Impact of traffic pollution on telomere length and chronic diseases: Results from the multi-ethnic study of atherosclerosis and the Mexican-American cohort study

Exposure to air pollutants in urban locales has been associated with increased risk for chronic diseases including cardiovascular disease (CVD) and pulmonary diseases in epidemiological studies. The exact mechanism explaining how air pollution affects chronic disease is still unknown. However, oxidative stress and inflammatory pathways have been posited as likely mechanisms. ^ Data from the Multi-Ethnic Study of Atherosclerosis (MESA) and the Mexican-American Cohort Study (2003-2009) were used to examine the following aims, respectively: 1) to evaluate the association between long-term exposure to ambient particulate matter (PM) (PM10 and PM2.5) and nitrogen oxides (NO x) and telomere length (TL) among approximately 1,000 participants within MESA; and 2) to evaluate the association between traffic-related air pollution with self-reported asthma, diabetes, and hypertension among Mexican-Americans in Houston, Texas. ^ Our results from MESA were inconsistent regarding associations between long-term exposure to air pollution and shorter telomere length based on whether the participants came from New York (NY) or Los Angeles (LA). Although not statistically significant, we observed a negative association between long-term air pollution exposure and mean telomere length for NY participants, which was consistent with our hypothesis. Positive (statistically insignificant) associations were observed for LA participants. It is possible that our findings were more influenced by both outcome and exposure misclassification than by the absence of a relationship between pollution and TL. Future studies are needed that include longitudinal measures of telomere length as well as focus on effects of specific constituents of PM and other pollutant exposures on changes in telomere length over time. ^ This research provides support that Mexican-American adults who live near a major roadway or in close proximity to a dense street network have a higher prevalence of asthma. There was a non-significant trend towards an increased prevalence of adult asthma with increasing residential traffic exposure especially for residents who lived three or more years at their baseline address. Even though the prevalence of asthma is low in the Mexican-origin population, it is the fastest growing minority group in the U.S. and we would expect a growing number of Mexican-Americans who suffer from asthma in the future. Future studies are needed to better characterize risks for asthma associated with air pollution in this population.^

Risk and protective factors associated with depression among racial and ethnic mothers of adolescents

The central paradigm linking disadvantaged social status and mental health has been the social stress model (Horwitz, 1999), the assumption being that individuals residing in lower social status groups are subjected to greater levels of stress not experienced by individuals from higher status groups. A further assumption is that such individuals have fewer resources to cope with stress, in turn leading to higher levels of psychological disorder, including depression (Pearlin, 1989). Despite these key assumptions, there is a dearth of literature comparing the social patterning of stress exposure (Hatch & Dohrenwend, 2007; Meyer, Schwartz, & Frost, 2008; Kessler, Mickelson, & Williams, 1999; Turner & Avison, 2003; Turner & Lloyd, 1999; Turner, Wheaton, & Lloyd, 1995), and the distribution and contribution of protective factors, posited to play a role in the low rates of depression found among African- and Latino-Americans (Alegria et al., 2007; Breslau, Aguilar-Gaxiola, Kendler, Su, Williams, & Kessler, 2006; Breslau, Borges, Hagar, Tancredi, Gilman, 2009; Gavin, Walton, Chae, Alegria, Jackson, & Takeuchi, 2010; Williams, & Neighbors, 2006). Thus, this study sought to describe both the distribution and contribution of risk and protective factors in relation to depression among a sample of African-, European-, and Latina-American mothers of adolescents, including testing a hypothesized mechanism through which social support, an important protective factor specific to women and depression, operates. ^ Despite the finding that the levels of depression were not statistically different across all three groups of women, surprising results were found in describing the distribution of both risk and protective factors, in that results reported among all women who were mothers when analyzed masked differences within each ethnic group when SES was assessed, a point made explicit by Williams (2002) regarding racial and ethnic variations in women's health. In the final analysis, while perceived social support was found to partially mediate the effect of social isolation on depression, among African-Americans, the direct effect of social isolation and depression was lower among this group of women, as was the indirect effect of social isolation and perceived social support when compared to European- and Latina-American mothers. Or, put differently, higher levels of social isolation were not found to be as associated with more depression or lower social support among African-American mothers when compared to their European- and Latina-American counterparts. ^ Women in American society occupy a number of roles, i.e., that of being female, married or single, mother, homemaker or employee. In addition, to these roles, ethnicity and SES also come into play, such that the intersection of all these roles and the social contexts that they occupy are equally important and must be taken into consideration when making predictions drawn from the social stress model. Based on these findings, it appears that the assumptions of the social stress model need to be revisited to include the variety of roles that intersect among individuals from differing social groups. More specifically, among women who are mothers and occupy a myriad of other roles, i.e., that of being female, married or single, African- or Latina-American, mother, homemaker or employee, the intersection of all the roles and the social contexts that women occupy are equally important and must be taken into consideration when looking at both the types and distribution of stressors across women. Predictions based on simple, mutually exclusive categories of social groups may lead to erroneous assumptions and misleading results.^

