Computing Opportunity Costs of Growing Local Varieties for On-farm Conservation: Illustrations Using Sorghum Data from Ethiopia

The recent shift of emphasis to on-farm conservation is driven by its diverse attractive features - participatory nature, dynamic nature, capacity to maintain not only crop diversity but the knowledge that evolves with it, the chance it offers and the challenge it brings to link conservation with farmers' livelihood. To make it operational, placing incentives and removal of perverse incentives are of critical importance. However, before placing sound incentives compatible to farmers' circumstances, the opportunity costs farmers face when using local varieties of public interest should be understood. This paper empirically examines farmers' opportunity costs of maintaining local varieties of sorghum using a household survey data collected from 198 sorghum growers in Eastern Ethiopia. Opportunity costs are generated using different homogeneous treatment statistical models and factors affecting them are further examined using switching regression model. The average opportunity costs suggest not only the size of policy incentive required for farmers to maintain local varieties of sorghum on-farm but also are useful to estimate the national costs of conserving crop genetic resources. The regression analysis shows that opportunity costs increase with access to output markets and extension, output price, access to input supply, experience in growing improved varieties, and relative importance of the crop. On the contrary, plot quality, input price and oxen ownership are reducing opportunity costs. The paper then concludes outlining the policy implications of the empirical findings to incentive design for on-farm conservation of crop genetic resources.Opportunity costs, incentive design, on-farm conservation, crop genetic resources, Ethiopia, Crop Production/Industries,

Developing Process Variables Necessary to Operate Simulacrum: The LCLS Accelerator Simulator

The Linac Coherent Light Source (LCLS) is a free electron laser that is located at SLAC National Accelerator Laboratory. It fires 120 pulses per second, creating x-ray snapshots of materials at the atomic and molecular level as it undergoes any changes or processes. This resulted in many scientific discoveries in chemistry, biology, energy science, and technology. Now, there is a new vision at SLAC regarding LCLS: to develop Simulacrum. Simulacrum is a system that simulates LCLS and its control system. Within Simulacrum there exits services that contain process variables that measure specific parts of a device on LCLS, which communicate through a high-performing messaging system called ZeroMQ. For instance, a PV be controlled and provide information to operators about a klystron’s amplitude or phase, which is needed to accelerate electrons in the linac. Because LCLS contains thousands of devices that contain complex subsystems, a major challenge is writing every PV that exists in LCLS into Simulacrum’s services. The goal of this project was to focus on two services, klystron and generic services, and write as many PVs that correspond to these two categories using MATLAB and Python. Then, we find methods to populate these PVs with sensible data so that it simulates LCLS with accuracy and updates graphical user interfaces from LCLS in Simulacrum

Association of Tenofovir Use With Risk of Incident Heart Failure in HIV-Infected Patients.

BackgroundThe antiretroviral medication, tenofovir disoproxil fumarate (TDF), is used by most human immunodeficiency virus-infected persons in the United States despite higher risks of chronic kidney disease. Although chronic kidney disease is a strong risk factor for heart failure (HF), the association of TDF with incident HF is unclear.Methods and resultsWe identified 21 435 human immunodeficiency virus-infected patients in the United States Veterans Health Administration actively using antiretrovirals between 2002 and 2011. We excluded patients with a prior diagnosis of HF. TDF was analyzed categorically (current, past, or never use) and continuously (per year of use). Proportional hazards regression and fully adjusted marginal structural models were used to determine the association of TDF exposure with risk of incident HF after adjustment for demographic, human immunodeficiency virus-related, and cardiovascular risk factors. During follow-up, 438 incident HF events occurred. Unadjusted 5-year event rates for current, past, and never users of TDF were 0.9 (95%CI 0.7-1.1), 1.7 (1.4-2.2), and 4.5 (3.9-5.0), respectively. In fully adjusted analyses, HF risk was markedly lower in current TDF users (HR=0.68; 95%CI 0.53-0.86) compared with never users. Among current TDF users, each additional year of TDF exposure was associated with a 21% lower risk of incident HF (95%CI: 0.68-0.92). When limited to antiretroviral-naive patients, HF risk remained lower in current TDF users (HR=0.53; 95%CI 0.36-0.78) compared to never users.ConclusionsAmong a large national cohort of human immunodeficiency virus-infected patients, TDF use was strongly associated with lower risk of incident HF. These findings warrant confirmation in other populations, both with TDF and the recently approved tenofovir alafenamide fumarate

Rhabdomyolysis in an HIV cohort: epidemiology, causes and outcomes.

BackgroundThe Literature on rhabdomyolysis in the HIV-positive population is sparse and limited. We aimed to explore the incidence, patient characteristics, etiologies and outcomes of rhabdomyolysis in a cohort of HIV-positive patients identified through the Johns Hopkins HIV clinical registry between June 1992 and April 2014.MethodsA retrospective analysis of 362 HIV-positive patients with non-cardiac CK elevation ≥1000 IU/L was performed. Both inpatients and outpatients were included. Incidence rate and potential etiologies for rhabdomyolysis were ascertained. The development of acute kidney injury (AKI, defined as doubling of serum creatinine), need for dialysis, and death in the setting of rhabdomyolysis were determined. Logistic regression was used to evaluate the association of peak CK level with the development of AKI.ResultsThree hundred sixty two cases of rhabdomyolysis were identified in a cohort of 7079 patients with a 38,382 person years follow-up time. The incidence rate was nine cases per 1000 person-years (95% CI: 8.5-10.5). Infection was the most common etiology followed by compression injury and drug/alcohol use. One-third of cases had multiple potential etiologies. AKI developed in 46% of cases; 20% of which required dialysis. Thirteen percent died during follow-up. After adjustment, AKI was associated with higher CK (OR 2.05 for each 1-log increase in CK [95% CI: 1.40-2.99]), infection (OR 5.48 [95% CI 2.65-11.31]) and higher HIV viral load (OR 1.22 per 1-log increase [95% CI: 1.03-1.45]).ConclusionRhabdomyolysis in the HIV-positive population has many possible causes and is frequently multifactorial. HIV-positive individuals with rhabdomyolysis have a high risk of AKI and mortality

The Effect of Residual Roundup on Showy Milkweed Growth and Cardenolide Production

Western monarch butterfly populations have sharply declined over the last three decades largely due to destruction of their habitat and larval food source, milkweed (Asclepias spp.). In order to aid reestablishment of milkweed habitat in support of Western monarch populations, the effects of soil pollutants and additives on the plant’s growth and toxin production should be examined. We evaluated five growth parameters and cardenolide concentration of showy milkweed (A. speciosa) exposed to various soil treatments of Roundup and arbuscular mycorrhizal fungi in controlled greenhouse conditions. Our results suggest that residual Roundup in soil does not affect cardenolide concentrations in showy milkweed but may interact with arbuscular mycorrhizal fungus symbionts to affect growth. More research is needed in order to understand the relationship between Roundup and mycorrhizal symbionts, but our results suggest that Roundup pollutants remaining in soil will not adversely affect milkweed restoration efforts in support of the imperiled Western monarch butterfly