285 research outputs found
Rhizobacterial influence on healthy stand establishment of canola grown in Rhizoctonia solani infested fields of Saskatchewan
Non-Peer ReviewedPre-emergence seedling damping-off, seedling blight, and brown girdling root rot caused by R. solani are important diseases of canola/rape seed in western Canada. Annual yield losses in excess of 20-30% have been reported in several infected fields. Cultural control methods or resistant cultivars are currently unavailable for these diseases. Chemical fungicides have been developed for use to control the disease, but the success rate has been varied. However, the use of chemicals is becoming less acceptable from an environmental point of view. Several studies indicated that biological control using plant growth promoting
rhizobacteria may also be effective in controlling R. solani. Field plots were established in Saskatoon, Regina and Melfort, SK, in 1990, 1991 and 1992 to evaluate the potential of rhizobacterial strains as
seed treatments to increase the healthy stand of canola CV. Westar grown in R. solani infested field. The bacteria were formulated either in sterile peat or in a liquid carrier and applied to seed just before planting. Bacterized seed were mechanically planted in replicated field plots artificially infested with R. solani. Final healthy stand was measured 30 days after planting. Grain yields were determined by harvesting the plots. Seed bacterization significantly increased the final healthy stand compared to non-bacterized controls. Strains which increased stand showed in vitro antagonistic activity to not only R. solani but also other pathogens such as Pythium ultimum, Fusarium solani and F. oxysporum. Some of these strains induced root elongation of canola under laboratory conditions. Rhizosphere colonization, chemical compatibility and shelf-life of the important bacteria will be discussed
Real-space local polynomial basis for solid-state electronic-structure calculations: A finite-element approach
We present an approach to solid-state electronic-structure calculations based
on the finite-element method. In this method, the basis functions are strictly
local, piecewise polynomials. Because the basis is composed of polynomials, the
method is completely general and its convergence can be controlled
systematically. Because the basis functions are strictly local in real space,
the method allows for variable resolution in real space; produces sparse,
structured matrices, enabling the effective use of iterative solution methods;
and is well suited to parallel implementation. The method thus combines the
significant advantages of both real-space-grid and basis-oriented approaches
and so promises to be particularly well suited for large, accurate ab initio
calculations. We develop the theory of our approach in detail, discuss
advantages and disadvantages, and report initial results, including the first
fully three-dimensional electronic band structures calculated by the method.Comment: replacement: single spaced, included figures, added journal referenc
Accelerating Bianchi Type-V Cosmology with Perfect Fluid and Heat Flow in Saez-Ballester Theory
In this paper we discuss the law of variation of scale factor which yields a time-dependent deceleration
parameter (DP) representing a new class of models that generate a transition of
universe from the early decelerated phase to the recent accelerating phase.
Exact solutions of Einstein's modified field equations with perfect fluid and
heat conduction are obtained within the framework of Saez-Ballester
scalar-tensor theory of gravitation and the model is found to be in good
agreement with recent observations. We find, for n = 3, k = 1, the present
value of DP in derived model as q_0 = -0.67 which is very near to the observed
value of DP at present epoch. We find that the time-dependent DP is sensible
for the present day Universe and give an earmark description of evolution of
universe. Some physical and geometric properties of the models are also
discussed.Comment: 12 pages, 5 figure
Abundances of the elements in the solar system
A review of the abundances and condensation temperatures of the elements and
their nuclides in the solar nebula and in chondritic meteorites. Abundances of
the elements in some neighboring stars are also discussed.Comment: 42 pages, 11 tables, 8 figures, chapter, In Landolt- B\"ornstein, New
Series, Vol. VI/4B, Chap. 4.4, J.E. Tr\"umper (ed.), Berlin, Heidelberg, New
York: Springer-Verlag, p. 560-63
Cost-Effectiveness of Long-Acting Injectable HIV Preexposure Prophylaxis in the United States: A Cost-Effectiveness Analysis
Background: The HIV Prevention Trials Network (HPTN) 083 trial demonstrated the superiority of long-acting injectable cabotegravir (CAB-LA) compared with oral emtricitabineâtenofovir disoproxil fumarate (F/TDF) for HIV preexposure prophylaxis (PrEP). Objective: To identify the maximum price premium (that is, greatest possible price differential) that society should be willing to accept for the additional benefits of CAB-LA over tenofovir-based PrEP among men who have sex with men and transgender women (MSM/TGW) in the United States. Design: Simulation, cost-effectiveness analysis. Data Sources: Trial and published data, including estimated HIV incidence (5.32, 1.33, and 0.26 per 100 person-years for off PrEP, generic F/TDF and branded emtricitabineâtenofovir alafenamide (F/TAF), and CAB-LA, respectively); 28% 6-year PrEP retention. Annual base-case drug costs: 16 800 for generic F/TDF and branded F/TAF. Fewer side effects with branded F/TAF versus generic F/TDF were assumed. Target Population: 476 700 MSM/TGW at very high risk for HIV (VHR). Time Horizon: 10 years. Perspective: Health care system. Intervention: CAB-LA versus generic F/TDF or branded F/TAF for HIV PrEP. Outcome Measures: Primary transmissions, quality-adjusted life-years (QALYs), costs (2020 U.S. dollars), incremental cost-effectiveness ratios (ICERs; U.S. dollars per QALY), maximum price premium for CAB-LA versus tenofovir-based PrEP. Results of Base-Case Analysis: Compared with generic F/ TDF (or branded F/TAF), CAB-LA increased life expectancy by 28 000 QALYs (26 000 QALYs) among those at VHR. Branded F/ TAF cost more per QALY gained than generic F/TDF compared with no PrEP. At 10 years, CAB-LA could achieve an ICER of at most 3700 per year over generic F/TDF (CAB-LA price <100 000 per QALY versus generic F/TDF at a maximum price premium of 1500 per year). Limitation: Uncertain clinical and economic benefits of averting future transmissions. Conclusion: Effective oral PrEP limits the additional price society should be willing to pay for CAB-LA
