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PubMed1991

Psychosocial impacts in populations exposed to solid waste facilities.

This interdisciplinary study uses a parallel case study design to investigate psychosocial impacts in populations exposed to three solid waste facilities in Southern Ontario. Impacts are examined at three social scales: individual, social network and community levels. The objectives and design derive from a feasibility study recently completed by the same research team. A two stage approach is adopted. The first is an epidemiologic survey to determine the prevalence of psychosocial impacts in the populations within a prescribed area around each site. A disproportionate stratified (by distance) random sample of 250 households is surveyed at each site. Data on awareness, knowledge, concern and action regarding the site are also obtained. Scores on pre-validated health measurement scales will be compared with population norms to determine the frequency distribution above, within and below the range of normal. The second stage involves the use of qualitative methodologies to provide an in-depth analysis of the individual, social network and community level factors affecting psychosocial impacts and reactions to the situation. Depth interviews with a sub-sample of survey respondents explore individual perceptions, attitudes and actions. Focus groups composed of members of relevant organizations and discussion groups comprising non-members uncover social network and community perspectives in an interactional setting. Interviews and group sessions are taped and transcribed for content analysis of salient themes. Textual analysis of media reports and other relevant documentation provide insights regarding the informational environment and the community context of the issues.

Adaptation, Psychological↗
PubMed2006

Background demographics and risk behaviors of injecting drug users in Karachi, Pakistan.

OBJECTIVE: To find the prevalence of HIV infection and risk behaviors among injecting drug users (IDUs) in Karachi, Pakistan. DESIGN: A cross-sectional study of IDUs conducted in Karachi, Pakistan from February through June 1996. RESULTS: Of the 242 IDUs, 11 (4%) refused HIV testing. One (0.4%; 95% confidence interval (CI) = 0.37-0.48%) was HIV positive. All subjects were male. Over the past 6 months 47% had engaged in receptive needle sharing, 38% had perceived a change in their social network, 22% had had sexual intercourse, of whom only 7% always used condoms, and none had washed their needles with bleach. Younger age (28 vs. 31 years; p = 0.01), younger age at first injection (25 vs. 28 years; p = 0.001), fewer years of schooling (3 vs. 5 years; p = 0.001), lower monthly income (70 dollars vs. 80 dollars; p = 0.03), inhaling fumes of heroin from a foil in the year before injecting (OR = 4.8; CI = 2.2-10.3), injecting first time with heroin (OR = 3.6; CI = 1.2-12.6), having a temporary job (OR = 2.5; CI = 1.2-5.2), and a perceived change in one's social network (OR = 4.4; CI = 2.4-7.9) were all associated with receptive needle sharing. IDUs who knew about HIV spread through contaminated needles were less likely to share (OR = 0.4; CI 0.2-0.8). In the final logistic regression model receptive needle sharing was associated with inhaling of fumes of heroin on a foil in the year prior to injecting (adjusted OR = 5.6; CI = 2.6-12.0), a perceived change in one's social network (adjusted OR = 4.0; CI = 2.2-7.4), and inversely associated with age at first time of injection (beta = -0.07; p = 0.002). CONCLUSION: Background HIV prevalence was low among IDUs in Karachi despite high-risk behavior in 1996. In order to control HIV transmission among IDUs in Pakistan, continual HIV surveillance with well-coordinated and effective HIV risk reduction, and drug demand reduction programs need to be implemented among drug users.

Adult↗
PubMed2003

Information-seeking behaviour and psycho-social interactions during the genetic testing process.

