WorldWideScience

Sample records for neighborhood size effect

  1. Does neighborhood size really cause the word length effect?

    Science.gov (United States)

    Guitard, Dominic; Saint-Aubin, Jean; Tehan, Gerald; Tolan, Anne

    2018-02-01

    In short-term serial recall, it is well-known that short words are remembered better than long words. This word length effect has been the cornerstone of the working memory model and a benchmark effect that all models of immediate memory should account for. Currently, there is no consensus as to what determines the word length effect. Jalbert and colleagues (Jalbert, Neath, Bireta, & Surprenant, 2011a; Jalbert, Neath, & Surprenant, 2011b) suggested that neighborhood size is one causal factor. In six experiments we systematically examined their suggestion. In Experiment 1, with an immediate serial recall task, multiple word lengths, and a large pool of words controlled for neighborhood size, the typical word length effect was present. In Experiments 2 and 3, with an order reconstruction task and words with either many or few neighbors, we observed the typical word length effect. In Experiment 4 we tested the hypothesis that the previous abolition of the word length effect when neighborhood size was controlled was due to a confounded factor: frequency of orthographic structure. As predicted, we reversed the word length effect when using short words with less frequent orthographic structures than the long words, as was done in both of Jalbert et al.'s studies. In Experiments 5 and 6, we again observed the typical word length effect, even if we controlled for neighborhood size and frequency of orthographic structure. Overall, the results were not consistent with the predictions of Jalbert et al. and clearly showed a large and reliable word length effect after controlling for neighborhood size.

  2. Development of neural basis for chinese orthographic neighborhood size effect.

    Science.gov (United States)

    Zhao, Jing; Li, Qing-Lin; Ding, Guo-Sheng; Bi, Hong-Yan

    2016-02-01

    The brain activity of orthographic neighborhood size (N size) effect in Chinese character naming has been studied in adults, meanwhile behavioral studies have revealed a developmental trend of Chinese N-size effect in developing readers. However, it is unclear whether and how the neural mechanism of N-size effect changes in Chinese children along with development. Here we address this issue using functional magnetic resonance imaging. Forty-four students from the 3(rd) , 5(th) , and 7(th) grades were scanned during silent naming of Chinese characters. After scanning, all participants took part in an overt naming test outside the scanner, and results of the naming task showed that the 3(rd) graders named characters from large neighborhoods faster than those from small neighborhoods, revealing a facilitatory N-size effect; the 5(th) graders showed null N-size effect while the 7(th) graders showed an inhibitory N-size effect. Neuroimaging results revealed that only the 3(rd) graders exhibited a significant N-size effect in the left middle occipital activity, with greater activation for large N-size characters. Results of 5(th) and 7(th) graders showed significant N-size effects in the left middle frontal gyrus, in which 5(th) graders induced greater activation in large N-size condition than in small N-size condition, while 7(th) graders exhibited an opposite effect which was similar to the adult pattern reported in a previous study. The current findings suggested the transition from broadly tuned to finely tuned orthographic representation with reading development, and the inhibition from neighbors' phonology for higher graders. Hum Brain Mapp 37:632-647, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  3. Does length or neighborhood size cause the word length effect?

    Science.gov (United States)

    Jalbert, Annie; Neath, Ian; Surprenant, Aimée M

    2011-10-01

    Jalbert, Neath, Bireta, and Surprenant (2011) suggested that past demonstrations of the word length effect, the finding that words with fewer syllables are recalled better than words with more syllables, included a confound: The short words had more orthographic neighbors than the long words. The experiments reported here test two predictions that would follow if neighborhood size is a more important factor than word length. In Experiment 1, we found that concurrent articulation removed the effect of neighborhood size, just as it removes the effect of word length. Experiment 2 demonstrated that this pattern is also found with nonwords. For Experiment 3, we factorially manipulated length and neighborhood size, and found only effects of the latter. These results are problematic for any theory of memory that includes decay offset by rehearsal, but they are consistent with accounts that include a redintegrative stage that is susceptible to disruption by noise. The results also confirm the importance of lexical and linguistic factors on memory tasks thought to tap short-term memory.

  4. The characteristics of Chinese orthographic neighborhood size effect for developing readers.

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    Full Text Available Orthographic neighborhood size (N size effect in Chinese character naming has been studied in adults. In the present study, we aimed to explore the developmental characteristics of Chinese N size effect. One hundred and seventeen students (40 from the 3(rd grade with mean age of 9 years; 40 from the 5(th grade with mean age of 11 years; 37 from the 7(th grade with mean age of 13 years were recruited in the study. A naming task of Chinese characters was adopted to elucidate N-size- effect development. Reaction times and error rates were recorded. Results showed that children in the 3(rd grade named characters from large neighborhoods faster than named those from small neighborhoods, revealing a facilitatory N size effect; the 5(th graders showed null N size effect; while the 7(th graders showed an inhibitory N size effect, with longer reaction times for the characters from large neighborhoods than for those from small neighborhoods. The change from facilitation to inhibition of neighborhood size effect across grades suggested the transition from broadly tuned to finely tuned lexical representation in reading development, and the possible inhibition from higher frequency neighbors for higher graders.

  5. The effect of lexical factors on recall from working memory: Generalizing the neighborhood size effect.

    Science.gov (United States)

    Derraugh, Lesley S; Neath, Ian; Surprenant, Aimée M; Beaudry, Olivia; Saint-Aubin, Jean

    2017-03-01

    The word-length effect, the finding that lists of short words are better recalled than lists of long words, is 1 of the 4 benchmark phenomena that guided development of the phonological loop component of working memory. However, previous work has noted a confound in word-length studies: The short words used had more orthographic neighbors (valid words that can be made by changing a single letter in the target word) than long words. The confound is that words with more neighbors are better recalled than otherwise comparable words with fewer neighbors. Two experiments are reported that address criticisms of the neighborhood-size account of the word-length effect by (1) testing 2 new stimulus sets, (2) using open rather than closed pools of words, and (3) using stimuli from a language other than English. In both experiments, words from large neighborhoods were better recalled than words from small neighborhoods. The results add to the growing number of studies demonstrating the substantial contribution of long-term memory to what have traditionally been identified as working memory tasks. The data are more easily explained by models incorporating the concept of redintegration rather than by frameworks such as the phonological loop that posit decay offset by rehearsal. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  6. The Role of Orthographic Neighborhood Size Effects in Chinese Word Recognition

    Science.gov (United States)

    Li, Meng-Feng; Lin, Wei-Chun; Chou, Tai-Li; Yang, Fu-Ling; Wu, Jei-Tun

    2015-01-01

    Previous studies about the orthographic neighborhood size (NS) in Chinese have overlooked the morphological processing, and the co-variation between the character frequency and the the NS. The present study manipulated the word frequency and the NS simultaneously, with the leading character frequency controlled, to explore their influences on word…

  7. Conduct Disorder and Neighborhood Effects.

    Science.gov (United States)

    Jennings, Wesley G; Perez, Nicholas M; Reingle Gonzalez, Jennifer M

    2018-05-07

    There has been a considerable amount of scholarly attention to the relationship between neighborhood effects and conduct disorder, particularly in recent years. Having said this, it has been nearly two decades since a comprehensive synthesis of this literature has been conducted. Relying on a detailed and comprehensive search strategy and inclusion criteria, this article offers a systematic and interdisciplinary review of 47 empirical studies that have examined neighborhood effects and conduct disorder. Described results suggest that there are generally robust linkages between adverse neighborhood factors and conduct disorder and externalizing behavior problems, as 67 of the 93 (72.04%) effect sizes derived from these studies yielded statistically significant neighborhood effects. The review also identifies salient mediating and moderating influences. It discusses study limitations and directions for future research as well.

  8. Estimation of effective population size in continuously distributed populations: There goes the neighborhood

    Science.gov (United States)

    M. C. Neel; K. McKelvey; N. Ryman; M. W. Lloyd; R. Short Bull; F. W. Allendorf; M. K. Schwartz; R. S. Waples

    2013-01-01

    Use of genetic methods to estimate effective population size (Ne) is rapidly increasing, but all approaches make simplifying assumptions unlikely to be met in real populations. In particular, all assume a single, unstructured population, and none has been evaluated for use with continuously distributed species. We simulated continuous populations with local mating...

  9. Neighborhood choices, neighborhood effects and housing vouchers

    OpenAIRE

    Davis, Morris A.; Gregory, Jesse; Hartley, Daniel A.; Tan, Kegon T. K.

    2017-01-01

    We study how households choose neighborhoods, how neighborhoods affect child ability, and how housing vouchers influence neighborhood choices and child outcomes. We use two new panel data sets with tract-level detail for Los Angeles county to estimate a dynamic model of optimal tract-level location choice for renting households and, separately, the impact of living in a given tract on child test scores (which we call "child ability" throughout). We simulate optimal location choices and change...

  10. Effects of semantic neighborhood density in abstract and concrete words.

    Science.gov (United States)

    Reilly, Megan; Desai, Rutvik H

    2017-12-01

    Concrete and abstract words are thought to differ along several psycholinguistic variables, such as frequency and emotional content. Here, we consider another variable, semantic neighborhood density, which has received much less attention, likely because semantic neighborhoods of abstract words are difficult to measure. Using a corpus-based method that creates representations of words that emphasize featural information, the current investigation explores the relationship between neighborhood density and concreteness in a large set of English nouns. Two important observations emerge. First, semantic neighborhood density is higher for concrete than for abstract words, even when other variables are accounted for, especially for smaller neighborhood sizes. Second, the effects of semantic neighborhood density on behavior are different for concrete and abstract words. Lexical decision reaction times are fastest for words with sparse neighborhoods; however, this effect is stronger for concrete words than for abstract words. These results suggest that semantic neighborhood density plays a role in the cognitive and psycholinguistic differences between concrete and abstract words, and should be taken into account in studies involving lexical semantics. Furthermore, the pattern of results with the current feature-based neighborhood measure is very different from that with associatively defined neighborhoods, suggesting that these two methods should be treated as separate measures rather than two interchangeable measures of semantic neighborhoods. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Positive Neighborhood Norms Buffer Ethnic Diversity Effects on Neighborhood Dissatisfaction, Perceived Neighborhood Disadvantage, and Moving Intentions.

    Science.gov (United States)

    Van Assche, Jasper; Asbrock, Frank; Roets, Arne; Kauff, Mathias

    2018-05-01

    Positive neighborhood norms, such as strong local networks, are critical to people's satisfaction with, perceived disadvantage of, and intentions to stay in their neighborhood. At the same time, local ethnic diversity is said to be detrimental for these community outcomes. Integrating both frameworks, we tested whether the negative consequences of diversity occur even when perceived social norms are positive. Study 1 ( N = 1,760 German adults) showed that perceptions of positive neighborhood norms buffered against the effects of perceived diversity on moving intentions via neighborhood satisfaction and perceived neighborhood disadvantage. Study 2 ( N = 993 Dutch adults) replicated and extended this moderated mediation model using other characteristics of diversity (i.e., objective and estimated minority proportions). Multilevel analyses again revealed consistent buffering effects of positive neighborhood norms. Our findings are discussed in light of the ongoing public and political debate concerning diversity and social and communal life.

  12. Neighborhood Frequency Effect in Chinese Word Recognition: Evidence from Naming and Lexical Decision

    Science.gov (United States)

    Li, Meng-Feng; Gao, Xin-Yu; Chou, Tai-Li; Wu, Jei-Tun

    2017-01-01

    Neighborhood frequency is a crucial variable to know the nature of word recognition. Different from alphabetic scripts, neighborhood frequency in Chinese is usually confounded by component character frequency and neighborhood size. Three experiments were designed to explore the role of the neighborhood frequency effect in Chinese and the stimuli…

  13. Neighborhood Effects on Youth Crime

    DEFF Research Database (Denmark)

    Rotger, Gabriel Pons; Galster, George Charles

    We investigate the degree to which youth (ages 14-29) criminal offenses are influenced by neighbors, identifying causal effects with a natural experimental allocation of social housing in Copenhagen. We find that youth exposed to a one percentage point higher concentration of neighbors with drug...... criminal records are 6% more likely to be charged for criminal offenses (both drug and property crimes), and this impact manifests itself after six months of exposure. This neighborhood effect is stronger for previous offenders, and does not lead to criminal partnerships. Our exploration of alternative...

  14. Incorporating Neighborhood Choice in a Model of Neighborhood Effects on Income.

    Science.gov (United States)

    van Ham, Maarten; Boschman, Sanne; Vogel, Matt

    2018-05-09

    Studies of neighborhood effects often attempt to identify causal effects of neighborhood characteristics on individual outcomes, such as income, education, employment, and health. However, selection looms large in this line of research, and it has been argued that estimates of neighborhood effects are biased because people nonrandomly select into neighborhoods based on their preferences, income, and the availability of alternative housing. We propose a two-step framework to disentangle selection processes in the relationship between neighborhood deprivation and earnings. We model neighborhood selection using a conditional logit model, from which we derive correction terms. Driven by the recognition that most households prefer certain types of neighborhoods rather than specific areas, we employ a principle components analysis to reduce these terms into eight correction components. We use these to adjust parameter estimates from a model of subsequent neighborhood effects on individual income for the unequal probability that a household chooses to live in a particular type of neighborhood. We apply this technique to administrative data from the Netherlands. After we adjust for the differential sorting of households into certain types of neighborhoods, the effect of neighborhood income on individual income diminishes but remains significant. These results further emphasize that researchers need to be attuned to the role of selection bias when assessing the role of neighborhood effects on individual outcomes. Perhaps more importantly, the persistent effect of neighborhood deprivation on subsequent earnings suggests that neighborhood effects reflect more than the shared characteristics of neighborhood residents: place of residence partially determines economic well-being.

  15. The impact of neighborhood walkability on walking: does it differ across adult life stage and does neighborhood buffer size matter?

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    Villanueva, Karen; Knuiman, Matthew; Nathan, Andrea; Giles-Corti, Billie; Christian, Hayley; Foster, Sarah; Bull, Fiona

    2014-01-01

    We explored the impact of neighborhood walkability on young adults, early-middle adults, middle-aged adults, and older adults' walking across different neighborhood buffers. Participants completed the Western Australian Health and Wellbeing Surveillance System Survey (2003-2009) and were allocated a neighborhood walkability score at 200m, 400m, 800m, and 1600m around their home. We found little difference in strength of associations across neighborhood size buffers for all life stages. We conclude that neighborhood walkability supports more walking regardless of adult life stage and is relevant for small (e.g., 200m) and larger (e.g., 1600m) neighborhood buffers. © 2013 The Authors. Published by Elsevier Ltd All rights reserved.

  16. Neighborhood-Specific and General Social Support: Which Buffers the Effect of Neighborhood Disorder on Depression?

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    Kim, Joongbaeck; Ross, Catherine E.

    2009-01-01

    Is neighborhood-specific social support the most effective type of social support for buffering the effect of neighborhood disorder on depression? Matching theory suggests that it is. The authors extend the research on neighborhood disorder and adult depression by showing that individuals who have higher levels of both general and…

  17. Neighborhood size and local geographic variation of health and social determinants

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    Emch Michael

    2005-06-01

    Full Text Available Abstract Background Spatial filtering using a geographic information system (GIS is often used to smooth health and ecological data. Smoothing disease data can help us understand local (neighborhood geographic variation and ecological risk of diseases. Analyses that use small neighborhood sizes yield individualistic patterns and large sizes reveal the global structure of data where local variation is obscured. Therefore, choosing an optimal neighborhood size is important for understanding ecological associations with diseases. This paper uses Hartley's test of homogeneity of variance (Fmax as a methodological solution for selecting optimal neighborhood sizes. The data from a study area in Vietnam are used to test the suitability of this method. Results The Hartley's Fmax test was applied to spatial variables for two enteric diseases and two socioeconomic determinants. Various neighbourhood sizes were tested by using a two step process to implement the Fmaxtest. First the variance of each neighborhood was compared to the highest neighborhood variance (upper, Fmax1 and then they were compared with the lowest neighborhood variance (lower, Fmax2. A significant value of Fmax1 indicates that the neighborhood does not reveal the global structure of data, and in contrast, a significant value in Fmax2 implies that the neighborhood data are not individualistic. The neighborhoods that are between the lower and the upper limits are the optimal neighbourhood sizes. Conclusion The results of tests provide different neighbourhood sizes for different variables suggesting that optimal neighbourhood size is data dependent. In ecology, it is well known that observation scales may influence ecological inference. Therefore, selecting optimal neigborhood size is essential for understanding disease ecologies. The optimal neighbourhood selection method that is tested in this paper can be useful in health and ecological studies.

  18. Neighborhood effects in a behavioral randomized controlled trial.

    Science.gov (United States)

    Pruitt, Sandi L; Leonard, Tammy; Murdoch, James; Hughes, Amy; McQueen, Amy; Gupta, Samir

    2014-11-01

    Randomized controlled trials (RCTs) of interventions intended to modify health behaviors may be influenced by neighborhood effects which can impede unbiased estimation of intervention effects. Examining a RCT designed to increase colorectal cancer (CRC) screening (N=5628), we found statistically significant neighborhood effects: average CRC test use among neighboring study participants was significantly and positively associated with individual patient's CRC test use. This potentially important spatially-varying covariate has not previously been considered in a RCT. Our results suggest that future RCTs of health behavior interventions should assess potential social interactions between participants, which may cause intervention arm contamination and may bias effect size estimation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. The neighborhoods they live in: the effects of neighborhood residence on child and adolescent outcomes.

    Science.gov (United States)

    Leventhal, T; Brooks-Gunn, J

    2000-03-01

    This article provides a comprehensive review of research on the effects of neighborhood residence on child and adolescent well-being. The first section reviews key methodological issues. The following section considers links between neighborhood characteristics and child outcomes and suggests the importance of high socioeconomic status (SES) for achievement and low SES and residential instability for behavioral/emotional outcomes. The third section identifies 3 pathways (institutional resources, relationships, and norms/collective efficacy) through which neighborhoods might influence development, and which represent an extension of models identified by C. Jencks and S. Mayer (1990) and R. J. Sampson (1992). The models provide a theoretical base for studying neighborhood mechanisms and specify different levels (individual, family, school, peer, community) at which processes may operate. Implications for an emerging developmental framework for research on neighborhoods are discussed.

  20. A hybrid adaptive large neighborhood search algorithm applied to a lot-sizing problem

    DEFF Research Database (Denmark)

    Muller, Laurent Flindt; Spoorendonk, Simon

    This paper presents a hybrid of a general heuristic framework that has been successfully applied to vehicle routing problems and a general purpose MIP solver. The framework uses local search and an adaptive procedure which choses between a set of large neighborhoods to be searched. A mixed integer...... of a solution and to investigate the feasibility of elements in such a neighborhood. The hybrid heuristic framework is applied to the multi-item capacitated lot sizing problem with dynamic lot sizes, where experiments have been conducted on a series of instances from the literature. On average the heuristic...

  1. It takes a village: Fixed-effects analysis of neighborhood collective efficacy and children's development

    Directory of Open Access Journals (Sweden)

    Kayoko Ichikawa

    2017-08-01

    Full Text Available Background: Previous studies suggest that neighborhood social capital is associated with children's mental health. The purpose of this study was to examine the association between neighborhood collective efficacy and children's psychosocial development. Methods: We used data on children and their parents (n = 918 who were part of the Japanese study of Stratification, Health, Income, and Neighborhood (JSHINE from 2010 to 2013 (wave 1 and wave 2. Households were recruited from the Tokyo metropolitan area through clustered random sampling. Changes in children's psychosocial development (assessed using a child behavioral checklist between waves 1 and 2 were regressed on parents' perceptions of changes in neighborhood collective efficacy (social cohesion and informal social control. Results: Change in perception of neighborhood social cohesion was inversely associated with change in child total problems (β = −0.22; 95% confidence interval [CI]: −0.37 to −0.001; effect size d = −0.03. Change in perceptions of neighborhood informal social control was inversely associated with change in children's externalizing problems (β = −0.16; 95% CI: −0.30 to −0.03; d = −0.02. Conclusions: The results of these fixed-effects models suggest that strengthening neighborhood collective efficacy is related to improvements in child psychosocial development.

  2. Neighborhood size of training data influences soil map disaggregation

    Science.gov (United States)

    Soil class mapping relies on the ability of sample locations to represent portions of the landscape with similar soil types; however, most digital soil mapping (DSM) approaches intersect sample locations with one raster pixel per covariate layer regardless of pixel size. This approach does not take ...

  3. Sustainable transportation according to certification systems: A viability analysis based on neighborhood size and context relevance

    International Nuclear Information System (INIS)

    Gouda, Amr Ah.; Masoumi, Houshmand E.

    2017-01-01

    Urban sustainability certification (USC) systems comprehensively assess and benchmark the sustainability of neighborhoods, communities, etc. However, it is important to understand what USCs mean by neighborhoods and communities in terms of definition and their certified developments' size. This study focuses on sustainable transportation and its measures in USCs in order to discern: how relevant are these measures to the varied local conditions, especially in developing countries? And whether they can generate palpable benefits vis-à-vis the certified developments' site areas. Taking descriptive analysis methods, this study focuses on four prominent USCs, namely, LEED for Neighborhood Development, BREEAM Communities, CASBEE for Urban Development, and The Pearl Community Rating System. The four USCs prescribed multiple measures for sustainable transportation, particularly in favor of active transportation and public transportation. However, the relatively small size of their citified developments and the varying transportation conditions among different contexts attenuate the viability and relevance of the advocated measures for both modes. In order to yield more benefits, USCs should underscore the integrative nature of neighborhoods and communities, and transportation within their prescribed criteria and measures. Moreover, sustainable transportation as a theme should be tailored to the local conditions rather than being adopted or adapted from global USCs. - Highlights: • Transportation measures in four prominent certification systems were investigated. • Most certified neighborhoods, communities and developments have small site areas. • Certifications are insensitive to realities of transport in developing countries. • Benefits from advocating active transport only within certified areas are minimal. • Certifications devalue the integrative nature of neighborhoods and transportation.

  4. Sustainable transportation according to certification systems: A viability analysis based on neighborhood size and context relevance

    Energy Technology Data Exchange (ETDEWEB)

    Gouda, Amr Ah., E-mail: amr.gouda@eng.asu.edu.eg [Center for Technology and Society, Technische Universität Berlin, Hardenbergstr, 16-18, Berlin 10623 (Germany); Architecture Department, Faculty of Engineering, Ain Shams University, 1 Sarayat St., Abassia, Cairo (Egypt); Masoumi, Houshmand E. [Center for Technology and Society, Technische Universität Berlin, Hardenbergstr, 16-18, Berlin 10623 (Germany)

    2017-03-15

    Urban sustainability certification (USC) systems comprehensively assess and benchmark the sustainability of neighborhoods, communities, etc. However, it is important to understand what USCs mean by neighborhoods and communities in terms of definition and their certified developments' size. This study focuses on sustainable transportation and its measures in USCs in order to discern: how relevant are these measures to the varied local conditions, especially in developing countries? And whether they can generate palpable benefits vis-à-vis the certified developments' site areas. Taking descriptive analysis methods, this study focuses on four prominent USCs, namely, LEED for Neighborhood Development, BREEAM Communities, CASBEE for Urban Development, and The Pearl Community Rating System. The four USCs prescribed multiple measures for sustainable transportation, particularly in favor of active transportation and public transportation. However, the relatively small size of their citified developments and the varying transportation conditions among different contexts attenuate the viability and relevance of the advocated measures for both modes. In order to yield more benefits, USCs should underscore the integrative nature of neighborhoods and communities, and transportation within their prescribed criteria and measures. Moreover, sustainable transportation as a theme should be tailored to the local conditions rather than being adopted or adapted from global USCs. - Highlights: • Transportation measures in four prominent certification systems were investigated. • Most certified neighborhoods, communities and developments have small site areas. • Certifications are insensitive to realities of transport in developing countries. • Benefits from advocating active transport only within certified areas are minimal. • Certifications devalue the integrative nature of neighborhoods and transportation.

  5. Neighborhood Effects in a Behavioral Randomized Controlled Trial

    OpenAIRE

    Pruitt, Sandi L.; Leonard, Tammy; Murdoch, James; Hughes, Amy; McQueen, Amy; Gupta, Samir

    2014-01-01

    Randomized controlled trials (RCTs) of interventions intended to modify health behaviors may be influenced by neighborhood effects which can impede unbiased estimation of intervention effects. Examining a RCT designed to increase colorectal cancer (CRC) screening (N=5,628), we found statistically significant neighborhood effects: average CRC test use among neighboring study participants was significantly and positively associated with individual patient’s CRC test use. This potentially import...

  6. Parental Perceptions of Neighborhood Effects in Latino Comunas

    Science.gov (United States)

    Horner, Pilar; Sanchez, Ninive; Castillo, Marcela; Delva, Jorge

    2011-01-01

    Objectives To obtain rich information about how adult Latinos living in high-poverty/high-drug use neighborhoods perceive and negotiate their environment. Methods In 2008, thirteen adult caregivers in Santiago, Chile were interviewed with open-ended questions to ascertain beliefs about neighborhood effects and drug use. Analysis Inductive analysis was used to develop the codebook/identify trends. Discussion Residents externalized their understanding of drug use and misuse by invoking the concept of delinquent youth. A typology of their perceptions is offered. Learning more about residents’ circumstances may help focus on needs-based interventions. More research with Latino neighborhoods is needed for culturally-competent models of interventions. PMID:22497879

  7. The influence of sampling unit size and spatial arrangement patterns on neighborhood-based spatial structure analyses of forest stands

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Zhang, G.; Hui, G.; Li, Y.; Hu, Y.; Zhao, Z.

    2016-07-01

    Aim of study: Neighborhood-based stand spatial structure parameters can quantify and characterize forest spatial structure effectively. How these neighborhood-based structure parameters are influenced by the selection of different numbers of nearest-neighbor trees is unclear, and there is some disagreement in the literature regarding the appropriate number of nearest-neighbor trees to sample around reference trees. Understanding how to efficiently characterize forest structure is critical for forest management. Area of study: Multi-species uneven-aged forests of Northern China. Material and methods: We simulated stands with different spatial structural characteristics and systematically compared their structure parameters when two to eight neighboring trees were selected. Main results: Results showed that values of uniform angle index calculated in the same stand were different with different sizes of structure unit. When tree species and sizes were completely randomly interspersed, different numbers of neighbors had little influence on mingling and dominance indices. Changes of mingling or dominance indices caused by different numbers of neighbors occurred when the tree species or size classes were not randomly interspersed and their changing characteristics can be detected according to the spatial arrangement patterns of tree species and sizes. Research highlights: The number of neighboring trees selected for analyzing stand spatial structure parameters should be fixed. We proposed that the four-tree structure unit is the best compromise between sampling accuracy and costs for practical forest management. (Author)

  8. A review of neighborhood effects and early child development: How, where, and for whom, do neighborhoods matter?

    Science.gov (United States)

    Minh, Anita; Muhajarine, Nazeem; Janus, Magdalena; Brownell, Marni; Guhn, Martin

    2017-07-01

    This paper describes a scoping review of 42 studies of neighborhood effects on developmental health for children ages 0-6, published between 2009 and 2014. It focuses on three themes: (1) theoretical mechanisms that drive early childhood development, i.e. how neighborhoods matter for early childhood development; (2) dependence of such mechanisms on place-based characteristics i.e. where neighborhood effects occur; (3) dependence of such mechanisms on child characteristics, i.e. for whom is development most affected. Given that ecological systems theories postulate diverse mechanisms via which neighborhood characteristics affect early child development, we specifically examine evidence on mediation and/or moderation effects. We conclude by discussing future challenges, and proposing recommendations for analyses that utilize ecological longitudinal population-based databases. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Spatial dimensions of the effect of neighborhood disadvantage on delinquency

    NARCIS (Netherlands)

    Vogel, M.S.; South, S.J.

    2016-01-01

    esearch examining the relationship between neighborhood socioeconomic disadvantage and adolescent offending typically examines only the influence of residential neighborhoods. This strategy may be problematic as 1) neighborhoods are rarely spatially independent of each other and 2) adolescents spend

  10. The moderating effect of psychosocial factors in the relation between neighborhood walkability and children's physical activity.

    Science.gov (United States)

    D'Haese, Sara; Gheysen, Freja; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Van Dyck, Delfien; Cardon, Greet

    2016-12-09

    The study aimed to investigate if psychosocial factors moderate the association between objective walkability and different domains of children's physical activity (PA). A second aim of the study was to investigate the direct associations between psychosocial factors and children's PA. Based on previous literature, it was hypothesized that walkability would be more strongly related to PA among children with negative psychosocial profiles. Data were collected between December 2011 and May 2013 as part of the Belgian Environmental Physical Activity Study in children (BEPAS-child). In total, data from 494 children and one of their parents were included in the study. Children wore an accelerometer for 7 consecutive days and together with one of their parents, they completed the Flemish Physical Activity Questionnaire. Parents filled out a questionnaire concerning their child's psychosocial factors toward PA (i.e. parental attitude toward their child's PA, parental social norm toward their child's PA, parental support, friend support, children's self-efficacy, and perceived benefits and barriers toward sports and PA). Neighborhood walkability was calculated using geographical information systems (GIS). Multilevel cross-classified analyses were conducted. Of the 42 investigated interactions between neighborhood walkability and psychosocial factors in relation to PA among children, only 7 significant interactions were found of which 3 were only significant among children from low-income neighborhoods. Parental support and self-efficacy were positive correlates of children's PA in high- and low-income neighborhoods independent of the level of walkability, but effect sizes were small. The hypothesis that walkability would be more strongly related to PA among children with negative psychosocial profiles could not be confirmed and in general, psychosocial factors and objective walkability did not interact in relation to children's PA. Focusing on parental support and self

  11. THE MASS-SIZE RELATION FROM CLOUDS TO CORES. II. SOLAR NEIGHBORHOOD CLOUDS

    International Nuclear Information System (INIS)

    Kauffmann, J.; Shetty, R.; Goodman, A. A.; Pillai, T.; Myers, P. C.

    2010-01-01

    We measure the mass and size of cloud fragments in several molecular clouds continuously over a wide range of spatial scales (0.05 ∼ 2 , is not well suited to describe the derived mass-size data. Solar neighborhood clouds not forming massive stars (∼ sun ; Pipe Nebula, Taurus, Perseus, and Ophiuchus) obey m(r) ≤ 870 M sun (r/pc) 1.33 . In contrast to this, clouds forming massive stars (Orion A, G10.15 - 0.34, G11.11 - 0.12) do exceed the aforementioned relation. Thus, this limiting mass-size relation may approximate a threshold for the formation of massive stars. Across all clouds, cluster-forming cloud fragments are found to be-at given radius-more massive than fragments devoid of clusters. The cluster-bearing fragments are found to roughly obey a mass-size law m ∝ r 1.27 (where the exponent is highly uncertain in any given cloud, but is certainly smaller than 1.5).

  12. The Relationship between Neighborhood Characteristics and Effective Parenting Behaviors: The Role of Social Support

    Science.gov (United States)

    Byrnes, Hilary F.; Miller, Brenda A.

    2012-01-01

    Neighborhood characteristics have been linked to healthy behavior, including effective parenting behaviors. This may be partially explained through the neighborhood's relation to parents' access to social support from friends and family. The current study examined associations of neighborhood characteristics with parenting behaviors indirectly…

  13. Effect of housing relocation and neighborhood environment on adolescent mental and behavioral health.

    Science.gov (United States)

    Byck, Gayle R; Bolland, John; Dick, Danielle; Swann, Gregory; Henry, David; Mustanski, Brian

    2015-11-01

    This study examined whether relocating from a high-poverty neighborhood to a lower poverty neighborhood as part of a federal housing relocation program (HOPE VI; Housing Opportunities for People Everywhere) had effects on adolescent mental and behavioral health compared to adolescents consistently living in lower poverty neighborhoods. Sociodemographic, risk behavior, and neighborhood data were collected from 592 low-income, primarily African-American adolescents and their primary caregivers. Structured psychiatric interviews were conducted with adolescents. Prerelocation neighborhood, demographic, and risk behavior data were also included. Hierarchical Linear Modeling (HLM) was used to test associations between neighborhood variables and risk outcomes. HLM was used to test whether the effect of neighborhood relocation and neighborhood characteristics might explain differences in sexual risk taking, substance use, and mental health outcomes. Adolescents who relocated of HOPE VI neighborhoods (n = 158) fared worse than control group participants (n = 429) on most self-reported mental health outcomes. The addition of subjective neighborhood measures generally did not substantively change these results. Our findings suggest that moving from a high-poverty neighborhood to a somewhat lower poverty neighborhood is not associated with better mental health and risk behavior outcomes in adolescents. The continued effects of having grown up in a high-poverty neighborhood, the small improvements in their new neighborhoods, the comparatively short length of time they lived in their new neighborhood, and/or the stress of moving appears to worsen most of the mental health outcomes of HOPE VI compared to control group participants who consistently lived in the lower poverty neighborhoods. © 2015 Association for Child and Adolescent Mental Health.

  14. Independent Effects of Neighborhood Poverty and Psychosocial Stress on Obesity Over Time.

    Science.gov (United States)

    Kwarteng, Jamila L; Schulz, Amy J; Mentz, Graciela B; Israel, Barbara A; Perkins, Denise White

    2017-12-01

    The objective of the study was to examine the independent effects of neighborhood poverty and psychosocial stress on increases in central adiposity over time. Data are from a community sample of 157 Non-Hispanic Black, Non-Hispanic White, and Hispanic adults collected in 2002-2003 and 2007-2008, and from the 2000 Decennial Census. The dependent variable was waist circumference. Independent variables included neighborhood poverty, perceived neighborhood physical environment, family stress, safety stress, everyday unfair treatment, and a cumulative stress index. Weighted 3-level hierarchical linear regression models for a continuous outcome were used to assess the effects of neighborhood poverty and psychosocial stress on central adiposity over time. We also assessed whether psychosocial stress mediated the association between neighborhood poverty and central adiposity. Neighborhood poverty and everyday unfair treatment at baseline were independently associated with increases in central adiposity over time, accounting for the other indicators of stress. Perceptions of the neighborhood physical environment and cumulative stress mediated associations between neighborhood poverty and central adiposity. Results suggest that residing in neighborhoods with higher concentrations of poverty and exposure to everyday unfair treatment independently heighten risk of increased central adiposity over time. Associations between neighborhood poverty and central adiposity were mediated by perceptions of the neighborhood physical environment and by the cumulative stress index. Public health strategies to reduce obesity should consider neighborhood poverty and exposure to multiple sources of psychosocial stress, including everyday unfair treatment.

  15. Urban Heat Island Effect Actions - Neighborhood Data

    Data.gov (United States)

    Louisville Metro Government — The urban heat island effect — defined as the difference in temperature between the core of Louisville and its suburbs — contributes to heat-related illnesses and...

  16. Perceptions as the crucial link? The mediating role of neighborhood perceptions in the relationship between the neighborhood context and neighborhood cohesion.

    Science.gov (United States)

    Laméris, Joran; Hipp, John R; Tolsma, Jochem

    2018-05-01

    This study examines the effects of neighborhood racial in-group size, economic deprivation and the prevalence of crime on neighborhood cohesion among U.S. whites. We explore to what extent residents' perceptions of their neighborhood mediate these macro-micro relationships. We use a recent individual-level data set, the American Social Fabric Study (2012/2013), enriched with contextual-level data from the U.S. Census Bureau (2010) and employ multi-level structural equation models. We show that the racial in-group size is positively related to neighborhood cohesion and that neighborhood cohesion is lower in communities with a high crime rate. Individuals' perceptions of the racial in-group size partly mediate the relationship between the objective racial in-group size and neighborhood cohesion. Residents' perceptions of unsafety from crime also appear to be a mediating factor, not only for the objective crime rate but also for the objective racial in-group size. This is in line with our idea that racial stereotypes link racial minorities to crime whereby neighborhoods with a large non-white population are perceived to be more unsafe. Residents of the same neighborhood differ in how they perceive the degree of economic decay of the neighborhood and this causes them to evaluate neighborhood cohesion differently, however perceptions of neighborhood economic decay do not explain the link between the objective neighborhood context and neighborhood cohesion. Copyright © 2018. Published by Elsevier Inc.

  17. Sequential Neighborhood Effects: The Effect of Long-Term Exposure to Concentrated Disadvantage on Children's Reading and Math Test Scores.

    Science.gov (United States)

    Hicks, Andrew L; Handcock, Mark S; Sastry, Narayan; Pebley, Anne R

    2018-02-01

    Prior research has suggested that children living in a disadvantaged neighborhood have lower achievement test scores, but these studies typically have not estimated causal effects that account for neighborhood choice. Recent studies used propensity score methods to account for the endogeneity of neighborhood exposures, comparing disadvantaged and nondisadvantaged neighborhoods. We develop an alternative propensity function approach in which cumulative neighborhood effects are modeled as a continuous treatment variable. This approach offers several advantages. We use our approach to examine the cumulative effects of neighborhood disadvantage on reading and math test scores in Los Angeles. Our substantive results indicate that recency of exposure to disadvantaged neighborhoods may be more important than average exposure for children's test scores. We conclude that studies of child development should consider both average cumulative neighborhood exposure and the timing of this exposure.

  18. Perceptions as the crucial link? The mediating role of neighborhood perceptions in the relationship between the neighborhood context and neighborhood cohesion

    NARCIS (Netherlands)

    Lamé ris, J.G.; Hipp, J.R.; Tolsma, J.

    2018-01-01

    This study examines the effects of neighborhood racial in-group size, economic deprivation and the prevalence of crime on neighborhood cohesion among U.S. whites. We explore to what extent residents' perceptions of their neighborhood mediate these macro-micro relationships. We use a recent

  19. Neighborhood effects on birthweight: an exploration of psychosocial and behavioral pathways in Baltimore, 1995--1996.

    Science.gov (United States)

    Schempf, Ashley; Strobino, Donna; O'Campo, Patricia

    2009-01-01

    Neighborhood characteristics have been proposed to influence birth outcomes through psychosocial and behavioral pathways, yet empirical evidence is lacking. Using data from an urban, low-income sample, this study examined the impact of the neighborhood environment on birthweight and evaluated mediation by psychosocial and behavioral factors. The sample included 726 women who delivered a live birth at Johns Hopkins Hospital in Baltimore, Maryland, USA between 1995 and 1996. Census-tract data were used to create a principal component index of neighborhood risk based on racial and economic stratification (% Black, % poverty), social disorder (violent crime rate), and physical deterioration (% boarded-up housing) (alpha=0.82). Information on sociodemographic, psychosocial, and behavioral factors was gathered from a postpartum interview and medical records. Random intercept multilevel models were used to estimate neighborhood effects and assess potential mediation. Controlling for sociodemographic characteristics, a standard deviation increase in neighborhood risk conferred a 76g birthweight decrement. This represents an approximate 300g difference between the best and worst neighborhoods. Although stress (daily hassles), perceived locus-of-control, and social support were related to birthweight, their adjustment reduced the neighborhood coefficient by only 12%. In contrast, the neighborhood effect was reduced by an additional 30% and was no longer statistically significant after adjustment for the behavioral factors of smoking, drug use, and delayed prenatal care. These findings suggest that neighborhood factors may influence birthweight by shaping maternal behavioral risks. Thus, neighborhood level interventions should be considered to address multiple maternal and infant health risks. Future studies should examine more direct measures of neighborhood stress, such as perceived neighborhood disorder, and evaluate alternative mechanisms by which neighborhood factors

  20. Neighborhood Effects on Health: Concentrated Advantage and Disadvantage

    Science.gov (United States)

    Finch, Brian K.; Do, D. Phuong; Heron, Melonie; Bird, Chloe; Seeman, Teresa; Lurie, Nicole

    2010-01-01

    We investigate an alternative conceptualization of neighborhood context and its association with health. Using an index that measures a continuum of concentrated advantage and disadvantage, we examine whether the relationship between neighborhood conditions and health varies by socio-economic status. Using NHANES III data geo-coded to census tracts, we find that while largely uneducated neighborhoods are universally deleterious, individuals with more education benefit from living in highly educated neighborhoods to a greater degree than individuals with lower levels of education. PMID:20627796

  1. Direct and indirect effects of neighborhood characteristics on the perpetration of dating violence across adolescence.

    Science.gov (United States)

    Chang, Ling-Yin; Foshee, Vangie A; Reyes, Heathe Luz McNaughton; Ennett, Susan T; Halpern, Carolyn T

    2015-03-01

    Neighborhood context plays a role in the development of adolescent health risk behaviors, but few studies have investigated the influence of neighborhoods on the perpetration of dating violence. This longitudinal study examined the direct effects of risky neighborhood structural and physical characteristics on trajectories of the perpetration of dating violence, tested whether collective efficacy mediated these relationships, and determined if the effects varied by the sex of the adolescent. Adolescent data are from a multi-wave longitudinal study from grades 8 to 12; neighborhood data were collected from parents' interviews and U.S. Census data. Multilevel growth curve models were conducted with 3,218 students; the sample was 50% male, 41% White, 50% Black, and 9% other race/ethnicity. In models examining risky neighborhood variables one at a time, and controlling for potential individual-level confounders, the sex of the adolescent interacted with economic disadvantage, residential instability, and physical disorder; these risky neighborhood characteristics increased risk for girls' but not boys' perpetrating of dating violence. In full models with all of the risky neighborhood variables, the sex of the adolescent continued to interact with neighborhood economic disadvantage; living in economically disadvantaged neighborhoods increased girls' but not boys' risk for dating violence across all ages. No other risky neighborhood effects were found for boys or girls. Collective efficacy did not mediate the relationships between other neighborhood characteristics and the outcome. These findings suggest that dating violence prevention strategies for girls should consider the contexts in which they live rather than only targeting changes in their individual characteristics.

  2. Semantic Neighborhood Effects for Abstract versus Concrete Words.

    Science.gov (United States)

    Danguecan, Ashley N; Buchanan, Lori

    2016-01-01

    Studies show that semantic effects may be task-specific, and thus, that semantic representations are flexible and dynamic. Such findings are critical to the development of a comprehensive theory of semantic processing in visual word recognition, which should arguably account for how semantic effects may vary by task. It has been suggested that semantic effects are more directly examined using tasks that explicitly require meaning processing relative to those for which meaning processing is not necessary (e.g., lexical decision task). The purpose of the present study was to chart the processing of concrete versus abstract words in the context of a global co-occurrence variable, semantic neighborhood density (SND), by comparing word recognition response times (RTs) across four tasks varying in explicit semantic demands: standard lexical decision task (with non-pronounceable non-words), go/no-go lexical decision task (with pronounceable non-words), progressive demasking task, and sentence relatedness task. The same experimental stimulus set was used across experiments and consisted of 44 concrete and 44 abstract words, with half of these being low SND, and half being high SND. In this way, concreteness and SND were manipulated in a factorial design using a number of visual word recognition tasks. A consistent RT pattern emerged across tasks, in which SND effects were found for abstract (but not necessarily concrete) words. Ultimately, these findings highlight the importance of studying interactive effects in word recognition, and suggest that linguistic associative information is particularly important for abstract words.

  3. Neighborhood Effects in Temporal Perspective: The Impact of Long-Term Exposure to Concentrated Disadvantage on High School Graduation

    Science.gov (United States)

    Wodtke, Geoffrey T.; Harding, David J.; Elwert, Felix

    2011-01-01

    Theory suggests that neighborhood effects depend not only on where individuals live today, but also on where they lived in the past. Previous research, however, usually measures neighborhood context only once and does not account for length of residence, thereby understating the detrimental effects of long-term neighborhood disadvantage. This…

  4. CHAPTER 9: USING CENSUS DATA TO APPROXIMATE NEIGHBORHOOD EFFECTS

    Science.gov (United States)

    INTRODUCTION Despite the development of innovative neighborhood data collection methods, such as systematic social observation (1, 2), and the utilization of novel administrative data sources including delinquent tax records, homelessness shelter utilization, reports of housing ...

  5. A Longitudinal Analysis of the Influence of the Neighborhood Environment on Recreational Walking within the Neighborhood: Results from RESIDE.

    Science.gov (United States)

    Christian, Hayley; Knuiman, Matthew; Divitini, Mark; Foster, Sarah; Hooper, Paula; Boruff, Bryan; Bull, Fiona; Giles-Corti, Billie

    2017-07-12

    There is limited longitudinal evidence confirming the role of neighborhood environment attributes in encouraging people to walk more or if active people simply choose to live in activity-friendly neighborhoods. Natural experiments of policy changes to create more walkable communities provide stronger evidence for a causal effect of neighborhood environments on residents' walking. We aimed to investigate longitudinal associations between objective and perceived neighborhood environment measures and neighborhood recreational walking. We analyzed longitudinal data collected over 8 yr (four surveys) from the RESIDential Environments (RESIDE) Study (Perth, Australia, 2003-2012). At each time point, participants reported the frequency and total minutes of recreational walking/week within their neighborhood and neighborhood environment perceptions. Objective measures of the neighborhood environment were generated using a Geographic Information System (GIS). Local recreational walking was influenced by objectively measured access to a medium-/large-size park, beach access, and higher street connectivity, which was reduced when adjusted for neighborhood perceptions. In adjusted models, positive perceptions of access to a park and beach, higher street connectivity, neighborhood esthetics, and safety from crime were independent determinants of increased neighborhood recreational walking. Local recreational walking increased by 9 min/wk (12% increase in frequency) for each additional perceived neighborhood attribute present. Our findings provide urban planners and policy makers with stronger causal evidence of the positive impact of well-connected neighborhoods and access to local parks of varying sizes on local residents' recreational walking and health. https://doi.org/10.1289/EHP823.

  6. Direct and indirect effects for neighborhood-based clustered and longitudinal data

    OpenAIRE

    VanderWeele, T.J.

    2010-01-01

    Definitions of direct and indirect effects are given for settings in which individuals are clustered in groups or neighborhoods and in which treatments are administered at the group level. A particular intervention may affect individual outcomes both through its effect on the individual and by changing the group or neighborhood itself. Identification conditions are given for controlled direct effects and for natural direct and indirect effects. The interpretation of these identification condi...

  7. Independent and Interactive Effects of Neighborhood Disadvantage and Social Network Characteristics on Problem Drinking after Treatment.

    Science.gov (United States)

    Mericle, Amy A; Kaskutas, Lee A; Polcin, Doug L; Karriker-Jaffe, Katherine J

    2018-01-01

    Socioecological approaches to public health problems like addiction emphasize the importance of person-environment interactions. Neighborhood and social network characteristics may influence the likelihood of relapse among individuals in recovery, but these factors have been understudied, particularly with respect to conceptualizing social network characteristics as moderators of neighborhood disadvantage. Drawing from a larger prospective study of individuals recruited from outpatient treatment (N=451) and interviewed 1, 3, 5, and 7 years later, the aim of this study was to examine the independent and interactive effects of neighborhood and social network characteristics on continued problem drinking after treatment. Models using generalized estimating equations controlling for demographic and other risk factors found the number of heavy drinkers in one's network increases risk of relapse, with the effects being significantly stronger among those living in disadvantaged neighborhoods than among those in non-disadvantaged neighborhoods. No independent effects were found for neighborhood disadvantage or for the number of network members supporting reduced drinking. Future research is needed to examine potential protective factors in neighborhoods which may offset socioeconomic disadvantage as well as to investigate the functions that network members serve in helping to improve long-term treatment outcomes.

  8. A hybrid adaptive large neighborhood search heuristic for lot-sizing with setup times

    DEFF Research Database (Denmark)

    Muller, Laurent Flindt; Spoorendonk, Simon; Pisinger, David

    2012-01-01

    This paper presents a hybrid of a general heuristic framework and a general purpose mixed-integer programming (MIP) solver. The framework is based on local search and an adaptive procedure which chooses between a set of large neighborhoods to be searched. A mixed integer programming solver and its......, and the upper bounds found by the commercial MIP solver ILOG CPLEX using state-of-the-art MIP formulations. Furthermore, we improve the best known solutions on 60 out of 100 and improve the lower bound on all 100 instances from the literature...

  9. Gender differences in the effects of urban neighborhood on depressive symptoms in Jamaica.

    Science.gov (United States)

    Mullings, Jasneth Asher; McCaw-Binns, Affette Michelle; Archer, Carol; Wilks, Rainford

    2013-12-01

    To explore the mental health effects of the urban neighborhood on men and women in Jamaica and the implications for urban planning and social development. A cross-sectional household sample of 2 848 individuals 15-74 years of age obtained from the Jamaica Health and Lifestyle Survey 2007-2008 was analyzed. Secondary analysis was undertaken by developing composite scores to describe observer recorded neighborhood features, including infrastructure, amenities/services, physical conditions, community socioeconomic status, and green spaces around the home. Depressive symptoms were assessed using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Bivariate and multivariate methods were used to explore the associations among gender, neighborhood factors, and risk of depressive symptoms. While no associations were found among rural residents, urban neighborhoods were associated with increased risk of depressive symptoms. Among males, residing in a neighborhood with poor infrastructure increased risk; among females, residing in an informal community/unplanned neighborhood increased risk. The urban neighborhood contributes to the risk of depression symptomatology in Jamaica, with different environmental stressors affecting men and women. Urban and social planners need to consider the physical environment when developing health interventions in urban settings, particularly in marginalized communities.

  10. Gender differences in the effects of urban neighborhood on depressive symptoms in Jamaica

    Directory of Open Access Journals (Sweden)

    Jasneth Asher Mullings

    2013-12-01

    Full Text Available OBJECTIVE: To explore the mental health effects of the urban neighborhood on men and women in Jamaica and the implications for urban planning and social development. METHODS: A cross-sectional household sample of 2 848 individuals 15-74 years of age obtained from the Jamaica Health and Lifestyle Survey 2007-2008 was analyzed. Secondary analysis was undertaken by developing composite scores to describe observer recorded neighborhood features, including infrastructure, amenities/services, physical conditions, community socioeconomic status, and green spaces around the home. Depressive symptoms were assessed using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV. Bivariate and multivariate methods were used to explore the associations among gender, neighborhood factors, and risk of depressive symptoms. RESULTS: While no associations were found among rural residents, urban neighborhoods were associated with increased risk of depressive symptoms. Among males, residing in a neighborhood with poor infrastructure increased risk; among females, residing in an informal community/unplanned neighborhood increased risk. CONCLUSIONS: The urban neighborhood contributes to the risk of depression symptomatology in Jamaica, with different environmental stressors affecting men and women. Urban and social planners need to consider the physical environment when developing health interventions in urban settings, particularly in marginalized communities.

  11. Cumulative Effects of Neighborhood Social Adversity and Personal Crime Victimization on Adolescent Psychotic Experiences.

    Science.gov (United States)

    Newbury, Joanne; Arseneault, Louise; Caspi, Avshalom; Moffitt, Terrie E; Odgers, Candice L; Fisher, Helen L

    2018-02-15

    Little is known about the impact of urbanicity, adverse neighborhood conditions and violent crime victimization on the emergence of adolescent psychotic experiences. Participants were from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally-representative cohort of 2232 British twins who were interviewed about adolescent psychotic experiences at age 18. Urbanicity, neighborhood characteristics, and personal victimization by violent crime were measured during childhood and adolescence via geocoded census data, surveys of over 5000 immediate neighbors of the E-Risk participants, and interviews with participants themselves. Adolescents raised in urban vs rural neighborhoods were significantly more likely to have psychotic experiences (OR = 1.67, 95% CI = 1.21-2.30, P = .002). This association remained significant after considering potential confounders including family socioeconomic status, family psychiatric history, and adolescent substance problems (OR = 1.43, 95% CI = 1.01-2.03, P = .042), but became nonsignificant after considering adverse social conditions in urban neighborhoods such as low social cohesion and high neighborhood disorder (OR = 1.35, 95% CI = 0.94-1.92, P = .102). The combined association of adverse neighborhood social conditions and personal crime victimization with adolescent psychotic experiences (adjusted OR = 4.86, 95% CI = 3.28-7.20, P < .001) was substantially greater than for either exposure alone, highlighting a potential interaction between neighborhood conditions and crime victimization (interaction contrast ratio = 1.81, 95% CI = -0.03 to 3.65) that was significant at the P = .054 level. Cumulative effects of adverse neighborhood social conditions and personal victimization by violent crime during upbringing partly explain why adolescents in urban settings are more likely to report psychotic experiences. Early intervention efforts for psychosis could be targeted towards victimized youth living in urban and socially

  12. Exploring the Influence of Neighborhood Characteristics on Burglary Risks: A Bayesian Random Effects Modeling Approach

    Directory of Open Access Journals (Sweden)

    Hongqiang Liu

    2016-06-01

    Full Text Available A Bayesian random effects modeling approach was used to examine the influence of neighborhood characteristics on burglary risks in Jianghan District, Wuhan, China. This random effects model is essentially spatial; a spatially structured random effects term and an unstructured random effects term are added to the traditional non-spatial Poisson regression model. Based on social disorganization and routine activity theories, five covariates extracted from the available data at the neighborhood level were used in the modeling. Three regression models were fitted and compared by the deviance information criterion to identify which model best fit our data. A comparison of the results from the three models indicates that the Bayesian random effects model is superior to the non-spatial models in fitting the data and estimating regression coefficients. Our results also show that neighborhoods with above average bar density and department store density have higher burglary risks. Neighborhood-specific burglary risks and posterior probabilities of neighborhoods having a burglary risk greater than 1.0 were mapped, indicating the neighborhoods that should warrant more attention and be prioritized for crime intervention and reduction. Implications and limitations of the study are discussed in our concluding section.

  13. The Effect of the Social and Physical Environment on Children's Independent Mobility to Neighborhood Destinations.

    Science.gov (United States)

    Christian, Hayley E; Klinker, Charlotte D; Villanueva, Karen; Knuiman, Matthew W; Foster, Sarah A; Zubrick, Stephan R; Divitini, Mark; Wood, Lisa; Giles-Corti, Billie

    2015-06-16

    Relationships between context-specific measures of the physical and social environment and children's independent mobility to neighborhood destination types were examined. Parents in RESIDE's fourth survey reported whether their child (8-15 years; n = 181) was allowed to travel without an adult to school, friend's house, park and local shop. Objective physical environment measures were matched to each of these destinations. Social environment measures included neighborhood perceptions and items specific to local independent mobility. Independent mobility to local destinations ranged from 30% to 48%. Independent mobility to a local park was less likely as the distance to the closest park (small and large size) increased and less likely with additional school grounds (P dependent upon the specific destination being visited and the impact of neighborhood features varies according to the destination examined. Findings highlight the importance of access to different types and sizes of urban green space for children's independent mobility to parks.

  14. Transgenerational effect of neighborhood poverty on low birth weight among African Americans in Cook County, Illinois.

    Science.gov (United States)

    Collins, James W; David, Richard J; Rankin, Kristin M; Desireddi, Jennifer R

    2009-03-15

    In perinatal epidemiology, transgenerational risk factors are defined as conditions experienced by one generation that affect the pregnancy outcomes of the next generation. The authors investigated the transgenerational effect of neighborhood poverty on infant birth weight among African Americans. Stratified and multilevel logistic regression analyses were performed on an Illinois transgenerational data set with appended US Census income information. Singleton African-American infants (n = 40,648) born in 1989-1991 were considered index births. The mothers of index infants had been born in 1956-1976. The maternal grandmothers of index infants were identified. Rates of infant low birth weight (birth weight for maternal grandmother's residence in a poor neighborhood (compared with an affluent neighborhood) equaled 1.3 (95% confidence interval: 1.1, 1.4). This study suggests that maternal grandmother's exposure to neighborhood poverty during her pregnancy is a risk factor for infant low birth weight among African Americans.

  15. Spatial prisoner's dilemma games with increasing neighborhood size and individual diversity on two interdependent lattices

    International Nuclear Information System (INIS)

    Meng, Xiao-Kun; Xia, Cheng-Yi; Gao, Zhong-Ke; Wang, Li; Sun, Shi-Wen

    2015-01-01

    Highlights: • A novel PDG model with individual diversity and utility interdependency is proposed. • Diversity can be represented by players with different strategy spreading abilities. • Interdependency is implemented by the payoff correlation between two lattices. • Cooperation can be remarkably promoted by combining these two kinds of mechanisms. - Abstract: We present an improved spatial prisoner's dilemma game model which simultaneously considers the individual diversity and increasing neighborhood size on two interdependent lattices. By dividing the players into influential and non-influential ones, we can discuss the impact of individual diversity on the cooperative behaviors. Meanwhile, we implement the utility interdependency by integrating the payoff correlations between two lattices. Extensive simulations indicate that the optimal density of influential players exists for the cooperation to be promoted, and can be further facilitated through the utility coupling. Current results are beneficial to understanding the origin of cooperation among selfish agents among realistic scenarios

  16. Spatial prisoner's dilemma games with increasing neighborhood size and individual diversity on two interdependent lattices

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xiao-Kun [Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Computer Vision and System (Ministry of Education), Tianjin University of Technology, Tianjin 300384 (China); Xia, Cheng-Yi, E-mail: xialooking@163.com [Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Computer Vision and System (Ministry of Education), Tianjin University of Technology, Tianjin 300384 (China); Gao, Zhong-Ke [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Wang, Li; Sun, Shi-Wen [Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology, Tianjin University of Technology, Tianjin 300384 (China); Key Laboratory of Computer Vision and System (Ministry of Education), Tianjin University of Technology, Tianjin 300384 (China)

    2015-04-03

    Highlights: • A novel PDG model with individual diversity and utility interdependency is proposed. • Diversity can be represented by players with different strategy spreading abilities. • Interdependency is implemented by the payoff correlation between two lattices. • Cooperation can be remarkably promoted by combining these two kinds of mechanisms. - Abstract: We present an improved spatial prisoner's dilemma game model which simultaneously considers the individual diversity and increasing neighborhood size on two interdependent lattices. By dividing the players into influential and non-influential ones, we can discuss the impact of individual diversity on the cooperative behaviors. Meanwhile, we implement the utility interdependency by integrating the payoff correlations between two lattices. Extensive simulations indicate that the optimal density of influential players exists for the cooperation to be promoted, and can be further facilitated through the utility coupling. Current results are beneficial to understanding the origin of cooperation among selfish agents among realistic scenarios.

