This study quantifies the anisotropic behavior of ultrasonic wave transmission for materials printed with three different 3D printers. As 3D printed materials become more prevalent in manufactured products, fully characterizing the physical properties of these materials become more important. This paper examines the longitudinal velocity of sound and acoustic impedance in two directions: orthogonal and parallel to the printed layers. Each of the 3D printed materials displayed slightly different transmission results. For PMMA like samples printed on a SLA printer waves travelled more quickly in the orthogonal direction than the parallel direction. For samples printed on an industrial FDM printer using ABS the opposite was true: the parallel direction was faster than the orthogonal. For samples printed on an entry level FDM printer with PLA there was no consistent pattern, instead there was a tight clustering of ultrasonic velocity in the parallel direction but substantial variation in the orthogonal direction. Overall the variation between the orthogonal and parallel directions was found to be less than 2% in all cases.
{"title":"Anisotropic Behavior of Ultrasonic Waves in 3D Printed Materials","authors":"E. Alexander, G. Hoople","doi":"10.33697/ajur.2019.027","DOIUrl":"https://doi.org/10.33697/ajur.2019.027","url":null,"abstract":"This study quantifies the anisotropic behavior of ultrasonic wave transmission for materials printed with three different 3D printers. As 3D printed materials become more prevalent in manufactured products, fully characterizing the physical properties of these materials become more important. This paper examines the longitudinal velocity of sound and acoustic impedance in two directions: orthogonal and parallel to the printed layers. Each of the 3D printed materials displayed slightly different transmission results. For PMMA like samples printed on a SLA printer waves travelled more quickly in the orthogonal direction than the parallel direction. For samples printed on an industrial FDM printer using ABS the opposite was true: the parallel direction was faster than the orthogonal. For samples printed on an entry level FDM printer with PLA there was no consistent pattern, instead there was a tight clustering of ultrasonic velocity in the parallel direction but substantial variation in the orthogonal direction. Overall the variation between the orthogonal and parallel directions was found to be less than 2% in all cases.","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"9 1","pages":"15-22"},"PeriodicalIF":0.0,"publicationDate":"2019-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88827948","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}
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.
{"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}
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.
{"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}
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
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
{"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}
Carla Cañas, Caitlyn Keeve, C. Ramos, Jocelyn O. Rivera, Michelle L Samuel
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.
{"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}
The purpose of this research was to see how the quality of a person’s attachment to their pet affects their perception of the amount of social support they are receiving from that pet. We recruited a sample of 309 undergraduate students who were pet owners. Students were enrolled in a General Psychology course at Kennesaw State University during Spring 2017. Data were collected using SurveyMonkey®. To measure the quality of pet attachment, we used the Lexington Attachment to Pets Scale. To measure perceived social support, we adapted the Multidimensional Scale of Perceived Social Support. There was a significant relationship between quality of attachment to one’s pet and perceived social support [r(307) = 0.77, p < 0.001, r = 0.59]. We also collected demographic data on variables such as ethnicity, gender, year in college, species of pet owned, number of years of pet ownership, and pet gender. We studied how these different variables affected the quality of pet attachment and perceived social support.
这项研究的目的是为了了解一个人对宠物的依恋程度如何影响他们对从宠物那里得到的社会支持的看法。我们招募了309名养宠物的大学生作为样本。2017年春季，学生们在肯尼索州立大学注册了一门普通心理学课程。使用SurveyMonkey®收集数据。为了测量宠物依恋的质量，我们使用了列克星敦宠物依恋量表。为了测量感知社会支持，我们采用了感知社会支持多维度量表。对宠物的依恋质量与感知到的社会支持之间存在显著相关[r(307) = 0.77, p < 0.001, r = 0.59]。我们还收集了人口统计数据，如种族、性别、大学年级、宠物种类、宠物饲养年限和宠物性别等变量。我们研究了这些不同的变量如何影响宠物依恋和感知社会支持的质量。
{"title":"Pet Attachment and the Social Support that Pets Provide to College Students","authors":"Olivia A Bekker, S. Mallavarapu","doi":"10.32727/25.2019.30","DOIUrl":"https://doi.org/10.32727/25.2019.30","url":null,"abstract":"The purpose of this research was to see how the quality of a person’s attachment to their pet affects their perception of the amount of social support they are receiving from that pet. We recruited a sample of 309 undergraduate students who were pet owners. Students were enrolled in a General Psychology course at Kennesaw State University during Spring 2017. Data were collected using SurveyMonkey®. To measure the quality of pet attachment, we used the Lexington Attachment to Pets Scale. To measure perceived social support, we adapted the Multidimensional Scale of Perceived Social Support. There was a significant relationship between quality of attachment to one’s pet and perceived social support [r(307) = 0.77, p < 0.001, r = 0.59]. We also collected demographic data on variables such as ethnicity, gender, year in college, species of pet owned, number of years of pet ownership, and pet gender. We studied how these different variables affected the quality of pet attachment and perceived social support.","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"11 1","pages":"4"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82137904","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}
Although interpersonal violence, such as stalking, is prevalent among college students, the factors that predict and contribute to a culture of campus violence are still obscure. Parallel to the established link between rape myth acceptance and rape perpetration, research has emphasized the ways in which stalking myth acceptance, societal attitudes, and false beliefs about stalking, normalize and perpetuate its occurrence (Lippman, 2015; McKeon, McEwan, & Leubbers, 2015). To further understand this dynamic, we examined the relationship between demographic variables, stalking myth acceptance (SMA), and stalking perpetration (SP) in a convenience sample of college students. Statistical analyses indicated that gender and sexual orientation were significant predictors of SMA. Moreover, SMA, gender, and sexual orientation significantly predicted SP. A better understanding of the relationship between demographic variables, attitudes, and stalking perpetration illuminates the need for targeted efforts to change social norms that have traditionally normalized and perpetuated campus violence.
