1025 research outputs found
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COMPARISON OF EMBRYONIC MALFORMATIONS AFTER FERTILIZATION WITH THALIDOMIDE-TREATED SPERM OR THALIDOMIDE TREATMENT IN CULTURE
No full textThalidomide\u27s mechanism of action as an infamous teratogen remains an unsolved mystery. The literature contains more than 30 theories explaining the human “thalidomide tragedy”. Studies continue to examine the mechanism(s) of action of this drug on both developing embryos and mammalian cells in culture. However, sperm-only exposure to thalidomide and the potential effects on embryonic development remain under research. Sea urchin embryos serve as model systems to study early development with thalidomide. We compared Lytechinus pictus embryos exposed to thalidomide in culture with embryos whose only thalidomide exposure resulted from fertilization with treated sperm. Additionally, we exposed embryos fertilized with thalidomide-treated sperm to thalidomide in the culture dishes as well. Spawning and fertilization followed standard sea urchin protocols. Aliquots of sperm; untreated, treated with seawater, DMSO or thalidomide (0.25nM) were incubated at 17°C for one hour. Thalidomide exposure in culture was 400µM. Examination of 100 embryos per treatment occurred at 24, 48, and 72-hour intervals. Caspase staining for apoptosis used CellEvent® Caspase-3/7 Green ReadyProbes® Reagent. Preliminary data at 48h indicated that fertilization with thalidomide-treated sperm resulted in the highest level of abnormalities, compared to either controls or embryos exposed only in culture. However, embryos fertilized with thalidomide-treated sperm and cultured with thalidomide exhibited more than additive numbers of abnormal embryos. Common malformations at 48 hours included embryonic development out of synchronization with controls, an overabundance of cells, and general aberrant morphology. Preliminary results suggest thalidomide exposure through sperm causes specific areas of cellular death in embryos, opposed to random apoptosis. Our findings indicate that the mode of embryo exposure to thalidomide affects the resulting observed malformations. These experiments suggest that the teratogenic potential of paternal exposure to thalidomide, with or without maternal exposure in humans, needs to be considered
Maximizing Efficiency of a Solar Panel
No full textSolar energy has been gaining more attention in recent years as a possible method to provide power to the United States with clean renewable energy. Currently, Photovoltaic (PV) devices, which are devices capable of harvesting solar energy such as solar cells, are being integrated into various applications such as powering homes, businesses, cars, and other everyday appliances. However, solar cells currently only have a maximum efficiency of converting ~34% of incident sunlight. Therefore, measures must be taken to optimally convert the output of solar panels to maintain its maximum efficiency. In this project, a solar panel is constructed utilizing devices such as a solar tracker and a Maximum Power Point Tracking (MPPT) charge converter that promote optimal energy conversion. The outputted energy of this system is measured and analyzed to determine the overall efficiency of the constructed solar panel and it’s potential to be used as a viable energy source
Ecological selection for small microbial genomes along a temperate-to-thermal soil gradient
No full textSmall bacterial and archaeal genomes provide insights into the minimal requirements for life(1) and are phylogenetically widespread(2). However, the precise environmental pressures that constrain genome size in free-living microorganisms are unknown. A study including isolates has shown that thermophiles and other bacteria with high optimum growth temperatures often have small genomes(3). It is unclear whether this relationship extends generally to microorganisms in nature(4,5) and more specifically to microorganisms that inhabit complex and highly variable environments, such as soils(3,6,7). To understand the genomic traits of thermally adapted microorganisms, here we investigated metagenomes from a 45 °C gradient of temperate-to-thermal soils that lie over the ongoing Centralia, Pennsylvania (USA) coal-seam fire. We found that hot soils harboured distinct communities with small genomes and small cell sizes relative to those in ambient soils. Hot soils notably lacked genes that encode known two-component regulatory systems, and antimicrobial production and resistance genes. Our results provide field evidence for the inverse relationship between microbial genome size and temperature in a diverse, free-living community over a wide range of temperatures that support microbial life. (1.) Hutchison, C. A. et al. Design and synthesis of a minimal bacterial genome. Science 351, aad6253 (2016). (2.) Hug, L. A. et al. A new view of the tree of life. Nat. Microbiol. 1, 16048 (2016). (3.) Sabath, N., Ferrada, E., Barve, A. & Wagner, A. Growth temperature and genome size in bacteria are negatively correlated, suggesting genomic streamlining during thermal adaptation. Genome Biol. Evol. 5, 966–977 (2013). (4.) Huete-Stauffer, T. M., Arandia-Gorostidi, N., Alonso-Sáez, L. & Morán, X. A. G. Experimental warming decreases the average size and nucleic acid content of marine bacterial communities. Front. Microbiol. 7, 730 (2016). (5.) Swan, B. K. et al. Prevalent genome streamlining and latitudinal divergence of planktonic bacteria in the surface ocean. Proc. Natl Acad. Sci. USA 110, 11463–11468 (2013). (6.) Brewer, T. E., Handley, K. M., Carini, P., Gilbert, J. A. & Fierer, N. Genome reduction in an abundant and ubiquitous soil bacterium ‘Candidatus Udaeobacter copiosus’. Nat. Microbiol. 2, 16198 (2016). (7.) Giovannoni, S. J., Thrash, J. C. & Temperton, B. Implications of streamlining theory for microbial ecology. ISME J. 8, 1553–1565 (2014)
Investigation of the Effect of Altering Residues on H2A.Z Deposition in Saccharomyces cerevisiae
