oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 14 )

2018 ( 4 )

2017 ( 11 )

2016 ( 9 )

Custom range...

Search Results: 1 - 10 of 4614 matches for " Ryan Burns "
All listed articles are free for downloading (OA Articles)
Page 1 /4614
Display every page Item
The Glowing Pickle and Other Vegetables
Ryan Burns,Brian Das
International School Bangkok Journal of Physics , 2009,
Abstract: The phenomenon known as the glowing pickle was investigated. Voltages ranging from 80-140 Volts AC were placed across a variety of vegetable specimens, both fresh and soaked in several salt solutions. The glowing was caused by electric arcing across a steam-filled cavity in the specimen. The emission spectra showed lines indicating the presence of potassium and sodium ions in the fresh specimens. In the specimens soaked in salt solutions, emission spectra matching the salt ions were observed.
Concurrent and Criterion-Referenced Validity of Trunk Muscular Fitness Tests in School-Aged Children  [PDF]
Ryan D. Burns, James C. Hannon, Pedro F. Saint-Maurice, Gregory J. Welk
Advances in Physical Education (APE) , 2014, DOI: 10.4236/ape.2014.42007
Abstract:

A cause of limited physical activity levels in youth is the presence of low back pain (LBP), therefore proper assessment of low back function in physical education settings is needed to identify children who may be at risk. The purpose of this study was to determine the concurrent and criterion-referenced validity of field tests of low back and core muscular endurance in school-aged children. The sample consisted of 4th through 10th grade students (N = 370) who completed low back and core muscular fitness tests on four separate testing days during their physical education classes. Field measures related to low back function included the Box 90° Trunk Extension (Box 90°) and the FITNESSGRAM Trunk Extension (FG-TE). Field measures related to overall core function consisted of a Lateral Plank, Prone Plank, and a Static and Dynamic Curl-up. Criterion measures of low-back muscular endurance included the Parallel Roman Chair Dynamic Trunk Extension (PRC-DTE) and the Parallel Roman Chair Static Trunk Extension (PRC-STE). Multivariate analysis using canonical correlations showed moderate correlations between low back and core measures (P < .001). The Lateral Plank, Prone Plank, and Dynamic Curl-up had moderate-to-strong canonical cross-loadings with the low back measure variate. The FG-TE displayed an insignificant canonical coefficient, and weak canonical loadings and cross-loadings. Measures of overall core function also significantly agreed with the criterion measures in classifying students into ranked tertile groups (P < .001). These results suggest that assessment of specific low back muscular function can be easily evaluated using tests of overall core muscular endurance as an alternative to the FG-TE in physical education settings.

