Contamination métallique des légumes des périmètres maraîchers urbains et péri urbains: Cas de la commune de Grand–Popo au Bénin

Cette étude se propose d’évaluer la contamination métallique des légumes produits à Grand-Popo au Bénin en liaison avec le maraîchage très développé dans la région. De façon spécifique, l’évaluation a concerné la contamination métallique par les engrais minéraux et la fiente de volaille utilisés de façon intensive par les producteurs pour la fertilisation des cultures. La méthode adoptée est basée sur des essais agronomiques conduits pendant quatre campagnes de production de 2009 à 2010 sur les sites de Yodo-Condji et d’Ayi-Guinnou. Il a été procédé à des analyses de laboratoire pour la recherche de quatre métaux lourds (cuivre, plomb, cadmium et fer) dans les échantillons de légumes et de fiente de volaille. Les teneurs moyennes du plomb dans la carotte, la grande morelle et la tomate, dépassent respectivement de 41, 6 et 38 fois les normes béninoises tandis que celles du cadmium le sont respectivement de 25, 6 et 40 fois. Cependant, dans la fiente de volaille, seules les teneurs du fer ont dépassé les normes requises, au cours des campagnes 1, 2 et 3 tandis queles autres métaux n’ont donné que des traces. Ces différentes teneurs ont révélé l’existence d’une relation de causalité entre les activités humaines non agricoles au niveau des sites étudiés et les degrés de contamination obtenus. Les conséquences induites par cette contamination sont des risques sanitaires pour les consommateurs et producteurs. Pour remédier à cette situation, il urge que des dispositions soient prises pour identifier toutes les sources potentielles de contamination notamment les activités domestiques et commerciales afin d’y renoncer ou de les contrôler.Mots clés: Maraîchage, métaux lourds, légumes, risques sanitaires, Béni

A simulation study of an autonomous steering system for on-road operation of automotive vehicles

The study of human driving of automotive vehicles is an important aid to the development of viable autonomous vehicle navigation techniques. Observation of human behavior during driving suggests that this activity involves two distinct levels, the conscious and the unconscious. Conscious actions relate to the logical behavior of a driver such as stopping the vehicle when a traffic light is red, slowing down the vehicle when it turns a bend, etc. Such behavior can be described using natural human language. The unconscious actions of a driver are much less obvious. There are many such activities occurring while we are driving a vehicle to a particular destination. One of the important unconscious efforts involves the selection of successive points on the road to steer the vehicle towards in order to achieve the desired road-following behavior. This research work attempts to mimic this unconscious behavior through the use of a computer simulation model. Keywords: Robotics; Artificial intelligence; Mobile; Mathematical models. (Author)Prepared for: Chief of Naval Researchhttp://archive.org/details/simulationstudyo00mcghsupported by Contract from the United States Army Combat Developments Experimentation Cente

Analysis of gender and governance of value chainbased systems on rice and vegetable crops in southern Benin and Mali

Published Online June 2015This present study analyses gender and governance in the rice and vegetable-based value chain systems in 3 lowlands of southern Benin and 2 lowlands in Southern Mali. A sample of 243 farmers, 1 modern processing unit, 18 traditional processors, 76 traders and 8 national institutions were interviewed in Benin and Mali. Descriptive statistics and Harvard analytical framework were used for the analysis of governance and gender respectively in the value chains. The majority of farmers have access to the use of land. Women produce up to 80% of basic foods for household consumption and sale. However they don’t have the control of these resources (capital and land). Decision making in relation to resources (land, water labor, credit) is under the control of men and natives. The governance analysis showed that the products of lowlands are not subject to quality control, with no public inspection for health and product quality. There is no input subsidy for actors in both countries. There are informal contracts between actors of the rice based systems in Mali and Benin. The markets are open for all the products and credit systems do exist. Some structures are involved in upstream and downstream chain components for training in various activitiesThis present study analyses gender and governance in the rice and vegetable-based value chain systems in 3 lowlands of southern Benin and 2 lowlands in Southern Mali. A sample of 243 farmers, 1 modern processing unit, 18 traditional processors, 76 traders and 8 national institutions were interviewed in Benin and Mali. Descriptive statistics and Harvard analytical framework were used for the analysis of governance and gender respectively in the value chains. The majority of farmers have access to the use of land. Women produce up to 80% of basic foods for household consumption and sale. However they don’t have the control of these resources (capital and land). Decision making in relation to resources (land, water labor, credit) is under the control of men and natives. The governance analysis showed that the products of lowlands are not subject to quality control, with no public inspection for health and product quality. There is no input subsidy for actors in both countries. There are informal contracts between actors of the rice based systems in Mali and Benin. The markets are open for all the products and credit systems do exist. Some structures are involved in upstream and downstream chain components for training in various activitie

Utilization of Alkali-Activated Olivine in Soil Stabilization and the Effect of Carbonation on Unconfined Compressive Strength and Microstructure

This paper reports for the first time the stabilization of soil using olivine and the application of novel techniques utilizing alkaline activation and carbonation. A rigorous study addressed the effect of carbon dioxide pressure and alkali concentration (10-M sodium hydroxide soil additions from 5 to 20%) between 7 and 90 days. Microstructural and compositional changes were evaluated using microscopic, spectroscopic, and diffraction techniques. Results demonstrate the advantages of using olivine in the presence of NaOH and the associated increases insoil shear strength of up to 40% over 90 days. Samples subjected to carbonation for a further 7 days led to additional increases in soil strength of up to 60%. Microstructural investigations before and after carbonation attributed the strength development to the formation of Mg(OH)2, hydrated magnesium carbonates, and M─S─H, A─S─H gel phases. The impact of this work is far reaching and provides a new soil stabilization approach. Key advantages include significant improvements in soil strength with a lower carbon footprint compared with lime or cement stabilization

