3,369 research outputs found
Neighborhood satisfaction, functional limitations, and self-efficacy influences on physical activity in older women
<p>Abstract</p> <p>Background</p> <p>Perceptions of one's environment and functional status have been linked to physical activity in older adults. However, little is known about these associations over time, and even less about the possible mediators of this relationship. We examined the roles played by neighborhood satisfaction, functional limitations, self-efficacy, and physical activity in a sample of older women over a 6-month period.</p> <p>Methods</p> <p>Participants (<it>N </it>= 137, <it>M </it>age = 69.6 years) completed measures of neighborhood satisfaction, functional limitations, self-efficacy, and physical activity at baseline and again 6 months later.</p> <p>Results</p> <p>Analyses indicated that changes in neighborhood satisfaction and functional limitations had direct effects on residual changes in self-efficacy, and changes in self-efficacy were associated with changes in physical activity at 6 months.</p> <p>Conclusion</p> <p>Our findings support a social cognitive model of physical activity in which neighborhood satisfaction and functional status effects on physical activity are in part mediated by intermediate individual outcomes such as self-efficacy. Additionally, these findings lend support to the position that individual perceptions of both the environment and functional status can have prospective effects on self-efficacy cognitions and ultimately, physical activity behavior.</p
Misalignment of Career and Educational Aspirations in Middle School: Differences Across Race, Ethnicity, and Socioeconomic Status
Misalignment of educational and career goals (i.e., educational aspirations expressed are inadequate for attaining one’s desired occupation) is associated with lower educational attainment and a lack of college readiness, and may contribute to persistent educational and employment disparities. Drawing on data from 249 sixth graders in low-income schools, this research examines misalignment between educational and career aspirations across racial and ethnic and socioeconomic groups. Findings indicate that students in low-income schools aspire to middle and upper middle class careers, but sometimes lack an understanding of the educational degrees required to achieve their goals. Latinos are significantly more likely than other groups to report misaligned aspirations, as are students in the free and reduced lunch program and those without a college-educated parent. Consequently, early gaps in misaligned career and educational goals for disadvantaged students may set them on a trajectory that perpetuates educational and occupational inequalities in this population. We discuss the programmatic implications of these findings in light of the elevated college and career planning needs of students traditionally underrepresented in higher education
Rotating traversable wormholes
The general form of a stationary, axially symmetric traversable wormhole is
discussed. This provides an explicit class of rotating wormholes that
generalize the static, spherically symmetric ones first considered by Morris
and Thorne. In agreement with general analyses, it is verified that such a
wormhole generically violates the null energy condition at the throat. However,
for suitable model wormholes, there can be classes of geodesics falling through
it which do not encounter any energy-condition-violating matter. The possible
presence of an ergoregion surrounding the throat is also noted.Comment: 15 pages, harvmac; 1 figure in PicTeX; minor changes; to appear in
Phys. Rev.
Jumping the Gun: Mapping Neural Correlates of Waiting Impulsivity and Relevance Across Alcohol Misuse.
