Characterization of biochar produced by pyrolysis of biomass and co-pyrolysis of biomass and agricultural mulch film

Agricultural wastes can be valuable materials because they are generated in large quantities all over the world and contain a variety of feedstocks. These feedstocks include dairy manure, food wastes, solid wastes and plastics. Current waste management techniques include landfilling and incineration, both leading to an increase in greenhouse gas emissions. However, alternative methods such as pyrolysis can present more sustainable pathways by transforming mixed wastes from the agricultural sector into value-added products such as biochar, bio-oil and syngas. Limited published literature has focused on producing biochar derived from co-pyrolysis of agricultural wastes with plastic wastes such as agricultural mulch films that are used for crop quality control. Most prior work has focused on fast co-pyrolysis of these materials, which favors bio-oil and syngas production rather than biochar. In this study, we explored the potential benefits of biochar generated from pyrolysis of agricultural solid wastes and co-pyrolysis of these wastes with agricultural mulch films plastics. We first produced and analyzed biochar derived from common biomass-based agricultural waste materials: hemp meal (HM), wood pellets (WP), pallet wood (PW) and hammer milled boxboard (HB) at two different temperatures (500 °C & 800 °C). These feedstocks were converted into biochar at laboratory conditions using a high temperature furnace with inert (N2) environment. We further studied the presence of low-density polyethylene (LDPE) agricultural mulch films in both hemp meal and wood pellets feedstocks at the same temperatures and at three different blend ratios of 100:0, 95:5 and 75:25wt.%. It was found that the presence of plastics had minimal effects on the biochar quality of the wood pellets. After processing, all biochar materials except that derived from hemp meal had high organic carbon content (Corg) and hydrogen to carbon (H:C) ratio less than 0.7, indicating long-term stability. Assessments of soil enhancement properties and heavy metals present in the biochar were also conducted. Additional analysis was performed to determine the effect of mid-point temperature pyrolysis temperature on the quality of the biochar product. Finally, carbon sequestration and techno-economic analyses were conducted to quantify the potential sustainability benefits of deploying a commercial scale pyrolysis system at a single farm for on-site waste processing. The computed carbon sequestration impact factors (t CO2e/t biochar) were consistent with prior studies modeling much larger systems, but profitability of biochar production was only achieved when processing wastes in a regional system including 10 times greater feedstock from surroundings farms, and assuming a relatively high biochar value of $500/t

Policy and Institutional effects on market participation by smallholder rice farmers: case studies in Burkina Faso, Mali and Niger

Rice sector contributes significantly to secure households with regard to their food needs but also to the creation of employments and income generation. The sector development and its evolution over the years have been marked by various policies and approaches. These development stages of the sector constitute nothing but the impact of the number of factors such as the rice policies put in place. A collaborative multi-country pilot study on policy and institutional arrangements effects on irrigated rice production and commercialization was conducted by WARDA and its country partners of Burkina Faso, Mali, and Niger. In-depth surveys were carried out at both village and household levels to collect qualitative and quantitative data on irrigated rice production, commercialization, and irrigated schemes governance. A common critical constrain cited by the producers in these countries is the commercialization of their product and their inability to take advantage of the market opportunities. Using village and household levels survey data on irrigated rice production and commercialization, this paper attempts to examine the impact of policy and institutional factors in market participation by smallholder rice producers. A farm level supply is estimated using the quantity of rice marketed as the dependant variable and factors such as output and inputs price, and policy and institutional variables as independent ones. The preliminary results indicate that most significant explanatory variable is the average irrigated rice plot (Mali and Niger) and total area of other crops grown by the producer.Agribusiness, Agricultural and Food Policy, Community/Rural/Urban Development, Environmental Economics and Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, Institutional and Behavioral Economics, International Relations/Trade, Labor and Human Capital, Marketing, Production Economics, Research and Development/Tech Change/Emerging Technologies, Research Methods/ Statistical Methods,

