seeds, and the amounts farmers are willing to pay for these technologies. Faced with the volatility of bean prices in an increasingly unstable external market, and with the galloping demand from emerging processing industries, farmers are looking for varieties with high productivity and capable of withstanding climate change and diseases. Hence their preference for the hybrid SNK cocoa variety to improve the productive capital of cocoa farms. However, little is known about the factors that determine willingness to pay for the adoption of improved seeds. The survey was conducted among 311 cocoa farming households in the Centre Region of Cameroon, specifically in 07 divisions with high cocoa production. The data were collected using a questionnaire. Heckman’s two-stage selection model was used to analyze the data. The results show that the sex of the farmer, the level of education and the number of people living in the respondent’s household have a positive influence on the willingness to pay for the SNK cocoa variety. The amounts they are prepared to pay to acquire it varies between FCFA 50 and FCFA 500 per unit, with an average of FCFA 150 per unit of acquisition. It is therefore recommended to produce more.
This paper presents the design and experimental study of a new electronic ESP32-based control device of an anti-mold enclosure for the conservation of luxury leather goods. The control specifications deal with temperature control inside the enclosure between 18 oC and 25 oC, while maintaining the internal humidity rate between 50% and 60%, for the sake of better conservation of leather products. The virtual schematic diagram of the device is developed with EasyEDA, then the virtual assembly diagram is realized using Fritzing. The complete experimental device is realized and well tested using several electronic modules, including: DHT22 sensor, ESP32 microcontroller, Peltier effect module and LCD display. In addition, an application program is developed using Arduino C++ and uploaded into ESP32. Finally, the testing results presented and discussed confirm the quality and originality of this novel device for digital control of leather product preservation enclosures.
This article presents the study of the behaviour of reinforced concrete steels, used in constructions in Senegal, under the effect of corrosion. The study is carried out on locally manufactured steels from three (03) companies located in Senegal and on control bars imported from France. Type 1 (E1), Type 2 (E2) and Type 3 (E3) steels are locally manufactured and Type 4 (E4) steels come from France. For each type of steel, samples with diameters of 8 mm, 10 mm and 12 mm were used. Mass losses were evaluated after immersion of these samples in a corrosive solution. For each type of steel and for all the diameters studied, the corrosion rate that initiates cracking of the asphalt concrete was evaluated from the actual diameter of the bars and the thickness of the nominal coating. From the mass lost over time, correlations between duration and mass loss were established for all diameters of the different types of steel. These relationships made it possible to calculate the time required to reach the corrosion rate that initiates concrete cracking. The results indicate that 66.67% of the steels studied, of local manufacture, have a corrosion time that initiates cracking of concrete lower than that of the control bars imported from France. Type E1 steels with a diameter of 8 mm have a duration to reach the corrosion rate that causes cracking of concrete, equal to 49.71% of the duration of type E4 steels. These results indicate that the steels used in construction in Senegal do not have the same behaviour vis-à-vis corrosion.
In West Africa, particularly in Burkina Faso, the urban freshwater bodies are amongst the most threatened exacerbating the urban environmental crises. Domestic and industrial discharges and fecal sludge are the main sources of urban water pollution. This systematic pollution, which deteriorates the physicochemical and biological condition of urban water ecosystems is a major concern for decision-makers and scientists. Thus, this study was undertaken to assess the effects of urban wastes on ecological status of physicochemical parameters et biological organisms. To do so, from September to October 2020, physicochemical and bacteriological parameters were analyzed using standard methods. Then, the macroinvertebrates were collected using hand net, and then identified in the laboratory. The results showed that the concentrations of physicochemical variables such as conductivity, COD, BOD5, nutrients and chlorides were high in downstream compared to those in upstream. The higher concentrations of total coliforms, Escherichia coli and faecal streptococci were reported in downstream. In regard of macroinvertebrates, the results revealed that taxonomic richness, the relative composition of polluo-sensitive taxa and the Shannon-Wiener index were very low in downstream. From our results, the urban freshwaters ecosystems are strongly impacted including waterborne diseases spreading, and for suitable management of these waterbodies and the well-being of riparian’s population, it is crucial to strengthen the legislation on the discharge of domestic and industrial waste, and to promote appropriate systems for the waste treatment in our cities, and to train and raise public awareness of environmental citizenship where ecology meet society.
