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Asymmetries in NCAA Division I Tennis Players Compared to An Athletic Control Group
Get PDFLimb asymmetries are an expected adaptation to years of training for athletes participating in dominant-sided sports. Previous research on this topic lacks an athletic control group. PURPOSE: To determine the magnitude of upper limb asymmetries in dominant-sided athletes (tennis players) compared to nondominant-sided athletes (cross-country runners). METHODS: Male and female NCAA Division I athletes (10 tennis, 11 cross-country) participated. Dual-energy x-ray absorptiometry (DXA) was used to measure bone mineral content (BMC), bone mineral density (BMD), and lean mass (LM) of the whole body, upper extremities, and forearms. Circumference measurements were taken at mid-biceps and the widest part of the forearms. The bony breadth of the elbow was measured with sliding calipers placed at the medial and lateral epicondyles. Grip strength was assessed with a dynamometer. Mixed-model ANOVA was used to analyze data between dominant/nondominant sides and between sports. RESULTS: There were no significant differences in age (p = .150), height (p =.783) or body mass (p = .066) between teams. No differences were shown between sports for total body BMC (p = .544), total body BMD (p = .535), or total body LM (p = .843). Sport × side interaction was significant (p \u3c .05) for lower arm circumference, elbow bony breadths, total upper extremity LM, total upper extremity BMC, total upper extremity BMD, forearm BMC, ultra-distal forearm BMC, mid-distal forearm BMC, one-third forearm BMC, and ultra-distal forearm BMD. CONCLUSION: Morphological differences between sports were localized to the arm. Sport specificity influences mass and volume (circumference, LM, BMC) of the limb, with BMD particularly enhanced in ultra-distal forearm
Environmental Factors Associated With Triploid Aspen Occurrence in Intermountain West Landscapes
Get PDFPolyploidy is common among plants and can contribute to physiological and morphological differences, altering how plants respond to environmental changes, promoting genetic diversification, and even species radiation. Quaking aspen (Populus tremuloides), a keystone species associated with high plant and animal diversity is frequently found in mixed diploid/triploid populations in the Intermountain West. High mortality rates and widespread population declines in aspen are of increasing concern in the Intermountain West, often ascribed to changing climates and drought stress events. The goal of this study was to better understand environmental factors influencing the distribution of triploid aspen population in the Intermountain West. Using restriction-site associated DNA sequencing (RAD-seq), we examined the occurrence of diploid and triploid aspen populations at various spatial scales in relation to environmental variables associated with soil moisture content. Our results suggest that triploidy in aspen on the landscape is associated with environmental variables related to soil moisture and may be influenced by specific local variations in topography, climate, and precipitation patterns. Overall, we found that conditions associated with low soil moisture were associated with lower frequencies of triploid aspen. Our results suggest that triploid aspen clones may be more susceptible to mortality than diploid clones in the warmer, drier climates expected with climate change. We acknowledge, however, that there are many knowledge gaps regarding the generation and persistence of triploid aspen clones. Understanding the causes and consequences of triploidy in aspen will be important in predicting and managing aspen persistence in landscapes of the western U. S. under changing climate conditions
Cocoa Polyphenols Modulate the Fecal Microbiome in a Mouse Model of Colitis, Independent of Basal Diet and Colon Inflammation
No full textChronic inflammation increases the risk of developing multiple chronic diseases, including cancer. The risk of developing colorectal cancer (CRC) specifically is increased in individuals who suffer from colitis. Diet is another risk factor for developing CRC, particularly a Western-type diet. Thus, supplementing a Western diet with functional foods containing anti-inflammatory polyphenols is a potential approach to decreasing CRC risk by reducing gut inflammation and altering the composition of the gut microbiome. The objective of this study was to determine the effects of cocoa polyphenol (CP) supplementation on inflammation status and microbiome profile before, during, and after colitis when fed in the context of a healthy diet or a Western diet in a mouse model of colitis-associated colorectal cancer (CAC). We hypothesized that mice fed a Western diet would experience greater colon inflammation than mice consuming a healthy rodent diet and that this effect would be attenuated when a Western diet is supplemented with cocoa flavanols. We further hypothesized that mice fed the cocoa-supplemented diet would have a differentiated microbiome profile than mice eating a Western diet alone. In this study, we used CocoaVia™ Cardio Health Powder, a polyphenol-enriched supplement, to achieve a high number of polyphenols in the diet. This experiment involved four experimental groups: one that was fed the AIN93G healthy rodent diet, one that was fed AIN supplemented with 2.6% CocoaVia™ powder, one that was fed the total Western diet (TWD), and one that was fed TWD supplemented with 2.6% CocoaVia™ powder. We found that dietary CP supplementation did not decrease inflammation in either a healthy or Western dietary context. Consumption of CP significantly altered the fecal microbiome profile of these mice before the development of colitis and continued to affect the abundance of some rare groups of bacteria during and after colitis. It was evident in this experiment that basal diet was the driving factor in promoting inflammation, mucosal damage, and symptoms of colitis in this model
Causes and Consequences of Space-Use Behavior Under Predation Risk in a Free-Living System