Associations between Health-Related Fitness and Cardio-Metabolic Blood Profiles in Low-Income Children  [PDF]
Ryan D. Burns, Timothy A. Brusseau, You Fu, James C. Hannon
Open Journal of Preventive Medicine (OJPM) , 2015, DOI: 10.4236/ojpm.2015.59041
Abstract: Children from low-income families have a higher incidence for developing early onset cardio-metabolic disease risk factors. Optimal levels of health-related fitness may attenuate risk, but little research has examined its relationships with individual cardio-metabolic blood markers in low-income children. The purpose of this study was to examine the prevalence and correlates of unfavorable cardio-metabolic blood profiles in children from low-income families. Data were collected and analyzed on 124 children (mean age = 10.4 ± 0.9 years; 57 girls, 67 boys; 97% Hispanic) recruited from three urban Title I schools from the state of Utah in the US Health-related fitness. Measures were collected using the validated FITNESSGRAM fitness test battery. The Cholestech LDX system was used to analyze students’ total cholesterol (TC), LDL cholesterol, HDL cholesterol, triglycerides (TRI), and blood glucose (BG). Capillary blood samples via finger sticks were collected while each student was in a fasted state before school hours. Unfavorable measurements were defined as TC ≥ 200 mg/dL, LDL ≥ 130 mg/dL, HDL < 40 mg/dL, TRI > 150 mg/dL, and BG ≥ 100 mg/dL (pre-diabetes). Approximately 5.3% of the total sample had unfavorable TC, 16.7% had unfavorable HDL, 16.0% had unfavorable LDL, 15.2% had unfavorable TRI, and 25.4% had unfavorable BG (pre-diabetes). Pearson’s chi-square tests revealed no significant differences between sexes on any unfavorable classification after alpha level adjustment (p > 0.01). When all parameters were analyzed as continuous variables, Spearman’s rank correlation revealed a statistically significant linear relationship between aerobic fitness and LDL in boys (rs = -?0.65, p < 0.01), between BMI and HDL in girls (rs = - 0.46, p < 0.01), and between BMI and BG in girls (rs = 0.56, p < 0.01). Aerobic fitness relates to LDL cholesterol in low-income boys and BMI relates to HDL cholesterol and BG in low-income girls.
Phase variation and microevolution at homopolymeric tracts in Bordetella pertussis
Emily B Gogol, Craig A Cummings, Ryan C Burns, David A Relman
BMC Genomics , 2007, DOI: 10.1186/1471-2164-8-122
Abstract: The genomes of B. pertussis and the two closely related species, B. bronchiseptica and B. parapertussis, were screened for homopolymeric tracts longer than expected on the basis of chance, given their nucleotide compositions. Sixty-nine such HPTs were found in total among the three genomes, 74% of which were polymorphic among the three species. Nine HPTs were genotyped in a collection of 90 geographically and temporally diverse B. pertussis strains using the polymerase chain reaction/ligase detection reaction (PCR/LDR) assay. Six HPTs were polymorphic in this collection of B. pertussis strains. Of note, one of these polymorphic HPTs was found in the fimX promoter, where a single base insertion variant was present in seven strains, all of which were isolated prior to introduction of the pertussis vaccine. Transcript abundance of fimX was found to be 3.8-fold lower in strains carrying the longer allele. HPTs in three other genes, tcfA, bapC, and BP3651, varied widely in composition across the strain collection and displayed allelic polymorphism within single cultures.Allelic polymorphism at homopolymeric tracts is common within the B. pertussis genome. Phase variability may be an important mechanism in B. pertussis for evasion of the immune system and adaptation to different