McNair Scholars Undergraduate Research Journal, 2011, Vol. 3
Permanent URI for this collectionhttp://hdl.handle.net/1903/12449
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Item Zipf ’s Law and Its Correlation to the GDP of Nations(2011) Skipper, Rachel K.; Rosenberg, JonathanThis study looks at power laws, specifically Zipf ’s law and Pareto distributions, previously used to describe city size distribution, income distribution within firms, and word distribution within languages and documents among other things, and Gibrat’s law describing growth rate. This study seeks to discover if Zipf’s law can also be used to model the distribution of GDP’s worldwide using Gibrat’s law as a justification. The simplest method to determine Zipf's law’s applicability, and the one used in this study, was to create a log log plot, plotting rank versus size of the GDPs. Using that plot, Zipf ’s law was verified through two criteria. First the plot must appear linear and second it must have a slope of -1. For the purpose of this study, the data looked at was for all countries and then countries split into categories of emerging economies and advanced economies for the years 2005, 2006, 2007, and 2008. The results of this study showed that all countries and countries with emerging economies did not appear linear on the log log plot while advanced economies appeared linear with a slope roughly -.70, suggesting that GDP distribution of advanced economies instead follow a Pareto distribution. Advanced economies also showed a significantly smaller variation in growth rates over the four years as implied by Gibrat’s law. This was used as a possible explanation for the distribution discovered.Item Does Situation Type Moderate the Relationship Between Maternal Attention-Deficit/Hyperactivity Disorder (ADHD) Symptoms and Observed Parenting?(2011) Santana, Erin Marie; O’Brien, Kelly; Chronis-Tuscano, AndreaPrevious research has found associations between parental attention-deficit/hyperactivity disorder (ADHD) symptoms and maladaptive parenting. In contrast, some suggest a “similarity-fit hypothesis,” in which equal levels of ADHD symptoms between parents and children may be associated with a shared behavioral tempo, which may result in a better “fit.” However, this theory has only been tested in a free-play situation (Psychogiou et al., 2008a). This study tested the “similarity-fit hypothesis” using two samples of children with ADHD and their mothers across two tasks to examine the extent situational context is associated with ineffective parenting. Mother-child dyads were observed in an unstructured free-play task and a structured homework task in two studies of parent-child interactions consisting of a total of 175 elementary-aged children with DSM-IV ADHD. A significant main effect for situation type on positive parenting and ineffective commands was found in Study 2. Mothers displayed higher rates of positive parenting and ineffective commands in the homework task compared to the free-play task. A trend-level interaction (Situation Type x Maternal ADHD symptoms) was found in Study 1. Probing the interaction revealed that higher levels of maternal ADHD symptoms predicted higher levels of ineffective commands in the homework task, but not in the free-play task. Although, our results were both consistent and inconsistent with the literature examining families where ADHD is present in children and parents, our study’s findings may contribute to the limited literature using observational measures to examine associations between maternal ADHD symptoms and parenting. Our results suggest the challenging nature of the structured homework task may tax a mother’s core symptoms of ADHD, which contrasts with the “similarity-fit hypothesis.” Further research testing the “similarity-fit hypothesis” is needed to determine the extent situational context impacts the relationship between maternal ADHD symptoms and parenting.Item Decline and Disparities in Mammography Use Trends by Socioeconomic Status and Race/Ethnicity(2011) Rattanawatkul, Kanokphan; Carter-Pokras, OliviaThe second leading cause of death in women in the United States is breast cancer. While it remains the most common type of cancer in women, early detection through mammography screening has been used to combat and treat breast cancer. But after the 2000, the rates of mammography have been declining. The purpose of this study is to examine whether or not the decline has continued and whether all racial/ethnic and socioeconomic groups experienced the same rate of decline. The study further explores the reasons why there are greater decline rates and breast cancer disparities among African American women, and women with lower income and education. Data from the National Health Interview Survey (2003 to 2005) and the Behavioral Risk Factor Surveillance System (2002 to 2004) were used to calculate the percent decline for the total population and by race/ethnicity and socioeconomic status. Mammography rates declined between 2003-2005 (NHIS) and 2002-2004 (BRFSS). Data from both the NHIS and BRFSS show a greater rate of decline for African American women, and women with lower income and education. An expert sampling method is used to recruit participants to explore their views on the reasons why breast cancer disparities existed among African American women, women with lower income, and women with lower education. These results differ from previous studies which examined broader time interval (2000 to 2005). Further research is recommended to explore whether the rates of decline have continued, the impact of the decline in mammography rates on breast cancer incidence, mortality, and stage of diagnosis, as well as the underlying reasons for the observed