Distilled Sensing: Adaptive Sampling for Sparse Detection and Estimation

Adaptive sampling results in dramatic improvements in the recovery of sparse signals in white Gaussian noise. A sequential adaptive sampling-and-refinement procedure called Distilled Sensing (DS) is proposed and analyzed. DS is a form of multi-stage experimental design and testing. Because of the adaptive nature of the data collection, DS can detect and localize far weaker signals than possible from non-adaptive measurements. In particular, reliable detection and localization (support estimation) using non-adaptive samples is possible only if the signal amplitudes grow logarithmically with the problem dimension. Here it is shown that using adaptive sampling, reliable detection is possible provided the amplitude exceeds a constant, and localization is possible when the amplitude exceeds any arbitrarily slowly growing function of the dimension.Comment: 23 pages, 2 figures. Revision includes minor clarifications, along with more illustrative experimental results (cf. Figure 2

Information Content of the Gravitational Field of a Quantum Superposition

When a massive quantum body is put into a spatial superposition, it is of interest to consider the quantum aspects of the gravitational field sourced by the body. We argue that in order to understand how the body may become entangled with other massive bodies via gravitational interactions, it must be thought of as being entangled with its own Newtonian-like gravitational field. Thus, a Newtonian-like gravitational field must be capable of carrying quantum information. Our analysis supports the view that table-top experiments testing entanglement of systems interacting via gravity do probe the quantum nature of gravity, even if no ``gravitons'' are emitted during the experiment.Comment: 4 pages, 1 figure. First prize essay in the Gravity Research Foundation 2019 Essays on Gravitation. To appear in IJMPD. arXiv admin note: substantial text overlap with arXiv:1807.0701

Regression-based seasonal unit root tests

The contribution of this paper is three-fold. Firstly, a characterisation theorem of the sub-hypotheses comprising the seasonal unit root hypothesis is presented which provides a precise formulation of the alternative hypotheses against which regression-based seasonal unit root tests test. Secondly, it proposes regressionbased tests for the seasonal unit root hypothesis which allow a general seasonal aspect for the data and are similar both exactly and asymptotically with respect to initial values and seasonal drift parameters. Thirdly, limiting distribution theory is given for these statistics where, in contrast to previous papers in the literature, in doing so it is not assumed that unit roots hold at all of the zero and seasonal frequencies. This is shown to alter the large sample null distribution theory for regression t-statistics for unit roots at the complex frequencies, but interestingly to not affect the limiting null distributions of the regression t-statistics for unit roots at the zero and Nyquist frequencies and regression Fstatistics for unit roots at the complex frequencies. Our results therefore have important implications for how tests of the seasonal unit root hypothesis should be conducted in practice. Associated simulation evidence on the size and power properties of the statistics presented in this paper is given which is consonant with the predictions from the large sample theory.Seasonal unit root tests; seasonal drifts; characterisation theorem

Quantum Superposition of Massive Objects and the Quantization of Gravity

We analyse a gedankenexperiment previously considered by Mari et al. that involves quantum superpositions of charged and/or massive bodies ("particles") under the control of the observers, Alice and Bob. In the electromagnetic case, we show that the quantization of electromagnetic radiation (which causes decoherence of Alice's particle) and vacuum fluctuations of the electromagnetic field (which limits Bob's ability to localize his particle to better than a charge-radius) both are essential for avoiding apparent paradoxes with causality and complementarity. We then analyze the gravitational version of this gedankenexperiment. We correct an error in the analysis of Mari et al. and of Baym and Ozawa, who did not properly account for the conservation of center of mass of an isolated system. We show that the analysis of the gravitational case is in complete parallel with the electromagnetic case provided that gravitational radiation is quantized and that vacuum fluctuations limit the localization of a particle to no better than a Planck length. This provides support for the view that (linearized) gravity should have a quantum field description.Comment: 9 pages, 1 figure. Version accepted for publication in Phys.Rev.

