Deterministic Mean-field Ensemble Kalman Filtering

The proof of convergence of the standard ensemble Kalman filter (EnKF) from Legland etal. (2011) is extended to non-Gaussian state space models. A density-based deterministic approximation of the mean-field limit EnKF (DMFEnKF) is proposed, consisting of a PDE solver and a quadrature rule. Given a certain minimal order of convergence $\kappa$ between the two, this extends to the deterministic filter approximation, which is therefore asymptotically superior to standard EnKF when the dimension $d<2\kappa$. The fidelity of approximation of the true distribution is also established using an extension of total variation metric to random measures. This is limited by a Gaussian bias term arising from non-linearity/non-Gaussianity of the model, which exists for both DMFEnKF and standard EnKF. Numerical results support and extend the theory

Evaluation in vitro et in vivo des proprietes anthelminthiques de feuilles de Spondias mombin sur Haemonchus contortus des ovins djallonke

Depuis longtemps, la lutte contre les maladies animales s’est faite avec l’utilisation des molécules chimiques de synthèse. Cette lutte chimique est à l’origine du développement de résistance de certains agents pathogènes. Face à cette contrainte, de nouvelles méthodes de lutte sont envisagées. La présente étude se propose d’évaluer in vitro et in vivo, les propriétés anthelminthiques de Spondias mombin sur Haemonchus contortus chez les ovins Djallonké. Des tests biologiques des extraits éthanoliques et méthanoliques de la plante ont été effectués sur les larves L3 et sur les vers adultes de H contortus. Pour les essais in vivo, trois lots de brebis parasitées sont constitués : Témoin sans traitement; Lot 1 et Lot 2 recevant respectivement 1,45g et 2,9g /kg/animal de poudre de feuilles de S. mombin pendant trois jours. Les tests in vitro ont montré des valeurs significatives (p &lt; 0,01) de la capacité des extraits de S. mombin à inhiber la migration des larves L3 (45 à 80 %) et à réduire la motilité des vers adultes après 30 heures d’exposition (77 à 100 %), comparativement au témoin de référence négatif (PBS). L’activité antiparasitaire des feuilles de S. mombin obtenue in vitro est confirmée in vivo sur les brebis. Les résultats des travaux révèlent que les traitements avec la poudre de S. mombin a permis une réduction de plus de 50 % du niveau d’excrétion des œufs chez les brebis traitées. Mots clés : Parasites, Haemonchus contortus, ovins Djallonké, Spondias mombin. Anthelmintic activity of Spondias mombin ‘sleaves against Haemonchus contortusFor a long time, the fight against animal diseases has been done with the use of synthetic chemical molecules. This chemical fight is at the origin of the development of resistance of certain pathogens. Faced with this constraint, new control methods are being considered. This study proposes to evaluate in vitro and in vivo, the anthelmintic properties of Spondias mombin on Haemonchus contortus of Djallonke sheep. Biological tests of the ethanolic and methanolic extracts of the plant were carried out on the L3 larvae and on the adult worms of H contortus. For in vivo tests, three lots of parasitized ewes consist of: Control without treatment; Lot 1 and Lot 2 receiving respectively 1.45g and 2.9 g / kg / animal leaf powder of S. mombin for three days. In vitro tests showed significant (p &lt; 0.01) values of the ability of S. mombin extracts to inhibit the migration of L3 larvae (45 - 80 %) and to reduce the motility of adult worms after 30 hours. exposure (77 to 100 %), compared to the negative reference control (PBS). It should be noted that, in general, the anthelmintic activity of S. mombin extracts is not influenced by the type of solvent used. The anti-parasitic activity of S. mombin leaves obtained in vitro is confirmed in vivo in ewes. The results of the work show that treatments with S. mombin powder resulted in a reduction of more than 50 % in the level of egg excretion in treated ewes. Key words: Parasites, Haemonchus contortus, Djallonke sheep, Spondias mombin

Abiotic Stresses Tolerance and Nutrients Contents in Groundnut, Pearl Millet and Sorghum Mini Core Collections for Food and Nutrition Security