decline in mammography rates and for disparities in the rates of decline.Item Understanding the Abscisic Acid Pathway Using Guard Cell Specific Genes and the Anti-Aging Drug Spermidine(2011) Pearson, Deryck; Kwak, June M.; Villiers, Florent; Jammes, FabienPlants must respond to environmental stress including drought and harsh winters. Overcoming these stresses depend heavily on timing of stomatal closure and seed germination. My research focused on both chemical and genetic aspects involved in the abscisic acid pathway that controls both stomatal closures in leaves and seed germination in Arabidopsis thaliana. My first study focused on recognizing specific proteins involved in the abscisic acid pathway for stomatal guard cell closure. Given specific promoters for their respective proteins, it is possible to determine whether or not proteins are guard cell specific. GatewayTM technology utilizes a series of reactions to create a clone containing a promoter of interest called an expression vector. By injecting this vector directly into the leaf of Arabidopsis, the plant will use the promoter to create the guard cell specific protein. The second study examined the effect of the anti-aging drug Spermidine on seed sensitivity to abscisic acid concentration during seed germination. By varying the concentration of Spermidine and abscisic acid exposure to seeds then observing the number of surviving seeds, the effects of Spermidine on seed germination can be measured. Spermidine is expected to reduce seed sensitivity to abscisic acid leading to increased seed germination.Item A Comparison of the Inhibition of Nucleocytoplasmic Trafficking by Viral Effectors from Cardioviruses and Rhinoviruses(2011) Okafor, Obiageri; Palmenberg, Ann; Basta, HollyCardioviruses and Enteroviruses of the Picornaviridae family exhibit similar infections. Viruses from the two genera inhibit nuclear import/export through the nuclear pore complex (NPC), a channel between the cytoplasm and nucleus. However, the diseases caused by viruses within these two genera vary in severity. Encephalomyocarditis virus (EMCV), a cardiovirus, uses a small potent protein called Leader (L) to inhibit trafficking through the NPC, thereby causing encephalitis in pigs and other animals. Human rhinovirus (HRV), an enterovirus, uses a protease, 2A, to inhibit trafficking through the nuclear pore and infection is associated with the common cold. It is unknown why cardioviruses and enteroviruses cause diseases of varying severity. In addition, little information is known about whether the mechanism of these viruses’ toxic proteins in inhibiting nuclear transport through the NPC, may correlate with the severity variation of the disease phenotypes of these viruses. To test this, we would compare the rates of nuclear efflux by three different Cardioviruses and three serotypes of HRV. Molecular techniques would be used to clone and express recombinant L proteins of the cardioviruses. Both nuclear efflux and nuclear import assays would be performed using recombinant green fluorescent protein (GFP) to track infection in HeLa cells for the effects of either L protein or 2A protease. This is done to determine the extent of inhibition of nuclear trafficking at the NPC. Knowledge of the kinetics between cardioviruses and HRV could hint at the different pathogenicities of these viruses. Also, it could add to our understanding of whether the genotype of a virus can infer the phenotype of the disease it causes.Item Does Parental Sexual Behavior Influence “Parental Fitness” and Child Custody Determinations?(2011) Norrington, Janette; Chateauvert, MelindaFamily Law typically promotes a nuclear family model and rules against parents who exhibit alternative sexual practices. The family court system uses the “best interest of the child” standard to guide custody decisions but the standard is vague so judges may consider nearly any kind of evidence or insert personal biases. This study examines the relationship between parental sexuality and child custody determinations, and specifically focuses on homosexual and sex worker parents. The courts and legislation have a tendency to rule against gay and lesbian parents in custody cases because there is fear that the children will grow up to be homosexual or experience social stigma. Sex worker mothers are at risk of losing their children to the State because there is concern that the children will lack morals and decency. Studies show virtually no difference between the children of homosexual parents or legal sex worker parents compared to normative heterosexual parents, so the arguments used to limit parental involvement in custody cases often lack merit. The current legislation and custody process does not solely focus on the best interests of the children involved, but instead impose moral biases and stereotypes on parents’ lifestyles. The study explores previous research and cases to examine the patterns concerning child custody and non-nuclear family models. The study will follow a mixed-methods approach to measure social workers’ attitudes and approaches to child custody decisions, and will also document sex worker parents’ experiences and difficulties regarding their occupations as sex workers and roles as parents.Item Exploring the Genetic Basis of Root Mucilage in Cowpea (Vigna unguiculata (L.) Walp.)