137 research outputs found

    A Comparative Investigation on Petroleum Demulsification Techniques (Centrifuge and Green Chemicals Versus Conventional Chemicals)

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    The breaking (demulsification) of 50-50% w/o petroleum emulsions of two oils (A and B) by Green (chemical and centrifuge) methods were studied in comparison to conventional (chemical) method. The green methods consisted of silicon based chemical demulsifiers and high-speed centrifuge operated at 12,000 RPM, while the conventional method consisted of Amine group based demulsifiers. In chemical method, the concentrations were varied (0.5%, 1.5% and 3%), while in centrifuge method, the processing time was varied (10 and 30 minutes). The efficiency of these methods was determined by measuring the amount of water separated from the emulsion after being treated. The maximum separation efficiencies for Silicon demulsifiers were 93 and 88% for oils A and B respectively, and that of Amine group demulsifiers were 72 and 86% for oils A and B respectively, While centrifuge demulsification gave maximum separations of 39 and 24% for oils A and B respectively. Based on these results, Silicon based demulsifiers are very effective and reliable method to treat emulsions for different types of oils with different composition, and have the potential to be used as an alternative method in the demulsification or breaking of water-in-crude oil emulsions

    Myrmécofaune arboricole associée aux couples Phragmanthera capitata (Sprengel) S. Balle/ hÎte au verger de la chefferie de Ndogbong (Douala, Cameroun)

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    Parmi les Loranthaceae, l’espĂšce Phragmanthera capitata s’est mieux adaptĂ©e aux conditions du milieu modifiĂ© par l’homme et aux arbres cultivĂ©s ou spontanĂ©s devenant un vĂ©ritable flĂ©au agronomique. La mĂ©thode de lutte ciblĂ©e plus prometteuse ne peut ĂȘtre satisfaisante que si les mĂ©canismes qui rĂ©gulent l’adaptation des Loranthaceae Ă  leurs hĂŽtes cultivĂ©s ou spontanĂ©s sont identifiĂ©s et maĂźtrisĂ©s. Dans cette optique, une Ă©tude de la myrmĂ©cofaune arboricole a Ă©tĂ© menĂ©e sur trois couples P. capitata/hĂŽte au verger de la chefferie de Ndogbong. Auparavant, un inventaire exhaustif de tous les arbres parasitĂ©s ou non et de la myrmĂ©cofaune du verger de la chefferie de Ndogbong (Douala) a Ă©tĂ© entrepris et toutes les touffes de P. capitata comptabilisĂ©s sur les arbreshĂŽtes qui en possĂ©daient. Tous les arbres du verger sont exotiques exceptĂ© Spondias mangifera. Le taux de parasitisme est de 42,85%. Quatre espĂšces de fourmis (Crematogaster sp. 1, Crematogaster sp.2, Pheidole megacephala et Camponotus sp.) ont une activitĂ© fourragĂšre notamment florifĂšre sur les individus de P. capitata. Leur densitĂ© varie avec la floraison et semble liĂ©e Ă  la chute des boutons floraux et des fleurs. Ces fourmis pourraient constituer des forces d’organisation et d’évolution exploitables dans la lutte biologique contre les Loranthaceae. Mots clĂ©s: Loranthaceae, myrmĂ©cofaune arboricole, plantes hĂŽtes

    Lowland Soils for Rice Cultivation in Ghana

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    Improving Soil Productivity and Increasing Lowland Rice Yields through the Integration of Organic and Inorganic Fertilizers in the Savannah and Forest Agro-ecological Zones of La Cote d’Ívoire

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    Sole mineral fertilizers use by poorly resourced farmers for rice production in the lowlands is usually low and unsustainable. Field experiments were therefore conducted within two contrasting environments (Forest and Savannah), using two common organic amendments (Poultry manure and Cattle manure) to establish an effective and integrated soil nutrient management system for improved lowland soil productivity and increased rice yields. The study was also partly intended to encourage and promote the effective and sustainable use of locally available organic amendments for nutrient management in lowland rice production. Results showed that organic amendments {cattle manure (CM) and poultry manure (PM)} contributed significantly to grain yield increases and total productivity with PM having a significantly greater and positive effect on grain yield than CM. In addition, the application of organic amendments in combination with mineral fertilizer significantly contributed to increased grain yield over the application of sole mineral fertilizer. Within the savannah agro- cological zone, there was a 130% (CM) and 203% (PM) grain yield increase over the control due to the application of organic amendments . When organic amendments were applied in combination with mineral fertilizer (MF), grain yield increased by 21% and 43% over sole MF for CM and PM respectively. However, sole CM contributed 12% increase in grain yield over the control while PM gave a 35% increase within the forest agro- cological zone. The combined application of MF and CM resulted in an 11% increase in grain yield while MF and PM combinations produced a 30% yield increase within the ecology. The non-addition of N, P, K as mineral fertilizer resulted in a yield reduction of about 84% at both sites. Resource poor farmers within the West African sub-region should therefore be encouraged to use organic amendments, which are not only available locally but also affordable. Proper storage and handling of these organic materials is very important to minimize nutrient losses.&nbsp