  17. Cumulative Effects of Neighborhood Social Adversity and Personal Crime Victimization on Adolescent Psychotic Experiences

    Science.gov (United States)

    Newbury, Joanne; Arseneault, Louise; Caspi, Avshalom; Moffitt, Terrie E; Odgers, Candice L

    2018-01-01

    Abstract Background: Little is known about the impact of urbanicity, adverse neighborhood conditions and violent crime victimization on the emergence of adolescent psychotic experiences. Methods: Participants were from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally-representative cohort of 2232 British twins who were interviewed about adolescent psychotic experiences at age 18. Urbanicity, neighborhood characteristics, and personal victimization by violent crime were measured during childhood and adolescence via geocoded census data, surveys of over 5000 immediate neighbors of the E-Risk participants, and interviews with participants themselves. Results: Adolescents raised in urban vs rural neighborhoods were significantly more likely to have psychotic experiences (OR = 1.67, 95% CI = 1.21–2.30, P = .002). This association remained significant after considering potential confounders including family socioeconomic status, family psychiatric history, and adolescent substance problems (OR = 1.43, 95% CI = 1.01–2.03, P = .042), but became nonsignificant after considering adverse social conditions in urban neighborhoods such as low social cohesion and high neighborhood disorder (OR = 1.35, 95% CI = 0.94–1.92, P = .102). The combined association of adverse neighborhood social conditions and personal crime victimization with adolescent psychotic experiences (adjusted OR = 4.86, 95% CI = 3.28–7.20, P crime victimization (interaction contrast ratio = 1.81, 95% CI = −0.03 to 3.65) that was significant at the P = .054 level. Conclusions: Cumulative effects of adverse neighborhood social conditions and personal victimization by violent crime during upbringing partly explain why adolescents in urban settings are more likely to report psychotic experiences. Early intervention efforts for psychosis could be targeted towards victimized youth living in urban and socially adverse neighborhoods. PMID:28535284

  18. Increased consumer density reduces the strength of neighborhood effects in a model system.

    Science.gov (United States)

    Merwin, Andrew C; Underwood, Nora; Inouye, Brian D

    2017-11-01

    An individual's susceptibility to attack can be influenced by conspecific and heterospecifics neighbors. Predicting how these neighborhood effects contribute to population-level processes such as competition and evolution requires an understanding of how the strength of neighborhood effects is modified by changes in the abundances of both consumers and neighboring resource species. We show for the first time that consumer density can interact with the density and frequency of neighboring organisms to determine the magnitude of neighborhood effects. We used the bean beetle, Callosobruchus maculatus, and two of its host beans, Vigna unguiculata and V. radiata, to perform a response-surface experiment with a range of resource densities and three consumer densities. At low beetle density, damage to beans was reduced with increasing conspecific density (i.e., resource dilution) and damage to the less preferred host, V. unguiculata, was reduced with increasing V. radiata frequency (i.e., frequency-dependent associational resistance). As beetle density increased, however, neighborhood effects were reduced; at the highest beetle densities neither focal nor neighboring resource density nor frequency influenced damage. These findings illustrate the importance of consumer density in mediating indirect effects among resources, and suggest that accounting for consumer density may improve our ability to predict population-level outcomes of neighborhood effects and our use of them in applications such as mixed-crop pest management. © 2017 by the Ecological Society of America.

  19. How Neighborhood Effects Vary: Childbearing and Fathering among Latino and African American Adolescents

    Directory of Open Access Journals (Sweden)

    Jessica L. Lucero

    2018-01-01

    Full Text Available This study examines what neighborhood conditions experienced at age 15 and after are associated with teen childbearing and fathering among Latino and African American youth and whether these neighborhood effects vary by gender and/or ethnicity. Administrative and survey data from a natural experiment are used for a sample of 517 Latino and African American youth whose families were quasi-randomly assigned to public housing operated by the Denver (CO Housing Authority (DHA. Characteristics of the neighborhood initially assigned by DHA to wait list applicants are utilized as identifying instruments for the neighborhood contexts experienced during adolescence. Cox Proportional Hazards (PH models reveal that neighborhoods having higher percentages of foreign-born residents but lower levels of social capital robustly predict reduced odds of teen parenting though the magnitude of these effects was contingent on gender and ethnicity. Specifically, the presence of foreign-born neighbors on the risk of teen parenting produced a stronger dampening effect for African American youth when compared to Latino youth. Additionally, the effects of social capital on teen parenting were stronger for males than females.

  20. The combined effect of individual and neighborhood socioeconomic status on cancer survival rates.

    Directory of Open Access Journals (Sweden)

    Chun-Ming Chang

    Full Text Available BACKGROUND: This population-based study investigated the relationship between individual and neighborhood socioeconomic status (SES and mortality rates for major cancers in Taiwan. METHODS: A population-based follow-up study was conducted with 20,488 cancer patients diagnosed in 2002. Each patient was traced to death or for 5 years. The individual income-related insurance payment amount was used as a proxy measure of individual SES for patients. Neighborhood SES was defined by income, and neighborhoods were grouped as living in advantaged or disadvantaged areas. The Cox proportional hazards model was used to compare the death-free survival rates between the different SES groups after adjusting for possible confounding and risk factors. RESULTS: After adjusting for patient characteristics (age, gender, Charlson Comorbidity Index Score, urbanization, and area of residence, tumor extent, treatment modalities (operation and adjuvant therapy, and hospital characteristics (ownership and teaching level, colorectal cancer, and head and neck cancer patients under 65 years old with low individual SES in disadvantaged neighborhoods conferred a 1.5 to 2-fold higher risk of mortality, compared with patients with high individual SES in advantaged neighborhoods. A cross-level interaction effect was found in lung cancer and breast cancer. Lung cancer and breast cancer patients less than 65 years old with low SES in advantaged neighborhoods carried the highest risk of mortality. Prostate cancer patients aged 65 and above with low SES in disadvantaged neighborhoods incurred the highest risk of mortality. There was no association between SES and mortality for cervical cancer and pancreatic cancer. CONCLUSIONS: Our findings indicate that cancer patients with low individual SES have the highest risk of mortality even under a universal health-care system. Public health strategies and welfare policies must continue to focus on this vulnerable group.

  1. Size effects in electrochemistry

    International Nuclear Information System (INIS)

    Petrii, Oleg A; Tsirlina, Galina A

    2001-01-01

    General characteristics of size-dependent phenomena in electrochemical systems are given. Primary attention is paid to methodical achievements of nanoelectrochemistry, which is a line of research created over the last 15 years. The development of the main concepts of electrochemistry initiated by the stream of nanoscopic information is considered. The prospects for local studies of processes on charged interfaces, elementary steps of these processes and application of nanoelectrodes and related systems in interdisciplinary fields are discussed. The bibliography includes 198 references.

  2. Durham Neighborhood Compass Neighborhoods

    Data.gov (United States)

    City and County of Durham, North Carolina — The Durham Neighborhood Compass is a quantitative indicators project with qualitative values, integrating data from local government, the Census Bureau and other...

  3. A unified frame of predicting side effects of drugs by using linear neighborhood similarity.

    Science.gov (United States)

    Zhang, Wen; Yue, Xiang; Liu, Feng; Chen, Yanlin; Tu, Shikui; Zhang, Xining

    2017-12-14

    Drug side effects are one of main concerns in the drug discovery, which gains wide attentions. Investigating drug side effects is of great importance, and the computational prediction can help to guide wet experiments. As far as we known, a great number of computational methods have been proposed for the side effect predictions. The assumption that similar drugs may induce same side effects is usually employed for modeling, and how to calculate the drug-drug similarity is critical in the side effect predictions. In this paper, we present a novel measure of drug-drug similarity named "linear neighborhood similarity", which is calculated in a drug feature space by exploring linear neighborhood relationship. Then, we transfer the similarity from the feature space into the side effect space, and predict drug side effects by propagating known side effect information through a similarity-based graph. Under a unified frame based on the linear neighborhood similarity, we propose method "LNSM" and its extension "LNSM-SMI" to predict side effects of new drugs, and propose the method "LNSM-MSE" to predict unobserved side effect of approved drugs. We evaluate the performances of LNSM and LNSM-SMI in predicting side effects of new drugs, and evaluate the performances of LNSM-MSE in predicting missing side effects of approved drugs. The results demonstrate that the linear neighborhood similarity can improve the performances of side effect prediction, and the linear neighborhood similarity-based methods can outperform existing side effect prediction methods. More importantly, the proposed methods can predict side effects of new drugs as well as unobserved side effects of approved drugs under a unified frame.

  4. Promoting walking in older adults: Perceived neighborhood walkability influences the effectiveness of motivational messages.

    Science.gov (United States)

    Notthoff, Nanna; Carstensen, Laura L

    2017-06-01

    Positively framed messages seem to promote walking in older adults better than negatively framed messages. This study targeted elderly people in communities unfavorable to walking. Walking was measured with pedometers during baseline (1 week) and intervention (4 weeks). Participants ( n = 74) were informed about either the benefits of walking or the negative consequences of not walking. Perceived neighborhood walkability was assessed with a modified version of the Neighborhood Walkability Scale. When perceived walkability was high, positively framed messages were more effective than negatively framed messages in promoting walking; when perceived walkability was low, negatively framed messages were comparably effective to positively framed messages.

  5. Neighborhoods, Schools, and Academic Achievement: A Formal Mediation Analysis of Contextual Effects on Reading and Mathematics Abilities.

    Science.gov (United States)

    Wodtke, Geoffrey T; Parbst, Matthew

    2017-10-01

    Although evidence indicates that neighborhoods affect educational outcomes, relatively little research has explored the mechanisms thought to mediate these effects. This study investigates whether school poverty mediates the effect of neighborhood context on academic achievement. Specifically, it uses longitudinal data from the Panel Study of Income Dynamics, counterfactual methods, and a value-added modeling strategy to estimate the total, natural direct, and natural indirect effects of exposure to an advantaged rather than disadvantaged neighborhood on reading and mathematics abilities during childhood and adolescence. Contrary to expectations, results indicate that school poverty is not a significant mediator of neighborhood effects during either developmental period. Although moving from a disadvantaged neighborhood to an advantaged neighborhood is estimated to substantially reduce subsequent exposure to school poverty and improve academic achievement, school poverty does not play an important mediating role because even the large differences in school composition linked to differences in neighborhood context appear to have no appreciable effect on achievement. An extensive battery of sensitivity analyses indicates that these results are highly robust to unobserved confounding, alternative model specifications, alternative measures of school context, and measurement error, which suggests that neighborhood effects on academic achievement are largely due to mediating factors unrelated to school poverty.

  6. Reconciling phonological neighborhood effects in speech production through single trial analysis.

    Science.gov (United States)

    Sadat, Jasmin; Martin, Clara D; Costa, Albert; Alario, F-Xavier

    2014-02-01

    A crucial step for understanding how lexical knowledge is represented is to describe the relative similarity of lexical items, and how it influences language processing. Previous studies of the effects of form similarity on word production have reported conflicting results, notably within and across languages. The aim of the present study was to clarify this empirical issue to provide specific constraints for theoretical models of language production. We investigated the role of phonological neighborhood density in a large-scale picture naming experiment using fine-grained statistical models. The results showed that increasing phonological neighborhood density has a detrimental effect on naming latencies, and re-analyses of independently obtained data sets provide supplementary evidence for this effect. Finally, we reviewed a large body of evidence concerning phonological neighborhood density effects in word production, and discussed the occurrence of facilitatory and inhibitory effects in accuracy measures. The overall pattern shows that phonological neighborhood generates two opposite forces, one facilitatory and one inhibitory. In cases where speech production is disrupted (e.g. certain aphasic symptoms), the facilitatory component may emerge, but inhibitory processes dominate in efficient naming by healthy speakers. These findings are difficult to accommodate in terms of monitoring processes, but can be explained within interactive activation accounts combining phonological facilitation and lexical competition. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Internet Bad Neighborhoods Aggregation

    NARCIS (Netherlands)

    Moreira Moura, Giovane; Sadre, R.; Sperotto, Anna; Pras, Aiko; Paschoal Gaspary, L.; De Turk, Filip

    Internet Bad Neighborhoods have proven to be an innovative approach for fighting spam. They have also helped to understand how spammers are distributed on the Internet. In our previous works, the size of each bad neighborhood was fixed to a /24 subnetwork. In this paper, however, we investigate if

  8. Size effects in shear interfaces

    OpenAIRE

    GARNIER, J

    2001-01-01

    In physical modelling (centrifuge tests, calibration chambers, laboratory tests), the size of the soil particles may not be negligible when compared to the dimensions of the models. Size effects may so disturb the response of the models and the experimental data obtained on these cannot be extended to true scale conditions. Different tests have been performed to study and quantify the size effects that may happen in shear interfaces between soils and structures : modified shear box tests, pul...

  9. Heat and Humidity in the City: Neighborhood Heat Index Variability in a Mid-Sized City in the Southeastern United States.

    Science.gov (United States)

    Hass, Alisa L; Ellis, Kelsey N; Reyes Mason, Lisa; Hathaway, Jon M; Howe, David A

    2016-01-11

    Daily weather conditions for an entire city are usually represented by a single weather station, often located at a nearby airport. This resolution of atmospheric data fails to recognize the microscale climatic variability associated with land use decisions across and within urban neighborhoods. This study uses heat index, a measure of the combined effects of temperature and humidity, to assess the variability of heat exposure from ten weather stations across four urban neighborhoods and two control locations (downtown and in a nearby nature center) in Knoxville, Tennessee, USA. Results suggest that trees may negate a portion of excess urban heat, but are also associated with greater humidity. As a result, the heat index of locations with more trees is significantly higher than downtown and areas with fewer trees. Trees may also reduce heat stress by shading individuals from incoming radiation, though this is not considered in this study. Greater amounts of impervious surfaces correspond with reduced evapotranspiration and greater runoff, in terms of overall mass balance, leading to a higher temperature, but lower relative humidity. Heat index and relative humidity were found to significantly vary between locations with different tree cover and neighborhood characteristics for the full study time period as well as for the top 10% of heat index days. This work demonstrates the need for high-resolution climate data and the use of additional measures beyond temperature to understand urban neighborhood exposure to extreme heat, and expresses the importance of considering vulnerability differences among residents when analyzing neighborhood-scale impacts.

  10. Neighborhood Effects in Wind Farm Performance: A Regression Approach

    Directory of Open Access Journals (Sweden)

    Matthias Ritter

    2017-03-01

    Full Text Available The optimization of turbine density in wind farms entails a trade-off between the usage of scarce, expensive land and power losses through turbine wake effects. A quantification and prediction of the wake effect, however, is challenging because of the complex aerodynamic nature of the interdependencies of turbines. In this paper, we propose a parsimonious data driven regression wake model that can be used to predict production losses of existing and potential wind farms. Motivated by simple engineering wake models, the predicting variables are wind speed, the turbine alignment angle, and distance. By utilizing data from two wind farms in Germany, we show that our models can compete with the standard Jensen model in predicting wake effect losses. A scenario analysis reveals that a distance between turbines can be reduced by up to three times the rotor size, without entailing substantial production losses. In contrast, an unfavorable configuration of turbines with respect to the main wind direction can result in production losses that are much higher than in an optimal case.

  11. Neighborhood Moderation of Sensation Seeking Effects on Adolescent Substance Use Initiation.

    Science.gov (United States)

    Jensen, Michaeline; Chassin, Laurie; Gonzales, Nancy A

    2017-09-01

    Adolescent substance use carries a considerable public health burden, and early initiation into use is especially problematic. Research has shown that trait sensation seeking increases risk for substance use initiation, but less is known about contextual factors that can potentially unmask this risk. This study utilized a diverse longitudinal subsample of youth (N = 454) from a larger study of familial alcoholism (53.1% female, 61% non-Hispanic Caucasian, 27.8% Hispanic, 11.2% other ethnicity). Study questions examined sensation seeking in early adolescence (mean age = 12.16) and its relations with later substance use initiation (mean age = 15.69), and tested whether neighborhood disadvantage moderated sensation seeking's effects on initiation of alcohol, tobacco, and marijuana use. Neighborhood disadvantage significantly moderated the relation between sensation seeking and all three forms of substance use. For the most part, sensation seeking effects were weakened as neighborhood disadvantage increased, with the most advantaged neighborhoods exhibiting the strongest link between sensation seeking and substance use initiation. These results highlight the importance of focusing on relatively advantaged areas as potentially risky environments for the sensation seeking pathway to substance use.

  12. Effects of cumulative risk on behavioral and psychological well-being in first grade: moderation by neighborhood context.

    Science.gov (United States)

    Lima, Julie; Caughy, Margaret; Nettles, Saundra M; O'Campo, Patricia J

    2010-10-01

    This study builds upon existing research by examining whether risk indices for child psychological well-being behave in the same way in different types of neighborhoods. Specifically, we sought to determine if neighborhood characteristics acted to exacerbate or, alternatively, to buffer risk factors at the family and/or child level. Families with a child entering first grade in Fall 2002 were recruited from Baltimore City neighborhoods, defined as census block groups. This study included 405 children, and data came from an interview with the primary caregiver and an assessment of the first grader. The dependent variables were externalizing behavior and internalizing problems. A family risk index consisting of 13 measures, and a child risk index consisting of three measures were the main independent variables of interest. We examined the effects of these indices on child psychological well-being and behavior across two neighborhood characteristics: neighborhood potential for community involvement with children and neighborhood negative social climate. Results of multivariate analyses indicated that cumulative family risk was associated with an increase in both internalizing and externalizing behavior problems. Perceived negative social climate moderated the effect of family risks on behavior problems such that more risk was associated with a larger increment in both externalizing behavior problems and psychological problems for children living in high versus low risk neighborhoods. These findings further emphasize the importance of considering neighborhood context in the study of child psychological well-being. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. The effects of social capital and neighborhood characteristics on intimate partner violence: a consideration of social resources and risks.

    Science.gov (United States)

    Kirst, Maritt; Lazgare, Luis Palma; Zhang, Yu Janice; O'Campo, Patricia

    2015-06-01

    Intimate partner violence (IPV) is a growing public health problem, and gaps exist in knowledge with respect to appropriate prevention and treatment strategies. A growing body of research evidence suggests that beyond individual factors (e.g., socio-economic status, psychological processes, substance abuse problems), neighborhood characteristics, such as neighborhood economic disadvantage, high crime rates, high unemployment and social disorder, are associated with increased risk for IPV. However, existing research in this area has focused primarily on risk factors inherent in neighborhoods, and has failed to adequately examine resources within social networks and neighborhoods that may buffer or prevent the occurrence of IPV. This study examines the effects of neighborhood characteristics, such as economic disadvantage and disorder, and individual and neighborhood resources, such as social capital, on IPV among a representative sample of 2412 residents of Toronto, Ontario, Canada. Using a population based sample of 2412 randomly selected Toronto adults with comprehensive neighborhood level data on a broad set of characteristics, we conducted multi-level modeling to examine the effects of individual- and neighborhood-level effects on IPV outcomes. We also examined protective factors through a comprehensive operationalization of the concept of social capital, involving neighborhood collective efficacy, community group participation, social network structure and social support. Findings show that residents who were involved in one or more community groups in the last 12 months and had high perceived neighborhood problems were more likely to have experienced physical IPV. Residents who had high perceived social support and low perceived neighborhood problems were less likely to experience non-physical IPV. These relationships did not differ by neighborhood income or gender. Findings suggest interesting contextual effects of social capital on IPV. Consistent with

  14. The Difference-in-Difference Method: Assessing the Selection Bias in the Effects of Neighborhood Environment on Health

    Science.gov (United States)

    Grafova, Irina; Freedman, Vicki; Lurie, Nicole; Kumar, Rizie; Rogowski, Jeannette

    2013-01-01

    This paper uses the difference-in-difference estimation approach to explore the self-selection bias in estimating the effect of neighborhood economic environment on self-assessed health among older adults. The results indicate that there is evidence of downward bias in the conventional estimates of the effect of neighborhood economic disadvantage on self-reported health, representing a lower bound of the true effect. PMID:23623818

  15. Green-Roof Effects on Neighborhood Microclimate and Human Thermal Sensation

    Directory of Open Access Journals (Sweden)

    C. Y. Jim

    2013-01-01

    Full Text Available Green roofs have been recognized as an effective sustainable design tool to mitigate urban heat island (UHI effects. Previous studies have identified green-roof benefits in cooling and energy-conservation at the building scale, with limited exploration of the wider influence on neighborhood microclimate and human thermal comfort (HTC. This paper investigated the impacts of community-scale green-roof installation on air temperature and HTC in five typical residential neighborhoods of subtropical Hong Kong. The microclimate models ENVI-met and RayMan permitted studies of two main green-roof scenarios, namely extensive (EGR and intensive (IGR. Microclimatic monitoring data from a local experimental green-roof site validated the modeling methods. The results verified that green-roof cooling effects were not restricted to rooftops, but extended to the ground to improve neighborhood microclimate. EGR reduced pedestrian-level air temperature by 0.4–0.7 °C, and IGR by 0.5–1.7 °C, with maximum effect in open-set low rise sites. Coverage by building footprints and building height dampened lateral and vertical advection of cool air generated by green roofs. Roof greening also improved notably the rooftop-podium level HTC. Diurnal duration of high heat stress was reduced by 6–9 h for EGR scenarios, and 9–11 h for IGR. The findings indicated that large-scale green-roof installation could bring neighborhood-wide cooling, mitigate urban heat island effect, and furnish more comfortable thermal environment for urban residents.

  16. Neighborhood structure effects on the Dynamic response of soil-structure interaction by harmonic analysis

    Directory of Open Access Journals (Sweden)

    Pan Dan-guang

    2015-01-01

    Full Text Available For realizing the variation of structural dynamic characteristics due to neighbor structure in buildings group, the surface structure is idealized as an equivalent single degree of freedom system with rigid base whose site consists of a single homogeneous layer. Based on the model, a equivalent method on the equivalent seismic excitation is proposed. Then, the differences of seismic response and equivalent seismic input between soil - structure interaction (SSI system and structure -soil-structure interaction (SSSI system are investigated by harmonic analysis. The numerical results show that dynamic responses would be underestimated in SSSI system when the forcing frequencies are close to the Natural frequency if the effects of neighborhood structure were ignored. Neighborhood structure would make the translational displacement increase and rocking vibration decrease. When establishing an effective seismic input, it is necessary to consider the impact of inertia interaction.

  17. Neighborhood Effects on Crime for Female and Male Youth: Evidence from a Randomized Housing Voucher Experiment

    OpenAIRE

    Jeffrey R. Kling; Jens Ludwig; Lawrence F. Katz

    2004-01-01

    The Moving to Opportunity (MTO) demonstration assigned housing vouchers via random lottery to public housing residents in five cities. We use the exogenous variation in residential locations generated by MTO to estimate neighborhood effects on youth crime and delinquency. The offer to relocate to lower-poverty areas reduces arrests among female youth for violent and property crimes, relative to a control group. For males the offer to relocate reduces arrests for violent crime, at least in the...

  18. Heat and Humidity in the City: Neighborhood Heat Index Variability in a Mid-Sized City in the Southeastern United States

    Directory of Open Access Journals (Sweden)

    Alisa L. Hass

    2016-01-01

    Full Text Available Daily weather conditions for an entire city are usually represented by a single weather station, often located at a nearby airport. This resolution of atmospheric data fails to recognize the microscale climatic variability associated with land use decisions across and within urban neighborhoods. This study uses heat index, a measure of the combined effects of temperature and humidity, to assess the variability of heat exposure from ten weather stations across four urban neighborhoods and two control locations (downtown and in a nearby nature center in Knoxville, Tennessee, USA. Results suggest that trees may negate a portion of excess urban heat, but are also associated with greater humidity. As a result, the heat index of locations with more trees is significantly higher than downtown and areas with fewer trees. Trees may also reduce heat stress by shading individuals from incoming radiation, though this is not considered in this study. Greater amounts of impervious surfaces correspond with reduced evapotranspiration and greater runoff, in terms of overall mass balance, leading to a higher temperature, but lower relative humidity. Heat index and relative humidity were found to significantly vary between locations with different tree cover and neighborhood characteristics for the full study time period as well as for the top 10% of heat index days. This work demonstrates the need for high-resolution climate data and the use of additional measures beyond temperature to understand urban neighborhood exposure to extreme heat, and expresses the importance of considering vulnerability differences among residents when analyzing neighborhood-scale impacts.

  19. Family, peer, and neighborhood influences on academic achievement among African-American adolescents: one-year prospective effects.

    Science.gov (United States)

    Gonzales, N A; Cauce, A M; Friedman, R J; Mason, C A

    1996-06-01

    Using a 1-year prospective design, this study examined the influence of family status variables (family income, parental education, family structure), parenting variables (maternal support and restrictive control), peer support, and neighborhood risk on the school performance of 120 African American junior high school students. In addition to main effects of these variables, neighborhood risk was examined as a moderator of the effects of parenting and peer support. Family status variables were not predictive of adolescent school performance as indexed by self-reported grade point average. Maternal support at Time 1 was prospectively related to adolescent grades at Time 2. Neighborhood risk was related to lower grades, while peer support predicted better grades in the prospective analyses. Neighborhood risk also moderated the effects of maternal restrictive control and peer support on adolescent grades in prospective analyses. These findings highlight the importance of an ecological approach to the problem of academic underachievement within the African American Community.

  20. The effect of individual and neighborhood socioeconomic status on gastric cancer survival.

    Directory of Open Access Journals (Sweden)

    Chin-Chia Wu

    Full Text Available PURPOSE: Gastric cancer is a leading cause of death, particularly in the developing world. The literature reports individual socioeconomic status (SES or neighborhood SES as related to survival, but the effect of both has not been studied. This study investigated the effect of individual and neighborhood SES simultaneously on mortality in gastric cancer patients in Taiwan. MATERIALS AND METHODS: A study was conducted of 3,396 patients diagnosed with gastric cancer between 2002 and 2006. Each patient was followed for five years or until death. Individual SES was defined by income-related insurance premium (low, moderate, and high. Neighborhood SES was based on household income dichotomized into advantaged and disadvantaged areas. Multilevel logistic regression model was used to compare survival rates by SES group after adjusting for possible confounding factors. RESULTS: In patients younger than 65 years, 5-year overall survival rates were lowest for those with low individual SES. After adjusting for patient characteristics (age, gender, Charlson Comorbidity Index Score, gastric cancer patients with high individual SES had 68% risk reduction of mortality (adjusted odds ratio [OR] of mortality, 0.32; 95% confidence interval [CI], 0.17-0.61. Patients aged 65 and above had no statistically significant difference in mortality rates by individual SES group. Different neighborhood SES did not statistically differ in the survival rates. CONCLUSION: Gastric cancer patients aged less than 65 years old with low individual SES have higher risk of mortality, even under an universal healthcare system. Public health strategies, education and welfare policies should seek to correct the inequality in gastric cancer survival, especially in those with lower individual SES.

  1. Within-Class and Neighborhood Effects on the Relationship between Composite Urban Classes and Surface Temperature

    Directory of Open Access Journals (Sweden)

    Peleg Kremer

    2018-02-01

    Full Text Available Understanding the relationship between urban structure and ecological function—or environmental performance—is important for the planning of sustainable cities, and requires examination of how components in urban systems are organized. In this paper, we develop a Structure of Urban Landscape (STURLA classification, identifying common compositions of urban components using Berlin, Germany as a case study. We compute the surface temperature corresponding to each classification grid cell, and perform within-cell and neighborhood analysis for the most common composite classes in Berlin. We found that with-class composition and neighborhood composition as well as the interaction between them drive surface temperature. Our findings suggest that the spatial organization of urban components is important in determining the surface temperature and that specific combinations, such as low-rise buildings surrounded by neighborhood trees, or mid-rise buildings surrounded by high-rise buildings, compound to create a cooling effect. These findings are important for developing an understanding of how urban planning can harness structure-function relationships and improve urban sustainability.

  2. Associations of neighborhood disorganization and maternal spanking with children's aggression: A fixed-effects regression analysis.

    Science.gov (United States)

    Ma, Julie; Grogan-Kaylor, Andrew; Lee, Shawna J

    2018-02-01

    This study employed fixed effects regression that controls for selection bias, omitted variables bias, and all time-invariant aspects of parent and child characteristics to examine the simultaneous associations between neighborhood disorganization, maternal spanking, and aggressive behavior in early childhood using data from the Fragile Families and Child Wellbeing Study (FFCWS). Analysis was based on 2,472 children and their mothers who participated in Wave 3 (2001-2003; child age 3) and Wave 4 (2003-2006; child age 5) of the FFCWS. Results indicated that higher rates of neighborhood crime and violence predicted higher levels of child aggression. Maternal spanking in the past year, whether frequent or infrequent, was also associated with increases in aggressive behavior. This study contributes statistically rigorous evidence that exposure to violence in the neighborhood as well as the family context are predictors of child aggression. We conclude with a discussion for the need for multilevel prevention and intervention approaches that target both community and parenting factors. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  3. The "Residential" Effect Fallacy in Neighborhood and Health Studies: Formal Definition, Empirical Identification, and Correction.

    Science.gov (United States)

    Chaix, Basile; Duncan, Dustin; Vallée, Julie; Vernez-Moudon, Anne; Benmarhnia, Tarik; Kestens, Yan

    2017-11-01

    Because of confounding from the urban/rural and socioeconomic organizations of territories and resulting correlation between residential and nonresidential exposures, classically estimated residential neighborhood-outcome associations capture nonresidential environment effects, overestimating residential intervention effects. Our study diagnosed and corrected this "residential" effect fallacy bias applicable to a large fraction of neighborhood and health studies. Our empirical application investigated the effect that hypothetical interventions raising the residential number of services would have on the probability that a trip is walked. Using global positioning systems tracking and mobility surveys over 7 days (227 participants and 7440 trips), we employed a multilevel linear probability model to estimate the trip-level association between residential number of services and walking to derive a naïve intervention effect estimate and a corrected model accounting for numbers of services at the residence, trip origin, and trip destination to determine a corrected intervention effect estimate (true effect conditional on assumptions). There was a strong correlation in service densities between the residential neighborhood and nonresidential places. From the naïve model, hypothetical interventions raising the residential number of services to 200, 500, and 1000 were associated with an increase by 0.020, 0.055, and 0.109 of the probability of walking in the intervention groups. Corrected estimates were of 0.007, 0.019, and 0.039. Thus, naïve estimates were overestimated by multiplicative factors of 3.0, 2.9, and 2.8. Commonly estimated residential intervention-outcome associations substantially overestimate true effects. Our somewhat paradoxical conclusion is that to estimate residential effects, investigators critically need information on nonresidential places visited.

  4. Size effects in crystal plasticity

    DEFF Research Database (Denmark)

    Borg, Ulrik

    2007-01-01

    Numerical analyses of plasticity size effects have been carried out for different problems using a developed strain gradient crystal plasticiy theory. The theory employs higher order stresses as work conjugates to slip gradients and uses higher order boundary conditions. Problems on localization...... of plastic flow in a single crystal, grain boundary effects in a bicrystal, and grain size effects in a polycrystal are studied. Single crystals containing micro-scale voids have also been analyzed at different loading conditions with focus on the stress and deformation fields around the voids, on void...... growth and interaction between neighboring voids, and on a comparison between the developed strain gradient crystal plasticity theory and a discrete dislocation plasticity theory. Furthermore, voids and rigid inclusions in isotropic materials have been studied using a strain gradient plasticity theory...

  5. NEIGHBORHOOD CHOICE AND NEIGHBORHOOD CHANGE

    OpenAIRE

    Bruch, Elizabeth; Mare, Robert D.

    2006-01-01

    This paper examines the relationships between the residential choices of individuals and aggregate patterns of neighborhood change. We investigate the conditions under which individuals’ preferences for the race-ethnic composition of their neighborhoods produce high levels of segregation. Using computational models, we find that high levels of segregation occur only when individuals’ preferences follow a threshold function. If individuals make finer-grained distinctions among neighborhoods th...

  6. Size effects on cavitation instabilities

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Tvergaard, Viggo

    2006-01-01

    growth is here analyzed for such cases. A finite strain generalization of a higher order strain gradient plasticity theory is applied for a power-law hardening material, and the numerical analyses are carried out for an axisymmetric unit cell containing a spherical void. In the range of high stress...... triaxiality, where cavitation instabilities are predicted by conventional plasticity theory, such instabilities are also found for the nonlocal theory, but the effects of gradient hardening delay the onset of the instability. Furthermore, in some cases the cavitation stress reaches a maximum and then decays...... as the void grows to a size well above the characteristic material length....

  7. Word length, set size, and lexical factors: Re-examining what causes the word length effect.

    Science.gov (United States)

    Guitard, Dominic; Gabel, Andrew J; Saint-Aubin, Jean; Surprenant, Aimée M; Neath, Ian

    2018-04-19

    The word length effect, better recall of lists of short (fewer syllables) than long (more syllables) words has been termed a benchmark effect of working memory. Despite this, experiments on the word length effect can yield quite different results depending on set size and stimulus properties. Seven experiments are reported that address these 2 issues. Experiment 1 replicated the finding of a preserved word length effect under concurrent articulation for large stimulus sets, which contrasts with the abolition of the word length effect by concurrent articulation for small stimulus sets. Experiment 2, however, demonstrated that when the short and long words are equated on more dimensions, concurrent articulation abolishes the word length effect for large stimulus sets. Experiment 3 shows a standard word length effect when output time is equated, but Experiments 4-6 show no word length effect when short and long words are equated on increasingly more dimensions that previous demonstrations have overlooked. Finally, Experiment 7 compared recall of a small and large neighborhood words that were equated on all the dimensions used in Experiment 6 (except for those directly related to neighborhood size) and a neighborhood size effect was still observed. We conclude that lexical factors, rather than word length per se, are better predictors of when the word length effect will occur. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  8. A Primer on Basic Effect Size Concepts.

    Science.gov (United States)

    Elmore, Patricia B.; Rotou, Ourania

    The increased interest in reporting effect sizes means that it is necessary to consider what should be included in a primer on effect sizes. A review of papers on effect sizes and commonly repeated statistical analyses suggests that it is important to discuss effect sizes relative to bivariate correlation, t-tests, analysis of variance/covariance,…

  9. The Protective Effects of Neighborhood Collective Efficacy on Adolescent Substance Use and Violence Following Exposure to Violence

    Science.gov (United States)

    Wright, Emily M.; Pinchevsky, Gillian M.

    2013-01-01

    Research has demonstrated that exposure to violence can result in many negative consequences for youth, but the degree to which neighborhood conditions may foster resiliency among victims is not well understood. This study tests the hypothesis that neighborhood collective efficacy attenuates the relationship between adolescent exposure to violence, substance use, and violence. Data were collected from 1,661–1,718 adolescents participating in the Project on Human Development in Chicago Neighborhoods (PHDCN), who were diverse in terms of sex (51% male, 49% female), race/ethnicity (48% Hispanic, 34% African American, 14% Caucasian, and 4% other race/ethnicity), and age (mean age 12 years; range: 8–16). Information on neighborhood collective efficacy was obtained from adult residents, and data from the 1990 U.S. Census were used to control for neighborhood disadvantage. Based on hierarchical modeling techniques to adjust for the clustered data, Bernoulli models indicated that more exposure to violence was associated with a greater likelihood of tobacco, alcohol, and marijuana use and perpetration of violence. Poisson models suggested that victimization was also related to a greater variety of substance use and violent behaviors. A moderating effect of collective efficacy was found in models assessing the variety of substance use; the relationship between victimization and substance use was weaker for youth in neighborhoods with higher versus lower levels of collective efficacy. These findings are consistent with literature indicating that social support can ameliorate the negative impact of victimization. This investigation extends this research to show that neighborhood social support can also help to promote resiliency among adolescents. PMID:24170438

  10. Measuring physical neighborhood quality related to health.

    Science.gov (United States)

    Rollings, Kimberly A; Wells, Nancy M; Evans, Gary W

    2015-04-29

    Although sociodemographic factors are one aspect of understanding the effects of neighborhood environments on health, equating neighborhood quality with socioeconomic status ignores the important role of physical neighborhood attributes. Prior work on neighborhood environments and health has relied primarily on level of socioeconomic disadvantage as the indicator of neighborhood quality without attention to physical neighborhood quality. A small but increasing number of studies have assessed neighborhood physical characteristics. Findings generally indicate that there is an association between living in deprived neighborhoods and poor health outcomes, but rigorous evidence linking specific physical neighborhood attributes to particular health outcomes is lacking. This paper discusses the methodological challenges and limitations of measuring physical neighborhood environments relevant to health and concludes with proposed directions for future work.

  11. Hit size effectiveness in relation to the microdosimetric site size

    International Nuclear Information System (INIS)

    Varma, M.N.; Wuu, C.S.; Zaider, M.

    1994-01-01

    This paper examines the effect of site size (that is, the diameter of the microdosimetric volume) on the hit size effectiveness function (HSEF), q(y), for several endpoints relevant in radiation protection. A Bayesian and maximum entropy approach is used to solve the integral equations that determine, given microdosimetric spectra and measured initial slopes, the function q(y). All microdosimetric spectra have been calculated de novo. The somewhat surprising conclusion of this analysis is that site size plays only a minor role in selecting the hit size effectiveness function q(y). It thus appears that practical means (e.g. conventional proportional counters) are already at hand to actually implement the HSEF as a radiation protection tool. (Author)

  12. Associations between socioeconomic status and allostatic load: effects of neighborhood poverty and tests of mediating pathways.

    Science.gov (United States)

    Schulz, Amy J; Mentz, Graciela; Lachance, Laurie; Johnson, Jonetta; Gaines, Causandra; Israel, Barbara A

    2012-09-01

    We examined relationships between neighborhood poverty and allostatic load in a low- to moderate-income multiracial urban community. We tested the hypothesis that neighborhood poverty is associated with allostatic load, controlling for household poverty. We also examined the hypotheses that this association was mediated by psychosocial stress and health-related behaviors. We conducted multilevel analyses using cross-sectional data from a probability sample survey in Detroit, Michigan (n = 919) and the 2000 US Census. The outcome measure was allostatic load. Independent variables included neighborhood and household poverty, psychosocial stress, and health-related behaviors. Covariates included neighborhood and individual demographic characteristics. Neighborhood poverty was positively associated with allostatic load (P poverty and controlling for potential confounders. Relationships between neighborhood poverty were mediated by self-reported neighborhood environment stress but not by health-related behaviors. Neighborhood poverty is associated with wear and tear on physiological systems, and this relationship is mediated through psychosocial stress. These relationships are evident after accounting for household poverty levels. Efforts to promote health equity should focus on neighborhood poverty, associated stressful environmental conditions, and household poverty.

  13. Effect of cross-level interaction between individual and neighborhood socioeconomic status on adult mortality rates.

    Science.gov (United States)

    Winkleby, Marilyn; Cubbin, Catherine; Ahn, David

    2006-12-01

    We examined whether the influence of neighborhood-level socioeconomic status (SES) on mortality differed by individual-level SES. We used a population-based, mortality follow-up study of 4476 women and 3721 men, who were predominately non-HIspanic White and aged 25-74 years at baseline, from 82 neighborhoods in 4 California cities. Participants were surveyed between 1979 and 1990, and were followed until December 31, 2002 (1148 deaths; mean follow-up time 17.4 years). Neighborhood SES was defined by 5 census variables and was divided into 3 levels. Individual SES was defined by a composite of educational level and household income and was divided into tertiles. Death rates among women of low SES were highest in high-SES neighborhoods (1907/100000 person-years), lower in moderate-SES neighborhoods (1323), and lowest in low-SES neighborhoods (1128). Similar to women, rates among men of low SES were 1928, 1646, and 1590 in high-, moderate-, and low-SES neighborhoods, respectively. Differences were not explained by individual-level baseline risk factors. The disparities in mortality by neighborhood of residence among women and men of low SES demonstrate that they do not benefit from the higher quality of resources and knowledge generally associated with neighborhoods that have higher SES.

  14. Word Recognition and Nonword Repetition in Children with Language Disorders: The Effects of Neighborhood Density, Lexical Frequency, and Phonotactic Probability

    Science.gov (United States)

    Rispens, Judith; Baker, Anne; Duinmeijer, Iris

    2015-01-01

    Purpose: The effects of neighborhood density (ND) and lexical frequency on word recognition and the effects of phonotactic probability (PP) on nonword repetition (NWR) were examined to gain insight into processing at the lexical and sublexical levels in typically developing (TD) children and children with developmental language problems. Method:…

  15. Do social relations buffer the effect of neighborhood deprivation on health-related quality of life? Results from the LifeLines Cohort Study

    NARCIS (Netherlands)

    Klijs, Bart; de Leon, Carlos F. Mendes; Kibele, Eva U. B.; Smidt, Nynke

    We investigated whether social relations buffer the effect of neighborhood deprivation on mental and physical health-related quality of life. Baseline data from the LifeLines Cohort Study (N=68,111) and a neighborhood deprivation index were used to perform mixed effect linear regression analyses.

  16. Neighborhood spaces

    OpenAIRE

    D. C. Kent; Won Keun Min

    2002-01-01

    Neighborhood spaces, pretopological spaces, and closure spaces are topological space generalizations which can be characterized by means of their associated interior (or closure) operators. The category NBD of neighborhood spaces and continuous maps contains PRTOP as a bicoreflective subcategory and CLS as a bireflective subcategory, whereas TOP is bireflectively embedded in PRTOP and bicoreflectively embedded in CLS. Initial and final structures are described in these categories, and it is s...

  17. Functional Interpretation of Neighborhood Public Spaces in Terms of Identity

    Directory of Open Access Journals (Sweden)

    Hamid Majedi

    2015-03-01

    Full Text Available The aim of this article is to evaluate the effect of neighborhood public space transformation due to rapid urbanization in Tehran since 1960s, on the formation of neighborhood identity. In order to find the role of public spaces in enhancing neighborhood identities, two middle class neighborhoods with different spatial organizations are compared with each other: Nazi Abad a planned neighborhood and Mehran a typical unplanned neighborhood which developed through rapid urbanization.   Next, the effect of neighborhood public spaces on neighborhood inhabitants is evaluated from two perspectives: Perceptual dimension and social dimension. The findings indicate that planned spatial organization and various neighborhood public spaces result in stronger neighborhood identity. It enhances both perceptual dimension of neighborhood identity(place attachment and its social dimension (sense of community. In contrast unplanned spatial organization which is the typical feature of Tehran neighborhoods leads to weak neighborhood identity.

  18. Choice Neighborhood Grantees

    Data.gov (United States)

    Department of Housing and Urban Development — Choice Neighborhoods grants transform distressed neighborhoods, public and assisted projects into viable and sustainable mixed-income neighborhoods by linking...

  19. The effect of neighborhood context on children's academic achievement in China: Exploring mediating mechanisms.

    Science.gov (United States)

    Lei, Lei

    2018-05-01

    Along with the economic reforms, rapid urbanization, and the growth of a free land market, Chinese cities witness new forms of neighborhood poverty and increasing residential segregation by social class, migration status, and housing tenure. But little is known about the consequences of the growing social-spatial differentiation for children's educational achievement in China. Using national-scale survey data from the China Family Panel Studies in 2010, this study examines the relationship between neighborhood socioeconomic status (SES) and children's test scores in urban China, and explores the mechanisms through which neighborhood environment is associated with children's academic achievement. The results show that neighborhood SES is positively associated with children's verbal and math test scores after accounting for myriad individual and family characteristics. The relationship between neighborhood SES and test scores is partially explained by neighborhood educational institutions and collective socialization. Peer contagion, neighborhood social organization, or neighborhood physical environment do not explain this relationship. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. The Conflicting Aims of the European Neighborhood Policy and its Secondary Effects

    DEFF Research Database (Denmark)

    Castan Pinos, Jaume

    2014-01-01

    to guarantee the security of Europe’s borders. The European Neighborhood Policy has played a pivotal role in ensuring that the neighbors complied with the EU’s interest by offering political and economic rewards. Compliance is also enhanced through the “Seville Doctrine.” The paper challenges the idea...... that the “war on migrants” is a common shared interest for the EU and North African states, arguing that it is rather an EU security interest which does not necessarily correspond with the neighbors priorities. Finally, the paper focuses on the implementation of externalization in Morocco and critically...... analyzes the non-desired secondary effects generated by the adoption of EU-made migration policies....

  1. NEIGHBORHOOD CRIME AND DEPRESSIVE SYMPTOMS AMONG AFRICAN AMERICAN WOMEN: GENETIC MODERATION AND EPIGENETIC MEDIATOIN OF EFFECTS

    Science.gov (United States)

    Lei, Man-Kit; Beach, Steven R. H.; Simons, Ronald L.; Philibert, Robert A.

    2015-01-01

    Introduction Social scientists have long recognized the important role that neighborhood crime can play in stress-related disease, but very little is known about potential biosocial mechanisms that may link the experience of living in high-crime neighborhoods with depression. Objective The current study introduces an integrated model that combines neighborhood, genetic, and epigenetic factors. Methods Hypotheses were tested with a sample of 99 African American women from the Family and Community Health Study (FACHS). Results Allele variants of the serotonin transporter gene (5-HTT) interact with neighborhood crime to predict depressive symptoms in a manner consonant with the differential susceptibility perspective. Furthermore, this association is mediated by DNA methylation of the promoter region of the serotonin transporter gene. Conclusion The findings provide support for an integrated model in which changes in DNA methylation, resulting from neighborhood crime, can result in an increase or decrease in gene activity which, in turn, influences depressive symptoms. PMID:26513121

  2. Neighborhood crime and depressive symptoms among African American women: Genetic moderation and epigenetic mediation of effects.

    Science.gov (United States)

    Lei, Man-Kit; Beach, Steven R H; Simons, Ronald L; Philibert, Robert A

    2015-12-01

    Social scientists have long recognized the important role that neighborhood crime can play in stress-related disease, but very little is known about potential biosocial mechanisms that may link the experience of living in high-crime neighborhoods with depression. The current study introduces an integrated model that combines neighborhood, genetic, and epigenetic factors. Hypotheses were tested with a sample of 99 African American women from the Family and Community Health Study (FACHS). Allele variants of the serotonin transporter gene (5-HTT) interact with neighborhood crime to predict depressive symptoms in a manner consonant with the differential susceptibility perspective. Furthermore, this association is mediated by DNA methylation of the promoter region of the serotonin transporter gene. The findings provide support for an integrated model in which changes in DNA methylation, resulting from neighborhood crime, can result in an increase or decrease in gene activity which, in turn, influences depressive symptoms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Size Effects on the Strength of Metals

    DEFF Research Database (Denmark)

    Huang, Xiaoxu

    2014-01-01

    The grain size effect and the specimen size effect on the strength of metals are briefly reviewed with respect to their history and current status of research. It is revealed that the fundamental strengthening mechanisms responsible for these two types of size effect are to increase the resistanc...

  4. Effect Sizes in Gifted Education Research

    Science.gov (United States)

    Gentry, Marcia; Peters, Scott J.

    2009-01-01

    Recent calls for reporting and interpreting effect sizes have been numerous, with the 5th edition of the "Publication Manual of the American Psychological Association" (2001) calling for the inclusion of effect sizes to interpret quantitative findings. Many top journals have required that effect sizes accompany claims of statistical significance.…

  5. Subjective neighborhood assessment and physical inactivity: An examination of neighborhood-level variance.

    Science.gov (United States)

    Prochaska, John D; Buschmann, Robert N; Jupiter, Daniel; Mutambudzi, Miriam; Peek, M Kristen

    2018-06-01

    Research suggests a linkage between perceptions of neighborhood quality and the likelihood of engaging in leisure-time physical activity. Often in these studies, intra-neighborhood variance is viewed as something to be controlled for statistically. However, we hypothesized that intra-neighborhood variance in perceptions of neighborhood quality may be contextually relevant. We examined the relationship between intra-neighborhood variance of subjective neighborhood quality and neighborhood-level reported physical inactivity across 48 neighborhoods within a medium-sized city, Texas City, Texas using survey data from 2706 residents collected between 2004 and 2006. Neighborhoods where the aggregated perception of neighborhood quality was poor also had a larger proportion of residents reporting being physically inactive. However, higher degrees of disagreement among residents within neighborhoods about their neighborhood quality was significantly associated with a lower proportion of residents reporting being physically inactive (p=0.001). Our results suggest that intra-neighborhood variability may be contextually relevant in studies seeking to better understand the relationship between neighborhood quality and behaviors sensitive to neighborhood environments, like physical activity. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Modelling of Size Effect with Regularised Continua

    Directory of Open Access Journals (Sweden)

    H. Askes

    2004-01-01

    Full Text Available A nonlocal damage continuum and a viscoplastic damage continuum are used to model size effects. Three-point bending specimens are analysed, whereby a distinction is made between unnotched specimens, specimens with a constant notch and specimens with a proportionally scaled notch. Numerical finite element simulations have been performed for specimen sizes in a range of 1:64. Size effects are established in terms of nominal strength and compared to existing size effect models from the literature. 

  7. Size effects in manufacturing of metallic components

    DEFF Research Database (Denmark)

    Vollertsen, F; Biermann, D; Hansen, Hans Nørgaard

    2009-01-01

    In manufacturing of metallic components, the size of the part plays an important role for the process behaviour. This is due to so called size effects, which lead to changes in the process behaviour even if the relationship between the main geometrical features is kept constant. The aim...... of this paper is to give a systematic review on Such effects and their potential use or remedy. First, the typology of size effects will be explained, followed by a description of size effects on strength and tribology. The last three sections describe size effects on formability, forming processes and cutting...... processes. (C) 2009 CIRP....

  8. On size effects in fracture

    International Nuclear Information System (INIS)

    Sinclair, G.B.

    1985-01-01

    This paper discusses the dependence of fracture stress on size. This conclusion is based on classical energy arguments. For an in-plane scaled specimen pair, the larger the specimen the smaller the fracture stress. In contrast the same theory gives a different dependence for out-of-plane specimen and the dependence involves plane stress, strain, fracture stresses and Poisson's ratio. The objective of this paper is to examine how well these predictions are actually complied with

  9. Do class size effects differ across grades?

    DEFF Research Database (Denmark)

    Nandrup, Anne Brink

    size cap that creates exogenous variation in class sizes. Significant (albeit modest) negative effects of class size increases are found for children on primary school levels. The effects on math abilities are statistically different across primary and secondary school. Larger classes do not affect......This paper contributes to the class size literature by analyzing whether short-run class size effects are constant across grade levels in compulsory school. Results are based on administrative data on all pupils enroled in Danish public schools. Identification is based on a government-imposed class...

  10. Neighborhood Effects on Birthweight: An Exploration of Psychosocial and Behavioral Pathways in Baltimore, 1995–1996

    OpenAIRE

    Schempf, Ashley; Strobino, Donna; O’Campo, Patricia

    2008-01-01

    Neighborhood characteristics have been proposed to influence birth outcomes through psychosocial and behavioral pathways, yet empirical evidence is lacking. Using data from an urban, low-income sample, this study examined the impact of the neighborhood environment on birthweight and evaluated mediation by psychosocial and behavioral factors. The sample included 726 women who delivered a live birth at Johns Hopkins Hospital in Baltimore, Maryland USA between 1995 and 1996. Census tract data we...

  11. Does Neighborhood Social Capital Buffer the Effects of Maternal Depression on Adolescent Behavior Problems?

    Science.gov (United States)

    Mays, Vickie M.; Cochran, Susan D.

    2014-01-01

    Neighborhood characteristics have been shown to impact child well-being. However, it remains unclear how these factors combine with family characteristics to influence child development. The current study helps develop that understanding by investigating how neighborhoods directly impact child and adolescent behavior problems as well as moderate the influence of family characteristics on behavior. Using multilevel linear models, we examined the relationship among neighborhood conditions (poverty and social capital) and maternal depression on child and adolescent behavior problems. The sample included 741 children, age 5–11, and 564 adolescents, age 12–17. Outcomes were internalizing (e.g. anxious/depressed) and externalizing (e.g. aggressive/hyperactive) behavior problems. Neighborhood poverty and maternal depression were both positively associated with behavior problems for children and adolescents. However, while neighborhood social capital was not directly associated with behavior problems, the interaction of social capital and maternal depression was significantly related to behavior problems for adolescents. This interaction showed that living in neighborhoods with higher levels of social capital attenuated the relationship between maternal depression and adolescent behavior problems and confirmed the expectation that raising healthy well-adjusted children depends not only on the family, but also the context in which the family lives. PMID:24659390

  12. Does neighborhood social capital buffer the effects of maternal depression on adolescent behavior problems?

    Science.gov (United States)

    Delany-Brumsey, Ayesha; Mays, Vickie M; Cochran, Susan D

    2014-06-01

    Neighborhood characteristics have been shown to impact child well-being. However, it remains unclear how these factors combine with family characteristics to influence child development. The current study helps develop that understanding by investigating how neighborhoods directly impact child and adolescent behavior problems as well as moderate the influence of family characteristics on behavior. Using multilevel linear models, we examined the relationship among neighborhood conditions (poverty and social capital) and maternal depression on child and adolescent behavior problems. The sample included 741 children, age 5–11, and 564 adolescents, age 12–17. Outcomes were internalizing (e.g. anxious/depressed) and externalizing (e.g. aggressive/hyperactive) behavior problems. Neighborhood poverty and maternal depression were both positively associated with behavior problems for children and adolescents. However, while neighborhood social capital was not directly associated with behavior problems, the interaction of social capital and maternal depression was significantly related to behavior problems for adolescents. This interaction showed that living in neighborhoods with higher levels of social capital attenuated the relationship between maternal depression and adolescent behavior problems and confirmed the expectation that raising healthy well-adjusted children depends not only on the family, but also the context in which the family lives.

  13. Do Class Size Effects Differ across Grades?

    Science.gov (United States)

    Nandrup, Anne Brink

    2016-01-01

    This paper contributes to the class size literature by analysing whether short-run class size effects are constant across grade levels in compulsory school. Results are based on administrative data on all pupils enrolled in Danish public schools. Identification is based on a government-imposed class size cap that creates exogenous variation in…

  14. Prevention of the Portion Size Effect

    NARCIS (Netherlands)

    I. Versluis (Iris)

    2016-01-01

    markdownabstractAn increase in the portion size leads to an increase in energy intake, a phenomenon which is also referred to as the portion size effect. The increase in portion sizes in recent years is regarded as an important contributor to the increase in the prevalence of obesity. Hence, the aim

  15. Neighborhood Poverty and Adolescent Development

    Science.gov (United States)

    McBride Murry, Velma; Berkel, Cady; Gaylord-Harden, Noni K.; Copeland-Linder, Nikeea; Nation, Maury

    2011-01-01

    This article provides a comprehensive review of studies conducted over the past decade on the effects of neighborhood and poverty on adolescent normative and nonnormative development. Our review includes a summary of studies examining the associations between neighborhood poverty and adolescent identity development followed by a review of studies…

  16. One size doesn't fit all: cross-sectional associations between neighborhood walkability, crime and physical activity depends on age and sex of residents.

    Science.gov (United States)

    Richardson, Andrea S; Troxel, Wendy M; Ghosh-Dastidar, Madhumita B; Beckman, Robin; Hunter, Gerald P; DeSantis, Amy S; Colabianchi, Natalie; Dubowitz, Tamara

    2017-01-19

    Low-income African American adults are disproportionately affected by obesity and are also least likely to engage in recommended levels of physical activity (Flegal et al. JAMA 303(3):235-41, 2010; Tucker et al. Am J Prev Med 40(4):454-61, 2011). Moderate-to-vigorous physical activity (MVPA) is an important factor for weight management and control, as well as for reducing disease risk (Andersen et al. Lancet 368(9532):299-304, 2006; Boreham and Riddoch J Sports Sci 19(12):915-29, 2001; Carson et al. PLoS One 8(8):e71417, 2013). While neighborhood greenspace and walkability have been associated with increased MVPA, evidence also suggests that living in areas with high rates of crime limits MVPA. Few studies have examined to what extent the confluence of neighborhood greenspace, walkability and crime might impact MVPA in low-income African American adults nor how associations may vary by age and sex. In 2013 we collected self-reported data on demographics, functional limitations, objective measures of MVPA (accelerometry), neighborhood greenspace (geographic information system), and walkability (street audit) in 791 predominantly African-American adults (mean age 56 years) living in two United States (U.S.) low-income neighborhoods. We also acquired data from the City of Pittsburgh on all crime events within both neighborhoods. To examine cross-sectional associations of neighborhood-related variables (i.e., neighborhood greenspace, walkability and crime) with MVPA, we used zero-inflated negative binomial regression models. Additionally, we examined potential interactions by age (over 65 years) and sex on relationships between neighborhood variables and MVPA. Overall, residents engaged in very little to no MVPA regardless of where they lived. However, for women, but not men, under the age of 65 years, living in more walkable neighborhoods was associated with more time engaged in MVPA in (β = 0.55, p = 0.007) as compared to their counterparts living in less

  17. One size doesn’t fit all: cross-sectional associations between neighborhood walkability, crime and physical activity depends on age and sex of residents

    Directory of Open Access Journals (Sweden)

    Andrea S. Richardson

    2017-01-01

    Full Text Available Abstract Background Low-income African American adults are disproportionately affected by obesity and are also least likely to engage in recommended levels of physical activity (Flegal et al. JAMA 303(3:235-41, 2010; Tucker et al. Am J Prev Med 40(4:454-61, 2011. Moderate-to-vigorous physical activity (MVPA is an important factor for weight management and control, as well as for reducing disease risk (Andersen et al. Lancet 368(9532:299-304, 2006; Boreham and Riddoch J Sports Sci 19(12:915-29, 2001; Carson et al. PLoS One 8(8:e71417, 2013. While neighborhood greenspace and walkability have been associated with increased MVPA, evidence also suggests that living in areas with high rates of crime limits MVPA. Few studies have examined to what extent the confluence of neighborhood greenspace, walkability and crime might impact MVPA in low-income African American adults nor how associations may vary by age and sex. Methods In 2013 we collected self-reported data on demographics, functional limitations, objective measures of MVPA (accelerometry, neighborhood greenspace (geographic information system, and walkability (street audit in 791 predominantly African-American adults (mean age 56 years living in two United States (U.S. low-income neighborhoods. We also acquired data from the City of Pittsburgh on all crime events within both neighborhoods. Exposure: To examine cross-sectional associations of neighborhood-related variables (i.e., neighborhood greenspace, walkability and crime with MVPA, we used zero-inflated negative binomial regression models. Additionally, we examined potential interactions by age (over 65 years and sex on relationships between neighborhood variables and MVPA. Results Overall, residents engaged in very little to no MVPA regardless of where they lived. However, for women, but not men, under the age of 65 years, living in more walkable neighborhoods was associated with more time engaged in MVPA in (β = 0.55, p = 0

  18. The dynamic and indirect spatial effects of neighborhood conditions on land value, spatial panel dynamic econometrics model

    Science.gov (United States)

    Fitriani, Rahma; Sumarminingsih, Eni; Astutik, Suci

    2017-05-01

    Land value is the product of past decision of its use leading to its value, as well as the value of the surrounded land. It is also affected by the local characteristic and the spillover development demand of the previous time period. The effect of each factor on land value will have dynamic and spatial virtues. Thus, a spatial panel dynamic model is used to estimate the particular effects. The model will be useful for predicting the future land value or the effect of implemented policy on land value. The objective of this paper is to derive the dynamic and indirect spatial marginal effects of the land characteristic and the spillover development demand on land value. Each effect is the partial derivative of the expected land value based on the spatial dynamic model with respect to each variable, by considering different time period and different location. The results indicate that the instant change of local or neighborhood characteristics on land value affect the local and the immediate neighborhood land value. However, the longer the change take place, the effect will spread further, not only on the immediate neighborhood.

  19. Assessment of the neighborhood environmental effects of highway improvements through micronetwork simulation

    Energy Technology Data Exchange (ETDEWEB)

    Schimpeler, C.C. (Schimpeler--Corradino Associates, Louisville, KY); Corradino, J.C.; Siria, B.S.