(2011) Massimino, Christopher; Muchero, Wellington; Roberts, Philip; Ehlers, Jeffrey; Close, TimothyCowpea (Vigna unguiculata (L.) Walp.) is a member of the legume family, Fabaceae. Cowpea varieties are vital agricultural crops in arid and semi-arid environments in Africa, Asia, India, and Central America. Cowpea sold in the United States is commonly known as black eyed peas. Breeding for specific cowpea varieties depends on environmental conditions where phenotypic traits may relate to drought tolerance, and resistance to fungal and bacterial pathogens, aphids, nematodes, viruses, and many others. The agricultural production of a variety with desirable traits is an important economic consideration that ultimately determines yield and quality of a harvest. The objectives of this study include phenotyping diverse germplasm for the mucilage trait, testing one or more candidate genes for polymorphisms, and the chemical quantitation and characterization of root mucilage. Phenotypes of several hundred cowpea germplasm accessions were compared to their existing SNP haplotypes spanning the region of interest to categorize haplotypes containing different alleles for the root mucilage trait. The gene sequences of different alleles for two candidate genes were determined for comparison between lines. Root mucilage will evenutally be analyzed for protein and carbohydrate content and specifically for arabinogalactans and proteins (Moody et al. 1988).Item The Effects of Brain Drain on Haiti(2011) Joseph, Whitney; Zeigler, RonaldThis study was conducted in the form of a historical analysis to understand and determine the various ways that human capital flight, better known as brain drain, has impacted Haiti and how occurrences such as political events, have influenced brain drain in return. The first research question seeks to identify determinants in Haiti that contribute to brain drain. An analysis shows that the three main contributors are the economy, healthcare, and education. Brain drain has impacted political development because there are not enough policies to address many of the issues faced by Haiti, while economic development has been effected because the output of human capital is not enough to sustain the lost capital from highly-skilled emigrants. The development of education has been impacted by brain drain in the same way that education has influenced brain drain through the absence and lack of necessary educational resources, which is a result of the very low funding allocated to post-secondary education. The lack of job and career opportunities, as well as opportunities to advance in education, motivates Haiti’s educated professionals to leave the country.Item Delineating the Differences in Veterinary Treatment between Domestic Companion Pets and Production Animals in the United States: Implications for Policy(2011) Johnson, DeKarraPeople’s attitudes toward animals impact the quality of veterinary treatment provided for domestic companion animals and production animals. The value of certain animal species in society is dependent on how humans can relate to and benefit from animals. In the United States, some domestic animals such as dogs and cats are held in high-esteem and are given near-human status. On the other hand, domestic animals like cattle and swine, which are primarily used as food sources, are given the status of inanimate objects to be treated as property. As a result, the allocation of resources, including capital and labor, is not proportionally distributed between companion animal medicine and production animal medicine. There are negative consequences of this uneven distribution that threaten the security of the United States’ food supply and human health. The spread of foodborne illnesses and antibiotic-resistant pathogens can be linked to weak food safety and antibiotic regulations for production animals. Such weaknesses enable diseased animals to enter the food supply contaminating millions of ponds of animal byproducts consumed by companion animals and humans. By understanding what factors influence people to continue providing inferior veterinary treatment to the production animals they depend on for subsistence, scholars and practitioners in the field of animal husbandry can create new and effective strategies that encourage sympathy toward production animal wellness for the sake of human wellness. Building upon a completed review of the literature, research addressing the aforementioned issues will be developed and implemented to satisfy requirements in the McNair Scholars Program.Item NCLB and Accountability: How Do Testing and Teachers Impact Retention?(2011) Harrison, Brittany; Costanzo, Richard; Gulemetova, MichaelaThis study seeks to uncover the role that high-stakes testing mandated by “No Child Left Behind” legislation and student-teacher ratio has on the retention of the traditional high-school student with an emphasis on the retention disparity between minority students and their White peers. This empirical, quantitative analysis uses school level data from the Common Core of Data. This data set was used to observe national trends between minority students and their White counterparts because minority students are generally the group plagued by underachievement and high dropout rates. Given the already expansive body of work surrounding what we refer to as the achievement gap, which can include issues of achievement ranging from grades to standardized test scores and even the issue of retention rates which this study focuses on, this study seeks to approach the issue from a different direction with a broader data set. Analyses showed that for minority male students (Black and Hispanic) a lower-student teacher ratio greatly contributed to their retention yet conversely White females’ retention seemed to be somewhat unaffected by student-teacher ratio fluctuations and high-stakes testing. Therefore, this study suggests that although student-teacher ratio and testing do have an impact on retention, this impact is primarily only for minority students, impacting minority males at the highest level.
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