    Evaluation of seasonal malaria chemoprevention in two areas of intense seasonal malaria transmission: Secondary analysis of a household-randomised, placebo-controlled trial in Houndé District, Burkina Faso and Bougouni District, Mali.

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    BACKGROUND: Seasonal malaria chemoprevention (SMC) is now widely deployed in the Sahel, including several countries that are major contributors to the global burden of malaria. Consequently, it is important to understand whether SMC continues to provide a high level of protection and how SMC might be improved. SMC was evaluated using data from a large, household-randomised trial in Houndé, Burkina Faso and Bougouni, Mali. METHODS AND FINDINGS: The parent trial evaluated monthly SMC plus either azithromycin (AZ) or placebo, administered as directly observed therapy 4 times per year between August and November (2014-2016). In July 2014, 19,578 children aged 3-59 months were randomised by household to study group. Children who remained within the age range 3-59 months in August each year, plus children born into study households or who moved into the study area, received study drugs in 2015 and 2016. These analyses focus on the approximately 10,000 children (5,000 per country) under observation each year in the SMC plus placebo group. Despite high coverage and high adherence to SMC, the incidence of hospitalisations or deaths due to malaria and uncomplicated clinical malaria remained high in the study areas (overall incidence rates 12.5 [95% confidence interval (CI): 11.2, 14.1] and 871.1 [95% CI: 852.3, 890.6] cases per 1,000 person-years, respectively) and peaked in July each year, before SMC delivery began in August. The incidence rate ratio comparing SMC within the past 28 days with SMC more than 35 days ago-adjusted for age, country, and household clustering-was 0.13 (95% CI: 0.08, 0.20), P < 0.001 for malaria hospitalisations and deaths from malaria and 0.21 (95% CI 0.20, 0.23), P < 0.001 for uncomplicated malaria, indicating protective efficacy of 87.4% (95% CI: 79.6%, 92.2%) and 78.3% (95% CI: 76.8%, 79.6%), respectively. The prevalence of malaria parasitaemia at weekly surveys during the rainy season and at the end of the transmission season was several times higher in children who missed the SMC course preceding the survey contact, and the smallest prevalence ratio observed was 2.98 (95% CI: 1.95, 4.54), P < 0.001. The frequency of molecular markers of sulfadoxine-pyrimethamine (SP) and amodiaquine (AQ) resistance did not increase markedly over the study period either amongst study children or amongst school-age children resident in the study areas. After 3 years of SMC deployment, the day 28 PCR-unadjusted adequate clinical and parasitological response rate of the SP + AQ regimen in children with asymptomatic malaria was 98.3% (95% CI: 88.6%, 99.8%) in Burkina Faso and 96.1% (95% CI: 91.5%, 98.2%) in Mali. Key limitations of this study are the potential overdiagnosis of uncomplicated malaria by rapid diagnostic tests and the potential for residual confounding from factors related to adherence to the monthly SMC schedule. CONCLUSION: Despite strong evidence that SMC is providing a high level of protection, the burden of malaria remains substantial in the 2 study areas. These results emphasise the need for continuing support of SMC programmes. A fifth monthly SMC course is needed to adequately cover the whole transmission season in the study areas and in settings with similar epidemiology. TRIAL REGISTRATION: The AZ-SMC trial in which these data were collected was registered at clinicaltrials.gov: NCT02211729

    Individual, household and national factors associated with iron, vitamin A and zinc deficiencies among children aged 6-59 months in Nepal

