Exploration of How People with Mobility Disabilities Rate Community Barriers to Physical Activity

Background and Significance: People with mobility disabilities (such as people who use a cane, walker, or wheelchair) are less likely to be physically active. Previous studies have identified community barriers to physical activity. However, these studies did not measure how people with mobility disabilities rated community barriers to physical activity. This study examined how people with mobility disabilities rate community barriers and explore relationships between these barriers and engagement in physical activity. Methods: Study participants (n = 150) were recruited from an accessible fitness center and an independent living center. Participants completed the Barriers to Physical Activity Questionnaire for People with Mobility Impairments and the Physical Activity and Disability Survey. Results: The most frequently reported community barriers were excessive crime or fear of crime (40.7%) and cars driving too fast (40.7%). The highest rated barrier was lack of accessible transportation to a fitness center, with a median rating of 5 out of 5. There was a significant, negative correlation between strength exercise and built environment and perceptions of safety. There was no significant correlation between aerobic exercise and built environment and perceptions of safety. Conclusion: People with disabilities face community barriers which contribute to a disparity in opportunities to be physically active. Future intervention studies are needed to determine whether physical activity rates change after improvements are made to make physical activity more accessible for people with disabilities

Learning Transferable Architectures for Scalable Image Recognition

Developing neural network image classification models often requires significant architecture engineering. In this paper, we study a method to learn the model architectures directly on the dataset of interest. As this approach is expensive when the dataset is large, we propose to search for an architectural building block on a small dataset and then transfer the block to a larger dataset. The key contribution of this work is the design of a new search space (the "NASNet search space") which enables transferability. In our experiments, we search for the best convolutional layer (or "cell") on the CIFAR-10 dataset and then apply this cell to the ImageNet dataset by stacking together more copies of this cell, each with their own parameters to design a convolutional architecture, named "NASNet architecture". We also introduce a new regularization technique called ScheduledDropPath that significantly improves generalization in the NASNet models. On CIFAR-10 itself, NASNet achieves 2.4% error rate, which is state-of-the-art. On ImageNet, NASNet achieves, among the published works, state-of-the-art accuracy of 82.7% top-1 and 96.2% top-5 on ImageNet. Our model is 1.2% better in top-1 accuracy than the best human-invented architectures while having 9 billion fewer FLOPS - a reduction of 28% in computational demand from the previous state-of-the-art model. When evaluated at different levels of computational cost, accuracies of NASNets exceed those of the state-of-the-art human-designed models. For instance, a small version of NASNet also achieves 74% top-1 accuracy, which is 3.1% better than equivalently-sized, state-of-the-art models for mobile platforms. Finally, the learned features by NASNet used with the Faster-RCNN framework surpass state-of-the-art by 4.0% achieving 43.1% mAP on the COCO dataset

Processing, Microstructure and Creep Behavior of Mo-Si-B-Based Intermetallic Alloys for Very High Temperature Structural Applications

