1,517 research outputs found

    Cool Companions to White Dwarfs from the 2MASS Second Incremental Data Release

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    We present near-infrared magnitudes for all white dwarfs (selected from the catalog of McCook & Sion) contained in the 2 Micron All Sky Survey Second Incremental Data Release(2MASS 2IDR). We show that the near-IR color-color diagram is an effective means of identifying candidate binary stars containing a WD and a low mass main sequence star. The loci of single WDs and WD + red dwarf binaries occupy distinct regions of the near-IR color-color diagram. We recovered all known unresolved WD + red dwarf binaries located in the 2IDR sky coverage, and also identified as many new candidate binaries (47 new candidates out of 95 total). Using observational near-IR data for WDs and M-L dwarfs, we have compared a sample of simulated WD + red dwarf binaries with our 2MASS data. The colors of the simulated binaries are dominated by the low mass companion through the late-M to early-L spectral types. As the spectral type of the companion becomes progressively later, however, the colors of unresolved binaries become progressively bluer. Binaries containing the lowest mass companions will be difficult to distinguish from single WDs solely on the basis of their near-IR colors.Comment: 18 pages, including 2 figures, accepted for publication in Ap

    Objective and subjective assessments of normal walking pace, in comparison with that recommended for moderate intensity physical activity

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    Despite its common application and widely reported health benefits, walking, in relation to pace and intensity, is under-researched. Few studies have addressed whether people normally walk at a pace that meets the public health recommendations for moderate intensity physical activity (1.34-1.79 ms-1) and there is no known research on individuals' perceptions of factors which influence walking pace. This study aimed to objectively assess if participants were reaching the pace required for moderate intensity physical activity during normal walking. This was examined via a Global Positioning System (GPS) over a 1 km outdoor walk and a timed 150 m trial. In both tests participants (n=10, 3 men, 7 women, mean age 54±8 y) were instructed to walk at their normal pace. Through short interviews, the study also investigated the factors that participants' thought influenced their pace. All participants successfully walked at a pace considered as moderate intensity (≥1.34 ms-1). Height was significantly correlated with normal walking pace. The interviews provided an in depth insight into factors that affect walking pace; ground surface and footwear were mentioned frequently and the influence of the weather provided conflicting views, prompting a need for further research in the area. The GPS device showed enormous potential as a human locomotion measurement tool, enabling participants to walk unobstructed and unobserved in an outdoor setting, making the results relevant to real life situations

    Objective and subjective assessments of normal walking pace, in comparison with that recommended for moderate intensity physical activity

    Get PDF
    Despite its common application and widely reported health benefits, walking, in relation to pace and intensity, is under-researched. Few studies have addressed whether people normally walk at a pace that meets the public health recommendations for moderate intensity physical activity (1.34-1.79 ms-1) and there is no known research on individuals' perceptions of factors which influence walking pace. This study aimed to objectively assess if participants were reaching the pace required for moderate intensity physical activity during normal walking. This was examined via a Global Positioning System (GPS) over a 1 km outdoor walk and a timed 150 m trial. In both tests participants (n=10, 3 men, 7 women, mean age 54±8 y) were instructed to walk at their normal pace. Through short interviews, the study also investigated the factors that participants' thought influenced their pace. All participants successfully walked at a pace considered as moderate intensity (≥1.34 ms-1). Height was significantly correlated with normal walking pace. The interviews provided an in depth insight into factors that affect walking pace; ground surface and footwear were mentioned frequently and the influence of the weather provided conflicting views, prompting a need for further research in the area. The GPS device showed enormous potential as a human locomotion measurement tool, enabling participants to walk unobstructed and unobserved in an outdoor setting, making the results relevant to real life situations

    Evaluating Intervention Fidelity: An Example from a High-Intensity Interval Training Study

