Good alumina production using the Bayer process depends on the regularity of the alumina dissolution parameters, as failure to control these factors leads to a drop in alumina yield. This work has enabled us to identify and propose solutions to the anomalies linked to alumina dissolution. An analysis of the dissolution parameters (temperature, liquor concentration, residence time and saturation rate) shows that the alumina yield from January to December was irregular. This fluctuation in alumina yield remains the same for all the parameters studied. Chemical analysis was used to provide results for certain parameters. These included spectral analysis, pH meter analysis and methrom analysis of samples taken from the etching plant. These analyses showed the different behaviours of the concentration of the liquor and the content of the different bauxite constituents. An analysis of the graphs shows that the parameters vary according to the plant’s instructions. All the results obtained show the need to regulate the alumina dissolution parameters. Better management of these factors will help to improve alumina yield.
Retinoblastoma is the most common malignant intraocular tumor in children under 5 years old. Survival rates, ocular and visual preservation are major challenges in this disease. This study aims to determine the epidemio-clinical, therapeutic and prognostic profile of patients with retinoblastoma who have been treated in the pediatric hemato-oncology department of the university Hospital Hassan II of Fez. It is a retrospective and descriptive study of all children followed for retinoblastoma at the pediatric hemato-oncology department, over a period of 11 years and 10 months from January 1st, 2012 to October 31, 2023. During this period, we collected 65 cases. The mean age at diagnosis is 25 months and the ratio is 0.9. The mean time to diagnosis is 5 months. Symptoms are dominated by leukocoria (84.2% of cases), followed by exophthalmia (15.8% of cases) and sarbismus (13,2% of cases). The retinoblastoma is unilateral in 70.7% of cases and bilateral in 29,3% of cases. Enucleation was indicated in 97% of cases. The majority of patients were treated by the combination of chemotherapy and surgery (69.2% of cases). Surgery only was indicated in 27,7% of cases and conservative treatment in 26,1% of cases. Radiotherapy was indicated in 9,5% of cases. The overall survival rate at the end of treatment is 75.4% and the five-year survival rate is 60%. The prognosis of retinoblastoma is generally good. In our context, most cases are still diagnosed at advanced stages of the disease, which considerably reduce the overall survival rate and the preservation of the eye and the vision.
With a population estimated at 17.07 million inhabitants in 2021 and an electrification rate of around 45.5% [1], the electricity supply deficit of the City-Province of Kinshasa is estimated at 54.5%. Reversing this trend is one of the concerns of the Government of the Republic. It is within this framework that several rehabilitation and extension programs are underway. These projects are financed by either international donors such as PMURR, PMEDE, PEPUR, EASE MALT, or SNEL SA itself with its own funds, or through direct intervention by the Congolese government. The implementation strategy of the EASE project by SNEL SA DKO will be the subject of this analysis. Considering the volume of data it is supposed to generate, computer management based on NoSQL data is the most appropriate to the point that it is likely to make it efficient.
Background: Water has an important place in the life of human beings. Regardless of the uses of water, water intended for human consumption must be clean. Despite the fact that the catchments of this water are chemically and microbiologically polluted. The objective of this study is to evaluate the interactions between types of water including that intended for human consumption in the city of Kinshasa.
Methods: Our analytical and experimental study based on laboratory analysis which was carried out over a period of approximately one month (the month of September 2023) while respecting a certain number of steps. This involves geo-environmental investigation, geographic location, collection and analysis of samples as well as interpretation of the results.
Results: After our chemical analyses, we found that the pH of the water is very acidic, the turbidity of the water analyzed is normal, the conductivity is below normal as well as the permanganate index, nitrites and chlorides. Phosphate and nitrates exceed the normal value. Bacteriological analyzes show the development of colonies with the presence of total and fecal coliforms and Escherichia Coli.
Conclusion: The results of the analyzes showed that the water is contaminated and polluted chemically and biologically by chemicals (through the abusive use of chemical fertilizers and pesticides which release nitrogen, phosphorus and chlorine) coming from the activities agricultural and livestock farming.
The Haute-Comoé watershed in southwest Burkina Faso is characterized by water resources used for irrigated agriculture, among other things. The water resources of the Haute-Comoé watershed consist mainly of the waters of the Comoé River and its tributaries. Over time, pressure on the basin’s water resources has increased due to the expansion of irrigated agricultural areas. With a view to preventing conflicts over the use of water resources, this study was carried out to examine the evolution, over nearly 40 years, of irrigated agricultural areas within market gardening areas. Market gardening is one of the fastest-growing components of irrigated agriculture, particularly since the promotion of small-scale private irrigation launched by the Burkina Faso government in the early 2000s. To achieve the study’s objective, a method based on the processing of a series of satellite images was adopted. The method used consists in classifying a series of images acquired on anniversary dates, but consecutively 7 to 15 years apart (1986, 2001, 2015 and 2023). On the basis of agronomic expertise, a post-classification phase, based on an analysis of the temporal trajectory of classified pixels, was carried out in order to correct certain unlikely pixel trajectories. Results were evaluated by measuring overall accuracy and the Kappa coefficient. Overall accuracies ranged from 72.57% to 81.90% (for the classification phase) and from 88.25% to 92.50% (for the post-classification phase). At the end of the image post-classification phase, a change detection analysis, i.e. a measurement of the intensity of change (spatial variations) within the classes considered, was carried out, making it possible to assess changes in terrain over time, and to identify categories and levels of transition between classes. The study showed that irrigated areas increased by 25% between 1986 and 2023 in the study area.
