Electrochemical monitoring of methyl parathion degradation based on carbon fiber microelectrodes (CFME)

The electrochemical degradation of methyl parathion (MP) has been investigated by using carbon fiber microelectrodes (CFME) as working electrode and acetate buffer pH 5.2 as supporting electrolyte. pnitrophenol (PNP) and p-aminophenol (PAP) recognized as by-products of MP degradation process have been detected and identified in real time using square wave voltammetry. This study shows for the first time that CFME could be used to follow MP degradation in real time and to identify its stables metabolites.Keywords: Organopollutants, decomposition, p-nitrophenol, p-aminophenol, Cyclic voltammetry, Square wave voltammetr

Pathotypic diversity of Hyaloperonospora brassicae collected from Brassica oleracea

Downy mildew caused by Hyaloperonospora brassicae is an economically destructive disease of brassica crops in many growing regions throughout the world. Specialised pathogenicity of downy mildews from different Brassica species and closely related ornamental or wild relatives has been described from host range studies. Pathotypic variation amongst Hyaloperonospora brassicae isolates from Brassica oleracea has also been described; however, a standard set of B. oleracea lines that could enable reproducible classification of H. brassicae pathotypes was poorly developed. For this purpose, we examined the use of eight genetically refined host lines derived from our previous collaborative work on downy mildew resistance as a differential set to characterise pathotypes in the European population of H. brassicae. Interaction phenotypes for each combination of isolate and host line were assessed following drop inoculation of cotyledons and a spectrum of seven phenotypes was observed based on the level of sporulation on cotyledons and visible host responses. Two host lines were resistant or moderately resistant to the entire collection of isolates, and another was universally susceptible. Five lines showed differential responses to the H. brassicae isolates. A minimum of six pathotypes and five major effect resistance genes are proposed to explain all of the observed interaction phenotypes. The B. oleracea lines from this study can be useful for monitoring pathotype frequencies in H. brassicae populations in the same or other vegetable growing regions, and to assess the potential durability of disease control from different combinations of the predicted downy mildew resistance genes

Cracking in asphalt materials

This chapter provides a comprehensive review of both laboratory characterization and modelling of bulk material fracture in asphalt mixtures. For the purpose of organization, this chapter is divided into a section on laboratory tests and a section on models. The laboratory characterization section is further subdivided on the basis of predominant loading conditions (monotonic vs. cyclic). The section on constitutive models is subdivided into two sections, the first one containing fracture mechanics based models for crack initiation and propagation that do not include material degradation due to cyclic loading conditions. The second section discusses phenomenological models that have been developed for crack growth through the use of dissipated energy and damage accumulation concepts. These latter models have the capability to simulate degradation of material capacity upon exceeding a threshold number of loading cycles.Peer ReviewedPostprint (author's final draft

Fertility and polygyny: Experimental evidence from Burkina Faso

Decision-making about fertility differs between monogamous and polygynous households. In an experiment in Burkina Faso that gives women access to free contraceptives, either alone or with their husband, involving the husband decreases contraceptive use among monogamous women, but not among polygynous women. Where there is co-wife rivalry, it increases contraceptive use. This is consistent with a model where monogamous women have a stronger preference for contraceptives than their husband, while this preference difference is smaller or even reversed among polygynous households due to co-wife competition around fertility

SWV determination of glyphosate in Burkina Faso soils using carbon fiber microelectrode

This paper presents an evaluation using carbon fiber microelectrode (CFME) for the determination of glyphosate in soils from Burkina Faso treated with Glyphonet SL 360 by square wave voltammetry (SWV).The maximum intensity of the electrochemical response signal of  glyphosate has been optimized and conditions using a 0.2 M of phosphate buffer solution at pH 5.2 as supporting electrolyte and the SWV parameters frequency of 60 Hz, a scan increment of 10 mV and a pulse height of 60 mV. The limit of detection for glyphosate in the Glyphonet SL 360 formulation was 25 ìg L-1 while the quantification limit was 83 ìgL-1with a linear dynamic range up to 50 ìg L-1. In these conditions, a sequence of experiments led to recoveries in the range 88.5 to 102.3% for soil samples spiked with 50, 100 and 200 ìgL-1 of glyphosate with a standard deviation of 11.5, 4.2 and 2.3% respectively indicating the precision of the method. The optimized method was successfully applied to determine the residues of glyphosate in soils collected in the fields in two different dates from the application period.Keywords: Glyphosate, Glyphonet SL 360, carbon fiber microelectrode, square wave voltammetry, sensitivit

