AJUR Volume 16 Issue 4 (March 2020)

Click on this link to download the full high-definition interactive pdf for AJUR Volume 16 Issue 4 (March 2020)


Links to individual manuscripts, abstracts, and keywords are provided below.

p.5. Coating Polyurethane with Palmitoleic Acid and Bovine Serum Albumin to Prevent the Host Response to Foreign Materials
Sheherbano Hussain, Zoha Babar, Jimmy Hadid, & Jacqueline McLaughlin
https://doi.org/10.33697/ajur.2020.002
ABSTRACT: Macrophages are cells of the immune system that play a pivotal role in the host inflammatory response by attacking and engulfing any foreign molecule not seen as ‘self.’ They also help regulate the host response by releasing a variety of cytokines and growth factors that act as signals to other cells to amplify the host response. However, the host response causes degradation of implanted medical devices composed of polyurethane as well as other synthetic materials which it does not identify as self. Research was undertaken to investigate the potential of coating polyurethane with the self-like molecules palmitoleic acid and albumin to reduce or prevent the body’s host response from damaging implanted medical devices. Using an in vitro THP-1 bioassay, polyurethane films coated with palmitoleic acid and bovine serum albumin showed a reduction in macrophage adherence. The individually coated palmitoleic acid and bovine serum albumin films significantly reduced the number of cells attached to the films with increasing concentration while the films coated with the conjugate of both showed no statistical difference. This suggests the potential role of self-like molecules in reducing the inflammatory response to foreign materials.
KEYWORDS: Macrophages; host inflammatory response; THP-1; prosthetics; palmitoleic acid; bovine serum albumin; cytokines; immune system

p.15 Music Intervention in Undergraduates: the Relationship between Heart Rate Variability and State Anxiety
Annalise J. Tolley & Robert S. Vick
https://doi.org/10.33697/ajur.2020.003
ABSTRACT: A low heart rate variability (HRV) is indicative of autonomic inflexibility, which has important implications for physical and psychological health. This study investigates autonomic functioning and its relationship to state anxiety in the context of music intervention. A within-subjects, quasi-experimental design was used with undergraduates, a population frequently impacted by state anxiety. Participants pre-selected music that they identified as the most “relaxing” before being administered the State-Trait Anxiety Inventory (STAI). Baseline physiological indices were then collected using an EKG, followed by administration of the selected music and an additional collection of physiological indices. After the full duration of music intervention was administered, participants took the STAI once more. Results indicated that even short durations of music listening may serve to reduce anxiety in the undergraduate student, as was evidenced by the significant increase in physiological indices and decrease in self-reported anxiety levels. However, while changes in HRV and anxiety may trend together, results indicated no statistical association between these parameters.
KEYWORDS: Heart Rate Variability; Anxiety; Music Intervention; Autonomic Tone; Vagal Control; Autonomic Flexibility; College Students; State Anxiety

p.23 Can Expense Ratios Signal Performance? An Analysis of Equity ETFs & Mutual Funds
James Monroe Gamble IV
https://doi.org/10.33697/ajur.2020.004
ABSTRACT: This study examines the impact of the emergence of exchange-traded funds (ETFs) as an alternative investment vehicle to mutual funds. As the number of ETFs continues to rise, we investigate potential risks and disadvantages posed by ETFs in comparison to traditional mutual funds. ­We compare the returns, performance, and expense ratios of ETFs to those of mutual funds. We find that expense ratios are positively correlated with actively managed mutual fund returns and that passive funds have outperformed active funds since their inception. There is downward pressure on mutual fund fees over time, suggesting increased competition between mutual funds and ETFs. We also find, up to a certain threshold, actively managed funds are worth their costs.
KEYWORDS: Exchange-Traded Fund (ETF); Mutual Fund; Investing; Fee Structure; Expense Ratio; Passive (Active) Investing; Portfolio Management; Indexing

p.41 Acoustic Identification of Wild Gray Wolves, Canis lupus, Using Low Quality Recordings
Cara B Hull, Caitlin M McCombe, & Angela M Dassow
https://doi.org/10.33697/ajur.2020.005
ABSTRACT: Invasive trapping and radio-collaring techniques are currently used by conservation biologists to study the population dynamics of gray wolves (Canis lupus). Previous research has found wolf howls can be used to determine individual identity on high quality recordings from captive animals, offering an opportunity for non-invasive monitoring of packs.We recorded wild wolves in Central Wisconsin to determine the effectiveness of these features in determining individuality in low quality recordings. The wolf howls analyzed were from two adult individuals from separate packs. Using a principle component analysis, maximum frequency and end frequency of the calls were determined to be most individualistic. Using these features in a discriminant function analysis, howls were able to be identified from individuals with 100% accuracy. Gray wolves play an important role in ecosystem maintenance, however, the current monitoring techniques are costly and invasive. The creation of an easily accessible, non-invasive technique that can be used by individuals with a variety of technical backgrounds is necessary to address concerns faced by conservation efforts. To address these issues, all analyses performed usedfree or low-cost software, making this method of individual identification a useful alternative for conservation biologists.
KEYWORDS: Canis lupus lycaon; Gray Wolf; Acoustic Signatures; Howls; Tracking Method; Conservation; Vocal Individuality

p.51 The Allele Frequency of the HFE gene mutation H63D (rs1799945) and Its Relationship to a Hereditary Hemochromatosis Diagnosis in Metabolic Nutrition Students at Virginia Tech
Tyler R. Ferqueron, Angela S. Anderson, & Deborah J. Good
https://doi.org/10.33697/ajur.2020.006
ABSTRACT: Hereditary hemochromatosis (HH) is a disease that causes excess iron absorption from the diet.  This excess iron can be stored in the liver, skin, heart, pancreas, and joints, and then can lead to other health conditions, as the human body has no way of actively excreting iron.  The human hemochromatosis protein (HFE protein) is encoded by the HFE gene, and mutations in this gene can lead to a dysfunction of the protein resulting in HH or iron overload later in adulthood.  The objective of this study was to analyze the mutant allele frequency and the penetrance of the H63D mutation (SNP rs1799945) of the HFE gene in a cohort of Virginia Tech students.  This study had a total of 69 participants.  Fifty-two participants provided saliva samples, genomic data from 23andMe®, and surveys with phenotypic information.  Of these, 6 were genotyped using the RFLP technique and served as controls for genotype confirmation. An additional 17 participants provided saliva samples, but did not provide 23andMe® data; genomic DNA from these participants were genotyped using the RFLP technique.  Our results showed that although none of the participants had been diagnosed with HH, the mutant allele frequency of this population was 13.04%.  In conclusion, as HH is usually diagnosed in older adults, we could not identify any students with a phenotype of HH, even though we could detect the mutant allele.  This data suggests that affordable and accessible genetic ancestry and health kits such as the 23andMe® kit, could provide an efficient way to identify, prevent, and manage HH and other genetic diseases before symptoms arise.
KEYWORDS: Hereditary Hemochromatosis; Iron Absorption; Single Nucleotide Polymorphism; Restriction Fragment Length Polymorphism; College Student Population; 23andMe®; Population Analysis; Survey Results

p.59 Meningococcal Meningitis in College Students at United States Universities
Mikafui Dzotsi
https://doi.org/10.33697/ajur.2020.007
ABSTRACT: The purpose of this study was to review current United States (US) university meningitis prevention and awareness efforts for college students with the objective of finding improved methods for meningitis control on college campuses. Meningococcal meningitis cases occurring amongst the students at 45 US universities, reported by the National Meningitis Association between 2013-2017, were reviewed.  Apart from analyzing the incidence of meningococcal serotype cases and prevention protocols at the 45 US universities, interviews were conducted with university health directors and health center staff to assess the nature of meningitis control programs on college campuses. the 45 US universities reported between the years, 2013-2017, 20 universities had cases of Meningococcal meningitis serotype B (Men B) while 25 universities had cases of serotype A (Men A), C (Men C), W (Men W), or Y (Men Y).   Among 80 cases across all US universities, there were 11 deaths for a case fatality rate of 11/80 (14%). While all universities adhere to state requirements of immunization against serotypes A, C, W and Y, the vaccine for Men B was only recently FDA approved and is not widely used. Further review of some university meningitis prevention and awareness efforts reveal a trend in more passive (e.g. posters, pamphlets, health portal guidance) approaches, while the uptake of active campaign efforts (e.g. vaccination drives, presentations) are not always prioritized until outbreaks occur.
KEYWORDS: Awareness; Epidemiology; Disease; Meningococcal; Prevention; Serotype; University; Vaccination

p.71 Urban Wind Harvesting Using Flow-Induced Vibrations
Levon Ghabuzyan, Christopher Luengas, Jim Kuo
https://doi.org/10.33697/ajur.2020.008
ABSTRACT: The growing global interest in sustainable energy has paved the way to the rapid development of large-scale wind farms, consisting of dozens to hundreds of wind turbines. Although these large wind farms can generate enormous amount of power, they are also costly and require large areas of land or water, and thus are not suitable for urban environments. Smaller urban wind turbines have been developed for urban environments, but there are significant challenges to their widespread deployment. One of these challenges are their urban wind flows as they are strongly affected by complex building structures, producing highly turbulent flows. Any urban wind turbine would need to be designed to function efficiently and safely under these flow conditions; however, these unpredictable and turbulent winds can induce undesirable vibrations and cause early failures. Recently, bladeless wind turbines are gaining interest due to their reduced costs compared with conventional wind turbines such as the vertical-axis wind turbine and horizontal-axis wind turbine. These bladeless turbines convert flow wind energy into vibration energy, then converts the vibration energy into electricity. This paper examines the effects of force-induced vibrations on a cantilever beam system through wind tunnel experimentation. When fluid flows around a bluff body, periodic shedding of vortices may occur under the right conditions. The vortex shedding process creates an asymmetric pressure distribution on the body which causes the body to oscillate, known as vortex-induced vibrations. The purpose of the paper is to understand the factors affecting flow-induced vibrations and to improve wind energy harvesting from these vibrations. The first part of the paper focuses on wind tunnel experiments, by utilizing a cantilever beam configuration, conceptualized by previous research. Then, the experimental model was tested in different configurations, to determine the best setup for maximizing vibrations induced on the model. The long-term goal of the project was utilizing the model to optimize the system to improve efficiency of wind energy harvesting. The experimental results showed that the presence of an upstream cylinder will significantly improve the amplitude of vibration for energy harvesting, furthermore, the experiments showed that spacing in different directions also affect the amplitude of the vibrations. A two tandem cylinder system was used in this work, including a fixed rigid upstream cylinder and a downstream cylinder supported by a cantilever beam. Various configurations of these two cylinders in terms of spanwise and streamwise separation distances were studied and their maximum and root mean square displacements are reported for different wind speeds. Results showed that the presence of an upstream cylinder will significantly improve the amplitude of vibrations. This work verified that a wind energy harvester needs to consider the effects of wind speed and separation configuration of the cylinders in order to maximize the harvester’s performance in urban environments.
KEYWORDS: Sustainable Energy; Energy Harvesting; Urban Environments; Bladeless Wind Turbines; Flow-Induced Vibrations; Cantilever Beam System; Wind Tunnel; Wake 

p. 81 Exploring the Relationship between Dystopian Literature and the Activism of Generation Z Young Adults
Aysha Jerald
https://doi.org/10.33697/ajur.2020.009
ABSTRACT: Some recent research has posited that the independent and revolutionary traits of Generation Z can be traced to the circumstances of their births, specifically the 9/11 attacks and the Great Recession. While there has been research examining the effect of these events on the type of behavior Generation Z exhibits towards political and societal issues, there has been little research that examines the literary culture in which they grew up. Did popular dystopian works such as Catching Fire by Suzanne Collins (2009), Divergent by Veronica Roth (2011), and The Maze Runner by James Dashner (2009) have an impact on their political identities and behaviors? This paper examines that question by using a mixed method approach: a public questionnaire, thirteen in-depth interviews with a select group of Generation Z students from the University of Georgia, and direct content analyses of the key works under consideration. This study argues that the relationship between dystopian literature and young adult activism may offer insight into the ways literature can be used as a revolutionary tool. This study also hopes to add to the literature exploring the characteristics of Generation Z and the significance dystopian literature may have not only on a young adult’s thoughts but also their actions.
KEYWORDS: Dystopian Literature; Dystopian Literary Media; Generation Z; Youth Activism; Literary Influence; Activist Typology; Aspects of Literary Response: A New Questionnaire; College Students; Divergent; Catching Fire; The Maze Runner; Literary Culture, The Hunger Games

