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Physical Distance (physical + distance)
Selected AbstractsBlack Employment, Segregation, and the Social Organization of Metropolitan Labor MarketsECONOMIC GEOGRAPHY, Issue 3 2007Niki T. Dickerson Abstract: This broad analysis of the employment of blacks in metropolitan areas examines the role of residential segregation in comparison with four other key structural explanations for racial metropolitan inequality: industrial composition, minority concentration, immigration, and the racial disparity in skills. The goal of the analysis was to determine whether the spatial configuration of blacks relative to whites in a metropolitan area influences the employment rates of black men and black women in the context of the structural conditions of the local labor market. The study expanded the analysis of space and work beyond an emphasis on the physical distance between black communities and jobs to a broader conceptualization of residential segregation as a structural feature of the entire metropolitan labor market that is representative of its social organization with regard to race. Using a longitudinal data set of the structural characteristics of the 95 largest U.S. cities from the 1980, 1990, and 2000 decennial censuses, the study used a cross-sectional analysis of the cities in 2000 and a fixed-effects analysis to assess the impact of five dimensions of residential segregation and the four other structural factors on the employment of blacks across different labor markets and across time within each labor market. The results revealed that when the other structural characteristics are controlled, the employment rates of blacks are lower in more segregated cities and decrease as cities become more segregated over time. The clustering and evenness dimensions of residential segregation were the most determinative of black employment. [source] Genetic variation in COL17A1 and the development of bullous pemphigoidEXPERIMENTAL DERMATOLOGY, Issue 3 2004Samantha Winsey Background: Bullous pemphigoid (BP) is an autoimmune blistering disease of the skin characterized by autoantibody attack on collagen XVII. Objectives: To characterize the genetic complexity of COL17A1, the gene which encodes for the autoantigen collagen XVII. The data will be used to determine whether there is an association between polymorphisms and haplotypes of COL17A1 and genetic susceptibility to development of BP. Methods: The genetic complexity in COL17A1 was deduced by screening and then sequencing the gene. Haplotypes were constructed from the resulting polymorphisms using the statistical programme PHASE. The linkage disequilibrium (D,) between the polymorphisms was deduced from haplotypic data using the statistical programme GOLD. Association of the polymorphisms and haplotypes was tested for, in a cohort of BP patients and controls. Results: Screening of COL17A1 for genetic variation was carried out in 29 individuals of North European caucasoid origin, and it revealed 19 single-nucleotide polymorphisms in approximately 14.7 kb of sequence. These variants resulted in 60 different haplotypes in 191 individuals, of which 13 occurred above 1% in the population. D, between the variants was found to be extensive, have a low correlation with physical distance and to extend over 33.8 kb. No association was found with any of the polymorphisms or haplotypes and development of BP, when tested for, in a cohort of patients and controls. Conclusion: This study provides an extensive description of the genetic variation in COL17A1 and shows no association of the genetic variants with susceptibility to BP. [source] The Demise of Distance?GROWTH AND CHANGE, Issue 1 2006The Declining Role of Physical Proximity for Knowledge Transmission ABSTRACT The transmission of knowledge diminishes with physical distance, one factor explaining the geographic clustering of scientific and industrial activity. The authors investigate how those distances have stretched over time,between collaborating inventors, and between inventors and the technology that inspires them. While physical distance is still a factor, it is clear that its constraining effects have weakened, especially for particular types of innovators, technologies, and regions of the United States. [source] Socio-economic distance and spatial patterns in unemploymentJOURNAL OF APPLIED ECONOMETRICS, Issue 4 2002Timothy G. Conley This paper examines the spatial patterns of unemployment in Chicago between 1980 and 1990. We study unemployment clustering with respect to different social and economic distance metrics that reflect the structure of agents' social networks. Specifically, we use physical distance, travel time, and differences in ethnic and occupational distribution between locations. Our goal is to determine whether our estimates of spatial dependence are consistent with models in which agents' employment status is affected by information exchanged locally within their social networks. We present non-parametric estimates of correlation across Census tracts as a function of each distance metric as well as pairs of metrics, both for unemployment rate itself and after conditioning on a set of tract characteristics. Our results indicate that