Contextualizing Walkability: Do Relationships Between Built Environments and Walking Vary by Socioeconomic Context?

Problem, research strategy, and findings: Supportive built environments for walking are linked to higher rates of walking and physical activity, but little is known about this relationship for socioeconomically disadvantaged (e.g., low-income and racial/ethnic minority) populations. We review 17 articles and find that most show that the built environment has weaker effects on walking and physical activity for disadvantaged than advantaged groups. Those who lived in supportive built environments walked more and were more physically active than those who did not, but the effect was about twice as large for advantaged groups. We see this difference because disadvantaged groups walked more in unsupportive built environments and less in supportive built environments, though the latter appears more influential.

Takeaway for practice: Defining walkability entirely in built environment terms may fail to account for important social and individual/household characteristics and other non–built environment factors that challenge disadvantaged groups, including fear of crime and lack of social support. Planners must be sensitive to these findings and to community concerns about gentrification and displacement in the face of planned built environment improvements that may benefit more advantaged populations. We recommend five planning responses: Recognize that the effects of the built environment may vary by socioeconomics; use holistic approaches to improve walkability; expand walkability definitions to address a range of social and physical barriers; partner across agencies, disciplines, and professions; and evaluate interventions in different socioeconomic environments.     

Voluntary physical exercise alters attentional orienting and social behavior in a rat model of attention-deficit/hyperactivity disorder.

The effects of voluntary physical exercise on attentional function and social behavior were examined in male and female spontaneously hypertensive rats (SHR), a commonly used animal model of attention-deficit/hyperactivity disorder (ADHD). Rats in the exercise groups had free access to a running wheel for 2 weeks and then all rats received nonreinforced presentations of a visual stimulus (light) during the 1st training session, followed by daily sessions in which the light was paired with food. Nonexercising male and female SHR rats exhibited more unconditioned orienting behavior than Wistar–Kyoto rats. SHRs also exhibited impaired conditioning when the light was paired with food. Exercise reduced orienting in female SHRs but not in male SHRs. In the social interaction task, nonexercising male and female SHRs interacted more with an unfamiliar rat than Wistar–Kyoto rats. Exercise reduced the number of social interactions in female SHRs but not male SHRs. There were no differences in general locomotor activity observed between the nonexercising and exercising SHRs. These data indicate that exercise may preferentially benefit female SHRs, and has implications for using exercise as an intervention for ADHD and for understanding sex differences in the effects of exercise on behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

来自英国的摩登家庭影院系统：KEF KHT2005.3卫星音箱组合

自2005起,RFID技术使得盐湖城图书馆服务机构（SLCLS）受益匪浅,主要体现在自助借书、自动分类以及防盗系统三个方面。SLCLS已经在其18个图书馆中的10个图书馆里成功推行RFID技术,下一步目标则是进一步提高性能,尤其是提高贴标CD和DVD的可靠性和成本效益。对馆藏CD和VCD使用这种基于RFID的系统时,经常会碰到各种各样的问题。经严格的试验证实,一种新的方案能够将这些问题予以解决。     

A pound of prevention,plus a pound of cure: Early detection and eradication of invasive species in the Laurentian Great Lakes

Ballast water regulations implemented in the early 1990s appear not to have slowed the rate of new aquatic invasive species (AIS) establishment in the Great Lakes. With more invasive species on the horizon, we examine the question of whether eradication of AIS is a viable management strategy for the Laurentian Great Lakes, and what a coordinated AIS early detection and eradication program would entail. In-lake monitoring would be conducted to assess the effectiveness of regulations aimed at stopping new AIS, and to maximize the likelihood of early detection of new invaders. Monitoring would be focused on detecting the most probable invaders, the most invasion-prone habitats, and the species most conducive to eradication. When a new non-native species is discovered, an eradication assessment would be conducted and used to guide the management response. In light of high uncertainty, management decisions must be robust to a range of impact and control scenarios. Though prevention should continue to be the cornerstone of management efforts, we believe that a coordinated early detection and eradication program is warranted if the Great Lakes management community and stakeholders are serious about reducing undesired impacts stemming from new AIS in the Great Lakes. Development of such a program is an opportunity for the Laurentian Great Lakes resource management community to demonstrate global leadership in invasive species management.     

Effects of lateral hypothalamic lesions on food intake of rats during exposure to cold.

Two experiments investigated the feeding behavior of 41 male Sprague-Dawley rats with lateral hypothalamic (LH) lesions and 13 Ss with chemical lesions of central dopaminergic neurons. LH damage impaired both physiological and behavioral responses of Ss during exposure to a 5°C environment. The LH-lesioned Ss usually did not conserve heat in the cold as well as did controls (n?=?13), nor did they always increase their caloric intake to meet their energy needs. However, when given sucrose solution to drink instead of water, LH-lesioned Ss increased their ingestion of chow in response to cold exposure. It is likely that the elevated consumption of palatable fluid served to relieve dehydration and thereby removed its constraints on eating, thus permitting hyperphagia to occur. In contrast to these results, Ss with large dopamine-depleting brain lesions, produced by intraventricular 6-hydroxydopamine treatments, always increased food intake when exposed to cold stress and demonstrated no apparent problems in peripheral vasoconstriction. Thus, it is unlikely that striatal dopamine depletions account for either the impaired feeding response or the inadequate heat conservation of rats with lateral hypothalamic lesions during cold stress. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cation Distributions in Rapidly Solidified Cobalt Ferrite

The cation distributions in two rapidly solidified cobalt ferrites have been determined using Mössbauer spectroscopy at 4.2 K in an 8-T magnetic field. The samples were obtained by gas atomization of a CoO–Fe₂O₃–P₂O₅ melt. The degree of cation disorder in both cases was greater than is obtainable by cooling unmelted cobalt ferrite. The more rapidly cooled sample exhibited a smaller departure from the equilibrium cation distribution than did the more slowly cooled sample. This result is explained on the basis of two competing effects of rapid solidification: high cooling rate of the solid, and large undercooling.     

Partial-transfer absorption imaging: A versatile technique for optimal imaging of ultracold gases

Partial-transfer absorption imaging is a tool that enables optimal imaging of atomic clouds for a wide range of optical depths. In contrast to standard absorption imaging, the technique can be minimally destructive and can be used to obtain multiple successive images of the same sample. The technique involves transferring a small fraction of the sample from an initial internal atomic state to an auxiliary state and subsequently imaging that fraction absorptively on a cycling transition. The atoms remaining in the initial state are essentially unaffected. We demonstrate the technique, discuss its applicability, and compare its performance as a minimally destructive technique to that of phase-contrast imaging.     

Oral exposure to polystyrene nanoparticles affects iron absorption

The use of engineered nanoparticles in food and pharmaceuticals is expected to increase, but the impact of chronic oral exposure to nanoparticles on human health remains unknown. Here, we show that chronic and acute oral exposure to polystyrene nanoparticles can influence iron uptake and iron transport in an in vitro model of the intestinal epithelium and an in vivo chicken intestinal loop model. Intestinal cells that are exposed to high doses of nanoparticles showed increased iron transport due to nanoparticle disruption of the cell membrane. Chickens acutely exposed to carboxylated particles (50?nm in diameter) had a lower iron absorption than unexposed or chronically exposed birds. Chronic exposure caused remodelling of the intestinal villi, which increased the surface area available for iron absorption. The agreement between the in vitro and in vivo results suggests that our in vitro intestinal epithelium model is potentially useful for toxicology studies.