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)

DOI for AJUR‘s Volume 15, Issue 4 is https://doi.org/10.33697/ajur.2019.000


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

AJUR Volume 14 Issue 2 (June 2017)

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

AJUR Volume 14 Issue 2 (June 2017)

https://doi.org/10.33697/ajur.2017.009


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

 

Blackseed (Nigella sativa) Oil and its Active Ingredient, Thymoquinone, Suppress the Aggressive Phenotype of Breast Cancer Cells

https://doi.org/10.33697/ajur.2017.010

Sabrina Chaudhry, Safia Siddiqui, Tyrnnon K. Steffen, & Stacey L. Raimondi 

ABSTRACT Breast cancer is a leading cause of cancer deaths in women within the United States. However, current treatment methods for the disease present deleterious side effects themselves. Therefore, there is a move towards finding natural cures in order to mitigate negative side effects while still providing effective treatment for the cancer. Blackseed (Nigella sativa) oil is one particular natural remedy, alongside its active ingredient thymoquinone (TQ), which has been successfully tested for suppressing certain types of breast cancer cell proliferation. TQ itself has been seen to be capable of preventing proliferation of both non-aggressive MCF-7 and highly aggressive MDA-MB-231 cancer cells. However, studies which looked at the effects of TQ on MCF-7 cells alone were limiting in their use of high concentrations of the chemical without emphasis on finding a minimum effective dosage. Additionally, a second study which tested the effects of TQ on both MCF-7 and MDA-MB-231 cell lines conducted the experiments in the presence of a lipid-carrier molecule. This, in turn, may have served as a confounding variable in the results. Therefore, it was hypothesized that a minimal effective dosage for both blackseed oil and TQ could be determined, where a significantly greater suppression of MDA-MB-231, in comparison to MCF-7, cell proliferation would be observed. Cell proliferation, cell adhesion, and soft agar assays were used to test the hypothesis of this study. The minimum effective dosage for each substance, characterized by proliferation of the non-aggressive MCF-7 cells to some extent and suppression of the aggressive MDA-MB-231 cells, were determined to be 0.5 µL for blackseed oil and 1.0 µM for TQ. Additionally, TQ’s effectiveness was noted to be more time-dependent than blackseed oil. This study supports the use of minimal effective doses for blackseed oil or TQ to naturally treat breast cancer while preventing damage to non-aggressive cells.

KEYWORDS Breast cancer; Blackseed oil; Nigella sativa; Thymoquinone; Effective dose; Natural remedies

Speech-Language Pathologists’ Perceptions of the Common Core State Standards: A Multi-State Study

https://doi.org/10.33697/ajur.2017.011

Nicole Ariza & Patrick R. Walden

ABSTRACT This study investigated the Common Core State Standards (CCSS) from the perspective of Speech-Language Pathologists (SLPs) working with students with communication disorders in public schools. An invitation to participate in an anonymous, online questionnaire with both closed- and open-ended questions was posted to three online communities comprised of SLP’s working in schools across the United States of America (U.S.). Eighty-seven SLPs working in states using the CCSS completed the survey. The survey focused on four primary areas—the perceived impact of the CCSS on service delivery, student outcomes, professional workload and continuing professional education. Participants reported consistent incorporation of standards into services, but varied methods of implementation, primarily unchanged student outcomes, increased professional workload and a need for additional training. Overall, the CCSS’ intent to create consistent goals may not be accomplished due to variability in approaches in implementation of the standards. Additionally, more resources and trainings for SLPs are needed to fully implement CCSS into speech-language intervention in the schools.

KEYWORDS Common Core State Standards; School-Based Services; School-Based Issues; Speech-Language Pathology; Service Delivery; Student Outcomes; Professional Workload; Continuing Professional Education

A Comparative Study of All-atom Molecular Dynamics Simulation and Coarse-grained Normal Mode Analysis in Identifying Pre-existing Residue Interaction Networks that Promote Coupled-Domain Dynamics in Escherichia coli Methionyl-tRNA Synthetase

https://doi.org/10.33697/ajur.2017.012

Samuel C. Fehling, Alexander M. Strom, Brent P. Lehman, Ryan J. Andrews, Sudeep Bhattacharyya, & Sanchita Hati

ABSTRACT Inter-domain communication plays a key role in the function of modular proteins. Earlier studies have demonstrated that the coupling of domain motions is important in mediating site-to-site communications in modular proteins. In the present study, bioinformatics and molecular simulations were usedto trace “pre-existing” residue-residue interaction networks that mediate coupled-domain dynamics in multi-domain Escherichia coli methionyl-tRNA synthetase (Ec MetRS). In particular, a comparative study was carried out to evaluate the effectiveness of coarse-grained normal mode analysis and all-atom molecular dynamic simulation in predicting pre-existing pathways of inter-domain communications in this enzyme. Integration of dynamic information of residues with their evolutionary features (conserved and coevolved) demonstrated that multiple residue-residue interaction networks exist in Ec MetRS that promote dynamic coupling between the anticodon binding domain and the connective polypeptide I domain, which are > 50Å apart, through correlated motions. Mutation of residues on these pathways have distinct impact on the dynamics and function of this enzyme. Moreover, the present study revealed that the dynamic information obtained from the coarse-grained normal mode analysis is comparable to the atomistic molecular dynamics simulations in predicting the interaction networks that are essential for promoting coupled-domain dynamics in Ec MetRS.