The purpose of this study was to improve knowledge on the evaluation of the ecological value of a plant formation. This process includes several stages including the definition of the evaluation objective, the inventory of the environment or data collection, the choice of criteria, the rating of the criteria, the calculation of the weighting by criterion and the total weighting and finally, the evaluation of the ecological value of the site. he practical case of the Mamadou Sangaré estate shows that denser and richer forest formations record a higher ecological value compared to savannah formations.
The Tanoe-Ehy swamp forest (FMTE) has been identified as a high-priority site for primate conservation in West Africa. In addition to a lack of knowledge of the plant communities, the site is subject to pressure from local populations both on the periphery and in the interior. The aim of this ethnobotanical study is therefore to determine the uses made of the plant species collected by the local populations. To achieve this, ethnobotanical surveys were carried out in seven localities on the outskirts of the forest. Generally speaking, direct interviews with local people enabled us to identify the techniques and practices used to plant crops and the plants harvested in the study area. A total of 160 people were interviewed, most of them male farmers. The survey showed that most of the plantation land had been acquired by inheritance and had been established on forest land. Monocultural plantations are the most abundant in the study area. It is worth noting that the preferred place for collecting plants is within the FMTE. Most of the plant species collected are used for traditional medicine. They include Landolphia membranacea, Tabernaemontana crassa, Combretum aphanopetalum, Parquetina nigrescens, Microdesmis keayana, Alchornea cordifolia, and Strophanthus hispidus with a rarity index of less than 80%. Given the importance of the FMTE in terms of a particular ecosystem and biodiversity conservation, it is desirable and urgent that, in addition to awareness campaigns for local populations, the process of its definitive classification be accelerated to put an end.
This study concerns environmental degradations noticed in the areas controlled by extractive industry and in the Congolese urban zones. Based on the legal framework established, 2002 – 2016, and on the available results of reserarch, it argues: the management of natural resources henceforth requires more rationality and more responsibility, more attention to ecological balance and to the needs of future generations.
It has really detected the notions of biodiversity in Congolese laws focused on the management of natural resources, and has examined the relevance of the Congolese legal framework in relation to environmental, health, ecological and axiological degradations. It has also assessed the quality of the implemention of laws promulgated. Analyses and reflections of this study therefore highlight three major challenges in the Congolese society, namely (1) economy of the cognitive resources, and of the cultural and ecological values, (2) management of the natural resources, and (3) Congolese tragedy.
In addition to the introduction and conclusion, analyses and reflections of the study are divided into three sections, that is (1) legal framework for the management of Congolese natural resources: the notions of biodiversity, (2) critique of the Congolese laws considered: their quality and that of their implementation, and (3) biodiversity issues.
In Mexico, the relationship of seed size with the productive and nutritional potential of maize silage needs to be studied. Thus, this study investigated the effect of seed size on yield and the nutritional value at the cutting stage for silage of various maize varieties. The research consisted of two phases: the productivity of maize for silage and the nutritional value estimated in the laboratory. Nine maize varieties, previously classified by their seed size, were used: flat large and flat medium. The experimental design was a randomized complete block with factorial arrangement and four repetitions. The harvest was carried out at the silage-cutting stage (30-35% DM, whole plant). Results for each estimated variable showed significant differences (P<0.001) among varieties, while seed size was significant for only some variables. Based on the absolute value of the standardized coefficients, the outstanding variables were female flowering, total protein, in vitro digestibility, and dry matter yield. In conclusion, maize variety for silage affects the productivity and nutritional value in the cutting stage. In contrast, the effect of seed size on protein yield, protein content, and plant digestibility was minor. The materials Campeón, H-135, H-157, HS-2, and A-791 yielded the highest, while the nutritional value of H-135, Campeón, HS-2, VS-22, and H-358 was outstanding.
The objectives of this study were to describe and analyze the modalities of prescription of psychotropic drugs in patients followed in ambulatory psychiatry. The study was cross-sectional, descriptive, and analytical on the prescription of psychotropic drugs in 205 patients followed at the outpatient clinic of the National Psychiatric Hospital of Thiaroye in Dakar, for a period of three months (from February 1 to April 30, 2019). The average age was 34.5 years, 64.9% of patients were without occupation and 15.6% had a history of hospitalization. The disorder had lasted between 1 - 10 years for 59.1% of patients. The most frequent diagnosis was schizophrenia (33.7%) followed by mood disorders (18.1%) and epilepsy (18.0%). The average number of medications per patient was 2.77 and monotherapy was exceptional (0.06% of patients). Antipsychotics were the most prescribed drugs (76.1%), followed by anxiolytics (31.7%), thymoregulators (27.3%), and antidepressants (23.4%). A synthetic antiparkinsonian was found in 51.2% of cases and delayed neuroleptics were prescribed in 13.7% of patients. Classic antipsychotics were prescribed in 50.4% of schizophrenic patients and second-generation antipsychotics in 33.3%. Second-generation antidepressants (serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors) were prescribed exclusively for depressive disorders and anxiety disorders, unlike tricyclics. One-third of bipolar patients (37.5%) received a combination of a thymoregulator and an antipsychotic. Contrary to antipsychotics, which are still dominated by the classics, we note a trend toward the prescription of new antidepressants. However, some prescriptions did not comply with international recommendations. It is important to set up national protocols, based on current scientific evidence but also on the socio-economic context of the country to optimize the quality of psychotropic drug prescriptions.