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Sample records for local walking neighbourhoods

  1. The Influence of the Local Neighbourhood Environment on Walking Levels during the Walking for Wellbeing in the West Pedometer-Based Community Intervention

    PubMed Central

    Robertson, L. B.; Ward Thompson, C.; Aspinall, P.; Millington, C.; McAdam, C.; Mutrie, N.

    2012-01-01

    We investigated the relationship between walking levels and the local neighbourhood physical environment during the Walking for Wellbeing in the West (WWW) randomised pedometer-based community intervention. Walking activity was recorded as step counts at baseline (n = 76), and at 3 months (n = 57), 6 months (n = 54), and 12 months (n = 45) post-intervention. Objective physical environment data were obtained from GIS datasets and street surveys conducted using the SWAT audit tool. Sixty-nine environment variables were reduced to eight environment factors using principal axis factoring, and the relationship between environment factors and (i) step counts, and (ii) the change in step counts relative to baseline, was examined using hierarchical multiple linear regression, controlling for age, gender, income, and deprivation. Five environment factors were significant predictors of step counts, but none were significant predictors of the change in step counts relative to baseline. None of the demographic variables included in the analysis were significant predictors at any stage of the study. Total variance explained by the environment ranged from 6% (P < 0.05) to 34% (P < 0.01), with lowest levels during the initial stages of the study. The physical environment appears to have influenced walking levels during the WWW intervention, and to have contributed to the maintenance of walking levels post-intervention. PMID:22899944

  2. Neighbourhood walkability, daily steps and utilitarian walking in Canadian adults

    PubMed Central

    Hajna, Samantha; Ross, Nancy A; Joseph, Lawrence; Harper, Sam; Dasgupta, Kaberi

    2015-01-01

    Objectives To estimate the associations of neighbourhood walkability (based on Geographic Information System (GIS)-derived measures of street connectivity, land use mix, and population density and the Walk Score) with self-reported utilitarian walking and accelerometer-assessed daily steps in Canadian adults. Design A cross-sectional analysis of data collected as part of the Canadian Health Measures Survey (2007–2009). Setting Home neighbourhoods (500 m polygonal street network buffers around the centroid of the participant's postal code) located in Atlantic Canada, Québec, Ontario, the Prairies and British Columbia. Participants 5605 individuals participated in the survey. 3727 adults (≥18 years) completed a computer-assisted interview and attended a mobile clinic assessment. Analyses were based on those who had complete exposure, outcome and covariate data (n=2949). Main exposure measures GIS-derived walkability (based on land use mix, street connectivity and population density); Walk Score. Main outcome measures Self-reported utilitarian walking; accelerometer-assessed daily steps. Results No important relationship was observed between neighbourhood walkability and daily steps. Participants who reported more utilitarian walking, however, accumulated more steps (<1 h/week: 6613 steps/day, 95% CI 6251 to 6975; 1 to 5 h/week: 6768 steps/day, 95% CI 6420 to 7117; ≥6 h/week: 7391 steps/day, 95% CI 6972 to 7811). There was a positive graded association between walkability and odds of walking ≥1 h/week for utilitarian purposes (eg, Q4 vs Q1 of GIS-derived walkability: OR=1.66, 95% CI 1.31 to 2.11; Q3 vs Q1: OR=1.41, 95% CI 1.14 to 1.76; Q2 vs Q1: OR=1.13, 95% CI 0.91 to 1.39) independent of age, sex, body mass index, married/common law status, annual household income, having children in the household, immigrant status, mood disorder, perceived health, ever smoker and season. Conclusions Contrary to expectations, living in more walkable Canadian

  3. Does walkable neighbourhood design influence the association between objective crime and walking?

    PubMed Central

    2014-01-01

    Background Few studies have investigated associations between objectively measured crime and walking, and findings are mixed. One explanation for null or counterintuitive findings emerges from criminology studies, which indicate that the permeable street layouts and non-residential land uses that underpin walkable neighbourhoods are also associated with more crime. This study examined associations between objective crime and walking, controlling for the characteristics of walkable neighbourhoods. Methods A population representative sample of adults (25–65 years) (n = 3,487) completed the Western Australian Health and Wellbeing Survey (2006–2008) demographic and walking frequency items. Objective environmental measures were generated for each participant’s 400 m and 1600 m neighbourhood areas, including burglary, personal crime (i.e., crimes committed against people) in public space, residential density, street connectivity and local destinations. Log-linear negative binomial regression models were used to examine associations between crime and walking frequency/week, with progressive adjustment for residential density, street connectivity and local destinations. Results Burglary and personal crime occurring within a participant’s 400 m and 1600 m neighbourhoods were positively and significantly associated with walking frequency. For example, for every additional 10 crimes against the person/year within 400 m of a participant’s home, walking frequency increased by 8% (relative change = 1.077, p = 0.017). Associations remained constant after controlling for residential density and street connectivity, but attenuated after adjusting for local destinations (e.g., for personal crime in 400 m: relative change = 1.054, p = 0.104). This pattern of attenuation was evident across both crime categories and both neighbourhood sizes. Conclusions The observed positive associations between objective crime and walking appear to be a function of

  4. Multilevel modelling of built environment characteristics related to neighbourhood walking activity in older adults

    PubMed Central

    Li, F.; Fisher, K; Brownson, R.; Bosworth, M.

    2005-01-01

    Objective: To examine the relation between built environment factors (representing several dimensions of urban form of neighbourhoods) and walking activity at both the neighbourhood level and the resident level, in an older adult sample. Design, setting, participants: A cross sectional, multilevel design with neighbourhoods as the primary sampling unit and senior residents as the secondary unit. Five hundred and seventy seven residents (mean age = 74 years, SD = 6.3 years) participated in the survey, which was conducted among 56 city defined neighbourhoods in Portland, Oregon, USA. Neighbourhood level variables were constructed using geographical information systems. Resident level variables consisted of a mix of self reports and geocoded data on the built environment. Main outcome measure: Self reported neighbourhood walking. Main results: A positive relation was found between built environment factors (density of places of employment, household density, green and open spaces for recreation, number of street intersections) and walking activity at the neighbourhood level. At the resident level, perceptions of safety for walking and number of nearby recreational facilities were positively related to high levels of walking activity. A significant interaction was observed between number of street intersections and perceptions of safety from traffic. Conclusions: Certain neighbourhood built environment characteristics related to urban form were positively associated with walking activity in the neighbourhoods of senior residents. Public health promotion of walking activity/urban mobility and the design of interventions need to consider the contribution of neighbourhood level built environment influences. PMID:15965138

  5. Walking in the neighbourhood: Performing social citizenship in dementia.

    PubMed

    Phinney, Alison; Kelson, Elizabeth; Baumbusch, Jennifer; O'Connor, Deborah; Purves, Barbara

    2016-05-01

    The proliferation of community-based activity programs for people with dementia suggests an appetite for new approaches to support quality of life and well-being for this population. Such groups also have potential to promote social citizenship, although this remains poorly understood. This article presents findings from a subset of data from an ethnographic study of a community-based program for people with young onset dementia; it focuses on Paul's Club and the experiences of 12-15 members who are physically healthy, with moderate to moderately severe dementia. Analysis suggests how aspects of social citizenship are constructed and revealed through the Club's everyday practice of walking in the neighbourhood. Three major themes emerged: Keeping the focus off dementia; Creating a place of belonging; and Claiming a place in the community How the group balances consideration of members' vulnerability and agency is discussed, and the article concludes with implications for future practice and research initiatives. PMID:27170588

  6. Neighbourhood inequalities in physical inactivity: the role of neighbourhood attractiveness, proximity to local facilities and safety in the Netherlands.

    PubMed

    van Lenthe, F J; Brug, J; Mackenbach, J P

    2005-02-01

    We investigated the association between the neighbourhood socioeconomic environment and physical inactivity, and explored the contribution of neighbourhood characteristics to this association. Data were analysed of 20-69 years old participants of the Dutch GLOBE study who lived in 78 neighbourhoods of Eindhoven (n = 8.767). The neighbourhood socioeconomic environment was assessed from aggregated self-reported information of participants' education and occupation level, and employment status. Aspects of physical inactivity investigated were based on the time spent on (a) walking and cycling to shops or work, (b) walking, cycling and gardening in leisure time, and (c) participation in sports activities. Characteristics of neighbourhoods included the proximity to food shops, general physical design of neighbourhoods, quality of green facilities, noise pollution from traffic and required police attention as evaluated by municipal services (professionals) responsible for these characteristics. Compared to those living in the most advantaged neighbourhoods, residents living in the quartile of socio-economically most disadvantaged neighbourhoods were more likely to walk or cycle to shops or work, but less likely to walk, cycle or garden in leisure time and less likely to participate in sports activities (adjusted for age, sex and individual educational level). Neighbourhood inequalities in walking or cycling to shops or work were not mediated by specific neighbourhood characteristics included in our analyses. The increased probability of almost never walking, cycling and gardening in leisure time in the most disadvantaged neighbourhoods was partly mediated by a poorer general physical design in these neighbourhoods. Similarly, the increased probability of almost never participating in sports activities in the most disadvantaged neighbourhoods was partly mediated by larger amounts of required police attention. The direction of neighbourhood inequalities differs for aspects

  7. The influence of urban design on neighbourhood walking following residential relocation: longitudinal results from the RESIDE study.

    PubMed

    Giles-Corti, Billie; Bull, Fiona; Knuiman, Matthew; McCormack, Gavin; Van Niel, Kimberly; Timperio, Anna; Christian, Hayley; Foster, Sarah; Divitini, Mark; Middleton, Nick; Boruff, Bryan

    2013-01-01

    The design of urban environments has the potential to enhance the health and well-being of residents by impacting social determinants of health including access to public transport, green space and local amenities. Commencing in 2003, RESIDE is a longitudinal natural experiment examining the impact of urban planning on active living in metropolitan Perth, Western Australia. Participants building homes in new housing developments were surveyed before relocation (n = 1813; 34·6% recruitment rate); and approximately 12 months later (n = 1437). Changes in perceived and objective neighbourhood characteristics associated with walking following relocation were examined, adjusted for changes in demographic, intrapersonal, interpersonal and baseline reasons for residential location choice. Self-reported walking was measured using the Neighbourhood Physical Activity Questionnaire. Following relocation, transport-related walking declined overall (p < 0.001) and recreational walking increased (p < 0.001): access to transport- and recreational destinations changed in similar directions. However, in those with increased access to destinations, transport-related walking increased by 5.8 min/week for each type of transport-related destination that increased (p = 0.045); and recreational walking by 17.6 min/week for each type of recreational destination that increased (p = 0.070). The association between the built environment and recreational walking was partially mediated by changes in perceived neighbourhood attractiveness: when changes in 'enjoyment' and 'attitude' towards local walking were removed from the multivariate model, recreational walking returned to 20.1 min/week (p = 0.040) for each type of recreational destination that increased. This study provides longitudinal evidence that both transport and recreational-walking behaviours respond to changes in the availability and diversity of local transport- and recreational destinations, and demonstrates the potential of

  8. Can the built environment reduce health inequalities? A study of neighbourhood socioeconomic disadvantage and walking for transport.

    PubMed

    Turrell, Gavin; Haynes, Michele; Wilson, Lee-Ann; Giles-Corti, Billie

    2013-01-01

    Residents of socioeconomically disadvantaged neighbourhoods are more likely to walk for transport than their counterparts in advantaged neighbourhoods; however, the reasons for higher rates of transport walking in poorer neighbourhoods remain unclear. We investigated this issue using data from the HABITAT study of physical activity among 11,037 mid-aged residents of 200 neighbourhoods in Brisbane, Australia. Using a five-step mediation analysis and multilevel regression, we found that higher levels of walking for transport in disadvantaged neighbourhoods was associated with living in a built environment more conducive to walking (i.e. greater street connectivity and land use mix) and residents of these neighbourhoods having more limited access to a motor vehicle. The health benefits that accrue to residents of disadvantaged neighbourhoods as a result of their higher levels of walking for transport might help offset the negative effects of less healthy behaviours (e.g. smoking, poor diet), thus serving to contain or reduce neighbourhood inequalities in chronic disease. PMID:23207291

  9. Inequitable walking conditions among older people: examining the interrelationship of neighbourhood socio-economic status and urban form using a comparative case study

    PubMed Central

    2010-01-01

    Background Supportive neighbourhood walking conditions are particularly important for older people as they age and who, as a group, prefer walking as a form of physical activity. Urban form and socio-economic status (SES) can influence neighbourhood walking behaviour. The objectives of this study were: a) to examine how urban form and neighbourhood SES inter-relate to affect the experiences of older people who walk in their neighbourhoods; b) to examine differences among neighbourhood stakeholder key informant perspectives on socio-political processes that shape the walkability of neighbourhood environments. Methods An embedded comparative case study examined differences among four Ottawa neighbourhoods that were purposefully selected to provide contrasts on urban form (inner-urban versus suburban) and SES (higher versus lower). Qualitative data collected from 75 older walkers and 19 neighbourhood key informants, as well as quantitative indicators were compared on the two axes of urban form and SES among the four neighbourhoods. Results and discussion Examining the inter-relationship of neighbourhood SES and urban form characteristics on older people's walking experiences indicated that urban form differences were accentuated positively in higher SES neighbourhoods and negatively in lower SES neighbourhoods. Older people in lower SES neighbourhoods were more affected by traffic hazards and more reliant on public transit compared to their higher SES counterparts. In higher SES neighbourhoods the disadvantages of traffic in the inner-urban neighbourhood and lack of commercial destinations in the suburban neighbourhood were partially offset by other factors including neighbourhood aesthetics. Key informant descriptions of the socio-political process highlighted how lower SES neighbourhoods may face greater challenges in creating walkable places. These differences pertained to the size of neighbourhood associations, relationships with political representatives

  10. Does dog-ownership influence seasonal patterns of neighbourhood-based walking among adults? A longitudinal study

    PubMed Central

    2011-01-01

    Background In general dog-owners are more physically active than non-owners, however; it is not known whether dog-ownership can influence seasonal fluctuations in physical activity. This study examines whether dog-ownership influences summer and winter patterns of neighbourhood-based walking among adults living in Calgary, Canada. Methods A cohort of adults, randomly sampled from the Calgary metropolitan area, completed postal surveys in winter and summer 2008. Both winter and summer versions of the survey included questions on dog-ownership, walking for recreation, and walking for transportation in residential neighbourhoods. Participation in neighbourhood-based walking was compared, among dog-owners and non-owners, and in summer and winter, using general linear modeling. Stability of participation in neighbourhood-based walking across summer and winter among dog-owners and non-owners was also assessed, using logistic regression. Results A total of 428 participants participated in the study, of whom 115 indicated owning dogs at the time of both surveys. Dog-owners reported more walking for recreation in their neighbourhoods than did non-owners, both in summer and in winter. Dog-owners were also more likely than non-owners to report participation in walking for recreation in their neighbourhoods, in summer as well as in winter. Dog-owners and non-owners did not differ in the amount of walking that they reported for transportation, either in summer or in winter. Conclusions By acting as cues for physical activity, dogs may help their owners remain active across seasons. Policies and programs related to dog-ownership and dog-walking, such as dog-supportive housing and dog-supportive parks, may assist in enhancing population health by promoting physical activity. PMID:21375754

  11. Socioeconomic differences in lack of recreational walking among older adults: the role of neighbourhood and individual factors

    PubMed Central

    Kamphuis, Carlijn BM; van Lenthe, Frank J; Giskes, Katrina; Huisman, Martijn; Brug, Johannes; Mackenbach, Johan P

    2009-01-01

    Background People with a low socioeconomic status (SES) are more likely to be physically inactive than their higher status counterparts, however, the mechanisms underlying this socioeconomic gradient in physical inactivity remain largely unknown. Our aims were (1) to investigate socioeconomic differences in recreational walking among older adults and (2) to examine to what extent neighbourhood perceptions and individual cognitions regarding regular physical activity can explain these differences. Methods Data were obtained by a large-scale postal survey among a stratified sample of older adults (age 55–75 years) (N = 1994), residing in 147 neighbourhoods of Eindhoven and surrounding areas, in the Netherlands. Multilevel logistic regression analyses assessed associations between SES (i.e. education and income), perceptions of the social and physical neighbourhood environment, measures of individual cognitions derived from the Theory of Planned Behaviour (e.g. attitude, perceived behaviour control), and recreational walking for ≥10 minutes/week (no vs. yes). Results Participants in the lowest educational group (OR 1.67 (95% CI, 1.18–2.35)) and lowest income group (OR 1.40 (95% CI, 0.98–2.01)) were more likely to report no recreational walking than their higher status counterparts. The association between SES and recreational walking attenuated when neighbourhood aesthetics was included in the model, and largely reduced when individual cognitions were added to the model (with largest effects of attitude, and intention regarding regular physical activity). The assiation between poor neighbourhood aesthetics and no recreational walking attenuated to (borderline) insignificance when individual cognitions were taken into account. Conclusion Both neighbourhood aesthetics and individual cognitions regarding physical activity contributed to the explanation of socioeconomic differences in no recreational walking. Neighbourhood aesthetics may explain the association

  12. Gender-Specific Associations between Perceived Neighbourhood Walkability and Meeting Walking Recommendations When Walking for Transport and Recreation for Czech Inhabitants over 50 Years of Age

    PubMed Central

    Pelclová, Jana; Frömel, Karel; Cuberek, Roman

    2013-01-01

    Few studies have investigated the different effects that the built environment may have on the physical activity behaviours of men and women. Therefore, the aim of this study was to estimate the gender differences in meeting walking recommendations in relation to perceived neighbourhood walkability attributes within the active transportation and leisure-time domains for Czech inhabitants over 50 years of age. The sample included 1,417 men and 1,422 women who were randomly selected. The Abbreviated Neighbourhood Environment Walkability Scale (ANEWS) was used to obtain information about the perceived environment. The self-administered long version of the IPAQ was used to assess physical activity levels. When walking for transport, men living in neighbourhoods with high street connectivity (OR = 1.47, CI = 1.04–2.9) and higher traffic and crime safety (OR = 1.28, CI = 1.02–1.6) and women living in neighbourhoods with high proximity (OR = 1.36, CI = 1.04–1.77) and high neighbourhood aesthetics (OR = 1.36, CI = 1.04–1.76) were more likely to meet recommended levels of walking. No environmental attributes were found to significantly influence the accomplishment of walking recommendations by men or women when walking for leisure. The study results indicate the gender-specific associations between transportation-related walking and the environment factors. The consideration of those factors in the design of gender-specific walking interventions for Czech inhabitants may help the interventions to be more effective in promotion of physical activity. PMID:24380981

  13. Local Belonging and "Geographies of Emotions": Immigrant Children's Experience of Their Neighbourhoods in Paris and Berlin

    ERIC Educational Resources Information Center

    den Besten, Olga

    2010-01-01

    This article argues that a sense of local belonging and emotional attitudes to one's neighbourhood are inherently interconnected. It explores immigrant children's emotional experiences of their neighbourhoods in Paris and Berlin through subjective maps drawn by the children. The article highlights the social and spatial nature of immigrant…

  14. Perceived neighbourhood environmental attributes associated with adults׳ recreational walking: IPEN Adult study in 12 countries.

    PubMed

    Sugiyama, Takemi; Cerin, Ester; Owen, Neville; Oyeyemi, Adewale L; Conway, Terry L; Van Dyck, Delfien; Schipperijn, Jasper; Macfarlane, Duncan J; Salvo, Deborah; Reis, Rodrigo S; Mitáš, Josef; Sarmiento, Olga L; Davey, Rachel; Schofield, Grant; Orzanco-Garralda, Rosario; Sallis, James F

    2014-07-01

    This study examined the strength and shape of associations between perceived environmental attributes and adults' recreational walking, using data collected from 13,745 adult participants in 12 countries. Perceived residential density, land use mix, street connectivity, aesthetics, safety from crime, and proximity to parks were linearly associated with recreational walking, while curvilinear associations were found for residential density, land use mix, and aesthetics. The observed associations were consistent across countries, except for aesthetics. Using data collected from environmentally diverse countries, this study confirmed findings from prior single-country studies. Present findings suggest that similar environmental attributes are associated with recreational walking internationally. PMID:24721737

  15. The Globe. Neighbourhood Agenda 21: Going Local in Reading.

    ERIC Educational Resources Information Center

    Welsh, Richard

    1994-01-01

    Reports on the philosophy underlying a project to promote local community involvement in neighborhood plans as a basis for a citywide Local Agenda 21 and the first stages of Go Local on a Better Environment (GLOBE) introduced to give the project a popular identify and communicate the environmental message. (LZ)

  16. Neighbourhood amenities and health: examining the significance of a local park.

    PubMed

    Plane, Jocelyn; Klodawsky, Fran

    2013-12-01

    This paper reports the results of a qualitative study that examines the links between neighbourhood spaces and quality of life for nine formerly homeless women who live in a supportive housing development in Ottawa, Ontario. It explores a local park that participants subjectively identified as the most meaningful place influencing their health and quality of life. Looking at the neighbourhood from the participants' perspectives, this paper discusses the links between access to nearby urban green space, feelings of well-being, and having a sense of belonging to the broader community. The primary methods used in our study were photovoice, whereby participants were asked to take pictures of both healthy and unhealthy aspects of their neighbourhood, and participant observation of the women's interactions with their immediate and neighbourhood living environments. The participants used photographs as a tool to help describe their experiences of the park as not only a therapeutic or health-promoting place, but also an un-therapeutic or health-denying place. Participant observation helped fill the gaps that women were unable to articulate in the interviews. The results reveal that participants placed more emphasis on inclusive (free of charge) social events and the ability to interact with others at the park than on its aesthetics. This finding supports the notion that while beautification certainly has value, resources to support free community events in public spaces are at least equally important for establishing feelings of inclusion in the community among marginalized populations. PMID:24355464

  17. Helping Neighbourhoods Help Themselves

    ERIC Educational Resources Information Center

    Richardson, Liz

    2012-01-01

    Not long after commentators were predicting the "death of neighbourhoods," they are back in policy vogue. Funding was withdrawn, attention went elsewhere. But neighbourhoods are a yo-yo policy idea, in and out of fashion, and they have bounced back under the coalition. Neighbourhoods are now a key focus for the coalition's localism agenda to…

  18. Localization in quantum walks on a honeycomb network

    NASA Astrophysics Data System (ADS)

    Lyu, Changyuan; Yu, Luyan; Wu, Shengjun

    2015-11-01

    We systematically study the localization effect in discrete-time quantum walks on a honeycomb network and establish the mathematical framework. We focus on the Grover walk first and rigorously derive the limit form of the walker's state, showing it has a certain probability to be localized at the starting position. The relationship between localization and the initial coin state is concisely represented by a linear map. We also define and calculate the average probability of localization by generating random initial states. Further, coin operators varying with positions are considered and the sufficient condition for localization is discussed. We also similarly analyze another four-state Grover walk. Theoretical predictions are all in accord with numerical simulation results. Finally, our results are compared with previous works to demonstrate the unusual trapping effect of quantum walks on a honeycomb network, as well as the advantages of our method.

  19. Developing an Integrated Approach for Local Urban Climate Models in London from Neighbourhood to Street Scale

    NASA Astrophysics Data System (ADS)

    Bakkali, M.; Davies, M.; Steadman, J. P.

    2012-04-01

    We currently have an incomplete understanding of how weather varies across London and how the city's microclimate will intensify levels of heat, cold and air pollution in the future. There is a need to target priority areas of the city and to promote design guidance on climate change mitigation strategies. As a result of improvements in the accuracy of local weather data in London, an opportunity is emerging for designers and planners of the built environment to measure the impact of their designs on local urban climate and to enhance the designer's role in creating more informed design choices at an urban micro-scale. However, modelling the different components of the urban environment separately and then collating and comparing the results invariably leads to discrepancies in the output of local urban climate modelling tools designed to work at different scales. Of particular interest is why marked differences appear between the data extracted from local urban climate models when we change the scale of modelling from city to building scale. An example of such differences is those that have been observed in relation to the London Unified Model and London Site Specific Air Temperature model. In order to avoid these discrepancies we need a method for understanding and assessing how the urban environment impacts on local urban climate as a whole. A step to achieving this is by developing inter-linkages between assessment tools. Accurate information on the net impact of the urban environment on the local urban climate will in turn facilitate more accurate predictions of future energy demand and realistic scenarios for comfort and health. This paper will present two key topographies of London's urban environment that influence local urban climate: land use and street canyons. It will look at the possibilities for developing an integrated approach to modelling London's local urban climate from the neighbourhood to the street scale.

  20. Upper limits on the probability of an interstellar civilization arising in the local Solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Cartin, Daniel

    2015-10-01

    At this point in time, there is very little empirical evidence on the likelihood of a space-faring species originating in the biosphere of a habitable world. However, there is a tension between the expectation that such a probability is relatively high (given our own origins on Earth), and the lack of any basis for believing the Solar System has ever been visited by an extraterrestrial colonization effort. From the latter observational fact, this paper seeks to place upper limits on the probability of an interstellar civilization arising on a habitable planet in its stellar system, using a percolation model to simulate the progress of such a hypothetical civilization's colonization efforts in the local Solar neighbourhood. To be as realistic as possible, the actual physical positions and characteristics of all stars within 40 parsecs of the Solar System are used as possible colony sites in the percolation process. If an interstellar civilization is very likely to have such colonization programmes, and they can travel over large distances, then the upper bound on the likelihood of such a species arising per habitable world is of the order of 10-3 on the other hand, if civilizations are not prone to colonize their neighbours, or do not travel very far, then the upper limiting probability is much larger, even of order one.

  1. Neighbourhood Walkability and Daily Steps in Adults with Type 2 Diabetes

    PubMed Central

    Hajna, Samantha; Ross, Nancy A.; Joseph, Lawrence; Harper, Sam; Dasgupta, Kaberi

    2016-01-01

    Introduction There is evidence that greater neighbourhood walkability (i.e., neighbourhoods with more amenities and well-connected streets) is associated with higher levels of total walking in Europe and in Asia, but it remains unclear if this association holds in the Canadian context and in chronic disease populations. We examined the relationships of different walkability measures to biosensor-assessed total walking (i.e., steps/day) in adults with type 2 diabetes living in Montreal (QC, Canada). Materials and Methods Participants (60.5±10.4 years; 48.1% women) were recruited through McGill University-affiliated clinics (June 2006 to May 2008). Steps/day were assessed once per season for one year with pedometers. Neighbourhood walkability was evaluated through participant reports, in-field audits, Geographic Information Systems (GIS)-derived measures, and the Walk Score®. Relationships between walkability and daily steps were estimated using Bayesian longitudinal hierarchical linear regression models (n = 131). Results Participants who reported living in the most compared to the least walkable neighbourhoods completed 1345 more steps/day (95% Credible Interval: 718, 1976; Quartiles 4 versus 1). Those living in the most compared to the least walkable neighbourhoods (based on GIS-derived walkability) completed 606 more steps per day (95% CrI: 8, 1203). No statistically significant associations with steps were observed for audit-assessed walkability or the Walk Score®. Conclusions Adults with type 2 diabetes who perceived their neighbourhoods as more walkable accumulated more daily steps. This suggests that knowledge of local neighborhood features that enhance walking is a meaningful predictor of higher levels of walking and an important component of neighbourhood walkability. PMID:26991308

  2. Including land use information for the spatial estimation of groundwater quality parameters - 1. Local estimation based on neighbourhood composition

    NASA Astrophysics Data System (ADS)

    Heißerer, T.; Haslauer, C. P.; Bárdossy, A.

    2016-04-01

    Most groundwater recharge comes from the infiltration of water through the land surface. Data analysis shows that solute concentrations at the water table vary between land use categories and depending on the land use composition within a certain neighbourhood. Driven by these observations, the goal of this paper is to estimate the solute distribution at a location depending on the composition of land use in the neighbourhood, even though land use information is categorical. This goal is achieved by mixing pure distributions of homogeneous land use according to their frequency of occurrence in the vicinity of, and their distance from an estimation location. These pure distributions are jointly inverted using a maximum likelihood-based approach. The neighbourhood size is optimized using cross-validation. Measurements below detection limit are included via their probabilities of non-exceedance. A solute-specific, spatially distributed measure of information content of the secondary information is presented. The method is applicable for many types of secondary information and can be used as drift for spatial estimation of the primary variable. This estimation is a local estimation and does not include larger scale spatial information. The information of measurements is included via the optimized concentration distributions for land use groups, not via a model of spatial dependence. The global estimation is described in the companion paper.

  3. Walkyourplace - Evaluating Neighbourhood Accessibility at Street Level

    NASA Astrophysics Data System (ADS)

    Steiniger, S.; Poorazizi, M. E.; Hunter, A. J. S.

    2013-05-01

    The popularity of a neighbourhood is often explained by its perceived "higher" quality of life. Good access to shops, restaurants, parks, etc., is seen as an indicator that reflects improved quality of life. We present a web-based tool for assessment of accessibility to such services. The system evaluates in real time an area that is accessible using pedestrian, transit, and cycling infrastructure. The accessible area is evaluated using "quality of life" indicators, such as the number of grocery stores, shopping and recreation facilities, and local crime within that area. This tool sets itself apart from pre-computed and neighbourhood-level walkability indices, because it makes use of detailed street-level data, rather than block-level generalizations. It uses real network travel time, and, when transit data are provided, permits the creation and evaluation of accessibility areas for a combination of travel modes such as walking with transit use.

  4. A national study of the association between neighbourhood access to fast-food outlets and the diet and weight of local residents.

    PubMed

    Pearce, Jamie; Hiscock, Rosemary; Blakely, Tony; Witten, Karen

    2009-03-01

    Differential locational access to fast-food retailing between neighbourhoods of varying socioeconomic status has been suggested as a contextual explanation for the social distribution of diet-related mortality and morbidity. This New Zealand study examines whether neighbourhood access to fast-food outlets is associated with individual diet-related health outcomes. Travel distances to the closest fast-food outlet (multinational and locally operated) were calculated for all neighbourhoods and appended to a national health survey. Residents in neighbourhoods with the furthest access to a multinational fast-food outlet were more likely to eat the recommended intake of vegetables but also be overweight. There was no association with fruit consumption. Access to locally operated fast-food outlets was not associated with the consumption of the recommended fruit and vegetables or being overweight. Better neighbourhood access to fast-food retailing is unlikely to be a key contextual driver for inequalities in diet-related health outcomes in New Zealand. PMID:18499502

  5. Demand response to improved walking infrastructure: A study into the economics of walking and health behaviour change.

    PubMed

    Longo, Alberto; Hutchinson, W George; Hunter, Ruth F; Tully, Mark A; Kee, Frank

    2015-10-01

    Walking is the most common form of moderate-intensity physical activity among adults, is widely accessible and especially appealing to obese people. Most often policy makers are interested in valuing the effect on walking of changes in some characteristics of a neighbourhood, the demand response for walking, of infrastructure changes. A positive demand response to improvements in the walking environment could help meet the public health target of 150 min of at least moderate-intensity physical activity per week. We model walking in an individual's local neighbourhood as a 'weak complement' to the characteristics of the neighbourhood itself. Walking is affected by neighbourhood characteristics, substitutes, and individual's characteristics, including their opportunity cost of time. Using compensating variation, we assess the economic benefits of walking and how walking behaviour is affected by improvements to the neighbourhood. Using a sample of 1209 respondents surveyed over a 12 month period (Feb 2010-Jan 2011) in East Belfast, United Kingdom, we find that a policy that increased walkability and people's perception of access to shops and facilities would lead to an increase in walking of about 36 min/person/week, valued at £13.65/person/week. When focussing on inactive residents, a policy that improved the walkability of the area would lead to guidelines for physical activity being reached by only 12.8% of the population who are currently inactive. Additional interventions would therefore be needed to encourage inactive residents to achieve the recommended levels of physical activity, as it appears that interventions that improve the walkability of an area are particularly effective in increasing walking among already active citizens, and, among the inactive ones, the best response is found among healthier, younger and wealthier citizens. PMID:26347960

  6. Motivated to walk but nowhere to walk to: Differential effect of a mass media campaign by mix of local destinations

    PubMed Central

    Barnes, Rosanne; Bauman, Adrian E.; Giles-Corti, Billie; Knuiman, Matthew W.; Rosenberg, Michael; Leyden, Kevin M.; Abildso, Christiaan G.; Reger-Nash, Bill

    2015-01-01

    Objective Built environment attributes are associated with walking but little is known about how the impact of walking campaigns varies across different environments. The objective of this study was to compare the impact of a campaign on changes in walking between respondents with a high versus low mix of local destinations. Methods Pre- and post-campaign data from a quasi-experimental study were used to compare changes in walking for residents aged 40–65 with high and low destination mix in a West Virginia community campaign (March–May 2005). Results Overall samples consisted of 777 intervention community respondents and 388 comparison community respondents with pre- and post-campaign data. Among insufficiently active intervention respondents, those with high destination mix increased their walking by 0.64 days more than those with low mix (p < 0.05). No significant differences were observed among the comparison community. Conclusion The walking response to campaigns in those insufficiently active may be influenced by neighborhood attributes. PMID:26844097

  7. The reliability of local dynamic stability in walking while texting and performing an arithmetical problem.

    PubMed

    Hamacher, Dennis; Hamacher, Daniel; Törpel, Alexander; Krowicki, Martin; Herold, Fabian; Schega, Lutz

    2016-02-01

    In the recent years, local dynamic stability of walking was frequently used to quantify motor control. Particularly, dual-task paradigms are used to assess a shift in gait control strategy to test walking in real life situations. Texting short messages while walking is a common motor-cognitive dual task of daily living. To able to monitor possible intervention effects on motor-cognitive dual-task performance, the test-retest reliability of the measure has to be evaluated. Since the reliability of the effects of cognitive tasks including texting while walking on local dynamic gait stability has not been assessed yet, this will be evaluated in the current study. Eleven young individuals were included. Gait data was registered twice (test-retest interval: seven days) using an inertial sensor fixed on the subjects' trunks in three conditions: normal walking, walking while texting a message and walking while reciting serials of 7. Short-term finite maximum Lyapunov Exponents were quantified to assess local dynamic stability. The test-retest reliability was calculated using intra-class correlation coefficients and Bland and Altman Plots (bias and limits of agreement). ICC values of the current study show that in normal walking and walking while texting, outcomes are comparable and indicate mostly good to excellent reliability. The reliability values were almost always the lowest in walking while reciting serials of 7. Local dynamic stability derived from kinematic data of walking while cell phone texting can be reliably collected and, in turn, be used as an outcome measure in clinical trials with repeated measures design. PMID:27004658

  8. Does visual augmented feedback reduce local dynamic stability while walking?

    PubMed

    Hamacher, Daniel; Hamacher, Dennis; Schega, Lutz

    2015-10-01

    Augmented feedback is frequently used in gait training to efficiently correct specific gait patterns in patients with different disorders. The patients use this external augmented feedback to align actual movements in a way that predefined gait characteristics can be achieved. Voluntary changes of gait characteristics are reported to reduce local dynamic stability (LDS) which in turn is associated with increased risk of falling. The aim of this study was to evaluate the instantaneous effect of visual feedback, provided to help patients to correct frontal plane pelvis and trunk movements, on the LDS of pelvis and trunk. Kinematic gait data was captured in ten women with gait disorders. The effect of visual feedback on LDS, quantified with the largest Lyapunov exponent, of walking was examined. We found a significant decreased LDS (e.g. pelvis: p=.009) in our subjects when they were using visual augmented feedback. Our data suggest that the use of visual augmented feedback causes less stable gait patterns indicating a reduced ability to respond to small perturbations which might increase risk of falling. Therefore, researchers or clinicians who aim to correct gait patterns through real time based external augmented feedback should consider the potential negative effect on gait stability. It should be evaluated if the possible increased fall risk provoked by visual feedback exceeds possible increases in fall risk induced by conventional gait-retraining interventions. The external validity of the study is limited because of the low sample size and inhomogeneous group characteristics. Thus, further studies including homogeneous cohorts are required. PMID:26296676

  9. From digital earth to digital neighbourhood: A study of subjective measures of walkability attributes in objectively assessed digital neighbourhood

    NASA Astrophysics Data System (ADS)

    Qureshi, S.; Ho, C. S.