    1978-01-01

    New Cut Road is a major arterial highway serving South Louisville. Until recently, it was a narrow two-lane highway of rural-type design carrying up to 14,000 vehicles per day under forced flow conditions. Then construction began to widen the road from Southside Drive to Old Third Street Road, as a result of Urban Corridor Demonstration Program funding. The impacts (traffic, noise, and air pollution) on the neighborhoods surrounding this widening have been measured through micronetwork simulation techniques. Traffic will be diverted from surrounding roads (up to 20 percent) to the widened New Cut facility, thereby eliminating ''over-capacity'' conditions in these facilities, adding several years' life. Further, expeditious movement of vehicles through the New Cut Road ''area of influence'' will have a beneficial, albeit small, effect on the local air and noise environment. New Cut Road will be a highly cost-effective, low-capital-intensive improvement.

  20. Neighborhood-level social processes and substantiated cases of child maltreatment.

    Science.gov (United States)

    Molnar, Beth E; Goerge, Robert M; Gilsanz, Paola; Hill, Andrea; Subramanian, S V; Holton, John K; Duncan, Dustin T; Beatriz, Elizabeth D; Beardslee, William R

    2016-01-01

    Child maltreatment is a preventable public health problem. Research has demonstrated that neighborhood structural factors (e.g. poverty, crime) can influence the proportion of a neighborhood's children who are victims of maltreatment. A newer strategy is the identification of potentially modifiable social processes at the neighborhood level that can also influence maltreatment. Toward this end, this study examines neighborhood-level data (maltreatment cases substantiated by Illinois' child protection agency, 1995-2005, social processes measured by the Project on Human Development in Chicago Neighborhoods, U.S. Census data, proportions of neighborhoods on public assistance, and crime data) that were linked across clusters of contiguous, relatively homogenous Chicago, IL census tracts with respect to racial/ethnic and socioeconomic composition. Our analysis-an ecological-level, repeated cross-sectional design utilizing random-intercept logit models-with a sensitivity analysis using spatial models to control for spatial autocorrelation-revealed consistent associations between neighborhood social processes and maltreatment. Neighborhoods higher in collective efficacy, intergenerational closure, and social networks, and lower in disorder had lower proportions of neglect, physical abuse, and sexual abuse substantiated cases, controlling for differences in structural factors. Higher collective efficacy and social network size also predicted a lower proportion of substance-exposed infants. This research indicates that strategies to mobilize neighborhood-level protective factors may decrease child maltreatment more effectively than individual and family-focused efforts alone. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Size effects in thin films

    CERN Document Server

    Tellier, CR; Siddall, G

    1982-01-01

    A complete and comprehensive study of transport phenomena in thin continuous metal films, this book reviews work carried out on external-surface and grain-boundary electron scattering and proposes new theoretical equations for transport properties of these films. It presents a complete theoretical view of the field, and considers imperfection and impurity effects.

  2. Temporal Effects of Child and Adolescent Exposure to Neighborhood Disadvantage on Black/White Disparities in Young Adult Obesity.

    Science.gov (United States)

    Kravitz-Wirtz, Nicole

    2016-05-01

    This study investigates the effects of duration and timing of exposure to neighborhood disadvantage from birth through age 17 years on obesity incidence in early adulthood and black/white disparities therein. Individual- and household-level data from the 1970-2011 waves of the Panel Study of Income Dynamics are merged with census data on respondents' neighborhoods (n = 1,498). Marginal structural models with inverse probability of treatment and censoring weights are used to quantify the probability of being obese at least once between ages 18 and 30 years as a function of cumulative exposure to neighborhood disadvantage throughout childhood and adolescence or during each of three developmental stages therein. Longer term exposure to neighborhood disadvantage from ages 0-17 years is more common among blacks than among whites and is associated with significantly greater odds of being obese at least once in early adulthood. Exposure to neighborhood-level deprivation during adolescence (ages 10-17 years) appears more consequential for future (young adult) obesity than exposure that occurs earlier in childhood. The duration and timing of exposure to neighborhood disadvantage during childhood and adolescence are associated with obesity incidence in early adulthood for both blacks and whites. However, given inequalities in the likelihood and persistence of experiencing neighborhood disadvantage as children and youth, such adverse effects are likely to be more concentrated among black versus white young adults. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  3. Racial/Ethnic Differences in the Relationship Between Neighborhood Disadvantage and Adolescent Substance Use.

    Science.gov (United States)

    Fagan, Abigail A; Wright, Emily M; Pinchevsky, Gillian M

    2013-01-01

    Although social disorganization theory hypothesizes that neighborhood characteristics influence youth delinquency, the impact of neighborhood disadvantage on adolescent substance use and racial/ethnic differences in this relationship have not been widely investigated. The present study examines these issues using longitudinal data from 1,856 African American, Hispanic, and Caucasian adolescents participating in the Project on Human Development in Chicago Neighborhoods (PHDCN). The results indicated that neighborhood disadvantage did not significantly increase the likelihood of substance use for the full sample. When relationships were analyzed by race/ethnicity, one significant ( p ≤ .10) effect was found; disadvantage increased alcohol use among African Americans only. The size of this effect differed significantly between African American and Hispanic youth. In no other cases did race/ethnicity moderate the impact of disadvantage on substance use. These results suggest that disadvantage is not a strong predictor of adolescent substance use, although other features of the neighborhood may affect such behaviors.

  4. The Effects of Low Income Housing Tax Credit Developments on Neighborhoods.

    Science.gov (United States)

    Baum-Snow, Nathaniel; Marion, Justin

    2009-06-01

    This paper evaluates the impacts of new housing developments funded with the Low Income Housing Tax Credit (LIHTC), the largest federal project based housing program in the U.S., on the neighborhoods in which they are built. A discontinuity in the formula determining the magnitude of tax credits as a function of neighborhood characteristics generates pseudo-random assignment in the number of low income housing units built in similar sets of census tracts. Tracts where projects are awarded 30 percent higher tax credits receive approximately six more low income housing units on a base of seven units per tract. These additional new low income developments cause homeowner turnover to rise, raise property values in declining areas and reduce incomes in gentrifying areas in neighborhoods near the 30th percentile of the income distribution. LIHTC units significantly crowd out nearby new rental construction in gentrifying areas but do not displace new construction in stable or declining areas.

  5. EFFECTS OF EFFECTS OF PARTICLE SIZE DISTRIBUTION ...

    African Journals Online (AJOL)

    eobe

    The parameters examined were: moisture content, particle size distribution, total isture content, particle size distribution, total hydrocarbon content, soil pH, available nitrogen, available phosphorus, total heterotrophic bacteria and fungi count. The analysis of the soil characteristics throughout the remediation period showed ...

  6. The combined effect of individual and neighborhood socioeconomic status on nasopharyngeal cancer survival.

    Directory of Open Access Journals (Sweden)

    Ting-Shou Chang

    Full Text Available BACKGROUND: The relationship between individual and neighborhood socioeconomic status (SES and mortality rates in patients with nasopharyngeal carcinoma (NPC is unknown. This population-based study aimed to examine the association between SES and survival of patients with NPC in Taiwan. MATERIALS AND METHODS: A population-based follow-up study was conducted of 4691 patients diagnosed with NPC between 2002 and 2006. Each patient was traced to death or for 5 years. Individual SES was defined by enrollee job category. Neighborhood SES was based on household income dichotomized into advantaged and disadvantaged areas. Cox proportional hazards model was used to compare the death-free survival rates between the different SES groups after adjusting for possible confounding factors and risk factors. RESULTS: In NPC patients below the age of 65 years, 5-year overall survival rates were worst for those with low individual SES living in disadvantaged neighborhoods. After adjusting for patient characteristics (age, gender, Charlson Comorbidity Index Score, NPC patients with low individual SES residing in disadvantaged neighborhoods were found to have a 2-fold higher risk of mortality than patients with high individual SES residing in advantaged neighborhoods. We found no significant difference in mortality rates between different SES groups in NPC patients aged 65 and above. CONCLUSIONS: Our findings indicate that NPC patients with low individual SES who live in disadvantaged neighborhoods have the higher risk of mortality than their more privileged counterparts. Public health strategies and welfare policies would be well advised to try to offset the inequalities in health care and pay more attention to addressing the needs of this vulnerable group.

  7. Advancing maternal age and infant birth weight among urban African Americans: the effect of neighborhood poverty.

    Science.gov (United States)

    Collins, James W; Simon, Dyan M; Jackson, Tara A; Drolet, Aimee

    2006-01-01

    This study sought to determine whether neighborhood poverty modifies the relationship between maternal age and infant birth weight among urban African Americans. Stratified analyses were performed on the vital records of African Americans born in Chicago by means of 1992-1995 computerized birth file with appended 1990 US Census income and 1995 Chicago Department of Public Health data. Four neighborhood-level variables (low median family income, high rates of unemployment, homicide, and lead poisoning) were analyzed. This is a population-based study. Twenty-one percent (n=21,811) of women resided in nonimpoverished neighborhoods (zero ecologic risk factors); 23% (n=24,914) of women lived in extremely impoverished neighborhoods (four ecologic risk factors). In nonimpoverished neighborhoods, 30-34 year old women had a moderately low birth weight (1500-2499 g) rate of 13.9% compared to 10.3% for women aged 20-24 years; risk difference (95% confidence interval [CI])=3.5 (2.2-4.6). In contrast, extremely impoverished women aged 30-34 years had a moderately low birth weight rate of 19.8% compared to 11.8% for women aged 20-24 years; risk difference (95% CI)=7.7 (6.1-9.3). This trend persisted among women who received early prenatal care and were primagravids or of low parity. Neighborhood poverty did not modify the association of advancing maternal age and the risk of very low birth weight (poverty accelerates the rise in moderately low birth weight but not very low birth weight; rates were associated with advancing maternal age among urban African Americans.

  8. Structural effect of size on interracial friendship.

    Science.gov (United States)

    Cheng, Siwei; Xie, Yu

    2013-04-30

    Social contexts exert structural effects on individuals' social relationships, including interracial friendships. In this study, we posit that, net of group composition, total context size has a distinct effect on interracial friendship. Under the assumptions of (i) maximization of preference in choosing a friend, (ii) multidimensionality of preference, and (iii) preference for same-race friends, we conducted analyses using microsimulation that yielded three main findings. First, increased context size decreases the likelihood of forming an interracial friendship. Second, the size effect increases with the number of preference dimensions. Third, the size effect is diluted by noise, i.e., the random component affecting friendship formation. Analysis of actual friendship data among 4,745 American high school students yielded results consistent with the main conclusion that increased context size promotes racial segregation and discourages interracial friendship.

  9. Transactional effects among maternal depression, neighborhood deprivation, and child conduct problems from early childhood through adolescence: A tale of two low-income samples.

    Science.gov (United States)

    Shaw, Daniel S; Sitnick, Stephanie L; Reuben, Julia; Dishion, Thomas J; Wilson, Melvin N

    2016-08-01

    The current study sought to advance our understanding of transactional processes among maternal depression, neighborhood deprivation, and child conduct problems (CP) using two samples of low-income families assessed repeatedly from early childhood to early adolescence. After accounting for initial levels of negative parenting, independent and reciprocal effects between maternal depressive symptoms and child CP were evident across both samples, beginning in early childhood and continuing through middle childhood and adolescence. In addition, neighborhood effects were consistently found in both samples after children reached age 5, with earlier neighborhood effects on child CP and maternal depression found in the one exclusively urban sample of families with male children. The results confirm prior research on the independent contribution of maternal depression and child CP to the maintenance of both problem behaviors. The findings also have implications for designing preventative and clinical interventions to address child CP for families living in high-risk neighborhoods.

  10. Interaction Effects of Neighborhood Disadvantage and Individual Social Support on Frequency of Alcohol Use in Youth Living with HIV.

    Science.gov (United States)

    Brick, Leslie Ann D; Nugent, Nicole R; Kahana, Shoshana Y; Bruce, Douglas; Tanney, Mary R; Fernández, M Isabel; Bauermeister, Jose A

    2018-02-05

    Youth living with HIV (YLH) experience multiple disease-related stresses along with the same structural and developmental challenges faced by their uninfected peers; alcohol use among YLH represents a risk behavior by virtue of potential effects on youth health and increased likelihood of engaging in unprotected sex while drinking alcohol. Research aimed at better understanding the interplay of individual- and neighborhood-level influences on alcohol use for YLH is needed to inform interventions. This study examined whether socioeconomic disadvantage (SED) and social support influence, independently and through interaction, alcohol use in YLH. Data from the Adolescent Medicine Trials Network for HIV/AIDS Interventions (ATN) consisted of YLH across 538 neighborhoods in the United States who acquired HIV behaviorally. Neighborhood-specific data were compiled from the 2010 U.S. Census Bureau and matched with individual-level data from the ATN (N = 1,357) to examine effects that contribute to variation in frequency of alcohol use. Other drug use, being male, being non-Black, and older age were associated with greater alcohol use. Higher social support was negatively associated with alcohol use frequency. A cross-level interaction indicated that the association found between decreasing social support and increasing alcohol use frequency was weakened in areas with lower SED. Implications are discussed. © Society for Community Research and Action 2018.

  11. Nanocoatings size effect in nanostructured films

    CERN Document Server

    Aliofkhazraei, Mahmood

    2014-01-01

    Size effect in structures has been taken into consideration over the last years. In comparison with coatings with micrometer-ranged thickness, nanostructured coatings usually enjoy better and appropriate properties, such as strength and resistance. These coatings enjoy unique magnetic properties and are used with the aim of producing surfaces resistant against erosion, lubricant system, cutting tools, manufacturing hardened sporadic alloys, being resistant against oxidation and corrosion. This book reviews researches on fabrication and classification of nanostructured coatings with focus on size effect in nanometric scale. Size effect on electrochemical, mechanical and physical properties of nanocoatings are presented.

  12. The effect of neighborhood socioeconomic status on education and health outcomes for children living in social housing.

    Science.gov (United States)

    Martens, Patricia J; Chateau, Daniel G; Burland, Elaine M J; Finlayson, Gregory S; Smith, Mark J; Taylor, Carole R; Brownell, Marni D; Nickel, Nathan C; Katz, Alan; Bolton, James M

    2014-11-01

    We explored differences in health and education outcomes between children living in social housing and not, and effects of social housing's neighborhood socioeconomic status. In this cohort study, we used the population-based repository of administrative data at the Manitoba Centre for Health Policy. We included children aged 0 to 19 years in Winnipeg, Manitoba, in fiscal years 2006-2007 to 2008-2009 (n = 13,238 social housing; n = 174,017 others). We examined 5 outcomes: age-2 complete immunization, a school-readiness measure, adolescent pregnancy (ages 15-19 years), grade-9 completion, and high-school completion. Logistic regression and generalized estimating equation modeling generated rates. We derived neighborhood income quintiles (Q1 lowest, Q5 highest) from average household income census data. Children in social housing fared worse than comparative children within each neighborhood income quintile. When we compared children in social housing by quintile, preschool indicators (immunization and school readiness) were similar, but adolescent outcomes (grade-9 and high-school completion, adolescent pregnancy) were better in Q3 to Q5. Children in social housing had poorer health and education outcomes than all others, but living in social housing in wealthier areas was associated with better adolescent outcomes.

  13. Effect of display size on visual attention.

    Science.gov (United States)

    Chen, I-Ping; Liao, Chia-Ning; Yeh, Shih-Hao

    2011-06-01

    Attention plays an important role in the design of human-machine interfaces. However, current knowledge about attention is largely based on data obtained when using devices of moderate display size. With advancement in display technology comes the need for understanding attention behavior over a wider range of viewing sizes. The effect of display size on test participants' visual search performance was studied. The participants (N = 12) performed two types of visual search tasks, that is, parallel and serial search, under three display-size conditions (16 degrees, 32 degrees, and 60 degrees). Serial, but not parallel, search was affected by display size. In the serial task, mean reaction time for detecting a target increased with the display size.

  14. The Effect of Urban Neighborhood Disorder on Evaluations of the Police and Courts

    Science.gov (United States)

    Sprott, Jane B.; Doob, Anthony N.

    2009-01-01

    Are people dissatisfied with the courts as well as the police when they perceive high levels of disorder in their neighborhoods? Consistent with previous research, this study, using a representative sample of Canadian adults, demonstrates that people are significantly more negative about the police when they perceive high levels of disorder. They…

  15. Reacting to Neighborhood Cues?: Political Sophistication Moderates the Effect of Exposure to Immigrants

    DEFF Research Database (Denmark)

    Danckert, Bolette; Dinesen, Peter Thisted; Sønderskov, Kim Mannemar

    2017-01-01

    is founded on politically sophisticated individuals having a greater comprehension of news and other mass-mediated sources, which makes them less likely to rely on neighborhood cues as sources of information relevant for political attitudes. Based on a unique panel data set with fine-grained information...

  16. Neighborhood disparities in access to healthy foods and their effects on environmental justice

    Science.gov (United States)

    Environmental justice is concerned with an equitable distribution of environmental burdens. These burdens comprise immediate health hazards as well as subtle inequities, such as limited access to healthy foods. We reviewed the literature on neighborhood disparities in access to fast-food outlets and...

  17. Neighborhood & Family Effects on Learning Motivation among Urban African American Middle School Youth

    Science.gov (United States)

    Whitaker, Damiya; Graham, Camelia; Severtson, Stevan Geoffrey; Furr-Holden, C. Debra; Latimer, William

    2012-01-01

    Motivational theorists in psychology have moved away from individual-based approaches to socio-cognitive and socio-ecological models to explain student engagement and motivation for learning. Such approaches consider, for example, the influence of family and neighborhood environments as important constructs in youth behavior. In this study, links…

  18. Stress and health behaviors as potential mediators of the relationship between neighborhood quality and allostatic load.

    Science.gov (United States)

    Buschmann, Robert N; Prochaska, John D; Cutchin, Malcolm P; Peek, M Kristen

    2018-03-29

    Neighborhood quality is associated with health. Increasingly, researchers are focusing on the mechanisms underlying that association, including the role of stress, risky health behaviors, and subclinical measures such as allostatic load (AL). This study uses mixed-effects regression modeling to examine the association between two objective measures and one subjective measure of neighborhood quality and AL in an ethnically diverse population-based sample (N = 2706) from a medium-sized Texas city. We also examine whether several measures of psychological stress and health behaviors mediate any relationship between neighborhood quality and AL. In this sample, all three separate measures of neighborhood quality were associated with individual AL (P < .01). However, only the subjective measure, perceived neighborhood quality, was associated with AL after adjusting for covariates. In mixed-effects multiple regression models there was no evidence of mediation by either stress or health behaviors. In this study, only one measure of neighborhood quality was related to a measure of health, which contrasts with considerable previous research in this area. In this sample, neighborhood quality may affect AL through other mechanisms, or there may be other health-affecting factors is this area that share that overshadow local neighborhood variation. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Disruption effects on the beam size measurement

    International Nuclear Information System (INIS)

    Raimondi, P.; Decker, F.J.; Chen, P.

    1995-01-01

    At the SLC Final Focus with higher currents and smaller beam sizes, the disruption parameter D y is close to one and so the pinch effect should produce a luminosity enhancement. Since a flat beam-beam function is fit to deflection scan data to measure the beam size, disruption can affect the measurement. Here the authors discuss the quantitative effects of disruption for typical SLC beam parameters. With 3.5 10 10 particles per pulse, bunch length of 0.8 mm and beam sizes of 2.1 μm horizontally and 0.55 μm vertically, the measured vertical size can be as much as 25% bigger than the real one. Furthermore during the collision the spot size actually decrease, producing an enhancement factor H D of about 1.25. This would yield to a true luminosity which is 1.6 times that which is estimated from the beam-beam deflection fit

  20. The Long-Term Effectiveness of the Family Check-Up on School-Age Conduct Problems: Moderation by Neighborhood Deprivation

    Science.gov (United States)

    Shaw, Daniel S.; Sitnick, Stephanie L.; Brennan, Lauretta M.; Choe, Daniel E.; Dishion, Thomas J.; Wilson, Melvin N.; Gardner, Frances

    2016-01-01

    Several studies suggest that neighborhood deprivation is a unique risk factor in child and adolescent development of problem behavior. We sought to examine whether previously established intervention effects of the Family Check-Up (FCU) on child conduct problems at age 7.5 would persist through age 9.5, and whether neighborhood deprivation would moderate these effects. In addition, we examined whether improvements in parent-child interaction during early childhood associated with the FCU would be related to later reductions in child aggression among families living in the highest-risk neighborhoods. Using a multisite cohort of at-risk children identified on the basis of family, child, and socioeconomic risk and randomly assigned to the FCU, intervention effects were found to be moderated by neighborhood deprivation, such that they were only directly present for those living at moderate versus extreme levels of neighborhood deprivation. Additionally, improvements in child aggression were evident for children living in extreme neighborhood deprivation when parents improved the quality of their parent-child interaction during the toddler period (i.e., moderated mediation). Implications of the findings are discussed in relation to the possibilities and possible limitations in prevention of early problem behavior for those children living in extreme and moderate levels of poverty. PMID:26646197

  1. Examining Differential Resilience Mechanisms by Comparing 'Tipping Points' of the Effects of Neighborhood Conditions on Anxiety by Race/Ethnicity.

    Science.gov (United States)

    Coman, Emil Nicolae; Wu, Helen Zhao

    2018-02-20

    Exposure to adverse environmental and social conditions affects physical and mental health through complex mechanisms. Different racial/ethnic (R/E) groups may be more or less vulnerable to the same conditions, and the resilience mechanisms that can protect them likely operate differently in each population. We investigate how adverse neighborhood conditions (neighborhood disorder, NDis) differentially impact mental health (anxiety, Anx) in a sample of white and Black (African American) young women from Southeast Texas, USA. We illustrate a simple yet underutilized segmented regression model where linearity is relaxed to allow for a shift in the strength of the effect with the levels of the predictor. We compare how these effects change within R/E groups with the level of the predictor, but also how the "tipping points," where the effects change in strength, may differ by R/E. We find with classic linear regression that neighborhood disorder adversely affects Black women's anxiety, while in white women the effect seems negligible. Segmented regressions show that the Ndis → Anx effects in both groups of women appear to shift at similar levels, about one-fifth of a standard deviation below the mean of NDis, but the effect for Black women appears to start out as negative, then shifts in sign, i.e., to increase anxiety, while for white women, the opposite pattern emerges. Our findings can aid in devising better strategies for reducing health disparities that take into account different coping or resilience mechanisms operating differentially at distinct levels of adversity. We recommend that researchers investigate when adversity becomes exceedingly harmful and whether this happens differentially in distinct populations, so that intervention policies can be planned to reverse conditions that are more amenable to change, in effect pushing back the overall social risk factors below such tipping points.

  2. FIRM SIZE EFFECTS ON TRANSACTION COSTS

    NARCIS (Netherlands)

    NOOTEBOOM, B

    1993-01-01

    Associated with effects of scale, scope, experience and learning there are effects of firm size on transaction costs; in the stages of contact, contract and control. These effects are due to ''threshold costs'' in setting up contacts, contracts and governance schemes, and to differences with respect

  3. Out Drinking the Joneses: Neighborhood Factors Moderating the Effects of Drinking on Relationship Quality over the First Four Years of Marriage.

    Science.gov (United States)

    Crasta, Dev; Funk, Janette L; Lee, Soonhee; Rogge, Ronald D

    2017-12-27

    Neighborhood quality has been cross-sectionally linked to both relationship behaviors and relationship well-being. Consistent with the Vulnerability Stress-Adaptation model of relationship functioning (Karney & Bradbury, 1995), we hypothesized that associations between social behaviors (e.g., drinking) and relationship quality could be moderated by neighborhood factors. Specifically, we characterized neighborhoods along multiple dimensions using multiple methods (self-report, census) to investigate how neighborhood factors might clarify ambiguous effects of alcohol use on marital functioning. A nationally recruited sample of 303 newlywed couples completed a baseline assessment around the time of marriage and was then assessed yearly across the first 4 years of marriage (94% retention). Three level HLM slope-intercept models were used to model changes in relationship satisfaction across the first 4 years of marriage. Results suggested that, for couples living in highly disordered neighborhoods, positive shifts in overall levels of drinking within specific waves of assessment were associated with corresponding negative shifts in satisfaction whereas in neighborhoods without perceived disorder, this effect was reversed. For couples living in neighborhoods with low levels of domestic structures (high census rates of single renters without children), within-couple discrepancies favoring higher rates of husband drinking in specific waves predicted poorer relationship quality for both partners in those same waves whereas those same discrepancies predicted higher satisfaction in high domesticity neighborhoods (high census rates of married homeowners with children). The findings provide insight into the different roles of alcohol use in relationship maintenance and highlight the importance of using external context to understand intradyadic processes. © 2017 Family Process Institute.

  4. A New Neighborhood Every Fall: Aging in Place in a College Town.

    Science.gov (United States)

    Powell, Kathleen H

    Older adults who live in residential neighborhoods adjacent to college and university campuses have a unique experience that makes them vulnerable to marginalization and displacement. As these neighborhoods become increasingly dominated by college students living in rental properties, older adults find themselves in the minority in a neighborhood where they have lived for many years. In addition, these neighborhoods are attractive to universities, city governments, and private companies for their development potential, which can result in gentrification. A year-long ethnographic study of a campus-adjacent neighborhood in a small US college town that is home to a medium-sized public university sheds light on the relationships between members of 5 stakeholder groups that have a vested interest in the neighborhood. The study highlights the need for additional research on different types of neighborhoods and their effects on aging in place in addition to outlining social work interventions in campus-adjacent neighborhoods that are designed to enhance these intergenerational spaces.

  5. Neighborhood context and health: How neighborhood social capital affects individual health

    NARCIS (Netherlands)

    Mohnen, S.M.

    2012-01-01

    Does it matter for my health in which neighborhood I live? The fact is, health is determined not only by individual characteristics but also by the neighborhood in which someone lives. This thesis shows that health clusters in Dutch neighborhoods and that this is not only a composition effect (that

  6. Neighborhood Effects on PND Symptom Severity for Women Enrolled in a Home Visiting Program.

    Science.gov (United States)

    Jones, David E; Tang, Mei; Folger, Alonzo; Ammerman, Robert T; Hossain, Md Monir; Short, Jodie; Van Ginkel, Judith B

    2018-05-01

    The aim of this study was to investigate the association between postnatal depression (PND) symptoms severity and structural neighborhood characteristics among women enrolled in a home visiting program. The sample included 295 mothers who were at risk for developing PND, observed as 3-month Edinburgh Postnatal Depression Scale (EPDS) scores ≥ 10. Two neighborhood predictor components (residential stability and social disadvantage) were analyzed as predictors of PND symptom severity using a generalized estimating equation. Residential stability was negatively associated with PND symptom severity. Social disadvantage was not found to be statistically significantly. The findings suggest that residential stability is associated with a reduction in PND symptom severity for women enrolled in home visiting program.

  7. Measuring wage effects of plant size

    DEFF Research Database (Denmark)

    Albæk, Karsten; Arai, Mahmood; Asplund, Rita

    1998-01-01

    There are large plant size–wage effects in the Nordic countries after taking into account individual and job characteristics as well as systematical sorting of the workers into various plant-sizes. The plant size–wage elasticities we obtain are, in contrast to other dimensions of the wage distrib......–wage elasticity. Our results indicate that using size–class midpoints yields essentially the same results as using exact measures of plant size...

  8. Using cross-classified multilevel models to disentangle school and neighborhood effects: an example focusing on smoking behaviors among adolescents in the United States.

    Science.gov (United States)

    Dunn, Erin C; Richmond, Tracy K; Milliren, Carly E; Subramanian, S V

    2015-01-01

    Despite much interest in understanding the influence of contexts on health, most research has focused on one context at a time, ignoring the reality that individuals have simultaneous memberships in multiple settings. Using the example of smoking behavior among adolescents in the National Longitudinal Study of Adolescent Health, we applied cross-classified multilevel modeling (CCMM) to examine fixed and random effects for schools and neighborhoods. We compared the CCMM results with those obtained from a traditional multilevel model (MLM) focused on either the school and neighborhood separately. In the MLMs, 5.2% of the variation in smoking was due to differences between neighborhoods (when schools were ignored) and 6.3% of the variation in smoking was due to differences between schools (when neighborhoods were ignored). However in the CCMM examining neighborhood and school variation simultaneously, the neighborhood-level variation was reduced to 0.4%. Results suggest that using MLM, instead of CCMM, could lead to overestimating the importance of certain contexts and could ultimately lead to targeting interventions or policies to the wrong settings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. How Neighborhood Disadvantage Reduces Birth Weight

    Directory of Open Access Journals (Sweden)

    Emily Moiduddin

    2008-06-01

    Full Text Available In this analysis we connect structural neighborhood conditions to birth outcomes through their intermediate effects on mothers’ perceptions of neighborhood danger and their tendency to abuse substances during pregnancy. We hypothesize that neighborhood poverty and racial/ethnic concentration combine to produce environments that mothers perceive as unsafe, thereby increasing the likelihood of negative coping behaviors (substance abuse. We expect these behaviors, in turn, to produce lower birth weights. Using data from the Fragile Families and Child Wellbeing Study, a survey of a cohort of children born between 1998 and 2000 and their mothers in large cities in the United States, we find little evidence to suggest that neighborhood circumstances have strong, direct effects on birth weight. Living in a neighborhood with more foreigners had a positive effect on birth weight. To the extent that neighborhood conditions influence birth weight, the effect mainly occurs through an association with perceived neighborhood danger and subsequent negative coping behaviors. Poverty and racial/ethnic concentration increase a mother’s sense that her neighborhood is unsafe. The perception of an unsafe neighborhood, in turn, associates with a greater likelihood of smoking cigarettes and using illegal drugs, and these behaviors have strong and significant effects in reducing birth weight. However, demographic characteristics, rather than perceived danger or substance abuse, mediate the influence of neighborhood characteristics on birth weight.

  10. Specimen size effects in Charpy impact testing

    International Nuclear Information System (INIS)

    Alexander, D.J.; Klueh, R.L.

    1989-01-01

    Full-size , half-size, and third-size specimens from several different steels have been tested as part of an ongoing alloy development program. The smaller specimens permit more specimens to be made from small trail heats and are much more efficient for irradiation experiments. The results of several comparisons between the different specimen sizes have shown that the smaller specimens show qualitatively similar behavior to large specimens, although the upper-shelf energy level and ductile-to-ductile transition temperature are reduced. The upper-shelf energy levels from different specimen sizes can be compared by using a simple volume normalization method. The effect of specimen size and geometry on the ductile-to-ductile transition temperature is more difficult to predict, although the available data suggest a simple shift in the transition temperature due to specimen size changes.The relatively shallower notch used in smaller specimens alters the deformation pattern, and permits yielding to spread back to the notched surface as well as through to the back. This reduces the constraint and the peak stresses, and thus the initiation of cleavage is more difficult. A better understanding of the stress and strain distributions is needed. 19 refs., 3 figs., 3 tabs

  11. Neighborhood and habitat effects on vital rates: expansion of the Barred Owl in the Oregon Coast Ranges

    Science.gov (United States)

    Yackulic, Charles B.; Reid, Janice; Davis, Raymond; Hines, James E.; Nichols, James D.; Forsman, Eric

    2012-01-01

    In this paper, we modify dynamic occupancy models developed for detection-nondetection data to allow for the dependence of local vital rates on neighborhood occupancy, where neighborhood is defined very flexibly. Such dependence of occupancy dynamics on the status of a relevant neighborhood is pervasive, yet frequently ignored. Our framework permits joint inference about the importance of neighborhood effects and habitat covariates in determining colonization and extinction rates. Our specific motivation is the recent expansion of the Barred Owl (Strix varia) in western Oregon, USA, over the period 1990-2010. Because the focal period was one of dramatic range expansion and local population increase, the use of models that incorporate regional occupancy (sources of colonists) as determinants of dynamic rate parameters is especially appropriate. We began our analysis of 21 years of Barred Owl presence/nondetection data in the Tyee Density Study Area (TDSA) by testing a suite of six models that varied only in the covariates included in the modeling of detection probability. We then tested whether models that used regional occupancy as a covariate for colonization and extinction outperformed models with constant or year-specific colonization or extinction rates. Finally we tested whether habitat covariates improved the AIC of our models, focusing on which habitat covariates performed best, and whether the signs of habitat effects are consistent with a priori hypotheses. We conclude that all covariates used to model detection probability lead to improved AIC, that regional occupancy influences colonization and extinction rates, and that habitat plays an important role in determining extinction and colonization rates. As occupancy increases from low levels toward equilibrium, colonization increases and extinction decreases, presumably because there are more and more dispersing juveniles. While both rates are affected, colonization increases more than extinction decreases

  12. Large Neighborhood Search

    DEFF Research Database (Denmark)

    Pisinger, David; Røpke, Stefan

    2010-01-01

    Heuristics based on large neighborhood search have recently shown outstanding results in solving various transportation and scheduling problems. Large neighborhood search methods explore a complex neighborhood by use of heuristics. Using large neighborhoods makes it possible to find better...... candidate solutions in each iteration and hence traverse a more promising search path. Starting from the large neighborhood search method,we give an overview of very large scale neighborhood search methods and discuss recent variants and extensions like variable depth search and adaptive large neighborhood...

  13. Effect of Growing Size of Interaction Neighbors on the Evolution of Cooperation in Spatial Snowdrift Game

    International Nuclear Information System (INIS)

    Zhang Juanjuan; Sun Shiwen; Wang Li; Xia Chengyi; Wang Juan; Wang Zhen

    2012-01-01

    In this paper, we study the influence of the size of interaction neighbors (k) on the evolution of cooperation in the spatial snowdrift game. At first, we consider the effects of noise K and cost-to-benefit ratio r, the simulation results indicate that the evolution of cooperation depends on the combined action of noise and cost-to-benefit ratio. For a lower r, the cooperators are multitudinous and the cooperation frequency ultimately increases to 1 as the increase of noise. However, for a higher r, the defectors account for the majority of the game and dominate the game if the noise is large enough. Then we mainly investigate how k influences the evolution of cooperation by varying the noise in detail. We find that the frequency of cooperators is closely related to the size of neighborhood and cost-to-benefit ratio r. In the case of lower r, the augmentation of k plays no positive role in promoting the cooperation as compared with that of k = 4, while for higher r the cooperation is improved for a growing size of neighborhood. At last, based on the above discussions, we explore the cluster-forming mechanism among the cooperators. The current results are beneficial to further understand the evolution of cooperation in many natural, social and biological systems. (general)

  14. Disruption effects on the beam size measurement

    Energy Technology Data Exchange (ETDEWEB)

    Raimondi, P.; Decker, F.J.; Chen, P.

    1995-06-01

    At the SLC Final Focus with higher currents and smaller beam sizes, the disruption parameter D{sub y} is close to one and so the pinch effect should produce a luminosity enhancement. Since a flat beam-beam function is fit to deflection scan data to measure the beam size, disruption can affect the measurement. Here the authors discuss the quantitative effects of disruption for typical SLC beam parameters. With 3.5 10{sup 10} particles per pulse, bunch length of 0.8 mm and beam sizes of 2.1 {mu}m horizontally and 0.55 {mu}m vertically, the measured vertical size can be as much as 25% bigger than the real one. Furthermore during the collision the spot size actually decrease, producing an enhancement factor H{sub D} of about 1.25. This would yield to a true luminosity which is 1.6 times that which is estimated from the beam-beam deflection fit.

  15. Introducing the Mean Absolute Deviation "Effect" Size

    Science.gov (United States)

    Gorard, Stephen

    2015-01-01

    This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

  16. Size Effect in Tension Perpendicular to Grain

    DEFF Research Database (Denmark)

    Astrup, Thomas; Clorius, Christian Odin; Hoffmeyer, Preben

    2004-01-01

    The strength of wood is reduced when the stressed volume is increased. The phenomenon is termed size effect and is often explained as being stochastic in the sense that the probability of weak locations occurring in the wood increases with increased volume. This paper presents a hypothesis where ...

  17. Size-effects in porous metals

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Tvergaard, Viggo

    The intrinsic size-effect for porous metals is investigated. The analyses are carried out numerically using a finite strain generalization of a higher order strain gradient plasticity model. Results for plane strain growth of cylindrical voids are presented in terms of response curves and curves...

  18. Size-effects in porous metals

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Tvergaard, Viggo

    2007-01-01

    The intrinsic size-effect for porous metals is investigated. The analyses are carried out numerically using a finite strain generalization of a higher order strain gradient plasticity model. Results for plane strain growth of cylindrical voids are presented in terms of response curves and curves...

  19. A Cost-Effective Smoothed Multigrid with Modified Neighborhood-Based Aggregation for Markov Chains

    Directory of Open Access Journals (Sweden)

    Zhao-Li Shen

    2015-01-01

    Full Text Available Smoothed aggregation multigrid method is considered for computing stationary distributions of Markov chains. A judgement which determines whether to implement the whole aggregation procedure is proposed. Through this strategy, a large amount of time in the aggregation procedure is saved without affecting the convergence behavior. Besides this, we explain the shortage and irrationality of the Neighborhood-Based aggregation which is commonly used in multigrid methods. Then a modified version is presented to remedy and improve it. Numerical experiments on some typical Markov chain problems are reported to illustrate the performance of these methods.

  20. Estimation of Hedonic Single-Family House Price Function Considering Neighborhood Effect Variables

    Directory of Open Access Journals (Sweden)

    Chihiro Shimizu

    2014-05-01

    Full Text Available In the formulation of hedonic models, in addition to locational factors and building structures which affect the house prices, the generation of the omitted variable bias is thought to occur in cases when local environmental variables and the individual characteristics of house buyers are not taken into consideration. However, since it is difficult to obtain local environmental information in a small neighborhood unit and to observe individual characteristics of house buyers, these variables have not been sufficiently considered in previous studies. We demonstrated that non-negligible levels of omitted variable bias are generated if these variables are not considered.

  1. Size effects in lithium ion batteries

    International Nuclear Information System (INIS)

    Yao Hu-Rong; Yin Ya-Xia; Guo Yu-Gao

    2016-01-01

    Size-related properties of novel lithium battery materials, arising from kinetics, thermodynamics, and newly discovered lithium storage mechanisms, are reviewed. Complementary experimental and computational investigations of the use of the size effects to modify electrodes and electrolytes for lithium ion batteries are enumerated and discussed together. Size differences in the materials in lithium ion batteries lead to a variety of exciting phenomena. Smaller-particle materials with highly connective interfaces and reduced diffusion paths exhibit higher rate performance than the corresponding bulk materials. The thermodynamics is also changed by the higher surface energy of smaller particles, affecting, for example, secondary surface reactions, lattice parameter, voltage, and the phase transformation mechanism. Newly discovered lithium storage mechanisms that result in superior storage capacity are also briefly highlighted. (topical review)

  2. Online learning from input versus offline memory evolution in adult word learning: effects of neighborhood density and phonologically related practice.

    Science.gov (United States)

    Storkel, Holly L; Bontempo, Daniel E; Pak, Natalie S

    2014-10-01

    In this study, the authors investigated adult word learning to determine how neighborhood density and practice across phonologically related training sets influence online learning from input during training versus offline memory evolution during no-training gaps. Sixty-one adults were randomly assigned to learn low- or high-density nonwords. Within each density condition, participants were trained on one set of words and then were trained on a second set of words, consisting of phonological neighbors of the first set. Learning was measured in a picture-naming test. Data were analyzed using multilevel modeling and spline regression. Steep learning during input was observed, with new words from dense neighborhoods and new words that were neighbors of recently learned words (i.e., second-set words) being learned better than other words. In terms of memory evolution, large and significant forgetting was observed during 1-week gaps in training. Effects of density and practice during memory evolution were opposite of those during input. Specifically, forgetting was greater for high-density and second-set words than for low-density and first-set words. High phonological similarity, regardless of source (i.e., known words or recent training), appears to facilitate online learning from input but seems to impede offline memory evolution.

  3. The Effects of Social Environments on Time Spent Gaming: Focusing on the Effects of Communities and Neighborhoods.

    Science.gov (United States)

    Lim, Tee Teng; Jung, Sun Young; Kim, Eunyi

    2018-04-01

    This study examined the impact of community and neighborhood on time spent computer gaming. Computer gaming for over 20 hours a week was set as the cutoff line for "engaged use" of computer games. For the analysis, this study analyzed data for about 1,800 subjects who participated in the Korean Children and Youth Panel Survey. The main findings are as follows: first, structural community characteristics and neighborhood social capital affected the engaged use of computer games. Second, adolescents who reside in regions with a higher divorce rate or higher residential mobility were likely to exhibit engaged use of computer games. Third, adolescents who highly perceive neighborhood social capital exhibited lower possibility of engaged use of computer games. Based on these findings, practical implications and directions for further study are suggested.

  4. Quality over Quantity: Contribution of Urban Green Space to Neighborhood Satisfaction.

    Science.gov (United States)

    Zhang, Yang; Van den Berg, Agnes E; Van Dijk, Terry; Weitkamp, Gerd

    2017-05-16

    There is increasing evidence that the quality of green space significantly contributes to neighborhood satisfaction and well-being, independent of the mere amount of green space. In this paper, we examined residents' perceptions of the quality and beneficial affordances of green space in relation to objectively assessed accessibility and usability. We used data from a survey in two neighborhoods ( N = 223) of a medium-sized city in the Netherlands, which were similar in the amount of green space and other physical and socio-demographic characteristics, but differed in the availability of accessible and usable green spaces. Results show that residents of the neighborhood with a higher availability of accessible and usable green spaces were more satisfied with their neighborhood. This difference was statistically mediated by the higher level of perceived green space quality. Neighborhood satisfaction was significantly positively related to well-being. However, residents of the two neighborhoods did not differ in self-reported well-being and beneficial affordances of green space. These analyses contribute to a further understanding of how the accessibility and usability of green spaces may increase people's neighborhood satisfaction. It highlights the importance of perceived quality in addition to the amount of green space when examining the beneficial effects of green space.

  5. Effect of bike lane infrastructure improvements on ridership in one New Orleans neighborhood.

    Science.gov (United States)

    Parker, Kathryn M; Rice, Janet; Gustat, Jeanette; Ruley, Jennifer; Spriggs, Aubrey; Johnson, Carolyn

    2013-02-01

    Incorporating cycling into daily life is one way to increase physical activity. This study examined the impact of building new bike lanes in New Orleans to determine whether more people were cycling on the street and with the flow of traffic after bike lanes were built. Through direct observation of one intervention and two adjacent streets, observers counted cyclists riding on the street and sidewalk, with and against traffic, before and after installation of the lanes. Data were tallied separately for adults, children, males, females, and by race for each location. There was an increase in cyclists on all three streets after the installation of the bike lanes, with the largest increase on the street with the new lane. Additionally, the proportion of riders cycling with traffic increased after the lanes were striped. Bike lanes can have a positive impact in creating a healthy neighborhood.

  6. Effects of neighborhood socioeconomic status on blood pressure in older adults

    Directory of Open Access Journals (Sweden)

    Katia Jakovljevic Pudla Wagner

    Full Text Available ABSTRACT OBJECTIVE To test if the neighborhood socioeconomic status is associated with systolic blood pressure and hypertension in older adults. METHODS A cross-sectional population-based study with a sample of 1,705 older adults from Florianópolis, SC, Southern Brazil. The contextual variable used was the average years of schooling of the head of the household in census tracts. Participants were considered hypertensive when the systolic blood pressure was ≥ 140 mmHg, diastolic ≥ 90 mmHg, or both. Additionally, the use of antihypertensive medication was also considered. Data were analyzed by using multilevel models of logistic and linear regression. RESULTS The average age of the sample was 70.7 years and the average of systolic and diastolic blood pressure was 133.5 mmHg (SD = 20.5 mmHg and 81.9 mmHg (SD = 12.5 mmHg, respectively. The systolic blood pressure was 4.46 mmHg (95%CI 1.00–7.92 higher and the chance of hypertension was 1.80 (95%CI 1.26–2.57 among those who lived in census tracts with lower level of schooling. When the use of antihypertensive medication was combined with blood pressure levels, none association was found between the outcome and the level of schooling of the census tract. CONCLUSIONS Analytical models more robust (such as multilevel analysis in Brazil are still little used, with a small number of articles published. Neighborhood socioeconomic status is associated with systolic blood pressure and the chance of hypertension, regardless of individual characteristics.

  7. Systematic Social Observation of Children's Neighborhoods Using Google Street View: A Reliable and Cost-Effective Method

    Science.gov (United States)

    Odgers, Candice L.; Caspi, Avshalom; Bates, Christopher J.; Sampson, Robert J.; Moffitt, Terrie E.

    2012-01-01

    Background: Children growing up in poor versus affluent neighborhoods are more likely to spend time in prison, develop health problems and die at an early age. The question of how neighborhood conditions influence our behavior and health has attracted the attention of public health officials and scholars for generations. Online tools are now…

  8. Rural Neighborhood Walkability: Implications for Assessment.

    Science.gov (United States)

    Kegler, Michelle C; Alcantara, Iris; Haardörfer, Regine; Gemma, Alexandra; Ballard, Denise; Gazmararian, Julie

    2015-06-16

    Physical activity levels, including walking, are lower in the southern U.S., particularly in rural areas. This study investigated the concept of rural neighborhood walkability to aid in developing tools for assessing walkability and to identify intervention targets in rural communities. Semi-structured interviews were conducted with physically active adults (n = 29) in rural Georgia. Mean age of participants was 55.9 years; 66% were male, 76% were white, and 24% were African American. Participants drew maps of their neighborhoods and discussed the relevance of typical domains of walkability to their decisions to exercise. Comparative analyses were conducted to identify major themes. The majority felt the concept of neighborhood was applicable and viewed their neighborhood as small geographically (less than 0.5 square miles). Sidewalks were not viewed as essential for neighborhood-based physical activity and typical destinations for walking were largely absent. Destinations within walking distance included neighbors' homes and bodies of water. Views were mixed on whether shade, safety, dogs, and aesthetics affected decisions to exercise in their neighborhoods. Measures of neighborhood walkability in rural areas should acknowledge the small size of self-defined neighborhoods, that walking in rural areas is likely for leisure time exercise, and that some domains may not be relevant.

  9. Size-Effects in Void Growth

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof

    2005-01-01

    The size-effect on ductile void growth in metals is investigated. The analysis is based on unit cell models both of arrays of cylindrical voids under plane strain deformation, as well as arrays of spherical voids using an axisymmetric model. A recent finite strain generalization of two higher order...... strain gradient plasticity models is implemented in a finite element program, which is used to study void growth numerically. The results based on the two models are compared. It is shown how gradient effects suppress void growth on the micron scale when compared to predictions based on conventional...... models. This increased resistance to void growth, due to gradient hardening, is accompanied by an increase in the overall strength for the material. Furthermore, for increasing initial void volume fraction, it is shown that the effect of gradients becomes more important to the overall response but less...

  10. A community based intervention program to enhance neighborhood cohesion: The Learning Families Project in Hong Kong.

    Science.gov (United States)

    Shen, Chen; Wan, Alice; Kwok, Lit Tung; Pang, Sally; Wang, Xin; Stewart, Sunita M; Lam, Tai Hing; Chan, Sophia S

    2017-01-01

    Neighborhood cohesion, which refers to the extent of the connectedness and solidarity among residents in a community or neighborhood, is an important determinant of human health. To enhance neighborhood cohesion, the "Learning Families Project" was developed with a series of intervention programs in Kwun Tong in Hong Kong, a district with low neighborhood cohesion. This project, based on the social ecological model, provided a platform for neighbors to learn, communicate and interact with each other. This quasi-experimental study included two nearby government subsidized low rent housing estates separated by busy main roads. One served as the intervention (Tsui Ping (South) Estate) and one as the control (Shun Tin Estate) estate. The intervention included promotion, resident training and learning programs, embodied by a series of community activities such as talks, day camp, thematic activities and horticulture class. Baseline (before the programs) and follow-up (one year after the programs) surveys were conducted both in the intervention and control estate to assess the impact of the programs on neighborhood cohesion. The number of residents who completed both the baseline and follow-up surveys was 502 in the intervention estate and 476 in the control estate. Neighborhood cohesion significantly improved in the intervention group after the programs (Cohen effect size d: 0.15). Compared with the control group, the improvements in closeness of the neighborhood and trust in neighbors were significantly greater in the intervention group (Cohen effect size d: 0.13 and 0.14, respectively). This brief intervention program using a quasi-experimental study design increased neighborhood cohesion in a low rent housing estate. ClinicalTrials.gov NCT02851667.

  11. The pack size effect: Influence on consumer perceptions of portion sizes

    NARCIS (Netherlands)

    Hieke, Sophie; Palascha, Aikaterini; Jola, Corinne; Wills, Josephine; Raats, Monique M.

    2016-01-01

    Larger portions as well as larger packs can lead to larger prospective consumption estimates, larger servings and increased consumption, described as 'portion-size effects' and 'pack size effects'. Although related, the effects of pack sizes on portion estimates have received less attention. While

  12. Effects of a Green Space Layout on the Outdoor Thermal Environment at the Neighborhood Level

    Directory of Open Access Journals (Sweden)

    Chi-Ming Lai

    2012-09-01

    Full Text Available This study attempted to address the existing urban design needs and computer-aided thermal engineering and explore the optimal green space layout to obtain an acceptable thermal environment at the neighborhood scale through a series of building energy and computational fluid dynamics (CFD simulations. The building-energy analysis software eQUEST and weather database TMY2 were adopted to analyze the electric energy consumed by air conditioners and the analysis results were incorporated to derive the heat dissipated from air conditioners. Then, the PHOENICS CFD software was used to analyze how the green space layout influences outdoor thermal environment based on the heat dissipated from air conditioners and the solar heat reemitted from the built surfaces. The results show that a green space located in the center of this investigated area and at the far side of the downstream of a summer monsoon is the recommended layout. The layouts, with green space in the center, can decrease the highest temperature by 0.36 °C.

  13. The effect of a tall tower on flow and dispersion through a model urban neighborhood: part 2. Pollutant dispersion.

    Science.gov (United States)

    Brixey, Laurie A; Heist, David K; Richmond-Bryant, Jennifer; Bowker, George E; Perry, Steven G; Wiener, Russell W

    2009-12-01

    This article is the second in a two-paper series presenting results from wind tunnel and computational fluid dynamics (CFD) simulations of flow and dispersion in an idealized model urban neighborhood. Pollutant dispersion results are presented and discussed for a model neighborhood that was characterized by regular city blocks of three-story row houses with a single 12-story tower located at the downwind edge of one of these blocks. The tower had three significant effects on pollutant dispersion in the surrounding street canyons: drawing the plume laterally towards the tower, greatly enhancing the vertical dispersion of the plume in the wake of the tower, and significantly decreasing the residence time of pollutants in the wake of the tower. In the wind tunnel, tracer gas released in the avenue lee of the tower, but several blocks away laterally, was pulled towards the tower and lifted in the wake of the tower. The same lateral movement of the pollutant was seen in the next avenue, which was approximately 2.5 tower heights downwind of the tower. The tower also served to ventilate the street canyon directly in its wake more rapidly than the surrounding areas. This was evidenced by CFD simulations of concentration decay where the residence time of pollutants lee of the 12-story tower was found to be less than half the residence time behind a neighboring three-story building. This same phenomenon of rapid vertical dispersion lee of a tower among an array of smaller buildings was also demonstrated in a separate set of wind tunnel experiments using an array of cubical blocks. A similar decrease in the residence time was observed when the height of one block was increased.

  14. Geographic Variations of Colorectal and Breast Cancer Late-Stage Diagnosis and the Effects of Neighborhood-Level Factors.

    Science.gov (United States)

    Lin, Yan; Wimberly, Michael C

    2017-04-01

    The purpose of this study was to examine the geographic variations of late-stage diagnosis in colorectal cancer (CRC) and breast cancer as well as to investigate the effects of 3 neighborhood-level factors-socioeconomic deprivation, urban/rural residence, and spatial accessibility to health care-on the late-stage risks. This study used population-based South Dakota cancer registry data from 2001 to 2012. A total of 4,878 CRC cases and 6,418 breast cancer cases were included in the analyses. Two-level logistic regression models were used to analyze the risk of late-stage CRC and breast cancer. For CRC, there was a small geographic variation across census tracts in late-stage diagnosis, and residing in isolated small rural areas was significantly associated with late-stage risk. However, this association became nonsignificant after adjusting for census-tract level socioeconomic deprivation. Socioeconomic deprivation was an independent predictor of CRC late-stage risk, and it explained the elevated risk among American Indians. No relationship was found between spatial accessibility and CRC late-stage risk. For breast cancer, no geographic variation in the late-stage diagnosis was observed across census tracts, and none of the 3 neighborhood-level factors was significantly associated with late-stage risk. Results suggested that socioeconomic deprivation, rather than spatial accessibility, contributed to CRC late-stage risks in South Dakota as a rural state. CRC intervention programs could be developed to target isolated small rural areas, socioeconomically disadvantaged areas, as well as American Indians residing in these areas. © 2016 National Rural Health Association.

  15. Unpacking Neighborhood Influences on Education Outcomes: Setting the Stage for Future Research. NBER Working Paper No. 16055

    Science.gov (United States)

    Harding, David J.; Gennetian, Lisa; Winship, Christopher; Sanbonmatsu, Lisa; Kling, Jeffrey R.

    2010-01-01

    We motivate future neighborhood research through a simple model that considers youth educational outcomes as a function of neighborhood context, neighborhood exposure, individual vulnerability to neighborhood effects, and non-neighborhood educational inputs--with a focus on effect heterogeneity. Research using this approach would require three…

  16. Publication Bias in Psychology: A Diagnosis Based on the Correlation between Effect Size and Sample Size

    Science.gov (United States)

    Kühberger, Anton; Fritz, Astrid; Scherndl, Thomas

    2014-01-01

    Background The p value obtained from a significance test provides no information about the magnitude or importance of the underlying phenomenon. Therefore, additional reporting of effect size is often recommended. Effect sizes are theoretically independent from sample size. Yet this may not hold true empirically: non-independence could indicate publication bias. Methods We investigate whether effect size is independent from sample size in psychological research. We randomly sampled 1,000 psychological articles from all areas of psychological research. We extracted p values, effect sizes, and sample sizes of all empirical papers, and calculated the correlation between effect size and sample size, and investigated the distribution of p values. Results We found a negative correlation of r = −.45 [95% CI: −.53; −.35] between effect size and sample size. In addition, we found an inordinately high number of p values just passing the boundary of significance. Additional data showed that neither implicit nor explicit power analysis could account for this pattern of findings. Conclusion The negative correlation between effect size and samples size, and the biased distribution of p values indicate pervasive publication bias in the entire field of psychology. PMID:25192357

  17. Work and Home Neighborhood Design and Physical Activity.

    Science.gov (United States)

    Carlson, Jordan A; Frank, Lawrence D; Ulmer, Jared; Conway, Terry L; Saelens, Brian E; Cain, Kelli L; Sallis, James F

    2018-01-01

    To investigate relations of perceived worksite neighborhood environments to total physical activity and active transportation, over and above home neighborhood built environments. Observational epidemiologic study. Baltimore, Maryland-Washington, DC, and Seattle-King County, Washington metropolitan areas. One thousand eighty-five adults (mean age = 45.0 [10.2]; 46% women) recruited from 32 neighborhoods stratified by high/low neighborhood income and walkability. The Neighborhood Environment Walkability Survey assessed perceptions of worksite and home neighborhood environments. Accelerometers assessed total moderate-to-vigorous physical activity (MVPA). The International Physical Activity Questionnaire assessed total active transportation and active transportation to and around work. Mixed-effects regression tested relations of home and worksite neighborhood environments to each physical activity outcome, adjusted for demographics. Home and worksite mixed land use and street connectivity had the most consistent positive associations with physical activity outcomes. Worksite traffic and pedestrian safety were also associated with multiple physical activity outcomes. The worksite neighborhood explained additional variance in physical activity outcomes than explained by the home neighborhood. Worksite and home neighborhood environments interacted in explaining active transportation to work, with the greatest impacts occurring when both neighborhoods were activity supportive. Both worksite and home neighborhood environments were independently related to total MVPA and active transportation. Community design policies should target improving the physical activity supportiveness of worksite neighborhood environments and integrating commercial and residential development.

  18. Size effects in ductile cellular solids. Part I : modeling

    NARCIS (Netherlands)

    Onck, P.R.; Andrews, E.W.; Gibson, L.J.

    2001-01-01

    In the mechanical testing of metallic foams, an important issue is the effect of the specimen size, relative to the cell size, on the measured properties. Here we analyze size effects for the modulus and strength of regular, hexagonal honeycombs under uniaxial and shear loadings. Size effects for

  19. Size effects in foams : Experiments and modeling

    NARCIS (Netherlands)

    Tekoglu, C.; Gibson, L. J.; Pardoen, T.; Onck, P. R.

    Mechanical properties of cellular solids depend on the ratio of the sample size to the cell size at length scales where the two are of the same order of magnitude. Considering that the cell size of many cellular solids used in engineering applications is between 1 and 10 mm, it is not uncommon to

  20. Board Size Effects in Closely Held Corporations

    DEFF Research Database (Denmark)

    Bennedsen, Morten; Kongsted, H.C.; Meisner Nielsen, Kasper

    2004-01-01

    of board size by using a new instrument given bythe number of children of the founders of the firms. Our analysis shows thatboard size can be taken as exogenous in the performance equation. Furthermore,based on a flexible model specification we find that there is noempirical evidence of adverse board size...

  1. Neighborhood Poverty and Nonmarital Fertility: Spatial and Temporal Dimensions

    Science.gov (United States)

    South, Scott J.; Crowder, Kyle

    2010-01-01

    Data from 4,855 respondents to the Panel Study of Income Dynamics were used to examine spatial and temporal dimensions of the effect of neighborhood poverty on teenage premarital childbearing. Although high poverty in the immediate neighborhood increased the risk of becoming an unmarried parent, high poverty in surrounding neighborhoods reduced…

  2. Effects of Seed Size on Germination and Early Morphorlogical and ...

    African Journals Online (AJOL)

    Effects of Seed Size on Germination and Early Morphorlogical and Physiological Characteristics of Gmelina Arborea , Roxb. ... African Research Review ... They were grouped into 3 categories as large seed size (LSS), medium seed size ...

  3. A synergetic combination of small and large neighborhood schemes in developing an effective procedure for solving the job shop scheduling problem.

    Science.gov (United States)

    Amirghasemi, Mehrdad; Zamani, Reza

    2014-01-01

    This paper presents an effective procedure for solving the job shop problem. Synergistically combining small and large neighborhood schemes, the procedure consists of four components, namely (i) a construction method for generating semi-active schedules by a forward-backward mechanism, (ii) a local search for manipulating a small neighborhood structure guided by a tabu list, (iii) a feedback-based mechanism for perturbing the solutions generated, and (iv) a very large-neighborhood local search guided by a forward-backward shifting bottleneck method. The combination of shifting bottleneck mechanism and tabu list is used as a means of the manipulation of neighborhood structures, and the perturbation mechanism employed diversifies the search. A feedback mechanism, called repeat-check, detects consequent repeats and ignites a perturbation when the total number of consecutive repeats for two identical makespan values reaches a given threshold. The results of extensive computational experiments on the benchmark instances indicate that the combination of these four components is synergetic, in the sense that they collectively make the procedure fast and robust.