BACKGROUND: Why do we jump the gun or speak out of turn? Waiting impulsivity has a preclinical basis as a predictor for the development of addiction. Here, we mapped the intrinsic neural correlates of waiting and dissociated it from stopping, both fundamental mechanisms of behavioral control. METHODS: We used a recently developed translational task to assess premature responding and assess response inhibition using the stop signal task. We mapped the neural correlates in 55 healthy volunteers using a novel multi-echo resting-state functional magnetic resonance imaging sequence and analysis, which robustly boosts signal-to-noise ratio. We further assessed 32 young binge drinkers and 36 abstinent subjects with alcohol use disorders. RESULTS: Connectivity of limbic and motor cortical and striatal nodes mapped onto a mesial-lateral axis of the subthalamic nucleus. Waiting impulsivity was associated with lower connectivity of the subthalamic nucleus with ventral striatum and subgenual cingulate, regions similarly implicated in rodent lesion studies. This network was dissociable from fast reactive stopping involving hyperdirect connections of the pre-supplementary area and subthalamic nucleus. We further showed that binge drinkers, like those with alcohol use disorders, had elevated premature responding and emphasized the relevance of this subthalamic network across alcohol misuse. Using machine learning techniques we showed that subthalamic connectivity differentiates binge drinkers and individuals with alcohol use disorders from healthy volunteers. CONCLUSIONS: We highlight the translational and clinical relevance of dissociable functional systems of cortical, striatal, and hyperdirect connections with the subthalamic nucleus in modulating waiting and stopping and their importance across dimensions of alcohol misuse.The study was funded by the Wellcome Trust Fellowship grant for VV (093705/Z/10/Z) and Cambridge NIHR Biomedical Research Centre. VV and NAH are Wellcome Trust (WT) intermediate Clinical Fellows. The BCNI is supported by a WT and MRC grant. ETB is employed part-time by the University of Cambridge and part-time by GSK PLC and is a shareholder of GSK. TWR is a consultant for Cambridge Cognition, Eli Lilly, GSK, Merck, Sharpe and Dohme, Lundbeck, Teva and Shire Pharmaceuticals. He is or has been in receipt of research grants from Lundbeck, Eli Lilly and GSK and is an editor for Springer-Verlag (Psychopharmacology). The remaining authors declare no competing financial interests.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.biopsych.2015.06.00
Fronto-striatal organization: Defining functional and microstructural substrates of behavioural flexibility.
Discrete yet overlapping frontal-striatal circuits mediate broadly dissociable cognitive and behavioural processes. Using a recently developed multi-echo resting-state functional MRI (magnetic resonance imaging) sequence with greatly enhanced signal compared to noise ratios, we map frontal cortical functional projections to the striatum and striatal projections through the direct and indirect basal ganglia circuit. We demonstrate distinct limbic (ventromedial prefrontal regions, ventral striatum - VS, ventral tegmental area - VTA), motor (supplementary motor areas - SMAs, putamen, substantia nigra) and cognitive (lateral prefrontal and caudate) functional connectivity. We confirm the functional nature of the cortico-striatal connections, demonstrating correlates of well-established goal-directed behaviour (involving medial orbitofrontal cortex - mOFC and VS), probabilistic reversal learning (lateral orbitofrontal cortex - lOFC and VS) and attentional shifting (dorsolateral prefrontal cortex - dlPFC and VS) while assessing habitual model-free (SMA and putamen) behaviours on an exploratory basis. We further use neurite orientation dispersion and density imaging (NODDI) to show that more goal-directed model-based learning (MBc) is also associated with higher mOFC neurite density and habitual model-free learning (MFc) implicates neurite complexity in the putamen. This data highlights similarities between a computational account of MFc and conventional measures of habit learning. We highlight the intrinsic functional and structural architecture of parallel systems of behavioural control.VV and NAH are Wellcome Trust (WT) intermediate Clinical Fellows. LM is in receipt of an MRC studentship. The BCNI is supported by a WT and MRC grant. ETB is employed part-time by the University of Cambridge and part-time by GSK PLC and is a shareholder of GSK. TWR is a consultant for Cambridge Cognition, Eli Lilly, GSK, Merck, Sharpe and Dohme, Lundbeck, Teva and Shire Pharmaceuticals. He is or has been in receipt of research grants from Lundbeck, Eli Lilly and GSK and is an editor for Springer-Verlag (Psychopharmacology). The remaining authors declare no competing financial interests. The study was funded by the Wellcome Trust Fellowship grant for VV (093705/Z/10/Z) and Cambridge NIHR Biomedical Research Centre.This is the final version of the article. It was first available from Elsevier via http://dx.doi.org/10.1016/j.cortex.2015.11.00
On Critchfield's proposal: student concerns and recommendations
This is the published version, reproduced here with the publisher's permission. This article is also available electronically from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3359848/.No abstract available for this item
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