AJUR Volume 16 Issue 3 (December 2019)

Click on the link below to download the full high-definition interactive pdf for

AJUR Volume 16 Issue 3 (December 2019)


Links to individual manuscripts, abstracts, and keywords are provided below.

p.5. Women in Higher Educational Leadership: Representation, Career Progression, and Compensation
Carla Cañas, Caitlyn Keeve, Carmen Ramos, Jocelyn Rivera, & Michelle L. Samuel
Department of Psychology, Mount Saint Mary’s University, Los Angeles, CA
https://doi.org/10.33697/ajur.2019.026
ABSTRACT: Men in university administration repeatedly outnumber women in leadership positions. The problem under investigation is that this gender gap exists due to barriers to advancement and discrimination in both the hiring process and in the workplace. With less representation of women in higher education leadership, there is a higher risk of bias for women in this field. This study used an ex-post facto methodology and gathered public data from the University of California (UC) Annual Payroll Compensation database. Three separate studies were run to determine the level of gender differences in the representation of educational leaders, compensation, and career progression. Significant differences in gender equity existed, with more men represented at several levels of educational leadership. Significant differences were also found in compensation levels, where men earned more money than women in the same position. Lastly, a small effect, although not significant, was observed when comparing early career gender representation to non-early career gender representation. There are more women recent graduates than men in leadership positions. Together these results suggest that while there are gender gaps in representation and compensation, there may be slow progress towards better representation in early career leadership positions in the UC system. The implication of this research supports further research into factors which impact the compensation of women leaders in academia. Higher education hiring professionals and candidates for leadership positions could benefit from further development of theories around gender equity and representation.
KEYWORDS: Gender Representation; Gender Equity; Higher Educational Leadership; Women; Higher Education; Psychology; Wage Gap; Higher Education Administration

p.15 Anisotropic Behavior of Ultrasonic Waves in 3D Printed Materials
Edward Alexandera* & Gordon D. Hoopleb
aDepartment of Mechanical Engineering, Shiley-Marcos School of Engineering, University of San Diego, San Diego, CA
bDepartment of Integrated Engineering, Shiley-Marcos School of Engineering, University of San Diego, San Diego, CA
https://doi.org/10.33697/ajur.2019.027
ABSTRACT: This study quantifies the anisotropic behavior of ultrasonic wave transmission for materials printed with three different 3D printers. As 3D printed materials become more prevalent in manufactured products, fully characterizing the physical properties of these materials become more important. This paper examines the longitudinal velocity of sound and acoustic impedance in two directions: orthogonal and parallel to the printed layers. Each of the 3D printed materials displayed slightly different transmission results. For PMMA like samples printed on a SLA printer waves travelled more quickly in the orthogonal direction than the parallel direction. For samples printed on an industrial FDM printer using ABS the opposite was true: the parallel direction was faster than the orthogonal. For samples printed on an entry level FDM printer with PLA there was no consistent pattern, instead there was a tight clustering of ultrasonic velocity in the parallel direction but substantial variation in the orthogonal direction. Overall the variation between the orthogonal and parallel directions was found to be less than 2% in all cases.
KEYWORDS: 3D Printing; Additive Manufacturing; Ultrasonic Waves; Anisotropic Material Properties; ABS; PLA

p.23 Why Regimes Repress: The Factors that Lead to Censorship of Social Media
Ezhan Hasan
Department of Political Science, Texas Christian University, Fort Worth, TX
https://doi.org/10.33697/ajur.2019.028
ABSTRACT: Social media have made it easier to create mass political action. Prominent examples include the Arab Spring movements, which took place in regions where information was previously tightly controlled by authoritarian regimes. Fearing radical change, several regimes have repressed social media use, but not all authoritarian regimes have taken the same measures. Previous research suggests that regime leadership is motivated to ensure its own survival but also influenced by a strong independent media and the need for citizens to vent grievances. To understand the relationship of these factors to social media repression, this research conducts a comparative process-tracing case study of Iran, Turkey, and Venezuela from 2004 to 2017, using a hypothesis-testing approach. It concludes with discussion of the findings for the nature of regime response to the role of social media in protest.
KEYWORDS: Internet; Media; Protest; Authoritarian; Iran; Turkey; Venezuela; Comparative; Case-Study

p.43 Investigation of Constant Volume and Constant Flux Initial Conditions on Bidensity Particle-Laden Slurries on an Incline
Dominic Diaz*, Jessica Bojorquez, Joshua Crasto, Margaret Koulikova, Tameez Latib, Aviva Prins, Andrew Shapiro, Clover Ye, David Arnold, Claudia Falcon, Michael R. Lindstrom, & Andrea L. Bertozzi
Department of Mathematics, University of California, Los Angeles, CA
https://doi.org/10.33697/ajur.2019.029
ABSTRACT: Particle-laden slurries are pervasive in both natural and industrial settings, whenever particles are suspended or transported in a fluid. Previous literature has investigated the case of a single species of negatively buoyant particles suspended in a viscous fluid. On an incline, three distinct regimes emerge depending on the particle concentration and inclination angle: settled (where particles settle and there is a pure fluid front), well-mixed (where particle concentration is constant throughout), and ridged (where a particle-rich ridge leads the flow). Recently, the same three regimes were also found for constant volume two species bidensity slurries. We extend the literature on bidensity slurries by presenting results on constant volume and a new type of initial condition: constant flux, where slurry is pumped onto the incline at a constant rate. We present front positions of the slurries and compare them to theoretical predictions. In addition, height profiles (film thicknesses) are also presented for the constant flux case, showing the distinct behavior of the ridged regime. We find that for constant flux conditions the settled regime forms for small particle volume fractions and inclination angles while the ridged regime forms for large corresponding values. Intermediate values of these two parameters are shown to produce a well-mixed regime.
KEYWORDS: Thin Films; Particle-Laden Flow; Multiphase Fluids; Interfacial Flows; Particle Segregation

p.59 A Monte Carlo Simulation Study on the Power of Autocorrelation Tests for ARMA Models
Zachary Wenning* & Emily Valenci
Department of Statistics, Pennsylvania State University, University Park, PA
https://doi.org/10.33697/ajur.2019.030
ABSTRACT: It is often the case when assessing the goodness of fit for an ARMA time series model that a portmanteau test of the residuals is conducted to assess residual serial correlation of the fitted ARMA model. Of the many portmanteau tests available for this purpose, one of the most famous and widely used is a variant of the original Box-Pierce test, the Ljung-Box test. Despite the popularity of this test, however, there are several other more modern portmanteau tests available to assess residual serial autocorrelation of the fitted ARMA model. These include two portmanteau tests proposed by Monti and Peña and Rodríguez. This paper focuses on the results of a power analysis comparing these three different portmanteau tests against different fits of ARMA – derived time series, as well as the behavior of the three different test statistics examined when applied to a real-world data set. We confirm that for situations in which the moving average component of a fitted ARMA model is underestimated or when the sample size is small, the portmanteau test proposed by Monti is a viable alternative to the Ljung-Box test. We show new evidence that the Peña and Rodríguez may also be a viable option for testing for residual autocorrelation for data with small sample sizes.
KEYWORDS: Time Series; Monte Carlo; ARMA Models; Power; Simulation; Autocorrelation Tests; Portmanteau Tests; Monti; Ljung-Box; Peña and Rodríguez

p.69 Evaluating the Effects of Bisphenols F and S with Respect to Bisphenol A on Primordial Germ Cell Migration in Zebrafish (Danio rerio) Embryos Using Immunofluorescent Microscopy
Siti Sarah Safura*, George Roba, & Edward Freeman
Department of Biology, St. John Fisher College, NY
https://doi.org/10.33697/ajur.2019.031
ABSTRACT: Primordial Germ Cell (PGC) migration occurs in early embryonic development and is highly conserved across taxa. PGC migration occurs within the first 24 hours post fertilization (hpf) in zebrafish, making the organism an efficient model for observing the migration pathway. Proper PGC migration is necessary for normal gonad development and, in some species, sex determination. Disruption of this process leads to defects in gonad formation and abnormal sex determination and differentiation. Studies show that endocrine-disrupting chemicals such as bisphenol A (BPA) disrupt PGC migration in zebrafish. BPA is an estrogenic compound that has been linked to a variety of human diseases, including various cancers, diabetes, reproductive disorders, obesity, and cardiovascular diseases. It is one of the most widely used synthetic compounds worldwide, as it used to make polycarbonate plastics. Many studies provide evidence of the harmful effects of BPA on living organisms. In response, manufacturers have started to use replacements such as bisphenol F (BPF) and bisphenol S (BPS). However, due to their structural similarity, it is likely that BPF and BPS are just as harmful to organisms as BPA. In this study, we use antibody staining and immunofluorescence microscopy to confirm that BPA exposure results in abnormal PGC migration in zebrafish embryos, as previously studied, and to illustrate that BPF and BPS exposure results in similar PGC migration defects.
KEYWORDS: Zebrafish; Zebrafish Embryos; Primordial Germ Cells; PGC Migration; Gonad Development; Endocrine-Disrupting Chemicals; Bisphenol A; Bisphenol S; Bisphenol F; Sex Determination

p.79 Exposure and Loss of Environmental Enrichment Mediates Ethanol Consumption in Adolescent Female Rats
Natalie Lipari*a, Max Baronb, & Joshua A. Pecka
aPsychology Department, State University of New York at Cortland, Cortland, NY
bPsychology Department, University of Michigan, Ann Harbor, MI
https://doi.org/10.33697/ajur.2019.032
ABSTRACT: Alcohol use among adolescent females has significantly increased in the United States with young women drinking alcohol at the same rate as young men. One potential treatment strategy that could help sustain alcohol abstinence is Environmental Enrichment (EE). Environmental enrichment is a process concerning the stimulation of the brain by one’s physical and social surrounding, which promotes non-drug reinforcement alternatives (e.g. voluntary exercise) supporting drug abstinence. Thus, the primary focus of this study was to investigate the effect of EE on ethanol (ETOH) abstinence in adolescent female rats. All adolescent female rats, starting on postnatal day 30, had 24-h access to 2%, then 4%, and then 6% ethanol concentrations. At the end of the four weeks, the environmental conditions were switched (EE→NEE and NEE→EE) and the 6% ethanol measure was repeated. We found that EE significantly reduced ethanol consumption for adolescent female rats compared to controls. Further, the removal of EE opportunities resulted in a significant increase in ethanol consumption. Collectively, the results suggest that access to enriched life conditions are important in facilitating alcohol abstinence in adolescent female rats.
KEYWORDS: Adolescent Females; Alcohol Consumption; Environmental Enrichment; Alcohol Use Disorder; Treatment Strategy; Alcohol Abstinence; Ethanol; Adolescent Female Rats

 

AJUR Volume 16 Issue 2 (September 2019)

Click on the link below to download the full high-definition interactive pdf for

AJUR Volume 16 Issue 2 (September 2019)


Links to individual manuscripts, abstracts, and keywords are provided below.