    2014-02-01

    According to IEA report (2011), about 23% of the World's CO2 emissions result from transport and this is one of the few areas where emissions are still rapidly increasing. The use of private vehicles is one of the principle contributors to green house gas emissions from transport sector. Therefore this paper focuses on the shift to more sustainable and low carbon forms of transportation mode such as walking. Neighbourhood built environment attributes may influence walkability. For this study, the author used a modified version of the "Neighbourhood Environment Walkability Scale" to make comparison between respondents' perceptions regarding attributes of two neighborhoods of Putrajaya. The 21st Century really needs planners to use the Digital Earth Concept, to go from global to regional to national to very local issues, using integrated, advanced technologies such as earth observation, GIS, virtual reality, etc. For this research, two (2) neighborhoods of different densities (High and Low density) were selected. A sample total of 381(195 and 186) between 7 to 65 years old participants were selected For subjective measures we used 54 questions questionnaire survey where as for the objective measures we used desktop 9.3 version of Arc GIS soft ware. Our results shows that respondents who reside in high-walkable neighbourhood precinct 9 in Putrajaya rated factors such as residential density, land use mix, proximity to destination and street connectivity, consistently higher then did respondents of the low walkable neighbourhood precinct 8 in Putrajaya.

  10. The defect-induced localization in many positions of the quantum random walk

    NASA Astrophysics Data System (ADS)

    Chen, Tian; Zhang, Xiangdong

    2016-05-01

    We study the localization of probability distribution in a discrete quantum random walk on an infinite chain. With a phase defect introduced in any position of the quantum random walk (QRW), we have found that the localization of the probability distribution in the QRW emerges. Different localized behaviors of the probability distribution in the QRW are presented when the defect occupies different positions. Given that the coefficients of the localized stationary eigenstates relies on the coin operator, we reveal that when the defect occupies different positions, the amplitude of localized probability distribution in the QRW exhibits a non-trivial dependence on the coin operator.

  11. The defect-induced localization in many positions of the quantum random walk.

    PubMed

    Chen, Tian; Zhang, Xiangdong

    2016-01-01

    We study the localization of probability distribution in a discrete quantum random walk on an infinite chain. With a phase defect introduced in any position of the quantum random walk (QRW), we have found that the localization of the probability distribution in the QRW emerges. Different localized behaviors of the probability distribution in the QRW are presented when the defect occupies different positions. Given that the coefficients of the localized stationary eigenstates relies on the coin operator, we reveal that when the defect occupies different positions, the amplitude of localized probability distribution in the QRW exhibits a non-trivial dependence on the coin operator. PMID:27216697

  12. The defect-induced localization in many positions of the quantum random walk

    PubMed Central

    Chen, Tian; Zhang, Xiangdong

    2016-01-01

    We study the localization of probability distribution in a discrete quantum random walk on an infinite chain. With a phase defect introduced in any position of the quantum random walk (QRW), we have found that the localization of the probability distribution in the QRW emerges. Different localized behaviors of the probability distribution in the QRW are presented when the defect occupies different positions. Given that the coefficients of the localized stationary eigenstates relies on the coin operator, we reveal that when the defect occupies different positions, the amplitude of localized probability distribution in the QRW exhibits a non-trivial dependence on the coin operator. PMID:27216697

  13. Neighbourhood selection for local modelling and prediction of hydrological time series

    NASA Astrophysics Data System (ADS)

    Jayawardena, A. W.; Li, W. K.; Xu, P.

    2002-02-01

    The prediction of a time series using the dynamical systems approach requires the knowledge of three parameters; the time delay, the embedding dimension and the number of nearest neighbours. In this paper, a new criterion, based on the generalized degrees of freedom, for the selection of the number of nearest neighbours needed for a better local model for time series prediction is presented. The validity of the proposed method is examined using time series, which are known to be chaotic under certain initial conditions (Lorenz map, Henon map and Logistic map), and real hydro meteorological time series (discharge data from Chao Phraya river in Thailand, Mekong river in Thailand and Laos, and sea surface temperature anomaly data). The predicted results are compared with observations, and with similar predictions obtained by using arbitrarily fixed numbers of neighbours. The results indicate superior predictive capability as measured by the mean square errors and coefficients of variation by the proposed approach when compared with the traditional approach of using a fixed number of neighbours.

  14. Neighbourhood perceptions of physical activity: a qualitative study

    PubMed Central

    Burgoyne, Louise N; Woods, Catherine; Coleman, Rosarie; Perry, Ivan J

    2008-01-01

    Background Effective promotion of physical activity in low income communities is essential given the high prevalence of inactivity in this sector. Methods This study explored determinants of engaging in physical activity in two Irish city based neighbourhoods using a series of six focus groups and twenty five interviews with adult residents. Data were analysed using constant comparison methods with a grounded theory approach. Results Study findings centred on the concept of 'community contentment'. Physical activity was related to the degree of contentment/comfort within the 'self' and how the 'self' interacts within the neighbourhood. Contemporary focus on outer bodily appearance and pressure to comply with societal expectations influenced participants' sense of confidence and competence. Social interaction, involvement, and provision of adequate social supports were viewed as positive and motivating. However normative expectations appeared to affect participants' ability to engage in physical activity, which may reflect the 'close knit' culture of the study neighbourhoods. Access to suitable local facilities and amenities such as structured and pleasant walking routes was regarded as essential. Indeed participants considered walking to be their preferred form of physical activity which may relate to the minimal skill requirement, ease of access and low financial costs incurred. Conclusion In the context of physical activity, health promoters need to be conscious of the difficulties that individuals feel in relation to bodily appearance and the pressure to comply with societal standards. This may be particularly relevant in low income settings where insufficient allocation of resources and social supports means that individuals have less opportunity to attend to physical activity than individuals living in higher income settings. PMID:18373842

  15. Revisiting the stability of 2D passive biped walking: Local behavior

    NASA Astrophysics Data System (ADS)

    Norris, James A.; Marsh, Anthony P.; Granata, Kevin P.; Ross, Shane D.

    2008-12-01

    Models of biped walking have demonstrated that stable walking motions are possible without active control. Stability of these motions has typically been quantified by studying the stability of an associated Poincaré map (orbital stability). However, additional insight may be obtained by examining how perturbations evolve over the short-term (local stability). For example, there may be regions where small perturbations actually diverge from the unperturbed trajectory, even if over the entire cycle small (but perhaps not large) perturbations are dissipated. We present techniques to calculate local stability, and demonstrate the utility of these techniques by examining the local stability of the 2D compass biped. These techniques are relevant to the design of controllers to maintain stability in robots, and in understanding how the neuromuscular system maintains stability in humans.

  16. Position and Orientation Distributions for Locally Self-Avoiding Walks in the Presence of Obstacles

    PubMed Central

    Skliros, Aris

    2008-01-01

    This paper presents a new approach to study the statistics of lattice random walks in the presence of obstacles and local self-avoidance constraints (excluded volume). By excluding sequentially local interactions within a window that slides along the chain, we obtain an upper bound on the number of self-avoiding walks (SAWs) that terminate at each possible position and orientation. Furthermore we develop a technique to include the effects of obstacles. Thus our model is a more realistic approximation of a polymer chain than that of a simple lattice random walk, and it is more computationally tractable than enumeration of obstacle-avoiding SAWs. Our approach is based on the method of the lattice-motion-group convolution. We develop these techniques theoretically and present numerical results for 2-D and 3-D lattices (square, hexagonal, cubic and tetrahedral/diamond). We present numerical results that show how the connectivity constant μ changes with the length of each self-avoiding window and the total length of the chain. Quantities such as 〈R〉 and others such as the probability of ring closure are calculated and compared with results obtained in the literature for the simple random walk case. PMID:18496591

  17. Position and Orientation Distributions for Locally Self-Avoiding Walks in the Presence of Obstacles.

    PubMed

    Skliros, Aris; Chirikjian, Gregory S

    2008-03-17

    This paper presents a new approach to study the statistics of lattice random walks in the presence of obstacles and local self-avoidance constraints (excluded volume). By excluding sequentially local interactions within a window that slides along the chain, we obtain an upper bound on the number of self-avoiding walks (SAWs) that terminate at each possible position and orientation. Furthermore we develop a technique to include the effects of obstacles. Thus our model is a more realistic approximation of a polymer chain than that of a simple lattice random walk, and it is more computationally tractable than enumeration of obstacle-avoiding SAWs. Our approach is based on the method of the lattice-motion-group convolution. We develop these techniques theoretically and present numerical results for 2-D and 3-D lattices (square, hexagonal, cubic and tetrahedral/diamond). We present numerical results that show how the connectivity constant mu changes with the length of each self-avoiding window and the total length of the chain. Quantities such as R and others such as the probability of ring closure are calculated and compared with results obtained in the literature for the simple random walk case. PMID:18496591

  18. Effect of active arm swing to local dynamic stability during walking.

    PubMed

    Wu, Yu; Li, Yue; Liu, An-Min; Xiao, Fei; Wang, Yin-Zhi; Hu, Fei; Chen, Jin-Ling; Dai, Ke-Rong; Gu, Dong-Yun

    2016-02-01

    Arm swing is an essential component in regulating dynamic stability of the whole body during walking, while the contribution of active arm swing to local dynamic stability of different motion segments remains unclear. This study investigated the effects of arm swing under natural arm swing condition and active arm swing condition on local dynamic stability and gait variability of the trunk segments (C7 and T10 joint) and lower extremity joints (hip, knee and ankle joint). The local divergence exponents (λs) and mean standard deviation over strides (MeanSD) of 24 young healthy adults were calculated while they were walking on treadmill with two arm swing conditions at their preferred walking speed (PWS). We found that in medial-lateral direction, both λs and MeanSD values of the trunk segments (C7 and T10 joint) in active arm swing condition were significantly lower than those in natural arm swing condition (p<0.05), while no significant difference of λs or MeanSD in lower extremity joints (hip, knee and ankle joint) was found between two arm swing conditions (p>0.05, respectively). In anterior-posterior and vertical direction, neither λs nor MeanSD values of all body segments showed significant difference between two arm swing conditions (p>0.05, respectively). These findings indicate that active arm swing may help to improve the local dynamic stability of the trunk segments in medial-lateral direction. PMID:26615477

  19. Being there: a brief visit to a neighbourhood induces the social attitudes of that neighbourhood

    PubMed Central

    Pepper, Gillian V.; Jobling, Ruth; Schroeder, Kari Britt

    2014-01-01

    There are differences between human groups in social behaviours and the attitudes that underlie them, such as trust. However, the psychological mechanisms that produce and reproduce this variation are not well understood. In particular, it is not clear whether assimilation to the social culture of a group requires lengthy socialization within that group, or can be more rapidly and reversibly evoked by exposure to the group’s environment and the behaviour of its members. Here, we report the results of a two-part study in two neighbourhoods of a British city, one economically deprived with relatively high crime, and the other affluent and lower in crime. In the first part of the study, we surveyed residents and found that the residents of the deprived neighbourhood had lower levels of social trust and higher levels of paranoia than the residents of the affluent neighbourhood. In the second part, we experimentally transported student volunteers who resided in neither neighbourhood to one or the other, and had them walk around delivering questionnaires to houses. We surveyed their trust and paranoia, and found significant differences according to which neighbourhood they had been sent to. The differences in the visitors mirrored the differences seen in the residents, with visitors to the deprived neighbourhood reporting lower social trust and higher paranoia than visitors to the affluent one. The magnitudes of the neighbourhood differences in the visitors, who only spent up to 45 min in the locations, were nearly as great as the magnitudes of those amongst the residents. We discuss the relevance of our findings to differential psychology, neighbourhood effects on social outcomes, and models of cultural evolution. PMID:24482758

  20. Kinematic variability, fractal dynamics and local dynamic stability of treadmill walking

    PubMed Central

    2011-01-01

    Background Motorized treadmills are widely used in research or in clinical therapy. Small kinematics, kinetics and energetics changes induced by Treadmill Walking (TW) as compared to Overground Walking (OW) have been reported in literature. The purpose of the present study was to characterize the differences between OW and TW in terms of stride-to-stride variability. Classical (Standard Deviation, SD) and non-linear (fractal dynamics, local dynamic stability) methods were used. In addition, the correlations between the different variability indexes were analyzed. Methods Twenty healthy subjects performed 10 min TW and OW in a random sequence. A triaxial accelerometer recorded trunk accelerations. Kinematic variability was computed as the average SD (MeanSD) of acceleration patterns among standardized strides. Fractal dynamics (scaling exponent α) was assessed by Detrended Fluctuation Analysis (DFA) of stride intervals. Short-term and long-term dynamic stability were estimated by computing the maximal Lyapunov exponents of acceleration signals. Results TW did not modify kinematic gait variability as compared to OW (multivariate T2, p = 0.87). Conversely, TW significantly modified fractal dynamics (t-test, p = 0.01), and both short and long term local dynamic stability (T2 p = 0.0002). No relationship was observed between variability indexes with the exception of significant negative correlation between MeanSD and dynamic stability in TW (3 × 6 canonical correlation, r = 0.94). Conclusions Treadmill induced a less correlated pattern in the stride intervals and increased gait stability, but did not modify kinematic variability in healthy subjects. This could be due to changes in perceptual information induced by treadmill walking that would affect locomotor control of the gait and hence specifically alter non-linear dependencies among consecutive strides. Consequently, the type of walking (i.e. treadmill or overground) is important to consider in each protocol

  1. Continuous time random walks for non-local radial solute transport

    NASA Astrophysics Data System (ADS)

    Dentz, Marco; Kang, Peter K.; Le Borgne, Tanguy

    2015-08-01

    This study formulates and analyzes continuous time random walk (CTRW) models in radial flow geometries for the quantification of non-local solute transport induced by heterogeneous flow distributions and by mobile-immobile mass transfer processes. To this end we derive a general CTRW framework in radial coordinates starting from the random walk equations for radial particle positions and times. The particle density, or solute concentration is governed by a non-local radial advection-dispersion equation (ADE). Unlike in CTRWs for uniform flow scenarios, particle transition times here depend on the radial particle position, which renders the CTRW non-stationary. As a consequence, the memory kernel characterizing the non-local ADE, is radially dependent. Based on this general formulation, we derive radial CTRW implementations that (i) emulate non-local radial transport due to heterogeneous advection, (ii) model multirate mass transfer (MRMT) between mobile and immobile continua, and (iii) quantify both heterogeneous advection in a mobile region and mass transfer between mobile and immobile regions. The expected solute breakthrough behavior is studied using numerical random walk particle tracking simulations. This behavior is analyzed by explicit analytical expressions for the asymptotic solute breakthrough curves. We observe clear power-law tails of the solute breakthrough for broad (power-law) distributions of particle transit times (heterogeneous advection) and particle trapping times (MRMT model). The combined model displays two distinct time regimes. An intermediate regime, in which the solute breakthrough is dominated by the particle transit times in the mobile zones, and a late time regime that is governed by the distribution of particle trapping times in immobile zones. These radial CTRW formulations allow for the identification of heterogeneous advection and mobile-immobile processes as drivers of anomalous transport, under conditions relevant for field tracer

  2. Localization and its consequences for quantum walk algorithms and quantum communication

    SciTech Connect

    Keating, J. P.; Linden, N.; Matthews, J. C. F.; Winter, A.

    2007-07-15

    The exponential speedup of quantum walks on certain graphs, relative to classical particles diffusing on the same graph, is a striking observation. It has suggested the possibility of new fast quantum algorithms. We point out here that quantum mechanics can also lead, through the phenomenon of localization, to exponential suppression of motion on these graphs (even in the absence of decoherence). In fact, for physical embodiments of graphs, this will be the generic behavior. It also has implications for proposals for using spin networks, including spin chains, as quantum communication channels.

  3. Localization of two-particle quantum walk on glued-tree and its application in generating Bell states

    NASA Astrophysics Data System (ADS)

    Wang, Huiquan; Wu, Junjie; He, Hongjuan; Tang, Yuhua

    2016-08-01

    Studies on two-particle quantum walks show that the spatial interaction between walkers will dynamically generate complex entanglement. However, those entanglement states are usually on a large state space and their evolutions are complex. It makes the entanglement states generated by quantum walk difficult to be applied directly in many applications of quantum information, such as quantum teleportation and quantum cryptography. In this paper, we firstly analyse a localization phenomena of two-particle quantum walk and then introduce how to use it to generate a Bell state. We will show that one special superposition component of the walkers' state is localized on the root vertex if a certain interaction exists between walkers. This localization is interesting because it is contrary to our knowledge that quantum walk spreads faster than its classical counterpart. More interestingly, the localized component is a Bell state in the coin space of two walkers. By this method, we can obtain a Bell state easily from the quantum walk with spatial interaction by a local measurement, which is required in many applications. Through simulations, we verify that this method is able to generate the Bell state 1/√{2}(|A rangle _1|Arangle _2 ± |Brangle _1|Brangle _2) in the coin space of two walkers with fidelity greater than 99.99999 % in theory, and we have at least a 50 % probability to obtain the expected Bell state after a proper local measurement.

  4. Conformal barrier and hidden local symmetry constraints: Walking technirhos in LHC diboson channels

    NASA Astrophysics Data System (ADS)

    Fukano, Hidenori S.; Matsuzaki, Shinya; Terashi, Koji; Yamawaki, Koichi

    2016-03-01

    We expand the previous analyses of the conformal barrier on the walking technirho for the 2 TeV diboson excesses reported by the ATLAS Collaboration, with a special emphasis on the hidden local symmetry (HLS) constraints. We first show that the Standard Model (SM) Higgs Lagrangian is equivalent to the scale-invariant nonlinear chiral Lagrangian, which is further gauge equivalent to the scale-invariant HLS model, with the scale symmetry realized nonlinearly via SM Higgs as a (pseudo-)dilaton. The scale symmetry forbids the new vector boson decay to the 125 GeV Higgs plus W / Z boson, in sharp contrast to the conventional "equivalence theorem" which is invalidated by the conformality. The HLS forbids mixing between the iso-triplet technirho's, ρΠ and ρP, of the one-family walking technicolor (with four doublets ND =NF / 2 = 4), which, without the HLS, would be generated when switching on the standard model gauging. We also present updated analyses of the walking technirho's for the diboson excesses by fully incorporating the constraints from the conformal barrier and the HLS as well as possible higher order effects: still characteristic of the one-family walking technirho is its smallness of the decay width, roughly of order Γ /Mρ ∼ [ 3 /NC × 1 /ND ] ×[ Γ /Mρ ] QCD ≃ 70 GeV / 2 TeV (ND =NC = 4), in perfect agreement with the expected diboson resonance with Γ < 100 GeV. The model is so sharply distinguishable from other massive spin 1 models without the conformality and HLS that it is clearly testable at the LHC Run II. If the 2 TeV boson decay to WH / ZH is not observed in the ongoing Run II, then the conformality is operative on the 125 GeV Higgs, strongly suggesting that the 2 TeV excess events are responsible for the walking technirhos and the 125 GeV Higgs is the technidilaton.

  5. Results from the Phoenix Urban Heat Island (UHI) experiment: effects at the local, neighbourhood and urban scales

    NASA Astrophysics Data System (ADS)

    di Sabatino, S.; Leo, L. S.; Hedquist, B. C.; Carter, W.; Fernando, H. J. S.

    2009-04-01

    This paper reports on the analysis of results from a large urban heat island experiment (UHI) performed in Phoenix (AZ) in April 2008. From 1960 to 2000, the city of Phoenix experienced a minimum temperature rise of 0.47 °C per decade, which is one of the highest rates in the world for a city of this size (Golden, 2004). Contemporaneously, the city has recorded a rapid enlargement and large portion of the land and desert vegetation have been replaced by buildings, asphalt and concrete (Brazel et al., 2007, Emmanuel and Fernando, 2007). Besides, model predictions show that minimum air temperatures for Phoenix metropolitan area in future years might be even higher than 38 °C. In order to make general statements and mitigation strategies of the UHI phenomenon in Phoenix and other cities in hot arid climates, a one-day intensive experiment was conducted on the 4th-5th April 2008 to collect surface and ambient temperatures within various landscapes in Central Phoenix. Inter alia, infrared thermography (IRT) was used for UHI mapping. The aim was to investigate UHI modifications within the city of Phoenix at three spatial scales i.e. the local (Central Business District, CBD), the neighborhood and the city scales. This was achieved by combining IRT measurements taken at ground level by mobile equipment (automobile-mounted and pedicab) and at high elevation by a helicopter. At local scale detailed thermographic images of about twenty building façades and several street canyons were collected. In total, about two thousand images were taken during the 24-hour campaign. Image analysis provides detailed information on building surface and pavement temperatures at fine resolution (Hedquist et al. 2009, Di Sabatino et al. 2009). This unique dataset allows us several investigations on local air temperature dependence on albedo, building thermal inertia, building shape and orientation and sky view factors. Besides, the mosaic of building façade temperatures are being analyzed

  6. Fuzzy overlapping community detection based on local random walk and multidimensional scaling

    NASA Astrophysics Data System (ADS)

    Wang, Wenjun; Liu, Dong; Liu, Xiao; Pan, Lin

    2013-12-01

    A fuzzy overlapping community is an important kind of overlapping community in which each node belongs to each community to different extents. It exists in many real networks but how to identify a fuzzy overlapping community is still a challenging task. In this work, the concept of local random walk and a new distance metric are introduced. Based on the new distance measurement, the dissimilarity index between each node of a network is calculated firstly. Then in order to keep the original node distance as much as possible, the network structure is mapped into low-dimensional space by the multidimensional scaling (MDS). Finally, the fuzzy c-means clustering is employed to find fuzzy communities in a network. The experimental results show that the proposed algorithm is effective and efficient to identify the fuzzy overlapping communities in both artificial networks and real-world networks.

  7. Literacy Mediation in Neighbourhood Houses

    ERIC Educational Resources Information Center

    Thompson, Sally

    2015-01-01

    Interactions between staff in Neighbourhood Houses, and the socially and educationally disadvantaged community members who visit Neighbourhood Houses, have been viewed through many lenses, including community development, social support, caring and compassion. This paper looks at Neighbourhood Houses as sites of pedagogical practice. More…

  8. Anisotropy of the monomer random walk in a polymer melt: local-order and connectivity effects.

    PubMed

    Bernini, S; Leporini, D

    2016-05-11

    The random walk of a bonded monomer in a polymer melt is anisotropic due to local order and bond connectivity. We investigate both effects by molecular-dynamics simulations on melts of fully-flexible linear chains ranging from dimers (M  =  2) up to entangled polymers (M  =  200). The corresponding atomic liquid is also considered a reference system. To disentangle the influence of the local geometry and the bond arrangements, and to reveal their interplay, we define suitable measures of the anisotropy emphasising either the former or the latter aspect. Connectivity anisotropy, as measured by the correlation between the initial bond orientation and the direction of the subsequent monomer displacement, shows a slight enhancement due to the local order at times shorter than the structural relaxation time. At intermediate times-when the monomer displacement is comparable to the bond length-a pronounced peak and then decays slowly as t (-1/2), becoming negligible when the displacement is as large as about five bond lengths, i.e. about four monomer diameters or three Kuhn lengths. Local-geometry anisotropy, as measured by the correlation between the initial orientation of a characteristic axis of the Voronoi cell and the subsequent monomer dynamics, is affected at shorter times than the structural relaxation time by the cage shape with antagonistic disturbance by the connectivity. Differently, at longer times, the connectivity favours the persistence of the local-geometry anisotropy, which vanishes when the monomer displacement exceeds the bond length. Our results strongly suggest that the sole consideration of the local order is not enough to understand the microscopic origin of the rattling amplitude of the trapped monomer in the cage of the neighbours. PMID:27070080

  9. Anisotropy of the monomer random walk in a polymer melt: local-order and connectivity effects

    NASA Astrophysics Data System (ADS)

    Bernini, S.; Leporini, D.

    2016-05-01

    The random walk of a bonded monomer in a polymer melt is anisotropic due to local order and bond connectivity. We investigate both effects by molecular-dynamics simulations on melts of fully-flexible linear chains ranging from dimers (M  =  2) up to entangled polymers (M  =  200). The corresponding atomic liquid is also considered a reference system. To disentangle the influence of the local geometry and the bond arrangements, and to reveal their interplay, we define suitable measures of the anisotropy emphasising either the former or the latter aspect. Connectivity anisotropy, as measured by the correlation between the initial bond orientation and the direction of the subsequent monomer displacement, shows a slight enhancement due to the local order at times shorter than the structural relaxation time. At intermediate times—when the monomer displacement is comparable to the bond length—a pronounced peak and then decays slowly as t ‑1/2, becoming negligible when the displacement is as large as about five bond lengths, i.e. about four monomer diameters or three Kuhn lengths. Local-geometry anisotropy, as measured by the correlation between the initial orientation of a characteristic axis of the Voronoi cell and the subsequent monomer dynamics, is affected at shorter times than the structural relaxation time by the cage shape with antagonistic disturbance by the connectivity. Differently, at longer times, the connectivity favours the persistence of the local-geometry anisotropy, which vanishes when the monomer displacement exceeds the bond length. Our results strongly suggest that the sole consideration of the local order is not enough to understand the microscopic origin of the rattling amplitude of the trapped monomer in the cage of the neighbours.

  10. Examining Aspects of the Built Environment: An Evaluation of a Community Walking Map Project

    PubMed Central

    Nykiforuk, Candace I.J.; Nieuwendyk, Laura M.; Mitha, Shaesta; Hosler, Ian

    2016-01-01

    Objective Interventions that address the built environment present an opportunity to affect behaviours such as physical activity. The purpose of this study was to evaluate a community walking map developed for eight neighbourhoods in the City of Edmonton (COE). Method A walking map developed in partnership with the COE’s Walkable Initiative was distributed to 11,994 households across eight neighbourhoods in July 2010. In total, 149 respondents completed an online follow-up survey that assessed the effectiveness of the walking maps in influencing physical activity. Results Of the 149 respondents, 89 (59.7%) reported that they had received a copy of the map, and 60 (40.2%) reported that they had not. Of those who had a copy, 76.4% (n=68) indicated that the routes and destinations on the map encouraged them to walk more in the community, 64.0% (n=57) stated they would walk more often to get to destinations, and 55.1% (n=49) indicated they would walk more often for physical activity or exercise as a result of having a copy of the map. Finally, 91.0% (n=81) stated that they found the map to be useful, as it provided walking routes (60/81, 74.1%,) and places to go in the community (57/81, 70.4%). Of those who did not receive a copy, 95.0% (n=57) indicated that they would use a community walking map. Conclusion This evaluation demonstrated that a community walking map was a valuable tool for not only encouraging walking for physical activity but also motivating individuals to explore their communities and visit local community destinations. PMID:23618093

  11. Exploring why residents of socioeconomically deprived neighbourhoods have less favourable perceptions of their neighbourhood environment than residents of wealthy neighbourhoods.

    PubMed

    Mackenbach, J D; Lakerveld, J; van Lenthe, F J; Bárdos, H; Glonti, K; Compernolle, S; De Bourdeaudhuij, I; Oppert, J-M; Roda, C; Rutter, H; Brug, J; Nijpels, G

    2016-01-01

    Residents of socioeconomically deprived areas perceive their neighbourhood as less conducive to healthy behaviours than residents of more affluent areas. Whether these unfavourable perceptions are based on objective neighbourhood features or other factors is poorly understood. We examined individual and contextual correlates of socioeconomic inequalities in neighbourhood perceptions across five urban regions in Europe. Data were analysed from 5205 participants of the SPOTLIGHT survey. Participants reported perceptions of their neighbourhood environment with regard to aesthetics, safety, the presence of destinations and functionality of the neighbourhood, which were summed into an overall neighbourhood perceptions score. Multivariable multilevel regression analyses were conducted to investigate whether the following factors were associated with socioeconomic inequalities in neighbourhood perceptions: objectively observed neighbourhood features, neighbourhood social capital, exposure to the neighbourhood, self-rated health and lifestyle behaviours. Objectively observed traffic safety, aesthetics and the presence of destinations in the neighbourhood explained around 15% of differences in neighbourhood perceptions between residents of high and low neighbourhoods; levels of neighbourhood social cohesion explained around 52%. Exposure to the neighbourhood, self-rated health and lifestyle behaviours were significant correlates of neighbourhood perceptions but did not contribute to socioeconomic differences. This cross-European study provided evidence that socioeconomic differences in neighbourhood perceptions are not only associated with objective neighbourhood features but also with social cohesion. Levels of physical activity, sleep duration, self-rated health, happiness and neighbourhood preference were also associated with neighbourhood perceptions. PMID:26879112

  12. RRW: repeated random walks on genome-scale protein networks for local cluster discovery

    PubMed Central

    Macropol, Kathy; Can, Tolga; Singh, Ambuj K

    2009-01-01

    Background We propose an efficient and biologically sensitive algorithm based on repeated random walks (RRW) for discovering functional modules, e.g., complexes and pathways, within large-scale protein networks. Compared to existing cluster identification techniques, RRW implicitly makes use of network topology, edge weights, and long range interactions between proteins. Results We apply the proposed technique on a functional network of yeast genes and accurately identify statistically significant clusters of proteins. We validate the biological significance of the results using known complexes in the MIPS complex catalogue database and well-characterized biological processes. We find that 90% of the created clusters have the majority of their catalogued proteins belonging to the same MIPS complex, and about 80% have the majority of their proteins involved in the same biological process. We compare our method to various other clustering techniques, such as the Markov Clustering Algorithm (MCL), and find a significant improvement in the RRW clusters' precision and accuracy values. Conclusion RRW, which is a technique that exploits the topology of the network, is more precise and robust in finding local clusters. In addition, it has the added flexibility of being able to find multi-functional proteins by allowing overlapping clusters. PMID:19740439

  13. Individual, social and environmental correlates of physical activity among women living in socioeconomically disadvantaged neighbourhoods.

    PubMed

    Cleland, Verity; Ball, Kylie; Hume, Clare; Timperio, Anna; King, Abby C; Crawford, David

    2010-06-01

    Women living in socioeconomically disadvantaged neighbourhoods are at heightened risk for physical inactivity, but little is known about the correlates of physical activity among this group. Using a social-ecological framework, this study aimed to determine the individual, social and neighbourhood environmental correlates of physical activity amongst women living in such neighbourhoods. During 2007-2008 women (n = 4108) aged 18-45 years randomly selected from urban and rural neighbourhoods of low socioeconomic status in Victoria, Australia completed the International Physical Activity Questionnaire (long). They reported on individual (self-efficacy, enjoyment, intentions, outcome expectancies, skills), social (childcare, social support from family and friends/colleagues, dog ownership) and neighbourhood environmental (neighbourhood cohesion, aesthetics, personal safety, 'walking environment') factors. Multinomial logistic regression was used to examine the odds of increasing categories of leisure time physical activity (LTPA) and transport-related physical activity (TRPA) for each individual, social and environmental factor. In partially adjusted analyses, all individual, social and environmental variables were positively associated with LTPA, while all individual factors, family and friend support and the walking environment were positively associated with TRPA. In fully adjusted multivariable models, all individual and social factors remained significantly associated with LTPA, while self-efficacy, enjoyment, intentions, social support, and neighbourhood 'walking environment' variables remained significantly associated with TRPA. In conclusion, individual and social factors were most important for LTPA, while individual, social and neighbourhood environmental factors were all associated with TRPA. Acknowledging the cross-sectional design, the findings highlight the importance of different levels of potential influence on physical activity in different domains

  14. Quantum walks on simplicial complexes

    NASA Astrophysics Data System (ADS)

    Matsue, Kaname; Ogurisu, Osamu; Segawa, Etsuo

    2016-05-01

    We construct a new type of quantum walks on simplicial complexes as a natural extension of the well-known Szegedy walk on graphs. One can numerically observe that our proposing quantum walks possess linear spreading and localization as in the case of the Grover walk on lattices. Moreover, our numerical simulation suggests that localization of our quantum walks reflects not only topological but also geometric structures. On the other hand, our proposing quantum walk contains an intrinsic problem concerning exhibition of non-trivial behavior, which is not seen in typical quantum walks such as Grover walks on graphs.

