Effects of a Thermal Nonlinear Resistance on the Power Output of the PV Cell

Within the existing approaches aiming to ameliorate the performances of the photovoltaic (PV) cell, we note that the nonlinear behaviour of the PV cell components is not exploited. In this paper, we examine the effects of a thermal nonlinear resistance on the characteristics of a PV cell known as the current-voltage I-V and power-voltage P-V. This thermal nonlinear resistance is constituted of a series resistance whose value varies as a quadratic function of the temperature across it. In the standard test condition and around this proposed model of the PV, analytical study and numerical simulations in MATLAB as well as experimental investigations with Multisim environment are made...........

The economic potential of Echinochloa pyramidalis (Lam.) Hitchc & Chase forage plant used in liquid waste treatment in Cameroon: Opportunity to link sanitation to food security

Cameroon, like other developing countries, faces major problems in the urban centres such as high rate of population increase, food and ruminant feed shortages as well as inadequate access to sanitation. However, Echinochloa pyramidalis, well-known forage adapted to the drying vegetated beds for wastewater and faecal sludge treatments with similar characteristics as Typha sp., Phragmites sp., might be used in the dual purpose as animal feed and as support material in sanitation treatment. This study aimed at linking sanitation technology to forage production. A socio-economic survey conducted in Douala, Yaoundé and Garoua to evaluate the economic potential of E. pyramidalis showed the daily quantities of marketed forage between 5 and 8-tons of fresh weight (FW) respectively during dry and rainy season. The forage price varies with season and species from USD 0.1–0.2 to USD 0.2–0.3/kg FW with daily income of USD 800–1’600 and USD 500–1’500 respectively to rainy and dry season. While comparable to most tropical forages, the nutritional values of E. pyramidalis after 45 and 100 days of wetland treatment were only affected by the advancing maturity. Thus, E. pyramidalis can be easily grown in wetland systems and sold for animal feeding in the local market.Keywords: Echinochloa pyramidalis, economic potential, forage production, nutritional values, sanitation technology, vertical-flow constructed wetland

A Review of Posttraumatic Bowel Injuries in Ibadan

Background. Bowel injuries are a leading cause of morbidity and mortality following trauma. Evaluating patients who sustained abdominal trauma with bowel injury may pose a significant diagnostic challenge to the surgeon. Prompt recognition and timely intervention is necessary to improve outcome. Aim. This study was undertaken to evaluate treatment and outcome of patients with bowel trauma. Methods. A 5-year retrospective study of all patients presenting with abdominal trauma requiring surgical intervention seen in the UCH Ibadan, Nigeria was undertaken. Results. There were 71 patients (59 males and 12 females). The majority of cases (70%) occurred between the 3rd and 5th decades of life. Some 37 patients (52%) sustained blunt abdominal injury, while 34 patients (48%) sustained penetrating abdominal injury. There were 27 patients with bowel injuries (38%). Isolated bowel injuries occurred in 19 patients (27%). The most common surgical operation performed was simple closure. There were 3 deaths in patients with bowel injuries. Conclusion. Most cases of bowel injury can be managed by simple closure, a technique that is not so technically demanding for surgeons in less-developed countries. This study has also incidentally identified a “rule of six” for patients with bowel injuries and abdominal trauma

Is host range of carrot restricted to Alternaria dauci?

International audienc

Evaluating aggressiveness and host range of Alternaria dauci in a controlled environment