Ethnic comparisons of adolescent sexual risk -taking and preventive behavior

For adolescents, unprotected sexual intercourse is the primary cause of sexually transmitted disease (STD), including Human Immunodeficiency Virus (HIV) infection (virus which causes Acquired Immunodeficiency Syndrome (AIDS)), and pregnancy. Although many studies on adolescent sexual behavior have addressed racial/ethnic differences, few studies have examined the relation between race/ethnicity while controlling for other sociocultural and psychosocial variables. The purpose of this study is to examine the relationship between racial/ethnic categories and selected sociocultural and psychosocial variables, with reported adolescent sexual risk-taking and preventive behavior.^ A self-administered questionnaire was used to collect information from 3132 students in a Texas school district (Section 3.5.2). The instrument contained approximately 100 questions on demographic characteristics, sexual behavior, and psychosocial determinants of sexual behavior. Based on the findings of this study, the following major conclusions are made: (1) There are differences in reported sexual risk-taking and preventive behavior among Black, Hispanic and White adolescents in this study. The stratified analysis by gender further suggests significant gender differences in reported sexual behavior among the three racial/ethnic groups. (2) Gender, living arrangement, academic grades, and language spoken at home modified the association between reported sexual risk-taking and preventive behavior and race/ethnicity in this study. This suggests that these sociocultural variables should be considered in future research and practice involving multicultural populations. (3) There are differences in selected psychosocial determinants among the three racial/ethnic groups and between males and females. These differences were consistent with the reported sexual risk-taking and preventive behaviors among race/ethnicity and gender for adolescents in this study. The findings support the consideration of psychosocial determinants in research and interventions addressing adolescent sexual behavior among different racial/ethnic groups.^ Based on the results of this study, two recommendations for practice are made. First, health professionals developing interventions for adolescents from different cultural backgrounds and gender need to be familiar with the specific sociocultural and psychosocial factors which will reduce risky sexual behavior, and promote protective behavior. Second, the need for immediate, realistic, and continuous HIV/STD and pregnancy prevention programs for children and adolescents should be considered. ^

Executive Managers in Peru's Family Businesses

As in many other developing countries, family businesses are major players in the Peruvian economy. Despite their growth into large-scale groups spanning a wide range of businesses, the owner families still have strong control over their ownership and management. However, Peru's liberal economic reforms in the 1990s brought intense competition into the national market. Not only have these family businesses been forced to compete against large-scale foreign capital that entered the national market through the privatization of state enterprises, but also against cheap goods imported from foreign countries. In order to compete, family businesses have had to move beyond the limited human resources available within the family. The advancement within owner families of new generations with better education and training together with the promotion to top managerial positions of professional salaried managers from outside the family are some of the measures owner families are taking to overcome their human resource limitations.

Executive Managers in Large Mexican Family Businesses

The involvement of members of owners' families in the running of large family businesses in Mexico is decreasing. Although family members still hold key posts such as that of CEO, other executive posts tend to be delegated to professional salaried managers. Top managers, including family members, share some common characteristics. They are young compared with managers in other developed countries, their quality as human resources is high, and many of them are graduates of overseas MBA courses. Most of them are sufficiently experienced. Improvement of quality among top managers is a recent phenomenon in Mexico, and has been encouraged mainly by the following two factors. First, globalization of business activities was promoted by intense competition among firms under conditions of market liberalization. In order to equip themselves with the ability to cope with the globalization of their operations, large family businesses tried hard to improve the quality of top management, by training and educating existing managers, and/or by recruiting managers in the outside labor market. Second, developments in the Mexican economy during the 1990s led to a growth in the labor market for top managers Thus, business restructuring caused by bankruptcy, as well as mergers and acquisitions, privatization and so on, led to the dismissal of business managers who then entered the labor market in large numbers. The increasing presence of these managers in the labor market helped family businesses to recruit well-qualified senior executives.

Comparing the Networks of Ethnic Japanese and Ethnic Chinese in International Trade

In this paper I re-examined the trade enhancing effects of ethnic Chinese networks, found by Rauch and Trindade (2002), on a newer and extended data set. The effects are estimated by the gravity equation with the product of the population ratio (or absolute number) of the ethnic Chinese in both the importing and exporting countries, and are reaffirmed positive and statistically significant. I also compared the effects of two different ethnic Japanese networks, i.e., the networks of long-term Japanese stayers in foreign countries, and the networks of permanent Japanese residents in foreign countries. It is found that the former has stronger trade enhancing effects than the latter. This shows that the effects of ethnic networks on international trade can be generalized beyond the ethnic Chinese, and the ’cohesiveness’ of the ethnic network matters to the trade enhancing effects of the network.

