Matching Items (23)
Description
A variety of studies have shown that the tendency toward nicotine dependence has a genetic component. The work described in this thesis addresses three separate questions: i) are there unidentified SNPs in the nicotinic receptors or other genes that contribute to the risk for nicotine dependence; ii) is there evidence of ongoing selection at nicotinic receptor loci; and, iii) since nicotine dependence is unlikely to be the phenotype undergoing selection, is a positive effect on memory or cognition the selected phenotype. I first undertook a genome –wide association scan of imputed data using samples from the Collaborative Study of the Genetics of Nicotine Dependence (COGEND). A novel association was found between nicotine dependence and SNPs at 13q31. The genes at this newly associated locus on chromosome 13 encode a group of micro-RNAs and a member of the glypican gene family. These are among the first findings to implicate a non-candidate gene in risk for nicotine dependence. I applied several complimentary methods to sequence data from the 1000 Genomes Project to test for evidence of selection at the nicotinic receptor loci. I found strong evidence for selection for alleles in the nicotinic receptor cluster on chromosome 8 that confer risk of nicotine dependence. I then used the dataset from the Collaborative Studies on the Genetics of Alcoholism (COGA) and looked for an association between neuropsychological phenotypes and SNPs conferring risk of nicotine dependence. One SNP passed multiple test correction for association with WAIS digit symbol score. This SNP is not itself associated with nicotine dependence but is in reasonable (r 2 = 0.75) LD with SNPs that are associated with nicotine dependence. These data suggest at best, a weak correlation between nicotine dependence and any of the tested cognitive phenotypes. Given the reproducible finding of an inverse relationship between SNPs associated with risk for nicotine dependence and cocaine dependence, I hypothesize that the apparently detrimental phenotype of nicotine dependence may confer decreased risk for cocaine dependence. As cocaine use impairs the positive rewards associated with social interactions, reducing the risk of cocaine addiction may be beneficial to both the individual and the group.
ContributorsSadler, Brooke (Author) / Hurtado, Ana Magdalena (Thesis advisor) / Goate, Alison (Thesis advisor) / Hill, Kim (Committee member) / Nagoshi, Craig (Committee member) / Arizona State University (Publisher)
Created2014
Description
The health situation of indigenous peoples is comparable to that of the world's poorest populations, but with the additional burdens of social and cultural marginalization, geographic and cultural barriers to accessing health services, and, in some areas, appropriation of land and natural resources. Cultural transmission (the transfer of beliefs, ideas, and behaviors from one culture to another) from outsider health institutions should presumably aid in closing this health gap by transferring knowledge, practices, and infrastructure to prevent and treat disease. This study examines the biosocial construction of the disease ecology of tuberculosis (TB) in indigenous communities of the Paraguayan Chaco with varying degrees of cultural transmission from outside institutions (government, religious, and NGOs), to determine the influence of cultural transmission on local disease ecologies. Using a biocultural epidemiological framework for the analysis of human infectious disease ecology, this study employed an interdisciplinary, mixed methods approach to examine the interactions of host, pathogen, and the environment in the Paraguayan Chaco. Three case studies examining aspects of TB disease ecology in indigenous communities are presented: (1) The effective cultural transmission of biomedical knowledge to isolated communities, (2) Public health infrastructure, hygiene, and the prevalence of intestinal parasites: co-morbidities that promote the progression to active TB disease, and (3) Community-level risk factors for TB and indigenous TB burden. Findings from the case studies suggest that greater influence from outside institutions was not associated with greater adoption of biomedical knowledge of TB. The prevalence of helminthiasis was unexpectedly low, but infection with giardia was common, even in a community with cleaner water sources. Communities with a health post were more likely to report active adult TB, while communities with more education were less likely to report active pediatric TB, suggesting that healthcare access is the major determinant of TB detection. More research is needed on the role of non-indigenous community residents and other measures of acculturation or integration in TB outcomes, especially at the household level. Indigenous TB burden in the Chaco is disproportionately high, and better understanding of the mechanisms that produce higher incidence and prevalence of the disease is needed.
ContributorsVansteelandt, Amanda (Author) / Hurtado, Ana Magdalena (Thesis advisor) / Stone, Anne (Thesis advisor) / Hruschka, Daniel (Committee member) / Rojas de Arias, Antonieta (Committee member) / Arizona State University (Publisher)
Created2014
Description
Sexual assault at colleges and universities in the United States is a significant health and human rights issue that impacts somewhere between one-in-four and one-in-five students. Despite the alarmingly high burden, overall rates of disclosing to crisis, health, and victim services, and reporting to schools and law enforcement remain low. In order to buffer students from associated short- and long-term harm, and help them reestablish safety and pursue justice, empirically-supported, innovative, and trauma-informed secondary prevention strategies are needed. To address this pressing issue, the current study used a trauma-informed, feminist community research approach to develop and design a prototype of an internet-based decision aid specifically tailored to assist students at Arizona State University who experience sexual assault with making informed choices about reporting and seeking care, advocacy, and support on and off campus. Results from preliminary alpha testing of the tool showed that: 1. It is feasible to adapt decision aids for use with the target population, and 2. While aspects of the tool can be improved during the next phases of redrafting and redesign, members of the target population find it to be acceptable, comprehensible, and usable.
