The Journal of Undergraduate Research最新文献_第4页

Anisotropic Behavior of Ultrasonic Waves in 3D Printed Materials 超声波在3D打印材料中的各向异性行为

The Journal of Undergraduate Research Pub Date : 2019-12-29 DOI: 10.33697/ajur.2019.027

E. Alexander, G. Hoople

引用次数: 0

Evaluating the Effects of Bisphenols F and S with Respect to Bisphenol Aon Primordial Germ Cell Migration in Zebrafish (Danio rerio) EmbryosUsing Immunofluorescence Microscopy 利用免疫荧光显微镜评价双酚F和S相对于双酚a对斑马鱼胚胎原始生殖细胞迁移的影响

The Journal of Undergraduate Research Pub Date : 2019-12-29 DOI: 10.33697/ajur.2019.031

S. Safura, George Roba, Edward A. Freeman

{"title":"Evaluating the Effects of Bisphenols F and S with Respect to Bisphenol A\u0000on Primordial Germ Cell Migration in Zebrafish (Danio rerio) Embryos\u0000Using Immunofluorescence Microscopy","authors":"S. Safura, George Roba, Edward A. Freeman","doi":"10.33697/ajur.2019.031","DOIUrl":"https://doi.org/10.33697/ajur.2019.031","url":null,"abstract":"Primordial Germ Cell (PGC) migration occurs in early embryonic development and is highly conserved across taxa. PGC migration occurs within the first 24 hours post fertilization (hpf) in zebrafish, making the organism an efficient model for observing the migration pathway. Proper PGC migration is necessary for normal gonad development and, in some species, sex determination. Disruption of this process leads to defects in gonad formation and abnormal sex determination and differentiation. Studies show that endocrine-disrupting chemicals such as bisphenol A (BPA) disrupt PGC migration in zebrafish. BPA is an estrogenic compound that has been linked to a variety of human diseases, including various cancers, diabetes, reproductive disorders, obesity, and cardiovascular diseases. It is one of the most widely used synthetic compounds worldwide, as it is used to make polycarbonate plastics. Many studies provide evidence of the harmful effects of BPA on living organisms. In response, manufacturers have started to use replacements such as bisphenol F (BPF) and bisphenol S (BPS). However, due to their structural similarity, it is likely that BPF and BPS are just as harmful to organisms as BPA. In this study, we use antibody staining and immunofluorescence microscopy to confirm that BPA exposure results in abnormal PGC migration in zebrafish embryos, as previously studied, and to illustrate that BPF and BPS exposure results in similar PGC migration defects.","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"108 1","pages":"69-77"},"PeriodicalIF":0.0,"publicationDate":"2019-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74277960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

A Monte Carlo Simulation Study on the Power of Autocorrelation Tests for ARMA Models ARMA模型自相关检验功率的蒙特卡罗模拟研究

The Journal of Undergraduate Research Pub Date : 2019-12-29 DOI: 10.33697/ajur.2019.030

Zachary Wenning, Emily Valenci

{"title":"A Monte Carlo Simulation Study on the Power of Autocorrelation Tests for ARMA Models","authors":"Zachary Wenning, Emily Valenci","doi":"10.33697/ajur.2019.030","DOIUrl":"https://doi.org/10.33697/ajur.2019.030","url":null,"abstract":"It is often the case when assessing the goodness of fit for an ARMA time series model that a portmanteau test of the residuals is conducted to assess residual serial correlation of the fitted ARMA model. Of the many portmanteau tests available for this purpose, one of the most famous and widely used is a variant of the original Box-Pierce test, the LjungBox test. Despite the popularity of this test, however, there are several other more modern portmanteau tests available to assess residual serial autocorrelation of the fitted ARMA model. These include two portmanteau tests proposed by Monti and Peña and Rodríguez. This paper focuses on the results of a power analysis comparing these three different portmanteau tests against different fits of ARMA derived time series, as well as the behavior of the three different teststatistics examined when applied to a real-world data set. We confirm that for situations in which the moving average component of a fitted ARMA model is underestimated or when the sample size is small, the portmanteau test proposed by Monti is a viable alternative to the Ljung-Box test. We show new evidence that the Peña and Rodríguez test may also be a viable option for testing for residual autocorrelation in cases where the sample size is small.","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"4 1","pages":"59-67"},"PeriodicalIF":0.0,"publicationDate":"2019-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75317415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of Constant Volume and Constant Flux Initial Conditions on Bidensity Particle-Laden Slurries on an Incline 斜面上双密度颗粒料浆等体积、等通量初始条件的研究