  4. Obesogenic and youth oriented restaurant marketing in public housing neighborhoods.

    Science.gov (United States)

    Lee, Rebecca E; Heinrich, Katie M; Reese-Smith, Jacqueline Y; Regan, Gail R; Adamus-Leach, Heather J

    2014-03-01

    To compare restaurant marketing by restaurant and neighborhood type. All restaurants (61=fast food, FF; 72=table service, TS) within an 800-meter radius of 13 public housing developments (HD) and 4 comparison neighborhoods were audited using the Restaurant Assessment Tool©2010. HD neighborhoods were lower income and higher minority than comparison neighborhoods with similar density and street connectivity. Restaurants in HD neighborhoods had fewer healthy entrées than comparison neighborhoods. FF restaurants had cheaper beverages and more children's meals, supersize drinks, free prize with purchase, super-size items, special characters, and more items geared to driving than TS restaurants. Residents of lower socioeconomic neighborhoods may be differentially exposed to unhealthy food options.

  5. Neighborhood Characteristics and Individual Homicide Risks : Effects of Social Cohesion, Confidence in the Police, and Socioeconomic Disadvantage

    NARCIS (Netherlands)

    Nieuwbeerta, Paul; McCall, Patricia L.; Elffers, Henk; Wittebrood, Karin

    2008-01-01

    This study tests hypotheses on the relationship between characteristics of neighborhoods in the Netherlands—their socioeconomic disadvantage, social cohesion, and residents’ confidence in the police—and the likelihood of homicide victimization. These hypotheses are derived from social

  6. Neighborhood Ethnic Density as an Explanation for the Academic Achievement of Ethnic Minority Youth Placed in Neighborhood Disadvantage

    Science.gov (United States)

    Madyun, Na'im; Lee, Moosung

    2010-01-01

    The underachievement of ethnic minority youth from disadvantaged neighborhoods is a pervasive educational issue this nation is facing. Based on an ecological perspective, we examined the contextual effects of neighborhood ethnic density and neighborhood disadvantage on the academic achievement of Hmong immigrant youths. Utilizing hierarchical…

  7. [Effects of an integrated neighborhood approach on older people's (health-related) quality of life and well-being].

    Science.gov (United States)

    van Dijk, Hanna M; Cramm, Jane M; Birnie, Erwin; Nieboer, Anna P

    2018-05-18

    Integrated neighborhood approaches (INAs) are increasingly advocated to support community-dwelling older people; their effectiveness however remains unknown. We evaluated INA effects on older people's (health-related) quality of life (HRQoL) and well-being in Rotterdam. We used a matched quasi-experimental design comparing INA with "usual" care and support. Community-dwelling people (aged ≥70) and control subjects (n = 186 each) were followed over a one-year period (measurements at baseline, 6 and 12 months). Primary outcomes were HRQoL (EQ-5D-3L, SF-20) and well-being (SPF-IL). The effect of INA was analysed with generalized linear mixed modeling of repeated measurements, using both an "intention to treat" and "as treated" approach. The results indicated that pre-intervention participants were significantly older, more often single, less educated, had lower incomes and more likely to have ≥1 disease than control subjects; they had lower well-being, physical functioning, role functioning, and mental health. No substantial difference in well-being or HRQoL was observed between the intervention and control group after 1 year. The lack of effects of INA highlights the complexity of integrated care and support initiatives.

  8. The Wisconsin Assessment of the Social and Built Environment (WASABE): a multi-dimensional objective audit instrument for examining neighborhood effects on health.

    Science.gov (United States)

    Malecki, Kristen C; Engelman, Corinne D; Peppard, Paul E; Nieto, F Javier; Grabow, Maggie L; Bernardinello, Milena; Bailey, Erin; Bersch, Andrew J; Walsh, Matthew C; Lo, Justin Y; Martinez-Donate, Ana

    2014-11-13

    Growing evidence suggests that mixed methods approaches to measuring neighborhood effects on health are needed. The Wisconsin Assessment of the Social and Built Environment (WASABE) is an objective audit tool designed as an addition to a statewide household-based health examination survey, the Survey of the Health of Wisconsin (SHOW), to objectively measure participant's neighborhoods. This paper describes the development and implementation of the WASABE and examines the instrument's ability to capture a range of social and built environment features in urban and rural communities. A systematic literature review and formative research were used to create the tool. Inter-rater reliability parameters across items were calculated. Prevalence and density of features were estimated for strata formed according to several sociodemographic and urbanicity factors. The tool is highly reliable with over 81% of 115 derived items having percent agreement above 95%. It captured variance in neighborhood features in for a diverse sample of SHOW participants. Sidewalk density in neighborhoods surrounding households of participants living at less than 100% of the poverty level was 67% (95% confidence interval, 55-80%) compared to 34% (25-44%) for those living at greater than 400% of the poverty level. Walking and biking trails were present in 29% (19-39%) of participant buffer in urban areas compared to only 7% (2-12%) in rural communities. Significant environmental differences were also observed for white versus non-white, high versus low income, and college graduates versus individuals with lower level of education. The WASABE has strong inter-rater reliability and validity properties. It builds on previous work to provide a rigorous and standardized method for systematically gathering objective built and social environmental data in a number of geographic settings. Findings illustrate the complex milieu of built environment features found in participants neighborhoods and have

  9. A Dynamic Neighborhood Learning-Based Gravitational Search Algorithm.

    Science.gov (United States)

    Zhang, Aizhu; Sun, Genyun; Ren, Jinchang; Li, Xiaodong; Wang, Zhenjie; Jia, Xiuping

    2018-01-01

    Balancing exploration and exploitation according to evolutionary states is crucial to meta-heuristic search (M-HS) algorithms. Owing to its simplicity in theory and effectiveness in global optimization, gravitational search algorithm (GSA) has attracted increasing attention in recent years. However, the tradeoff between exploration and exploitation in GSA is achieved mainly by adjusting the size of an archive, named , which stores those superior agents after fitness sorting in each iteration. Since the global property of remains unchanged in the whole evolutionary process, GSA emphasizes exploitation over exploration and suffers from rapid loss of diversity and premature convergence. To address these problems, in this paper, we propose a dynamic neighborhood learning (DNL) strategy to replace the model and thereby present a DNL-based GSA (DNLGSA). The method incorporates the local and global neighborhood topologies for enhancing the exploration and obtaining adaptive balance between exploration and exploitation. The local neighborhoods are dynamically formed based on evolutionary states. To delineate the evolutionary states, two convergence criteria named limit value and population diversity, are introduced. Moreover, a mutation operator is designed for escaping from the local optima on the basis of evolutionary states. The proposed algorithm was evaluated on 27 benchmark problems with different characteristic and various difficulties. The results reveal that DNLGSA exhibits competitive performances when compared with a variety of state-of-the-art M-HS algorithms. Moreover, the incorporation of local neighborhood topology reduces the numbers of calculations of gravitational force and thus alleviates the high computational cost of GSA.

  10. Modelling the effect of size-asymmetric competition on size inequality

    DEFF Research Database (Denmark)

    Rasmussen, Camilla Ruø; Weiner, Jacob

    2017-01-01

    Abstract The concept of size asymmetry in resource competition among plants, in which larger individuals obtain a disproportionate share of contested resources, appears to be very straightforward, but the effects of size asymmetry on growth and size variation among individuals have proved...... to be controversial. It has often been assumed that competition among individual plants in a population has to be size-asymmetric to result in higher size inequality than in the absence of competition, but here we question this inference. Using very simple, individual-based models, we investigate how size symmetry...... of competition affects the development in size inequality between two competing plants and show that increased size inequality due to competition is not always strong evidence for size-asymmetric competition. Even absolute symmetric competition, in which all plants receive the same amount of resources...

  11. Sensitivities Affecting Heat and Urban Heat Island Effect on Local Scale Projected to Neighborhood Scale in Baltimore, Maryland

    Science.gov (United States)

    Sze, C.; Zaitchik, B. F.; Scott, A.

    2015-12-01

    Urban regions are often impacted more by heat than adjacent rural areas, which is a phenomenon known as the urban heat island (UHI) effect. Urban areas are also highly heterogeneous and notoriously difficult to monitor using standard meteorological protocols—the hottest microclimates within a city often occur in locations that lack open, representative installation sites that are an adequate distance from buildings and direct heat sources. To investigate the challenges of monitoring urban heat, this study examines the sensitivity of temperature and humidity sensors currently used in a Baltimore UHI monitoring network to differences in sun exposure, material on which the data collecting instrument is attached, and land cover class of the vicinity. Sensitivity to sun exposure and attachment site can be interpreted as sources of uncertainty for urban heat monitoring, while sensitivity to land cover may reflect a true source of local temperature and humidity variability. In this study, we present results from a test deployment designed to assess the sensitivity of heat measurements to each of these three factors. We then apply these results to interpret measurements taken across the entire Baltimore UHI monitoring network. These results can then be used to improve heat measurements and more accurately represent and quantify the UHI effect on a broader scale, such as in neighborhoods or urban centers.

  12. [Effect sizes, statistical power and sample sizes in "the Japanese Journal of Psychology"].

    Science.gov (United States)

    Suzukawa, Yumi; Toyoda, Hideki

    2012-04-01

    This study analyzed the statistical power of research studies published in the "Japanese Journal of Psychology" in 2008 and 2009. Sample effect sizes and sample statistical powers were calculated for each statistical test and analyzed with respect to the analytical methods and the fields of the studies. The results show that in the fields like perception, cognition or learning, the effect sizes were relatively large, although the sample sizes were small. At the same time, because of the small sample sizes, some meaningful effects could not be detected. In the other fields, because of the large sample sizes, meaningless effects could be detected. This implies that researchers who could not get large enough effect sizes would use larger samples to obtain significant results.

  13. Strong crystal size effect on deformation twinning

    DEFF Research Database (Denmark)

    Yu, Qian; Shan, Zhi-Wei; Li, Ju

    2010-01-01

    plasticity. Accompanying the transition in deformation mechanism, the maximum flow stress of the submicrometre-sized pillars was observed to saturate at a value close to titanium’s ideal strength9, 10. We develop a ‘stimulated slip’ model to explain the strong size dependence of deformation twinning......Deformation twinning1, 2, 3, 4, 5, 6 in crystals is a highly coherent inelastic shearing process that controls the mechanical behaviour of many materials, but its origin and spatio-temporal features are shrouded in mystery. Using micro-compression and in situ nano-compression experiments, here we...... find that the stress required for deformation twinning increases drastically with decreasing sample size of a titanium alloy single crystal7, 8, until the sample size is reduced to one micrometre, below which the deformation twinning is entirely replaced by less correlated, ordinary dislocation...

  14. How to Estimate and Interpret Various Effect Sizes

    Science.gov (United States)

    Vacha-Haase, Tammi; Thompson, Bruce

    2004-01-01

    The present article presents a tutorial on how to estimate and interpret various effect sizes. The 5th edition of the Publication Manual of the American Psychological Association (2001) described the failure to report effect sizes as a "defect" (p. 5), and 23 journals have published author guidelines requiring effect size reporting. Although…

  15. Size effect in the strength of concrete structures

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The fracture mechanics size effect, as opposed to the Weibull statistical size effect, is a .... Solutions for TPB beam and a typical wedge-splitting geometry have been ..... Bazant Z P 1984 Size effect in blunt fracture: Concrete, rock, metal. J. Eng.

  16. Effect of the new C-12(alpha, gamma)O-16 rate on the chemical evolution of the solar neighborhood

    International Nuclear Information System (INIS)

    Matteucci, F.

    1986-01-01

    New models of chemical evolution of the solar neighborhood have been computed by taking into account the effect of the revised rate of the C-12(alpha, gamma)O-16 reaction on the chemical yields from massive stars, together with the yields from low- and intermediate-mass stars which also include those from Type I supernova explosions (C-deflagration in white dwarfs). In particular, the evolution of C-12, N-14, O-16, Ne-20, Mg-24, Si-28, and Fe-56 has been followed in detail, and their predicted solar absolute abundances as well as their relative ratios, both in the sun and in metal-poor stars, have been compared with the observed ones. It is concluded that a model with the new yields combined with a Salpeter initial mass function, an upper cutoff mass of 100 solar masses (the mass beyond which stars are not contributing to the galactic enrichment), and an upper limiting mass for intermediate-mass stars of the order of 5 solar masses, is in best agreement with the observations. 34 references

  17. Cross-Sectional and Longitudinal Effects of Racism on Mental Health Among Residents of Black Neighborhoods in New York City

    Science.gov (United States)

    Goodman, Melody S.

    2015-01-01

    Objectives. We investigated the impact of reported racism on the mental health of African Americans at cross-sectional time points and longitudinally, over the course of 1 year. Methods. The Black Linking Inequality, Feelings, and the Environment (LIFE) Study recruited Black residents (n = 144) from a probability sample of 2 predominantly Black New York City neighborhoods during December 2011 to June 2013. Respondents completed self-report surveys, including multiple measures of racism. We conducted assessments at baseline, 2-month follow-up, and 1-year follow-up. Weighted multivariate linear regression models assessed changes in racism and health over time. Results. Cross-sectional results varied by time point and by outcome, with only some measures associated with distress, and effects were stronger for poor mental health days than for depression. Individuals who denied thinking about their race fared worst. Longitudinally, increasing frequencies of racism predicted worse mental health across all 3 outcomes. Conclusions. These results support theories of racism as a health-defeating stressor and are among the few that show temporal associations with health. PMID:25521873

  18. When urban taps run dry: sachet water consumption and health effects in low income neighborhoods of Accra, Ghana.

    Science.gov (United States)

    Stoler, Justin; Fink, Günther; Weeks, John R; Otoo, Richard Appiah; Ampofo, Joseph A; Hill, Allan G

    2012-03-01

    Intraurban differentials in safe drinking water in developing cities have been exacerbated by rapid population growth that exceeds expansion of local water infrastructure. In Accra, Ghana, municipal water is rationed to meet demand, and the gap in water services is increasingly being filled by private water vendors selling packaged "sachet" water. Sachets extend drinking water coverage deeper into low-income areas and alleviate the need for safe water storage, potentially introducing a health benefit over stored tap water. We explore correlates of using sachets as the primary drinking water source for 2093 women in 37 census areas classified as slums by UN-Habitat, and links between sachet water and reported diarrhea episodes in a subset of 810 children under five. We find that neighborhood rationing exerts a strong effect on a household's likelihood of buying sachet water, and that sachet customers tend to be the poorest of the poor. Sachet use is also associated with higher levels of self-reported overall health in women, and lower likelihood of diarrhea in children. We conclude with implications for sachet regulation in Accra and other sub-Saharan cities facing drinking water shortages. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. When urban taps run dry: Sachet water consumption and health effects in low income neighborhoods of Accra, Ghana

    Science.gov (United States)

    Stoler, Justin; Fink, Günther; Weeks, John R.; Otoo, Richard Appiah; Ampofo, Joseph A.; Hill, Allan G.

    2011-01-01

    Intraurban differentials in safe drinking water in developing cities have been exacerbated by rapid population growth that exceeds expansion of local water infrastructure. In Accra, Ghana, municipal water is rationed to meet demand, and the gap in water services is increasingly being filled by private water vendors selling packaged “sachet” water. Sachets extend drinking water coverage deeper into low-income areas and alleviate the need for safe water storage, potentially introducing a health benefit over stored tap water. We explore correlates of using sachets as the primary drinking water source for 2,093 women in 37 census areas classified as slums by UN-Habitat, and links between sachet water and reported diarrhea episodes in a subset of 810 children under five. We find that neighborhood rationing exerts a strong effect on a household's likelihood of buying sachet water, and that sachet customers tend to be the poorest of the poor. Sachet use is also associated with higher levels of self-reported overall health in women, and lower likelihood of diarrhea in children. We conclude with implications for sachet regulation in Accra and other sub-Saharan cities facing drinking water shortages. PMID:22018970

  20. Cross-sectional and longitudinal effects of racism on mental health among residents of Black neighborhoods in New York City.

    Science.gov (United States)

    Kwate, Naa Oyo A; Goodman, Melody S

    2015-04-01

    We investigated the impact of reported racism on the mental health of African Americans at cross-sectional time points and longitudinally, over the course of 1 year. The Black Linking Inequality, Feelings, and the Environment (LIFE) Study recruited Black residents (n = 144) from a probability sample of 2 predominantly Black New York City neighborhoods during December 2011 to June 2013. Respondents completed self-report surveys, including multiple measures of racism. We conducted assessments at baseline, 2-month follow-up, and 1-year follow-up. Weighted multivariate linear regression models assessed changes in racism and health over time. Cross-sectional results varied by time point and by outcome, with only some measures associated with distress, and effects were stronger for poor mental health days than for depression. Individuals who denied thinking about their race fared worst. Longitudinally, increasing frequencies of racism predicted worse mental health across all 3 outcomes. These results support theories of racism as a health-defeating stressor and are among the few that show temporal associations with health.

  1. The causal effect of board size in the performance of small and medium-sized firms

    DEFF Research Database (Denmark)

    Bennedsen, Morten; Kongsted, Hans Christian; Meisner Nielsen, Kasper

    2008-01-01

    correlation between family size and board size and show this correlation to be driven by firms where the CEO's relatives serve on the board. Second, we find empirical evidence of a small adverse board size effect driven by the minority of small and medium-sized firms that are characterized by having......Empirical studies of large publicly traded firms have shown a robust negative relationship between board size and firm performance. The evidence on small and medium-sized firms is less clear; we show that existing work has been incomplete in analyzing the causal relationship due to weak...... identification strategies. Using a rich data set of almost 7000 closely held corporations we provide a causal analysis of board size effects on firm performance: We use a novel instrument given by the number of children of the chief executive officer (CEO) of the firms. First, we find a strong positive...

  2. Effects of tai chi qigong on psychosocial well-being among hidden elderly, using elderly neighborhood volunteer approach: a pilot randomized controlled trial

    OpenAIRE

    Chan,Aileen; Yu,Doris; Choi,Kai

    2017-01-01

    Aileen WK Chan, Doris SF Yu, KC Choi The Nethersole School of Nursing, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR Purpose: To test the feasibility and preliminary effectiveness of a tai chi qigong program with the assistance of elderly neighborhood volunteers in strengthening social networks and enhancing the psychosocial well-being of hidden elderly. Patients and methods: “Hidden elderly” is a term used to describe older adults w...

  3. Neighborhood and Friendship Composition in Adolescence

    OpenAIRE

    Edling, Christofer; Rydgren, Jens

    2010-01-01

    The social surroundings in which an individual grows up and spends his or her everyday life have an effect on his or her life chances. Much of the research into this phenomenon focuses on so-called neighborhood effects and has put particular emphasis on the negative effects of growing up in a poor neighborhood. Originating from the sociological study of inner-city problems in the United States, the research has recentl...

  4. Characterization of resonances using finite size effects

    International Nuclear Information System (INIS)

    Pozsgay, B.; Takacs, G.

    2006-01-01

    We develop methods to extract resonance widths from finite volume spectra of (1+1)-dimensional quantum field theories. Our two methods are based on Luscher's description of finite size corrections, and are dubbed the Breit-Wigner and the improved ''mini-Hamiltonian'' method, respectively. We establish a consistent framework for the finite volume description of sufficiently narrow resonances that takes into account the finite size corrections and mass shifts properly. Using predictions from form factor perturbation theory, we test the two methods against finite size data from truncated conformal space approach, and find excellent agreement which confirms both the theoretical framework and the numerical validity of the methods. Although our investigation is carried out in 1+1 dimensions, the extension to physical 3+1 space-time dimensions appears straightforward, given sufficiently accurate finite volume spectra

  5. Causality in Statistical Power: Isomorphic Properties of Measurement, Research Design, Effect Size, and Sample Size

    Directory of Open Access Journals (Sweden)

    R. Eric Heidel

    2016-01-01

    Full Text Available Statistical power is the ability to detect a significant effect, given that the effect actually exists in a population. Like most statistical concepts, statistical power tends to induce cognitive dissonance in hepatology researchers. However, planning for statistical power by an a priori sample size calculation is of paramount importance when designing a research study. There are five specific empirical components that make up an a priori sample size calculation: the scale of measurement of the outcome, the research design, the magnitude of the effect size, the variance of the effect size, and the sample size. A framework grounded in the phenomenon of isomorphism, or interdependencies amongst different constructs with similar forms, will be presented to understand the isomorphic effects of decisions made on each of the five aforementioned components of statistical power.

  6. Biofuel manufacturing from woody biomass: effects of sieve size used in biomass size reduction.

    Science.gov (United States)

    Zhang, Meng; Song, Xiaoxu; Deines, T W; Pei, Z J; Wang, Donghai

    2012-01-01

    Size reduction is the first step for manufacturing biofuels from woody biomass. It is usually performed using milling machines and the particle size is controlled by the size of the sieve installed on a milling machine. There are reported studies about the effects of sieve size on energy consumption in milling of woody biomass. These studies show that energy consumption increased dramatically as sieve size became smaller. However, in these studies, the sugar yield (proportional to biofuel yield) in hydrolysis of the milled woody biomass was not measured. The lack of comprehensive studies about the effects of sieve size on energy consumption in biomass milling and sugar yield in hydrolysis process makes it difficult to decide which sieve size should be selected in order to minimize the energy consumption in size reduction and maximize the sugar yield in hydrolysis. The purpose of this paper is to fill this gap in the literature. In this paper, knife milling of poplar wood was conducted using sieves of three sizes (1, 2, and 4 mm). Results show that, as sieve size increased, energy consumption in knife milling decreased and sugar yield in hydrolysis increased in the tested range of particle sizes.

  7. Neighborhood cohesion, neighborhood disorder, and cardiometabolic risk.

    Science.gov (United States)

    Robinette, Jennifer W; Charles, Susan T; Gruenewald, Tara L

    2018-02-01

    Perceptions of neighborhood disorder (trash, vandalism) and cohesion (neighbors trust one another) are related to residents' health. Affective and behavioral factors have been identified, but often in studies using geographically select samples. We use a nationally representative sample (n = 9032) of United States older adults from the Health and Retirement Study to examine cardiometabolic risk in relation to perceptions of neighborhood cohesion and disorder. Lower cohesion is significantly related to greater cardiometabolic risk in 2006/2008 and predicts greater risk four years later (2010/2012). The longitudinal relation is partially accounted for by anxiety and physical activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Effects of sample size on the second magnetization peak in ...

    Indian Academy of Sciences (India)

    the sample size decreases – a result that could be interpreted as a size effect in the order– disorder vortex matter phase transition. However, local magnetic measurements trace this effect to metastable disordered vortex states, revealing the same order–disorder transition induction in samples of different size. Keywords.

  9. Interpreting and Reporting Effect Sizes in Research Investigations.

    Science.gov (United States)

    Tapia, Martha; Marsh, George E., II

    Since 1994, the American Psychological Association (APA) has advocated the inclusion of effect size indices in reporting research to elucidate the statistical significance of studies based on sample size. In 2001, the fifth edition of the APA "Publication Manual" stressed the importance of including an index of effect size to clarify…

  10. Effectiveness of the Size Matters Handwriting Program.

    Science.gov (United States)

    Pfeiffer, Beth; Rai, Gillian; Murray, Tammy; Brusilovskiy, Eugene

    2015-04-01

    The purpose of the research was to study changes in handwriting legibility among kindergarten, first- and second-grade students in response to the Size Matters curricular-based handwriting program. A two-group pre-post-test design was implemented at two public schools with half of the classrooms assigned to receive the Size Matters program and the other continuing to receive standard instruction. All participants completed two standardized handwriting measures at pre-test and after 40 instructional sessions were completed with the classes receiving the handwriting program. Results identified significant changes in legibility in the handwriting intervention group for all three grades when compared with the standard instruction group. The results of this study support the use of a curricular-embedded handwriting program and provide the foundation for future research examining the impact of handwriting legibility on learning outcomes.

  11. Banks and the Racial Patterning of Homicide: A Study of Chicago Neighborhoods

    Directory of Open Access Journals (Sweden)

    María B. Veléz

    2009-12-01

    Full Text Available While bank investment is a driving force behind neighborhood viability, few studies have directly examined the effects of bank loan practices on neighborhood crime rates. This paper proposes that variation in residential bank loans helps explain the higher rates of homicide in minority neighborhoods in Chicago compared to white neighborhoods. It finds that black and Latino neighborhoods would experience fewer homicides if more financial capital were infused into these neighborhoods. These findings suggest that neighborhoods are shaped profoundly by the decisions of external economic actors.

  12. Enemies and Friends in the Neighborhood: Orthographic Similarity Effects in Semantic Categorization

    Science.gov (United States)

    Pecher, Diane; Zeelenberg, Rene; Wagenmakers, Eric-Jan

    2005-01-01

    Studies investigating orthographic similarity effects in semantic tasks have produced inconsistent results. The authors investigated orthographic similarity effects in animacy decision and in contrast with previous studies, they took semantic congruency into account. In Experiments 1 and 2, performance to a target (cat) was better if a previously…

  13. Effect size estimates: current use, calculations, and interpretation.

    Science.gov (United States)

    Fritz, Catherine O; Morris, Peter E; Richler, Jennifer J

    2012-02-01

    The Publication Manual of the American Psychological Association (American Psychological Association, 2001, American Psychological Association, 2010) calls for the reporting of effect sizes and their confidence intervals. Estimates of effect size are useful for determining the practical or theoretical importance of an effect, the relative contributions of factors, and the power of an analysis. We surveyed articles published in 2009 and 2010 in the Journal of Experimental Psychology: General, noting the statistical analyses reported and the associated reporting of effect size estimates. Effect sizes were reported for fewer than half of the analyses; no article reported a confidence interval for an effect size. The most often reported analysis was analysis of variance, and almost half of these reports were not accompanied by effect sizes. Partial η2 was the most commonly reported effect size estimate for analysis of variance. For t tests, 2/3 of the articles did not report an associated effect size estimate; Cohen's d was the most often reported. We provide a straightforward guide to understanding, selecting, calculating, and interpreting effect sizes for many types of data and to methods for calculating effect size confidence intervals and power analysis.

  14. Simulation of finite size effects of the fiber bundle model

    Science.gov (United States)

    Hao, Da-Peng; Tang, Gang; Xun, Zhi-Peng; Xia, Hui; Han, Kui

    2018-01-01

    In theory, the macroscopic fracture of materials should correspond with the thermodynamic limit of the fiber bundle model. However, the simulation of a fiber bundle model with an infinite size is unrealistic. To study the finite size effects of the fiber bundle model, fiber bundle models of various size are simulated in detail. The effects of system size on the constitutive behavior, critical stress, maximum avalanche size, avalanche size distribution, and increased step number of external load are explored. The simulation results imply that there is no feature size or cut size for macroscopic mechanical and statistical properties of the model. The constitutive curves near the macroscopic failure for various system size can collapse well with a simple scaling relationship. Simultaneously, the introduction of a simple extrapolation method facilitates the acquisition of more accurate simulation results in a large-limit system, which is better for comparison with theoretical results.

  15. The Effect of Incremental Changes in Phonotactic Probability and Neighborhood Density on Word Learning by Preschool Children

    Science.gov (United States)

    Storkel, Holly L.; Bontempo, Daniel E.; Aschenbrenner, Andrew J.; Maekawa, Junko; Lee, Su-Yeon

    2013-01-01

    Purpose: Phonotactic probability or neighborhood density has predominately been defined through the use of gross distinctions (i.e., low vs. high). In the current studies, the authors examined the influence of finer changes in probability (Experiment 1) and density (Experiment 2) on word learning. Method: The authors examined the full range of…

  16. Neighborhood Alcohol Outlet Density and Rates of Child Abuse and Neglect: Moderating Effects of Access to Substance Abuse Services

    Science.gov (United States)

    Morton, Cory M.; Simmel, Cassandra; Peterson, N. Andrew

    2014-01-01

    This study investigates the relationship between concentrations of on- and off-premises alcohol outlets and rates of child abuse and neglect. Additionally, the study seeks to locate protective features of a neighborhood's built environment by investigating the potentially moderating role that access to substance abuse treatment and prevention services plays in the relationship between alcohol outlet density and child maltreatment. Using a cross-sectional design, this ecological study utilized data from 163 census tracts in Bergen County, New Jersey, on reports of child abuse and neglect, alcohol outlets, substance abuse treatment and prevention facilities, and the United States Census to investigate the linkages between socioeconomic structure, alcohol availability, and access to substance abuse service facilities on rates of child abuse and neglect. Findings indicate areas with a greater concentration of on-premises alcohol outlets (i.e., bars) had higher rates of child neglect, and those with easier access to substance abuse services had lower rates of neglect, controlling for neighborhood demographic and socioeconomic structure. Additionally, the relationship between on-premises alcohol outlet density and rates of child neglect was moderated by the presence of substance abuse service facilities. A greater concentration of off-premises outlets (i.e., liquor stores) was associated with lower rates of physical abuse. Findings suggest that the built environment and socioeconomic structure of neighborhoods have important consequences for child well-being. The implications for future research on the structural features of neighborhoods that are associated with child well-being are discussed. PMID:24529493

  17. Neighborhood environment, physical activity, and quality of life in adults: Intermediary effects of personal and psychosocial factors

    Directory of Open Access Journals (Sweden)

    Eleni Theodoropoulou

    2017-03-01

    Conclusion: Results indicated that the most important mediators in the examined models were exercise self-efficacy and health. Further, findings demonstrated the role of neighborhood environment in enhancing PA and QoL. Future studies should be carried out applying longitudinal data for a better understanding of these associations over time.

  18. The effect of incremental changes in phonotactic probability and neighborhood density on word learning by preschool children

    Science.gov (United States)

    Storkel, Holly L.; Bontempo, Daniel E.; Aschenbrenner, Andrew J.; Maekawa, Junko; Lee, Su-Yeon

    2013-01-01

    Purpose Phonotactic probability or neighborhood density have predominately been defined using gross distinctions (i.e., low vs. high). The current studies examined the influence of finer changes in probability (Experiment 1) and density (Experiment 2) on word learning. Method The full range of probability or density was examined by sampling five nonwords from each of four quartiles. Three- and 5-year-old children received training on nonword-nonobject pairs. Learning was measured in a picture-naming task immediately following training and 1-week after training. Results were analyzed using multi-level modeling. Results A linear spline model best captured nonlinearities in phonotactic probability. Specifically word learning improved as probability increased in the lowest quartile, worsened as probability increased in the midlow quartile, and then remained stable and poor in the two highest quartiles. An ordinary linear model sufficiently described neighborhood density. Here, word learning improved as density increased across all quartiles. Conclusion Given these different patterns, phonotactic probability and neighborhood density appear to influence different word learning processes. Specifically, phonotactic probability may affect recognition that a sound sequence is an acceptable word in the language and is a novel word for the child, whereas neighborhood density may influence creation of a new representation in long-term memory. PMID:23882005

  19. Reconciling phonological neighborhood effects in speech production through single trial analysis

    OpenAIRE

    Sadat Schaffai, Jasmin, 1982-; Martin, Clara D.; Costa Martínez, Albert, 1970-; Alario, F.-Xavier (François -Xavier),

    2014-01-01

    A crucial step for understanding how lexical knowledge is represented is to describe the relative similarity of lexical items, and how it influences language processing. Previous studies of the effects of form similarity on word production have reported conflicting results, notably within and across languages. The aim of the present study was to clarify this empirical issue to provide specific constraints for theoretical models of language production. We investigated the role of phonological ...

  20. Examining Differential Resilience Mechanisms by Comparing ‘Tipping Points’ of the Effects of Neighborhood Conditions on Anxiety by Race/Ethnicity

    Directory of Open Access Journals (Sweden)

    Emil Nicolae Coman

    2018-02-01

    Full Text Available Exposure to adverse environmental and social conditions affects physical and mental health through complex mechanisms. Different racial/ethnic (R/E groups may be more or less vulnerable to the same conditions, and the resilience mechanisms that can protect them likely operate differently in each population. We investigate how adverse neighborhood conditions (neighborhood disorder, NDis differentially impact mental health (anxiety, Anx in a sample of white and Black (African American young women from Southeast Texas, USA. We illustrate a simple yet underutilized segmented regression model where linearity is relaxed to allow for a shift in the strength of the effect with the levels of the predictor. We compare how these effects change within R/E groups with the level of the predictor, but also how the “tipping points,” where the effects change in strength, may differ by R/E. We find with classic linear regression that neighborhood disorder adversely affects Black women’s anxiety, while in white women the effect seems negligible. Segmented regressions show that the Ndis → Anx effects in both groups of women appear to shift at similar levels, about one-fifth of a standard deviation below the mean of NDis, but the effect for Black women appears to start out as negative, then shifts in sign, i.e., to increase anxiety, while for white women, the opposite pattern emerges. Our findings can aid in devising better strategies for reducing health disparities that take into account different coping or resilience mechanisms operating differentially at distinct levels of adversity. We recommend that researchers investigate when adversity becomes exceedingly harmful and whether this happens differentially in distinct populations, so that intervention policies can be planned to reverse conditions that are more amenable to change, in effect pushing back the overall social risk factors below such tipping points.

  1. Finite size effects of a pion matrix element

    International Nuclear Information System (INIS)

    Guagnelli, M.; Jansen, K.; Palombi, F.; Petronzio, R.; Shindler, A.; Wetzorke, I.

    2004-01-01

    We investigate finite size effects of the pion matrix element of the non-singlet, twist-2 operator corresponding to the average momentum of non-singlet quark densities. Using the quenched approximation, they come out to be surprisingly large when compared to the finite size effects of the pion mass. As a consequence, simulations of corresponding nucleon matrix elements could be affected by finite size effects even stronger which could lead to serious systematic uncertainties in their evaluation

  2. Neighborhood Risk, Parental Socialization Styles, and Adolescent Conduct Problems

    Directory of Open Access Journals (Sweden)

    Enrique Gracia

    2010-12-01

    Full Text Available This article aims to analyze the influence of parental socialization styles (authoritarian, authoritative, indulgent and neglectful, and perceived neighborhood risk on three indicators of conduct problems in adolescence (school misconduct, delinquency, and drug use. The sample consists of 1,017 adolescents, aged between 12 and 17. Results from four multivariate factorial designs yielded only main effects of parenting styles and neighborhood risk. Adolescents from authoritative and indulgent families showed lower conduct problems than those with authoritarian and neglectful parents. Also, higher levels of perceived neighborhood risk were significantly associated with more conduct problems. There were no significant interaction effects between parenting styles and perceived neighborhood risk, but results yielded a significant interaction effect between neighborhood risk and sex. Overall, results do not support the idea that parenting styles are more effective under certain neighborhood risk conditions, and suggest that neighbourhood risk influences adolescents’ psychosocial adjustment beyond the influence of parental socialization styles.

  3. Neighborhood Mapping Tool

    Data.gov (United States)

    Department of Housing and Urban Development — This tool assists the public and Choice Neighborhoods applicants to prepare data to submit with their grant application by allowing applicants to draw the exact...

  4. Neighborhood-based physical activity differences: Evaluation of the effect of health promotion program.

    Directory of Open Access Journals (Sweden)

    Amanda Cristina de Souza Andrade

    Full Text Available The practice of physical activity is an important factor in the prevention of health problems. However, a small portion of the population is physically active. Recent reviews show that physical activity classes in community settings have the potential to increase population levels of physical activity and reduce health inequalities.To evaluate the effect of the Academias da Cidade Program in Belo Horizonte on the practice of physical activity in leisure time (PALT by non-users living near the program centers.We conducted a home-based health survey in Belo Horizonte (2008-2009 with 1,581 adults who were non-users of the program and who lived within a 1,500-meter radius of one active program center (exposed group and two nonoperational centers with sites reserved for their construction (unexposed group. We collected data on PALT levels (≥150 minutes/week, which was measured with the Physical Activity International Questionnaire and analyzed with binary logistic regression using the Generalized Estimating Equations method. The propensity score was used as an adjustment variable to control the potential confusion in the measures of effect of exposure studied.The overall prevalence of the PALT was 26.5% in the exposed group and 22.7% in the unexposed group. The exposed group was more likely to be active in leisure time (OR = 1.05; CI 95%: 1.01-1.10. When considering the interaction between exposed group and distance, individuals in the exposed group who lived less than 500 meters from the program center were more likely to be active in leisure time (OR = 1.18, CI 95%: 1.03-1.35 compared to their counterparts.Promoting physical activity in the community can favorably affect PALT levels among residents, especially those living closest to intervention centers. We believe the Academias da Cidade Program is a promising strategy to facilitate the access to appropriate spaces for the practice of physical activity and contribute to increase the levels

  5. Comparison of switching control algorithms effective in restricting the switching in the neighborhood of the origin

    International Nuclear Information System (INIS)

    Joung, JinWook; Chung, Lan; Smyth, Andrew W

    2010-01-01

    The active interaction control (AIC) system consisting of a primary structure, an auxiliary structure and an interaction element was proposed to protect the primary structure against earthquakes and winds. The objective of the AIC system in reducing the responses of the primary structure is fulfilled by activating or deactivating the switching between the engagement and the disengagement of the primary and auxiliary structures through the interaction element. The status of the interaction element is controlled by switching control algorithms. The previously developed switching control algorithms require an excessive amount of switching, which is inefficient. In this paper, the excessive amount of switching is restricted by imposing an appropriately designed switching boundary region, where switching is prohibited, on pre-designed engagement–disengagement conditions. Two different approaches are used in designing the newly proposed AID-off and AID-off 2 algorithms. The AID-off 2 algorithm is designed to affect deactivated switching regions explicitly, unlike the AID-off algorithm, which follows the same procedure of designing the engagement–disengagement conditions of the previously developed algorithms, by using the current status of the AIC system. Both algorithms are shown to be effective in reducing the amount of switching times triggered from the previously developed AID algorithm under an appropriately selected control sampling period for different earthquakes, but the AID-off 2 algorithm outperforms the AID-off algorithm in reducing the number of switching times

  6. Portion size and intended consumption. Evidence for a pre-consumption portion size effect in males?

    Science.gov (United States)

    Robinson, Eric; te Raa, Wesselien; Hardman, Charlotte A

    2015-08-01

    Larger portions increase energy intake (the 'portion size effect'); however, the mechanisms behind this effect are unclear. Although pre-meal intentions are thought to be an important determinant of energy intake, little research has examined how much of a meal individuals intend to eat when served standard versus larger portion sizes. Three studies examined the effect of manipulating portion size on intended food consumption. In Studies 1 (spaghetti bolognese) and 2 (curry and rice) male participants were shown an image of either a standard or a larger meal and indicated how much of the meal they intended to consume. In Study 3 male and female participants were served either a standard or a larger portion of ice cream for dessert, they indicated how much they intended to consume and then ate as much of the ice cream as they desired. Regardless of being shown standard or large portion sizes, in Studies 1 and 2 participants reported that they intended to eat the majority of the meal, equating to a large difference in intended energy consumption between portion size conditions (a 'pre-consumption portion size effect'). This finding was replicated in male participants in Study 3, although females intended to eat a smaller proportion of the larger portion of ice cream, compared to the standard portion. Both male and female participants tended to eat in accordance with their pre-meal intentions and a portion size effect on actual consumption was subsequently observed in males, but not in females. The portion size effect may be observed when measuring pre-meal intended consumption in males. Copyright © 2015. Published by Elsevier Ltd.

  7. The Moderating Effect of Substance Abuse Service Accessibility on the Relationship between Child Maltreatment and Neighborhood Alcohol Availability

    OpenAIRE

    Morton, Cory M.

    2013-01-01

    This study investigates how the relationship between dense concentrations of alcohol retailers and high rates of child maltreatment may be moderated by the presence of substance abuse service facilities. Using a cross-sectional design, the study utilized data from Bergen County, New Jersey on child maltreatment reports, alcohol-selling retailers, substance abuse service facilities, and the United States Census. Findings indicate child maltreatment rates were higher in neighborhoods with lower...

  8. Neighborhood alcohol outlet density and rates of child abuse and neglect: moderating effects of access to substance abuse services.

    Science.gov (United States)

    Morton, Cory M; Simmel, Cassandra; Peterson, N Andrew

    2014-05-01

    This study investigates the relationship between concentrations of on- and off-premises alcohol outlets and rates of child abuse and neglect. Additionally, the study seeks to locate protective features of a neighborhood's built environment by investigating the potentially moderating role that access to substance abuse treatment and prevention services plays in the relationship between alcohol outlet density and child maltreatment. Using a cross-sectional design, this ecological study utilized data from 163 census tracts in Bergen County, New Jersey, on reports of child abuse and neglect, alcohol outlets, substance abuse treatment and prevention facilities, and the United States Census to investigate the linkages between socioeconomic structure, alcohol availability, and access to substance abuse service facilities on rates of child abuse and neglect. Findings indicate areas with a greater concentration of on-premises alcohol outlets (i.e., bars) had higher rates of child neglect, and those with easier access to substance abuse services had lower rates of neglect, controlling for neighborhood demographic and socioeconomic structure. Additionally, the relationship between on-premises alcohol outlet density and rates of child neglect was moderated by the presence of substance abuse service facilities. A greater concentration of off-premises outlets (i.e., liquor stores) was associated with lower rates of physical abuse. Findings suggest that the built environment and socioeconomic structure of neighborhoods have important consequences for child well-being. The implications for future research on the structural features of neighborhoods that are associated with child well-being are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Effect of particle size distribution on sintering of tungsten

    International Nuclear Information System (INIS)

    Patterson, B.R.; Griffin, J.A.

    1984-01-01

    To date, very little is known about the effect of the nature of the particle size distribution on sintering. It is reasonable that there should be an effect of size distribution, and theory and prior experimental work examining the effects of variations in bimodal and continuous distributions have shown marked effects on sintering. Most importantly, even with constant mean particle size, variations in distribution width, or standard deviation, have been shown to produce marked variations in microstructure and sintering rate. In the latter work, in which spherical copper powders were blended to produce lognormal distributions of constant geometric mean particle size by weight frequency, blends with larger values of geometric standard deviation, 1nσ, sintered more rapidly. The goals of the present study were to examine in more detail the effects of variations in the width of lognormal particle size distributions of tungsten powder and determine the effects of 1nσ on the microstructural evolution during sintering

  10. Family size and effective population size in a hatchery stock of coho salmon (Oncorhynchus kisutch)

    Science.gov (United States)

    Simon, R.C.; McIntyre, J.D.; Hemmingsen, A.R.

    1986-01-01

    Means and variances of family size measured in five year-classes of wire-tagged coho salmon (Oncorhynchus kisutch) were linearly related. Population effective size was calculated by using estimated means and variances of family size in a 25-yr data set. Although numbers of age 3 adults returning to the hatchery appeared to be large enough to avoid inbreeding problems (the 25-yr mean exceeded 4500), the numbers actually contributing to the hatchery production may be too low. Several strategies are proposed to correct the problem perceived. Argument is given to support the contention that the problem of effective size is fairly general and is not confined to the present study population.

  11. Contextual Effects of Neighborhoods and Schools on Adolescent and Young Adult Marijuana Use in the United States

    Directory of Open Access Journals (Sweden)

    Carly E Milliren

    2017-06-01

    Full Text Available Little is known about the unique contribution of schools vs neighborhoods in driving adolescent marijuana use. This study examined the relative contribution of each setting and the influence of school and neighborhood socioeconomic status on use. We performed a series of cross-classified multilevel logistic models predicting past 30-day adolescent (N = 18 329 and young adult (N = 13 908 marijuana use using data from Add Health. Marijuana use differed by age, sex, race/ethnicity, and public assistance in adjusted models. Variance parameters indicated a high degree of clustering by school (σ 2  = 0.30 and less pronounced clustering by neighborhood (σ 2  = 0.06 in adolescence when accounting for both levels simultaneously in a cross-classified multilevel model. Clustering by school persisted into young adulthood (σ 2  = 0.08. Parental receipt of public assistance increased the likelihood of use during adolescence (odds ratio = 1.39; 95% confidence interval: 1.19-1.59, and higher parental education was associated with increased likelihood of use in young adulthood. These findings indicate that both contexts may be promising locations for intervention.

  12. Size effects in nanoindentation: an experimental and analytical study

    NARCIS (Netherlands)

    Voyiadjis, G.Z.; Peters, Rick

    2009-01-01

    This work addresses the size effect encountered in nanoindentation experiments. It is generally referred to as the indentation size effect (ISE). Classical descriptions of the ISE show a decrease in hardness for increasing indentation depth. Recently new experiments have shown that after the initial

  13. Do Effect-Size Measures Measure up?: A Brief Assessment

    Science.gov (United States)

    Onwuegbuzie, Anthony J.; Levin, Joel R.; Leech, Nancy L.

    2003-01-01

    Because of criticisms leveled at statistical hypothesis testing, some researchers have argued that measures of effect size should replace the significance-testing practice. We contend that although effect-size measures have logical appeal, they are also associated with a number of limitations that may result in problematic interpretations of them…

  14. Perceived School and Neighborhood Safety, Neighborhood Violence and Academic Achievement in Urban School Children

    Science.gov (United States)

    AJ, Milam; CDM, Furr-Holden; PJ, Leaf

    2010-01-01

    Community and school violence continue to be a major public health problem, especially among urban children and adolescents. Little research has focused on the effect of school safety and neighborhood violence on academic performance. This study examines the effect of the school and neighborhood climate on academic achievement among a population of 3rd-5th grade students in an urban public school system. Community and school safety were assessed using the School Climate Survey, an annual city-wide assessment of student’s perception of school and community safety. Community violence was measured using the Neighborhood Inventory for Environmental Typology, an objective observational assessment of neighborhood characteristics. Academic achievement was measured using the Maryland State Assessment (MSA), a standardized exam given to all Maryland 3rd-8th graders. School Climate Data and MSA data were aggregated by school and grade. Objective assessments of neighborhood environment and students’ self-reported school and neighborhood safety were both strongly associated with academic performance. Increasing neighborhood violence was associated with statistically significant decreases from 4.2%-8.7% in math and reading achievement; increasing perceived safety was associated with significant increases in achievement from 16%-22%. These preliminary findings highlight the adverse impact of perceived safety and community violence exposure on primary school children’s academic performance. PMID:21197388

  15. Reconsidering the Neighborhood Effect

    DEFF Research Database (Denmark)

    Bisgaard, Martin; Dinesen, Peter Thisted; Sønderskov, Kim Mannemar

    2016-01-01

    The state of the national economy often directs voting. But how do citizens form perceptions of a complex and abstract macroeconomy? This study examines whether exposure to unemployment in citizens’ immediate residential surroundings shapes their perceptions of the national economy. Using novel d...

  16. Cultural mechanisms and the persistence of neighborhood violence.

    Science.gov (United States)

    Kirk, David S; Papachristos, Andrew V

    2011-01-01

    Sociologists have given considerable attention to identifying the neighborhood-level social-interactional mechanisms that influence outcomes such as crime, educational attainment, and health. Yet, cultural mechanisms are often overlooked in quantitative studies of neighborhood effects. This paper adds a cultural dimension to neighborhood effects research by exploring the consequences of legal cynicism. Legal cynicism refers to a cultural frame in which people perceive the law as illegitimate, unresponsive, and ill equipped to ensure public safety. The authors find that legal cynicism explains why homicide persisted in certain Chicago neighborhoods during the 1990s despite declines in poverty and declines in violence city-wide.

  17. Hall measurements and grain-size effects in polycrystalline silicon

    International Nuclear Information System (INIS)

    Ghosh, A.K.; Rose, A.; Maruska, H.P.; Eustace, D.J.; Feng, T.

    1980-01-01

    The effects of grain size on Hall measurements in polycrystalline silicon are analyzed and interpreted, with some modifications, using the model proposed by Bube. This modified model predicts that the measured effective Hall voltage is composed of components originating from the bulk and space-charge regions. For materials with large grain sizes, the carrier concentration is independent of the intergrain boundary barrier, whereas the mobility is dependent on it. However, for small grains, both the carrier density and mobility depend on the barrier. These predictions are consistent with experimental results of mm-size Wacker and μm-size neutron-transmutation-doped polycrystalline silicon

  18. The Effect of Light Rail Transit on Physical Activity: Design and Methods of the Travel-Related Activity in Neighborhoods Study.

    Science.gov (United States)

    Durand, Casey P; Oluyomi, Abiodun O; Gabriel, Kelley Pettee; Salvo, Deborah; Sener, Ipek N; Hoelscher, Deanna M; Knell, Gregory; Tang, Xiaohui; Porter, Anna K; Robertson, Michael C; Kohl, Harold W

    2016-01-01

    Use of mass transit has been proposed as a way to incorporate regular physical activity into daily life because transit use typically requires additional travel to access and depart the stop or station. If this additional travel is active, a small but potentially important amount of physical activity can be achieved daily. Although prior research has shown that transit use is associated with physical activity, important questions remain unanswered. Utilizing a major expansion of the Houston, TX, USA light-rail system as a natural experiment, the Houston Travel-Related Activity in Neighborhoods (TRAIN) Study was developed to address these unanswered questions. The purpose of the TRAIN Study is to determine if the development of light-rail lines in Houston, TX, USA will prospectively affect both transit use and physical activity over 4 years. We also aim to understand how contextual effects (i.e., moderators or interaction effects), such as the neighborhood built environment and socioeconomic factors, affect the primary relations under study. The TRAIN Study is a longitudinal cohort design, in which participants are recruited at baseline from a 3-mile buffer around each of the three new lines and measured annually four times. Recruitment is accomplished via telephone contact, ads in newspapers and advertising circulars, and targeted community outreach. Data are collected via mail and include questionnaire-assessed factors, such as perceived neighborhood characteristics, attitudes about transportation, demographics, and reported physical activity; a travel diary; and accelerometry. Additionally, field-based neighborhood audits are conducted to capture micro-scale environmental features. To assess macro-scale environmental characteristics, we utilize GIS mapping and spatial analyses. Statistical analyses will be conducted using latent growth curve modeling and discrete choice models, with a focus on identifying moderating factors (i.e., statistical interaction

  19. Neighborhood Disorder and Children’s Antisocial Behavior: The Protective Effect of Family Support Among Mexican American and African American Families

    Science.gov (United States)

    Conger, Rand D.; Conger, Katherine J.; Martin, Monica J.; Brody, Gene; Simons, Ronald; Cutrona, Carolyn

    2012-01-01

    Using data from a sample of 673 Mexican Origin families, the current investigation examined the degree to which family supportiveness acted as a protective buffer between neighborhood disorder and antisocial behavior during late childhood (i.e. intent to use controlled substances, externalizing, and association with deviant peers). Children’s perceptions of neighborhood disorder fully mediated associations between census and observer measures of neighborhood disorder and their antisocial behavior. Family support buffered children from the higher rates of antisocial behavior generally associated with living in disorderly neighborhoods. An additional goal of the current study was to replicate these findings in a second sample of 897 African American families, and that replication was successful. These findings suggest that family support may play a protective role for children living in dangerous or disadvantaged neighborhoods. They also suggest that neighborhood interventions should consider several points of entry including structural changes, resident perceptions of their neighborhood and family support. PMID:22089092

  20. Increasing overweight and obesity erodes engagement in one's neighborhood by women, but not men.

    Science.gov (United States)

    Schuster, Roseanne C; Han, Seung Yong; Brewis, Alexandra A; Wutich, Amber

    2018-06-01

    Obesity is socially stigmatized in the U.S., especially for women. Significant research has focused on the role that the social and built environments of neighborhoods play in shaping obesity. However, the role of obesity in shaping neighborhood social structure has been largely overlooked. We test the hypothesis that large body size inhibits an individual's engagement in his or her neighborhood. Our study objectives are to assess if (1) body size (body mass index) interacts with gender to predict engagement in one's neighborhood (neighborhood engagement) and (2) if bonding social capital interacts with gender to predict neighborhood engagement independent of body size. We used data collected from the cross-sectional 2011 Phoenix Area Social Survey (PASS), which systematically sampled residents across four neighborhood types (core urban, urban fringe, suburban, retirement) across the Phoenix Metopolitian Area. Survey data was analyzed using logistic regression for 804 participants, including 35% for whom missing data was computed using multiple imputation. We found that as body size increases, women-but not men-have reduced engagement in their neighborhood, independent of bonding social capital and other key covariates (objective 1). We did not observe the interaction between gender and bonding social capital associated with neighborhood engagement (objective 2). Prior scholarship suggests obesity clusters in neighborhoods due to processes of social, economic, and environmental disadvantage. This finding suggests bi-directionality: obesity could, in turn, undermine neighborhood engagement through the mechanism of weight stigma and discrimination.

  1. A Longitudinal Analysis of the Influence of the Neighborhood Environment on Recreational Walking within the Neighborhood: Results from RESIDE

    OpenAIRE

    Christian, Hayley; Knuiman, Matthew; Divitini, Mark; Foster, Sarah; Hooper, Paula; Boruff, Bryan; Bull, Fiona; Giles-Corti, Billie

    2017-01-01

    Background: There is limited longitudinal evidence confirming the role of neighborhood environment attributes in encouraging people to walk more or if active people simply choose to live in activity-friendly neighborhoods. Natural experiments of policy changes to create more walkable communities provide stronger evidence for a causal effect of neighborhood environments on residents’ walking. Objectives: We aimed to investigate longitudinal associations between objective and perceived neighbor...

  2. Promoting physical activity in a low-income neighborhood of the Paris suburb of Saint-Denis: effects of a community-based intervention to increase physical activity

    Directory of Open Access Journals (Sweden)

    Camille Buscail

    2016-07-01

    Full Text Available Abstract Background Physical activity (PA is a key factor for facing the increasing prevalence of obesity and overweight, and should be part of every public health programs. In this context, a community-based public health program promoting PA was developed in a low-income neighborhood of the city of Saint-Denis (France. Methods This work aimed at assessing the effectiveness of a 2-year PA promotion program. A quasi-experimental study was carried out using a pre/post design, with an assessment before (2013 and after (2015 the program. The interviewees were selected using a stratified random cluster sampling. The primary outcome was the proportion of participants practicing sufficient PA (WHO guidelines, and was measured using the RPAQ questionnaire. External interventions (on both neighborhood environment and inhabitants were listed. Results We collected 199 questionnaires at baseline and 217 in 2015. There was a majority of women in both samples: 64.3 % in 2013 and 58.2 % in 2015. The average age of participants was 38.1 years (+/−1.1 and 40.6 (+/−1.1 respectively. The proportion of people practicing sufficient PA was modified from 48.1 % in 2013 to 63.5 % in 2015 (p = 0.001. This was mainly driven by women whose level of PA, increased from 40.3 % to 60.3 % (p = 0.002, reaching the average national French estimation of PA level among adults (63.5 %. Conclusions This work showed a significant increase of the proportion of people practicing PA in a disadvantaged neighborhood where a community-based program promoting PA was developed. Simultaneous external interventions contributed to the results, showing the necessity of synergic interventions to reach efficiency.

  3. Electrokinetic Flow in Microchannels with Finite Reservoir Size Effects

    International Nuclear Information System (INIS)

    Yan, D; Yang, C; Nguyen, N-T; Huang, X

    2006-01-01

    In electrokinetically-driven microfluidic applications, reservoirs are indispensable and have finite sizes. During operation processes, as the liquid level difference in reservoirs keeps changing as time elapses, the flow characteristics in a microchannel exhibit a combination of the electroosmotic flow and the time-dependent induced backpressure-driven flow. In this work, an assessment of the finite reservoir size effect on electroosmotic flows is presented theoretically and experimentally. A model is developed to describe the timedependent electrokinetic flow with finite reservoir size effects. The theoretical analysis shows that under certain conditions the finite reservoir size effect is significant. The important parameters that describe the effect of finite reservoir size on the flow characteristics are discussed. A new concept denoted as 'effective pumping period' is introduced to characterize the reservoir size effect. The proposed model clearly identifies the mechanisms of the finitereservoir size effects and is further confirmed by using micro-PIV technique. The results of this study can be used for facilitating the design of microfluidic devices

  4. "When you got nothing to do, you do somebody": A community's perceptions of neighborhood effects on adolescent sexual behaviors.

    Science.gov (United States)

    Akers, Aletha Y; Muhammad, Melvin R; Corbie-Smith, Giselle

    2011-01-01

    This study explores community members' perspectives regarding the relationship between neighborhood characteristics and adolescent sexual behaviors in two rural, African American communities. The data were collected as part of a community needs assessment to inform the development of HIV prevention interventions in two contiguous counties in northeastern North Carolina, USA. We conducted eleven focus groups with three population groups: adolescents and young adults aged 16-24 (N = 38), adults over age 25 (N = 42), and formerly incarcerated individuals (N = 13). All focus groups were audio-recorded, transcribed and analyzed using a grounded theory approach to content analysis and a constant comparison method. Six major themes emerged from the discussions linking neighborhood context and adolescents sexual behavior: the overwhelming absence of recreational options for community members; lack of diverse leisure-time activities for adolescents; lack of recreational options for adolescents who are dating; adolescent access to inappropriate leisure time activities that promote multiple risk behaviors; limited safe environments for socializing; and cost-barriers to recreational activities for adolescents. In addition, lack of adequate parental supervision of adolescents' time alone and with friends of the opposite sex, as well as ineffective community monitoring of adolescent social activities, were thought to create situations that promoted sexual and other risk behaviors. These findings allowed us to develop a conceptual model linking neighborhood structural and social organization factors to adolescent sexual behaviors and provided insights for developing interventions tailored to address local socioeconomic realities. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. EFFECTS OF ULTRASOUND ON THE MORPHOLOGY, PARTICLE SIZE, CRYSTALLINITY, AND CRYSTALLITE SIZE OF CELLULOSE

    Directory of Open Access Journals (Sweden)

    SUMARI SUMARI

    2014-05-01

    Full Text Available The aim of this study is to optimize ultrasound treatment to produce fragment of cellulose that is low in particles size, crystallite size, and crystallinity. Slurry of 1 % (w/v the cellulose was sonicated at different time periods and temperatures. An ultrasonic reactor was operated at 300 Watts and 28 kHz to cut down the polymer into smaller particles. We proved that ultrasound damages and fragments the cellulose particles into shorter fibers. The fiber lengths were reduced from in the range of 80-120 µm to 30-50 µm due to an hour ultrasonication and became 20-30 µm after 5 hours. It was also found some signs of erosion on the surface and stringy. The acoustic cavitation also generated a decrease in particle size, crystallinity, and crystallite size of the cellulose along with increasing sonication time but it did not change d-spacing. However, the highest reduction of particle size, crystallite size, and crystallinity of the cellulose occurred within the first hour of ultrasonication, after which the efficiency was decreased. The particle diameter, crystallite size, and crystallinity were decreased from 19.88 µm to 15.96 µm, 5.81 Å to 2.98 Å, and 77.7% to 73.9% respectively due to an hour ultrasound treatment at 40 °C. The treatment that was conducted at 40 °C or 60 °C did not give a different effect significantly. Cellulose with a smaller particle and crystallite size as well as a more amorphous shape is preferred for further study.

  6. Size effects in the mechanical behavior of cellular materials

    NARCIS (Netherlands)

    Tekoglu, C; Onck, PR

    Effective mechanical properties of cellular materials depend strongly on the specimen size to the cell size ratio. Experimental studies performed on aluminium foams show that under uniaxial compression, the stiffness of these materials falls below the corresponding bulk value, when the ratio of the

  7. Effects of sample size on the second magnetization peak in ...

    Indian Academy of Sciences (India)

    8+ crystals are observed at low temperatures, above the temperature where the SMP totally disappears. In particular, the onset of the SMP shifts to lower fields as the sample size decreases - a result that could be interpreted as a size effect in ...