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    Iron, vitamin A and zinc deficiencies are the top three micronutrients contributing to disability‐adjusted life years globally. The study assessed the factors associated with iron, vitamin A, and Zinc deficiencies among Nepalese children (n = 1709) aged 6–59 months using data from the 2016 Nepal National Micronutrient Status Survey. The following cut‐off points were applied: iron deficiency [ferritin 8.3 mg/L], vitamin A deficiency (retinol‐binding protein < 0.69 ÎŒmol/L) and zinc deficiency (serum zinc < 65 ÎŒg/dl for morning sample and <57”g/dl for afternoon sample). We used multiple logistic regression adjusted for sampling weights and clustering to examine the predictors of micronutrient deficiencies. The prevalence of iron depletion (ferritin), tissue iron (sTfR), vitamin A and zinc deficiencies were 36.7%, 27.6%, 8.5% and 20.4%, respectively. Children were more likely to be iron deficient (ferritin) if aged 6–23 months, stunted, and in a middle‐wealth quintile household. Vitamin A deficiency was associated with development region and was higher among children living in severe food‐insecure households and those who did not consume fruits. Zinc deficiency was higher among children in rural areas and the poorest wealth quintile. The Government of Nepal should focus on addressing micronutrient deficiencies in the early years, with emphasis on improving food systems, promote healthy diets, among younger and stunted children and provide social cash transfer targeting high‐risk development regions, poorest and food insecure households

    Invagination Intestinale AiguĂ« De L’adulte: Aspects Diagnostiqsues, ThĂ©rapeutiques Et Étiologiques

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    Introduction: Acute intussusception is a rare clinical entity in adults where it accounts for only 1-2% of intestinal obstructions. The authors wanted to report cases of acute intussusception in adult patients, their diagnostic aspects, their management, and their etiologies. Patients and Methods: This study is a retrospective study of the medical files of patients of both sexes. They include adults over 15 years of age, operated between January 2010 and December 2014, who were diagnosed with obstruction due to acute intestinal intussusception. Results: Six cases of adult intestinal intussusception were collected. The average age was 26.5 years. The sex ratio was 1 and there were so many men as women. Five out of six patients were unstable on admission. The diagnosis was made preoperative in two cases out of six, 33.3%. Ultrasound revealed a target sign in two cases. The ileo-ileal form was the most frequent (5 cases out of 6) or 83.3%. Also, there were two cases of intestinal necrosis out of six. Intestinal resection was performed in five cases or 83.33%. The cause of intussusception was found in four cases out of six or 66.7%. Here, a tumor was the cause in half of the cases. Immediate surgical follow-up was uncomplicated in all patients. Conclusion: Acute intestinal intussusception of the adult is a very rare condition. The preoperative diagnosis of acute intussusception of the adult remains delicate. The ileo-ileal form is more frequent than the ileo-colic form in adults. Treatment is always surgical in adults

    Different methodological approaches to the assessment of in vivo efficacy of three artemisinin-based combination antimalarial treatments for the treatment of uncomplicated falciparum malaria in African children.

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    BACKGROUND: Use of different methods for assessing the efficacy of artemisinin-based combination antimalarial treatments (ACTs) will result in different estimates being reported, with implications for changes in treatment policy. METHODS: Data from different in vivo studies of ACT treatment of uncomplicated falciparum malaria were combined in a single database. Efficacy at day 28 corrected by PCR genotyping was estimated using four methods. In the first two methods, failure rates were calculated as proportions with either (1a) reinfections excluded from the analysis (standard WHO per-protocol analysis) or (1b) reinfections considered as treatment successes. In the second two methods, failure rates were estimated using the Kaplan-Meier product limit formula using either (2a) WHO (2001) definitions of failure, or (2b) failure defined using parasitological criteria only. RESULTS: Data analysed represented 2926 patients from 17 studies in nine African countries. Three ACTs were studied: artesunate-amodiaquine (AS+AQ, N = 1702), artesunate-sulphadoxine-pyrimethamine (AS+SP, N = 706) and artemether-lumefantrine (AL, N = 518).Using method (1a), the day 28 failure rates ranged from 0% to 39.3% for AS+AQ treatment, from 1.0% to 33.3% for AS+SP treatment and from 0% to 3.3% for AL treatment. The median [range] difference in point estimates between method 1a (reference) and the others were: (i) method 1b = 1.3% [0 to 24.8], (ii) method 2a = 1.1% [0 to 21.5], and (iii) method 2b = 0% [-38 to 19.3].The standard per-protocol method (1a) tended to overestimate the risk of failure when compared to alternative methods using the same endpoint definitions (methods 1b and 2a). It either overestimated or underestimated the risk when endpoints based on parasitological rather than clinical criteria were applied. The standard method was also associated with a 34% reduction in the number of patients evaluated compared to the number of patients enrolled. Only 2% of the sample size was lost when failures were classified on the first day of parasite recurrence and survival analytical methods were used. CONCLUSION: The primary purpose of an in vivo study should be to provide a precise estimate of the risk of antimalarial treatment failure due to drug resistance. Use of survival analysis is the most appropriate way to estimate failure rates with parasitological recurrence classified as treatment failure on the day it occurs

    Nutritional status in young children prior to the malaria transmission season in Burkina Faso and Mali, and its impact on the incidence of clinical malaria.

