Utilisation de l'expérience de drainage à pas de pression multiples pour la détermination des fonctions hydrauliques du sol par la méthode inverse : résultats expérimentaux

La méthode de drainage à pas de pression multiples, combinée avec la méthode inverse, permet la détermination des fonctions hydrauliques du sol (têta(h) et K(h)) simultanément. Cependant, le choix des fonctions décrivant têta(h) et K(h) du sol est d'une importance capitale dans cette méthode. Les résultats expérimentaux montrent que le modèle de CAMPBELL (1974) dans sa version améliorée par HUTSON et CASS (1987) permet une description raisonnable du processus du drainage en fonction du temps et correspondant à des pas de pression croissants. Les courbes de rétention d'eau déduites des paramètres optimisés par la méthode inverse ont les mêmes allures que celles déterminées par la méthode standard (bac de sable et cellules à basses et hautes pressions). Ces résultats sont plus représentatifs de la réalité lorsque les paramètres têta(s) et K(s) sont fixes et égaux aux valeurs expérimentales, avec une précision sensiblement la même dans les cas d'optimisation, où têta(s) est fixe et têta(s) et K(s) fixes et égaux aux valeurs expérimentales; le premier cas où seulement le paramètre têta(s) est fixe est suggéré (il y a moins de paramètres à mesurer). (Résumé d'auteur

Utilisation de l'expérience de drainage à pas de pression multiples pour la détermination des fonctions hydrauliques du sol par la méthode inverse : présentation et évaluation de la méthode

L'optimisation des paramètres des fonctions décrivant les propriétés hydrauliques du sol têta(h) et K(h), basée sur les résultats de l'expérience de drainage interne à pas de pression multiples est une méthode prometteuse. En effet, cette dernière fournit suffisamment d'informations sur les propriétés hydrauliques essentielles d'un sol. Le modèle utilisé pour décrire les relations entre la teneur en eau volumique têta et la pression de l'eau h, d'une part, et entre la conductivité hydraulique K et h, d'autre part, est celui de CAMPBELL (1974) dans sa version améliorée par HUTSON et CASS (1987). Les résultats montrent que ce modèle décrit raisonnablement le processus du drainage en fonction du temps correspondant à des pas de pressions croissantes. La solution de la méthode d'identification des paramètres est unique tant que les valeurs assignées aux paramètres au départ sont proches (plus ou moins 20 %) de celles du sol étudié. L'effet d'une erreur expérimentale allant jusqu'à 10 % n'est pas significatif pour les résultats des paramètres optimisés. (Résumé d'auteur

Caracterização fenológica de viníferas em região não tradicional do Agreste de Pernambuco.

O estudo teve como objetivo avaliar o desenvolvimento vegetativo, fenologia e exigência térmica de cultivares de videira para elaboração de vinhos finos introduzidas em microrregião de altitude no Nordeste

Caracterização fenológica de viníferas em região não tradicional do Agreste de Pernambuco.

O estudo teve como objetivo avaliar o desenvolvimento vegetativo, fenologia e exigência térmica de cultivares de videira para elaboração de vinhos finos introduzidas em microrregião de altitude no Nordeste.XV Congresso Latino-Americano de Viticultura e Enologia E XIII Congresso Brasileiro de Viticultura e Enologia. Bento Gonçalves-RS, 3 a 7 de Novembro de 2015

Population-based prevalence survey of follicular trachoma and trachomatous trichiasis in the Casamance region of Senegal.

BACKGROUND: Trachoma, caused by ocular infection with Chlamydia trachomatis, is the leading infectious cause of blindness worldwide. We conducted the first population-based trachoma prevalence survey in the Casamance region of Senegal to enable the Senegalese National Eye Care Programme (NECP) to plan its trachoma control activities. The World Health Organization (WHO) guidelines state that any individual with trachomatous trichiasis (TT) should be offered surgery, but that surgery should be prioritised where the prevalence is >0.1%, and that districts and communities with a trachomatous inflammation, follicular (TF) prevalence of ≥10% in 1-9 year-olds should receive mass antibiotic treatment annually for a minimum of three years, along with hygiene promotion and environmental improvement, before re-assessing the prevalence to determine whether treatment can be discontinued (when TF prevalence in 1-9 year-olds falls 1% in all districts. CONCLUSION: With a prevalence <5%, TF does not appear to be a significant public health problem in this region. However, TF monitoring and surveillance at sub-district level will be required to ensure that elimination targets are sustained and that TF does not re-emerge as a public health problem. TT surgery remains the priority for trachoma elimination efforts in the region, with an estimated 1819 TT surgeries to conduct

