176 research outputs found
Re-test of Rhinocyllus conicus host specificity, and the prediction of ecological risk in biological control
Biological control is proposed as an ecological strategy to manage the threat of invasive plants, especially in natural areas. To pursue this strategy, we need to know that the host specificity criteria used to evaluate ecological risk with deliberate introduction of an exotic insect for biocontrol are sufficient to predict potential impact on native species. Host specificity is defined by adult feeding and oviposition preferences and larval development. One way to evaluate the criteria is to re-examine case histories where ecological effects are recorded, such as that of Rhinocyllus conicus Frölich. This flower head weevil, released in North America in 1968 to control exotic thistles like Musk thistle (Carduus nutans L), is now reducing seed production by multiple native North American thistle species (Cirsium spp.), and local population density of Platte thistle (Cirsium canescens Nutt.). We hypothesized that host specificity of R. conicus has changed since pre-release testing, providing an explanation for the unexpected magnitude of the documented ecological effects. Instead, when we re-tested host specificity of weevils naturalized over 28 generations, we found that host specificity has not changed. Naturalized adults of R. conicus showed strong feeding and oviposition preference for Musk thistle over Platte thistle. In addition, larval development by these weevils was faster and more successful (to larger size) on Musk thistle than on Platte thistle. Thus, our results indicate that a change in host specificity cannot explain the unexpectedly large build-up of R. conicus and significant ecological effect on Platte thistle. We conclude that accurate prediction of the potential level of impact on native host plants in the field requires further ecological information in addition to host specificity
The Literacy Proficiencies of Oregon Tanf Recipients : A Human Capital Approach
On August 22, 1996, President Clinton signed new legislation that dismantled the United State\u27s welfare system. Consequently, thousands of welfare recipients had to move into the work-force. It is essential to discover if former welfare recipients are prepared to obtain employment and achieve self-sufficiency. Previous research suggests that human capital assets, such as level of literacy proficiency and grade completed in school are important factors in predicting welfare receipt. The purpose of this study is to investigate how literacy skills are associated with having received TANF for people without a high school degree or GED. The 941 subjects were located in the Portland, metropolitan area and were between the ages of 18-44.
Using data from Wave 1 of the Longitudinal Study of Adult Literacy, a quantitative analysis was conducted in order to investigate the following two hypotheses: For people with low-levels of education, there will be a strong, inverse relationship between literacy proficiency and having received T ANF; In a multivariate context, after controlling for other relevant variables, a statistically significant relationship between literacy proficiency and T ANF receipt will exist.
The Pearson\u27s correlation for literacy proficiency and TANF receipt is - .026, but statistical significance was not achieved. Consequently, support cannot be concluded for the first hypothesis. When all pertinent variables are properly controlled for in a multivariate logistic regression model, statistical significance was achieved for the association between literacy proficiency and having received TANF, but the effect was not in the expected direction. Therefore, the second hypothesis also was not supported.
This study yielded mixed results and no definitive statement can be made about how human capital assets affect the likelihood of having received T ANF. However, literacy proficiency, when other important factors are controlled for, do appear to be important. Future research is needed in order to better understand the relationship between human capital assets and having received T ANF. It is essential that social science researchers continue to uncover the complex forces at work in the lives of welfare recipients so that we can better aid them in their journey to self-sufficiency
Linking remote sensing and various site factors for predicting the spatial distribution of eastern hemlock occurrence and relative basal area in Maine, USA
