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Over 40% of adults in the United States are considered obese. Obesity is known to cause abnormal metabolic effects and lead to other negative health consequences. Interestingly, differences in metabolism and contractile performance between obese and healthy weight individuals are associated with differences in skeletal muscle fiber type composition between these groups. Each fiber type is characterized by unique metabolic and contractile properties, which are largely determined by the myosin heavy chain isoform (MHC) or isoform combination that the fiber expresses. In previous studies, SDS-PAGE single fiber analysis has been utilized as a method to determine MHC isoform distribution and single fiber type distribution in skeletal muscle. Herein, a methodological approach to analyze MHC isoform and fiber type distribution in skeletal muscle was fine-tuned for use in human and rodent studies. In the future, this revised methodology will be implemented to evaluate the effects of obesity and exercise on the phenotypic fiber type composition of skeletal muscle.
This ASU Science Book Discussion Poster was presented at the STS Research Forum and Poster Session in Chicago in conjunction with ALA 2013.
Programming is an essential part of library services. Having a regular program at the library and a wide distribution list raises awareness of the library to those associated with the university and beyond. Through programming, libraries demonstrate the vital role they play in the community. The ASU Science Book Discussion began meeting in the summer of 2011.
This presentation was given at the Montana Library Association conference in Billings, MT in 2011 and the Arizona Library Association conference in Tucson, AZ in 2011.
The giant green sea anemone, Anthopleura xanthogrammica, hosts two different endosymbiotic algae. One is a unicellular chlorophyte, Elliptochloris marina; the other is Symbiodinium muscatinei, a dinoflagellate. Hosting these different symbionts influences the life history strategy of A. xanthogrammica's congener A. elegantissima, directly impacting its reproductive strategy (asexual vs. sexual). My study sought to examine whether the type and density of symbiont also affects the reproductive condition of A. xanthogrammica, which reproduces only sexually. Gonad development was measured in anemones from Slip Point, Clallam Bay, WA and Tongue Point, WA along with symbiont type and density per mg of anemone protein. The results indicate a trend towards brown anemones having more developed gonads, especially in males. This may mean that A. xanthogrammica anemones that host zooxanthellae are more reproductively fit than zoochlorellate anemones. Thus, it may be favorable for anemones to host zooxanthellae. This is especially true in summer months when the high temperatures and mid-day low tides coincide with the period of most rapid gonad development.
The transition from high school to college is associated with considerable life strain for adolescents, including higher reported levels of daily stress and negative affect (NA), and alterations in stress physiology have been linked to poor health. The purpose of this thesis was to use an ecological momentary assessment design to study associations between momentary experiences of negative affect and cortisol levels in a sample of adolescents transitioning to college. I also examined the potential moderating effects of two potential vulnerability or protective factors, alone status and perceived social support from friends. Adolescents provided salivary samples and completed paper-and-pencil diary reports of socioemotional experiences and alone status five times per day for three consecutive weekdays, as well as completed self-report questionnaires on perceived social support from friends. Within-person increases in momentary negative affect were associated with momentary cortisol reactivity. Alone status significantly moderated this association such that the association between momentary negative affect and momentary cortisol levels was only significant when individuals were with others and not when they were alone. Perceived social support from friends did not significantly moderate the within-person associations between negative affect and momentary cortisol levels. The findings add to our understanding of physiological correlates of socioemotional experiences, as well as contexts in which these associations may be exaggerated or attenuated. The findings inform our understanding of potential pathways by which physiological reactivity to socioemotional experiences may affect the health of adolescents as well as how prevention efforts could reduce potential poor health outcomes associated with heightened stress reactivity.
V(D)J Recombination is the mechanism responsible for generating diversity in the repertoire of antigen receptors of T and B cells. This recombination process proceeds in two steps: site-specific cleavage mediated lymphocyte-specific recombinase known as Recombination Activating Genes 1 and 2 complex (RAG) at the junction of coding gene segments and their flanking recombination signal sequence (RSS) and then followed by rejoining of the double strand broken DNA by the non-homologous end joining (NHEJ) complex. Mutations and truncations of the RAG-recombinase have been found associated with genomic instability and chromosomal translocation. It has been hypothesized that these RAG mutants may have abnormality in their interactions with recombination intermediates, ultimately causing premature release of the ends for aberrant joining. Additionally, these mutations have an increase in targeting non-B type DNA instead of legitimate recombination substrates that contain RSSs. To directly test these hypotheses, we have developed a fluorescence-based detection system to monitor in real time the recombination cleavage reaction from the pre-cleavage to the post-cleavage stages and to compare RAG-DNA interactions between wild type and mutant RAG1/2 during this process. Our study provides important insight into the ability of the C-terminus of RAG to regulate RAG recombinase activity.