Bisalbuminemia is a rare electrophoretic abnormality of the albumin fraction, characterized by a doubling of this fraction on the electrophoretic trace of serum proteins, reflecting the presence in the same individual of normal plasma albumin and structurally altered albumin, which may be of acquired etiology, rarely hereditary. The aim of this article is to study the etiologies and prevalence of bisalbuminemias associated with nephropathies discovered on serum protein electrophoresis at the biochemistry laboratory of the university hospital Ibn Rochd in Casablanca. This is a retrospective study of serum protein electrophoretic capillary tracings revealing bisalbuminemia in patients hospitalized in the nephrology department at university hospital Ibn Rochd in Casablanca over an 18-month period. 29 electrophoretic profiles out of 242 showed bisalbuminemia, i.e. 12% of all electrophoretic tracings in 29 patients presenting with acute or chronic nephropathy. The average age was 45±22 years, with a sex ratio (M/F) of 2.22. The etiologies of the nephropathies were dominated by renal amyloidosis with 24.14%, followed by minimal glomerular lesion nephropathies, extramembranous glomerulonephritis and lupus nephropathies with 17.24% each, and finally membranoproliferative glomerulonephritis with 6.9%. Among secondary etiologies, betalactam use was highlighted in 13.8% of cases, no patient in the series had a labelled pancreatopathy, and the presence of a monoclonal gammapathy was objectified in only one case in the series. This study illustrates the varied etiologies of bisalbuminemia associated with nephropathy, requiring detailed knowledge to enable proper interpretation of electrophoretic profiles.
The poor condition of Grand-Bassam’s boreholes and the drinking water wells of the local population led to an assessment of their hygienic quality. Several data analysis approaches were performed on 4 boreholes and 17 well water samples. Indeed, physico-chemical and bacteriological analysis, as well as Water Quality Index and Principal Component Analysis were used to differentiate the characteristics of borehole and well water in order to determine the level and origin of water pollution. The results showed that all chemical borehole water quality was poor, while of 35% and 65% of well chemical water quality were good and satisfactory, respectively. Owns to soil nature, the iron and manganese contents were 0.73 ± 0.23 mg.L-1 and 0.1 ± 0.07 mg.L-1, respectively. The high presence of fecal streptococci, salmonella and shigella in the borehole water, as well as Escherichia coli, total coliforms and fecal coliforms in the well water, thereby underscoring the poor microbiological quality of water (90,53% of borehole and 92% of well), which is contaminated by septic tank water. Furthermore, the high presence of Salmonella in borehole water suggests that it may contain hydrogen sulfide, which is responsible for its unpleasant odors.
The main objective of this study is to measure empirically the level of use of accounting and accounting documents in the informal sector (food stores, shops and stores). To record economic phenomena within an administration and their results, identify management principles, establish forecasts and monitor them, you need an instrument. Among the instruments linked to its organization, accounting, beyond its real mission, currently appears as the regulatory instrument of the company. Climatic contrasts have a notable influence on the soils and, as we will see, on the vegetation of the city. 'Uvira. Accounting, considered as a basic cell and key institution of the economy of a country, The use of accounting documents explains positively and significantly the use of accounting to the extent that accounting is kept on the basis of the information contained in various accounting documents used to record current operations within the company.