Introduced invasive pests are perhaps the most important and persistent catalyst for changes in forest composition. Infestation and outbreak of the hemlock woolly adelgid (Adelges tsugae; HWA) along the eastern coast of the USA, has led to widespread loss of hemlock (Tsuga canadensis (L.) Carr.), and a shift in tree species composition toward hardwood stands. Developing an understanding of the geographic distribution of individual species can inform conservation practices that seek to maintain functional capabilities of ecosystems. Modeling is necessary for understanding changes in forest composition, and subsequent changes in biodiversity, and one that can be implemented at the species level. By integrating the use of remote sensing, modeling, and Geographic Information Systems (GIS) coupled with expert knowledge in forest ecology and disturbance, we can advance the methodologies currently available in the literature on predictive modeling. This paper describes an approach to modeling the spatial distribution of the less common but foundational tree species eastern hemlock throughout the state of Maine (∼84,000 km2) at a high resolution. There are currently no published accuracy assessments on predictive models for high resolution continuous distribution of eastern hemlock relative basal area that span the geographic extent covered by our model, which is at the northern limit of the species’ range. A two stage mapping approach was used where presence/absence was predicted with an overall accuracy of 85% and the continuous distribution (percent basal area) was predicted with an accuracy of 84%. Overall, these findings are quite good despite high variability in the training dataset and the general minor component that eastern hemlock represents in the primary forest types in Maine. Eastern hemlock occurs along the southern half of the state stretching the east-west span with little to no occurrence in the northern regions. Several environmental and site characteristics, particularly average yearly maximum and minimum temperatures, were found to be positively correlated with hemlock occurrence. Eastern hemlock dominated stands appeared predominantly in the southwest corner of the state where HWA monitoring efforts can be focused. Given the importance of climate variables in predicting eastern hemlock, forecasts of future range shifts should be possible using data generated from climate scenarios
Two Maine Forest Pests: A Comparison of Approaches to Understanding Threats to Hemlock and Ash Trees in Maine
The authors describe two invasive insect forest pests; the hemlock wooly adelgid (HWA) has already arrived in Maine, and the emerald ash borer (EAB) has not yet reached Maine, but will have a devastating effect on the state’s Indian basketmakers when it does arrive. With funding through Maine’s Sustainability Solutions Initiative, teams based at the University of Maine and Unity College are bringing together faculty, students, and stakeholders to better understand the threats that infestations pose to the ecology and economy of the Maine’s forests and to longstanding cultural practices
Pharmacogenetic Association of NOS3 Variants with Cardiovascular Disease in Patients with Hypertension: The GenHAT Study
Nitric oxide synthase 3 (NOS3) catalyzes production of NO in the endothelium and may play a role in cardiovascular disease (CVD). We assessed the pharmacogenetic associations of three NOS3 polymorphisms and three antihypertensive drugs with CVD outcomes. Hypertensive subjects (n = 30,280) from a multi-center, double-blind clinical trial were randomized to chlorthalidone, amlodipine, or lisinopril treatment (mean follow up, 4.9 years). Outcomes included coronary heart disease (CHD: fatal CHD and nonfatal myocardial infarction); stroke; heart failure (fatal, requiring hospitalization, or outpatient treatment); all-cause mortality; and end-stage renal disease (ESRD). Main effects of NOS3 variants on outcome and genotype-treatment interactions were tested. For NOS3 −690 C>T (rs3918226), a higher hazard ratio (HR) was found in minor allele carriers for CHD (CC = 1.00, CT+TT = 1.12 (95% confidence interval (CI) = 1.00–1.26), P = 0.048). For NOS3 −922 A>G (rs1800779), a higher HR was found in minor allele carriers for heart failure (AA = 1.00, AG+GG = 1.10 (CI = 1.00–1.21), P = 0.046). Significant pharmacogenetic findings were observed for stroke and all-cause mortality. For −690 C>T, a lower HR was observed for stroke in minor allele carriers when treated with amlodipine versus lisinopril (CC = 0.85 (CI = 0.73–0.99), CT+TT = 0.49 (CI = 0.31–0.80), P = 0.04). For glu298asp G>T (rs1799983), a lower HR was observed for all-cause mortality in minor allele carriers when treated with amlodipine versus lisinopril (GG = 1.01 (CI = 0.91–1.13), GT+TT = 0.85 (CI = 0.75–0.97), P = 0.04). We observed significant associations with NOS3 variants and CHD and heart failure and significant pharmacogenetic effects for stroke and all cause mortality. This suggests that NOS3 variants may potentially provide useful clinical information with respect to treatment decisions in the future
Whole-Exome Sequencing and hiPSC Cardiomyocyte Models Identify \u3ci\u3eMYRIP\u3c/i\u3e, \u3ci\u3eTRAPPC11\u3c/i\u3e, and \u3ci\u3eSLC27A6\u3c/i\u3e of Potential Importance to Left Ventricular Hypertrophy in an African Ancestry Population
Background: Indices of left ventricular (LV) structure and geometry represent useful intermediate phenotypes related to LV hypertrophy (LVH), a predictor of cardiovascular (CV) disease (CVD) outcomes.
