Factors Influencing the Adoption of Russian Varroa-Resistant Honey Bees

Factors influencing the adoption of Russian Varroa-Resistant honey bees were assessed. Logit results indicate factors associated with the adoption include sales, internet use, and contact with other beekeepers. Negatively associated factors are age and income. Future adoption depends upon previous use and perception.Agribusiness,

Count Data Analysis of the Adoption of Best Management Practices in Beef Cattle Production

Factors influencing the adoption of Best Management Practices by cattle producers are analyzed using negative binomial regression analysis. Fifteen hundred farms were surveyed. Analysis identified diversification, hilly land, contact with regulatory personnel, college education, household income, and percentage of income from beef as significant factors in BMPs adoption.Livestock Production/Industries,

Awareness of and Application to the Environmental Quality Incentives Program By Cow–Calf Producers

This study uses a bivariate probit model with partial observability to examine Louisiana beef producers’ awareness of the Environmental Quality Incentives Program (EQIP) and how awareness translates to application to the program. Results indicate that awareness of and application to the EQIP depend on portion of income derived from off-farm sources, extent of previous best management practice adoption at one’s own expense, household income, farmed land that is highly erodible, contact with Natural Resource Conservation Service and extension service personnel, and producer age.BMPs, bivariate probit, EQIP, probit, Agribusiness, Environmental Economics and Policy, Livestock Production/Industries, Q12, Q16, Q18,

Awareness of EQIP and Subsequent Adoption of BMPs by Cattle Farmers

In summer, 2003, roughly half of Louisiana cattle producers had never heard of the Environmental Quality Incentives Program. Those who had heard of it and had applied for funds were more diversified, larger, and had contact with Natural Resources and Conservation Service personnel within the past year.Environmental Economics and Policy,

Knowledge, Application and Adoption of Best Management Practices by Cattle Farmers under the Environmental Quality Incentives Program - A Sequential Analysis

This study examines Louisiana farmers' awareness of EQIP and their subsequent adoption of best management practices (BMPs) using a sequential logit model. Results indicate that farmers likely to be aware of EQIP and eventually adopt BMPs under the program were mainly those who had been in contact with NRCS officials.BMPs, EQIP, Sequential logit model, Environmental Economics and Policy, Livestock Production/Industries,

Activated but functionally impaired memory Tregs are expanded in slow progressors to type 1 diabetes

This is the final version. Available on open access from Springer via the DOI in this recordData availability: The datasets generated and/or analysed during the current study are available from the corresponding author on reasonable request.Aims/hypothesis Slow progressors to type 1 diabetes are individuals positive for multiple pancreatic islet autoantibodies who have remained diabetes-free for at least 10 years; regulation of the autoimmune response is understudied in this group. Here, we profile CD4+ regulatory T cells (Tregs) in a small but well-characterised cohort of extreme slow progressors with a median age 43 (range 31–72 years), followed up for 18–32 years. Methods Peripheral blood samples were obtained from slow progressors (n = 8), age- and sex-matched to healthy donors. One participant in this study was identified with a raised HbA1c at the time of assessment and subsequently diagnosed with diabetes; this donor was individually evaluated in the analysis of the data. Peripheral blood mononuclear cells (PBMCs) were isolated, and to assess frequency, phenotype and function of Tregs in donors, multi-parameter flow cytometry and T cell suppression assays were performed. Unsupervised clustering analysis, using FlowSOM and CITRUS (cluster identification, characterization, and regression), was used to evaluate Treg phenotypes. Results Unsupervised clustering on memory CD4+ T cells from slow progressors showed an increased frequency of activated memory CD4+ Tregs, associated with increased expression of glucocorticoid-induced TNFR-related protein (GITR), compared with matched healthy donors. One participant with a raised HbA1c at the time of assessment had a different Treg profile compared with both slow progressors and matched controls. Functional assays demonstrated that Treg-mediated suppression of CD4+ effector T cells from slow progressors was significantly impaired, compared with healthy donors. However, effector CD4+ T cells from slow progressors were more responsive to Treg suppression compared with healthy donors, demonstrated by increased suppression of CD25 and CD134 expression on effector CD4+ T cells. Conclusions/interpretations We conclude that activated memory CD4+ Tregs from slow progressors are expanded and enriched for GITR expression, highlighting the need for further study of Treg heterogeneity in individuals at risk of developing type 1 diabetes.Diabetes UKJDR

