Diversity and longitudinal species turnover of small mammals in the forests of watersheds of western Madagascar

The species diversity of Malagasy small mammals is assessed along three different east-west flowing rivers passing through different forest formations and of different length: Soahany (short river), Manambolo (medium-length river), and the Mangoky (long river). The levels of species replacement (β-diversity) are evaluated along these three different longitudinal gradients. Twenty-two sites were inventoried, six along the Soahany River, five along the Manambolo River, and 11 along the Mangoky River. Thirty-five species of small mammals were documented at these sites, composed of 21 species of endemic Afrosoricida (Tenrecidae); two species of Soricomorpha including one endemic (Suncus madagascariensis) and one introduced (S. murinus); and 12 species of Rodentia including 10 endemics (Nesomyidae) and two introduced species (Rattus rattus and Mus musculus). There was a correlation between species richness and the length of each river basin: Mangoky has the greatest species richness (29 taxa), followed by the Manambolo (11 taxa) and the Soahany (10 taxa). α-diversity augments with increasing habitat complexity and surface area. Humid forest sites in the central highlands near the Zomandao River (the source of the Mangoky) possess high α-diversity. For dry forest sites, those towards the interior in relatively large forested areas have greater α-diversity measures than those of smaller or coastal forest sites. β-diversity augments along the river systems with increasing habitat heterogeneity. The transect along the Soahany River has the highest β-diversity values, indicating higher levels of species turnover than the other two river systemsDans des sites situés le long de trois fleuves de différentes longueurs, coulant d'est en ouest vers le Canal de Mozambique (Soahany [fleuve court], Manambolo [fleuve de longueur moyenne] et Mangoky [fleuve long]), avec différents types des forêts, ont été évalués d'une part la diversité locale des petits mammifères et d'autre part le taux de remplacement des espèces suivant un gradient longitudinal. Vingt-deux sites ont été inventoriés dont six le long du Soahany, cinq pour le Manambolo et 11 le long du Mangoky. Au total 35 espèces de petits mammifères ont été recensées le long de ces transects dont 21 espèces endémiques d'Afrosoricida (Tenrecidae), deux espèces de Soricomorpha dont une endémique (Suncus madagascariensis) et une allogène (S. murinus) et 12 espèces de Rodentia dont 10 endémiques (Nesomyidae) et deux allogènes (Rattus rattus et Mus musculus). Il semblerait que la richesse spécifique varie proportionnellement avec la longueur de chaque transect: Mangoky est le plus riche (29 espèces) suivi de Manambolo (11 espèces) et de Soahany (10 espèces). La diversité α augmente avec le type d'habitat, sa superficie et sa complexité. Les sites des forêts humides situés dans le haut plateau central du côté de la rivière Zomandao (source du Mangoky) possèdent une diversité a élevée. Pour les sites des forêts sèches, ceux situés à l'intérieur des blocs forestiers de larges étendues ont la diversité α la plus élevée. La diversité β augmente avec l'hétérogénéité des habitats le long de chaque transect. Le transect Soahany, le plus court, possède la diversité β la plus élevée, traduisant un taux de remplacement d'espèce plus rapide que ceux des deux autres transects

Pattern of Reaction Diffusion Front in Laminar Flows

Autocatalytic reaction between reacted and unreacted species may propagate as solitary waves, namely at a constant front velocity and with a stationary concentration profile, resulting from a balance between molecular diffusion and chemical reaction. The effect of advective flow on the autocatalytic reaction between iodate and arsenous acid in cylindrical tubes and Hele-Shaw cells is analyzed experimentally and numerically using lattice BGK simulations. We do observe the existence of solitary waves with concentration profiles exhibiting a cusp and we delineate the eikonal and mixing regimes recently predicted.Comment: 4 pages, 3 figures. This paper report on experiments and simulations in different geometries which test the theory of Boyd Edwards on flow advection of chemical reaction front which just appears in PRL (PRL Vol 89,104501, sept2002

University Students Dealing with Sexually Transmitted Infections and HIV/AIDS: Knowledge and Practice, a Cross-sectional study Conducted in Fianarantsoa, Madagascar