Feasibility of Onchocerciasis Elimination with Ivermectin Treatment in Endemic Foci in Africa: First Evidence from Studies in Mali and Senegal

The control of onchocerciasis, or river blindness, is based on annual or six-monthly ivermectin treatment of populations at risk. This has been effective in controlling the disease as a public health problem, but it is not known whether it can also eliminate infection and transmission to the extent that treatment can be safely stopped. Many doubt that this is feasible in Africa. A study was undertaken in three hyperendemic onchocerciasis foci in Mali and Senegal where treatment has been given for 15 to 17 years. The results showed that only few infections remained in the human population and that transmission levels were everywhere below postulated thresholds for elimination. Treatment was subsequently stopped in test areas in each focus, and follow-up evaluations did not detect any recrudescence of infection or transmission. Hence, the study has provided the first evidence that onchocerciasis elimination is feasible with ivermectin treatment in some endemic foci in Africa. Although further studies are needed to determine to what extent these findings can be extrapolated to other areas in Africa, the principle of onchocerciasis elimination with ivermectin treatment has been established

A double-blind placebo-controlled trial of azithromycin to reduce mortality and improve growth in high-risk young children with non-bloody diarrhoea in low resource settings: the Antibiotics for Children with Diarrhoea (ABCD) trial protocol

Background Acute diarrhoea is a common cause of illness and death among children in low- to middle-income settings. World Health Organization guidelines for the clinical management of acute watery diarrhoea in children focus on oral rehydration, supplemental zinc and feeding advice. Routine use of antibiotics is not recommended except when diarrhoea is bloody or cholera is suspected. Young children who are undernourished or have a dehydrating diarrhoea are more susceptible to death at 90 days after onset of diarrhoea. Given the mortality risk associated with diarrhoea in children with malnutrition or dehydrating diarrhoea, expanding the use of antibiotics for this subset of children could be an important intervention to reduce diarrhoea-associated mortality and morbidity. We designed the Antibiotics for Childhood Diarrhoea (ABCD) trial to test this intervention. Methods ABCD is a double-blind, randomised trial recruiting 11,500 children aged 2–23 months presenting with acute non-bloody diarrhoea who are dehydrated and/or undernourished (i.e. have a high risk for mortality). Enrolled children in Bangladesh, India, Kenya, Malawi, Mali, Pakistan and Tanzania are randomised (1:1) to oral azithromycin 10 mg/kg or placebo once daily for 3 days and followed-up for 180 days. Primary efficacy endpoints are all-cause mortality during the 180 days post-enrolment and change in linear growth 90 days post-enrolment. Discussion Expanding the treatment of acute watery diarrhoea in high-risk children to include an antibiotic may offer an opportunity to reduce deaths. These benefits may result from direct antimicrobial effects on pathogens or other incompletely understood mechanisms including improved nutrition, alterations in immune responsiveness or improved enteric function. The expansion of indications for antibiotic use raises concerns about the emergence of antimicrobial resistance both within treated children and the communities in which they live. ABCD will monitor antimicrobial resistance. The ABCD trial has important policy implications. If the trial shows significant benefits of azithromycin use, this may provide evidence to support reconsideration of antibiotic indications in the present World Health Organization diarrhoea management guidelines. Conversely, if there is no evidence of benefit, these results will support the current avoidance of antibiotics except in dysentery or cholera, thereby avoiding inappropriate use of antibiotics and reaffirming the current guidelines. Trial registration Clinicaltrials.gov, NCT03130114. Registered on April 26 2017