Effet du régime hydrique sur la densité de l’inoculum de Phytophthora spp. chez le clémentinier Sidi Aissa greffé sur différents porte-greffes dans la région du Gharb (Sidi Allal Tazi) au Maroc

We examined the combined influence of irrigation regime and rootstock on Phytophthora spp. population density in citrus rhizosphere under field conditions. We carried out the study in a young orchard of Clementine, variety Sidi Aissa, grafted onto five rootstocks:, i.e. carrizo citrange, citrange C35, Citrus macrophylla, sour orange and the hybrid Cleopatra mandarin x citrange Carrizo 30577. Three water regimes were applied: Control (T0) irrigated at 100% of ETc, and deficit irrigation (T1) and (T2) at 75% and 50% of ETc, respectively. Results show that Phytophthora spp. Inoculum density varied significantly between the different irrigation regimes and rootstock genotypes. Phytophthora spp. density was significantly lower under the more severe deficit irrigation T2 than under T0 or T1. Also, a significant and positive correlation was found between soil moisture and inoculum density of Phytophthora spp. in the rhizosphere of C. macrophylla and Carrizo citrange rootstocks. Among rootstocks, the highest population densities of Phytophthora spp. were demonstrated for C. macrophylla and sour orange rhizosphere under 100% ETc regime, while no inoculum was evidenced from the root zone of C. macrophylla under 50% ETc. Results showed that Carrizo citrange and C. macrophylla were more sensitive to soil moisture indicating that watering regime is a key factor to minimize Phytophthora spp. density in the rhizosphere of these rootstocks. Results also revealed that Carrizo citrange and C. macrophylla rootstocks can be recommended under deficit irrigation in order to reduce Phytophthora spp. infection in citrus orchards.L’effet du régime hydrique sur la densité de l’inoculum de Phytophthora spp. sur les racines de jeunes plants du clémentinier Sidi Aissa a été étudié dans des conditions de plein champ de Sidi Allal Tazi au Gharb (Maroc). L’étude a été menée sur une parcelle de clémentinier Sidi Aissa plantée en décembre 2010 avec une densité de 5 x 3 m² au Domaine expérimental de Sidi Allal Tazi, situé à 49 km au Nord de Kenitra. La variété a été greffée sur cinq porte-greffes d’agrumes : citange C35, citrange Carrizo, Citrus macrophylla, l’hybride Mand. Cleo X citrange Carrizo 30577 et le Bigaradier. Trois régimes hydriques ont été testés : 100%, 75% et 50% d’ETc. Les résultats ont mis en évidence que la densité de l’inoculum de Phytophthora spp. au niveau du sol varie significativement avec le régime hydrique appliqué et le porte-greffe utilisé. Cette densité a été significativement réduite sous les conditions de déficit hydrique (50% d’ETc) comparativement aux autres doses (100% et 75% d’ETc). Dans la même veine, nous avons démontré une corrélation significative et positive entre l’humidité du sol et la densité de l’inoculum de Phytophthora spp. au niveau du rhizosphère chez le C. macrophylla et le citrange Carrizo. Cette étude a révélé que le régime hydrique influence de manière importante la densité de l’inoculum de Phytophthora spp. au niveau de la zone racinaire des porte-greffes utilisés. A la lumière de cette étude, on peut conclure que C. macrophylla et le citrange Carrizo peuvent être recommandés comme porte-greffes pour les agrumes dans des conditions de culture à irrigation déficitaire

Effect of watering regime on inoculum density of Phytophthora spp. in the rhizosphere of young plantations of the sidi aissa clementine variety grafted onto different rootstocks in the Gharb region (Sidi Allal Tazi) of Morocco