Assessment of Some Old Earth Dams in Malaysia Through Observation and Computer Simulation

In this study, two earth dams located in Malaysia were studied. The Labong Dam is a non-homogenous earth dam, whilst the Bukit Merah Dam is a homogenous earth dam. The performances of both dams against seepage were studied through the analyses of both observed and simulated phreatic surfaces. Simulations of seepage rate and phreatic surfaces through the dam were conducted by using SEEP/W model. The study showed that the SEEP/W model was able to predict (simulate) both the seepage rates and phreatic surfaces of the homogeneous and non-homogeneous earth dams with a reasonable accuracy. The Absolute Error (AE) between the predicted and observed seepage rates of both dams were found to be 0.03 m3/min to 0.18 m3/min. The average AE in the predicted phreatic surfaces for the maximum and minimum water levels in the reservoir were 0.6 m and 0.38 m for the non-homogeneous dam (Labong Dam), and 0.595 m and 0.75 m for the homogeneous dam (Bukit Merah Dam)

Phenotypic MicroArray (PM) profiles (carbon sources and sensitivity to osmolytes and pH) of Campylobacter jejuni ATCC 33560 in response to temperature

The present study aimed to provide an insight of C. jejuni ATCC 33560 phenotype profiles (carbon sources and sensitivity to osmolytes and pH) using Phenotypic MicroArray (PM) system in response to optimal and suboptimal temperature. C. jejuni ATCC 33560 showed utilization carbon sources from amino acids and carboxylates but not from sugars. C. jejuni ATCC 33560 is sensitive to NaCl at 2% and above but showed survival in a wide range of food preservatives (sodium lactate, sodium phosphate, sodium benzoate, ammonium sulphate and sodium nitrate). When incubated at suboptimal temperature, no phenotype loss was observed in carbon source plates. Phenotype loss of C. jejuni ATCC 33560 was observed in sodium chloride (1%), sodium sulphate (2-3%), sodium formate (1%), sodium lactate (7-12%), sodium phosphate pH7 (100mM and 200mM), ammonium sulphate pH8 (50mM), sodium nitrate (60mM, 80mM and 100mM), sodium nitrite (10mM), and growth in pH5. The phenotypic profile from present study will provide a better insight related to survival of C. jejuni ATCC 33560

Comparison of Body Mass Index (BMI), Body Adiposity Index (BAI), Waist Circumference (WC), Waist-To-Hip Ratio (WHR) and Waist-To-Height Ratio (WHtR) as predictors of cardiovascular disease risk factors in an adult population in Singapore

10.1371/journal.pone.0122985PLoS ONE104e012298

Divergent Roles for RalA and RalB in Malignant Growth of Human Pancreatic Carcinoma Cells

SummaryBackgroundThe Ral guanine nucleotide-exchange factors (RalGEFs) serve as key effectors for Ras oncogene transformation of immortalized human cells. RalGEFs are activators of the highly related RalA and RalB small GTPases, although only the former has been found to promote Ras-mediated growth transformation of human cells. In the present study, we determined whether RalA and RalB also had divergent roles in promoting the aberrant growth of pancreatic cancers, which are characterized by the highest occurrence of Ras mutations.ResultsWe now show that inhibition of RalA but not RalB expression universally reduced the transformed and tumorigenic growth in a panel of ten genetically diverse human pancreatic cancer cell lines. Despite the apparent unimportant role of RalB in tumorigenic growth, it was nevertheless critical for invasion in seven of nine pancreatic cancer cell lines and for metastasis as assessed by tail-vein injection of three different tumorigenic cell lines tested. Moreover, both RalA and RalB were more commonly activated in pancreatic tumor tissue than other Ras effector pathways.ConclusionsRalA function is critical to tumor initiation, whereas RalB function is more important for tumor metastasis in the tested cell lines and thus argues for critical, but distinct, roles of Ral proteins during the dynamic progression of Ras-driven pancreatic cancers

The magnetic field of the B3V star 16 Pegasi

The Slowly Pulsating B3V star 16 Pegasi was discovered by Hubrig (2006) to be magnetic, based on low-resolution spectropolarimetric observations with FORS1 at the VLT. We have confirmed the presence of a magnetic field with new measurements with the spectropolarimeters Narval at TBL, France and Espadons at CFHT, Hawaii during 2007. The most likely period is about 1.44 d for the modulation of the field, but this could not be firmly established with the available data set. No variability has been found in the UV stellar wind lines. Although the star was reported once to show H alpha in emission, there exists at present no confirmation that the star is a Be star.Comment: 2 pages, 4 figures, contrubuted poster at IAU Symposium 259 "Cosmic Magnetic Fields: from Planets, to Stars and Galaxies", Tenerife, Spain, November 3-7, 200

Limonite – a weathered residual soil heterogeneous at all scales

Limonite is a residual soil produced by the decomposition of magnesium silicate (olivine) rocks in tropical environments. During weathering most of the original rock is leached away leaving only its iron content, which is precipitated out in the form of iron sesqui-oxides to create a soft and highly porous soil. The predominant mineral present in limonite is goethite, which forms acicular nanoparticles that agglomerate to produce a silty sand with porous particles. The void ratio varies from 2 to 6, with higher values being a consequence of structure-supported voids. An extensive set of laboratory tests have been performed on a limonite soil profile which extends 50 m to rock. These data show that there is no pattern to shear strength with depth, with the shear strength equally likely to be 50 or 200 kPa through much of the profile. It is argued that the shear strength parameters for failure mechanisms, having any significant length, should be based on average values. The letter presents scanning electron microscopy photographs showing the fundamental particles, the results of triaxial tests comparing natural and reconstituted behaviour which show the effects of microstructure on the meso-scale response, and field data to show site variability