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The study of a sea level fluctuation based on ostracods is carried out for the first time using core sediments of Mbawane and Retba Lakes, north coast of Senegal. A total of 26 species have been identified and most of them are encountered in the Gulf of Guinea shelf and its adjacent lagoons. The Retba Lake core, which is closer to the seashore, has yielded a richer and more diversified ostracod fauna composed of four assemblages. The F1 assemblage is composed of Cyprideis nigeriensis, Neomonoceratina iddoensis, and Aglaiocypris gambiensis, which characterises a slightly open lagoon developing under a humid climate with its edges covered with mangrove swamps. Assemblage F2, composed mainly of C. nigeriensis, N. iddoensis and “marine species”, which is richer and more diversified, points to a marine little gulf bordered by mangrove swamps. The F3 monospecific assemblage composed of C. nigeriensis indicates a drying confined lagoon under an arid climate. The F4 oligospecific association at the top, composed of C. nigeriensis and Pseudoconcha omatsolai, is typical of a slightly open saline lagoon under arid climate. Core sediments from Mbawane Lake have yielded scarce and badly preserved microfaunas which are distributed into three discontinuous levels that have been correlated to those of the Retba Lake core assemblages. The F1 assemblage composed of Leptocythere culpata and Xestoleberis sp. 2 corresponds to a slightly open lagoon covered at its bottom by marine macrophytes and algae. The F2 assemblage composed of N.iddoensis, Hemicytherura sp. A, Aglaiocypris gambiensis and Ruggieria tricostata characterises a more open lagoon bordered by mangrove swamps under a humid climate. The F3 assemblage is absent in the Mbawane Lake. The F4 monospecific association composed of C. nigeriensis characterises a drying lagoon under an arid climate. The overall marine influences were stronger in the Retba Lake while continental effects were dominant in Mbawane Lake during the same period. The two marine intrusions mentioned above may correspond to those of the Dakarian (3000 years B.P.) and the Saint-Louisian eras (2000–680 years B.P.) that existed during the Upper Holocene on the Senegalese coast.  相似文献   
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Background

The serogroup A conjugate meningococcal vaccine, MenAfriVac, was introduced in mass vaccination campaigns in December 2010 in Burkina Faso, Mali and Niger. In the coming years, vaccination will be extended to other African countries at risk of epidemics. To document the molecular characteristics of disease-causing meningococcal strains circulating in the meningitis belt of Africa before vaccine introduction, the World Health Organization Collaborating Centers on Meningococci in Europe and United States established a common strain collection of 773 isolates from cases of invasive meningococcal disease collected between 2004 and 2010 from 13 sub-Saharan countries.

Methodology

All isolates were characterized by multilocus sequence typing, and 487 (62%) were also analyzed for genetic variation in the surface antigens PorA and FetA. Antibiotic susceptibility was tested for part of the collection.

Principal Findings

Only 19 sequence types (STs) belonging to 6 clonal complexes were revealed. ST-5 clonal complex dominated with 578 (74.8%) isolates. All ST-5 complex isolates were remarkably homogeneous in their PorA (P1.20,9) and FetA (F3-1) and characterized the serogroup A strains which have been responsible for most epidemics during this time period. Sixty-eight (8.8%) of the 773 isolates belonged to the ST-11 clonal complex which was mainly represented by serogroup W135, while an additional 38 (4.9%) W135 isolates belonged to the ST-175 complex. Forty-eight (6.2%) serogroup X isolates from West Africa belonged to the ST-181 complex, while serogroup X cases in Kenya and Uganda were caused by an unrelated clone, ST-5403. Serogroup X, ST-181, emerged in Burkina Faso before vaccine introduction.

Conclusions

In the seven years preceding introduction of a new serogroup A conjugate vaccine, serogroup A of the ST-5 clonal complex was identified as the predominant disease-causing strain.  相似文献   
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Methodology

This was a transverse randomized survey of subjects over the age of 18 years. Subjects completed a self-administered questionnaire composed of two parts. The first part contained information on demographic characteristics, associated diseases, erectile dysfunction and associated sexual disorders and the second part was based on IIEF5. Two groups were identified: a group with erectile dysfunction (ED group) and another group without erectile dysfunction (No ED group). Differences between the two groups were considered to be statistically significant for p ≤ 0.05 on the Chi-square test.

Results

The global prevalence of erectile dysfunction was 26%. The prevalence by age-group revealed a progressive increase of ED with age from 11% between 20 and 30 years to 76% between 70 and 80 years. The rate of polygamous men was significantly higher in the group with ED (29.2%) compared to the group without ED (6.6%) (p < 0.0001) and the severity of ED increased in relation to the number of wives. Chronic alcoholism was significantly more frequent in the group with ED (p = 0.023). The frequency of ED increased with the duration of cigarette smoking from 11.9% for less than 5 years, 16.9% between 5 years and 10 years and 71.2% for more than 10 years. Some diseases (diabetes, hypertension and depression) were significantly more frequent in the group with ED. Analysis of the type of ED revealed that secondary erectile dysfunction was more frequent (95.6%) than primary erectile dysfunction (4.4%). Associated sexual disorders were significantly more frequent in the group with ED.  相似文献   
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Online UV/visible extinction measurement have been achieved during nanosecond Nd:YAG laser irradiation at 532 nm of a silver-exchanged silicate glass after each shot. We have explained the evolution of the integrated spectral evolution with the help of a few observed spots after the laser/glass interaction and completed them by optical and surface measurements. This optical method allows to in situ follow silver ions precipitation in nanoparticles (NPs) and the consequently surface plasmon resonance evolution (SPR). In this study, we focus on the interest of this method for one silver-exchanged soda-lime glass by direct observation of the sample surface. Scanning electron microscopy measurement and optical microscopy were used to identify the various ablation mechanisms. Profilometry was used to evaluate the material distribution and the surface roughness evolution (Rms parameter). Thus, we explain the silver NPs effect on glass matrix at various micrometric scales according to the deposited fluence and silver concentration.  相似文献   
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Introduction

Factors explaining the greater susceptibility of preterm infants to severe lower respiratory infections with respiratory syncytial virus (RSV) remain poorly understood. Fetal/newborn lambs are increasingly appreciated as a model to study key elements of RSV infection in newborn infants due to similarities in lung alveolar development, immune response, and susceptibility to RSV. Previously, our laboratory demonstrated that preterm lambs had elevated viral antigen and developed more severe lesions compared to full-term lambs at seven days post-infection. Here, we compared the pathogenesis and immunological response to RSV infection in lungs of preterm and full-term lambs.

Methods

Lambs were delivered preterm by Caesarian section or full-term by natural birth, then inoculated with bovine RSV (bRSV) via the intratracheal route. Seven days post-infection, lungs were collected for evaluation of cytokine production, histopathology and cellular infiltration.

Results

Compared to full-term lambs, lungs of preterm lambs had a heightened pro-inflammatory response after infection, with significantly increased MCP-1, MIP-1α, IFN-γ, TNF-α and PD-L1 mRNA. RSV infection in the preterm lung was characterized by increased epithelial thickening and periodic acid-Schiff staining, indicative of glycogen retention. Nitric oxide levels were decreased in lungs of infected preterm lambs compared to full-term lambs, indicating alternative macrophage activation. Although infection induced significant neutrophil recruitment into the lungs of preterm lambs, neutrophils produced less myeloperoxidase than those of full-term lambs, suggesting decreased functional activation.

Conclusions

Taken together, our data suggest that increased RSV load and inadequate immune response may contribute to the enhanced disease severity observed in the lungs of preterm lambs.  相似文献   
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