ContributorsVillegas-Gold, Michelle (Author) / Hurtado, Ana Magdalena (Thesis advisor) / Gaughan, Monica (Thesis advisor) / Durfee, Alesha (Committee member) / Arizona State University (Publisher)
Created2018
Description
The purpose of this study is to discover the exposure and network patterns during the 2013-2015 Ebola Virus Disease epidemic. The author accomplished this by taking an opportunistic sample of news and academic articles, some of which may also capture cases untreated and therefore unrecorded by hospitals and treatment units. Most of the 315 cases came from the Washington Post, New York Times, and World Health Organization, and they consistently captured between 1-2% of WHO case numbers. The results show that of cases with known exposures, 53.6% became infected through contact with sick family members. Hospital and funeral transmission accounted for the second and third most frequent exposure scenarios at 24.6% and 12.9% respectively. The exposures over time imply that hospital and funeral transmission prevention efforts have been successful, but family transmission has remained common throughout the outbreak. Prevention initiatives should focus on families earlier in epidemics to help control EVD's spread.
ContributorsCleaton, Julie Marie (Author) / Chowell, Gerardo (Thesis director) / Hurtado, Ana Magdalena (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
This study aims to determine if there are differences in body mass index (BMI) across ethnic groups in the United States. Modern medicine is increasingly going the way of personalized medicine, and existing literature has begun to suggest that cultural differences may have an effect on physical health. Initially, this study was to explore anorexia nervosa prevalence, but the data is simply not there; this led to a shift in focus to exploring health differences in terms of BMI. The data analyzed is from the National Health and Nutritional Examination Survey (NHANES) collected by the Centers of Disease Control and Prevention (CDC) from 1999-2013. The subjects used were aged 13-25, and the ethnicities compared were African American, Caucasian American, Mexican American, Other Hispanic American, Asian American, and Other (including multiracial). Statistical tests were run through the software program SAS and included ANOVA tests, t-tests, and z-tests. It was found that there are differences across ethnicities, and that there are far more differences among females than among males. Asian American males and Mexican American males appear to be the groups that caused males to have significant differences. Asian Americans were also found to have the lowest average BMI by far. On the other hand, African Americans and Mexican Americans appeared to have the highest average BMIs. Although these findings and others detailed in the paper are intriguing, the BMI data is not strictly normal, and is still not normalized even by transforming the variable into a log of BMI. The data is still right skewed, and must be attacked in the future with different transformations and non-parametric tests to increase the accuracy and strength of these findings.
ContributorsJohnson, Courtney Elizabeth (Author) / Hurtado, Ana Magdalena (Thesis director) / Samara, Marko (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This project studies two single nucleotide polymorphisms (SNPs) within the HBS1L-MYB loci. Both SNPs are associated with a heightened expression of fetal hemoglobin. DNA samples of NCAA athletes who have sickle cell trait were genotyped to find the allele frequency of each SNP. When comparing all populations using information provided from the Human Genome Project on Ensembl, the minor A allele has a frequency of 22% and the major, G, allele has a frequency of 78%. The frequency distribution of the minor allele in the population data was higher than the frequency obtained from the sampled data by 15%. This means that the samples, which are heterozygous for sickle cell, display a lower frequency for the mutation than the global population.
ContributorsCiambella, Michelle Lynn (Author) / Stone, Anne (Thesis director) / Foy, Joseph (Committee member) / Madrigal, Lorena (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
Dire wolves have recently risen to fame as a result of the popular television program Game of Thrones, and thus many viewers know dire wolves as the sigil and loyal companions of the Stark house. Far fewer recognize dire wolves by their scientific name, Canis dirus, or understand the population history of this ‘fearsome wolf’ species that roamed the Americas until the megafaunal mass extinction event of the Late Pleistocene. Although numerous studies have examined the species using morphological and geographical methods, thus far their results have been either inconclusive or contradictory. Remaining questions include the relationships dire wolves share with other members of the Canis genus and the internal structure of their populations. Advancements in ancient DNA recovery methods may make it possible to study dire wolf specimens at the molecular level for the first time and may therefore prove useful in clarifying the answers to these questions. Eighteen dire wolf specimens were collected from across the United States and subjected to ancient DNA extraction, library preparation, amplification and purification, bait preparation and capture, and next-generation sequencing. There was an average of 76.9 unique reads and 5.73% coverage when mapped to the Canis familiaris reference genome in ultraconserved regions of the mitochondrial genome. The results indicate that endogenous ancient DNA was not successfully recovered and perhaps ancient DNA recovery methods have not advanced to the point of retrieving informative amounts of DNA from particularly old, thermally degraded specimens. Nevertheless, the ever-changing nature of ancient DNA research makes it vital to continually test the limitations of the field and suggests that ancient DNA recovery methods will prove useful in illuminating dire wolf population history at some point in the future.
