Correspondence of perceived vs. objective proximity to parks and their relationship to park-based physical activity

<p>Abstract</p> <p>Background</p> <p>Parks are key environmental resources for encouraging population-level physical activity (PA). In measuring availability of parks, studies have employed both self-reported and objective indicators of proximity, with little correspondence observed between these two types of measures. However, little research has examined how the degree of correspondence between self-reported and objectively-measured distance to parks is influenced by individual, neighborhood, and park-related variables, or which type of measure is more strongly related to physical activity outcomes.</p> <p>Methods</p> <p>We used data from 574 respondents who reported the distance to their closest park and compared this with objective measurements of proximity to the closest park. Both indicators were dichotomized as having or not having a park within 750 m. Audits of all park features within this distance were also conducted and other personal characteristics and neighborhood context variables (safety, connectedness, aesthetics) were gleaned from participants' survey responses. Participants also completed detailed seven-day PA log booklets from which measures of neighborhood-based and park-based PA were derived.</p> <p>Results</p> <p>Agreement was poor in that only 18% of respondents achieved a match between perceived and objective proximity to the closest park (kappa = 0.01). Agreement was higher among certain subgroups, especially those who reported engaging in at least some park-based PA. As well, respondents with a greater number of parks nearby, whose closest park had more features, and whose closest park contained a playground or wooded area were more likely to achieve a match. Having a ball diamond or soccer field in the closest park was negatively related to achieving a match between perceived and objective proximity. Finally, engaging in at least some park-based PA was not related to either perceived or objective proximity to a park, but was more likely when a match between and perceived and objective proximity occurred.</p> <p>Conclusion</p> <p>Poor levels of correspondence were observed between self-reported and objective proximity to parks, but certain individual, neighborhood, and park variables increased the likelihood of a participant being aware of local parks. Future research should examine how people conceptualize parks and what urban and park planners can do to increase awareness and use of these community assets.</p

Alignment and Aperture Scan at the Fermilab Booster

The Fermilab booster has an intensity upgrade plan called the Proton Improvement plan (PIP). The flux throughput goal is 2E17 protons/hour, which is almost double the current operation at 1.1E17 protons/hour. The beam loss in the machine is going to be the source of issues. The booster accelerates beam from 400 MeV to 8 GeV and extracts to the Main Injector. Several percent of the beam is lost within 3 msec after the injection. The aperture at injection energy was measured and compared with the survey data. The magnets are going to be realigned in March 2012 in order to increase the aperture. The beam studies, analysis of the scan and alignment data, and the result of the magnet moves will be discussed in this paper.Comment: 3 pp. 3rd International Particle Accelerator Conference (IPAC 2012) 20-25 May 2012, New Orleans, Louisian

Structural modeling of aircraft tires

A theoretical and experimental investigation of the feasibility of determining the mechanical properties of aircraft tires from small-scale model tires was accomplished. The theoretical results indicate that the macroscopic static and dynamic mechanical properties of aircraft tires can be accurately determined from the scale model tires although the microscopic and thermal properties of aircraft tires can not. The experimental investigation was conducted on a scale model of a 40 x 12, 14 ply rated, type 7 aircraft tire with a scaling factor of 8.65. The experimental results indicate that the scale model tire exhibited the same static mechanical properties as the prototype tire when compared on a dimensionless basis. The structural modeling concept discussed in this report is believed to be exact for mechanical properties of aircraft tires under static, rolling, and transient conditions

Mars mission solar array Semiannual progress report, period ending 31 Dec. 1969

Design and testing of beryllium-structure solar panel for Mars missio

Assertion, Uniqueness and Epistemic Hypocrisy

Pascal Engel (2008) has insisted that a number of notable strategies for rejecting the knowledge norm of assertion are put forward on the basis of the wrong kinds of reasons. A central aim of this paper will be to establish the contrast point: I argue that one very familiar strategy for defending the knowledge norm of assertion—viz., that it is claimed to do better in various respects than its competitors (e.g. the justification and the truth norms)— relies on a presupposition that is shown to be ultimately under motivated. That presupposition is the uniqueness thesis—that there is a unique epistemic rule for assertion, and that such a rule will govern assertions uniformly. In particular, the strategy I shall take here will be to challenge the sufficiency leg of the knowledge norm in a way that at the same time counts against Williamson’s (2000) own rationale for the uniqueness thesis. However, rather than to challenge the sufficiency leg of the knowledge norm via the familiar style of ‘expert opinion’ and, more generally, ‘second-hand knowledge’ cases (e.g. Lackey (2008)), a strategy that has recently been called into question by Benton (2014), I’ll instead advance a very different line of argument against the sufficiency thesis, one which turns on a phenomenon I call epistemic hypocrisy

Atomic resolution scanning tunneling microscopy images of Au(111) surfaces in air and polar organic solvents

Atomic features of a close‐packed metal surface have been observed for the first time by scanning tunneling microscopy in organic polar solvents. Evaporated gold films, exhibiting large reconstructed (111) terraces, have been imaged with a resolution far superior to previous results in aqueous environments