Get PDFPredators can have important ecological effects through killing and eating their prey, the so-called consumptive effect, but predators can also have a nonconsumptive effect (NCE) on their prey – this happens when the risk of predation itself causes prey to alter their behaviors or other traits and these alterations ultimately reduce prey survival, reproduction, or population size. While scientists understand the consumptive effects of predators well, we are still unsure whether NCEs are important in free-living systems. In this dissertation, I sought to better understand the potential NCEs of predators (wolves and cougars) on elk in northern Yellowstone National Park by leveraging data collected over 4 decades by the National Park Service. I first investigated the importance of elk density in shaping elk use of risky places. Increasing density means more mouths to feed, but it also means safety in numbers; as a result, increasing population density shifts the balance of the food-safety tradeoff common in ecosystems from safety at low density to food at high density. I then investigated the importance of elk age in determining how they respond to predators. Wolves hunt by singling out the weakest members of a herd, whereas cougars hunt by ambushing an unaware individual; therefore, wolf predation risk increases more sharply with age. I found that elk respond to this by taking fewer risks with wolves as they age. On the other hand, they take more risks with cougars as they age, a result of trying to maximize reproduction (by increasing their food intake) in their remaining years. Finally, I measured the potential NCE of wolves and cougars on elk birth rates, while controlling for the effects of elk density and age. I found evidence that an NCE likely occurs, but the overall effect was too weak to explain large changes to elk population size over the decades. This information improves our understanding of how predators affect prey populations, which is particularly important given large carnivore recovery and reintroductions around the world
Role of Proneurotrophin-p75NTR Signaling in a Mouse Model of Depression
Get PDFMajor depressive disorder, or depression, is among the leading causes of disability globally. Despite being a large public health challenge, depression remains difficult to treat as the underlying biology is still unknown and the currently available treatments are limited in effectiveness. This experiment was to test the efficacy of the drug LM11A-31, which works on the signaling pathway of proneurotrophin-p75NTR, a pathway that is not targeted by any currently used antidepressants. Male mice underwent a repeated forced swim, with all the mice receiving saline the first two days and then half the mice receiving saline and half receiving LM11A-31 before the swim on the last day. Increased immobility in the swim was recorded as a measure of depression or behavioral despair. A second experiment was conducted to determine if LM11A-31 increased overall activity or anxiety, which could be confound factors for the forced swim results. The outcome of both experiments points to LM11A-31 having antidepressant properties. This is significant as it suggests that proneurotrophin-p75NTR signaling may underlie symptoms of depression, gives a new drug that has antidepressant potential that works in a different way than any currently used antidepressants, and validates proneurotrophin-p75NTR as a novel target for future antidepressant drug development
Investigating the Impact of Pre-Professional Organization Participation on Undergraduate Technology and Engineering Education Student Retention and Interest in Teaching
Get PDFThe field of Technology and Engineering Education (TEE) has evolved in name and content throughout its existence. Throughout these evolutions, the number of TEE programs across the United States have decreased along with a decrease in the number of students graduating from undergraduate TEE programs. Previous investigations into the recruitment of TEE students have identified social interactions with TEE program faculty and technology and engineering educators as influential in students\u27 interest in teaching technology and engineering at the secondary level. This study sought to investigate how social interactions through participation in Technology and Engineering Educators Association (TEECA), as a community of practice, may influence undergraduate students\u27 interest in teaching and intent to complete their undergraduate TEE program. A Spearman\u27s rho correlation was used to investigate what relationship, if any, existed between TEECA participation and undergraduate students\u27 interest in teaching TEE and intent to complete their TEE degree. Additionally, a moderation analysis was performed to investigate whether undergraduate students\u27 beliefs about the social contribution of educators as well as the undergraduate students\u27 perceived abilities within the TEE content area have a moderating effect on the relationship between TEECA participation and undergraduate students\u27 interest in teaching and intent to complete their undergraduate program.
The study utilized a multiple method approach to further investigate additional aspects of participating in pre-professional communities of practice that undergraduate students recognize as influential in their intentions for their future studies and career. Lastly, this investigation also sought to identify the contextual factors that influence current and potential TEECA members\u27 perception and understanding of the TEE profession through a review of published data and responses from TEE program leaders from varying universities.
Findings revealed no statistically significant relationship between TEECA participation and undergraduate students\u27 interest in teaching and their intent to complete their undergraduate degree. Additionally, no statistical significance was found on the moderating impact of students\u27 beliefs on the relationship between TEECA participation and undergraduate students\u27 interest in teaching as well as their intent to complete their undergraduate degree.
Qualitative data collection and analysis revealed that students recognized TEECA participation as influential in helping them to develop skills and experiences in additional content within TEE. Student responses also indicated a struggle in finding undergraduate TEE programs.
