Value at Risk and Market Risk: Case of the Regional Securities Exchange

The study of the BRVM market risk using the VaR method is a determining factor in assessing the performance of our equity portfolio composed of the BRVM composite index and the BRVM10 index. It has enabled us, with the help of Basel regulations, to use backtesting to determine the minimum amount of capital that an investor must hold per day to protect against risk. The kupiec test enables us to determine the reliability of VaR calculated at different confidence levels. The result of our study confirms, using the extreme VaR method, the robustness of our threshold-based portfolio risk management approach. It also confirms the problem of market attractiveness during times of financial crisis

LES MODELES FACTORIELS APPLIQUES AU CAS DE LA BOURSE REGIONALE DES VALEURS MOBILIERES

This study tests and compares the classical factorial models applicable on the BRVM market. These are the CAPM, Fama and French and CAPM models with liquidity. Our analysis covers a daily frequency from September 16, 1998 to December 31, 2016. We have subdivided our study into ex ante and ex post periods. The first step uses time series regression to estimate the parameters of these models. The second step is to use these in cross-sectional regression. This approach technique allowed us to rank the models according to their ability to predict the return of securities on the BRVM market. The results of our study gave us the predominance of the CAPM model followed by the Fama and French model. The CAPM with liquidity is not efficient for the good reason that this market is not liquid

EFFET DE L’ANNONCE D’EMISSION D’ACTIONS NOUVELLES SUR LES RENDEMENTS BOURSIERS

The purpose of this study is to test the reaction of stock market returns to the announcement of the issue of new shares in the BVA / BRVM market. Theoretical and empirical works link the stock market behavior to the issue operations. When one assumes the neutrality of financial structure (Modigliani and Miller, 1958), one should observe no reaction of the market.Other research (agency and signal theories) has shown that in the presence of conflict of interest and information asymmetry between managers and investors, the market reaction will not be neutral. Based on a sample of companies listed on the BVA / BRVM over a period spanning the period from its creation to the present day, we found that the stock price reacted negatively in the medium and long term to the announcement of issue of new shares

Dynamiques territoriales des Niayes: divergences économiques entre industrie extractive minière et agriculture (littoral Nord du Sénégal)

Cet article a pour objectif l’analyse de l’insertion des entreprises minières dans les Niayes à travers l’implication socioéconomique des déplacements des populations et l’impact de la RSE sur le développement local. Cet article essaie de montrer comment ces populations autochtones du littoral Nord sénégalais sont détachées de leur territoire et de leurs activités productives de subsistance. Depuis l’installation des entreprises minières, la zone des Niayes connait de fortes dynamiques socio-économiques s’exerçant sur son environnement physique et humain à travers l’emprise des sociétés sur les espaces agricoles et ceux habités. Le développement du secteur minier induit une exclusion des communautés locales habitant les sites et qui sont relogées ailleurs. La documentation faite sur les questions de conflits dans les espaces miniers et des enquêtes de terrains et entrevues ont permis de comprendre les dynamiques socio-spatiales et économiques dans les zones minières en général et dans les Niayes en particulier. Les résultats montrent que les Niayes ont fortement connu l’intervention des sociétés minières qui causent la modification de cet environnement primitif, la réduction des espaces agricoles (les parcelles cultivées sont réduites) et déplacent des habitations en leur faveur. Cette situation fait des Niayes un espace d’enjeu socioéconomique et écologique conduisant à l’apparition de divergences conflictuelles autour des sites miniers. This article aims to analyze the integration of mining companies in the Niayes through the socio-economic implication of the displacement of populations and the impact of CSR on local development. This article tries to show how these indigenous populations of the northern Senegalese coast are detached from their territory and their productive subsistence activities. Since the establishment of mining companies, the Niayes area has experienced strong socio-economic dynamics exerted on its physical and human environment through the influence of societies on agricultural and inhabited areas. The development of the mining sector leads to the exclusion of local communities living on the sites and who are relocated elsewhere. The documentation made on conflict issues in mining areas and field surveys and interviews made it possible to understand the socio-spatial and economic dynamics in the mining areas in general and in the Niayes in particular. The results show that the Niayes have greatly experienced the intervention of mining companies which cause the modification of this primitive environment, the reduction of agricultural spaces (cultivated plots are reduced) and move houses in their favor. This situation makes the Niayes a socio-economic and ecological area of stake, leading to the emergence of conflicting differences around the mining sites

