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Background: Calcium (Ca) and magnesium (Mg) are crucial in metabolism, excitability and neuroglial plasticity. Our aim was to evaluate whether Mg (20 mg/kg) or Ca (100 mg/kg) could improve the memory prognosis in the kainic model of mesial temporal epilepsy. Methods: Seizures were induced by systemic injection of kainate (8mg/kg) and mice were then treated by ions every 48 hours. A placebo (physiological solution) replaced kainate or ions in specific groups. Six cohorts were studied for seven weeks: control group (G0: no kainate and no ion, only placebo); untreated reference group (GR: kainate and then placebo); G1 groups were treated from the third day (G1m, G1c: kainate and then Mg/Ca); G2 groups were treated from the third week (G2m, G2c: kainate and then Mg/Ca). Radial maze and a classic maze were used for cognition evaluation. Results: The memory (short/long term) was differently affected by kainate or improved by Mg/Ca. The treated groups performed better than GR mice, but Mg was more effective. In addition, Mg demonstrated an increasing therapeutic effect over time while Ca showed an acute and apparently decreasing action in the G1c group. Conclusions: Mg should be considered for a clinical evaluation of its effect on epileptic disorders.
The 2017 plague outbreak in Madagascar was unprecedented in the African region, resulting in 2417 cases (498 confirmed, 793 probable and 1126 suspected) and 209 deaths by the end of the acute urban pneumonic phase of the outbreak. The Health Emergencies Programme of the WHO Regional Office for Africa together with the WHO Country Office and WHO Headquarters assisted the Ministry of Public Health of Madagascar in the rapid implementation of plague prevention and control measures while collecting and analysing quantitative and qualitative data to inform immediate interventions. We document the key findings of the evidence available to date and actions taken as a result. Based on the four goals of operational research – effective dissemination of results, peer-reviewed publication, changes to policy and practice and improvements in programme performance and health – we evaluate the use of evidence to inform response to the outbreak and describe lessons learned for future outbreak responses in the WHO African region. This article may not be reprinted or reused in any way in order to promote any commercial products or services.
This work reports on the synthesis and the main physical and chemical properties of ZnO nanoparticles synthesized by an entirely green Bio-physical-chemical process using natural dye extract from Adansonia digitata leaves as an efficient reduction/oxidizing agent. Their structural and surfaces properties by electron microscopy, X-rays diffraction, Raman and TGA, as well as gas adsorption analysis are reported.
We examined the association between a history of smallpox vaccination and immune activation (IA) in a population of antiretroviral therapy-naïve people living with HIV (PLHIV). A cross-sectional study was conducted in Senegal from July 2015 to March 2017. Smallpox vaccination was ascertained by the presence of smallpox vaccine scar and IA by the plasma level of β-2-microglobulin (β2m). The association was analysed using logistic regression and linear regression models. The study population comprised 101 PLHIV born before 1980 with a median age of 47 years (interquartile range (IQR) = 42–55); 57·4% were women. Smallpox vaccine scar was present in 65·3% and the median β2m level was 2·59 mg/l (IQR = 2·06–3·86). After adjustment, the presence of smallpox vaccine scar was not associated with a β2m level ⩾2·59 mg/l (adjusted odds ratio 0·94; 95% confidence interval 0·32–2·77). This result was confirmed by the linear regression model. Our study does not find any association between the presence of smallpox vaccine scar and the β2m level and does not support any association between a previous smallpox vaccination and HIV disease progression. In this study, IA is not a significant determinant of the reported non-targeted effect of smallpox vaccination in PLHIV.