Classifying Lensed Gravitational Waves in the Geometrical Optics Limit with Machine Learning
Amit Jit Singh, Ivan S.C. Li, Otto A. Hannuksela, Tjonnie G.F. Li, & Kyungmin Kim
https://doi.org/10.33697/ajur.2019.019
ABSTRACT: Gravitational waves are theorized to be gravitationally lensed when they propagate near massive objects. Such lensing effects cause potentially detectable repeated gravitational wave patterns in ground- and space-based gravitational wave detectors. These effects are difficult to discriminate when the lens is small and the repeated patterns superpose. Traditionally, matched filtering techniques are used to identify gravitational-wave signals, but we instead aim to utilize machine learning techniques to achieve this. In this work, we implement supervised machine learning classifiers (support vector machine, random forest, multi-layer perceptron) to discriminate such lensing patterns in gravitational wave data. We train classifiers with spectrograms of both lensed and unlensed waves using both point-mass and singular isothermal sphere lens models. As the result, classifiers return F1 scores ranging from 0:852 to 0:996, with precisions from 0:917 to 0:992 and recalls ranging from 0:796 to 1:000 depending on the type of classifier and lensing model used. This supports the idea that machine learning classifiers are able to correctly determine lensed gravitational wave signals. This also suggests that in the future, machine learning classifiers may be used as a possible alternative to identify lensed gravitational wave events and to allow us to study gravitational wave sources and massive astronomical objects through further analysis.
KEYWORDS: Gravitational Waves; Gravitational Lensing; Geometrical Optics; Machine Learning; Classification; Support Vector Machine; Random Tree Forest; Multi-layer Perceptron

Cost, Quality, and Access of Healthcare in Piura, Peru
Julia B. Griffin & Elaina F. Osterbur
https://doi.org/10.33697/ajur.2019.020
ABSTRACT: The aim of the study is to investigate the patient perceptions on the cost, quality, and access of health care services in Piura, Peru. Although one of the largest cities in Peru, Piura has one of the lowest densities of health care workers in the country which greatly impacts the population’s ability to receive medical treatment. Lack of financial resources and health literacy, among other health disparities exist. Modeled after CAHPSâ Health Plan Adult Commercial Survey 5.0 and the Patient Satisfaction Survey, a forty-four question English and Spanish survey was created with questions to study healthcare variables. As a correlational study with convenience sampling, the survey was administered to both patients and medical providers in eight city health centers. Over a period of twelve days, 107 surveys were collected. After eliminating subjects who did not meet the study criteria, 92 patients and 13 medical providers were included in the study. Findings from medical providers are not reported because of the small sample size. The results of this study suggests that 32% of subjects do not have health insurance, 24% of subjects rated their healthcare received as average, 18% of participants rated their healthcare as the best possible on a scale of zero to ten, and 29% of subjects had to wait an average of seven days for access to healthcare services when care is urgent. The results of this analysis can be used to better understand the Peruvian healthcare system and educate the Piura community and the Parish Santísimo Sacramento as they continue to improve and expand their health care services.
KEYWORDS: Cost; Quality; Access; Healthcare; Piura; Peru; Satisfaction; Parroquia Santísimo Sacramento; EsSalud; SIS; MINSA
APPENDICES: AJUR_Vol_16_Issue_2_September_2019_p17_appendices

The Effectiveness of Debt Relief: Assessing the Influence of the HIPC Initiative and MDRI on Tanzania’s Health Sector
Fernando Lopez Oggier
https://doi.org/10.33697/ajur.2019.021
ABSTRACT: Debt relief initiatives have been part of the international development sphere since the early 1990s. With the launch of the Heavily Indebted Poor Country (HIPC) Initiative in 1996 and the Multilateral Debt Relief Initiative (MDRI) in 2005 many countries have been able to successfully qualify for debt relief. Tanzania has been one of the primary beneficiaries of debt relief over the years. While empirical evidence demonstrates that the country’s economic growth has been positively impacted by debt relief initiatives, other aspects of human development need to be analyzed to ensure a comprehensive assessment of the HIPC Initiative and the MDRI. This study compiles Tanzania’s health data into a composite indicator to perform a graphical analysis to compare the trends between health outcomes and external debt. The graphical analysis is contextualized through a qualitative analysis of political, economic and health financing literature from the Bank of Tanzania, UNICEF and USAID. The results indicate that there health outcomes improved throughout the whole study’s time period particularly after the HIPC Initiative. The health financing literature also points to increased development expenditure during this period. Nonetheless, the effects of debt relief seem to diminish in the long-term due to fluctuations in external donors and logistical barriers to budget execution. Tanzania also continues to face socio-economic and geographic disparities in health outcomes and funding. Some of the literature also states that the country’s weak system of checks and balances and the lack of robust institutions could cause opportunistic policy preferences that might not necessarily improve Tanzania’s health outcomes.
KEYWORDS: Child Mortality Rate; Debt Relief; External Debt; Heavily Indebted Poor Country Initiative; International Monetary Fund; Life Expectancy; Maternal Mortality Rate; Multilateral Debt Relief Initiative; Official Development Aid; Prevalence of Undernourishment

The Association of TAS1R2 to Dental and Cardiovascular Health
Joseph Keryakos, Annika van Oosbree, & Alyssa Marie Kiesow
https://doi.org/10.33697/ajur.2019.022
ABSTRACT: Despite brushing and/or flossing their teeth twice daily, many people are still susceptible to dental cavities and tooth decay. This research investigates the genetic and cardiovascular health behind this phenomenon. Two gene variants related to taste pathways, taste 1 receptor member 2 (TAS1R2) and taste 2 receptor member 38 (TAS2R38), were tested on the DNA of 20 students at Northern State University (10 males and 10 females). In concert with genetic screening, tooth impressions were taken of the participants’ upper and lower jaws along with salivary pH, heart rates, and blood pressures. Participants’ cavities and fillings were counted and their gums examined for inflammation. Results showed that seven out of 10 males and two out of 10 females had the gene variant (TAS1R2). Students with this gene variant had an average salivary pH of 5.22—significantly lower than the salivary pH for the other non-carrier students (p < 0.05). These students also had smaller-sized tooth enamel, with none showing a size greater than one millimeter (x̄ = 0.84 millimeters). Students not expressing the gene variant had fewer cavities than those expressing the TAS1R2 gene variant (i.e., one of the regions amplified). Four of the males and both of the females that carried the gene variant also showed signs of swollen gums, possibly contributing to heart disease in the future. Blood pressures and heart rates for the carriers were statistically significant (p < 0.05), showing higher pressures and faster rates compared to non-carriers; meanwhile, all of the non-carriers had normal pressures and rates. Further, body mass index was lower among individuals without the gene variant. The results this limited study indicate that the TAS1R2 gene variant may play a role in cavity development and impact (or indicate poor) cardiovascular health, highlighting the importance of understanding the role of gene variants with regard to risk of tooth decay and gum and heart disease.
KEYWORDS: Dental cavities; Tooth decay; Gum and heart disease; Taste pathway gene; Gene variant; Blood pressure; Heart rate; Salivary pH; Tooth enamel

Body Image and Self-Esteem in Female College Students of Healthy Weight and Excess Weight: The Mediating Role of Weight Stigma
Carlie Smith, Jennifer Becnel, & Amanda Williams
https://doi.org/10.33697/ajur.2019.025
ABSTRACT: Emerging adulthood is an important transition in which the development of lifelong behaviors emerge. Recent research suggests that women in college are particularly vulnerable to poor body image and low self-esteem. This is also a time of possible weight gain as individuals learn to eat and exercise on their own. These are important as body mass index (BMI) influences how women feel about themselves and how others view them. Thus, the purpose of the present study was to examine the associations between body image, self-esteem, and weight stigma among female college students of healthy weight and excess weight. Participants (n=124; 83% White) were recruited to take a short survey administered online through Facebook advertisements and snowball sampling. Results reveled poorer body image and more experiences with weight stigma among individuals with excess weight. Additionally, weight stigma fully mediated the relationship between BMI and self-esteem as well as BMI and body image. Results were consistent with previous research noting the stigma and stereotypes associated with excess weight. Future work should examine these relationships in more diverse groups to identify those at greatest risk for negative self-concept for intervention.
KEYWORDS: Weight; Weight Stigma; Self-Esteem; Body Image; College Students; Women

After Hurricanes Irma and Matthew: Living Shorelines Stabilize Sediments
Taryn Chaya, Jessica Veenstra, & Melissa Southwell
https://doi.org/10.33697/ajur.2019.024
ABSTRACT: Constructed intertidal oyster reefs, an example of a “living shoreline”, can protect against erosion and loss of habitat, but can they prevent erosion during high-energy storm events such as hurricanes? Oyster reefs were constructed in 2012 within the Guana Tolomato Matanzas National Estuarine Research Reserve in Northeast Florida to stabilize the shoreline sediment and prevent erosion of an archeological site. Sediment cores were collected behind constructed oyster reefs before and after hurricanes Matthew (2016) and Irma (2017) to study changes in sediment particle size due to these high-energy storms. Pre-hurricane data were collected in 2016 from three different constructed reefs, as well as three control sites where no reef was present. Pre-hurricane sediment profiles behind the constructed reefs consisted of finer sediments, ~36% silt and clay, in the surface ~10-12 cm, with decreasing silt and clay and increasing sand content as depth increased. This was different than the sediment from the control sites with ~4% silt and clay in all depths sampled. Like the sediment profiles before the high energy storms, the post-hurricane sediment data showed a clear layer of finer sediment ~10-12 cm over coarser sediment. Although they were high-energy storms, the storms did not appear to significantly affect the sediment behind the constructed oyster reefs. Sediment profiles remained consistent after these storms but may not remain undisturbed during the next storm without some intervention because the oyster reefs have been degrading.
KEYWORDS: Oyster Restoration; Living Shorelines; Hurricanes; Coastal Erosion; Sedimentation; Salt Marsh

 

AJUR Volume 16 Issue 1 (June 2019)

Click on the link below to download the full high-definition interactive pdf for

AJUR Volume 16 Issue 1 (June 2019)


Links to individual manuscripts, abstracts, and keywords are provided below.

 

p.5. Should high-top or low-top cleats be used when playing baseball?
Margo P. Wohlfeil, Cole R. Neary, Mitchell M. Klocke, Johnny G Mills, Rich C. Calvert, & David S. Senchina
https://doi.org/10.33697/ajur.2019.011
ABSTRACT: There is a shortage of knowledge about how baseball cleat design may impact athletes. The purpose of this experiment was to determine if the height of the baseball cleat affected performance, perception of the cleat, and ankle range-of-motion. Thirteen subjects participated in the study, and each subject performed three drills (base-running, 5:10:5 “pro agility,” and hitting) in both high-top and low-top baseball cleats. Performance time was measured for the first two drills. Perception of comfort, heaviness, shoe climate (heat), stability, and traction were measured for all three drills using 10-cm visual analog scales (VAS). Ankle range-of-motion (dorsiflexion, plantarflexion, eversion, and inversion) was measured using goniometry in both cleats, plus socks-only as baseline control. Shoe height did not significantly affect completion time in either the base-running drill (6.1±0.1 sec. in high-top vs. 6.1±0.1 sec. in low-top) or pro-agility drill (4.8±0.1 sec. in high-top vs. 4.6±0.1 sec. in low-top). There were significant differences in perception of heat (6.4 in high-top vs. 4.6 in low-top; p<.001), stability (6.9 in high-top vs. 5.1 in low-top; p=.001), and heaviness (6.0 in high-top vs. 4.1 in low-top; p<.001), but not in perception of comfort (6.1±2.0 in high-top vs. 6.6±1.5 in low top) or traction (7.3±2.0 in high-top vs. 7.4±1.5 in low-top). There were significant differences between high-top and low-top cleats in plantarflexion (42.5° in high-top vs. 47.5° in low-top; p=.033), eversion (7.9° in high-top vs. 11.3° in low-top; p=.003), and inversion (12.8° in high-top vs. 16.6° in low-top; p=.044), but not dorsiflexion (8.2° in high-top vs. 10.9°). For baseball players concerned about excessive ankle movements during play, these results suggest that using a high-top baseball cleat might reduce ankle range-of-motion without impairing performance or feeling burdensome.
KEYWORDS: Baseball; Cleats; High-Top; Low-Top; Perception; Performance; Range-of-Motion; Shoes

p.15 Transcription of nanos-1 in Zebrafish Embryos is not Affected by Bisphenol A: Evaluated Using Quantitative Real-Time PCR
Bridget Babich, George Roba, Siti Sarah Safura*, Kevin Callahan, & Edward Freeman
https://doi.org/10.33697/ajur.2019.012
ABSTRACT: The presence of primordial germ cells (PGCs) is crucial for proper gonad formation in zebrafish (Danio rerio). The many aspects of PGC migration that allow these cells to reach the proper location at the gonadal ridge include receptors, ligands, germ plasm components, and internal maintenance of PGCs. Any one of these factors could be affected by endocrine-disrupting chemicals (EDCs), which have been shown to alter the directed migration of these cells during early embryonic development. Based on recent research wherein the EDC bisphenol A (BPA) inhibited normal PGC migration, we have used the same dose of BPA to determine the impact of BPA on a gene central to proper germ cell migration. Zebrafish embryos were exposed to BPA, and the levels of the target gene nanos-1 were analyzed using quantitative real-time PCR (q-PCR). The target gene nanos-1 is a critically important germplasm component that allows for survival and proper migration of PGCs. The q-PCR results showed that BPA did not affect the transcription level of nanos-1 in zebrafish embryos.
KEYWORDS: Zebrafish; Zebrafish Embryos; nanos-1; Primordial Germ Cells; PGC Migration; Gonad Development; Endocrine-Disrupting Chemicals; Bisphenol A; Sex Determination