L’effet du régime hydrique sur la densité de l’inoculum de Phytophthora spp. sur les racines de jeunes plants du clémentinier Sidi Aissa a été étudié dans des conditions de plein champ de Sidi Allal Tazi au Gharb (Maroc). L’étude a été menée sur une parcelle de clémentinier Sidi Aissa plantée en décembre 2010 avec une densité de 5 x 3 m² au Domaine expérimental de Sidi Allal Tazi, situé à 49 km au Nord de Kenitra. La variété a été greffée sur cinq porte-greffes d’agrumes : citange C35, citrange Carrizo, Citrus macrophylla, l’hybride Mand. Cleo X citrange Carrizo 30577 et le Bigaradier. Trois régimes hydriques ont été testés : 100%, 75% et 50% d’ETc. Les résultats ont mis en évidence que la densité de l’inoculum de Phytophthora spp. au niveau du sol varie significativement avec le régime hydrique appliqué et le porte-greffe utilisé. Cette densité a été significativement réduite sous les conditions de déficit hydrique (50% d’ETc) comparativement aux autres doses (100% et 75% d’ETc). Dans la même veine, nous avons démontré une corrélation significative et positive entre l’humidité du sol et la densité de l’inoculum de Phytophthora spp. au niveau du rhizosphère chez le C. macrophylla et le citrange Carrizo. Cette étude a révélé que le régime hydrique influence de manière importante la densité de l’inoculum de Phytophthora spp. au niveau de la zone racinaire des porte-greffes utilisés. A la lumière de cette étude, on peut conclure que C. macrophylla et le citrange Carrizo peuvent être recommandés comme porte-greffes pour les agrumes dans des conditions de culture à irrigation déficitaire.We examined the combined influence of irrigation regime and rootstock on Phytophthora spp. population density in citrus rhizosphere under field conditions. We carried out the study in a young orchard of Clementine, variety Sidi Aissa, grafted onto five rootstocks:, i.e. carrizo citrange, citrange C35, Citrus macrophylla, sour orange and the hybrid Cleopatra mandarin x citrange Carrizo 30577. Three water regimes were applied: Control (T0) irrigated at 100% of ETc, and deficit irrigation (T1) and (T2) at 75% and 50% of ETc, respectively. Results show that Phytophthora spp. Inoculum density varied significantly between the different irrigation regimes and rootstock genotypes. Phytophthora spp. density was significantly lower under the more severe deficit irrigation T2 than under T0 or T1. Also, a significant and positive correlation was found between soil moisture and inoculum density of Phytophthora spp. in the rhizosphere of C. macrophylla and Carrizo citrange rootstocks. Among rootstocks, the highest population densities of Phytophthora spp. were demonstrated for C. macrophylla and sour orange rhizosphere under 100% ETc regime, while no inoculum was evidenced from the root zone of C. macrophylla under 50% ETc. Results showed that Carrizo citrange and C. macrophylla were more sensitive to soil moisture indicating that watering regime is a key factor to minimize Phytophthora spp. density in the rhizosphere of these rootstocks. Results also revealed that Carrizo citrange and C. macrophylla rootstocks can be recommended under deficit irrigation in order to reduce Phytophthora spp. infection in citrus orchards

Alternative flood irrigation strategies that improve water conservation in citrus

Citrus production in Texas is concentrated in the Lower Rio Grande Valley (LRGV). This area is well known for its high quality horticultural crops due to the close proximity to the Rio Grande River and climate. The majori-ty of citrus groves are irrigated in this region using traditional flood (TFd) irrigation practices. The purpose of this study was to compare an alternative form of flood irrigation practice called border flood (BFd) that channels water faster down the tree row. In this research study, water was metered to evaluate total water applied in a replicated field study comparing TFd water use to that of BFd. The water savings results observed in this research study were very similar to on-farm demonstration investigations of water use comparing TFd and BFd irrigators. It was found that using BFd irrigation method saved about 36% of water compared to TFd irrigation practices. This amount of water savings is nearly equivalent to the amount of water saved by current growers using more expen-sive drip and microjet sprinkers systems. The results of this study suggest that citrus growers can implement mod-est changes to their cultural practices by raising berms between rows and, in turn, save water

The immunological and virological consequences of planned treatment interruptions in children with HIV infection

Contains fulltext : 126098.pdf (publisher's version ) (Open Access)OBJECTIVES: To evaluate the immunological and viral consequences of planned treatment interruptions (PTI) in children with HIV. DESIGN: This was an immunological and virological sub-study of the Paediatric European Network for Treatment of AIDS (PENTA) 11 trial, which compared CD4-guided PTI of antiretroviral therapy (ART) with continuous therapy (CT) in children. METHODS: HIV-1 RNA and lymphocyte subsets, including CD4 and CD8 cells, were quantified on fresh samples collected during the study; CD45RA, CD45RO and CD31 subpopulations were evaluated in some centres. For 36 (18 PTI, 18 CT) children, immunophenotyping was performed and cell-associated HIV-1 DNA analysed on stored samples to 48 weeks. RESULTS: In the PTI group, CD4 cell count fell rapidly in the first 12 weeks off ART, with decreases in both naive and memory cells. However, the proportion of CD4 cells expressing CD45RA and CD45RO remained constant in both groups. The increase in CD8 cells in the first 12 weeks off ART in the PTI group was predominantly due to increases in RO-expressing cells. PTI was associated with a rapid and sustained increase in CD4 cells expressing Ki67 and HLA-DR, and increased levels of HIV-1 DNA. CONCLUSIONS: PTI in children is associated with rapid changes in CD4 and CD8 cells, likely due to increased cell turnover and immune activation. However, children off treatment may be able to maintain stable levels of naive CD4 cells, at least in proportion to the memory cell pool, which may in part explain the observed excellent CD4 cell recovery with re-introduction of ART

Cannabis Use and Reduced Risk of Insulin Resistance in HIV-HCV Infected Patients: A Longitudinal Analysis (ANRS CO13 HEPAVIH)