The 9th meeting of the African Society of Human Genetics, in partnership with the Senegalese Cancer Research and Study Group and the Human Heredity and Health in Africa (H3Africa) Consortium, was held in Dakar, Senegal. The theme was Strengthening Human Genetics Research in Africa. The 210 delegates came from 21 African countries and from France, Switzerland, UK, UAE, Canada and the USA. The goal was to highlight genetic and genomic science across the African continent with the ultimate goal of improving the health of Africans and those across the globe, and to promote the careers of young African scientists in the field. A session on the sustainability of genomic research in Africa brought to light innovative and practical approaches to supporting research in resource-limited settings and the importance of promoting genetics in academic, research funding, governmental and private sectors. This meeting led to the formation of the Senegalese Society for Human Genetics.
In this paper, we study the strong candidate stability of a voting procedure as denned by Dutta et al.  through the experimental method. In this sense, a voting rule is said to be strongly candidate stable if the winner of the election remains unchanged after an attempted manipulation by strategic candidacy of a potential candidate. In an election with three candidates and a small electorate, we evaluate experimentally frequencies of the strong candidate stability of parliamentary voting rules and plurality.
Since its introduction in the late 19th century, symmetry breaking has been found to play a crucial role in physics. In particular, it appears as one key phenomenon controlling hydrodynamic and acoustic instabilities in problems with rotational symmetries. A previous paper investigated its desired potential application to the control of circumferential thermoacoustic modes in one annular cavity coupled with multiple flames (Bauerheim et al., J. Fluid Mech., vol. 760, 2014, pp. 431–465). The present paper focuses on a similar problem when symmetry breaking appears unintentionally, for example when uncertainties due to tolerances are taken into account. It yields a large uncertainty quantification (UQ) problem containing numerous uncertain parameters. To tackle this well-known ‘curse of dimensionality’, a novel UQ methodology is used. It relies on the active subspace approach to construct a reduced set of input variables. This strategy is applied on two annular cavities coupled by 19 flames to determine its modal risk factor, i.e. the probability of an azimuthal acoustic mode being unstable. Since each flame is modelled by two uncertain parameters, it leads to a large UQ problem involving 38 parameters. An acoustic network model is then derived, which yields a nonlinear dispersion relation for azimuthal modes. This nonlinear problem, subject to bifurcations, is solved quasi-analytically. Results show that the dimension of the probabilistic problem can be drastically reduced, from 38 uncertain parameters to only 3. Moreover, it is found that the three active variables are related to physical quantities, which unveils underlying phenomena controlling the stability of the two coupled cavities. The first active variable is associated with a coupling strength controlling the bifurcation of the system, while the two others correspond to a symmetry-breaking effect induced by the uncertainties. Thus, an additional destabilization effect appear caused by the non-uniform pattern of the uncertainty distribution, which breaks the initial rotating symmetry of the annular cavities. Finally, the active subspace is exploited by fitting the response surface with polynomials (linear, quadratic and cubic). By comparing accuracy and cost, results prove that 5 % error can be achieved with only 30 simulations on the reduced space, whereas 2000 are required on the complete initial space. It exemplifies that this novel UQ technique can accurately predict the risk factor of an annular configuration at low cost as well as unveil key parameters controlling the stability.
The main target of this paper is to determine the seasonal features of the wind speed in
the northwestern of Senegal and to assess the cost of annual energy output using wind
turbines provided from several manufactures. The wind data used for this study were
collected in four sites located in the northwestern coast of Senegal and cover the period
of one year. The seasonal mean wind speed and the annual distribution curves were obtained
by using the Weibull distribution function. A technical assessment of electricity
generation from five big wind turbines which power is between 640 kW and 2000 kW and from
six small wind turbines which power is between 250 W and 10 kW were carried out. The
results obtained show that the lower cost (0.0265 €/kWh in Sokhar) was observed for the
wind turbine Ecotècnia 62. The highest cost was 0.5103 €/kWh (in Gandon) observed for the
technology of Alize. All wind turbines was better suited to the site of Sokhar with the
highest capacity factor and the lowest cost of output energy.
Introduction. Detarium senegalense J.F. Gmel is
a forest tree found in Senegal whose fruits are locally called ditax in Wolof. It is eaten
fresh but it is widely used as nectar, which is one of the most popular beverages in
Senegal. However, the chemical characterization of ditax pulp remains incomplete. This
paper describes the volatile compounds of ditax to assess its organoleptic qualities.