The Journal of Undergraduate Research Pub Date : 2019-12-29 DOI: 10.33697/ajur.2019.029

Dominic Diaz, J. Bojorquez, J. Crasto, Margaret Koulikova, Tameez Latib, Aviva Prins, A. Shapiro, Clover Ye, David Arnold, C. Falcon, Michael R. Lindstrom, A. Bertozzi

{"title":"Investigation of Constant Volume and Constant Flux Initial Conditions on Bidensity Particle-Laden Slurries on an Incline","authors":"Dominic Diaz, J. Bojorquez, J. Crasto, Margaret Koulikova, Tameez Latib, Aviva Prins, A. Shapiro, Clover Ye, David Arnold, C. Falcon, Michael R. Lindstrom, A. Bertozzi","doi":"10.33697/ajur.2019.029","DOIUrl":"https://doi.org/10.33697/ajur.2019.029","url":null,"abstract":"Author(s): Diaz, Dominic; Bojorquez, Jessica; Crasto, Joshua; Koulikova, Margaret; Latib, Tameez; Prins, Aviva; Shapiro, Andrew; Ye, Clover; Arnold, David; Falcon, Claudia; Lindstrom, Michael; Bertozzi, Andrea | Abstract: Particle-laden slurries are pervasive in both natural and industrial settings, whenever particles are suspended or transported in a fluid. Previous literature has investigated the case of a single species of negatively buoyant particles suspended in a viscous fluid. On an incline, three distinct regimes emerge depending on the particle concentration and inclination angle: settled (where particles settle and there is a pure fluid front), well-mixed (where particle concentration is constant throughout), and ridged (where a particle-rich ridge leads the flow). Recently, the same three regimes were also found for constant volume two species bidensity slurries. We extend the literature on bidensity slurries by presenting results on constant volume and a new type of initial condition: constant flux, where slurry is pumped onto the incline at a constant rate. We present front positions of the slurries and compare them to theoretical predictions. In addition, height profiles (film thicknesses) are also presented for the constant flux case, showing the distinct behavior of the ridged regime. We find that for constant flux conditions the settled regime forms for small particle volume fractions and inclination angles while the ridged regime forms for large corresponding values. Intermediate values of these two parameters are shown to produce a well-mixed regime. KEYWORDS: Thin Films; Particle-Laden Flow; Multiphase Fluids; Interfacial Flows; Particle Segregation","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"25 1","pages":"42-57"},"PeriodicalIF":0.0,"publicationDate":"2019-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83310534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Women in Higher Educational Leadership: Representation, Career Progression, and Compensation 高等教育领导中的女性:代表性、职业发展和薪酬

The Journal of Undergraduate Research Pub Date : 2019-12-29 DOI: 10.33697/ajur.2019.026

Carla Cañas, Caitlyn Keeve, C. Ramos, Jocelyn O. Rivera, Michelle L Samuel

{"title":"Women in Higher Educational Leadership: Representation, Career Progression, and Compensation","authors":"Carla Cañas, Caitlyn Keeve, C. Ramos, Jocelyn O. Rivera, Michelle L Samuel","doi":"10.33697/ajur.2019.026","DOIUrl":"https://doi.org/10.33697/ajur.2019.026","url":null,"abstract":"Men in university administration repeatedly outnumber women in leadership positions. The problem under investigation is that this gender gap exists due to barriers to advancement and discrimination in both the hiring process and in the workplace. With less representation of women in higher education leadership, there is a higher risk of bias for women in this field. This study used an ex-post facto methodology and gathered public data from the University of California (UC) Annual Payroll Compensation database. Three separate studies were run to determine the level of gender differences in the representation of educational leaders, compensation, and career progression. Significant differences in gender equity existed, with more men represented at several levels of educational leadership. Significant differences were also found in compensation levels, where men earned more money than women in the same position. Lastly, a small effect, although not significant, was observed when comparing early career gender representation to non-early career gender representation. There are more women recent graduates than men in leadership positions. Together these results suggest that while there are gender gaps in representation and compensation, there may be slow progress towards better representation in early career leadership positions in the UC system. The implication of this research supports further research into factors which impact the compensation of women leaders in academia. Higher education hiring professionals and candidates for leadership positions could benefit from further development of theories around gender equity and representation.","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"10 1","pages":"5-13"},"PeriodicalIF":0.0,"publicationDate":"2019-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79672120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Pet Attachment and the Social Support that Pets Provide to College Students 宠物依恋与宠物对大学生的社会支持