KEYWORDS Domain-domain Communication; Molecular Dynamics; Methionyl-tRNA Synthetase; Normal Mode Analysis; Coupled-domain Dynamics; Course-grained Normal Mode Analysis; Aminoacyl tRNA Synthetases; Statistical Coupling Analysis

Skewed and Flexible Skewed Distributions: A Modern Look at the Distribution of BMI

https://doi.org/10.33697/ajur.2017.013

Thao Tran, Cara Wiskow, Mohammad Abdus Aziz

ABSTRACT The purpose of this study is to find distributions that best model body mass index (BMI) data. BMI has become a standard health indicator and numerous studies have been done to examine the distribution of BMI. Due to the skew and bimodal nature, we focus on modeling BMI with flexible skewed distributions. The distributions are fitted to University of Wisconsin–Eau Claire (UWEC) BMI data and to a data obtained from National Health and Nutrition Survey (NHANES). The model parameters are obtained using maximum likelihood estimation method. We compare flexible models to more conventional distributions, such as skew-normal, and skew-t distributions using AIC and BIC and Kolmogorov-Smirnov (K-S) goodness-of-fit test. Our results indicate that the skew-t and Alpha-Skew-Laplace distributions are reasonably competitive when describing unimodal BMI data whereas Alpha-Skew-Laplace and finite mixture of scale mixture of skew-normal and skew-t distributions are better alternatives to both unimodal and bimodal conventional distributions. The results we obtained are useful because we believe the models discussed in ours study will offer a framework for testing features such as bimodality, asymmetry, and robustness of the BMI data, thus providing a more detailed and accurate understanding of the distribution of BMI.

KEYWORDS Body Mass Index; Skew-normal distribution; Skew-t distribution; Flexible skewed distributions; Mixture distributions; Scale mixture of skew-normal distribution; K-S test

Exploration of the Influence of Smiling on Initial Reactions Across Levels of Facial Attractiveness

https://doi.org/10.33697/ajur.2017.014

Stephanie M. Shields, Caitlin E. Morse, Paige Arrington, & David F. Nichols

ABSTRACT Both attractiveness and emotionality independently affect perception and interact to influence how a person perceives others. It has previously been shown that expressing positive emotions increases perceived attractiveness in general, but the relative influence of smiling across attractiveness levels and timing of this interaction is unknown. Such an interaction could entail dependent brain processing with interactions between brain areas or independent processing within each brain area. The present studies aimed to investigate this interaction and how it occurs through behavioral, specifically self-report, and physiological, specifically electrophysiological, methods. In each study, female undergraduate participants were shown images of male faces with smiling or neutral expressions. Study 1 used participant ratings to provide insight into the interaction and to establish an image subset of faces of high attractiveness (HA) and low attractiveness (LA). An interaction was found wherein HA faces were rated significantly higher on attractiveness when smiling whereas LA faces were rated similarly attractive regardless of emotional expression. Study 2 used electroencephalography (EEG) to examine the timing of brain responses to attractiveness, emotionality, and their interaction. Though a main effect of attractiveness consistently occurred prior to a main effect of emotional expression across two data sets, the presence of an interaction effect was inconsistent. There was some evidence for independent processing wherein the earliest brain responses are predominantly affected by attractiveness and are influenced by emotional expression, but dependent interactions between modular processing areas cannot be ruled out. Together, these results help to shed light on the interplay of attractiveness and emotionality though additional research could help to clarify the timing of the interaction on a neural level.

KEYWORDS Attractiveness, Emotionality, Emotional Expression, Smiling, Electroencephalography, Event Related Potentials

How to Become a “Real Chicagoan” in No Time: The Promise and Pedagogy of Walking Tourism

https://doi.org/10.33697/ajur.2017.015

Jacob Henry

ABSTRACT This study takes seriously the tourist’s desire to feel like a local and examines how walking tour guides work toward fulfilling that desire. The paper examines some of the techniques used by urban walking tour guides to convey local cultural cues. The tourist, armed with these cues, may feel able to fit into a new culture as a quasi-insider. Through qualitative methods, primarily participant observation, the researcher identifies three tactics that guides implement to make the tourist to feel like a local. These tactics are labeled agent alignment, urban alchemy, and material action. These tactics take place within a borderzone, the liminal time-space between insider and outsider status. A successful guide facilitates the border crossing, allowing the tourist to transition from tourist to perceived ‘real Chicagoan.’ However, the unsuccessful guide forces tourists to exit the borderzone unchanged, still as tourists. These findings highlight the uniqueness of walking tourism as a niche tourism and wade into the conceptual milieu of ‘localism’ and ‘the local.’

KEYWORDS Walking Tourism; Urban Tourism; Tour Guides; Localization; Interculturalism; Urban Alchemy; Agent Alignment; Chicago

Characterization of Rectifying and Sphere Curves in 3

https://doi.org/10.33697/ajur.2017.016

Julie Logan & Yun Myung Oh

ABSTRACT Studies of curves in 3D-space have been developed by many geometers and it is known that any regular curve in 3D space is completely determined by its curvature and torsion, up to position. Many results have been found to characterize various types of space curves in terms of conditions on the ratio of torsion to curvature. Under an extra condition on the constant curvature, Y. L. Seo and Y. M. Oh found the series solution when the ratio of torsion to curvature is a linear function. Furthermore, this solution is known to be a rectifying curve by B. Y. Chen’s work. This project, uses a different approach to characterize these rectifying curves.

This paper investigates two problems. The first problem relates to figuring out what we can say about a unit speed curve with nonzero curvature if every rectifying plane of the curve passes through a fixed point  in ℝ3. Secondly, some formulas of curvature and torsion for sphere curves are identified.