Materials and methods. Free volatile compounds of fresh ditax pulp were
isolated by solvent-assisted flavor evaporation and analysis by GC-MS. Results and
discussion. Among the 53 compounds tentatively identified, 49 are reported for
the first time in this fruit. In total, 17 aldehydes, 11 aliphatic alcohols, 1 terpene
alcohol, 7 free fatty acids, 3 unsaturated hydrocarbons, 1 terpene hydrocarbon, 7
sesquiterpene hydrocarbons, 1 phenol, 2 ketones, 2 esters and 1 organic acid compound were
tentatively identified in ditax fresh pulp. The main volatiles identified in fresh ditax
pulp were trans, cis-2,6-nonadienal (2.47 mg×kg–1),
cis-2-heptenal (1.93 mg×kg–1), trans-a-bergamotene
(1.11 mg×kg–1), bicyclo [2,2,0] hexane-1-carboxaldehyde (0.80 mg×kg–1), butyl
octadecanoate (0.55 mg×kg–1) and trans-2-nonenal (0.47 mg×kg–1 fresh
pulp). Conclusion. Among the volatile compounds identified, aldehyde
compounds were widely predominant. To assess the aromatic qualities of ditax pulp, the
primary impact aromas should be determined by identifying the aroma-active compounds by
Introduction. African fruit production, as well as regional and
international fruit trade, have experienced heavy economic losses over the past decade due
to the damage caused by fruit flies, especially B. invadens Drew Tsuruta
& White (Tephritidae: Diptera). Bactrocerainvadens
attacks fruits belonging to numerous botanical families, several of which are of great
economic importance. The females of these flies generally lay their eggs in mature fruits,
but some can lay in green-immature fruits. Materials and methods. The
influence of the species, variety and phenology of fruits on the fruit attractiveness to
B. invadens and the elicitation of B. invadens
egg-laying behaviour were studied in the laboratory. Fruits harvested regularly during the
years 2008 and 2009 from orchards in the Niayes area (Senegal) were exposed to gravid
females in cages set for the different factors tested. The exposed fruits were then
incubated and the pupae emerging from them were counted. Results and
discussion. Bactrocera invadens females laid eggs in ripe
fruits. Within the same fruit species, the variety plays an important role in egg-laying
preference. Hence, among the mango varieties tested, the Pêche variety hosted the highest
number of pupae per fruit, while the Palmer variety hosted the lowest number. Comparison
among different fruit species showed that mature papaya was more infested than mature
mango or citrus. Furthermore, flies were unable to develop on lime.
Conclusion. Our study showed that B. invadens can infest
green and ripe host fruits, and even immature abscised fruits. Consequently, management of
this pest must include preventive measures in the development and implementation of an
integrated management system.
The current study was designed to increase the spermatological ultrastructural database on Digenea, thus contributing to the future establishment of phylogenetic relationships within this group based on ultrastructural characteristics of both spermiogenesis and spermatozoa. Spermiogenesis in Elstia stossichianum begins with the formation of a differentiation zone containing two centrioles, two striated rootlets, a nucleus, several mitochondria and an intercentriolar body constituted by seven electron-dense layers. Each centriole develops into a free flagellum growing orthogonally to the median cytoplasmic process. Proximo-distal fusion of the flagella with the median cytoplasmic process occurs after flagellar rotation. Both nucleus and mitochondria migrate before the complete proximo-distal fusion of both flagella with the median cytoplasmic process. Finally, the constriction of the ring of arched membranes gives rise to the young spermatozoon. The mature spermatozoon of E. stossichianum exhibits two axonemes of different length of the 9+‘1’ trepaxonematan pattern, a nucleus, a mitochondrion, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, a lateral expansion, spine-like bodies, cytoplasmic ornamented buttons and granules of glycogen. The formation of cytoplasmic ornamented buttons during the final stages of spermiogenesis is reported here for the first time.