This study aimed to evaluate the Knowledge and attitude of the academic students about sexually transmitted infections and HIV at the university of Fianarantsoa in 2018. Materials and methods: This was an analytical cross-sectional study conducted among undergraduate students at the University Andrainjato-Fianarantsoa. Knowledge was assessed using a score where each correct answer was given one point. Results: 1035 students were included, 67.7% (n=701) had good knowledge about STIs, and HIV/AIDS. Sexual transmission (83.9%; n=868) was the most known. On multivariate analysis, being a student at the faculty of medicine (p<0.001, aOR 137.3 [19.1-988]), faculty of Letters (p<0.001, aOR 4.5 [2.8-7.2)]), or the Normal Graduate School (NGS) (p<0.001, aOR 6.7 [3.3-13.7]), being tested for HIV before (p= 0.002, aOR 1.6 [1.2-2.2]) constitute the major factor of good knowledge about the sexual infections. The majority (71.8%, n=743) have had sexual intercourse before, and the median age of first sexual activities was 18 years (17-20). The use of Condoms (44.4%, n=460) was the most practiced in the STIs prevention method, followed by fidelity (19.8%; n=205) and abstinence (11.4%, n=118). Among the students, 29.3% (302) had high-risk sexual behavior in the last 3 months. Conclusion: The proportion of academic students with good knowledge of STIs and HIV is not satisfactory. There was a discordance between the knowledge of STI prevention and the daily university practice of the students

University Students Dealing with Sexually Transmitted Infections and HIV/AIDS: Knowledge and Practice, a Cross-sectional study Conducted in Fianarantsoa, Madagascar

This study aimed to evaluate the Knowledge and attitude of the academic students about sexually transmitted infections and HIV at the university of Fianarantsoa in 2018. Materials and methods: This was an analytical cross-sectional study conducted among undergraduate students at the University Andrainjato-Fianarantsoa. Knowledge was assessed using a score where each correct answer was given one point. Results: 1035 students were included, 67.7% (n=701) had good knowledge about STIs, and HIV/AIDS. Sexual transmission (83.9%; n=868) was the most known. On multivariate analysis, being a student at the faculty of medicine (p<0.001, aOR 137.3 [19.1-988]), faculty of Letters (p<0.001, aOR 4.5 [2.8-7.2)]), or the Normal Graduate School (NGS) (p<0.001, aOR 6.7 [3.3-13.7]), being tested for HIV before (p= 0.002, aOR 1.6 [1.2-2.2]) constitute the major factor of good knowledge about the sexual infections. The majority (71.8%, n=743) have had sexual intercourse before, and the median age of first sexual activities was 18 years (17-20). The use of Condoms (44.4%, n=460) was the most practiced in the STIs prevention method, followed by fidelity (19.8%; n=205) and abstinence (11.4%, n=118). Among the students, 29.3% (302) had high-risk sexual behavior in the last 3 months. Conclusion: The proportion of academic students with good knowledge of STIs and HIV is not satisfactory. There was a discordance between the knowledge of STI prevention and the daily university practice of the students

Lessons from the pandemic: new best practices in selecting molecular diagnostics for point-of-care testing of infectious diseases in sub-Saharan Africa

Introduction: Point-of-care molecular diagnostics offer solutions to the limited diagnostic availability and accessibility in resource-limited settings. During the COVID-19 pandemic, molecular diagnostics became essential tools for accurate detection and monitoring of SARS-CoV-2. The unprecedented demand for molecular diagnostics presented challenges and catalyzed innovations which may provide lessons for the future selection of point-of-care molecular diagnostics. Areas Covered: We searched PubMed from January 2020 to August 2023 to identify lessons learned from the COVID-19 pandemic which may impact the selection of point-of-care molecular diagnostics for future use in sub-Saharan Africa. We evaluated this in the context of REASSURED criteria (Real-time connectivity; Ease of specimen collection; Affordable; Sensitive; Specific; User-friendly; Rapid and robust; Equipment free; and Deliverable to users at the point of need) for point-of-care diagnostics for resource-limited settings. Expert Opinion: The diagnostic challenges and successes during the COVID-19 pandemic affirmed the importance of the REASSURED criteria but demonstrated that these are not sufficient to ensure new diagnostics will be appropriate for public health emergencies. Capacity for rapid scale-up of diagnostic testing and transferability of assays, data, and technology are also important, resulting in updated REST-ASSURED criteria. Few diagnostics will meet all criteria, and trade-offs between criteria will need to be context-specific

Epidemiological characteristics of cryptococcal meningoencephalitis associated with Cryptococcus neoformans var. grubii from HIV-infected patients in Madagascar : a cross-sectional study