KEYWORDS Space Curve; Rectifying Curve; Curvature; Torsion; Rectifying Plane; Tangent Vector; Normal Vector; Binormal Vector

Previvors’ Perceptions of Hereditary Breast and Ovarian Cancer Health-related Information 

https://doi.org/10.33697/ajur.2017.017

Rachel Koruo, Marleah Dean, Courtney L. Scherr, Meredith Clements, Amy A. Ross

ABSTRACT The purpose of this study is to identify female previvors’ perceptions of hereditary breast and ovarian cancer (HBOC) health-related information. Previvors are individuals who have tested positive for a harmful BRCA genetic mutation, which increases their lifetime risk for HBOC, but who have never been diagnosed with cancer. As a part of a larger research project where 25 qualitative interviews were conducted, this manuscript reports on the analysis of ten interviews which are most relevant to the research focus. Using the constant comparative method, themes were created and developed from the interview data. The results indicate previvors view information as a source of power. These women reported feeling personally responsible for seeking and sharing information, while also relying on medical professionals to provide credible sources of information. Furthermore, previvors emphasized a desire for medical professionals to be more informed about BRCA in order to assist them in making personal health decisions.  This study presents the perceptions regarding HBOC information as reported by this population of previvors. The findings indicate that information is not provided in an organized way relative to their specific needs. Therefore, the authors recommend an educational intervention tool for previvors and their medical professionals.

KEYWORDS BRCA; Communication; Qualitative; Hereditary Cancer; Health Experiences; Previvors; Medicine; Patient Perspectives; Health Information

Determination of Fitted Size Distribution for Atmospheric Aerosols

https://doi.org/10.33697/ajur.2017.018

Kaitlin M. DuPaul, Adam T. Whitten

ABSTRACT A synthetic set of aerosol optical depths (AODs) generated from a standard set of aerosol size distributions was analyzed by a parameter based particle swarm optimization (PBPSO) routine in order to test the reproducibility of the results. Junge and lognormal size distributions were consistently reproduced. Gamma and bimodal distributions showed large variability in solutions.  values were used to determine the best subset of possible solutions allowing quantification of parameters with uncertainties when using PBPSO. AODs measured by a sun photometer on a clear day (20160413) and a foggy day (20160508) were then processed by the PBPSO program for both bimodal and lognormal distributions. Results showed that in general the foggy day has smaller  values indicating that the PBPSO algorithm is better able to match AODs when there is a larger aerosol load in the atmosphere. The bimodal distribution from the clear day best describes the aerosol size distribution since the  values are lower. The lognormal distribution best describes the aerosol size distribution on the foggy day (20160508).

KEYWORDS Atmospheric Aerosols; Size Distributions; Junge; Bimodal; Gamma; Lognormal; Particle Swarm Optimization; Inverse Problem; Aerosol Optical Depth

Strategy Abandonment Effects in Cued Recall

https://doi.org/10.33697/ajur.2017.019

Stephanie A. Robinson, Amy A. Overman, & Joseph D.W. Stephens

ABSTRACT Decades of research have investigated the effects of encoding strategies in the formation of associations in memory. Despite this, it is not known whether or how changes in the use of strategies within a brief time span may affect memory. For example, what is the effect on memory of abandoning a recent strategy or switching to a different strategy? The present study systematically varied the strategies used by participants in two closely-spaced associative memory tasks. Results indicated that intentional abandonment of a verbal (sentence-generation) strategy had disproportionately negative consequences on memory for semantically unrelated word pairs. The findings suggest that memory encoding is affected by differences in strategy use across recent memory tasks, and have implications for effective use of memory strategies in practical settings.

KEYWORDS Cued Recall; Encoding Strategies; Inhibition

AJUR Volume 14 Issue 1 (April 2017)

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

AJUR Volume 14 Issue 1 (April 2017)

https://doi.org/10.33697/ajur.2017.001


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

 

pp. 5-10 Identifying Issues Surrounding First Generation Students

https://doi.org/10.33697/ajur.2017.002

Lena Rubio, Candi Mireles, Quinlan Jones, & Melody Mayse
Social Work Department, Tarleton State University
ABSTRACT
First-generation students compose a subpopulation within the institution of higher education, which exhibits its own set of resources in areas such as academic preparation, support systems, family background, and finances to apply to education. This quantitative study examined gaps and barriers to resources currently available to assist the population. The researchers utilized four pre-developed demographic questions along with a 34-item survey instrument assessing the experiences of first generation students, to gather the data presented in the study. The analysis involved coding and elementary data analysis of demographics and reporting frequencies. The 200 participants in the study identified as first-generation students at four-year universities within the United States. The majority of the participants surveyed were white (69.5%; n= 139), between the ages of 17 and 26 (94.5%; n=189), and from families within the middle-class income bracket of (39.5%; n= 79). The results indicated that most common barrier to participants attending college was tuition-cost (63%; n=126), followed by a lack of information about a college, such as financial aid availability and required documents (34.5%; n=69). Over 64% (n=129) received support or guidance from support networks in the form of parents and/or guardians. The study provided information about the issues encountered by first-generation students, as well as the accessed support networks, and preferred resources.
KEYWORDS
First-Generation Student; College Retention; Academic Preparation; Financial Assistance; Support Systems

pp. 11-16 A Comparative Analysis of the Fitness of Collegiate Dancers as compared to Collegiate Volleyball and Softball Players