Methods and Results: We conducted an exome-wide association study of LV mass (LVM) adjusted to height2.7, LV internal diastolic dimension (LVIDD), and relative wall thickness (RWT) among 1,364 participants of African ancestry (AAs) in the Hypertension Genetic Epidemiology Network (HyperGEN). Both single-variant and gene-based sequence kernel association tests were performed to examine whether common and rare coding variants contribute to variation in echocardiographic traits in AAs. We then used a data-driven procedure to prioritize and select genes for functional validation using a human induced pluripotent stem cell cardiomyocyte (hiPSC-CM) model. Three genes [myosin VIIA and Rab interacting protein (MYRIP), trafficking protein particle complex 11 (TRAPPC11), and solute carrier family 27 member 6 (SLC27A6)] were prioritized based on statistical significance, variant functional annotations, gene expression in the hiPSC-CM model, and prior biological evidence and were subsequently knocked down in the hiPSC-CM model. Expression profiling of hypertrophic gene markers in the knockdowns suggested a decrease in hypertrophic expression profiles. MYRIP knockdowns showed a significant decrease in atrial natriuretic factor (NPPA) and brain natriuretic peptide (NPPB) expression. Knockdowns of the heart long chain fatty acid (FA) transporter SLC27A6 resulted in downregulated caveolin 3 (CAV3) expression, which has been linked to hypertrophic phenotypes in animal models. Finally, TRAPPC11 knockdown was linked to deficient calcium handling.
Conclusions: The three genes are biologically plausible candidates that provide new insight to hypertrophic pathways
Multi-Ancestry Sleep-by-SNP Interaction Analysis in 126,926 Individuals Reveals Lipid Loci Stratified by Sleep Duration
Both short and long sleep are associated with an adverse lipid profile, likely through different biological pathways. To elucidate the biology of sleep-associated adverse lipid profile, we conduct multi-ancestry genome-wide sleep-SNP interaction analyses on three lipid traits (HDL-c, LDL-c and triglycerides). In the total study sample (discovery + replication) of 126,926 individuals from 5 different ancestry groups, when considering either long or short total sleep time interactions in joint analyses, we identify 49 previously unreported lipid loci, and 10 additional previously unreported lipid loci in a restricted sample of European-ancestry cohorts. In addition, we identify new gene-sleep interactions for known lipid loci such as LPL and PCSK9. The previously unreported lipid loci have a modest explained variance in lipid levels: most notable, gene-short-sleep interactions explain 4.25% of the variance in triglyceride level. Collectively, these findings contribute to our understanding of the biological mechanisms involved in sleep-associated adverse lipid profiles
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Multi-ancestry study of blood lipid levels identifies four loci interacting with physical activity.
Many genetic loci affect circulating lipid levels, but it remains unknown whether lifestyle factors, such as physical activity, modify these genetic effects. To identify lipid loci interacting with physical activity, we performed genome-wide analyses of circulating HDL cholesterol, LDL cholesterol, and triglyceride levels in up to 120,979 individuals of European, African, Asian, Hispanic, and Brazilian ancestry, with follow-up of suggestive associations in an additional 131,012 individuals. We find four loci, in/near CLASP1, LHX1, SNTA1, and CNTNAP2, that are associated with circulating lipid levels through interaction with physical activity; higher levels of physical activity enhance the HDL cholesterol-increasing effects of the CLASP1, LHX1, and SNTA1 loci and attenuate the LDL cholesterol-increasing effect of the CNTNAP2 locus. The CLASP1, LHX1, and SNTA1 regions harbor genes linked to muscle function and lipid metabolism. Our results elucidate the role of physical activity interactions in the genetic contribution to blood lipid levels
Admixture Mapping of Quantitative Trait Loci for BMI in African Americans: Evidence for Loci on Chromosomes 3q, 5q, and 15q
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93743/1/oby_1443_sm_2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/93743/2/oby_1443_sm_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/93743/3/oby.2009.24.pd
Pharmacogenetic Associations of MMP9 and MMP12 Variants with Cardiovascular Disease in Patients with Hypertension
MMP-9 and -12 function in tissue remodeling and may play roles in cardiovascular disease (CVD). We assessed associations of four MMP polymorphisms and three antihypertensive drugs with cardiovascular outcomes.Hypertensives (n = 42,418) from a double-blind, randomized, clinical trial were randomized to chlorthalidone, amlodipine, lisinopril, or doxazosin treatment (mean follow up, 4.9 years). The primary outcome was coronary heart disease (CHD). Secondary outcomes included combined CHD, all CVD outcomes combined, stroke, heart failure (HF), and mortality. Genotype-treatment interactions were tested. = 0.015). for CHD and composite CVD. The data suggest that these genes may provide useful clinical information with respect to treatment decisions
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