OBJECTIVES: The first aim of this study was to investigate the information-seeking behaviour (ISB) of women attending cancer genetic consultations at which the possibility of BRCA testing is considered. We focused here specifically on ISB apart from the cancer genetic consultation, i.e. on what complementary sources of information about genetic testing were consulted and what factors were involved in this behaviour. The second aim was to study the role of the social network used by the patients to collect various opinions on which to base their decisions about being tested. METHODS: A prospective cohort study (2000-2002) was therefore carried out on all women attending a single cancer genetic clinic in France after a BRCA1/2 analysis had been proposed. Closed questionnaires were administered before and after the second cancer genetic consultation. The purpose of this consultation was to confirm the patient's decision to be tested. RESULTS: Results were analysed in 108 subjects (mean age 47 years, SD 11 years; 74% affected by breast/ovarian cancer). Prior to the 2nd consultation, 35.2% of the women had actively looked for information about BRCA1/2 testing, as compared to 25.0% afterwards. After multivariate adjustment by logistic regression, the pre-consultation ISB was found to be associated with greater satisfaction with the information about the psycho-social consequences of genetic testing [adjusted odds ratio (ORadj) 1.03, 95% confidence interval (CI) 1.01-1.06] (scale from 0 to 100) and about the certainty of being a gene carrier (ORadj 3.04, 95% CI 1.16-7.98). Those who actively looked for complementary information were also more often accompanied at the consultation by a family member (ORadj 4.82, 95% CI 1.85-12.56). The other variables tested (depression, coping, socio-demographic and medical characteristics) were not significant (p > 0.05). The role of the social network in the decision making process was perceived as being less helpful when the persons consulted tended to have neutral or unfavourable opinions about genetic testing. CONCLUSIONS: Few women actively sought complementary information about BRCA genetic testing in addition to the cancer genetic consultation. Those who did so differed from the others in terms of their social network and their satisfaction with the consultation. The cancer geneticist is the key actor in women's decision making about genetic testing.

Attitude to Health↗
PubMed1985

Adolescent coping and support across multiple social environments.

This paper considers how research on stress, coping, and social support in adolescence may be informed by a social ecological perspective. Two case studies are presented which examine contrasting strategies by which adolescents at risk may cope successfully. One strategy focuses on the use of a strong peer social network, the other on the use of school involvements. In both cases, the analyses emphasize coping and social network processes across multiple social environments. Preventive social-community interventions are suggested to circumvent potential trouble spots associated with the use of these strategies.

Achievement↗
PubMed2006

Structure and evolution of online social relationships: Heterogeneity in unrestricted discussions.

With the advancement in the information age, people are using electronic media more frequently for communications, and social relationships are also increasingly resorting to online channels. While extensive studies on traditional social networks have been carried out, little has been done on online social networks. Here we analyze the structure and evolution of online social relationships by examining the temporal records of a bulletin board system (BBS) in a university. The BBS dataset comprises of 1908 boards, in which a total of 7446 students participate. An edge is assigned to each dialogue between two students, and it is defined as the appearance of the name of a student in the from- and to-field in each message. This yields a weighted network between the communicating students with an unambiguous group association of individuals. In contrast to a typical community network, where intracommunities (intercommunities) are strongly (weakly) tied, the BBS network contains hub members who participate in many boards simultaneously but are strongly tied, that is, they have a large degree and betweenness centrality and provide communication channels between communities. On the other hand, intracommunities are rather homogeneously and weakly connected. Such a structure, which has never been empirically characterized in the past, might provide a new perspective on the social opinion formation in this digital era.

Journal Article↗
PubMed1973

A frequency-dependent natural selection model for the evolution of social cooperation networks.

A model is presented for the evolution of several aspects of sociality based on reciprocal ties of social cooperation, modeling especially cooperative hunting behavior in carnivores. This model captures the possibility of a critical threshold in gene frequency, which, if reached, will lead to an explosion toward fixation of the "social" trait. This threshold phenomenon might be restated as follows: the precondition for evolution favorable to the specific form of social behavior considered is hard to satisfy, but-once this condition is satisfied-the tendency toward sociality is effectively irreversible. The simple model proposed appears to be highly robust, with most realistic changes additionally favoring the social gene.

Alleles↗
PubMed1987

Strain, social support, and distress in old age.

This analysis examined the relationship between life-strain (e.g., physical health problems, economic deprivation, and ADL impairment) and psychosomatic and emotional distress in old age, while taking into account the effects of age, race, sex, education, social support, and other measures of social resources. The data was drawn from a statewide household survey (N = 2,146) of noninstitutionalized older people. Using multiple regression analysis with tests for statistical interaction, the findings revealed that women, whites, those living alone, and those with less education had greater sources of strain. Individuals with greater sources of strain were also more likely to receive social support, although they tended to have smaller social networks and less social contact. Health status and ADL were the strongest predictors of distress. Social support was positively related whereas social contact was negatively related to distress. Social support had a moderating influence on the relationship between ADL impairment and psychosomatic symptoms of distress. Other measures of social resources, such as living arrangement and support network size, had neither main nor interactive effects on distress. The findings were discussed in light of their implications for future research.

Activities of Daily Living↗
PubMed1994

Salvadorian migration to the United States in the 1980s: what can we learn about it and from it?