p.23 Investigation of Atmospheric Aerosol Size Distributions from Ground-Based Solar Spectrometer Measurements Synthesized with Satellite Data
Dane T. Kuhr & Adam T. Whitten
https://doi.org/10.33697/ajur.2019.013
ABSTRACT: Data collected by a ground-based solar spectrometer at Collegeville, MN, was used to generate Aerosol Optical Depths (AODs) throughout the 2017 calendar year. The AOD data was then visualized at 13 selected wavelengths throughout the year and analyzed in comparison to satellite imagery, upper air charts and backwards trajectories of air masses moving towards Central Minnesota in order to determine key dates of interest that correspond to times before (20170615), during (20170729), and at the conclusion of (20170914) forest fires that burned in British Columbia (BC) during the summer of 2017. The data from these specific days were analyzed further by inputting the maximum and minimum AODs for each day into a Parameter Based Particle Swarm Optimization (PBPSO) algorithm in order to generate bimodal lognormal particle size distributions. The bimodal distributions were chosen because they carry more information about the aerosol loads across the entire spectrum of particle radii. The resulting distributions show an increase in number density and decrease in median radius in the Aitken mode during the BC forest fires and a relatively constant (within uncertainty) number density of accumulation mode particles at daily maximum AODs. Comparing the resulting bimodal lognormal distribution for daily minimum AODs (where evaporation and other diurnal effects are at a minimum) shows an increased number density of Aitken mode particles by two orders of magnitude from pre- to post-forest fires. This measured increase in the number density of smaller radii particles due to forest fires illustrates the PBPSO’s capability of distinguishing variations in atmospheric aerosol particle number size distributions in the Aitken mode based on data collected by the Kipp-Zonen PGS-100 solar spectrometer.
KEYWORDS: Atmospheric Aerosol; Particle Swarm Optimization; Aerosol Optical Depth; Solar Spectrometer; Size Distributions; Forest Fire; Satellite Imagery; Upper Air Charts; Backward Trajectory

p.33 Diol Mediated Tautomerization of Glycine: a DFT Study
Francis Suh, Vanessa Rivera, & Ruben D. Parra
https://doi.org/10.33697/ajur.2019.014
ABSTRACT: The tautomerization of glycine via a triple proton transfer was investigated both in the gas phase and in aqueous solution using the B3LYP/6-31+G(d,p) level of theory. Fully optimized complexes of the neutral and zwitterion forms of glycine with 1,3-propanediol were used for the reactant and product forms, respectively. The hydroxyl groups in the diol are conveniently oriented for glycine tautomerization through a concerted triple proton transfer facilitated by a network of three hydrogen bonds: N-H…O-H…O-H…O=C. The activation energy for the zwitterion à neutral process increases in solution. Also, the diol-glycine complex favors the neutral over the zwitterion form in a vacuum, but the opposite is true in solution. For comparative purposes, the tautomerization of glycine via a three-proton transfer mediated by two molecules of water was also examined. The results are qualitatively similar, albeit with activation energies that are smaller to those found in the corresponding diol-mediated tautomerization.
KEYWORDS: Glycine; zwitterion, diol-mediated tautomerization; water-mediated tautomerization

p.41 Psychological Constructs as Predictors of Strength Gains in a Strength Training Course
Kathrine Hadley & Joanna Morrissey
https://doi.org/10.33697/ajur.2019.015
ABSTRACT: Strength training has many benefits, both affective and physical health-related. However, little research has been done on the psychological constructs that play an important role in exercise adherence, maintenance, and outcomes regarding strength training specifically. The purpose of this study was to examine self-efficacy (SE), perceived competence (PC), and outcome expectancy (OE), several of the key psychological constructs, as predictors of strength gains in a strength training course. It was hypothesized that the changes in participants’ measures of SE, PC, and OE from baseline to post-training would predict participants’ actual strength gains, but not the levels of SE, PC, and OE at baseline and post-training independently. Participants (n=20; 50% 20-21 years old, 40% 22-24 years old, 10% 25 years or older; 60% female, 40% male; 45% Caucasian, 30% Hispanic/Latino, 20% multiracial, 5% Asian/Pacific Islander) in a 15-week strength training technique (STT) course completed a battery of psychological questionnaires assessing SE, PC, and OE in addition to fitness tests consisting of a vertical jump test, an estimated one repetition maximum bench press and a back squat at baseline, mid- and post-training. One-way repeated measures ANOVA was used to examine differences in SE, PC, and OE at baseline, mid-, and post-training. Spearman correlation and multiple regression analyses were used to determine the predictive specificity of baseline, mid-, post-training levels, and changes in SE, PC, and OE on strength gains. ANOVA results show a significant time effect, as there was a significant increase in all three variables over time, suggesting that course participation increased students’ SE, OE, and PC about strength training. Baseline scores, post-training scores, and changes in SE, PC, and OE were not significant predictors of changes in strength or power scores. These results suggest that while an instructor-led STT course may increase SE, OE, and PC for individuals with varying strength training experience and positively influence college students’ well-being, these psychological constructs may not predict strength gains. Future research should examine possible predictive factors for strength training outcomes in larger, more heterogeneous populations.
KEYWORDS: StrengthTraining; Self-Efficacy; Perceived Competence; Outcome Expectancy; Psychological Constructs; Kinesiology; Strength and Conditioning; Resistance Training

p.49 Modeling Networks of Evolving Populations
Sean Elliott
https://doi.org/10.33697/ajur.2019.016
ABSTRACT: The goal of this research is to devise a method of differential equation based modeling of evolution that can scale up to capture complex dynamics by enabling the inclusion of many—potentially thousands—of biological characteristics. Towards that goal, a mathematical model for evolution based on the well-established Fisher-Eigen process is built with a unique and efficient structure. The Fisher-Eigen partial differential equation (PDE) describes the evolution of a probability density function representing the distribution of a population over a phenotype space. This equation depends on the choice of a fitness function representing the likelihood of reproductive success at each point in the phenotype space. The Fisher-Eigen model has been studied analytically for simple fitness functions, but in general no analytic solution is known. Furthermore, with traditional numerical methods, the equation becomes exponentially complex to simulate as the dimensionality of the problem expands to include more phenotypes. For this research, a network model is synthesized and a set of ordinary differential equations (ODEs) is extracted based on the Fisher-Eigen PDE to describe the dynamic behavior of the system. It is demonstrated that, when juxtaposed with full numerical PDE simulations, this ODE model finds well-matched transient and precise equilibrium solutions. This prototype method makes modeling of high-dimensional data possible, allowing researchers to examine and even predict complex dynamic behavior based on a snapshot of a population.
KEYWORDS: Evolutionary Modeling; Mathematical Biology; Network Dynamics; Ordinary Differential Equations; Partial Differential Equations; Fisher-Eigen model; Phenotype; Fitness Function

p 65 Assessing the Use of Cooking Demonstrations on Healthy Eating Barriers in City Bus Riders
Julianne Evans & Diana Cuy Castellanos
https://doi.org/10.33697/ajur.2019.017
ABSTRACT: People living in food-insecure households may experience access-related barriers to preparing and consuming fresh produce, such as high cost and limited local availability. Nutrition interventions that incorporate improved access play a decisive role in overcoming these barriers. The urban bus hub fresh produce market was developed to address food insecurity in Dayton, Ohio. Over four months, dietetic students from a four-year, private, mid-western university provided cooking demonstrations and recipe distribution nutrition interventions at the market. We used a quasi-experimental study design to determine the effectiveness of the cooking demonstration and recipe distribution intervention on access-related barriers at the urban bus hub fresh produce market. A ten-item quantitative questionnaire, on a Likert-type scale from 1-10, with 10 as a more favorable response, and four open-ended questions were administered once to each consented participant (N=33) to examine the recipe effectives and explore the access-related barriers. T-tests were used to examine barriers from the questionnaire and determine differences between participants who made the recipe and participants who did not make the recipe. Results of the t-test indicate no significant difference between those who made the recipe and those who did not make the recipe (p>0.05). Mean scores for affordability, acceptability, accommodation, availability, and accessibility on the then ten-item questionnaire were 7.83, 8.44, 9.19, 9.38, and 8.44, respectively. Thematic analysis results were used to examine the barriers from the open-ended questions further and revealed that affordability and time barriers were present in the priority population. Lack of money, job loss, and unemployment were identified as contributing to affordability barriers and transportation and time to shop, prepare, or cook produce, and to find mealtimes were identified as contributing to time barriers. Nutrition professionals should continue developing appropriate interventions for affordability and time barriers in convenient locations for participants to encourage fruit and vegetable consumption and to establish evidence-based practices.
KEYWORDS: Cooking demonstrations; food insecurity; produce consumption barriers; nutrition intervention; food stand; recipe distribution; bus hub

AJUR Volume 15 Issue 4 (March 2019)

Click on the link below to download the full high-definition interactive pdf for

AJUR Volume 15 Issue 4 (March 2019)


Links to individual manuscripts, abstracts, and keywords are provided below.

 

p.5 Mechanotransduction in Ischemic Cardiac Tissue: A Mechanical Bidomain Approach under Plane Stress
https://doi.org/10.33697/ajur.2019.001
Justin Fee & Bradley J. Roth
ABSTRACT: Mechanotransduction is the process by which biological tissue translates mechanical forces and signals, such as those produced by strains or membrane forces, into biological reactions including cell remodeling, growth, and differentiation. While some analyses assume strain (the derivative of either the intracellular or extracellular displacement) as the cause of mechanotransduction, this paper assumes that differences between the intracellular and extracellular displacements, known as membrane force, result in mechanical forces acting on integrin proteins, causing mechanotransduction. The mechanical bidomain model is a two-dimensional mathematical representation that describes this behavior. Previous analyses describe mechanotransduction using plane strain, which assumes zero displacement in the z-direction. This analysis uses plane stress, which assumes zero stress in the z-direction, to describe where mechanotransduction occurs in comparison to plane strain models. A sample of healthy tissue with a circular ischemic region with no active tension in the center is analyzed using numerical methods. Fixed and free boundary conditions are implemented. Under fixed conditions, the membrane force was largest in the ischemic border zone and zero everywhere else. However, the strain was found to be largest in the ischemic region. Under free conditions, the membrane force was largest on the vertical edges and in the ischemic border zone. The strain was found to be nearly zero in the ischemic region and ranged up to 10%throughout the tissue. In conclusion, this paper found that both plane strain and plane stress predict a membrane force in the ischemic border zone, but the distribution of individual displacements and strain vary according to each model. These results are significant in determining which model is most appropriate to use in predicting how mechanical forces affect cellular remodeling when analyzing thin monolayers of tissue.
KEYWORDS: Mechanotransduction; Plane Stress; Tissue Engineering; Mechanical Bidomain Model; Biomechanics; Strain; Intracellular Cytoskeleton; Extracellular Matrix; Ischemia; Finite Differences

p.17 Potential Consequences of Hosting an Ant-tended Treehopper, Publilia concava, for Tall Goldenrod, Solidago altissima
https://doi.org/10.33697//ajur.2019.002
Luke J. McCartin, Nabil A. Nasseri,
& Alison K. Brody
ABSTRACT: In ant-hemipteran mutualisms, ‘tending’ ants indiscriminately defend hemipterans from other arthropods, protecting mutualism-hosting plants from defoliating herbivores in some cases. Censuses of a treehopper, Publilia concava, observations of tending ants, and measurements of leaf area were conducted on tall goldenrod, Solidago altissima, over the course of a summer at a field site in central Vermont. Hosting ant-tended treehopper aggregations had no effect on leaf area or the ability for goldenrod to flower, suggesting that in the absence of an herbivore outbreak this mutualism is neither necessary nor inherently detrimental for goldenrod. These findings support the hypothesis that the net consequence of the ant-hemipteran mutualism for its host plant depends on the costs of hemipteran damage, and the benefits of ant defense from other arthropods.
KEYWORDS: Ants; Mutualism; Ant-plant Interactions; Treehopper; Hemiptera; Ant-hemipteran Mutualism

p.23 Using Smart Glasses for Facial Recognition
https://doi.org/10.33697/ajur.2019.003
Gabriella A. Mayorga, Xuan Do, & Vahid Heydari