  8. Effects of Neighborhood Walkability on Physical Activity and Sedentary Behavior Long-Term Post-Bariatric Surgery.

    Science.gov (United States)

    Reid, Ryan E R; Carver, Tamara E; Reid, Tyler G R; Picard-Turcot, Marie-Aude; Andersen, Kathleen M; Christou, Nicolas V; Andersen, Ross E

    2017-06-01

    ᅟ: Chronic inactivity and weight regain are serious health concerns following bariatric surgery. Neighborhood walkability is associated with higher physical activity and lower obesity rates in normal weight populations. Explore the influence of neighborhood walkability on physical activity and sedentarism among long-term post-bariatric surgery patients. Fifty-eight adults aged 50.5 ± 9.1 years, with a BMI of 34.6 ± 9.7 kg/m 2 having undergone surgery 9.8 ± 3.15 years earlier participated in this study. Participants were asked to wear an ActivPAL™ tri-axial accelerometer attached to their mid-thigh for 7-consecutive days, 24 hours/day. The sample was separated into those that live in Car-Dependent (n = 23), Somewhat Walkable (n = 14), Very Walkable (n = 16), and Walker's Paradise (n = 5) neighborhoods as defined using Walk Score®. ANCOVA was performed comparing Walk Score® categories on steps and sedentary time controlling for age and sex. Neighborhood walkability did not influence either daily steps (F (3, 54) = 0.921, p = 0.437) or sedentary time (F (3, 54) = 0.465, p = 0.708), Car-Dependent (6359 ± 2712 steps, 9.54 ± 2.46 hrs), Somewhat Walkable (6563 ± 2989 steps, 9.07 ± 2.70 hrs), Very Walkable (5261 ± 2255 steps, 9.97 ± 2.06 hrs), and Walker's Paradise (6901 ± 1877 steps, 10.14 ± 0.815 hrs). Walkability does not appear to affect sedentary time or physical activity long-term post-surgery. As the built-environment does not seem to influence activity, sedentarism, or obesity as it does with a normal weight population, work needs to be done to tailor physical activity programming after bariatric surgery.

  9. The effects of meal size, body size and temperature on gastric evacuation in pikeperch

    DEFF Research Database (Denmark)

    Koed, Anders

    2001-01-01

    Prey size had no effect on the gastric evacuation rate of pikeperch Stizostedion lucioperca. The gastric evacuation was adequately described applying an exponent of 0.5 in the power model. Applying length instead of weight of pikeperch in the gastric evacuation model resulted in a change of estim...

  10. Neighborhoods, US, 2017, Zillow, SEGS

    Data.gov (United States)

    U.S. Environmental Protection Agency — This web service depicts nearly 17,000 neighborhood boundaries in over 650 U.S. cities. Zillow created the neighborhood boundaries and is sharing them with the...

  11. NeighborHood

    OpenAIRE

    Corominola Ocaña, Víctor

    2015-01-01

    NeighborHood és una aplicació basada en el núvol, adaptable a qualsevol dispositiu (mòbil, tablet, desktop). L'objectiu d'aquesta aplicació és poder permetre als usuaris introduir a les persones del seu entorn més immediat i que aquestes persones siguin visibles per a la resta d'usuaris. NeighborHood es una aplicación basada en la nube, adaptable a cualquier dispositivo (móvil, tablet, desktop). El objetivo de esta aplicación es poder permitir a los usuarios introducir a las personas de su...

  12. Effects of anion size and concentration on electrolyte invasion into molecular-sized nanopores

    International Nuclear Information System (INIS)

    Liu Ling; Chen Xi; Kim, Taewan; Han Aijie; Qiao Yu

    2010-01-01

    When an electrolyte solution is pressurized into a molecular-sized nanopore, oppositely charged ions are strongly inclined to aggregate, which effectively reduces the ion solubility to zero. Inside the restrictive confinement, a unique quasi-periodic structure is formed where the paired ion couples are periodically separated by a number of water molecules. As the anion size or ion concentration varies, the geometrical characteristics of the confined ion structure would change considerably, leading to a significant variation in the transport pressure. Both experimental and simulation results indicate that, contradictory to the prediction of conventional theory, infiltration pressure decreases as the anions become larger.

  13. Neighborhood educational disparities in active commuting among women: the effect of distance between the place of residence and the place of work/study (an ACTI-Cités study).

    Science.gov (United States)

    Perchoux, Camille; Nazare, Julie-Anne; Benmarhnia, Tarik; Salze, Paul; Feuillet, Thierry; Hercberg, Serge; Hess, Franck; Menai, Mehdi; Weber, Christiane; Charreire, Hélène; Enaux, Christophe; Oppert, Jean-Michel; Simon, Chantal

    2017-06-12

    Active transportation has been associated with favorable health outcomes. Previous research highlighted the influence of neighborhood educational level on active transportation. However, little is known regarding the effect of commuting distance on social disparities in active commuting. In this regard, women have been poorly studied. The objective of this paper was to evaluate the relationship between neighborhood educational level and active commuting, and to assess whether the commuting distance modifies this relationship in adult women. This cross-sectional study is based on a subsample of women from the Nutrinet-Santé web-cohort (N = 1169). Binomial, log-binomial and negative binomial regressions were used to assess the associations between neighborhood education level and (i) the likelihood of reporting any active commuting time, and (ii) the share of commuting time made by active transportation modes. Potential effect measure modification of distance to work on the previous associations was assessed both on the additive and the multiplicative scales. Neighborhood education level was positively associated with the probability of reporting any active commuting time (relative risk = 1.774; p education was greater at long distances to work for both outcomes. Our results suggest that neighborhood educational disparities in active commuting tend to increase with commuting distance among women. Further research is needed to provide geographically driven guidance for health promotion intervention aiming at reducing disparities in active transportation among socioeconomic groups.

  14. EFFECT OF FARM SIZE AND FREQUENCY OF CUTTING ON ...

    African Journals Online (AJOL)

    EFFECT OF FARM SIZE AND FREQUENCY OF CUTTING ON OUTPUT OF ... the use of Ordinary Least Square (OLS) estimation technique was used in analyzing ... frequency of cutting that would produce maximum output of the vegetable as ...

  15. Size effect in tension perpendicular to the grain

    DEFF Research Database (Denmark)

    Pedersen, Martin Bo Uhre; Clorius, Christian Odin; Damkilde, Lars

    1999-01-01

    The strength in tension perpendicular to the grain is known to decrease with an increase in the stressed volume. Usually this size effect is explained on a stochastic basis, that is an explanation relying on an increased probability of encountering a strength reducing flaw when the volume...... of the material under stress is increased. This paper presents a small experimental investigation on specimens with well defined structural orientation of the material. The experiments exhibit a larger size effect than expected and furthermore the data and the nature of the failures encountered suggest...... that the size effect can be explained on a deterministic basis. Arguments for such a simple deterministic explanation of size effect is found in finite element modelling using the orthotropic stiffness characteristics in the transverse plane of wood....

  16. Distinguishing crystallite size effects from those of structural disorder ...

    Indian Academy of Sciences (India)

    Administrator

    Both crystallite size effects and structural disorder contribute to the broadening of lines in .... ple contributions to the peak profiles. ... the fit is then corrected by accounting for sample ... Authors thank the Department of Science and Tech-.

  17. Effects of being uninsured or underinsured and living in extremely poor neighborhoods on colon cancer care and survival in California: historical cohort analysis, 1996—2011

    Directory of Open Access Journals (Sweden)

    Gorey Kevin M

    2012-10-01

    Full Text Available Abstract Background We examined the mediating effects of health insurance on poverty-colon cancer care and survival relationships and the moderating effects of poverty on health insurance-colon cancer care and survival relationships among women and men in California. Methods We analyzed registry data for 3,291 women and 3,009 men diagnosed with colon cancer between 1996 and 2000 and followed until 2011 on lymph node investigation, stage at diagnosis, surgery, chemotherapy, wait times and survival. We obtained socioeconomic data for individual residences from the 2000 census to categorize the following neighborhoods: high poverty (30% or more poor, middle poverty (5-29% poor and low poverty (less than 5% poor. Primary health insurers were Medicaid, Medicare, private or none. Results Evidence of mediation was observed for women, but not for men. For women, the apparent effect of poverty disappeared in the presence of payer, and the effects of all forms of health insurance seemed strengthened. All were advantaged on 6-year survival compared to the uninsured: Medicaid (RR = 1.83, Medicare (RR = 1.92 and private (RR = 1.83. Evidence of moderation was also only observed for women. The effects of all forms of health insurance were stronger for women in low poverty neighborhoods: Medicaid (RR = 2.90, Medicare (RR = 2.91 and private (RR = 2.60. For men, only main effects of poverty and payers were observed, the advantaging effect of private insurance being largest. Across colon cancer care processes, Medicare seemed most instrumental for women, private payers for men. Conclusions Health insurance substantially mediates the quality of colon cancer care and poverty seems to make the effects of being uninsured or underinsured even worse, especially among women in the United States. These findings are consistent with the theory that more facilitative social and economic capital is available in more affluent neighborhoods, where women

  18. Community, Democracy, and Neighborhood News.

    Science.gov (United States)

    Hindman, Elizabeth Blanks

    1998-01-01

    Contributes to scholarship on democracy, community, and journalism by examining the interplay between communication, democracy, and community at an inner-city neighborhood newspaper. Concludes that, through its focus on neighborhood culture, acknowledgment of conflict, and attempts to provide a forum for the neighborhood's self-definition, the…

  19. Finite size effects in the intermittency analysis of the fragment-size correlations

    International Nuclear Information System (INIS)

    Bozek, P.; Ploszajczak, M.; Tucholski, A.

    1991-01-01

    An influence of the finite size effect on the fragment-size correlations in the nuclear multifragmentation is studied using the method of scaled factorial moments for a 1 - dim percolation model and for a statistical model of the fragmentation process, which for a certain value of a tuning parameter yields the power-law behaviour of the fragment-size distribution. It is shown that the statistical models of this type contain only repulsive correlations due to the conservation laws. The comparison of the results with those obtained in the non-critical 1 - dim percolation and in the 3 - dim percolation at around the critical point is presented. Correlations in the 1 - dim percolation model are analysed analytically and the mechanism of the attractive correlations in 1 - dim and 3 - dim is identified. (author) 30 refs., 7 figs

  20. Economic Effects of Increased Control Zone Sizes in Conflict Resolution

    Science.gov (United States)

    Datta, Koushik

    1998-01-01

    A methodology for estimating the economic effects of different control zone sizes used in conflict resolutions between aircraft is presented in this paper. The methodology is based on estimating the difference in flight times of aircraft with and without the control zone, and converting the difference into a direct operating cost. Using this methodology the effects of increased lateral and vertical control zone sizes are evaluated.

  1. Temperament as a moderator of the relation between neighborhood and children's adjustment☆

    OpenAIRE

    Bush, Nicole R.; Lengua, Liliana J.; Colder, Craig R.

    2010-01-01

    Although proposed by bioecological models, there has been minimal empirical examination of whether children's individual differences moderate neighborhood effects on development. We used an urban community sample (8–12 years, N = 316) to examine interactions among neighborhood characteristics (problems and social organization) and children's temperament (fear, irritability and impulsivity) in predicting psychosocial adjustment. The main effects of neighborhood and temperament on outcomes were...

  2. A Neighborhood Story

    Science.gov (United States)

    Gerrish, Michael

    2009-01-01

    Blue collar doesn't have to mean drab and dull. At least, not to Troy, New York, historian Mike Esposito, who is a member of a neighborhood revitalization movement seeking to celebrate the people and events that brought diversity, prosperity, and vitality to this upstate New York community more than 100 years ago. Esposito and others invited…

  3. Reacting to Neighborhood Cues?

    DEFF Research Database (Denmark)

    Danckert, Bolette; Dinesen, Peter Thisted; Sønderskov, Kim Mannemar

    2017-01-01

    is founded on politically sophisticated individuals having a greater comprehension of news and other mass-mediated sources, which makes them less likely to rely on neighborhood cues as sources of information relevant for political attitudes. Based on a unique panel data set with fine-grained information...

  4. Effect of particle size on the glass transition.

    Science.gov (United States)

    Larsen, Ryan J; Zukoski, Charles F

    2011-05-01

    The glass transition temperature of a broad class of molecules is shown to depend on molecular size. This dependency results from the size dependence of the pair potential. A generalized equation of state is used to estimate how the volume fraction at the glass transition depends on the size of the molecule, for rigid molecule glass-formers. The model shows that at a given pressure and temperature there is a size-induced glass transition: For molecules larger than a critical size, the volume fraction required to support the effective pressure due to particle attractions is above that which characterizes the glassy state. This observation establishes the boundary between nanoparticles, which exist in liquid form only as dispersions in low molecular weight solvents and large molecules which form liquids that have viscosities below those characterized by the glassy state.

  5. Interviewer Effects on a Network-Size Filter Question

    Directory of Open Access Journals (Sweden)

    Josten Michael

    2016-06-01

    Full Text Available There is evidence that survey interviewers may be tempted to manipulate answers to filter questions in a way that minimizes the number of follow-up questions. This becomes relevant when ego-centered network data are collected. The reported network size has a huge impact on interview duration if multiple questions on each alter are triggered. We analyze interviewer effects on a network-size question in the mixed-mode survey “Panel Study ‘Labour Market and Social Security’” (PASS, where interviewers could skip up to 15 follow-up questions by generating small networks. Applying multilevel models, we find almost no interviewer effects in CATI mode, where interviewers are paid by the hour and frequently supervised. In CAPI, however, where interviewers are paid by case and no close supervision is possible, we find strong interviewer effects on network size. As the area-specific network size is known from telephone mode, where allocation to interviewers is random, interviewer and area effects can be separated. Furthermore, a difference-in-difference analysis reveals the negative effect of introducing the follow-up questions in Wave 3 on CAPI network size. Attempting to explain interviewer effects we neither find significant main effects of experience within a wave, nor significantly different slopes between interviewers.

  6. Working with neighborhood organizations to promote wildfire preparedness

    Science.gov (United States)

    Holly Johnson Shiralipour; Martha C. Monroe; Michelle Payton

    2006-01-01

    Several government agencies and other natural resource managers have instituted outreach programs to promote wildfire preparedness in wildland-urban interface (WUI) neighborhoods that complement community-wide efforts. To help these programs become more effective, research was undertaken to gain a better understanding of the role that neighbors and neighborhood...

  7. Contemporary Neighborhood Theories: Integration versus Romance and Reaction.

    Science.gov (United States)

    Stever, James A.

    1978-01-01

    This paper discusses the integrative, romantic, and reactive theories of neighborhood government within the context of the urban reform movement and argues that the integrative theory is the one best suited for an effective political relationship between the neighborhood and the greater metropolis. (EB)

  8. Counseling in the Gentrified Neighborhood: What School Counselors Should Know

    Science.gov (United States)

    Bell, Lauren E.; Van Velsor, Patricia

    2018-01-01

    Gentrification occurs when the prevailing demographic and economic environment of an urban neighborhood changes in ways related to social class and physical renewal. Gentrification effects are both positive and negative; however, low-income residents may be disproportionately negatively affected. As neighborhoods transform, schools also change.…

  9. Cognitive Aspects of Regularity Exhibit When Neighborhood Disappears

    Science.gov (United States)

    Chen, Sau-Chin; Hu, Jon-Fan

    2015-01-01

    Although regularity refers to the compatibility between pronunciation of character and sound of phonetic component, it has been suggested as being part of consistency, which is defined by neighborhood characteristics. Two experiments demonstrate how regularity effect is amplified or reduced by neighborhood characteristics and reveals the…

  10. Atomistic calculation of size effects on elastic coefficients in nanometre-sized tungsten layers and wires

    International Nuclear Information System (INIS)

    Villain, P.; Beauchamp, P.; Badawi, K.F.; Goudeau, P.; Renault, P.-O.

    2004-01-01

    Equilibrium state and elastic coefficients of nanometre-sized single crystal tungsten layers and wires are investigated by atomistic simulations. The variations of the equilibrium distances as a function of the layer thickness or wire cross-section are mainly due to elastic effects of surface tension forces. A strong decrease of the Young's modulus is observed when the transverse dimensions are reduced below 2-3 nm

  11. Long-Term Effects of School Size on Students' Outcomes

    DEFF Research Database (Denmark)

    Humlum, Maria Knoth; Smith, Nina

    We estimate the effect of school size on students' long-term outcomes such as high school completion, being out of the labor market, and earnings at the age of 30. We use rich register data on the entire population of Danish children attending grade 9 in the period 1986-2004. This allows us...... school size and alternative measures of long-term success in the educational system and the labor market. The positive impact of school size seems mainly to be driven by boys, students from families with a low educational level and students attending schools in urban areas....

  12. Impact of neighborhood separation on the spatial reciprocity in the prisoner’s dilemma game

    International Nuclear Information System (INIS)

    Xia, Chengyi; Miao, Qin; Zhang, Juanjuan

    2013-01-01

    Highlights: • We present a novel game model in which interaction and learning neighborhood is not identical. • The separation between interaction and learning neighborhood can largely influence the cooperative behaviors. • Monte Carlo simulations are utilized to verify the evolution of cooperation. • When IN is fixed to be 4, medium-sized LN = 8 is the optimal size to promote the cooperation. • When LN is fixed to be 4, the cooperation can also be highly enhanced when IN > 4. -- Abstract: The evolutionary game theory is a very powerful tool to understand the collective cooperation behavior in many real-world systems. In the spatial game model, the payoff is often first obtained within a specific neighborhood (i.e., interaction neighborhood) and then the focal player imitates or learns the behavior of a randomly selected one inside another neighborhood which is named after the learning neighborhood. However, most studies often assume that the interaction neighborhood is identical with the learning neighborhood. Beyond this assumption, we present a spatial prisoner’s dilemma game model to discuss the impact of separation between interaction neighborhood and learning neighborhood on the cooperative behaviors among players on the square lattice. Extensive numerical simulations demonstrate that separating the interaction neighborhood from the learning neighborhood can dramatically affect the density of cooperators (ρ C ) in the population at the stationary state. In particular, compared to the standard case, we find that the medium-sized learning (interaction) neighborhood allows the cooperators to thrive and substantially favors the evolution of cooperation and ρ C can be greatly elevated when the interaction (learning) neighborhood is fixed, that is, too little or much information is not beneficial for players to make the contributions for the collective cooperation. Current results are conducive to further analyzing and understanding the emergence of

  13. Combined effect of individual and neighborhood socioeconomic status on mortality in patients with newly diagnosed dyslipidemia: A nationwide Korean cohort study from 2002 to 2013.

    Science.gov (United States)

    Shin, J; Cho, K H; Choi, Y; Lee, S G; Park, E-C; Jang, S-I

    2016-03-01

    The study aims to determine whether dyslipidemia patients living in less affluent neighborhood are at a higher risk of mortality compared to those living in more affluent neighborhoods. A population-based cohort study was conducted using a stratified representative sampling from the National Health Insurance claim data from 2002 to 2013. The target subjects comprise patients newly diagnosed with dyslipidemia receiving medication. We performed a survival analysis using the Cox proportional hazard model. Of 11,946 patients with dyslipidemia, 1053 (8.8%) subjects died during the follow-up period. Of the dyslipidemia patients earning a middle-class income, the adjusted HR in less affluent neighborhoods was higher than that in the more affluent neighborhoods compared to the reference category of high individual SES in more affluent neighborhoods (less affluent; hazard ratio (HR) = 1.64, 95% confidence interval (CI): 1.35-1.99 vs. more affluent; HR = 1.48, 95% CI: 1.20-1.81, respectively). We obtained consistent results in patients with lower income, wherein the adjusted HR in less affluent neighborhoods was higher than that in more affluent neighborhoods (less affluent; HR = 1.52, 95% CI: 1.16-1.97 vs. more affluent; HR = 1.41, 95% CI: 1.04-1.92, respectively). Living in a less affluent neighborhood contributes to higher mortality among dyslipidemia patients. The individual- and neighborhood-level variables cumulatively affect individuals such that the most at-risk individuals include those having both individual- and neighborhood-level risk factors. These findings raise important clinical and public health concerns and indicate that neighborhood SES approaches should be essentially considered in health-care policies similar to individual SES. Copyright © 2015 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University

  14. Selection dramatically reduces effective population size in HIV-1 infection

    Directory of Open Access Journals (Sweden)

    Mittler John E

    2008-05-01

    Full Text Available Abstract Background In HIV-1 evolution, a 100–100,000 fold discrepancy between census size and effective population size (Ne has been noted. Although it is well known that selection can reduce Ne, high in vivo mutation and recombination rates complicate attempts to quantify the effects of selection on HIV-1 effective size. Results We use the inbreeding coefficient and the variance in allele frequency at a linked neutral locus to estimate the reduction in Ne due to selection in the presence of mutation and recombination. With biologically realistic mutation rates, the reduction in Ne due to selection is determined by the strength of selection, i.e., the stronger the selection, the greater the reduction. However, the dependence of Ne on selection can break down if recombination rates are very high (e.g., r ≥ 0.1. With biologically likely recombination rates, our model suggests that recurrent selective sweeps similar to those observed in vivo can reduce within-host HIV-1 effective population sizes by a factor of 300 or more. Conclusion Although other factors, such as unequal viral reproduction rates and limited migration between tissue compartments contribute to reductions in Ne, our model suggests that recurrent selection plays a significant role in reducing HIV-1 effective population sizes in vivo.

  15. Effect of small mapping population sizes on reliability of quantitative ...

    African Journals Online (AJOL)

    A limitation of quantitative trait loci (QTL) mapping is that accuracy of determining QTL position and effects are largely determined by population size. Despite the importance of this concept, known as the "Beavis effect there has generally been a lack of understanding by molecular geneticists and breeders. One possible ...

  16. Nanometer size field effect transistors for terahertz detectors

    International Nuclear Information System (INIS)

    Knap, W; Rumyantsev, S; Coquillat, D; Dyakonova, N; Teppe, F; Vitiello, M S; Tredicucci, A; Blin, S; Shur, M; Nagatsuma, T

    2013-01-01

    Nanometer size field effect transistors can operate as efficient resonant or broadband terahertz detectors, mixers, phase shifters and frequency multipliers at frequencies far beyond their fundamental cut-off frequency. This work is an overview of some recent results concerning the application of nanometer scale field effect transistors for the detection of terahertz radiation. (paper)

  17. Does Perceived Neighborhood Walkability and Safety Mediate the Association Between Education and Meeting Physical Activity Guidelines?

    OpenAIRE

    Pratt, Michael; Yin, Shaoman; Soler, Robin; Njai, Rashid; Siegel, Paul Z.; Liao, Youlian

    2015-01-01

    The role of neighborhood walkability and safety in mediating the association between education and physical activity has not been quantified. We used data from the 2010 and 2012 Communities Putting Prevention to Work Behavioral Risk Factor Surveillance System and structural equation modeling to estimate how much of the effect of education level on physical activity was mediated by perceived neighborhood walkability and safety. Neighborhood walkability accounts for 11.3% and neighborhood safet...

  18. Large size self-assembled quantum rings: quantum size effect and modulation on the surface diffusion.

    Science.gov (United States)

    Tong, Cunzhu; Yoon, Soon Fatt; Wang, Lijun

    2012-09-24

    We demonstrate experimentally the submicron size self-assembled (SA) GaAs quantum rings (QRs) by quantum size effect (QSE). An ultrathin In0.1 Ga0.9As layer with different thickness is deposited on the GaAs to modulate the surface nucleus diffusion barrier, and then the SA QRs are grown. It is found that the density of QRs is affected significantly by the thickness of inserted In0.1 Ga0.9As, and the diffusion barrier modulation reflects mainly on the first five monolayer . The physical mechanism behind is discussed. The further analysis shows that about 160 meV decrease in diffusion barrier can be achieved, which allows the SA QRs with density of as low as one QR per 6 μm2. Finally, the QRs with diameters of 438 nm and outer diameters of 736 nm are fabricated using QSE.

  19. Phonotactics, Neighborhood Activation, and Lexical Access for Spoken Words

    Science.gov (United States)

    Vitevitch, Michael S.; Luce, Paul A.; Pisoni, David B.; Auer, Edward T.

    2012-01-01

    Probabilistic phonotactics refers to the relative frequencies of segments and sequences of segments in spoken words. Neighborhood density refers to the number of words that are phonologically similar to a given word. Despite a positive correlation between phonotactic probability and neighborhood density, nonsense words with high probability segments and sequences are responded to more quickly than nonsense words with low probability segments and sequences, whereas real words occurring in dense similarity neighborhoods are responded to more slowly than real words occurring in sparse similarity neighborhoods. This contradiction may be resolved by hypothesizing that effects of probabilistic phonotactics have a sublexical focus and that effects of similarity neighborhood density have a lexical focus. The implications of this hypothesis for models of spoken word recognition are discussed. PMID:10433774

  20. Specific cesium activity in freshwater fish and the size effect

    International Nuclear Information System (INIS)

    Kulikov, A.O.; Ryabov, I.N.; USSR Academy of Sciences, Moscow

    1992-01-01

    The specific Cs-137 activity of muscle tissues of silver carp (Hypophthalmichthys molitrix) from the cooling pond of the Chernobyl nuclear power plant caught in 1987 and 1988 increased almost linearly with fish weight ('size effect') in contrast to liver tissue, whose specific activity remained independent of weight. A kinetic model for uptake and excretion was developed to describe the size effect in muscle tissue by introducing a weight-dependent Cs biological half-time to fish. Similar size effects of specific Cs-137 activity were also found for other species of fish from cooling pond, but were primarily attributed to changes in feeding habits with increasing weight of fish rather than to metabolic changes in feeding habits with both of muscle and liver tissue increased with fish weight for those species in contrast to silver carp. (author). 12 refs.; 12 figs.; 1 tab

  1. The Effect of Social Isolation on Depressive Symptoms Varies by Neighborhood Characteristics: A Study of an Urban Sample of Women with Pre-School Aged Children

    Science.gov (United States)

    Rajaratnam, Julie Knoll; O'Campo, Patricia; Caughy, Margaret O'Brien; Muntaner, Carles

    2008-01-01

    Objectives: To examine how individual characteristics, social isolation, and neighborhood context affect depressive symptoms in a socio-economically diverse population of women with young children. Methods: Interviews were conducted with 261 mothers from 68 neighborhoods in Baltimore between 1998 and 2000. Depressive symptoms were measured using…

  2. Study of Cluster-size Effect on Damage Formation

    International Nuclear Information System (INIS)

    Aoki, Takaaki; Seki, Toshio; Nakai, Atsuko; Matsuo, Jiro; Takaoka, Gikan

    2003-01-01

    Computer simulation and experiments were performed in order to understand the effect of cluster size on damage formation. Results of molecular dynamics simulations of cluster impact on solid targets derived the model function, which explains the relationship among cluster size, incident energy and number of displacements. On the other hand, time of flight mass measurement system was installed a cluster irradiation system, so that cluster ion beam which cluster size distribution is well known can be irradiated on the target. The damage properties under various cluster irradiation conditions were examined using RBS. The results from computer simulations and experiments showed good agreements with each other, which suggests that irradiation damage by cluster ion beam can be controlled by selecting cluster size distribution and incident energy

  3. Walks on SPR neighborhoods.

    Science.gov (United States)

    Caceres, Alan Joseph J; Castillo, Juan; Lee, Jinnie; St John, Katherine

    2013-01-01

    A nearest-neighbor-interchange (NNI)-walk is a sequence of unrooted phylogenetic trees, T1, T2, . . . , T(k) where each consecutive pair of trees differs by a single NNI move. We give tight bounds on the length of the shortest NNI-walks that visit all trees in a subtree-prune-and-regraft (SPR) neighborhood of a given tree. For any unrooted, binary tree, T, on n leaves, the shortest walk takes Θ(n²) additional steps more than the number of trees in the SPR neighborhood. This answers Bryant’s Second Combinatorial Challenge from the Phylogenetics Challenges List, the Isaac Newton Institute, 2011, and the Penny Ante Problem List, 2009.

  4. Computer Simulation of Noise Effects of the Neighborhood of Stimulus Threshold for a Mathematical Model of Homeostatic Regulation of Sleep-Wake Cycles

    Directory of Open Access Journals (Sweden)

    Wuyin Jin

    2017-01-01

    Full Text Available The noise effects on a homeostatic regulation of sleep-wake cycles’ neuronal mathematical model determined by the hypocretin/orexin and the local glutamate interneurons spatiotemporal behaviors are studied within the neighborhood of stimulus threshold in this work; the neuronal noise added to the stimulus, the conductance, and the activation variable of the modulation function are investigated, respectively, based on a circadian input skewed in sine function. The computer simulation results suggested that the increased amplitude of external current input will lead to the fact that awakening time is advanced but the sleepy time remains the same; for the bigger conductance and modulation noise, the regulatory mechanism of the model sometimes will be collapsed and the coupled two neurons of the model show very irregular activities; the falling asleep or wake transform appears at nondeterminate time.

  5. Neighborhood context and the Hispanic health paradox: differential effects of immigrant density on children׳s wheezing by poverty, nativity and medical history.

    Science.gov (United States)

    Kim, Young-An; Collins, Timothy W; Grineski, Sara E

    2014-05-01

    Prior research suggests that immigrant enclaves provide respiratory health benefits for US Hispanic residents. We test if immigrant enclaves provide differential respiratory health benefits for Hispanic children in El Paso (Texas) based on individual-level factors. Results reveal that higher neighborhood immigrant density is associated with reduced odds of wheezing, but that the protective immigrant enclave effect is modified by poverty, general health status, body mass index (BMI), and caretaker nativity. Higher immigrant density is significantly more protective for poor children and those with foreign-born caretakers; conversely, it is significantly less protective for children in worse health and those with higher BMI. These findings foster a novel understanding of how immigrant enclaves may be differentially protective for Hispanic children based on individual-level factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. R2 effect-size measures for mediation analysis

    Science.gov (United States)

    Fairchild, Amanda J.; MacKinnon, David P.; Taborga, Marcia P.; Taylor, Aaron B.

    2010-01-01

    R2 effect-size measures are presented to assess variance accounted for in mediation models. The measures offer a means to evaluate both component paths and the overall mediated effect in mediation models. Statistical simulation results indicate acceptable bias across varying parameter and sample-size combinations. The measures are applied to a real-world example using data from a team-based health promotion program to improve the nutrition and exercise habits of firefighters. SAS and SPSS computer code are also provided for researchers to compute the measures in their own data. PMID:19363189

  7. R2 effect-size measures for mediation analysis.

    Science.gov (United States)

    Fairchild, Amanda J; Mackinnon, David P; Taborga, Marcia P; Taylor, Aaron B

    2009-05-01

    R(2) effect-size measures are presented to assess variance accounted for in mediation models. The measures offer a means to evaluate both component paths and the overall mediated effect in mediation models. Statistical simulation results indicate acceptable bias across varying parameter and sample-size combinations. The measures are applied to a real-world example using data from a team-based health promotion program to improve the nutrition and exercise habits of firefighters. SAS and SPSS computer code are also provided for researchers to compute the measures in their own data.

  8. The effect of scaffold pore size in cartilage tissue engineering.

    Science.gov (United States)

    Nava, Michele M; Draghi, Lorenza; Giordano, Carmen; Pietrabissa, Riccardo

    2016-07-26

    The effect of scaffold pore size and interconnectivity is undoubtedly a crucial factor for most tissue engineering applications. The aim of this study was to examine the effect of pore size and porosity on cartilage construct development in different scaffolds seeded with articular chondrocytes. We fabricated poly-L-lactide-co-trimethylene carbonate scaffolds with different pore sizes, using a solvent-casting/particulate-leaching technique. We seeded primary bovine articular chondrocytes on these scaffolds, cultured the constructs for 2 weeks and examined cell proliferation, viability and cell-specific production of cartilaginous extracellular matrix proteins, including GAG and collagen. Cell density significantly increased up to 50% with scaffold pore size and porosity, likely facilitated by cell spreading on the internal surface of bigger pores, and by increased mass transport of gases and nutrients to cells, and catabolite removal from cells, allowed by lower diffusion barriers in scaffolds with a higher porosity. However, both the cell metabolic activity and the synthesis of cartilaginous matrix proteins significantly decreased by up to 40% with pore size. We propose that the association of smaller pore diameters, causing 3-dimensional cell aggregation, to a lower oxygenation caused by a lower porosity, could have been the condition that increased the cell-specific synthesis of cartilaginous matrix proteins in the scaffold with the smallest pores and the lowest porosity among those tested. In the initial steps of in vitro cartilage engineering, the combination of small scaffold pores and low porosity is an effective strategy with regard to the promotion of chondrogenesis.

  9. Atomic size effect on critical cooling rate and glass formation

    International Nuclear Information System (INIS)

    Jalali, Payman; Li Mo

    2005-01-01

    Atomic size effect on critical cooling rate and glass formability in a model binary system is investigated using molecular dynamics simulation. To isolate atomic size effect from the rest of the factors that critically influence the glass formation, a hard sphere model is employed in conjunction with a newly developed densification method. The glass formability is defined as a set of optimal conditions that result in the slowest cooling rate of the glass-forming liquid. Critical cooling rates are identified from extensive molecular dynamics simulations. A kinetic glass-forming diagram is mapped out that marks the boundary between the glass-forming regions and competing crystalline phases in terms of the parameters of the atomic size ratio and alloy concentration. It is found that the potency of the atomic size difference on glass formation is influenced greatly by the competing metastable and equilibrium crystalline phases in the system, and the kinetic processes leading to the formation of these phases. The mechanisms of the atomic size effect on topological instability of crystal packing and glass formation are discussed

  10. Appropriate assessment of neighborhood effects on individual health: integrating random and fixed effects in multilevel logistic regression

    DEFF Research Database (Denmark)

    Larsen, Klaus; Merlo, Juan

    2005-01-01

    The logistic regression model is frequently used in epidemiologic studies, yielding odds ratio or relative risk interpretations. Inspired by the theory of linear normal models, the logistic regression model has been extended to allow for correlated responses by introducing random effects. However......, the model does not inherit the interpretational features of the normal model. In this paper, the authors argue that the existing measures are unsatisfactory (and some of them are even improper) when quantifying results from multilevel logistic regression analyses. The authors suggest a measure...... of heterogeneity, the median odds ratio, that quantifies cluster heterogeneity and facilitates a direct comparison between covariate effects and the magnitude of heterogeneity in terms of well-known odds ratios. Quantifying cluster-level covariates in a meaningful way is a challenge in multilevel logistic...

  11. Core size effects on safety performances of LMRs

    Energy Technology Data Exchange (ETDEWEB)

    Na, Byung Chan; Hahn, Do Hee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    An oxide fuel small size core (1200 MWt) was analyzed in comparison with a large size core (3600 MWt) in order to evaluate the size effects on transient safety performances of liquid-metal reactors (LMRs). In the first part of the study, main static safety parameters (i.e., Doppler coefficient, sodium void effect, etc.) of the two cores were characterized, and the second part of the study was focused on the dynamic behavior of the cores in two representative transient events: the unprotected loss-of-flow (ULOF) and the unprotected transient overpower (UTOP). Margins to fuel melting and sodium boiling have been evaluated for these representative transients. Results show that the small core has a generally better or equivalent level of safety performances during these events. 6 refs., 4 figs., 2 tabs. (Author)

  12. Core size effects on safety performances of LMRs

    Energy Technology Data Exchange (ETDEWEB)

    Na, Byung Chan; Hahn, Do Hee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    An oxide fuel small size core (1200 MWt) was analyzed in comparison with a large size core (3600 MWt) in order to evaluate the size effects on transient safety performances of liquid-metal reactors (LMRs). In the first part of the study, main static safety parameters (i.e., Doppler coefficient, sodium void effect, etc.) of the two cores were characterized, and the second part of the study was focused on the dynamic behavior of the cores in two representative transient events: the unprotected loss-of-flow (ULOF) and the unprotected transient overpower (UTOP). Margins to fuel melting and sodium boiling have been evaluated for these representative transients. Results show that the small core has a generally better or equivalent level of safety performances during these events. 6 refs., 4 figs., 2 tabs. (Author)

  13. Effect of microfluidization on casein micelle size of bovine milk

    Science.gov (United States)

    Sinaga, H.; Deeth, H.; Bhandari, B.

    2018-02-01

    The properties of milk are likely to be dependent on the casein micelle size, and various processing technologies produce particular change in the average size of casein micelles. The main objective of this study was to manipulate casein micelle size by subjecting milk to microfluidizer. The experiment was performed as a complete block randomised design with three replications. The sample was passed through the microfluidizer at the set pressure of 83, 97, 112 and 126 MPa for one, two, three, four, five and six cycles, except for the 112 MPa. The results showed that microfluidized milk has smaller size by 3% with pressure up to 126 MPa. However, at each pressure, no further reduction was observed after increasing the passed up to 6 cycles. Although the average casein micelle size was similar, elevating pressure resulted in narrower size distribution. In contrast, increasing the number of cycles had little effect on casein micelle distribution. The finding from this study can be applied for future work to characterize the fundamental and functional properties of the treated milk.

  14. Self-reported physical activity in perceived neighborhood in Czech adults – national study

    Directory of Open Access Journals (Sweden)

    Josef Mitáš

    2013-06-01

    Full Text Available BACKGROUND: International studies associate physical activity (PA to other factors such as the environment, culture, and policy. External influences on lifestyle and PA, such as the effect of the physical and built environment, are discussed. Neighborhood environments seem to be one of the important aspects in prevention of unhealthy lifestyle and physical inactivity research. OBJECTIVE: The main objective is to analyze the relationship between PA and neighborhood environment of the adult population of the Czech Republic. The study tries to define the basic correlates of PA in relation to environmental and other socio-demographic factors. METHODS: Nationwide data collection of adult PA was done regionally in the Czech Republic between the years 2005–2009 using the IPAQ (long and ANEWS questionnaires. RESULTS: The results show that males realize significantly more vigorous PA than females while females realize more moderate PA and walking than males. PA of residents of smaller communities is higher than those living in large cities. The level of weekly PA does not significantly affect the neighborhood walkability [H(3, 8708 = 19.60; p CONCLUSIONS: The results clearly indicate the need to connect multiple sectors that affect the lifestyle of the general population. Possible solution is an interdisciplinary approach to the evaluation of the fundamental environmental factors influencing the level of PA (walkability; SES; participation in organized and voluntary PA; neighborhood safety; type of transportation; size of the community.

  15. Statistical Significance and Effect Size: Two Sides of a Coin.

    Science.gov (United States)

    Fan, Xitao

    This paper suggests that statistical significance testing and effect size are two sides of the same coin; they complement each other, but do not substitute for one another. Good research practice requires that both should be taken into consideration to make sound quantitative decisions. A Monte Carlo simulation experiment was conducted, and a…

  16. Adaptive evolution and effective population size in wild house mice

    Czech Academy of Sciences Publication Activity Database

    Phifer-Rixey, M.; Bonhomme, F.; Boursot, P.; Churchill, G. A.; Piálek, Jaroslav; Tucker, P.; Nachman, M.

    2012-01-01

    Roč. 29, č. 10 (2012), s. 2949-2955 ISSN 0737-4038 R&D Projects: GA ČR GA206/08/0640 Institutional support: RVO:68081766 Keywords : substitution * adaptation * evolution * effective population size * house mouse Subject RIV: EG - Zoology Impact factor: 10.353, year: 2012

  17. Effect of limestone particle size on bone quality characteristics of ...

    African Journals Online (AJOL)

    A study was conducted to determine the effect of different limestone particle sizes in layer diets on bone quality characteristics at end-of-lay hens. Calcitic limestone (360 g Ca/kg DM) that is extensively used in commercial poultry diets was obtained from a specific South African source. Limestone particles were graded as ...

  18. Effects of Particle Size Distribution on Bioremediation of Crude Oil ...

    African Journals Online (AJOL)

    Bioremediation has been proven to be the most effective method of cleaning up oil contaminated soils through the application of nutrients and microorganism. ... The parameters examined were: moisture content, particle size distribution, total hydrocarbon content, soil pH, available nitrogen, available phosphorus, total ...

  19. Origin of size effect on efficiency of organic photovoltaics

    DEFF Research Database (Denmark)

    Manor, Assaf; Katz, Eugene A.; Tromholt, Thomas

    2011-01-01

    It is widely accepted that efficiency of organic solar cells could be limited by their size. However, the published data on this effect are very limited and none of them includes analysis of light intensity dependence of the key cell parameters. We report such analysis for bulk heterojunction sol...

  20. Reporting effect sizes as a supplement to statistical significance ...

    African Journals Online (AJOL)

    The purpose of the article is to review the statistical significance reporting practices in reading instruction studies and to provide guidelines for when to calculate and report effect sizes in educational research. A review of six readily accessible (online) and accredited journals publishing research on reading instruction ...

  1. Short communication Effective population size and inbreeding rate ...

    African Journals Online (AJOL)

    201010100

    2013-05-30

    May 30, 2013 ... Understanding and estimating effective population size for practical application in marine species management. Conservation Biology 25 (3), 438-449. Mapiye, C., Chimonyo, M., Muchenje, V., Dzama, K., Marufu, M.C. & Raats, J.G., 2007. Potential for value-addition of Nguni cattle products in the communal ...

  2. The effect of surface albedo and grain size distribution on ...

    African Journals Online (AJOL)

    Sand dams are very useful in arid and semi arid lands (ASALs) as facilities for water storage and conservation. Soils in ASALs are mainly sandy and major water loss is by evaporation and infiltration. This study investigated the effect of sand media characteristics, specifically surface albedo, grain size and stratification on ...

  3. Application of size effect to compressive strength of concrete members

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    (LSM) to obtain parameters for the modified size effect law (MSEL) by Kim and co workers. The results of the ... in tensile failure, because the formation of microcracks in compressive failure is distributed in a wider region ...... Benjamin J R, Cornell C A 1970 Probability, statistics, and decision for civil engineers (New York:.

  4. Effect of directional selection for body size on fluctuating asymmetry ...

    Indian Academy of Sciences (India)

    In this study, we investigated whether stress caused by artificial bidirectional selection for body size has any effect on the levels of FA of different morphological traits in Drosophila ananassae. The realised heritability (h2) was higher in low-line females and high-line males, which suggests an asymmetrical response to ...

  5. Effect size, confidence intervals and statistical power in psychological research.

    Directory of Open Access Journals (Sweden)

    Téllez A.

    2015-07-01

    Full Text Available Quantitative psychological research is focused on detecting the occurrence of certain population phenomena by analyzing data from a sample, and statistics is a particularly helpful mathematical tool that is used by researchers to evaluate hypotheses and make decisions to accept or reject such hypotheses. In this paper, the various statistical tools in psychological research are reviewed. The limitations of null hypothesis significance testing (NHST and the advantages of using effect size and its respective confidence intervals are explained, as the latter two measurements can provide important information about the results of a study. These measurements also can facilitate data interpretation and easily detect trivial effects, enabling researchers to make decisions in a more clinically relevant fashion. Moreover, it is recommended to establish an appropriate sample size by calculating the optimum statistical power at the moment that the research is designed. Psychological journal editors are encouraged to follow APA recommendations strictly and ask authors of original research studies to report the effect size, its confidence intervals, statistical power and, when required, any measure of clinical significance. Additionally, we must account for the teaching of statistics at the graduate level. At that level, students do not receive sufficient information concerning the importance of using different types of effect sizes and their confidence intervals according to the different types of research designs; instead, most of the information is focused on the various tools of NHST.

  6. Effect of limestone particle size on egg production and eggshell ...

    African Journals Online (AJOL)

    Different limestone particle sizes had no effect on any of the tested egg production and eggshell quality parameters. These results suggested that larger particles limestone are not necessarily essential to provide sufficient Ca2+ to laying hens for egg production and eggshell quality at end-of-lay, provided that the dietary Ca ...

  7. Sampling strategies for estimating brook trout effective population size

    Science.gov (United States)

    Andrew R. Whiteley; Jason A. Coombs; Mark Hudy; Zachary Robinson; Keith H. Nislow; Benjamin H. Letcher

    2012-01-01

    The influence of sampling strategy on estimates of effective population size (Ne) from single-sample genetic methods has not been rigorously examined, though these methods are increasingly used. For headwater salmonids, spatially close kin association among age-0 individuals suggests that sampling strategy (number of individuals and location from...

  8. An Introductory Summary of Various Effect Size Choices.

    Science.gov (United States)

    Cromwell, Susan

    This paper provides a tutorial summary of some of the many effect size choices so that members of the Southwest Educational Research Association would be better able to follow the recommendations of the American Psychological Association (APA) publication manual, the APA Task Force on Statistical Inference, and the publication requirements of some…

  9. Short communication: Effective population size and inbreeding rate ...

    African Journals Online (AJOL)

    Short communication: Effective population size and inbreeding rate of indigenous Nguni cattle under in situ conservation in the low-input communal production ... as not at risk of extinction, while the individual enterprises were classified as being endangered-maintained without the exchange of germ plasm among them.

  10. Finite-size effects for anisotropic bootstrap percolation : Logarithmic corrections

    NARCIS (Netherlands)

    van Enter, Aernout C. D.; Hulshof, Tim

    In this note we analyse an anisotropic, two-dimensional bootstrap percolation model introduced by Gravner and Griffeath. We present upper and lower bounds on the finite-size effects. We discuss the similarities with the semi-oriented model introduced by Duarte.

  11. Finite-size effects for anisotropic bootstrap percolation: logerithmic corrections

    NARCIS (Netherlands)

    Enter, van A.C.D.; Hulshof, T.

    2007-01-01

    In this note we analyse an anisotropic, two-dimensional bootstrap percolation model introduced by Gravner and Griffeath. We present upper and lower bounds on the finite-size effects. We discuss the similarities with the semi-oriented model introduced by Duarte.

  12. Effect of coal stress on grain size of the gotten

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, W; Tront, A

    1988-09-01

    Presents investigation results on the effect of seam stress and strain state on winning as measured by the grain size of the gotten. The investigations were carried out at the Institute of Mining Mechanization of the Silesian Politechnical where the relations between parameters of seams and cutters and their effect on coal grain size and energy consumption have been studied for several years. The effect was examined on coal samples taken from 4 mines in the Upper Silesian coal basin using a model of the system: seam - cutter. Cubic samples (400x400x400 mm) were tested on the CMG KOMAG test stand equipped with the POS-1 cutting apparatus. Two types of coal were distinguished: that particularly sensitive to increased pressure on seam and that only negligibly susceptible. Corresponding graphs of coal grain size versus vertical pressure are shown. A function has been developed that characterizes this sensitivity depending on a material parameter that can be determined by workability tests. The relationship between coal strength and grain size yield greater than 10 mm in the gotten depending on dynamic crushability of coal is shown in graphs. 6 refs.

  13. The Effect of Size and Ecology on Extinction Susceptibility

    Science.gov (United States)

    Huynh, C.; Yuan, A.; Heim, N.; Payne, J.

    2015-12-01

    Although life on Earth first emerged as prokaryotic organisms, it eventually evolved into billions of different species. However, extinctions on Earth, especially the five mass extinctions, have decimated species. So what leads to a species survival or demise during a mass extinction? Are certain species more susceptible to extinctions based on their size and ecology? For this project, we focused on the data of marine animals. To examine the impact of size and ecology on a species's likelihood of survival, we compared the sizes and ecologies of the survivors and victims of the five mass extinctions. The ecology, or life mode, of a genus consists of the combination of tiering, motility, and feeding mechanism. Tiering refers to the animal's typical location in the water column and sediments, motility refers to its ability to move, and feeding mechanism describes the way the organism eats; together, they describe the animal's behavior. We analyzed the effect of ecology on survival using logistic regression, which compares life mode to the success or failure of a genus during each mass extinction interval. For organism size, we found the extinct organisms' mean size (both volume and length) and compared it with the average size of survivors on a graph. Our results show that while surviving genera of mass extinctions tended to be slightly larger than those that went extinct, there was no significant difference. Even though the Permian (Changhsingian) and Triassic (Rhaetian) extinctions had larger surviving species, likewise the difference was small. Ecology had a more obvious impact on the likelihood of survival; fast-moving, predatory pelagic organisms were the most likely to go extinct, while sedentary, infaunal suspension feeders had the greatest chances of survival. Overall, ecology played a greater role than size in determining the survival of a species. With this information, we can use ecology to predict which species would survive future extinctions.

  14. Effects of portion size on chronic energy intake

    Directory of Open Access Journals (Sweden)

    Pentel Paul R

    2007-06-01

    Full Text Available Abstract Background This study experimentally examined the effects of repeated exposure to different meal portion sizes on energy intake. Methods Nineteen employees of a county medical center were given free box lunches for two months, one month each of 1528 and 767 average kcal. Foods were identical in the two conditions, but differed in portion size. Meals averaged 44% calories from fat. Participants self-reported how much of each lunch was eaten. Unannounced 24-hour dietary recalls were also conducted by phone twice per week during each exposure period. Results Mean energy intake at the lunch meal was 332 kcal/day higher in large lunch than in small lunch periods (p Conclusion This study suggests that chronic exposure to large portion size meals can result in sustained increases in energy intake and may contribute to body weight increases over time.

  15. A Streaming Distance Transform Algorithm for Neighborhood-Sequence Distances

    Directory of Open Access Journals (Sweden)

    Nicolas Normand

    2014-09-01

    Full Text Available We describe an algorithm that computes a “translated” 2D Neighborhood-Sequence Distance Transform (DT using a look up table approach. It requires a single raster scan of the input image and produces one line of output for every line of input. The neighborhood sequence is specified either by providing one period of some integer periodic sequence or by providing the rate of appearance of neighborhoods. The full algorithm optionally derives the regular (centered DT from the “translated” DT, providing the result image on-the-fly, with a minimal delay, before the input image is fully processed. Its efficiency can benefit all applications that use neighborhood- sequence distances, particularly when pipelined processing architectures are involved, or when the size of objects in the source image is limited.

  16. Size effects of latex nanomaterials on lung inflammation in mice

    International Nuclear Information System (INIS)

    Inoue, Ken-ichiro; Takano, Hirohisa; Yanagisawa, Rie; Koike, Eiko; Shimada, Akinori

    2009-01-01

    Effects of nano-sized materials (nanomaterials) on sensitive population have not been well elucidated. This study examined the effects of pulmonary exposure to (latex) nanomaterials on lung inflammation related to lipopolysaccharide (LPS) or allergen in mice, especially in terms of their size-dependency. In protocol 1, ICR male mice were divided into 8 experimental groups that intratracheally received a single exposure to vehicle, latex nanomaterials (250 μg/animal) with three sizes (25, 50, and 100 nm), LPS (75 μg/animal), or LPS plus latex nanomaterials. In protocol 2, ICR male mice were divided into 8 experimental groups that intratracheally received repeated exposure to vehicle, latex nanomaterials (100 μg/animal), allergen (ovalbumin: OVA; 1 μg/animal), or allergen plus latex nanomaterials. In protocol 1, latex nanomaterials with all sizes exacerbated lung inflammation elicited by LPS, showing an overall trend of amplified lung expressions of proinflammatory cytokines. Furthermore, LPS plus nanomaterials, especially with size less than 50 nm, significantly elevated circulatory levels of fibrinogen, macrophage chemoattractant protein-1, and keratinocyte-derived chemoattractant, and von Willebrand factor as compared with LPS alone. The enhancement tended overall to be greater with the smaller nanomaterials than with the larger ones. In protocol 2, latex nanomaterials with all sizes did not significantly enhance the pathophysiology of allergic asthma, characterized by eosinophilic lung inflammation and Igs production, although latex nanomaterials with less than 50 nm significantly induced/enhanced neutrophilic lung inflammation. These results suggest that latex nanomaterials differentially affect two types of (innate and adaptive immunity-dominant) lung inflammation

  17. Size Effect of Defects on the Mechanical Properties of Graphene

    Science.gov (United States)

    Park, Youngho; Hyun, Sangil

    2018-03-01

    Graphene, a two-dimensional material, has been studied and utilized for its excellent material properties. In reality, achieving a pure single-crystalline structure in graphene is difficult, so usually graphene may have various types of defects in it. Vacancies, Stone-Wales defects, and grain boundaries can drastically change the material properties of graphene. Graphene with vacancy defects has been of interest because it is a two-dimensional analogy of three-dimensional porous materials. It has efficient material properties, and can function as a part of modern devices. The mechanical properties have been studied by using molecular dynamics for either a single vacancy defect with various sizes or multiple vacancy defects with same defect ratios. However, it is not clear which one has more influence on the mechanical properties between the size of the defects and the defect ratio. Therefore, we investigated the hole-size effect on the mechanical properties of single-crystalline graphene at various defect ratios. A void defect with large size can have a rather high tensile modulus with a low fracture strain compared to a void defect with small size. We numerically found that the tensile properties of scattered single vacancies is similar to that of amorphous graphene. We suspect that this is due to the local orbital change of the carbon atoms near the boundary of the void defects, so-called the interfacial phase.

  18. Effect Size Analyses of Souvenaid in Patients with Alzheimer's Disease.

    Science.gov (United States)

    Cummings, Jeffrey; Scheltens, Philip; McKeith, Ian; Blesa, Rafael; Harrison, John E; Bertolucci, Paulo H F; Rockwood, Kenneth; Wilkinson, David; Wijker, Wouter; Bennett, David A; Shah, Raj C

    2017-01-01

    Souvenaid® (uridine monophosphate, docosahexaenoic acid, eicosapentaenoic acid, choline, phospholipids, folic acid, vitamins B12, B6, C, and E, and selenium), was developed to support the formation and function of neuronal membranes. To determine effect sizes observed in clinical trials of Souvenaid and to calculate the number needed to treat to show benefit or harm. Data from all three reported randomized controlled trials of Souvenaid in Alzheimer's disease (AD) dementia (Souvenir I, Souvenir II, and S-Connect) and an open-label extension study were included in analyses of effect size for cognitive, functional, and behavioral outcomes. Effect size was determined by calculating Cohen's d statistic (or Cramér's V method for nominal data), number needed to treat and number needed to harm. Statistical calculations were performed for the intent-to-treat populations. In patients with mild AD, effect sizes were 0.21 (95% confidence intervals: -0.06, 0.49) for the primary outcome in Souvenir II (neuropsychological test battery memory z-score) and 0.20 (0.10, 0.34) for the co-primary outcome of Souvenir I (Wechsler memory scale delayed recall). No effect was shown on cognition in patients with mild-to-moderate AD (S-Connect). The number needed to treat (6 and 21 for Souvenir I and II, respectively) and high number needed to harm values indicate a favorable harm:benefit ratio for Souvenaid versus control in patients with mild AD. The favorable safety profile and impact on outcome measures converge to corroborate the putative mode of action and demonstrate that Souvenaid can achieve clinically detectable effects in patients with early AD.

  19. China’s Neighborhood Environment and Options for Neighborhood Strategy

    Institute of Scientific and Technical Information of China (English)

    ZHOU FANGYIN

    2016-01-01

    Since the 18th CPC National Congress,especially since the Central Conference on Work Relating to Neighborhood Diplomacy held in October 2013,China’s neighborhood diplomacy has been energetic,proactive and promising,achieving important results in several aspects.At the same time,it is also in face of challenges

  20. A neighborhood analysis of the consequences of Quercus suber decline for regeneration dynamics in Mediterranean forests.

    Directory of Open Access Journals (Sweden)

    Beatriz Ibáñez

    Full Text Available In forests, the vulnerable seedling stage is largely influenced by the canopy, which modifies the surrounding environment. Consequently, any alteration in the characteristics of the canopy, such as those promoted by forest dieback, might impact regeneration dynamics. Our work analyzes the interaction between canopy neighbors and seedlings in Mediterranean forests affected by the decline of their dominant species (Quercus suber. Our objective was to understand how the impacts of neighbor trees and shrubs on recruitment could affect future dynamics of these declining forests. Seeds of the three dominant tree species (Quercus suber, Olea europaea and Quercus canariensis were sown in six sites during two consecutive years. Using a spatially-explicit, neighborhood approach we developed models that explained the observed spatial variation in seedling emergence, survival, growth and photochemical efficiency as a function of the size, identity, health, abundance and distribution of adult trees and shrubs in the neighborhood. We found strong neighborhood effects for all the performance estimators, particularly seedling emergence and survival. Tree neighbors positively affected emergence, independently of species identity or health. Alternatively, seedling survival was much lower in neighborhoods dominated by defoliated and dead Q. suber trees than in neighborhoods dominated by healthy trees. For the two oak species, these negative effects were consistent over the three years of the experimental seedlings. These results indicate that ongoing changes in species' relative abundance and canopy trees' health might alter the successional trajectories of Mediterranean oak-forests through neighbor-specific impacts on seedlings. The recruitment failure of dominant late-successional oaks in the gaps opened after Q. suber death would indirectly favor the establishment of other coexisting woody species, such as drought-tolerant shrubs. This could lead current

  1. The effect of laser unit on photodynamic therapy spot size.

    Science.gov (United States)

    Ansari-Shahrezaei, Siamak; Binder, Susanne; Stur, Michael

    2011-01-01

    To determine the effect of the laser unit on photodynamic therapy (PDT) spot size. A calibrated Gullstrand-type model eye was used for this study. The axial length of the model eye was set to different values ranging from 22.2 to 27.0 mm, and the actual spot size from the laser console was recorded for treating a spot of 4 mm in the center of the artificial fundus using two different laser units (Coherent Opal laser; Coherent Inc, Santa Clara, California, USA and Zeiss Visulas laser; Carl Zeiss Meditec Inc, Dublin, California, USA) and two indirect contact laser lenses (Volk PDT laser lens and Volk Area Centralis lens; Volk Optical Inc, Mentor, Ohio, USA). From myopia to hyperopia, the total deviation from the intended spot size was -22.5% to -7.5% (Opal laser and PDT laser lens), and -17.5% to +2.5% (Visulas laser and PDT laser lens), -12.5% to +7.5% (Opal laser and Area Centralis lens), and -7.5% to +10% (Visulas laser and Area Centralis lens). The used laser unit has a significant effect on PDT spot size in this model. These findings may be important for optimizing PDT of choroidal neovascular lesions.

  2. Size, Shape and Impurity Effects on Superconducting critical temperature.

    Science.gov (United States)

    Umeda, Masaki; Kato, Masaru; Sato, Osamu

    Bulk superconductors have their own critical temperatures Tc. However, for a nano-structured superconductor, Tc depends on size and shape of the superconductor. Nishizaki showed that the high pressure torsion on bulks of Nb makes Tc higher, because the torsion makes many nano-sized fine grains in the bulks. However the high pressure torsion on bulks of V makes Tc lower, and Nishizaki discussed that the decrease of Tc is caused by impurities in the bulks of V. We studied size, shape, and impurity effects on Tc, by solving the Gor'kov equations, using the finite element method. We found that smaller and narrower superconductors show higher Tc. We found how size and shape affects Tc by studying spacial order parameter distributions and quasi-particle eigen-energies. Also we studied the impurity effects on Tc, and found that Tc decreases with increase of scattering rate by impurities. This work was supported in part of KAKENHI Grant Number JP26400367 and JP16K05460, and program for leading graduate schools of ministry of education, culture, sports, science and technology-Japan.