International audienceDiabetes and insulin resistance (IR) is common in human immunodeficiency virus-hepatitis C virus (HIV-HCV)-coinfected patients, a population also concerned with elevated cannabis use. Cannabis has been associated with reduced IR risk in some population-based surveys. We determined whether cannabis use was consistently associated with reduced IR risk in HEPAVIH, a French nationwide cohort of HIV-HCV-coinfected patients.Methods: HEPAVIH medical and sociobehavioral data were collected (using annual self-administered questionnaires). We used 60 months of follow-up data for patients with at least 1 medical visit where IR (using homeostatic model assessment of insulin resistance [HOMA-IR]) and cannabis use were assessed. A mixed logistic regression model was used to evaluate the association between IR risk (HOMA-IR > 2.77) and cannabis use (occasional, regular, daily).Results: Among the 703 patients included in the study (1287 visits), 323 (46%) had HOMA-IR > 2.77 for at least 1 follow-up visit and 319 (45%) reported cannabis use in the 6 months before the first available visit. Cannabis users (irrespective of frequency) were less likely to have HOMA-IR > 2.77 (odds ratio [95% confidence interval], 0.4 [.2-.5]) after adjustment for known correlates/confounders. Two sensitivity analyses with HOMA-IR values as a continuous variable and a cutoff value of 3.8 confirmed the association between reduced IR risk and cannabis use.Conclusions: Cannabis use is associated with a lower IR risk in HIV-HCV-coinfected patients. The benefits of cannabis-based pharmacotherapies for patients concerned with increased risk of IR and diabetes need to be evaluated in clinical research and practice

Post‐HCV cure self‐reported changes in physical activity, eating behaviours, and fatigue in people living with HIV (ANRS CO13 HEPAVIH)

International audienc

First-line antiretroviral therapy with a protease inhibitor versus non-nucleoside reverse transcriptase inhibitor and switch at higher versus low viral load in HIV-infected children: An open-label, randomised phase 2/3 trial

Background: Children with HIV will be on antiretroviral therapy (ART) longer than adults, and therefore the durability of first-line ART and timing of switch to second-line are key questions. We assess the long-term outcome of protease inhibitor and non-nucleoside reverse transcriptase inhibitor (NNRTI) first-line ART and viral load switch criteria in children. Methods: In a randomised open-label factorial trial, we compared effectiveness of two nucleoside reverse transcriptase inhibitors (NRTIs) plus a protease inhibitor versus two NRTIs plus an NNRTI and of switch to second-line ART at a viral load of 1000 copies per mL versus 30 000 copies per mL in previously untreated children infected with HIV from Europe and North and South America. Random assignment was by computer-generated sequentially numbered lists stratified by age, region, and by exposure to perinatal ART. Primary outcome was change in viral load between baseline and 4 years. Analysis was by intention to treat, which we defined as all patients that started treatment. This study is registered with ISRCTN, number ISRCTN73318385. Findings: Between Sept 25, 2002, and Sept 7, 2005, 266 children (median age 6\ub75 years; IQR 2\ub78-12\ub79) were randomly assigned treatment regimens: 66 to receive protease inhibitor and switch to second-line at 1000 copies per mL (PI-low), 65 protease inhibitor and switch at 30 000 copies per mL (PI-higher), 68 NNRTI and switch at 1000 copies per mL (NNRTI-low), and 67 NNRTI and switch at 30 000 copies per mL (NNRTI-higher). Median follow-up was 5\ub70 years (IQR 4\ub72-6\ub70) and 188 (71%) children were on first-line ART at trial end. At 4 years, mean reductions in viral load were -3\ub716 log10copies per mL for protease inhibitors versus -3\ub731 log10copies per mL for NNRTIs (difference -0\ub715 log10copies per mL, 95% CI -0\ub741 to 0\ub711; p=0\ub726), and -3\ub726 log10copies per mL for switching at the low versus -3\ub720 log10copies per mL for switching at the higher threshold (difference 0\ub706 log10copies per mL, 95% CI -0\ub720 to 0\ub732; p=0\ub756). Protease inhibitor resistance was uncommon and there was no increase in NRTI resistance in the PI-higher compared with the PI-low group. NNRTI resistance was selected early, and about 10% more children accumulated NRTI mutations in the NNRTI-higher than the NNRTI-low group. Nine children had new CDC stage-C events and 60 had grade 3/4 adverse events; both were balanced across randomised groups. Interpretation: Good long-term outcomes were achieved with all treatments strategies. Delayed switching of protease-inhibitor-based ART might be reasonable where future drug options are limited, because the risk of selecting for NRTI and protease-inhibitor resistance is low. Funding: Paediatric European Network for Treatment of AIDS (PENTA) and Pediatric AIDS Clinical Trials Group (PACTG/IMPAACT). \ua9 2011 Elsevier Ltd