Search

Background In recognition of the threat of insecticide resistance in vectors of malaria, the WHO Global Malaria Programme recommends the development of an appropriate and comprehensive response to insecticide resistance. In principle, good resistance management practice requires the application of multiple insecticides of different modes of action, for example, in rotations and mixtures. Insecticides recommended by the World Health Organization for indoor residual spraying and long-lasting insecticide nets are limited. It is, therefore, judicious to prevent the rapid spread of insecticide resistance by evaluating new insecticides formulations with different modes of action and long residual effect. Methods Fludora® Fusion, a new neonicotinoid IRS formulation (a mixture of 500 g/kg clothianidin and 62.5 g/kg deltamethrin applied 200 mg ai/sqm + 25 mg ai/sqm, respectively) was tested. Small scale field evaluation of this product was conducted in the district of Dangbo in Benin, to compare its efficacy and residual effect on cement and mud walls against those of clothianidin 200 mg ai/sqm (WG 70) alone, and of deltamethrin 25 mg ai/sqm (WG 250) alone. WHO wall cone bioassays were conducted monthly with laboratory susceptible Anopheles “Kisumu” and wild Anopheles gambiae sensu stricto (s.s.) population from Dangbo. The induced mortality by each treatment per wall substrate for 24 h, 48 h, and 72 h post exposure were recorded every month and analysed. Results Fludora® Fusion and clothianidin WG 70 showed mortality rates over 80% WHO bio-efficacy threshold on cement walls either with susceptible or resistant An. gambiae s.s. over a period of 10 and 9 months, respectively. Treatment with Fludora® Fusion and clothianidin WG 70 on the mud walls showed residual effect for 6 months and 5 months respectively against both susceptible and resistant mosquitoes. During the whole evaluation period, deltamethrin WG 250 showed mortality rates below 80% against resistant Anopheles population. Furthermore, the knock down rates observed with the Fludora® Fusion combination were significantly higher (p

The definitive version is available at www3.interscience.wiley.com, Risk factors for Buruli ulcer (BU) are poorly understood. We conducted a case-control study in southern Benin to investigate the association between haemoglobin variants S or C and BU, and particularly the association between haemoglobinopathies HbSS/SC and BU osteomyelitis. We compared the haemoglobin genotype of 179 patients with BU and 44 with BU osteomyelitis to that of 242 community controls. We found no evidence of an increased risk of BU according to the presence of haemoglobin variants S and/or C [odds ratio adjusted for sex, age, region of residence and ethnicity: 1.24 (95% CI: 0.80-1.93), P = 0.34]. Haemoglobin variants S and C are unlikely to play a role in the BU burden. However, haemoglobinopathies HbSS/SC were more frequent among BU osteomyelitis patients than among controls (6.8% vs. 1.0%, Fisher's exact P-value = 0.045), which may suggest that those disorders facilitate growth of Mycobacterium ulcerans in the bone matrix.

OBJECTIVES To evaluate former Buruli ulcer disease (BUD) patients to assess the factors associated with functional limitations and subsequent employment or schooling. METHODS The previously validated Buruli ulcer functional limitation score (BUFLS) questionnaire and interviews about educational and professional consequences incurred by BUD. RESULTS Of 638 participants, 362 (57%) had a functional limitation after a median period of almost 4 years after treatment for BUD. A lesion on a joint, older age, female gender, a lesion on a distal part of an extremity and a persistent wound were found to be independent risk factors for stopping work or education. The same risk factors applied to the development of a functional limitation. Both functional limitations and financial difficulties due to BUD disease often led to job loss and school dropout. CONCLUSIONS Rehabilitation programmes are urgently needed to diminish the suffering from the functional limitations and employment or schooling problems caused by BUD.

Science, Technology, and Education - Empowering Caribbean Agriculture; National audience

Science, Technology, and Education - Empowering Caribbean Agriculture; National audience

75 ref.; International audience

Quelle recherche ? Pour quel développement ?

