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Regulation of Seam Cell Function by the Non-Receptor Tyrosine Kinase, FRK-1, in C. elegans
No full textWe have characterized FRK-1, a homologue of the mammalian Fer non-receptor tyrosine kinase, and found it to be required for differentiation and maintenance of epithelial cell types, including the stem cell-like seam cells of the hypodermis. A genomic knockout of frk-1 (allele ok760) results in severely uncoordinated larvae that arrest at the L1 stage. Homozygous frk-1(ok760) larvae have an excess number of lateral hypodermal cells which appear to have lost asymmetry in the stem cell-like divisions of the seam cell lineage. frk-1(ok760) mutants immunostained with the epithelial adherens junction marker, MH27, show that the lateral hypodermal cells are abnormally shaped and smaller in size (during division), similar to the anterior daughter of a normal asymmetric seam cell division. Although we have observed an increase in seam cell nuclei using scm::GFP and elt-5::GFP (egl-18), we have also detected a general loss of alae formation. Crossing frk-1(ok760) with transgenic reporter lines containing non-seam hypodermal GFP markers, such as elt-3, and later markers such as col-19, show the lateral hypodermal cells do not precociously differentiate as adult-hyp7 cells. Interestingly, we have observed a significant change in the expression of key heterochronic regulators in frk-1(ok760) mutants, including up-regulation of let-7 and lin-4 and down-regulation of lin-14, lin-28, lin-41 and hbl-1. Finally, our data also show a clear role for FRK-1 in seam cell proliferation, as eliminating FRK-1 via RNAi during the L3-L4 transition results in supernumerary seam cell nuclei, that is dependent on asymmetric Wnt signaling. We are currently investigating the dependence on FRK-1 kinase activity and FRK-1 interactions in the nucleus during mitosis for the stem cell-like self-renewal exhibited by seam cells during post-embryonic development. Our data suggest a requirement for FRK-1 in maintaining the identity and proliferation of the asymmetric, stem-cell like state of the seam cells, thereby preventing precocious differentiation prior to adulthood
Radiation-Resistant Electrical Insulation Materials for Nuclear Reactors using Novel Nanocomposite Dielectrics
No full textRecently there has been renewed interest in nuclear reactor safety as commercial reactors approach 40 years of service and lifetime extensions are considered. Unfortunately, some of the current materials used as electrical cable insulators in these reactors are degrading more rapidly than anticipated. New polymer nanocomposites are of increasing interest as they can yield a material with the flexibility of a polymer, and improved thermal stability, mechanical stability and dielectric properties of the inorganic particles. We chose polyimide (PI) to investigate due to its well-known thermal and radiation properties. We prepared PI films with ceramic oxide dispersed nanoparticles. We confirmed particle dispersion by UV-Vis spectroscopy and performed dynamic mechanical analysis (DMA) to determine the PI material’s activation energy (Ea) and glass transition (Tg). Certain oxide nanoparticles had large effects on Ea and Tg for the PI films. The samples were analyzed post irradiation, using DMA and electrical breakdown techniques to determine if these polyimide films could be a new viable insulation material for nuclear reactors. Improved insulation materials will decrease reactor down time, decrease nuclear waste, and increase the overall lifetime of reactors
Community Involvement, Culture and Happiness
Get PDFResearch in positive psychology suggests that relationships and giving are key predictors of happiness across collectivist and individualist cultures (Myers, 1993 & Putnam, 2000), but little research has explored the impact of community involvement on happiness. The purpose of this study is to explore whether community involvement is more predictive of happiness in a collectivist nation (Lebanon), than an individualist nation (United States). The hypotheses of this study are that the level of happiness increases when there is more community involvement, and that community involvement will be a stronger predictor of happiness within the more collectivistic culture. In addition, we explore whether different motivations for community involvement might be differentially effective in increasing happiness. Results demonstrate that there are significant differences between the United States and Lebanon in the levels of participants’ happiness, community involvement, motivation for personal development, motivation for relationship development, motivation for volunteering, and enmeshment with community. ANOVA shows the average scores for United States participants are higher on all of these variables. Regression analyses reveal that the motivation for personal development is the best predictor of subjective happiness. The hypothesis