niches in the human host. High sensitivity and specificity make the PCR/LDR assay a powerful tool for investigating allelic variation at HPTs. Using this method, allelic diversity and phase variation were demonstrated at several B. pertussis loci.Bordetella pertussis causes whooping cough, a highly communicable disease that killed roughly 279,000 people and infected 17.6 million people globally in a recent typical year [1]. B. pertussis and the closely related human- and sheep-adapted species, B. parapertussis, have diverged independently by genome decay from a putative common ancestor that they share with B. bronchiseptica, which has a broader host range, and unlike the other two species, causes
Indices of Abdominal Adiposity and Cardiorespiratory Fitness Test Performance in Middle-School Students
Ryan Burns,James C. Hannon,Timothy A. Brusseau,Barry Shultz,Patricia Eisenman
Journal of Obesity , 2013, DOI: 10.1155/2013/912460
Abstract: Background. Previous research suggests that use of BMI as a screening tool to assess health in youth has limitations. Valid alternative measures to assess body composition are needed to accurately identify children who are aerobically fit, which is an indicator of health status. The purpose of this study was to examine the associations between select anthropometric measures and cardiorespiratory fitness test performance in middle-school students. Methods. Participants included 134 students (65 boys and 69 girls) recruited from the 6th, 7th, and 8th grades. Anthropometric measures consisted of BMI, waist circumference (WC), waist-to-height ratio (WHtR), and percent body fat estimated from two-site skinfolds (%BF-SKF), as well as the hand-held OMRON BIA device (%BF-BIA). Cardiorespiratory fitness tests included the one-mile run and PACER test. Data were collected on four separate testing days during the students’ physical education classes. Results. There were statistically significant moderate correlations between the %BF estimations, WHtR, and cardiorespiratory fitness test scores in both genders . BMI at best only displayed weak correlations with the cardiorespiratory fitness test scores. Conclusions. The results suggest that alternative measures such as %BF-SKF, %BF-BIA, and WHtR may be more valid indicators of youth aerobic fitness lending to their preferred use over BMI. 1. Introduction The current pediatric obesity epidemic manifests concerns for adverse cardiovascular risk factors among overweight youth. However, Eisenmann et al. [1], using body mass index (BMI) as the marker of adiposity, found that youth in both the low- and high-BMI categories were associated with a more favorable cardiovascular disease (CVD) risk-factor profile than individuals whose BMIs were in the “healthy” range. This paradox leads to a significant issue in assessing health and fitness in youth when using BMI. Research has also suggested that along with body composition, aerobic fitness must also be considered to accurately assess health status in a population. Lee et al. [2] found that unfit lean men had a higher risk of cardiovascular disease and all-cause mortality than fit but overweight men. These findings suggest that fitness offers some protection against CVD risk even if the individual is overweight. Similar results have been reported for the female population [3]. Using skinfold thickness as the measure of body fatness and stratifying youth into high-fat/high-fitness, high-fat/low-fitness, low-fat/high-fitness, and low-fat/low-fitness groups, it was found that
Gender Differences in the Validity of Career Interest Inventories  [PDF]
Stephanie T. Burns
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.58089
Abstract:

