Search Content

Matching Items (43)

Pikas, grasslands, and pastoralists: understanding the roles of plateau pikas in a coupled social-ecological system

Description

The plateau pika (Ochotona curzoniae), a small burrowing lagomorph that occupies the high alpine grassland ecosystems of the Qinghai-Tibetan Plateau in western China, remains a controversial subject among policymakers and researchers. One line of evidence points to pikas being a pest, which has led to massive attempts to eradicate pika populations. Another point of view is that pikas are a keystone species and an ecosystem engineer in the grassland ecosystem of the QTP. The pika eradication program raises a difficult ethical and religious dilemma for local pastoralists, and is criticized for not being supported by scientific evidence. Complex interactions between pikas, livestock, and habitat condition are poorly understood. My dissertation research examines underpinning justifications of the pika poisoning program leading to these controversies. I investigated responses of pikas to habitat conditions with field experimental manipulations, and mechanisms of pika population recovery following pika removal. I present policy recommendations based on an environmental ethics framework and findings from the field experiments. After five years of a livestock grazing exclusion experiment and four years of pika monitoring, I found that grazing exclusion resulted in a decline of pika habitat use, which suggests that habitat conditions determine pika population density. I also found that pikas recolonized vacant burrow systems following removal of residents, but that distances travelled by dispersing pikas were extremely short (~50 m). Thus, current pika eradication programs, if allowed to continue, could potentially compromise local populations as well as biodiversity conservation on the QTP. Lethal management of pikas is a narrowly anthropocentric-based form of ecosystem management that has excluded value-pluralism, such as consideration of the intrinsic value of species and the important ecological role played by pikas. These conflicting approaches have led to controversies and policy gridlock. In response, I suggest that the on-going large-scale pika eradication program needs reconsideration. Moderation of stocking rates is required in degraded pika habitats, and Integrated Pest Management may be required when high stocking rate and high pika density coexist. A moderate level of livestock and pika density can be consistent with maintaining the integrity and sustainability of the QTP alpine steppe ecosystem.

ContributorsBadingqiuying (Author) / Smith, Andrew T. (Thesis advisor) / Wu, Jianguo (Committee member) / Minteer, Ben (Committee member) / Anderies, John (Committee member) / Harris, Richard B. (Committee member) / Arizona State University (Publisher)

Created2016

Psychosocial Mechanisms Linking the Social Environment to Mental Health in African Americans

Description

Resource-poor social environments predict poor health, but the mechanisms and processes linking the social environment to psychological health and well-being remain unclear. This study explored psychosocial mediators of the association between the social environment and mental health in African American adults. African American men and women (n = 1467) completed questionnaires on the social environment, psychosocial factors (stress, depressive symptoms, and racial discrimination), and mental health. Multiple-mediator models were used to assess direct and indirect effects of the social environment on mental health. Low social status in the community (p < .001) and U.S. (p < .001) and low social support (p < .001) were associated with poor mental health. Psychosocial factors significantly jointly mediated the relationship between the social environment and mental health in multiple-mediator models. Low social status and social support were associated with greater perceived stress, depressive symptoms, and perceived racial discrimination, which were associated with poor mental health. Results suggest the relationship between the social environment and mental health is mediated by psychosocial factors and revealed potential mechanisms through which social status and social support influence the mental health of African American men and women. Findings from this study provide insight into the differential effects of stress, depression and discrimination on mental health. Ecological approaches that aim to improve the social environment and psychosocial mediators may enhance health-related quality of life and reduce health disparities in African Americans.

ContributorsMama, Scherezade K. (Author) / Li, Yisheng (Author) / Basen-Engquist, Karen (Author) / Lee, Rebecca (Author) / Thompson, Deborah (Author) / Wetter, David W. (Author) / Nguyen, Nga T. (Author) / Reitzel, Lorraine R. (Author) / McNeill, Lorna H. (Author) / Arizona State University. College of Nursing & Healthcare Innovation (Contributor)

Created2016-04-27

The Relationship Between Grip Strength and Physical Activity in Preschoolers Aged 3-5 Years Old at Early Care Education Sites in Low-Income Communities

Description

As obesity rates continue to rise in adolescents and young children, the concern for poor future health of the younger population grows. Physical activity and improving nutrition are two ways to combat obesity rates, and the Sustainability via Active Gardening Education (SAGE) project addresses this in underserved and low-income communities in Maricopa County. This project employs a curriculum designed to promote physical activity and healthy eating for Early Care and Education (ECE) sites, most of which are daycares. Further, utilizing indicators of future health can also allow for us to understand and lower obesity rates. One indicator of future health is grip strength: greater grip strength is associated with healthier outcomes such as lower triglycerides, blood pressure, and body mass index. Grip strength has been observed in the older population; however, there are few studies looking at grip strength in younger children, namely preschoolers. As grip strength is a predictor of health, it follows that it should be observed in preschoolers, and improved, if possible, by factors such as physical activity, which would ultimately improve obesity rates. This study aimed to see if there was any relationship between physical activity and grip strength in preschoolers aged 3-5 years old. To do so, grip strength, hand length, height, weight, and information regarding physical activity of preschoolers enrolled in the SAGE project were collected. Physical activity and grip strength were not found to be significantly associated in this study; however, hand length and hand strength were associated. Among secondary outcomes, it was observed that males of ages 3 to 5-years-old may have greater hand grip strength than females of the same age group. Although this was not statistically significant, there was a trend toward statistical significance. Small sample size hampered observation of expected relationships between hand grip strength and dominant hand of the participants, and hand grip strength was not significantly related with BMI. Future directions would consist of collecting longitudinal data, as well as calling back previous years’ participants for additional data, so that there is a larger sample size for data analysis.

ContributorsAtluri, Haarika (Author) / Lee, Rebecca (Thesis director) / Tucker, Derek (Committee member) / Cantu Garcia, Lisbeth (Committee member) / De Mello, Gabrielli (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)

Created2024-05