  3. Finite size effects in neutron star and nuclear matter simulations

    Energy Technology Data Exchange (ETDEWEB)

    Giménez Molinelli, P.A., E-mail: pagm@df.uba.ar; Dorso, C.O.

    2015-01-15

    single structure per cell while the cubic and truncated octahedron show consistent results, with more than one structure per cell. For systems of the size studied in this work these effects are still noticeable, but we find evidence to support that the dependence of the results on the cell geometry becomes smaller as the system size is increased. When the Coulomb interaction is present, the competition between opposing interactions of different range results in a proper, physically meaningful length scale that is independent of the system size and periodic cell of choice. Only under these conditions “finite size effects” will vanish for large enough systems (i.e. cells much larger than this characteristic length). Larger simulations are in order, but our computational capabilities forbid it for the time being.

  4. Does screen size matter for smartphones? Utilitarian and hedonic effects of screen size on smartphone adoption.

    Science.gov (United States)

    Kim, Ki Joon; Sundar, S Shyam

    2014-07-01

    This study explores the psychological effects of screen size on smartphone adoption by proposing an extended Technology Acceptance Model (TAM) that integrates an empirical comparison between large and small screens with perceived control, affective quality, and the original TAM constructs. A structural equation modeling analysis was conducted on data collected from a between-subjects experiment (N=130) in which users performed a web-based task on a smartphone with either a large (5.3 inches) or a small (3.7 inches) screen. Results show that a large screen, compared to a small screen, is likely to lead to higher smartphone adoption by simultaneously promoting both the utilitarian and hedonic qualities of smartphones, which in turn positively influence perceived ease of use of-and attitude toward-the device respectively. Implications and directions for future research are discussed.

  5. Neighborhood Design for Walking and Biking

    Science.gov (United States)

    Brown, Barbara B.; Smith, Ken R.; Hanson, Heidi; Fan, Jessie X.; Kowaleski-Jones, Lori; Zick, Cathleen D.

    2013-01-01

    Background Neighborhood designs often relate to physical activity and to BMI. Purpose Does neighborhood walkability/bikeability relate to BMI and obesity risk and does moderate-to-vigorous physical activity (MVPA) account for some of the relationship? Methods Census 2000 provided walkability/bikeability measures—block group proportions of workers who walk or bike to work, housing age, and population density—and National Health and Nutrition Examination Study (NHANES 2003–2006) provided MVPA accelerometer measures. Regression analyses (2011–2012) adjusted for geographic clustering and multiple control variables. Results Greater density and older housing were associated with lower male BMI in bivariate analyses, but there were no density and housing age effects in multivariate models. For women, greater proportions of neighborhood workers who walk to work (M=0.02) and more MVPA was associated with lower BMI and lower obesity risk. For men, greater proportions of workers who bike to work (M=0.004) and more MVPA was associated with lower BMI and obesity risk. For both effects, MVPA partially mediated the relationships between walkability/bikeability and BMI. If such associations are causal, doubling walk and bike-to-work proportions (to 0.04 and 0.008) would have –0.3 and –0.33 effects on the average BMIs of adult women and men living in the neighborhood. This equates to 1.5 lbs for a 64” woman and 2.3 lbs for a 69” man. Conclusions Although walking/biking to work is rare in the U.S., greater proportions of such workers in neighborhoods relate to lower weight and higher MVPA. Bikeability merits greater attention as a modifiable activity-friendliness factor, particularly for men. PMID:23415119

  6. Effect of particle size on mixing degree in dispensation.

    Science.gov (United States)

    Nakamura, Hitoshi; Yanagihara, Yoshitsugu; Sekiguchi, Hiroko; Ohtani, Michiteru; Kariya, Satoru; Uchino, Katsuyoshi; Suzuki, Hiroshi; Iga, Tatsuji

    2004-03-01

    By using lactose colored with erythrocin, we examined the effect of particle size on mixing degree during the preparation of triturations with a mortar and pestle. We used powders with different distributions of particle sizes, i.e., powder that passed through 32-mesh but was trapped on a 42-mesh sieve (32/42-mesh powder), powder that passed through a 42-mesh sieve but was trapped on a 60-mesh sieve (42/60-mesh powder), powder that passed through a 60-mesh sieve but was trapped on a 100-mesh sieve (60/100-mesh powder), and powder that passes through a 100-mesh sieve (> 100-mesh powder). The mixing degree of colored powder and non-colored powder whose distribution of particle sizes was the same as that of the colored powder was excellent. The coefficient of variation (CV) value of the mixing degree was 6.08% after 40 rotations when colored powder was mixed with non-colored powder that both passed through a 100-mesh sieve. The CV value of the mixing degree was low in the case of mixing of colored and non-colored powders with different particle size distributions. After mixing, about 50% of 42/60-mesh powder had become smaller particles, whereas the distribution of particle sizes was not influenced by the mixing of 60/100-mesh powder. It was suggested that the mixing degree is affected by distribution of particle sizes. It may be important to determine the mixing degrees for drugs with narrow therapeutic ranges.

  7. Effect of nanofillers' size on surface properties after toothbrush abrasion.

    Science.gov (United States)

    Cavalcante, Larissa M; Masouras, Konstantinos; Watts, David C; Pimenta, Luiz A; Silikas, Nick

    2009-02-01

    To investigate the effect of filler-particle size of experimental and commercial resin composites, undergoing toothbrush abrasion, on three surface properties: surface roughness (SR), surface gloss (G) and color stability (CS). Four model (Ivoclar/Vivadent) and one commercial resin composite (Tokuyama) with varying filler-size from 100-1000 nm were examined. Six discs (10 mm x 2 mm) from each product were prepared and mechanically polished. The samples were then submitted to 20,000 brushing strokes in a toothbrush abrasion machine. SR parameters (Ra, Rt and RSm), G, and CS were measured before and after toothbrush abrasion. Changes in SR and G were analyzed by 2-way ANOVA, with Bonferroni post hoc test. CS values were submitted to one-way ANOVA and Bonferroni post hoc test (alpha=0.05). Initial G values ranged between 73-87 gloss units (GU) and were reduced after toothbrush abrasion to a range of 8-64 GU. Toothbrush abrasion resulted in significant modifications in SR and G amongst the materials tested, attributed to filler sizes. There was statistically significant difference in color (delta E* ranged from 0.38-0.88). Filler size did not affect color stability. Toothbrush abrasion resulted in rougher and matte surfaces for all materials tested. Although the individual differences in surface roughness among filler sizes were not always significant, the correlation showed a trend that larger filler sizes resulted in higher surface roughness after abrasion for the SR parameters Ra and Rt (r = 0.95; r = 0.93, respectively). RSm showed an increase after toothbrush abrasion for all resin composites, however no significant correlation was detected (r = 0.21).There was a significant correlation between G and Ra ratios (r = - 0.95).

  8. Size effect related to damping caused by water submersion

    International Nuclear Information System (INIS)

    Dong, R.G.

    1981-01-01

    An important effect of water submersion on the dynamic response of a structure is the increase in effective damping. The dynamic response of submerged structures is of interest in the nuclear power industry for reasons of operational safety during seismic and other dynamic excitations. In this paper, the added damping contribution that results from the viscosity of water and the dependence of the contribution on structural size are examined. Other factors considered are the applicable range of viscous damping with respect to displacement amplitude and, as far as damping is concerned, how far neighboring members must be from each other to respond as if in open water. An expression is derived for relating the damping value to structural size. Estimated added-damping values for representative fuel elements, fuel bundles, and main steam-pressure-relief-valve lines are given based on our derived expression for added damping

  9. Effective source size as related to 252Cf neutron radiography

    International Nuclear Information System (INIS)

    Wada, Nobuo; Enomoto, Shigemasa; Tachikawa, Noboru; Nojiri, Toshiaki.

    1977-01-01

    The effective source size in 252 Cf thermal neutron radiography, relating to its geometrical unsharpness in image formation, is experimentally studied. A neutron radiographic system consists of a 160 μg 252 Cf neutron source, water moderator and divergent cadmium lined collimator. Thermal neutron image detection is performed with using a LiF scintillator and a high speed X-ray film to employ direct exposure method. The modulation transfer function, used for describing image quality, is derived from radiographic image corresponding to a cadmium plate with sharp edge. The modulation transfer function for the system is expressed by the product of the function for both geometrical and inherent unsharpness, and allows isolation of geometrical unsharpness as related to the effective size of the thermal neutron source. It is found to be 80 -- 90% of the collimator inlet diameter. (auth.)

  10. Effect of eating rate on binge size in Bulimia Nervosa

    Science.gov (United States)

    Kissileff, Harry R; Zimmerli, Ellen J; Torres, Migdalia I; Devlin, Michael J; Walsh, B Timothy

    2008-01-01

    Effect of eating rate on binge size in bulimia nervosa. Bulimia Nervosa (BN) is an eating disorder characterized by recurrent episodes of binge eating. During binge eating episodes, patients often describe the rapid consumption of food, and laboratory studies have shown that during binges patients with BN eat faster than normal controls (NC), but the hypothesis that a rapid rate of eating contributes to the excessive intake of binge meals has not yet been experimentally tested. The aim of this study was to assess the effect of eating rate on binge size in BN, in order to determine whether binge size is mediated, in part, by rate of eating. Thirteen BN and 14 NC subjects were asked to binge eat a yogurt shake that was served at a fast rate (140g/min) on one occasion and at a slow rate (70g/min) on another. NC subjects consumed 169 g more when eating at the fast rate than when eating at the slow rate. In contrast, consumption rates failed to influence binge size in patients with BN (fast: 1205 g; slow: 1195 g). Consequently, there was a significant group by rate interaction. As expected, patients with BN consumed more overall than NC subjects (1200 g vs. 740 g). When instructed to binge in the eating laboratory, patients with BN ate equally large amounts of food at a slow rate as at a fast rate. NC subjects ate less at a slow rate. These findings indicate that in a structured laboratory meal paradigm binge size is not affected by rate of eating. PMID:17996257

  11. Finite size effects on hydrogen bonds in confined water

    International Nuclear Information System (INIS)

    Musat, R.; Renault, J.P.; Le Caer, S.; Pommeret, S.; Candelaresi, M.; Palmer, D.J.; Righini, R.

    2008-01-01

    Femtosecond IR spectroscopy was used to study water confined in 1-50 nm pores. The results show that even large pores induce significant changes (for example excited-state lifetimes) to the hydrogen-bond network, which are independent of pore diameter between 1 and 50 nm. Thus, the changes are not surface-induced but rather finite size effects, and suggest a confinement-induced enhancement of the acidic character of water. (authors)

  12. Influences of population size and density on birthplace effects.

    Science.gov (United States)

    Hancock, David J; Coutinho, Patrícia; Côté, Jean; Mesquita, Isabel

    2018-01-01

    Contextual influences on talent development (e.g., birthplace effects) have become a topic of interest for sport scientists. Birthplace effects occur when being born in a certain city size leads to participation or performance advantages, typically for those born in smaller or mid-sized cities. The purpose of this study was to investigate birthplace effects in Portuguese volleyball players by analysing city size, as well as population density - an important but infrequently used variable. Participants included 4062 volleyball players (M age  = 33), 53.2% of whom were men. Using Portuguese national census data from 1981, we compared participants (within each sex) across five population categories. In addition, we used ANOVAs to study expertise and population density. Results indicated that men and women athletes born in districts of 200,000-399,999 were 2.4 times more likely to attain elite volleyball status, while all other districts decreased the odds of expert development. For men, being born in high-density areas resulted in less chance of achieving expertise, whereas there were no differences for women. The results suggest that athletes' infrastructure and social structure play an important role in talent development, and that these structures are influenced by total population and population density, respectively.

  13. Size effects on magnetoelectric response of multiferroic composite with inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Y.M. [Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Department of Mechanics, Shanghai University, Shanghai 200072 (China); Xu, K.Y., E-mail: kyxu@shu.edu.cn [Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Department of Mechanics, Shanghai University, Shanghai 200072 (China); Chen, T. [Shanghai Institute of Applied Mathematics and Mechanics, Shanghai Key Laboratory of Mechanics in Energy Engineering, Department of Mechanics, Shanghai University, Shanghai 200072 (China); Aifantis, E.C. [Laboratory of Mechanics and Materials (LMM), Aristotle University of Thessaloniki, Thessaloniki GR-54124 (Greece); Michigan Technological University, Houghton, MI 49931 (United States); King Abdulaziz University, Jeddah 21589 (Saudi Arabia); School of Mechanics and Engineering, Southwest Jiaotong University, Chengdu, 610031 (China); International Laboratory for Modern Functional Materials, ITMO University, St. Petersburg 191002 (Russian Federation)

    2015-12-01

    This paper investigates the influence of size effects on the magnetoelectric performance of multiferroic composite with inhomogeneities. Based on a simple model of gradient elasticity for multiferroic materials, the governing equations and boundary conditions are obtained from an energy variational principle. The general formulation is applied to consider an anti-plane problem of multiferroic composites with inhomogeneities. This problem is solved analytically and the effective magnetoelectric coefficient is obtained. The influence of the internal length (grain size or particle size) on the effective magnetoelectric coefficients of piezoelectric/piezomagnetic nanoscale fibrous composite is numerically evaluated and analyzed. The results suggest that with the increase of the internal length of piezoelectric matrix (PZT and BaTiO{sub 3}), the magnetoelectric coefficient increases, but the rate of increase is ratcheting downwards. If the internal length of piezoelectric matrix remains unchanged, the magnetoelectric coefficient will decrease with the increase of internal length scale of piezomagnetic nonfiber (CoFe{sub 2}O{sub 3}). In a composite consisiting of a piezomagnetic matrix (CoFe{sub 2}O{sub 3}) reinforced with piezoelectric nanofibers (BaTiO{sub 3}), an increase of the internal length in the piezomagnetic matrix, results to a decrease of the magnetoelectric coefficient, with the rate of decrease diminishing.

  14. Size effects on magnetoelectric response of multiferroic composite with inhomogeneities

    Science.gov (United States)

    Yue, Y. M.; Xu, K. Y.; Chen, T.; Aifantis, E. C.

    2015-12-01

    This paper investigates the influence of size effects on the magnetoelectric performance of multiferroic composite with inhomogeneities. Based on a simple model of gradient elasticity for multiferroic materials, the governing equations and boundary conditions are obtained from an energy variational principle. The general formulation is applied to consider an anti-plane problem of multiferroic composites with inhomogeneities. This problem is solved analytically and the effective magnetoelectric coefficient is obtained. The influence of the internal length (grain size or particle size) on the effective magnetoelectric coefficients of piezoelectric/piezomagnetic nanoscale fibrous composite is numerically evaluated and analyzed. The results suggest that with the increase of the internal length of piezoelectric matrix (PZT and BaTiO3), the magnetoelectric coefficient increases, but the rate of increase is ratcheting downwards. If the internal length of piezoelectric matrix remains unchanged, the magnetoelectric coefficient will decrease with the increase of internal length scale of piezomagnetic nonfiber (CoFe2O3). In a composite consisiting of a piezomagnetic matrix (CoFe2O3) reinforced with piezoelectric nanofibers (BaTiO3), an increase of the internal length in the piezomagnetic matrix, results to a decrease of the magnetoelectric coefficient, with the rate of decrease diminishing.

  15. Neighborhood Environment and Cognition in Older Adults: A Systematic Review.

    Science.gov (United States)

    Besser, Lilah M; McDonald, Noreen C; Song, Yan; Kukull, Walter A; Rodriguez, Daniel A

    2017-08-01

    Some evidence suggests that treating vascular risk factors and performing mentally stimulating activities may delay cognitive impairment onset in older adults. Exposure to a complex neighborhood environment may be one mechanism to help delay cognitive decline. PubMed, Web of Science, and ProQuest Dissertation and Theses Global database were systematically reviewed, identifying 25 studies published from February 1, 1989 to March 5, 2016 (data synthesized, May 3, 2015 to October 7, 2016). The review was restricted to quantitative studies focused on: (1) neighborhood social and built environment and cognition; and (2) community-dwelling adults aged ≥45 years. The majority of studies were cross-sectional, U.S.-based, and found at least one significant association. The diversity of measures and neighborhood definitions limited the synthesis of findings in many instances. Evidence was moderately strong for an association between neighborhood SES and cognition, and modest for associations between neighborhood demographics, design, and destination accessibility and cognition. Most studies examining effect modification found significant associations, with some evidence for effect modification of the neighborhood SES-cognition association by individual-level SES. No studies had low risk of bias and many tested multiple associations that increased the chance of a statistically significant finding. Considering the studies to date, the evidence for an association between neighborhood characteristics and cognition is modest. Future studies should include longitudinal measures of neighborhood characteristics and cognition; examine potential effect modifiers, such as sex and disability; and study mediators that may help elucidate the biological mechanisms linking neighborhood environment and cognition. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  16. Blade size and weight effects in shovel design.

    Science.gov (United States)

    Freivalds, A; Kim, Y J

    1990-03-01

    The shovel is a basic tool that has undergone only nominal systematic design changes. Although previous studies found shovel-weight and blade-size effects of shovelling, the exact trade-off between the two has not been quantified. Energy expenditure, heart rate, ratings of perceived exertion and shovelling performance were measured on five subjects using five shovels with varying blade sizes and weights to move sand. Energy expenditure, normalised to subject weight and load handled, varied quadratically with the blade-size/shovel-weight (B/W) ratio. Minimum energy cost was at B/W = 0.0676 m2/kg, which for an average subject and average load would require an acceptable 5.16 kcal/min of energy expenditure. Subjects, through the ratings of perceived exertion, also strongly preferred the lighter shovels without regard to blade size. Too large a blade or too heavy a shovel increased energy expenditure beyond acceptable levels, while too small a blade reduced efficiency of the shovelling.

  17. Size effects on free vibration of heterogeneous beams

    Directory of Open Access Journals (Sweden)

    Hassanati Bahman

    2018-01-01

    Full Text Available In this paper the influence of microstructure on the free vibration of geometrically similar heterogeneous beams with free-free boundary conditions was numerically investigated by detailed finite element analysis (FEA to identify and quantify any effect of beam size on transverse modal frequencies when the microstructural scale is comparable to the overall size. ANSYS Mechanical APDL was used to generate specific unit cells at the microstructural scale comprised of two isotropic materials with different material properties. Unit cell variants containing voids and inclusions were considered. At the macroscopic scale, four beam sizes consisting of one, two, three or four layers of defined unit cells were represented by repeatedly regenerating the unit cell as necessary. In all four beam sizes the aspect ratio was kept constant. Changes to the volume fractions of each material were introduced while keeping the homogenized properties of the beam fixed. The influence of the beam surface morphology on the results was also investigated. The ANSYS results were compared with the analytical results from solution to Timoshenko beam and nonlocal Timoshenko beam as well as numerical results for a Micropolar beam. In nonlocal Timoshenko beams the Eringen’s small length scale coefficients were estimated for some of the studied models. Numerical analyses based on Micropolar theory were carried out to study the modal frequencies and a method was suggested to estimate characteristic length in bending and coupling number via transverse vibration which verifies the use of Micropolar elasticity theory in dynamic analysis.

  18. [The effect of disinfectant soaking on dental gypsum model size].

    Science.gov (United States)

    Zhu, Cao-yun; Xu, Yun-wen; Xu, Kan

    2012-12-01

    To study the influence of disinfectant soaking on the dimensional stability of three kinds of dental gypsum model. Three commonly used gypsums ( type III,IV,Vtype) in clinic were used to make 24 specimens for 50 mm×15 mm×10 mm in size. One hour after release, the specimens were placed for 24 h. A digital caliper was used to measure the size of the gypsum model. Distilled water immersion was as used control, glutaraldehyde disinfectant and Metrix CaviCide disinfectant soaking were used for the experimental group. After soaking for 0.5h, the gypsum models were removed and placed for 0.5 h, 1 h, 2 h, 24 h. The size of the models was measured again using the same method. The data was analyzed with SPSS10.0 software package. The initial gypsum model length was (50.07±0.017) mm, (50.048±0.015) mm and (50.027±0.015) mm. After soaking for different times, the size of the model changed little, and the dimensions changed less than 0.01%. The results show that disinfectant soaking has no significant effect on dental model dimensions.

  19. Effect of geometric base roughness on size segregation

    Directory of Open Access Journals (Sweden)

    Jing L.

    2017-01-01

    Full Text Available The geometric roughness at boundaries has a profound impact on the dynamics of granular flows. For a bumpy base made of fixed particles, two major factors have been separately studied in the literature, namely, the size and spatial distribution of base particles. A recent work (Jing et al. 2016 has proposed a roughness indicator Ra, which combines both factors for any arbitrary bumpy base comprising equally-sized spheres. It is shown in mono-disperse flows that as Ra increases, a transition occurs from slip (Ra 0.62 conditions. This work focuses on such a phase transition in bi-disperse flows, in which Ra can be a function of time. As size segregation takes place, large particles migrate away from the bottom, leading to a variation of size ratio between flow- and base-particles. As a result, base roughness Ra evolves with the progress of segregation. Consistent with the slip/non-slip transition in mono-disperse flows, basal sliding arises at low values of Ra and the development of segregation might be affected; when Ra increases to a certain level (Ra > 0.62, non-slip condition is respected. This work extends the validity of Ra to bi-disperse flows, which can be used to understand the geometric boundary effect during segregation.

  20. Analyzing ROC curves using the effective set-size model

    Science.gov (United States)

    Samuelson, Frank W.; Abbey, Craig K.; He, Xin

    2018-03-01

    The Effective Set-Size model has been used to describe uncertainty in various signal detection experiments. The model regards images as if they were an effective number (M*) of searchable locations, where the observer treats each location as a location-known-exactly detection task with signals having average detectability d'. The model assumes a rational observer behaves as if he searches an effective number of independent locations and follows signal detection theory at each location. Thus the location-known-exactly detectability (d') and the effective number of independent locations M* fully characterize search performance. In this model the image rating in a single-response task is assumed to be the maximum response that the observer would assign to these many locations. The model has been used by a number of other researchers, and is well corroborated. We examine this model as a way of differentiating imaging tasks that radiologists perform. Tasks involving more searching or location uncertainty may have higher estimated M* values. In this work we applied the Effective Set-Size model to a number of medical imaging data sets. The data sets include radiologists reading screening and diagnostic mammography with and without computer-aided diagnosis (CAD), and breast tomosynthesis. We developed an algorithm to fit the model parameters using two-sample maximum-likelihood ordinal regression, similar to the classic bi-normal model. The resulting model ROC curves are rational and fit the observed data well. We find that the distributions of M* and d' differ significantly among these data sets, and differ between pairs of imaging systems within studies. For example, on average tomosynthesis increased readers' d' values, while CAD reduced the M* parameters. We demonstrate that the model parameters M* and d' are correlated. We conclude that the Effective Set-Size model may be a useful way of differentiating location uncertainty from the diagnostic uncertainty in medical

  1. Group-size effect on scanning behaviour of Maasai Ostrich Struthio ...

    African Journals Online (AJOL)

    Group-size effect on scanning behaviour of Maasai Ostrich Struthio camelus ... minute) among different group sizes in late 2006 in Serengeti National Park, ... be influenced by factors other than group size, such as body size and habitat type.

  2. Size-dependent nonlocal effects in plasmonic semiconductor particles

    DEFF Research Database (Denmark)

    Maack, Johan Rosenkrantz; Mortensen, N. Asger; Wubs, Martijn

    2017-01-01

    Localized surface plasmons (LSP) in semiconductor particles are expected to exhibit spatial nonlocal response effects as the geometry enters the nanometer scale. To investigate these nonlocal effects, we apply the hydrodynamic model to nanospheres of two different semiconductor materials: intrinsic...... InSb and n-doped GaAs. Our results show that the semiconductors indeed display nonlocal effects, and that these effects are even more pronounced than in metals. In a 150 nm InSb particle at 300 K, the LSP frequency is blueshifted 35%, which is orders of magnitude larger than the blueshift in a metal...... particle of the same size. This property, together with their tunability, makes semiconductors a promising platform for experiments in nonlocal effects. Copyright (C)EPLA, 2017...

  3. Beam size effects in the radiative Bhabha scattering

    International Nuclear Information System (INIS)

    Szczekowski, M.

    1990-01-01

    In some electromagnetic processes the measured cross section can be substantially smaller than calculated in standard Quantum Electrodynamics. The process of single bremsstrahlung, e + e - → e + e - γ is an example of such effect. If the size of the effect for large angle γ radiation is similar to its magnitude at low angles, then standard calculations of the radiative Bahbha background to e.g. the reaction used in counting the number of neutrino generations, e + e - → νν-barγ, at LEP energies can be overestimated by 10-20%. 5 refs., 5 figs. (author)

  4. Relationship of corporal punishment and antisocial behavior by neighborhood.

    Science.gov (United States)

    Grogan-Kaylor, Andrew

    2005-10-01

    To examine the relationship of corporal punishment with children's behavior problems while accounting for neighborhood context and while using stronger statistical methods than previous literature in this area, and to examine whether different levels of corporal punishment have different effects in different neighborhood contexts. Longitudinal cohort study. General community. 1943 mother-child pairs from the National Longitudinal Survey of Youth. Internalizing and externalizing behavior problem scales of the Behavior Problems Index. Parental use of corporal punishment was associated with a 0.71 increase (Pcorporal punishment and children's externalizing behavior problems was not dependent on neighborhood context. The research found no discernible relationship between corporal punishment and internalizing behavior problems.

  5. Good and Bad Neighborhood Approximations for Outlier Detection Ensembles

    DEFF Research Database (Denmark)

    Kirner, Evelyn; Schubert, Erich; Zimek, Arthur

    2017-01-01

    Outlier detection methods have used approximate neighborhoods in filter-refinement approaches. Outlier detection ensembles have used artificially obfuscated neighborhoods to achieve diverse ensemble members. Here we argue that outlier detection models could be based on approximate neighborhoods...... in the first place, thus gaining in both efficiency and effectiveness. It depends, however, on the type of approximation, as only some seem beneficial for the task of outlier detection, while no (large) benefit can be seen for others. In particular, we argue that space-filling curves are beneficial...

  6. Size effects in PbTiO3 nanocrystals: Effect of particle size on spontaneous polarization and strains

    Science.gov (United States)

    Akdogan, E. K.; Rawn, C. J.; Porter, W. D.; Payzant, E. A.; Safari, A.

    2005-04-01

    The spontaneous polarization (Ps) and spontaneous strains (xi) in mechanically unclamped and surface charge compensated PbTiO3 nanocrystals were determined as a function of particle size in the range <150nm by differential scanning calorimetry and x-ray powder diffraction, respectively. Significant deviations from bulk order parameters (P,xi) have been observed as the particle size decreased below ˜100nm. The critical size (rc) below which the ferroelectric tetragonal phase transforms to the paraelectric cubic phase was determined as ˜15nm. The depression in transition temperature with particle size is 14 °C at 28 nm. No change in the order of m3m →4mm ferrodistortive phase transition is observed. A simple analysis showed that ΔHtr/(kBT )˜103 at 25 °C for r =16nm, indicating that the stabilization of the cubic phase at rc cannot be linked to an instability in dipolar ordering due to thermal agitations. Comparison of the spontaneous volumetric strains with the strain induced by surface stress indicated that the effect of surface stress on ferroelectric phase stability was negligible. Anomalies in electrostrictive properties were determined for r →rc. The observed size dependence of PS is attributed to the reduced extent of long-range dipole-dipole interactions that arise due to the changes in bonding characteristics of ions with decreasing particle size in the perovskite lattice, in conformity with a recent study by Tsunekawa et al. [Phys. Rev. Lett. 85 (16), 4340 (2000)].

  7. Finite size effects in simulations of protein aggregation.

    Directory of Open Access Journals (Sweden)

    Amol Pawar

    Full Text Available It is becoming increasingly clear that the soluble protofibrillar species that proceed amyloid fibril formation are associated with a range of neurodegenerative disorders such as Alzheimer's and Parkinson diseases. Computer simulations of the processes that lead to the formation of these oligomeric species are starting to make significant contributions to our understanding of the determinants of protein aggregation. We simulate different systems at constant concentration but with a different number of peptides and we study the how the finite number of proteins affects the underlying free energy of the system and therefore the relative stability of the species involved in the process. If not taken into account, this finite size effect can undermine the validity of theoretical predictions regarding the relative stability of the species involved and the rates of conversion from one to the other. We discuss the reasons that give rise to this finite size effect form both a probabilistic and energy fluctuations point of view and also how this problem can be dealt by a finite size scaling analysis.

  8. Effect of Particle Size on Thermal Conductivity of Nanofluid

    Science.gov (United States)

    Chopkar, M.; Sudarshan, S.; Das, P. K.; Manna, I.

    2008-07-01

    Nanofluids, containing nanometric metallic or oxide particles, exhibit extraordinarily high thermal conductivity. It is reported that the identity (composition), amount (volume percent), size, and shape of nanoparticles largely determine the extent of this enhancement. In the present study, we have experimentally investigated the impact of Al2Cu and Ag2Al nanoparticle size and volume fraction on the effective thermal conductivity of water and ethylene glycol based nanofluid prepared by a two-stage process comprising mechanical alloying of appropriate Al-Cu and Al-Ag elemental powder blend followed by dispersing these nanoparticles (1 to 2 vol pct) in water and ethylene glycol with different particle sizes. The thermal conductivity ratio of nanofluid, measured using an indigenously developed thermal comparator device, shows a significant increase of up to 100 pct with only 1.5 vol pct nanoparticles of 30- to 40-nm average diameter. Furthermore, an analytical model shows that the interfacial layer significantly influences the effective thermal conductivity ratio of nanofluid for the comparable amount of nanoparticles.

  9. Dynamic Vehicle Routing Using an Improved Variable Neighborhood Search Algorithm

    Directory of Open Access Journals (Sweden)

    Yingcheng Xu

    2013-01-01

    Full Text Available In order to effectively solve the dynamic vehicle routing problem with time windows, the mathematical model is established and an improved variable neighborhood search algorithm is proposed. In the algorithm, allocation customers and planning routes for the initial solution are completed by the clustering method. Hybrid operators of insert and exchange are used to achieve the shaking process, the later optimization process is presented to improve the solution space, and the best-improvement strategy is adopted, which make the algorithm can achieve a better balance in the solution quality and running time. The idea of simulated annealing is introduced to take control of the acceptance of new solutions, and the influences of arrival time, distribution of geographical location, and time window range on route selection are analyzed. In the experiment, the proposed algorithm is applied to solve the different sizes' problems of DVRP. Comparing to other algorithms on the results shows that the algorithm is effective and feasible.

  10. Effects of tai chi qigong on psychosocial well-being among hidden elderly, using elderly neighborhood volunteer approach: a pilot randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Chan AW

    2017-01-01

    Full Text Available Aileen WK Chan, Doris SF Yu, KC Choi The Nethersole School of Nursing, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR Purpose: To test the feasibility and preliminary effectiveness of a tai chi qigong program with the assistance of elderly neighborhood volunteers in strengthening social networks and enhancing the psychosocial well-being of hidden elderly. Patients and methods: “Hidden elderly” is a term used to describe older adults who are socially isolated and refuse social participation. This pilot randomized controlled trial recruited 48 older adults aged 60 or above who did not engage in any social activity. They were randomized into tai chi qigong (n=24 and standard care control (n=24 groups. The former group underwent a three-month program of two 60-minute sessions each week, with the socially active volunteers paired up with them during practice. Standard care included regular home visits by social workers. Primary outcomes were assessed by means of the Lubben social network and De Jong Gieveld loneliness scales, and by a revised social support questionnaire. Secondary outcomes were covered by a mental health inventory and the Rosenberg self-esteem scale, and quality of life by using the 12-Item Short Form Health Survey. Data was collected at baseline, and at three and six months thereafter. Results: The generalized estimating equations model revealed general improvement in outcomes among participants on the tai chi qigong program. In particular, participants reported a significantly greater improvement on the loneliness scale (B=-1.32, 95% confidence interval [CI] -2.54 to -0.11, P=0.033 and the satisfaction component of the social support questionnaire (B=3.43, 95% CI 0.10–6.76, P=0.044 than the control group. Conclusion: The pilot study confirmed that tai chi qigong with elderly neighborhood volunteers is a safe and feasible social intervention for hidden elderly. Its potential benefits in

  11. Neighborhood crime and travel behavior : an investigation of the influence of neighborhood crime rates on mode choice - phase II.

    Science.gov (United States)

    2012-01-01

    There are considerable environmental and public health benefits if people choose to walk, bicycle, or ride transit, instead of drive. : However, little work has been done on the effects of neighborhood crimes on mode choice. Instinctively, we underst...

  12. Neighborhood crime and travel behavior : an investigation of the influence of neighborhood crime rates on mode choice, phase II.

    Science.gov (United States)

    2012-01-01

    There are considerable environmental and public health benefits if people choose to walk, bicycle, or ride transit, instead of drive. However, little work has been done on the effects of neighborhood crimes on mode choice. Instinctively, we understan...

  13. Do Neighborhood Characteristics in Amsterdam Influence Adiposity at Preschool Age?

    Directory of Open Access Journals (Sweden)

    E. Jessica Hrudey

    2015-05-01

    Full Text Available Background: Neighborhood characteristics may contribute to adiposity in young children, but results in the current literature are inconsistent. This study aimed to investigate whether objective (socioeconomic status (SES and subjective (perceived safety, satisfaction with green spaces and perceived physical disorder neighborhood characteristics directly influence child adiposity (as measured by BMI, percent body fat (%BF and waist-to-height ratio (WHtR. Methods: Data on child BMI, %BF and WHtR were obtained from the Amsterdam Born Children and their Development cohort at 5–6 years of age. Three thousand four hundred and sixty nine (3469 children were included in the analyses. Mixed models, using random intercepts for postal code area to account for neighborhood clustering effects, were used to analyze the relationships of interest. Results: Associations were observed for both perceived safety and neighborhood SES with %BF after adjustment for maternal education and ethnicity. All relationships were eliminated with the inclusion of individual covariates and parental BMI into the models. Conclusions: In general, child adiposity at age 5–6 years was not independently associated with neighborhood characteristics, although a small relationship between child %BF and both neighborhood SES and perceived safety cannot be ruled out. At this young age, familial and individual factors probably play a more important role in influencing child adiposity than neighborhood characteristics.

  14. Effects of picture size reduction and blurring on emotional engagement.

    Directory of Open Access Journals (Sweden)

    Andrea De Cesarei

    Full Text Available The activity of basic motivational systems is reflected in emotional responses to arousing stimuli, such as natural pictures. The manipulation of picture properties such as size or detail allows for investigation into the extent to which separate emotional reactions are similarly modulated by perceptual changes, or, rather, may subserve different functions. Pursuing this line of research, the present study examined the effects of two types of perceptual degradation, namely picture size reduction and blurring, on emotional responses. Both manipulations reduced picture relevance and dampened affective modulation of skin conductance, possibly because of a reduced action preparation in response to degraded or remote pictures. However, the affective modulation of the startle reflex did not vary with picture degradation, suggesting that the identification of these degraded affective cues activated the neural circuits mediating appetitive or defensive motivation.

  15. Asteroid collisional history - Effects on sizes and spins

    International Nuclear Information System (INIS)

    Davis, D.R.; Weidenschilling, S.J.; Farinella, P.; Paolicchi, P.; Binzel, R.P.

    1989-01-01

    The effects of asteroid collisional history on sizes and spins of present-day objects are discussed. Collisional evolution studies indicate that collisions have altered the spin-rates of small bodies, but that the largest asteroids may have retained their primordial rotation rates. Most asteroids larger than 100 km diam have probably been shattered, but have gravitationally recaptured their fragments to form a rubble-pile structure. Large angular momentum asteroids appear to have Maclaurian spheroidal or Jacobi-ellipsoid-like shapes; some of them may have fissioned into binaries. An integrated size and spin collisional evolution model is presented, with two critical parameters: one which determines the spin rates for small fragments resulting from a shattering collision, and the other determines the fraction of impact angular momentum that is retained by the target. 36 refs

  16. Fast and accurate determination of modularity and its effect size

    International Nuclear Information System (INIS)

    Treviño, Santiago III; Nyberg, Amy; Bassler, Kevin E; Del Genio, Charo I

    2015-01-01

    We present a fast spectral algorithm for community detection in complex networks. Our method searches for the partition with the maximum value of the modularity via the interplay of several refinement steps that include both agglomeration and division. We validate the accuracy of the algorithm by applying it to several real-world benchmark networks. On all these, our algorithm performs as well or better than any other known polynomial scheme. This allows us to extensively study the modularity distribution in ensembles of Erdős–Rényi networks, producing theoretical predictions for means and variances inclusive of finite-size corrections. Our work provides a way to accurately estimate the effect size of modularity, providing a z-score measure of it and enabling a more informative comparison of networks with different numbers of nodes and links. (paper)

  17. Effect of particle size on degree of inversion in ferrites

    International Nuclear Information System (INIS)

    Siddique, M.; Butt, N.M.

    2012-01-01

    Ferrites with the spinel structure are important materials because of their structural, magnetic and electrical properties. The suitability of these materials depends on both the intrinsic behavior of the material and the effects of the grain size. Moessbauer spectroscopy was employed to investigate the cation distribution and degree of inversion in bulk and nano sized particles of CuFe/sub 2/O/sub 4/, MnFe/sub 2/O/sub 4/ and NiFe/sub 2/O/sub 4/ ferrites. The Moessbauer spectra of all bulk ferrites showed complete magnetic behavior, whereas nanoparticle ferrites showed combination of ferromagnetic and superparamagnetic components. Moreover, the cation distribution in nanoparticle materials was also found to be different to that of their bulk counterparts indicating the particle size dependency. The inversion of Cu and Ni ions in bulk sample was greater than that of nanoparticles; whereas the inversion of Mn ions was less in bulk material as compared to the nanoparticles. Hence the degree of inversion decreased in CuFe/sub 2/O/sub 4/ and NiFe/sub 2/O/sub 4/ samples whereas, it increased in MnFe/sub 2/O/sub 4/ as the particle size decreased and thus showed the anomalous behavior in this case. The nanoparticle samples also showed paramagnetic behaviour due to superparamagnetism and this effect is more prominent in MnFe/sub 2/O/sub 4/. Moessbauer spectra of bulk and nanoparticles CuFe/sub 2/O/sub 4/ is shown. (Orig./A.B.)

  18. Neighborhood differences in social capital in Ghent (Belgium): a multilevel approach.

    Science.gov (United States)

    Neutens, Tijs; Vyncke, Veerle; De Winter, Dieter; Willems, Sara

    2013-11-13

    Little research has focused on the spatial distribution of social capital, despite social capital's rising popularity in health research and policy. This study examines the neighborhood differences in social capital and the determinants that explain these differences. Five components of neighborhood social capital are identified by means of factor and reliability analyses using data collected in the cross-sectional SWING study from 762 inhabitants in 42 neighbourhoods in the city of Ghent (Belgium). Neighborhood differences in social capital are explored using hierarchical linear models with cross-level interactions. Significant neighborhood differences are found for social cohesion, informal social control and social support, but not for social leverage and generalized trust. Our findings suggest that neighborhood social capital depends on both characteristics of individuals living in the neighborhood (attachment to neighborhood) and characteristics of the neighborhood itself (deprivation and residential turnover). Our analysis further shows that neighborhood deprivation reinforces the negative effect of declining neighborhood attachment on social cohesion and informal social control. This study foregrounds the importance of contextual effects in encouraging neighborhood social capital. Given the importance of neighborhood-level characteristics, it can be anticipated social capital promoting initiatives are likely to be more effective when tailored to specific areas. Second, our analyses show that not all forms of social capital are influenced by contextual factors to the same extent, implying that changes in neighborhood characteristics are conducive to, say, trust while leaving social support unaffected. Finally, our analysis has demonstrated that complex interrelationships between individual- and neighborhood-level variables exist, which are often overlooked in current work.

  19. No Effect of Featural Attention on Body Size Aftereffects

    Directory of Open Access Journals (Sweden)

    Ian David Stephen

    2016-08-01

    Full Text Available Prolonged exposure to images of narrow bodies has been shown to induce a perceptual aftereffect, such that observers’ point of subjective normality (PSN for bodies shifts towards narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level stimuli, object attention (attention directed to the object and spatial attention (attention directed to the location of the object have been shown to increase the magnitude of visual aftereffects, while object-based attention enhances the adaptation effect in faces. It is not known whether featural attention (attention directed to a specific aspect of the object affects the magnitude of adaptation effects in body stimuli. Here, we manipulate the attention of Caucasian observers to different featural information in body images, by asking them to rate the fatness or sex typicality of male and female bodies manipulated to appear fatter or thinner than average. PSNs for body fatness were taken at baseline and after adaptation, and a change in PSN (ΔPSN was calculated. A body size adaptation effect was found, with observers who viewed fat bodies showing an increased PSN, and those exposed to thin bodies showing a reduced PSN. However, manipulations of featural attention to body fatness or sex typicality produced equivalent results, suggesting that featural attention may not affect the strength of the body size aftereffect.

  20. Finite-size effects on multibody neutrino exchange

    CERN Document Server

    Abada, A; Rodríguez-Quintero, J; Abada, As

    1998-01-01

    The effect of multibody massless neutrino exchanges between neutrons inside a finite-size neutron star is studied. We use an effective Lagrangian, which incorporates the effect of the neutrons on the neutrinos. Following Schwinger, it is shown that the total interaction energy density is computed by comparing the zero point energy of the neutrino sea with and without the star. It has already been shown that in an infinite-size star the total energy due to neutrino exchange vanishes exactly. The opposite claim that massless neutrino exchange would produce a huge energy is due to an improper summation of an infrared-divergent quantity. The same vanishing of the total energy has been proved exactly in the case of a finite star in a one-dimensional toy model. Here we study the three-dimensional case. We first consider the effect of a sharp star border, assumed to be a plane. We find that there is a non- vanishing of the zero point energy density difference between the inside and the outside due to the refraction ...

  1. Size-effect features on the magnetothermopower of bismuth nanowires

    International Nuclear Information System (INIS)

    Condrea, E.; Nicorici, A.

    2011-01-01

    Full text: In this work we have studied the magnetic field dependence of the thermopower (TEP) and resistance of glass-coated Bi wires with diameter (d) from 100 nm to at 1.5 μm below 80 K. Nanowires have anomalously large values of the thermopower (+100 μV K.1) and relatively high effective resistivities, but their frequencies of SdH oscillations remain those of bulk Bi. The TEP stays positive in longitudinal magnetic fields up to 15 T, where the surface scattering of charge carriers is negligible. Our analysis shows that the anomalous thermopower has a diffusion origin and is a consequence of the microstructure rather than the result of the strong scattering of electrons by the wire walls. The intensities of field at which the size-effect features appear on the magnetothermopower curves correspond to a value at which the diameter of the hole cyclotron orbit equals d. Size-effect features were observed only for set of nanowires with d = 100-350 nm, where diffusion TEP is dominant. The contribution of the phonon-drag effect was observed in a wire with diameter larger than 400 nm and becomes dominant at diameter of 1 μm. (authors)

  2. No Effect of Featural Attention on Body Size Aftereffects.

    Science.gov (United States)

    Stephen, Ian D; Bickersteth, Chloe; Mond, Jonathan; Stevenson, Richard J; Brooks, Kevin R

    2016-01-01

    Prolonged exposure to images of narrow bodies has been shown to induce a perceptual aftereffect, such that observers' point of subjective normality (PSN) for bodies shifts toward narrower bodies. The converse effect is shown for adaptation to wide bodies. In low-level stimuli, object attention (attention directed to the object) and spatial attention (attention directed to the location of the object) have been shown to increase the magnitude of visual aftereffects, while object-based attention enhances the adaptation effect in faces. It is not known whether featural attention (attention directed to a specific aspect of the object) affects the magnitude of adaptation effects in body stimuli. Here, we manipulate the attention of Caucasian observers to different featural information in body images, by asking them to rate the fatness or sex typicality of male and female bodies manipulated to appear fatter or thinner than average. PSNs for body fatness were taken at baseline and after adaptation, and a change in PSN (ΔPSN) was calculated. A body size adaptation effect was found, with observers who viewed fat bodies showing an increased PSN, and those exposed to thin bodies showing a reduced PSN. However, manipulations of featural attention to body fatness or sex typicality produced equivalent results, suggesting that featural attention may not affect the strength of the body size aftereffect.

  3. White dwarf cosmochronology in the solar neighborhood

    Energy Technology Data Exchange (ETDEWEB)

    Tremblay, P.-E.; Kalirai, J. S.; Soderblom, D. R.; Cignoni, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Cummings, J., E-mail: tremblay@stsci.edu [Center for Astrophysical Sciences, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

    2014-08-20

    The study of the stellar formation history in the solar neighborhood is a powerful technique to recover information about the early stages and evolution of the Milky Way. We present a new method that consists of directly probing the formation history from the nearby stellar remnants. We rely on the volume complete sample of white dwarfs within 20 pc, where accurate cooling ages and masses have been determined. The well characterized initial-final mass relation is employed in order to recover the initial masses (1 ≲ M {sub initial}/M {sub ☉} ≲ 8) and total ages for the local degenerate sample. We correct for moderate biases that are necessary to transform our results to a global stellar formation rate, which can be compared to similar studies based on the properties of main-sequence stars in the solar neighborhood. Our method provides precise formation rates for all ages except in very recent times, and the results suggest an enhanced formation rate for the solar neighborhood in the last 5 Gyr compared to the range 5 < Age (Gyr) < 10. Furthermore, the observed total age of ∼10 Gyr for the oldest white dwarfs in the local sample is consistent with the early seminal studies that have determined the age of the Galactic disk from stellar remnants. The main shortcoming of our study is the small size of the local white dwarf sample. However, the presented technique can be applied to larger samples in the future.

  4. White dwarf cosmochronology in the solar neighborhood

    International Nuclear Information System (INIS)

    Tremblay, P.-E.; Kalirai, J. S.; Soderblom, D. R.; Cignoni, M.; Cummings, J.

    2014-01-01

    The study of the stellar formation history in the solar neighborhood is a powerful technique to recover information about the early stages and evolution of the Milky Way. We present a new method that consists of directly probing the formation history from the nearby stellar remnants. We rely on the volume complete sample of white dwarfs within 20 pc, where accurate cooling ages and masses have been determined. The well characterized initial-final mass relation is employed in order to recover the initial masses (1 ≲ M initial /M ☉ ≲ 8) and total ages for the local degenerate sample. We correct for moderate biases that are necessary to transform our results to a global stellar formation rate, which can be compared to similar studies based on the properties of main-sequence stars in the solar neighborhood. Our method provides precise formation rates for all ages except in very recent times, and the results suggest an enhanced formation rate for the solar neighborhood in the last 5 Gyr compared to the range 5 < Age (Gyr) < 10. Furthermore, the observed total age of ∼10 Gyr for the oldest white dwarfs in the local sample is consistent with the early seminal studies that have determined the age of the Galactic disk from stellar remnants. The main shortcoming of our study is the small size of the local white dwarf sample. However, the presented technique can be applied to larger samples in the future.

  5. Neighborhood Disadvantage, Neighborhood Safety and Cardiometabolic Risk Factors in African Americans: Biosocial Associations in the Jackson Heart Study

    Science.gov (United States)

    Clark, Cheryl R.; Ommerborn, Mark J.; Hickson, DeMarc A.; Grooms, Kya N.; Sims, Mario; Taylor, Herman A.; Albert, Michelle A.

    2013-01-01

    Objective We examined associations between neighborhood socioeconomic disadvantage, perceived neighborhood safety and cardiometabolic risk factors, adjusting for health behaviors and socioeconomic status (SES) among African Americans. Methods Study participants were non-diabetic African Americans (n = 3,909) in the baseline examination (2000–2004) of the Jackson Heart Study. We measured eight risk factors: the metabolic syndrome, its five components, insulin resistance and cardiovascular inflammation. We assessed neighborhood socioeconomic disadvantage with US Census 2000 data. We assessed perceived neighborhood safety, health behaviors and SES via survey. We used generalized estimating equations to estimate associations with a random intercept model for neighborhood effects. Results After adjustment for health behaviors and SES, neighborhood socioeconomic disadvantage was associated with the metabolic syndrome in women (PR 1.13, 95% CI 1.01, 1.27). Lack of perceived safety was associated with elevated glucose (OR 1.36, 95% CI 1.03, 1.80) and waist circumference (PR 1.06, 95% CI 1.02, 1.11) among women, and with elevated glucose (PR 1.30, 95% CI 1.02, 1.66) and insulin resistance (PR 1.25, 95% CI 1.08, 1.46) among men. Conclusions Neighborhood socioeconomic disadvantage and perceived safety should be considered as targets for intervention to reduce cardiometabolic risks among African Americans. PMID:23691005

  6. The Effect of Family Size on Incentive Effects of Welfare Transfers in Two-Parent Families

    Science.gov (United States)

    Lewin, Alisa C.; Maurin, Eric

    2005-01-01

    Family size is an important determinant of family well-being, and it is a good predictor of poverty. This study examines effects of waiving the 100-hour rule, by family size, and distinguishes between the "work-incentive effects" and the "eligibility effects" of the waiver. The 100-hour rule limits eligibility to aid to…

  7. Neighborhood Factors and Dating Violence Among Youth: A Systematic Review.

    Science.gov (United States)

    Johnson, Renee M; Parker, Elizabeth M; Rinehart, Jenny; Nail, Jennifer; Rothman, Emily F

    2015-09-01

    The purpose of this review is to summarize the empirical research on neighborhood-level factors and dating violence among adolescents and emerging adults to guide future research and practice. In 2015, a total of 20 articles were identified through a search of the literature using PubMed. Eligible articles included those that (1) had been published in a peer-reviewed journal since 2005; (2) reported a measure of association between at least one neighborhood-level factor and dating violence; and (3) had a study population of youth aged dating violence and neighborhood factors, and measures of effect. Results were summarized into three categories based on the aspect of neighborhood that was the focus of the work: demographic and structural characteristics (n=11); neighborhood disorder (n=12); and social disorganization (n=8). There was some evidence to suggest that neighborhood disadvantage is associated with dating violence, but very little evidence to suggest that residence characteristics (e.g., racial heterogeneity) are associated with dating violence. Results do suggest that perceived neighborhood disorder is associated with physical dating violence perpetration, but do not suggest that it is associated with physical dating violence victimization. Social control and community connectedness are both associated with dating violence, but findings on collective efficacy are mixed. Existing research suggests that neighborhood factors may be associated with dating violence. However, there is a limited body of research on the neighborhood context of dating violence, and more rigorous research is needed. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  8. Neighborhood Environmental Watch Network

    International Nuclear Information System (INIS)

    Sanders, L.D.

    1993-01-01

    The Neighborhood Environmental Watch Network (NEWNET) is a regional network of environmental monitoring stations and a data archival center that supports collaboration between communities, industry, and government agencies to solve environmental problems. The stations provide local displays of measurements for the public and transmit measurements via satellite to a central site for archival and analysis. Station managers are selected from the local community and trained to support the stations. Archived data and analysis tools are available to researchers, educational institutions, industrial collaborators, and the public across the nation through a communications network. Los Alamos National Laboratory and the Environmental Protection Agency have developed a NEWNET pilot program for the Department of Energy. The pilot program supports monitoring stations in Nevada, Arizona, Utah, Wyoming, and California. Additional stations are being placed in Colorado and New Mexico. Pilot stations take radiological and meteorological measurements. Other measurements are possible by exchanging sensors

  9. Size Effect Studies on Tensile Tests for Hot Stamping Steel

    Science.gov (United States)

    Chen, Xiaodu; Li, Yuanyuan; Han, Xianhong; Zhang, Junbo

    2018-02-01

    Tensile tests have been widely used to determine basic mechanical properties of materials. However, the properties measured may be related to geometrical factors of the tested samples especially for high-strength steels; this makes the properties' definitions and comparisons difficult. In this study, a series of tensile tests of ultra-high-strength hot-stamped steel were performed; the geometric shapes and sizes as well as the cutting direction were modified. The results demonstrate that the hot-stamped parts were isotropic and the cutting direction had no effect; the measured strengths were practically unrelated to the specimen geometries, including both size and shape. The elongations were slightly related to sample sizes within the studied range but highly depended on the sample shape, represented by the coefficient K. Such phenomena were analyzed and discussed based on microstructural observations and fracture morphologies. Moreover, two widely used elongation conversion equations, the Oliver formula and Barba's law, were introduced to verify their applicability, and a new interpolating function was developed and compared.

  10. Assessing the psychometric and ecometric properties of neighborhood scales using adolescent survey data from urban and rural Scotland.

    Science.gov (United States)

    Martin, Gina; Inchley, Joanna; Humphris, Gerry; Currie, Candace

    2017-03-28

    future studies of neighborhoods and health. However, trade-offs between neighborhood sample size and reliability must be considered.

  11. The effect of nanocrystalline magnetite size on arsenic removal

    Directory of Open Access Journals (Sweden)

    J.T. Mayo et al

    2007-01-01

    Full Text Available Higher environmental standards have made the removal of arsenic from water an important problem for environmental engineering. Iron oxide is a particularly interesting sorbent to consider for this application. Its magnetic properties allow relatively routine dispersal and recovery of the adsorbent into and from groundwater or industrial processing facilities; in addition, iron oxide has strong and specific interactions with both As(III and As(V. Finally, this material can be produced with nanoscale dimensions, which enhance both its capacity and removal. The objective of this study is to evaluate the potential arsenic adsorption by nanoscale iron oxides, specifically magnetite (Fe3O4 nanoparticles. We focus on the effect of Fe3O4 particle size on the adsorption and desorption behavior of As(III and As(V. The results show that the nanoparticle size has a dramatic effect on the adsorption and desorption of arsenic. As particle size is decreased from 300 to 12 nm the adsorption capacities for both As(III and As(V increase nearly 200 times. Interestingly, such an increase is more than expected from simple considerations of surface area and suggests that nanoscale iron oxide materials sorb arsenic through different means than bulk systems. The desorption process, however, exhibits some hysteresis with the effect becoming more pronounced with small nanoparticles. This hysteresis most likely results from a higher arsenic affinity for Fe3O4 nanoparticles. This work suggests that Fe3O4 nanocrystals and magnetic separations offer a promising method for arsenic removal.

  12. The flexoelectric effect associated size dependent pyroelectricity in solid dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Gang, E-mail: baigang@njupt.edu.cn [Jiangsu Provincial Engineering Laboratory for RF Integration and Micropackaging and College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Liu, Zhiguo [Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Xie, Qiyun; Guo, Yanyan; Li, Wei [Jiangsu Provincial Engineering Laboratory for RF Integration and Micropackaging and College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Yan, Xiaobing [College of Electronic and information Engineering, Hebei University, Baoding 071002 (China)

    2015-09-15

    A phenomenological thermodynamic theory is used to investigate the effect of strain gradient on the pyroelectric effect in centrosymmetric dielectric solids. Direct pyroelectricity can exist as external mechanical stress is applied to non-pyroelectric dielectrics with shapes such as truncated pyramids, due to elastic strain gradient induced flexoelectric polarization. Effective pyroelectric coefficient was analyzed in truncated pyramids. It is found to be controlled by size, ambient temperature, stress, and aspect ratio and depends mainly on temperature sensitivity of flexoelectric coefficient (TSFC) and strain gradient of the truncated pyramids dielectric solids. These results show that the pyroelectric property of Ba{sub 0.67}Sr{sub 0.33}TiO{sub 3} above T{sub c} similar to PZT and other lead-based ferroelectrics can be obtained. This feature might widely broaden the selection of materials for infrared detectors with preferable properties.

  13. The flexoelectric effect associated size dependent pyroelectricity in solid dielectrics

    Science.gov (United States)

    Bai, Gang; Liu, Zhiguo; Xie, Qiyun; Guo, Yanyan; Li, Wei; Yan, Xiaobing

    2015-09-01

    A phenomenological thermodynamic theory is used to investigate the effect of strain gradient on the pyroelectric effect in centrosymmetric dielectric solids. Direct pyroelectricity can exist as external mechanical stress is applied to non-pyroelectric dielectrics with shapes such as truncated pyramids, due to elastic strain gradient induced flexoelectric polarization. Effective pyroelectric coefficient was analyzed in truncated pyramids. It is found to be controlled by size, ambient temperature, stress, and aspect ratio and depends mainly on temperature sensitivity of flexoelectric coefficient (TSFC) and strain gradient of the truncated pyramids dielectric solids. These results show that the pyroelectric property of Ba0.67Sr0.33TiO3 above Tc similar to PZT and other lead-based ferroelectrics can be obtained. This feature might widely broaden the selection of materials for infrared detectors with preferable properties.

  14. Why herd size matters - mitigating the effects of livestock crashes.

    Directory of Open Access Journals (Sweden)

    Marius Warg Næss

    Full Text Available Analysing the effect of pastoral risk management strategies provides insights into a system of subsistence that have persevered in marginal areas for hundreds to thousands of years and may shed light into the future of around 200 million households in the face of climate change. This study investigated the efficiency of herd accumulation as a buffer strategy by analysing changes in livestock holdings during an environmental crisis in the Saami reindeer husbandry in Norway. We found a positive relationship between: (1 pre- and post-collapse herd size; and (2 pre-collapse herd size and the number of animals lost during the collapse, indicating that herd accumulation is an effective but costly strategy. Policies that fail to incorporate the risk-beneficial aspect of herd accumulation will have a limited effect and may indeed fail entirely. In the context of climate change, official policies that incorporate pastoral risk management strategies may be the only solution for ensuring their continued existence.

  15. Pleiotropic Effects of DDT Resistance on Male Size and Behaviour.

    Science.gov (United States)

    Rostant, Wayne G; Bowyer, Jemima; Coupland, Jack; Facey, James; Hosken, David J; Wedell, Nina

    2017-07-01

    Understanding the evolution and spread of insecticide resistance requires knowing the relative fitness of resistant organisms. In the absence of insecticides, resistance is predicted to be costly. The Drosophila melanogaster DDT resistance allele (DDT-R) is associated with a male mating cost. This could be because resistant males are generally smaller, but DDT-R may also alter courtship behaviours. Here we tested for body size and courtship effects of DDT-R on mating success in competitive and non-competitive mating trials respectively. We also assessed relative aggression in resistant and susceptible males because aggression can also influence mating success. While the effect of DDT-R on male size partly contributed to reduced mating success, resistant males also had lower rates of courtship and were less aggressive than susceptible males. These differences contribute to the observed DDT-R mating costs. Additionally, these pleiotropic effects of DDT-R are consistent with the history and spread of resistance alleles in nature.

  16. Effect Sizes for Research Univariate and Multivariate Applications

    CERN Document Server

    Grissom, Robert J

    2011-01-01

    Noted for its comprehensive coverage, this greatly expanded new edition now covers the use of univariate and multivariate effect sizes. Many measures and estimators are reviewed along with their application, interpretation, and limitations. Noted for its practical approach, the book features numerous examples using real data for a variety of variables and designs, to help readers apply the material to their own data. Tips on the use of SPSS, SAS, R, and S-Plus are provided. The book's broad disciplinary appeal results from its inclusion of a variety of examples from psychology, medicine, educa

  17. Finite size effects in quark-gluon plasma formation

    International Nuclear Information System (INIS)

    Gopie, Andy; Ogilvie, Michael C.

