Semi-Parametric Geographically Weighted Regression (S-GWR): a Case Study on Invasive Plant Species Distribution in Subtropical Nepal

Geographically weighted regression (GWR) is a spatial statistical methodology to explore the impact of non-stationarity on the interaction between spatially measured dependent and independent variables. In this paper we use a semi-parametric geographically weighted regression (SGWR) and demonstrate the effectiveness of the method on a case study on socio-ecological factors on forest vulnerability. The case study is based on community forests in and around the buffer zone of Chitwan National Park, Nepal, a biodiversity hotspot that is being rapidly degraded by exotic invasive plant species. This research integrated heterogeneous data sources such as observational ecological surveys, household interviews, and remotely sensed imagery. These data were utilized to extract and represent invasive plant species coverage, human activity intensity, topographical parameters and vegetation greenness indices. Research findings both demonstrate the S-GWR method and offer possible interventions that could slow the catastrophic spread of invasive plant species in Chitwan, Nepal

TRIADD: THE RISK FOR ALCOHOL ABUSE, DEPRESSION, AND DIABETES MULTIMORBIDITY IN THE AMERICAN INDIAN AND ALASKA NATIVE POPULATION

Abstract: This study examined the risk for alcoholism, diabetes, and depression (triADD) American Indian/Alaska Native (AI/AN) populations are affl icted disproportionately with a number of chronic illnesses (Indian Health Service [IHS], 2001). Specifi cally, the rates of Type 2 Diabetes, alcohol abuse, and suicide have consistently been higher in these populations for many years (IHS). To date the majority of research has focused on these three disorders alone or in dyads; little attention has been given to the co-occurrence of all three simultaneously in AI/AN populations. The Behavioral Risk Factor Surveillance System (BRFSS) provides annual data on estimates of risk factors and health-related behavior in state populations across the nation. This article reports an analysis of the prevalence and correlates of diabetes and associated risk factors for depression and alcohol abuse in AI/AN adults sampled in the fi fty states as part of the 2003 BRFSS survey

American Indian and Alaska Native Mental Health Research

Abstract: This study examined the risk for alcoholism, diabetes, and depression (triADD) American Indian/Alaska Native (AI/AN) populations are affl icted disproportionately with a number of chronic illnesses (Indian Health Service [IHS], 2001). Specifi cally, the rates of Type 2 Diabetes, alcohol abuse, and suicide have consistently been higher in these populations for many years (IHS). To date the majority of research has focused on these three disorders alone or in dyads; little attention has been given to the co-occurrence of all three simultaneously in AI/AN populations. The Behavioral Risk Factor Surveillance System (BRFSS) provides annual data on estimates of risk factors and health-related behavior in state populations across the nation. This article reports an analysis of the prevalence and correlates of diabetes and associated risk factors for depression and alcohol abuse in AI/AN adults sampled in the fi fty states as part of the 2003 BRFSS survey

Social organization and marriage timing in Nepal.

This dissertation examines the relationship between nonfamily social organization and marriage timing in the Chitwan Valley of Nepal. I develop hypotheses of how marriage timing is influenced by three sets of factors: nonfamily individual experiences, proximity to nonfamily organizations and services, and neighbors' nonfamily experiences. I test these hypotheses with survey data from the Chitwan Valley Family Study, which includes 5,271 individuals and 171 neighborhoods. I use discrete-time, multilevel hazard modeling to estimates these models. I find that a variety of individuals' nonfamily activities influence marriage, including schooling, work, nonfamily living, and media consumption. School enrollment tended to decrease marriage rates, while the accumulated years of schooling increased marriage rates. The effects of work and nonfamily living differed by gender, with these experiences increasing marriage rates for men, but leading to decreases for women. Media consumption, such as watching TV or listening to radios, delayed the transition to marriage. Also, of all the measured nonfamily experiences, educational experiences tended to explain the largest amount of variation between birth cohorts. When located close to individuals' communities, a variety of nonfamily organizations and services also decreased the rates of marriage. Proximity to schools, markets, bus stops, health posts, movies, and police stations delayed marriage. I tested if individuals' own experiences were the intervening mechanisms of these community effects, but the effects of community organizations were largely independent of the individual experiences for which I had measures. I also find that measures of neighbors' nonfamily experiences tended to have limited effects on individuals' marriage rates, but neighbors' experiences with marriage did influence individuals' marriage rates. The neighbors' experiences, however, failed to explain the effects of community organizations. A main contribution of this dissertation is that nonfamily factors at both the level of the individual and the community influence the transition to marriage. This finding emphasizes the importance of conceptualizing behavior as responding to factors at multiple levels. Because the intervening mechanisms between these levels remain elusive, the findings highlight a need for improved measurement and richer theory of how different levels of social context influence behavior.Ph.D.DemographySocial SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/123315/2/3068995.pd

