264 research outputs found
Effets des demi-lunes associées au scarifiage sur les productions fourragères en région sahélienne du Burkina Faso
L’effet des demi-lunes associées au scarifiage sur la production fourragère a été étudié dans quatre terroirs sahéliens. Des parcelles d’observation de un ha sur terrain aménagé en demi-lune et un ha sur un témoin respectif ont été mises en place. Les observations ont concerné l’analyse de la composition floristique, la valeur fourragère et le recouvrement. Les résultats obtenus montrent une amélioration de la composition floristique et le recouvrement de la végétation. Les espèces fourragères telles Panicum laetum (+9,8%), Cassia obtusifolia (+17,1%) et Alysicarpus ovalifolius (+2,7%) ont connu une amélioration tandis que Schoenefeldiagracilis (-30%) et Eragrostis tenella (-1,1%) ont subit une régression. La production de fourrage a augmenté significativement (P < 0,05) entre les parcelles aménagées (2115,9 kg de MS.ha-1) et les témoins (463 kg deMS.ha-1). Cependant, l’apparition de Cassia obtusifolia en très forte contribution spécifique suggère que des essais d’alimentation soient menés sur cette espèce pour mieux valoriser l’impact des aménagements en demilune surtout qu’elle est bien appétée à l’état sec. Les demi-lunes + scarification sont rentables mais des recherches doivent cependant être menées pour trouver les modalités de gestion des espaces aménagés, afin d’éviter leur surexploitation et leur dégradation.Mots clés : Pâturage, fourrage, dégradation, Sahel, Burkina Faso
T-cell epitope polymorphisms of the Plasmodium falciparum circumsporozoite protein among field isolates from Sierra Leone: age-dependent haplotype distribution?
<p>Abstract</p> <p>Background</p> <p>In the context of the development of a successful malaria vaccine, understanding the polymorphisms exhibited by malaria antigens in natural parasite populations is crucial for proper vaccine design. Recent observations have indicated that sequence polymorphisms in the C-terminal T-cell epitopes of the <it>Plasmodium falciparum </it>circumsporozoite protein (Pf<it>csp</it>) are rather low and apparently stable in low endemic areas. This study sought to assess the pattern in a malaria endemic setting in Africa, using samples from Freetown, Sierra Leone.</p> <p>Methods</p> <p>Filter-paper blood samples were collected from subjects at a teaching hospital in Freetown during September–October 2006 and in April–May 2007. The C-terminal portion of the Pf<it>csp </it>gene spanning the Th2R and Th3R epitopes was amplified and directly sequenced; sequences were analysed with subject parameters and polymorphism patterns in Freetown were compared to that in other malaria endemic areas.</p> <p>Results and Discussion</p> <p>Overall, the genetic diversity in Freetown was high. From a total of 99 sequences, 42 haplotypes were identified with at least three accounting for 44.4% (44/99): the 3D7-type (19.2%), a novel type, P-01 (17.2%), and E12 (8.1%). Interestingly, all were unique to the African sub-region and there appeared to be predilection for certain haplotypes to distribute in certain age-groups: the 3D7 type was detected mainly in hospitalized children under 15 years of age, while the P-01 type was common in adult antenatal females (Pearson Chi-square = 48.750, degrees of freedom = 34, <it>P </it>= 0.049). In contrast, the single-haplotype predominance (proportion > 50%) pattern previously identified in Asia was not detected in Freetown.</p> <p>Conclusion</p> <p>Haplotype distribution of the T-cell epitopes of Pf<it>csp </it>in Freetown appeared to vary with age in the study population, and the polymorphism patterns were similar to that observed in neighbouring Gambia, but differed significantly at the sequence level from that observed in Asia. The findings further emphasize the role of local factors in generating polymorphisms in the T-cell epitopes of the <it>P. falciparum </it>circumsporozoite protein.</p
Distribution, characterization and the commercialization of elite Rhizobia strains in Africa
Grain legumes play a significant role in smallholder farming systems in Africa because of their contribution to nutrition and income security and their role in fixing nitrogen. Biological Nitrogen Fixation (BNF) serves a critical role in improving soil fertility for legumes. Although much research has been conducted on rhizobia in nitrogen fixation and their contribution to soil fertility, much less is known about the distribution and diversity of the bacteria strains in different areas of the world and which of the strains achieve optimal benefits for the host plants under specific soil and environmental conditions. This paper reviews the distribution, characterization, and commercialization of elite rhizobia strains in Africa
Ureteroscopie Retrograde: Expérience de l’Hôpital Général Grand Yoff de Dakar