    1999-01-01

    Using lattice simulations of quenched QCD we estimate the finite size effects present when a gluon plasma equilibrates in a slab geometry, i.e., finite width but large transverse dimensions. Significant differences are observed in the free energy density for the slab when compared with bulk behavior. A small shift in the critical temperature is also seen. The free energy required to liberate heavy quarks relative to bulk is measured using Polyakov loops; the additional free energy required is on the order of 30 - 40 MeV at 2 - 3 T c

  18. Size effect of glulam beams in tension perpendicular to grain

    DEFF Research Database (Denmark)

    Astrup, Thomas; Clorius, Christian Odin; Damkilde, Lars

    2007-01-01

    The strength of wood is reduced when the stressed volume is increased. The phenomenon is termed size effect and is often explained as being stochastic in the sense that the probability of weak locations occurring in the wood increases with increased volume. This paper presents the hypothesis...... that the lower strength is caused by stress concentrations. The stress concentrations arise from the anisotropic structure of wood, and are therefore deterministic. The hypothesis is substantiated through extensive FEM-calculations and experiments. A reasonable agreement between ultimate stresses determined...

  19. The size effects upon shock plastic compression of nanocrystals

    Science.gov (United States)

    Malygin, G. A.; Klyavin, O. V.

    2017-10-01

    For the first time a theoretical analysis of scale effects upon the shock plastic compression of nanocrystals is implemented in the context of a dislocation kinetic approach based on the equations and relationships of dislocation kinetics. The yield point of crystals τy is established as a quantitative function of their cross-section size D and the rate of shock deformation as τy ɛ2/3 D. This dependence is valid in the case of elastic stress relaxation on account of emission of dislocations from single-pole Frank-Read sources near the crystal surface.

  20. Parental and Adolescent Perceptions of Neighborhood Safety Related to Adolescents' Physical Activity in Their Neighborhood

    Science.gov (United States)

    Esteban-Cornejo, Irene; Carlson, Jordan A.; Conway, Terry L.; Cain, Kelli L.; Saelens, Brian E.; Frank, Lawrence D.; Glanz, Karen; Roman, Caterina G.; Sallis, James F.

    2016-01-01

    Purpose: The purpose of this study was to examine the association between adolescent and parental perceptions of neighborhood safety and adolescents' physical activity in multiple locations and to investigate the moderating effect of sex within this association. Method: This cross-sectional study was conducted with 928 adolescents aged 12 to 16…

  1. Neighborhood Context and Immigrant Young Children's Development

    Science.gov (United States)

    Leventhal, Tama; Shuey, Elizabeth A.

    2014-01-01

    This study explored how neighborhood social processes and resources, relevant to immigrant families and immigrant neighborhoods, contribute to young children's behavioral functioning and achievement across diverse racial/ethnic groups. Data were drawn from the Project on Human Development in Chicago Neighborhoods, a neighborhood-based,…

  2. The Relation of Neighborhood Income to the Age-Related Patterns of Preterm Birth Among White and African-American Women: The Effect of Cigarette Smoking.

    Science.gov (United States)

    Hibbs, Shayna; Rankin, Kristin M; David, Richard J; Collins, James W

    2016-07-01

    Objectives We investigated the contributions of cigarette smoking to the age-related patterns of preterm (White women within the context of lifelong neighborhood income. Methods Stratified and multilevel logistic regression analyses were performed on an Illinois transgenerational dataset of non-Hispanic White and African-American infants (1989-1991) and their mothers (1956-1976) with appended US census income information. Among non-smoking African-American women (n = 20,107) with a lifelong residence in lower income neighborhoods, PTB rates decreased from 18.5 % for teens to 15.0 % for 30-35 year-olds, p smokers (n = 5936) with a lifelong residence in lower income neighborhoods, p smokers (n = 756), PTB rates increased from 11.1 % for teens to 24.9 % for 30-35 year-olds, p White women, even cigarette smokers with a lifelong residence in lower income neighborhoods, exhibited weathering with regard to PTB. Conclusions A weathering pattern of rising PTB rates with advancing age occurs only among African-American women cigarette smokers with an early-life or lifelong residence in lower income neighborhoods, underscoring the public health policy importance of targeted smoking cessation programs in eliminating the racial disparity in the age-related patterns of PTB rates.

  3. Transport, retention, and size perturbation of graphene oxide in saturated porous media: Effects of input concentration and grain size

    Science.gov (United States)

    Accurately predicting the fate and transport of graphene oxide (GO) in porous media is critical to assess its environmental impact. In this work, sand column experiments were conducted to determine the effect of input concentration and grain size on transport, retention, and size perturbation of GO ...

  4. Neighborhood Risk, Parental Socialization Styles, and Adolescent Conduct Problems

    OpenAIRE

    Enrique Gracia; Mª Castillo Fuentes; Fernando García

    2010-01-01

    This article aims to analyze the influence of parental socialization styles (authoritarian, authoritative, indulgent and neglectful), and perceived neighborhood risk on three indicators of conduct problems in adolescence (school misconduct, delinquency, and drug use). The sample consists of 1,017 adolescents, aged between 12 and 17. Results from four multivariate factorial designs yielded only main effects of parenting styles and neighborhood risk. Adolescents from authoritative and indulgent...

  5. Size Effects on Deformation and Fracture of Scandium Deuteride Films.

    Energy Technology Data Exchange (ETDEWEB)

    Teresi, C. S. [Univ. of Minnesota, Minneapolis, MN (United States); Hintsala, E. [Univ. of Minnesota, Minneapolis, MN (United States); Hysitron, Inc., Eden Prairie, MN (United States); Adams, David P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yang, Nancy Y. C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kammler, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moody, N. R. [Univ. of Minnesota, Minneapolis, MN (United States); Gerberich, W. W. [Univ. of Minnesota, Minneapolis, MN (United States)

    2017-07-01

    Metal hydride films have been observed to crack during production and use, prompting mechanical property studies of scandium deuteride films. The following focuses on elastic modulus, fracture, and size effects observed in the system for future film mechanical behavior modeling efforts. Scandium deuteride films were produced through the deuterium charging of electron beam evaporated scandium films using X-ray diffraction, scanning Auger microscopy, and electron backscatter diffraction to monitor changes in the films before and after charging. Scanning electron microscopy, nanoindentation, and focused ion beam machined micropillar compression tests were used for mechanical characterization of the scandium deuteride films. The micropillars showed a size effect for flow stress, indicating that film thickness is a relevant tuning parameter for film performance, and that fracture was controlled by the presence of grain boundaries. Elastic modulus was determined by both micropillar compression and nanoindentation to be approximately 150 GPa, Fracture studies of bulk film channel cracking as well as compression induced cracks in some of the pillars yielded a fracture toughness around 1.0 MPa-m1/2. Preliminary Weibull distributions of fracture in the micropillars are provided. Despite this relatively low value of fracture toughness, scandium deuteride micropillars can undergo a large degree of plasticity in small volumes and can harden to some degree, demonstrating the ductile and brittle nature of this material

  6. fB from finite size effects in lattice QCD

    International Nuclear Information System (INIS)

    Guagnelli, M.; Palombi, F.; Petronzio, R.; Tantalo, N.

    2003-01-01

    We discuss a novel method to calculate f B on the lattice, introduced in [1], based on the study of the dependence of finite size effects upon the heavy quark mass of flavoured mesons and on a non-perturbative recursive finite size technique. This method avoids the systematic errors related to extrapolations from the static limit or to the tuning of the coefficients of effective Lagrangian and the results admit an extrapolation to the continuum limit. We show the results of a first estimate at finite lattice spacing, but close to the continuum limit, giving f B = 170(11)(5)(22) MeV. We also obtain f B s = 192(9)(5)(24)MeV. The first error is statistical, the second is our estimate of the systematic error from the method and the third the systematic error from the specific approximations adopted in this first exploratory calculation. The method can be generalized to two-scale problems in lattice QCD

  7. Generation time and effective population size in Polar Eskimos

    Science.gov (United States)

    Matsumura, Shuichi; Forster, Peter

    2008-01-01

    North Greenland Polar Eskimos are the only hunter–gatherer population, to our knowledge, who can offer precise genealogical records spanning several generations. This is the first report from Eskimos on two key parameters in population genetics, namely, generation time (T) and effective population size (Ne). The average mother–daughter and father–son intervals were 27 and 32 years, respectively, roughly similar to the previously published generation times obtained from recent agricultural societies across the world. To gain an insight for the generation time in our distant ancestors, we calculated maternal generation time for two wild chimpanzee populations. We also provide the first comparison among three distinct approaches (genealogy, variance and life table methods) for calculating Ne, which resulted in slightly differing values for the Eskimos. The ratio of the effective to the census population size is estimated as 0.6–0.7 for autosomal and X-chromosomal DNA, 0.7–0.9 for mitochondrial DNA and 0.5 for Y-chromosomal DNA. A simulation of alleles along the genealogy suggested that Y-chromosomal DNA may drift a little faster than mitochondrial DNA in this population, in contrast to agricultural Icelanders. Our values will be useful not only in prehistoric population inference but also in understanding the shaping of our genome today. PMID:18364314

  8. Association of Mothers’ Perception of Neighborhood Quality and Maternal Resilience with Risk of Preterm Birth

    Directory of Open Access Journals (Sweden)

    Namrata Bhatia

    2015-08-01

    Full Text Available We examined the associations of mothers’ perception of neighborhood quality and maternal resilience with risk of preterm birth and whether maternal resilience moderated the effect of neighborhood quality perception. We analyzed data from 10,758 women with singleton births who participated in 2010–2012 Los Angeles Mommy and Baby surveys. Multilevel logistic regression models assessed the effects of mothers’ perception of neighborhood quality and maternal resilience on preterm birth (yes/no, controlling for potential confounders and economic hardship index, a city-level measure of neighborhood quality. Interaction terms were assessed for moderation. Mothers’ perception of neighborhood quality and maternal resilience were each uniquely associated with preterm birth, independent of potential confounders (p-values < 0.05. The risk of preterm birth among mothers who perceived their neighborhood as of poor quality was about 30% greater compared to mothers who perceived their neighborhood as of good quality; the risk was 12% greater among mothers with low resilience compared to those with high resilience. Effects of neighborhood quality were not modified by maternal resilience. The findings suggest that mothers’ perception of neighborhood quality and resilience are associated with the risk of preterm birth. Further research should explore whether initiatives aimed at improving neighborhood quality and women’s self-esteem may improve birth outcomes.

  9. Equipment size effects on open pit mining performance

    Energy Technology Data Exchange (ETDEWEB)

    A. Bozorgebrahimi; R.A. Hall; M.A. Morin [University of British Columbia, Vancouver, BC (Canada). Mining Engineering Department

    2005-03-01

    This paper discusses the exploitation of economies of scale in open pit mining through the use of increasingly larger equipment. It presents a method adopted to evaluate the impact of increased scale on operational performance factors. The work identifies equipment size sensitive variables (ESSVs) in the mine design process that affect the performance of the production process. Data from a set of case studies show that the ESSV influence extends beyond mine production to encompass milling performance, environmental footprint and community impacts. Some ESSVs (such as reliability, tyre costs and productivity) are shown to be related to the current state of equipment technology and their effects are therefore comparable for different mines. Other ESSVs relate to the mine and deposit characteristics; their effects therefore vary from mine to mine. A detailed analytical approach, developed to model the impact of ESSVs, suggests that for truck/shovel operations, the industry may be approaching a situation of diseconomies of scale.

  10. Cost-effective unilateral climate policy design: Size Matters

    Energy Technology Data Exchange (ETDEWEB)

    Boehringer, Christoph; Fischer, Carolyn; Rosendahl, Knut Einar

    2011-07-01

    Given the bleak prospects for a global agreement on mitigating climate change, pressure for unilateral abatement is increasing. A major challenge is emissions leakage. Border carbon adjustments and output-based allocation of emissions allowances can increase effectiveness of unilateral action but introduce distortions of their own. We assess antileakage measures as a function of abatement coalition size. We first develop a partial equilibrium analytical framework to see how these instruments affect emissions within and outside the coalition. We then employ a computable general equilibrium model of international trade and energy use to assess the strategies as the coalition grows. We find that full border adjustments rank first in global cost-effectiveness, followed by import tariffs and output-based rebates. The differences across measures and their overall appeal decline as the abatement coalition grows. In terms of cost, the coalition countries prefer border carbon adjustments; countries outside the coalition prefer output-based rebates.(Author)

  11. How Does the Neighborhood "Come through the Door?" Concentrated Disadvantage, Residential Instability, and the Home Environment for Preschoolers

    Science.gov (United States)

    May, Emily M.; Azar, Sandra T.; Matthews, Stephen A.

    2018-01-01

    Living in a disadvantaged neighborhood is associated with heightened risk for poor school readiness and health outcomes in early childhood, and the home environment is thought to be a primary mechanism by which neighborhood context impacts preschoolers. This study examined the effects of neighborhood concentrated disadvantage and neighborhood…

  12. Computation of Effect Size for Moderating Effects of Categorical Variables in Multiple Regression

    Science.gov (United States)

    Aguinis, Herman; Pierce, Charles A.

    2006-01-01

    The computation and reporting of effect size estimates is becoming the norm in many journals in psychology and related disciplines. Despite the increased importance of effect sizes, researchers may not report them or may report inaccurate values because of a lack of appropriate computational tools. For instance, Pierce, Block, and Aguinis (2004)…

  13. Neighborhood design and rates of walking and biking to elementary school in 34 California communities.

    Science.gov (United States)

    Braza, Mark; Shoemaker, Wendy; Seeley, Anne

    2004-01-01

    This study evaluates the relationship between neighborhood design and rates of students walking and biking to elementary school. Pairwise correlations and multiple regression models were estimated based on a cross-sectional study of elementary schools and their surrounding neighborhoods. Setting and Subjects. Thirty-four (23%) of 150 California public elementary schools holding October 1999 Walk to School Day events participated in the study. Teachers asked fifth-grade students how they arrived to school 1 week before Walk to School Day. 1990 U.S. Census data measured population density and number of intersections per street mile, whereas 1998-1999 California Department of Education data measured school size, the percentage of students receiving public welfare, and the percentage of students of various ethnicities. Population density (p = .000) and school size (p = .053) were significantly associated with walking and biking rates in regression models controlling for number of intersections per street mile, the percentage of students receiving public welfare, and the percentage of students of various ethnicities. The number of intersections per street mile was associated with walking and biking rates in pairwise correlations (p = .003) but not in regression models. The results support the hypothesis that the walking and biking rates are higher in denser neighborhoods and to smaller schools but do not support the hypothesis that rates are higher in neighborhoods with a high number of intersections per street mile. We suggest that detailed data for a larger sample of students would allow statistical models to isolate the effect of specific design characteristics.

  14. The neighborhood energy balance equation: does neighborhood food retail environment + physical activity environment = obesity? The CARDIA study.

    Directory of Open Access Journals (Sweden)

    Janne Boone-Heinonen

    Full Text Available Recent obesity prevention initiatives focus on healthy neighborhood design, but most research examines neighborhood food retail and physical activity (PA environments in isolation. We estimated joint, interactive, and cumulative impacts of neighborhood food retail and PA environment characteristics on body mass index (BMI throughout early adulthood.We used cohort data from the Coronary Artery Risk Development in Young Adults (CARDIA Study [n=4,092; Year 7 (24-42 years, 1992-1993 followed over 5 exams through Year 25 (2010-2011; 12,921 person-exam observations], with linked time-varying geographic information system-derived neighborhood environment measures. Using regression with fixed effects for individuals, we modeled time-lagged BMI as a function of food and PA resource density (counts per population and neighborhood development intensity (a composite density score. We controlled for neighborhood poverty, individual-level sociodemographics, and BMI in the prior exam; and included significant interactions between neighborhood measures and by sex. Using model coefficients, we simulated BMI reductions in response to single and combined neighborhood improvements. Simulated increase in supermarket density (from 25(th to 75(th percentile predicted inter-exam reduction in BMI of 0.09 kg/m(2 [estimate (95% CI: -0.09 (-0.16, -0.02]. Increasing commercial PA facility density predicted BMI reductions up to 0.22 kg/m(2 in men, with variation across other neighborhood features [estimate (95% CI range: -0.14 (-0.29, 0.01 to -0.22 (-0.37, -0.08]. Simultaneous increases in supermarket and commercial PA facility density predicted inter-exam BMI reductions up to 0.31 kg/m(2 in men [estimate (95% CI range: -0.23 (-0.39, -0.06 to -0.31 (-0.47, -0.15] but not women. Reduced fast food restaurant and convenience store density and increased public PA facility density and neighborhood development intensity did not predict reductions in BMI.Findings suggest that

  15. Neighborhood perceptions and allostatic load

    DEFF Research Database (Denmark)

    van Deurzen, Ioana; Rod, Naja Hulvej; Christensen, Ulla

    2016-01-01

    An influential argument explaining why living in certain neighborhoods can become harmful to one's health maintains that individuals can perceive certain characteristics of the neighborhood as threatening and the prolonged exposure to a threatening environment could induce chronic stress. Following...... this line of argumentation, in the present study we test whether subjective perceptions of neighborhood characteristics relate to an objective measure of stress-related physiological functioning, namely allostatic load (AL). We use a large dataset of 5280 respondents living in different regions of Denmark...... and we account for two alternative mechanisms, i.e., the objective characteristics of the living environment and the socio-economic status of individuals. Our results support the chronic stress mechanisms linking neighborhood quality to health. Heightened perceptions of disorder and pollution were found...

  16. Durham Neighborhood Compass Block Groups

    Data.gov (United States)

    City and County of Durham, North Carolina — The Durham Neighborhood Compass is a quantitative indicators project with qualitative values, integrating data from local government, the Census Bureau and other...

  17. Effects of Na and Ca on particle size; Effect of filtering on UV absorbance

    Data.gov (United States)

    U.S. Environmental Protection Agency — Effects of Na and Ca on particle size; Effect of filtering on UV absorbance. This dataset is associated with the following publication: Bouchard, D., C. Knightes, X....

  18. Effect of meal size and body size on specific dynamic action and gastric processing in decapod crustaceans.

    Science.gov (United States)

    McGaw, Iain J; Curtis, Daniel L

    2013-11-01

    Meal size and animal size are important factors affecting the characteristics of the specific dynamic action (SDA) response across a variety of taxa. The effects of these two variables on the SDA of decapod crustaceans are based on just a couple of articles, and are not wholly consistent with the responses reported for other aquatic ectotherms. Therefore, the effects of meal size and animal size on the characteristics of SDA response were investigated in a variety of decapod crustaceans from different families. A 6 fold increase in meal size (0.5%-3% body mass) resulted a pronounced increase in the duration of increased oxygen consumption, resulting in an increase in the SDA of Callinectes sapidus, Cancer gracilis, Hemigrapsus nudus, Homarus americanus, Pugettia producta and Procambarus clarkii. Unlike many other aquatic ectotherms a substantial increase between meal sizes was required, with meal size close to their upper feeding limit (3% body mass), before changes were evident. In many organisms increases in both duration and scope contribute to the overall SDA, here changes in scope as a function of meal size were weak, suggesting that a similar amount of energy is required to upregulate gastric processes, regardless of meal size. The SDA characteristics were less likely to be influenced by the size of the animal, and there was no difference in the SDA (kJ) as a function of size in H. americanus or Cancer irroratus when analysed as mass specific values. In several fish species characteristics of the SDA response are more closely related to the transit times of food, rather than the size of a meal. To determine if a similar trend occurred in crustaceans, the transit rates of different sized meals were followed through the digestive system using a fluoroscope. Although there was a trend towards larger meals taking longer to pass through the gut, this was only statistically significant for P. clarkii. There were some changes in transit times as a function of animal

  19. Does Race Matter in Neighborhood Preferences? Results from a Video Experiment

    Science.gov (United States)

    Krysan, Maria; Couper, Mick P.; Farley, Reynolds; Forman, Tyrone

    2013-01-01

    Persistent racial residential segregation is often seen as the result of the preferences of whites and blacks: whites prefer to live with whites while blacks wish to live near many other blacks. The origin of these preferences and their social psychological underpinnings are hotly debated. Are neighborhood preferences colorblind or race-conscious? Does neighborhood racial composition have a net influence upon preferences or is race a proxy for social class? If preferences are race-conscious, is this more a matter of a desire to be in a neighborhood with one’s “own kind” or to avoid being in a neighborhood with another racial group? We tested the racial proxy hypothesis using an innovative experiment that isolated the net effects of race and social class and followed it with an analysis of the social psychological factors associated with residential preferences. Face-to-face surveys using computer assisted interviewing were conducted with random samples of Detroit and Chicago residents. Respondents were asked how desirable they would rate neighborhoods shown in videos in which racial composition and social class characteristics were manipulated and they also completed—via computer assisted self-interviews—questions tapping into perceptions of discrimination, racial and neighborhood stereotypes, and in-group identity. We find that net of social class, the race of a neighborhood's residents significantly influenced how it was rated. Whites said the all-white neighborhoods were most desirable. The independent effect of racial composition was smaller among blacks and blacks identified the racially mixed neighborhood as most desirable. Hypotheses about how racial group identity, stereotypes, and experiences of discrimination influenced the effect of race of residents upon neighborhood preferences were tested and show that for whites, those who hold negative stereotypes about African Americans and the neighborhoods where they live are significantly influenced by

  20. On the development of online cities and neighborhoods: an exploration of cumulative and segmentive network effects in social media

    NARCIS (Netherlands)

    Maris, I.; Huizinga, A; Bouman, W.; Tuunainen, V.K.; Rossi, M.; Nandhakumar, J.

    2011-01-01

    This paper outlines a research in progress set to study network effects in social media. The focus is on outlining the theoretical framework in which this study is embedded. The concepts of cumulative network effects and segmentive network effects are introduced to explain the processes by which

  1. Nearest neighbors by neighborhood counting.

    Science.gov (United States)

    Wang, Hui

    2006-06-01

    Finding nearest neighbors is a general idea that underlies many artificial intelligence tasks, including machine learning, data mining, natural language understanding, and information retrieval. This idea is explicitly used in the k-nearest neighbors algorithm (kNN), a popular classification method. In this paper, this idea is adopted in the development of a general methodology, neighborhood counting, for devising similarity functions. We turn our focus from neighbors to neighborhoods, a region in the data space covering the data point in question. To measure the similarity between two data points, we consider all neighborhoods that cover both data points. We propose to use the number of such neighborhoods as a measure of similarity. Neighborhood can be defined for different types of data in different ways. Here, we consider one definition of neighborhood for multivariate data and derive a formula for such similarity, called neighborhood counting measure or NCM. NCM was tested experimentally in the framework of kNN. Experiments show that NCM is generally comparable to VDM and its variants, the state-of-the-art distance functions for multivariate data, and, at the same time, is consistently better for relatively large k values. Additionally, NCM consistently outperforms HEOM (a mixture of Euclidean and Hamming distances), the "standard" and most widely used distance function for multivariate data. NCM has a computational complexity in the same order as the standard Euclidean distance function and NCM is task independent and works for numerical and categorical data in a conceptually uniform way. The neighborhood counting methodology is proven sound for multivariate data experimentally. We hope it will work for other types of data.

  2. What big size you have! Using effect sizes to determine the impact of public health nursing interventions.

    Science.gov (United States)

    Johnson, K E; McMorris, B J; Raynor, L A; Monsen, K A

    2013-01-01

    The Omaha System is a standardized interface terminology that is used extensively by public health nurses in community settings to document interventions and client outcomes. Researchers using Omaha System data to analyze the effectiveness of interventions have typically calculated p-values to determine whether significant client changes occurred between admission and discharge. However, p-values are highly dependent on sample size, making it difficult to distinguish statistically significant changes from clinically meaningful changes. Effect sizes can help identify practical differences but have not yet been applied to Omaha System data. We compared p-values and effect sizes (Cohen's d) for mean differences between admission and discharge for 13 client problems documented in the electronic health records of 1,016 young low-income parents. Client problems were documented anywhere from 6 (Health Care Supervision) to 906 (Caretaking/parenting) times. On a scale from 1 to 5, the mean change needed to yield a large effect size (Cohen's d ≥ 0.80) was approximately 0.60 (range = 0.50 - 1.03) regardless of p-value or sample size (i.e., the number of times a client problem was documented in the electronic health record). Researchers using the Omaha System should report effect sizes to help readers determine which differences are practical and meaningful. Such disclosures will allow for increased recognition of effective interventions.

  3. Community Size Effects on Epidemic Spreading in Multiplex Social Networks.

    Directory of Open Access Journals (Sweden)

    Ting Liu

    Full Text Available The dynamical process of epidemic spreading has drawn much attention of the complex network community. In the network paradigm, diseases spread from one person to another through the social ties amongst the population. There are a variety of factors that govern the processes of disease spreading on the networks. A common but not negligible factor is people's reaction to the outbreak of epidemics. Such reaction can be related information dissemination or self-protection. In this work, we explore the interactions between disease spreading and population response in terms of information diffusion and individuals' alertness. We model the system by mapping multiplex networks into two-layer networks and incorporating individuals' risk awareness, on the assumption that their response to the disease spreading depends on the size of the community they belong to. By comparing the final incidence of diseases in multiplex networks, we find that there is considerable mitigation of diseases spreading for full phase of spreading speed when individuals' protection responses are introduced. Interestingly, the degree of community overlap between the two layers is found to be critical factor that affects the final incidence. We also analyze the consequences of the epidemic incidence in communities with different sizes and the impacts of community overlap between two layers. Specifically, as the diseases information makes individuals alert and take measures to prevent the diseases, the effective protection is more striking in small community. These phenomena can be explained by the multiplexity of the networked system and the competition between two spreading processes.

  4. Community Size Effects on Epidemic Spreading in Multiplex Social Networks.

    Science.gov (United States)

    Liu, Ting; Li, Ping; Chen, Yan; Zhang, Jie

    2016-01-01

    The dynamical process of epidemic spreading has drawn much attention of the complex network community. In the network paradigm, diseases spread from one person to another through the social ties amongst the population. There are a variety of factors that govern the processes of disease spreading on the networks. A common but not negligible factor is people's reaction to the outbreak of epidemics. Such reaction can be related information dissemination or self-protection. In this work, we explore the interactions between disease spreading and population response in terms of information diffusion and individuals' alertness. We model the system by mapping multiplex networks into two-layer networks and incorporating individuals' risk awareness, on the assumption that their response to the disease spreading depends on the size of the community they belong to. By comparing the final incidence of diseases in multiplex networks, we find that there is considerable mitigation of diseases spreading for full phase of spreading speed when individuals' protection responses are introduced. Interestingly, the degree of community overlap between the two layers is found to be critical factor that affects the final incidence. We also analyze the consequences of the epidemic incidence in communities with different sizes and the impacts of community overlap between two layers. Specifically, as the diseases information makes individuals alert and take measures to prevent the diseases, the effective protection is more striking in small community. These phenomena can be explained by the multiplexity of the networked system and the competition between two spreading processes.

  5. Effect of head size on 10B dose distribution

    International Nuclear Information System (INIS)

    Gupta, N.; Blue, T.E.; Gahbauer, R.

    1992-01-01

    Boron neutron capture therapy (BNCT) for treatment of brain tumors is based on the utilization of large epithermal-neutron fields. Epithermal neutrons thermalize at depths of ∼2.5 cm inside the head and provide a maximum thermal fluence at deep-seated tumor sites with minimum damage to normal tissue. Brain tissue is a highly scattering medium for epithermal and thermal neutrons; therefore, a broad treatment field enables epithermal neutrons to enter the head over a large area. These neutrons slow down as they undergo scattering collisions and contribute to the thermal-neutron fluence at the tumor location. With the use of large neutron fields, the size of the head affects the thermal-neutron distribution and thereby the 10 B absorbed dose distribution inside the head. In this paper, the authors describe measurements using a boron trifluoride (BF 3 )-filled proportional counter to determine the effect of head size on 10 B absorbed dose distributions for a broad field accelerator epithermal-neutron source

  6. Nosewitness Identification: Effects of Lineup Size and Retention Interval.

    Science.gov (United States)

    Alho, Laura; Soares, Sandra C; Costa, Liliana P; Pinto, Elisa; Ferreira, Jacqueline H T; Sorjonen, Kimmo; Silva, Carlos F; Olsson, Mats J

    2016-01-01

    Although canine identification of body odor (BO) has been widely used as forensic evidence, the concept of nosewitness identification by human observers was only recently put to the test. The results indicated that BOs associated with male characters in authentic crime videos could later be identified in BO lineup tests well above chance. To further evaluate nosewitness memory, we assessed the effects of lineup size (Experiment 1) and retention interval (Experiment 2), using a forced-choice memory test. The results showed that nosewitness identification works for all lineup sizes (3, 5, and 8 BOs), but that larger lineups compromise identification performance in similarity to observations from eye- and earwitness studies. Also in line with previous eye- and earwitness studies, but in disagreement with some studies on odor memory, Experiment 2 showed significant forgetting between shorter retention intervals (15 min) and longer retention intervals (1-week) using lineups of five BOs. Altogether this study shows that identification of BO in a forensic setting is possible and has limits and characteristics in line with witness identification through other sensory modalities.

  7. Heating temperature effect on ferritic grain size of rotor steel

    International Nuclear Information System (INIS)

    Cheremnykh, V.G.; Derevyankin, E.V.; Sakulin, A.A.

    1983-01-01

    The heating temperature effect on ferritic grain size of two steels 13Kh1M1FA and 25Kh1M1FA is evaluated. It is shown that exposure time increase at heating temperatures below 1000 deg C up to 10h changes but slightly the size of the Cr-Mo-V ferritic grain of rotor steel cooled with 25 deg C/h rate. Heating up to 1000 deg C and above leads to substantial ferritic grain growth. The kinetics of ferritic grain growth is determined by the behaviour of phases controlling the austenitic grain growth, such as carbonitrides VCsub(0.14)Nsub(0.78) in 13Kh1M1FA steel and VCsub(0.18)Nsub(0.72) in 25Kh1M1FA steel. Reduction of carbon and alloying elements content in steel composition observed at the liquation over rotor length leads to a certain decrease of ferritic grain resistance to super heating

  8. Artificial fish schools : Collective effects of school size, body size, and body form

    NARCIS (Netherlands)

    Kunz, H.; Hemelrijk, C.K.

    2003-01-01

    Individual-based models of schooling in fish have demonstrated that, via processes of self-organization. artificial fish may school in the absence of a leader or external stimuli, using local information only. We study for the first time how body size and body form of artificial fish affect school

  9. Spatial Supermarket Redlining and Neighborhood Vulnerability: A Case Study of Hartford, Connecticut.

    Science.gov (United States)

    Zhang, Mengyao; Debarchana, Ghosh

    2016-02-01

    The disinclination of chain supermarkets to locate or pull out existing stores from impoverished neighborhoods is termed as "supermarket redlining". This paper attempts to map and understand the spatial effects of potential supermarket redlining on food vulnerability in urban disadvantaged neighborhoods of Hartford, Connecticut. Using a combination of statistical and spatial analysis functions, we first, built a Supermarket Redlining Index (SuRI) from five indicators such as sales volume, employee count, accepts food coupons from federally assisted programs, and size and population density of the service area to rank supermarkets in the order of their importance. Second, to understand the effect of redlining, a Supermarket Redlining Impact Model (SuRIM) was built with eleven indicators describing both the socioeconomic and food access vulnerabilities. The interaction of these vulnerabilities would identify the final outcome: neighborhoods where the impact of supermarket redlining would be critical. Results mapped critical areas in the inner-city of Hartford where if a nearby supermarket closes or relocates to a suburb with limited mitigation efforts to gill the grocery gap, a large number of minority, poor, and disadvantaged residents will experience difficulties to access healthy food leading to food insecurity or perhaps a food desert. We also suggest mitigation efforts to reduce the impact of large supermarket closures.

  10. Creep cavitation in the neighborhood of stress concentrations

    International Nuclear Information System (INIS)

    Liu, T.S.; Delph, T.J.; Fields, R.J.

    1983-01-01

    The results of several experiments into the formation and distribution of creep cavitation in the neighborhood of stress concentrations is reported. Of particular interest is the use of an image analyzing computer to construct quantitative maps of cavity sizes and distributions. Comparisons are drawn in one case with the results of a finite element simulation, and some degree of overall agreement is noted. (orig.)

  11. Network neighborhood analysis with the multi-node topological overlap measure.

    Science.gov (United States)

    Li, Ai; Horvath, Steve

    2007-01-15

    The goal of neighborhood analysis is to find a set of genes (the neighborhood) that is similar to an initial 'seed' set of genes. Neighborhood analysis methods for network data are important in systems biology. If individual network connections are susceptible to noise, it can be advantageous to define neighborhoods on the basis of a robust interconnectedness measure, e.g. the topological overlap measure. Since the use of multiple nodes in the seed set may lead to more informative neighborhoods, it can be advantageous to define multi-node similarity measures. The pairwise topological overlap measure is generalized to multiple network nodes and subsequently used in a recursive neighborhood construction method. A local permutation scheme is used to determine the neighborhood size. Using four network applications and a simulated example, we provide empirical evidence that the resulting neighborhoods are biologically meaningful, e.g. we use neighborhood analysis to identify brain cancer related genes. An executable Windows program and tutorial for multi-node topological overlap measure (MTOM) based analysis can be downloaded from the webpage (http://www.genetics.ucla.edu/labs/horvath/MTOM/).

  12. Finite-size effect on optimal efficiency of heat engines.

    Science.gov (United States)

    Tajima, Hiroyasu; Hayashi, Masahito

    2017-07-01

    The optimal efficiency of quantum (or classical) heat engines whose heat baths are n-particle systems is given by the strong large deviation. We give the optimal work extraction process as a concrete energy-preserving unitary time evolution among the heat baths and the work storage. We show that our optimal work extraction turns the disordered energy of the heat baths to the ordered energy of the work storage, by evaluating the ratio of the entropy difference to the energy difference in the heat baths and the work storage, respectively. By comparing the statistical mechanical optimal efficiency with the macroscopic thermodynamic bound, we evaluate the accuracy of the macroscopic thermodynamics with finite-size heat baths from the statistical mechanical viewpoint. We also evaluate the quantum coherence effect on the optimal efficiency of the cycle processes without restricting their cycle time by comparing the classical and quantum optimal efficiencies.

  13. Anharmonic, dimensionality and size effects in phonon transport

    Science.gov (United States)

    Thomas, Iorwerth O.; Srivastava, G. P.

    2017-12-01

    We have developed and employed a numerically efficient semi- ab initio theory, based on density-functional and relaxation-time schemes, to examine anharmonic, dimensionality and size effects in phonon transport in three- and two-dimensional solids of different crystal symmetries. Our method uses third- and fourth-order terms in crystal Hamiltonian expressed in terms of a temperature-dependent Grüneisen’s constant. All input to numerical calculations are generated from phonon calculations based on the density-functional perturbation theory. It is found that four-phonon processes make important and measurable contribution to lattice thermal resistivity above the Debye temperature. From our numerical results for bulk Si, bulk Ge, bulk MoS2 and monolayer MoS2 we find that the sample length dependence of phonon conductivity is significantly stronger in low-dimensional solids.

  14. Finite-size effects on current correlation functions

    Science.gov (United States)

    Chen, Shunda; Zhang, Yong; Wang, Jiao; Zhao, Hong

    2014-02-01

    We study why the calculation of current correlation functions (CCFs) still suffers from finite-size effects even when the periodic boundary condition is taken. Two important one-dimensional, momentum-conserving systems are investigated as examples. Intriguingly, it is found that the state of a system recurs in the sense of microcanonical ensemble average, and such recurrence may result in oscillations in CCFs. Meanwhile, we find that the sound mode collisions induce an extra time decay in a current so that its correlation function decays faster (slower) in a smaller (larger) system. Based on these two unveiled mechanisms, a procedure for correctly evaluating the decay rate of a CCF is proposed, with which our analysis suggests that the global energy CCF decays as ˜t-2/3 in the diatomic hard-core gas model and in a manner close to ˜t-1/2 in the Fermi-Pasta-Ulam-β model.

  15. Effect of particle size on the thermoluminescent response of hydroxyapatite

    International Nuclear Information System (INIS)

    Barrera V, A.; Zarate M, J.; Contreras, M. E.; Rivera M, T.

    2016-10-01

    We present the study of the structural characterization and the thermoluminescent response of the hydroxyapatite as a function of the calcination temperature and the effect of the particle size. For precipitation synthesis, calcium nitrate (Ca(NO_3)_2 and dibasic ammonium phosphate ((NH_4)_2HPO_4) were used as precursors and ammonium hydroxide (NH_4OH) as a ph controlling agent. The characterization of the samples was carried out by the techniques of X-ray diffraction, scanning electron microscopy and infrared spectroscopy. The powders obtained are composed of hydroxyapatite, with a different degree of dehydroxylation. The thermoluminescent characterization indicates that at higher calcination temperature there is a higher thermoluminescent response, the calcined powders at 1300 degrees Celsius show a very well defined brightness curve with a higher intensity, with its maximum intensity located at a temperature of 210 degrees Celsius, which indicates that this material can be used as a dosimeter. (Author)

  16. Indentation size effect and the plastic compressibility of glass

    Energy Technology Data Exchange (ETDEWEB)

    Smedskjaer, Morten M., E-mail: mos@bio.aau.dk [Section of Chemistry, Aalborg University, 9000 Aalborg (Denmark)

    2014-06-23

    Oxide glasses exhibit significant densification under an applied isostatic pressure at the glass transition temperature. The glass compressibility is correlated with the chemical composition and atomic packing density, e.g., borate glasses with planar triangular BO{sub 3} units are more disposed for densification than silicate glasses with tetrahedral units. We here show that there is a direct relation between the plastic compressibility following hot isostatic compression and the extent of the indentation size effect (ISE), which is the decrease of hardness with indentation load exhibited by most materials. This could suggest that the ISE is correlated with indentation-induced shear bands, which should form in greater density when the glass network is more adaptable to volume changes through structural and topological rearrangements under an applied pressure.

  17. Aerodynamic Ground Effect in Fruitfly Sized Insect Takeoff.

    Directory of Open Access Journals (Sweden)

    Dmitry Kolomenskiy

    Full Text Available Aerodynamic ground effect in flapping-wing insect flight is of importance to comparative morphologies and of interest to the micro-air-vehicle (MAV community. Recent studies, however, show apparently contradictory results of either some significant extra lift or power savings, or zero ground effect. Here we present a numerical study of fruitfly sized insect takeoff with a specific focus on the significance of leg thrust and wing kinematics. Flapping-wing takeoff is studied using numerical modelling and high performance computing. The aerodynamic forces are calculated using a three-dimensional Navier-Stokes solver based on a pseudo-spectral method with volume penalization. It is coupled with a flight dynamics solver that accounts for the body weight, inertia and the leg thrust, while only having two degrees of freedom: the vertical and the longitudinal horizontal displacement. The natural voluntary takeoff of a fruitfly is considered as reference. The parameters of the model are then varied to explore possible effects of interaction between the flapping-wing model and the ground plane. These modified takeoffs include cases with decreased leg thrust parameter, and/or with periodic wing kinematics, constant body pitch angle. The results show that the ground effect during natural voluntary takeoff is negligible. In the modified takeoffs, when the rate of climb is slow, the difference in the aerodynamic forces due to the interaction with the ground is up to 6%. Surprisingly, depending on the kinematics, the difference is either positive or negative, in contrast to the intuition based on the helicopter theory, which suggests positive excess lift. This effect is attributed to unsteady wing-wake interactions. A similar effect is found during hovering.

  18. Optimal neighborhood indexing for protein similarity search.

    Science.gov (United States)

    Peterlongo, Pierre; Noé, Laurent; Lavenier, Dominique; Nguyen, Van Hoa; Kucherov, Gregory; Giraud, Mathieu

    2008-12-16

    Similarity inference, one of the main bioinformatics tasks, has to face an exponential growth of the biological data. A classical approach used to cope with this data flow involves heuristics with large seed indexes. In order to speed up this technique, the index can be enhanced by storing additional information to limit the number of random memory accesses. However, this improvement leads to a larger index that may become a bottleneck. In the case of protein similarity search, we propose to decrease the index size by reducing the amino acid alphabet. The paper presents two main contributions. First, we show that an optimal neighborhood indexing combining an alphabet reduction and a longer neighborhood leads to a reduction of 35% of memory involved into the process, without sacrificing the quality of results nor the computational time. Second, our approach led us to develop a new kind of substitution score matrices and their associated e-value parameters. In contrast to usual matrices, these matrices are rectangular since they compare amino acid groups from different alphabets. We describe the method used for computing those matrices and we provide some typical examples that can be used in such comparisons. Supplementary data can be found on the website http://bioinfo.lifl.fr/reblosum. We propose a practical index size reduction of the neighborhood data, that does not negatively affect the performance of large-scale search in protein sequences. Such an index can be used in any study involving large protein data. Moreover, rectangular substitution score matrices and their associated statistical parameters can have applications in any study involving an alphabet reduction.

  19. Optimal neighborhood indexing for protein similarity search

    Directory of Open Access Journals (Sweden)

    Nguyen Van

    2008-12-01

    Full Text Available Abstract Background Similarity inference, one of the main bioinformatics tasks, has to face an exponential growth of the biological data. A classical approach used to cope with this data flow involves heuristics with large seed indexes. In order to speed up this technique, the index can be enhanced by storing additional information to limit the number of random memory accesses. However, this improvement leads to a larger index that may become a bottleneck. In the case of protein similarity search, we propose to decrease the index size by reducing the amino acid alphabet. Results The paper presents two main contributions. First, we show that an optimal neighborhood indexing combining an alphabet reduction and a longer neighborhood leads to a reduction of 35% of memory involved into the process, without sacrificing the quality of results nor the computational time. Second, our approach led us to develop a new kind of substitution score matrices and their associated e-value parameters. In contrast to usual matrices, these matrices are rectangular since they compare amino acid groups from different alphabets. We describe the method used for computing those matrices and we provide some typical examples that can be used in such comparisons. Supplementary data can be found on the website http://bioinfo.lifl.fr/reblosum. Conclusion We propose a practical index size reduction of the neighborhood data, that does not negatively affect the performance of large-scale search in protein sequences. Such an index can be used in any study involving large protein data. Moreover, rectangular substitution score matrices and their associated statistical parameters can have applications in any study involving an alphabet reduction.

  20. Negative life events vary by neighborhood and mediate the relation between neighborhood context and psychological well-being.

    Directory of Open Access Journals (Sweden)

    Katherine King

    Full Text Available Researchers have speculated that negative life events are more common in troubled neighborhoods, amplifying adverse effects on health. Using a clustered representative sample of Chicago residents (2001-03; n = 3,105 from the Chicago Community Adult Health Survey, we provide the first documentation that negative life events are highly geographically clustered compared to health outcomes. Associations between neighborhood context and negative life events were also found to vary by event type. We then demonstrate the power of a contextualized approach by testing path models in which life events mediate the relation between neighborhood characteristics and health outcomes, including self-rated health, anxiety, and depression. The indirect paths between neighborhood conditions and health through negative life event exposure are highly significant and large compared to the direct paths from neighborhood conditions to health. Our results indicate that neighborhood conditions can have acute as well as chronic effects on health, and that negative life events are a powerful mechanism by which context may influence health.

  1. Negative life events vary by neighborhood and mediate the relation between neighborhood context and psychological well-being.

    Science.gov (United States)

    King, Katherine; Ogle, Christin

    2014-01-01

    Researchers have speculated that negative life events are more common in troubled neighborhoods, amplifying adverse effects on health. Using a clustered representative sample of Chicago residents (2001-03; n = 3,105) from the Chicago Community Adult Health Survey, we provide the first documentation that negative life events are highly geographically clustered compared to health outcomes. Associations between neighborhood context and negative life events were also found to vary by event type. We then demonstrate the power of a contextualized approach by testing path models in which life events mediate the relation between neighborhood characteristics and health outcomes, including self-rated health, anxiety, and depression. The indirect paths between neighborhood conditions and health through negative life event exposure are highly significant and large compared to the direct paths from neighborhood conditions to health. Our results indicate that neighborhood conditions can have acute as well as chronic effects on health, and that negative life events are a powerful mechanism by which context may influence health.

  2. The Effects of Neighborhood Proportion of Single-Parent Families and Mother-Adolescent Relationships on Adolescents' Number of Sexual Partners.

    Science.gov (United States)

    Cleveland, H. Harrington; Gilson, Michael

    2004-01-01

    Using both individual-level and census-level data, this study predicts the number of sexual partners reported by male and female adolescents from the quality of their mother relationship and neighborhood proportion of single-parent families. Both predictors were associated with number of sexual partners for both males and females in OLS analyses.…

  3. X-ray tube focal spot sizes: comprehensive studies of their measurement and effect of measured size in angiography

    International Nuclear Information System (INIS)

    Doi, K.; Loo, L.N.; Chan, H.P.

    1982-01-01

    Thirty-two focal spot sizes of four x-ray tubes were measured by the pinhole, star pattern, slit, and root-mean-square (RMS) methods under various exposure conditions. The modulation transfer functions (MTFs) and line spread functions (LSFs) were also determined. The star pattern focal spot sizes agreed with the effective sizes calculated from the frequencies at the first minimum of the MTF within 0.04 mm for large focal spots and within 0.01 mm for small focal spots. The focal spot size determined by the slit method was approximately equal to the width of the LSF at the cutoff level of 0.15 +/- 0.06 of the peak value. The RMS method provided the best correlation between the measured focal spot sizes and the corresponding image distributions of blood vessels. The pinhole and slit methods tended to overestimate the focal spot size, but the star pattern method tended to underestimate it. For approximately 90% of the focal spots, the average of the star and slit (or pinhole) focal spot sizes agreed with the RMS focal spot size within +/- 0.1 mm

  4. Effect of sample size on bias correction performance

    Science.gov (United States)

    Reiter, Philipp; Gutjahr, Oliver; Schefczyk, Lukas; Heinemann, Günther; Casper, Markus C.

    2014-05-01

    The output of climate models often shows a bias when compared to observed data, so that a preprocessing is necessary before using it as climate forcing in impact modeling (e.g. hydrology, species distribution). A common bias correction method is the quantile matching approach, which adapts the cumulative distribution function of the model output to the one of the observed data by means of a transfer function. Especially for precipitation we expect the bias correction performance to strongly depend on sample size, i.e. the length of the period used for calibration of the transfer function. We carry out experiments using the precipitation output of ten regional climate model (RCM) hindcast runs from the EU-ENSEMBLES project and the E-OBS observational dataset for the period 1961 to 2000. The 40 years are split into a 30 year calibration period and a 10 year validation period. In the first step, for each RCM transfer functions are set up cell-by-cell, using the complete 30 year calibration period. The derived transfer functions are applied to the validation period of the respective RCM precipitation output and the mean absolute errors in reference to the observational dataset are calculated. These values are treated as "best fit" for the respective RCM. In the next step, this procedure is redone using subperiods out of the 30 year calibration period. The lengths of these subperiods are reduced from 29 years down to a minimum of 1 year, only considering subperiods of consecutive years. This leads to an increasing number of repetitions for smaller sample sizes (e.g. 2 for a length of 29 years). In the last step, the mean absolute errors are statistically tested against the "best fit" of the respective RCM to compare the performances. In order to analyze if the intensity of the effect of sample size depends on the chosen correction method, four variations of the quantile matching approach (PTF, QUANT/eQM, gQM, GQM) are applied in this study. The experiments are further

  5. A systematic review of relations between neighborhoods and mental health.

    Science.gov (United States)

    Truong, Khoa D; Ma, Sai

    2006-09-01

    The relationship between neighborhood characteristics and resident mental health has been widely investigated in individual studies in recent years, but this literature is not adequately reviewed. To systematically review relevant individual research of the relation between neighborhoods and adult mental health by identifying and synthesizing all relevant studies in this literature. We conducted an electronic search with PubMed and PsycINFO, and manual reference-checking, resulting in 8,562 screened studies of which 29 were selected. Studies were included in the main synthesis if they (i) were published in English in peer reviewed journals; (ii) had relevant definitions and measures of neighborhood characteristics; (iii) utilized standardized measures of adult mental health; (iv) controlled for individual characteristics; (v) reported quantitative results; and, (vi) studied a population in a developed country. We focused on two key areas within this literature: the methodologies utilized to study neighborhood effects and quantitative results. With regard to the former, we examined five major issues: (i) definitions and measures of neighborhoods; (ii) definitions and measures of mental health; (iii) controls for individual level characteristics; (iv) conceptual models; and (v) analytical models. As for quantitative results, the relation was reviewed by types of neighborhood characteristics. We summarized general quantitative findings and drew common conclusions across groups of studies. 27/29 studies found statistically significant association between mental health and at least one measure of neighborhood characteristics, after adjusting for individual factors. This association was evident for all types of neighborhood features, varying from sociodemographic characteristics to physical environment, and from objective to subjective measures. Neighborhood effects were weakened when adding individual-level characteristics into the regression models, and were generally

  6. Mediators of the effect of the JUMP-in intervention on physical activity and sedentary behavior in Dutch primary schoolchildren from disadvantaged neighborhoods

    Directory of Open Access Journals (Sweden)

    van Stralen Maartje M

    2012-11-01

    Full Text Available Abstract Background Important health benefits can be achieved when physical activity in children from low socio-economic status is promoted and sedentariness is limited. By specifying the mediating mechanisms of existing interventions one can improve future physical activity interventions. This study explored potential mediators of the long-term effect of the school-based multicomponent JUMP-in intervention on sport participation, outdoor play and screen time in Dutch primary schoolchildren from disadvantaged neighborhoods. Methods In total, 600 primary schoolchildren (aged 9.8 ± 0.7, 51% girls, 13% Dutch ethnicity, 35% overweight from 9 intervention and 10 control schools were included in the analyses. JUMP-in was developed using Intervention Mapping, and targeted psychological and environmental determinants of physical activity. Outcome behaviors were self-reported sport participation, outdoor play, TV-viewing behavior and computer use. Potential mediators were self-reported psychological, social and physical environmental factors. Results JUMP-in was effective in improving sport participation after 20 months, but not in improving outdoor play, or reducing TV-viewing or computer time. JUMP-in was not effective in changing hypothesized mediators so no significant mediated effects could be identified. However, changes in self-efficacy, social support and habit strength were positively associated with changes in sport participation, and changes in social support, self-efficacy, perceived planning skills, enjoyment and habit strength were positively associated with changes in outdoor play. Changes in enjoyment was positively associated with changes in TV-viewing while parental rules were negatively associated. Having a computer in the bedroom and enjoyment were positively associated with changes in computer use, while changes in parental rules were negatively associated. Conclusions Besides a significant positive effect on sports participation

  7. Do psychosocial factors moderate the association between neighborhood walkability and adolescents' physical activity?

    Science.gov (United States)

    De Meester, Femke; Van Dyck, Delfien; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Cardon, Greet

    2013-03-01

    Ecological models emphasize the interaction between individuals and their environment. Furthermore, they posit that environmental variables influence physical activity (PA) not only directly but also indirectly through their interaction with other factors. This study explored if the association between neighborhood walkability and adolescents' PA is moderated by psychosocial factors using data from the Belgian Environmental PA Study in Youth (BEPAS-Y). BEPAS-Y recruited adolescents from 32 neighborhoods differing in objectively determined neighborhood walkability and income. Between 2008 and 2009, 637 adolescents (13-15 years; 49.4% boys) completed a survey measuring socio-demographic and psychosocial factors and wore an accelerometer for seven days. Multilevel-regression analyses revealed that for adolescents living in low-income neighborhoods, the association between neighborhood walkability and PA is moderated by perceived barriers and perceived benefits toward PA. Neighborhood walkability was positively associated with PA among adolescents, living in low-income neighborhoods, who perceived many barriers and few benefits, while for adolescents who perceived few barriers and many benefits, the PA level was high, irrespective of neighborhood walkability. For adolescents, living in high-income neighborhoods, none of the psychosocial attributes moderated the association between neighborhood walkability and PA. These findings provide some support for the predicted interactions posited by ecological models. Improving neighborhood walkability might increase PA-levels of adolescents living in low-income neighborhoods, with less positive psychosocial profiles, or in other words; those who are most difficult to reach through PA interventions. However, in order to increase PA in large populations, interventions focusing solely on improving neighborhood walkability may not have the desired effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Walkable new urban LEED_Neighborhood-Development (LEED-ND community design and children's physical activity: selection, environmental, or catalyst effects?

    Directory of Open Access Journals (Sweden)

    Stevens, Robert B

    2011-12-01

    Full Text Available Abstract Background Interest is growing in physical activity-friendly community designs, but few tests exist of communities explicitly designed to be walkable. We test whether students living in a new urbanist community that is also a pilot LEED_ND (Leadership in Energy and Environmental Design-Neighborhood Development community have greater accelerometer-measured moderate-to-vigorous physical activity (MVPA across particular time periods compared to students from other communities. We test various time/place periods to see if the data best conform to one of three explanations for MVPA. Environmental effects suggest that MVPA occurs when individuals are exposed to activity-friendly settings; selection effects suggest that walkable community residents prefer MVPA, which leads to both their choice of a walkable community and their high levels of MVPA; catalyst effects occur when walking to school creates more MVPA, beyond the school commute, on schooldays but not weekends. Methods Fifth graders (n = 187 were sampled from two schools representing three communities: (1 a walkable community, Daybreak, designed with new urbanist and LEED-ND pilot design standards; (2 a mixed community (where students lived in a less walkable community but attended the walkable school so that part of the route to school was walkable, and (3 a less walkable community. Selection threats were addressed through controlling for parental preferences for their child to walk to school as well as comparing in-school MVPA for the walkable and mixed groups. Results Minutes of MVPA were tested with 3 × 2 (Community by Gender analyses of covariance (ANCOVAs. Community walkability related to more MVPA during the half hour before and after school and, among boys only, more MVPA after school. Boys were more active than girls, except during the half hour after school. Students from the mixed and walkable communities--who attended the same school--had similar in-school MVPA levels, and

  9. Walkable new urban LEED_Neighborhood-Development (LEED-ND) community design and children's physical activity: selection, environmental, or catalyst effects?

    Science.gov (United States)

    2011-01-01

    Background Interest is growing in physical activity-friendly community designs, but few tests exist of communities explicitly designed to be walkable. We test whether students living in a new urbanist community that is also a pilot LEED_ND (Leadership in Energy and Environmental Design-Neighborhood Development) community have greater accelerometer-measured moderate-to-vigorous physical activity (MVPA) across particular time periods compared to students from other communities. We test various time/place periods to see if the data best conform to one of three explanations for MVPA. Environmental effects suggest that MVPA occurs when individuals are exposed to activity-friendly settings; selection effects suggest that walkable community residents prefer MVPA, which leads to both their choice of a walkable community and their high levels of MVPA; catalyst effects occur when walking to school creates more MVPA, beyond the school commute, on schooldays but not weekends. Methods Fifth graders (n = 187) were sampled from two schools representing three communities: (1) a walkable community, Daybreak, designed with new urbanist and LEED-ND pilot design standards; (2) a mixed community (where students lived in a less walkable community but attended the walkable school so that part of the route to school was walkable), and (3) a less walkable community. Selection threats were addressed through controlling for parental preferences for their child to walk to school as well as comparing in-school MVPA for the walkable and mixed groups. Results Minutes of MVPA were tested with 3 × 2 (Community by Gender) analyses of covariance (ANCOVAs). Community walkability related to more MVPA during the half hour before and after school and, among boys only, more MVPA after school. Boys were more active than girls, except during the half hour after school. Students from the mixed and walkable communities--who attended the same school--had similar in-school MVPA levels, and community groups

  10. Dispersant Effectiveness, In-Situ Droplet Size Distribution and ...

    Science.gov (United States)

    This report summarizes two projects covered under an Interagency Agreement between the Bureau of Safety and Environmental Enforcement (BSEE) and the U.S. Environmental Protection Agency (EPA) in collaboration with the Bedford Institute of Oceanography, Department of Fisheries and Oceans Canada (BIO DFO), New Jersey Institute of Technology (NJIT) and Dalhousie University. Both projects dovetail together in addressing the ability to differentiate physical from chemical dispersion effectiveness using dispersed oil simulations within a flume tank for improving forensic response monitoring tools. This report is split into separateTasks based upon the two projects funded by BSEE: 1) Dispersant Effectiveness, In-Situ Droplet Size Distribution and Numerical Modeling to Assess Subsurface Dispersant Injection as a Deepwater Blowout Oil Spill Response Option. 2) Evaluation of Oil Fluorescence Characteristics to Improve Forensic Response Tools. This report summarizes 2 collaborative projects funded through an Interagency Agreement with DOI BSEE and a Cooperative Agreement with DFO Canada. BSEE required that the projects be combined into one report as they are both covered under the one Interagency Agreement. Task B (Fluorescence of oils) is an SHC 3.62 FY16 product.

  11. Neighborhood fast food restaurants and fast food consumption: A national study

    OpenAIRE

    Richardson, Andrea S; Boone-Heinonen, Janne; Popkin, Barry M; Gordon-Larsen, Penny

    2011-01-01

    Abstract Background Recent studies suggest that neighborhood fast food restaurant availability is related to greater obesity, yet few studies have investigated whether neighborhood fast food restaurant availability promotes fast food consumption. Our aim was to estimate the effect of neighborhood fast food availability on frequency of fast food consumption in a national sample of young adults, a population at high risk for obesity. Methods We used national data from U.S. young adults enrolled...

  12. Strategies of Building a Stronger Sense of Community for Sustainable Neighborhoods: Comparing Neighborhood Accessibility with Community Empowerment Programs

    Directory of Open Access Journals (Sweden)

    Te-I Albert Tsai

    2014-05-01

    Full Text Available New Urbanist development in the U.S. aims at enhancing a sense of community and seeks to return to the design of early transitional neighborhoods which have pedestrian-oriented environments with retail shops and services within walking distances of housing. Meanwhile, 6000 of Taiwan’s community associations have been running community empowerment programs supported by the Council for Cultural Affairs that have helped many neighborhoods to rebuild so-called community cohesion. This research attempts to evaluate whether neighborhoods with facilities near housing and shorter travel distances within a neighborhood would promote stronger social interactions and form a better community attachment than neighborhoods that have various opportunities for residents to participate in either formal or informal social gatherings. After interviewing and surveying residents from 19 neighborhoods in Taipei’s Beitou District, and correlating the psychological sense of community with inner neighborhood’s daily travel distances and numbers of participatory activities held by community organizations under empowerment programs together with frequencies of regular individual visits and casual meetings, statistical evidence yielded that placing public facilities near residential locations is more effective than providing various programs for elevating a sense of community.

  13. Assessment Of Market Facilities And Locational Effects On Adjoining Neighborhoods In Nigerian Urban Centers Empirical Evidence From Akure Nigeria

    Directory of Open Access Journals (Sweden)

    Adeyinka S. A.