Introduction. Senegal produces
up to 150,000 t of fruit, of which 60,000 t are mangoes. Fruit production
is important for the Niayes region, where 60% of total production
is of mangoes, with citrus production coming next at 24%. Mango losses
have become more substantial since the arrival of Bactrocera
invadens in Senegal. The pest population increases in the mango
ripening period, but little is known about its secondary hosts. Materials
and methods. Fruits of cultivated and wild plants were collected
regularly from April to December 2008 inside and around 19 orchards in
eleven localities in the Niayes and Thiès areas in Senegal. The
samples were monitored to identify any fruit flies present so that
a list of host plants could be compiled. For mango, the study focused
on establishing the influence of certain parameters such as the
variety, the fruit size, the color, the flowering pattern and the
physiological levels of infestation due to B. invadens and
Ceratitis cosyra. Orchards were classified either as traditional (many
mango varieties and many fruit species grown together in a stand) or
intensive (fields of monovarietal mango trees), according to their
composition and how they were managed. Results and discussion.
A total of 663.2 kg of fruit, including those of 24 mango varieties,
13 citrus species with five lime varieties, two orange varieties
and four pomelo varieties along with other cultivated and wild plants,
were sampled both as fallen fruit and from the trees. Traditional orchards
were more infested than the modern ones. B. invadens was significantly
dominant over the other flies emerging such as C. cosyra,
C. capitata, C. punctata, C. bremii,
Bactrocera cucurbitae, Capparimyia bipustulata,
Carpomyia sp. and Dacus sp. B. invadens was
found on the 24 varieties of Mangifera indica,
the 13 citrus species, and the other cultivated
plants and wild plants sampled. Some host plants supported a relatively
high level of fruit flies before the mango ripening period. Mangifera indica was
infested principally by B. invadens and C. cosyra.
C. cosyra was significantly present on the first
fruit trees to flower, mostly in early varieties, while B.
invadens infested all the varieties whatever the fruit
development stage, the color, or the flowering pattern. Conclusion.
Because of the host plants' diversity and varieties the traditional
orchards were more infested than the modern ones. The management
of this pest needs an Integrated Pest Management system based on
a back-to-basics study of the infesting fruit flies, existing parasitoids
and their hosts.
Powdered maize cobs were tested as an alternative for pesticide use in stored maize. Five doses (2, 4, 6, 8 and 10 g/250 g seed) of powdered maize cobs applied at particle sizes of 1.4 and 0.4 mm diameter were compared with actellic powder against Sitophilus zeamais Motschulsky for 120 days. Mortality and survival data showed that cob powders did not act as fumigant but exerted a potent inhibition of progeny on direct contact with S. zeamais adults. The particle size of powdered cobs had no effect on maize damage and losses. At doses equal to or higher than 6 g powdered maize cobs/250 g grain maize, i.e. 2.4% (w/w), damage to grain was < 5% and weight losses < 1%. The protection offered at the highest dose was comparable to the pesticide control. The use of powdered maize cobs is discussed as a natural alternative to synthetic pesticides for protection of maize against S. zeamais.
ZnO nanorods arrays were prepared on soda lime glass substrate by pulsed laser deposition method. Hexagonal rod-like ZnO rods were obtained under different conditions. Well-defined ZnO nanorods arrays were selected among different samples having various morphologies and sizes already studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). Here, we report on the contact angle measurement (CAM) of one of these samples. A systematic change of the surface wettability is observed in W-doped ZnO nanostructures. The water contact angle (WCA) of a 1 wt.% of WO3 target content was found to be the transition doping level from hydrophilic surface to a hydrophobic surface. We attributed the transition in surface wettability of the film with the doping to incorporation increase of tungsten into the film. Such characteristic surface wettability can play a key role in the adhesion of various layers on W-ZnO nanorods arrays for optoelectronic device applications.