there is a strong positive and statistically significant degree of spatial dependence in the distribution of raw unemployment rates, for all our metrics. However, once we condition on a set of covariates, most of the spatial autocorrelation is eliminated, with the exception of physical and occupational distance. Racial and ethnic composition variables are the single most important factor in explaining the observed correlation patterns. Copyright © 2002 John Wiley & Sons, Ltd. [source] The American Master Bedroom: Its Changing Location and Significance to the FamilyJOURNAL OF INTERIOR DESIGN, Issue 1 2005John L. Vollmer M. S. ABSTRACT This article discusses the possible relationship between changes in the master bedroom and parenting values in middle class America. The authors review information from the US homebuilding industry, statistical data on housing trends, literature on the history of the bedroom from the Colonial period to the present, and literature on family sleep practices. The owner's bedroom, one domain among various domains in the home, is an individual-private domain that functions to ensure adult privacy and increase physical barriers between parents and children. The authors contend that changes in the location and function of the master bedroom in the American home over the past centuries reflect the upward social mobility afforded by rising incomes, expansive and undeveloped land, and shared concepts of prestige held by home builders and homeowners. These influences have helped develop a purely American sense of parenting among middle and upper-income families that reflects their individualism. Middle class parents have encouraged more physical distance between themselves and their offspring. Consistent with this trend, they have shown a preference for houses with large master suites that are sometimes located at a distance from other bedrooms in the house. Using a model by Chermayeff and Alexander (1965), the authors examine the relationship between parenting practices and private space, highlighting the implications of this trend for home planners and interior designers. [source] Relational closeness: Comparing undergraduate college students' geographically close and long-distance friendshipsPERSONAL RELATIONSHIPS, Issue 4 2009AMY JANAN JOHNSON As interpersonal relationships change with the advent of new technology, researchers need to reexamine their theoretical constructs (R. G. Adams, 1998). This study uses survey methodology to examine college undergraduates from the United States. It explores the concept of relational closeness by comparing how geographically close and long-distance friends define closeness in their relationships. It assesses prior methods of defining and measuring closeness in interpersonal relationships for the impact of physical distance between the friends. Differences illustrate factors that are important in understanding relational closeness in general and in long-distance relationships in particular. [source] Social capital, social currency, and portable assets: The impact of residential mobility on exchanges of social supportPERSONAL RELATIONSHIPS, Issue 2 2003Lynn Magdol We examined the impact of physical distance on mobilized social capital resources. Social capital theory assumes that physical proximity and residential stability are prerequisites to social capital assets. We tested these assumptions using a two-wave panel sample from the National Survey of Families and Households consisting of respondents who experienced residential moves between waves. We found local duration since the last move to be beneficial for involvement in social exchanges. Mobility distance was related to deficits for some exchanges but not for others. Rather than a simple dichotomy between material resources that require proximity and nonmaterial resources that do not, we found that emotional and financial support are not affected by mobility distance but that tangible favors and companionship are affected negatively. Although kin exchanges are negatively affected by distant and recent mobility, nonkin exchanges are more extensive for respondents whose kin ties are more distant, suggesting a process of substitutability whereby nonkin may replace kin in the network. Our findings confirm the assumption of social capital theory about distance. They also point to the importance of adding the dimension of distance to exchange theory. Our study demonstrates that place has not lost all relevance in our highly technological postmodern society. [source] Genetic analysis and gene mapping of a rice recessive male sterile mutantPLANT BREEDING, Issue 3 2010J. B. Chen With 3 figures and 2 tables Abstract Male sterility of rice is one of the major genetic tools used for hybrid rice production. In this study, a spontaneous male sterile mutant, SC-ms-2, was obtained from the F4 progeny of the cross D 297B × Changfeng B. Microscopic observation revealed that the microspores were developed abnormally and the tapetum cells were incrassated during microsporogenesis. Genetic analysis indicated that male sterility of SC-ms-2 was controlled by a single recessive gene. By using bulked segregant analysis on two F2 populations developed from crossing SC-ms-2 with Hua B and ,Nipponbare', this