Studying the Graduate Record Examinations\u27 Ability to Predict Student Success as Measured by Graduate Grade Point Averages

The Graduate Record Examination (GRE) is the most widely used graduate level admission test in the world, yet conflicts exist across the findings of many studies of the ability of the GRE to predict the success test takers will have as graduate students or in professional life. Additionally, most of the studies that exist on the GRE’s ability to predict graduate student success use data from a previous version of the GRE that may not be applicable to the current version, thus rendering their use for policy making among makers of admission decisions limited and flawed. These studies also tend to focus on one specific degree program or type of degree, leaving no guidance for how the GRE might be useful for other programs. In an attempt to provide a basis from which more comprehensive analyses can be modeled in the future, this quantitative study examines how well the three sections of the GRE predict success for graduate students at the University of Kentucky (UK), using the Graduate Grade Point Averages (GGPA) of 2,349 active graduate students in degree seeking programs as a measure of intermediate success, as is common practice in the literature. Two linear regressions are reported, one which includes only UK graduate students in non-STEM programs, and one which includes only UK graduate students in STEM programs. STEM or non-STEM is used to separate these students from one another because it allows an overall picture of how GREs might be useful for admission decisions at UK while still providing results that can be relevant to programs with key differences, as “the economic and social benefits of scientific thinking and STEM education are widely believed to have broad application for workers in both STEM and non-STEM occupations” (Gonzalez and Kuenzi 2012). Results show that the three sections of the GRE General Test are predictors of success for non-STEM graduate students at UK, while two of the three (Verbal and Quantitative Reasoning) are predictors of success for STEM students. Further, the Verbal Reasoning section is a better predictor of success for non-STEM students than for STEM students, while the Quantitative Reasoning section is a better predictor for STEM students than non-STEM students. The Analytical Reasoning section is found to predict success only for non-STEM students. These findings do not evaluate whether GRE scores are the best way of predicting the success of graduate students, nor should they be used exclusively to make admission decisions for applicants to an academic program. Instead, it is recommended that GRE scores be used as a portion of a holistic review of such applications, a recommendation which the owners of the GRE also make. According to some of the literature, the GRE puts some minorities and women at a disadvantage for admission to graduate programs. With this in mind, other studies have found the undergraduate GPA of a student is the best predictor of how well they will do in a graduate program, thus it is recommended that programs considering revision of their policies concerning GRE requirements for admission offer waivers for students that have or exceed an undergraduate GPA they deem appropriate to succeed in their program in lieu of removing an existing requirement for the purposes of increasing diversity or attracting more students. Additionally, programs without GRE requirements should consider adding it to the list of what an applicant needs for admission (with or without waivers), as it provides a standardized score that can assist in gauging the cognitive abilities and potential successes of its takers. Lastly, programs that do have GRE requirements and are classified as STEM should place more emphasis on the Quantitative section of the GRE than the others, while non-STEM programs should do the opposite

Oxygen isotopic composition of carbon dioxide in the middle atmosphere

The isotopic composition of long-lived trace molecules provides a window into atmospheric transport and chemistry. Carbon dioxide is a particularly powerful tracer, because its abundance remains >100 parts per million by volume (ppmv) in the mesosphere. Here, we successfully reproduce the isotopic composition of CO2 in the middle atmosphere, which has not been previously reported. The mass-independent fractionation of oxygen in CO2 can be satisfactorily explained by the exchange reaction with O(1D). In the stratosphere, the major source of O(1D) is O3 photolysis. Higher in the mesosphere, we discover that the photolysis of 16O17O and 16O18O by solar Lyman-{alpha} radiation yields O(1D) 10–100 times more enriched in 17O and 18O than that from ozone photodissociation at lower altitudes. This latter source of heavy O(1D) has not been considered in atmospheric simulations, yet it may potentially affect the "anomalous" oxygen signature in tropospheric CO2 that should reflect the gross carbon fluxes between the atmosphere and terrestrial biosphere. Additional laboratory and atmospheric measurements are therefore proposed to test our model and validate the use of CO2 isotopic fractionation as a tracer of atmospheric chemical and dynamical processes

Engineered single nucleotide polymorphisms in the mosquito MEK docking site alter Plasmodium berghei development in Anopheles gambiae.

BackgroundSusceptibility to Plasmodium infection in Anopheles gambiae has been proposed to result from naturally occurring polymorphisms that alter the strength of endogenous innate defenses. Despite the fact that some of these mutations are known to introduce non-synonymous substitutions in coding sequences, these mutations have largely been used to rationalize knockdown of associated target proteins to query the effects on parasite development in the mosquito host. Here, we assay the effects of engineered mutations on an immune signaling protein target that is known to control parasite sporogonic development. By this proof-of-principle work, we have established that naturally occurring mutations can be queried for their effects on mosquito protein function and on parasite development and that this important signaling pathway can be genetically manipulated to enhance mosquito resistance.MethodsWe introduced SNPs into the A. gambiae MAPK kinase MEK to alter key residues in the N-terminal docking site (D-site), thus interfering with its ability to interact with the downstream kinase target ERK. ERK phosphorylation levels in vitro and in vivo were evaluated to confirm the effects of MEK D-site mutations. In addition, overexpression of various MEK D-site alleles was used to assess P. berghei infection in A. gambiae.ResultsThe MEK D-site contains conserved lysine residues predicted to mediate protein-protein interaction with ERK. As anticipated, each of the D-site mutations (K3M, K6M) suppressed ERK phosphorylation and this inhibition was significant when both mutations were present. Tissue-targeted overexpression of alleles encoding MEK D-site polymorphisms resulted in reduced ERK phosphorylation in the midgut of A. gambiae. Furthermore, as expected, inhibition of MEK-ERK signaling due to D-site mutations resulted in reduction in P. berghei development relative to infection in the presence of overexpressed catalytically active MEK.ConclusionMEK-ERK signaling in A. gambiae, as in model organisms and humans, depends on the integrity of conserved key residues within the MEK D-site. Disruption of signal transmission via engineered SNPs provides a purposeful proof-of-principle model for the study of naturally occurring mutations that may be associated with mosquito resistance to parasite infection as well as an alternative genetic basis for manipulation of this important immune signaling pathway