ABSTRACT: Facial recognition is one of the most promising applications of smart glasses and can help many organizations become more efficient. For example, police traditionally identify criminals by manually going through pictures in a database which makes face matching a slow process. However, with the combination of facial recognition software, smart glasses, and databases, the police can quickly scan through multiple databases of faces to find a match. The police would also be able to spot criminals in crowds, identify unknown victims at crime scenes, retrieve background information on individuals, and verify if someone is a missing person. The Transportation Security Administration (TSA) can also use this combination to identify potential terror suspects or verify the identity of travelers. Lastly, academia can benefit from these tools by being able to identify individuals at events (e.g. conferences) and display relevant information about them. The goal of this project is to write an Android program that takes a photo via Google Glass, compares it with a predefined sample database held within the smartphone, and outputs information based on its analysis. The results are displayed with an accuracy acceptance level to the user both on their Android smartphone and on their Google Glass.
KEYWORDS:Face Detection; Facial Recognition; Smart Glasses; Android Smartphone; Mobile Application; Google Glass; Java; SQLite

p.37 Sexual Assault Among College Students Attending a Historically Black College/University
https://doi.org/10.33697/ajur.2019.004
Deshawn Collington, Markea Carter, Aliyah Tolliver, & Jocelyn Turner-Musa
ABSTRACT: Sexual assault constitutes a significant public health problem on college campuses including historically Black colleges and universities (HBCU). Recent research suggests that sexual assault is increasing on college campuses.  However, there are few studies examining the prevalence and risk factors for sexual assault at HBCUs. To address this gap, the current study examined the prevalence, correlates, and outcomes of sexual assault at an HBCU. Participants in the study were 264 undergraduate students from an HBCU in the mid-Atlantic region. The majority of participants were female (71%), African American (91%), and seniors (41%). After providing informed consent, participants completed a Climate Assessment survey administered by the university’sOffice of Diversity. Findings revealed that since starting college about 20% of students experienced sexual contact without consent. Of those sexually assaulted, 20% reported they were incapacitated or under the influence of alcohol (15%) at the time of the assault. About 17% of those assaulted experienced a physical injury and/or poor mental health outcomes (e.g., anxiety, depression, flashbacks). Participants reported not disclosing information of their assault due to embarrassment, afraid of retaliation from the perpetrator, believing it was a private matter. Close friends were more likely to be told about sexual assault. The study supports the need to address sexual assault on HBCU campuses through strong prevention and intervention programs and to address barriers to reporting.
KEYWORDS: Sexual Assault; HBCU; College Students; Prevalence; Risk Factors; Outcomes; Barriers of Reporting; Sexual Assault Climate Assessment Survey 

p.47 Examining Collection Biases Across Different Taxonomic Groups: Understanding How Biases Can Compare Across Herbarium Datasets
https://doi.org/10.33697/ajur.2019.005
Jordan Williams & Katelin D. Pearson
ABSTRACT: Specimen-based data are an invaluable resource for an increasing diversity of scientific fields, including global change biology, ecology, evolution, and genetics; however, certain analyses of these data may be limited by the non-random nature of collecting activity. Geographic, temporal, and trait-based collecting biases may consequently affect the understanding of species’ distributions, obviating the need to determine what biases exist and how they may impact further analyses. Trait-based biases were examined in herbarium specimen records of two abundant and diverse families (Asteraceae and Fabaceae) in a well-collected and digitized region (California) by comparing geographic-bias-adjusted simulations of random collections to actual collecting patterns. Collecting biases were fairly similar between families for a number of traits, such as a strong bias against collecting introduced species, while seasonal collecting biases showed a peak in activity in the Spring for both families. However, while there was only a dip in the fall for Asteraceae, Fabaceae were seriously under-collected for the majority of the year. These results demonstrate that significant collecting biases exist and may differ depending on the dataset, highlighting the importance of understanding the dataset and potentially accounting for its sampling limitations.
KEYWORDS: Biodiversity; Natural History Collection; Sampling Bias; Biodiversity Specimens; iDigBio; Botanical Databases; Plant Traits

p.55 Valveless Fluid Pumping via Zero-Net-Momentum Injection
https://doi.org/10.33697/ajur.2019.006
Johnathan Cace
ABSTRACT: A novel mechanical method to valvelessly pump fluid has been developed using zero-net-momentum injection via a syringe and a tilted canister that function together as a periodic mass source and sink. Unlike previously discovered valveless pumping methods, this method does not require any elastic tubing and can be achieved by simple manual actuation, making it a simpler and less expensive valveless alternative. The flow rate is highly dependent on the frequency at which momentum is injected and retracted from the system. The direction of the flow can be changed by switching the location of the syringes. This pumping paradigm has potential applications in microfluidics where elastic channels are difficult to fabricate and valveless fluid actuation methods are preferred.
KEYWORDS: Valveless Pumping; Momentum Injection; Microfluidics; Fluid Mechanics; Windkessel Effect

p.61 Sex Bias in Tuberculosis in the Developing World
https://doi.org/10.33697/ajur.2019.007
Sophie Shaw & Kevin J Purdy
ABSTRACT: Tuberculosis (TB), the most deadly global single organism infectious disease, kills nearly twice as many men as women. Understanding the factors that drive this bias in TB mortality is an important aspect of the global effort to reduce the enormous burden of this disease in the developing world. One third of the world’s population is estimated to be infected TB, with Low and Middle Income Countries (LMIC) bearing the greatest disease burden. In LMIC sex bias in TB is influenced by sociocultural, behavioural as well as biological factors, with dynamic interactions between reporting variables, other confounding variables and physiological mechanisms, which each influence one another to produce the male-biased sex ratio observed in TB transmission, prevalence and mortality. While confounding factors are addressed in the existing global drive to tackle TB it is the biological aspects of sex bias in TB that present specific challenges for diagnosis and treatment in men and women as they potentially influence future immunological-based interventions to treat TB.
KEYWORDS: Tuberculosis; Low and Middle Income Countries; Sociocultural Influences; Behavioural Bias; Biological Sex Bias; Reporting Bias; TB and Sex Hormones

p.71 Obstructive Sleep Apnea is Associated with Longitudinal Increases in Amyloid Burden in Elderly Mild Cognitive Impairment Individuals
https://doi.org/10.33697/ajur.2019.008
Megan Hogan, Amanda Shim, Umasabor-Bubu Ogie Queen, Mukhtar Fahad, & Omonigho Michael Bubu
ABSTRACT: Cross sectional analysis has shown an association between Obstructive Sleep Apnea (OSA) severity and Aβ burden using amyloid-PET among Mild Cognitive Impairment (MCI) patients. However, whether OSA accelerates longitudinal increases in amyloid beta (Aβ) burden in MCI patients is presently unclear.Study participants included a total of 798 subjects with a diagnosis of MCI and were a subset of the ADNI cohort (adni.loni.usc.edu). OSA was self-reported and participants were labeled either as OSA+ or OSA−. Aβ burden was determined by florbetapir SUVRs. To test whether OSA is associated with the rate of change in Aβ data longitudinally, multilevel mixed effects linear regression was used to fit the models with randomly varying intercepts and slopes allowing dependence on OSA status. The final model was adjusted for age, sex, body mass index, education, CPAP use status, history of respiratory disease, hypertension, diabetes, and history of cardiovascular disease. A significant variation in the change (slope) in Aβ volumes over time was seen (p<.0001). The covariance between the baseline Aβ level and Aβ volume change over time indicated that OSA subjects experienced greater mean change differences in brain Aβ volumes over time (p < .0001). The rate of change in Aβ deposition also varied significantly across OSA groups over the follow-up period.Obstructive Sleep Apnea possibly facilitates longitudinal increases in amyloid burden in elderly Mild Cognitive Impairment individuals. Further research examining mechanisms underlying effects of OSA on the longitudinal increases in Aβ burden is needed.
KEYWORDS: Obstructive Sleep Apnea; OSA; Amyloid; Mild Cognitive Impairment; MCI; Elderly

p.79 It Gets Better with Time: The Perception of Stigma Among Older Adults with Chronic Physical Illness and in Recovery from Mental Health Condition
https://doi.org/10.33697/ajur.2019.009
Angela J. Johnson & Kyaien O. Conner
ABSTRACT: Older adults are a vulnerable population who are more susceptible to developing mental health conditions, and the symptoms are often exacerbated by the co-occurrence of various physical health complications. Despite available evidence-based interventions, many older adults neglect to utilize mental health services, due to the stigmatization of mental health conditions. Limited research has focused on the unique experiences of older adults who have overcome the adverse effects of stigma, have sought help for their mental health condition and are currently in recovery. There are even fewer studies that have addressed perceptions of stigma among older adults in recovery from a mental health condition who are currently living with a chronic physical illness. The present study investigated the unique experiences of seeking professional mental health services and the perceptions of stigma among nine older adults living with a chronic physical illness and currently in recovery from a mental health condition utilizing semi-structured interviews. Through an in-depth thematic analysis of the data, four over-arching themes were identified: Resilience from the Stigma of a Mental Illness, Community Engagement, Cultural Barriers and Social Support System. Findings from the current study suggest that older adults who have previously experienced a mental health condition and were able to overcome the stigma of their condition, were more likely to seek professional help. Additionally, engaging in community engagement programs to help other older adults who are currently experiencing acute mental health conditions seemed to reduce perceptions of stigma and positively impacted participants self-esteem and overall outlook on life.
KEYWORDS: Stigma; Perception; Older Adults; Mental Health Condition; Co-Occurring Disorders

AJUR Volume 15 Issue 3 (December 2018)

Click on the link below to download the full high-definition interactive pdf for

AJUR Volume 15 Issue 3 (December 2018)

https://doi.org/10.33697/ajur.2018.019


Links to individual manuscripts, abstracts, and keywords are provided below.

 

p.5 Faunal Remains as an Indicator of Change in Social Stratification at Pecica Şanţul Mare

https://doi.org/10.33697/ajur.2018.020

Brett Meyer
ABSTRACT: The Bronze Age tell settlement of Pecica “Şanţul Mare” in Romania is regarded as a regional center of the Mureş culture due to the flourishing of higher-status activity experienced during the Florescent Period (1820-1680 B.C.). Recent excavations at the site began to examine whether this higher-status activity was present during the Initial Period (1950-1900 B.C.), the earliest period, or if it grew out of the transition between these periods. This analysis compared faunal remains from the Initial Period and the Florescent Period to examine changing inequality over time. Species utilization, cull patterns, and body part representation were used to infer social organization during these periods. The combination of secondary product utilization, low quantity of horse, and presence of low quality meat during the Initial Period suggests that social inequality intensified over time and reached its pinnacle during the Florescent Period. These results can also be used to examine the development of social stratification in the Bronze Age as a whole.
KEYWORDS: Pecica; Zooarchaeology; Social organization; Power and Wealth; Bronze Age; Elite Activity; Horse Breeding; Tell Settlement

p.23 Enhancing Number System Knowledge to Promote Number Sense and Adaptive Expertise: A Case Study of a Second-Grade Mathematics Student

https://doi.org/10.33697/ajur.2018.021

Cami C. Player & Jessica F. Shumway
ABSTRACT: Instruction for developing students’ number sense is a critical area of research in mathematics education due to the role number sense plays in early mathematics learning. Specifically, number system knowledge—systematic relations among numerals and the use of number relations to solve arithmetic problems—has been identified as a key cognitive mechanism in number sense development. Number system knowledge is a component of number sense, and the researchers of this study hypothesize that it plays a critical role in second-grade students’ understanding of relationships among numbers and adaptive expertise with mathematics problems. The purpose of this exploratory case study was to investigate the variations of an eight-year-old student’s number system knowledge learning as she participated in an instructional treatment over nine weeks. The main research question of this study was: In what ways does a student struggling in mathematics develop number system knowledge during a nine-week period in her second-grade classroom as she engages in a number system knowledge instructional treatment? The case in this study was selected based on her low pretest score combined with her desire for making sense of mathematics. The data sources for this study were a number system knowledge assessment and student interviews. The analysis involved a multiple-cycle coding process that resulted in themes of adaptive expertise and the union of procedural and conceptual knowledge in mathematics instruction. The results suggest that this number system knowledge instructional treatment provided this case-study student to develop more pronounced adaptive expertise in solving mathematics problems. An in-depth analysis of how and why one struggling student develops number system knowledge during a nine-week instructional treatment within the context of her mathematics class provides exploratory evidence to help researchers and teachers develop and implement similar practices in elementary mathematics instruction.
KEYWORDS: Number Sense; Number System Knowledge; Mathematics Education; Whole Numbers and Operations; Elementary Education; Teaching and Learning; Case Study Research

p.35 Measuring the Mechanical Properties of Laminated Wood Structures Using a Homemade Bending Tester

https://doi.org/10.33697/ajur.2018.022

J. Weber & A. J. Stollenwerk
ABSTRACT: The choice of materials used to build a laminate recurve bow is crucial to optimizing performance. To this end, a low-cost bending tester was designed and built to measure the flexural modulus and modulus of rupture on a variety of wooden laminates. To gain a better understanding of the relationship between the properties of the laminates and the individual species comprising the laminates, woods with a wide range of elastic and strength properties were chosen. Differences between the expected and experimental results are attributed to the properties of the adhesive and defects in the wood.
KEYWORDS: bending test; recurve bow; wood; laminates; modulus of rupture; flexural modulus