Recombination rate and selection strength in HIV intra-patient evolution

The evolutionary dynamics of HIV during the chronic phase of infection is driven by the host immune response and by selective pressures exerted through drug treatment. To understand and model the evolution of HIV quantitatively, the parameters governing genetic diversification and the strength of selection need to be known. While mutation rates can be measured in single replication cycles, the relevant effective recombination rate depends on the probability of coinfection of a cell with more than one virus and can only be inferred from population data. However, most population genetic estimators for recombination rates assume absence of selection and are hence of limited applicability to HIV, since positive and purifying selection are important in HIV evolution. Here, we estimate the rate of recombination and the distribution of selection coefficients from time-resolved sequence data tracking the evolution of HIV within single patients. By examining temporal changes in the genetic composition of the population, we estimate the effective recombination to be r=1.4e-5 recombinations per site and generation. Furthermore, we provide evidence that selection coefficients of at least 15% of the observed non-synonymous polymorphisms exceed 0.8% per generation. These results provide a basis for a more detailed understanding of the evolution of HIV. A particularly interesting case is evolution in response to drug treatment, where recombination can facilitate the rapid acquisition of multiple resistance mutations. With the methods developed here, more precise and more detailed studies will be possible, as soon as data with higher time resolution and greater sample sizes is available.Comment: to appear in PLoS Computational Biolog

Risk factors for falls in adults with rheumatoid arthritis: a prospective study.

OBJECTIVE: To investigate the association between potential risk factors and falls in community-dwelling adults with rheumatoid arthritis (RA). METHODS: We followed patients for 1 year of followup in a prospective cohort study with monthly falls calendars and telephone calls. Lower extremity muscle strength, postural stability, number of swollen and tender joints, functional status, history of falling, fear of falling, pain, fatigue, medication, and use of steroids were assessed as risk factors for falls. RESULTS: A total of 386 women and 173 men with RA (n = 559) ages 18-88 years completed baseline assessments and 535 participants (96%) completed 1-year followup. Bivariate logistic regression showed that falls risk was not associated with age or sex. Multivariate logistic regression revealed that a history of multiple falls in the previous 12 months was the most significant predictive risk factor (odds ratio [OR] 5.3, 95% confidence interval [95% CI] 2.3-12.3). The most significant modifiable risk factors were swollen and tender lower extremity joints (OR 1.7, 95% CI 1.1-2.7), psychotropic medication (OR 1.8, 95% CI 1.1-3.1), and fatigue (OR 1.13, 95% CI 1.02-1.2). CONCLUSION: Adults with RA are at high risk of falls. In clinical practice, high-risk fall patients with RA can be identified by asking whether patients have fallen in the past year. Important risk factors highlighted in this study include swollen and tender lower extremity joints, fatigue, and use of psychotropic medications

Predictability of evolutionary trajectories in fitness landscapes

Experimental studies on enzyme evolution show that only a small fraction of all possible mutation trajectories are accessible to evolution. However, these experiments deal with individual enzymes and explore a tiny part of the fitness landscape. We report an exhaustive analysis of fitness landscapes constructed with an off-lattice model of protein folding where fitness is equated with robustness to misfolding. This model mimics the essential features of the interactions between amino acids, is consistent with the key paradigms of protein folding and reproduces the universal distribution of evolutionary rates among orthologous proteins. We introduce mean path divergence as a quantitative measure of the degree to which the starting and ending points determine the path of evolution in fitness landscapes. Global measures of landscape roughness are good predictors of path divergence in all studied landscapes: the mean path divergence is greater in smooth landscapes than in rough ones. The model-derived and experimental landscapes are significantly smoother than random landscapes and resemble additive landscapes perturbed with moderate amounts of noise; thus, these landscapes are substantially robust to mutation. The model landscapes show a deficit of suboptimal peaks even compared with noisy additive landscapes with similar overall roughness. We suggest that smoothness and the substantial deficit of peaks in the fitness landscapes of protein evolution are fundamental consequences of the physics of protein folding.Comment: 14 pages, 7 figure