International audience

La composition minérale et glucidique a été étudiée au cours du grossissement du fruit de christophine, Sechium edule Sw. L’ovaire est riche en azote et en potassium. D’une façon générale, les teneurs en éléments minéraux, N, P, K, Ca et Mg, baissent progressivement jusqu’à la récolte du fruit (30 jours après l’anthèse) sauf cette du phosphore qui ne varie pratiquement plus dès le 10e jour. L’étude des glucides a porté sur les sucres solubles neutres, l’amidon, les hémicelluloses et la lignocellulose. Les sucres solubles sont constitués essentiellement de fructose, glucose et saccharose. Le fructose et le glucose s’accumulent dans une première phase qui couvre les 15 jours après l’anthèse. Ce sont les formes de stockage temporaire dans le fruit avant leur incorporation dans les polysaccharides. La synthèse de l’amidon, qui atteint 27 p. cent de la matière sèche à la récolte, n’est active que dans la deuxième phase du grossissement du fruit. Les hémicelluloses, dont la teneur évolue peu jusqu’à la récolte, contiennent du galactose, glucose, mannose, xylose et arabinose. La teneur en lignocellulose est constante jusqu’au démarrage de la synthèse active de l’amidon, augmente pendant 5 jours puis se restabilise. La forte accumulation du fructose et du glucose avant leur incorporation dans les polysaccharides semble être le résultat d’une forte activité β-fructosidasique qui transforme le saccharose., The mineral and carbohydrate changes in the developing fruit of mirliton (Sechium edule Sw.) have been investigated. The ovary of the flower was rich in nitrogen and potassium. On a dry matter basis, the contents of N, P, K, Ca and Mg decreased gradually until picking (30 days after anthesis) except for the phosphorus content which did not change after the 10th day following anthesis. Glucose, fructose and sucrose were the major sugars detected in the carbohydrate fraction solubilized by ethanol/water : 80/20. Fructose and glucose attained a maximum value 15 days after anthesis. Starch content gradually increased with the simultaneous decline in fructose and glucose and reached 27 % of dry matter at picking. Lignocellulose content was constant until the start of active starch synthesis, increased afterwards during 5 days and then stabilized again. The high accumulation of glucose and fructose and the low level of sucrose during the first stage of the developing fruit might be the result of a high activity of β-fructosidase which hydrolyses sucrose. The content of hemicellulose (essentially composed of galactose, glucose, mannose, xylose and arabinose) did not vary markedly in the developing fruit.

National audience

National audience; An increase in irradiance stimulated 14CO2 incorporation into chayote leaves ; it also increased 14CO2 incorporation into he xose monophosphates, sucrose, starch and photorespiratory metabolites. A substantial rate of 14C incorporation by β-carboxylation was observed. With a high agronomic yield and a high protein content, chayote seems to be an attractive material for investigating the regulation of photosynthetic metabolism.; Une augmentation de l’énergie lumineuse incidente sur des feuilles de christophine a pour effet d’accroître l’incorporation de 14CO2 dans la matière organique, dans les oses monophosphates, le saccharose, l’amidon et dans les métabolites photorespiratoires. On constate chez cette plante une incorporation assez importante de 14C dans les métabolites par (β-carboxylation. La christophine, par ailleurs plante à haut rendement agronomique, riche en protéines, apparaît comme un modèle intéressant pour une recherche sur le métabolisme de la photosynthèse.

Low input farming techniques: A world alternative *INRA, Service de documentation, Antilles-Guyane (FRA)

International audience

Yam bean plants formed efficient nodules with indigenous strains of Rhizobium living in vertisols (pH 8.4), in neutral ferralitic soils (pH 6.9) but not in.acid ferrallitic soils (pH 4.6). Mineral amendments imploying Urea, basic slag, lime incorporation in the acid soils overcome the pH inhibition of nodule formation. Rhizobium strains from the different soils were isolated and characterized. Apparent rate of growth (ARG) and rate of nodulation in gibson tubes (RNG) were determined. Their aptitude to use sugars and other compounds was assessed by API STAPH tests. The efficiency of the symbiosis of each strain of Rhizobium-Pachyrhizus was measured by estimating the biomass produced in gibson tubes and by determining carbohydrates, ureides and amino-compounds in the nodules of the plant. ----- Le dolique tubéreux forme des nodosités efficientes avec des souches de Rhizobium indigènes des vertisols (pH 8) et des sols ferralitiques neutres (pH 6.9). La nodulation est inexistante dans les sols ferralitiques acides (pH 4.6). L'incorporation des amendements minéraux (urée, scories de déphosphoration, chaux) capables d'élever le pH permet de lever l'inhibition de la formation des nodosités dans ces derniers sols. Les souches de Rhizobiumont été sélectionnées et caractérisées. Les vitesses de croissance apparente et de nodulation en tubes Gibson ont été déterminées. Leur aptitude à utiliser les sucres et d'autres composés ont été mis en évidence par les tests API STAPH. L'efficience de chaque souche a été estimée par la matière organique produite en tubes Gibson, les quantités de sucres solubles, d'uréides, et composés aminés des nodosités.