  15. SU-D-201-06: Random Walk Algorithm Seed Localization Parameters in Lung Positron Emission Tomography (PET) Images

    SciTech Connect

    Soufi, M; Asl, A Kamali; Geramifar, P

    2015-06-15

    Purpose: The objective of this study was to find the best seed localization parameters in random walk algorithm application to lung tumor delineation in Positron Emission Tomography (PET) images. Methods: PET images suffer from statistical noise and therefore tumor delineation in these images is a challenging task. Random walk algorithm, a graph based image segmentation technique, has reliable image noise robustness. Also its fast computation and fast editing characteristics make it powerful for clinical purposes. We implemented the random walk algorithm using MATLAB codes. The validation and verification of the algorithm have been done by 4D-NCAT phantom with spherical lung lesions in different diameters from 20 to 90 mm (with incremental steps of 10 mm) and different tumor to background ratios of 4:1 and 8:1. STIR (Software for Tomographic Image Reconstruction) has been applied to reconstruct the phantom PET images with different pixel sizes of 2×2×2 and 4×4×4 mm{sup 3}. For seed localization, we selected pixels with different maximum Standardized Uptake Value (SUVmax) percentages, at least (70%, 80%, 90% and 100%) SUVmax for foreground seeds and up to (20% to 55%, 5% increment) SUVmax for background seeds. Also, for investigation of algorithm performance on clinical data, 19 patients with lung tumor were studied. The resulted contours from algorithm have been compared with nuclear medicine expert manual contouring as ground truth. Results: Phantom and clinical lesion segmentation have shown that the best segmentation results obtained by selecting the pixels with at least 70% SUVmax as foreground seeds and pixels up to 30% SUVmax as background seeds respectively. The mean Dice Similarity Coefficient of 94% ± 5% (83% ± 6%) and mean Hausdorff Distance of 1 (2) pixels have been obtained for phantom (clinical) study. Conclusion: The accurate results of random walk algorithm in PET image segmentation assure its application for radiation treatment planning and

  16. Exoskeletons and economics: indoor arthropod diversity increases in affluent neighbourhoods.

    PubMed

    Leong, Misha; Bertone, Matthew A; Bayless, Keith M; Dunn, Robert R; Trautwein, Michelle D

    2016-08-01

    In urban ecosystems, socioeconomics contribute to patterns of biodiversity. The 'luxury effect', in which wealthier neighbourhoods are more biologically diverse, has been observed for plants, birds, bats and lizards. Here, we used data from a survey of indoor arthropod diversity (defined throughout as family-level richness) from 50 urban houses and found that house size, surrounding vegetation, as well as mean neighbourhood income best predict the number of kinds of arthropods found indoors. Our finding, that homes in wealthier neighbourhoods host higher indoor arthropod diversity (consisting of primarily non-pest species), shows that the luxury effect can extend to the indoor environment. The effect of mean neighbourhood income on indoor arthropod diversity was particularly strong for individual houses that lacked high surrounding vegetation ground cover, suggesting that neighbourhood dynamics can compensate for local choices of homeowners. Our work suggests that the management of neighbourhoods and cities can have effects on biodiversity that can extend from trees and birds all the way to the arthropod life in bedrooms and basements. PMID:27484644

  17. Processing of species-specific auditory patterns in the cricket brain by ascending, local, and descending neurons during standing and walking

    PubMed Central

    Zorović, M.

    2011-01-01

    The recognition of the male calling song is essential for phonotaxis in female crickets. We investigated the responses toward different models of song patterns by ascending, local, and descending neurons in the brain of standing and walking crickets. We describe results for two ascending, three local, and two descending interneurons. Characteristic dendritic and axonal arborizations of the local and descending neurons indicate a flow of auditory information from the ascending interneurons toward the lateral accessory lobes and point toward the relevance of this brain region for cricket phonotaxis. Two aspects of auditory processing were studied: the tuning of interneuron activity to pulse repetition rate and the precision of pattern copying. Whereas ascending neurons exhibited weak, low-pass properties, local neurons showed both low- and band-pass properties, and descending neurons represented clear band-pass filters. Accurate copying of single pulses was found at all three levels of the auditory pathway. Animals were walking on a trackball, which allowed an assessment of the effect that walking has on auditory processing. During walking, all neurons were additionally activated, and in most neurons, the spike rate was correlated to walking velocity. The number of spikes elicited by a chirp increased with walking only in ascending neurons, whereas the peak instantaneous spike rate of the auditory responses increased on all levels of the processing pathway. Extra spiking activity resulted in a somewhat degraded copying of the pulse pattern in most neurons. PMID:21346206

  18. Processing of species-specific auditory patterns in the cricket brain by ascending, local, and descending neurons during standing and walking.

    PubMed

    Zorović, M; Hedwig, B

    2011-05-01

    The recognition of the male calling song is essential for phonotaxis in female crickets. We investigated the responses toward different models of song patterns by ascending, local, and descending neurons in the brain of standing and walking crickets. We describe results for two ascending, three local, and two descending interneurons. Characteristic dendritic and axonal arborizations of the local and descending neurons indicate a flow of auditory information from the ascending interneurons toward the lateral accessory lobes and point toward the relevance of this brain region for cricket phonotaxis. Two aspects of auditory processing were studied: the tuning of interneuron activity to pulse repetition rate and the precision of pattern copying. Whereas ascending neurons exhibited weak, low-pass properties, local neurons showed both low- and band-pass properties, and descending neurons represented clear band-pass filters. Accurate copying of single pulses was found at all three levels of the auditory pathway. Animals were walking on a trackball, which allowed an assessment of the effect that walking has on auditory processing. During walking, all neurons were additionally activated, and in most neurons, the spike rate was correlated to walking velocity. The number of spikes elicited by a chirp increased with walking only in ascending neurons, whereas the peak instantaneous spike rate of the auditory responses increased on all levels of the processing pathway. Extra spiking activity resulted in a somewhat degraded copying of the pulse pattern in most neurons. PMID:21346206

  19. Classification of Airborne Laser Scanning Data Using Geometric Multi-Scale Features and Different Neighbourhood Types

    NASA Astrophysics Data System (ADS)

    Blomley, R.; Jutzi, B.; Weinmann, M.

    2016-06-01

    In this paper, we address the classification of airborne laser scanning data. We present a novel methodology relying on the use of complementary types of geometric features extracted from multiple local neighbourhoods of different scale and type. To demonstrate the performance of our methodology, we present results of a detailed evaluation on a standard benchmark dataset and we show that the consideration of multi-scale, multi-type neighbourhoods as the basis for feature extraction leads to improved classification results in comparison to single-scale neighbourhoods as well as in comparison to multi-scale neighbourhoods of the same type.

  20. Are residents of downtown Toronto influenced by their urban neighbourhoods? Using concept mapping to examine neighbourhood characteristics and their perceived impact on self-rated mental well-being

    PubMed Central

    2012-01-01

    Background There is ample evidence that residential neighbourhoods can influence mental well-being (MWB), with most studies relying on census or similar data to characterize communities. Few studies have actively investigated local residents’ perceptions. Methods Concept mapping was conducted with residents from five Toronto neighbourhoods representing low income and non-low income socio-economic groups. These residents participated in small groups and attended two sessions per neighbourhood. The first session (brainstorming) generated neighbourhood characteristics that residents felt influenced their MWB. A few weeks later, participants returned to sort these neighbourhood characteristics and rate their relative importance in affecting residents’ ‘good’ and ‘poor’ MWB. The data from the sorting and rating groups were analyzed to generate conceptual maps of neighbourhood characteristics that influence MWB. Results While agreement existed on factors influencing poor MWB (regardless of neighbourhood, income, gender and age), perceptions related to factors affecting good MWB were more varied. For example, women were more likely to rank physical beauty of their neighbourhood and range of services available as more important to good MWB, while men were more likely to cite free access to computers/internet and neighbourhood reputation as important. Low-income residents emphasized aesthetic attributes and public transportation as important to good MWB, while non-low-income residents rated crime, negative neighbourhood environment and social concerns as more important contributors to good MWB. Conclusion These findings contribute to the emerging literature on neighbourhoods and MWB, and inform urban planning in a Canadian context. PMID:22862839

  1. Localization and limit laws of a three-state alternate quantum walk on a two-dimensional lattice

    NASA Astrophysics Data System (ADS)

    Machida, Takuya; Chandrashekar, C. M.

    2015-12-01

    A two-dimensional discrete-time quantum walk (DTQW) can be realized by alternating a two-state DTQW in one spatial dimension followed by an evolution in the other dimension. This was shown to reproduce a probability distribution for a certain configuration of a four-state DTQW on a two-dimensional lattice. In this work we present a three-state alternate DTQW with a parametrized coin-flip operator and show that it can produce localization that is also observed for a certain other configuration of the four-state DTQW and nonreproducible using the two-state alternate DTQW. We will present two limit theorems for the three-state alternate DTQW. One of the limit theorems describes a long-time limit of a return probability, and the other presents a convergence in distribution for the position of the walker on a rescaled space by time. We find that the spatial entanglement generated by the three-state alternate DTQW is higher than that by the four-state DTQW. Using all our results, we outline the relevance of these walks in three-level physical systems.

  2. Home and neighbourhood correlates of BMI among children living in socioeconomically disadvantaged neighbourhoods.

    PubMed

    Crawford, David A; Ball, Kylie; Cleland, Verity J; Campbell, Karen J; Timperio, Anna F; Abbott, Gavin; Brug, Johannes; Baur, Louise A; Salmon, Jo A

    2012-04-01

    A detailed understanding of the underlying drivers of obesity-risk behaviours is needed to inform prevention initiatives, particularly for individuals of low socioeconomic position who are at increased risk of unhealthy weight gain. However, few studies have concurrently considered factors in the home and local neighbourhood environments, and little research has examined determinants among children from low socioeconomic backgrounds. The present study examined home, social and neighbourhood correlates of BMI (kg/m2) in children living in disadvantaged neighbourhoods. Cross-sectional data were collected from 491 women with children aged 5-12 years living in forty urban and forty rural socioeconomically disadvantaged areas (suburbs) of Victoria, Australia in 2007 and 2008. Mothers completed questionnaires about the home environment (maternal efficacy, perceived importance/beliefs, rewards, rules and access to equipment), social norms and perceived neighbourhood environment in relation to physical activity, healthy eating and sedentary behaviour. Children's height and weight were measured at school or home. Linear regression analyses controlled for child sex and age. In multivariable analyses, children whose mothers had higher efficacy for them doing physical activity tended to have lower BMI z scores (B = - 0·04, 95 % CI - 0·06, - 0·02), and children who had a television (TV) in their bedroom (B = 0·24, 95 % CI 0·04, 0·44) and whose mothers made greater use of food as a reward for good behaviour (B = 0·05, 95 % CI 0·01, 0·09) tended to have higher BMI z scores. Increasing efficacy among mothers to promote physical activity, limiting use of food as a reward and not placing TV in children's bedrooms may be important targets for future obesity prevention initiatives in disadvantaged communities. PMID:21824445

  3. Neighbourhoods and potential access to health care: the role of spatial and aspatial factors.

    PubMed

    Bissonnette, Laura; Wilson, Kathi; Bell, Scott; Shah, Tayyab Ikram

    2012-07-01

    The availability of, and access to, primary health care is one neighbourhood characteristic that has the potential to impact health thus representing an important area of focus for neighbourhood-health research. This research examines neighbourhood access to primary health care in the city of Mississauga, Ontario, Canada. A modification of the Two Step Floating Catchment Area method is used to measure multiple spatial and aspatial (social) dimensions of potential access to primary health care in natural neighbourhoods of Mississauga. The analysis reveals that neighbourhood-level potential access to primary care is dependant on spatial and aspatial dimensions of access selected for examination. The results also show that potential accessibility is reduced for linguistic minorities as well as for recent immigrant populations who appear, on the surface, to have better access to walk-in clinics than dedicated physicians. The research results reinforce the importance of focusing on intra-urban variations in access to care and demonstrate the utility of a new approach for studying neighbourhood impacts that better represents spatial variations in health care access and demand. PMID:22503565

  4. Neighbourhood Based Residential Child Care: A Local Residential Child Care Unit as a Resource for Integrated and Flexible Child and Family Care in Dublin.

    ERIC Educational Resources Information Center

    Gilligan, Robbie

    A pioneering residential child care project in inner city Dublin began operations in July 1981. The project was designed to function as a resource for seriously deprived or at-risk children and their families. The community served is one characterized by exceptionally high unemployment, a 10 percent rate of heroin addiction among local 15- to…

  5. Do perceptions of the neighbourhood food environment predict fruit and vegetable intake in low-income neighbourhoods?

    PubMed Central

    Flint, Ellen; Cummins, Steven; Matthews, Stephen

    2014-01-01

    The aim of this study is to investigate the extent to which perceptions of the quality, variety and affordability of the local food retail provision predict fruit and vegetable intake. Secondary analysis of baseline data from the Philadelphia Neighbourhood Food Environment Study was undertaken. This study investigating the role of the neighbourhood food environment on diet and obesity comprised a random sample of households from two low-income Philadelphia neighbourhoods, matched on socio-demographic characteristics and food environment. The analytic sample comprised adult men and women aged 18–92 (n=1263). Perception of food environment was measured using five related dimensions pertaining to quality, choice and expense of local food outlets and locally available fruits and vegetables. The outcome, portions of fruits and vegetables consumed per day, was measured using the Block Food Frequency Questionnaire. Results from multivariate regression analyses suggested that measured dimensions of perceived neighbourhood food environment did not predict fruit and vegetable consumption. Further investigation of what constitutes an individual’s ‘true’ food retail environment is required. PMID:23999578

  6. Neighbourhoods for Active Kids: study protocol for a cross-sectional examination of neighbourhood features and children's physical activity, active travel, independent mobility and body size

    PubMed Central

    Oliver, Melody; McPhee, Julia; Carroll, Penelope; Ikeda, Erika; Mavoa, Suzanne; Mackay, Lisa; Kearns, Robin A; Kyttä, Marketta; Asiasiga, Lanuola; Garrett, Nicholas; Lin, Judy; Mackett, Roger; Zinn, Caryn; Moewaka Barnes, Helen; Egli, Victoria; Prendergast, Kate; Witten, Karen

    2016-01-01

    Introduction New Zealand children's physical activity, including independent mobility and active travel, has declined markedly over recent decades. The Neighbourhoods for Active Kids (NfAK) study examines how neighbourhood built environments are associated with the independent mobility, active travel, physical activity and neighbourhood experiences of children aged 9–12 years in primary and intermediate schools across Auckland, New Zealand's largest city. Methods and analysis Child-specific indices of walkability, destination accessibility and traffic exposure will be constructed to measure the built environment in 8 neighbourhoods in Auckland. Interactive online-mapping software will be used to measure children's independent mobility and transport mode to destinations and to derive measures of neighbourhood use and perceptions. Physical activity will be measured using 7-day accelerometry. Height, weight and waist circumference will be objectively measured. Parent telephone interviews will collect sociodemographic information and parent neighbourhood perceptions. Interviews with school representative will capture supports and barriers for healthy activity and nutrition behaviours at the school level. Multilevel modelling approaches will be used to understand how differing built environment variables are associated with activity, neighbourhood experiences and health outcomes. Discussion We anticipate that children who reside in neighbourhoods considered highly walkable will be more physically active, accumulate more independent mobility and active travel, and be more likely to have a healthy body size. This research is timely as cities throughout New Zealand develop and implement plans to improve the liveability of intensifying urban neighbourhoods. Results will be disseminated to participants, local government agencies and through conventional academic avenues. PMID:27531740

  7. Perception of place and health: differences between neighbourhoods in the Québec City region.

    PubMed

    Pampalon, Robert; Hamel, Denis; De Koninck, Maria; Disant, Marie-Jeanne

    2007-07-01

    This paper addresses two questions: (1) Can people's perceptions of problems and social cohesion in the neighbourhood be considered as contextual variables; and (2) are these perceptions related to people's health? Data come from a general health survey carried out in 2004 among 1634 individuals living in three localities of the region of Québec City, namely a downtown, a suburban and a rural area, which were further subdivided into 34 smaller spatial units, hereafter called neighbourhoods. The survey included questions on individuals' perception of problems (social and environmental) and social cohesion (attraction to neighbourhood, neighbouring and psychological sense of community) in the neighbourhood, as well as questions on self-rated health, long-term disability and self-mastery. A first set of logistic multilevel models was performed to ascertain the existence of neighbourhood variations in the perception of problems and social cohesion, after accounting for individual attributes. A second set of multilevel models was carried out to examine the association between perceived problems and social cohesion in the neighbourhood and people's health. Results show that, after accounting for individual attributes, the perception of problems and social cohesion varies significantly by neighbourhood and/or localities and can be considered as contextual variables. Furthermore, these perceptions of place appear to be significant predictors of people's health. PMID:17418468

  8. Grafting, Going to College and Working on Road: Youth Transitions and Cultures in an East London Neighbourhood

    ERIC Educational Resources Information Center

    Gunter, Anthony; Watt, Paul

    2009-01-01

    The local neighbourhood has an enduring significance for British urban, working-class youth in relation to their transitions, cultures and leisure practices. This paper examines these interrelated issues by drawing upon ethnographic research undertaken in "Manor", a deprived, multi-ethnic East London neighbourhood. It explores the transitions…

  9. Prediction of leisure-time walking: an integration of social cognitive, perceived environmental, and personality factors

    PubMed Central

    Rhodes, Ryan E; Courneya, Kerry S; Blanchard, Chris M; Plotnikoff, Ronald C

    2007-01-01

    Background Walking is the primary focus of population-based physical activity initiatives but a theoretical understanding of this behaviour is still elusive. The purpose of this study was to integrate personality, the perceived environment, and planning into a theory of planned behaviour (TPB) framework to predict leisure-time walking. Methods Participants were a random sample (N = 358) of Canadian adults who completed measures of the TPB, planning, perceived neighbourhood environment, and personality at Time 1 and self-reported walking behaviour two months later. Results Analyses using structural equation modelling provided evidence that leisure-time walking is largely predicted by intention (standardized effect = .42) with an additional independent contribution from proximity to neighbourhood retail shops (standardized effect = .18). Intention, in turn, was predicted by attitudes toward walking and perceived behavioural control. Effects of perceived neighbourhood aesthetics and walking infrastructure on walking were mediated through attitudes and intention. Moderated regression analysis showed that the intention-walking relationship was moderated by conscientiousness and proximity to neighbourhood recreation facilities but not planning. Conclusion Overall, walking behaviour is theoretically complex but may best be addressed at a population level by facilitating strong intentions in a receptive environment even though individual differences may persist. PMID:17974022

  10. Neighbourhood environment, sitting time and motorised transport in older adults: a cross-sectional study in Hong Kong

    PubMed Central

    Barnett, Anthony; Cerin, Ester; Ching, Claudia S-K; Johnston, Janice M; Lee, Ruby S Y

    2015-01-01

    Objectives Sitting time is a public health concern. This study examined associations of objectively measured neighbourhood environmental attributes with non-transport sitting time and motorised transport in 484 Hong Kong older adults. Neighbourhood attributes encouraging walking may help older adults replace some sitting time at home and on motorised transport with light-to-moderate-intensity activities such as strolling around the neighbourhood or walking to/from neighbourhood destinations. Thus, we hypothesised environmental attributes found to be related to walking would show associations with non-transport sitting time and motorised transport opposite to those seen for walking. Design Cross-sectional. Setting Hong Kong, an ultradense urban environment. Participants 484 ethnic Chinese Hong Kong residents aged 65+ recruited from membership lists of four Hong Kong Elderly Health Centres representing catchment areas of low and high transport-related walkability stratified by socioeconomic status (response rate: 78%). Primary and secondary outcome measures Attributes of participants’ neighbourhood environments were assessed by environmental audits, while non-transport sitting time and motorised transport were ascertained using the International Physical Activity Questionnaire—Long Form (Chinese version). Results Daily non-transport sitting minutes were 283 (SD=128) and motorised transport 23 (SD=28). Prevalence of signs of crime/disorder, streetlights, public facilities (toilets and benches) and pedestrian safety were independently negatively related, and sloping streets positively related, to sitting outcomes. Places of worship in the neighbourhood were predictive of more, and prevalence of public transit points of less, non-transport sitting. Associations of either or both sitting outcomes with prevalence of food/grocery stores and presence of parks were moderated by path obstructions and signs of crime/disorder. Conclusions The findings suggest that access to

  11. Chip-based nanoelectrospray ionization with Fourier transform mass spectrometric detection to screen for local anesthetics intended to mask limb sore in walking horses.

    PubMed

    Szarka, Szabolcs; Prokai, Laszlo

    2015-03-01

    We report a high-throughput chip-based nanoelectrospray ionization method coupled with Fourier transform mass spectrometry to screen for local anesthetics in samples collected by swabbing. These drugs have been used to mask pain on the limbs of walking horses after forbidden practices of soring or physical abuse. Optimized for lidocaine, the method afforded sub-ppm mass accuracy for nine local anesthetics included in the study. From doped cotton swabs, two third and all of the analytes were detected after adding 10 ng and 100 ng of each drug, respectively. Benzocaine and/or lidocaine were found on positive swab samples collected during walking horse competitions. PMID:25800188

  12. Walking Problems

    MedlinePlus

    ... daily activities, get around, and exercise. Having a problem with walking can make daily life more difficult. ... walk is called your gait. A variety of problems can cause an abnormal gait and lead to ...

  13. Neighbourhood Continuity Is Not Required for Correct Testis Gene Expression in Drosophila

    PubMed Central

    Meadows, Lisa A.; Chan, Yuk Sang; Roote, John; Russell, Steven

    2010-01-01

    It is now widely accepted that gene organisation in eukaryotic genomes is non-random and it is proposed that such organisation may be important for gene expression and genome evolution. In particular, the results of several large-scale gene expression analyses in a range of organisms from yeast to human indicate that sets of genes with similar tissue-specific or temporal expression profiles are clustered within the genome in gene expression neighbourhoods. While the existence of neighbourhoods is clearly established, the underlying reason for this facet of genome organisation is currently unclear and there is little experimental evidence that addresses the genomic requisites for neighbourhood organisation. We report the targeted disruption of three well-defined male-specific gene expression neighbourhoods in the Drosophila genome by the synthesis of precisely mapped chromosomal inversions. We compare gene expression in individuals carrying inverted chromosomes with their non-inverted but otherwise identical progenitors using whole-transcriptome microarray analysis, validating these data with specific quantitative real-time PCR assays. For each neighbourhood we generate and examine multiple inversions. We find no significant differences in the expression of genes that define each of the neighbourhoods. We further show that the inversions spatially separate both halves of a neighbourhood in the nucleus. Thus, models explaining neighbourhood organisation in terms of local sequence interactions, enhancer crosstalk, or short-range chromatin effects are unlikely to account for this facet of genome organisation. Our study challenges the notion that, at least in the case of the testis, expression neighbourhoods are a feature of eukaryotic genome organisation necessary for correct gene expression. PMID:21151342

  14. Walking the walk

    SciTech Connect

    Butler, B.

    1994-12-31

    Earth Day, celebrated this April, brought out a spate of press conferences, fairs and media spots. The White House announced its plans to green itself by incorporating energy efficiency and recycling, and Vice President Gore and Energy Secretary O`Leary announced the President`s Executive Order, which mandates the use of energy efficiency in federal facilities with solar as a high-profile option. At the White House itself, however, no solar application has yet been selected for installation. Another Earth Day media spot showed how the nation`s utility companies have joined Secretary O`Leary`s Climate Challenge, an ambitious voluntary program to cut greenhouse-gas emissions. During Earth Day 1994, it became clear how many houses use solar water heating and how often photovoltaics is used to power road signs and sign boards, telephones and repeaters, and for cathodic protection and security lighting. Solar energy is expanding. But if it is to become a truly everyday technology, more institution, governments, businesses and individual consumers are going to have to walk the walk. This means that Earth Day will have to last longer, environmental concerns must become more genuine, and the focus of government and business decisions must be more long-term.

  15. Intergenerational transmission of neighbourhood poverty: an analysis of neighbourhood histories of individuals

    PubMed Central

    van Ham, Maarten; Hedman, Lina; Manley, David; Coulter, Rory; Östh, John

    2014-01-01

    The extent to which socioeconomic (dis)advantage is transmitted between generations is receiving increasing attention from academics and policymakers. However, few studies have investigated whether there is a spatial dimension to this intergenerational transmission of (dis)advantage. Drawing on the concept of neighbourhood biographies, this study contends that there are links between the places individuals live with their parents and their subsequent neighbourhood experiences as independent adults. Using individual-level register data tracking the whole Stockholm population from 1990 to 2008, and bespoke neighbourhoods, this study is the first to use sequencing techniques to construct individual neighbourhood histories. Through visualisation methods and ordered logit models, we demonstrate that the socioeconomic composition of the neighbourhood children lived in before they left the parental home is strongly related to the status of the neighbourhood they live in 5, 12 and 18 years later. Children living with their parents in high poverty concentration neighbourhoods are very likely to end up in similar neighbourhoods much later in life. The parental neighbourhood is also important in predicting the cumulative exposure to poverty concentration neighbourhoods over a long period of early adulthood. Ethnic minorities were found to have the longest cumulative exposure to poverty concentration neighbourhoods. These findings imply that for some groups, disadvantage is both inherited and highly persistent. PMID:26074624

  16. Neighbourhood social capital and common mental disorder: testing the link in a general population sample.

    PubMed

    Stafford, Mai; De Silva, Mary; Stansfeld, Stephen; Marmot, Michael

    2008-09-01

    General population multilevel studies of social capital and mental health are few in number. This multilevel study examined external measures of neighbourhood social capital and common mental disorders (CMD). Main effects and stress buffering models were tested. Based on data from over 9000 residents in 239 neighbourhoods in England and Scotland, there was no evidence of a main effect of social capital. For people living in deprived circumstances only, associations between neighbourhood social capital and CMD were seen. Elements of bridging social capital (contact amongst local friends) were associated with lower reporting of CMD. Elements of bonding social capital (attachment to neighbourhood) were associated with higher reporting of CMD. Findings provide some support for the hypothesis that social capital may protect against CMD, but indicate that initiatives should be targeted to deprived groups, focus on specific elements of social capital and not neglect the important relationship between personal socioeconomic disadvantage and CMD. PMID:17919964

  17. Encouraging walking for transport and physical activity in children and adolescents: how important is the built environment?

    PubMed

    Giles-Corti, Billie; Kelty, Sally F; Zubrick, Stephen R; Villanueva, Karen P

    2009-01-01

    In the post-World War II era, there have been dramatic changes to the environment that appear to be having a detrimental impact on the lifestyles and incidental physical activities of young people. These changes are not trivial and have the potential to influence not only physical health, but also mental health and child development. However, the evidence of the impact of the built environment on physical activity to date is inconsistent. This review examines the evidence on the association between the built environment and walking for transport as well as physical activity generally, with a focus on methodological issues that may explain inconsistencies in the literature to date. It appears that many studies fail to measure behaviour-specific environmental correlates, and insufficient attention is being given to differences according to the age of study participants. Higher levels of out-of-school-hours physical activity and walking appear to be significantly associated with higher levels of urban density and neighbourhoods with mixed-use planning, especially for older children and adolescents. Proximate recreational facilities also appear to predict young people's level of physical activity. However, there are inconsistencies in the literature involving studies with younger children. Independent mobility increases with age. For younger children, the impact of the built environment is influenced by the decision-making of parents as the gatekeepers of their behaviour. Cross-cultural differences may also be present and are worthy of greater exploration. As children develop and are given more independent mobility, it appears that the way neighbourhoods are designed - particularly in terms of proximity and connectivity to local destinations, including schools and shopping centres, and the presence of footpaths - becomes a determinant of whether children are able, and are permitted by their parents, to walk and use destinations locally. If older children and

  18. Neighbourhood walkability and physical activity among family members of people with heart disease who participated in a randomized controlled trial of a behavioural risk reduction intervention.

    PubMed

    Riley, Dana L; Mark, Amy E; Kristjansson, Elizabeth; Sawada, Michael C; Reid, Robert D

    2013-05-01

    This study adds to the current literature investigating the relationship between individuals' physical activity (PA) and the built environment. Self-reported PA from a prospective behavioural risk reduction intervention was explored in the context of objectively measured Walk Score(®) and neighbourhood walkability in Ottawa, Canada. Participants in the intervention arm had significantly higher odds of meeting PA guidelines at 12-weeks compared to the standard care control group. This was not influenced by Walk Score(®) or walkability. This individual-level intervention was effective in assisting participants to overcome potential structural barriers presented by their neighbourhood to meet PA guidelines at 12-weeks. PMID:23474354

  19. An ecometric analysis of neighbourhood cohesion

    PubMed Central

    Fone, David L; Farewell, Daniel M; Dunstan, Frank D

    2006-01-01

    Background It is widely believed that the social environment has an important influence on health, but there is less certainty about how to measure specific factors within the social environment that could link the neighbourhood of residence to a health outcome. The objectives of the study were to examine the underlying constructs captured by an adapted version of Buckner's neighbourhood cohesion scale, and to assess the reliability of the scale at the small-area-level by combining ecometric methodology with ordinal modelling of a five-point scale. Methods Data were analysed from 11,078 participants in the Caerphilly Health and Social Needs Study, who were sampled from within 325 UK census enumeration districts in Caerphilly county borough, Wales, UK. The responses of interest came from 15 question items designed to capture different facets of neighbourhood cohesion. Factor analysis was used to identify constructs underlying the neighbourhood cohesion item responses. Using a multilevel ecometric model, the variability present in these ordinal responses was decomposed into contextual, compositional, item-level and residual components. Results Two constructs labelled neighbourhood belonging and social cohesion were identified, and variability in both constructs was modelled at each level of the multilevel structure. The intra-neighbourhood correlations were 6.4% and 1.0% for the neighbourhood belonging and social cohesion subscales, respectively. Given the large sample size, contextual neighbourhood cohesion scores can be estimated reliably. The wide variation in the observed frequency of occurence of the scale item activities suggests that the two subscales have desirable ecometric properties. Further, the majority of between-neighbourhood variation is not explained by the socio-demographic characteristics of the individual respondents. Conclusion Assessment of the properties of the adapted neighbourhood cohesion scale using factor analysis and ecometric analysis

  20. Re-visiting the relationship between neighbourhood environment and BMI: an instrumental variables approach to correcting for residential selection bias

    PubMed Central

    2013-01-01

    Background A burgeoning literature links attributes of neighbourhoods’ built environments to residents’ physical activity, food and transportation choices, weight, and/or obesity risk. In cross-sectional studies, non-random residential selection impedes researchers’ ability to conclude that neighbourhood environments cause these outcomes. Methods Cross-sectional data for the current study are based on 14,689 non-Hispanic white women living in Salt Lake County, Utah, USA. Instrumental variables techniques are used to adjust for the possibility that neighbourhoods may affect weight but heavier or lighter women may also choose to live in certain neighbourhoods. All analyses control for the average BMI of siblings and thus familial predisposition for overweight/obesity, which is often an omitted variable in past studies. Results We find that cross-sectional analyses relating neighbourhood characteristics to BMI understate the strength of the relationship if they do not make statistical adjustments for the decision to live in a walkable neighbourhood. Standard cross-sectional estimation reveals no significant relationship between neighbourhood walkability and BMI. However, the instrumental variables estimates reveal statistically significant effects. Conclusions We find evidence that residential selection leads to an understatement of the causal effects of neighbourhood walkability features on BMI. Although caution should be used in generalizing from research done with one demographic group in a single locale, our findings support the contention that public policies designed to alter neighbourhood walkability may moderately affect the BMI of large numbers of individuals. PMID:23425701

  1. Plant traits respond to the competitive neighbourhood at different spatial and temporal scales

    PubMed Central

    Bittebiere, Anne-Kristel; Mony, Cendrine

    2015-01-01

    Background and Aims Clonal plants can plastically modify their traits in response to competition, but little is known regarding the spatio-temporal scale at which a competitive neighbourhood determines the variability in species traits. This study tests the hypothesis that the local neighbourhood can be expected to influence the processes that are involved in competition tolerance and avoidance, and that this effect depends on organ lifespan. Methods Fragments of the rhizomatous Elytrigia repens (Poaceae) were sampled in 2012 in experimental plant communities that varied in species identity and abundance. These communities had been cultivated since 2009 in mesocosms in a common garden. Fragment performance, shoot and clonal traits were measured, and the effects of past and present local neighbourhoods of five different radius sizes (5–25 cm) were examined. Past and present local neighbourhood compositions were assessed in 2011 and 2012, respectively. Key Results Most of the measured traits of E. repens responded to the local neighbourhood (5–10 cm radius), with an additional effect of the larger neighbourhood (20–25 cm radius) on ramet height, leaf dry matter content, maximal internode length and specific rhizome mass. Contrary to the expectation of the hypothesis, the temporal influence was not due to the organ lifespan. Indeed, five of the eight traits studied responded to both the past and present neighbourhoods. With the exception of specific rhizome mass, all trait responses were explained by the abundance of specific species. Conclusions This study demonstrates that the traits of a single clonal individual can respond to different competitive environments in space and time. The results thus contribute to the understanding of competition mechanisms. PMID:25429007

  2. Household and neighbourhood risks for injury to 5-14 year old children.

    PubMed

    Haynes, Robin; Reading, Richard; Gale, Susan

    2003-08-01

    Injuries in childhood are strongly related to poverty at the household level and to living in a deprived neighbourhood, but it is not clear whether these effects are independent. In this prospective population study, all injuries to 5-14 year old children living in the city of Norwich, UK, and presented at the hospital Accident and Emergency Department over a 13 month period were recorded (N=3526). Information on the population of resident children and household composition was assembled from the health authority population register. Neighbourhood information was extracted from the census and local surveys. Unadjusted risks were calculated for individual and neighbourhood factors, followed by multilevel modelling in which predictors were included at three levels: individual, enumeration district and social area (neighbourhood). The overall injury rate was 16.44 per 100 children per year. Injury rates between neighbourhoods varied two-fold and were highest in more deprived areas. In the final multilevel model injury risk was related to gender (boys vs. girls OR=1.35), age of child (OR=1.07 per year), number of adults in the household (OR=0.91 per adult), and age gap between child and eldest female (15-24 years vs. 25-34 years, OR=1.15). Injury rates were also related to social area deprivation, although variations in injury rates between neighbourhoods were not wholly explained by deprivation. The adjusted odds ratio between the most and least deprived social areas was 1.35. Excluding less serious injuries did not substantially change the results. The risks were very similar to those found in a previous study of pre-school children, with the same neighbourhoods identified as high and low risk as before. This evidence that neighbourhood factors independently influence injury risk over and above individual and household factors supports the use of area-based policies to reduce injuries in children. PMID:12821011

  3. Genome walking.

    PubMed

    Shapter, Frances M; Waters, Daniel L E

    2014-01-01

    Genome walking is a method for determining the DNA sequence of unknown genomic regions flanking a region of known DNA sequence. The Genome walking has the potential to capture 6-7 kb of sequence in a single round. Ideal for identifying gene promoter regions where only the coding region. Genome walking also has significant utility for capturing homologous genes in new species when there are areas in the target gene with strong sequence conservation to the characterized species. The increasing use of next-generation sequencing technologies will see the principles of genome walking adapted to in silico methods. However, for smaller projects, PCR-based genome walking will remain an efficient method of characterizing unknown flanking sequence. PMID:24243201

  4. Accidents to preschool children: comparing family and neighbourhood risk factors.

    PubMed

    Reading, R; Langford, I H; Haynes, R; Lovett, A

    1999-02-01

    Accidental injury in young children is more common among poorer families and in deprived areas but little is known about how these factors interact. This paper describes a study to measure the contribution of individual family factors and area characteristics in determining risk of accidental injury among preschool children. We conducted a population based study of preschool accident and emergency attendances over two years in and around the city of Norwich, UK. Information on individual families was extracted from the district child health information system while "social areas" were constructed from adjacent census enumeration districts with homogeneous social and demographic characteristics. Statistical analysis was by multilevel modelling. Accidental injury rates were much higher in deprived urban neighbourhoods than in affluent areas but the multilevel analysis showed that, for all accidents, much of the variation in rates was accounted for by factors at the individual level i.e. male sex, young maternal age, number of elder siblings and distance from hospital, with a smaller, but independent, influence of living in a deprived neighbourhood. The model for more severe injuries was similar except single parenthood was now significant at the level of individuals and the effect of area deprivation was stronger. We conclude that preschool accidental injuries are influenced by factors operating at both the level of individual families and between areas. This evidence suggests that both social policy changes to improve child care among unsupported young families and targeting accident prevention measures at a local level towards deprived neighbourhoods would reduce accidents. PMID:10077280

  5. Walking Perception by Walking Observers

    ERIC Educational Resources Information Center

    Jacobs, Alissa; Shiffrar, Maggie

    2005-01-01

    People frequently analyze the actions of other people for the purpose of action coordination. To understand whether such self-relative action perception differs from other-relative action perception, the authors had observers either compare their own walking speed with that of a point-light walker or compare the walking speeds of 2 point-light…

  6. A comparison study of local dynamic stability measures of daily life walking in older adult community-dwelling fallers and non-fallers.

