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Search Results: 1 - 10 of 2302 matches for " Barry Shultz "
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Future Intent to Run and Running Performance of Students Exposed to a Traditional versus an Autonomy Supportive Motivational Running Program
Andrea Silva,James C. Hannon,Barry Shultz,Leslie Podlog
Psychiatry Journal , 2013, DOI: 10.1155/2013/471657
Abstract: Background. The study's primary purpose was to investigate whether an autonomy supportive motivational climate in a running program would increase future running intent among high school students. A secondary purpose was to examine whether the program would increase individual performance in the Cooper 12-minute run. Methods. Students participated in a 4-month running intervention program which included four timed runs, one per month, and a future intent questionnaire prior to the start of the timed runs and following the last run. Results. Factorial repeated measures ANOVA revealed significance regarding future intent ( ) at both schools. Factorial repeated measures ANOVA indicated differences between the runs at both schools ( ). Paired samples -tests were conducted to look at significance with paired runs. Results revealed significance in two of the six pairs at the treatment school, notably between the first and last timed runs ( ). Only one pair was found to be significant ( ) with the control school. Conclusion. At both schools, the overall number of laps increased as well as future intent to run scores. The results do not support evidence of a greater effect from the autonomy supportive environment over a traditional environment. 1. Introduction Since the 1970s the prevalence of obesity among adolescents in the US has doubled and it has more than tripled among children aged 6–11 [1]. In fact, one out of every six individuals aged 2–19 are obese in the US [2]. Obesity in childhood and adolescence increases risks of developing cardiovascular disease, orthopedic issues, and psychosocial problems [3]. In an effort to reduce the prevalence of obesity and associated health problems among youth, many schools have begun implementing running programs [4]. Running has been recommended by governmental agencies, including the National Institutes of Health and the Centers for Disease Control and Prevention, as well as professional organizations such as the American Alliance for Health Physical Education Recreation and Dance as an integral element in physical education (PE) curricula across all levels of schooling [5]. Running has many health enhancing benefits including the prevention and management of diabetes and heart attacks, lowering blood pressure, and enhancing weight loss. Running also improves bone health and coordination, while boosting the immune system and improving mood [6–8]. Several studies focusing on the outcomes of compulsory running programs at elementary and middle schools have been published [9–14]. However, there has been little research
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
Lumbar segmental mobility disorders: comparison of two methods of defining abnormal displacement kinematics in a cohort of patients with non-specific mechanical low back pain
J Haxby Abbott, Julie M Fritz, Brendan McCane, Barry Shultz, Peter Herbison, Brett Lyons, Georgia Stefanko, Richard M Walsh
BMC Musculoskeletal Disorders , 2006, DOI: 10.1186/1471-2474-7-45
Abstract: A cohort of 138 consecutive patients with recurrent or chronic low back pain (RCLBP) were recruited in this prospective, pragmatic, multi-centre study. Consenting patients completed pain and disability rating instruments, and were referred for flexion-extension radiographs. Sagittal angular rotation and sagittal translation of each lumbar spinal motion segment was measured from the radiographs, and compared to a reference range derived from a study of 30 asymptomatic volunteers. In order to define reference intervals for normal motion, and define LSR and LSI, we approached the kinematic data using two different models. The first model used a conventional Gaussian definition, with motion beyond two standard deviations (2sd) from the reference mean at each segment considered diagnostic of rotational LSMD and translational LSMD. The second model used a novel normalised within-subjects approach, based on mean normalised contribution-to-total-lumbar-motion. An LSMD was then defined as present in any segment that contributed motion beyond 2sd from the reference mean contribution-to-normalised-total-lumbar-motion. We described reference intervals for normal segmental mobility, prevalence of LSMDs under each model, and the association of LSMDs with pain and disability.With the exception of the conventional Gaussian definition of rotational LSI, LSMDs were found in statistically significant prevalences in patients with RCLBP. Prevalences at both the segmental and patient level were generally higher using the normalised within-subjects model (2.8 to 16.8% of segments; 23.3 to 35.5% of individuals) compared to the conventional Gaussian model (0 to 15.8%; 4.7 to 19.6%). LSMDs are associated with presence of LBP, however LSMDs do not appear to be strongly associated with higher levels of pain or disability compared to other forms of non-specific LBP.LSMDs are a valid means of defining sub-groups within non-specific LBP, in a conservative care population of patients with RCLBP. P
Dimension groups for interval maps II: the transitive case
Fred Shultz
Mathematics , 2004,
Abstract: Any continuous, transitive, piecewise monotonic map is determined up to a binary choice by its dimension module with the associated finite sequence of generators. The dimension module by itself determines the topological entropy of any transitive piecewise monotonic map, and determines any transitive unimodal map up to conjugacy. For a transitive piecewise monotonic map which is not essentially injective, the associated dimension group is a direct sum of simple dimension groups, each with a unique state.
