Universality Class of One-Dimensional Directed Sandpile Models

A general n-state directed `sandpile' model is introduced. The stationary properties of the n-state model are derived for n < infty, and analytical arguments based on a central limit theorem show that the model belongs to the universality class of the totally asymmetric Oslo model, with a crossover to uncorrelated branching process behavior for small system sizes. Hence, the central limit theorem allows us to identify the existence of a large universality class of one-dimensional directed sandpile models.Comment: 4 pages, 2 figure

Adherence to Appropriate Instructional Practice Guidelines in American College and University Physical Activity Programs

Background/Purpose: Higher education physical activity programs (HEPAP) in physical education have existed in American college and universities for over 100 years. Initially used to teach physical education and promote physical activity to prepare students for potential wartime conflicts, they have evolved in response to changes in societal and educational purposes and needs. In 2008, NASPE published its updated Guidelines for Appropriate Instructional Practice in Higher Education Physical Activity Programs. The guidelines educate professionals about effective physical education for post-secondary students, but knowledge of their use is limited. The purpose of the study was to examine familiarity and adherence to these guidelines.;Method: Researchers developed and piloted an electronic survey to assess familiarity and adherence with the guidelines related to curriculum and instruction. The survey included 61- items arranged in pre-existing content areas: Administration/Support, Assessment, Instruction Strategies, Professionalism, Learning Environment, and Curriculum. The survey was distributed to HEPAP representatives at U.S. colleges/universities offering a physical education teaching degree (N=596).;Analysis/Results: In total, 159 participants (26.7%) initiated the survey with 90 (15.1%) providing usable responses and the remaining 69 (11.5%) excluded due to no HEPAP or incomplete data. The data were transformed into categorical levels indicating a high degree of overall familiarity (96.7% full or partially familiar) and adherence (99% full or partially adherent). Full adherence to the content areas ranged from 91.8% (Administration/Support) to 0% (Instruction Strategies). Significant associations between Administration/Support and location (AAHPERD district)( chi2(10, n=71) = 23.98, p= .008) and Assessment and location (chi2(10, n=90) =19.39, p=.036) were seen.;Conclusions: College physical education programs have been called on to provide students opportunities to develop an appreciation for, and increased participation in lifetime activity. While overall adherence to relevant professional guidelines appears high among HEPAPs, there is room for improvement in selected areas including Instruction Strategies and Assessment.;Key Words: program evaluation, college physical activity program, college student

Transfer ideals and torsion in the Morava EE-theory of abelian groups

Let $A$ be a finite abelian $p$ group of rank at least $2$. We show that $E^0(BA)/I_{tr}$, the quotient of the Morava $E$-cohomology of $A$ by the ideal generated by the image of the transfers along all proper subgroups, contains $p$-torsion. The proof makes use of transchromatic character theory

Field Based Assessment of Running Metrics

Click the PDF icon to download the abstract

Power operations in the Stolz-Teichner program

The Stolz–Teichner program proposes a deep connection between geometric field theories and certain cohomology theories. We extend this connection by developing a theory of geometric power operations for geometric field theories restricted to closed bordisms. These operations satisfy relations analogous to the ones exhibited by their homotopical counterparts. We also provide computational tools to identify the geometrically defined operations with the usual power operations on complexified equivariant K–theory. Further, we use the geometric approach to construct power operations for complexified equivariant elliptic cohomology

A sequential classification rule based on multiple quantitative tests in the absence of a gold standard

In many medical applications, combining information from multiple biomarkers could yield a better diagnosis than any single one on its own. When there is a lack of a gold standard, an algorithm of classifying subjects into the case and non-case status is necessary for combining multiple markers. The aim of this paper is to develop a method to construct a composite test from multiple applicable tests and derive an optimal classification rule under the absence of a gold standard. Rather than combining the tests, we treat the tests as a sequence. This sequential composite test is based on a mixture of two multivariate normal latent models for the distribution of the test results in case and non-case groups, and the optimal classification rule is derived returning the greatest sensitivity at a given specificity. This method is applied to a real-data example and simulation studies have been carried out to assess the statistical properties and predictive accuracy of the proposed composite test. This method is also attainable to implement nonparametrically

Management of diabetic neuropathic foot and ankle malunions and nonunions

The management of diabetic neuropathic foot and ankle malunions and/or nonunions is often complicated by the presence of broken or loosened hardware, Charcot joints, infection, osteomyelitis, avascular bone necrosis, unstable deformities, bone loss, disuse and pathologic osteopenia, and ulcerations. The author discusses a rational approach to functional limb salvage with various surgical techniques that are aimed at achieving anatomic alignment, long-term osseous stability, and adequate soft tissue coverage. Emphasis is placed on techniques to overcome the inherent challenges that are encountered when surgically managing a diabetic nonunion and/or malunion. Particular attention is directed to the management of deep infection and Charcot neuroarthropathy in the majority of the cases presented

One-Dimensional Directed Sandpile Models and the Area under a Brownian Curve

We derive the steady state properties of a general directed ``sandpile'' model in one dimension. Using a central limit theorem for dependent random variables we find the precise conditions for the model to belong to the universality class of the Totally Asymmetric Oslo model, thereby identifying a large universality class of directed sandpiles. We map the avalanche size to the area under a Brownian curve with an absorbing boundary at the origin, motivating us to solve this Brownian curve problem. Thus, we are able to determine the moment generating function for the avalanche-size probability in this universality class, explicitly calculating amplitudes of the leading order terms.Comment: 24 pages, 5 figure