This study investigates "why and how Salvadorian migrants came to the United States, and the implications of their migration....First, it presents evidence that the dichotomy used to distinguish economic and political migrations may not be adequate for examining current migration trends....Second, it illustrates the importance of social networks in international migrations from politically conflictive regions....Third, it points out that assumptions regarding the viability of social networks as sources of support among immigrants may also need revision." (SUMMARY IN FRE AND SPA)

Americas↗
PubMed1981

Toward a resolution of methodological dilemmas in network mapping.

In mapping social networks, investigators have confronted the following choices in the selection of an instrument to assess networks: (1) qualitative versus quantitative approaches; (2) subjective versus objective criteria; (3) synchronic versus diachronic descriptions. Evolving out of fieldwork with discharged mental patients, the Network Analysis Profile was designed to resolve these methodological dilemmas. Although it has not been completely successful in meeting this goal, the Network Analysis Profile offers distinct advantages over other instruments. A description and an illustration of its use are provided.

Halfway Houses↗
PubMed2005

Life strain and psychological distress of older women and older men in Hong Kong.

This study examined the life strain and psychological distress among a group of older adults (N = 1034, 51.2% female) in Hong Kong. Data were collected through individual interviews in which a standardized questionnaire was administered. The results indicated that older women had more somatic complaints and poorer self-rated health. Family network and interdependent relationships were significantly poorer among the older women than in the older men. Women were also found to experience a higher level of psychological distress (as measured by GDS-15 and GHQ-12) than did men. Perceived financial strain and poor physical health had similar direct effect on the psychological distress of both older women and older men. In contrast to Western findings, a poor family network was observed to exert a greater direct effect on psychological distress than an inadequate social network of friends. Generally, a good social network was found to mitigate the negative impact of life strain factors among older men, but not among older women.

Aged↗
PubMed2001

Navigating the time-space context of HIV and AIDS: daily routines and access to care.

Geographers have shown that daily activities and social networks are constrained by time-space, but there are also enabling facets or opportunities created by daily routines for accessing material and emotional resources, improving quality of life, and even challenging existing power relations. Time-geography in this paper is taken as a starting point to assess how individuals living with HIV and AIDS navigate the complex and often difficult time space contexts defining their access to services. The concept of time space windows of access is offered as a way to understand the opportunities created by daily routines and social network interaction even in highly marginalized social, economic, and political circumstances. Survey data and in-depth interviews conducted with a diverse group of persons living with HIV and AIDS are used to illustrate this conceptual argument. Results indicate that the time space characteristics of daily routines, such as frequency of activities, variety or heterogeneity in activities, and whether activities are self- or social network-oriented, serve to define the availability of temporal and spatial windows of access to services. In addition, daily routines seem to matter for specific types of services, and have a limited role to play in terms of primary medical services or those associated with basic needs. The implications of these findings for theorizing and for enhancing access to services are provided.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Social control in personal relationships: impact on health behaviors and psychological distress.

This study examines associations among social control, health behavior change, and psychological distress. Social control refers to interactions between social network members that entail regulation, influence, and constraint. Social control is predicted to have dual effects leading to better health practices while also arousing psychological distress. A random sample of 242 individuals answered questions about health practices, overall exposure to social control in their networks, and social control attempts made by a specific network member. Analyses yielded mixed support for the hypotheses, but analyses of responses to the social control attempts of a specific network member did reveal that social control predicted less health-compromising behavior and more health-enhancing behavior as well as more distress. The results suggest that social control warrants greater attention in efforts to understand how personal relationships influence health.

Adult↗
PubMed2006

Does social capital enhance health and well-being? Evidence from rural China.

Despite increasing acknowledgement that social capital is an important determinant of health and overall well-being, empirical evidence regarding the direction and strength of these linkages in the developing world is limited and inconclusive. This paper empirically examines relationships between social capital and health and well-being-as well as the suitability of commonly used social capital measures-in rural China, where rapid economic growth coexists with gradual and fundamental social changes. To measure social capital, we adopt a structural/cognitive distinction, whereby structural social capital is measured by organizational membership and cognitive social capital is measured by a composite index of trust, reciprocity, and mutual help. Our outcome measures included self-reported general health, psychological health, and subjective well-being. We adopt multi-level estimation methods to account for our conceptualization of social capital as both an individual- and contextual-level resource. Results indicate that cognitive social capital (i.e., trust) is positively associated with all three outcome measures at the individual level and psychological health/subjective well-being at the village level as well. We further find that trust affects health and well-being through pathways of social network and support. In contrast, there is little statistical association or consistent pattern between structural social capital (organizational membership) and the outcome variables. Furthermore, although organizational membership is highly correlated with collective action, neither is associated with health or well-being. Our results suggest that policies aimed at producing an environment that enhances social networks and facilitates the exchange of social support hold promise for improving the health and well-being of the rural Chinese population. In addition, China may not have fully taken advantage of the potential contribution of structural social capital in advancing health and well-being. A redirection of collective action from economic to social activities may be worth considering.