Our overall objective was to know the ecological and food relations between Tilapia niloticus and Clarias gariepinus in Lake Kivu, precisely in the Kalengera site. The statistical method helped us to compile tables of data from our surveys in our field of study; the analytical method allowed us to analyze all the data and to interpret them, the techniques of the interview by the questionnaire and the documentation allowed us to collect the data of this study, the tools used are the questionnaire, the notepad , pencil and pen. The random sample was determined by Lynch's formula, which for us was more scientific in nature. 25 questionnaires were administered to fishermen and other individuals working in the Kalengera site and 25 others to provincial inspection agents of Agriculture, Fisheries and Livestock with a size of 152 surveyed. The feeding of Tilapia niloticus and Clarias gariepinus must be done taking into account the species but also the stages, among others the fry between them, the juveniles between them and the marsh fish each other according to size, weight and feeding rate to avoid prey and predators in natural selection and protected species umbrellas by several methods in their ecology by the The method of occurrence, number, volume and weight allowed us to study the food ecology of fish (Tilapia niloticus and Clarias gariepinus) which allows to know the number of fish in which each type of food appears to be expressed as a percentage of the total number of fish examined with the total number of individuals of each type of food given as dominant or recessive and to express the volume or weight of each type of food in each stomach with the beneficial percentage of its contents because 99% of Tilapia niloticus species reproduce in pelagic zones by storing their nests in benthic bottom rocks and only 1% can do so at littoral level with the risk of predators while 100% of Clarias gariepinus species bottom their nests. nesting in spawning grounds precisely in coastal macrophytes.
The resistance of malaria vectors to insecticides used in vector control is a major obstacle for national malaria control programs. It is in this context that an entomological study was conducted in urban, peri-urban and rural sites in the Oyem area (Northern Gabon). This study looks at species of the An. gambiae complex and the resistance mechanisms developed by Anopheles to escape to insecticides in Oyem, northern Gabon. To this end, Anopheles larvae were collected in the above-mentioned areas and reared to the adult stage in the field laboratory. Subsequently, the adult anopheles were subjected to sensitivity tests following the World Health Organization protocol.
Seven insecticides (DDT 4%, Deltamethrin 0.05%, Permethrin 0.75%, Lambda-cyhalothrin 0.05%, Cyfluthrin 0.15%, Bendiocarb 0.1% and Malathion 5%) were used for these bioassays. The mosquitoes tested (live and dead) were analyzed using PCR to identify the species of the An. gambiae complex. The results obtained showed that the species Anopheles gambiae, the only species identified, has resistance to dichlorodiphenyltrichloroethane (DDT 4%) and Pyrethroids. However, this species is sensitive to Bendiocarb 0.1% and Malathion 5%. These statuses are confirmed by the presence of Kdr mutations (East and West) and the absence of the Ace-1R mutation in this vector.
The Ayorou and Kandadji sectors are located in northern Niger’s Liptako in the Téra-Ayorou pluton, composed mainly of granodiorites and various granites. This study investigates the structural characteristics of the granitoids of the Téra-Ayorou pluton in the Ayorou and Kandadji areas. Field and laboratory work revealed two major deformation phases, D1 and D2. Tectonic structures observed on granodiorites and synkinematic biotite granite (foliation, mineral lineation, shear corridors, folds and boudins identified) were assigned to deformation phase D1, which is ductile to semi-ductile. Other structures (quartzo-feldspathic, pegmatitic and doleritic fractures and veins) affecting all lithologies, have been linked to deformation phase D2, which is frankly brittle. The average direction of shortening of the compressive stress responsible for setting up the foliation (S) is generally N-S (Z N185° in Ayorou) and NNE-SSW (Z N225° in Kandadji). The shear zones were controlled by a shortening of average direction Z N195° (dextral shear zones) and Z N135° (senestial shear zones).
School performance is explained in the literature by a trilogy of factors coming from the school, the family and the student himself. This study focuses on the family and examines whether there is a relationship between family characteristics and the performance of lower secondary school students in Togo. To achieve this objective, a sample of 944 students was mobilized using the convenience sampling technique. Participants completed a sociodemographic questionnaire and a parenting style scale. Inferential analyses of the collected data found that not only were parenting style and performance related to family structure, but also that the two variables were positively correlated. On the other hand, the results do not show a relationship between parenting style on the one hand, academic performance on the other hand and family size.