International audience

D. alata plantlets from in vitro culture were planted at dates staggered between September and April and grown under irrigation conditions. Successive plantings did not initially differ in plantlet morphology, but further growth of both aerial parts (architecture and maximum size) and underground parts made them quite different from each other after a few months. Tuber yields of the October or December plantings were dramatically reduced compared to those of the January, March or April plantings. The duration of the leafy phase and of tuber dormancy also varied widely among plantings, so that tuber sprouting in all cases occurred around April, as observed in normal cultivation. These results were very close to those obtained from staggered plantings of more or less obviously aged D. alata tubers. Since they could not in this case be due to the mother-tuber, it was concluded that problems met when trying to cultivate the species out-of-season must mostly be related to its sensitivity to environmental conditions (thermo-photoperiodism).; Après plantation à des dates échelonnées entre les mois de septembre et d’avril, de jeunes plantules de D. alata produites par culture in vitro, de morphologie comparable, ont été cultivées en conditions irriguées. En plein champ, ces plantes diffèrent d’une plantation à l’autre par le développement et la croissance des parties aériennes (architecture et taille maximale) et par les rendements en poids de tubercules qui, pour les plantations des mois d’octobre à décembre, deviennent infimes par rapport aux plantations des mois de janvier à avril. Parallèlement, les variations dans les durées de végétation des plantes et de repos végétatif des tubercules-fils, suivant la date de plantation, sont telles que, dans tous les cas, les dates de germination des tubercules, situées sur 2 années successives, ne sont jamais très éloignées du mois d’avril, qui est l’époque de germination des tubercules en culture traditionnelle. Ces résultats sont très proches de ceux généralement donnés par des plantations échelonnées de tubercules de D. alata présentant des signes plus ou moins nets de vieillissement. Ne pouvant, ici, les attribuer au tuberculemère, on en conclut que les problèmes rencontrés lors des tentatives de culture hors-saison de cette espèce sont liés surtout à sa sensibilité aux facteurs de l’environnement (thermo-photopériodisme).

La christophine, plante tubérifère ne produit que des fruits aux Antilles alors que, dans son aire d'origine (Mexique), elle fournit en plus des tubercules comestibles appelés "Chinchayotes". Les travaux menés sur le déterminisme de la floraison et de la fructification chez cette plante montrent que les conditions thermophotopériodiques régnant tout au long de l'année dans ces régions privilègient la floraison et maintiennent l'état reproducteur, une fois acquis, pendant toute la vie de la plante. Une longueur moyenne de jour supérieure à 14 h semble nécessaire pour obtenir l'inhibition de la floraison et pour promouvoir la tubérisation chez les plantes ayant fleuri au moins une fois. Les tubercules formés en jours longs ont été analysés et leur composition glucidique a été comparée à celle des fruits à maturité.

National audience

Plantlets of yam (Dioscorea alata L.) from in vitro culture were adapted to field conditions by culturing in two successive, transition media. After planting in April, the early growth pattern of these plantlets was different from that of traditional sets obtained by breaking up tubers, and resembled instead that of young seedlings of related yam species. Later, these juvenile-looking characteristics vanished with the emergence of long vines identical to those of normal yam plants. As observed in normal cultivation, tubers, though present soon after planting, did not grow significantly before August, when the growth rate of the aerial parts fell. At the end of the cycle, the number and shape of tubers was the same as for conventional plants, but their weight was halved (in our experimental conditions). Tubers could be harvested several weeks before vine drying without any consequences for yield or for the subsequent rest period. The correlations between tuber dry matter weight and several parameters which characterize development of the aerial parts could be used to forecast yield and to evaluate the plant’s efficiency in converting incident light into tuber starch.; La culture in vitro des ignames Dioscorea alata L. produit des plantes aptes à croître en plein champ après passage par 2 milieux d’adaptation intermédiaires. La morphogenèse initiale de ces vitroplants les distingue du matériel traditionnel obtenu par fragmentation des tubercules, et les apparente au contraire aux jeunes semis d’espèces voisines. Ultérieurement, ces particularités juvéniles sont masquées par l’émergence de grandes lianes semblables à celles du matériel usuel. Comme en culture traditionnelle, la partie aérienne est d’abord seule (avec les racines) à croître pendant plusieurs mois. La mise en réserve dans les tubercules, différenciés pourtant très précocement, ne devient significative qu’après diminution de l’intensité de croissance aérienne. Le nombre et la morphologie des tubercules en fin de cycle sont comparables à ce que l’on observe sur le matériel conventionnel ; mais, dans nos conditions expérimentales, leur poids est inférieur de moitié. On peut les récolter plusieurs semaines avant la disparition totale de l’appareil aérien sans conséquence sur le rendement ni sur le comportement ultérieur des tubercules. Les corrélations entre poids de matière sèche des tubercules et plusieurs paramètres caractérisant le développement de la partie aérienne sont utilisables pour une aide à la prévision des rendements et pour une évaluation de l’efficacité de la plante à convertir l’énergie lumineuse incidente en amidon stocké dans le tubercule.