A rule of seven in Watson-Crick base-pairing of mismatched sequences

Sequence recognition through base-pairing is essential for DNA repair and gene regulation, but the basic rules governing this process remain elusive. In particular, the kinetics of annealing between two imperfectly matched strands is not well characterized, despite its potential importance in nucleic acid–based biotechnologies and gene silencing. Here we use single-molecule fluorescence to visualize the multiple annealing and melting reactions of two untethered strands inside a porous vesicle, allowing us to precisely quantify the annealing and melting rates. The data as a function of mismatch position suggest that seven contiguous base pairs are needed for rapid annealing of DNA and RNA. This phenomenological rule of seven may underlie the requirement for seven nucleotides of complementarity to seed gene silencing by small noncoding RNA and may help guide performance improvement in DNA- and RNA-based bio- and nanotechnologies, in which off-target effects can be detrimental

Impacts Socio-Économiques Du Diabète Chez Les Diabétiques Suivis À Porto-Novo En 2016

Le diabète est une affection qui pose un problème de santé publique avec des complications sur divers organes. Son impact socio-économique est peu étudié au Bénin. L’objectif de la présente étude était de décrire l’impact socio-économique du diabète chez les diabétiques suivis à l’hôpital universitaire de Porto-Novo en 2016. Il s’est agi d’une étude transversale et descriptive allant du 7 Novembre au 23 Décembre 2016. La population d’étude était constituée des diabétiques des deux sexes, âgés d’au moins 18 ans et ayant donné leur consentement. L’échantillonnage a été exhaustif. L’impact social et économique du diabète a été apprécié grâce à un questionnaire pré-établi. La saisie et l’analyse des données ont été faites par les logiciels EPI DATA 3.1, EPI INFO 7 et STATA 11. Au total, 133 diabétiques ont été recrutés pour l’étude. L’âge moyen est de 54±8 ans. Il y avait une prédominance féminine avec un sexe ratio de 0,6. Sur le plan social, 26,3 % avaient une atténuation des relations avec le conjoint, 83,5 % n’arrivaient pas à remplir les besoins de la famille et 69,9 % avaient une altération de la qualité de vie. Sur le plan économique, 94 % avaient des absences répétées au travail, 68,4 % avaient diminué les heures de travail, 54,3 % ont signalé une diminution de leur revenu mensuel et tous avaient signalé l’augmentation de leurs dépenses mensuelles. Le diabète a un impact socio-économique négatif important sur les diabétiques à Porto-Novo. La prise en charge des diabétiques devrait aborder ce volet. Diabetes is a disease that poses a public health problem with complications on various organs. Its socio-economic impact is little studied in Benin. The objective of this study was to describe the socio-economic impact of diabetes in diabetics followed in teaching hospital of Porto-Novo in 2016. This was a cross-sectional and descriptive study from November 7 to December 23, 2016. The study population consisted of diabetics of both sexes who have age at least 18 years old and have given their consent. The sampling was exhaustive. The social and economic impact of diabetes was assessed using a pre-established questionnaire. Data entry and analysis was done by software EPI DATA 3.1, EPI INFO 7 and STATA 11. A total of 133 diabetics were recruited for the study. The average age is 54 ± 8 years. The sex ratio men/women is 0.6. On a social level, 26.3% had a weakening of relationships with the spouse, 83.5% could not meet the needs of the family and 69.9% had an impairment in the quality of life. Economically, 94% had repeated absences fromwork, 68.4% had reduced work hours, 54.3% reported a decrease in their monthly income and all had reported an increase in their monthly expenses. Diabetes has a significant negative socio-economic impact on diabetics in Porto-Novo. The management of diabetics should address this aspect. &nbsp

Facteurs comportementaux et environnementaux associés au paludisme à Tourou (Bénin) en période de faible endémicité