https://doi.org/10.33697/ajur.2017.003

Leanna Miller* & Fred L. Miller III
Department of Kinesiology, Anderson University, Anderson, IN
ABSTRACT
Few studies directly compare the various fitness components of collegiate dancers and athletes in acknowledged sports. The limited studies that do exist fail to consider certain variables or to assess multiple fitness components. The purpose of this study was to provide a more comprehensive comparison of collegiate dancers and collegiate volleyball and softball players. We used multiple fitness components as an indicator of the comparative physical demands of these activities, to assess whether the physical demands of collegiate dance may warrant a comparable level of medical support as afforded to the volleyball and softball players. Thirty dancers and thirty volleyball and softball players were tested using six different measurements of physical fitness commonly used in athletic assessments at universities. A two-tailed independent t-test was performed to determine differences between dancers and athletes in each fitness component. Three tests revealed significant differences between the groups, with the dancers having a lower percent body fat and greater flexibility, and the athletes having greater relative upper body strength. No significant differences were found in relative leg strength, core strength, or estimated VO2max. The results of the current study suggest that dance provides training adaptations equivalent to traditional intermittent sports and thus support the use of similar levels of medical care for collegiate dancers to that afforded to collegiate volleyball and softball players.
KEYWORDS
Physical Fitness; Dance; Dance Medicine; Athletics; Dance Health Benefits

pp. 17-24 Adaptation of Esherichia coli to Antiobiotic Cycling via Single Nucleotide Polymorphisms

https://doi.org/10.33697/ajur.2017.004

Samuel E. Hager, Ellen Jensen, Timothy J. Johnson, & David Mitchell*
Department of Biology, College of Saint Benedict/Saint John’s University, Collegeville, MN
Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN
ABSTRACT
Bacteria are quick to adapt and evolve, especially under the effects of selective pressures from chemical antibiotics. In addition, bacteria may develop resistance to antibiotics from multiple classes simultaneously, making their eradication from the human body particularly challenging. This study aims to demonstrate that bacterial multiple-drug resistance can be developed and retained in a laboratory setting. Escherichia coli B was grown in tryptic soy broth in the presence of a small, increasing concentration of streptomycin. This exposure resulted in a strain of E. coli, which had an increased minimum inhibitory concentration (MIC) towards streptomycin, or “resistance.” This resistant strain was then grown in like manner in nalidixic acid and then penicillin G. The result was a strain that became resistant to streptomycin and nalidixic acid, and increasingly resistant to nalidixic acid after penicillin G exposure. Additionally, the bacteria retained resistance to streptomycin and nalidixic acid even after exposure to those chemicals ceased. Genome sequencing and comparison to E. coli B reference strain REL606 revealed the emergence of point mutations with each exposure to an antibiotic. Of particular interest is a mutation associated with the appearance of nalidixic acid resistance. Base pair 4,553,488 was changed from adenine to guanine, resulting in a change from aspartate to glycine in the protein helicase. Previous studies have not indicated mutations to this locus as nalidixic acid resistance conferring. Thus, this mutation may be a novel mutation conferring E. coli B nalidixic acid resistance. Since the region of the mutated helicase is functionally undefined, a mechanism is not apparent. Further research needs to be done to confirm this hypothesis and illuminate a mechanism.
KEYWORDS
Bacteria; Escherichia coli; Evolution; Antibiotic Resistance; Nalidixic Acid; Streptomycin; Point Mutation; Single-nucleotide Polymorphism; Helicase; Minimum Inhibitory Concentration

pp. 25-34 Constructing the Imaginative Bridge: Third-Generation Holocaust Narratives

https://doi.org/10.33697/ajur.2017.005

Megan Reynolds*
Department of English, Trinity University, San Antonio, TX
ABSTRACT
Reynolds’s research examines the ways in which third-generation Holocaust writers, the grandchildren of Holocaust survivors, approach the subject of their own traumatic history and the intergenerational transmission of trauma and memory. Despite the two generational divide that separates the third generation from the preceding two generations of Holocaust writers, the trans-generational transmission of trauma continues to preoccupy contemporary narratives. This research examines the ways the grandchildren of survivors, represented in this paper by Margot Singer and Jonathan Safran Foer, confront and include lost worlds in their narratives as well as their attempts to resurrect these fractured pasts through innovative uses of imaginative leaps. The third generation continues to suffer from the intergenerational transmission of trauma and memory yet discovers innovative ways to share that trauma, evidence of evolving modes of bearing witness.
KEYWORDS
Holocaust Narratives; Third-Generation; Intergenerational Transmission of Trauma; Literature; Trauma; Memory Studies; Jewish Identity; Grandchildren of Survivors

pp. 35-48 Mathematical Modeling Analysis to Simulate the Dynamics of Immune Cells, HIV, and Tuberculosis

https://doi.org/10.33697/ajur.2017.006

Rumana Ahmed & Mahbubur Rahman
Department of Biology, the City College of the City University of New York, New York, NY
Department of Mathematics and Statistics, University of North Florida, Jacksonville, FL
ABSTRACT
The dynamics of immune cells, HIV, and tuberculosis can be described by a system of differential equations. We developed the formulations for this dynamical system. To evaluate the system as time goes to infinity, we investigated the equilibrium solutions. We established the criteria for stability based on the characteristics of the Jacobian matrix associated with the dynamical system. To investigate the bifurcation of the solution, we developed phase plane diagrams for the sets of assumed values of the parameters. we have investigated the curves for different values of the starting conditions of immune cells and the antigens. Along the curves, we observed the growth and decay processes. The stability of the system has been established by examining the phase plane diagrams as the solution approaches the equilibrium point. Based on phase diagrams, both stable and unstable systems have been simulated and examined in this study. Finally, we developed and evaluated the graphs for the unsteady variations of immune cells, HIV, and tuberculosis to see how the antigens grow because of the diminishing effects of immune cells in the system as time increases.
KEY WORDS
Mathematical Biology; Infectious Disease Modeling; Dynamical System; Simulation of Immune Cells and Antigens