Risk and Return: The Case of Securities Listed on the West African Economic and Monetary Union Regional Exchange of Securities (BRVM)

The purpose of this research is to study the relationship between risk and return on the BRVM. The empirical results, obtained using the Asymmetric Response Model (ARM) model, show the asymmetric nature of the return of the securities that are rated on them. This does not reflect the level of risk taken by investors, which is much higher than the return obtained. While this result is consistent with the distancing characteristics of risk and return observed in emerging markets, it highlights above all the need to rebalance the relationship between risk and return at the RSE in order to make it more attractive for investors

Impact of day of delivery on obstetric and perinatal outcome: a 10 years retrospective descriptive and analytical study at the Phillipe Maguilen Senghor Health Centre, Dakar, Senegal

Background: For a lot of women, childbirth is still a feared moment. Despite considerable progress in the management of childbirth and its complications, maternal and neonatal morbidity and mortality are still a major problem even in developed countries. To evaluate the influence of day of delivery on obstetrical and perinatal outcome.Methods: Retrospective cohort study conducted at the Philippe Maguilen SENGHOR health center maternity ward from January 1, 2011 to June 30, 2019, on patients with a pregnancy of more than 22 weeks of amenorrhea who were received for delivery management. The deliveries periods were divided according to whether they occurred on a working day (deliveries from Monday to Friday, excluding public holidays) or on weekends and public holidays (deliveries on Saturdays, Sundays and days declared as public holidays according to the Gregorian and Senegalese event calendars). The data were extracted from our E-perinatal database and analysed in the Statistical Package for Social Science (SPSS 24, Mac version).Results: Over 102 months, we recorded 42 870 deliveries. The average age of the patients was 27 years with extremes of 13 and 50 years. Nearly one in three deliveries took place on a holiday or weekend (n=13566-31.6%). The rate of caesarean delivery on weekends/holidays (18.8%) was lower than that on weekdays (21%). The odds ratio of having/benefiting from a weekend/holiday caesarean section was 0.87 (CI 0.83-0.92, p<0.0001). Our results suggest that patients who deliver on weekdays are more likely to receive a caesarean section than those who deliver on weekends or holidays. Perineal injury, World Health Organization obstetric complications, and neonatal outcome showed no significant difference by day of delivery.Conclusions: Our results contradict the idea that deliveries on weekends and holidays are more risky for patients and their children

The influence of the thickness of the Cds emitter layer on the performance of a CIGS solar cell with acceptor defects

In this work, we simulated a solar cell based on CIGS with simple default acceptor, using software (SCAPS) version 3.302 in order to study certain parameters. In particular, we have varied the thickness of the CdS emitter (0.05 mum, 0.04 mum and 0.03 mum) to study its influence on the performance of the cell. We were able to record that the energy efficiency increased from 16.50% for a thickness of 0.05 mum of the emitter to 16.87% for a thickness of 0.03 mum of the emitter. We also noted an improvement in other parameters, such as the form factor from FF = 79.81% to 80.10%, with the decrease in the thickness of the CdS. And from the Nyquist diagram, we also determined parameters like the series resistance to get an idea on the equivalent electrical circuit of the studied cell

Apport des explorations radiologiques et neurophysiologiques dans le bilan des nevralgies cervico-brachiales observees dans un laboratoire de neurophysiologie clinique a Dakar Au Senegal