No full textThere are numerous ways in which chromatin structure can be changed. Two of these mechanisms involve alteration of histones through post-translational modifications and additions of histone variants. These variants differ from canonical histones through their structure and function. The most abundant variant, H2A.Z, is a specialized form of the canonical histone H2A. H2A.Z containing nucleosomes are located near the telomeres of chromosomes. We believe that on this histone, the threonine 87 residue is phosphorylated post-translationally and has biological functionality. As a consequence of telomeric silencing, the ADE2 gene may or may not be expressed. We plan to use placement of ADE2 gene to test if telomeric silencing is abrogated in our mutant. This is associated to the placement and functionality of the H2A.Z histone variant. Both ChIP and telomeric silencing assays are used to detect the presence and placement of H2A.Z containing nucleosomes in T87 mutants of Saccharomyces cerevisiae
Effects of gestational protein restriction on brain reward system
No full textGestational environment impacts life-long offspring health, and it may influence offspring susceptibility to addiction. Lack of maternal protein intake during pregnancy perturbs physiological development, especially for the brain. Changes in brain development due to a poor maternal diet might increase susceptibility to addiction by affecting central reward systems. Tyrosine hydroxylase (TH), the rate limiting enzyme to produce dopamine, the primary reward neurotransmitter, is made in the ventral tegmental area (VTA) and is sent to the nucleus accumbens (NAcc). We hypothesize that gestational maternal protein restriction will influence offspring reward pathways in the brain. To test this hypothesis, we restricted maternal protein intake during gestation and examined offspring reward pathway TH expression. We expect that gestationally restricted offspring will exhibit reduced TH expression, indicative of a functional reward deficit, requiring offspring to consume greater quantities of rewarding substances to experience any kind of reward, thus increasing the risk of addiction
How Positive Feedback and Praise Affects My Teaching Practice
No full textThis presentation focuses on how providing positive feedback and praise in the classroom affects my teaching practice. Specifically, this will include forms of feedback and praise and how this affected myself. This topic was chosen in order to share important research that has been done and to see how, and if, positive feedback and praise affects my teaching practice
The Role of JNK in the Cleavage-Stage Development of Sea Urchin Embryos
No full textFertilization results in the rapid conversion of the egg from a non-dividing cell to an actively dividing zygote. We have been studying the role of a MAPK, c-jun N-terminal kinase (JNK) in activating the cell cycle in the fertilized sea urchin egg. Varying concentrations of the JNK-specific inhibitor SP600125 (0-5uM) were added to cultures immediately following fertilization and the number of embryos successfully progressing through the cell cycle to the 2-cell stage was determined. NucBlue was used to visualize the nuclei of the embryos, we observed multiple (2 or 4) nuclei in a small percentage of the inhibited embryos, suggesting that cytokinesis was inhibited but not nuclear division in these eggs. We are exploring the impact of JNK inhibition on specific steps required for successful division, including spindle formation, DNA replication, and cleavage furrow formation in order to determine the specific steps that require JNK activity
Paleoecological Analysis of Shell Hash Beds from the Trimmers Rock Formation (Upper Devonian- Frasnian) along Route 11-15
No full textShell beds from the Trimmers Rock Formation (Upper Devonian) along Rt 11-15 were compared to determine the controls acting on deposition of a prograding ramp. These shell beds are comprised of fossils that may have been strongly influenced by periodic high energy storm events, hypopycnal flows, and turbidity currents. The shell beds may have been deposited by the same regional events, and similar beds from nearby that were used to compare are laterally discontinuous and non-correlative. Along Rt 11-15, the rock is greenish gray, shale with laterally discontinuous thin beds of shaley sandstone that contain ripples, laminae, and shell beds. This succession is overlain by reddish-gray sandstone dominated by ball and pillow structures. This study focused on samples collected north of Liverpool, PA; the number of organisms were counted per unit cm2. Thin sections contain bryozoans, brachiopods, and crinoids with less abundant tentaculites, carbonized plant material, and fish bone
Understanding Veteran Homelessness: Does Improved Access Affect Veteran Homelessness?
No full textThe Veterans Affairs Health Administration is the largest integrated health care system in the United States. As such, it faces serious challenges in providing adequate accessibility to its health care resources. This research examines one aspect of accessibility, number of facilities, and its effect on veteran homelessness. The data is examined using U.S. Housing and Urban Development Continuums of Care (CoCs). These are designated areas across the U.S. that coordinate local, state, federal, and nonprofit homeless services in their selected area. The number of VA health facilities was compared with the share of veteran homelessness to total homelessness in a CoC. It was found that while the number of facilities does not seem to have an effect on veteran homelessness, a variety of other factors do seem to indicate where veteran homelessness may be higher
Traveling Into the Classroom
No full textThis poster presentation focuses on the importance of travel and how it can enhance the classroom experience including how teachers may use travel experiences in the classroom. This poster will focus on my personal travel experiences and how they influence my teaching practices. It will examine the positive attributes of travel and the benefits these experiences bring to the classroom. The presentation will include personal experiences of how my travel broadened my own learning