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    BACKGROUND: Malaria and malnutrition remain major problems in Sahel countries, especially in young children. The direct effect of malnutrition on malaria remains poorly understood, and may have important implications for malaria control. In this study, nutritional status and the association between malnutrition and subsequent incidence of symptomatic malaria were examined in children in Burkina Faso and Mali who received either azithromycin or placebo, alongside seasonal malaria chemoprevention. METHODS: Mid-upper arm circumference (MUAC) was measured in all 20,185 children who attended a screening visit prior to the malaria transmission season in 2015. Prior to the 2016 malaria season, weight, height and MUAC were measured among 4149 randomly selected children. Height-for-age, weight-for-age, weight-for-height, and MUAC-for-age were calculated as indicators of nutritional status. Malaria incidence was measured during the following rainy seasons. Multivariable random effects Poisson models were created for each nutritional indicator to study the effect of malnutrition on clinical malaria incidence for each country. RESULTS: In both 2015 and 2016, nutritional status prior to the malaria season was poor. The most prevalent form of malnutrition in Burkina Faso was being underweight (30.5%; 95% CI 28.6-32.6), whereas in Mali stunting was most prevalent (27.5%; 95% CI 25.6-29.5). In 2016, clinical malaria incidence was 675 per 1000 person-years (95% CI 613-744) in Burkina Faso, and 1245 per 1000 person-years (95% CI 1152-1347) in Mali. There was some evidence that severe stunting was associated with lower incidence of malaria in Mali (RR 0.81; 95% CI 0.64-1.02; p = 0.08), but this association was not seen in Burkina Faso. Being moderately underweight tended to be associated with higher incidence of clinical malaria in Burkina Faso (RR 1.27; 95% CI 0.98-1.64; p = 0.07), while this was the case in Mali for moderate wasting (RR 1.27; 95% CI 0.98-1.64; p = 0.07). However, these associations were not observed in severely affected children, nor consistent between countries. MUAC-for-age was not associated with malaria risk. CONCLUSIONS: Both malnutrition and malaria were common in the study areas, high despite high coverage of seasonal malaria chemoprevention and long-lasting insecticidal nets. However, no strong or consistent evidence was found for an association between any of the nutritional indicators and the subsequent incidence of clinical malaria

    Factors associated with inadequate receipt of components and non-use of antenatal care services in India : a regional analysis

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    Background: Failure to use antenatal care (ANC) and inadequate receipt of components of ANC pose a significant risk for the pregnant woman and the baby. This study aimed to examine a regional analysis of factors associated with receiving no ANC and inadequate receipt of components of ANC services among Indian women. Method: Information from 173,970 women of reproductive age 15–49 years from the 2019–21 India National Family Health Survey (NFSH-5) was analysed. Logistic regression analyses that adjusted for cluster and survey weights were conducted to assess the socio-demographic and other factors associated with receiving non-use of ANC and inadequate receipt of components of ANC, respectively, in the six regions and 28 states, and 8 union territories in India. Results: Across regions in India, 7% of women reported no ANC, and the prevalence of inadequate and adequate receipt of components of ANC in all six regions ranged from 67 to 89% and 8% to 24%, respectively. Of all the 36 federated entities, the prevalence of inadequate receipt of ANC components was less than two-thirds in Tamil Nadu, Puducherry, Andaman and the Nicobar Islands, Odisha, and Gujarat. Our analyses revealed that associated factors vary by region, state, and union territories. Women from poor households reported increased odds of receiving no ANC in North, East and North-eastern regions. Women who reported no schooling in South, East and Central regions were associated with increased odds of receiving no ANC. Women from poor households in Himachal Pradesh, Bihar, Uttar Pradesh, Nagaland, Manipur, Uttar Pradesh, and Madhya Pradesh states reported significantly higher odds of inadequate components ANC than women from rich households. The receipt of inadequate components of ANC was significantly higher among women who never read magazines in Delhi, Ladakh, Karnataka, Telangana, Jharkhand, Maharashtra, Uttar Pradesh, Chhattisgarh, Arunachal Pradesh, Manipur, and Mizoram states in India. Conclusion: A better understanding of the factors associated with and incorporating them into the short- and long-term intervention strategies, including free financial support from the Indian government to encourage pregnant women from lower socioeconomic groups to use health services across all regions, states and union territories
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