A note on ethnic return migration policy in Kazakhstan : changing priorities and a growing dilemma

This paper offers a brief analysis of the legal aspects of the ethnic return migration policy of Kazakhstan, a post-Soviet Central Asian state that has been active in seeking ties with its diaspora since independence. This paper examines the definition of oralman (repatriates) and the establishment of a quota on the number of Kazakh immigrants who are eligible for government funds to show how the rationale and preferences in repatriation policy have changed over the years. By focusing on changes in migration-related legislation in the late 2000s and early 2010s, the paper notes that two key goals of Kazakhstan’s migration policy are not necessarily consistent with each other: the promotion of an ethnically based nation-building project by encouraging the "return" of co-ethnics living abroad, and building a workforce that is best suited for the development of the state’s economy.

Perception of employers and employees regarding the attitude of businesses toward the environment: a qualitative analysis

Commitment and involvement from the different members of an organization are two key elements for an organization to achieve its environmental excellence. Firstly, businesses are aware of the close relationship between their activities and the environment, for they are not only polluting agents but also agents with the capacity to reduce adverse environmental impacts. Secondly, the fact that employees can play a relevant role in terms of the socially responsible measures to be taken by organizations has started to become an irrefutably important issue. This piece of research is intended to help gain knowledge concerning the attitude of the two main actors in productive activity toward the environmental, that is, employers and employees; as well, this research intends to identify factors determining behaviour towards the environmental. For this, we have gathered the ideas and assessments contained in the discourse of a group of small and medium-sized businesses, large company owners and officers, employees, and work related risk prevention representatives. Qualitative work consisted of in-depth interviews and the creation of discussion groups.

Different response to Plasmodium falciparum malaria in West African sympatric ethnic groups

The comparison of malaria indicators among populations that have different genetic backgrounds and are uniformly exposed to the same parasite strains is one approach to the study of human heterogeneities in the response to the infection. We report the results of comparative surveys on three sympatric West African ethnic groups, Fulani, Mossi, and Rimaibé, living in the same conditions of hyperendemic transmission in a Sudan savanna area northeast of Ouagadougou, Burkina Faso. The Mossi and Rimaibé are Sudanese negroid populations with a long tradition of sedentary farming, while the Fulani are nomadic pastoralists, partly settled and characterized by non-negroid features of possible caucasoid origin. Parasitological, clinical, and immunological investigations showed consistent interethnic differences in Plasmodium falciparum infection rates, malaria morbidity, and prevalence and levels of antibodies to various P. falciparum antigens. The data point to a remarkably similar response to malaria in the Mossi and Rimaibé, while the Fulani are clearly less parasitized, less affected by the disease, and more responsive to all antigens tested. No difference in the use of malaria protective measures was demonstrated that could account for these findings, and sociocultural or environmental factors do not seem to be involved. Known genetic factors of resistance to malaria did not show higher frequencies in the Fulani. The differences in the immune response were not explained by the entomological observations, which indicated substantially uniform exposure to infective bites. The available data support the existence of unknown genetic factors, possibly related to humoral immune responses, determining interethnic differences in the susceptibility to malaria.

Major histocompatibility complex class II DR alleles DRB1*1501 and those encoding HLA-DR13 are preferentially associated with a diminution in maternally transmitted human immunodeficiency virus 1 infection in different ethnic groups: determination by an automated sequence-based typing method.

Transmission of human immunodeficiency virus 1 (HIV-1) from an infected women to her offspring during gestation and delivery was found to be influenced by the infant's major histocompatibility complex class II DRB1 alleles. Forty-six HIV-infected infants and 63 seroreverting infants, born with passively acquired anti-HIV antibodies but not becoming detectably infected, were typed by an automated nucleotide-sequence-based technique that uses low-resolution PCR to select either the simpler Taq or the more demanding T7 sequencing chemistry. One or more DR13 alleles, including DRB1*1301, 1302, and 1303, were found in 31.7% of seroreverting infants and 15.2% of those becoming HIV-infected [OR (odds ratio) = 2.6 (95% confidence interval 1.0-6.8); P = 0.048]. This association was influenced by ethnicity, being seen more strongly among the 80 Black and Hispanic children [OR = 4.3 (1.2-16.4); P = 0.023], with the most pronounced effect among Black infants where 7 of 24 seroreverters inherited these alleles with none among 12 HIV-infected infants (Haldane OR = 12.3; P = 0.037). The previously recognized association of DR13 alleles with some situations of long-term nonprogression of HIV suggests that similar mechanisms may regulate both the occurrence of infection and disease progression after infection. Upon examining for residual associations, only only the DR2 allele DRB1*1501 was associated with seroreversion in Caucasoid infants (OR = 24; P = 0.004). Among Caucasoids the DRB1*03011 allele was positively associated with the occurrence of HIV infection (P = 0.03).