that community involvement would be a stronger predictor of happiness in a collectivistic culture was not supported. This study is important because previous research has suggested that community involvement predicts happiness (Putnam, 2000), but it has not examined what motivations for community involvement actually improve happiness, or whether these relationships are consistent across cultures. This study raises new questions regarding previous research that identifies giving and relationships as predictors of happiness, given that in this study, community involvement and volunteering were not the best predictors of happiness. Rather, results revealed that community involvement was not as important to overall happiness as the motivation for why the individual chose to be involved with their respective community
Tutor Perceptions of Their Participation In the CASA Program: Qualitative Data Analysis
No full textThe present study collected survey data about tutors’ perceptions of their participation in the CASA program. Leaders in the Children’s After School Achievement (CASA) program sought data to inform and facilitate program improvement. The CASA program provides free after-school tutoring and other programs to benefit school-age, at-risk children. The CASA tutors provide tutoring services voluntarily, without pay. Nearly all of the CASA tutors are students enrolled in the local undergraduate college. Data collection was accomplished through the administration of an anonymous survey, created with input from CASA supervisors. The survey collected both quantitative and qualitative data. This report focuses on the qualitative data analysis, drawn from brief participant responses to ten open-ended questions that followed up initial responses, rated by participants using a Likert scale. Preliminary data analysis was focused by question and analyzed across all respondents to identify consistencies and differences. Major themes included that CASA tutors found benefits for themselves and the CASA students. Tutor benefits included personal growth and enjoyment, relationships with students and improved knowledge and skills for future career and educational endeavors. Student benefits included relationships with tutors and peers, enjoyable interactions and improved behavior, academic achievement, ability to focus and desire to learn. CASA tutors also identified challenges to program participation including the twice-weekly time commitment, concerns about their effectiveness in working with students and frustration with student’s sporadic attendance. Tutors also recommended shortening, revising and differentiating the current Life Skills content of the CASA Program to better meet student’s needs and interests
Feasibility of Surface Stimulation to Alleviate Phantom Limb Pain
No full textPhantom Limb Pain, a pain or discomfort in the missing limb, is experienced by 50-80% of amputees. A leading hypothesis suggests phantom limb pain is due to reorganization of the somotosensory cortex of the brain. Our working hypothesis states that by eliciting a “real” sensation in the phantom limb, the progression of cortical reorganization may be reduced or even reversed to decrease or eliminate phantom limb pain.
To obtain distal sensation in able-bodied subjects, the median and ulnar nerves were stimulated at the elbow using surface electrodes. A non-symmetric rectangular voltage controlled pulse train was created using optically isolated biostimulators and MATLAB software. The adaptive procedure Parameter Estimation by Sequential Testing (PEST) was used to determine threshold values for sensation in the hand. A strength-duration curve was found for both electrode positions to relate pulse width and threshold values for hand sensation. Stimulation was then sent at 25% and 75% of the subject’s voltage range at pulse widths of 50, 100, and 500µs. Data was collected on the magnitude, position, and type of sensation (prickly/buzzing/tapping…). Results showed that changing the amplitude and pulse width changed the magnitude of sensation, but did not change the position or type of sensation. Future work will include using different waveforms in order to vary the sensation. In addition, the effect of using an array of electrodes in order to vary the location of sensation in the hand will be investigated
Surface Stimulation to Alleviate Phantom Limb Pain: Current Control Waveform
No full textPhantom limb pain is a post-amputation phenomenon where an amputee experiences painful sensations in their missing limb. The cause of phantom limb pain may be cortical reorganization, which occurs when areas that controlled the missing limb are activated by adjacent areas of the cerebral cortex. This reorganization could result in painful sensations when an adjacent area is touched. By using electrical stimuli as a substitute for sensory input from the missing limb, cortical reorganization may be reversed and therefore provide some relief from phantom limb pain.