    PubMed

    Ihlen, Espen A F; Weiss, Aner; Beck, Yoav; Helbostad, Jorunn L; Hausdorff, Jeffrey M

    2016-06-14

    In the present study we compared the performance of three different estimations of local dynamic stability λ to distinguish between the dynamics of the daily-life walking of elderly fallers and non-fallers. The study re-analyses inertial sensor data of 3-days daily-life activity originally described by Weiss et al. (2013). The data set contains inertial sensor data from 39 older persons who reported less than 2 falls and 31 older persons who reported two or more falls the previous year. 3D-acceleration and 3D-velocity signals from walking epochs of 50s were used to reconstruct a state space using three different methods. Local dynamic stability was estimated with the algorithms proposed by Rosenstein et al. (1993), Kantz (1994), and Ihlen et al. (2012a). Median λs assessed by Ihlen׳s and Kantz׳ algorithms discriminated better between elderly fallers and non-fallers (highest AUC=0.75 and 0.73) than Rosenstein׳s algorithm (highest AUC=0.59). The present results suggest that the ability of λ to distinguish between fallers and non-fallers is dependent on the parameter setting of the chosen algorithm. Further replication in larger samples of community-dwelling older persons and different patient groups is necessary before including the suggested parameter settings in fall risk assessment and prediction models. PMID:27040389

  7. Deterministic Walks with Choice

    SciTech Connect

    Beeler, Katy E.; Berenhaut, Kenneth S.; Cooper, Joshua N.; Hunter, Meagan N.; Barr, Peter S.

    2014-01-10

    This paper studies deterministic movement over toroidal grids, integrating local information, bounded memory and choice at individual nodes. The research is motivated by recent work on deterministic random walks, and applications in multi-agent systems. Several results regarding passing tokens through toroidal grids are discussed, as well as some open questions.

  8. Neighbourhood vitality and physical activity among the elderly: The role of walkable environments on active ageing in Barcelona, Spain.

    PubMed

    Marquet, Oriol; Miralles-Guasch, Carme

    2015-06-01

    This study investigated whether neighbourhood vitality and walkability were associated with active ageing of the elderly. Immobility, activity engagement and physical activity were explored in relation with age, gender and walkability of the built environment. Number of trips per day and minutes spent on walking by the elderly were extracted from a broad travel survey with more than 12,000 CATI interviews and were compared across vital and non-vital urban environments. Results highlight the importance of vital environments for elderly active mobility as subpopulations residing in highly walkable neighbourhoods undertook more trips and spent more minutes walking than their counterparts. The results also suggest that the built environment has different effects in terms of gender, as elderly men were more susceptible to urban vitality than elderly women. PMID:25939073

  9. Sense of community and its relationship with walking and neighborhood design.

    PubMed

    Wood, Lisa; Frank, Lawrence D; Giles-Corti, Billie

    2010-05-01

    The aim of this study is to examine the association between sense of community, walking, and neighborhood design characteristics. The current study is based on a sub-sample of participants (n=609) from the US Atlanta SMARTRAQ study who completed a telephone survey capturing physical activity patterns, neighborhood perceptions, and social interactions. Objective measures of neighborhood form were also computed. Univariate and multivariate models (General Linear Models (GLM)) were used to examine the association between sense of community (SofC) and aspects of the built environment, physical activity, and neighborhood perceptions. In multivariate models the impact on SofC was examined with progressive adjustment for demographics characteristics followed by walking behavior, neighborhood design features, neighborhood perceptions and time spent traveling in a car. After adjustment, SofC was positively associated with leisurely walking (days/week), home ownership, seeing neighbors when walking and the presence of interesting sites. SofC was also associated with higher commercial floor space to land area ratios (FAR) - a proxy for walkable site design that captures the degree to which retail destinations are set back from the street, the amount of surface parking, and urban design of an area. Conversely the presence of more mixed use and perceptions of steep hills were inversely associated with SofC. SofC is enhanced by living in areas that encourage leisurely walking, hence it is associated with living in neighbourhoods with lower levels of land use mix, but higher levels of commercial FAR. Our results suggest that in terms of SofC, the presence of commercial destinations may inhibit social interaction among local residents unless urban design is used to create convivial pedestrian-friendly commercial areas, e.g., providing street frontage, rather than flat surface parking. This finding has policy implications and warrants further investigation. PMID:20189699

  10. Geodemographics as a tool for targeting neighbourhoods in public health campaigns

    NASA Astrophysics Data System (ADS)

    Petersen, Jakob; Gibin, Maurizio; Longley, Paul; Mateos, Pablo; Atkinson, Philip; Ashby, David

    2011-06-01

    Geodemographics offers the prospects of integrating, modelling and mapping health care needs and other health indicators that are useful for targeting neighbourhoods in public health campaigns. Yet reports about this application domain has to date been sporadic. The purpose of this paper is to examine the potential of a bespoke geodemographic system for neighbourhood targeting in an inner city public health authority, Southwark Primary Care Trust, London. This system, the London Output Area Classification (LOAC), is compared to six other geodemographic systems from both governmental and commercial sources. The paper proposes two new indicators for assessing the performance of geodemographic systems for neighbourhood targeting based on local hospital demand data. The paper also analyses and discusses the utility of age- and sex standardisation of geodemographic profiles of health care demand.

  11. Block observations of neighbourhood physical disorder are associated with neighbourhood crime, firearm injuries and deaths, and teen births

    PubMed Central

    Wei, E.; Hipwell, A.; Pardini, D.; Beyers, J.; Loeber, R.

    2005-01-01

    Study objective: To provide reliability information for a brief observational measure of physical disorder and determine its relation with neighbourhood level crime and health variables after controlling for census based measures of concentrated poverty and minority concentration. Design: Psychometric analysis of block observation data comprising a brief measure of neighbourhood physical disorder, and cross sectional analysis of neighbourhood physical disorder, neighbourhood crime and birth statistics, and neighbourhood level poverty and minority concentration. Setting: Pittsburgh, Pennsylvania, US (2000 population = 334 563). Participants: Pittsburgh neighbourhoods (n = 82) and their residents (as reflected in neighbourhood level statistics). Main results: The physical disorder index showed adequate reliability and validity and was associated significantly with rates of crime, firearm injuries and homicides, and teen births, while controlling for concentrated poverty and minority population. Conclusions: This brief measure of neighbourhood physical disorder may help increase our understanding of how community level factors reflect health and crime outcomes. PMID:16166368

  12. Children's Perspectives on Disorder and Violence in Urban Neighbourhoods

    ERIC Educational Resources Information Center

    de Carvalho, Maria Joao Leote

    2013-01-01

    Based on the analysis of 312 children's neighbourhood drawings and narratives, this article discusses children's socialization in six public housing neighbourhoods in Portugal, through children's personal accounts of their lives. It then examines their perspectives on disorder and violence. Most complained about living in their neighbourhoods,…

  13. Reading Beyond School: Literacies in a Neighbourhood Library

    ERIC Educational Resources Information Center

    Ward, Angela; Wason-Ellam, Linda

    2005-01-01

    This ethnographic study describes family and community literacy practices in a neighbourhood public library. As an intercultural research team, we observed patterns of library use and held extended conversations with librarians and neighbourhood parents about literacy activities in the library. The neighbourhood public library was a hub of…

  14. Acknowledging Ambivalence in a Multicultural Neighbourhood: In Search of an Educational Space in Narrative Practices

    ERIC Educational Resources Information Center

    Roets, Griet; Vandenabeele, Joke; Bouverne-De Bie, Maria

    2012-01-01

    In this article, we focus on narrative practices in adult education in Flanders (the Dutch-speaking part of Belgium), and reflect on a current project in a multicultural neighbourhood that is socially and economically marked by poverty and where turbulence and conflict are rife amongst local inhabitants. While adult education aims to energize the…

  15. Quantum random walks without walking

    SciTech Connect

    Manouchehri, K.; Wang, J. B.

    2009-12-15

    Quantum random walks have received much interest due to their nonintuitive dynamics, which may hold the key to a new generation of quantum algorithms. What remains a major challenge is a physical realization that is experimentally viable and not limited to special connectivity criteria. We present a scheme for walking on arbitrarily complex graphs, which can be realized using a variety of quantum systems such as a Bose-Einstein condensate trapped inside an optical lattice. This scheme is particularly elegant since the walker is not required to physically step between the nodes; only flipping coins is sufficient.

  16. Neighbourhood Book Exchanges: Localising Information Practices

    ERIC Educational Resources Information Center

    Webster, Tenny; Gollner, Kathleen; Nathan, Lisa

    2015-01-01

    Introduction: Through this paper we report on an exploratory study into the design and use of neighbourhood book exchanges in North America. We identify dominant media framings of these book exchanges in North America, along with claims made concerning the influence of the exchanges. We compare the media claims with insights from interviews with…

  17. Visualization of neighbourhoods in some FK spaces

    NASA Astrophysics Data System (ADS)

    Veličković, Vesna; Malkowsky, Eberhard

    2015-09-01

    In this extended abstract, we present the graphical representations of some neighbourhoods in certain FK spaces that have recently been studied. These visualizations strongly support the understanding of the topological and geometric structures of the spaces. We emphasize that the graphics in this paper were created by our own software package and its extensions [1-4].

  18. Comparing the capitalisation benefits of light-rail transit and overlay zoning for single-family houses and condos by neighbourhood type in metropolitan Phoenix, Arizona.

    PubMed

    Atkinson-Palombo, Carol

    2010-01-01

    Light rail transit (LRT) is increasingly accompanied by overlay zoning which specifies the density and type of future development to encourage landscapes conducive to transit use. Neighbourhood type (based on land use mix) is used to partition data and investigate how pre-existing land use, treatment with a park-and-ride (PAR) versus walk-and-ride (WAR) station and overlay zoning interrelate. Hedonic models estimate capitalisation effects of LRT-related accessibility and overlay zoning on single-family houses and condos in different neighbourhoods for the system in metropolitan Phoenix, Arizona. Impacts differ by housing and neighbourhood type. Amenity-dominated mixed-use neighbourhoods-predominantly WAR communities-experience premiums of 6 per cent for single-family houses and over 20 per cent for condos, the latter boosted an additional 37 per cent by overlay zoning. Residential neighbourhoods-predominantly PAR communities-experience no capitalisation benefits for single-family houses and a discount for condos. The results suggest that land use mix is an important variable to select comparable neighbourhoods. PMID:20857563

  19. Environmental perceptions as mediators of the relationship between the objective built environment and walking among socio-economically disadvantaged women

    PubMed Central

    2013-01-01

    Background Women living in socio-economically disadvantaged neighbourhoods are at increased risk for physical inactivity and associated health outcomes and are difficult to reach through personally tailored interventions. Targeting the built environment may be an effective strategy in this population subgroup. The aim of this study was to examine the mediating role of environmental perceptions in the relationship between the objective environment and walking for transportation/recreation among women from socio-economically disadvantaged neighbourhoods. Methods Baseline data of the Resilience for Eating and Activity Despite Inequality (READI) study were used. In total, 4139 women (18–46 years) completed a postal survey assessing physical environmental perceptions (aesthetics, neighbourhood physical activity environment, personal safety, neighbourhood social cohesion), physical activity, and socio-demographics. Objectively-assessed data on street connectivity and density of destinations were collected using a Geographic Information System database and based on the objective z-scores, an objective destinations/connectivity score was calculated. This index was positively scored, with higher scores representing a more favourable environment. Two-level mixed models regression analyses were conducted and the MacKinnon product-of-coefficients test was used to examine the mediating effects. Results The destinations/connectivity score was positively associated with transport-related walking. The perceived physical activity environment mediated 6.1% of this positive association. The destinations/connectivity score was negatively associated with leisure-time walking. Negative perceptions of aesthetics, personal safety and social cohesion of the neighbourhood jointly mediated 24.1% of this negative association. Conclusion For women living in socio-economically disadvantaged neighbourhoods, environmental perceptions were important mediators of the relationship between the

  20. Neighbourhood Factors and Depression among Adolescents in Four Caribbean Countries

    PubMed Central

    Gibson, Roger C.; Halliday, Sharon; Morris, Amrie; Clarke, Nelson; Wilson, Rosemarie N.

    2014-01-01

    Background Past research suggests that perceived neighbourhood conditions may influence adolescents' emotional health. Relatively little research has been conducted examining the association of perceived neighbourhood conditions with depressive symptoms among Caribbean adolescents. This project examines the association of perceived neighbourhood conditions with levels of depressive symptoms among adolescents in Jamaica, the Bahamas, St. Kitts and Nevis, and St. Vincent. Methods Adolescents attending grade ten of the academic year 2006/2007 in Jamaica, the Bahamas, St. Vincent, and St. Kitts and Nevis were administered the Neighbourhood Characteristics Questionnaire along with the BDI-II. Social cohesion, attachment to the neighbourhood, neighbourhood quality, neighbourhood crime, and neighbourhood disorder scales were created by summing the relevant subscales of the Neighbourhood Characteristics Questionnaire. Multiple regression analyses were used to examine the relationships of perceived neighbourhood conditions to depressive symptoms. Results A wide cross-section of tenth grade students in each nation was sampled (n = 1955; 278 from Jamaica, 217 from the Bahamas, 737 St. Kitts and Nevis, 716 from St. Vincent; 52.1% females, 45.6% males and 2.3% no gender reported; 12 to 19 years, mean = 15.3 yrs, sd = .95 yr). Nearly half (52.1%) of all adolescents reported mild to severe symptoms of depression with 29.1% reporting moderate to severe symptoms of depression. Overall, Jamaican adolescents perceived their neighbourhoods in a more positive manner than those in the Bahamas, St. Vincent and St. Kitts and Nevis. Results of a series of hierarchical multiple regression analyses suggested that a different pattern of neighbourhood factors for each island were associated with depressive symptoms. However, neighbourhood factors were more highly associated with depressive symptoms for Jamaican students than for students in the other three islands. Conclusions

  1. Associations between neighbourhood environmental characteristics and obesity and related behaviours among adult New Zealanders

    PubMed Central

    2014-01-01

    Background The prevalence of adult obesity is escalating in most wealthy and middle income countries. Due to the magnitude of this issue, research and interventions at the individual-level abound. However, the limited success and high costs of such interventions has led to a growing recognition of the potential role of environmental factors in reducing obesity and promoting physical activity and healthy diets. Methods This study utilised individual-level data from the 2006/7 New Zealand Health Survey on obesity, physical activity, diet and socio-economic variables linked to geographic information from other sources on potentially aetiologically-relevant environmental factors, based on the respondent’s residential address. We fitted logistic regression models for eight binary measures of weight or weight-related behaviours: 1) overweight; 2) obesity; 3) overweight + obesity; 4) active at least 30 minutes a day for 5+ days per week; 5) active <30 minutes per week; 6) walk 150 minutes + per week; 7) walk <30 minutes per week; and 8) consumption of 5+ fruits and vegetables per day. We included a range of independent environmental characteristics of interest in separate models. Results We found that increased neighbourhood deprivation and decreased access to neighbourhood greenspace were both significantly associated with increased odds of overweight and/or obesity. The results for weight-related behaviours indicate that meeting the recommended level of physical activity per week was associated with urban/rural status, with higher activity in the more rural areas and a surprising tendency for less activity among those living in areas with higher levels of active travel to work. Increased access to greenspace was associated with high levels of walking, while decreased access to greenspace was associated with low levels of walking. There was also a significant trend for low levels of walking to be positively associated with neighbourhood deprivation. Results

  2. Creation of synthetic homogeneous neighbourhoods using zone design algorithms to explore relationships between asthma and deprivation in Strasbourg, France.

    PubMed

    Sabel, C E; Kihal, W; Bard, D; Weber, C

    2013-08-01

    The concept of 'neighbourhood' as a unit of analysis has received considerable research attention over the last decade. Many of these studies raise the question of the influence of local characteristics on variations in health and more recently, researchers have sought to understand how the neighbourhood can influence individual health through individual behaviour. Relatively few studies discuss the question of the borders and definition of a neighbourhood but we know that the results from health or population datasets are very sensitive to how zones are constructed - part of the Modifiable Areal Unit Problem (MAUP). In reality, we know that neighbourhoods are not constrained by artificial statistical boundaries, but rather exist as complex multi-dimensional living communities. This paper tries to better represent the reality on the ground of these communities to better inform studies of health. In this work, we have developed an experimental approach for the automated design of neighbourhoods using a small tessellated cell as a basic building block. Using the software AZTool, we considered population, shape and homogeneity constraints to develop a highly innovative approach to zone construction. The paper reports the challenges and compromises involved in building these new synthetic neighbourhoods. We provide a fully worked example of how our new synthetic homogeneous zones perform using data from Strasbourg, France. We examine data on Asthma reported through calls to the emergency services, and compare these rates with an index of multiple deprivation (NDI) which we have constructed and reported elsewhere. Higher correlations between Asthma and NDI were found using our newly constructed synthetic zones than using the existing French census areas of similar size. The significance of our work is that we show that careful construction of neighbourhoods - which we claim are more realistic than census areas - can greatly aid unpacking our understanding of

  3. Measuring food availability and accessibility among adolescents: Moving beyond the neighbourhood boundary.

    PubMed

    Shearer, Cindy; Rainham, Daniel; Blanchard, Chris; Dummer, Trevor; Lyons, Renee; Kirk, Sara

    2015-05-01

    Geographic methods have provided insight about food location availability and accessibility in understanding neighbourhood variations in health. However, quantifying exposure to food locations within a pre-defined range of an individual's residence ignores locations outside of the residential neighbourhood encountered in daily life. Global positioning system (GPS) data enables exploration of multiple contextual influences on health. This study defines place in relation to behaviour, employing GPS data to 1) describe adolescent food environments within and outside of the residential buffer, 2) quantify actual food location visits, and 3) explore associations between availability and accessibility of food locations and dietary intake. Adolescents (N = 380; ages 12-16), wore GPS loggers for up to seven days. Availability and accessibility of food locations were defined by counts and distances to food locations within a 15-min walk (1 km) of home, as well as within 50 m of an adolescent's GPS track. We compared the proportion of food locations within the residential buffer to the proportion outside but within the GPS buffer. These proportions were compared to counts and distances to food locations actually visited. We explored associations between food location availability and accessibility with dietary intake variables. Food location availability and accessibility was greater and visits occurred more commonly outside of the residential buffer than within it. Food location availability and accessibility was greater for urban than suburban and rural adolescents. There were no associations between home-based measures of availability and accessibility and dietary intake and only one for GPS-based measures, with greater distance to convenience stores associated with greater fruit and vegetable consumption. This study provides important descriptive information about adolescent exposure to food locations. Findings confirm that traditional home-based approaches

  4. Crossover between the extended and localized regimes in stochastic partially self-avoiding walks in one-dimensional disordered systems.

    PubMed

    Berbert, Juliana Militão; Martinez, Alexandre Souto

    2010-06-01

    Consider N sites randomly and uniformly distributed in a d-dimensional hypercube. A walker explores this disordered medium going to the nearest site, which has not been visited in the last μ (memory) steps. The walker trajectory is composed of a transient part and a periodic part (cycle). For one-dimensional systems, travelers can or cannot explore all available space, giving rise to a crossover between localized and extended regimes at the critical memory μ1=log2 N. The deterministic rule can be softened to consider more realistic situations with the inclusion of a stochastic parameter T (temperature). In this case, the walker movement is driven by a probability density function parameterized by T and a cost function. The cost function increases as the distance between two sites and favors hops to closer sites. As the temperature increases, the walker can escape from cycles that are reminiscent of the deterministic nature and extend the exploration. Here, we report an analytical model and numerical studies of the influence of the temperature and the critical memory in the exploration of one-dimensional disordered systems. PMID:20866398

  5. Quantum snake walk on graphs

    SciTech Connect

    Rosmanis, Ansis

    2011-02-15

    I introduce a continuous-time quantum walk on graphs called the quantum snake walk, the basis states of which are fixed-length paths (snakes) in the underlying graph. First, I analyze the quantum snake walk on the line, and I show that, even though most states stay localized throughout the evolution, there are specific states that most likely move on the line as wave packets with momentum inversely proportional to the length of the snake. Next, I discuss how an algorithm based on the quantum snake walk might potentially be able to solve an extended version of the glued trees problem, which asks to find a path connecting both roots of the glued trees graph. To the best of my knowledge, no efficient quantum algorithm solving this problem is known yet.

  6. The French eco-neighbourhood evaluation model: Contributions to sustainable city making and to the evolution of urban practices.

    PubMed

    Chastenet, Cédissia About-de; Belziti, Daniela; Bessis, Bruno; Faucheux, Franck; Le Sceller, Thibaut; Monaco, François-Xavier; Pech, Pierre

    2016-07-01

    In this article we discuss whether the French eco-neighbourhood policy tool may be considered as an original experimentation in sustainable urban planning. From scientific literature across a number of countries and especially in European context, we present what kind of policies may achieve eco-neighbourhoods. Then we present what the French framework is, and what tools to promote and elaborate eco-neighbourhoods there are in France. Thirdly, in fact, both French policies, national and local, concerning eco-neighbourhood projects, seem to integrate means of assessing urban projects and this assessment achieves a kind of certification. While the Ministry in charge of Urban Planning has developed the national EcoQuartier ("EcoNeighbourhood" in English) certification, the City of Paris and other local authorities have designed similar tools, which integrate a large number of parameters dealing with urban sustainability and which are designed to evolve over time. Finally, we discuss whether the French tool is really original and whether it prefigures new practices in the field of sustainable urban development. PMID:27039366

  7. Cosmography of OB stars in the solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Bouy, H.; Alves, J.

    2015-12-01

    We construct a 3D map of the spatial density of OB stars within 500 pc from the Sun using the Hipparcos catalogue and find three large-scale stream-like structures that allow a new view on the solar neighbourhood. The spatial coherence of these blue streams and the monotonic age sequence over hundreds of parsecs suggest that they are made of young stars, similar to the young streams that are conspicuous in nearby spiral galaxies. The three streams are 1) the Scorpius to Canis Majoris stream, covering 350 pc and 65 Myr of star formation history; 2) the Vela stream, encompassing at least 150 pc and 25 Myr of star formation history; and 3) the Orion stream, including not only the well-known Orion OB1abcd associations, but also a large previously unreported foreground stellar group lying only 200 pc from the Sun. The map also reveals a remarkable and previously unknown nearby OB association, between the Orion stream and the Taurus molecular clouds, which might be responsible for the observed structure and star formation activity in this cloud complex. This new association also appears to be the birthplace of Betelgeuse, as indicated by the proximity and velocity of the red giant. If this is confirmed, it would solve the long-standing puzzle of the origin of Betelgeuse. The well-known nearby star-forming low-mass clouds, including the nearby T and R associations Lupus, Cha, Oph, CrA, Taurus, Vela R1, and various low-mass cometary clouds in Vela and Orion, appear in this new view of the local neighbourhood to be secondary star formation episodes that most likely were triggered by the feedback from the massive stars in the streams. We also recover well-known star clusters of various ages that are currently cruising through the solar neighbourhood. Finally, we find no evidence of an elliptical structure such as the Gould belt, a structure we suggest is a 2D projection effect, and not a physical ring. Table 3 is available in elctronic form at http://www.aanda.org

  8. Neighbourhood density and genetic relatedness interact to determine fruit set and abortion rates in a continuous tropical tree population

    PubMed Central

    Jones, F.A; Comita, L.S

    2008-01-01

    Tropical trees may show positive density dependence in fruit set and maturation due to pollen limitation in low-density populations. However, pollen from closely related individuals in the local neighbourhood might reduce fruit set or increase fruit abortion in self-incompatible tree species. We investigated the role of neighbourhood density and genetic relatedness on individual fruit set and abortion in the neotropical tree Jacaranda copaia in a large forest plot in central Panama. Using nested neighbourhood models, we found a strong positive effect of increased conspecific density on fruit set and maturation. However, high neighbourhood genetic relatedness interacted with density to reduce total fruit set and increase the proportion of aborted fruit. Our results imply a fitness advantage for individuals growing in high densities as measured by fruit set, but realized fruit set is lowered by increased neighbourhood relatedness. We hypothesize that the mechanism involved is increased visitation by density-dependent invertebrate pollinators in high-density populations, which increases pollen quantity and carry-over and increases fruit set and maturation, coupled with self-incompatibility at early and late stages due to biparental inbreeding that lowers fruit set and increases fruit abortion. Implications for the reproductive ecology and conservation of tropical tree communities in continuous and fragmented habitats are discussed. PMID:18713714

  9. Dangerous Encounters? Boys' Peer Dynamics and Neighbourhood Risk

    ERIC Educational Resources Information Center

    Parkes, Jenny; Conolly, Anna

    2013-01-01

    This article traces links between subjectivity, peer relations and neighbourhood risk for a group of boys living in an area of London with high levels of crime, gang activity and socio-economic inequality. Drawing on data from a qualitative study of young people and neighbourhood risk, we use a psycho-social approach to analyse how gendered…

  10. Complementarity and quantum walks

    SciTech Connect

    Kendon, Viv; Sanders, Barry C.

    2005-02-01

    We show that quantum walks interpolate between a coherent 'wave walk' and a random walk depending on how strongly the walker's coin state is measured; i.e., the quantum walk exhibits the quintessentially quantum property of complementarity, which is manifested as a tradeoff between knowledge of which path the walker takes vs the sharpness of the interference pattern. A physical implementation of a quantum walk (the quantum quincunx) should thus have an identifiable walker and the capacity to demonstrate the interpolation between wave walk and random walk depending on the strength of measurement.

  11. Neighbourhood reaction in the evolution of cooperation.

    PubMed

    Yang, Guoli; Zhang, Weiming; Xiu, Baoxin

    2015-05-01

    Combining evolutionary games with adaptive networks, an entangled model between strategy evolution and structure adaptation is researched in this paper. We consider a large population of cooperators C and defectors D placed in the networks, playing the repeated prisoner׳s dilemma (PD) games. Because of the conflicts between social welfare and personal rationality, both strategy and structure are allowed to change. In this paper, the dynamics of strategy originates form the partner imitation based on social learning and the dynamics of structure is driven by the active linking and neighbourhood reaction. Notably, the neighbourhood reaction is investigated considering the changes of interfaces between cooperators and defectors, where some neighbours may get away from the interface once the focal agent changes to different strategy. A rich landscape is demonstrated by changing various embedding parameters, which sheds light upon that reacting promptly to the shifted neighbour will promote the prevalence of cooperation. Our model encapsulates the dynamics of strategy, reaction and structure into the evolutionary games, which manifests some intriguing principles in the competition between two groups in natural populations, artificial systems and even human societies. PMID:25746844

  12. Fire-walking

    NASA Astrophysics Data System (ADS)

    Willey, David

    2010-09-01

    This article gives a brief history of fire-walking and then deals with the physics behind fire-walking. The author has performed approximately 50 fire-walks, took the data for the world's hottest fire-walk and was, at one time, a world record holder for the longest fire-walk (www.dwilley.com/HDATLTW/Record_Making_Firewalks.html). He currently teaches Physics for the University of Pittsburgh at Johnstown, USA.

  13. Fire-Walking

    ERIC Educational Resources Information Center

    Willey, David

    2010-01-01

    This article gives a brief history of fire-walking and then deals with the physics behind fire-walking. The author has performed approximately 50 fire-walks, took the data for the world's hottest fire-walk and was, at one time, a world record holder for the longest fire-walk (www.dwilley.com/HDATLTW/Record_Making_Firewalks.html). He currently…

  14. Qualitative developmental research among low income African American adults to inform a social marketing campaign for walking

    PubMed Central

    2013-01-01

    Background This study describes the development of a social marketing campaign for increasing walking in a low income, high crime community as part of the Positive Action for Today’s Health (PATH) trial. Methods Focus groups were conducted with 52 African American adults (ages 18 to 65 yrs), from two underserved communities to develop themes for a social marketing campaign to promote walking. Participants responded to questions concerning social marketing principles related to product, price, place, promotion, and positioning for increasing neighbourhood walking. Results Focus group data informed the development of the campaign objectives that were derived from the “5 Ps” to promote physical and mental health, social connectedness, safety, and confidence in walking regularly. Focus group themes indicated that physical and mental health benefits of walking were important motivators. Walking for social reasons was also important for overcoming barriers to walking. Police support from trusted officers while walking was also essential to promoting safety for walking. Print materials were developed by the steering committee, with a 12-month calendar and door hangers delivered to residents’ homes to invite them to walk. Pride Stride walks empowered community walkers to serve as peer leaders for special walking events to engage new walkers. Conclusions Essential elements for developing culturally tailored social marketing interventions for promoting walking in underserved communities are outlined for future researchers. PMID:23497164

  15. On the relevance of chaos for halo stars in the solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Maffione, N. P.; Gómez, F. A.; Cincotta, P. M.; Giordano, C. M.; Cooper, A. P.; O'Shea, B. W.

    2015-11-01

    We show that diffusion due to chaotic mixing in the neighbourhood of the Sun may not be as relevant as previously suggested in erasing phase space signatures of past Galactic accretion events. For this purpose, we analyse solar neighbourhood-like volumes extracted from cosmological simulations that naturally account for chaotic orbital behaviour induced by the strongly triaxial and cuspy shape of the resulting dark matter haloes, among other factors. In the approximation of an analytical static triaxial model, our results show that a large fraction of stellar halo particles in such local volumes have chaos onset times (i.e. the time-scale at which stars commonly associated with chaotic orbits will exhibit their chaotic behaviour) significantly larger than a Hubble time. Furthermore, particles that do present a chaotic behaviour within a Hubble time do not exhibit significant diffusion in phase space.

  16. Neighbourhood socioeconomic inequalities in food access and affordability.

    PubMed

    Ball, Kylie; Timperio, Anna; Crawford, David

    2009-06-01

    This study investigated whether the availability and accessibility of supermarkets and fruit and vegetable stores, and the availability, variety and price of foods within these stores, varied across areas of different levels of socioeconomic disadvantage in Melbourne, Australia. Data on food store locations, and food variety and price within stores were obtained through objective audits of 45 neighbourhoods of varying socioeconomic disadvantage. Geographical accessibility of healthy food stores was mostly better amongst those living in more advantaged neighbourhoods. Availability of healthy foods within stores only slightly favoured those in advantaged neighbourhoods. However food prices favoured those living in disadvantaged areas. PMID:19046654

  17. How important is the land use mix measure in understanding walking behaviour? Results from the RESIDE study

    PubMed Central

    2011-01-01

    Background Understanding the relationship between urban design and physical activity is a high priority. Different representations of land use diversity may impact the association between neighbourhood design and specific walking behaviours. This study examined different entropy based computations of land use mix (LUM) used in the development of walkability indices (WIs) and their association with walking behaviour. Methods Participants in the RESIDential Environments project (RESIDE) self-reported mins/week of recreational, transport and total walking using the Neighbourhood Physical Activity Questionnaire (n = 1798). Land use categories were incrementally added to test five different LUM models to identify the strongest associations with recreational, transport and total walking. Logistic regression was used to analyse associations between WIs and walking behaviour using three cut points: any (> 0 mins), ≥ 60 mins and ≥ 150 mins walking/week. Results Participants in high (vs. low) walkable neighbourhoods reported up to almost twice the amount of walking, irrespective of the LUM measure used. However, different computations of LUM were found to be relevant for different types and amounts of walking (i.e., > 0, ≥ 60 or ≥ 150 mins/week). Transport walking (≥ 60 mins/week) had the strongest and most significant association (OR = 2.24; 95% CI:1.58-3.18) with the WI when the LUM included 'residential', 'retail', 'office', 'health, welfare and community', and 'entertainment, culture and recreation'. However, any (> 0 mins/week) recreational walking was more strongly associated with the WI (OR = 1.36; 95% CI:1.04-1.78) when land use categories included 'public open space', 'sporting infrastructure' and 'primary and rural' land uses. The observed associations were generally stronger for ≥ 60 mins/week compared with > 0 mins/week of transport walking and total walking but this relationship was not seen for recreational walking. Conclusions Varying the

  18. Theorising and testing environmental pathways to behaviour change: natural experimental study of the perception and use of new infrastructure to promote walking and cycling in local communities

    PubMed Central

    Panter, Jenna; Ogilvie, David

    2015-01-01

    Objective Some studies have assessed the effectiveness of environmental interventions to promote physical activity, but few have examined how such interventions work. We investigated the environmental mechanisms linking an infrastructural intervention with behaviour change. Design Natural experimental study. Setting Three UK municipalities (Southampton, Cardiff and Kenilworth). Participants Adults living within 5 km of new walking and cycling infrastructure. Intervention Construction or improvement of walking and cycling routes. Exposure to the intervention was defined in terms of residential proximity. Outcome measures Questionnaires at baseline and 2-year follow-up assessed perceptions of the supportiveness of the environment, use of the new infrastructure, and walking and cycling behaviours. Analysis proceeded via factor analysis of perceptions of the physical environment (step 1) and regression analysis to identify plausible pathways involving physical and social environmental mediators and refine the intervention theory (step 2) to a final path analysis to test the model (step 3). Results Participants who lived near and used the new routes reported improvements in their perceptions of provision and safety. However, path analysis (step 3, n=967) showed that the effects of the intervention on changes in time spent walking and cycling were largely (90%) explained by a simple causal pathway involving use of the new routes, and other pathways involving changes in environmental cognitions explained only a small proportion of the effect. Conclusions Physical improvement of the environment itself was the key to the effectiveness of the intervention, and seeking to change people's perceptions may be of limited value. Studies of how interventions lead to population behaviour change should complement those concerned with estimating their effects in supporting valid causal inference. PMID:26338837

  19. DNF - Galaxy photometric redshift by Directional Neighbourhood Fitting

    NASA Astrophysics Data System (ADS)

    De Vicente, J.; Sánchez, E.; Sevilla-Noarbe, I.