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    AimIntervention fidelity refers to the degree to which an experimental manipulation has been implemented as intended, but simple, robust methods for quantifying fidelity have not been well documented. Therefore, we aim to illustrate a rigorous quantitative evaluation of intervention fidelity, using data collected during a high-intensity interval training intervention.DesignSingle-group measurement study.MethodsSeventeen adolescents (mean age ± standard deviation [SD] 14.0 ± 0.3 years) attended a 10-week high-intensity interval training intervention, comprising two exercise sessions per week. Sessions consisted of 4-7 45-s maximal effort repetitions, interspersed with 90-s rest. We collected heart rate data at 5-s intervals and recorded the peak heart rate for each repetition. The high-intensity exercise criterion was ≥90% of individual maximal heart rate. For each participant, we calculated the proportion of total exercise repetitions exceeding this threshold. A linear mixed model was applied to properly separate the variability in peak heart rate between- and within-subjects. Results are presented both as intention to treat (including missed sessions) and per protocol (only participants with 100% attendance; n=8).ResultsFor intention to treat, the median (interquartile range) proportion of repetitions meeting the high-intensity criterion was 58% (42% to 68%). The mean peak heart rate was 85% of maximal, with a between-subject SD of 7.8 (95% confidence interval 5.4 to 11.3) percentage points and a within-subject SD of 15.1 (14.6 to 15.6) percentage points. For the per protocol analysis, the median proportion of high-intensity repetitions was 68% (47% to 86%). The mean peak heart rate was 91% of maximal, with between- and within-subject SDs of 3.1 (-1.3 to 4.6) and 3.4 (3.2 to 3.6) percentage points, respectively.ConclusionsSynthesising information on exercise session attendance and compliance (exercise intensity) quantifies the intervention dose and informs evaluations of treatment fidelity

    Modular Synthesis of Functional Nanoscale Coordination Polymers

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    The coordination-directed assembly of metal ions and organic bridging ligands has afforded a variety of bulk-scale hybrid materials with promising characteristics for a number of practical applications, such as gas storage and heterogeneous catalysis. Recently, so-called coordination polymers have emerged as a new class of hybrid nanomaterials. Herein, we highlight advances in the syntheses of both amorphous and crystalline nanoscale coordination polymers. We also illustrate how scaling down these materials to the nano-regime has enabled their use in a broad range of applications including catalysis, spin-crossover, templating, biosensing, biomedical imaging, and anticancer drug delivery. These results underscore the exciting opportunities of developing next-generation functional nanomaterials based on molecular components

    Surface Modification and Functionalization of Nanoscale Metal-Organic Frameworks for Controlled Release and Luminescence Sensing

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    We describe in this paper a general method for synthesizing a new class of nanocomposites with a nanoscale metal-organic framework (NMOF) core and a silica shell. Silica shells of variable thickness were deposited on the NMOFs that had been surface-modified with polyvinylpyrrolidone (PVP) using a sol-gel procedure. The NMOF core of the nanocomposite could be completely removed (via dissolution) at low pH to afford hollow silica shells with varied thickness and aspect ratios. We also showed that the silica shell of such nanocomposites significantly stabilized the NMOF core against dissolution, thus demonstrating the ability to control the release of metal constituents from such silica-coated NMOFs. The silica shell was further functionalized with a silylated Tb-EDTA monoamide derivative for the luminescence sensing of dipicolinic acid (DPA), which is a major constituent of many pathogenic spore-forming bacteria. Owing to the tunability of NMOF composition and morphology, the present approach should allow for the synthesis of not only interesting nanoshells that are not accessible with presently available templates but also novel core-shell hybrid nanostructures for future imaging, sensing, and drug delivery applications

    Multidisciplinary Protocol for the Management of Violent Patients and Promotion of Workplace Safety in the Intensive Care Unit

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    Introduction: Workplace violence is a prevalent issue in healthcare, yet limited evidence informs management options to improve workplace safety associated with violent patients and families. Even less is known about reducing violence in intensive care units (ICUs), a healthcare setting that commonly serves patients at high risk of aggressive behaviors. Multifaceted, interdisciplinary and institution-specific interventions are recommended to address workplace safety. Methods: Our institution developed four interventions to address the issue of violent patients in our ICUs. The interventions included a Disruptive/Aggressive Behavior Algorithm, Code Grey Box, Rapid Sedation Protocol and a Customer Service Representative. Security calls to the ICUs were the primary measure used to assess effectiveness of the interventions. Results: Security calls to the ICUs decreased from October 2013 to August 2016, after the implementation of the four interventions. Discussion: The implementation of four interventions decreased the calls to security, despite encouraging early escalation to security for potentially violent patients. The trend may represent a decrease in violent episodes, increased staff confidence in managing violent patients, or improved early recognition of high-risk patients. Conclusions: Violent patients and families in the ICU is an understudied workplace safety issue. Our institution used a multifaceted interdisciplinary approach to create and implement interventions which led to a reduction in the need for security personnel response to threats of ICU staff safety. These interventions serve as a guide for other institutions with the aim to decrease workplace violence and promote workplace safety
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