174 research outputs found

    Comparison of Space-Plant Versus Sward Plot Selection in Thickspike Wheatgrass (\u3ci\u3eElymus lanceolatus\u3c/i\u3e)

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    Thickspike wheatgrass (Elymus lanceolatus [Scribn. & J.G. Sm.] Gould) is an important native perennial grass species used for rangeland revegetation in North America. Plant breeding efforts relying on space‐plant evaluations have resulted in limited improvement in this species. The purpose of this study was to characterize the performance of thickspike wheatgrass half‐sib families under space‐plant and sward plot evaluations, estimate the correlation between measured traits in both evaluation settings, and determine the validity of selecting thickspike wheatgrass for rangeland revegetation in the nontarget environment space‐plant plots. The study included 50 thickspike wheatgrass half‐sib families and five commercial cultivars and experimental populations which were evaluated over 3 years in space‐plant and sward plot evaluations at a field site in Box Elder County, Utah, USA. Collected data included stand percentage, flag leaf height, and herbage dry mass. Narrow‐sense heritability estimates were low to moderate (h2 \u3c 0.60) and Spearman and genetic correlation estimates among traits were also generally low to moderate. Overall, there was little evidence to suggest the use space‐plant evaluations in thickspike wheatgrass improvement programmes

    Biomass Yield Stability in Alfalfa

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    In addition to biomass production, alfalfa (Medicago sativa) cultivars also need to express yield stability across diverse environments. The objective of this experiment was to analyze the nature of biomass yield stability in ten commercial alfalfa cultivars by evaluating performance of individual genotypes. Biomass yield was measured in each of five environments across two years, and the yield stability computed for the overall cultivar mean performance and the mean performance of each of the genotypes comprising the cultivars using the genotype x environment variance statistic of Shukla and the superiority statistic of Lin and Binns\u27. The GxE variance of the cultivars was not correlated with the mean GxE variance of the genotypes comprising the cultivar. A strong positive correlation was observed between the superiority value of the cultivar as a whole and the mean superiority value of its genotypes. Alfalfa cultivars can be stable, as measured by the GxE variance, without being composed of stable genotypes. However, cultivars identified as superior only result if the individual genotypes are also superior. The top 10% of individual genotypes selected based on GxE variance do not include any genotypes with high yield. However, truncation based on the superiority statistic selected seven of the ten rap yielding genotypes. It seems that for an applied breeding program selection based on the superiority statistic would have a greater chance of improving yield and yield stability concurrently

    Adiposity, Cardiometabolic Risk, and Vitamin D Status: The Framingham Heart Study

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    OBJECTIVE: Because vitamin D deficiency is associated with a variety of chronic diseases, understanding the characteristics that promote vitamin D deficiency in otherwise healthy adults could have important clinical implications. Few studies relating vitamin D deficiency to obesity have included direct measures of adiposity. Furthermore, the degree to which vitamin D is associated with metabolic traits after adjusting for adiposity measures is unclear. RESEARCH DESIGN AND METHODS: We investigated the relations of serum 25-hydroxyvitamin D (25[OH]D) concentrations with indexes of cardiometabolic risk in 3,890 nondiabetic individuals; 1,882 had subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) volumes measured by multidetector computed tomography (CT). RESULTS: In multivariable-adjusted regression models, 25(OH)D was inversely associated with winter season, waist circumference, and serum insulin (P < 0.005 for all). In models further adjusted for CT measures, 25(OH)D was inversely related to SAT (−1.1 ng/ml per SD increment in SAT, P = 0.016) and VAT (−2.3 ng/ml per SD, P < 0.0001). The association of 25(OH)D with insulin resistance measures became nonsignificant after adjustment for VAT. Higher adiposity volumes were correlated with lower 25(OH)D across different categories of BMI, including in lean individuals (BMI <25 kg/m2). The prevalence of vitamin D deficiency (25[OH]D <20 ng/ml) was threefold higher in those with high SAT and high VAT than in those with low SAT and low VAT (P < 0.0001). CONCLUSIONS: Vitamin D status is strongly associated with variation in subcutaneous and especially visceral adiposity. The mechanisms by which adiposity promotes vitamin D deficiency warrant further study.National Institutes of Health's National Heart, Lung, and Blood Institute (N01-HC-25195, R01-DK-80739): American Heart Associatio