p.41 College Students’ WellBeing: Use of Counseling Services

https://doi.org/10.33697/ajur.2018.023

Morgan Huenergarde
ABSTRACT: A significant number of college students experience varying levels of stress, anxiety, homesickness, and depression which may negatively impact their academic performance or personal functioning. However, many college students do not seek professional help from campus counselors. Recent research supports the effectiveness of counseling centers in reducing the effect of stress, anxiety, homesickness, and depression on the students’ well-being. The purpose to the current study was to analyze students’ reports on their levels of stress, anxiety, homesickness, and depression, grouping them based on previous counseling participation. It was hypothesized that those who had gone to counseling or were currently attending counseling would report better overall improvement than those students who had never attended counseling. The following study included college students at a Southeastern university who have attended counseling or were currently attending counseling through the services provided by the University, or from any outside service. A group of students who had never attended counseling previously also participated. The research assessed varying levels of mood and academic performance and any differences between the groups. To gather a broader scope of knowledge, the study investigated demographic information and potential hindrances to treatment. It also focused on any barriers that would impact the likelihood of counseling attendance, and the manner in which students learned about the services offered. It was found that those students who attended six or more counseling sessions reported more positive perceived change in their levels of depression, anxiety, and stress than did students who attended five or fewer counseling sessions. Most students reported that they would not attend counseling due to not having enough time and suggested online or weekend sessions. Finally, students stated that they predominantly learned about services from advertisement.
KEYWORDS: Counseling; College Students; Depression; Homesickness; Anxiety; Stress; Mood; Academic Performance

p.61 Underneath it All: Soil Differences May Explain Contrasting Outcomes of Adjacent Prairie Restorations in Madison, Wisconsin

https://doi.org/10.33697/ajur.2018.024

Krista Marshall, Nick J. Balster, & Alex W. Bajcz
ABSTRACT: The evaluation of prairie restorations tends to focus on aboveground properties such as changes in plant diversity and the encroachment of non-native species. As a result, knowledge gaps persist concerning belowground controls of restoration success. To address these gaps at a 13-year-old prairie restoration site in Madison, Wisconsin, we spatially compared soil chemical, physical, and hydrological properties in two adjacent parcels that differed markedly in response to a tallgrass prairie restoration. We hypothesized that soil properties and their heterogeneity would differ significantly between the two parcels and that these differences would help explain the divergent response. In support of this hypothesis, soil organic matter, pH, and total nitrogen were significantly lower (p = 0.007, p < 0.001, and p = 0.006, respectively) in the restored parcel compared to the parcel that has yet to respond to any restoration efforts. Moreover, despite no significant difference in soil average bulk density between the two parcels, the restored parcel had significantly lower sand and silt fractions overall (p = 0.039 and p = 0.040, respectively). In contrast, except for total nitrogen, there were no apparent differences in the spatial heterogeneity of the measured soil properties between the restored and unrestored parcels, which did not support the second hypothesis of this study. These results demonstrate the utility of measuring belowground properties when assessing unexpected outcomes of prairie restorations as well as inform future hypothesis-driven experiments to determine which soil properties impede restoration and under what circumstances.
KEYWORDS: Prairie Restoration; Bulk Density; Soil Organic Matter; Soil Properties; Soil Texture; Spatial Heterogeneity

p.73 Selective Extraction of Red Phosphor (Y2O3:Eu3+) Constituents from Waste Fluorescent Lamps Phosphor Using Acid Leaching

https://doi.org/10.33697/ajur.2018.025

Parul Johar, Vishal Jangir, Yogita Choudhary, & Sudhanshu Mallick
ABSTRACT: Modern fluorescent lamp phosphor powder contains tricolor phosphor. This tricolor phosphor consists of three different types of rare earth phosphors: red (YOX), green (CMAT/LAP) and blue (BAM); mixed in varying proportions. The exact separation of these three rare earth phosphors is essential in order to precisely recover the contained rare earth elements from waste lamps phosphor. In this present work, we reported an efficient methodology for the separation of these three tricolor phosphors and the selective extraction of predominantly presented red phosphor (YOX) constituents using acid leaching. The waste phosphor powder was leached with different acids: both organic and inorganic type. The 3 M H2SO4 leaching was found to be most suitable for the selective extraction of red phosphor constituents, i.e. Y and Eu. The recovered phosphor powder was analyzed with SEM/EDS and XRD analysis. The obtained XRD pattern was refined using Rietveld refinement method for the quantification of phases present. Recovered red phosphor powder contained three main crystalline phases Y2O3, Eu2O3 and Y2OS2.
KEYWORDS: Waste Lamp Phosphor; Tricolor Phosphor; Rare Earth Elements; Acid Leaching

AJUR Volume 15 Issue 2 (September 2018)

Click on the link below to download the full high-definition interactive pdf for

AJUR Volume 15 Issue 2 (September 2018)

https://doi.org/10.33697/ajur.2018.013


Links to individual manuscripts, abstracts, and keywords are provided below.

 

p.5 Determining Nutritional Barriers to Access to Fresh Fruits, Vegetables, and Whole Grains in Older Americans

https://doi.org/10.33697/ajur.2018.014

Tornia C. Anderson-Morgan, Melissa Fett, Michelle Jasso, Aisha Moten, & Elgloria Harrison
ABSTRACT: The University of the District of Columbia is a partner of the Northeast Hatch Multistate Research Collaborative. This research project, known as the UDC NE 1439, was designed as a pilot study to determine the barriers that prevented the consumption of fresh fruits, vegetables, and whole grains among older adults in Wards 5, 7, and 8 in the District of Columbia (DC). The residents of these wards have been shown to have higher rates of chronic diseases. Data shows that Ward 7 has the highest rate of deaths due to diabetes. Furthermore, Wards 5, 7, and 8 have the highest percentage of hypertension and diabetes This project used a quantitative and qualitative survey instrument, which included 53 questions and/or statements using a Likert scale: demographics (8 questions); household information (2 questions); shopping habits (8 questions); eating habits, including the identity of the person who prepared meals in the home (21 questions); physical fitness (11 questions); and policy (3 questions). Ninety-six (96) older adults participated in the survey, with a gender distribution of 77% female (68 individuals), 22% male (24 individuals), and 1% not reported (1 individual). The racial distribution of the participants was 91% (87) African American, .01% (one) Asian American, .01% (one) Caucasian, .01% (one) Native American, and .03% (three) others/not reported. Additionally, according to the participants’ residency results, Ward 5 accounted for 23% of the participants (24 participants), Ward 7 for 38% (33 participants), and Ward 8 for 38% (33 participants). The participants’ average age was ≥ 56, (45 to 76 and over) and most were the primary financial supporters of their households and the primary grocery shoppers in their families. In conclusion, this project determined that access to fresh fruits and vegetables and travel time to a full-service grocer were less prominent barriers; this was an unexpected finding. Though the participants indicated sufficient access to fresh fruits, vegetables, and whole grains, they lacked nutrition-based knowledge. Many of them viewed unfitting food choices as healthy. An intervention centered on nutrition education using food demonstrations and grocer tours would improve nutrition knowledge in this population. This offered these nutrition and dietetics research assistants with an opportunity to provide nutrition education to the population in question. Moreover, it presents an opportunity to extend nutrition education to all seniors across the Washington, DC region.
KEYWORDS: Fruits; Vegetables; Whole Grains; Urban; Disease; African American; Health; Nutrition; Food Security; Food Desert, Senior Citizens

p.17 Minimizing the Cost of Guessing Games

https://doi.org/10.33697/ajur.2018.015

David Clark, Lindsay Czap
ABSTRACT: A two-player “guessing game” is a game in which the first participant, the “Responder,” picks a number from a certain range. Then, the second participant, the “Questioner,” asks only yes-or-no questions in order to guess the number. In this paper, we study guessing games with lies and costs. In particular, the Responder is allowed to lie in one answer, and the Questioner is charged a cost based on the content of each question. Guessing games with lies are closely linked to error correcting codes, which are mathematical objects that allow us to detect an error in received information and correct these errors. We will give basic definitions in coding theory and show how error correcting codes allow us to still guess the correct number even if one lie is involved. We will additionally seek to minimize the total cost of our games. We will provide explicit constructions, for any cost function, for games with the minimum possible cost and an unlimited number of questions. We also find minimum cost games for games with a restricted number of questions and a constant cost function.
KEYWORDS: Ulam’s Game; Guessing Games With Lies; Error Correcting Codes; Pairwise Balanced Designs; Steiner Triple Systems

p.33 Analysis of Fungal Contamination on Commercially Sold Rice in Puerto Rico

https://doi.org/10.33697/ajur.2018.016

Nicole Colón Carrión, Chad Lozada Troche
ABSTRACT: Crops and stored grains are susceptible to pathogens that represent a threat to our health. The study presented herein compares the normal surface and endophytic fungal communities present on white and brown rice grains. One hundred grains of each rice variety was analyzed to determine their fungal contaminants and endophytes. Fungi were inoculated on SDA media, and purified in PDA media; morphological characterization was performed followed by amplification of the ITS region using PCR for all fungal isolates. Statistical analysis indicated significant differences between medium brown rice compared to white rice for surface and endophytic communities (p-value £ 0.05). In addition, a higher fungal diversity was found on brown rice grains compared to white rice. This variation may be due to differences in the processing methods used for each rice grain type. BLAST analysis revealed the presence of toxigenic strains of Aspergillus flavus, A.oryzae, Penicillium verrucosum, and P. viridicatum. The study of fungal growth in rice grains can contribute to the minimization of mycotoxin production by its prevention and control; therefore, decreasing crop contamination and human exposure to their metabolites.
KEYWORDS: Fungi; Rice; Fungal contaminants; Fungal endophytes

p.41 Characterization of Ambient Particulate Matter Sampled at an Active Sand Mine Facility in Northwestern Wisconsin

https://doi.org/10.33697/ajur.2018.017

Julie Zhang, Callie Fischer, Joe Oster, Gabriel de Carvalho Chaves, Rachel Mooney, &Patricia Cleary
ABSTRACT: Concern has arisen about levels of silica in ambient particles near sand mines in Northwestern Wisconsin. Airborne particles released from mining and processing activity may release respirable silica into the air, which can have adverse health effects on individuals exposed to significant quantities. In order to assess these levels of silica, this study developed a parallel analysis using an X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS) analysis to test particles in real air samples. Calibrations were constructed for the XRD analysis (following NIOSH Method 7500) with silica standards containing 10 μg – 500 μg respirable silica on filter media with detection limits of 19-28 μg.  SEM-EDS methods incorporated identifying the geologic composition of particles using the elemental analysis. Real air samples were collected at a sand mining site using a cascade impactor. Filter substrates were pre-weighed and post-weighed to determine the total dry mass of particles sampled and XRD results show at maximum 16 % of the mass can be attributed to crystalline silica in the samples. An SEM-EDS analysis to categorize the particles geologic classification using ratios of elements shows more than 70% of sampled particles are classified as potassium feldspars.
KEYWORDS: Particulate Matter; Sand Mining; Silica; Atmospheric Characterization; XRD; SEM-EDS; Fugitive Dust

p.51 Dextran Sulfate Based Gel Coating for Drug Eluting Balloon Angioplasty

https://doi.org/10.33697/ajur.2018.018

Jenna Mosier, Hannah Stealey, Kalifa Stringfield, Katie Webb, & C. LaShan Simpson
ABSTRACT: Vascular calcification, a consequence of cardiovascular disease, disrupts natural blood flow and can result in death. Common treatment efforts include various anti-inflammatory medications, balloon angioplasty, or stents, with little success in completely reversing calcification. The proposed design focuses on improving current drug-eluting stents by developing a dextran-sulfate-based gel drug delivery system loaded with receptor activator of nuclear kappa B-ligand (RANKL) to induce osteoclast differentiation. To ensure that the gel could properly deliver RANKL, the gel was tested for its affinity for hydroxyapatite (HA), a critical component of calcification, and its ability to withstand shear. Infrared spectroscopy (IR) indicated binding to HA. Preliminary scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS) results confirmed the presence of calcium on the gel after a one-hour soak in a HA mixture. Shear testing demonstrated that negligible protein, an average of 0.029± 0.024 μg/mL, was sheared off under flow conditions, indicating that the gel is stable for duration of balloon delivery. These preliminary results indicate that a dextran-sulfate-based gel has potential to serve as a therapeutic gel-coating to treat vascular calcification. Future experimentation will include a co-culture study to determine whether osteoclast progenitor cells will properly proliferate and differentiate in the presence of the RANKL-loaded gel.
KEYWORDS: Angioplasty; Calcification; Cardiovascular; Dextran; Gel; Osteoclast; Stent; Vascular

AJUR Volume 15 Issue 1 (June 2018)

Click on the link below to download the full high-definition interactive pdf for

AJUR Volume 15 Issue 1 (June 2018)

https://doi.org/10.33697/ajur.2018.007


Links to individual manuscripts, abstracts, and keywords are provided below.