The effects of the consumption of newly formulated feeds (A1, A2 and A3) and of a control feed (AT) on the physical and organoleptic characteristics of the eggs and flesh of the Japanese quail (Coturnix japonica), bred in captivity, have been evaluated. The experiment was carried out on 80 one-day-old quail. At the end of the experiment, which lasted 9 weeks, the physical and organoleptic characteristics of the eggs, as well as those of the flesh of these quails, were studied. It appears that the eggs of the quails fed with food A3 had the highest masses and shell thicknesses. The sensory analysis carried out in this work showed that all the flesh of the quails fed with the newly formulated feeds was accredited with the same appreciation as those fed with the commercial feed, both in terms of tenderness, aroma, and flavor.
With regard to quail eggs, it has been observed that, with the exception of the color parameter where the color of the egg yolk of the quails fed with the newly formulated feed is darker than that of the quails fed with the feed of trade, the statistical analysis did not reveal any statistically significant difference at the 5% level for the other parameters. In short, all the quails were equally appreciated by the panelists, this makes newly formulated feeds good feeds for quail.
The analytical resolution of the problems posed in descriptive geometry by the MONGE method would be a plus that we bring to the scientific world and to secondary education.
Our subject is entitled: Determination by the analytical-graphical method of the distance from a point C to a straight line AB.
To solve the problem thus posed in this article, we have used:
- To the formula which makes it possible to calculate the distance between two points in space,
- To the construction in elementary geometry seen in the first scientific year, of a triangle knowing the lengths of its three sides as well as that of the height resulting from a given point of the triangle,
- To the notion of similar triangles.
Cowpea, Vigna unguiculata [L.] Walp, is an important seed legume in tropical and sub-tropical regions, particularly in sub-Saharan Africa. Despite its wide adaptation and importance, cowpea productivity is generally very low due to numerous biotic and abiotic constraints. In Burkina Faso, climatic hazards accentuate drought, which limits cowpea production. The aim of this study is to determine the water regime and periods of the year suitable for cold dry-season cultivation of cowpea varieties. To this end, two cowpea varieties (Vigna unguiculata L. Walp.) KN1 and KVX 61.1 were grown in six (06) liter pots in a real environment, during the cold period of the year. Trials were separated by an interval of fifteen (15) days. Each variety was subjected to three watering frequencies. During the study, environmental, growth and agronomic parameters were determined. The study revealed that in cold periods, low temperatures and the application of water regimes reduced most agronomic parameters in both cultivars. Nevertheless, KVX 61.1 produced throughout the study period, while KN1 did not flower when sown from December 09 onwards. The KN1 variety can be sown before December 9 for pod production during the cold off-season, and after that date for its tops, which rich in beneficial elements for livestock are feed. For these two varieties, watering every other day is the best watering regime to ensure good growth and better pod production. These results will serve as an indicator of period and variety for cold dry-season pod and leaf production of these cowpea varieties.
The development of the city of Abidjan in recent years has led to an explosion in the number of buildings. However, hygrothermal comfort in these buildings leaves much to be desired. These buildings therefore consume large amounts of energy to restore comfort. This energy expenditure contributes to global warming through the emission of greenhouse gases. The aim of this study is to check whether buildings in the city of Abidjan are constructed with the climate in mind. To achieve this objective, a bioclimatic study of the city of Abidjan was carried out using the Mahoney and Szokolay methods. The recommendations made by the bioclimatic analysis are then compared with the characteristics of the buildings encountered in the field. The bioclimatic studies carried out during this study and superimposed on the characteristics of the buildings encountered in the field show that the orientation of the buildings encountered in the field in the three municipalities studied was different from that recommended by the bioclimatic study. The construction of the various buildings did not take into account the elements of the climate in order to achieve thermal comfort with low energy consumption. To overcome these problems, a set of recommendations derived from the bioclimatic study was proposed.