    Characterization of Testing Locations for Developing Cool-Season Grass Species

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    The identification of best testing locations facilitates the allocation of resources in a breeding program, allowing emphasis to be placed at the sites best suited for identifying superior plant materials for the target environment. The objective of this study was the identification of best locations for the evaluation and testing of cool-season grass species within the Northern Great Plains and Intermountain regions of the USA. This study also sought to subdivide the locations into meaningful environmental groupings based on similar entry performance. The study characterized initial stand frequency and forage production (over a 3-yr period) of crested wheatgrass [Agropyron cristatum (L.) Gaertn.; A. desertorum (Fisch. ex Link) Schultes; A. fragile (Roth) Candargy], intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D.R. Dewey], and smooth bromegrass (Bromus inermis Leyss.) at six locations within these regions. Results suggested the existence of best testing locations and environmental groupings for each of the species. For example, the Ithaca, NE, location was consistently a good location for testing forage production. Although there were some consistencies, generally, the best testing locations and environmental groupings were species and trait specific. Thus, the targeted use of locations appeared to be most useful on an individual species basis, rather than considered across the cool-season grass species

    Genome-Wide Association with Select Biomarker Traits in the Framingham Heart Study

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    BACKGROUND: Systemic biomarkers provide insights into disease pathogenesis, diagnosis, and risk stratification. Many systemic biomarker concentrations are heritable phenotypes. Genome-wide association studies (GWAS) provide mechanisms to investigate the genetic contributions to biomarker variability unconstrained by current knowledge of physiological relations. METHODS: We examined the association of Affymetrix 100K GeneChip single nucleotide polymorphisms (SNPs) to 22 systemic biomarker concentrations in 4 biological domains: inflammation/oxidative stress; natriuretic peptides; liver function; and vitamins. Related members of the Framingham Offspring cohort (n = 1012; mean age 59 ± 10 years, 51% women) had both phenotype and genotype data (minimum-maximum per phenotype n = 507–1008). We used Generalized Estimating Equations (GEE), Family Based Association Tests (FBAT) and variance components linkage to relate SNPs to multivariable-adjusted biomarker residuals. Autosomal SNPs (n = 70,987) meeting the following criteria were studied: minor allele frequency ≥ 10%, call rate ≥ 80% and Hardy-Weinberg equilibrium p ≥ 0.001. RESULTS: With GEE, 58 SNPs had p < 10-6: the top SNPs were rs2494250 (p = 1.00*10-14) and rs4128725 (p = 3.68*10-12) for monocyte chemoattractant protein-1 (MCP1), and rs2794520 (p = 2.83*10-8) and rs2808629 (p = 3.19*10-8) for C-reactive protein (CRP) averaged from 3 examinations (over about 20 years). With FBAT, 11 SNPs had p < 10-6: the top SNPs were the same for MCP1 (rs4128725, p = 3.28*10-8, and rs2494250, p = 3.55*10-8), and also included B-type natriuretic peptide (rs437021, p = 1.01*10-6) and Vitamin K percent undercarboxylated osteocalcin (rs2052028, p = 1.07*10-6). The peak LOD (logarithm of the odds) scores were for MCP1 (4.38, chromosome 1) and CRP (3.28, chromosome 1; previously described) concentrations; of note the 1.5 support interval included the MCP1 and CRP SNPs reported above (GEE model). Previous candidate SNP associations with circulating CRP concentrations were replicated at p < 0.05; the SNPs rs2794520 and rs2808629 are in linkage disequilibrium with previously reported SNPs. GEE, FBAT and linkage results are posted at . CONCLUSION: The Framingham GWAS represents a resource to describe potentially novel genetic influences on systemic biomarker variability. The newly described associations will need to be replicated in other studies.National Heart, Lung, and Blood Institute's Framingham Heart Study (N01-HC25195); National Institutes of Health National Center for Research Resources Shared Instrumentation grant (1S10RR163736-01A1); National Institutes of Health (HL064753, HL076784, AG028321, HL71039, 2 K24HL04334, 1K23 HL083102); Doris Duke Charitable Foundation; American Diabetes Association Career Developement Award; National Center for Research Resources (GCRC M01-RR01066); US Department of Agriculture Agricultural Research Service (58-1950-001, 58-1950-401); National Institute of Aging (AG14759