Migrant children and migrants' children: Nativity differences in school enrollment in Mexico and the United States

Background: The growing prevalence of migrant children in diverse contexts requires a re-consideration of the intergenerational consequences of migration. To understand how migration and duration of residence are associated with children's schooling, we need more comparative work that can point to the similarities and differences in outcomes for children across contexts. Objective: This paper addresses the importance of nativity and duration of residence for children's school enrollment on both sides of a binational migration system: The United States and Mexico. The analyses are designed to determine whether duration of residence has a similar association with school enrollment across these different settings. Methods: The analyses are based on nationally representative household data from the 2010 Mexican Census and the 2006‒2010 American Community Survey. Logistic regression models compare school enrollment patterns of Mexican and U.S.-born children of Mexican origin in the United States and those of Mexican and U.S.-born children in Mexico. Interactions for nativity/duration of residence and age are also included. Results: The results demonstrate that, adjusting for household resources and household-level migration experience, Mexican-born children in the United States and U.S.-born children in Mexico, particularly those who arrived recently, lag behind in school enrollment. These differences are most pronounced at older ages. Conclusions: The comparisons across migration contexts point to greater school attrition and non-enrollment among older, recent migrant youth, regardless of the context. The interactions suggest that recent migration is associated with lower schooling for youth who engage in migration at older ages in both the United States and Mexico. Contribution: These analyses point to the importance of considering different types of migration and age at arrival to understand educational patterns

Who Has the Time? the Relationship Between Household Labor Time and Sexual Frequency

Motivated by the trend of women spending more time in paid labor and the general speedup of everyday life, the authors explore whether the resulting time crunch affects sexual frequency among married couples. Although prior research has examined the associations between relationship quality and household labor time, few have examined a dimension of relationship quality that requires time: sexual frequency. This study tests three hypotheses based on time availability, gender ideology, and a new multiple-spheres perspective using the National Survey of Families and Households. The results contradict the hypothesis that time spent on household labor reduces the opportunity for sex. The authors find support for the multiple-spheres hypothesis suggesting that both women and men who work hard also play hard. Results show that wives and husbands who spend more hours in housework and paid work report more frequent sex

Sexual Frequency and the Stability of Marital and Cohabiting Unions

Prior research found that lower sexual frequency and satisfaction were associated with higher rates of divorce, but little research had examined the role of sexual activity in the dissolution of cohabiting unions. We drew upon social exchange theory to hypothesize why sexual frequency is more important in cohabitation: (a) cohabitors\u27 lower costs of finding sexual alternatives, (b) cohabitors\u27 lower barriers to ending the relationship in the form of union-specific economic and noneconomic capital, and (c) cohabitors\u27 higher expectations for sexual activity. Using the National Survey of Families and Households (N = 5,902), we examined the relationship between sexual frequency and union dissolution. Results indicated that low sexual frequency was associated with significantly higher rates of union dissolution among cohabitors than married couples

Digital divide and body size disparities among Chinese adults

Background: The rapid development of information and communication technology (ICT) in China has increased people's sedentary behavior and raised a number of related issues. ICT screen-viewing activities are increasingly considered to contribute to obesity, and sociodemographic characteristics such as gender, income, age, education, and geographical location seem to magnify the digital divide. Objective: This study first examines dissimilar stages of ICT transition, and then establishes how ICT screen-viewing activities relate to the Chinese obesity epidemic. Finally, this study assesses whether unequal access to digital resources and technology by geographic location and gender reinforces existing obesity disparities in China. Methods: This study uses longitudinal data drawn from 10,616 households and 17,377 person-years of those aged 18-55 who participated in the 2006, 2009, and 2011 China Health and Nutrition Survey (CHNS). Fixed effect linear regression models capture the link between ICT screen-viewing activities and body mass index (BMI). Results: The results show that while between 91.37Š and 96.70Š of individuals had access to televisions during 2006-2011, there is a significant disparity in terms of Internet activity by gender and geographical location. The results show that Internet use could decrease a rural women's BMI by .87 kg/m2, while playing computer games could increase a rural man's BMI by .42 kg/m2. Contribution: This study highlights that unequal access to digital resources and technology might reinforce existing obesity disparities in China