An Interprofessional Prediabetes and Diabetes Self--Management Education Quality Improvement Project Among Vulnerable Populations at a Tuberculosis Hospital

Background. Patients greatly benefit from diabetes self-management education (DSME) as it boosts knowledge and self-efficacy, decreases body weight, fasting blood sugar, and hemoglobin A1C levels, and improves overall health outcomes in a cost-effective manner. Unfortunately, many individuals with prediabetes and diabetes who qualify for DSMEs do not attend these classes nor receive sufficient prediabetes and diabetes support elsewhere to attain guideline recommended metrics. However, individuals from vulnerable populations and without DSME education experience disproportionate diabetes-related complications worsening health outcomes. Aims: Increase general prediabetes and diabetes knowledge, facilitate behavior change, improve glycemic, metabolic, and lipid values, and increase healthy dietary planning and physical activity among patients with prediabetes and diabetes. Purpose. Provide an interdisciplinary team DSME education program to patients at a tuberculosis hospital with diabetes and prediabetes in order to empower patients in self-management knowledge and skills in order to prevent or delay complications. Objectives. Review American Diabetes Association (ADA) medical care guidelines with providers, monitor changes to ordered dietary and medication regimens based on laboratory values as per guideline recommendations, reduce individual glycemic, metabolic, and lipid laboratory markers, improve patients’ verbalization of guideline-supported dietary and exercise recommendations, increase patient recognition of signs and symptoms of dysglycemia along with its management, and increase aerobic and resistance exercise participation. Interventions. Provide a closed-caption television (CCTV) prediabetes and diabetes educational programming, conduct weekly DSME classes, initiate a walking and yoga exercise program, encourage online educational module learning, and reinforce class and CCTV interventions with prediabetes and diabetes infographic handouts. Evaluation. Monitor the electronic health record for orders, laboratory results, and staff documentation of education and participation along with the use of patient surveys to assess changes in knowledge, motivation, and self-efficacy. Practice Implications. Many studies have researched the effectiveness of DSMEs in many settings, but none have studied the application of this intervention in a long-term care setting among individuals from vulnerable populations who are experiencing an acute bout of illness. The findings from this quality improvement project will help establish the efficacy of implementing prediabetes and diabetes education programs in hospitals as this presents an opportune time to educate patients

Role of Fiber Orientation in Atrial Arrythmogenesis

Electrical wave-front propagation in the atria is determined largely by local fiber orientation. Recent study suggests that atrial fibrillation (AF) progresses with enhanced anisotropy. In this work, a 3D rabbit atrial anatomical model at 20 × 20 × 20 μm3 resolution with realistic fiber orientation was constructed based on the novel contrast-enhanced micro-CT imaging. The Fenton-Karma cellular activation model was adapted to reproduce rabbit atrial action potential period of 80 ms. Diffusivities were estimated for longitudinal and transverse directions of the fiber orientation respectively. Pacing was conducted in the 3D anisotropic atrial model with a reducing S2 interval to facilitate initiation of atrial arrhythmia. Multiple simulations were conducted with varying values of diffusion anisotropy and stimulus locations to evaluate the role of anisotropy in initiating AF. Under physiological anisotropy conditions, a rapid right atrial activation was followed by the left atrial activation. Excitation waves reached the atrio-ventricular border where they terminated. Upon reduction of conduction heterogeneity, re-entry was initiated by the rapid pacing and the activation of both atrial chambers was almost simultaneous. Myofiber orientation is an effective mechanism for regulating atrial activation. Modification of myoarchitecture is proarrhythmic

Estudio comparativo de dos topologías de filtro activo de potencia en sistemas trifásicos con cargas no lineales desbalanceadas

Se plantea la comparación de dos topologías de filtro activo de potencia bajo las mismas condiciones de operación, es decir; misma carga no lineal desbalanceada, iguales escenarios de tensión, iguales estrategias de control y modulación de la corriente. Se considera un APF trifásico con tres ramas y otro de cuatro ramas. Para el control de cada filtro se implementa tres diferentes estrategias de control; la teoría pq, la teoría pqr y el marco de referencia síncrono o teoría dq0 respectivamente. Para el caso de la modulación de la corriente del filtro se implementa el control por banda fija de histéresis en cada una de las dos topologías de filtro mencionadas anteriormente. Finalmente se realiza un análisis de los resultados obtenidos para cada uno de los métodos de control aplicados a cada topología por medio de simulación para un sistema de distribución de baja tensión

A Program to Change the Approach to Care of Children with Asthma in the Primary Care Setting Did Not Reduce Rates of Hospital Admissions: Lessons Learned from a Descriptive Study

Asthma is a critical global health issue. It affects people of all ages in countries throughout the world. The prevalence of asthma is increasing in most countries among young children who also represent the greatest proportion of health care utilization. Outpatient asthma-treatment programs managed by chest physicians or allergists have reduced hospitalizations, yet programs in pediatric offices have not successfully impacted hospitalizations. The Community Asthma Program (CAP) was designed to support pediatrician use of clinical guidelines in their everyday office practice. The goal was to reduce asthma hospitalizations by 15 percent from selected pediatric practices. A study was done in 4 pediatric practices closely associated with St. Louis Children’s Hospital. The program included a continuous quality improvement process quarterly