    Stand Establishment and Persistence of Perennial Cool-Season Grasses in the Intermountain West and the Central and Northern Great Plains

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    The choice of plant materials is an important component of revegetation following disturbance. To determine the utility and effectiveness of various perennial grass species for revegetation on varied landscapes, a meta analysis was used to evaluate the stand establishment and persistence of 18 perennial cool-season grass species in 34 field studies in the Intermountain and Great Plains regions of the United States under monoculture conditions. Combined across the 34 studies, stand establishment values ranged from 79% to 43% and stand persistence values ranged from 70% to 0%. Intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D. R. Dewey), tall wheatgrass (Thinopyrum ponticum [Podp.] Z.-W. Liu & R.-C. Wang), crested wheatgrass (Agropyron spp.), Siberian wheatgrass (Agropyron fragile [Roth] P. Candargy), and meadow brome (Bromus riparius Rehmann) possessed the highest stand establishment (≥69%). There were no significant differences among the 12 species with the largest stand persistence values. Basin wildrye (Leymus cinereus (Scribn. & Merr.) A. Love), Altai wildrye (Leymus angustus [Trin.] Pilg.), slender wheatgrass (Elymus trachycaulus [Link] Gould ex Shinners), squirreltail (Elymus spp.), and Indian ricegrass (Achnatherum hymenoides [Roem. & Schult.] Barkworth) possessed lower stand persistence (≤32%) than the majority of the other species, and Indian ricegrass (0%) possessed the lowest stand persistence of any of the species. Correlations between environmental conditions and stand establishment and persistence showed mean annual study precipitation to have the most consistent, although moderate effect (r=~0.40) for establishment and persistence. This relationship was shown by the relatively poor stand establishment and persistence of most species at sites receiving less than 310 mm of annual precipitation. These results will be a tool for land managers to make decisions concerning the importance of stand establishment, stand persistence, and annual precipitation for revegetation projects on disturbed sites

    Coordination as a function of skill level in the gymnastics longswing

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    The purpose of this study was to investigate the nature of inter-joint coordination at different levels of skilled performance to: (1) distinguish learners who were successful versus unsuccessful in terms of their task performance; (2) investigate the pathways of change during the learning of a new coordination pattern and (3) examine how the learner’s coordination patterns relate to those of experts in the longswing gymnastics skill. Continuous relative phase of hip and shoulder joint motions was examined for longswings performed by two groups of novices, successful (n = 4) and unsuccessful (n = 4) over five practice sessions, and two expert gymnasts. Principal component analysis showed that during longswing positions where least continuous relative phase variability occurred for expert gymnasts, high variability distinguished the successful from the unsuccessful novice group. Continuous relative phase profiles of successful novices became more out-of-phase over practice and less similar to the closely in-phase coupling of the expert gymnasts. Collectively, the findings support the proposition that at the level in inter-joint coordination a technique emerges that facilitates successful performance but is not more like an expert’s movement coordination. This finding questions the appropriateness of inferring development towards a “gold champion” movement coordination

    Improving the Deaf community's access to prostate and testicular cancer information: a survey study