    2016-07-01

    Wide field images taken in several photometric bands allow simultaneous measurement of redshifts for thousands of galaxies. A variety of algorithms to make this measurement have appeared in the last few years, the majority of which can be classified as either template- or training-based methods. Among the latter, nearest neighbour estimators stand out as one of the most successful, in terms of both precision and the quality of error estimation. In this paper we describe the Directional Neighbourhood Fitting (DNF) algorithm based on the following: a new neighbourhood metric (Directional Neighbourhood), a photo-z estimation strategy (Neighbourhood Fitting) and a method for generating the photo-z probability distribution function. We compare DNF with other well-known empirical photometric redshift tools using different public data sets (Sloan Digital Sky Survey, VIMOS VLT Deep Survey and Photo-z Accuracy Testing). DNF achieves high-quality results with reliable error.

  20. Strongly trapped two-dimensional quantum walks

    NASA Astrophysics Data System (ADS)

    Kollár, B.; Kiss, T.; Jex, I.

    2015-02-01

    Discrete time quantum walks (DTQWs) are nontrivial generalizations of random walks with a broad scope of applications. In particular, they can be used as computational primitives, and they are suitable tools for simulating other quantum systems. DTQWs usually spread ballistically due to their quantumness. In some cases, however, they can remain localized at their initial state (trapping). The trapping and other fundamental properties of DTQWs are determined by the choice of the coin operator. We introduce and analyze a type of walks driven by a coin class leading to strong trapping, complementing the known list of walks. This class of walks exhibits a number of exciting properties with possible applications ranging from light pulse trapping in a medium to topological effects and quantum search.

  1. Quantum walk computation

    SciTech Connect

    Kendon, Viv

    2014-12-04

    Quantum versions of random walks have diverse applications that are motivating experimental implementations as well as theoretical studies. Recent results showing quantum walks are “universal for quantum computation” relate to algorithms, to be run on quantum computers. We consider whether an experimental implementation of a quantum walk could provide useful computation before we have a universal quantum computer.

  2. Walking Wellness. Student Workbook.

    ERIC Educational Resources Information Center

    Sweetgall, Robert; Neeves, Robert

    This comprehensive student text and workbook, for grades four through eight, contains 16 workshop units focusing on walking field trips, aerobic pacing concepts, walking techniques, nutrition, weight control and healthy life-style planning. Co-ordinated homework assignments are included. The appendixes include 10 tips for walking, a calorie chart,…

  3. Walk This Way

    ERIC Educational Resources Information Center

    Mason, Nick

    2007-01-01

    A generation ago, it was part of growing up for all kids when they biked or walked to school. But in the last 30 years, heavier traffic, wider roads and more dangerous intersections have made it riskier for students walking or pedaling. Today, fewer than 15 percent of kids bike or walk to school compared with more than 50 percent in 1969. In the…

  4. Neighbourhood social capital: measurement issues and associations with health outcomes.

    PubMed

    Mackenbach, J D; Lakerveld, J; van Lenthe, F J; Kawachi, I; McKee, M; Rutter, H; Glonti, K; Compernolle, S; De Bourdeaudhuij, I; Feuillet, T; Oppert, J-M; Nijpels, G; Brug, J

    2016-01-01

    We compared ecometric neighbourhood scores of social capital (contextual variation) to mean neighbourhood scores (individual and contextual variation), using several health-related outcomes (i.e. self-rated health, weight status and obesity-related behaviours). Data were analysed from 5,900 participants in the European SPOTLIGHT survey. Factor analysis of the 13-item social capital scale revealed two social capital constructs: social networks and social cohesion. The associations of ecometric and mean neighbourhood-level scores of these constructs with self-rated health, weight status and obesity-related behaviours were analysed using multilevel regression analyses, adjusted for key covariates. Analyses using ecometric and mean neighbourhood scores, but not mean neighbourhood scores adjusted for individual scores, yielded similar regression coefficients. Higher levels of social network and social cohesion were not only associated with better self-rated health, lower odds of obesity and higher fruit consumption, but also with prolonged sitting and less transport-related physical activity. Only associations with transport-related physical activity and sedentary behaviours were associated with mean neighbourhood scores adjusted for individual scores. As analyses using ecometric scores generated the same results as using mean neighbourhood scores, but different results when using mean neighbourhood scores adjusted for individual scores, this suggests that the theoretical advantage of the ecometric approach (i.e. teasing out individual and contextual variation) may not be achieved in practice. The different operationalisations of social network and social cohesion were associated with several health outcomes, but the constructs that appeared to represent the contextual variation best were only associated with two of the outcomes. PMID:26879117

  5. Evolution of interstellar dust and stardust in the solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Zhukovska, S.; Gail, H.-P.; Trieloff, M.

    2008-02-01

    Aims:We studied the evolution of the abundance in interstellar dust species that originate in stellar sources and from condensation in molecular clouds in the local interstellar medium of the Milky Way. We determined from this the input of dust material to the Solar System. Methods: A one-zone chemical evolution model of the Milky Way for the elemental composition of the disk combined with an evolution model for its interstellar dust component similar to that of Dwek (1998) is developed. The dust model considers dust-mass return from AGB stars as calculated from synthetic AGB models combined with models for dust condensation in stellar outflows. Supernova dust formation is included in a simple parametrised form that is gauged by observed abundances of presolar dust grains with a supernova origin. For dust growth in the ISM, a simple method is developed for coupling this with disk and dust evolution models. Results: A chemical evolution model of the solar neighbourhood in the Milky Way is calculated, which forms the basis for calculating a model of the evolution of the interstellar dust population at the galactocentric radius of the Milky Way. The model successfully passes all standard tests for the reliability of such models. In particular the abundance evolution of the important dust-forming elements is compared with observational results for the metallicity-dependent evolution of the abundances for G-type stars from the solar neighbourhood. It is found that the new tables of Nomoto et al. (2006) for the heavy element production give much better results for the abundance evolution of these important elements than the widely used tables of Woosley & Weaver (1995). The time evolution for the abundance of the following dust species is followed in the model: silicate, carbon, silicon carbide, and iron dust from AGB stars and from supernovae, as well as silicate, carbon, and iron dust grown in molecular clouds. It is shown that the interstellar dust population is

  6. Dynamical Streams in the Solar Neighbourhood

    NASA Astrophysics Data System (ADS)

    Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C.

    2005-01-01

    The true nature of the Hyades and Sirius superclusters is still an open question. In this contribution, we confront Eggen's hypothesis that they are cluster remnants with the results of a kinematic analysis of more than 6000 K and M giants in the solar neighbourhood. This analysis includes new radial velocity data from a large survey performed with the CORAVEL spectrometer, complemented by Hipparcos parallaxes and Tycho-2 proper motions (Famaey et al. 2004). A maximum-likelihood method, based on a bayesian approach, has been applied to the data, in order to make full use of all the available data (including less precise parallaxes) and to derive the properties of the different kinematic subgroups. Two such subgroups can be identified with the Hyades and Sirius superclusters. Stars belonging to them span a very wide range of age, which is difficult to account for in Eggen's scenario. These groups are thus most probably dynamical streams related to the dynamical perturbation by spiral waves rather than to cluster remnants. An explanation for the presence of young clusters in the same area of velocity-space is that they have been put there by the same wave. Indeed, the scale of a cluster is small in comparison to the scale of the perturbation of the potential linked with a spiral wave. The response of a cluster to a spiral wave is thus similar to the response of a single star. Thus, in this scenario, the Hyades and Ursa Major clusters just happen to be in the Hyades and Sirius streams, which are purely dynamical features that have nothing to do with the remnants of more massive primordial clusters. This mechanism could be the key to understanding the presence of an old metal-rich population, and of many exoplanetary systems in our neighbourhood. Moreover, a strong spiral pattern seems to be needed in order to yield such prominent streams. Since spiral structure is usually baryonic, this would leave very little room for dark matter. This may be an indication that the

  7. Resident Well-Being, Community Connections, and Neighbourhood Perceptions, Pride, and Opportunities among Disadvantage Metropolitan and Regional Communities: Evidence from the Neighbourhood Renewal Project

    ERIC Educational Resources Information Center

    Renzaho, Andre M. N.; Richardson, Ben; Strugnell, Claudia

    2012-01-01

    The current study aims investigate the relationship between participants' neighbourhood perceptions and social capital and resident well-being using data from the Neighbourhood Renewal Project (NRP; n = 7855). Resident well-being was positively associated with the quality of the physical environment and safety of the neighbourhood, but negatively…

  8. Health assets for adolescents: opinions from a neighbourhood in Spain.

    PubMed

    Pérez-Wilson, Patricia; Hernán, Mariano; Morgan, Antony R; Mena, Angel

    2015-09-01

    This study uses a health asset (HA) framework to explore current perspectives on health, wellbeing and their determinants amongst a group of 15-18-year-old adolescents living in the neighbourhood of Zaidin (Granada, Spain). The study was carried out in Summer 2011 using a qualitative approach. It included 20 semi-structured interviews, 2 focus groups with adolescents and 4 semi-structured interviews with key informants (adults who work with adolescents). Narrative data were analysed by means of content analysis methodology, considering the concept of health, HAs and how they are prioritized as dimensions for the analysis. The concept of health defined by adolescents involves physical, psychological and social dimensions. According to them, health is associated with happiness and quality of life. A range of HAs were identified and classified as internal (belonging to the adolescents) and external or contextual. Internal assets are classified into three types: personal traits (assets of 'being'), behaviour (assets of 'doing') and social resources which contribute to their feeling of health and well-being (assets of 'having'). The latter connects internal and external assets. The classification of HAs ('being', 'doing' and 'having') proposed in this study provides a useful starting framework of thinking about how these assets could be organized to support the development of health promotion programmes. The study highlights the opportunity for public policy to contribute to the improvement of the conditions and local scenarios that improve the possibilities for positive connections at the community level. PMID:24334370

  9. Quantifying the Fermi Paradox in the Local Solar Neighbourhood

    NASA Astrophysics Data System (ADS)

    Cartin, D.

    The Fermi paradox highlights the dichotomy between the lack of physical contact with other civilizations and the expectation that technological civilizations are assumed likely to evolve in many locations in the Milky Way galaxy, given the large number of planetary systems within this galaxy. Work by Landis and others has modeled this question in terms of percolation theory and cellular automata, using this method to parametrize our ignorance about possible other civilizations as a function of the probability of one system to colonize another, and the maximum number of systems reachable from each starting location (i.e. the degree in the network used for percolation). These models used a fixed lattice of sites to represent a stellar region, so the degree of all sites were identical. In this paper, the question is examined again, but instead of using a pre-determined lattice, the actual physical positions of all known star systems within 40 parsecs of the Solar System are used as percolation sites; in addition, the number of sites accessible for further colonization from a given system is determined by a choice of maximum distance such efforts can travel across. The resulting simulations show that extraterrestrial colonization efforts may reach the Solar System, but only for certain values of the maximum travel distance and probability of an occupied system further colonizing other systems. Indeed, large numbers of systems may be colonized with either vessels that lack insufficient travel distance to reach the Solar System or else have a colonization probability where they are statistically unlikely to reach us.

  10. Standardized observation of neighbourhood disorder: does it work in Canada?

    PubMed Central

    2010-01-01

    Background There is a growing body of evidence that where you live is important to your health. Despite numerous previous studies investigating the relationship between neighbourhood deprivation (and structure) and residents' health, the precise nature of this relationship remains unclear. Relatively few investigations have relied on direct observation of neighbourhoods, while those that have were developed primarily in US settings. Evaluation of the transferability of such tools to other contexts is an important first step before applying such instruments to the investigation of health and well-being. This study evaluated the performance of a systematic social observational (SSO) tool (adapted from previous studies of American and British neighbourhoods) in a Canadian urban context. Methods This was a mixed-methods study. Quantitative SSO ratings and qualitative descriptions of 176 block faces were obtained in six Toronto neighbourhoods (4 low-income, and 2 middle/high-income) by trained raters. Exploratory factor analysis was conducted with the quantitative SSO ratings. Content analysis consisted of independent coding of qualitative data by three members of the research team to yield common themes and categories. Results Factor analysis identified three factors (physical decay/disorder, social accessibility, recreational opportunities), but only 'physical decay/disorder' reflected previous findings in the literature. Qualitative results (based on raters' fieldwork experiences) revealed the tool's shortcomings in capturing important features of the neighbourhoods under study, and informed interpretation of the quantitative findings. Conclusions This study tested the performance of an SSO tool in a Canadian context, which is an important initial step before applying it to the study of health and disease. The tool demonstrated important shortcomings when applied to six diverse Toronto neighbourhoods. The study's analyses challenge previously held assumptions (e

  11. Walk Score®

    PubMed Central

    Brown, Scott C.; Pantin, Hilda; Lombard, Joanna; Toro, Matthew; Huang, Shi; Plater-Zyberk, Elizabeth; Perrino, Tatiana; Perez-Gomez, Gianna; Barrera-Allen, Lloyd; Szapocznik, José

    2013-01-01

    Background Walk Score® is a nationally and publicly available metric of neighborhood walkability based on proximity to amenities (e.g., retail, food, schools). However, few studies have examined the relationship of Walk Score to walking behavior. Purpose To examine the relationship of Walk Score to walking behavior in a sample of recent Cuban immigrants, who overwhelmingly report little choice in their selection of neighborhood built environments when they arrive in the U.S. Methods Participants were 391 recent healthy Cuban immigrants (M age=37.1 years) recruited within 90 days of arrival in the U.S., and assessed within 4 months of arrival (M=41.0 days in the U.S.), who resided throughout Miami-Dade County FL. Data on participants’ addresses, walking and sociodemographics were collected prospectively from 2008 to 2010. Analyses conducted in 2011 examined the relationship of Walk Score for each participant’s residential address in the U.S. to purposive walking, controlling for age, gender, education, BMI, days in the U.S., and habitual physical activity level in Cuba. Results For each 10-point increase in Walk Score, adjusting for covariates, there was a significant 19% increase in the likelihood of purposive walking, a 26% increase in the likelihood of meeting physical activity recommendations by walking, and 27% more minutes walked in the previous week. Conclusions Results suggest that Walk Score is associated with walking in a sample of recent immigrants who initially had little choice in where they lived in the U.S. These results support existing guidelines indicating that mixed land use (such as parks and restaurants near homes) should be included when designing walkable communities. PMID:23867028

  12. Effects of ‘Target’ Plant Species Body Size on Neighbourhood Species Richness and Composition in Old-Field Vegetation

    PubMed Central

    Schamp, Brandon S.; Aarssen, Lonnie W.; Wight, Stephanie

    2013-01-01

    Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with the fact that large and small plant species generally coexist, and relatively smaller species are more common in virtually all plant communities. Here, we use replicates of ten relatively large old-field plant species to explore the competitive impact of target individual size on their surrounding neighbourhoods compared to nearby neighbourhoods of the same size that are not centred by a large target individual. While target individuals of the largest of our test species, Centaurea jacea L., had a strong impact on neighbouring species, in general, target species size was a weak predictor of the number of other resident species growing within its immediate neighbourhood, as well as the number of resident species that were reproductive. Thus, the presence of a large competitor did not restrict the ability of neighbouring species to reproduce. Lastly, target species size did not have any impact on the species size structure of neighbouring species; i.e. they did not restrict smaller, supposedly poorer competitors, from growing and reproducing close by. Taken together, these results provide no support for a size-advantage in competition restricting local species richness or the ability of small species to coexist and successfully reproduce in the immediate neighbourhood of a large species. PMID:24349177

  13. A qualitative geographical information systems approach to explore how older people over 70 years interact with and define their neighbourhood environment

    PubMed Central

    Milton, Sarah; Pliakas, Triantafyllos; Hawkesworth, Sophie; Nanchahal, Kiran; Grundy, Chris; Amuzu, Antoinette; Casas, Juan-Pablo; Lock, Karen

    2015-01-01

    A growing body of literature explores the relationship between the built environment and health, and the methodological challenges of understanding these complex interactions across the lifecourse. The impact of the neighbourhood environment on health and behaviour amongst older adults has received less attention, despite this age group being potentially more vulnerable to barriers in their surrounding social and physical environment. A qualitative geographical information systems (QGIS) approach was taken to facilitate the understanding of how older people over 70 in 5 UK towns interact with their local neighbourhood. The concept of neighbourhood changed seasonally and over the lifecourse, and was associated with social factors such as friends, family, or community activities, rather than places. Spaces stretched further than the local, which is problematic for older people who rely on variable public transport provision. QGIS techniques prompted rich discussions on interactions with and the meanings of ‘place’ in older people. PMID:26513597

  14. A qualitative geographical information systems approach to explore how older people over 70 years interact with and define their neighbourhood environment.

    PubMed

    Milton, Sarah; Pliakas, Triantafyllos; Hawkesworth, Sophie; Nanchahal, Kiran; Grundy, Chris; Amuzu, Antoinette; Casas, Juan-Pablo; Lock, Karen

    2015-11-01

    A growing body of literature explores the relationship between the built environment and health, and the methodological challenges of understanding these complex interactions across the lifecourse. The impact of the neighbourhood environment on health and behaviour amongst older adults has received less attention, despite this age group being potentially more vulnerable to barriers in their surrounding social and physical environment. A qualitative geographical information systems (QGIS) approach was taken to facilitate the understanding of how older people over 70 in 5 UK towns interact with their local neighbourhood. The concept of neighbourhood changed seasonally and over the lifecourse, and was associated with social factors such as friends, family, or community activities, rather than places. Spaces stretched further than the local, which is problematic for older people who rely on variable public transport provision. QGIS techniques prompted rich discussions on interactions with and the meanings of 'place' in older people. PMID:26513597

  15. Constraining MOND using the vertical motion of stars in the solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Margalit, Ben; Shaviv, Nir J.

    2016-02-01

    Stars with a different vertical motion relative to the Galactic disc have a different average acceleration. According to modified Newtonian dynamics (MOND) theories, they should therefore have a different average orbital velocity while revolving around the Milky Way. We show that this property can be used to constrain MOND theories by studying stars in the local neighbourhood. With the Hipparcos (Perryman et al. 1997) data set we can only place marginal constraints. However, the forthcoming Gaia (Perryman et al. 2001) catalogue with its significantly fainter cutoff should allow placing a stringent constraint.

  16. Neighbourhood-scale urban forest ecosystem classification.

    PubMed

    Steenberg, James W N; Millward, Andrew A; Duinker, Peter N; Nowak, David J; Robinson, Pamela J

    2015-11-01

    Urban forests are now recognized as essential components of sustainable cities, but there remains uncertainty concerning how to stratify and classify urban landscapes into units of ecological significance at spatial scales appropriate for management. Ecosystem classification is an approach that entails quantifying the social and ecological processes that shape ecosystem conditions into logical and relatively homogeneous management units, making the potential for ecosystem-based decision support available to urban planners. The purpose of this study is to develop and propose a framework for urban forest ecosystem classification (UFEC). The multifactor framework integrates 12 ecosystem components that characterize the biophysical landscape, built environment, and human population. This framework is then applied at the neighbourhood scale in Toronto, Canada, using hierarchical cluster analysis. The analysis used 27 spatially-explicit variables to quantify the ecosystem components in Toronto. Twelve ecosystem classes were identified in this UFEC application. Across the ecosystem classes, tree canopy cover was positively related to economic wealth, especially income. However, education levels and homeownership were occasionally inconsistent with the expected positive relationship with canopy cover. Open green space and stocking had variable relationships with economic wealth and were more closely related to population density, building intensity, and land use. The UFEC can provide ecosystem-based information for greening initiatives, tree planting, and the maintenance of the existing canopy. Moreover, its use has the potential to inform the prioritization of limited municipal resources according to ecological conditions and to concerns of social equity in the access to nature and distribution of ecosystem service supply. PMID:26311086

  17. A brief conceptual tutorial on multilevel analysis in social epidemiology: interpreting neighbourhood differences and the effect of neighbourhood characteristics on individual health

    PubMed Central

    Merlo, J.; Chaix, B.; Yang, M.; Lynch, J.; Rastam, L.

    2005-01-01

    Study objective: Using a conceptual rather than a mathematical approach, this article proposed a link between multilevel regression analysis (MLRA) and social epidemiological concepts. It has been previously explained that the concept of clustering of individual health status within neighbourhoods is useful for operationalising contextual phenomena in social epidemiology. It has been shown that MLRA permits investigating neighbourhood disparities in health without considering any particular neighbourhood characteristic but only information on the neighbourhood to which each person belongs. This article illustrates how to analyse cross level (neighbourhood–individual) interactions, how to investigate associations between neighbourhood characteristics and individual health, and how to use the concept of clustering when interpreting those associations and geographical differences in health. Design and participants: A MLRA was performed using hypothetical data pertaining to systolic blood pressure (SBP) from 25 000 subjects living in the 39 neighbourhoods of an imaginary city. Associations between individual characteristics (age, body mass index (BMI), use of antihypertensive drug, income) or neighbourhood characteristic (neighbourhood income) and SBP were analysed. Results: About 8% of the individual differences in SBP were located at the neighbourhood level. SBP disparities and clustering of individual SBP within neighbourhoods increased along individual BMI. Neighbourhood low income was associated with increased SBP over and above the effect of individual characteristics, and explained 22% of the neighbourhood differences in SBP among people of normal BMI. This neighbourhood income effect was more intense in overweight people. Conclusions: Measures of variance are relevant to understanding geographical and individual disparities in health, and complement the information conveyed by measures of association between neighbourhood characteristics and health. PMID

  18. Neighbourhood environment, physical activity, quality of life and depressive symptoms in Hong Kong older adults: a protocol for an observational study

    PubMed Central

    Cerin, Ester; Sit, Cindy H P; Zhang, Casper J P; Barnett, Anthony; Cheung, Martin M C; Lai, Poh-chin; Johnston, Janice M; Lee, Ruby S Y

    2016-01-01

    Introduction The neighbourhood environment can assist the adoption and maintenance of an active lifestyle and affect the physical and mental well-being of older adults. The psychosocial and behavioural mechanisms through which the environment may affect physical and mental well-being are currently poorly understood. Aim This observational study aims to examine associations between the physical and social neighbourhood environments, physical activity, quality of life and depressive symptoms in Chinese Hong Kong older adults. Methods and analyses An observational study of the associations of measures of the physical and social neighbourhood environment, and psychosocial factors, with physical activity, quality of life and depressive symptoms in 900 Hong Kong older adults aged 65+ years is being conducted in 2012–2016. The study involves two assessments taken 6 months apart. Neighbourhood walkability and access to destinations are objectively measured using Geographic Information Systems and environmental audits. Demographics, socioeconomic status, walking for different purposes, perceived neighbourhood and home environments, psychosocial factors, health status, social networks, depressive symptoms and quality of life are being assessed using validated interviewer-administered self-report measures and medical records. Physical functionality is being assessed using the Short Physical Performance Battery. Physical activity and sedentary behaviours are also being objectively measured in approximately 45% of participants using accelerometers over a week. Physical activity, sedentary behaviours, quality of life and depressive symptoms are being assessed twice (6 months apart) to examine seasonality effects on behaviours and their associations with quality of life and depressive symptoms. Ethics and dissemination The study received ethical approval from the University of Hong Kong Human Research Ethics Committee for Non-Clinical Faculties (EA270211) and the Department

  19. Spatial clustering of mental disorders and associated characteristics of the neighbourhood context in Malmö, Sweden, in 2001

    PubMed Central

    Chaix, Basile; Leyland, Alastair H; Sabel, Clive E; Chauvin, Pierre; Råstam, Lennart; Kristersson, Håkan; Merlo, Juan

    2006-01-01

    Study objective Previous research provides preliminary evidence of spatial variations of mental disorders and associations between neighbourhood social context and mental health. This study expands past literature by (1) using spatial techniques, rather than multilevel models, to compare the spatial distributions of two groups of mental disorders (that is, disorders due to psychoactive substance use, and neurotic, stress related, and somatoform disorders); and (2) investigating the independent impact of contextual deprivation and neighbourhood social disorganisation on mental health, while assessing both the magnitude and the spatial scale of these effects. Design Using different spatial techniques, the study investigated mental disorders due to psychoactive substance use, and neurotic disorders. Participants All 89 285 persons aged 40–69 years residing in Malmö, Sweden, in 2001, geolocated to their place of residence. Main results The spatial scan statistic identified a large cluster of increased prevalence in a similar location for the two mental disorders in the northern part of Malmö. However, hierarchical geostatistical models showed that the two groups of disorders exhibited a different spatial distribution, in terms of both magnitude and spatial scale. Mental disorders due to substance consumption showed larger neighbourhood variations, and varied in space on a larger scale, than neurotic disorders. After adjustment for individual factors, the risk of substance related disorders increased with neighbourhood deprivation and neighbourhood social disorganisation. The risk of neurotic disorders only increased with contextual deprivation. Measuring contextual factors across continuous space, it was found that these associations operated on a local scale. Conclusions Taking space into account in the analyses permitted deeper insight into the contextual determinants of mental disorders. PMID:16614334

  20. Use of health care among febrile children from urban poor households in Senegal: does the neighbourhood have an impact?

    PubMed

    Kone, Georges Karna; Lalou, Richard; Audibert, Martine; Lafarge, Hervé; Dos Santos, Stéphanie; Ndonky, Alphousseyni; Le Hesran, Jean-Yves

    2015-12-01

    Urban malaria is considered a major public health problem in Africa. The malaria vector is well adapted in urban settings and autochthonous malaria has increased. Antimalarial treatments prescribed presumptively or after rapid diagnostic tests are also highly used in urban settings. Furthermore, health care strategies for urban malaria must comply with heterogeneous neighbourhood ecosystems where health-related risks and opportunities are spatially varied. This article aims to assess the capacity of the urban living environment to mitigate or increase individual or household vulnerabilities that influence the use of health services. The data are drawn from a survey on urban malaria conducted between 2008 and 2009. The study sample was selected using a two-stage randomized sampling. The questionnaire survey covered 2952 households that reported a case of fever episode in children below 10 years during the month before the survey.Self-medication is a widespread practice for children, particularly among the poorest households in Dakar. For rich households, self-medication for children is more a transitional practice enabling families to avoid opportunity costs related to visits to health facilities. For the poorest, it is a forced choice and often the only treatment option. However, the poor that live in well-equipped neighbourhoods inhabited by wealthy residents tend to behave as their rich neighbours. They grasp the opportunities provided by the area and adjust their behaviours accordingly. Though health care for children is strongly influenced by household socio-economic characteristics, neighbourhood resources (facilities and social networks) will promote health care among the poorest and reduce access inequalities. Without being a key factor, the neighbourhood of residence-when it provides resources-may be of some help to overcome the financial hurdle. Findings suggest that the neighbourhood (local setting) is a relevant scale for health programmes in African

  1. Residents' diverse perspectives of the impact of neighbourhood renewal on quality of life and physical activity engagement: Improvements but unresolved issues

    PubMed Central

    Coulson, J.C.; Fox, K.R.; Lawlor, D.A.; Trayers, T.

    2011-01-01

    Few studies have been published on the reactions of residents to modifications of their residential landscape. We explored residents' experiences of home zone remodelling and construction of a new cycle-walkway in a deprived neighbourhood with a particular focus on aspects of quality of life and physical activity participation. Focus groups (n=5 groups, 21 individuals) were used to investigate residents' perceptions of the effects of neighbourhood change on their lives. Consultation by planners was received positively. Several aspects of the neighbourhood were perceived to have improved, including spatial aesthetics, lighting and streetscape planting. However, influence on physical activity was minimal. Car-focused behaviour and ownership remained dominant, and safety related concerns limited behavioural choices. Residents highlighted many socio-environmental challenges that remained such as sense of neighbourhood safety, poor public transport provision, people's parking behaviour locally, and problem neighbours, and these tended to dominate conversations. Infrastructural intervention may be one important part of multi-layered solutions to improved neighbourhood life. PMID:21145277

  2. Symbolic violence and the neighbourhood: the educational aspirations of 7-8 year old working-class girls.

    PubMed

    Connolly, Paul; Healy, Julie

    2004-12-01

    This article focuses on the experiences of 7-8 year old working-class girls in Belfast, Northern Ireland and their attitudes towards education. It shows how their emerging identities tend to emphasize relationships, marriage and motherhood at the expense of a concern with education and future careers. The article suggests that one important factor that can help explain this is the influence of the local neighbourhood. In drawing upon Bourdieu's concepts of symbolic violence and habitus and Elias' notion of figuration, the article shows how the local neighbourhood represents the parameters of the girls' social worlds. It provides the context within which the girls tend to focus on social relations within their community and particularly on family relationships, marriage and children. It also provides the context within which the girls tend to develop strong interdependent relationships with their mothers that also tend to encourage and reinforce the girls' particular gendered identities. The article concludes by arguing that there is a need for more research on working-class girls and education to look beyond the school to incorporate, more fully, an understanding of the influence of the family and local neighbourhood on their attitudes towards education and their future career aspirations. PMID:15663422

  3. Anyonic quantum walks

    SciTech Connect

    Brennen, Gavin K.; Ellinas, Demosthenes; Kendon, Viv; Pachos, Jiannis K. Tsohantjis, Ioannis; Wang Zhenghan

    2010-03-15

    The one dimensional quantum walk of anyonic systems is presented. The anyonic walker performs braiding operations with stationary anyons of the same type ordered canonically on the line of the walk. Abelian as well as non-Abelian anyons are studied and it is shown that they have very different properties. Abelian anyonic walks demonstrate the expected quadratic quantum speedup. Non-Abelian anyonic walks are much more subtle. The exponential increase of the system's Hilbert space and the particular statistical evolution of non-Abelian anyons give a variety of new behaviors. The position distribution of the walker is related to Jones polynomials, topological invariants of the links created by the anyonic world-lines during the walk. Several examples such as the SU(2){sub k} and the quantum double models are considered that provide insight to the rich diffusion properties of anyons.

  4. Lévy walks

    NASA Astrophysics Data System (ADS)

    Zaburdaev, V.; Denisov, S.; Klafter, J.

    2015-04-01

    Random walk is a fundamental concept with applications ranging from quantum physics to econometrics. Remarkably, one specific model of random walks appears to be ubiquitous across many fields as a tool to analyze transport phenomena in which the dispersal process is faster than dictated by Brownian diffusion. The Lévy-walk model combines two key features, the ability to generate anomalously fast diffusion and a finite velocity of a random walker. Recent results in optics, Hamiltonian chaos, cold atom dynamics, biophysics, and behavioral science demonstrate that this particular type of random walk provides significant insight into complex transport phenomena. This review gives a self-consistent introduction to Lévy walks, surveys their existing applications, including latest advances, and outlines further perspectives.

  5. Walking on Mars

    NASA Astrophysics Data System (ADS)

    Cavagna, G. A.; Willems, P. A.; Heglund, N. C.

    1998-06-01

    Sometime in the near future humans may walk in the reduced gravity of Mars. Gravity plays an essential role in walking. On Earth, the body uses gravity to `fall forwards' at each step and then the forward speed is used to restore the initial height in a pendulum-like mechanism. When gravity is reduced, as on the Moon or Mars, the mechanism of walking must change. Here we investigate the mechanics of walking on Mars onboard an aircraft undergoing gravity-reducing flight profiles. The optimal walking speed on Mars will be 3.4 km h-1 (down from 5.5 km h-1 on Earth) and the work done per unit distance to move the centre of mass will be half that on Earth.

  6. Twenty years of socioeconomic inequalities in premature mortality in Barcelona: The influence of population and neighbourhood changes.

    PubMed

    Rodríguez-Sanz, Maica; Gotsens, Mercè; Marí-Dell'Olmo, Marc; Mehdipanah, Roshanak; Borrell, Carme

    2016-05-01

    The objective of this study was to analyse trends in socioeconomic inequalities in premature mortality in Barcelona from 1992 to 2011, accounting for population changes. We conducted a repeated cross-sectional study of the Barcelona population (25-64 years) using generalized linear mixed models for trend analysis, and found that socioeconomic inequalities in premature mortality persisted between neighbourhoods, but tended to diminish. However, the reduction in inequality was related to an increase in the number of foreign-born individuals mainly in socioeconomic disadvantaged neighbourhoods, in which the decrease in premature mortality was more marked. To study trends in geographical inequalities in mortality, it is essential to understand demographic changes occurred in different places related to local levels of deprivation. PMID:27105035

  7. Relationships between Population Density and the Perceived Quality of Neighbourhood

    ERIC Educational Resources Information Center

    Walton, D.; Murray, S. J.; Thomas, J. A.

    2008-01-01

    Two overseas survey-based scales measuring perceived quality of neighbourhood were adapted and replicated in a New Zealand context. An Italian study (Bonaiuto, Fornara, and Bonnes. (2003). "Landscape and Urban Planning," 65, 41-52) measuring Perceived Residential Environmental Quality (PREQ) and an American study (Carp and Carp. (1982). "Journal…

  8. A framework of boundary collision data aggregation into neighbourhoods.

    PubMed

    Cui, Ge; Wang, Xin; Kwon, Dae-Won

    2015-10-01

    A large portion of the total number of motor collisions can be boundary collisions; therefore, exaggerated or underestimated numbers for boundary collisions aggregated into neighbourhoods may hamper road safety analyses and management. In this paper, we propose a systematic framework for boundary collision aggregation. First, an entropy-based histogram thresholding method is utilized to determine the boundary zone size and identify boundary collisions. Next, the collision density probability distribution is then established, based on the collisions in each neighbourhood. Last, an effective boundary collision aggregation method, called the collision density ratio (CDR), is used to aggregate boundary collisions into neighbourhoods. The proposed framework is applied to collision data in the City of Edmonton for a case study. The experimental results show that the proposed entropy-based histogram thresholding method can identify boundary collision with the high precision and recall, and the proposed CDR method is more effective than the existing methods, the half-to-half ratio method and the one-to-one ratio method, to aggregate boundary collisions into neighbourhoods. PMID:26143631

  9. Coin state properties in quantum walks

    PubMed Central

    Andrade, R. F. S.