Previous studies by our group used voltage control stimulation while many other electrical stimulation applications used current control. The goal of this study was to compare the different sensations obtained between the two types of stimulation. The hand thresholds and maximum stimulation were determined to define the parameter space. Points within that area were tested at 100µs and 500µs pulse widths, all at 25%, 50%, and 75% of the range between the hand thresholds and maximum stimulation. These points were tested varying between current and voltage controlled stimulation. The type, magnitude, and location of sensation were recorded for each trial. Hand sensation and magnitude results were similar between the two types of stimulations; therefore voltage controlled stimulation will be used in future trials as there is less risk for painful sensation during testing
Cultural Exchange: The Story of William Angus and His Poetry
No full textFrom 1925-1952, William Angus served as a missionary for the Reformed Church of America in China’s Fujian province. During his time in China, Angus wrote over three hundred poems. When he returned back to the United States , he compiled the poems into five separate books, which, however, were never published. Angus’s poems are a valuable avenue to understanding his missionary experience, for they reveal his transition from one culture to another as well as his desire to fit into Chinese culture as a Western missionary. The poems also show how difficult it was to do this, and how missionaries brought their own culture into China. In Angus’s case, the poems show how natural it was for missionaries, and local Chinese, to notice the differences in one another. Angus’s poems also reveal the delicate nature of his American political power. More surprisingly, his poems show how the local Chinese used his American status to further their own ends. The too often one-sided analysis of foreign missionaries forcing culture onto the indigenous people is challenged through Angus’s poetry
The Validity of VO2max Testing Modalities in Running, Cycling and Swimming Populations
Get PDFWhile it is generally accepted that the treadmill and cycle ergometer are valid modalities of testing maximal oxygen uptake (VO2max) in athletes, the reasoning behind this assumption is largely unknown. Numerous studies have shown significant differences in VO2max between various athletic populations due to the demands of their sport and training habits. As a result of these variances, the question has been raised as to how valid testing results are for different modalities in various athletic populations. Therefore, the purpose of the research project will be to determine the validity of two VO2max testing modalities (treadmill and cycle ergometer) in swimming, running, and cycling populations. The main question this project aims to answer is which modality will provide a better measure of VO2max for swimmers based on the differences between a whole body workout (treadmill) and a region specific workout (cycling). Fifteen healthy, untrained, college-aged participants with experience in running, cycling or swimming took part in the study. Participants were randomized and completed two VO2max tests (treadmill and cycle ergometer) on separate occasions. Results from individual participants testing will be analyzed to determine differences between modalities. Participants will be grouped by history of running, cycling or swimming and then results will be analyzed to determine significant differences between groups. Results from testing are forthcoming
Predicting Insect Development in Changing Climates: Bean Beetle Phenology Modeling
No full textTraditional development models for poikilotherms assume that development rates depend on temperature, but do not allow rates to vary as an individual ages within a life stage. We designed experiments to test this assumption using bean beetles. Our hypothesis is that the time that bean beetle embryos are exposed to a period of higher or lower temperature will impact their development time. According to the age-independent model, embryos spending the same amount of time at each temperature, regardless of when they are exposed to those temperatures, will take the same amount of time to develop. Our preliminary results suggest that this is not the case, supporting the possibility of age-dependent aging
The Religious-Social Constraints on Sexuality in Fifth Century Athens and Crete and How They Manifest Themselves
No full textExperts in human sexuality have theorized that a person’s sexual orientation is the result of a number of biological and social factors. Our sexuality is partly determined by biology, but another component determines how that sexuality presents itself in society. For example, in our society, a homosexual cultural construct placed on heterosexual relationships creates: “bromances” and “girl crushes.” This is where men and women have intimate relationships with their same gender replacing physical intimacy with emotional. The main focus of this paper is to understand and probe the extent to which religious practice controlled, regulated, and determined sexual behavior in fifth century Athens and Crete. I will examine two main bodies of evidence: vase paintings and mythological literary texts. The vase paintings show scenes of pederastic relationships between men and young boys. The two myths of Zeus and Ganymede and Apollo and Hyacinthos depict pederastic relationships between the gods and young boys. I will use this to argue that the ancient Athenians used these myths as a model to express their sexuality in similar ways. Also, I will show that the Cretan rituals and Dionysian religious festivals were various manifestations of sexuality. My conclusion is that the Ancient Athenians and Cretans used the Gods and their religious festivals as anthropomorphic models for expressing their sexuality and those religious-social constraints on sexuality play a major role in the overall cultural shaping of sexuality. Through adducing myth as a viable model for sexual behavior and emphasizing religion as a major component in shaping sexuality, I add to existing analysis of sexuality from social theorists such as Michel Foucault