This research project is concerned with developing a fundamental understanding of the effects of processing and microstructure on the creep behavior of refractory intermetallic alloys based on the Mo-Si-B system. In the first part of this project, the compression creep behavior of a Mo-8.9Si-7.71B (in at.%) alloy, at 1100 and 1200 C was studied, whereas in the second part of the project, the constant strain rate compression behavior at 1200, 1300 and 1400 C of a nominally Mo-20Si-10B (in at.%) alloy, processed such as to yield five different {alpha}-Mo volume fractions ranging from 5 to 46%, was studied. In order to determine the deformation and damage mechanisms and rationalize the creep/high temperature deformation data and parameters, the microstructure of both undeformed and deformed samples was characterized in detail using x-ray diffraction, scanning electron microscopy (SEM) with back scattered electron imaging (BSE) and energy dispersive x-ray spectroscopy (EDS), electron back scattered diffraction (EBSD)/orientation electron microscopy in the SEM and transmission electron microscopy (TEM). The microstructure of both alloys was three-phase, being composed of {alpha}-Mo, Mo{sub 3}Si and T2-Mo{sub 5}SiB{sub 2} phases. The values of stress exponents and activation energies, and their dependence on microstructure were determined. The data suggested the operation of both dislocation as well as diffusional mechanisms, depending on alloy, test temperature, stress level and microstructure. Microstructural observations of post-crept/deformed samples indicated the presence of many voids in the {alpha}-Mo grains and few cracks in the intermetallic particles and along their interfaces with the {alpha}-Mo matrix. TEM observations revealed the presence of recrystallized {alpha}-Mo grains and sub-grain boundaries composed of dislocation arrays within the grains (in Mo-8.9Si-7.71B) or fine sub-grains with a high density of b = 1/2<111> dislocations (in Mo-20Si-10B), which are consistent with the values of the respective stress exponents and activation energies that were obtained and provide confirmatory evidence for the operation of diffusional (former alloy) or dislocation (latter alloy) creep mechanisms. In contrast, the intermetallic phases contained very few dislocations, but many cracks. The relative contributions of the {alpha}-Mo and the intermetallic particles to the overall deformation process, including their individual and collective dependence on temperature and strain rate are discussed in light of the present results and those from previous reports

Scheduling jobs with hard deadlines over Multiple Access and Degraded Broadcast Channels

We consider the problem of scheduling jobs with given start and finish times over two classes of multi-user channels, namely Multiple Access Channels and Degraded Broadcast Channels, and derive necessary and sufficient conditions for feasible scheduling of the jobs

The Effect of Alloying on Topologically Close Packed Phase Instability in Advanced Nickel-Based Superalloy Rene N6

An investigation was conducted to describe topologically close packed (TCP) phase instability as a function of composition in the advanced Ni-base superalloy Rene N6. TCP phases are detrimental to overall high-temperature performance of Ni-base superalloys because of their brittle nature and because they deplete the Ni-rich matrix of potent solid solution strengthening elements. Thirty-four variations of polycrystalline Rene N6 determined from a design-of-experiments approach were cast and homogenized at 1315"C for 80 hours followed by exposure at 10930C for 400 hours to promote TCP formation. The alloys had the following composition ranges in atomic percent: Co 10.61 to 16.73%, Mo 0.32 to 1.34%, W 1.85 to 2.52%, Re 1.80 to 2.1 1 %, Ta 2.36 to 3.02%, Al 11.90 to 14.75%, and Cr 3.57 to 6.23%. Physical and chemical characteristics of all n-ticrostructures obtained were described using various analytical techniques. From these observations, a mathematical description of TCP occurrence (omega and P phase) was generated for polycrystalline Rene N6

An outbreak investigation of typhoid fever in Pondicherry, South India, 2013

Background: Preliminary investigation at Pediatric ward of Indira Gandhi Medical College revealed admission of a cluster of typhoid cases who were residents of one particular street in a nearby locality. Objectives: This study was undertaken to estimate the magnitude of the outbreak, identify the source of infection, and, thereby, institute control measures. Materials and Methods: An investigation team including 10 MBBS students carried out a sanitary survey, house-to-house survey, data collection using epidemiological case sheets, and spot mapping. Typhoid diagnosis was confirmed as per the IDSP guidelines, i.e., either a blood culture growth positive for Salmonella typhi or a fourfold rise in antibody titer. An age- and gender-matched case–control study was conducted to find the association of occurrence of typhoid with various possible sources of infection. Water samples were collected from the affected households and public taps for investigation. Results: Rapid survey of all the 6 streets of Thilaspet covered 1106 people living in 283 households. All nine confirmed cases were residents of one particular street. The attack rate calculated was 3.4% in this street. A significant association of occurrence of typhoid was found only with consumption of raw drinking water (OR = 12.6, P = 0.01). Water samples only from the affected street tested positive for the presence of coliforms. The sanitary survey documented water pipeline breakage at the junction of this street. Further spread of disease was stopped by advocating drinking of boiled water and repair of pipeline. Conclusion: Strengthening of disease surveillance for early identification of localized outbreaks and instituting control measures can effectively control disease spread