The Journal of Undergraduate Research Pub Date : 2019-01-01 DOI: 10.32727/25.2019.30

Olivia A Bekker, S. Mallavarapu

引用次数: 2

An Examination of the Predictors of Stalking Myth Acceptance and Perpetration 跟踪神话的接受和实施的预测因素研究

The Journal of Undergraduate Research Pub Date : 2019-01-01 DOI: 10.32727/25.2019.33

Amber Wallace, Corinne L. McNamara

引用次数: 1

Influence of Sport Specialization on Athletic Performance and Injury Risk in Collegiate Swimmers 体育专业化对大学生游泳运动员运动成绩和损伤风险的影响

The Journal of Undergraduate Research Pub Date : 2018-01-01 DOI: 10.32727/25.2019.31

Samantha M Gunn, G. Mangine, Trisha A. VanDusseldorp, G. M. Hester

{"title":"Influence of Sport Specialization on Athletic Performance and Injury Risk in Collegiate Swimmers","authors":"Samantha M Gunn, G. Mangine, Trisha A. VanDusseldorp, G. M. Hester","doi":"10.32727/25.2019.31","DOIUrl":"https://doi.org/10.32727/25.2019.31","url":null,"abstract":"To assess the effect of swimming specialization on performance and injury risk in collegiate swimmers, thirty collegiate swimmers (20.1 ± 0.9 years [18.5 – 22.3 years]) were asked to complete an anonymous survey to provide information regarding their sports participation history, success in swimming, and the occurrence and quantity of swimming-related injuries. Specialization status was determined by the swimmers claiming they had specialized and by the number of months (≥ 8 months) they participated in swimming each year. Correlation analysis revealed several significant (p < 0.05) relationships between all determinants of specialization, swimming success, and swimming injuries. Stepwise regression analysis revealed that the age at which an athlete specialized was the best predictor of the occurrence of a swimming-related injury (R = 0.34, p = 0.004) and the number of injuries sustained (R = 0.25, p = 0.019). Years of competitive swimming experience was the best predictor (p < 0.008) of performance in the freestyle stroke at 50-yards (R = 0.47), 100-yards (R = 0.53), and 500-yards (R= 0.43), the back stroke at 200-yards (R = 0.41), and the 100-yard butterfly (R = 0.55). The age at which the athlete specialized in swimming was the best predictor of the 200-yard individual medley (R = 0.30, p = 0.037). Our data suggests that swimming specialization may be beneficial for success in select swimming events but is not as important as years of competitive experience and may also lead to a greater number of swimming-related injuries.","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"32 1","pages":"3"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86719808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Factors affecting Psi Chi members' satisfaction with research opportunities 影响Psi成员对研究机会满意度的因素

The Journal of Undergraduate Research Pub Date : 2018-01-01 DOI: 10.24839/1089-4136.JN13.1.6

K. Mcdougal, M. Rodríguez

引用次数: 0

The Effect of CO 2 , Intracellular pH and Extracellular pH on Mechanosensory Proprioceptor Responses in Crayfish and Crab co2、细胞内pH和细胞外pH对小龙虾和螃蟹机械感觉本体感受器反应的影响

The Journal of Undergraduate Research Pub Date : 2017-11-16 DOI: 10.33697/AJUR.2017.025

Viresh Dayaram, Cole A. Malloy, S. Martha, Brenda Alvarez, Ikenna Chukwudolue, Nadera Dabbain, Dlovan D.mahmood, Slavina Goleva, Tori Hickey, A. Ho, M. King, Paige Kington, Matthew Mattingly, Samuel Potter, Landon Simpson, A. Spence, Henry Uradu, J. Doorn, dlovan faiq, R. Cooper

{"title":"The Effect of CO 2 , Intracellular pH and Extracellular pH on Mechanosensory Proprioceptor Responses in Crayfish and Crab","authors":"Viresh Dayaram, Cole A. Malloy, S. Martha, Brenda Alvarez, Ikenna Chukwudolue, Nadera Dabbain, Dlovan D.mahmood, Slavina Goleva, Tori Hickey, A. Ho, M. King, Paige Kington, Matthew Mattingly, Samuel Potter, Landon Simpson, A. Spence, Henry Uradu, J. Doorn, dlovan faiq, R. Cooper","doi":"10.33697/AJUR.2017.025","DOIUrl":"https://doi.org/10.33697/AJUR.2017.025","url":null,"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.","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"203 1","pages":"85-99"},"PeriodicalIF":0.0,"publicationDate":"2017-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83622557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10