Introduction: L‘imagerie occupe une place de choix dans le bilan d‘une Névralgie Cervico-Brachiale (NCB). D‘autres explorations paracliniques peuvent aider et dans notre laboratoire, l‘Electro-Neuro-Myographie (ENMG) et les Potentiels Evoqués Somesthésiques (PES) sont couramment réalisés dans le cadre du bilan des NCB. Dans cette étude, nous avons voulu montrer l‘apport des examens&nbsp; radiologiques et neurophysiologiques dans le diagnostic de NCB.Méthodes: Il s‘agit d‘une étude rétrospective sur une période d‘un an, réalisée chez des patients reçus dans un laboratoire de neurophysiologie à Dakar pour une suspicion clinique de NCB et ayant eu une Radiographie standard et/ou une TDM et /ou une IRM du rachis cervical. Chez ces patients nous avons réalisé un ENMG des membres supérieurs avec l‘étude des paramètres suivants : latences des Ondes F, des Vitesses de Conduction Nerveuse et Détection à l‘aiguille dans les muscles aux membres supérieurs. L‘ENMG a été couplé aux Potentiels Evoqués Somesthésiques (PES) des membres supérieurs obtenus par stimulation digitale des territoires radiculaires avec recueil des Ondes N9, N13 et N20.Résultats: 14 patients ont été inclus dans l‘étude, 8 examens radiologiques sur 14 étaient anormaux objectivant en majorité des lésions de cervico-uncarthrose étagée. L‘ENMG était normal chez 13/14 patients, la seule anomalie était une atteinte axonale tronculaire du nerf cubital chez un patient dont les PES étaient en faveur d‘un tableau de polyradiculopathies. Chez 1 patient seulement sur 14 tous les examens (imagerie, ENMG et PES) étaient normaux. Les 13 autres patients présentaient un allongement des latences des PES en faveur majoritairement d‘une polyradiculopathie C6 et/ou C7 et/ou C8. Parmi ces 13 patients, 05 avaient une imagerie normale. Commentaires L‘imagerie et les explorations neurophysiologiques normales n‘éliminent pas une NCB. L‘apport de ces différents examens se situe au niveau du diagnostic positif, différentiel et étiologique des NCB à condition de les coupler. &nbsp; English title: Contribution of radiological and neurophysiological exams in cervico brachial Neuralgia&nbsp; assessment seen in a laboratory of clinical neurophysiology in Dakar/Senegal Introduction: Imaging plays a key role in Cervico-Brachial Neuralgia (CBN) assessment. Other paraclinical explorations may help and in our laboratory, Electro-Neuro-Myography (ENMG) and Somesthesic Evoked Potentials (SEPs) are commonly performed as part of the CBN assessment. In this study, we wanted to identify the contribution of each of the different radiological and neurophysiological exams in the diagnosis of CBN.Methods: This is a retrospective study over a one-year period, performed in patients received in one neurophysiological laboratory in Dakar for a clinical suspicion of CBN and who performed also cervical radiological exams: standard radiography and/or CTscan and/or MRI. For these patients, we performed an ENMG of the upper limbs with the study of latencies, amplitudes, Nerve conduction velocity, F waves latencies, followed by Detection of muscles of the upper limbs. We coupled ENMG with the study of SEPs of the upper limbs by finger‘s stimulation of root territories with recorded of N9, N13 and N20 waves.Results: 14 patients were included in the study, 8/14 radiological exams were abnormal and most of the cases show lesions of cervical arthrosis. ENMG was normal for 13/14 patients, the only abnormality was an axonopathy of the ulnar nerve for a patient whose SEPs were in favor of polyradiculopathies. For only 1/14 patients, all exams (imaging, ENMG and SEPs) were normal. The others 13 patients had long latencies SEPs in favor of C6 and/or C7 and/or C8 polyradiculopathies. For these 13 patients, 05 had normal imaging.Comments: Normal imaging and neurophysiological exams do not rule out a CBN. The contribution of these different exams is for positive, differential and etiological diagnosis. It seems important to link all these exams to optimize the CBN diagnosis

Characterization of element and mineral content in Artemisia annua and Camellia sinensis leaves by handheld X-ray fluorescence

Tea infusion is the most frequently worldwide consumed beverage next to water, with about 20 billion cups consumed daily. Artemisia annua leaves contain comparable levels of nutrients and mineral elements (dry matter basis) to many marketed tea (Camellia sinensis) leading us to suspect that this crop could also serve as an alternative source of nutrients for humans. Analyzer moveable X-ray fluorescence is used to evaluate the content of major, minor and toxic elements in A. annua from two different countries compared to six marketed tea in Senegal. To ensure qualified results, certified reference materials were used to perform the calibration. The very low and often negligible levels of inherent elements in the leaves, which are far below recommended toxic levels, establishes A. annua and selected marketed tea as a good reservoir of elements that might favour its use as a potential herbal tonic by humans. The mineral elements are present in different kinds of herbal leaves in various proportions depending on soil composition and the climate in which the plant grows.Keywords: X-ray fluorescence (XRF), Artemisia annua, Camellia sinensis, elements, leaves, medicinal plantAfrican Journal of Biotechnology Vol. 12(26), pp. 4179-418