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    BACKGROUND: Members of the Deaf community face communication barriers to accessing health information. To resolve these inequalities, educational programs must be designed in the appropriate format and language to meet their needs. METHODS: Deaf men (102) were surveyed before, immediately following, and two months after viewing a 52-minute prostate and testicular cancer video in American Sign Language (ASL) with open text captioning and voice overlay. To provide the Deaf community with information equivalent to that available to the hearing community, the video addressed two cancer topics in depth. While the inclusion of two cancer topics lengthened the video, it was anticipated to reduce redundancy and encourage men of diverse ages to learn in a supportive, culturally aligned environment while also covering more topics within the partnership's limited budget. Survey data were analyzed to evaluate the video's impact on viewers' pre- and post-intervention understanding of prostate and testicular cancers, as well as respondents' satisfaction with the video, exposure to and use of early detection services, and sources of cancer information. RESULTS: From baseline to immediately post-intervention, participants' overall knowledge increased significantly, and this gain was maintained at the two-month follow-up. Men of diverse ages were successfully recruited, and this worked effectively as a support group. However, combining two complex cancer topics, in depth, in one video appeared to make it more difficult for participants to retain as many relevant details specific to each cancer. Participants related that there was so much information that they would need to watch the video more than once to understand each topic fully. When surveyed about their best sources of health information, participants ranked doctors first and showed a preference for active rather than passive methods of learning. CONCLUSION: After viewing this ASL video, participants showed significant increases in cancer understanding, and the effects remained significant at the two-month follow-up. However, to achieve maximum learning in a single training session, only one topic should be covered in future educational videos

    Credibility in Policy Expertise: The Function of Boundaries Between Research and Policy

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    As science becomes an increasingly crucial resource for addressing complex challenges in society, extensive demands are placed upon the researchers who produce it. Creating valuable expert knowledge that intervenes in policy or practice requires knowledge brokers to facilitate interactions at the boundary between research and policy. Yet, existing research lacks a compelling account of the ways in which brokerage is performed to gain credibility. Drawing on mixed-method analysis of twelve policy research settings, I outline a novel set of strategies for attaining symbolic power, whereby policy experts position themselves and others via conceptual distances drawn between the ‘world of ideas’ and the ‘world of policy and practice’. Disciplinary distance works to situate research as either disciplinary or undisciplinary, epistemic distance creates a boundary between complex specialist research and direct digestible outputs, temporal distance represents the separation of slow rigorous research and agile responsive analysis, and economic distance situates research as either pure and intrinsic or marketable and fundable. I develop a theoretical account that unpacks the boundaries between research communities and shows how these boundaries permit policy research actors to achieve various strategic aims.ESRC Future Research Leaders ES/N016319/1 Commonwealth Scholarship Commissio

    Does methylphenidate improve inhibition and other cognitive abilities in adults with childhood-onset ADHD?

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    Contains fulltext : 48908.pdf (publisher's version ) (Closed access)We examined the effect of methylphenidate (Mph) on inhibition and several other cognitive abilities in 43 adults with Attention Deficit Hyperactivity Disorder (ADHD) by use of Conners' Continuous Performance Test (CPT) and the Change Task (ChT), an extension of the Stop Signal Test (SST). In a double blind, cross-over, placebo controlled study with Mph, tests were administered during the third week of individually titrated treatment with Mph (maximum dose 1 mg / kg / day) and during the third week of treatment with placebo. We established large medication effects for commission errors, standard error of mean reaction time, and attentiveness on the CPT, as well as moderate medication effects for mean reaction time on the CPT and response re-engagement speed on the ChT. For Stop Signal Reaction Time (SSRT) on the ChT, we also established large effects of Mph, but only in a group of participants who showed slow SSRTs on placebo. Mph indeed ameliorates inhibition, which is the core problem of ADHD, and certain other cognitive abilities in adults with ADHD
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