    2013-01-01

    Recent experimental advances have measured individual coin components in discrete time quantum walks, which have not received the due attention in most theoretical studies on the theme. Here is presented a detailed investigation of the properties of M, the difference between square modulus of coin states of discrete quantum walks on a linear chain. Local expectation values are obtained in terms of real and imaginary parts of the Fourier transformed wave function. A simple expression is found for the average difference between coin states in terms of an angle θ gauging the coin operator and its initial state. These results are corroborated by numerical integration of dynamical equations in real space. The local dependence is characterized both by large and short period modulations. The richness of revealed patterns suggests that the amount of information stored and retrieved from quantum walks is significantly enhanced if M is taken into account. PMID:23756358

  10. Neighbourhood effects on educational attainment of adolescents, buffered by personality and educational commitment.

    PubMed

    Nieuwenhuis, Jaap; Hooimeijer, Pieter; Meeus, Wim

    2015-03-01

    Research has repeatedly shown that neighbourhood disadvantage negatively influences individual educational outcomes. However, the great variation in outcomes indicates substantial unobserved heterogeneity. Looking at the rates of obtaining a basic educational qualification, the hypothesis is that individual traits of adolescents can buffer neighbourhood effects. First, adolescents with a more resilient personality may be better able to cope with neighbourhood adversity. And second, educational commitments might buffer adolescents from negative neighbourhood influences. These hypotheses are tested employing survival analysis, using six wave panel data, containing information on ten years of adolescents' lives. The results show that resilients experience no negative influence of neighbourhood disadvantage, while both undercontrollers and overcontrollers do. And, the stronger adolescents' educational commitments, the less they experience the negative effect of neighbourhood adversity. In sum, neighbourhood effects are found, but not for everybody. PMID:25592923

  11. Neighbourhood socioeconomic status and cardiovascular risk factors: a multilevel analysis of nine cities in the Czech Republic and Germany

    PubMed Central

    Dragano, Nico; Bobak, Martin; Wege, Natalia; Peasey, Anne; Verde, Pablo E; Kubinova, Ruzena; Weyers, Simone; Moebus, Susanne; Möhlenkamp, Stefan; Stang, Andreas; Erbel, Raimund; Jöckel, Karl-Heinz; Siegrist, Johannes; Pikhart, Hynek

    2007-01-01

    Background Previous studies have shown that deprived neighbourhoods have higher cardiovascular mortality and morbidity rates. Inequalities in the distribution of behaviour related risk factors are one possible explanation for this trend. In our study, we examined the association between cardiovascular risk factors and neighbourhood characteristics. To assess the consistency of associations the design is cross-national with data from nine industrial towns from the Czech Republic and Germany. Methods We combined datasets from two population based studies, one in Germany ('Heinz Nixdorf Recall (HNR) Study'), and one in the Czech Republic ('Health, Alcohol and Psychosocial Factors in Eastern Europe (HAPIEE) Study'). Participation rates were 56% in the HNR and 55% in the HAPIEE study. The subsample for this particular analysis consists of 11,554 men and women from nine German and Czech towns. Census based information on social characteristics of 326 neighbourhoods were collected from local administrative authorities. We used unemployment rate and overcrowding as area-level markers of socioeconomic status (SES). The cardiovascular risk factors obesity, hypertension, smoking and physical inactivity were used as response variables. Regression models were complemented by individual-level social status (education) and relevant covariates. Results Smoking, obesity and low physical activity were more common in deprived neighbourhoods in Germany, even when personal characteristics including individual education were controlled for. For hypertension associations were weak. In the Czech Republic associations were observed for smoking and physical inactivity, but not for obesity and hypertension when individual-level covariates were adjusted for. The strongest association was found for smoking in both countries: in the fully adjusted model the odds ratio for 'high unemployment rate' was 1.30 [95% CI 1.02–1.66] in the Czech Republic and 1.60 [95% CI 1.29–1.98] in Germany

  12. Walking: technology and biology.

    PubMed

    Pfeiffer, Friedrich; Inoue, Hirochika

    2007-01-15

    If all the signs are to be believed, then the twenty-first century will technologically be characterized by machine walking and its relevant products, which possess all chances to become real bulk goods in the course of the next decades. With several university institutes and with Honda and Sony from the industrial side, Japan is today and without any doubt the leading nation in research and development of walking machines. The US and Europe follow at some distance. Walking machines will influence all areas of daily and industrial life and, with the fast evolution of artificial intelligence, will become a real partner of human beings. All relevant technologies are highly interdisciplinary, they will push the future technologies of all technical fields. The special issue on this topic gives a selection of walking machine research and development including some aspects from biology. PMID:17148046

  13. Early Walking of Geriatric Amputees

    PubMed Central

    Devas, M. B.

    1971-01-01

    After amputation geriatric patients have been enabled to get up and walk with the help of a prosthesis, an “early walking aid.” The physiotherapist measures the patient, fits the early walking aid, and instructs him in walking. The prosthesis is simple to make, easy to apply, and allows early walking with the use of a walking frame or sticks. Thus the geriatric amputee can walk as soon after operation as his general condition allows and the surgeon wishes. ImagesFIG. 1FIG. 2 PMID:5100378

  14. Weighing the importance of neighbourhood: a multilevel exploration of the determinants of overweight and obesity.

    PubMed

    Harrington, Daniel W; Elliott, Susan J

    2009-02-01

    Overweight and obesity have reached epidemic proportions in many countries, including Canada. In addition to becoming critical public health challenges in and of themselves, they represent major risk factors for chronic disease and disability (e.g. cardiovascular disease, diabetes). The various symptoms and co-morbidities associated with these chronic conditions place tremendous stress on the Canadian health care system, generating economic concern. This research takes a population health approach to the study of obesity, examining the complex relationships between individual demographics and behaviours, and aspects of the local social and physical environments. A subset of a nationally representative survey was linked to neighbourhood-level data from the 1991 Canadian Census, and analysed from a multilevel perspective. This study found substantial area-level variation in body mass index and waist circumference, and discovered an important role for neighbourhood-level characteristics independent of individual-level characteristics. These findings provide evidence that the underlying mechanisms driving the increasing prevalence of overweight and obesity may be so called obesogenic environments that encourage physical inactivity and unhealthy eating. An effective policy response must address environmental conditions in order to curb current obesity trends. PMID:19095339

  15. Health-Risk Behaviour in Deprived Neighbourhoods Compared with Non-Deprived Neighbourhoods: A Systematic Literature Review of Quantitative Observational Studies

    PubMed Central

    Algren, Maria Holst; Bak, Carsten Kronborg; Berg-Beckhoff, Gabriele; Andersen, Pernille Tanggaard

    2015-01-01

    Background There has been increasing interest in neighbourhoods’ influence on individuals’ health-risk behaviours, such as smoking, alcohol consumption, physical activity and diet. The aim of this review was to systematically review recent studies on health-risk behaviour among adults who live in deprived neighbourhoods compared with those who live in non-deprived neighbourhoods and to summarise what kind of operationalisations of neighbourhood deprivation that were used in the studies. Methods PRISMA guidelines for systematic reviews were followed. Systematic searches were performed in PubMed, Embase, Web of Science and Sociological Abstracts using relevant search terms, Boolean operators, and truncation, and reference lists were scanned. Quantitative observational studies that examined health-risk behaviour in deprived neighbourhoods compared with non-deprived neighbourhoods were eligible for inclusion. Results The inclusion criteria were met by 22 studies. The available literature showed a positive association between smoking and physical inactivity and living in deprived neighbourhoods compared with non-deprived neighbourhoods. In regard to low fruit and vegetable consumption and alcohol consumption, the results were ambiguous, and no clear differences were found. Numerous different operationalisations of neighbourhood deprivation were used in the studies. Conclusion Substantial evidence indicates that future health interventions in deprived neighbourhoods should focus on smoking and physical inactivity. We suggest that alcohol interventions should be population based rather than based on the specific needs of deprived neighbourhoods. More research is needed on fruit and vegetable consumption. In future studies, the lack of a uniform operationalisation of neighbourhood deprivation must be addressed. PMID:26506251

  16. A one-dimensional quantum walk with multiple-rotation on the coin

    PubMed Central

    Xue, Peng; Zhang, Rong; Qin, Hao; Zhan, Xiang; Bian, Zhihao; Li, Jian

    2016-01-01

    We introduce and analyze a one-dimensional quantum walk with two time-independent rotations on the coin. We study the influence on the property of quantum walk due to the second rotation on the coin. Based on the asymptotic solution in the long time limit, a ballistic behaviour of this walk is observed. This quantum walk retains the quadratic growth of the variance if the combined operator of the coin rotations is unitary. That confirms no localization exhibits in this walk. This result can be extended to the walk with multiple time-independent rotations on the coin. PMID:26822563

  17. Random Walk Method for Potential Problems

    NASA Technical Reports Server (NTRS)

    Krishnamurthy, T.; Raju, I. S.

    2002-01-01

    A local Random Walk Method (RWM) for potential problems governed by Lapalace's and Paragon's equations is developed for two- and three-dimensional problems. The RWM is implemented and demonstrated in a multiprocessor parallel environment on a Beowulf cluster of computers. A speed gain of 16 is achieved as the number of processors is increased from 1 to 23.

  18. Searching via walking: How to find a marked clique of a complete graph using quantum walks

    NASA Astrophysics Data System (ADS)

    Hillery, Mark; Reitzner, Daniel; Bužek, Vladimír

    2010-06-01

    We show how a quantum walk can be used to find a marked edge or a marked complete subgraph of a complete graph. We employ a version of a quantum walk, the scattering walk, which lends itself to experimental implementation. The edges are marked by adding elements to them that impart a specific phase shift to the particle as it enters or leaves the edge. If the complete graph has N vertices and the subgraph has K vertices, the particle becomes localized on the subgraph in O(N/K) steps. This leads to a quantum search that is quadratically faster than a corresponding classical search. We show how to implement the quantum walk using a quantum circuit and a quantum oracle, which allows us to specify the resources needed for a quantitative comparison of the efficiency of classical and quantum searches—the number of oracle calls.

  19. A growth walk model for estimating the canonical partition function of interacting self-avoiding walk.

    PubMed

    Narasimhan, S L; Krishna, P S R; Ponmurugan, M; Murthy, K P N

    2008-01-01

    We have explained in detail why the canonical partition function of interacting self-avoiding walk (ISAW) is exactly equivalent to the configurational average of the weights associated with growth walks, such as the interacting growth walk (IGW), if the average is taken over the entire genealogical tree of the walk. In this context, we have shown that it is not always possible to factor the density of states out of the canonical partition function if the local growth rule is temperature dependent. We have presented Monte Carlo results for IGWs on a diamond lattice in order to demonstrate that the actual set of IGW configurations available for study is temperature dependent even though the weighted averages lead to the expected thermodynamic behavior of ISAW. PMID:18190183

  20. Fluorine abundances in dwarf stars of the solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Recio-Blanco, A.; de Laverny, P.; Worley, C.; Santos, N. C.; Melo, C.; Israelian, G.

    2012-02-01

    Context. In spite of many observational efforts to characterize the chemical evolution of our Galaxy, not much is known about the origin of fluorine (F). Models suggest that the F found in the Galaxy might have been produced mainly in three different ways, namely, Type II supernovae, asymptotic giant branch nucleosynthesis, or in the core of Wolf-Rayet stars. Only a few observational measurements of F abundances are available in the literature and mostly for objects whose characteristics might hamper an accurate determination of fluorine abundance (e.g., complex mixing and nucleosynthesis processes, external/internal contamination). Aims: We acquire data using the high-resolution IR-spectrograph CRIRES and gather FEROS data from the European Southern Observatory archive. The classical method of spectral synthesis in local thermodynamic equilibrium has been used to perform the abundance analysis. Methods: We derive the F abundances of nine cool main-sequence dwarfs in the solar neighbourhood, based on an unblended line of the HF molecule at 2.3 microns. In addition, we study the s-process elements of five of these stars. Results: Several of the analysed stars seem to be slightly fluorine enhanced with respect to the Sun, although no correlation is found between the F abundance and the iron content. In addition, the most fluorine enriched stars are also yttrium and zirconium enriched, which suggests that AGB fluorine nucleosynthesis is the dominant source of fluorine production for the observed stars. Nevertheless, the correlation between [F/Fe] and the s-elements is rather weak and possibly masked by the uncertainties in the F abundance measurements. Finally, we compare our derived F abundances to previous measurements of alpha-element and iron-peak element abundances. Type II core collapse supernovae do not appear to be the main site of F production for our targets, as no correlation seems to exist between the [F/Fe] and the [α/Fe] ratios. Based on VLT

  1. Staying connected: neighbourhood correlates of social participation among older adults living in an urban environment in Montréal, Quebec.

    PubMed

    Richard, Lucie; Gauvin, Lise; Gosselin, Céline; Laforest, Sophie

    2009-03-01

    Alongside community involvement, promoting social participation has been identified as a key strategy of fostering empowerment, one of the central tenets of the health promotion movement. Engagement in social and productive activities appears to be particularly beneficial to older adults, as it has been found to be associated with positive outcomes on a variety of health indicators. It is therefore critical to identify factors that might lead to greater social participation within these age groups. The objective of this study was to investigate the relationship between perceptions of neighbourhood user-friendliness and social participation while controlling for personal characteristics in a sample of seniors living in an urban environment. A convenience sample of older adults (n = 282) was recruited through community organizations located in high- average- and low-income Montreal neighbourhoods. Data were collected via an interviewer-administered questionnaire assessing social participation and various variables at the neighbourhood level (e.g. housing and social environment, walking environment and transportation, and services and amenities) and at the individual-level (e.g. health status and socio-demographic characteristics). Five variables emerged as independent predictors of social participation. Positive predictors retained in the final regression model included frequent walking episodes (almost every day), higher Vitality and General Health SF-12v2 scores, and perceived accessibility to key resources for older adults. Also included was a negative predictor: age (R2 of the final model = 0.28). Implications of the findings for research and action pertaining to ecological, health promotion interventions for older adults are identified. PMID:19098293

  2. D.U.C.K. Walking.

    ERIC Educational Resources Information Center

    Steller, Jenifer J.

    This manual presents a schoolwide walking program that includes aerobic fitness information, curriculum integration, and walking tours. "Discover and Understand Carolina Kids by Walking" is D.U.C.K. Walking. An aerobic walking activity, D.U.C.K. Walking has two major goals: (1) to promote regular walking as a way to exercise at any age; and (2) to…

  3. Examining methodological details of neighbourhood observations and the relationship to health: a literature review.

    PubMed

    Schaefer-McDaniel, Nicole; Caughy, Margaret O'Brien; O'Campo, Patricia; Gearey, Wayne

    2010-01-01

    Neighbourhood research has been growing steadily over the past two decades across the social sciences, and, in particular in the area of public health. Despite this increase, there is currently no consensus on which measure and data source researchers should use to assess neighbourhood attributes. In the past, researchers have relied on census data and household surveys to assess neighbourhood conditions, but in recent years, neighbourhood observations have become a popular alternative method for characterizing neighbourhood environments. Rooted in sociology of crime research, observations are conducted by trained observers who use a checklist to observe and rate neighbourhoods on a number of conditions such as physical (e.g., traffic volume, housing conditions) and social (e.g., presence of people, gang activity) attributes. While this methodology has been gaining momentum in recent years, notably absent from the literature is a review to examine this methodology in detail. The purpose of the present study was to examine research that has used neighbourhood observations as a method. We do so by critically reviewing 51 English language studies published from 1990 onward paying particular attention to the areas of (1) methodological rigor (i.e. how observations are carried out in the field and how data are analyzed), (2) geographical boundaries (i.e. how neighbourhoods and areas of observation are spatially defined), and (3) the relationship between neighbourhood observations and residents' health (i.e. how studies examine and analyze the link between observed neighbourhood attributes and health). We find that little attention is given to details of neighbourhood observations as a method. Further, there is wide variability in how observations are conducted and analyzed making it impossible to confidently compare findings across studies. We see this review as a first step in developing sound observational measures of neighbourhood factors and conclude by providing

  4. Labyrinth walking in corrections.

    PubMed

    Zucker, Donna M; Sharma, Amy

    2012-02-01

    A 6 week labyrinth walking program was pilot tested in a correctional setting and goals were to: 1) determine the feasibility of a labyrinth walking curriculum; 2) pilot test measures of health related quality of life (QOL) (pre and post-surveys) and blood pressure; and 3) examine the influence of relationship-centered teaching on subject satisfaction. Relational communication was used as a framework for this study, emphasizing concepts of trust, competency and similarly in the teacher. A pretest/posttest descriptive design was used. The sample was 14 offenders at a Massachusetts county jail. The intervention included six 90 minute sessions, composed of a lecture, a labyrinth walk, and journal writing. Measures included a demographic survey; pre and post session walk blood pressures; pre and post program QOL measures; and a post program measure of satisfaction. The sample was 57% Caucasian, 36% Hispanic, and 7% African American, with an average age of 34, mostly high school educated and single. Drug of choice was alcohol with age of use at 12 and 1/2 years. Seventy-nine percent were previously incarcerated more than twice. QOL data were not changed pre to post. BP data trended in a healthy direction from weeks 1 to 6. Satisfaction with the teacher and the program was high. The labyrinth walking pilot program was proven feasible, low cost and satisfying for the participants. Recommendations for future studies are discussed. PMID:22468660

  5. Contribution of the physical environment to socioeconomic gradients in walking in the Whitehall II study.

    PubMed

    Pliakas, Triantafyllos; Wilkinson, Paul; Tonne, Cathryn

    2014-05-01

    Socioeconomic gradients in walking are well documented but the underlying reasons remain unclear. We examined the contribution of objective measures of the physical environment at residence to socioeconomic gradients in walking in 3363 participants (50-74years) from the Whitehall II study (2002-2004). Individual-level socioeconomic position was measured as most recent employment grade. The contribution of multiple measures of the physical environment to socioeconomic position gradients in self-reported log transformed minutes walking/week was examined by linear regression. Objective measures of the physical environment contributed only to a small extent to socioeconomic gradients in walking in middle-aged and older adults living in Greater London, UK. Of these, only the number of killed and seriously injured road traffic casualties per km of road was predictive of walking. More walking in areas with high rates of road traffic casualties per km of road may signal an effect not of injury risk but of more central locations with multiple destinations within short distances ('compact neighbourhoods'). This has potential implications for urban planning to promote physical activity. PMID:24637091

  6. MIND: modality independent neighbourhood descriptor for multi-modal deformable registration.

    PubMed

    Heinrich, Mattias P; Jenkinson, Mark; Bhushan, Manav; Matin, Tahreema; Gleeson, Fergus V; Brady, Sir Michael; Schnabel, Julia A

    2012-10-01

    Deformable registration of images obtained from different modalities remains a challenging task in medical image analysis. This paper addresses this important problem and proposes a modality independent neighbourhood descriptor (MIND) for both linear and deformable multi-modal registration. Based on the similarity of small image patches within one image, it aims to extract the distinctive structure in a local neighbourhood, which is preserved across modalities. The descriptor is based on the concept of image self-similarity, which has been introduced for non-local means filtering for image denoising. It is able to distinguish between different types of features such as corners, edges and homogeneously textured regions. MIND is robust to the most considerable differences between modalities: non-functional intensity relations, image noise and non-uniform bias fields. The multi-dimensional descriptor can be efficiently computed in a dense fashion across the whole image and provides point-wise local similarity across modalities based on the absolute or squared difference between descriptors, making it applicable for a wide range of transformation models and optimisation algorithms. We use the sum of squared differences of the MIND representations of the images as a similarity metric within a symmetric non-parametric Gauss-Newton registration framework. In principle, MIND would be applicable to the registration of arbitrary modalities. In this work, we apply and validate it for the registration of clinical 3D thoracic CT scans between inhale and exhale as well as the alignment of 3D CT and MRI scans. Experimental results show the advantages of MIND over state-of-the-art techniques such as conditional mutual information and entropy images, with respect to clinically annotated landmark locations. PMID:22722056

  7. Multilevel selection and neighbourhood effects from individual to metapopulation in a wild passerine.

    PubMed

    Laiolo, Paola; Obeso, José Ramón

    2012-01-01

    Multilevel selection has rarely been studied in the ecological context of animal populations, in which neighbourhood effects range from competition among territorial neighbours to source-sink effects among local populations. By studying a Dupont's lark Chersophilus duponti metapopulation, we analyze neighbourhood effects mediated by song repertoires on fitness components at the individual level (life-span) and population level (growth rate). As a sexual/aggressive signal with strong effects on fitness, birdsong creates an opportunity for group selection via neighbour interactions, but may also have population-wide effects by conveying information on habitat suitability to dispersing individuals. Within populations, we found a disruptive pattern of selection at the individual level and an opposite, stabilizing pattern at the group level. Males singing the most complex songs had the longest life-span, but individuals with the poorest repertoires lived longer than 'average' males, a finding that likely reflects two male strategies with respect to fitness and sexual trait expression. Individuals from groups with intermediate repertoires had the longest life-span, likely benefitting from conspecific signalling to attract females up to the detrimental spread of competitive interactions in groups with superior vocal skills. Within the metapopulation selection was directional but again followed opposite patterns at the two levels: Populations had the highest growth rate when inhabiting local patches with complex repertoires surrounded by patches with simple repertoires. Here the song may impact metapopulation dynamics by guiding prospecting individuals towards populations advertising habitat quality. Two fitness components linked to viability were therefore influenced by the properties of the group, and birdsong was the target of selection, contributing to linking social/sexual processes at the local scale with regional population dynamics. PMID:22745665

  8. Empirical spatial econometric modelling of small scale neighbourhood

    NASA Astrophysics Data System (ADS)

    Gerkman, Linda

    2012-07-01

    The aim of the paper is to model small scale neighbourhood in a house price model by implementing the newest methodology in spatial econometrics. A common problem when modelling house prices is that in practice it is seldom possible to obtain all the desired variables. Especially variables capturing the small scale neighbourhood conditions are hard to find. If there are important explanatory variables missing from the model, the omitted variables are spatially autocorrelated and they are correlated with the explanatory variables included in the model, it can be shown that a spatial Durbin model is motivated. In the empirical application on new house price data from Helsinki in Finland, we find the motivation for a spatial Durbin model, we estimate the model and interpret the estimates for the summary measures of impacts. By the analysis we show that the model structure makes it possible to model and find small scale neighbourhood effects, when we know that they exist, but we are lacking proper variables to measure them.

  9. Key stakeholder perspectives on the development of walkable neighbourhoods

    PubMed Central

    Clark, Marianne I.; Berry, Tanya R.; Spence, John C.; Nykiforuk, Candace; Carlson, Marie; Blanchard, Christopher

    2016-01-01

    Evidence supports the link between the built environment and physical activity. This study investigated factors that influence the decisions made by key stakeholders as they relate to neighbourhood development. Seventeen stakeholders including public health and municipal employees (n = 9), city councillors (n = 3), and the private sector (e.g., land developers, food retailers) (n = 5), participated in interviews. Private sector participants considered healthy lifestyle choices (e.g., PA) to be related more to individual choice than did other groups. All groups agreed that consumer behaviour is essential to invoking change but did not agree on who is responsible for invoking change. Common barriers included financial costs, car dependency, and social norms. Facilitators included growing awareness of health and environmental issues and increasing buy-in from governing bodies for innovative neighbourhood development. More work is needed that acknowledges the differences between while integrating the diverse perspectives of those responsible for the planning of neighbourhoods that are conducive for physical activity. PMID:19733495

  10. Extra-Pair Mating and Evolution of Cooperative Neighbourhoods

    PubMed Central

    Eliassen, Sigrunn; Jørgensen, Christian

    2014-01-01

    A striking but unexplained pattern in biology is the promiscuous mating behaviour in socially monogamous species. Although females commonly solicit extra-pair copulations, the adaptive reason has remained elusive. We use evolutionary modelling of breeding ecology to show that females benefit because extra-pair paternity incentivizes males to shift focus from a single brood towards the entire neighbourhood, as they are likely to have offspring there. Male-male cooperation towards public goods and dear enemy effects of reduced territorial aggression evolve from selfish interests, and lead to safer and more productive neighbourhoods. The mechanism provides adaptive explanations for the common empirical observations that females engage in extra-pair copulations, that neighbours dominate as extra-pair sires, and that extra-pair mating correlates with predation mortality and breeding density. The models predict cooperative behaviours at breeding sites where males cooperate more towards public goods than females. Where maternity certainty makes females care for offspring at home, paternity uncertainty and a potential for offspring in several broods make males invest in communal benefits and public goods. The models further predict that benefits of extra-pair mating affect whole nests or neighbourhoods, and that cuckolding males are often cuckolded themselves. Derived from ecological mechanisms, these new perspectives point towards the evolution of sociality in birds, with relevance also for mammals and primates including humans. PMID:24987839

  11. Mesoscopic description of random walks on combs.

    PubMed

    Méndez, Vicenç; Iomin, Alexander; Campos, Daniel; Horsthemke, Werner

    2015-12-01

    Combs are a simple caricature of various types of natural branched structures, which belong to the category of loopless graphs and consist of a backbone and branches. We study continuous time random walks on combs and present a generic method to obtain their transport properties. The random walk along the branches may be biased, and we account for the effect of the branches by renormalizing the waiting time probability distribution function for the motion along the backbone. We analyze the overall diffusion properties along the backbone and find normal diffusion, anomalous diffusion, and stochastic localization (diffusion failure), respectively, depending on the characteristics of the continuous time random walk along the branches, and compare our analytical results with stochastic simulations. PMID:26764637

  12. Mesoscopic description of random walks on combs

    NASA Astrophysics Data System (ADS)

    Méndez, Vicenç; Iomin, Alexander; Campos, Daniel; Horsthemke, Werner

    2015-12-01

    Combs are a simple caricature of various types of natural branched structures, which belong to the category of loopless graphs and consist of a backbone and branches. We study continuous time random walks on combs and present a generic method to obtain their transport properties. The random walk along the branches may be biased, and we account for the effect of the branches by renormalizing the waiting time probability distribution function for the motion along the backbone. We analyze the overall diffusion properties along the backbone and find normal diffusion, anomalous diffusion, and stochastic localization (diffusion failure), respectively, depending on the characteristics of the continuous time random walk along the branches, and compare our analytical results with stochastic simulations.

  13. Walks on SPR neighborhoods.

    PubMed

    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. PMID:23702562

  14. Revisiting the Role of Neighbourhood Change in Social Exclusion and Inclusion of Older People

    PubMed Central

    Burns, Victoria F.; Lavoie, Jean-Pierre; Rose, Damaris

    2012-01-01

    Objective. To explore how older people who are “aging in place” are affected when the urban neighbourhoods in which they are aging are themselves undergoing socioeconomic and demographic change. Methods. A qualitative case study was conducted in two contrasting neighbourhoods in Montréal (Québec, Canada), the analysis drawing on concepts of social exclusion and attachment. Results. Participants express variable levels of attachment to neighbourhood. Gentrification triggered processes of social exclusion among older adults: loss of social spaces dedicated to older people led to social disconnectedness, invisibility, and loss of political influence on neighbourhood planning. Conversely, certain changes in a disadvantaged neighbourhood fostered their social inclusion. Conclusion. This study thus highlights the importance of examining the impacts of neighbourhood change when exploring the dynamics of aging in place and when considering interventions to maintain quality of life of those concerned. PMID:22013528

  15. Revisiting the role of neighbourhood change in social exclusion and inclusion of older people.

    PubMed

    Burns, Victoria F; Lavoie, Jean-Pierre; Rose, Damaris

    2012-01-01

    Objective. To explore how older people who are "aging in place" are affected when the urban neighbourhoods in which they are aging are themselves undergoing socioeconomic and demographic change. Methods. A qualitative case study was conducted in two contrasting neighbourhoods in Montréal (Québec, Canada), the analysis drawing on concepts of social exclusion and attachment. Results. Participants express variable levels of attachment to neighbourhood. Gentrification triggered processes of social exclusion among older adults: loss of social spaces dedicated to older people led to social disconnectedness, invisibility, and loss of political influence on neighbourhood planning. Conversely, certain changes in a disadvantaged neighbourhood fostered their social inclusion. Conclusion. This study thus highlights the importance of examining the impacts of neighbourhood change when exploring the dynamics of aging in place and when considering interventions to maintain quality of life of those concerned. PMID:22013528

  16. Random walks on networks

    NASA Astrophysics Data System (ADS)

    Donnelly, Isaac

    Random walks on lattices are a well used model for diffusion on continuum. They have been to model subdiffusive systems, systems with forcing and reactions as well as a combination of the three. We extend the traditional random walk framework to the network to obtain novel results. As an example due to the small graph diameter, the early time behaviour of subdiffusive dynamics dominates the observed system which has implications for models of the brain or airline networks. I would like to thank the Australian American Fulbright Association.

  17. SNPhood: investigate, quantify and visualise the epigenomic neighbourhood of SNPs using NGS data

    PubMed Central

    Arnold, Christian; Bhat, Pooja; Zaugg, Judith B.

    2016-01-01

    Motivation: The vast majority of the many thousands of disease-associated single nucleotide polymorphisms (SNPs) lie in the non-coding part of the genome. They are likely to affect regulatory elements, such as enhancers and promoters, rather than the function of a protein. To understand the molecular mechanisms underlying genetic diseases, it is therefore increasingly important to study the effect of a SNP on nearby molecular traits such as chromatin or transcription factor binding. Results: We developed SNPhood, a user-friendly Bioconductor R package to investigate, quantify and visualise the local epigenetic neighbourhood of a set of SNPs in terms of chromatin marks or TF binding sites using data from NGS experiments. Availability and implementation: SNPhood is publicly available and maintained as an R Bioconductor package at http://bioconductor.org/packages/SNPhood/. Contact: judith.zaugg@embl.de Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27153574

  18. Community off-sales provision and the presence of alcohol-related detritus in residential neighbourhoods.

    PubMed

    Forsyth, Alasdair J M; Davidson, Neil

    2010-03-01

    This paper investigates the relationship between community off-sales premises and alcohol-related detritus (litter/remains) in residential neighbourhoods. This was accomplished by photographing all brand-identifiable alcohol product detritus (glass, packaging, etc.) where they lay and mapping these against the presence of off-sales outlets (licensed convenience stores) in the community. It was hypothesised that alcohol-related detritus would be greatest near to such alcohol outlets. However, although there was some evidence of a "broken bottles effect", accumulations of alcohol-related detritus near some off-sales premises, it is concluded that local area deprivation is a better predictor of such alcohol-related incivility than is outlet provision. The implications of these findings are discussed in relation to current social responsibility policy developments which are designed to make the alcohol industry liable for alcohol-related incivilities. PMID:20004129

  19. Defining Neighbourhoods as a Measure of Exposure to the Food Environment

    PubMed Central

    Lyseen, Anders K.; Hansen, Henning S.; Harder, Henrik; Jensen, Anders S.; Mikkelsen, Bent E.

    2015-01-01

    Neighbourhoods are frequently used as a measure for individuals’ exposure to the food environment. However, the definitions of neighbourhoods fluctuate and have not been applied consistently in previous studies. Neighbourhoods defined from a single fixed location fail to capture people’s complete exposure in multiple locations, but measuring behaviour using traditional methods can be challenging. This study compares the traditional methods of measuring exposure to the food environment to methods that use data from GPS tracking. For each of the 187 participants, 11 different neighbourhoods were created in which the exposure to supermarkets and fast food outlets were measured. ANOVA, Tukey’s Honestly Significant Difference (HSD) test and t-tests were performed to compare the neighbourhoods. Significant differences were found between area sizes and the exposure to supermarkets and fast food outlets for different neighbourhood types. Second, significant differences in exposure to food outlets were found between the urban and rural neighbourhoods. Neighbourhoods are clearly a diffused and blurred concept that varies in meaning depending on each person’s perception and the conducted study. Complexity and heterogeneity of human mobility no longer appear to correspond to the use of residential neighbourhoods but rather emphasise the need for methods, concepts and measures of individual activity and exposure. PMID:26197331

  20. Defining Neighbourhoods as a Measure of Exposure to the Food Environment.

    PubMed

    Lyseen, Anders K; Hansen, Henning S; Harder, Henrik; Jensen, Anders S; Mikkelsen, Bent E

    2015-07-01

    Neighbourhoods are frequently used as a measure for individuals' exposure to the food environment. However, the definitions of neighbourhoods fluctuate and have not been applied consistently in previous studies. Neighbourhoods defined from a single fixed location fail to capture people's complete exposure in multiple locations, but measuring behaviour using traditional methods can be challenging. This study compares the traditional methods of measuring exposure to the food environment to methods that use data from GPS tracking. For each of the 187 participants, 11 different neighbourhoods were created in which the exposure to supermarkets and fast food outlets were measured. ANOVA, Tukey's Honestly Significant Difference (HSD) test and t-tests were performed to compare the neighbourhoods. Significant differences were found between area sizes and the exposure to supermarkets and fast food outlets for different neighbourhood types. Second, significant differences in exposure to food outlets were found between the urban and rural neighbourhoods. Neighbourhoods are clearly a diffused and blurred concept that varies in meaning depending on each person's perception and the conducted study. Complexity and heterogeneity of human mobility no longer appear to correspond to the use of residential neighbourhoods but rather emphasise the need for methods, concepts and measures of individual activity and exposure. PMID:26197331

  1. Walking: the Cheap, Easy Workout

    MedlinePlus

    ... news/fullstory_159582.html Walking: The Cheap, Easy Workout And it's a good way to start exercising, ... endurance. You can give your upper body a workout while walking by carrying one to five pound ...

  2. Hybridisations of Variable Neighbourhood Search and Modified Simplex Elements to Harmony Search and Shuffled Frog Leaping Algorithms for Process Optimisations

    NASA Astrophysics Data System (ADS)

    Aungkulanon, P.; Luangpaiboon, P.

    2010-10-01

    Nowadays, the engineering problem systems are large and complicated. An effective finite sequence of instructions for solving these problems can be categorised into optimisation and meta-heuristic algorithms. Though the best decision variable levels from some sets of available alternatives cannot be done, meta-heuristics is an alternative for experience-based techniques that rapidly help in problem solving, learning and discovery in the hope of obtaining a more efficient or more robust procedure. All meta-heuristics provide auxiliary procedures in terms of their own tooled box functions. It has been shown that the effectiveness of all meta-heuristics depends almost exclusively on these auxiliary functions. In fact, the auxiliary procedure from one can be implemented into other meta-heuristics. Well-known meta-heuristics of harmony search (HSA) and shuffled frog-leaping algorithms (SFLA) are compared with their hybridisations. HSA is used to produce a near optimal solution under a consideration of the perfect state of harmony of the improvisation process of musicians. A meta-heuristic of the SFLA, based on a population, is a cooperative search metaphor inspired by natural memetics. It includes elements of local search and global information exchange. This study presents solution procedures via constrained and unconstrained problems with different natures of single and multi peak surfaces including a curved ridge surface. Both meta-heuristics are modified via variable neighbourhood search method (VNSM) philosophy including a modified simplex method (MSM). The basic idea is the change of neighbourhoods during searching for a better solution. The hybridisations proceed by a descent method to a local minimum exploring then, systematically or at random, increasingly distant neighbourhoods of this local solution. The results show that the variant of HSA with VNSM and MSM seems to be better in terms of the mean and variance of design points and yields.

  3. Walking with a Slower Friend

    ERIC Educational Resources Information Center

    Bailey, Herb; Kalman, Dan

    2011-01-01

    Fay and Sam go for a walk. Sam walks along the left side of the street while Fay, who walks faster, starts with Sam but walks to a point on the right side of the street and then returns to meet Sam to complete one segment of their journey. We determine Fay's optimal path minimizing segment length, and thus maximizing the number of times they meet…

  4. The walking robot project

    NASA Technical Reports Server (NTRS)

    Williams, P.; Sagraniching, E.; Bennett, M.; Singh, R.