pp. 49-60 Gender and Sexuality in Medieval Islamic Mysticism: A Comparative Study of Ibn ‘Arabi and al-Ghazali

https://doi.org/10.33697/ajur.2017.007

Emily Dovel*
History Department, University of Portland, Portland, OR
ABSTRACT
Mysticism, defined as a direct experience with God that cannot occur through intellectual knowledge, has the potential to offer women opportunities disallowed by a patriarchal society. Because mysticism exists outside of religious institutions and hierarchies, female mystics could receive opportunities for public expression often prohibited by Medieval Islamic societies. Islamic Mysticism, or Sufism, has a long history of prominent female mystics. However, Sufi thought in the 12th and 13th centuries was certainly affected by the misogynistic influences of the greater society. In order to explore the ideological conflict within medieval Sufism, between the potential for gender egalitarianism within mysticism and the influences of patriarchy, this paper examines the theology of two prominent Sufi mystics, Ibn ‘Arabi and al-Ghazali, and proposes some explanations for the large disparity between the two Sufis’ opinions on gender and sexuality. Specifically, al-Ghazali fully supports the subjugation of women, and even equates the perpetuation of patriarchy to religious piety. This paper argues that, living under the politically turbulent and authoritarian reign of the Seljuks in Iraq, during the late 11th and early 12th centuries, al-Ghazali was particularly disinclined to question traditional orthodoxy, particularly with regard to gender. Ibn ‘Arabi, by contrast, accepts the spiritual, intellectual, and legal equality of women to a remarkable extent. Raised in Muslim Spain in the late 12th and early 13th centuries, Ibn ‘Arabi was exposed to female mystics as teachers and experienced little political pressure to conform to traditional doctrine. Further, Ibn ‘Arabi subscribes to Oneness of Being theology in which the created, material universe is an emanation of God, and is ultimately part of the same divine being. As such, unlike many religious thinkers within patriarchal societies, who tend to reject worldliness—along with women and female sexuality—in an attempt to reach God, Ibn ‘Arabi believes that all things material—including women and the human body—are ultimately connected to divinity.
KEY WORDS
Islam; Sufism; Gender; Sexuality; Theology; Medieval History

pp. 61-77 Breaking the Chain of Silence: Political Activism and Social Justice in Omar Offendum’s Syrian-American Hip-Hop

https://doi.org/10.33697/ajur.2017.008

Harry Olafsen, Mohammed Ali, Mikayla McCord, and Dr. Roxana Cazan*
Department of Literature and Languages, Saint Francis University, PA
Pre-Medicine Track, Indiana University of Pennsylvania, PA
Department of Business, University of South Carolina in Columbia, SC
ABSTRACT
Dissatisfied with the decisions of the Western political class to remain uninvolved in helping settle the conflict in Syria, many hip-hop, rap, and pop artists from Syria and the surrounding region have been creating and performing politically charged music that promotes liberty, and justice in the Middle East. One artist in particular, Omar Offendum (in the United States), writes and brings to the stage his hip-hop music in a way that continues and enhances this political-artistic movement across the Atlantic. Employing rhymes and rhythms that foster commotion and make noise, Offendum breaks the global indifference accumulated around the topics of the Syrian war and the unsolvable debates about allowing a certain number of Syrian asylum seekers to apply for refugee status in Western nations. He underscores that apathy is not an option for those who oppose the oppressor. In this paper, we argue that Offendum’s music constitutes an effective tool of political propaganda that can raise social consciousness of the needs of Syrians today and inspire social justice. Because the political-ideological space that feeds his creative act is set in a civil-rights-conscious U.S., Offendum often appeals to a heritage, reminding the listener of the activism of the Black Panthers, the legacy of Malcom X, and the freedom battles of Rodney King and his followers. In many of his songs, Offendum uses Arabic, both as a means of highlighting the authenticity of his hybrid identity and as a method of marking a cultural space for a diverse audience to come together. In this paper, we offer a brief historical look at the role of hip-hop in the struggle for civil rights in the US in order to locate the legacy Offendum’s music builds on and to assess its power. We then perform a close analysis of three of his most famous songs and conclude with a brief discussion of the impact of Offendum’s on social media platforms globally.
KEYWORDS
Hip-Hop; Activism; Social Justice; Omar Offendum; Social Consciousness; Syrian War; Syrian Refugees; Civil Rights

AJUR Volume 13 Issue 4 (December 2016)