 

p.5 An All-Atomistic Molecular Dynamics Study to Determine the Structural Importance of Disulfide Bonds in Immunoglobulin G and Bovine Serum Albumin

https://doi.org/10.33697/ajur.2018.008

Akshay Mathavan, Akash Mathavan, Michael E. Fortunato, & Coray M. Colina
ABSTRACT: A fully-atomistic molecular dynamics study was performed to determine the importance of disulfide bonds on the stability of immunoglobulin G (IgG) and bovine serum albumin (BSA).The transferability of a previous prescreening methodology to assess contributions from individual disulfide bonds on conformational stability was tested on both proteins. In IgG, it was apparent that inter-chain and intra-chain disulfide bonds play different roles in maintaining structure, evidenced by clear separation of inter-chain cysteine residues upon cleavage of disulfide bonds. In BSA, a set of double disulfide bonds required both to be broken in order to observe significant structural changes, equivalently seen in a previous study of human serum albumin (HSA), a structurally similar protein. Structural analysis of IgG showed deviations in distances between domains, while analysis of BSA suggested more local structural changes. This work helps confirm the efficacy and reproducibility of the prescreening methodology on both a novel, larger protein such as IgG and a more homologous (to HSA), globular protein such as BSA. The results provide insight into the role of specific disulfide bonds in the stability of IgG and BSA.
KEYWORDS: Molecular Dynamics; Atomistic Simulations; Immunoglobulin G; Bovine Serum Albumin; Disulfide Bonds

p.23 Syndecan Affects Odor Response as well as Learning and Memory in Drosophila melanogaster

https://doi.org/10.33697/ajur.2018.009

Dena Arizanovska, Jonathan King, &Karl G. Johnson
ABSTRACT: Syndecan (Sdc) is a transmembrane heparan sulfate proteoglycan that plays a crucial role in axon guidance and synapse formation during CNS development in Drosophila melanogaster. To further examine the effect of syndecan on CNS function, Sdc23 mutant D. melanogaster larvae were used to examine odor preference and the capacity for learning and memory. A series of olfaction assays in both wild type and mutant larvae were performed to characterize naive odor responses before adding a training period to identify the capacity for associative learning. These results showed that Sdc23 larvae prefer odors that wild type larvae do not respond to, suggesting a difference in odor receptor pathways and wiring. In addition, associative learning has been documented in wild type larvae, yet no evidence of associative learning in Sdc23 larvae was found, suggesting that the syndecan also plays a role in learning and memory in D. melanogaster larvae.
KEYWORDS: Syndecan; Proteoglycans; Neurodevelopment; Axon Guidance; Olfaction; Attraction Index; Associative Learning; Drosophila

p.33 Investigation of Flow Rate on Chemical Bath Deposition of Silver Films Inside Hollow Polymer Cylinders

https://doi.org/10.33697/ajur.2018.010

M. Ehrsam, H. Taz, A. Malasi, C. Carr, & R. Kalyanaraman
ABSTRACT:
In thin film solar cells made as planar structures, the absorption of solar light and hence, the solar conversion efficiency, is heavily determined by the position and orientation of the sun. One way to overcome this is to use solar cell geometries that could better absorb sunlight from different angles. One potential geometry is a hollow cylinder, which has the ability to better absorb the sun’s rays incident at various angles due to the light trapping nature of the cylindrical geometry. If such solar cells could be fabricated inside polymer tubes with micrometer diameters, many potential applications built around non-woven or woven textiles could be realized. Here we investigate the deposition of homogeneous thin metallic films inside hollow polymer cylinders using the process of chemical bath deposition (CBD). Although films deposited via CBD have been studied extensively, mechanisms to achieve high quality deposition inside hollow cylinders are still not well understood. The objective of this project was to deposit a smooth, homogeneous silver film inside a hollow cylindrical structure using varying flow rates. The early stage film growth for very short deposition times was observed by the localized surface plasmon resonance of the silver nanoclusters via absorption spectra along the length of the tube. For longer deposition times, silver films formed and were analyzed for their morphology, thickness, roughness, and resistance using a combination of optical microscopy, scanning electron microscopy, and two-probe conductivity. The findings from this study showed that deposition under flow with different Reynolds numbers had a strong influence on the morphology and electrical resistance of the deposited films.
KEYWORDS: Thin-films; Chemical Bath Deposition; Nanoparticles; Solar Cells; Silver

p.43 Feasibility of Man-Portable Power Generation Systems

https://doi.org/10.33697/ajur.2018.011

Earl C. Allen & Nelson Fumo
ABSTRACT: Electric power is the most common source of power for many portable devices used in outdoor recreation, emergency scenarios, and military applications. Batteries that have limitations regarding power and energy are currently meeting the power demand for most of these devices. There is a search to use alternative power sources for portable energy needs. This search has mostly been researched particularly for the military to satisfy functions necessary for soldiers. However, any alternative that would provide electricity in an efficient and timely manner is useful in many applications beyond the military. The feasibility of man-portable power generation systems using thermal energy from any kind of fuels needs to be studied further, to understand if they are truly an option for situations where batteries are currently used. In this study, the feasibility of fueled power systems is investigated. Commercially available small power systems show that they are not small enough to satisfy the definition of man-portable power system. However, power systems working on an internal combustion engine show to be a better option when compared to batteries and fuel cells.
KEYWORDS: Fueled Power Generation; Man-portable Power; Power Density; Energy Density

p.55 The Role of Gender Stereotypes in Gubernatorial Campaign Coverage

https://doi.org/10.33697/ajur.2018.012

Karen Bjerre
ABSTRACT: Through a content analysis of 1,152 articles covering 20 different gubernatorial races between 2004 and 2014, I examine how the presence of a woman candidate in a gubernatorial race affects media coverage of that campaign. This paper considers the prevalence of gender biases and stereotypes and examines whether print media outlets perpetuate these stereotypes or subvert them. Existing research suggests that voters favor traditionally masculine traits over traditionally feminine traits when evaluating candidates for public office. The difference in media coverage may therefore influence women’s chances of getting elected, and thereby influence women’s descriptive and substantive representation. I find that races with a woman candidate receive less issue coverage and more horse race coverage than races with two men running. Additionally, the types of adjectives used in campaign coverage differ depending on the gender of the candidate: women are more likely to be described as able to “change government,” while men are more likely to be described as “experienced.”
KEYWORDS: Media Coverage; Gender; Gubernatorial Campaigns; Women in Politics; Gender Stereotypes; Newspaper Coverage; American Politics

AJUR Volume 14 Issue 4 (March 2018)

Click on the link below to download the full high-definition interactive pdf for

AJUR Volume 14 Issue 4 (March 2018)

https://doi.org/10.33697/ajur.2018.001


Links to individual manuscripts, abstracts, and keywords are provided below.

 

p.5. Thermodynamics of Concanavalin A Self-Association in the Presence of Osmolytes

https://doi.org/10.33697/ajur.2018.002

Tyler Pfister*, Shamus Cooper, & Jeffrey K. Myers
Department of Chemistry, Davidson College, NC
Students: Typfister17@alumni.davidson.edu*, Shcooper16@alumni.davidson.edu
Mentor: Jemyers@davidson.edu
ABSTRACT: Protein-protein interactions are critical for biological function and depend significantly on environmental factors. A wide variety of small organic molecules that comprise the cellular environment are capable of interacting with proteins to affect folding, binding, and association. The plant lectin concanavalin A (ConA) undergoes a reversible, pH dependent dimer-to-tetramer equilibrium and has been used in our laboratory as a model system to study the effect of osmolytes on protein self-association. Previous research determined that trimethylamine N-oxide (TMAO) stabilizes the tetrameric conformation, while urea favors the dimer. Studying the equilibrium over a range of temperatures allowed quantification of the enthalpy change (∆H) and entropy change (∆S) of tetramer formation. Urea increased both the ∆H and ∆S of tetramer formation, while TMAO decreased both.  These effects are consistent with preferential hydration of the dimer-dimer interface in TMAO solution and preferential binding of urea to the interface.
KEYWORDS: Concanavalin A; Osmolytes; Trimethylamine N-oxide; Urea; Protein-Protein Interaction; Equilibrium; Enthalpy; Preferential Hydration

p.13. Perception of peer drinking and access to alcohol mediate the effect of residence status on alcohol consumption

https://doi.org/10.33697/ajur.2018.003

KatrinaA.Williams*a, Nathaniel S. Thomas b,c, Amy E. Adkins b,c, & Danielle M. Dick b,c,d
a Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, United States
b College Behavioral and Emotional Health Institute, Virginia Commonwealth University, Richmond, VA,  United States
c Department of Psychology, Virginia Commonwealth University, Richmond, VA,  United States
d Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA,  United States
Student: williamska5@vcu.edu*
Mentor: thomasns@vcu.edu
ABSTRACT: Alcohol consumption is common in college attending populations and can have a negative impact on an individual’s academic, physical, and mental health. Previous research suggests that living at home could act as a protective measure. The current research looks at potential mediators of the association between living with parents while attending college and amount of alcohol consumed. In particular, this study examined access to alcohol, parental involvement, and perception of peer drinking as mediators of the association.  This study examined freshman data collected from a survey conducted at a large public university in the mid-Atlantic United States.  A pathway model was fit to test the relationships between residence status, access to alcohol, parental involvement, and perception of peer drinking on alcohol consumption.  We observed statistically significant indirect effects of residence status on alcohol consumption through the perception of peer drinking and access to alcohol. Parental involvement was significantly related to lower alcohol consumption and there was a direct effect of residence status on alcohol consumption.  There were significant indirect effects of residence status on alcohol consumption through both peer drinking and access to alcohol. Parental involvement was associated with decreased alcohol consumption, with no indirect effect in association with residence status. These effects were persistent in the presence of a range of covariates, including age, gender, ethnicity, and parental education.
KEYWORDS: Emerging Adult; Alcohol; Residence Status; Peer Drinking; Access to Alcohol; Parental involvement; Path Analysis

p.23. Speedup Potential for Reconstruction Techniques for Prompt Gamma Imaging During Proton Radiotherapy

https://doi.org/10.33697/ajur.2018.004

James Della-Giustina*a, Johnlemuel Casilagb, Elizabeth Gregorioc, & Aniebiet Jacobsb
aDepartment of Information Technology & Computer Science, Community College of Baltimore County, Baltimore, MD
bDepartment of Computer Science & Electrical Engineering, University of Maryland, Baltimore County, Baltimore, MD
cDepartment of Physics, Hamline University, St. Paul, MN
dDepartment of Mathematics and Statistics, University of Maryland, Baltimore County, Baltimore, MD
eDepartment of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD
fDepartment of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
Students: jdella@umbc.edu*, cas6@umbc.edu, anie1@umbc.edu, egregorio01@gmail.com
Research Assistant: Carlos Barajasd, barajasc@umbc.edu
Faculty Mentor: Matthias K. Gobbertd, gobbert@umbc.edu
Clients: Dennis Mackinf, dsmackin@mdanderson.org, Jerimy Polfe, jpolf@umm.edu
ABSTRACT: Proton beam radiation treatment was first proposed by Robert Wilson in 1946. The advantage of proton beam radiation is that the lethal dose of radiation is delivered by a sharp increase toward the end of the beam range. This sharp increase, known as the Bragg peak, allows for the possibility of reducing the exposure of healthy tissue to radiation when comparing to x-ray radiation treatment. As the proton beam interacts with the molecules in the body, gamma rays are emitted. The origin of the gamma rays gives the location of the proton beam in the body, therefore, gamma ray imaging allows physicians to better take advantage of the benefits of proton beam radiation. These gamma rays are detected using a Compton Camera (CC) while the SOE algorithm is used to reconstruct images of these gamma rays as they are emitted from the patient. This imaging occurs while the radiation dose is delivered, which would allow the physician to make adjustments in real time in the treatment room, provided the image reconstruction is computed fast enough. This project focuses on speeding up the image reconstruction software with the use of of parallel computing techniques involving MPI. Additionally, we demonstrate the use of the VTune performance analyzer to identify bottlenecks in a parallel code.
KEYWORDS: Proton Beam Therapy; Image Reconstruction; SOE Algorithm; Parallel Computing; High Performance Computing; Medical Imaging; Prompt Gamma Imaging; Radiotherapy