Food and nutrition security still require new sources of tolerance to major abiotic stresses and high nutritional quality. Groundnut, pearl millet and sorghum mini core collections are representing diversity of global collections but few studies investigated the nutrients contents and the tolerance to low phosphorus (LP) and drought stress (WS). Under lysimetre and pots conditions, subsets of these mini core collections were used to assess genotypic variation in nutrients contents and identify new sources of tolerance to WS and LP. In a randomized completely block design with 5 replications, water regimes and phosphorus treatments were imposed. Agromorphological and nutrients contents parameters were investigated. ANOVA were performed to assess the genotype and treatments effects. WS decreased the transpiration efficiency (47%), yield and its components (68%) in groundnut. Combined WS-LP reduced pods weight (83%). ICG3312, ICG81, ICG13395 and ICG467 revealed tolerant to WS/LP. In Pearl millet, LP decreased 100 seeds weight (14%), panicle and shoot biomass weight (25%), the booting date delayed except on IP1060, IP5869, IP9000, IP17532 and IP17775. WS-LP decreased total biomass (35%) while LP reduced total N(4.5%), P(20%), K(23%), Fe(25%) and Zn(3%). IP17532, IP 5153 and IP 5581 revealed highest Fe content (524mgkg-1). In sorghum, LP delayed the booting date, decreased biomass (32%) and WS-LP reduced biomass (74%). ISS2151, ISS705 and ISS862 revealed tolerant to WS-LP. LP decreased total N(11%), P(32%), K(13%), Fe(13%) and Zn(11%). IS1412, IS311 and IS376 showed high Fe content (515mgKg-1). Selected genotypes and traits might be useful in crops improvement for more adaptation and productivity

Systemic and immune manifestations in myelodysplasia: a multicenter retrospective study

OBJECTIVE: The presence of systemic and/or immune manifestations in myelodysplasia has been currently reported. The influence of these manifestations on the natural outcome of myelodysplastic syndrome has to be considered. We present a multicenter retrospective study (2002-2009) of patients with myelodysplastic syndrome disclosing systemic and/or immune manifestations. METHODS: Forty-six patients with myelodysplasia presenting with systemic and/or immune manifestations were compared in terms of survival with 189 patients with myelodysplasia lacking these features. RESULTS: The clinical picture in these cases consisted of fever (13%), arthralgia or arthritis (13%), and cutaneous manifestations (67%). Four cases of systemic vasculitis have been reported in our series, and they have a worse prognosis. Immune anomalies were recorded in 29% of the cases, and the presence of cryoglobulins was also associated with a worse prognosis. CONCLUSION: A difference in survival between patients with myelodysplastic syndrome with systemic manifestations and patients lacking these manifestations has been observed in the presence of systemic vasculitis and/or cryoglobulins

Drought (WS) and low phosphorus (LP) stress in groundnut: Water extraction pattern and tolerance related traits for breeding program

Drought (WS) and low soil phosphorus (LP) are major constraints of groundnut productivity. This study aims to (i) understand the relative importance of phosphorus (P) deficiency, water stress and their interaction, (ii )investigate water extraction pattern under WS and LP, and (iii) identify field and controlled conditions measured traits related to better performance of genotypes under WS and LP. Six groundnut varieties were assessed under field and lysimetre conditions. Two water regimes (WW, WS) and 2 phosphorus treatments (HP, LP) were imposed. Leaf Area Index (LAI), roots volume (RV), length density (RLD) and roots dry matter (RDM), water extraction (WEx), transpiration efficiency (TE), soil moisture content (SMC) and yield were investigated. LP stress decreased LAI and pod weight (Pwt) (42 and 28 % respectively). ICGV 12991 and 12CS-116 varieties showed the highest LAI and Pwt. LAI, correlated to Pwt(r2 = 0.77), revealed relevant trait for LP tolerance.LP and WS decreased roots and canopy measured traits. WS and LP decreased WEx (51 and 7% respectively). Combined LP and WS (WS-LP) decreased WEx up to 60%. ICG 12991 and 12CS-116 showed the highest WEx, RLD and RDM under WS-LP; RLDcould contribute to water uptake to avoid dehydration. Significant genotypic variation observed on SMC revealed different pattern of WEx. TE increased under WS and decreased under LP; factors driving TE would be different.12CS-116, 55-437 and ICG 12991 revealed high TEand tolerant to WS-LP but showed different tolerance mechanism. This study revealed that ICG 12991 and 12CS-116 were tolerant to WS-LP and LAI, RLD, while WEx and TE revealed relevant traits for groundnut improvement

Elevated soluble Flt1 mediates an anti-angiogenic state in patients with ANCA-associated vasculitis

International audiencen.