Adolescent↗
PubMed2006

Design principles of molecular networks revealed by global comparisons and composite motifs.

BACKGROUND: Molecular networks are of current interest, particularly with the publication of many large-scale datasets. Previous analyses have focused on topologic structures of individual networks. RESULTS: Here, we present a global comparison of four basic molecular networks: regulatory, co-expression, interaction, and metabolic. In terms of overall topologic correlation--whether nearby proteins in one network are close in another--we find that the four are quite similar. However, focusing on the occurrence of local features, we introduce the concept of composite hubs, namely hubs shared by more than one network. We find that the three 'action' networks (metabolic, co-expression, and interaction) share the same scaffolding of hubs, whereas the regulatory network uses distinctly different regulator hubs. Finally, we examine the inter-relationship between the regulatory network and the three action networks, focusing on three composite motifs--triangles, trusses, and bridges--involving different degrees of regulation of gene pairs. Our analysis shows that interaction and co-expression networks have short-range relationships, with directly interacting and co-expressed proteins sharing regulators. However, the metabolic network contains many long-distance relationships: far-away enzymes in a pathway often have time-delayed expression relationships, which are well coordinated by bridges connecting their regulators. CONCLUSION: We demonstrate how basic molecular networks are distinct yet connected and well coordinated. Many of our conclusions can be mapped onto structured social networks, providing intuitive comparisons. In particular, the long-distance regulation in metabolic networks agrees with its counterpart in social networks (namely, assembly lines). Conversely, the segregation of regulator hubs from other hubs diverges from social intuitions (as managers often are centers of interactions).

Amino Acid Motifs↗
PubMed2003

Chlamydia trachomatis omp1 genotypic diversity and concordance with sexual network data.

Sexual and social network analysis have been proposed as novel sexually transmitted disease control and research tools. Here, the concordance between chlamydia genotype data and a large sexual network constructed from routinely collected contact tracing data was examined. A sexual network was constructed for Manitoba, Canada, from province-wide contact tracing data. Positive chlamydia specimens from the same time period were collected and genotyped by omp1 DNA sequencing. A high degree of concordance was found between transmission events, on the basis of molecular data, and proposed transmission events, on the basis of sexual network data. Discordant results appeared to occur when a portion of the network contained potential core group members or in areas where contact tracing is difficult to carry out. The agreement between the molecular and epidemiologic data suggests that the use of routine contact tracing data is a valid approach for the construction of sexual networks.

Chlamydia Infections↗
PubMed2001

Search in power-law networks.

Many communication and social networks have power-law link distributions, containing a few nodes that have a very high degree and many with low degree. The high connectivity nodes play the important role of hubs in communication and networking, a fact that can be exploited when designing efficient search algorithms. We introduce a number of local search strategies that utilize high degree nodes in power-law graphs and that have costs scaling sublinearly with the size of the graph. We also demonstrate the utility of these strategies on the GNUTELLA peer-to-peer network.

Journal Article↗
PubMed2002

Spread of epidemic disease on networks.

The study of social networks, and in particular the spread of disease on networks, has attracted considerable recent attention in the physics community. In this paper, we show that a large class of standard epidemiological models, the so-called susceptible/infective/removed (SIR) models can be solved exactly on a wide variety of networks. In addition to the standard but unrealistic case of fixed infectiveness time and fixed and uncorrelated probability of transmission between all pairs of individuals, we solve cases in which times and probabilities are nonuniform and correlated. We also consider one simple case of an epidemic in a structured population, that of a sexually transmitted disease in a population divided into men and women. We confirm the correctness of our exact solutions with numerical simulations of SIR epidemics on networks.

Journal Article↗
PubMed1993

[Illness adjustment of adult patients with cystic fibrosis II. 2. Social support and coping].

As a part of our study of the coping with cystic fibrosis we examined the social network and the social support of adult patients. The results suggests that there is only little difference between women and men in the size of network and perceived support and that the family is of great importance as a source of support. Compared with healthy adults, perceived social support seems to be less but greater than for depressive patients. Only some coping-clusters do correlate positively with social support.

Adaptation, Psychological↗