Introduction. Many desirable properties make cloudy fruit juice widely produced according to consumer acceptance. The pulp of mango (Mangifera indica L.), a good source of carbohydrates and water, has many uses including the production of juice. Nowadays, the use of food enzymes has become widespread in the juice industry for various reasons. However, the application of enzymes has not yet been tested in the context of the production of cloudy mango juice, except for the stabilization of nectars. Thus, the aim of our study was to examine and optimize some parameters involved in the enzymatic production of cloudy mango juice. Materials and methods. To achieve our objective, we used Response Surface Methodology (RSM) by combining five factors: time (30–50 min), temperature (35–55 °C), pH 4–5.5, Pectinexr Ultra SP-L (20–40 μL·L-1) and Cellubrixr L (15–25 μL· L-1). Results and discussion. The study of juice yield, cloud stability and the browning index showed that the coefficients of determination (R2 values) of these traits with the studied parameters were greater than 0.900. The optimized juice yield, cloud stability and browning index varied with specific values chosen for the five parameters mentioned above. Conclusions. Finally, the use of 30 μ L·L-1 Pectinexr Ultra SP-L and 22 μL·L-1 Cellubrix at 45 °C, for 43 min, at pH 5.5, was found to be the optimum set of conditions for processing cloudy mango juice.
Introduction. Knowledge of tephritid diversity in Senegal was poor before
2004, so PIP-COLEACP and CIRAD, in collaboration with Cérès-DPV, carried out, in 2004,
trapping for preliminary detection of fruit flies in six orchards in the Niayes zone.
Materials and methods. We selected three mixed mango orchards and three
homogeneous mango orchards in this zone. In each orchard, we used three attractants:
Terpinyl acetate (Ter), Trimedlure (Tri) and Torula (Tor). Traps were serviced weekly.
Results. We captured 77 642 fruit flies in more than 4 months including
mango season; they were represented by 18 identified fly species, including ten
Ceratitis, six Dacus and two Bactrocera
species. Two very serious pests were identified with the confirmation of
Bactrocera cucurbitae (Coquillett) for cucurbit crops and the detection
of B. invadens Drew Tsuruta & White for fruit crops. The two most
abundant species of Ceratitis were C. cosyra and
C. silvestrii. Discussion. We captured more fruit fly
species in mixed mango orchards than in homogeneous mango orchards. Bactrocera
invadens was also more abundant in mixed orchards, probably because of its
polyphagous status. This new invasive species, B. invadens, can have many
hosts in mixed mango orchards, enhancing its breeding potential. Conclusion.
Effective management to deal with this alien species requires: (i) improvement of basic
and applied research; (ii) an effective IPM package; (iii) an area-wide management
approach; (iv) a sub-regional effort on the part of researchers, extension services,
growers, exporters, farming associations and the different actors in fruit value chains
Optical properties of GaN templates grown by the Epitaxial Lateral Overgrowth (ELO) technique along the nonpolar (1120) and the semipolar (1122) directions on R- and M-sapphire were investigated. Spatially resolved Cathodoluminescence (CL) was carried out in order to identify defect related transitions, to resolve their localization and to study the efficiency of ELO concerning defect filtration. The wing region of semipolar GaN is shown to be almost defect free with a luminescence spectrum dominated by the GaN emission at 3,472 eV. It is shown that the defect related emissions are localized in the seed, but different defects occur as well in the wing, especially in A-plane (nonpolar) GaN.
