Quantitative proteomics and systems analysis of cultured H9C2 cardiomyoblasts during differentiation over time supports a ‘function follows form’ model of differentiation

The rat cardiomyoblast cell line H9C2 has emerged as a valuable tool for studying cardiac development, mechanisms of disease and toxicology. We present here a rigorous proteomic analysis that monitored the changes in protein expression during differentiation of H9C2 cells into cardiomyocyte-like cells over time. Quantitative mass spectrometry followed by gene ontology (GO) enrichment analysis revealed that early changes in H9C2 differentiation are related to protein pathways of cardiac muscle morphogenesis and sphingolipid synthesis. These changes in the proteome were followed later in the differentiation time-course by alterations in the expression of proteins involved in cation transport and beta-oxidation. Studying the temporal profile of the H9C2 proteome during differentiation in further detail revealed eight clusters of co-regulated proteins that can be associated with early, late, continuous and transient up- and downregulation. Subsequent reactome pathway analysis based on these eight clusters further corroborated and detailed the results of the GO analysis. Specifically, this analysis confirmed that proteins related to pathways in muscle contraction are upregulated early and transiently, and proteins relevant to extracellular matrix organization are downregulated early. In contrast, upregulation of proteins related to cardiac metabolism occurs at later time points. Finally, independent validation of the proteomics results by immunoblotting confirmed hereto unknown regulators of cardiac structure and ionic metabolism. Our results are consistent with a function follows form' model of differentiation, whereby early and transient alterations of structural proteins enable subsequent changes that are relevant to the characteristic physiology of cardiomyocytes

Non-linear static and linear dynamic analysis for reinforced concrete building as complementary method of analysis and design

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Changement climatique dans le Bassin du Congo : informations et connaissances échangées entre les acteurs

Ce document présente l'état des lieux des informations et connaissances sur le changement climatique échangées entre acteurs dans quatre pays du Bassin du Congo, à savoir au Cameroun, au Congo, au Gabon et en République démocratique du Congo. Il ressort de cette étude les observations suivantes : la REDD + et plus particulièrement le MNV sont au centre des discussions concernant la réduction des émissions de CO 2 du fait de leurs liens avec les politiques forestières ; l'adaptation est dominée par l'évaluation de la vulnérabilité des communautés locales et, dans une moindre mesure, des systèmes naturels ; les politiques et pratiques d'adaptation des communautés et des écosystèmes sont inséparables des politiques générales de développement et de lutte contre la pauvreté ; les séminaires et les ateliers, principaux canaux de transmission et de partage de l'information et connaissances utilisés dans la région, sont peu appropriés du fait qu'ils ciblent un nombre très réduit d'acteurs ; laissant la plupart en dehors du circuit de l'information ; on note également une insuffisance des compétences nationales, ce qui oblige généralement les pays à recourir aux compétences extérieures et à compter en majorité sur les organisations internationales, tant de recherche que de coopération, ainsi que sur les partenaires au développement pour obtenir des informations nécessaires. Afin de réduire les écarts existants entre les informations disponibles au niveau mondial sur la REDD + et l'adaptation et celles circulant dans les pays du Bassin du Congo, il est important de 1) mettre sur pied des mécanismes de coordination, de gestion stratégique et de dissémination des informations et connaissances ; 2) d'adapter aux contextes spécifiques les informations venant de la sphère mondiale et 3) d'utiliser autant que faire se peut, les canaux d'information et le langage adaptés aux besoins et capacités des différents acteurs. (Résumé d'auteur

Climate change commitments and agriculture sectoral strategies in Cameroon: Interplay and perspectives

International audienceCameroon like other developing countries is developing approaches to respond to national and global climate change adaptation and mitigation commitments. Sufficient information on the interplay between sector policies and the causes, impacts and response to climate change is relevant for developing sustainable climate change response plans. Using the agriculture sector as a case, this paper examines this interplay in the context of the humid forest zone (HFZ) of Cameroon. Drawing on secondary information from agriculture sector strategies, forest cover change, climate vulnerability and agriculture systems in the HFZ, we found that: (i) the objectives of agriculture expansion and avoided deforestation and forest degradation are at crossroads ; (ii) agriculture as a livelihood strategy is vulnerable to climate variability and change; (iii) strengthening agriculture production systems technically, materially and financially are main suggestions for climate resilient and low carbon emission agriculture practices. We highlight barriers that need to be addressed for the agriculture intensification mechanism , i.e. the agriculture research and extension services in Cameroon to respond to the needs of adaptation and carbon emission reductions from avoided deforestation. These ABOUT THE AUTHOR Eugene L Chia is a researcher/expert with an interdisciplinary background that cuts across environment and development issues. He has published extensively on climate change and has years of experience working on climate change mitigation and adaptation from the policy level to the project level in the Congo basin region. He is currently providing advisory services to the government of Cameroon on climate change response policies and actions related to adaptation and carbon emission reduction. This paper is part of his contribution to policy inputs (information and knowledge) and the debate in the climate change policy response process in Cameroon