But: Présenter les résultats de la pratique de l’urétéroscopie à l’Hôpital Général Grand Yoff (HOGGY) de Dakar (Sénégal).Sujets et méthodes: Il s’agit d’une étude descriptive de 91 urétéroscopies effectuées dans le service d’Urologie de l’Hôpital Général Grand Yoff de janvier 2012 à décembre 2013. Les variables de l’étude étaient l’indication, l’âge, la nature de l’urétéroscopie associées ou non au laser, les résultats de la lithotripsie.Résultats: Sept urétéroscopies diagnostiques et 84 urétéroscopies thérapeutiques ont été effectuées. L’âge moyen des patients était de 44,7 ans + - 13,9 ans. L’urétéroscope semi rigide a été utilisé dans 43 cas, l’urétéroscope souple dans 15 cas, l’urétéroscope rigide dans 9 cas. La topographie du calcul était pyélique dans 30 cas, lombaire dans 28 cas, pelvienne dans 13 cas, calicielle dans 10 cas et iliaque dans 3 cas. Le nombre de calcul fragmenté au laser était de 87 calculs. Les complications étaient dominées par les fausses routes dans 8 cas. Le succès global de l’urétéroscopie était de 85,7%.Conclusion: La pratique courante de l’urétéroscopie constitue un défi pour l’urologue en Afrique subsaharienne. Elle est devenue le traitement de choix de la lithiase de la voie excrétrice supérieure.Mots clés: ithiase; Urétéroscopie; Laser; Sonde JJEnglish AbstractObjective: To present the results of the ureteroscopy at the GrandYoff General Hospital (Hoggy) in Dakar (Senegal).Subjects and methods: This is a descriptive study of 91 ureteroscopy procedures performed at the Urology department of Grand Yoff General Hospital from January 2012 to December 2013. The variables of the study were indication, age, type of ureteroscopy associate or no laser, results of lithotripsy.Results: Seven diagnostic ureteroscopy and 84 therapeutic ureteroscopy were done. The average age of the patients was 44.7 years + - 13,9 years. Semi-rigid ureteroscope was used in 43 cases, flexible ureteroscope in 15 cases and rigid ureteroscope in 9 cases. The location of the stones was renal pelvis in 30 cases, upper ureter in 28 cases, distal ureter in 13 cases, calix in 10 cases and middle ureter in 3 cases. The number of laser (Nd:Yag) fragmented stones was 87. Complications were dominated by false passages in 8 cases. The overall success of endoscopic treatment was 85.7%.Conclusion: The current practice of endoscopic treatment for upper urinary tract stone is quite challenging to the urologist practising in sub- Sahara Africa. The effectiveness and lesser morbidity of laser lithotripsy has made it the treatment of choice for upper urinary tract stones.Keywords: Lithiasis; Ureteroscopy; Laser; JJ sten
How can health systems be strengthened to control and prevent an Ebola outbreak? a narrative review
The emergence and re-emergence of infectious diseases are now more than ever considered threats to public health systems. There have been over 20 outbreaks of Ebola in the past 40 years. Only recently, the World Health Organization has declared a public health emergency of international concern (PHEIC) in West
Africa, with a projected estimate of 1.2 million deaths expected in the next 6 months. Ebola virus is a highly
virulent pathogen, often fatal in humans and non-human primates. Ebola is now a great priority for global
health security and often becomes fatal if left untreated. This study employed a narrative review. Three major databases MEDLINE, EMBASE, and Global Health were searched using both ‘text-words’ and
‘thesaurus terms’. Evidence shows that low- and middle-income countries (LMICs) are not coping well with
the current challenges of Ebola, not only because they have poor and fragile systems but also because there are poor infectious disease surveillance and response systems in place. The identification of potential cases is problematic, particularly in the aspects of contact tracing, infection control, and prevention, prior to the diagnosis of the case. This review therefore aims to examine whether LMICs’ health systems would be able to control and manage Ebola in future and identifies two key elements of health systems strengthening that are needed to ensure the robustness of the health system to respond effectively
Establishing an antimicrobial stewardship program in Sierra Leone: a report of the experience of a low-income country in West Africa
Antimicrobial Resistance (AMR) is a growing global health challenge that threatens to undo gains in human and animal health. Prevention and control of AMR requires functional antimicrobial stewardship (AMS) program, which is complex and often difficult to implement in low- and middle-income countries. We aimed to describe the processes of establishing and implementing an AMS program at Connaught Hospital in Sierra Leone. The project involved the setting up of an AMS program, capacity building and performing a global point prevalence survey (GPPS) at Sierra Leone's national referral hospital. Connaught Hospital established a multidisciplinary AMS subcommittee in 2021 to provide AMS services such as awareness campaigns, education and training and review of guidelines. We performed a GPPS on 175 patients, of whom more than half (98, 56.0%) were prescribed an antibiotic: 63 (69.2%) in the surgical wards and 53 (51.2%) in the medical wards. Ceftriaxone (60, 34.3%) and metronidazole (53, 30.3%) were the most common antibiotics prescribed to patients. In conclusion, it is feasible to establish and implement an AMS program in low-income countries, where most hospitalized patients were prescribed an antibiotic
Niger
Niger is a landlocked country in West Africa located between 11°37´ and
23°23´ north latitude and between 00°10´ and 16°00´ east longitude,
with an area of 1,267,000 square kilometers. Niger shares borders with
Algeria and Libya in the north, Chad in the east, Nigeria and Benin in the
south, and Burkina Faso and Mali in the west. Three-fourths of Niger is covered
by the Sahara Desert. The southern part of the country is in the Sahelian
climate zone, with Sudan savannah vegetation. The rainy season lasts for only
three months, with total rainfall ranging from 150 to 600 millimeters per
year in the Sudan savannah; maximum temperatures are high (45°C in the
shade in April–May). The vegetation cover is sparse, and nomadic agriculture
is dominant..