microRNAs (miRNAs) are short ~22nt non-coding RNAs that regulate gene output at the post-transcriptional level. Via targeting of degenerate elements primarily in 3'untranslated regions (3'UTR) of mRNAs, miRNAs can target thousands of varying genes and suppress their protein translation. The precise mechanistic function and bio- logical role of miRNAs is not fully understood and yet it is a major contributor to a pleth- ora of diseases, including neurological disorders, muscular disorders, and cancer. Cer- tain model organisms are valuable in understanding the function of miRNA and there- fore fully understanding the biological significance of miRNA targeting. Here I report a mechanistic analysis of miRNA targeting in C. elegans, and a bioinformatic approach to aid in further investigation of miRNA targeted sequences. A few of the biologically significant mechanisms discussed in this thesis include alternative polyadenylation, RNA binding proteins, components of the miRNA recognition machinery, miRNA secondary structures, and their polymorphisms. This thesis also discusses a novel bioinformatic approach to studying miRNA biology, including computational miRNA target prediction software, and sequence complementarity. This thesis allows a better understanding of miRNA biology and presents an ideal strategy for approaching future research in miRNA targeting.
Collective decision making in social organism societies involves a large network of communication systems. Studying the processes behind the transmission of information allows for greater understanding of the decision making capabilities of a group. For Temnothorax rugatulus colonies, information is commonly spread in the form of tandem running, a linear recruitment pattern where a leading ant uses a short-ranged pheromone to direct a following ant to a target location (in tandem).The observed phenomenon of reverse tandem running (RTR), where a follower is lead from a target back to the home nest, has not been as extensively studied as forward tandem running and transportation recruitment activities. This study seeks to explain a potential reason for the presence of the RTR behavior; more specifically, the study explores the idea that reverse tandem run followers are being shown a specific route to the home nest by a highly experienced and efficient leading ant. Ten colonies had migrations induced experimentally in order to generate some reverse tandem running activity. Once an RTR has been observed, the follower and leader were studied for behavior and their pathways were analyzed. It was seen that while RTR paths were quite efficient (1.4x a straight line distance), followers did not experience a statistically significant improvement in their pathways between the home and target nests (based on total distance traveled) when compared to similar non-RTR ants. Further, RTR leading ants were no more efficient than other non-RTR ants. It was observed that some followers began recruiting after completion of an RTR, but the number than changed their behavior was not significant. Thus, the results of this experiment cannot conclusively show that RTR followers are utilizing reverse tandem runs to improve their routes between the home and target nests.
A Guiding Hand: Grief Response in Young Adults works to guide young adults thought the grieving process after the traumatic death of a loved one. It goes through the steps of grieving and what a person can expect when they suddenly lose someone dear. Written from the point of view of someone who had lost their best friend in a murder/suicide, A Guiding Hand, shares a personal view that is often missing in other books on grief. This piece works to prepare other young adults for the unexpected emotions that are associated with grief. It also works to provide coping strategies to help recover from a traumatic loss in a healthy manner and to put people in touch with resources they may not know exist in order to help with healing.
There is growing concern among physicians, scholars, medical educators, and most importantly among patients, that science and technology have begun to eclipse fundamental attributes, such as empathy in the doctor-patient relationship. As a result, “humanism” in medicine has been a widely debated topic—how to define it, how to promote it, whether it can be taught, and how to qualify (much less quantify) its value in the practice of medicine. Through this research project I sought to better understand the role of humanities coursework in American medical school curricula, and determine whether there was a relationship between the integration of humanities coursework and the maintenance or enhancement of empathy levels in medical students. I reviewed literature with three objectives. (1) To better understand the influential social and political factors of pervasive reforms in US medical school curricula at the beginning of the 20th century, which led to science exclusive pedagogy in physician training (2) To become familiar with the works of iconic personalities in the history of American medical school pedagogy, paying special attention to attitudes and claims describing the role of humanities coursework, and the concept of humanism in the practice of medicine. (3) To observe the discourse underway across a variety of disciplines with regard to the current role of humanities coursework in medical curricula. My research shows that empathy is an essential attribute in the healing relationship, which benefits patients, physicians and improves health outcomes. Despite the importance of empathy, current physician training is documented as eroding empathy levels in medical students. Though the definition of ‘humanities’ in the context of medical school curricula remains vague and even contradictory, support for integration of humanities coursework is growing as an effective intervention for maintaining or enhancing levels of empathy.