Click on the link below to download the full high-definition interactive pdf for
AJUR Volume 13 Issue 4 (December 2016)

https://doi.org/10.33697/ajur.2016.029

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

p. 5 Green Chemistry: Comparison of Ionic Liquid vs Conventional Solvent for
Indole Alkylation

https://doi.org/10.33697/ajur.2016.030

Jonathan G. Redrico & John L. Krstenansky
ABSTRACT
A comparison of the effectiveness of two synthetic methods was done for a green chemistry method using an ionic liquid-based solvent relative to a conventional method using organic solvents for the N-alkylation of indole. The green method used potassium hydroxide in the ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, followed by addition of the alkyl halide. The conventional method used sodium hydride in dimethylformamide. Possible advantages of the green method would be the use of a non-volatile solvent, the possibility of recycling the solvent, and the use of a less reactive base. However, its reaction yield was lower than for the conventional method, the reagent expense was higher, and recycling and reuse of the ionic solvent require considerable amounts of conventional solvent to clean it up sufficiently for reuse. On a laboratory scale, the ionic liquid method yielded neither a “green” nor an efficiency advantage. It is possible that with optimization on an industrial scale involving solvent reclamation that the green method could realize its promise.
KEYWORDS
Green Chemistry; Sustainable Chemistry; Ionic Liquids; N-alkylation; Indole; Solvent Recycling; Organic Chemistry; 1-Butyl-3-methylimidazolium Tetrafluoroborate; Synthesis

p. 11 Use of the Bruker AXS SMART BREEZE™ System for Macromolecular
X-ray Data Collection

https://doi.org/10.33697/ajur.2016.031

Christiana Standler, G. Blake Overson, Cody A. Black, Guizella A. Rocabado,
& Bruce R. Howard
ABSTRACT
The Bruker AXS SMART BREEZE™ system is a single-crystal X-ray diffractometer designed to collect data from crystals of small organic or inorganic compounds. It is typically equipped with a Molybdenum-anode sealed tube to facilitate data collection from small unit cells. We recently acquired this system, but chose to have it installed with a copper-anode sealed tube with the hope of using it to collect data from larger unit cells such as those found in crystals of proteins or other macromolecules. This is the first and only BREEZE™ system installed by Bruker AXS with a copper-anode to date. Here we show that this system is capable of efficiently collecting quality X-ray diffraction data from crystals of the enzymes lysozyme and xylanase. This capability to collect diffraction data from both macromolecular and small-molecule crystals greatly expands the scope of undergraduate research projects that can be addressed using this instrument.
KEYWORDS
X-ray; Diffraction; Crystallography; Diffractometer; Protein; Enzyme; Crystal; Structure

p. 21 Ebola Impact and Quarantine in a Network Model

https://doi.org/10.33697/ajur.2016.032

Anca Radulescu & Joanna Herron
ABSTRACT
Much effort has been directed towards using mathematical models to understand and predict contagious disease, in particular Ebola outbreaks. Classical SIR (susceptible-infected-recovered) compartmental models capture well the dynamics of the outbreak in certain communities, and accurately describe the differences between them based on a variety of parameters. However, repeated resurgence of Ebola contagions suggests that there are components of the global disease dynamics that we don’t yet fully understand and can’t effectively control. In order to understand the dynamics of a more widespread contagion, we placed SIR models within the framework of dynamic networks, with the communities at risk of contracting the virus acting as nonlinear systems, coupled based on a connectivity graph. We study how the effects of the disease (measured as the outbreak impact and duration) change with respect to local parameters, but also with changes in both short-range and long-range connectivity patterns in the graph. We discuss the implications of optimizing both these measures in increasingly realistic models of coupled communities.
KEYWORDS
Epidemic Spread; Network Dynamics; Network Connectivity; Coupled Differential Equations; Compartmental Model; Information Transfer; Outbreak Impact; Outbreak Duration

p. 37 Analysis of Vortex Pool-and-Chute Fishway

https://doi.org/10.33697/ajur.2016.033

Mathew Nyberg, Brian Draeger, Brian Weekly, Eileen Cashman, & Michael Love
ABSTRACT
Fishways are constructed in riverine habitats where structures such as culverts, dams, and flood channels have negatively impacted flow conditions suitable for the movement of native and migratory fish species. These auxiliary channels are engineered to resist gravitational force with frictional force, resulting in sustained depth and reduced velocity over a range of design flow rates. The Chézy hydraulic resistance coefficient accounts for such forces and provides a metric useful for determining the effectiveness of a fishway to alter flow conditions prohibitive to the passage of fish. The objective of this analysis was to use a scale model of an innovative vortex pool-and-chute fishway, that operates with both plunging and streaming flow simultaneously, designed by Michael Love and Associates, to determine the Chézy resistance coefficients over a range of flow rates under controlled hydraulic conditions. Using dimensional analysis to ensure proper scaling allowed laboratory measurements of the model to be translated into a real-world prototype design. The conceptual prototype fishway is a 144-foot-long by 30-foot-wide channel with an 8% slope. A 1:15 scale model was constructed to evaluate the design at prototype equivalent flow rates between 58 and 283 cubic feet per second (cfs). Chézy coefficients were estimated by two different calculation methods; the streaming flow method and the streaming and plunging flow method. Coefficients ranging between 22.3 and 39.2 ft1/2/s were determined by the streaming flow calculation method, whereas the streaming and plunging flow calculation method yielded estimates from 18.9 to 25.0 ft1/2/s at corresponding flow rates. For flows that were exclusively plunging, values of 32.2 to 41.9 ft1/2/s were found. In general, Chézy coefficient estimates were observed to decrease with increasing discharge and values were found to be comparable to those calculated for fishways implemented at similar slopes. The preliminary model fishway results indicated that implementation of a prototype fishway could effectively alter flows for adequate fish passage under the given conditions.
KEYWORDS
Hydraulics; Fish Passage; Fishway; Chézy Coefficient; Geometric Scaling; Froude Scaling; Streaming Flow; Plunging Flow; Dimensional Analysis; Similitude

p. 59 Dynamic Visualization of Time-Based Changes to Data Generated by
Reddit.com: The Real Time Conversation Project

