49 research outputs found

    Physiological and photosynthetic response of quinoa to drought stress

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    Water shortage is a critical problem touching plant growth and yield in semi-arid areas, for instance the Mediterranean región. For this reason was studied the physiological basis of drought tolerance of a new, drought tolerant crop quinoa (Chenopodium quinoa Willd.) tested in Morocco in two successive seasons, subject to four irrigation treatments (100, 50, and 33%ETc, and rainfed). The chlorophyll a fluorescence transients were analyzed by the JIP-test to transíate stress-induced damage in these transients to changes in biophysical parameter's allowing quantification of the energy flow through the photosynthetic apparatus. Drought stress induced a significant decrease in the maximum quantum yield of primary photochemistry (Φpo = Fv/Fm), and the quantum yield of electron transport (Φeo). The amount of active Photosystem II (PSII) reaction centers (RC) per excited cross section (RC/CS) also decreased when exposed to the highest drought stress. The effective antenna size of active RCs (ABS/RC) increased and the effective dissipation per active reaction centers (DIo/RC) increased by increasing drought stress during the growth season in comparison to the control. However the performance index (PI), was a very sensitive indicator of the physiological status of plants. Leaf area index, leaf water potential and stomatal conductance decreased as the drought increased. These results indicate that, in quinoa leaf, JIP-test can be used as a sensitive method for measuring drought stress effects

    Effects of environmental conditions on healthcare worker wellbeing and quality of care: A qualitative study in Niger

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    Environmental conditions (water, sanitation, hygiene, waste management, cleaning, energy, building design) are important for a safe and functional healthcare environment. Yet their full range of impacts are not well understood. In this study, we assessed the impact of environmental conditions on healthcare workers’ wellbeing and quality of care, using qualitative interviews with 81 healthcare workers at 26 small healthcare facilities in rural Niger. We asked participants to report successes and challenges with environmental conditions and their impacts on wellbeing (physical, social, mental, and economic) and quality of care. We found that all environmental conditions contributed to healthcare workers’ wellbeing and quality of care. The norm in facilities of our sample was poor environmental conditions, and thus participants primarily reported detrimental effects. We identified previously documented effects on physical health and safety from pathogen exposure, but also several novel effects on healthcare workers’ mental and economic wellbeing and on efficiency, timeliness, and patient centeredness of care. Key wellbeing impacts included pathogen exposure for healthcare workers, stress from unsafe and chaotic working environments, staff dissatisfaction and retention challenges, out-of-pocket spending to avoid stockouts, and uncompensated labor. Key quality of care impacts included pathogen exposure for patients, healthcare worker time dedicated to non-medical tasks like water fetching (i.e., reduced efficiency), breakdowns and spoilage of equipment and supplies, and patient satisfaction with cleanliness and privacy. Inefficiency due to time lost and damaged supplies and equipment likely have substantial economic value and warrant greater consideration in research and policy making. Impacts on staff retention and care efficiency also have implications for health systems. We recommend that future research and decision making for policy and practice incorporate more holistic impact measures beyond just healthcare acquired infections and reconsider the substantial contribution that environmental conditions make to the safety of healthcare facilities and strength of health systems