Introduction. Tamarind (Tamarindus indica L.) belongs to
the Fabaceae family; it is a multipurpose tree with slow growth. In order to help improve
its growth and development, we assessed mycorrhizal diversity of tamarind parklands in
Senegal. Materials and methods. Three sites of tamarind populations were
sampled for each agro-ecological zone in Senegal: the Sahelian zone (i), Sahelo-Sudan zone
(ii) and Sudan zone (iii). Soil and root samples were collected in each site and used for
arbuscular mycorrhizal (AM) spore isolation and root colonization assessment. We
identified the mycorrhizal fungi from spore collections and evaluated the root
mycorrhization rate, defined as percentage of roots colonized according to agro-ecological
zones. Results and discussion. The results did not reveal a specific AM
fungal strain associated with tamarind plants. Three arbuscular mycorrhizal fungi (AMF)
were identified from spores on the genus level: Glomus,
Scutellospora and Acaulospora. Tamarind sites with
sandy soil texture (70–90%) and located in dry areas (Sahel and Sudano-Sahel zones) were
shown to be rich in mycorrhizal propagules. High densities of soil AM propagules evaluated
with the Most Probable Number method (MPN) were found in Niokhoul (1100 propagules per 50
g of soil), Sakal (790 propagules per 50 g of soil) and Mbassis (780 propagules per 50 g
of soil). However, higher mycorrhizal colonization (11%) was observed in the Sahel
agro-ecological zone compared with the Sudano-Sahelian and Sahelian zones (3%) of Senegal.
Conclusion. Our study explored natural AMF diversity as a starting point to
develop inocula to be used in commercial nursery production of tamarinds.
Botanique. Originaire d’Afrique tropicale, Detarium
senegalense J.F. Gmel. appartient à la famille des Caesalpiniaceae et au genre
Detarium Juss. C’est un grand arbre multicaule de (15 à 40) m de haut.
Ses feuilles sont composées, paripennées, avec cinq à six paires de folioles opposées,
disposées de manière alterne. Répartition. D. senegalense
est rencontré sur les lisières de la forêt dense humide, dans les régions côtières,
septentrionales et dans la zone soudano-guinéenne. Désigné par le terme « ditax » en
Wolof, D. senegalense fait partie des espèces fruitières forestières les
plus importantes dans l’économie d’exploitation au Sénégal. Il pousse de façon sauvage
dans les îles du Sine-Saloum et en Casamance. Composition et transformation.
Le fruit est caractérisé par sa pulpe verte très riche en vitamine C (plus de
1 g·100 g–1). C’est un fruit très populaire et largement consommé au Sénégal
principalement sous forme de boisson, de marmelade, de sorbet ou à l’état frais. Le fruit
possède également des vertus thérapeutiques contre la toux, les maux de reins et la lèpre.
Certaines variétés de D. senegalense produisent des fruits toxiques mais
les composés responsables de la toxicité n’ont pas encore été totalement identifiés.
Aucune méthode objective permettant de différencier les fruits comestibles des fruits
toxiques n’est disponible à l’heure actuelle. Bilan. Malgré ses potentialités
nutritionnelles et organoleptiques, le ditax reste sous-exploité. Dès lors, la
caractérisation biochimique complète des fruits, l’évaluation du potentiel technologique,
le développement de méthodes de détection rapide des fruits toxiques et l’amélioration de
la stabilité des produits transformés à base de ditax seraient des perspectives de
recherches intéressantes pour mieux valoriser ce fruit riche en vitamine C. La culture
contrôlée de la plante mériterait également d’être envisagée pour le développement de la
In 2005, a serological study was carried out on horses in five ecologically contrasted zones of the Senegal River basin (Senegal) to assess West Nile virus (WNV) transmission and investigate underlying environmental risk factors. In each study zone, horses were randomly selected and blood samples taken. A land-cover map of the five study areas was built using two satellite ETM+ images. Blood samples were screened by ELISA for anti-WNV IgM and IgG and positive samples were confirmed by seroneutralization. Environmental data were analysed using a principal components analysis. The overall IgG seroprevalence rate was 85% (n=367; 95% CI 0·81–0·89). The proximity to sea water, flooded banks and salted mudflats were identified as protective factors. These environmental components are unfavourable to the presence of Culex mosquitoes suggesting that in Senegal, the distribution of the vector species is more limiting for WNV transmission than for the hosts' distribution.