Sweet Sorghum Planting Effects on Stalk Yield and Sugar Quality in Semi-Arid Tropical Environment
Sweet sorghum [Sorghum bicolor (L.) Moench] has potential as a bioenergy crop for producing food, fiber, and fermentable sugar. Unlike dryland grain sorghum, little information is available on the influence of staggered planting and genotypes, especially in semiarid tropical environments. The objectives of the present study were (i) to quantify the effects of planting time and genotype on stalk and biomass yields, juice sugar quality, and (ii) to identify the most productive genotypes and planting windows for sustainable feedstock supply. Four commercial sweet sorghum genotypes (SSV84, SSV74, CSV19SS, and CSH22SS) were planted on five planting dates (1 June, 16 June, 1 July, 16 July, and 1 August) during the rainy (JuneâOctober) season of 2008 and 2009 in Hyderabad (17°27ÂŽ N, 78°28ÂŽ E), India. Planting in early and mid-June produced significantly (P †0.05) higher fresh stalk yield and grain yield than later planting dates. Commercial hybrid CSH22SS produced significantly more stalk, grain, sugar, and ethanol yield over genotypes SSV84 or SSV74. Based on the stalk yield, juice sugar quality, sugar, and ethanol yields, the optimum planting dates for sweet sorghum in semiarid tropical climate is early June to early July. Planting sweet sorghum during this time allows more feedstock to be harvested and hence extends the period for sugar mill operation by about 1 mo, that is, from the first to the last week of October
Hepatitis B care cascade among people with HIV/HBV coinfection in the North American AIDS Cohort Collaboration on Research and Design, 2012-2016
A care cascade is a critical tool for evaluating delivery of care for chronic infections across sequential stages, starting with diagnosis and ending with viral suppression. However, there have been few data describing the hepatitis B virus (HBV) care cascade among people living with HIV infection who have HBV coinfection. We conducted a cross-sectional study among people living with HIV and HBV coinfection receiving care between January 1, 2012 and December 31, 2016 within 13 United States and Canadian clinical cohorts contributing data to the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD). We evaluated each of the steps in this cascade, including: 1) laboratory-confirmed HBV infection, 2) tenofovir-based or entecavir-based HBV therapy prescribed, 3) HBV DNA measured during treatment, and 4) viral suppression achieved via undetectable HBV DNA. Among 3,953 persons with laboratory-confirmed HBV (median age, 50 years; 6.5% female; 43.8% were Black; 7.1% were Hispanic), 3,592 (90.9%; 95% confidence interval, 90.0-91.8%) were prescribed tenofovir-based antiretroviral therapy or entecavir along with their antiretroviral therapy regimen, 2,281 (57.7%; 95% confidence interval, 56.2-59.2%) had HBV DNA measured while on therapy, and 1,624 (41.1%; 95% confidence interval, 39.5-42.6) achieved an undetectable HBV DNA during HBV treatment. Our study identified significant gaps in measurement of HBV DNA and suppression of HBV viremia among people living with HIV and HBV coinfection in the United States and Canada. Periodic evaluation of the HBV care cascade among persons with HIV/HBV will be critical to monitoring success in completion of each step
Non-local rheology in dense granular flows -- Revisiting the concept of fluidity
Granular materials belong to the class of amorphous athermal systems, like foams, emulsion or suspension they can resist shear like a solid, but flow like a liquid under a sufficiently large applied shear stress. They exhibit a dynamical phase transition between static and flowing states, as for phase transitions of thermodynamic systems, this rigidity transition exhibits a diverging length scales quantifying the degree of cooperatively. Several experiments have shown that the rheology of granular materials and emulsion is non-local, namely that the stress at a given location does not depend only on the shear rate at this location but also on the degree of mobility in the surrounding region. Several constitutive relations have recently been proposed and tested successfully against numerical and experimental results. Here we use discrete elements simulation of 2D shear flows to shed light on the dynamical mechanism underlying non-locality in dense granular flows
Association between Features of Spontaneous Late Preterm Labor and Late Preterm Birth
Objective This study aimed to evaluate the association between clinical and examination features at admission and late preterm birth. Study Design The present study is a secondary analysis of a randomized trial of singleton pregnancies at 34 0/7 to 36 5/7 weeks' gestation. We included women in spontaneous preterm labor with intact membranes and compared them by gestational age at delivery (preterm vs. term). We calculated a statistical cut-point optimizing the sensitivity and specificity of initial cervical dilation and effacement at predicting preterm birth and used multivariable regression to identify factors associated with late preterm delivery. Results A total of 431 out of 732 (59%) women delivered preterm. Cervical dilation â„ 4 cm was 60% sensitive and 68% specific for late preterm birth. Cervical effacement â„ 75% was 59% sensitive and 65% specific for late preterm birth. Earlier gestational age at randomization, nulliparity, and fetal malpresentation were associated with late preterm birth. The final regression model including clinical and examination features significantly improved late preterm birth prediction (81% sensitivity, 48% specificity, area under the curve = 0.72, 95% confidence interval [CI]: 0.68-0.75, and p -value < 0.01). Conclusion Four in 10 women in late-preterm labor subsequently delivered at term. Combination of examination and clinical features (including parity and gestational age) improved late-preterm birth prediction
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