    Epidemiology of hepatitis C: related hepatocellular carcinoma in Cameroon

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    Introduction: hepatocellular carcinoma (HCC) is a global public health problem. Hepatitis C virus (HCV) infection accounts for close to 24% of HCC in developing countries especially when associated with cirrhosis. There exists no vaccine against HCV to prevent the occurrence of HCV-related HCC. A sound knowledge of the epidemiology and prevention of the initial infection is vital. The aim of our study was to determine the epidemiologic profile of HCV-related HCC in Cameroon to improve its’ management. Methods: it was a prospective study of histologically proven HCV-related HCC seen in two University Centers in Yaounde, Cameroon from March 2012 to January 2013. Demographic data (age, gender), alcohol abuse (>80g/day), presence of cirrhosis, tobacco abuse and parenteral exposition were analyzed. Results: twenty-six patients with histologically proven HCV–related HCC were included (18 men (69.2%) and 8 women (30.8%); mean age +/- SD, 61.46+/-10.18 years). A total of 22 (84.6%) patients had a parenteral exposition, 02 (7.7%) patients were alcoholics and 06 (23.1%) patients were smokers. The proportion of patients with cirrhosis was 69.2% against 30.8% cirrhosis-free. Patients with cirrhosis were relatively younger than those cirrhosis-free (mean age +/- SD, 59.05+/-10.05 years vs 66.87+/- 8.72 years, p=0.06). HCV-related HCC was more prevalent in 60 years and above patients (53.8%, 95%CI: 33.4-73.4). The relative risk of HCC among alcoholics patients was high (RR: 1.5, 95%CI: 1.13-1.99, p<0.05). Conclusion: in Cameroon, HCV-related HCC is more prevalent among age older than 60 years, a finding which is relatively less to that found in western countries, male gender is twice more at risk than female gender and cirrhosis frequency is less compared to that observed elsewhere. HCV and alcohol play a synergistic role in the occurrence of HCC in our environment

    Molecular Dynamic Simulation Reveals Structure Differences in APOL1 Variants and Implication in Pathogenesis of Chronic Kidney Disease.

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    BACKGROUND: According to observational studies, two polymorphisms in the apolipoprotein L1 (APOL1) gene have been linked to an increased risk of chronic kidney disease (CKD) in Africans. One polymorphism involves the substitution of two amino-acid residues (S342G and I384M; known as G1), while the other involves the deletion of two amino-acid residues in a row (N388 and Y389; termed G2). Despite the strong link between APOL1 polymorphisms and kidney disease, the molecular mechanisms via which these APOL1 mutations influence the onset and progression of CKD remain unknown. METHODS: To predict the active site and allosteric site on the APOL1 protein, we used the Computed Atlas of Surface Topography of Proteins (CASTp) and the Protein Allosteric Sites Server (PASSer). Using an extended molecular dynamics simulation, we investigated the characteristic structural perturbations in the 3D structures of APOL1 variants. RESULTS: According to CASTp's active site characterization, the topmost predicted site had a surface area of 964.892 Å2 and a pocket volume of 900.792 Å3. For the top three allosteric pockets, the allostery probability was 52.44%, 46.30%, and 38.50%, respectively. The systems reached equilibrium in about 125 ns. From 0-100 ns, there was also significant structural instability. When compared to G1 and G2, the wildtype protein (G0) had overall high stability throughout the simulation. The root-mean-square fluctuation (RMSF) of wildtype and variant protein backbone Cα fluctuations revealed that the Cα of the variants had a large structural fluctuation when compared to the wildtype. CONCLUSION: Using a combination of different computational techniques, we identified binding sites within the APOL1 protein that could be an attractive site for potential inhibitors of APOL1. Furthermore, the G1 and G2 mutations reduced the structural stability of APOL1

    Sorption of hydrophobic organic compounds on natural sorbents and organoclays from aqueous and non-aqueous solutions: a mini-review