The aggressiveness of Alternaria dauci isolates was investigated in greenhouse conditions. Twenty-seven isolates were pre-selected from a large collection to represent high diversity according to geographic or host origins and intergenic spacer (IGS) polymorphism. IGS sequence analysis revealed that isolates were grouped within three different clusters. Eleven isolates were selected and inoculated on a susceptible carrot cultivar. Three criteria (mean lesion number, mean necrotic leaf area and mean disease index) were used to assess the aggressiveness of isolates. Continuous variation in aggressiveness was shown and no clear division into isolate classes was evident. For the host range study, two isolates were inoculated under greenhouse conditions onto nine cultivated Apiaceae species, two wild Daucus species and six cultivated non-Apiaceae species representing six botanical families. Lesions varying in severity were observed on all dicot species (Apiaceae and non-Apiaceae), but no symptoms developed on the two monocots studied (leek and sweetcorn). Plant species were also differentiated on the basis of expanding lesions (cultivated and wild carrot, dill and fennel) or non-expanding lesions (other dicot species). Typical A. dauci conidia were observed after in vitro incubation of leaves with symptoms. Fungal structures were isolated from lesions and A. dauci was confirmed on the basis of conidial morphology and specific conventional PCR results. Genotyping of individual isolates performed with microsatellite markers confirmed the presence of the inoculated isolate. The results clearly showed that, in controlled conditions, the host range of A. dauci is not restricted to carrot

Effect of an integrated intervention package of preventive chemotherapy, community-led total sanitation and health education on the prevalence of helminth and intestinal protozoa infections in Côte d'Ivoire

Preventive chemotherapy with donated anthelminthic drugs is the cornerstone for the control of helminthiases. However, reinfection can occur rapidly in the absence of clean water and sanitation coupled with unhygienic behaviour. The purpose of this study was to assess the effect of an integrated package of interventions, consisting of preventive chemotherapy, community-led total sanitation (CLTS) and health education, on the prevalence of helminth and intestinal protozoa infections and on participants' knowledge, attitude, practice and beliefs (KAPB) towards these diseases including water, sanitation and hygiene (WASH).; A cross-sectional survey was carried out in nine communities of south-central Côte d'Ivoire to assess people's infection with helminths and intestinal protozoa and KAPB. Subsequently, interventions were targeted to five communities, while the remaining communities served as control. The intervention encouraged latrine construction and an evaluation was done 6-7 months later to determine open defecation status of the respective communities. Anthelminthic treatment was provided to all community members. A follow-up cross-sectional survey was conducted approximately one year later, using the same procedures.; Overall, 810 people had complete baseline and follow-up data and were given anthelminthic treatment. The baseline prevalence of hookworm, Schistosoma haematobium, Trichuris trichiura, Schistosoma mansoni and Ascaris lumbricoides was 31.1%, 7.0%, 2.0%, 1.0% and 0.3%, respectively. Four of the five intervention communities were classified open-defecation free. For hookworm infection, we observed higher negative changes in terms of proportion of decrease (-0.10; 95% confidence interval (CI): - 0.16, -0.04) and higher egg reduction rate (64.9 vs 15.2%) when comparing intervention with control communities. For intestinal protozoa, prevalence reduction was higher in intervention compared to control communities (8.2 vs 2.6%) and WASH indicators and intervention outcomes associated with lower odds for infection at follow-up. The intervention significantly impacted on reported latrine use (before: 15.5%, after: 94.6%), open defecation in the community surroundings (before: 75.0%, after: 16.7%) and awareness for environmental contamination through open defecation (before: 20.4%, after: 52.2%).; An integrated package of interventions consisting of preventive chemotherapy, health education and CLTS reduces the prevalence of helminth and intestinal protozoa infection. Additional studies in other social-ecological settings are warranted to confirm our findings

Are schoolchildren less infected if they have good knowledge about parasitic worms? A case study from rural Côte d'Ivoire