gene was finely mapped between two simple sequence repeat (SSR) markers on chromosome 9, RM24451 and RM7048, with genetic distance of 0.3 cM and 0.6 cM respectively, and the approximate physical distance was 172 kb. Our results showed that this gene was distinguished from all the other male sterility genes in rice reported and it was designated ms92(t), temporally. Moreover, candidate genes in the region of 172kb, including the rice homologue to the Arabidopsis MALE STERILITY1 (MS1) gene, were surveyed and discussed. [source] Spatial patterns in pond invertebrate communities: separating environmental and distance effectsAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 6 2005Robert A. Briers Abstract 1.The nature and extent of spatial pattern in communities has important implications for their dynamics and conservation. Previous studies of pond ecosystems, over relatively small spatial scales, have found little evidence of spatial autocorrelation of community composition. Patterns in community composition over greater spatial distances have not been documented. 2.Here, data on macroinvertebrate communities and physico-chemical characteristics of 102 ponds over a 60 × 60 km area of Oxfordshire, UK, were used to examine evidence for spatial autocorrelation in community composition and to separate the effects of environmental similarity and physical distance on community similarity. 3.Overall similarity between communities was low, but showed significant positive spatial autocorrelation. There was evidence for both environmental and physical distance effects on spatial autocorrelation of community similarity. Community similarity was negatively related to differences in environmental conditions, but effects were only significant for large environmental differences. 4.When environmental effects were accounted for, there was significant positive spatial autocorrelation of community composition over inter-site distances of up to 13 km. These results suggest that interactions between pond sites, potentially through dispersal, are evident over larger spatial scales than has previously been appreciated, and emphasize the need to consider spatial issues when developing strategies for pond conservation. Copyright © 2005 John Wiley & Sons, Ltd. [source] CARD15 mutations in familial granulomatosis syndromes: A study of the original Blau syndrome kindred and other families with large-vessel arteritis and cranial neuropathyARTHRITIS & RHEUMATISM, Issue 11 2002Xiaoju Wang Objective To analyze the CARD15 gene in families with heritable multi-organ granulomatoses, including the original Blau syndrome kindred as well as other families with related granulomatous conditions. Methods Linkage mapping was performed in 10 families. Observed recombination events were used to exclude regions centromeric or telomeric to 16q12.1, and the Blau gene critical region was refined to <3 cM, corresponding to a physical distance of 3.5 megabasepairs. Based on its known biochemical function, CARD15 was analyzed as a positional candidate for the Blau syndrome susceptibility gene, by direct DNA sequencing. Results These studies resulted in the identification, in 5 of the families, of 2 sequence variants at position 334 of the gene product (R334W and R334Q). Affected family members from the original Blau syndrome kindred were heterozygous for the R334W missense mutation; mutations at the same position were also observed in several unrelated Blau syndrome families, some of whose phenotypes included large-vessel arteritis and cranial neuropathy. The missense mutations segregated with the disease phenotype in the families, and were not seen in 208 control alleles. Conclusion These findings demonstrate that CARD15 is an important susceptibility gene for Blau syndrome and for other familial granulomatoses that display phenotypic traits beyond those of classic Blau syndrome. [source] Self in Context: Autonomy and Relatedness in Japanese and U.S. Mother,Preschooler DyadsCHILD DEVELOPMENT, Issue 6 2002Tracy A. Dennis Cultural differences and similarities in socialization during two contrasting laboratory tasks were examined in 30 Japanese mothers and their preschoolers, both temporarily residing in the United States, and 30 U.S. mothers and their preschoolers (age: M= 55.8 months, SD= 4.9). Mother and child actions, speech, emotion, and attention were coded from videotaped observations during a free play task and waiting task. Cross,cultural comparisons showed that U.S. mothers had more conversations that emphasized individual experiences, more often acted as playmates and used joint attention, maintained more physical distance, showed more positive emotions, and made more positive responses to child accomplishment. In contrast, Japanese mothers had more conversations that emphasized shared experiences, showed more divided attention, and maintained social role distinctions. Similar, but fewer cultural differences emerged for children. However, maternal and child characteristics also varied by task context. The results suggested an emphasis on autonomy in U.S. dyads and an emphasis on relatedness in Japanese dyads, but the interactions with task context revealed the coexistence of autonomy and relatedness. [source] | |||||||||||||||||||