Physico-chemical analysis of Logone River water at Moundou City in Southern Chad

The physico-chemical parameters and some heavy metal concentrations in the Logone River water at Moundou City, Chad, are studied for two stations from July 2013 to December 2014, one upstream and another downstream of the city. Standard methods are used. A total of twenty-two physico-chemical parameters were determined by spectrophotometers showed clear seasonal variations of; BOD5, COD, sulphate, phosphate, and nitrate, among the stations. The Moundou City wastewater negatively impacted the concentrations of physicochemical parameters of Logone River water samples when compared with the World Health Organization (WHO) permissible limits. It was observed that the water quality parameters exceed the permissible limits downstream of the river:BOD5 (198mg/l), COD (897 mg/l), MES (287 mg/l), F(1.87 mg/l), heavy metals Cr (0,934 mg/l), Fe (5,55 mg/l) Cu (0,294 mg/l), Pb (17 mg/l), As (0,894 mg/l), Mb (14,2 mg/l). This study shows that industrial discharge into Logone River seriously contributes to the pollution of the river at the level which poses health and environmental hazards to those using it in downstream for domestic and agricultural purposes.Keywords: Heavy metals, river water pollution, physico-chemical properties, Logone river, Moundou, Chad

Evaluation des pertes post-recolte dans la chaine de production et de commercialisation des legumes feuilles traditionnels a Yaounde (Cameroun)

Les légumes feuilles traditionnels contribuent à l’alimentation quotidienne de la population au Cameroun. La nature particulièrement périssable de la plupart de ces légumes, limite leur durée de conservation après récolte. Cette étude montre la situation des pertes post-récolte de ces légumes telle que perçue par les acteurs de la chaîne d’approvisionnement de  Yaoundé. L’enquête auprès des producteurs et des commerçants a porté sur l’analyse de la manutention de la filière pour déterminer les types,    l’ampleur, et les causes des pertes. La méthodologie utilisée a été adaptée de celle de La Gra (1990). Les pertes observées sont causées par des facteurs mécaniques, physiologiques ou pathologiques pouvant être aggravés par des techniques après récolte déficientes. L’ampleur de ces  dommages sur les légumes a varié selon la sensibilité de l’espèce.  L’étude a révélé en outre, des pertes moyennes d’environ 10 % pour l’amarante et 20 % pour la morelle noire et la corète. Des pertes  financières de 2 000 F CFA/semaine, soit 4 $pour la vente de l’amarante et de 4 000 F CFA/semaine, soit 8$ pour chacun des deux autres légumesont ainsi été enregistrées. Pour minimiser les pertes après récolte, l’étude recommande, le développement de techniques simples de manutention, d’infrastructures de transport, de commercialisation et de conservation des produits.Mots clés : Légumes feuilles traditionnelles, manutention post-récolte, facteur de détérioration, estimation des pertes, Cameroun

Vegetable Consumption patterns in Yaounde, Cameroon

A survey was conducted in August and September 2008 in Yaoundé, Cameroon to assess vegetable consumption attitudes, constraints and factors that stimulate households’ consumption. Stratified sample based on district size, socioeconomic status and ethnics groups were used. Three hundred households were interviewed using a questionnaire and there were four times as many women as men in the sample. Data were analyzed using SNAP. More than 80% of the respondents were educated at the secondary (54%) and tertiary (30%) levels. The respondents were generally the wife (35%) or children (30%), and sometimes the husband (20%). More than 50% of the respondents were landlords living in their own homes and the rest were tenants. On average, the population of Yaoundé consumed vegetables frequently (2 to 4 times per week). Tomato, onion, carrot, and chili pepper were the most preferred exotic vegetables while bitter leaf (>80%) and okra (>70%), were the most preferred traditional vegetables. Attitudes towards vegetables varied according to socioeconomic and ethnic group. Main constraints to vegetable consumption were preparation time for respondents in the upper class (30%) and social taboos (amaranth is an ominous crop and can cause impotency in men; okra can inhibit the traditional treatment of some diseases) for the middle and lower classes. Freshness, wholesomeness, and color of the fruit or leaves determined the decision to purchase vegetables. Diversification of diet which is good for health, the preference of family members, and taste were the main reasons for consuming vegetables. Taste, degree of sliminess (okra), and smell after cooking were factors that increased satisfaction during consumption. Two-thirds of the respondents knew the benefits of vegetable consumption but their knowledge was not specific and is influenced by social taboos. Willingness to pay for processed traditional vegetables was higher among respondents in the upper income class (56.9%) than the lower (45.8%) and middle (37.1%) classes. The study revealed a need to further promote the consumption vegetables and inform consumers of their nutritional benefits.Keywords: vegetables, consumption, nutrition, vitamins, mineralsAfrican Journal of Food, Agriculture, Nutrition and Development, Volume 13 No. 2 April 201

