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Describes the method for screening rice germplasm for resistance to the African rice gall midge (AfRGM) in Nigeria. Role of partial resistance on the management of AfRGM; Development of resistant varieties; Percentage rate of tiller infestation levels.

Farmer-managed trials of the rice variety Cisadane were undertaken at 47 rainfed lowland sites around Abakaliki, south-east Nigeria, a major outbreak area of the African rice gall midge (ARGM). At each site a plot of Cisadane was grown alongside a control plot of the participating farmer's usual variety. On average the Cisadane yielded 26% higher than the controls but ARGM infestation levels on it were only slightly lower, suggesting thatithad greater tolerance to the pest butlittle antixenotic or antibiotic resistance. For all of 14 evaluation criteria, most participating farmers rated Cisadane as better than their control varieties. It appears to be a useful component for an ARGM management strategy. Regression analyses of yield on alternative variables for ARGM infestation derived from data recorded at 3, 7 or 11 w.a.t. (weeks after transplanting) showed that the log-transformed percent tiller infestation at 7 w.a.t. was the best predictor of yield. Variables for site topography, water level, fertilizer use in the nursery, and plant spacing also had significant partial regression coefficients. Excluding plots with tiller infestation levels above 30%, the relationship between yield and infestation was approximately linear and suggested a yield loss of 2.9% per 1% increase in infestation. [ABSTRACT FROM AUTHOR]

Survival in patients requiring RVAD support is known to be poor. However, outcomes in those undergoing subsequent RVAD explant and predictors of mortality remain unknown. Of 16482 patients in IMACS, 723 patients had an isolated RVAD (n=29) or BiVAD (n=694) in place. Using Kaplan Meier methods, survival was estimated for the LVAD-only cohort and within the subgroup of RVAD/BiVAD patients with and without RVAD explant. Correlates of mortality in the RVAD explant group were identified with Cox multivariable regression. Within the BiVAD group, 240 patients (33%) had an RVAD explant. Of these, 221 (92%) were performed for RV recovery, 17 (7.1%) for device malfunction and 2 (0.8%) were for other reasons. Survival at 1Y was 53±2.0% in the BiVAD group vs. 82±0.3% in LVAD-only patients (p<0.0001). Within the BiVAD group, patients undergoing RVAD explant had equivalent survival (1Y=54±2.5%) to those with ongoing BiVAD support (1Y=52±3.4%, p=0.54). BiVAD patients who died after RVAD explant were older, more likely to be BTT, and had higher preimplant creatinine (table). On multivariable analysis, older age, higher preimplant pulmonary systolic pressure, explant for RVAD dysfunction, and BTT indication predicted death after RVAD explant (table). Within the subgroup of BTT BiVAD (n=51) patients undergoing RVAD explant, survival was only 62% at 3 months. Patients undergoing RVAD explant, even for RV-recovery, have very poor survival. Patients who are transplant eligible with signs of RVAD dysfunction should be given urgent listing status. Rather than RVAD explant, BTT patients with signs of RV recovery may be better served with transplant. [ABSTRACT FROM AUTHOR]

Presently, 50% of patients on LVAD support are alive on therapy at 5 years. While preoperative (preop) variables can predict short term (ST) survival, correlates of long term (LT) survival remain poorly characterized. Using Intermacs-STS, we aim to identify preop and postoperative correlates of LT survival. Patients (n=16474) undergoing LVAD implant (2012-18) in Intermacs-STS were categorized as ST (survival ≤1 year postoperative, n=7483), mid-term (MT, 1-3 years, n=5976) and LT (>3 years, n=3015) survivors. Pre-implant characteristics and events during support were compared between the three groups to identify mortality correlates. Compared with patients dying in the ST, LT survivors were more likely to be younger, not listed for transplant, with higher BSA and VAS scores and several lower risk preop characteristics but differences between MT and LT survivors were not clinically significant (table). On multi-variable analysis, patients suffering post-LVAD stroke (HR 1.42, image), any major infection (HR 1.13), pump related infection (HR 1.19), and/or device malfunction (HR=1.22) (all p<0.001) were less likely to live >1 year, as were patients with a history of pulmonary disease (HR 1.19, 0.01), cancer (HR 1.26, p=0.01), CABG (HR 1.24, p<0.001), hepatitis (HR 1.54, p=0.002) and active smoking (1.44, p <0.001). The preop clinical features of ST and LT survivors vary significantly. Preop characteristics mainly select out early deaths, failing to accurately characterize survival after 1 year. LT survival is heavily influenced by device complications and pre-existing medical co-morbidities. [ABSTRACT FROM AUTHOR]