Simulated Inhibitory Effects of Typical Byproducts of Biomass Pretreatment Process on the Viability of Saccharomyces cerevisiae and Bioethanol Production Yield

The abundance of second generation feedstock reinforces the consideration of biofuel over fossil fuel, as bioethanol can be produced from lignocellulosic materials. However, the pretreatment required for oxidation of lignocellulose into hexose often results in the production of inhibitors likely to impede the activity of Saccharomyces cerevisiae during bioethanol production. This study aimed to investigate the comparative inhibitory effects of acetic acid and vanillin on the viability of S. cerevisiae and the production yield of bioethanol. Different concentrations of inhibitors were spiked in the fermentation broth then the production of bioethanol monitored overtime and correlated with cell viability. The results showed that the inhibition of S. cerevisiae by vanillin is more potent compared to acetic acid; however the reduction of bioethanol yield after 12 h was more pronounced with acetic acid (42.8% reduction) than with vanillin (33.3% reduction) which was ascribed to the simultaneous production of weak acids during the fermentation process. The viability test has shown that in the presence of lower concentrations of inhibitors, S. cerevisiae can adapt for the first 12 h of fermentation and then may improve ethanol production yield overtime. At lower concentrations (2 g/l vanillin and 4 g/l acetic acid) the effect of inhibitors on the viability of S. cerevisiae and ethanol productivity does not last and can be overcome by the adaptation of the yeast. However, the presence of higher concentrations (4 g/l vanillin and 6 g/l acetic acid) results to nearly total inhibition of bioethanol production and the remediation of such effect may therefore require a detoxification process.Keywords: Bioethanol Production, Saccharomyces cerevisiae, Inhibition, Acetic Acid, Vanillin, Cell Viabilit

Exposure of rural households to toxic cyanobacteria in container-stored water

Cyanobacteria are potent producers of cyanotoxins that may present a health risk to people. This is especially important in rural areas where people use untreated surface water, containing cyanobacteria, for household purposes including cooking and drinking. Water is collected from these sources mainly in plastic containers, transported home and stored during use. This study investigated the occurrence of cyanobacteria and their associated toxins in these containers as well as in the associated surface water sources. The results suggest that cyanobacteria are transferred from the water sources to the containers and then survive and possibly grow in biofilm forming inside the vessels. Their associated cyanotoxins were not found in any health-significant quantities in containers. However, the occurrence of cyanobacteria in the water used by the households collected in containers clearly indicates that it can be an important route of exposure especially if toxic cyanobacteria are present in the source water. In several cases a risk of cyano-intoxication might exist unless the households undertake preventative measures.Keywords: cyanobacteria, cyanotoxin, microcystin, surface water sources, drinking water containers, biofil

Assessing the effectiveness of a biological recovery of nickel for tailing dumps management

The mobilization of nickel from sulphide minerals using sulfuric acid and heterotrophic microorganism (Bacillus subtilis) was independently examined. The influences of parameters such as the concentration of acid and bacteria as well as reaction time were considered. Results of the monod-type kinetic study showed faster recovery of nickel from tailings (20 ppm/h) than from ore (8.07 ppm/h) by biological mobilization and similar trend with sulfuric acid

Application of solar treatment for the disinfection of geophagic clays from markets and mining sites