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    Renewed focus on the sorption of hydrophobic organic chemicals (HOCs) onto mineral surfaces and soil components is required due to the increased and wider range of organic pollutants being released into the environment. This mini-review examines the possibility of the contribution and mechanism of HOC sorption onto clay mineral sorbents such as kaolinite, and soil organic matter and the possible role of both in the prevention of environmental contamination by HOCs. Literature data indicates that certain siloxane surfaces can be hydrophobic. Therefore soils can retain HOCs even at low soil organic levels and the extent will depend on the structure of the pollutant and the type and concentration of clay minerals in the sorbent. Clay minerals are wettable by nonpolar solvents and so sorption of HOCs onto them from aqueous and non-aqueous solutions is possible. This is important for two reasons: firstly, the movement and remediation of soil environments will be a function of the concentration and type of clay minerals in the soil. Secondly, low-cost sorbents such as kaolinite and expandable clays can be added to soils or contaminated environments as temporary retention barriers for HOCs. Inorganic cations sorbed onto the kaolinite have a strong influence on the rate and extent of sorption of hydrophobic organic pollutants onto kaolinite. Structural sorbate classes that can be retained by the kaolinite matrix are limited by hydrogen bonding between hydroxyl groups of the octahedral alumosilicate sheet and the tetrahedral sheet with silicon. Soil organic carbon plays a key role in the sorption of HOCs onto soils, but the extent will be strongly affected by the structure of the organic soil matter and the presence of soot. Structural characterisation of soil organic matter in a particular soil should be conducted during a particular contamination event. Contamination by mining extractants and antibiotics will require renewed focus on the use of the QSAR approaches in the context of the sorption of HOCs onto clay minerals from aqueous and non-aqueous solutions

    Discussional issues between the Hanafis and Malikis on the Islamic marriage contract

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    Yüksek Lisans TeziSosyal düzen kurallarından oluşan İslam Hukuku, bu niteliğiyle Müslümanların ibadet hayatı yanında sosyal ve iktisadi hayatına dair ayrıntılı hükümler ihtiva etmektedir. Muâmalât bölümünde yer alan evlilik, fıkıh bilimi içinde önemli bir yere sahiptir. Günümüzde olduğu gibi, İslam Hukukunda da yuvanın tesisi görüşme, söz kesimi, evlilik hazırlığı ve nikâh akdi gibi birtakım aşamalardan geçer. Biz bu incelememizde fıkıh literatüründe nikâh konusunu, Hanefî mezhebi ile Malikî mezhebi arasındaki ihtilaflı meseleleri mukayeseli şekilde ele alarak fıkıh araştırmalarına katkıda bulunmayı amaçladık. Nikâh akdi konusunda mukayeseli inceleme olan bu çalışmamız, bir giriş ve iki bölümden oluşmaktadır. Giriş kısmında: Araştırmanın amaç, yöntem, problemi ile kaynaklarına dair bilgiler vermenin yanında, konunun fıkıh içindeki konumuna ve kapsamına değinilmiştir. Birinci bölüm içinde Nişan ve Nikâh Akdiyle İlgili İhtilaflı Meseleler, başlığı altı nda nişan, nikâhta velayet, denklik ve şahitlik, mehirle ilgili meseleler ele alınmıştır. İkinci bölümde ise geçersiz evlilikler konusunda Hanefî ve Malikîler arasında tartışmalı meseleleri ve eşler arasında haklar konusunda tartışmalı meseleler irdelenmiştir. Çalışmamız, ulaştığımız neticeleri ve önerilerimizi içeren bir sonuç bölümüyle tamamlanmıştır.Islamic Law, which consists of social order rules, contains detailed provisions regarding the social and economic life of Muslims as well as their worship life. Marriage, which is included in the treatment “muâmalât” section, has an important place in the science of fiqh. As it is today, the establishment of a family in Islamic Law goes through some stages such as marriage intended meeting, marriage preparation, and marriage contract. In this study, we aimed to turn the subject of marriage into a theory by comparing the controversial issues between the Hanafi and Maliki sects in the fiqh literature and thus to contribute to fiqh studies. This study, which is a comparative study on the marriage contract, consists of an introduction and two chapters. In the introduction part, besides giving information about the purpose, method, and sources of the research, the position and scope of the subject in fiqh are mentioned. In the first chapter, the controversial issues related to engagement and marriage contract, issues related to engagement under topic, issues related to custody, engagement and witnessing in marriage, and issues related to mahr in marriage are discussed. In the second chapter, controversial issues between Hanafi and Malikis about invalid marriages and controversial issues about rights between spouses are discussed. Our study has been completed with a conclusion that includes our conclusions and recommendations

    Analysis and sorption of pyrethroids in soil environments

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