484 research outputs found

    Versatile surrogate models for IC buffers

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    In previous papers [1,2] the authors have investigated the use of Volterra series in the identification of IC buffer macro-models. While the approach benefited from some of the inherent qualities of Volterra series it preserved the two-state paradigm of earlier methods (see [3] and its references) and was thus limited in its versatility. In the current paper the authors tackle the challenge of going beyond an application or device-oriented approach and build versatile surrogate models that mimic the behavior of IC buffers over a wide frequency band and for a variety of loads thus achieving an unprecedented degree of generality. This requires the use of a more general system identification paradig

    Absence of Helicobacter pylori in the oral cavity of 10 non-dyspeptic subjects demonstrated by real-time polymerase chain reaction

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    Helicobacter pylori plays a significant role in gastric disease. However, the presence of this bacterium in the oral cavity remains controversial. The aim of the present study was to detect and quantify H. pylori in 29 different sites of the oral cavity in non-dyspeptic subjects by means of real-time polymerase chain reactions (PCR). Ten subjects without gastric symptoms were studied. Samples from unstimulated saliva, three sites of the tongue, oral mucosa, and 12 sites of both supragingival and subgingival plaque were collected from each subject. DNA was extracted from the oral samples and analysed for the presence of H. pylori by real-time PCR (LightCycler) using JW23/22 primers which targeted the 16S rRNA gene. DNA from H. pylori DSM 4867 was used as a positive control. Amplification efficiency for the LightCycler 2.0 runs ranged from 1.8 to 2.4. Melting curve analysis identified all the positive control capillaries, which contained H. pylori reference DNA, as a single and narrow peak at a melting temperature between 84.5 and 84.9 degrees C. All the negative control capillaries with no template control and the 29 oral samples from each subject showed either no melting peaks or broad melting peaks below 80 degrees C, which were considered as primer dimers. Therefore, H. pylori was not detected from any of the 290 oral samples. As a conclusion, H. pylori seems not to be permanently present in the oral cavity of a non-dyspeptic population

    Impact of daily consumption of Moringa (Moringa oleifera) dry leaf powder on iron status of Senegalese lactating women

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    A randomized study was conducted to test the efficacy of Moringa powder on iron status and weight gain in women. In an open-labelled randomized trial, 82 moderately anaemic, lactating women, aged 26.7ďż˝ 6.5 years, received a weekly dose of either 100g of Moringa powder(Moringa group) or 120 mg iron sulphate with 0.5 mg folicacid (Control group). Data from 64 women (33 from Moringa group and 31 from Control group) were analyzed. Baseline parameters, socio-economic, anthropometry, haematology, plasma ferritin, and acute phase proteins were comparable in both groups. Low plasma ferritin (< 12 ďż˝g/l) indicating iron deficiency was found in 13 and 14 women from the Moringa and Control groups, respectively. After 3 months oftreatment, mean haemoglobin concentrations significantly increased in both groups (p<0.001) but iron stores were unchanged in the Moringa group while they significantly increased in the Control group indicating that consumption of Moringa leaves failed to restore iron stores in anaemic subjects. A slight improvement was observed in the prevalence of anaemia in both groups but anaemia still persisted due to other reasons than iron deficiency anaemia. None of the groups gained weightduring the 3 months. However, the average weight lost was less important in the Moringa group (-0.8 ďż˝ 2.1 kg) compared to the control group (-1.2ďż˝ 2.3 kg) but the difference was not significant (p=0.45).The amount of digestible protein in the powder could suggest that the consumption of Moringa was beneficial to the rural women by preventing weight loss during the rainy season. Micronutrient status improvement of vulnerable people in developing countries like Senegal shouldcombine diet-based strategies through production and consumption of animal derived food, vegetable, fruits and food fortification program. However, Moringa Oleifera is one example of local food that can be used in nutritional intervention program, but its use needs additional rigorous clinical trials to confirm its nutritional benefits.&nbsp

    Etude de la germination de cinq provenances de Tamarindusindica L. en conditions de stress hydrique au Sénégal

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    Ce présent travail se propose d’évaluer le comportement germinatif de cinq provenances de tamarinier (Tamarindus indica L.) dans des conditions de stress  hydrique. Six concentrations croissantes 0 ; - 1,4 ; - 2,8 ; - 4,2 ; - 5,6 ; -7 bar de polyéthylène glycol (PEG 6000) ont été testées. Les résultats ont montré une  variabilité de la germination de l’espèce en fonction de l’intensité du stress et de la provenance. Le seuil critique de germination des provenances du tamarinier est  de -7 bar. La provenance Sakkal de la zone sahélienne s’est montrée plus tolérante au stress hydrique avec un taux de germination de 2% en conditions de stress  sévère. Toutefois, ces faibles résultats sont imputables aux conditions de conservation des graines. Ces informations sur l'écologie et la physiologie de la  germination du tamarinier sont vitales, non seulement pour comprendre les variations génétiques des différentes populations de tamarinier au Sénégal, mais aussi pour développer des stratégies pour la conservation de la biodiversité et la restauration des forêts tropicales.Mots clés : Germination, provenances, Tamarindus indica L., stress hydrique, Sénégal