Most of the microorganisms occurring in geophagic clays are undesirable and may to some extent be harmful to geophagists; it is therefore important to develop a cheap and sustainable technique for the treatment of these clays prior to consumption. In this study, a solar treatment simulated in a chamber has been investigated for its potential to inactivate the microorganisms found in the geophagic clays obtained from mining sites and from the markets. The results have shown that irrespective of the sources of the clays, they were contaminated with large amount of potentially harmful microorganisms which could have been sustained by suitable conditions such as relatively high moisture content (average of 3.6%) and the presence of organic carbon (between 1.06 and 1.5%). Treatment with simulated solar irradiation has resulted in most instances to the reduction of the number (up to 100% inactivation) of microorganisms although in few cases the same conditions have stimulated the growth of some dormant microorganisms including Bacillus subtilis, Paenibacillus, Bacillus cereus, Bacillus thuringiensis, Bacillus humi and Arthrobacterarilaitensis. This study shows that the solar treatment has the potential to significantly reduce the amount of microorganisms occurring in the geophagic clays, but require further investigation for improvement of the technique.Keywords: Geophagic clays, solar treatment, microorganisms, moisture content, organic carbon, mining sites, market

The Financial Burden of Non-Communicable Chronic Diseases in Rural Nigeria: Wealth and Gender Heterogeneity in Health Care Utilization and Health Expenditures

Objectives Better insights into health care utilization and out-of-pocket expenditures for non-communicable chronic diseases (NCCD) are needed to develop accessible health care and limit the increasing financial burden of NCCDs in Sub-Saharan Africa. Methods A household survey was conducted in rural Kwara State, Nigeria, among 5,761 individuals. Data were obtained using biomedical and socio-economic questionnaires. Health care utilization, NCCD-related health expenditures and distances to health care providers were compared by sex and by wealth quintile, and a Heckman regression model was used to estimate health expenditures taking selection bias in health care utilization into account. Results The prevalence of NCCDs in our sample was 6.2%. NCCD-affected individuals from the wealthiest quintile utilized formal health care nearly twice as often as those from the lowest quintile (87.8% vs 46.2%, p = 0.002). Women reported foregone formal care more often than men (43.5% vs. 27.0%, p = 0.058). Health expenditures relative to annual consumption of the poorest quintile exceeded those of the highest quintile 2.2-fold, and the poorest quintile exhibited a higher rate of catastrophic health spending (10.8% among NCCD-affected households) than the three upper quintiles (4.2% to 6.7%). Long travel distances to the nearest provider, highest for the poorest quintile, were a significant deterrent to seeking care. Using distance to the nearest facility as instrument to account for selection into health care utilization, we estimated out-of-pocket health care expenditures for NCCDs to be significantly higher in the lowest wealth quintile compared to the three upper quintiles. Conclusions Facing potentially high health care costs and poor accessibility of health care facilities, many individuals suffering from NCCDs—particularly women and the poor—forego formal care, thereby increasing the risk of more severe illness in the future. When seeking care, the poor spend less on treatment than the rich, suggestive of lower quality care, while their expenditures represent a higher share of their annual household consumption. This calls for targeted interventions that enhance health care accessibility and provide financial protection from the consequences of NCCDs, especially for vulnerable populations

Le réseau relationnel de l’entreprise familiale : une ressource non négligeable pour sa performance

Les entreprises familiales bien qu’étant l’une des formes d’organisation les plus ancienne dans l’histoire économique (Gersick et al., 1997 ; Bienaymé, 2009) connaissent des difficultés dans leurs évolutions. Car en effet, entre disparitions et absorption par les grandes entreprises non familiales, on observe l’échec dans la transition à la seconde génération, taux de croissance faible, vulnérabilité et inertie dans la prise de décision, couts d’agence élevés (Lin et Hu, 2007 ; Litz, 2008 ; Lester et Cannella, 2006). Ces difficultés marquantes ainsi le point de réflexion de cette recherche pose ainsi le problème de la performance des entreprises familiale.  En vue de trouver des stratégies pour répondre à ces difficultés on se propose de recourir au réseau relationnel de l’entreprise familiale. L’objectif de cette étude est donc d’apprécier l’apport du réseau relationnel de l’entreprise familiale sur leur performance. Pour mener à bien cette recherche, nous avons opté pour une démarche quantitative. Les données recueillies à partir d’un questionnaire destiné aux dirigeants et cadres des entreprises familiales des villes de Bafoussam, Douala et Yaoundé, ont permis de collecter 94 questionnaires et soumettre aux différents analyses descriptives, factorielle et explicatives à l’aide du test de corrélation de Pearson et de régression linéaire multiple, ceci grâce aux au logiciel SPSS 20. Les principaux résultats nous permettent de faire mention d’une influence significative et positive du réseau relationnel de l’entreprise familiale sur la performance globale des entreprises familiale