Burkina Faso
Burkina Faso is a landlocked country in West Africa covering about
274,000 square kilometers. It is bordered by the Republic of Mali on the
north and west; by Cote d’Ivoire on the Southwest; by Ghana, Togo, and
Benin on the South; and by Niger on the east. The country has a dry tropical
climate with two contrasting seasons. The rainy season generally lasts from
May to October, but its duration decreases progressively from the southwest,
amounting to only three months in the northern part of the country.
Agriculture accounts for 40 percent of the gross domestic product (GDP)
and 60 percent of the total exports of Burkina Faso. Its cropped area is 3.5–
4.0 million hectares, representing about 13 percent of the country’s total area
and one-third of the arable land. Rainfed agriculture dominates, with largely
rudimentary agricultural techniques prevailing among small-scale farmers.
Crop production is more diversified in the Sudanian zone (in the southwest),
with a variety of roots and tubers (yams, sweet potatoes, and cocoyams), fruits
(mangoes, bananas, and citrus fruits), cashews, and sugarcane. The major cash
crops are cotton, groundnuts, cowpeas, and sesame..
Advanced magnetic resonance imaging and neuropsychological assessment for detecting brain injury in a prospective cohort of university amateur boxers
The safety of amateur and professional boxing is a contentious issue. We hypothesised that advanced magnetic resonance imaging and neuropsychological testing could provide evidence of acute and early brain injury in amateur boxers.
We recruited 30 participants from a university amateur boxing club in a prospective cohort study. Magnetic resonance imaging (MRI) and neuropsychological testing was performed at three time points: prior to starting training; within 48 hours following a first major competition to detect acute brain injury; and one year follow-up. A single MRI acquisition was made from control participants. Imaging analysis included cortical thickness measurements with Advanced Normalization Tools (ANTS) and FreeSurfer, voxel based morphometry (VBM), and Tract Based Spatial Statistics (TBSS). A computerized battery of neuropsychological tests was performed assessing attention, learning, memory and impulsivity.
During the study period, one boxer developed seizures controlled with medication while another developed a chronic subdural hematoma requiring neurosurgical drainage. A total of 10 boxers contributed data at to the longitudinal assessment protocol. Reasons for withdrawal were: logistics (10), stopping boxing (7), withdrawal of consent (2), and development of a chronic subdural hematoma (1). No significant changes were detected using VBM, TBSS, cortical thickness measured with FreeSurfer or ANTS, either cross-sectionally at baseline, or longitudinally. Neuropsychological assessment of boxers found attention/concentration improved over time while planning and problem solving ability latency decreased after a bout but recovered after one year.
While this neuroimaging and neuropsychological assessment protocol could not detect any evidence of brain injury, one boxer developed seizures and another developed a chronic sub-dural haematoma.PJH is supported by a NIHR Research Professorship. VFJN is supported by a Health Foundation / Academy of Medical Sciences Clinician Scientist Fellowship. BJS holds a grant from the NIHR Brain Injury Healthcare Technology Co-operative. This study was supported through the Cambridge National Institute for Health Research (NIHR) Biomedical Research Centre (BRC). Control data were acquired with the support of the Medical Research Council as part of their Addiction Initiative (grant number G1000018), and a Pathfinder award from Medical Research Council (G0401099)
Ghana
Including inland water bodies, Ghana covers 238,539 square kilometers and
is located on the south central coast of West Africa. The country shares borders
in the east with Togo, in the north with Burkina Faso, and in the west
with Côte d’Ivoire. The topography of Ghana is mainly undulating, with most
slopes less than 5 percent and many not exceeding 1 percent. The topography
of the high rainforest is, however, mainly strongly rolling. The uplifted edges
of the Voltarian basin give rise to narrow plateaus between 300 and 600 meters
in elevation (Boateng 1998). Moving from the rainforest zone in the south to
the Sahara Desert in the north, rainfall generally decreases and temperature
increases. Rainfall is the most important climatic factor influencing vegetation
in Ghana. The wettest area is in the extreme southwest, where the rainfall is
over 2,000 millimeters per year. In the extreme north, the annual rainfall is less
than 1,100 millimeters. The driest area is at the southeastern coastal tip, where
the rainfall is about 750 millimeters. Much of the rain falls in intense storms
of short duration, especially at the beginning of the season, resulting in heavy
runoff and erosion. The annual mean relative humidity is about 80 percent in
the south and 44 percent in the north (Dickson and Benneh 1988). The mean
monthly temperature for the entire country is 25°C. Although temperatures
are uniformly moderate, there are important variations over different parts of
the country, reflecting altitude and distance from the sea..
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