p.39. Knowledge and Behaviors Associated with a Campus Tobacco-Free Policy

https://doi.org/10.33697/ajur.2018.005

Sarah Powell*a, Cassie Odahowskib,c, Elizabeth Crouchd, Erica Sercyb,c, Jackie Knighte, & Jan M. Eberthb,c
a Department of Epidemiology and Biostatistics, College of Public Health, University of South Florida, Tampa, FL
b Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC
c Statewide Cancer Prevention and Control Program, Arnold School of Public Health, University of South Carolina, Columbia, SC
d Department of Health Services Policy and Management, Arnold School of Public Health, University of South Carolina, Columbia, SC
e Healthy Carolina Coalition, University of South Carolina, Columbia, SC
Student: sepowell1@health.usf.edu *
Mentor: jmeberth@mailbox.sc.edu
ABSTRACT: Objective: Nearly half of U.S. colleges/universities have implemented tobacco-free campus policies. This study analyzed knowledge, attitudes, and practices associated with the tobacco-free policy at a large public university. It is important to study public university tobacco policies to determine the most efficient and cost-effective way to reduce tobacco related disease due to tobacco use and exposure. Methods: This study used a cross-sectional, campus-wide electronic survey distributed in November 2016. The primary outcomes of interest included 1) correct knowledge of the tobacco-free policy, 2) community member willingness to approach observed violation of the policy, and 3) a positive opinion of the policy’s effectiveness. Descriptive statistics and logistic regression were used to examine the impact of demographic factors on the outcomes. Results: After analysis, the team found that 23% of university faculty, staff, and students had incorrect knowledge about the campus tobacco-free policy. Almost 70% of the university community reported not having approached a smoking violator. Males were significantly less likely to understand the tobacco-free policy in full, approach a violator, or have a positive opinion about its effectiveness.  Staff had better knowledge of the policy, a higher likelihood of approaching a violator, and a better opinion about the policy’s effectiveness compared to graduate and undergraduate students. Conclusions: Interventions are needed to increase awareness and confidence regarding implementation and enforcement of the tobacco-free policy on campus, particularly among faculty and students. This paper expands on the currently increasing knowledge of tobacco-free policy enforcement and benefits.
KEYWORDS: Campus; Tobacco Regulation; Tobacco; Secondhand Smoke; Cross-Sectional Survey

p.49. Conduction Mechanism in Electrically Conducting Polymers

https://doi.org/10.33697/ajur.2018.006

Daniel L.Gochnauer & T. H. Gilani*
Department of Physics, Millersville University, P. O. Box 1002, Millersville PA-17551
Student: dlg15@uw.edu
Mentor: tariq.gilani@millersville.edu
ABSTRACT: The conduction mechanism in conducting polymers is reviewed and experimental results of temperature dependence of electrical conductivity of PF6 doped polypyrrole in temperature range of 77 to 300 K are discussed. The room-temperature conductivitywas experimentally determined to be 73 ± 3.4 S/m and temperature dependence follows the Mott’s variable range hopping model. The average hopping distance at 298 K was (6.75 ± 0.97) ×10-8 cm. The coefficient of decay of the localized states, the density states at the Fermi level, and the hopping activation energy were calculated to be (3.5±0.51) ×107 cm-1, (1.92 ± 0.83) ×1022 cm-3 eV-1, and 0.040 ± 0.001 eV respectively.
KEYWORDS: Electrically Conducting Polymers; Doped Polypyrrole; Temperature Dependence of Conductivity; Hopping Activation Energy; Density of State at Fermi level

AJUR Volume 14 Issue 3 (November 2017)

Click on the link below to download the full high-definition interactive pdf for

AJUR Volume 14 Issue 3 (November 2017)

https://doi.org/10.33697/ajur.2017.020


Links to individual manuscripts, abstracts, and keywords are provided below.

 

p.5 Strategies for Making Best Offers on eBay

https://doi.org/10.33697/ajur.2017.021

William J. Britt, William E. Gryc, Jamie A. Oliva, Brittney N. Tuff, & Charli E. White
ABSTRACT: We model for “Buy-It-Now or Best Offer” auctions on eBay using two different models. In the first model, risk-neutral bidders submit bids in serial and try to surpass a stochastic seller threshold while taking into account how many previous failed bids were made by other bidders. We compute optimal strategies for this model and show that bidder expected surplus decreases in the number of previous failed bids. In the second model we assume bidders do not know how many previous failed bids have been made, and instead use a first-price sealed-bid mechanism with a buy-out price where bidders serially submit bids with the knowledge that no previous bidders have used the buy-out price. We derive a unique equilibrium bidding strategy for risk-neutral bidders in this serial model, show that any equilibrium in a similar parallel bidding model is the same as the equilibrium in the serial model, and compute seller revenue. In particular, under certain circumstances, bidders will bid more in this format than they would in a standard first-price sealed-bid auction, but that a seller maximizes expected revenue by setting a buy-out price higher than any bidder is willing to pay thereby making the auction essentially a first-price auction.
KEYWORDS: Auction Theory; eBay; Buy-It-Now or Best Offer; Symmetric Bayesian Nash Equilibrium; Buy-Out Price; First-Price Sealed-Bid

p. 37 The Relationship Between Parenting Styles and Substance Use Among University Students

https://doi.org/10.33697/ajur.2017.022

Zackaria I. Niazi, Danielle Dick, Amy Adkins, & Megan Cooke
ABSTRACT: Parenting styles are important in the behavioral development of adolescents. The environment created by the parent, in regards to communication with their child and level of independence given to their child, may influence the child’s susceptibility to risk behaviors. This study examines the relationship between parenting style and substance use among university students. We hypothesized that university students exposed to lower levels of autonomy granting (AG) or parental involvement (PI) parenting styles would have an increased likelihood of alcohol and nicotine use. We also hypothesized that religiosity, parental education level, ethnicity, and gender would act as moderators of parenting styles and alcohol and nicotine use. Data from a diverse university-wide sample was collected in the fall semester of the student’s freshman year from 2011-2014 (N = 9889, 61.5% female). Results demonstrated that AG had a significant, negative association with alcohol use (B = -0.033, p = 0.006) and nicotine use (B = -0.066, p <0.001). All moderators were found to be significant predictors of alcohol use, however only father education level demonstrated a borderline significant moderation of the relationship between PI and alcohol use. Religiosity, Black race, Asian race, and gender were found to be significant predictors of nicotine use. Only gender moderated the association between PI and nicotine use. Even though alcohol and nicotine use and AG were associated, our results indicate that once students enter university, previous parenting style does not have a strong effect on alcohol and nicotine use behaviors in our sample.
KEYWORDS: Parenting Styles; University Students; Risky Behaviors; Autonomy Granting; Parental Involvement; Alcohol; Nicotine; Drug; Behavioral Biology; Substance Use

p.45 Matricial Representations of Certain Finitely Presented Groups Generated by Order-2 Generators and Their Applications

https://doi.org/10.33697/ajur.2017.023

Ryan Golden & Ilwoo Cho
ABSTRACT: In this paper, we study matricial representations of certain finitely presented groups Γ2Nwith N-generators of order-2. As an application, we consider a group algebra Aof Γ22; under our representations. Specifically, we characterize the inverses g-1of all group elements g in Γ22; in terms of matrices in the group algebra A2. From the study of this characterization, we realize there are close relations between the trace of the radial operator of A2; and the Lucas numbers appearing in the Lucas triangle.
KEYWORDS: Matricial Representation; Group Presentation; Group Algebras; Lucas Numbers; Lucas Triangle; Finitely Presented Group;Group Relations; Free Probability

p.69 Evolution of Leucyl-tRNA Synthetase Through Eukaryotic Speciation

https://doi.org/10.33697/ajur.2017.024

Katelyn E. Unvert, Frank A. Kovacs, Chi Zhang, Rachel A. Hellmann-Whitaker, & Katelin N. Arndt
ABSTRACT: Aminoacyl-tRNA synthetases (aaRSs) are part of the cellular translation machinery and as such, they are essential enzymes for every known cell. Due to their ubiquitous nature, their evolutionary history has been intensely researched to better understand the origins of life on a molecular level. Herein, we examine the evolutionary relatedness of leucyl-tRNA synthetases (LeuRS) from each major eukaryotic branch through the speciation process. This research effort was centered on amino acid sequence data as well as generating homology protein models for each LeuRS enzyme. Comparative analysis of this sequence and structural data for LeuRS amongst eukaryotes has indicated a high level of conservation within the active sites of these enzymes. Phylogenetic analysis confirmed this high degree of conservation as well as established evolutionary relatedness between these LeuRS enzymes. Based on this data, vertical gene transfer propagated LeuRS throughout the eukaryotic domain. Horizontal gene transfer and domain acquisition events were not observed within the eukaryotic organisms studied. Our data also highlighted LeuRS adaptation through the speciation process due to slight variability of scaffolding residues outside of the active site regions. We hypothesize that this variability may be due to mechanistic differences amongst LeuRS enzymes that have assumed non-translational functionality through the evolutionary process.
KEYWORDS: tRNA Synthetase; Leucyl-tRNA Synthetase; Eukaryotic Evolution; LeuRS Conservation; Vertical Gene Transfer; Horizontal Gene Transfer; Convergent Evolution; Primordial Enzymes

p.85 The Effect of CO2, Intracellular pH and Extracellular pH on Mechanosensory Proprioceptor Responses in Crayfish and Crab

https://doi.org/10.33697/ajur.2017.025

Viresh Dayaram, Cole Malloy, Sarah Martha, Brenda Alvarez, Ikenna Chukwudolue, Nadera Dabbain, Dlovan Mahmood, Slavina Goleva, Tori Hickey, Angel Ho, Molly King, Paige Kington, Matthew Mattingly, Samuel Potter, Landon Simpson, Amanda Spence, Henry Uradu, Jacob Van Doorn, dlovan faiq, & Robin L. Cooper
ABSTRACT: Proprioceptive neurons monitor the movements of limbs and joints to transduce the movements into electrical signals. These neurons function similarly in species from arthropods to humans. These neurons can be compromised in disease states and in adverse environmental conditions such as with changes in external and internal pH. We used two model preparations (the crayfish muscle receptor organ and a chordotonal organ in the limb of a crab) to characterize the responses of these proprioceptors to external and internal pH changes as well as raised CO2. The results demonstrate the proprioceptive organs are not highly sensitive to changes in extracellular pH, when reduced to 5.0 from 7.4. However, if intracellular pH is decreased by exposure to propionic acid or saline containing CO2, there is a rapid decrease in firing rate in response to joint movements. The responses recover quickly upon reintroduction of normal pH (7.4) or saline not tainted with CO2. These basic understandings may help to address the mechanistic properties of mechanosensitive receptors in other organisms, such as muscle spindles in skeletal muscles of mammals and tactile as well as pressure (i.e., blood pressure) sensory receptors.
KEYWORDS: Proprioception; Sensory; Invertebrate; Carbon Dioxide; Protons; Mechanosensory; Intracellular pH; Extracellular pH

p.101 Derivation of Explicit Solutions Describing Early Stages of Platelet Activation

https://doi.org/10.33697/ajur.2017.026

Rachel Austin, Scott Fones, Dominic Santoleri, Kaitlyn Thomesen, & Pak-Wing Fok
ABSTRACT: The formation of blood clots is vital for biological repair of injured blood vessels. When a blood vessel is injured, platelets come into contact with collagen, causing glycoprotein VI (GPVI) to undergo a conformational change and initialize the clotting process. This project aimed to simplify and solve a system of coupled ordinary differential equations (ODEs) proposed in Model A of Regulation of Early Steps of GPVI Signal Transduction by Phosphatase: A Systems Biology Approach by JL Dunster et al., modeling early platelet activation kinetics. In doing so, the ODEs were non-dimensionalized and the approximate analytical solutions were then found. The approximate solutions compare favorably to the numerical solutions and provide deeper insight into the signal regulation pathway. Most notably, the solutions expose a time at which the pathway dynamics change drastically. This illustrates the critical role of cytosolic spleen tyrosine kinase (Syk) as a molecular timer in the cascade.
KEYWORDS: Platelet Activation; Signal Cascade; Coupled Differential Equations; Asymptotic Analysis; Systems Biology; Mathematical Modeling; Model Simplification; Glycoprotein VI; Spleen Tyrosine Kinase; Syk Activation Dynamics