    1991-01-01

    A walking robot was designed, analyzed, and tested as an intelligent, mobile, and a terrain adaptive system. The robot's design was an application of existing technologies. The design of the six legs modified and combines well understood mechanisms and was optimized for performance, flexibility, and simplicity. The body design incorporated two tripods for walking stability and ease of turning. The electrical hardware design used modularity and distributed processing to drive the motors. The software design used feedback to coordinate the system and simple keystrokes to give commands. The walking machine can be easily adapted to hostile environments such as high radiation zones and alien terrain. The primary goal of the leg design was to create a leg capable of supporting a robot's body and electrical hardware while walking or performing desired tasks, namely those required for planetary exploration. The leg designers intent was to study the maximum amount of flexibility and maneuverability achievable by the simplest and lightest leg design. The main constraints for the leg design were leg kinematics, ease of assembly, degrees of freedom, number of motors, overall size, and weight.

  5. Walking in My Shoes

    ERIC Educational Resources Information Center

    Salia, Hannah

    2010-01-01

    The Walking in My Shoes curriculum at St. Thomas School in Medina, Washington, has been developed to deepen students' understanding of their own heritage and the cultural similarities and differences among their global peers. Exploring the rich diversity of the world's cultural heritage and the interactions of global migrations throughout history,…

  6. Tips for Leading Walks.

    ERIC Educational Resources Information Center

    Kriesberg, Daniel

    2001-01-01

    Offers reminders and tips for improving interpretive walks, including having a theme, drawing on basic teaching methods, drawing on all senses rather than just talking, being a role model to show how learning can be fun, using picture books, using tools of the trade to encourage visitors to learn for themselves, and playing games. (PVD)

  7. A Walk through Time.

    ERIC Educational Resources Information Center

    Renfroe, Mark; Letendre, Wanda

    1996-01-01

    Describes a seventh-grade class project where students constructed a "time tunnel" (a walk-through display with models and exhibits illustrating various themes and eras). Beginning modestly, the tunnel grew over seven years to include 11 different display scenes. Discusses the construction of the project and benefits to the school. (MJP)

  8. Take a Planet Walk

    ERIC Educational Resources Information Center

    Schuster, Dwight

    2008-01-01

    Physical models in the classroom "cannot be expected to represent the full-scale phenomenon with complete accuracy, not even in the limited set of characteristics being studied" (AAAS 1990). Therefore, by modifying a popular classroom activity called a "planet walk," teachers can explore upper elementary students' current understandings; create an…

  9. Walking On Air

    NASA Video Gallery

    This video features a series of time lapse sequences photographed by the Expedition 30 crew aboard the International Space Station. Set to the song “Walking in the Air,” by Howard Blake, the v...

  10. Walking Out Graphs

    ERIC Educational Resources Information Center

    Shen, Ji

    2009-01-01

    In the Walking Out Graphs Lesson described here, students experience several types of representations used to describe motion, including words, sentences, equations, graphs, data tables, and actions. The most important theme of this lesson is that students have to understand the consistency among these representations and form the habit of…

  11. Random Walks on Random Graphs

    NASA Astrophysics Data System (ADS)

    Cooper, Colin; Frieze, Alan

    The aim of this article is to discuss some of the notions and applications of random walks on finite graphs, especially as they apply to random graphs. In this section we give some basic definitions, in Section 2 we review applications of random walks in computer science, and in Section 3 we focus on walks in random graphs.

  12. Nonlinear time series analysis of normal and pathological human walking

    NASA Astrophysics Data System (ADS)

    Dingwell, Jonathan B.; Cusumano, Joseph P.

    2000-12-01

    Characterizing locomotor dynamics is essential for understanding the neuromuscular control of locomotion. In particular, quantifying dynamic stability during walking is important for assessing people who have a greater risk of falling. However, traditional biomechanical methods of defining stability have not quantified the resistance of the neuromuscular system to perturbations, suggesting that more precise definitions are required. For the present study, average maximum finite-time Lyapunov exponents were estimated to quantify the local dynamic stability of human walking kinematics. Local scaling exponents, defined as the local slopes of the correlation sum curves, were also calculated to quantify the local scaling structure of each embedded time series. Comparisons were made between overground and motorized treadmill walking in young healthy subjects and between diabetic neuropathic (NP) patients and healthy controls (CO) during overground walking. A modification of the method of surrogate data was developed to examine the stochastic nature of the fluctuations overlying the nominally periodic patterns in these data sets. Results demonstrated that having subjects walk on a motorized treadmill artificially stabilized their natural locomotor kinematics by small but statistically significant amounts. Furthermore, a paradox previously present in the biomechanical literature that resulted from mistakenly equating variability with dynamic stability was resolved. By slowing their self-selected walking speeds, NP patients adopted more locally stable gait patterns, even though they simultaneously exhibited greater kinematic variability than CO subjects. Additionally, the loss of peripheral sensation in NP patients was associated with statistically significant differences in the local scaling structure of their walking kinematics at those length scales where it was anticipated that sensory feedback would play the greatest role. Lastly, stride-to-stride fluctuations in the

  13. Influence of neighbourhood-level crowding on sleep-disordered breathing severity: mediation by body size.

    PubMed

    Johnson, Dayna A; Drake, Christopher; Joseph, Christine L M; Krajenta, Richard; Hudgel, David W; Cassidy-Bushrow, Andrea E

    2015-10-01

    Neighbourhood-level crowding, a measure of the percentage of households with more than one person per room, may impact the severity of sleep-disordered breathing. This study examined the association of neighbourhood-level crowding with apnoea-hypopnoea index in a large clinical sample of diverse adults with sleep-disordered breathing. Sleep-disordered breathing severity was quantified as the apnoea-hypopnoea index calculated from overnight polysomnogram; analyses were restricted to those with apnoea-hypopnoea index ≥5. Neighbourhood-level crowding was defined using 2000 US Census tract data as percentage of households in a census tract with >1 person per room. Multivariable linear mixed models were fit to examine the associations between the percentage of neighbourhood-level crowding and apnoea-hypopnoea index, and a causal mediation analysis was conducted to determine if body mass index acted as a mediator between neighbourhood-level crowding and apnoea-hypopnoea index. Among 1789 patients (43% African American; 68% male; 80% obese), the mean apnoea-hypopnoea index was 29.0 ± 25.3. After adjusting for race, age, marital status and gender, neighbourhood-level crowding was associated with apnoea-hypopnoea index; for every one-unit increase in percentage of neighbourhood-level crowding mean, the apnoea-hypopnoea index increased by 0.40 ± 0.20 (P = 0.04). There was a statistically significant indirect effect of neighbourhood-level crowding through body mass index on the apnoea-hypopnoea index (P < 0.001). Neighbourhood-level crowding is associated with severity of sleep-disordered breathing. Body mass index partially mediated the association between neighbourhood-level crowding and sleep-disordered breathing. Investigating prevalent neighbourhood conditions impacting breathing in urban settings may be promising. PMID:25950087

  14. Physical Activity in Deprived Communities in London: Examining Individual and Neighbourhood-Level Factors

    PubMed Central

    Watts, Paul; Phillips, Gemma; Petticrew, Mark; Hayes, Richard; Bottomley, Christian; Yu, Ge; Schmidt, Elena; Tobi, Patrick; Moore, Derek; Frostick, Caroline; Lock, Karen; Renton, Adrian

    2013-01-01

    Introduction The objectives of this study were to examine relationships between neighbourhood-level and individual-level characteristics and physical activity in deprived London neighbourhoods. Methods In 40 of the most deprived neighbourhoods in London (ranked in top 11% in London by Index of Multiple Deprivation) a cross-sectional survey (n = 4107 adults aged > = 16 years), neighbourhood audit tool, GIS measures and routine data measured neighbourhood and individual-level characteristics. The binary outcome was meeting the minimum recommended (CMO, UK) 5×30 mins moderate physical activity per week. Multilevel modelling was used to examine associations between physical activity and individual and neighbourhood-level characteristics. Results Respondents living more than 300 m away from accessible greenspace had lower odds of achieving recommended physical activity levels than those who lived within 300 m; from 301–600 m (OR = 0.7; 95% CI 0.5–0.9) and from 601–900 m (OR = 0.6; 95% CI 0.4–0.8). There was substantial residual between-neighbourhood variance in physical activity (median odds ratio = 1.7). Other objectively measured neighbourhood-level characteristics were not associated with physical activity levels. Conclusions Distance to nearest greenspace is associated with meeting recommended physical activity levels in deprived London neighbourhoods. Despite residual variance in physical activity levels between neighbourhoods, we found little evidence for the influence of other measured neighbourhood-level characteristics. PMID:23922717

  15. [Walking abnormalities in children].

    PubMed

    Segawa, Masaya

    2010-11-01

    Walking is a spontaneous movement termed locomotion that is promoted by activation of antigravity muscles by serotonergic (5HT) neurons. Development of antigravity activity follows 3 developmental epochs of the sleep-wake (S-W) cycle and is modulated by particular 5HT neurons in each epoch. Activation of antigravity activities occurs in the first epoch (around the age of 3 to 4 months) as restriction of atonia in rapid eye movement (REM) stage and development of circadian S-W cycle. These activities strengthen in the second epoch, with modulation of day-time sleep and induction of crawling around the age of 8 months and induction of walking by 1 year. Around the age of 1 year 6 months, absence of guarded walking and interlimb cordination is observed along with modulation of day-time sleep to once in the afternoon. Bipedal walking in upright position occurs in the third epoch, with development of a biphasic S-W cycle by the age of 4-5 years. Patients with infantile autism (IA), Rett syndrome (RTT), or Tourette syndrome (TS) show failure in the development of the first, second, or third epoch, respectively. Patients with IA fail to develop interlimb coordination; those with RTT, crawling and walking; and those with TS, walking in upright posture. Basic pathophysiology underlying these condition is failure in restricting atonia in REM stage; this induces dysfunction of the pedunculopontine nucleus and consequently dys- or hypofunction of the dopamine (DA) neurons. DA hypofunction in the developing brain, associated with compensatory upward regulation of the DA receptors causes psychobehavioral disorders in infancy (IA), failure in synaptogenesis in the frontal cortex and functional development of the motor and associate cortexes in late infancy through the basal ganglia (RTT), and failure in functional development of the prefrontal cortex through the basal ganglia (TS). Further, locomotion failure in early childhood causes failure in development of functional

  16. The role of vegetation in the CO2 flux from a tropical urban neighbourhood

    NASA Astrophysics Data System (ADS)

    Velasco, E.; Roth, M.; Tan, S. H.; Quak, M.; Nabarro, S. D. A.; Norford, L.

    2013-03-01

    Urban surfaces are usually net sources of CO2. Vegetation can potentially have an important role in reducing the CO2 emitted by anthropogenic activities in cities, particularly when vegetation is extensive and/or evergreen. Negative daytime CO2 fluxes, for example have been observed during the growing season at suburban sites characterized by abundant vegetation and low population density. A direct and accurate estimation of carbon uptake by urban vegetation is difficult due to the particular characteristics of the urban ecosystem and high variability in tree distribution and species. Here, we investigate the role of urban vegetation in the CO2 flux from a residential neighbourhood in Singapore using two different approaches. CO2 fluxes measured directly by eddy covariance are compared with emissions estimated from emissions factors and activity data. The latter includes contributions from vehicular traffic, household combustion, soil respiration and human breathing. The difference between estimated emissions and measured fluxes should approximate the biogenic flux. In addition, a tree survey was conducted to estimate the annual CO2 sequestration using allometric equations and an alternative model of the metabolic theory of ecology for tropical forests. Palm trees, banana plants and turfgrass were also included in the survey with their annual CO2 uptake obtained from published growth rates. Both approaches agree within 2% and suggest that vegetation captures 8% of the total emitted CO2 in the residential neighbourhood studied. A net uptake of 1.4 ton km-2 day-1 (510 ton km-2 yr-1 ) was estimated from the difference between the daily CO2 uptake by photosynthesis (3.95 ton km-2 ) and release by respiration (2.55 ton km-2). The study shows the importance of urban vegetation at the local scale for climate change mitigation in the tropics.

  17. Neighbourhood deprivation and very preterm birth in an English and French cohort

    PubMed Central

    2013-01-01

    Background Social factors affect the risk of very preterm birth and may affect subsequent outcomes in those born preterm. We assessed the influence of neighbourhood socio-economic characteristics on the risk and outcomes of singleton very preterm birth (<32 weeks of gestation) in two European regions with different health systems. Methods Live births (n=1118) from a population-based cohort of very preterm infants in 2003 in Trent (UK) and Ile-de-France (France) regions were geocoded to their neighbourhood census tracts. Odds ratios for very preterm singleton birth by neighbourhood characteristics (unemployment rate, proportion manual workers, proportion with high school education only, non home ownership) were computed using infants enumerated in the census as a control population. The impact of neighbourhood variables was further assessed by pregnancy and delivery characteristics and short term infant outcomes. Results Risk of very preterm singleton birth was higher in more deprived neighbourhoods in both regions (OR between 2.5 and 1.5 in the most versus least deprived quartiles). No consistent associations were found between neighbourhood deprivation and maternal characteristics or health outcomes for very preterm births, although infants in more deprived neighbourhoods were less likely to be breastfed at discharge. Conclusions Neighbourhood deprivation had a strong consistent impact on the risk of singleton very preterm birth in two European regions, but did not appear to be associated with maternal characteristics or infant outcomes. Differences in breastfeeding at discharge suggest that socio-economic factors may affect long term outcomes. PMID:23617598

  18. Do Neighbours Affect Teenage Outcomes? Evidence from Neighbourhood Changes in England. CEE DP 122

    ERIC Educational Resources Information Center

    Gibbons, Stephen; Silva, Olmo; Weinhardt, Felix

    2010-01-01

    There are large disparities between the achievements, behaviour and aspirations of children growing up in different neighbourhoods. This has contributed to the view that neighbourhoods can determine individuals' outcomes. Notably, in the long run these effects could lead to larger social inequality and reduce social mobility, which is why they…

  19. Tensions and Troubles in Young People's Talk about Safety and Danger in a Violent Neighbourhood

    ERIC Educational Resources Information Center

    Parkes, Jenny

    2007-01-01

    This paper examines how young people living in a violent neighbourhood construct understandings about danger, violence and safety. Reporting findings from a qualitative study that investigated these issues with 8-14 year olds in a South African neighbourhood, the paper identifies how young people attempted to stay safe through reliance on adult…

  20. Urban Neighbourhood Quality and School Leaving Age: Gender Differences and Some Hypotheses

    ERIC Educational Resources Information Center

    Flouri, Eirini; Ereky-Stevens, Katharina

    2008-01-01

    This study used longitudinal data from the 1970 British Cohort Study (BCS70) to examine the role of neighbourhood quality, assessed when cohort members were aged five, in boys' and girls' school leaving age. It was expected that, since context is in general more strongly predictive of boys' rather than girls' behaviour, neighbourhood quality would…

  1. Neighbourhood Density Effects in Auditory Non-Word Processing in Aphasic Listeners

    ERIC Educational Resources Information Center

    Janse, Esther

    2009-01-01

    This study investigates neighbourhood density effects on lexical decision performance (both accuracy and response times) of aphasic patients. Given earlier results on lexical activation and deactivation in Broca's and Wernicke's aphasia, the prediction was that smaller neighbourhood density effects would be found for Broca's aphasic patients,…

  2. School Choice in Colorado Springs: The Relationship between Parental Decisions, Location and Neighbourhood Characteristics

    ERIC Educational Resources Information Center

    Theobald, Rebecca

    2005-01-01

    The influence of location as exemplified by neighbourhood factors and school characteristics on primary education is examined in the context of the school choice movement of the last two decades. The analysis incorporates statistical information about schools and population data from Census 2000 describing neighbourhoods and schools in one…

  3. Air Quality in Hamilton: Who Is Concerned? Perceptions from Three Neighbourhoods

    ERIC Educational Resources Information Center

    Simone, Dylan; Eyles, John; Newbold, K. Bruce; Kitchen, Peter; Williams, Allison

    2012-01-01

    This study investigates the factors influencing perceptions of air quality in the industrial city of Hamilton, Canada. The research employs data collected via a telephone survey of 1,002 adult residents in three neighbourhoods. Perceptions in the neighbourhoods were examined by individual socio-demographic factors (age, gender, marital and…

  4. Relativistic Weierstrass random walks.

    PubMed

    Saa, Alberto; Venegeroles, Roberto

    2010-08-01

    The Weierstrass random walk is a paradigmatic Markov chain giving rise to a Lévy-type superdiffusive behavior. It is well known that special relativity prevents the arbitrarily high velocities necessary to establish a superdiffusive behavior in any process occurring in Minkowski spacetime, implying, in particular, that any relativistic Markov chain describing spacetime phenomena must be essentially Gaussian. Here, we introduce a simple relativistic extension of the Weierstrass random walk and show that there must exist a transition time t{c} delimiting two qualitative distinct dynamical regimes: the (nonrelativistic) superdiffusive Lévy flights, for tt{c} . Implications of this crossover between different diffusion regimes are discussed for some explicit examples. The study of such an explicit and simple Markov chain can shed some light on several results obtained in much more involved contexts. PMID:20866862

  5. Discrete-time quantum walks: Continuous limit and symmetries

    SciTech Connect

    Molfetta, G. di; Debbasch, F.

    2012-12-15

    The continuous limit of one-dimensional discrete-time quantum walks with time-and space-dependent coefficients is investigated. A given quantum walk does not generally admit a continuous limit but some families (1-jets) of quantum walks do. All families (1-jets) admitting a continuous limit are identified. The continuous limit is described by a Dirac-like equation or, alternately, a couple of Klein-Gordon equations. Variational principles leading to these equations are also discussed, together with local invariance properties.

  6. Walking with springs

    NASA Astrophysics Data System (ADS)

    Sugar, Thomas G.; Hollander, Kevin W.; Hitt, Joseph K.

    2011-04-01

    Developing bionic ankles poses great challenges due to the large moment, power, and energy that are required at the ankle. Researchers have added springs in series with a motor to reduce the peak power and energy requirements of a robotic ankle. We developed a "robotic tendon" that reduces the peak power by altering the required motor speed. By changing the required speed, the spring acts as a "load variable transmission." If a simple motor/gearbox solution is used, one walking step would require 38.8J and a peak motor power of 257 W. Using an optimized robotic tendon, the energy required is 21.2 J and the peak motor power is reduced to 96.6 W. We show that adding a passive spring in parallel with the robotic tendon reduces peak loads but the power and energy increase. Adding a passive spring in series with the robotic tendon reduces the energy requirements. We have built a prosthetic ankle SPARKy, Spring Ankle with Regenerative Kinetics, that allows a user to walk forwards, backwards, ascend and descend stairs, walk up and down slopes as well as jog.

  7. Quantifying the link between art and property prices in urban neighbourhoods

    PubMed Central

    Seresinhe, Chanuki Illushka

    2016-01-01

    Is there an association between art and changes in the economic conditions of urban neighbourhoods? While the popular media and policymakers commonly believe this to be the case, quantitative evidence remains lacking. Here, we use metadata of geotagged photographs uploaded to the popular image-sharing platform Flickr to quantify the presence of art in London neighbourhoods. We estimate the presence of art in neighbourhoods by determining the proportion of Flickr photographs which have the word ‘art’ attached. We compare this with the relative gain in residential property prices for each Inner London neighbourhood. We find that neighbourhoods which have a higher proportion of ‘art’ photographs also have greater relative gains in property prices. Our findings demonstrate how online data can be used to quantify aspects of the visual environment at scale and reveal new connections between the visual environment and crucial socio-economic measurements. PMID:27152228

  8. Image signal-to-noise ratio estimation using adaptive slope nearest-neighbourhood model.

    PubMed

    Sim, K S; Teh, V

    2015-12-01

    A new technique based on nearest neighbourhood method is proposed. In this paper, considering the noise as Gaussian additive white noise, new technique single-image-based estimator is proposed. The performance of this new technique such as adaptive slope nearest neighbourhood is compared with three of the existing method which are original nearest neighbourhood (simple method), first-order interpolation method and shape-preserving piecewise cubic hermite autoregressive moving average. In a few cases involving images with different brightness and edges, this adaptive slope nearest neighbourhood is found to deliver an optimum solution for signal-to-noise ratio estimation problems. For different values of noise variance, the adaptive slope nearest neighbourhood has highest accuracy and less percentage estimation error. Being more robust with white noise, the new proposed technique estimator has efficiency that is significantly greater than those of the three methods. PMID:26292081

  9. Quantifying the link between art and property prices in urban neighbourhoods.

    PubMed

    Seresinhe, Chanuki Illushka; Preis, Tobias; Moat, Helen Susannah

    2016-04-01

    Is there an association between art and changes in the economic conditions of urban neighbourhoods? While the popular media and policymakers commonly believe this to be the case, quantitative evidence remains lacking. Here, we use metadata of geotagged photographs uploaded to the popular image-sharing platform Flickr to quantify the presence of art in London neighbourhoods. We estimate the presence of art in neighbourhoods by determining the proportion of Flickr photographs which have the word 'art' attached. We compare this with the relative gain in residential property prices for each Inner London neighbourhood. We find that neighbourhoods which have a higher proportion of 'art' photographs also have greater relative gains in property prices. Our findings demonstrate how online data can be used to quantify aspects of the visual environment at scale and reveal new connections between the visual environment and crucial socio-economic measurements. PMID:27152228

  10. Backward Walking in Parkinson Disease

    PubMed Central

    Hackney, Madeleine E.; Earhart, Gammon M.

    2010-01-01

    We walk backward on a daily basis, such as when backing away from the kitchen sink or stepping back from a curb as a swiftly moving bus passes. This task may be particularly difficult for individuals with PD who often fall as a result of moving or being perturbed in the backward direction (Horak et al. 2005, Bloem et al 2004). The aim of this study was to assess backward walking in individuals with PD. Both forward and backward gait were assessed in 78 people with idiopathic PD (H&Y range: 0.5–3) in the ON state, and 74 age- and sex-matched controls. In forward walking, those with PD had significantly shorter strides, lower swing percents, higher stance percents and lower functional ambulation profiles than controls. Both groups walked significantly slower and with a wider base of support during backward walking than forward walking. Additionally, in backward walking those with PD walked significantly slower with shorter strides, lower swing percents, and higher double support and stance percents, and lower functional ambulation profiles compared to controls. Those with mild to moderate PD have impaired forward and backward walking, but differences between those with and without PD are more pronounced in backward walking. PMID:18951535

  11. Relative contributions of neighbourhood and animal movements to Coxiella burnetii infection in dairy cattle herds.

    PubMed

    Nusinovici, Simon; Hoch, Thierry; Widgren, Stefan; Joly, Alain; Lindberg, Ann; Beaudeau, François

    2014-05-01

    Q fever in dairy cattle herds occurs mainly after inhalation of contaminated aerosols generated from excreta by shedder animals. Propagation of Coxiella burnetii, the cause of the disease between ruminant herds could result from transmission between neighbouring herds and/or the introduction of infected shedder animals in healthy herds. The objective of this study were (i) to describe the spatial distribution C. burnetii-infected dairy cattle herds in two different regions: the Finistère District in France (2,829 herds) and the island of Gotland in Sweden (119 herds) and (ii) to quantify and compare the relative contributions of C. burnetii transmission related to neighbourhood and to animal movements on the risk for a herd to be infected. An enzyme--linked immunosorbent assay was used for testing bulk tank milk in May 2012 and June 2011, respectively. Only one geographical cluster of positive herds was identified in north-western Finistère. Logistic regression was used to assess the association of risk for a herd to test positively with local cattle density (the total number of cattle located in a 5 km radius circle) and the in-degree (ID) parameter, a measure of the number of herds from which each herd had received animals directly within the last 2 years. The risk for a herd to test positively was higher for herds with a higher local cattle density [odds ratio (OR) = 2.3, 95% confidence interval (CI) = 1.6-3.2, for herds with a local density between 100 and 120 compared to herds with a local density 60]. The risk was also higher for herds with higher IDs (OR = 2.3, 95% CI = 1.6-3.2, for herds with ID 3 compared to herds that did not introduce animals). The proportion of cases attributable to infections in the neighbourhood in high-density areas was twice the proportion attributable to animal movements, suggesting that wind plays a main role in the transmission. PMID:24893024

  12. An Original Stepwise Multilevel Logistic Regression Analysis of Discriminatory Accuracy: The Case of Neighbourhoods and Health

    PubMed Central

    Wagner, Philippe; Ghith, Nermin; Leckie, George

    2016-01-01

    Background and Aim Many multilevel logistic regression analyses of “neighbourhood and health” focus on interpreting measures of associations (e.g., odds ratio, OR). In contrast, multilevel analysis of variance is rarely considered. We propose an original stepwise analytical approach that distinguishes between “specific” (measures of association) and “general” (measures of variance) contextual effects. Performing two empirical examples we illustrate the methodology, interpret the results and discuss the implications of this kind of analysis in public health. Methods We analyse 43,291 individuals residing in 218 neighbourhoods in the city of Malmö, Sweden in 2006. We study two individual outcomes (psychotropic drug use and choice of private vs. public general practitioner, GP) for which the relative importance of neighbourhood as a source of individual variation differs substantially. In Step 1 of the analysis, we evaluate the OR and the area under the receiver operating characteristic (AUC) curve for individual-level covariates (i.e., age, sex and individual low income). In Step 2, we assess general contextual effects using the AUC. Finally, in Step 3 the OR for a specific neighbourhood characteristic (i.e., neighbourhood income) is interpreted jointly with the proportional change in variance (i.e., PCV) and the proportion of ORs in the opposite direction (POOR) statistics. Results For both outcomes, information on individual characteristics (Step 1) provide a low discriminatory accuracy (AUC = 0.616 for psychotropic drugs; = 0.600 for choosing a private GP). Accounting for neighbourhood of residence (Step 2) only improved the AUC for choosing a private GP (+0.295 units). High neighbourhood income (Step 3) was strongly associated to choosing a private GP (OR = 3.50) but the PCV was only 11% and the POOR 33%. Conclusion Applying an innovative stepwise multilevel analysis, we observed that, in Malmö, the neighbourhood context per se had a negligible

  13. Learning and Skills for Neighbourhood Renewal: Final Report to the Neighbourhood Renewal Unit. Research Report.

    ERIC Educational Resources Information Center

    Taylor, Sue; Doyle, Lisa

    A study of adult learning and neighborhood renewal examined how further education (FE) colleges and Local Education Authority (LEA) adult education services contribute to neighborhood renewal in deprived areas and considered how their strategic role might develop in this field. The study indicates that the policy framework for post-16 learning and…

  14. Neighbourhood demolition, relocation and health. A qualitative longitudinal study of housing-led urban regeneration in Glasgow, UK

    PubMed Central

    Egan, Matt; Lawson, Louise; Kearns, Ade; Conway, Ellie; Neary, Joanne

    2015-01-01

    We conducted a qualitative longitudinal study to explore how adult residents of disadvantaged urban neighbourhoods (Glasgow, UK) experienced neighbourhood demolition and relocation. Data from 23 households was collected in 2011 and 2012. Some participants described moves to new or improved homes in different neighbourhoods as beneficial to their and their families’ wellbeing. Others suggested that longstanding illnesses and problems with the new home and/or neighbourhood led to more negative experiences. Individual-level contextual differences, home and neighbourhood-level factors and variations in intervention implementation influence the experiences of residents involved in relocation programmes. PMID:25814338

  15. Neighbourhood demolition, relocation and health. A qualitative longitudinal study of housing-led urban regeneration in Glasgow, UK.

    PubMed

    Egan, Matt; Lawson, Louise; Kearns, Ade; Conway, Ellie; Neary, Joanne

    2015-05-01

    We conducted a qualitative longitudinal study to explore how adult residents of disadvantaged urban neighbourhoods (Glasgow, UK) experienced neighbourhood demolition and relocation. Data from 23 households was collected in 2011 and 2012. Some participants described moves to new or improved homes in different neighbourhoods as beneficial to their and their families' wellbeing. Others suggested that longstanding illnesses and problems with the new home and/or neighbourhood led to more negative experiences. Individual-level contextual differences, home and neighbourhood-level factors and variations in intervention implementation influence the experiences of residents involved in relocation programmes. PMID:25814338

  16. Agile Walking Robot

    NASA Technical Reports Server (NTRS)

    Larimer, Stanley J.; Lisec, Thomas R.; Spiessbach, Andrew J.; Waldron, Kenneth J.

    1990-01-01

    Proposed agile walking robot operates over rocky, sandy, and sloping terrain. Offers stability and climbing ability superior to other conceptual mobile robots. Equipped with six articulated legs like those of insect, continually feels ground under leg before applying weight to it. If leg sensed unexpected object or failed to make contact with ground at expected point, seeks alternative position within radius of 20 cm. Failing that, robot halts, examines area around foot in detail with laser ranging imager, and replans entire cycle of steps for all legs before proceeding.

  17. Built Environment Influences of Children's Physical Activity: Examining Differences by Neighbourhood Size and Sex.

    PubMed

    Mitchell, Christine A; Clark, Andrew F; Gilliland, Jason A

    2016-01-01

    Neighbourhoods can facilitate or constrain moderate-to-vigorous physical activity (MVPA) among children by providing or restricting opportunities for MVPA. However, there is no consensus on how to define a child's neighbourhood. This study examines the influence of the neighbourhood built environment on objectively measured MVPA among 435 children (aged 9-14 years) in London (ON, Canada). As there is no consensus on how to delineate a child's neighbourhood, a geographic information system was used to generate measures of the neighbourhood built environment at two buffer sizes (500 m and 800 m) around each child's home. Linear regression models with robust standard errors (cluster) were used to analyze the relationship between built environment characteristics and average daily MVPA during non-school hours on weekdays. Sex-stratified models assessed sex-specific relationships. When accounting for individual and neighbourhood socio-demographic variables, park space and multi-use path space were found to influence children's MVPA. Sex-stratified models found significant associations between MVPA and park space, with the 800 m buffer best explaining boys' MVPA and the 500 m buffer best explaining girls' MVPA. Findings emphasize that, when designing built environments, programs, and policies to facilitate physical activity, it is important to consider that the size of the neighbourhood influencing a child's physical activity may differ according to sex. PMID:26784212

  18. Built Environment Influences of Children’s Physical Activity: Examining Differences by Neighbourhood Size and Sex

    PubMed Central

    Mitchell, Christine A.; Clark, Andrew F.; Gilliland, Jason A.

    2016-01-01

    Neighbourhoods can facilitate or constrain moderate-to-vigorous physical activity (MVPA) among children by providing or restricting opportunities for MVPA. However, there is no consensus on how to define a child’s neighbourhood. This study examines the influence of the neighbourhood built environment on objectively measured MVPA among 435 children (aged 9–14 years) in London (ON, Canada). As there is no consensus on how to delineate a child’s neighbourhood, a geographic information system was used to generate measures of the neighbourhood built environment at two buffer sizes (500 m and 800 m) around each child’s home. Linear regression models with robust standard errors (cluster) were used to analyze the relationship between built environment characteristics and average daily MVPA during non-school hours on weekdays. Sex-stratified models assessed sex-specific relationships. When accounting for individual and neighbourhood socio-demographic variables, park space and multi-use path space were found to influence children’s MVPA. Sex-stratified models found significant associations between MVPA and park space, with the 800 m buffer best explaining boys’ MVPA and the 500 m buffer best explaining girls’ MVPA. Findings emphasize that, when designing built environments, programs, and policies to facilitate physical activity, it is important to consider that the size of the neighbourhood influencing a child’s physical activity may differ according to sex. PMID:26784212

  19. Quantum walks and discrete gauge theories

    NASA Astrophysics Data System (ADS)

    Arnault, Pablo; Debbasch, Fabrice

    2016-05-01

    A particular example is produced to prove that quantum walks can be used to simulate full-fledged discrete gauge theories. A family of two-dimensional walks is introduced and its continuous limit is shown to coincide with the dynamics of a Dirac fermion coupled to arbitrary electromagnetic fields. The electromagnetic interpretation is extended beyond the continuous limit by proving that these discrete-time quantum walks (DTQWs) exhibit an exact discrete local U(1) gauge invariance and possess a discrete gauge-invariant conserved current. A discrete gauge-invariant electromagnetic field is also constructed and that field is coupled to the conserved current by a discrete generalization of Maxwell equations. The dynamics of the DTQWs under crossed electric and magnetic fields is finally explored outside the continuous limit by numerical simulations. Bloch oscillations and the so-called E ×B drift are recovered in the weak-field limit. Localization is observed for some values of the gauge fields.

  20. To walk or not to walk: insights from a qualitative description study with women suffering from fibromyalgia.

    PubMed

    Sanz-Baños, Yolanda; Pastor, María-Ángeles; Velasco, Lilian; López-Roig, Sofía; Peñacoba, Cecilia; Lledo, Ana; Rodríguez, Charo

    2016-08-01

    Walking improves health outcomes in fibromyalgia; however, there is low adherence to this practice. The aim of this research was to explore the beliefs of women suffering from fibromyalgia toward walking, and the meaning that they attribute to the behavior of walking as part of their fibromyalgia treatment. This study is a qualitative description research. Forty-six (46) women suffering from fibromyalgia and associated with local fibromyalgia associations located in four different Spanish cities (Elche, Alicante, Madrid, and Talavera de la Reina) participated in focus group discussions in the summer 2012. Thematic content analysis was performed in transcribed verbatim from interviews. Participants perceived several inhibitors for walking even when they had positive beliefs toward its therapeutic value. Whereas participants believed that walking can generate improvement in their disease and their health in general, they did not feel able to actually do so given their many physical impediments. Furthermore, participants struggled with social isolation and stigma, which was lessened through the conscious support of family. Advice from family doctors was also a very important facilitator to participants. In a health care delivery context that favors person-centered care, and in order to foster adherence to walking-based fibromyalgia treatments, it is recommended that therapeutic walking programs be tailored to each woman' individual circumstances, and developed in close collaboration with them to help them increase control over their health and their condition. PMID:26979604

  1. Coalescent simulation in continuous space: algorithms for large neighbourhood size.

    PubMed

    Kelleher, J; Etheridge, A M; Barton, N H

    2014-08-01

    Many species have an essentially continuous distribution in space, in which there are no natural divisions between randomly mating subpopulations. Yet, the standard approach to modelling these populations is to impose an arbitrary grid of demes, adjusting deme sizes and migration rates in an attempt to capture the important features of the population. Such indirect methods are required because of the failure of the classical models of isolation by distance, which have been shown to have major technical flaws. A recently introduced model of extinction and recolonisation in two dimensions solves these technical problems, and provides a rigorous technical foundation for the study of populations evolving in a spatial continuum. The coalescent process for this model is simply stated, but direct simulation is very inefficient for large neighbourhood sizes. We present efficient and exact algorithms to simulate this coalescent process for arbitrary sample sizes and numbers of loci, and analyse these algorithms in detail. PMID:24910324

  2. Noisy neighbourhoods: quorum sensing in fungal–polymicrobial infections

    PubMed Central

    Dixon, Emily F.