Finally, this investigation showed inconsistency in defining and counting university TEE programs across the United States of America. This inconsistency may contribute to the obstacles students may experience in finding and enrolling in TEE programs
Coming Out Experiences Related to Improved Well-Being Among Religious Sexual and Gender Minorities
Get PDFSexual and gender minorities (SGMs; individuals who identify as LGBTQ+ and/or who do not identify as cisgender and heterosexual) often come out to others as a way to improve their connections, feel more authentic, and improve their mental health. However, coming out is often a frightening and stress-inducing process, and SGMs’ overall well-being may depend on how they approach these conversations and how others respond. In an effort to better understand these experiences and to provide a scientifically-validated “guide” to SGMs and those to whom they come out, we conducted three studies that examine when coming out goes well and how these factors relate to SGMs’ well-being.
The first study focused on interviews with SGMs who are or were members of the Church of Jesus Christ of Latter-day Saints, a religion in which coming out conversations are sometimes met with rejection. Participants indicated what they did to feel better about their coming out conversations, as well as how others responded that made them feel more positive about the conversations. The second study utilized these themes to develop two scales (Coming Out Vigilance and Positive Coming Out Responses) so that we could measure the frequency with which SGMs employ these approaches and perceive these positive responses from others when coming out. The third study then used these two measures with SGMs across a variety of religious traditions (including no religious affiliation) to examine how these approaches and responses relate to SGMs’ well-being. We found that these two measures are appropriately valid to use and that both the identified approaches and responses to SGMs’ coming out relate to improvements in well-being. It is our hope that SGMs, their support systems, mental health practitioners, and community leaders utilize these findings to make coming out experiences less stressful and enhance the well-being of SGM
An Investigation of the Essential Nature of Advanced Placement Students\u27 Psychological Safety and Participation in Mathematics Class Discourse
Get PDFAll students need to feel that their classes are safe spaces where they can explore and discuss their ideas. When students do not feel free to share their reasoning or understandings without fear of negative personal or social consequences, they may intentionally limit their participation in discussions. This study investigated the relationship between Advanced Placement Calculus students\u27 perceived feelings of psychological safety and their professed level of participation in class mathematics discourse, as well as the reasons why they would choose their particular level of participation. Findings indicated that these students generally liked to share their ideas because they wanted to further their own or other students\u27 understanding of mathematics, wanted to demonstrate their knowledge, or felt that the class environment was discussion friendly. Students in the study also reported that they did not want to share their ideas when they felt the critical judgment of others, feared being wrong, lacked knowledge or confidence in their understanding, or various other personal perspectives. Results of this study showed that mathematically-knowledgeable high school students were willing to participate in the mathematics discussions of their class when they felt assured of no negative consequences. These feelings of psychological safety were valued by the students in this study to promote an open class environment where they felt accepted and their ideas were respected and appreciated. The findings of this study support the essential nature of establishing psychologically safe environments for productive class mathematics discourse
Pile Burning After Conifer Removal From Aspen Stands Affects Tree Mortality, Regeneration, And Understory Recovery
Get PDFQuaking aspen (Populus tremuloides Michx.) stands throughout the western United States provide valuable ecosystem services but can be lost via succession from aspen to conifer. Forest managers are cutting conifers, but disposal of cut wood can be challenging in remote or sensitive areas. Piling and burning is being tested within aspen stands but ecosystem responses to this treatment are understudied. We assessed aspen tree mortality, tree regeneration, and understory vegetation after forest restoration thinning followed by pile burning in seven aspen-conifer stands around Lake Tahoe, California and Nevada, USA. Pile burning was conducted after cut wood had dried (1.5–7.5 years post cutting). Pile burning was more likely to kill aspen trees closer to piles regardless of tree size or pile size. Aspen regenerated rapidly inside the footprint of some burned piles, more often inside piles located in close proximity to other aspen, presumably by suckering from lateral roots beneath burned piles. Similarly, areas where higher densities of conifers were regenerating naturally were indicative of a greater likelihood for conifer regeneration inside pile footprints. Understory vegetation varied within and among study sites, and had similar vegetation cover and species richness inside pile footprints to vegetation in the vicinity of each pile. Overall, understory vegetation had mostly recovered after 2.5–8.5 years since pile burning. Thinning followed by burning of hand piles and smaller machine piles appears to be effective at promoting regeneration of aspen without lasting impact on understory vegetation. However, without further disturbance such as continued cutting and piling or use of prescribed fire, we caution that succession to conifer appears to continue, albeit slowly, via seedling regeneration
Investigating Sprite Halo Optical Signatures and Associated Lightning Characteristics Over South America
No full textAs part of the southern Brazil sprite campaign conducted from Santa Maria, Brazil during the summer 2006 almost 600 transient luminous events were imaged from two large thunderstorms located over north-eastern Argentina on February 22-23 and March 3- 4 2006. These ground-based measurements were made from the Southern Space Observatory (SSO) using an array of intensified CCD cameras arranged to view the low-elevation sky over a broad angle to capture the TLE information from the extensive storm systems. This paper focuses on the optical characteristics of over 60 sprite/halos (imaged on 23 March) and their associated polarity and charge moments as determined by an ELF-VLF lightning sensor also deployed at the SSO. Recent satellite measurements of halos over land-sea interfaces suggest that they are mainly associated with negative cloud-to-ground discharges (H. Frey, private communication). The prime location of our coordinated measurements centered over the Pampas of South America has enabled us to quantify the polarity of the halos and to study their associated charge moments