Simulation synergy : expanding TRNSYS capabilities and usability

Developers of simulation packages are now able to take advantage of the increase in available desktop computing power to expand the capabilities and usability of their programs. This paper will illustrate these opportunities by discussing the different techniques the developers of the TRNSYS software package have used to try and create a synergy between TRNSYS and external programs and between the developers and users of the program

Spectral Wave Decay Due to Bottom Friction on the Inner Shelf

LONG-TERM GOALS: Long term goals are to observe and model wave and current boundary layer processes to determine to wave dissipation and wave-bed interactions in coastal and nearshore regions using novel instrumentation techniques.Award#: N0001499WR3001

Retention in Continuous Care and Sustained Viral Suppression: Examining the Association Among Individuals Living with HIV

Objectives: To examine the relationship between retention in continuous care and sustained viral suppression. Methods: The authors retrospectively followed 653 persons who were virally suppressed and seeking care at an infectious disease clinic in Kentucky for an average of 6 years to determine the rates of retention in medical care (≥2 visits separated by ≥3 months within a 12-month period) and sustained viral suppression (\u3c400 copies/mL). A generalized linear mixed model was used to determine an association between retention and suppression over time. Results: Approximately 61% of the study population were retained in continuous care and 75% had sustained viral suppression for all patient-years. Persons retained in care were 3 times the odds of sustaining viral suppression over time (P \u3c .001). Conclusion: Retention is essential to achieving and maintaining viral suppression. Strategies should be set in place that emphasize increasing the rates of retention, which in turn may increase the rates of suppression

Near Shore Wave Processes

LONG-TERM GOALS: Long-term goals are to predict the wave-induced three-dimensional velocity field and induced sediment transport over arbitrary bathymetry in the near shore given the offshore wave conditions.Award #s: N0001499WR30116||N0001499WR30098||N0001499WR30146||N0001499WR30147Award #’s: N0001402WR20188, N0001402WR20376, N0001402WR2015

Impact of Poor Retention in HIV Medical Care on Time to Viral Load Suppression

Objective: The purpose of this study was to evaluate how poor retention in HIV care impacts time to viral suppression after initiating highly active antiretroviral therapy. Methods: A retrospective cohort study design, employing a medical chart review, was conducted at an academic infectious disease clinic at the University of Kentucky. Patients seeking care between 2003 and 2011 were included in the study. A log-normal model was employed to determine the factors associated with time to viral suppression. Results: Of the 532 patients in the study, 426 (80.1%) patients were virally suppressed. Controlling for insurance status, race, baseline CD4 counts, and viral loads, the expected time to viral suppression for nonoptimal retainers was longer compared to optimal retainers (100% retained in care; time ratio: 2.04; 95% confidence interval: 1.40-2.90). Conclusion: Researchers should continue to study the impact of retention on clinical outcomes and strategies to improve retention and reengage those lost to follow-up back into care. © The Author(s) 2013

Genetic variation modifies risk for neurodegeneration based on biomarker status

Background: While a great deal of work has gone into understanding the relationship between CSF biomarkers, brain atrophy, and disease progression, less work has attempted to investigate how genetic variation modifies these relationships. The goal of this study was two-fold. First, we sought to identify high-risk v. low-risk individuals based on their CSF tau and Aβ load and characterize these individuals with regard to brain atrophy in an AD-relevant region of interest. Next, we sought to identify genetic variants that modified the relationship between biomarker classification and neurodegeneration.Methods: Participants were categorized based on established cut-points for biomarker positivity. Mixed model regression was used to quantify longitudinal change in the left inferior lateral ventricle. Interaction analyses between single nucleotide polymorphisms (SNPs) and biomarker group status were performed using a genome wide association study (GWAS) approach. Correction for multiple comparisons was performed using the Bonferroni procedure. Results: One intergenic SNP (rs4866650) and one SNP within the SPTLC1 gene (rs7849530) modified the association between amyloid positivity and neurodegeneration. A transcript variant of WDR11-AS1 gene (rs12261764) modified the association between tau positivity and neurodegeneration. These effects were consistent across the two sub-datasets and explained approximately 3% of variance in ventricular dilation. One additional SNP (rs6887649) modified the association between amyloid positivity and baseline ventricular volume, but was not observed consistently across the sub-datasets.Conclusions: Genetic variation modifies the association between AD biomarkers and neurodegeneration. Genes that regulate the molecular response in the brain to oxidative stress may be particularly relevant to neural vulnerability to the damaging effects of amyloid-β