Cryptococcal meningoencephalitis (CM) remains the most prevalent invasive fungal infection worldwide. The main objective of this study was to describe the prevalence of CM and cryptococcal infection in HIV-infected patients in Madagascar. The secondary objectives were to assess the adjusted prevalence of CM according to clinical presentation and patient characteristics, to determine crude 90-day survival according to cryptococcal antigen (CrAg) status and CM, and to identify the genotypes of Cryptococcus clinical isolates. This cross-sectional study was carried out at two urban hospitals in Antananarivo (central highlands) and Toamasina (east coast) between November 2014 and December 2016. Consecutive HIV-infected adults presenting with CD4 cell counts 64200/\u3bcl were enrolled. Lateral flow immunoassays of CrAg were performed on serum for all patients, and on cerebrospinal fluid for patients with CM symptoms. MALDI-ToF MS, ITS sequencing, and determinations of the molecular and mating types of the isolates were performed. Fluconazole is the only drug for CM treatment available in Madagascar. Patients were treated orally, with high doses (1200 mg/day) for 10-12 weeks and then with 200 mg/day. Minimum inhibitory concentrations were determined for amphotericin B, flucytosine, voriconazole and fluconazole in E-tests. Overall prevalence was 13.2% (95% CI 7.9-20.3) for cryptococcal infection and 10.9% (95% CI 6.1-17.5) for CM, among the 129 HIV-infected patients studied. The 90-day mortality rate was 58.8% (10/17) in CrAg-positive patients and 17.9% (20/112) in CrAg-negative patients (p<0.001). The 13 Cryptococcus strains obtained at baseline were all Cryptococcus neoformans var. grubii, genotypes VNI-\u3b1A (3 isolates), VNII-\u3b1A (4 isolates) or hybrid VNI/VNII-\u3b1AA\u3b1 (6 isolates), suggesting high diversity. Two strains acquired fluconazole resistance after four and five months of exposure, respectively. The prevalence of cryptococcosis is high in Madagascar and this serious condition is life-threatening in HIV-infected patients. These findings will be used to raise the awareness of national authorities to strengthen the national HIV/AIDS control program

Factors related to the death of diabetic patients with COVID-19 hospitalized in Joseph Raseta Befelatanana University Hospital in Antananarivo, Madagascar

Background: Diabetes mellitus is associated with severe and even fatal forms of COVID-19. The objective of this study was to identify the factors linked to the death of COVID-19 diabetic patients in order to improve their care.Methods: An analytical cross-sectional study was carried out in the endocrinology department of the Joseph Raseta Befelatanana University Hospital Center, Antananarivo, Madagascar. It has concerned all the cases of COVID-19 diabetics (162 patients) recorded from April 2020 to July 2021 (16 months).Results: In our study, the case fatality rate of COVID-19 in diabetics was 14.49%. Significant factors related to death, after univariate analysis, were:  vascular complications including nephropathy (OR=4.74), neuropathy  (OR=5.38) and ischemic heart disease (OR=3.9), presence of other comorbidities (OR=9.02), dyspnea (OR=4.60), seizures (OR=6.22) or alertness disorder (OR=4.35), lower oxygen saturation (p=0.04), pleurisy (OR=4.67), signs of cardiac decompensation (OR=3.46), an elevated mean blood sugar level (p<0.001), leukocytosis (p=0.02) and thrombocytopenia (p<0.001), impaired renal function (p=0.02) and pleurisy on chest imaging (OR=5.29).Conclusions: Death factors in diabetics with COVID-19 can be diverse. They do not only include the cardiovascular complications of the diabetes, but also a worse clinical respiratory presentation on the admission, a higher inflammatory syndrome, and a greater imbalance of blood sugar during the hospitalization.

Advanced glycation inhibition and protection against endothelial dysfunction induced by coumarins and procyanidins from Mammea neurophylla.

Advanced glycation end-products (AGEs) are associated with many pathogenic disorders such as pathogenesis of diabetes or endothelial dysfunction leading to cardiovascular events. Therefore, the identification of new anti-AGE molecules or extracts aims at preventing such pathologies. Many Clusiaceae and Calophyllaceae species are used in traditional medicines to treat arterial hypertension as well as diabetes. Focusing on these plant families, an anti-AGE plant screening allowed us to select Mammea neurophylla for further phytochemical and biological studies. Indeed, both DCM and MeOH stem bark extracts demonstrated in vitro their ability to prevent inflammation in endothelial cells and to reduce vasoconstriction. A bioguided fractionation of these extracts allowed us to point out 4-phenyl- and 4-(1-acetoxypropyl)coumarins and procyanidins as potent inhibitors of AGE formation, potentially preventing endothelial dysfunction. The fractionation steps also led to the isolation of two new compounds, namely neurophyllols A and B from the DCM bark extract together with thirteen known mammea A and E coumarins (mammea A/AA, mammea A/AB, mammea A/BA, mammea A/BB, mammea A/AA cycloD, mammea A/AB cycloD, disparinol B, mammea A/AB cycloE, ochrocarpin A, mammea A/AA cycloF, mammea A/AB cycloF, mammea E/BA, mammea E/BB) as well as δ-tocotrienol, xanthones (1-hydroxy-7-methoxyxanthone, 2-hydroxyxanthone) and triterpenes (friedelin and betulinic acid). During this study, R,S-asperphenamate, previously described from fungal origin was also purified