Disponibilite, modes et frequence de consommation des legumes traditionnels Africains dans quatre localites du burkina faso a diverses activites de maraichage : Ouagadougou, Koubri, Loumbila, Kongoussi

Les légumes traditionnels constituent une source importante de nutriments pour les ménages des pays en développement. La présente étude s’est intéressée à la diversité, à la  disponibilité, et  aux modes de consommation des légumes traditionnels africains dans des localités à  diverses activités de maraîchage au Burkina Faso. Des enquêtes de consommation alimentaire ont été réalisées auprès de 400 ménages dans quatre localités: Ouagadougou, Loumbila, Koubri et Kongoussi. Quatre principaux légumes sont retrouvés en toute saison dans les différentes localités : l’oseille (Hibiscus sabdariffa), la corète (Corchorus olitorius), l’amarante (Amaranthus cruentus) et le gombo (Abelmoschus callei). A Kongoussi d’autres légumes tels que les feuilles de morelle noire (Solanum scabrum) et de vernonia (Vernonia amygdalina) sont disponibles toute l’année. La fréquence de consommation est d’une fois par semaine pour plus de 50 % des ménages dans les zones à faible activité de maraichage, Ouagadougou, Loumbila et Koubri. A Kongoussi, plus de 45 % des ménages consomment plus d’une fois par semaine le gombo (Abelmoschus callei), les feuilles de corète (Corchorus olitorius), les feuilles d’oseille (Hibiscus sabdariffa) et les feuilles de haricot (Vigna unguiculata). Le marché est la source d’approvisionnement pour 71 % des ménages enquêtés. La saison, l’origine socio-culturelle et les habitudes alimentaires sont les principaux facteurs influant le choix des légumes. L’état frais est la principale forme de préférence des légumes. Pour l’utilisation des légumes dans les ménages, 74,25 % des ménages lavent 02 à 03 fois et découpent finement juste au moment de les préparer. Trois principaux modes de consommation ont été évoqués : la sauce, la soupe et le ragoût. La sauce est le principal mode de consommation et pour la cuisson 97,25 % procèdent par ébullition. Près de 62,50 % ; 53,33 % ; 45,22 % des ménages respectivement à Koubri, Loumbila et Ouagadougou procèdent par blanchiment et rejettent le liquide résiduel. A Ouagadougou et à Kongoussi, respectivement 66,67 % et 33,65 % des ménages pratiquant le blanchiment sont des non natifs. L’importance nutritive et l’effet antioxydant des légumes a été confirmée par près de 87% des répondants. L’étude a permis de conclure que l’activité de maraichage influe positivement sur la disponibilité, la diversité et la fréquence de consommation des légumes dans les ménages. Cependant des séances de sensibilisation sur les traitements post récoltes et les procédés de transformation des légumes sont nécessaires pour en tirer un meilleur profit au plan nutritionnel.Mots clés : légumes, maraîchage, diversité, traitement, blanchiment, cuisson, saison,consommatio

Triacilgliceroles y composición de ácidos grasos del aceite de semilla de egusi (Cucumeropsis Mannii Naudin)

Triacylglycerols were determined from a Cameroonian (African) white egusi seed oil (Cucumeropsis Mannii Naudin) using reversed phase high performance liquid chromatography. The fatty acid composition of two types of seed (red and white) is obtained by capillary gas chromatography. The study of the triacyiglycerol composition obtained in white egusi seed oil revealed that only nine triacylglycerols were present in amounts above 1% (area). The first five triglycerides represent more than 80% of the total triacylglycerols, and the major triacyiglycerol was palmitoyldilinoleoylglycerol, accounting for 23.6% of the oil. This oil contains a high proportion of linoleic acid (60% wt/wt).Se determinó la composición en triacilgliceroles del aceite de semilla de egusi del Camerún (Cucumeropsis Mannii Naudin) utilizando cromatografía líquida de alta eficacia en fase inversa. La composición en ácidos grasos de dos tipos de semillas de egusi (roja y blanca) fue obtenida por cromatografía de gases en columna capilar. El estudio de la composición en triacilgliceroles del aceite obtenido de semilla blanca de egusi reveló que sólo nueve de ellos se encontraban en proporción superior al 1% (en área). Cinco triacilgliceroles representaron más del 80% del total y el mayoritario fue el palmitoildilinoleoilglicerol (23,6%). Este aceite contiene una alta proporción de ácido linoleico (60%)