Predictive validity (including hit rates, kappa coefficients, and chance expectancy rates) between standard scoring and person matching was compared by gender based upon ex post facto data collected on 5143 medical students who had taken a career interest inventory and entered their medical residency. Hit rate accuracy for person matching with females and males in this study was lower than standard scoring. However, person matching demonstrated greater gender balancing in first match hit rates. Additionally, person matching increased career interest inventory validity over standard scoring as it has the greater ability to a) differentiate between and b) assign to specific occupational groups for females and males. Furthermore, person matching has the potential to offer female and male test takers the ability to receive narrative career data, which could improve the career decision making process over the scoring reports of career interest inventories using standard scoring.

Rational Choice Theory: Toward a Psychological, Social, and Material Contextualization of Human Choice Behavior  [PDF]
Tom Burns, Ewa Roszkowska
Theoretical Economics Letters (TEL) , 2016, DOI: 10.4236/tel.2016.62022
Abstract: The main purpose of this paper is to provide a brief overview of the rational choice approach, followed by an identification of several of the major criticisms of RCT and its conceptual and empirical limitations. It goes on to present a few key initiatives to develop alternative, more realistic approaches which transcend some of the limitations of Rational Choice Theory (RCT). Finally, the article presents a few concluding reflections and a table comparing similarities and differences between the mainstream RCT and some of the initial components of an emerging choice theory. Our method has been to conduct a brief selective review of rational choice theoretical formulations and applications as well as a review of diverse critical literature in the social sciences where rational choice has been systematically criticized. We have focused on a number of leading contributors (among others, several Nobel Prize Recipients in economics, who have addressed rational choice issues). So this article makes no claim for completeness. The review maps a few key concepts and assumptions underpinning the conceptual model and empirical applications of RCT. It reviews also a range of critical arguments and evidence of limitations. It identifies selected emerging concepts and theoretical revisions and adaptations to choice theory and what they entail. The results obtained, based on our literature reviews and analyses, are the identification of several major limitations of RCT as well as selected modifications and adaptations of choice theory which overcome or promise to overcome some of the RCT limitations. Thus, the article with Table 1 in hand provides a point of departure for follow-up systematic reviews and more precise questions for future theory development. The criticisms and adaptations of RCT have contributed to greater realism, empirical relevance, and increased moral considerations. The developments entail, among other things: the now well-known cognitive limitations (“bounded rationality”) and, for instance, the role of satisficing rather than maximizing in decision-making to deal with cognitive complexity and the uncertainties of multiple values; choice situations are re-contextualized with psychology, sociology, economic, and material conditions and factors which are taken into account explicitly and insightfully in empirical and theoretical work. Part of the contextualization concerns the place of multiple values, role and norm contradictions, and moral dilemmas in much choice behavior. In conclusion, the article suggests that the adaptations and
Boom and Bust Cycles in Financial Markets—Causes and Cures: Multiple Contradictory Functions of Money and Collective Action Problems  [PDF]
Tom R. Burns
Theoretical Economics Letters (TEL) , 2017, DOI: 10.4236/tel.2017.74062
Abstract: The aim of this conceptualization article is to formulate propositions about: (1) systemic faults in established money and financial systems, in particular the mechanisms that make for boom-and-bust cycles; and (2) the cognitive and action factors which limit the central banks capabilities to consistently and effectively to regulate or to limit these cycles. Drawing on earlier research (our own as well as that of others), this conceptualization is presented in Section 1. Section 2 identifies a new design and institutional arrangement, which would minimize the boom-and-bust predispositions in money and financial systems. This work builds on earlier research invested in the Chicago Plan (from the 1930s) in addition to our own research. Section 3 considers the expected political and ideological constraints on reforming financial systems. Previously operating constraints—including Neo-liberal erosion of New Deal banking arguments and reforms—make for formidable barriers. The paper concludes that reform is necessary—if boom-and-bust cycles on the scale of those since 1929 are to be effectively regulated; but it is suggested that such reform is politically and ideologically difficult if not impossible in the short-run.
Is There an Association between Social Connectedness, Social Identity, Alcohol Consumption and Mental Health among Young University Students?  [PDF]
Kristen Hunt, Sharyn Burns
Open Journal of Preventive Medicine (OJPM) , 2017, DOI: 10.4236/ojpm.2017.76009
Abstract: Social connectedness has been identified as a protective factor for a range of health issues however the literature is not conclusive. The high prevalence of hazardous alcohol consumption and mental health problems among university students along with the potential for the university as a setting for health promotion prompted this study. The study aims to explore the association between levels of alcohol consumption, mental health, social connectedness and social identity among university students. Online data were collected from a random sample of university undergraduate students (n = 2506) aged 18 - 24 years old. Outcomes were measured using the Alcohol Use Disorders Identification Test (AUDIT), the Kessler Psychological Distress Scale, Social Connectedness Scale, Social Identity Scale and measures of paid employment and study (hours), and participation in sports and other clubs. The majority of students had consumed alcohol in the last 12 months (87%). Of these students 38% reported to drink at hazardous levels (AUDIT ≥ 8). When all factors were considered: gender, living arrangements, being a domestic student, hours spent at work, participation in university and community sport, higher levels of psychological distress, higher levels of social connectedness, and lower levels of social identity were significant predictors of hazardous alcohol consumption. The finding highlights the need for the inclusion of integrated, multi-strategy health promotion interventions on campus. Further exploration of the associations between social connectedness and social identity as influences of health behaviors will better inform the development of targeted strategies for specific groups.
On the optimal stacking of noisy observations
?. Ryan
Mathematics , 2010,
Abstract: Observations where additive noise is present can for many models be grouped into a compound observation matrix, adhering to the same type of model. There are many ways the observations can be stacked, for instance vertically, horizontally, or quadratically. An estimator for the spectrum of the underlying model can be formulated for each stacking scenario in the case of Gaussian noise. We compare these spectrum estimators for the different stacking scenarios, and show that all kinds of stacking actually decreases the variance when compared to just taking an average of the observations. We show that, regardless of the number of observations, the variance of the estimator is smallest when the compound observation matrix is made as square as possible. When the number of observations grow, however, it is shown that the difference between the estimators is marginal: Two stacking scenarios where the number of columns and rows grow to infinity are shown to have the same variance asymptotically, even if the asymptotic matrix aspect ratios differ. Only the cases of vertical and horizontal stackings display different behaviour, giving a higher variance asymptotically. Models where not all kinds of stackings are possible are also discussed.
Page 1 /4614
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.