    2015-08-01

    Full Text Available There is the need for people to buy and sell and transact their businesses in a way that life can go on normally. This study examined the markets facilities level and locational effects on adjoining neighbourhoods in Akure Township. Both primary and secondary data types were employed in the study primary data were collected through the administration of questionnaire on traders and patronsbuyers in the markets and residents of adjoining neighbourhoods and personal observation. Secondary data were collected from government publications. Data collected were analysed using descriptive statistical methods which included frequency counts and Likerts scale to analyse the satisfaction of traders and patrons on the facilities in the markets and severity of locational effects on residents of adjoining neighbourhoods. Findings from the study showed that facilities such as parking spaces fire extinguishers circulation spaces within the markets trading spaces safe area for children perimeter fencing and loading and off-loading bay were inadequately provided. While on-street display of goods traffic congestion air pollution on-street parking due to inadequate parking spaces were the severely perceived locational effects. The study concluded that facilities in the markets were inadequate and that markets constitute nuisances to the adjoining areas. It hereby recommends that markets in the study area be provided with the required level of facilities to prevent future urban problems.

  14. Use of a bioindicator system in the study of the mutagenetical effects in the neighborhoods of deposits of radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Santos Leal, Teresa Cristina dos [Post-graduation in Environmental Science (PGCA), UFF, Niteroi (Brazil)], E-mail: teresa@tcleal.eng.br; Crispim, Verginia R. [Nuclear Engineering Program/COPPE/UFRJ, Rio de Janeiro (Brazil); Frota, Marcos [Laboratory of Radiobiology and Radiometry (LARARA), Department of General Biology, UFF, Niteroi (Brazil); Kelecom, Alphonse [Post-graduation in Environmental Science (PGCA), UFF, Niteroi (Brazil); Laboratory of Radiobiology and Radiometry (LARARA), Department of General Biology, UFF, Niteroi (Brazil); Silva, Ademir Xavier da [Nuclear Engineering Program/COPPE/UFRJ, Rio de Janeiro (Brazil)

    2008-04-15

    The purpose of the research described in this paper was to analyze the biological mutational effects caused by low doses of ionizing radiation on biological samples placed nearby and around deposits of radioactive waste, as a way of monitoring the environment close to them. In order to do this, the plant Tradescantia pallida was chosen, and through micronuclei tests the sensitivity of the dose/response to bio-monitoring could be observed. The plants were exposed for a period of 24 h in previously chosen sites around Brazil, within the proximity of nuclear waste deposits. In each location, three points were chosen for bio-monitoring. The results obtained at these locations showed a small increment in the frequency of micronuclei per cell of the biosensor. From these data, a scale of mutagenesis effects due to low-dose radiation was built up. T. pallida is a good alternative for environmental bio-monitoring in tropical climates, as it is an excellent alternative tool in the studies of the effects of ionizing radiation on the environment.

  15. Effects of Meaning and Symmetry on Judgments of Size

    DEFF Research Database (Denmark)

    Reber, Rolf; Christensen, Bo T.; Meier, Beat

    2014-01-01

    to be judged as larger than asymmetric numbers (e.g., 43). However, recent research found that symmetric numbers were judged to be smaller than asymmetric numbers. This finding suggests that the mechanisms underlying size judgments may differ in meaningful and meaningless materials. Supporting this notion, we...... showed in Experiment 1 that meaning increased judged size, whereas symmetry decreased judged size. In the next two experiments, we excluded several alternative explanations for the differences in size judgments between meaningful and meaningless materials in earlier studies. This finding contradicts...

  16. Neighborhood Inequalities in Adverse Pregnancy Outcomes in an Urban Setting in Spain: A Multilevel Approach

    OpenAIRE

    Garcia-Subirats, Irene; Pérez, Glòria; Rodríguez-Sanz, Maica; Muñoz, Dolores Ruiz; Salvador, Joaquín

    2012-01-01

    The aim of the present study was to describe socioeconomic inequalities in low birth weight (LBW), premature birth (PM) and small size for gestational age at birth (SGA) between 2000 and 2005 in Barcelona, Spain, jointly evaluating the effect of mother’s country of origin, and neighborhood of residence socioeconomic level measured using unemployment and educational level. We performed a cross-sectional study of births to mothers aged 12–49 years who were residents in the city of Barcelona in ...

  17. Assessing the benefits of a rising tide: Educational attainment and increases in neighborhood socioeconomic advantage.

    Science.gov (United States)

    Johnston, William R

    2017-02-01

    An emerging approach to studying associations between neighborhood contexts and educational outcomes is to estimate the outcomes of adolescents growing up in neighborhoods that are experiencing economic growth in comparison to peers that reside in economically stable or declining communities. Using data from the National Longitudinal Study of Adolescent Health (Add Health), I examine the association between education attainment and changes in socioeconomic advantage in urban neighborhoods between 1990 and 2000. I find that residing in a neighborhood that experiences economic improvements has a positive association with educational attainment for urban adolescents. Furthermore, race-based analyses suggest consistently positive associations for all race subgroups, lending support to protective models of neighborhood effects that argue high neighborhood SES supports positive outcomes for adolescents residing in these contexts. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. On size-effects in single crystal wedge indentation

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2012-01-01

    constitutive length parameters to model sizeeffects. The problem is studied numerically using a strain gradient crystal visco-plasticity theory formulated along the lines proposed by Fleck andWillis (2009). It is shown how the force-indentation relation is affected due to size-dependence in the material. Size...

  19. Practical implementation of Channelized Hotelling Observers: Effect of ROI size.

    Science.gov (United States)

    Ferrero, Andrea; Favazza, Christopher P; Yu, Lifeng; Leng, Shuai; McCollough, Cynthia H

    2017-03-01

    Fundamental to the development and application of channelized Hotelling observer (CHO) models is the selection of the region of interest (ROI) to evaluate. For assessment of medical imaging systems, reducing the ROI size can be advantageous. Smaller ROIs enable a greater concentration of interrogable objects in a single phantom image, thereby providing more information from a set of images and reducing the overall image acquisition burden. Additionally, smaller ROIs may promote better assessment of clinical patient images as different patient anatomies present different ROI constraints. To this end, we investigated the minimum ROI size that does not compromise the performance of the CHO model. In this study, we evaluated both simulated images and phantom CT images to identify the minimum ROI size that resulted in an accurate figure of merit (FOM) of the CHO's performance. More specifically, the minimum ROI size was evaluated as a function of the following: number of channels, spatial frequency and number of rotations of the Gabor filters, size and contrast of the object, and magnitude of the image noise. Results demonstrate that a minimum ROI size exists below which the CHO's performance is grossly inaccurate. The minimum ROI size is shown to increase with number of channels and be dictated by truncation of lower frequency filters. We developed a model to estimate the minimum ROI size as a parameterized function of the number of orientations and spatial frequencies of the Gabor filters, providing a guide for investigators to appropriately select parameters for model observer studies.

  20. The effect of group size on vigilance in Ruddy Turnstones

    NARCIS (Netherlands)

    Fuller, R.A.; Bearhop, S.; Metcalfe, N.B.; Piersma, T.

    2013-01-01

    Foraging birds can manage time spent vigilant for predators by forming groups of various sizes. However, group size alone will not always reliably determine the optimal level of vigilance. For example, variation in predation risk or food quality between patches may also be influential. In a field

  1. Eliminating high-order scattering effects in optical microbubble sizing.

    Science.gov (United States)

    Qiu, Huihe

    2003-04-01

    Measurements of bubble size and velocity in multiphase flows are important in much research and many industrial applications. It has been found that high-order refractions have great impact on microbubble sizing by use of phase-Doppler anemometry (PDA). The problem has been investigated, and a model of phase-size correlation, which also takes high-order refractions into consideration, is introduced to improve the accuracy of bubble sizing. Hence the model relaxes the assumption of a single-scattering mechanism in a conventional PDA system. The results of simulation based on this new model are compared with those based on a single-scattering-mechanism approach or a first-order approach. An optimization method for accurately sizing air bubbles in water has been suggested.

  2. Latent hardening size effect in small-scale plasticity

    Science.gov (United States)

    Bardella, Lorenzo; Segurado, Javier; Panteghini, Andrea; Llorca, Javier

    2013-07-01

    We aim at understanding the multislip behaviour of metals subject to irreversible deformations at small-scales. By focusing on the simple shear of a constrained single-crystal strip, we show that discrete Dislocation Dynamics (DD) simulations predict a strong latent hardening size effect, with smaller being stronger in the range [1.5 µm, 6 µm] for the strip height. We attempt to represent the DD pseudo-experimental results by developing a flow theory of Strain Gradient Crystal Plasticity (SGCP), involving both energetic and dissipative higher-order terms and, as a main novelty, a strain gradient extension of the conventional latent hardening. In order to discuss the capability of the SGCP theory proposed, we implement it into a Finite Element (FE) code and set its material parameters on the basis of the DD results. The SGCP FE code is specifically developed for the boundary value problem under study so that we can implement a fully implicit (Backward Euler) consistent algorithm. Special emphasis is placed on the discussion of the role of the material length scales involved in the SGCP model, from both the mechanical and numerical points of view.

  3. Latent hardening size effect in small-scale plasticity

    International Nuclear Information System (INIS)

    Bardella, Lorenzo; Panteghini, Andrea; Segurado, Javier; Llorca, Javier

    2013-01-01

    We aim at understanding the multislip behaviour of metals subject to irreversible deformations at small-scales. By focusing on the simple shear of a constrained single-crystal strip, we show that discrete Dislocation Dynamics (DD) simulations predict a strong latent hardening size effect, with smaller being stronger in the range [1.5 µm, 6 µm] for the strip height. We attempt to represent the DD pseudo-experimental results by developing a flow theory of Strain Gradient Crystal Plasticity (SGCP), involving both energetic and dissipative higher-order terms and, as a main novelty, a strain gradient extension of the conventional latent hardening. In order to discuss the capability of the SGCP theory proposed, we implement it into a Finite Element (FE) code and set its material parameters on the basis of the DD results. The SGCP FE code is specifically developed for the boundary value problem under study so that we can implement a fully implicit (Backward Euler) consistent algorithm. Special emphasis is placed on the discussion of the role of the material length scales involved in the SGCP model, from both the mechanical and numerical points of view. (paper)

  4. Droplet size effects on film drainage between droplet and substrate.

    Science.gov (United States)

    Steinhaus, Benjamin; Spicer, Patrick T; Shen, Amy Q

    2006-06-06

    When a droplet approaches a solid surface, the thin liquid film between the droplet and the surface drains until an instability forms and then ruptures. In this study, we utilize microfluidics to investigate the effects of film thickness on the time to film rupture for water droplets in a flowing continuous phase of silicone oil deposited on solid poly(dimethylsiloxane) (PDMS) surfaces. The water droplets ranged in size from millimeters to micrometers, resulting in estimated values of the film thickness at rupture ranging from 600 nm down to 6 nm. The Stefan-Reynolds equation is used to model film drainage beneath both millimeter- and micrometer-scale droplets. For millimeter-scale droplets, the experimental and analytical film rupture times agree well, whereas large differences are observed for micrometer-scale droplets. We speculate that the differences in the micrometer-scale data result from the increases in the local thin film viscosity due to confinement-induced molecular structure changes in the silicone oil. A modified Stefan-Reynolds equation is used to account for the increased thin film viscosity of the micrometer-scale droplet drainage case.

  5. A Case Study in Citizen Science: The Effectiveness of a Trap-Neuter-Return Program in a Chicago Neighborhood

    Directory of Open Access Journals (Sweden)

    Daniel D. Spehar

    2018-01-01

    Full Text Available The use of trap-neuter-return (TNR as a method of managing free-roaming cat populations has increased in the United States in recent decades. Historically, TNR has been conducted most often at a grassroots level, which has led to inconsistent data collection and assessment practices. Consequently, a paucity of analyzable data exists. An initiative is underway to standardize TNR program data collection and assessment. However, it could be some time before scientifically sound protocols are implemented on a broad scale. In the interim, sets of data collected by nascent citizen scientists offer valid opportunities to evaluate grassroots TNR programs. The purpose of the present study was to examine the effectiveness of a TNR program conducted by a citizen scientist located in Chicago, Illinois, where a county law permitting TNR was enacted in 2007. Colony populations, when grouped by the number of years enrolled in the program, declined by a mean of 54% from entry and 82% from peak levels. Results from coexistent TNR programs in the Chicago area are consistent with these findings.

  6. THE EFFECT OF SEDIMENT GRAIN SIZE ON HEAVY METAL CONTENT

    Directory of Open Access Journals (Sweden)

    Svetlana Maslennikova

    2012-06-01

    Full Text Available In the natural surroundings tectonical, climatological, dynamic and physico-chemical conditions of sedimentation are the crucial factors in the process of sediment composition formation. Grain size is one of the most investigated reasons of space and temporary variability in heavy metal concentration. In general, the data on grain size measurement afford to appreciate sorption capacity of sediments and arrange them. The dependence heavy metal content on grain size of sediments has been examined in the enormous amount of research works. The main conclusion is that if grain size decreases, metal content increases.We have carried out sediment grain size measurement of two lakes (Chebachje Lake, Piketnoye Lake located in the South of Western Siberia, Russia. To define grain size of these sediments the sorting of samples collected layer-by-layer has been conducted by nest of sieves (from 43 to 1000 µm. Accomplished examinations allow to state that layer-by-layer grain size measurement of sediments has significant importance in reconstruction of paleoecologic peculiarities and also influences organic and inorganic matter concentrating in the sediments in dynamics

  7. Ultraviolet (UV) disinfection of grey water: particle size effects.

    Science.gov (United States)

    Winward, G P; Avery, L M; Stephenson, T; Jefferson, B

    2008-02-01

    The impact of water quality on the ultraviolet (UV) disinfection of grey water was investigated with reference to urban water reuse. Direct UV disinfection of grey water did not meet the stringent California State Title 22 criteria for unrestricted urban water reuse due to the presence of particulate material ranging from or = 2000 microm in size. Grey water was manipulated by settling to produce fractions of varying particle size distributions and blending was employed post-disinfection to extract particle-associated coliforms (PACs). The efficacy of UV disinfection was found to be linked to the particle size of the grey water fractions. The larger particle size fractions with a mean particle size of 262 microm and above were observed to shield more coliforms from UV light than did the smaller particles with a mean particle size below 119 microm. Up to 70% of total coliforms in the larger particle size fractions were particle-associated following a UV dose (fluence) of 260 mJ.cm(-2) and would remain undetected by standard coliform enumeration techniques. Implications for urban water reuse are discussed and recommendations made for grey water treatment to ensure removal of particle-associated indicator bacteria and pathogens prior to UV disinfection.

  8. Effect Size Measures for Mediation Models: Quantitative Strategies for Communicating Indirect Effects

    Science.gov (United States)

    Preacher, Kristopher J.; Kelley, Ken

    2011-01-01

    The statistical analysis of mediation effects has become an indispensable tool for helping scientists investigate processes thought to be causal. Yet, in spite of many recent advances in the estimation and testing of mediation effects, little attention has been given to methods for communicating effect size and the practical importance of those…

  9. Socioeconomic Segregation of Activity Spaces in Urban Neighborhoods: Does Shared Residence Mean Shared Routines?

    Directory of Open Access Journals (Sweden)

    Christopher R. Browning

    2017-02-01

    Full Text Available Residential segregation by income and education is increasing alongside slowly declining black-white segregation. Segregation in urban neighborhood residents’ nonhome activity spaces has not been explored. How integrated are the daily routines of people who live in the same neighborhood? Are people with different socioeconomic backgrounds that live near one another less likely to share routine activity locations than those of similar education or income? Do these patterns vary across the socioeconomic continuum or by neighborhood structure? The analyses draw on unique data from the Los Angeles Family and Neighborhood Survey that identify the location where residents engage in routine activities. Using multilevel p2 (network models, we analyze pairs of households in the same neighborhood and examine whether the dyad combinations across three levels of SES conduct routine activities in the same location, and whether neighbor socioeconomic similarity in the co-location of routine activities is dependent on the level of neighborhood socioeconomic inequality and trust. Results indicate that, on average, increasing SES diminishes the likelihood of sharing activity locations with any SES group. This pattern is most pronounced in neighborhoods characterized by high levels of socioeconomic inequality. Neighborhood trust explains a nontrivial proportion of the inequality effect on the extent of routine activity sorting by SES. Thus stark, visible neighborhood-level inequality by SES may lead to enhanced effects of distrust on the willingness to share routines across class.

  10. RACE, CODE OF THE STREET, AND VIOLENT DELINQUENCY: A MULTILEVEL INVESTIGATION OF NEIGHBORHOOD STREET CULTURE AND INDIVIDUAL NORMS OF VIOLENCE*

    Science.gov (United States)

    Stewart, Eric A.; Simons, Ronald L.

    2011-01-01

    The study outlined in this article drew on Elijah Anderson’s (1999) code of the street perspective to examine the impact of neighborhood street culture on violent delinquency. Using data from more than 700 African American adolescents, we examined 1) whether neighborhood street culture predicts adolescent violence above and beyond an adolescent’s own street code values and 2) whether neighborhood street culture moderates individual-level street code values on adolescent violence. Consistent with Anderson’s hypotheses, neighborhood street culture significantly predicts violent delinquency independent of individual-level street code effects. Additionally, neighborhood street culture moderates individual-level street code values on violence in neighborhoods where the street culture is widespread. In particular, the effect of street code values on violence is enhanced in neighborhoods where the street culture is endorsed widely. PMID:21666759

  11. Influences of Neighborhood Context, Individual History and Parenting Behavior on Recidivism among Juvenile Offenders

    Science.gov (United States)

    Grunwald, Heidi E.; Lockwood, Brian; Harris, Philip W.; Mennis, Jeremy

    2010-01-01

    This study examined the effects of neighborhood context on juvenile recidivism to determine if neighborhoods influence the likelihood of reoffending. Although a large body of literature exists regarding the impact of environmental factors on delinquency, very little is known about the effects of these factors on juvenile recidivism. The sample…

  12. Effects of primary and secondary morphological family size in monolingual and bilingual word processing

    NARCIS (Netherlands)

    Mulder, K.; Dijkstra, A.F.J.; Schreuder, R.; Baayen, Harald

    2014-01-01

    This study investigated primary and secondary morphological family size effects in monolingual and bilingual processing, combining experimentation with computational modeling. Family size effects were investigated in an English lexical decision task for Dutch-English bilinguals and English

  13. Effect of size heterogeneity on community identification in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Danon, L.; Diaz-Guilera, A.; Arenas, A.

    2008-01-01

    Identifying community structure can be a potent tool in the analysis and understanding of the structure of complex networks. Up to now, methods for evaluating the performance of identification algorithms use ad-hoc networks with communities of equal size. We show that inhomogeneities in community sizes can and do affect the performance of algorithms considerably, and propose an alternative method which takes these factors into account. Furthermore, we propose a simple modification of the algorithm proposed by Newman for community detection (Phys. Rev. E 69 066133) which treats communities of different sizes on an equal footing, and show that it outperforms the original algorithm while retaining its speed.

  14. The global financial crisis and neighborhood decline

    NARCIS (Netherlands)

    Zwiers, Merle; Bolt, Gideon; Van Ham, Maarten; Van Kempen, Ronald

    2016-01-01

    Neighborhood decline is a complex and multidimensional process. National and regional variations in economic and political structures (including varieties in national welfare state arrangements), combined with differences in neighborhood history, development, and population composition, make it

  15. Geographic object-based delineation of neighborhoods of Accra, Ghana using QuickBird satellite imagery.

    Science.gov (United States)

    Stow, Douglas A; Lippitt, Christopher D; Weeks, John R

    2010-08-01

    The objective was to test GEographic Object-based Image Analysis (GEOBIA) techniques for delineating neighborhoods of Accra, Ghana using QuickBird multispectral imagery. Two approaches to aggregating census enumeration areas (EAs) based on image-derived measures of vegetation objects were tested: (1) merging adjacent EAs according to vegetation measures and (2) image segmentation. Both approaches exploit readily available functions within commercial GEOBIA software. Image-derived neighborhood maps were compared to a reference map derived by spatial clustering of slum index values (from census data), to provide a relative assessment of potential map utility. A size-constrained iterative segmentation approach to aggregation was more successful than standard image segmentation or feature merge techniques. The segmentation approaches account for size and shape characteristics, enabling more realistic neighborhood boundaries to be delineated. The percentage of vegetation patches within each EA yielded more realistic delineation of potential neighborhoods than mean vegetation patch size per EA.

  16. Finite size effects in lattice QCD with dynamical Wilson fermions

    Energy Technology Data Exchange (ETDEWEB)

    Orth, B.

    2004-06-01

    Due to limited computing resources choosing the parameters for a full lattice QCD simulation always amounts to a compromise between the competing objectives of a lattice spacing as small, quarks as light, and a volume as large as possible. Aiming at pushing unquenched simulations with the standard Wilson action towards the computationally expensive regime of small quark masses, the GRAL project addresses the question whether computing time can be saved by sticking to lattices with rather modest numbers of grid sites and extrapolating the finite-volume results to the infinite volume (prior to the usual chiral and continuum extrapolations). In this context we investigate in this work finite-size effects in simulated light hadron masses. Understanding their systematic volume dependence may not only help saving computer time in light quark simulations with the Wilson action, but also guide future simulations with dynamical chiral fermions which for a foreseeable time will be restricted to rather small lattices. We analyze data from hybrid Monte Carlo simulations with the N{sub f} = 2 Wilson action at two values of the coupling parameter, {beta} = 5.6 (lattice spacing {alpha} {approx} 0.08 fm) and {beta} = 5.32144 ({alpha} {approx} 0.13 fm). The larger {beta} corresponds to the coupling used previously by SESAM/T{chi}L. The considered hopping parameters {kappa} = 0.1575, 0.158 (at the larger {beta}) and {kappa} = 0.1665 (at the smaller {beta}) correspond to quark masses of 85, 50 and 36% of the strange quark mass, respectively. At each quark mass we study at least three different lattice extents in the range from L = 10 to L = 24 (0.85-2.04 fm). Estimates of autocorrelation times in the stochastic updating process and of the computational cost of every run are given. For each simulated sea quark mass we calculate quark propagators and hadronic correlation functions in order to extract the pion, rho and nucleon masses as well as the pion decay constant and the quark mass

  17. Effective population size and evolutionary dynamics in outbred ...

    Indian Academy of Sciences (India)

    populations of fruit flies is not primarily driven by new mutations, but rather by changes in the frequency of ..... Drift simulation: The sex ratio, total population size and ...... Gillespie J. H. 1994a Substitution processes in molecular evolution. II.

  18. Electric field engineering using quantum-size-effect-tuned heterojunctions

    KAUST Repository

    Adinolfi, V.; Ning, Z.; Xu, J.; Masala, Silvia; Zhitomirsky, D.; Thon, S. M.; Sargent, E. H.

    2013-01-01

    be tuned across the light-absorbing semiconductor layer via control over CQD size, employing solution-processed, room-temperature fabricated materials. We exploit this feature by designing and demonstrating a field-enhanced heterojunction architecture. We

  19. The effect of meal size on gastric evacuation in whiting

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    1998-01-01

    Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe...

  20. The Effects of Rain Garden Size on Hydrological Performance

    Science.gov (United States)

    Bioretention systems are vegetated depressions designed to accept stormwater runoff from impervious surfaces. Manuals and guidance documents recommend sizing bioretention cells anywhere from 3% to 43% of their associated drainage areas, based on factors including soil type, slop...

  1. Switching-on quantum size effects in silicon nanocrystals.

    Science.gov (United States)

    Sun, Wei; Qian, Chenxi; Wang, Liwei; Wei, Muan; Mastronardi, Melanie L; Casillas, Gilberto; Breu, Josef; Ozin, Geoffrey A

    2015-01-27

    The size-dependence of the absolute luminescence quantum yield of size-separated silicon nanocrystals reveals a "volcano" behavior, which switches on around 5 nm, peaks at near 3.7-3.9 nm, and decreases thereafter. These three regions respectively define: i) the transition from bulk to strongly quantum confined emissive silicon, ii) increasing confinement enhancing radiative recombination, and iii) increasing contributions favoring non-radiative recombination. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Size and liquidity effects in Nigeria: an industrial sector study

    OpenAIRE

    Hearn, Bruce

    2013-01-01

    This study estimates liquidity premiums using the recently developed Liu (2006) measure within a multifactor capital asset pricing model (CAPM) including size premiums and a time varying parameter model for the West African emerging market of Nigeria. The evidence suggests that liquidity factors are relevant only for financial and basic materials sector stocks while size factor is more generally relevant in explaining the cross section of stock returns in the Nigerian domestic equity market....

  3. “When you got nothing to do, you do somebody”: A Community’s perceptions of neighborhood effects on adolescent sexual behaviors

    Science.gov (United States)

    Muhammad, Melvin R; Corbie-Smith, Giselle

    2010-01-01

    This study explores community members’ perspectives regarding the relationship between neighborhood characteristics and adolescent sexual behaviors in two rural, African American communities. The data were collected as part of a community needs assessment to inform the development of HIV prevention interventions in two contiguous counties in northeastern North Carolina, USA. We conducted eleven focus groups with three population groups: adolescents and young adults aged 16–24 (N=38), adults over age 25 (N=42), and formerly incarcerated individuals (N=13). All focus groups were audio-recorded, transcribed and analyzed using a grounded theory approach to content analysis and a constant comparison method. Six major themes emerged from the discussions linking neighborhood context and adolescents sexual behavior: the overwhelming absence of recreational options for community members; lack of diverse leisure-time activities for adolescents; lack of recreational options for adolescents who are dating; adolescent access to inappropriate leisure time activities that promote multiple risk behaviors; limited safe environments for socializing; and cost-barriers to recreational activities for adolescents. In addition, lack of adequate parental supervision of adolescents’ time alone and with friends of the opposite sex, as well as ineffective community monitoring of adolescent social activities, were thought to create situations that promoted sexual and other risk behaviors. These findings allowed us to develop a conceptual model linking neighborhood structural and social organization factors to adolescent sexual behaviors and provided insights for developed interventions tailored to the local socioeconomic realities. PMID:21129833

  4. Neighborhood racial discrimination and the development of major depression.

    Science.gov (United States)

    Russell, Daniel W; Clavél, Frederick D; Cutrona, Carolyn E; Abraham, W Todd; Burzette, Rebecca G

    2018-02-01

    This study examined the impact of neighborhood racial discrimination on the development of major depressive disorder (MDD) in a sample of African American women. Participants were 499 women from Georgia and Iowa with no history of MDD who were followed for 9 to 11 years. Several neighborhood characteristics (community social disorder, community cohesion, and community racism) and individual characteristics (negative life events, financial strain, personal outlook, religious involvement, relationship quality, negative affectivity, and individual experiences of racism) were employed as predictors of whether or not the women met criteria for MDD during this period of time. In a multilevel logistic regression analysis, neighborhood-level discrimination as well as individual-level variables including the number of negative life events, financial strain, and negative affectivity were found to be significant predictors of developing MDD. Analyses of cross-level interactions indicated that the effects of neighborhood-level discrimination were moderated by the quality of individuals' relationships, such that better relationships with others served to lessen the effect of neighborhood discrimination on depression. Implications of these findings for understanding the negative effects of racial discrimination are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  5. An Effect Size Measure for Raju's Differential Functioning for Items and Tests

    Science.gov (United States)

    Wright, Keith D.; Oshima, T. C.

    2015-01-01

    This study established an effect size measure for differential functioning for items and tests' noncompensatory differential item functioning (NCDIF). The Mantel-Haenszel parameter served as the benchmark for developing NCDIF's effect size measure for reporting moderate and large differential item functioning in test items. The effect size of…

  6. Family Configuration and Achievement: Effects of Birth Order and Family Size in a Sample of Brothers.

    Science.gov (United States)

    Olneck, Michael R.; Bills, David B.

    1979-01-01

    Birth order effects in brothers were found to derive from difference in family size. Effects for family size were found even with socioeconomic background controlled. Nor were family size effects explained by parental ability. The importance of unmeasured preferences or economic resources that vary across families was suggested. (Author/RD)

  7. Schools, Neighborhood Risk Factors, and Crime

    Science.gov (United States)

    Willits, Dale; Broidy, Lisa; Denman, Kristine

    2013-01-01

    Prior research has identified a link between schools (particularly high schools) and neighborhood crime rates. However, it remains unclear whether the relationship between schools and crime is a reflection of other criminogenic dynamics at the neighborhood level or whether schools influence neighborhood crime patterns independently of other…

  8. Numerical Evaluation of Size Effect on the Stress-Strain Behaviour of Geotextile-Reinforced Sand

    DEFF Research Database (Denmark)

    Hosseinpour, I.; Mirmoradi, S.H.; Barari, Amin

    2010-01-01

    This paper studies the effect of sample size on the stress-strain behavior and strength characteristics of geotextile reinforced sand using the finite element numerical analysis. The effect of sample size was investigated by studying the effects of varying the number of geotextile layers, the con......This paper studies the effect of sample size on the stress-strain behavior and strength characteristics of geotextile reinforced sand using the finite element numerical analysis. The effect of sample size was investigated by studying the effects of varying the number of geotextile layers...... on the mechanical behavior of reinforced sand decreases with an increase in the sample size....

  9. The effect of size on the oxygen electroreduction activity of mass-selected platinum nanoparticles

    DEFF Research Database (Denmark)

    Pérez Alonso, Francisco; McCarthy, David N; Nierhoff, Anders

    2012-01-01

    A matter of size: The particle size effect on the activity of the oxygen reduction reaction of size-selected platinum clusters was studied. The ORR activity decreased with decreasing Pt nanoparticle size, corresponding to a decrease in the fraction of terraces on the surfaces of the Pt nanopartic...

  10. The Effect of Size on the Oxygen Electroreduction Activity of Mass‐Selected Platinum Nanoparticles

    DEFF Research Database (Denmark)

    Pérez Alonso, Francisco; McCarthy, David Norman; Nierhoff, Anders Ulrik Fregerslev

    2012-01-01

    A matter of size: The particle size effect on the activity of the oxygen reduction reaction of size-selected platinum clusters was studied. The ORR activity decreased with decreasing Pt nanoparticle size, corresponding to a decrease in the fraction of terraces on the surfaces of the Pt nanopartic...

  11. Effects of climate on size structure and functioning of aquatic food webs

    NARCIS (Netherlands)

    Lacerot, G.

    2010-01-01

    In aquatic food webs, the role of body size is notoriously strong. It is also well known that temperature has an effect on body size. For instance, Bergmann’s rule states that body size increases from warm to cold climates. This thesis addresses the question how climate shapes the size structure of

  12. Polymer-Particle Nanocomposites: Size and Dispersion Effects

    Science.gov (United States)

    Moll, Joseph

    Polymer-particle nanocomposites are used in industrial processes to enhance a broad range of material properties (e.g. mechanical, optical, electrical and gas permeability properties). This dissertation will focus on explanation and quantification of mechanical property improvements upon the addition of nanoparticles to polymeric materials. Nanoparticles, as enhancers of mechanical properties, are ubiquitous in synthetic and natural materials (e.g. automobile tires, packaging, bone), however, to date, there is no thorough understanding of the mechanism of their action. In this dissertation, silica (SiO2) nanoparticles, both bare and grafted with polystyrene (PS), are studied in polymeric matrices. Several variables of interest are considered, including particle dispersion state, particle size, length and density of grafted polymer chains, and volume fraction of SiO2. Polymer grafted nanoparticles behave akin to block copolymers, and this is critically leveraged to systematically vary nanoparticle dispersion and examine its role on the mechanical reinforcement in polymer based nanocomposites in the melt state. Rheology unequivocally shows that reinforcement is maximized by the formation of a transient, but long-lived, percolating polymer-particle network with the particles serving as the network junctions. The effects of dispersion and weight fraction of filler on nanocomposite mechanical properties are also studied in a bare particle system. Due to the interest in directional properties for many different materials, different means of inducing directional ordering of particle structures are also studied. Using a combination of electron microscopy and x-ray scattering, it is shown that shearing anisotropic NP assemblies (sheets or strings) causes them to orient, one in front of the other, into macroscopic two-dimensional structures along the flow direction. In contrast, no such flow-induced ordering occurs for well dispersed NPs or spherical NP aggregates! This work

  13. The neighborhood environment and obesity: Understanding variation by race/ethnicity.

    Science.gov (United States)

    Wong, Michelle S; Chan, Kitty S; Jones-Smith, Jessica C; Colantuoni, Elizabeth; Thorpe, Roland J; Bleich, Sara N

    2018-06-01

    Neighborhood characteristics have been associated with obesity, but less is known whether relationships vary by race/ethnicity. This study examined the relationship between soda consumption - a behavior strongly associated with obesity - and weight status with neighborhood sociodemographic, social, and built environments by race/ethnicity. We merged data on adults from the 2011-2013 California Health Interview Survey, U.S. Census data, and InfoUSA (n=62,396). Dependent variables were soda consumption and weight status outcomes (body mass index and obesity status). Main independent variables were measures of three neighborhood environments: social (social cohesion and safety), sociodemographic (neighborhood socioeconomic status, educational attainment, percent Asian, percent Hispanic, and percent black), and built environments (number of grocery stores, convenience stores, fast food restaurants, and gyms in neighborhood). We fit multi-level linear and logistic regression models, stratified by individual race/ethnicity (NH (non-Hispanic) Whites, NH African Americans, Hispanics, and NH Asians) controlling for individual-level characteristics, to estimate neighborhood contextual effects on study outcomes. Lower neighborhood educational attainment was associated with higher odds of obesity and soda consumption in all racial/ethnic groups. We found fewer associations between study outcomes and the neighborhood, especially the built environment, among NH African Americans and NH Asians. While improvements to neighborhood environment may be promising to reduce obesity, null associations among minority subgroups suggest that changes, particularly to the built environment, may alone be insufficient to address obesity in these groups. Published by Elsevier Inc.

  14. Girls' self-efficacy in the context of neighborhood gender stratification.

    Science.gov (United States)

    Soller, Brian; Jackson, Aubrey L

    2018-05-01

    Scholars have linked neighborhood characteristics to self-efficacy, but few have considered how gender factors into this association. We integrate literature on neighborhoods, gender stratification, and self-efficacy to examine the association between women's relative resources among neighborhood residents and adolescents' self-efficacy. We hypothesize that girls report more self-efficacy when they reside in neighborhoods where women have more socioeconomic resources relative to men. We test this hypothesis using data from the Project on Human Development in Chicago Neighborhoods and the 1990 Census. Results from multilevel regression models with gender-interacted effects indicate the neighborhood level of women's relative resources was not associated with boys' self-efficacy. However, girls reported higher self-efficacy when women's relative resources in their neighborhoods were greater. This association persisted after including potential individual- and neighborhood-level confounding variables. Our study underscores the importance of attending to gendered processes when understanding how neighborhoods impact youth. Copyright © 2018. Published by Elsevier Inc.

  15. Neighborhood Deprivation and Childhood Asthma Outcomes, Accounting for Insurance Coverage.

    Science.gov (United States)

    Nkoy, Flory L; Stone, Bryan L; Knighton, Andrew J; Fassl, Bernhard A; Johnson, Joseph M; Maloney, Christopher G; Savitz, Lucy A

    2018-01-09

    Collecting social determinants data is challenging. We assigned patients a neighborhood-level social determinant measure, the area of deprivation index (ADI), by using census data. We then assessed the association between neighborhood deprivation and asthma hospitalization outcomes and tested the influence of insurance coverage. A retrospective cohort study of children 2 to 17 years old admitted for asthma at 8 hospitals. An administrative database was used to collect patient data, including hospitalization outcomes and neighborhood deprivation status (ADI scores), which were grouped into quintiles (ADI 1, the least deprived neighborhoods; ADI 5, the most deprived neighborhoods). We used multivariable models, adjusting for covariates, to assess the associations and added a neighborhood deprivation status and insurance coverage interaction term. A total of 2270 children (median age 5 years; 40.6% girls) were admitted for asthma. We noted that higher ADI quintiles were associated with greater length of stay, higher cost, and more asthma readmissions ( P < .05 for most quintiles). Having public insurance was independently associated with greater length of stay (β: 1.171; 95% confidence interval [CI]: 1.117-1.228; P < .001), higher cost (β: 1.147; 95% CI: 1.093-1.203; P < .001), and higher readmission odds (odds ratio: 1.81; 95% CI: 1.46-2.24; P < .001). There was a significant deprivation-insurance effect modification, with public insurance associated with worse outcomes and private insurance with better outcomes across ADI quintiles ( P < .05 for most combinations). Neighborhood-level ADI measure is associated with asthma hospitalization outcomes. However, insurance coverage modifies this relationship and needs to be considered when using the ADI to identify and address health care disparities. Copyright © 2018 by the American Academy of Pediatrics.

  16. Neighborhood Environmental Health and Premature Death From Cardiovascular Disease

    Science.gov (United States)

    Xu, Junjun; Rollins, Latrice; Baltrus, Peter; O’Connell, Laura Kathryn; Cooper, Dexter L.; Hopkins, Jammie; Botchwey, Nisha D.; Akintobi, Tabia Henry

    2018-01-01

    Introduction Cardiovascular disease (CVD) is the leading cause of death in the United States and disproportionately affects racial/ethnic minority groups. Healthy neighborhood conditions are associated with increased uptake of health behaviors that reduce CVD risk, but minority neighborhoods often have poor food access and poor walkability. This study tested the community-driven hypothesis that poor access to food at the neighborhood level and poor neighborhood walkability are associated with racial disparities in premature deaths from CVD. Methods We examined the relationship between neighborhood-level food access and walkability on premature CVD mortality rates at the census tract level for the city of Atlanta using multivariable logistic regression models. We produced maps to illustrate premature CVD mortality, food access, and walkability by census tract for the city. Results We found significant racial differences in premature CVD mortality rates and geographic disparities in food access and walkability among census tracts in Atlanta. Improved food access and walkability were associated with reduced overall premature CVD mortality in unadjusted models, but this association did not persist in models adjusted for census tract population composition and poverty. Census tracts with high concentrations of minority populations had higher levels of poor food access, poor walkability, and premature CVD mortality. Conclusion This study highlights disparities in premature CVD mortality and neighborhood food access and walkability at the census tract level in the city of Atlanta. Improving food access may have differential effects for subpopulations living in the same area. These results can be used to calibrate neighborhood-level interventions, and they highlight the need to examine race-specific health outcomes. PMID:29389312

  17. Cancer mortality disparities among New York City's Upper Manhattan neighborhoods.

    Science.gov (United States)

    Hashim, Dana; Manczuk, Marta; Holcombe, Randall; Lucchini, Roberto; Boffetta, Paolo

    2017-11-01

    The East Harlem (EH), Central Harlem (CH), and Upper East Side (UES) neighborhoods of New York City are geographically contiguous to tertiary medical care, but are characterized by cancer mortality rate disparities. This ecological study aims to disentangle the effects of race and neighborhood on cancer deaths. Mortality-to-incidence ratios were determined using neighborhood-specific data from the New York State Cancer Registry and Vital Records Office (2007-2011). Ecological data on modifiable cancer risk factors from the New York City Community Health Survey (2002-2006) were stratified by sex, age group, race/ethnicity, and neighborhood and modeled against stratified mortality rates to disentangle race/ethnicity and neighborhood using logistic regression. Significant gaps in mortality rates were observed between the UES and both CH and EH across all cancers, favoring UES. Mortality-to-incidence ratios of both CH and EH were similarly elevated in the range of 0.41-0.44 compared with UES (0.26-0.30). After covariate and multivariable adjustment, black race (odds ratio=1.68; 95% confidence interval: 1.46-1.93) and EH residence (odds ratio=1.20; 95% confidence interval: 1.07-1.35) remained significant risk factors in all cancers' combined mortality. Mortality disparities remain among EH, CH, and UES neighborhoods. Both neighborhood and race are significantly associated with cancer mortality, independent of each other. Multivariable adjusted models that include Community Health Survey risk factors show that this mortality gap may be avoidable through community-based public health interventions.

  18. Neighborhood Environmental Health and Premature Death From Cardiovascular Disease.

    Science.gov (United States)

    Gaglioti, Anne H; Xu, Junjun; Rollins, Latrice; Baltrus, Peter; O'Connell, Laura Kathryn; Cooper, Dexter L; Hopkins, Jammie; Botchwey, Nisha D; Akintobi, Tabia Henry

    2018-02-01

    Cardiovascular disease (CVD) is the leading cause of death in the United States and disproportionately affects racial/ethnic minority groups. Healthy neighborhood conditions are associated with increased uptake of health behaviors that reduce CVD risk, but minority neighborhoods often have poor food access and poor walkability. This study tested the community-driven hypothesis that poor access to food at the neighborhood level and poor neighborhood walkability are associated with racial disparities in premature deaths from CVD. We examined the relationship between neighborhood-level food access and walkability on premature CVD mortality rates at the census tract level for the city of Atlanta using multivariable logistic regression models. We produced maps to illustrate premature CVD mortality, food access, and walkability by census tract for the city. We found significant racial differences in premature CVD mortality rates and geographic disparities in food access and walkability among census tracts in Atlanta. Improved food access and walkability were associated with reduced overall premature CVD mortality in unadjusted models, but this association did not persist in models adjusted for census tract population composition and poverty. Census tracts with high concentrations of minority populations had higher levels of poor food access, poor walkability, and premature CVD mortality. This study highlights disparities in premature CVD mortality and neighborhood food access and walkability at the census tract level in the city of Atlanta. Improving food access may have differential effects for subpopulations living in the same area. These results can be used to calibrate neighborhood-level interventions, and they highlight the need to examine race-specific health outcomes.

  19. Effect of beamlet step-size on IMRT plan quality

    International Nuclear Information System (INIS)

    Zhang Guowei; Jiang Ziping; Shepard, David; Earl, Matt; Yu, Cedric

    2005-01-01

    We have studied the degree to which beamlet step-size impacts the quality of intensity modulated radiation therapy (IMRT) treatment plans. Treatment planning for IMRT begins with the application of a grid that divides each beam's-eye-view of the target into a number of smaller beamlets (pencil beams) of radiation. The total dose is computed as a weighted sum of the dose delivered by the individual beamlets. The width of each beamlet is set to match the width of the corresponding leaf of the multileaf collimator (MLC). The length of each beamlet (beamlet step-size) is parallel to the direction of leaf travel. The beamlet step-size represents the minimum stepping distance of the leaves of the MLC and is typically predetermined by the treatment planning system. This selection imposes an artificial constraint because the leaves of the MLC and the jaws can both move continuously. Removing the constraint can potentially improve the IMRT plan quality. In this study, the optimized results were achieved using an aperture-based inverse planning technique called direct aperture optimization (DAO). We have tested the relationship between pencil beam step-size and plan quality using the American College of Radiology's IMRT test case. For this case, a series of IMRT treatment plans were produced using beamlet step-sizes of 1, 2, 5, and 10 mm. Continuous improvements were seen with each reduction in beamlet step size. The maximum dose to the planning target volume (PTV) was reduced from 134.7% to 121.5% and the mean dose to the organ at risk (OAR) was reduced from 38.5% to 28.2% as the beamlet step-size was reduced from 10 to 1 mm. The smaller pencil beam sizes also led to steeper dose gradients at the junction between the target and the critical structure with gradients of 6.0, 7.6, 8.7, and 9.1 dose%/mm achieved for beamlet step sizes of 10, 5, 2, and 1 mm, respectively

  20. Effect of silica particle size on macrophage inflammatory responses.

    Directory of Open Access Journals (Sweden)

    Toshimasa Kusaka

    Full Text Available Amorphous silica particles, such as nanoparticles (<100 nm diameter particles, are used in a wide variety of products, including pharmaceuticals, paints, cosmetics, and food. Nevertheless, the immunotoxicity of these particles and the relationship between silica particle size and pro-inflammatory activity are not fully understood. In this study, we addressed the relationship between the size of amorphous silica (particle dose, diameter, number, and surface area and the inflammatory activity (macrophage phagocytosis, inflammasome activation, IL-1β secretion, cell death and lung inflammation. Irrespective of diameter size, silica particles were efficiently internalized by mouse bone marrow-derived macrophages via an actin cytoskeleton-dependent pathway, and induced caspase-1, but not caspase-11, activation. Of note, 30 nm-1000 nm diameter silica particles induced lysosomal destabilization, cell death, and IL-1β secretion at markedly higher levels than did 3000 nm-10000 nm silica particles. Consistent with in vitro results, intra-tracheal administration of 30 nm silica particles into mice caused more severe lung inflammation than that of 3000 nm silica particles, as assessed by measurement of pro-inflammatory cytokines and neutrophil infiltration in bronchoalveolar lavage fluid of mice, and by the micro-computed tomography analysis. Taken together, these results suggest that silica particle size impacts immune responses, with submicron amorphous silica particles inducing higher inflammatory responses than silica particles over 1000 nm in size, which is ascribed not only to their ability to induce caspase-1 activation but also to their cytotoxicity.

  1. Bottom-up and top-down attentional contributions to the size congruity effect.

    Science.gov (United States)

    Sobel, Kenith V; Puri, Amrita M; Faulkenberry, Thomas J

    2016-07-01

    The size congruity effect refers to the interaction between the numerical and physical (i.e., font) sizes of digits in a numerical (or physical) magnitude selection task. Although various accounts of the size congruity effect have attributed this interaction to either an early representational stage or a late decision stage, only Risko, Maloney, and Fugelsang (Attention, Perception, & Psychophysics, 75, 1137-1147, 2013) have asserted a central role for attention. In the present study, we used a visual search paradigm to further study the role of attention in the size congruity effect. In Experiments 1 and 2, we showed that manipulating top-down attention (via the task instructions) had a significant impact on the size congruity effect. The interaction between numerical and physical size was larger for numerical size comparison (Exp. 1) than for physical size comparison (Exp. 2). In the remaining experiments, we boosted the feature salience by using a unique target color (Exp. 3) or by increasing the display density by using three-digit numerals (Exps. 4 and 5). As expected, a color singleton target abolished the size congruity effect. Searching for three-digit targets based on numerical size (Exp. 4) resulted in a large size congruity effect, but search based on physical size (Exp. 5) abolished the effect. Our results reveal a substantial role for top-down attention in the size congruity effect, which we interpreted as support for a shared-decision account.

  2. Size effect on magnetic ordering in Ce3Al11

    International Nuclear Information System (INIS)

    Wang, C.R.; Chen, Y.Y.; Neeleshwar, S.; Ou, M.N.; Ho, J.C.

    2003-01-01

    To study the size dependence of magnetic ordering, magnetic measurements have been made between 1.8 and 300 K on Ce 3 Al 11 particles having an average particle size of 1400 A. The nanoparticles were single phase as confirmed by X-ray diffraction. At low temperatures a ferromagnetic transition occurs at T C =6.2 K, which is the same as that for the bulk material. On the other hand, the antiferromagnetic transition at T N =3.2 K for the bulk material is not visible down to 1.8 K. Meanwhile, the slightly smaller Curie constant of nanoparticles as compared to that of the bulk indicates a certain degree of demagnetization of Ce ions when the particle size is sufficiently reduced

  3. Efeitos de vizinhança ortográfica no português brasileiro: um estudo com a tarefa de identificação perceptual Orthographic neighborhood effects in brazilian portuguese: a study on perceptual identification tasks

    Directory of Open Access Journals (Sweden)

    Francis Ricardo dos Reis Justi

    2012-01-01

    Full Text Available Esse estudo investigou os efeitos do número de vizinhos ortográficos (N e do número de vizinhos ortográficos de maior frequência de ocorrência (NF na tarefa de identificação perceptual. Trinta e dois estudantes de psicologia falantes do português brasileiro participaram do estudo. Os estímulos experimentais consistiram em 64 palavras que atenderam a uma manipulação fatorial 2 x 2 de N e NF. Os participantes apresentaram uma maior porcentagem de erros nas palavras com vizinhos ortográficos de maior frequência e uma menor porcentagem de erros nas palavras com muitos vizinhos ortográficos. Argumentou-se que esses resultados refletem o efeito dessas variáveis no processo de acesso lexical e que os modelos de Dupla Rota e PPD têm dificuldades em acomodá-los.This study investigated the effects of Neighborhood Density (ND and Neighborhood Frequency (NF on visual word recognition in 32 Brazilian Portuguese speakers. Participants were given a standard perceptual identification task in which they had a 3-second time-limit for saying aloud what the target word was. Experimental stimuli consisted of 64 words according to an ND (2 x NF (2 factorial design. Higher percentages of errors were made for words with a higher frequency neighbor and lower percentages of errors were made for words with a high neighborhood density. It is argued that the results were due to ND and NF effects on lexical access and that they pose difficulties for Dual Route and PDP models of visual word recognition.

  4. Internet Bad Neighborhoods temporal behavior

    NARCIS (Netherlands)

    Moreira Moura, Giovane; Sadre, R.; Pras, Aiko

    2014-01-01

    Malicious hosts tend to be concentrated in certain areas of the IP addressing space, forming the so-called Bad Neighborhoods. Knowledge about this concentration is valuable in predicting attacks from unseen IP addresses. This observation has been employed in previous works to filter out spam. In

  5. Internet Bad Neighborhoods Temporal Behavior

    NARCIS (Netherlands)

    Moreira Moura, G.C.; Sadre, R.; Pras, A.

    2014-01-01

    Malicious hosts tend to be concentrated in certain areas of the IP addressing space, forming the so-called Bad Neighborhoods. Knowledge about this concentration is valuable in predicting attacks from unseen IP addresses. This observation has been employed in previous works to filter out spam. In

  6. Bad Neighborhoods on the Internet

    NARCIS (Netherlands)

    Moreira Moura, G.C.; Sadre, R.; Pras, A.

    2014-01-01

    Analogous to the real world, sources of malicious activities on the Internet tend to be concentrated in certain networks instead of being evenly distributed. In this article, we formally define and frame such areas as Internet Bad Neighborhoods. By extending the reputation of malicious IP addresses

  7. Effects of grain size evolution on mantle dynamics

    Science.gov (United States)

    Schulz, Falko; Tosi, Nicola; Plesa, Ana-Catalina; Breuer, Doris

    2016-04-01

    The rheology of planetary mantle materials is strongly dependent on temperature, pressure, strain-rate, and grain size. In particular, the rheology of olivine, the most abundant mineral of the Earth's upper mantle, has been extensively studied in the laboratory (e.g., Karato and Wu, 1993; Hirth and Kohlstedt, 2003). Two main mechanisms control olivine's deformation: dislocation and diffusion creep. While the former implies a power-law dependence of the viscosity on the strain-rate that leads to a non-Newtonian behaviour, the latter is sensitively dependent on the grain size. The dynamics of planetary interiors is locally controlled by the deformation mechanism that delivers the lowest viscosity. Models of the dynamics and evolution of planetary mantles should thus be capable to self-consistently distinguish which of the two mechanisms dominates at given conditions of temperature, pressure, strain-rate and grain size. As the grain size can affect the viscosity associated with diffusion creep by several orders of magnitude, it can strongly influence the dominant deformation mechanism. The vast majority of numerical, global-scale models of mantle convection, however, are based on the use of a linear diffusion-creep rheology with constant grain-size. Nevertheless, in recent studies, a new equation has been proposed to properly model the time-dependent evolution of the grain size (Austin and Evens, 2007; Rozel et al., 2010). We implemented this equation in our mantle convection code Gaia (Hüttig et al., 2013). In the framework of simple models of stagnant lid convection, we compared simulations based on the fully time-dependent equation of grain-size evolution with simulations based on its steady-state version. In addition, we tested a number of different parameters in order to identify those that affects the grain size to the first order and, in turn, control the conditions at which mantle deformation is dominated by diffusion or dislocation creep. References Austin

  8. Finite size effects for giant magnons on physical strings

    International Nuclear Information System (INIS)

    Minahan, J.A.; Ohlsson Sax, O.

    2008-01-01

    Using finite gap methods, we find the leading order finite size corrections for an arbitrary number of giant magnons on physical strings, where the sum of the momenta is a multiple of 2π. Our results are valid for the Hofman-Maldacena fundamental giant magnons as well as their dyonic generalizations. The energy corrections turn out to be surprisingly simple, especially if all the magnons are fundamental, and at leading order are independent of the magnon flavors. We also show how to use the Bethe ansatz to find finite size corrections for dyonic giant magnons with large R-charges

  9. G-NEST: A gene neighborhood scoring tool to identify co-conserved, co-expressed genes

    Science.gov (United States)

    In previous studies, gene neighborhoods--spatial clusters of co-expressed genes in the genome--have been defined using arbitrary rules such as requiring adjacency, a minimum number of genes, a fixed window size, or a minimum expression level. In the current study, we developed a Gene Neighborhood Sc...

  10. Examining the social porosity of environmental features on neighborhood sociability and attachment.

    Directory of Open Access Journals (Sweden)

    John R Hipp

    Full Text Available The local neighborhood forms an integral part of our lives. It provides the context through which social networks are nurtured and the foundation from which a sense of attachment and cohesion with fellow residents can be established. Whereas much of the previous research has examined the role of social and demographic characteristic in relation to the level of neighboring and cohesion, this paper explores whether particular environmental features in the neighborhood affect social porosity. We define social porosity as the degree to which social ties flow over the surface of a neighborhood. The focus of our paper is to examine the extent to which a neighborhood's environmental features impede the level of social porosity present among residents. To do this, we integrate data from the census, topographic databases and a 2010 survey of 4,351 residents from 146 neighborhoods in Australia. The study introduces the concepts of wedges and social holes. The presence of two sources of wedges is measured: rivers and highways. The presence of two sources of social holes is measured: parks and industrial areas. Borrowing from the geography literature, several measures are constructed to capture how these features collectively carve up the physical environment of neighborhoods. We then consider how this influences residents' neighboring behavior, their level of attachment to the neighborhood and their sense of neighborhood cohesion. We find that the distance of a neighborhood to one form of social hole-industrial areas-has a particularly strong negative effect on all three dependent variables. The presence of the other form of social hole-parks-has a weaker negative effect. Neighborhood wedges also impact social interaction. Both the length of a river and the number of highway fragments in a neighborhood has a consistent negative effect on neighboring, attachment and cohesion.

  11. Object size effects on initial lifting forces under microgravity conditions

    NARCIS (Netherlands)

    Kingma, I.; Savelsbergh, G.J.P.; Toussaint, H.M.

    1999-01-01

    Individuals usually report for two objects of equal mass but different volume that the larger object feels lighter. This so-called size-weight illusion has been investigated for more than a century. The illusion is accompanied by increased forces, used to lift the larger object, resulting in a

  12. Gravity and Heater Size Effects on Pool Boiling Heat Transfer

    Science.gov (United States)

    Kim, Jungho; Raj, Rishi

    2014-01-01

    The current work is based on observations of boiling heat transfer over a continuous range of gravity levels between 0g to 1.8g and varying heater sizes with a fluorinert as the test liquid (FC-72/n-perfluorohexane). Variable gravity pool boiling heat transfer measurements over a wide range of gravity levels were made during parabolic flight campaigns as well as onboard the International Space Station. For large heaters and-or higher gravity conditions, buoyancy dominated boiling and heat transfer results were heater size independent. The power law coefficient for gravity in the heat transfer equation was found to be a function of wall temperature under these conditions. Under low gravity conditions and-or for smaller heaters, surface tension forces dominated and heat transfer results were heater size dependent. A pool boiling regime map differentiating buoyancy and surface tension dominated regimes was developed along with a unified framework that allowed for scaling of pool boiling over a wide range of gravity levels and heater sizes. The scaling laws developed in this study are expected to allow performance quantification of phase change based technologies under variable gravity environments eventually leading to their implementation in space based applications.

  13. Effects of plot size on forest-type algorithm accuracy

    Science.gov (United States)

    James A. Westfall

    2009-01-01

    The Forest Inventory and Analysis (FIA) program utilizes an algorithm to consistently determine the forest type for forested conditions on sample plots. Forest type is determined from tree size and species information. Thus, the accuracy of results is often dependent on the number of trees present, which is highly correlated with plot area. This research examines the...

  14. Effects of Morphological Family Size for Young Readers

    Science.gov (United States)

    Perdijk, Kors; Schreuder, Robert; Baayen, R. Harald; Verhoeven, Ludo

    2012-01-01

    Dutch children, from the second and fourth grade of primary school, were each given a visual lexical decision test on 210 Dutch monomorphemic words. After removing words not recognized by a majority of the younger group, (lexical) decisions were analysed by mixed-model regression methods to see whether morphological Family Size influenced decision…

  15. Effect of population size on prospect of species survival

    Czech Academy of Sciences Publication Activity Database

    Münzbergová, Zuzana

    2006-01-01

    Roč. 41, - (2006), s. 137-150 ISSN 1211-9520 R&D Projects: GA AV ČR KJB6111303 Institutional research plan: CEZ:AV0Z60050516 Keywords : population * size * survival Subject RIV: EF - Botanics Impact factor: 1.196, year: 2006

  16. Size effect in self consolidating concrete beams with and without ...

    Indian Academy of Sciences (India)

    the decrease in nominal stress of notched beam is more when compared with that ... The differences between HPC and SCC is essentially in the use of special .... elements fail in ductile or plastic manner, while large sized elements of the ...

  17. The Effect of Organizational Size on Sport Centers' Employees Burnout.

    Directory of Open Access Journals (Sweden)

    ATHANASIOS KOUSTELIOS

    2009-01-01

    Full Text Available Organizational size and its relation with burnout were examined among 163 sport centres employees in Greece. Findings showed that there is a significant difference on employees' burnout between small and large sport organizations. Particularly, it was found that employees in small sport organizations experienced lower level of Emotional Exhaustion (p<.05 and higher level of Personal Accomplishment (p<.005.

  18. The effects of gold nanoparticles size and concentration on viscosity ...

    African Journals Online (AJOL)

    This study was carried out to investigate viscosity in relation with the temperature, flow activation energy and dielectric properties for 10, 20 and 50 nm gold nanoparticles size (GNPs) in addition to absorption and fluorescence spectra at different concentrations (0.2 × 10-3 to 1 × 10-2%) in an attempt to cover and understand ...

  19. The Effects of Rain Garden Size on Hydrologic Performance

    Science.gov (United States)

    Rain gardens are vegetated depressions designed to accept stormwater runoff. Manuals and guidance documents recommend sizing rain garden cells from 3% to 43% of the associated drainage area, based on factors including soil type, slope, amount of impervious cover in the drainage ...

  20. Effect of particle size on iron nanoparticle oxidation state

    International Nuclear Information System (INIS)

    Lombardo, Jeffrey J.; Lysaght, Andrew C.; Goberman, Daniel G.; Chiu, Wilson K.S.

    2012-01-01

    Selecting catalyst particles is a very important part of carbon nanotube growth, although the properties of these nanoscale particles are unclear. In this article iron nanoparticles are analyzed through the use of atomic force microscopy and x-ray photoelectron spectroscopy in order to understand how the size affects the chemical composition of nanoparticles and thus their physical structure. Initially, atomic force microscopy was used to confirm the presence of iron particles, and to determine the average size of the particles. Next an analytical model was developed to estimate particle size as a function of deposition time using inputs from atomic force microscopy measurement. X-ray photoelectron spectroscopy analysis was then performed with a focus on the spectra relating to the 2p Fe electrons to study the chemical state of the particles as a function of time. It was shown that as the size of nanoparticles decreased, the oxidation state of the particles changed due to a high proportion of atoms on the surface.