Background: Parasitic worms (helminths) are common infections in low- and middle-income countries. For most helminth species, school-aged children are at highest risk of infection and morbidity, such as impaired cognitive and physical development. Preventive chemotherapy is the current mainstay for helminthiases control. Sanitation improvement and hygiene-related education are important complementary strategies, which act by altering children’s behaviour. However, little is known about the effect of improved knowledge on the risk of helminth infection. The aim of this study was to assess the potential influence of knowledge that children acquired at home or in school, without any specific health education intervention, on helminth infections. Methods: In May 2014, we conducted a cross-sectional survey in western Côte d’Ivoire. A total of 2498 children, aged 9-12 years, were subjected to three consecutive stool examinations using duplicate Kato-Katz thick smears to determine infections with soil-transmitted helminths and Schistosoma mansoni. Additionally, children were interviewed to assess their knowledge about helminth infections. Four knowledge scores were constructed by factor analysis; one, reflecting general knowledge about helminths and three manifesting helminth species-specific knowledge. The effect of general and specific knowledge on children’s helminth infection status was determined using meta-analysis. Results: Children who scored high in the hookworm-specific knowledge were less likely to be infected with hookworm but no association was found for the other helminth species. Moreover, greater general knowledge was not associated with lower odds of being infected with any helminth species. Most of the children interviewed believed that the effect of preventive chemotherapy is permanent, and hence, re-treatment is not necessary. Conclusions: Specific knowledge about different types of helminths might not suffice to induce behavioural change which in turn reduces infection and reinfection with helminths. Health education interventions should strive to strengthen the perception of risk and to clarify the true benefit of preventive chemotherapy.publishersversionpublishe

Canonicalizing Knowledge Base Literals

Ontology-based knowledge bases (KBs) like DBpedia are very valuable resources, but their usefulness and usability is limited by various quality issues. One such issue is the use of string literals instead of semantically typed entities. In this paper we study the automated canonicalization of such literals, i.e., replacing the literal with an existing entity from the KB or with a new entity that is typed using classes from the KB. We propose a framework that combines both reasoning and machine learning in order to predict the relevant entities and types, and we evaluate this framework against state-of-the-art baselines for both semantic typing and entity matching

Evaluación preliminar de los niveles de cloro residual (Cl2) y contaminación por cloraminas en agua potable de la ciudad de Arequipa – 2015

Chlorine is a strong oxidizing agent and is the conventional chemical used in the disinfection process for water purification, reducing the risk of pathogenic infection. However, it may represent a chemical threat to human health due to waste and hazardous disinfection by-products formed as trihalomethanes, nitrosamines, chlorophenols, among others. This paper aims is to assess and monitor the concentration of free chlorine and chloramines in drinking water distributed in the city of Arequipa, to establish whether it is within the parameters set by the competent authority. Three monthly monitoring were performed in the distribution network of the three water treatment plants, performing the DPD spectrophotometric method, the experimental values to first order kinetic model were adjusted using the value of k = 0.0018 as decay constant. The values of free chlorine and chloramines, showed significant difference (p <0.05) in the months of monitoring, different water treatment plants and districts evaluated. It was concluded that the average values of free chlorine are within the parameters defined by the DIGESA and WHO. In addition chloramine concentration values are below the limit of 5 mg.L-1 that sets the international standard WHO.El cloro (Cl2) es un agente oxidante fuerte y es la sustancia química convencional utilizada en el proceso de desinfección para la potabilización del agua, reduciendo el riesgo de infección patógena. Sin embargo, puede representar una amenaza química para la salud humana debido a los residuos de desinfección y los subproductos peligrosos formados como los trihalometanos, nitrosaminas, cloro fenoles, entre otros. El presente trabajo tiene como objetivo evaluar y monitorear la concentración de cloro libre y cloraminas en el agua potable distribuida en la ciudad de Arequipa, para establecer si se encuentra dentro de los parámetros establecidos por la autoridad competente. Se realizaron tres monitoreos mensuales, en la red de distribución de las tres plantas potabilizadoras, empleando el método espectrofotométrico con DPD, se ajustaron los valores experimentales al modelo cinético de primer orden, empleando el valor de k = 0.0018 como constante de decaimiento. Los valores de cloro libre y cloraminas, presentaron diferencia significativa (p<0,05) en los meses de monitoreo, las diferentes plantas potabilizadoras y los distritos evaluados. Se concluyó que el promedio de los valores de cloro libre están dentro de los parámetros definidos por la DIGESA norma y por la OMS norma WHO/SDE/ WSH/03.04/45. Además los valores de concentración de cloraminas se encuentran por debajo del límite de 5 mg.L-1 que establece la norma internacional OMS