Hospital readmissions for COPD:a retrospective longitudinal study

Prevention of chronic obstructive pulmonary disease hospital readmissions is an international priority aimed to slow disease progression and limit costs. Evidence of the risk of readmission and of interventions that might prevent it is lacking. We aimed to determine readmission risk for chronic obstructive pulmonary disease, factors influencing that risk, and variation in readmission risk between hospitals across 7.5 million people in London. This retrospective longitudinal observational study included all chronic obstructive pulmonary disease admissions to any hospital in the United Kingdom among patients registered at London general practices who had emergency National Health Service chronic obstructive pulmonary disease hospital admissions between April 2006 and March 2010. Influence of patient characteristics, geographical deprivation score, length of stay, day of week of admission or of discharge, and admitting hospital, were assessed using multiple logistic regression. 38,894 chronic obstructive pulmonary disease admissions of 20,932 patients aged ≥ 45 years registered with London general practices were recorded. 6295 patients (32.2%) had at least one chronic obstructive pulmonary disease readmission within 1 year. 1993 patients (10.2%) were readmitted within 30 days and 3471 patients (17.8%) were readmitted within 90 days. Age and patient geographical deprivation score were very weak predictors of readmission. Rates of chronic obstructive pulmonary disease readmissions within 30 days and within 90 days did not vary among the majority of hospitals. The finding of lower chronic obstructive pulmonary disease readmission rates than was previously estimated and the limited variation in these rates between hospitals suggests that the opportunity to reduce chronic obstructive pulmonary disease readmission risk is small

Persistence of Macrocytosis After Discontinuation of Zidovudine in HIV-Infected Patients

The duration of macrocytosis after stopping zidovudine (ZDV) is unknown. Among 104 HIV-infected patients treated with ZDV for more than 1 year, 84 patients had macrocytosis at ZDV discontinuation. The median mean corpuscular volume (MCV) was 114.6 fL (range 100-128 fL). Patients were divided into 2 groups: those who did (resolved macrocytosis, n = 36) and did not (persistent macrocytosis, n = 48) normalize MCV at 3 to 6 months after ZDV discontinuation. Alcohol use (P = .02), smoking (P = .03), and lower (but within normal range) folic acid levels (P = .05) were related to the persistence of macrocytosis. A persistence of macrocytosis was observed in 57% at 3 to 6 months, 38% at 1 year and 37% at 2 years after ZDV therapy had stopped. Duration of ZDV therapy did not have an effect on the persistence of macrocytosis (P = .73). The median time for the MCV to normalize after stopping ZDV was 12.5 months

Accuracy of Gene Expression Prediction From Genotype Data With PrediXcan Varies Across and Within Continental Populations

Using genetic data to predict gene expression has garnered significant attention in recent years. PrediXcan has become one of the most widely used gene-based methods for testing associations between predicted gene expression values and a phenotype, which has facilitated novel insights into the relationship between complex traits and the component of gene expression that can be attributed to genetic variation. The gene expression prediction models for PrediXcan were developed using supervised machine learning methods and training data from the Depression Genes and Networks (DGN) study and the Genotype-Tissue Expression (GTEx) project, where the majority of subjects are of European descent. Many genetic studies, however, include samples from multi-ethnic populations, and in this paper we evaluate the accuracy of PrediXcan for predicting gene expression in diverse populations. Using transcriptomic data from the GEUVADIS (Genetic European Variation in Disease) RNA sequencing project and whole genome sequencing data from the 1000 Genomes project, we evaluate and compare the predictive performance of PrediXcan in an African population (Yoruban) and four European ancestry populations for thousands of genes. We evaluate a range of models from the PrediXcan weight databases and use Pearson's correlation coefficient to assess gene expression prediction accuracy with PrediXcan. From our evaluation, we find that the predictive performance of PrediXcan varies substantially among populations from different continents (F-test p-value < 2.2 × 10−16), where prediction accuracy is lower in the Yoruban population from West Africa compared to the European-ancestry populations. Moreover, not only do we find differences in predictive performance between populations from different continents, we also find highly significant differences in prediction accuracy among the four European ancestry populations considered (F-test p-value < 2.2 × 10−16). Finally, while there is variability in prediction accuracy across different PrediXcan weight databases, we also find consistency in the qualitative performance of PrediXcan for the five populations considered, with the African ancestry population having the lowest accuracy across databases

Locating poor livestock keepers at the global level for research and development targeting

P.K. Thornton, R.L. Kruska, P.M. Kristjanson, R.S. Reid and T.P. Robinson are ILRI authorsMany research and development agencies are committed to halving the number of people living in extreme poverty by 2015. Knowledge of where the poor are, and what characterises them, is patchy at best. Here we describe a global livestock and poverty mapping study designed to assist in targeting research and development activities concerning livestock. Estimates of the numbers of poor livestock keepers by production system and region are presented. While these estimates suffer from various problems, improvements in global databases are critical to improve the targeting of interventions that can meet the challenges posed by poverty and to chart progress against international development indicators