    2015-01-01

    Summary Quorum sensing was once considered a way in which a species was able to sense its cell density and regulate gene expression accordingly. However, it is now becoming apparent that multiple microbes can sense particular quorum‐sensing molecules, enabling them to sense and respond to other microbes in their neighbourhood. Such interactions are significant within the context of polymicrobial disease, in which the competition or cooperation of microbes can alter disease progression. Fungi comprise a small but important component of the human microbiome and are in constant contact with bacteria and viruses. The discovery of quorum‐sensing pathways in fungi has led to the characterization of a number of interkingdom quorum‐sensing interactions. Here, we review the recent developments in quorum sensing in medically important fungi, and the implications these interactions have on the host's innate immune response. PMID:26243526

  3. The Multipupil Fiber Spectroscopy of the Crab-pulsar Neighbourhood

    NASA Astrophysics Data System (ADS)

    Zharikov, S.; Shibanov, Y.; Koptsevich, A.; Afanas'ev, V.; Dodonov, S.

    2001-03-01

    We present the spatially resolved optical spectroscopy of the 12 arcsec × 24 arcsec Crab pulsar neighbourhood in the range λ λ 4600 - 5700 Å made with the Multipupil Fiber Spectrograph at the 6 m telescope of the SAO RAS. The spectra exhibit blue- and red-shifted strong [O III] and weaker Hβ and He II emission lines with the shifts and intensities varying with the position in the field. They hint the presence of a cone-like rotating structure centered at the pulsar position and oriented along the symmetry axis of the compact, torus-like pulsar nebula seen in optical continuum and soft X-rays. The kinematic structure is most likely associated with the pulsar nebula. If so, the compact nebular rotates counter-clockwise with respect to its symmetry axis, or the pulsar spin axis, and the estimated rotational velocity within cylindrical radii of several thousand AU from the pulsar is ~ 2000-3000 km/s.

  4. Random-walk enzymes

    NASA Astrophysics Data System (ADS)

    Mak, Chi H.; Pham, Phuong; Afif, Samir A.; Goodman, Myron F.

    2015-09-01

    Enzymes that rely on random walk to search for substrate targets in a heterogeneously dispersed medium can leave behind complex spatial profiles of their catalyzed conversions. The catalytic signatures of these random-walk enzymes are the result of two coupled stochastic processes: scanning and catalysis. Here we develop analytical models to understand the conversion profiles produced by these enzymes, comparing an intrusive model, in which scanning and catalysis are tightly coupled, against a loosely coupled passive model. Diagrammatic theory and path-integral solutions of these models revealed clearly distinct predictions. Comparison to experimental data from catalyzed deaminations deposited on single-stranded DNA by the enzyme activation-induced deoxycytidine deaminase (AID) demonstrates that catalysis and diffusion are strongly intertwined, where the chemical conversions give rise to new stochastic trajectories that were absent if the substrate DNA was homogeneous. The C →U deamination profiles in both analytical predictions and experiments exhibit a strong contextual dependence, where the conversion rate of each target site is strongly contingent on the identities of other surrounding targets, with the intrusive model showing an excellent fit to the data. These methods can be applied to deduce sequence-dependent catalytic signatures of other DNA modification enzymes, with potential applications to cancer, gene regulation, and epigenetics.

  5. Random-walk enzymes

    PubMed Central

    Mak, Chi H.; Pham, Phuong; Afif, Samir A.; Goodman, Myron F.

    2015-01-01

    Enzymes that rely on random walk to search for substrate targets in a heterogeneously dispersed medium can leave behind complex spatial profiles of their catalyzed conversions. The catalytic signatures of these random-walk enzymes are the result of two coupled stochastic processes: scanning and catalysis. Here we develop analytical models to understand the conversion profiles produced by these enzymes, comparing an intrusive model, in which scanning and catalysis are tightly coupled, against a loosely coupled passive model. Diagrammatic theory and path-integral solutions of these models revealed clearly distinct predictions. Comparison to experimental data from catalyzed deaminations deposited on single-stranded DNA by the enzyme activation-induced deoxycytidine deaminase (AID) demonstrates that catalysis and diffusion are strongly intertwined, where the chemical conversions give rise to new stochastic trajectories that were absent if the substrate DNA was homogeneous. The C → U deamination profiles in both analytical predictions and experiments exhibit a strong contextual dependence, where the conversion rate of each target site is strongly contingent on the identities of other surrounding targets, with the intrusive model showing an excellent fit to the data. These methods can be applied to deduce sequence-dependent catalytic signatures of other DNA modification enzymes, with potential applications to cancer, gene regulation, and epigenetics. PMID:26465508

  6. Evaluation of aerosol processes between roadside and neighbourhood scale

    NASA Astrophysics Data System (ADS)

    Karl, Matthias; Kukkonen, Jaakko; Pirjola, Liisa; Keuken, Menno P.

    2015-04-01

    Particle emissions from road transport include vehicle exhaust emissions, tire/brake wear and re-suspension of road dust. Vehicle exhaust emissions usually constitute the most significant source of ultrafine particles (UFP), i.e. particles with diameters <100 nm, in urban environments. Several toxicological studies have concluded that UFP are more toxic than larger particles with the same chemical composition and at the same mass concentration. Since UFP contribute negligibly to the mass concentration of PM10 and PM2.5, they should be described in terms of particle number (PN) concentration. However, only PM10 and PM2.5 are regulated by current air pollution legislation. UFP emitted from road traffic are subject to complex dilution and transformation processes in the urban environment. This model study evaluates the influence of aerosol processes on PN concentration on the spatial and temporal range between the roadside, typically represented by measurements at a traffic monitoring site, and the neighbourhood scale, extending from several hundred meters to several kilometres. Several dispersion scenarios for the cities Oslo, Helsinki and Rotterdam were simulated using the multicomponent aerosol dynamics process model MAFOR, approximating dilution by a power-law function. Aerosol processes considered in this study were condensation/evaporation of n-alkanes, coagulation and the dry deposition of particles. Under typical dispersion conditions dilution clearly dominated the change of total PN on the neighbourhood scale. Dry deposition and coagulation of particles were identified to be the most important aerosol dynamical processes controlling the removal of particles from emitted from vehicular exhaust on urban time scales. The effect of condensation/evaporation of organic vapours emitted by vehicles on particle numbers and on particle size distributions was examined. A simplified parameterization for the implementation of coagulation and dry deposition of particles in

  7. Quantum stochastic walks: A generalization of classical random walks and quantum walks

    NASA Astrophysics Data System (ADS)

    Whitfield, James D.; Rodríguez-Rosario, César A.; Aspuru-Guzik, Alán

    2010-02-01

    We introduce the quantum stochastic walk (QSW), which determines the evolution of a generalized quantum-mechanical walk on a graph that obeys a quantum stochastic equation of motion. Using an axiomatic approach, we specify the rules for all possible quantum, classical, and quantum-stochastic transitions from a vertex as defined by its connectivity. We show how the family of possible QSWs encompasses both the classical random walk (CRW) and the quantum walk (QW) as special cases but also includes more general probability distributions. As an example, we study the QSW on a line and the glued tree of depth three to observe the behavior of the QW-to-CRW transition.

  8. The relationship of individual and neighbourhood deprivation with morbidity in older adults: an observational study.

    PubMed

    Jordan, Kelvin P; Hayward, Richard; Roberts, Eyitope; Edwards, John J; Kadam, Umesh T

    2014-06-01

    The objective was to determine the relative association of social class and neighbourhood deprivation with primary care consultation for eight morbidities. In 18,047 survey responders aged ≥50 years, living in more deprived neighbourhoods was independently associated with new consultation for chronic obstructive pulmonary disease, ischaemic heart disease, diabetes, asthma and depression. Lower social class was associated with diabetes and chronic obstructive pulmonary disease. No such associations were found with otitis media, osteoarthritis or upper respiratory tract infection. These findings suggest a role of social environment in certain morbidities and indicate the importance of identifying and acting on neighbourhood deprivation to reduce health inequalities. PMID:24148556

  9. Earthquake risk communication as dialogue - insights from a workshop in Istanbul's urban renewal neighbourhoods

    NASA Astrophysics Data System (ADS)

    Ickert, Johanna; Stewart, Iain S.

    2016-05-01

    An important paradox of hazard communication is that the more effectively a potential physical threat is made public by the scientist, the more readily the scientific message becomes normalized into the daily discourses of ordinary life. As a result, a heightened risk awareness does not necessarily motivate personal or collective preparedness. If geoscientists are to help at-risk communities adopt meaningful measures to protect themselves, new strategies are needed for public communication and community engagement. This paper outlines an attempt to develop a novel approach to train geoscientists, using doctoral and post-doctoral researchers in an EU integrated training network studying tectonic processes and geohazards in Turkey. An urban field visit to seismically vulnerable neighbourhoods in Istanbul allowed the researchers to meet with local residents facing the seismic threat. Those meetings exposed the complex social, political and cultural concerns among Istanbul's at-risk urban communities. These concerns were used to provoke subsequent focus group discussions among the group of geoscientists about roles, responsibilities and methods of communicating hazard information to the public. Through the direct testimony of local residents and geoscientists, we explore the form that new strategies for public communication and community engagement might take.

  10. Recruiting participants to walking intervention studies: a systematic review

    PubMed Central

    2011-01-01

    Purpose Most researchers who are conducting physical activity trials face difficulties in recruiting participants who are representative of the population or from specific population groups. Participants who are often the hardest to recruit are often those who stand to benefit most (the least active, from ethnic and other minority groups, from neighbourhoods with high levels of deprivation, or have poor health). The aim of our study was to conduct a systematic review of published literature of walking interventions, in order to identify the impact, characteristics, and differential effects of recruitment strategies among particular population groups. Methods We conducted standard searches for studies from four sources, (i) electronic literature databases and websites, (ii) grey literature from internet sources, (iii) contact with experts to identify additional "grey" and other literature, and (iv) snowballing from reference lists of retrieved articles. Included studies were randomised controlled trials, controlled before-and-after experimental or observational qualitative studies, examining the effects of an intervention to encourage people to walk independently or in a group setting, and detailing methods of recruitment. Results Forty seven studies met the inclusion criteria. The overall quality of the descriptions of recruitment in the studies was poor with little detail reported on who undertook recruitment, or how long was spent planning/preparing and implementing the recruitment phase. Recruitment was conducted at locations that either matched where the intervention was delivered, or where the potential participants were asked to attend for the screening and signing up process. We identified a lack of conceptual clarity about the recruitment process and no standard metric to evaluate the effectiveness of recruitment. Conclusion Recruitment concepts, methods, and reporting in walking intervention trials are poorly developed, adding to other limitations in the

  11. Associations between Moderate-to-Vigorous Physical Activity and Neighbourhood Recreational Facilities: The Features of the Facilities Matter

    PubMed Central

    Lee, Ka Yiu; Lee, Paul H.; Macfarlane, Duncan

    2014-01-01

    Objectives: To examine the associations between objectively-assessed moderate-to-vigorous physical activity (MVPA) and perceived/objective measures of neighbourhood recreational facilities categorized into indoor or outdoor, public, residential or commercial facilities. The associations between facility perceptions and objectively-assessed numbers of recreational facilities were also examined. Method: A questionnaire was used on 480 adults to measure local facility perceptions, with 154 participants wearing ActiGraph accelerometers for ≥4 days. The objectively-assessed number of neighbourhood recreational facilities were examined using direct observations and Geographical Information System data. Results: Both positive and negative associations were found between MVPA and perceived/objective measures of recreational facilities. Some associations depended on whether the recreational facilities were indoor or outdoor, public or residential facilities. The objectively-assessed number of most public recreational facilities was associated with the corresponding facility perceptions, but the size of effect was generally lower than for residential recreational facilities. Conclusions: The objectively-assessed number of residential outdoor table tennis courts and public indoor swimming pools, the objectively-assessed presence of tennis courts and swimming pools, and the perceived presence of bike lanes and swimming pools were positive determinants of MVPA. It is suggested to categorize the recreational facilities into smaller divisions in order to identify unique associations with MVPA. PMID:25485980

  12. Endless self-avoiding walks

    NASA Astrophysics Data System (ADS)

    Clisby, Nathan

    2013-06-01

    We introduce a self-avoiding walk model for which end-effects are completely eliminated. We enumerate the number of these walks for various lattices in dimensions two and three, and use these enumerations to study the properties of this model. We find that endless self-avoiding walks have the same connective constant as self-avoiding walks, and the same Flory exponent ν. However, there is no power law correction to the exponential number growth for this new model, i.e. the critical exponent γ = 1 exactly in any dimension. In addition, the number growth has no analytic corrections to scaling, and we have convincing numerical evidence to support the conjecture that the amplitude for the number growth is a universal quantity. The technique by which end-effects are eliminated may be generalized to other models of polymers such as interacting self-avoiding walks.

  13. Quantum walks on quotient graphs

    SciTech Connect

    Krovi, Hari; Brun, Todd A.

    2007-06-15

    A discrete-time quantum walk on a graph {gamma} is the repeated application of a unitary evolution operator to a Hilbert space corresponding to the graph. If this unitary evolution operator has an associated group of symmetries, then for certain initial states the walk will be confined to a subspace of the original Hilbert space. Symmetries of the original graph, given by its automorphism group, can be inherited by the evolution operator. We show that a quantum walk confined to the subspace corresponding to this symmetry group can be seen as a different quantum walk on a smaller quotient graph. We give an explicit construction of the quotient graph for any subgroup H of the automorphism group and illustrate it with examples. The automorphisms of the quotient graph which are inherited from the original graph are the original automorphism group modulo the subgroup H used to construct it. The quotient graph is constructed by removing the symmetries of the subgroup H from the original graph. We then analyze the behavior of hitting times on quotient graphs. Hitting time is the average time it takes a walk to reach a given final vertex from a given initial vertex. It has been shown in earlier work [Phys. Rev. A 74, 042334 (2006)] that the hitting time for certain initial states of a quantum walks can be infinite, in contrast to classical random walks. We give a condition which determines whether the quotient graph has infinite hitting times given that they exist in the original graph. We apply this condition for the examples discussed and determine which quotient graphs have infinite hitting times. All known examples of quantum walks with hitting times which are short compared to classical random walks correspond to systems with quotient graphs much smaller than the original graph; we conjecture that the existence of a small quotient graph with finite hitting times is necessary for a walk to exhibit a quantum speedup.

  14. Walking indoors, walking outdoors: an fMRI study

    PubMed Central

    Dalla Volta, Riccardo; Fasano, Fabrizio; Cerasa, Antonio; Mangone, Graziella; Quattrone, Aldo; Buccino, Giovanni

    2015-01-01

    An observation/execution matching system for walking has not been assessed yet. The present fMRI study was aimed at assessing whether, as for object-directed actions, an observation/execution matching system is active for walking and whether the spatial context of walking (open or narrow space) recruits different neural correlates. Two experimental conditions were employed. In the execution condition, while being scanned, participants performed walking on a rolling cylinder located just outside the scanner. The same action was performed also while observing a video presenting either an open space (a country field) or a narrow space (a corridor). In the observation condition, participants observed a video presenting an individual walking on the same cylinder on which the actual action was executed, the open space video and the narrow space video, respectively. Results showed common bilateral activations in the dorsal premotor/supplementary motor areas and in the posterior parietal lobe for both execution and observation of walking, thus supporting a matching system for this action. Moreover, specific sectors of the occipital–temporal cortex and the middle temporal gyrus were consistently active when processing a narrow space versus an open one, thus suggesting their involvement in the visuo-motor transformation required when walking in a narrow space. We forward that the present findings may have implications for rehabilitation of gait and sport training. PMID:26483745

  15. Comparison of heart rate responses. Water walking versus treadmill walking.

    PubMed

    Whitley, J D; Schoene, L L

    1987-10-01

    The purpose of this study was to compare heart rate responses to water walking versus treadmill walking to determine whether the responses were of sufficient magnitude to elicit cardiorespiratory training effects. The heart rates of 12 healthy, female college students were measured immediately after walking in waist-deep water and on a treadmill at the same distance, durations, and speeds (2.55, 2.77, 3.02, and 3.31 km/hr). A significant increase in heart rate with increased speeds resulted from water walking (p less than .05); from rest to the fastest speed, it was 135% (96 bpm). For treadmill walking, the increase of 19% (13 bpm) was not significant. The heart rates for the water condition were significantly higher (p less than .05) at each speed. These findings indicate that water walking could serve as an effective exercise mode, for example, for cardiorespiratory fitness for individuals who are unable to perform such weight-bearing activities as jogging, fast walking, cycling, and dancing. PMID:3659133

  16. Water-walking devices

    NASA Astrophysics Data System (ADS)

    Hu, David L.; Prakash, Manu; Chan, Brian; Bush, John W. M.

    2007-11-01

    We report recent efforts in the design and construction of water-walking machines inspired by insects and spiders. The fundamental physical constraints on the size, proportion and dynamics of natural water-walkers are enumerated and used as design criteria for analogous mechanical devices. We report devices capable of rowing along the surface, leaping off the surface and climbing menisci by deforming the free surface. The most critical design constraint is that the devices be lightweight and non-wetting. Microscale manufacturing techniques and new man-made materials such as hydrophobic coatings and thermally actuated wires are implemented. Using high-speed cinematography and flow visualization, we compare the functionality and dynamics of our devices with those of their natural counterparts.

  17. Water-walking devices

    NASA Astrophysics Data System (ADS)

    Hu, David L.; Prakash, Manu; Chan, Brian; Bush, John W. M.

    We report recent efforts in the design and construction of water-walking machines inspired by insects and spiders. The fundamental physical constraints on the size, proportion and dynamics of natural water-walkers are enumerated and used as design criteria for analogous mechanical devices. We report devices capable of rowing along the surface, leaping off the surface and climbing menisci by deforming the free surface. The most critical design constraint is that the devices be lightweight and non-wetting. Microscale manufacturing techniques and new man-made materials such as hydrophobic coatings and thermally actuated wires are implemented. Using highspeed cinematography and flow visualization, we compare the functionality and dynamics of our devices with those of their natural counterparts.

  18. Diffraction of walking droplets

    NASA Astrophysics Data System (ADS)

    Harris, Daniel M.; Pucci, Giuseppe; Bush, John W. M.

    2014-11-01

    We present results from our revisitation of the experiment of a walking droplet passing through a single slit, originally investigated by Couder & Fort (PRL, 2006). On each passage, the walker's trajectory is deviated as a result of the spatial confinement of its guiding wave. We explore the role of the droplet size and the bath's vibration amplitude on both the dynamics and statistics. We find the behavior to be remarkably sensitive to these control parameters. A complex physical picture emerges. The authors gratefully acknowledge the financial support of the NSF through Grant CMMI-1333242, DMH through the NSF Graduate Research Fellowship Program, and GP through the Programma Operativo Regionale (POR) Calabria - FSE 2007/2013.

  19. Social change or business as usual at city hall? Examining an urban municipal government's response to neighbourhood-level health inequities.

    PubMed

    Cahuas, Madelaine C; Wakefield, Sarah; Peng, Yun

    2015-05-01

    There is a renewed interest in the potential of municipal governments working collaboratively with local communities to address health inequities. A growing body of literature has also highlighted the benefits and limitations of participatory approaches in neighbourhood interventions initiated by municipal governments. However, few studies have investigated how neighbourhood interventions tackling health inequities work in real-time and in context, from the perspectives of Community Developers (CDs) who promote community participation. This study uses a process evaluation approach and semi-structured interviews with CDs to explore the challenges they face in implementing a community development, participatory process in the City of Hamilton's strategy to reduce health inequities - Neighbourhood Action. Findings demonstrate that municipal government can facilitate and suppress community participation in complex ways. CDs serve as significant but conflicted intermediaries as they negotiate and navigate power differentials between city and community actors, while also facing structural challenges. We conclude that community participation is important to bottom-up, resident-led social change, and that CDs are central to this work. PMID:25245453

  20. Residential outcomes of forced relocation: lifting a corner of the veil on neighbourhood selection.

    PubMed

    Doff, Wenda; Kleinhans, Reinout

    2011-01-01

    Fear of the detrimental effects of ethnic segregation has pervaded the debate on the population composition of cities and neighbourhoods. However, little is known about mechanisms underlying the spatial sorting of ethnic minorities. Hence, policies aimed at desegregation may result in exactly the opposite - that is, new ethnic concentrations and segregation. This paper studies the residential outcomes of 658 forced movers from urban restructuring areas in The Hague. Compared with "native" Dutch (those with both parents born in the Netherlands), ethnic minorities report neighbourhood improvement less often and are more likely to stay within or move into other ethnically concentrated neighbourhoods. These differences are not fully explained by differences in individual characteristics, resources, institutional factors, pre-relocation preferences or other relocation outcomes. Ethnic specificities in neighbourhood choices thus remain a pressing issue for further research. PMID:21584982

  1. Life expectancy, economic inequality, homicide, and reproductive timing in Chicago neighbourhoods.

    PubMed

    Wilson, M; Daly, M

    1997-04-26

    In comparisons among Chicago neighbourhoods, homicide rates in 1988-93 varied more than 100-fold, while male life expectancy at birth ranged from 54 to 77 years, even with effects of homicide mortality removed. This "cause deleted" life expectancy was highly correlated with homicide rates; a measure of economic inequality added significant additional prediction, whereas median household income did not. Deaths from internal causes (diseases) show similar age patterns, despite different absolute levels, in the best and worst neighbourhoods, whereas deaths from external causes (homicide, accident, suicide) do not. As life expectancy declines across neighbourhoods, women reproduce earlier; by age 30, however, neighbourhood no longer affects age specific fertility. These results support the hypothesis that life expectancy itself may be a psychologically salient determinant of risk taking and the timing of life transitions. PMID:9154035

  2. Exploring the Relationship Between Perceptions of Neighbourhoodresources, Sense of Coherence and Health for Different Groups in a Norwegian Neighbourhood

    PubMed Central

    Maass, Ruca; Lindstrøm, Bengt; Lillefjell, Monica

    2014-01-01

    Background Health and conditions for health are unevenly distributed across neighbourhoods. Within a salutogenic perspective, neighbourhood-resources can be internalised, and become generalised resistance resources. This paper aims to examine whether the neighbourhood could be a supportive arena for health-promotion, and for whom. Design and Methods A cross-sectional study, based on register data from the population-survey in Malvik, Norway, (N=865) was conducted. Using multiple regression analysis, total sample and sub-group analyses (men/women, low/high earners, employed/unemployed) of 5 independent neighbourhood-measures (overall satisfaction, neighbourhood Social Capital, satisfaction with availability and quality of neighbourhood-resources, and neighbourhood participation) on Sense of Coherence (SOC) and health respectively were obtained. Results Overall satisfaction (β=0.153) and neighbourhood social capital (β=0.134) emerged as the most consistent partial correlates of SOC across groups. In turn, SOC was the strongest coefficient for health-outcomes (β=0.238). Neighbourhood participation had more consistent correlations with health than SOC across groups. Group-differences became visible in proportions of explained variance in SOC (varying from 7 to 23.7%) and health (varying from 6.7 to 20.6%), and in the relative importance of neighbourhood-variables. Satisfaction with quality of neighbourhood-resources was significantly related to SOC in non-workers (β=0.451) and low-earners (β=0.261), and health-outcomes in women (β=0.143). Conclusions Health might be promoted in the neighbourhood mainly through strengthening SOC, and deprived groups, especially non-workers, may benefit most from health-promotion in the neighbourhood. Findings suggest that high satisfaction with quality can contribute to better health-outcomes for groups with weaker average SOC. The proposed theoretical framework is only partly supported. Significance for public health The creation

  3. Latino youth’s internalising behaviours: links to immigrant status and neighbourhood characteristics

    PubMed Central

    Lara-Cinisomo, Sandraluz; Xue, Yange; Brooks-Gunn, Jeanne

    2014-01-01

    Objectives Latinos are the fastest-growing immigrant group in the USA. Yet, little is known about the emotional well-being of this population, such as the links among family, neighbourhood context and Latino immigrant youth mental health. Understanding this link will help determine which contexts negatively impact Latino immigrant youth mental health. Design Drawing data from the Project on Human Development in Chicago Neighbourhoods collected in 1994–1995 and 1997–1999, this study examined links between Latino youth’s internalising behaviours, based on the Child Behavior Checklist (CBCL), and neighbourhood characteristics as a function of immigrant status. The sample included 1040 (aged 9–17) Latino immigrant youth seen twice over three years and identified as first, second or third generation. In this study, neighbourhoods are made up of two to three census tracts that reflect similar racial/ethnic and socioeconomic composition. Using hierarchical linear regression models, the study also explored links between internalising behaviours and neighbourhood characteristics, including concentrated disadvantage, immigrant concentration and residential stability. Results First- and second-generation youth had higher internalising behaviour scores (i.e., worse mental health) than third-generation youth after controlling for youth internalising behaviours at Wave 1, maternal depression and family characteristics. First- and second-generation youth were more likely to live in high immigrant-concentrated neighbourhoods and first-generation youth were more likely to live in residentially unstable neighbourhoods. Controlling for neighbourhood clusters eliminated the immigrant-generation internalising association. However, second-generation Latino youth living in neighbourhoods with higher residential stability had higher levels of internalising behaviour problems compared to first- and third-generation youth living in similar neighbourhoods. Conclusions We found that

  4. Quantum stochastic walks: A generalization of classical random walks and quantum walks

    NASA Astrophysics Data System (ADS)

    Aspuru-Guzik, Alan

    2010-03-01

    We introduce the quantum stochastic walk (QSW), which determines the evolution of generalized quantum mechanical walk on a graph that obeys a quantum stochastic equation of motion. Using an axiomatic approach, we specify the rules for all possible quantum, classical and quantum-stochastic transitions from a vertex as defined by its connectivity. We show how the family of possible QSWs encompasses both the classical random walk (CRW) and the quantum walk (QW) as special cases, but also includes more general probability distributions. As an example, we study the QSW on a line, the QW to CRW transition and transitions to genearlized QSWs that go beyond the CRW and QW. QSWs provide a new framework to the study of quantum algorithms as well as of quantum walks with environmental effects.

  5. Time to prioritise safe walking.

    PubMed

    Toroyan, Tami; Khayesi, Meleckidzedeck; Peden, Margie

    2013-01-01

    This study draws on information from two recently published documents on pedestrian safety and global status of road safety to draw attention to the need to prioritize safe walking in planning and policy at local, national and international levels. The study shows that each year, more than 270 000 pedestrians lose their lives on the world's roads. The study argues that this situation need not persist because proven pedestrian safety interventions exist but do not attract the merit they deserve in many locations. The study further shows that the key risk factors for pedestrian road traffic injury such as vehicle speed, alcohol use by drivers and pedestrians, lack of infrastructure facilities for pedestrians and inadequate visibility of pedestrians are fairly well documented. The study concludes that pedestrian collisions, like all road traffic crashes, should not be accepted as inevitable because they are, in fact, both predictable and preventable. While stressing that reduction or elimination of risks faced by pedestrians is an important and achievable policy goal, the study emphasizes the importance of a comprehensive, holistic approach that includes engineering, enforcement and education measures. PMID:23701478

  6. Relationship between individual characteristics, neighbourhood contexts and help-seeking intentions for mental illness

    PubMed Central

    Suka, Machi; Yamauchi, Takashi; Sugimori, Hiroki

    2015-01-01

    Objective Encouraging help-seeking for mental illness is essential for prevention of suicide. This study examined the relationship between individual characteristics, neighbourhood contexts and help-seeking intentions for mental illness for the purpose of elucidating the role of neighbourhood in the help-seeking process. Design, setting and participants A cross-sectional web-based survey was conducted among Japanese adults aged 20–59 years in June 2014. Eligible respondents who did not have a serious health condition were included in this study (n=3308). Main outcome measures Participants were asked how likely they would be to seek help from someone close to them (informal help) and medical professionals (formal help), respectively, if they were suffering from serious mental illness. Path analysis with structural equation modelling was performed to represent plausible connections between individual characteristics, neighbourhood contexts, and informal and formal help-seeking intentions. Results The acceptable fitting model indicated that those who had a tendency to consult about everyday affairs were significantly more likely to express an informal help-seeking intention that was directly associated with a formal help-seeking intention. Those living in a communicative neighbourhood, where neighbours say hello whenever they pass each other, were significantly more likely to express informal and formal help-seeking intentions. Those living in a supportive neighbourhood, where neighbours work together to solve neighbourhood problems, were significantly more likely to express an informal help-seeking intention. Adequate health literacy was directly associated with informal and formal help-seeking intentions, along with having an indirect effect on the formal help-seeking intention through developed positive perception of professional help. Conclusions The results of this study bear out the hypothesis that neighbourhood context contributes to help-seeking intentions

  7. Neighbourhood cohesion and mental wellbeing among older adults: a mixed methods approach.

    PubMed

    Elliott, Jane; Gale, Catharine R; Parsons, Samantha; Kuh, Diana

    2014-04-01

    There is now a body of evidence that demonstrates strong links between neighbourhood characteristics and mental health and wellbeing. There is an increasing interest in how this relationship varies for individuals of different ages. Understanding the link between neighbourhood and wellbeing for older adults is of particular significance, given the changing age structure of the population and the desire among policy makers and practitioners to promote healthy and active ageing. This paper provides further evidence on the nature and strength of the link between individual perceptions of neighbourhood belonging and mental wellbeing among those over age fifty using both qualitative and quantitative data from three British cohort studies. Between 2008 and 2011 quantitative data were collected from 10,312 cohort members, and 230 of them took part in qualitative biographical interviews. Quantitative analysis confirms that there is a moderate association between neighbourhood cohesion and wellbeing measured at the individual level in each of the three cohorts. This association persists after controlling for a range of covariates including personality. The association between neighbourhood cohesion and wellbeing is stronger for individuals in the older two cohorts than in the younger cohort. Using qualitative biographical interviews with 116 men and 114 women we illustrate how individuals talk about their sense of neighbourhood belonging. The importance of social participation as a mechanism for promoting neighbourhood belonging, and the use of age and life stage as characteristics to describe and define neighbours, is clear. In addition, the qualitative interviews point to the difficulties of using a short battery of questions to capture the varied and multi-dimensional nature of neighbourhood relations. PMID:24602970

  8. Neighbourhood socioeconomic status and coronary heart disease in individuals between 40 and 50 years

    PubMed Central

    Carlsson, Axel C; Li, Xinjun; Holzmann, Martin J; Wändell, Per; Gasevic, Danijela; Sundquist, Jan; Sundquist, Kristina

    2016-01-01

    Objective The incidence of myocardial infarction (MI) has decreased in general but not among younger middle-aged adults. We performed a cohort study of the association between neighbourhood socioeconomic status (SES) at the age of 40 and risk of MI before the age of 50 years. Methods All individuals in Sweden were included in the year of their 40th birthday, if it occurred between 1998 and 2010. National registers were used to categorise neighbourhood SES into high, middle and low, and to retrieve information on incident MI and coronary heart disease (CHD). Cox regression models, adjusted for marital status, education level, immigrant status and region of residence, provided an estimate of the HRs and 95% CIs for MI or CHD. Results Out of 587 933 men and 563 719 women, incident MI occurred in 2877 (0.48%) men and 932 (0.17%) women; and CHD occurred in 4400 (0.74%) men and 1756 (0.31%) women during a mean follow-up of 5.5 years. Using individuals living in middle-SES neighbourhoods as referents, living in high-SES neighbourhoods was associated with lower risk of MI in both sexes (HR (95% CI): men: 0.72 (0.64 to 0.82), women: 0.66 (0.53 to 0.81)); living in low-SES neighbourhoods was associated with a higher risk of MI (HR (95% CI): men: 1.31 (1.20 to 1.44), women: 1.28 (1.08 to 1.50)). Similar risk estimates for CHD were found. Conclusions The results of our study suggest an increased risk of MI and CHD among residents from low-SES neighbourhoods and a lower risk in those from high-SES neighbourhoods compared with residents in middle-SES neighbourhoods. PMID:26864672

  9. Urban neighbourhood unemployment history and depressive symptoms over time among late middle age and older adults

    PubMed Central

    Wight, Richard G; Aneshensel, Carol S; Barrett, Christopher; Ko, Michelle; Chodosh, Joshua; Karlamangla, Arun S

    2013-01-01

    Background Little is known about how a neighbourhood’s unemployment history may set the stage for depressive symptomatology. This study examines the effects of urban neighbourhood unemployment history on current depressive symptoms and subsequent symptom trajectories among residentially stable late middle age and older adults. Contingent effects between neighbourhood unemployment and individual-level employment status (ie, cross-level interactions) are also assessed. Methods Individual-level survey data are from four waves (2000, 2002, 2004 and 2006) of the original cohort of the nationally representative US Health and Retirement Study. Neighbourhoods are operationalised with US Census tracts for which historical average proportion unemployed between 1990 and 2000 and change in proportion unemployed between 1990 and 2000 are used to characterise the neighbourhood’s unemployment history. Hierarchical linear regressions estimate three-level (time, individual and neighbourhood) growth models. Results Symptoms in 2000 are highest among those residing in neighbourhoods characterised by high historical average unemployment beginning in 1990 and increasing unemployment between 1990 and 2000, net of a wide range of socio-demographic controls including individual-level employment status. These neighbourhood unemployment effects are not contingent upon individual-level employment status in 2000. 6-year trajectories of depressive symptoms decrease over time on average but are not significantly influenced by the neighbourhood’s unemployment history. Conclusions Given the current US recession, future studies that do not consider historical employment conditions may underestimate the mental health impact of urban neighbourhood context. The findings suggest that exposure to neighbourhood unemployment earlier in life may be consequential to mental health later in life. PMID:22918896

  10. Poverty concentration and determinants in China's urban low-income neighbourhoods and social groups.

    PubMed

    He, Shenjing; Wu, Fulong; Webster, Chris; Liu, Yuting

    2010-01-01

    Based on a large-scale household survey conducted in 2007, this article reports on poverty concentration and determinants in China's low-income neighbourhoods and social groups. Three types of neighbourhood are recognized: dilapidated inner-city neighbourhoods, declining workers' villages and urban villages. Respondents are grouped into four categories: working, laid-off/unemployed and retired urban residents, together with rural migrants. We first measure poverty concentration across different types of neighbourhood and different groups. The highest concentrations are found in dilapidated inner-city neighbourhoods and among the laid-off/unemployed. Mismatches are found between actual hardships, sense of deprivation and distribution of social welfare provision. Second, we examine poverty determinants. Variations in institutional protection and market remuneration are becoming equally important in predicting poverty generation, but are differently associated with it in the different neighbourhoods and groups. As China's urban economy is increasingly shaped by markets, the mechanism of market remuneration is becoming a more important determinant of poverty patterns, especially for people who are excluded from state institutions, notably laid-off workers and rural migrants. PMID:20726146