FeCl\u3csub\u3e2\u3c/sub\u3e-Mediated Rearrangement of Allylic Alcohols

A mild, one-pot procedure to produce 3-substituted allylic alcohols from α,β-unsaturated ketones is described. The addition of an organolithium nucleophile produces a tertiary allylic alcohol as an intermediate, which undergoes a 1,3-OH-migration assisted by FeCl2. The proposed mechanism indicates that a syn-facial migration occurs for the major product. Yields as high as 98% for the one-pot reaction are reported

Assessment of the cross-protective capability of recombinant capsid proteins derived from pig, rat, and avian hepatitis E viruses (HEV) against challenge with a genotype 3 HEV in pigs

Hepatitis E virus (HEV), the causative agent of hepatitis E, is primarily transmitted via the fecal-oral route through contaminated water supplies, although many sporadic cases of hepatitis E are transmitted zoonotically via direct contact with infected animals or consumption of contaminated animal meats. Genotypes 3 and 4 HEV are zoonotic and infect humans and other animal species, whereas genotypes 1 and 2 HEV are restricted to humans. There exists a single serotype of HEV, although the cross-protective ability among the animal HEV strains is unknown. Thus, in this study we expressed and characterized N-terminal truncated ORF2 capsid antigens derived from swine, rat, and avian HEV strains and evaluated their cross-protective ability in a pig challenge model. Thirty, specific-pathogen-free, pigs were divided into 5 groups of 6 pigs each, and each group of pigs were vaccinated with 200 µg of swine HEV, rat HEV, or avian HEV ORF2 antigen or PBS buffer (2 groups) as positive and negative control groups. After a booster dose immunization at 2 weeks post-vaccination, the vaccinated animals all seroconverted to IgG anti-HEV. At 4 weeks post-vaccination, the animals were intravenously challenged with a genotype 3 mammalian HEV, and necropsied at 4 weeks post-challenge. Viremia, fecal virus shedding, and liver histological lesions were compared to assess the protective and cross-protective abilities of these antigens against HEV challenge in pigs. The results indicated that pigs vaccinated with truncated recombinant capsid antigens derived from three animal strains of HEV induced a strong IgG anti-HEV response in vaccinated pigs, but these antigens confer only partial cross-protection against a genotype 3 mammalian HEV. The results have important implications for the efficacy of current vaccines and for future vaccine development, especially against the novel zoonotic animal strains of HEV

Metaglue : a programming language for multi-agent systems

Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 83-84).by Brenton A. Phillips.S.B.and M.Eng

SPARC regulates transforming growth factor beta induced (TGFBI) extracellular matrix deposition and paclitaxel response in ovarian cancer cells

TGFBI has been shown to sensitize ovarian cancer cells to the cytotoxic effects of paclitaxel via an integrin receptor-mediated mechanism that modulates microtubule stability. Herein, we determine that TGFBI localizes within organized fibrillar structures in mesothelial-derived ECM. We determined that suppression of SPARC expression by shRNA decreased the deposition of TGFBI in mesothelial-derived ECM, without affecting its overall protein expression or secretion. Conversely, overexpression of SPARC increased TGFBI deposition. A SPARC-YFP fusion construct expressed by the Met5a cell line co-localized with TGFBI in the cell-derived ECM. Interestingly, in vitro produced SPARC was capable of precipitating TGFBI from cell lysates dependent on an intact SPARC carboxy-terminus with in vitro binding assays verifying a direct interaction. The last 37 amino acids of SPARC were shown to be required for the TGFBI interaction while expression of a SPARC-YFP construct lacking this region (aa 1–256) did not interact and co-localize with TGFBI in the ECM. Furthermore, ovarian cancer cells have a reduced motility and decreased response to the chemotherapeutic agent paclitaxel when plated on ECM derived from mesothelial cells lacking SPARC compared to control mesothelial-derived ECM. In conclusion, SPARC regulates the fibrillar ECM deposition of TGFBI through a novel interaction, subsequently influencing cancer cell behavior

Larval Duration, Settlement, and Larval Growth Rates of the Endangered Tidewater Goby (Eucyclogobius newberryi) and the Arrow Goby (Clevelandia ios) (Pisces, Teleostei)

The early life history of the federally endangered tidewater goby (Eucyclogobius newberryi) and its sister species the arrow goby (Clevelandia ios) has been poorly documented to date. Both are endemic to estuarine habitats throughout the California coast, however, habitat use differs between these two species. The arrow goby is commonly found in fully marine tidal bays and mudflats. The tidewater goby, however, prefers lagoons with some degree of seasonal isolation from the sea. Here, we used otoliths to examine the larval duration, size at settlement, and growth rates of newly settled gobies collected from 18 estuaries in California. The tidewater goby had a larval duration that was ~2 days shorter than the arrow goby (23.95 vs. 26.11 days, respectively), but a larger size at settlement based on back-calculated size (12.38 vs. 10.00 mm SL) due to a faster larval growth rate (2.86 vs. 2.60 μm/day-1). There are several reasons that could explain these differences in larval traits, such as differences in temperature or food resources between the two estuary types, or the faster, annual life cycle of the tidewater goby relative to the arrow goby