{"title":"An Examination of the Predictors of Stalking Myth Acceptance and Perpetration","authors":"Amber Wallace, Corinne L. McNamara","doi":"10.32727/25.2019.33","DOIUrl":"https://doi.org/10.32727/25.2019.33","url":null,"abstract":"Although interpersonal violence, such as stalking, is prevalent among college students, the factors that predict and contribute to a culture of campus violence are still obscure. Parallel to the established link between rape myth acceptance and rape perpetration, research has emphasized the ways in which stalking myth acceptance, societal attitudes, and false beliefs about stalking, normalize and perpetuate its occurrence (Lippman, 2015; McKeon, McEwan, & Leubbers, 2015). To further understand this dynamic, we examined the relationship between demographic variables, stalking myth acceptance (SMA), and stalking perpetration (SP) in a convenience sample of college students. Statistical analyses indicated that gender and sexual orientation were significant predictors of SMA. Moreover, SMA, gender, and sexual orientation significantly predicted SP. A better understanding of the relationship between demographic variables, attitudes, and stalking perpetration illuminates the need for targeted efforts to change social norms that have traditionally normalized and perpetuated campus violence.","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"29 1","pages":"5"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75781143","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}
Samantha M Gunn, G. Mangine, Trisha A. VanDusseldorp, G. M. Hester
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.
为了评估游泳专业化对大学生游泳运动员成绩和损伤风险的影响，我们对30名年龄为20.1±0.9岁[18.5 - 22.3岁]的大学生游泳运动员进行了匿名调查，提供了他们的运动参与史、游泳成功情况以及游泳相关损伤的发生和数量等信息。专业状况由声称专业的游泳者和每年参加游泳的月数(≥8个月)确定。相关分析显示，专业化、游泳成功和游泳损伤的所有决定因素之间存在显著(p < 0.05)的关系。逐步回归分析显示，运动员的专业年龄是游泳相关损伤发生的最佳预测因子(R = 0.34, p = 0.004)和持续受伤次数(R = 0.25, p = 0.019)。多年的竞技游泳经验是50码自由泳(R= 0.47)、100码自由泳(R= 0.53)和500码自由泳(R= 0.43)、200码仰泳(R= 0.41)和100码蝶泳(R= 0.55)成绩的最佳预测因子(p < 0.008)。游泳运动员的年龄是200码个人混合泳成绩的最佳预测因子(R = 0.30, p = 0.037)。我们的数据表明，游泳专业化可能有利于在特定的游泳项目中取得成功，但不如多年的比赛经验重要，也可能导致更多的游泳相关伤害。
{"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}
Pub Date : 2018-01-01DOI: 10.24839/1089-4136.JN13.1.6
K. Mcdougal, M. Rodríguez
{"title":"Factors affecting Psi Chi members' satisfaction with research opportunities","authors":"K. Mcdougal, M. Rodríguez","doi":"10.24839/1089-4136.JN13.1.6","DOIUrl":"https://doi.org/10.24839/1089-4136.JN13.1.6","url":null,"abstract":"","PeriodicalId":22986,"journal":{"name":"The Journal of Undergraduate Research","volume":"39 1","pages":"6-13"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79045099","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}
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
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.
{"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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：