The commodity systems of four indigenous leafy vegetables in Senegal

Increasing the production of traditional leafy vegetables that are well adapted to the agro-ecology of Senegal, easy to grow and requiring low inputs, could greatly help to solve the poverty and malnutrition problems in Senegal. However, leafy vegetables are often overlooked by the scientific community. The species of leafy vegetables dealt with in this paper are roselle (Hibiscus sabdariffa L.), cowpea (Vigna unguiculata (L.) Walp), amaranths (Amaranthus L. spp.) and Moringa (Moringa oleifera Lam). To increase production of traditional leafy vegetables, access to good quality seeds is necessary. Two plantcollecting missions were undertaken throughout Senegal by a multidisciplinary research team. Experimentation on Hibiscus regeneration and characterisation was conducted at ISRA-CDH research station. Sixty-four accessions were collected among the four species. Forty-eight accessions of roselle (Hibiscus sabdariffa L.) were characterised. The level of dissimilarity (63%) within the accessions of roselle confirmed the high degree of intra-species variability. The Richness Index determined for the Diaobe and Matam markets indicated a high degree of genetic diversity of roselle. These are used to select three new lines according to farmers’ preference criteria.In addition, socio-economic surveys were conducted in two pilot villages. It was found that planting dates for leafy vegetables varied greatly, depending on species, locality and season. Sowing was mainly done broadcast. Organic fertilisers were commonly applied. Eighty per cent (80%) of the farmers applied an NPK formulation and small quantities of urea. Traditional irrigation methods are often used in the growing of traditional leafy vegetables. The seeds used by farmers were a mixture of varieties. Farmers identified four types of each of roselle, amaranth and cowpea, but could not differentiate any variety for Moringa. Local markets constitute the main roselle seed supply source. Few farmers have developed traditional methods of seed conservation. Selling of seed is not a common activity in rural areas. Generally, farmers exchange gratuitously theirs seeds. Leaves are commonly sold at the field, in the village, in the nearest city and weekly at local markets called ’Louma‘. Average annual income generated by leaves varies from 41 to 500 USD. Leafy vegetables are used as food and for medicinal purposes. Leafy vegetable consumption in Senegal is around 23 g/person·d.Keywords: leafy vegetables, production, species, seed and genetic diversit

Abiotic-biotic characterization of Pt/Ir microelectrode arrays in chronic implants

Pt/Ir electrodes have been extensively used in neurophysiology research in recent years as they provide a more inert recording surface as compared to tungsten or stainless steel. While floating microelectrode arrays (FMA) consisting of Pt/Ir electrodes are an option for neuroprosthetic applications, long-term in vivo functional performance characterization of these FMAs is lacking. In this study, we have performed comprehensive abiotic-biotic characterization of Pt/Ir arrays in 12 rats with implant periods ranging from 1 week up to 6 months. Each of the FMAs consisted of 16-channel, 1.5 mm long, and 75 μm diameter microwires with tapered tips that were implanted into the somatosensory cortex. Abiotic characterization included (1) pre-implant and post-explant scanning electron microscopy (SEM) to study recording site changes, insulation delamination and cracking, and (2) chronic in vivo electrode impedance spectroscopy. Biotic characterization included study of microglial responses using a panel of antibodies, such as Iba1, ED1, and anti-ferritin, the latter being indicative of blood-brain barrier (BBB) disruption. Significant structural variation was observed pre-implantation among the arrays in the form of irregular insulation, cracks in insulation/recording surface, and insulation delamination. We observed delamination and cracking of insulation in almost all electrodes post-implantation. These changes altered the electrochemical surface area of the electrodes and resulted in declining impedance over the long-term due to formation of electrical leakage pathways. In general, the decline in impedance corresponded with poor electrode functional performance, which was quantified via electrode yield. Our abiotic results suggest that manufacturing variability and insulation material as an important factor contributing to electrode failure. Biotic results show that electrode performance was not correlated with microglial activation (neuroinflammation) as we were able to observe poor performance in the absence of neuroinflammation, as well as good performance in the presence of neuroinflammation. One biotic change that correlated well with poor electrode performance was intraparenchymal bleeding, which was evident macroscopically in some rats and presented microscopically by intense ferritin immunoreactivity in microglia/macrophages. Thus, we currently consider intraparenchymal bleeding, suboptimal electrode fabrication, and insulation delamination as the major factors contributing toward electrode failure

Acetabular fractures: epidemiological, lesional, therapeutic and evolutionary aspects

Background: Fractures of the acetabulum are serious because they affect a deep, load-bearing joint that is difficult to repair surgically at first. They occur in a context of polytrauma. The aim of our work is to study the epidemiological, lesional, therapeutic and evolutionary aspects of acetabulum fractures.Methods: This is a 5-year retrospective study from January 2012 to December 2016 including 45 patients treated for acetabulum fracture.Results: 45 patients including 38 men and 7 women with a mean age of 36 years (extremes 18 and 74). The circumstances of occurrence were dominated by road traffic accidents with 42 cases (93.3%).According to the Judet-Letournel classification, we observed 28 elementary fractures (16 posterior wall fractures, 11 posterior column fractures, 1 anterior column fracture) and 17 complex fractures (7 posterior column and posterior wall fractures, 6 transverse and posterior wall fractures, 3 posterior and anterior column fractures, 1 anterior column and posterior hemi-transverse fracture). The association of a dislocation with an acetabulum fracture was found in 32 cases. Associated lesions (fractures) were observed in 23 patients. One case of associated TCE was noted. Treatment was orthopedic in 18 patients, surgical in 18 patients and functional in 9 patients. According to the Matta criteria we obtained after treatment 46.7% good reduction, 51.1% satisfactory and 2.2% unsatisfactory reduction. According to the Postel-Merle D'Aubigné rating, 16 patients obtained excellent results with overall 93.3% satisfactory results. The complications found were coxarthrosis (15 cases), para-articular ossification (2 cases) and vicious callus (1 case).Conclusions: The treatment of acetabulum fractures depends on the type of fracture, the age and activities of the patients. Orthopedic, surgical as well as functional treatment can give good acetabular reconstructions and functional results

Étude de la réponse métabolique de Pseudomonas syringae 32b-74 isolée des nuages à une exposition sub –létale au mercure.

International audienc

Electrode impedance analysis of chronic tungsten microwire neural implants: understanding abiotic vs. biotic contributions

Changes in biotic and abiotic factors can be reflected in the complex impedance spectrum of the microelectrodes chronically implanted into the neural tissue. The recording surface of the tungsten electrode in vivo undergoes abiotic changes due to recording site corrosion and insulation delamination as well as biotic changes due to tissue encapsulation as a result of the foreign body immune response. We reported earlier that large changes in electrode impedance measured at 1 kHz were correlated with poor electrode functional performance, quantified through electrophysiological recordings during the chronic lifetime of the electrode. There is a need to identity the factors that contribute to the chronic impedance variation. In this work, we use numerical simulation and regression to equivalent circuit models to evaluate both the abiotic and biotic contributions to the impedance response over chronic implant duration. COMSOL® simulation of abiotic electrode morphology changes provide a possible explanation for the decrease in the electrode impedance at long implant duration while biotic changes play an important role in the large increase in impedance observed initially