Effet antihypertensif de BpF2, une fraction d\'extrait aqueux de feuilles de Bidens pilosa L. (Asteraceae) chez le lapin

Les feuilles de Bidens pilosa L. sont largement utilisées dans la pharmacopée traditionnelle. Nous avons cherché à mettre en évidence les effets antihypertensifs de ces feuilles. L'analyse phytochimique révèle que la fraction 2, dénommée BpF2, de l\'extrait aqueux des feuilles de Bidens pilosa L. (Asteraceae), contient des flavonoïdes, des polyphénols et des tanins catéchiques. Pour des doses comprises entre 1 et 25 mg/kg de poids corporel, cette fraction chromatographique induit une hypotension dose-dépendante chez le lapin. Cet effet explique le potentiel antihypertenseur de cette fraction. Ces effets ressemblent à ceux bien connus de l\'acétylcholine (ACh). Toutefois, alors que l\'atropine inhibe totalement l\'hypotension induite par l\'ACh, elle ne reverse que partiellement l\'hypotension provoquée par BpF2. Ces résultats suggèrent fortement la présence de deux types de principes actifs dans cette fraction active BpF2: - les principes actifs cholinomimétiques de type muscarinique, - les principes actifs non cholinomimétiques dont la nature reste à déterminer. La présence de ces substances dans la fraction active pourrait justifier, au moins en partie, l\'utilisation traditionnelle de Bidens pilosa L. contre l\'hypertension artérielle.The fraction 2, called BpF2, of the aqueous extract from Bidens pilosa L. (Asteraceae) leaves, contained flavonoids, polyphenols and catechic tannins. For doses ranging from 1 to 25 mg/kg of body weight, this chromatographic fraction induced a dose-dependent hypotension in the rabbit. This effect explained the antihypertensive potential of the fraction. These effects resembled those well-known of acetylcholine (ACh). However, whereas atropine completely inhibited the effect induced by ACh, its action remained partial on that caused by BpF2. These results suggested the presence of two types of active components in BpF2 fraction. - muscarinic and cholinomimetic activity, - non cholinomimetic activity to be clarified. The study showed at least two hypotensive activities in BpF2 fraction, justifying the traditional use of Bidens pilosa L. against hypertension. Keywords: Bidens pilosa L., acetylcholine, muscarinic cholinomimetic activity, non cholinomimetic activity.Sciences & Nature Vol. 5 (1) 2008: pp. 29-3

AFLP/SSR mapping of resistance genes to Alectra vogelii in cowpea (Vigna unguiculata l. Walp)

The parasite weed Alectra vogelii (Benth) causes significant yield reduction of cowpea in Africa. To find and map the resistance gene to A. vogelii in cowpea, a F2 population from a cross involving a resistant parent IT81D-994 and a susceptible TVX3236 was screened. Amplified fragment length polymorphism (AFLP) in combination with Single Sequence Repeat (SSR) analysis was used to identify markers that may be linked to the gene Rav3 conferring resistance to A. vogelii in the cowpea cultivar IT81D-994. The analysis of F2 individuals scored for resistance showedthat a single dominant gene conditioned A. vogelii resistance in IT81D-994 with a probability of 30 to 50%. Sixty-six AFLP/SSR markers were identified. Using MAPMAKER, four linkage groups were found. The first group showed 33 markers linked to the susceptible gene. The closest identified marker was 21.4 centimorgans away from the susceptible gene. The primer combination that showed the closest linkage was 809ACG8 (E-ACG 8 + UBC-809). The second group indicated 4 markers linked together while the third and the fourth groups showed 2 markers linkedtogether respectively. No markers were found linked to the resistance gene Rav3 conferring the resistance in the cultivated cowpea cultivar IT81D-994.La plante parasite Alectra vogelii (Benth) provoque une réduction significative du rendement de niébé en Afrique. Pour repérer et cartographier le gène de résistance à A. vogelii, une population F2 issue d’un croisement impliquant le cultivar résistant IT81D-994 et le cultivar sensible TVX3236 a été criblée. La technique Amplified fragment length polymorphism (AFLP) en combinaison avec des Séquences Simples Répétés (SSR) a été utilisée pour identifier les marqueurs qui seraient liés au gène Rav3 qui confère la résistance à A. vogelii chez le cultivar de niébé IT81D- 994. L’analyse des individus F2 montrant une résistance indique qu’un seul gène dominant conditionne la résistance à A. vogelii chez IT81D-994 avec une probabilité de 30 à 50 %. Soixante six marqueurs AFLP/SSR ont été identifiés. A l’aide de MAPMAKER, 4 groupes de liaison ont été trouvés. Le premier groupe montre 33 marqueurs liés au gène sensible. Le marqueur le plus proche identifié est à 21.4 centimorgans du gène sensible. La combinaison d’amorces ayant des liaisons les plus proches était 809ACG8 (E-ACG 8 + UBC-809). Le secondgroupe montre 4 marqueurs liés ensemble tandis que le troisième et le quatrième groupe montrent 2 marqueurs liés entre eux respectivement. Aucun marqueur n’a été trouvé lié au gène Rav3 qui confère la résistance au cultivar de niébé cultivé IT81D-994.Key words: Parasite, weeds, legumes, molecular marker

Nitrogen and Fiber Digestion in Sheep Fed Fresh-Frozen and Field-Dried High and Low Tannin Sericea Lespedeza