Dimension groups for interval maps
Fred Shultz
Mathematics , 2004,
Abstract: With each piecewise monotonic map of the unit interval, a dimension triple is associated. The dimension triple, viewed as a Z[t, t^{-1}] module, is finitely generated, and generators are identified. Dimension groups are computed for Markov maps, unimodal maps, multimodal maps, and interval exchange maps. It is shown that the dimension group defined here is isomorphic to K_0(A), where A is a C*-algebra (an "AI-algebra") defined in dynamical terms.
Early Human Speciation, Brain Expansion and Dispersal Influenced by African Climate Pulses
Susanne Shultz, Mark Maslin
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0076750
Abstract: Early human evolution is characterised by pulsed speciation and dispersal events that cannot be explained fully by global or continental paleoclimate records. We propose that the collated record of ephemeral East African Rift System (EARS) lakes could be a proxy for the regional paleoclimate conditions experienced by early hominins. Here we show that the presence of these lakes is associated with low levels of dust deposition in both West African and Mediterranean records, but is not associated with long-term global cooling and aridification of East Africa. Hominin expansion and diversification seem to be associated with climate pulses characterized by the precession-forced appearance and disappearance of deep EARS lakes. The most profound period for hominin evolution occurs at about 1.9 Ma; with the highest recorded diversity of hominin species, the appearance of Homo (sensu stricto) and major dispersal events out of East Africa into Eurasia. During this period, ephemeral deep-freshwater lakes appeared along the whole length of the EARS, fundamentally changing the local environment. The relationship between the local environment and hominin brain expansion is less clear. The major step-wise expansion in brain size around 1.9 Ma when Homo appeared was coeval with the occurrence of ephemeral deep lakes. Subsequent incremental increases in brain size are associated with dry periods with few if any lakes. Plio-Pleistocene East African climate pulses as evinced by the paleo-lake records seem, therefore, fundamental to hominin speciation, encephalisation and migration.
Unique decompositions, faces, and automorphisms of separable states
Erik Alfsen,Fred Shultz
Mathematics , 2009, DOI: 10.1063/1.3399808
Abstract: Let S_k be the set of separable states on B(C^m \otimes C^n) admitting a representation as a convex combination of k pure product states, or fewer. If m>1, n> 1, and k \le max(m,n), we show that S_k admits a subset V_k such that V_k is dense and open in S_k, and such that each state in V_k has a unique decomposition as a convex combination of pure product states, and we describe all possible convex decompositions for a set of separable states that properly contains V_k. In both cases we describe the associated faces of the space of separable states, which in the first case are simplexes, and in the second case are direct convex sums of faces that are isomorphic to state spaces of full matrix algebras. As an application of these results, we characterize all affine automorphisms of the convex set of separable states, and all automorphisms of the state space of B(C^m otimes C^n). that preserve entanglement and separability.
Finding decompositions of a class of separable states
Erik Alfsen,Fred Shultz
Mathematics , 2012,
Abstract: By definition a separable state has the form \sum A_i \otimes B_i, where 0 \leq A_i, B_i for each i. In this paper we consider the class of states which admit such a decomposition with B_1, ..., B_p having independent images. We give a simple intrinsic characterization of this class of states, and starting with a density matrix in this class, describe a procedure to find such a decomposition with B_1, ..., B_p having independent images, and A_1, ..., A_p being distinct with unit trace. Such a decomposition is unique, and we relate this to the facial structure of the set of separable states. A special subclass of such separable states are those for which the rank of the matrix matches one marginal rank. Such states have arisen in previous studies of separability (e.g., they are known to be a class for which the PPT condition is equivalent to separability). The states investigated also include a class that corresponds (under the Choi-Jamio{\l}kowski isomorphism) to the quantum channels called quantum-classical and classical-quantum by Holevo.
C*-algebras associated with interval maps
Valentin Deaconu,Fred Shultz
Mathematics , 2004,
Abstract: For each piecewise monotonic map tau of [0,1], we associate a pair of C*-algebras F_tau and O_tau and calculate their K-groups. The algebra F_tau is an AI-algebra. We characterize when F_tau and O_\tau are simple. In those cases, F_tau has a unique trace, and O_tau is purely infinite with a unique KMS-state. In the case that tau is Markov, these algebras include the Cuntz-Krieger algebras O_A, and the associated AF-algebras F_A. Other examples for which the K-groups are computed include tent maps, quadratic maps, multimodal maps, interval exchange maps, and beta-transformations. For the case of interval exchange maps and of beta-transformations, the C*-algebra O_tau coincides with the algebras defined by Putnam and Katayama-Matsumoto-Watatani respectively.
Managing Uncertainty in Rule Based Cognitive Models
Thomas R. Shultz
Computer Science , 2013,
Abstract: An experiment replicated and extended recent findings on psychologically realistic ways of modeling propagation of uncertainty in rule based reasoning. Within a single production rule, the antecedent evidence can be summarized by taking the maximum of disjunctively connected antecedents and the minimum of conjunctively connected antecedents. The maximum certainty factor attached to each of the rule's conclusions can be sealed down by multiplication with this summarized antecedent certainty. Heckerman's modified certainty factor technique can be used to combine certainties for common conclusions across production rules.
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