This study reviews the state of knowledge on the availability, feed value and use of agro-industrial by-products in ruminant feed in Burkina Faso by means of a literature review. Searches were mainly carried out online using the Google Scholar engine. A total of 150 documents were inventoried, of which 49 were selected and used for this literature review. Various by-products, notably oilcake, cereal bran, cereal straw and legume tops, are used to feed cattle and sheep for fattening, and dairy cows. Cereal straws are energy-free, rich in NDF and ADF fiber, and low in total nitrogen. Legume tops are richer in total nitrogen and energy than straws. Tuber peelings are low in total nitrogen, richer in fiber and energy than tops. Mango by-products are low in total nitrogen, high in fiber and richer in energy than other by-products. Mango and manioc by-products are available, but are rarely, if ever, used in animal feed. Further work is needed to scale up the use of mango and cassava by-products to increase the availability, low-cost and high-quality feeds for meat and milk production.
This study made it possible to analyze the marketing and consumption of catches from Lake Songori in the Gontougo Region. To do this, a survey was conducted among 8 wholesalers working on this dam and 101 consumers drawn at random from June to August 2014. The results show that the commercial activity is practiced by nationals who have no training in management. of business. The transport and trade of fish takes place in a completely unhygienic environment with rudimentary means of preservation. However, with Oreochromis niloticus as an economically more important species, wholesalers achieve a turnover greater than or equal to 50% compared to fishermen. The local population, for its part, hardly benefits from the catches made, most of the production (75% to 100%) being sold in urban areas. Thus, irregular consumers (46.5%) remain the most numerous. Faced with this situation, the customary authorities should really get involved in the management of this body of water to enable local residents to benefit from it and fight against food insecurity in rural areas. The development of this activity seems logically inevitable to help meet the challenge of self-sufficiency in animal protein at the local level.
The lagoon waters of Côte d’Ivoire contribute to the country’s self-sufficiency in fish products, in the face of ever-increasing needs. This study examines the current state of exploitation of the Aby lagoon by individual fishermen. It is the result of three months of surveys, from April to June 2022, with fishermen and the fisheries administration of Adiaké. The results show that fishing is in the hands of nationals. Mostly uneducated (50%), those traditional fishermen use as dominant gears: small-mesh nets (75.20%) and nailed plank pirogues (61.91%). The most important species in catches are Ethmalosa fimbriata and Sarotherodon melanotheron with proportions of 34.78% and 30.43% respectively. The annual biomass is estimated at around 275.73 tons. There is a poor cooperation between fishermen and the administration, which impacts negatively the statistical data. The use of non-selective gears remains one the major constraints against the preservation of aquatic biodiversity. Therefore, management programs and research projects have to be implemented for avoiding an eventual collapse of stocks. A study on the spatio-temporal distribution of species with high aquaculture potential could be considered.
This work investigated, using a 3-D modelling, the influence of electrons losses on the performance of a polycrystalline silicon PV cell.
The electrons transport equations have been solved by taking into account the rate of electrons lost at the junction (Sf0) to find the expression of the electrons’ density which allowed to derive the expressions of the electrical parameters (Jph, Vph, P) then those of the performance parameters (η, Rsh) of the PV cell grain. Then we analyzed, from a numerical simulation, the effects of the rate of electrons lost at the junction (Sf0) on the performance parameters (η, Rsh) found from the curves of output power (PT) -diffusion velocity (Sfj).
Results of simulation showed that, in open circuit, there is a leakage current at the junction of the PV cell grain whose density increases from 0 mA.cm-2 à 58.80 mA.cm-2 resulting in a drastic drop in the shunt resistance from infinity to 4.273 Ω.cm 2 and a drop in the conversion efficiency of 34.376%. Considering the manufacturers’ standards, 20% drop in efficiency, so for Sf0 = 1,790×104 cm.s-1 the PV cell is degraded.