Field-drying reduces extractable condensed tannin (CT) of sericea lespedeza [Lespedeza cuneata (Dum-Cours) G. Don], but effects on specific bound and unbound forms of CT and the relationship to protein and fiber digestion in ruminants are unclear. Intake and digestibility of fresh-frozen and field-dried high- and low-tannin sericea were investigated in a feeding trial with sheep (Ovis spp.). Field-drying had no effect on crude protein (CP) and fiber content of sericea, but shifted CT from extractable to bound forms. Digestion coefficients for CP, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were lower for high-tannin sericea than the low-tannin type. Field-drying had no effect on fiber digestibility but increased CP digestibility and N retention in sheep fed high-tannin forage. Apparent digestion of CT was high for all treatments, but this is likely due to difficulty in analyzing CT in fecal material. Nutritional effects of CT in sericea lespedeza are related to both total CT and proportion of bound and unbound CT in the forage

Group-based pelvic floor muscle training is a more cost-effective approach to treat urinary incontinence in older women: economic analysis of a randomised trial

Question(s): How cost-effective is group-based pelvic floor muscle training (PFMT) for treating urinary incontinence in older women? Design: Economic evaluation conducted alongside an assessor-blinded, multicentre randomised non-inferiority trial with 1-year follow-up. Participants: A total of 362 women aged 60 years with stress or mixed urinary incontinence. Intervention: Twelve weekly 1-hour PFMT sessions delivered individually (one physiotherapist per woman) or in groups (one physiotherapist per eight women). Outcome measures: Urinary incontinence-related costs per woman were estimated from a participant and provider perspective over 1 year in Canadian dollars, 2019. Effectiveness was based on reduction in leakage episodes and quality-adjusted life years. Incremental cost-effectiveness ratios and net monetary benefit were calculated for each of the effectiveness outcomes and perspectives. Results: Both group-based and individual PFMT were effective in reducing leakage and promoting gains in quality-adjusted life years. Furthermore, group-based PFMT was 60% less costly than individual treatment, regardless of the perspective studied: –$914 (95$509 (95% CI –523 to –496) from the provider’s perspective. Differences in effects between study arms were minor and negligible. Adherence to treatment was high, with low loss to follow-up and no between-group differences. Conclusion: Compared with standard individual PFMT, group-based PFMT was less costly and as clinically effective and widely accepted. These results indicate that patients and healthcare decisionmakers should consider group-based PFMT to be a cost-effective first-line treatment option for urinary incontinence. Trial registration: ClinicalTrials.gov NCT0203983

Biofunctool®, a multifunctional approach of soil health related to soil biota activities

In a context of global soil biodiversity loss, we need to find effective way to measure the functions supported by biodiversity. This constitutes the main challenge of soil health assessments, particularly in the agroecological transition context. The most shared definition of soil health is based on the ability of soil to function (Karlen et al., 1997) and to provide ecosystem services. However, most methods focus on stock measurements rather than functions. Also, measurements are usually performed in the laboratory, reflecting the potential level of soil functions rather than true field performance. To overcome these methodological limitations, a new framework is proposed to assess soil health based on functional methods that considers the links between abiotic and biotic soil compartments. This method, called Biofunctool®, incorporates nine rapid, cost-effective, and in-field indicators to evaluate three main soil functions: C transformation, nutrient cycling, structure maintenance. The capacity of the set of indicators to assess the impact of land management on soil health will be illustrated in various agroecological contexts in the tropics. Biofunctool® allows to better understand the impacts of agricultural practices on soil functions driven by soil biodiversity and could be in the future included in environmental analyses

Interactions of mean climate change and climate variability on food security extremes. [P-2223-18]

The Coordinated Climate-Crop Modeling Project (C3MP) has conducted a common set of sensitivity tests on more than 1100 simulation sets representing different farm systems in more than 50 countries, with carbon dioxide, temperature, and precipitation change sensitivities gauged for ~20 crop species and ~20 crop models. Here we present an analysis of C3MP results indicating how mean climate changes are likely to affect variability and extreme events within future time periods. Recognizing that climate change will affect agricultural systems both through mean changes and through shifts in climate variability and associated extreme events, C3MP can elucidate several aspects of these changes. First, mean climate changes can affect yields across an entire time period. Second, extreme events (when they do occur) may be more sensitive to climate changes than a year with normal climate. Third, mean climate changes can alter the likelihood of climate extremes exceeding critical biophysical thresholds, leading to more food security extremes. Finally, shifts in climate variability can result in an increase or reduction of mean yield, as extreme climate events tend to have lower yield than years with normal climate.This presentation will demonstrate each of these effects and illustrate the potential implications for future food production and associated agricultural economies under climate change

Application De L’ultrason A L’étude De L’homogénéité Des Briques Réfractaires

The quality of refractory bricks such as their ability to resist to thermal shocks essentially depends on the homogeneity of their structure. The imperfections observed in the structure of some refractory bricks arise from the mode of their preparation. Thus, the homogeneity of bricks manually elaborated with refractory clays and sintered at 1280°C was studied. The speed of ultrasounds in different areas of the bricks was measured with an ultrasound auscultation device. The results point out the speeds of ultrasounds may vary from one zone to another revealing heterogeneities into some bricks. This technique allows showing the distribution of possible heterogeneities in these materials