Eales’ Disease: Case report

Eales’ disease is a retinal vasculopathy of unknown origin. Ischaemic step associated retinal perivasculitis. Neovascularisation step after the previous one, characterised by vitreous haemorrhage in relation with retinal neo vessels. This observation presents the first reported case of this pathology in Brazzaville. A man of 32 was followed for more than five episodes of vitreous haemorrhage over three years. These episodes had an average duration of two months, inter-spersed with complete clinical silence period of variable duration. During crises, visual acuity was under 2/10, and then it went back up to 10/10 spontaneously. Successive tests were normal: blood count, serologies (syphilis, HIV, Lyme), blood tests (converting enzyme, angiotensin II, calcium), tuberculin skin test, fluorescein angiography (FA), chest x-ray. The last episode was unusual, by the depth of visual impairment (light perception), by the existence of retinal neovascularisation (sea fan aspect). The outcome was favorable after retinal photocoagulation and corticotherapy

Nosocomial Urinary Infections at the Urogoly Unit of the National University Hospital (Yalgado Ouedraogo), Ouagadougou: Feb.-Sept. 2012

Objective: The aim of this study was to identify the risk factors and the microorganisms susceptibilities of nosocomial urinary infections at the urology unit of the national university hospital of Ouagadougou in Burkina Faso.Method: From February to September 2012, two bacteriological analyzes have been performed for any of the 75 inpatients in the urology unit of the national university hospital of Ouagadougou in Burkina Faso.Results: During the study period, 43 cases of nosocomial urinary infection were identified (57.3%) and we found no statistically significant associated risk factors with age groups, sex, arterial blood pressure, kidney illness and urinary obstructive pathologies.The most frequently isolated bacteria were Escherichia coli (30.9%),  Klebsiella spp (26.9%) and Staphylococcus spp (15.4%). The yeasts strains were very sensitive to antifungal but the bacteria susceptibility rate to antibiotics was very variable. Thus, the cocci were rather sensitive to  association clavulanic acid + amoxicilline and ceftriaxone and enoughsensitive to gentamicine ; the bacilli were enough sensitive to gentamicin and very sensitive to imipenem.Conclusion: From the antibiogram results, we recommend gentamicin in combination with penicillin or metronidazole as the first antibiotics to be used in the treatment of nosocomial urinary tract infections.Keywords: urinary infection, nosocomial infection, bacteria, antibiotic

Dietary patterns of adults living in Ouagadougou and their association with overweight

<p>Abstract</p> <p>Background</p> <p>Urbanization in developing countries comes along with changes in food habits and living conditions and with an increase in overweight and associated health risks. The objective of the study was to describe dietary patterns of adults in Ouagadougou and to study their relationship with anthropometric status of the subjects.</p> <p>Methods</p> <p>A qualitative food frequency questionnaire was administered to 1,072 adults living in two contrasted districts of Ouagadougou. Dietary patterns were defined by principal component analysis and described by multivariate analysis. Logistic regression was used to study their association with overweight.</p> <p>Results</p> <p>The diet was mainly made of cereals, vegetables and fats from vegetable sources. The two first components of the principal component analysis were interpreted respectively as a "snacking" score and as a "modern foods" score. Both scores were positively and independently associated with the economic level of households and with food expenditures (p ≤ 0.001 for both). The "snacking" score was higher for younger people (p = 0.004), for people having a formal occupation (p = 0.006), for those never married (p = 0.005), whereas the "modern foods" score was associated with ethnic group (p = 0.032) and district of residence (p < 0.001). Thirty-six percent of women and 14.5% of men were overweight (Body Mass Index > 25 kg/m²). A higher "modern foods" score was associated with a higher prevalence of overweight when confounding factors were accounted for (OR = 1.19 [95% CI 1.03-1.36]) but there was no relationship between overweight and the "snacking" score.</p> <p>Conclusions</p> <p>Modernisation of types of foods consumed was associated with the living conditions and the environment and with an increased risk of overweight. This should be accounted for to promote better nutrition and prevent non communicable diseases.</p