ContributorsSkerry, Katherine Marie (Author) / Stone, Anne (Thesis director) / Amdam, Gro (Committee member) / Larson, Greger (Committee member) / School of Human Evolution and Social Change (Contributor) / School of Nutrition and Health Promotion (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Unlike the autosomes, recombination on the sex chromosomes is limited to the pseudoautosomal regions (PARs) at each end of the chromosome. PAR1 spans approximately 2.7 Mb from the tip of the proximal arm of each sex chromosome, and a pseudoautosomal boundary between the PAR1 and non-PAR region is thought to have evolved from a Y-specific inversion that suppressed recombination across the boundary. In addition to the two PARs, there is also a human-specific X-transposed region (XTR) that was duplicated from the X to the Y chromosome. Genetic diversity is expected to be higher in recombining than nonrecombining regions, particularly because recombination reduces the effects of linked selection, allowing neutral variation to accumulate. We previously showed that diversity decreases linearly across the previously defined pseudoautosomal boundary (rather than drop suddenly at the boundary), suggesting that the pseudoautosomal boundary may not be as strict as previously thought. In this study, we analyzed data from 1271 genetic females to explore the extent to which the pseudoautosomal boundary varies among human populations (broadly, African, European, South Asian, East Asian, and the Americas). We found that, in all populations, genetic diversity was significantly higher in the PAR1 and XTR than in the non-PAR regions, and that diversity decreased linearly from the PAR1 to finally reach a non-PAR value well past the pseudoautosomal boundary in all populations. However, we also found that the location at which diversity changes from reflecting the higher PAR1 diversity to the lower nonPAR diversity varied by as much as 500 kb among populations. The lack of genetic evidence for a strict pseudoautosomal boundary and the variability in patterns of diversity across the pseudoautosomal boundary are consistent with two potential explanations: (1) the boundary itself may vary across populations, or (2) that population-specific demographic histories have shaped diversity across the pseudoautosomal boundary.
ContributorsCotter, Daniel Juetten (Author) / Wilson Sayres, Melissa (Thesis director) / Stone, Anne (Committee member) / Webster, Timothy (Committee member) / School of Life Sciences (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Within the primate lineage, skeletal traits that contribute to inter-specific anatomical variation and enable varied niche occupations and forms of locomotion are often described as the result of environmental adaptations. However, skeletal phenotypes are more accurately defined as complex traits, and environmental, genetic, and epigenetic mechanisms, such as DNA methylation which regulates gene expression, all contribute to these phenotypes. Nevertheless, skeletal complexity in relation to epigenetic variation has not been assessed across the primate order. In order to gain a complete understanding of the evolution of skeletal phenotypes across primates, it is necessary to study skeletal epigenetics in primates. This study attempts to fill this gap by identifying intra- and inter-specific variation in primate skeletal tissue methylation in order to test whether specific features of skeletal form are related to specific variations in methylation. Specifically, methylation arrays and gene-specific methylation sequencing are used to identify DNA methylation patterns in femoral trabecular bone and cartilage of several nonhuman primate species. Samples include baboons (Papio spp.), macaques (Macaca mulatta), vervets (Chlorocebus aethiops), chimpanzees (Pan troglodytes), and marmosets (Callithrix jacchus), and the efficiencies of these methods are validated in each taxon. Within one nonhuman primate species (baboons), intra-specific variations in methylation patterns are identified across a range of comparative levels, including skeletal tissue differences (bone vs. cartilage), age cohort differences (adults vs. juveniles), and skeletal disease state differences (osteoarthritic vs. healthy), and some of the identified patterns are evolutionarily conserved with those known in humans. Additionally, in all nonhuman primate species, intra-specific methylation variation in association with nonpathological femur morphologies is assessed. Lastly, inter-specific changes in methylation are evaluated among all nonhuman primate taxa and used to provide a phylogenetic framework for methylation changes previously identified in the hominin lineage. Overall, findings from this work reveal how skeletal DNA methylation patterns vary within and among primate species and relate to skeletal phenotypes, and together they inform our understanding of epigenetic regulation and complex skeletal trait evolution in primates.
ContributorsHousman, Genevieve (Author) / Stone, Anne (Thesis advisor) / Quillen, Ellen (Committee member) / Kusumi, Kenro (Committee member) / Stojanowski, Christopher (Committee member) / Arizona State University (Publisher)
Created2017
Description
The purpose of this research is to exploit the neglect of specific populations and diseases in Latin America through an epidemiological literature review. As a small part of a larger publication, the foci of this research was the infectious disease, helminthiasis. Using manually indexed abstracts from the National Library of Medicine database in PubMed, 4,594 papers were synthesized and then processed for further review. Of those papers, 29 provided information about helminths in indigenous populations. These papers were reviewed and used in prevalence data extraction and variable analysis. The main conclusion was to reveal the fact that from an entire health database less than 30 papers provided information about the persistence of helminths in indigenous communities of Latin America. Not only that but the few papers that could be analyzed had consistently high prevalence ratios.
ContributorsGregory, Cassandre June (Author) / Hurtado, Ana Magdalena (Thesis director) / Estevez, Dulce (Committee member) / School of Life Sciences (Contributor) / School of Human Evolution & Social Change (Contributor, Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05