Designing Efficient Taxi Pickup Operations at Airports

This paper provides a practical procedure for designing efficient taxi pickup operations at airports. How to do this effectively is an open question. Solutions are not available, and practices vary. They reflect different approaches to and lack of research on the subject. The solutions are often unsatisfactory. At many airports, passengers routinely suffer long waits outdoors, exposed to the elements, after a tiring journey. Such disagreeable experiences are avoidable. Designing efficient taxi pickup operations at airports is problematic. The peculiarities of the process preclude easy solutions. First, the process involves queuing, so system performance is a nonlinear function of the loads. Second, it features unstable transient situations, since travelers typically arrive in bulk over short periods. Third, traffic is significantly differentiated and consists of a wide variety of groups implying different service characteristics. Standard results from queuing theory thus do not have a useful application to this problem. The design process uses simulation that is based on detailed observation of local practices. It involves four steps: (a) detailed local measurements of the arrival of both travelers and taxis, and the service rates provided by taxis in different queuing positions; (b) creation and validation of a simulation model sufficiently detailed to account for these realities; (c) exploration of design alternatives to estimate the characteristics of the service they would provide; and (d) selection of a preferred design that properly balances efforts to minimize average and extreme wait times. The paper demonstrates the procedure through application to Lisbon International Airport, Portugal.SIMUL8 Corporatio

Epidemiology of Coxiella burnetii infection in Africa: a OneHealth systematic review

Background: Q fever is a common cause of febrile illness and community-acquired pneumonia in resource-limited settings. Coxiella burnetii, the causative pathogen, is transmitted among varied host species, but the epidemiology of the organism in Africa is poorly understood. We conducted a systematic review of C. burnetii epidemiology in Africa from a “One Health” perspective to synthesize the published data and identify knowledge gaps.<p></p> Methods/Principal Findings: We searched nine databases to identify articles relevant to four key aspects of C. burnetii epidemiology in human and animal populations in Africa: infection prevalence; disease incidence; transmission risk factors; and infection control efforts. We identified 929 unique articles, 100 of which remained after full-text review. Of these, 41 articles describing 51 studies qualified for data extraction. Animal seroprevalence studies revealed infection by C. burnetii (≤13%) among cattle except for studies in Western and Middle Africa (18–55%). Small ruminant seroprevalence ranged from 11–33%. Human seroprevalence was <8% with the exception of studies among children and in Egypt (10–32%). Close contact with camels and rural residence were associated with increased seropositivity among humans. C. burnetii infection has been associated with livestock abortion. In human cohort studies, Q fever accounted for 2–9% of febrile illness hospitalizations and 1–3% of infective endocarditis cases. We found no studies of disease incidence estimates or disease control efforts.<p></p> Conclusions/Significance: C. burnetii infection is detected in humans and in a wide range of animal species across Africa, but seroprevalence varies widely by species and location. Risk factors underlying this variability are poorly understood as is the role of C. burnetii in livestock abortion. Q fever consistently accounts for a notable proportion of undifferentiated human febrile illness and infective endocarditis in cohort studies, but incidence estimates are lacking. C. burnetii presents a real yet underappreciated threat to human and animal health throughout Africa.<p></p&gt

Genome-wide analysis of ivermectin response by Onchocerca volvulus reveals that genetic drift and soft selective sweeps contribute to loss of drug sensitivity

Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana-exposed to more than a decade of regular ivermectin treatment-have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread.Pooled next generation sequencing (Pool-seq) was used to characterise genetic diversity within and between 108 adult female worms differing in ivermectin treatment history and response. Genome-wide analyses revealed genetic variation that significantly differentiated good responder (GR) and sub-optimal responder (SOR) parasites. These variants were not randomly distributed but clustered in ~31 quantitative trait loci (QTLs), with little overlap in putative QTL position and gene content between the two countries. Published candidate ivermectin SOR genes were largely absent in these regions; QTLs differentiating GR and SOR worms were enriched for genes in molecular pathways associated with neurotransmission, development, and stress responses. Finally, single worm genotyping demonstrated that geographic isolation and genetic change over time (in the presence of drug exposure) had a significantly greater role in shaping genetic diversity than the evolution of SOR.This study is one of the first genome-wide association analyses in a parasitic nematode, and provides insight into the genomics of ivermectin response and population structure of O. volvulus. We argue that ivermectin response is a polygenically-determined quantitative trait (QT) whereby identical or related molecular pathways but not necessarily individual genes are likely to determine the extent of ivermectin response in different parasite populations. Furthermore, we propose that genetic drift rather than genetic selection of SOR is the underlying driver of population differentiation, which has significant implications for the emergence and potential spread of SOR within and between these parasite populations

Prevalence and Antibiotic Resistance Pattern of Streptococcus, Staphylococcus, Neisseria meningitidis and Enterobacteriaceae in Two Reference Hospitals of Yaoundé: An Overview before and during COVID-19 Pandemic Era

peer reviewe