Le paludisme demeure un problème de santé publique au Bénin malgré l’utilisation des moustiquaires. La présente étude avait pour objectif de déterminer la prévalence du paludisme à Tourou et d’identifier les facteurs comportementaux et environnementaux associés en période de faible endémicité. Il s’agissait d’une étude transversale, descriptive à visée analytique menée dans la population de Tourou. Le diagnostic du paludisme était fait par un test de diagnostic rapide. L’analyse des données a été faite par le logiciel SPSS version 21. Les facteurs de risque du paludisme ont été déterminés par régression logistique. Une p inférieure à 0,05 a été considérée comme significative. Au total 390 sujets ont été inclus dans l’étude. Une prédominance féminine (50,6%) est observée avec un sex-ratio de 0,97. Sur les 390 sujets, 145 étaient infectés par le paludisme soit prévalence du 37,4%. Le fait de dormir dehors (OR : 1,31) et après 23 heures (OR : 5,12) étaient des facteurs comportementaux à risque du paludisme tandis que l’absence d’eaux stagnantes (OR : 0,67) et celle des mauvaises herbes (OR : 0,67) étaient les facteurs environnementaux protecteurs contre le paludisme. La présente étude a montré que les facteurs environnementaux et comportementaux sont associés au paludisme dans la localité de Tourou. La lutte contre le paludisme devra considérer en plus de l’éradication du vecteur l’assainissement de l’environnement et le changement du mode de vie.Mots clés : Paludisme, Prévalence, Facteurs associés, Bénin.   English Title: Behavioral and environmental factors associated with malaria in Tourou (Benin) during periods of low endemicityMalaria remains a public health problem in Benin despite the use of mosquito nets. The objective of the present study was to determine the prevalence of malaria in Tourou and to identify behavioral and environmental factors associated to malaria in times of low endemicity. This was a cross-sectional, descriptive, analytical study carried out in the population of Tourou. The diagnosis of malaria was made by a rapid diagnostic test. Data analysis was done by SPSS version 21 software. Factors risk factor with malaria was determined by logistic regression. A p less than 0.05 was considered significant. A total of 390 subjects were included in the study. A female predominance (50.6%) was observed with a sex ratio of 0.97. Of the 390 subjects, 145 were infected with malaria and the prevalence was 37.4%. Sleeping outside (OR: 1.31) and after 11 p.m. (OR: 5.12) were behavioral risk factors for malaria, while the absence of standing water (OR: 0.67) and that of weeds (OR: 0.67) were the protective environmental factors against malaria. The present study has shown that environmental and behavioral factors were associated with malaria in the locality of Tourou. The fight against malaria will have to consider in addition to the eradication of the vector the sanitation of the environment and the change of lifestyle.Keys words: Malaria, prevalence, associated factors, Benin

Super-resolution imaging of fluorescently labeled, endogenous RNA Polymerase II in living cells with CRISPR/Cas9-mediated gene editing

Live cell imaging of mammalian RNA polymerase II (Pol II) has previously relied on random insertions of exogenous, mutant Pol II coupled with the degradation of endogenous Pol II using a toxin, α-amanitin. Therefore, it has been unclear whether over-expression of labeled Pol II under an exogenous promoter may have played a role in reported Pol II dynamics in vivo. Here we label the endogenous Pol II in mouse embryonic fibroblast (MEF) cells using the CRISPR/Cas9 gene editing system. Using single-molecule based super-resolution imaging in the living cells, we captured endogenous Pol II clusters. Consistent with previous studies, we observed that Pol II clusters were short-lived (cluster lifetime ~8 s) in living cells. Moreover, dynamic responses to serum-stimulation, and drug-mediated transcription inhibition were all in agreement with previous observations in the exogenous Pol II MEF cell line. Our findings suggest that previous exogenously tagged Pol II faithfully recapitulated the endogenous polymerase clustering dynamics in living cells, and our approach may in principle be used to directly label transcription factors for live cell imaging.National Cancer Institute (U.S.) (Award DP2CA195769)Massachusetts Institute of Technology. Department of Physic

A first order phase transition mechanism underlies protein aggregation in mammalian cells

The formation of misfolded protein aggregates is a hallmark of neurodegenerative diseases. The aggregate formation process exhibits an initial lag phase when precursor clusters spontaneously assemble. However, most experimental assays are blind to this lag phase. We develop a quantitative assay based on super-resolution imaging in fixed cells and light sheet imaging of living cells to study the early steps of aggregation in mammalian cells. We find that even under normal growth conditions mammalian cells have precursor clusters. The cluster size distribution is precisely that expected for a so-called super-saturated system in first order phase transition. This means there exists a nucleation barrier, and a critical size above which clusters grow and mature. Homeostasis is maintained through a Szilard model entailing the preferential clearance of super-critical clusters. We uncover a role for a putative chaperone (RuvBL) in this disassembly of large clusters. The results indicate early aggregates behave like condensates