    Fractures of the proximal femur in the elderly in a sub-Saharan country

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    Background: The aim of this study was to describe the epidemiological, radiographic and therapeutic profile of the fractures of the proximal femur in the elderly in a sub-Saharan country.Methods: A retrospective longitudinal study was carried out at the orthopedic trauma department of Idrissa Pouye Hospital in Senegal. Sixty-six patients recruited were aged at least 90 years; and treated for proximal femur fracture between 2008 and 2017.Results: The median age of the patients was 91 years (90-107). Females represented 54.5%. The fracture was located in the right 65.2%. Femoral neck fractures were 53% predominant with 94.3% type IV according to Garden’s classification. Concerning the 31 patients with a pertrochanteric fractures, 61.3% were stable and 38.7% unstable. The time taken for seeking hospital care was an average of 5.8±9.7 days. All patients had a preoperative anesthesic score less than 4 according to the American society of anesthesiologists (ASA). The therapeutic indication was functional in 15.1% of cases, surgical by internal fixation in 39.2% and by arthroplasty in 45.7% of cases. Pertrochanteric fractures were managed by a dynamic hip screw (DHS) in 68.2% and by gamma nail in 18.2%. Femoral neck fractures were managed by Moore's arthroplasty in 93.3% and by bipolar hip prothesis (BHP) in 6.7%.Conclusions: Fractures of the proximal femur represent a growing problem in sub-Saharan Africa. For patients above 90 years, the management remains essentially surgical by internal fixation in pertrochanteric fractures or by arthroplasty in cervical fractures

    Mosquito salivary gland protein preservation in the field for immunological and biochemical analysis

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    Mosquito salivary proteins are involved in several biological processes that facilitate their blood feeding and have also been reported to elicit an IgG response in vertebrates. A growing number of studies have focused on this immunological response for its potential use as a biological marker of exposure to arthropod bites. As mosquito saliva collection is extremely laborious and inefficient, most research groups prefer to work on mosquito salivary glands (SGs). Thus, SG protein integrity is a critical factor in obtaining meaningful data from immunological and biochemical analysis. Current methodologies rely on an immediate freezing of SGs after their collection. However, the maintenance of samples in a frozen environment can be hard to achieve in field conditions. In this study, SG proteins from two mosquito species (Aedes aegypti and Anopheles gambiae s.s.) stored in different media for 5 days at either +4°C or room temperature (RT) were evaluated at the quantitative (i.e., ELISA) and qualitative (i.e., SDS-PAGE and immunoblotting) levels. Our results indicated that PBS medium supplemented with an anti-protease cocktail seems to be the best buffer to preserve SG antigens for 5 days at +4°C for ELISA analysis. Conversely, cell-lysis buffer (Urea-Thiourea-CHAPS-Tris) was best at preventing protein degradation both at +4°C and RT for further qualitative analysis. These convenient storage methods provide an alternative to freezing and are expected to be applicable to other biological samples collected in the field

    Acute complications of preeclampsia: prognosis and management at Pikine National Hospital in Dakar (Senegal)

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    ABSTRACTBackground: The objective of this study was to evaluate the prevalence of acute complications of preeclampsia in order to describe the epidemiological profile of the disease, to assess its prognosis and management.Methods: This was a retrospective study of patients admitted to the Pikine National Hospital from 1 January 2010 to 31 December 2013 (48 months) with severe complicated pre-eclampsia. Included in this study were patients admitted or diagnosed with severe complicated pre-eclampsia and having given birth in the structure or not.Results: The incidence of severe preeclampsia in childbirth varied from 9.7% to 11.5% during the four years of our study. Patients were largely paucigest (55.7% of cases) and paucipares (58.5% of cases). The mean age was 28.14 years with extremes of 14 and 47 years. More than half of the patients (57.7%) were between 21 and 34 years of age. They were mostly married (90.7%). Three-quarters of the patients (76.8%) had proteinuria with ≥ 3 cross-bands. Thrombocytopenia was found in 9.7% of patients, hepatic cytolysis in 12.1%, and elevation of serum creatinine in 13.8%. The level of transaminases was found to be greater than 2 in the normal range in 12.1%. Complicated forms were the most represented in our study. These were acute complications, with 715 cases, or 57.3% of the patients. They were either isolated (52.8%) or associated (4.5%). These included eclampsia (24.9%), followed by retroplacental hematoma (24.6%), fetal death in utero (23.7%), HELLP syndrome (3.4%). , Acute edema of the lungs (1.5%), and acute renal failure (1.4%). The lethality was 2.4%. The causes of maternal death were dominated by eclampsia (14 cases), DIC (3 cases) and OAP (2 cases). We counted 77.7% of live births and a stillbirth of 254.5 ‰.Conclusions: Pre-eclampsia is a serious complication of pregnancy. Its frequency is still high in sub-Saharan Africa. In the presence of signs of severity, maternal (vital and functional) and neonatal prognosis are inevitably involved. If management is based on fetal extraction, resuscitation measures are a guarantee of maternal survival

    Rodents as natural hosts of zoonotic Schistosoma species and hybrids: an epidemiological and evolutionary perspective from West Africa

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    The complex multi-host disease dynamics of schistosomiasis and Schistosoma spp., including the emergence of zoonotic parasite hybrids, remain largely unexplored in West Africa. We elucidated the role of wild small mammals as reservoir for zoonotic Schistosoma species and hybrids in endemic areas of Senegal. We identified Schistosoma mansoni, Schistosoma bovis, and a Schistosoma haematobium/S. bovis hybrid, with local prevalence in wild rodents ranging from 1.9% to 28.6%. Our findings indicate that rodents may be an important local reservoir for zoonotic schistosomiasis in endemic areas of West Africa, amplifying transmission to humans and acting as natural definitive hosts of schistosome hybrids
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