https://doi.org/10.33697/ajur.2016.034

Daniel Wang, Andy Luse, & Jim Burkman
ABSTRACT
With the increased amount of data generated by social networking sites there is also increased difficulty in the analysis of this data, including time-based changes, which can provide unique insights in social network analysis. Information visualization is a vital tool in assisting social scientists with analysis of large quantities of data; however, the gathering, formatting, and visualizing of time-related data from social networking sites still remains an obstacle. This research explores the process of gathering time-based data in real time and using dynamic visualization techniques to visualize and analyze time-based changes in data generated by discussions on the social networking site Reddit. The outcome culminates in our deliverable, the Real Time Conversation Project.
KEYWORDS
Visualization; Network Analysis; Social Network; Reddit; Gephi

p. 69 Effects similar to anxiolysis in an organic extract of Stypopodium zonale on an anxiety-related behavior in Drosophila melanogaster

https://doi.org/10.33697/ajur.2016.035

Keysh Mejías, Grisel Robles, Zulmari Martínez, Anamaris Torres, Lee Algarín, Genesis López, & Ricardo Chiesa
ABSTRACT
Nature has a great diversity of organisms whose bioactive compounds may potentially be studied. When it comes to aquatic life we find that algae are organisms that are well suited for screening and identification of bioactive compounds due to their widespread distribution in both salt and freshwater. Our hypothesis is that a crude organic extract of the brown algae Stypopodium zonale can decrease anxiety-related behaviors in Drosophila melanogaster. Stypopodium zonale was collected in the south coast of Puerto Rico and the potential anxiolytic-like effects of the extract were studied in an anxiogenic-like behavioral paradigm in Drosophila melanogaster. This behavior is called centrophobia and is measured using an Open Field Arena (OFA). Validation of the paradigm gave the expected results as reported in the literature, in which Drosophila exhibits a phobia (avoidance) of remaining in the center of the OFA, which corresponds to a behavior with anxiety components. The organic extract was dissolved with dimethyl sulfoxide (DMSO). Toxicity tests were performed both for DMSO and the crude organic extract, and neither showed positive results. To perform the behavioral trials, 1 mL of the crude extract and 4 mL of water were mixed with 1.8 g of Drosophila food. The final concentration of the crude extract in the food was 5.4 mg/mL. The adult flies were grown in a tube with the extract until a considerable quantity of larvae was observed, and then the adults were removed. These new larvae, once turned into adult flies, were used for the behavioral trials. The behavior of control flies (food without extract) and experimental flies (extract containing food) was recorded with a video camera and the results of the centrophobic behavior were analyzed and compared using quantitative criteria. Both the control and experimental trials were performed in triplicate. The results show that flies grown in food containing the crude extract present a significant reduction in centrophobia compared with control flies. In conclusion, our results suggest that the organic crude extract from Stypopodium zonale has anxiolytic-like effects in a Drosophila melanogaster model with anxiety components. We are currently performing Nuclear Magnetic Resonance (NMR) studies on the crude extracts to identify the most abundant secondary metabolites. Future experiments should include the administration of the crude extracts (or fractions of the most abundant secondary metabolites) to a vertebrate model in to test the effect in a behavior with anxiety components. We are also in the process of developing a preliminary model of possible mechanisms of action of the crude organic extract in the reduction of centrophobia.
KEYWORDS
Anxiety; Algae; Drosophila melanogaster; Open Field Arena; Organic extracts; Centrophobia; Stypopodium zonale

AJUR Volume 13 Issue 3 (August 2016)

Click on the link below to download the full high-definition interactive pdf for
AJUR Volume 13 Issue 3 (August 2016)

https://doi.org/10.33697/ajur.2016.021

Links to individual manuscripts, abstracts and keywords are provided in the section below:

 

p. 5 Effects of the Electronegativity of Second Row Elements on Their Bonding to Boron

https://doi.org/10.33697/ajur.2016.022

Xavier Shiu & J. Conceicao
ABSTRACT The effects of electronegativity on the bonding between boron and second row elements are studied in this paper. Calculations using Density Functional Theory (DFT), Moller-Plesset Theory (MP2) and Natural Bonding Orbital (NBO) analysis were performed on BF3, B(OH)3 and B(NH2)3 and the localized bonding properties of these molecules were elucidated. All of these molecules showed the absence of pi-bonding and did not obey the octet rule. With decreasing electronegativity of the terminal atoms, F, O and N in BF3, B(OH)3, B(NH2)3 there is increasing the propensity of electron donation from these terminal atoms to the empty p-orbital of the central boron.  Within the BH2−F, BH2−OH and BH2−NH2 series, the amino-borane showed the largest change in relative bond length and angle across this set. Furthermore, the borate anion, O−B(OH) 2 was subjected to identical analysis and pi-bond formation was observed. Our results show that a good match orbital energies between the donor and acceptor orbitals are important for pi-bond formation.
KEYWORDS Electronegativity; Boron Trifluoride; Boric Acid; Triaminoborane; Borate Anion; Octet Rule; Density Functional Theory; Natural Bonding Orbital; Pi-Bond; Double Bond

p.13 What Angle Will You Take? Patterns of Perspective-Taking in a Body-Based Task

https://doi.org/10.33697/ajur.2016.023

Tegan Garon
ABSTRACT When people conceptualize abstract ideas, different perspectives can help them to make connections and develop their reasoning. In this study, three third grade students who engaged in a body-based angle task, using the Kinect for Windows, were analyzed. Descriptions of their interviews are presented, including a detailed analysis of their patterns of perspective-taking and factors that might have been conducive to their learning. It was observed that students typically adopted a body-based perspective before transitioning to other perspectives. Further, the design of the task and interviewer comments were important factors that prompted students to take different perspectives. The implications for perspectives and their impacts on learning are discussed.
KEYWORDS Embodied Cognition; Angles; Mathematics Education; Perspectives; Movement