The mineral and carbohydrate changes in the developing fruit of mirliton (Sechium edule Sw.) have been investigated. The ovary of the flower was rich in nitrogen and potassium. On a dry matter basis, the contents of N, P, K, Ca and Mg decreased gradually until picking (30 days after anthesis) except for the phosphorus content which did not change after the 10th day following anthesis. Glucose, fructose and sucrose were the major sugars detected in the carbohydrate fraction solubilized by ethanol/water : 80/20. Fructose and glucose attained a maximum value 15 days after anthesis. Starch content gradually increased with the simultaneous decline in fructose and glucose and reached 27 % of dry matter at picking. Lignocellulose content was constant until the start of active starch synthesis, increased afterwards during 5 days and then stabilized again. The high accumulation of glucose and fructose and the low level of sucrose during the first stage of the developing fruit might be the result of a high activity of β-fructosidase which hydrolyses sucrose. The content of hemicellulose (essentially composed of galactose, glucose, mannose, xylose and arabinose) did not vary markedly in the developing fruit.; La composition minérale et glucidique a été étudiée au cours du grossissement du fruit de christophine, Sechium edule Sw. L’ovaire est riche en azote et en potassium. D’une façon générale, les teneurs en éléments minéraux, N, P, K, Ca et Mg, baissent progressivement jusqu’à la récolte du fruit (30 jours après l’anthèse) sauf cette du phosphore qui ne varie pratiquement plus dès le 10e jour. L’étude des glucides a porté sur les sucres solubles neutres, l’amidon, les hémicelluloses et la lignocellulose. Les sucres solubles sont constitués essentiellement de fructose, glucose et saccharose. Le fructose et le glucose s’accumulent dans une première phase qui couvre les 15 jours après l’anthèse. Ce sont les formes de stockage temporaire dans le fruit avant leur incorporation dans les polysaccharides. La synthèse de l’amidon, qui atteint 27 p. cent de la matière sèche à la récolte, n’est active que dans la deuxième phase du grossissement du fruit. Les hémicelluloses, dont la teneur évolue peu jusqu’à la récolte, contiennent du galactose, glucose, mannose, xylose et arabinose. La teneur en lignocellulose est constante jusqu’au démarrage de la synthèse active de l’amidon, augmente pendant 5 jours puis se restabilise. La forte accumulation du fructose et du glucose avant leur incorporation dans les polysaccharides semble être le résultat d’une forte activité β-fructosidasique qui transforme le saccharose.

Yam bean is a tropical tuber and grain legume that needs to be better known as a crop for human consumption and animal feed. The seeds are poisonous but can be used for planting. The tuber is edible and can be eaten as a fresh vegetable or cooked. Large tubers and better fruiting occurred when the growing season coincided with long days, but marketable tubers were produced, especially under short days. In all cases tuber production competes with seed production. Investigations were undertaken to study the effects of foliar application of GA3 and CCC on growth, sugar composition and tuber yield of yam bean under short days. GA3 promoted shoot growth, tuber enlargement,. yield increase, sucrose accumulation and starch content increase. CCC did not consistently affect growth, but reduced tuber size, increased starch content, therefore reduced tuber and starch yields per plant. Foliar applications of GA3 might be used to increase tuber and starch yields per plant under short days. This result was obtained because of a partial or total inhibition of flowering and seed set by that growth substance.

National audience

Science, Technology and Education - Empowring Caribbean Agriculture; International audience

International audience

The reliability and validity of the earlier developed Buruli ulcer functional limitation score (BUFLS) questionnaire was assessed. Of 638 former Buruli ulcer patients (of 678 individuals examined), sufficient items on daily activities (>= 13 of the 19) were applicable to calculate a score. To determine the validity, the functional limitation scores of the 638 individuals were compared with the global impression of the limitations, range of motion (ROM), and the social impact (change of occupation or education) of Buruli ulcer. To determine inter-observer reliability, the functional limitation score was reassessed in 107 participants within one and three weeks after the first interview by another interviewer and interpreter. Both global impression and ROM correlated well with the functional limitation scores (p 0.66 and p = 0.61). The inter-observer reliability of 107 participants as measured by an intra-class correlation coefficient of 0.86 was very good. The functional limitation scores measured in the second assessment were significantly higher than in the first assessment. This should be taken into account when the functional limitation score is used for the individual patient. The BUFLS can be used as for between group comparisons of endpoints in clinical trials and in the planning of resources.