p.27 Affine Symmetry Tensors in Minkowski Space

https://doi.org/10.33697/ajur.2016.024

Isaac Ahern & Sam Cook
ABSTRACT Killing vectors are generators of symmetries in a spacetime. This article defines certain generalizations of Killing vectors, called affine symmetry tensors, or simply affine tensors. While the affine vectors of the Minkowski spacetime are well known, and partial results for valence n = 2 have been discussed, affine tensors of valence n > 2 have never been exhibited. In this article, we discuss a computational algorithm to compute affine tensors in Minkowski spacetime, and discuss the results for affine tensors of valence 2 ≤ n ≤ 7. After comparison with analogous results concerning Killing tensors, we make several conjectures about the spaces of affine tensors in Minkowski spacetime.
KEYWORDS Affine Symmetry Tensors; Affine Vectors; Killing Tensors; Killing Vectors; Minkowski Spacetime; Dimension; Maple CAS; Lie Derivative; Generalized Killing Tensor

p.33 A Relationship Between Time Perception and State-Anxiety

https://doi.org/10.33697/ajur.2016.025

James Brown
ABSTRACT Participants in this study were randomly assigned to one of three interval groups of either one, three, or five minutes. All participants were asked to estimate a group-assigned time interval and complete the state portion of the State Trait Anxiety Inventory (STAI). It was hypothesized that higher levels of state anxiety would cause participants to overestimate the passage of time. It was also hypothesized that shorter interval durations would be estimated more accurately than longer interval durations. Results of a t-test did not support the first hypothesis. Results of a linear trend analysis did support the second hypothesis (P < .05). These results indicate that state-anxiety does not cause the passage of time to be overestimated and that interval duration length affects how accurately time is estimated. Implications of this study are important to the understanding of human time-management ability and time estimation errors.
KEYWORDS Time estimation; Perception; State-anxiety; Attention; Working memory; Emotion

p.41 On Closure Properties of Irrational and Transcendental Numbers under Addition and Multiplication

https://doi.org/10.33697/ajur.2016.026

Shekh Mohammed Zahid & Prasanta Kumar Ray
ABSTRACT In the article ‘There are Truth and Beauty in Undergraduate Mathematics Research’, the author posted a problem regarding the closure properties of irrational and transcendental numbers under addition and multiplication. In this study, we investigate the problem using elementary mathematical methods and provide a new approach to the closure properties of irrational numbers. Further, we also study the closure properties of transcendental numbers.
KEYWORDS Irrational numbers; Transcendental numbers; Dedekind cuts; Algebraic numbers

p.45 Peaked T-Waves and Potassium: The Reliability of Peaked T-Waves as Indicators of Hyperkalemia in End-Stage Renal Patients Undergoing Hemodialysis

https://doi.org/10.33697/ajur.2016.027

Ryan D. Pappal, Ilse M. Espina & Zubaid Rafique
ABSTRACT While peaked T-waves have traditionally been associated with hyperkalemia cases, previous studies have called their reliability for hyperkalemia diagnosis into question. This study examined 89 ESRD patients totaling to 736 patient visits. Linear regressions and receiver operating characteristic (ROC) analyses were utilized to assess the reliability of peaked T-waves as a diagnostic criterion for hyperkalemia. Poor correlations between T/R ratio (leads V2-V4) and serum potassium were found, r = 0.23, 0.17, and 0.17, p < 0.001. R2 values ranged from 0.03 to 0.05. ROC analysis found poor sensitivity and specificity of T/R as a predictor of hyperkalemia (area under the curve: 0.61 – 0.66), and the T/R ≥ 0.75 threshold yielded a sensitivity of 0.83 with a specificity of 0.40 when predicting hyperkalemia (serum potassium > 5.5 mEq/L). We conclude that the peaked T-wave is a poor indicator for the early identification of hyperkalemia in ESRD patients presenting to the emergency department.
KEYWORDS Hyperkalemia; Electrocardiography; End-stage Renal Disease; Hemodialysis; Arrhythmias, Potassium; Sensitivity and Specificity; ROC Curve

p.53 Modeling Internet Traffic Generations Based on Individual Users and Activities for Telecommunication Applications

https://doi.org/10.33697/ajur.2016.028

Sara Stoudt, Pamela Badian-Pessot, Blanche Ngo Mahop, Erika Earley, Jordan Menter, Yadira Flores, Danielle Williams, Weijia Zhang, Liza Maharjan, Yixin Bao, Laura Rosenbauer, Van Nguyen, Veena Mendiratta & Nessy Tania
ABSTRACT A traffic generation model is a stochastic model of the data flow in a communication network. These models are useful during the development of telecommunication technologies and for analyzing the performance and capacity of various protocols,algorithms, and network topologies. We present here two modeling approaches for simulating internet traffic. In our models, we simulate the length and interarrival times of individual packets, the discrete unit of data transfer over the internet. Our first modeling approach is based on fitting data to known theoretical distributions. The second method utilizes empirical copulae and is completely data driven. Our models were based on internet traffic data generated by different individuals performing specific tasks (e.g., web browsing, video streaming, and online gaming). When combined, these models can be used to simulate internet traffic from multiple individuals performing typical tasks.
KEYWORDS Internet Traffic Simulation; Stochastic Models; Empirical Copula; Cumulative distribution function; Wireshark