247 research outputs found
The Successful Characteristics That Contribute to Black Male Students Matriculating into Medical School
In 2019, individuals that identified as Black represented 13.4% of the U.S. population, 12.5% of the undergraduate student enrollment population and 7.1% of the medical school population. Subsequently, this has yielded a 5% Black physician population and workforce consisting of just 2.3% Black male physicians (AAMC, 2018). The disproportionately low Black physician representation contributes to greater healthcare disparity outcomes within the U.S. Black population. This study is centered on the post-positive characteristics of Black male medical students that have successfully overcome barriers to entry and matriculated into medical school. The phenomenological post-positive study was conducted through the lens of Self-Efficacy Theory and Critical Race Theory. This qualitative study utilizes a phenomenological approach and semi-structured interviews to collect the steep, rich-lived experiences of the participants (Siedman, 1991). A purposive sampling and snowballing sampling methodology was used to acquire a six-participant sample population of Black male medical students. An in-depth review of the data revealed seven emerging themes associated with Black male students overcoming barriers to matriculate into medical school: 1) Educational Cost, 2) Honors College, 3) Motivation, 4) Support, 5) Academic Excellence, 6) Diversity and Inclusion, and 7) AMCAS Application Process. Higher education institutions, higher education practitioners and Black male premedical students would benefit from the findings outlined in the study. Future research should center on comparative studies focused on the role of the honors college, PWI and HBCU medical institutions and cultural variances among Black subcultures
Infrared Observations During the Secondary Eclipse of HD 209458b: I. 3.6-Micron Occultation Spectroscopy Using the VLT
We search for an infrared signature of the transiting extrasolar planet HD
209458b during secondary eclipse. Our method, which we call `occultation
spectroscopy,' searches for the disappearance and reappearance of weak spectral
features due to the exoplanet as it passes behind the star and later reappears.
We argue that at the longest infrared wavelengths, this technique becomes
preferable to conventional `transit spectroscopy'. We observed the system in
the wing of the strong nu-3 band of methane near 3.6 microns during two
secondary eclipses, using the VLT/ISAAC spectrometer at a spectral resolution
of 3300. Our analysis, which utilizes a model template spectrum, achieves
sufficient precision to expect detection of the spectral structure predicted by
an irradiated, low-opacity (cloudless), low-albedo, thermochemical equilibrium
model for the exoplanet atmosphere. However, our observations show no evidence
for the presence of this spectrum from the exoplanet, with the statistical
significance of the non-detection depending on the timing of the secondary
eclipse, which depends on the assumed value for the orbital eccentricity. Our
results reject certain specific models of the atmosphere of HD 209458b as
inconsistent with our observations at the 3-sigma level, given assumptions
about the stellar and planetary parameters.Comment: 26 pages, 8 figures Accepted to Astrophysical Journa
Cubic lead perovskite PbMoO3 with anomalous metallic behavior
A previously unreported Pb-based perovskite PbMoO is obtained by
high-pressure and high-temperature synthesis. This material crystallizes in the
cubic structure at room temperature, making it distinct from
typical Pb-based perovskite oxides with a structural distortion. PbMoO
exhibits a metallic behavior down to 0.1 K with an unusual -sub linear
dependence of the electrical resistivity. Moreover, a large specific heat is
observed at low temperatures accompanied by a peak in around 10 K, in
marked contrast to the isostructural metallic system SrMoO. These transport
and thermal properties for PbMoO, taking into account anomalously large Pb
atomic displacements detected through diffraction experiments, are attributed
to a low-energy vibrational mode, associated with incoherent off-centering of
lone pair Pb cations. We discuss the unusual behavior of the electrical
resistivity in terms of a polaron-like conduction, mediated by the strong
coupling between conduction electrons and optical phonons of the local
low-energy vibrational mode.Comment: 5 pages, 5 figure
Value of a small control group for estimating intervention effectiveness: results from simulations of immunization effectiveness studies
To improve evidence for public health practice, the conduct of effectiveness studies by practitioners is needed and may be stimulated if knowledge that smaller than usual samples may provide the same reliability of intervention effect size as larger samples
Characterization of chilling-shock responses in four genotypes of Miscanthus reveals the superior tolerance of M. Ă— giganteus compared with M. sinensis and M. sacchariflorus
Abstract
Background and Aims
The bioenergy grass Miscanthus is native to eastern Asia. As Miscanthus uses C4 photosynthesis, the cooler temperatures experienced in much of northern Europe are expected to limit productivity. Identification of genetic diversity in chilling tolerance will enable breeders to generate more productive varieties for these cooler regions. Characterizing the temporal relationships between photosynthesis, carbohydrate and molecular expression of relevant genes is key to understanding genotypic differences in tolerance or sensitivity.
Methods
To characterize chilling responses in four Miscanthus genotypes, plants were exposed to a sudden reduction in temperature. The genotypes studied comprised of two M. sinensis, one M. sacchariflorus and one inter-species hybrid, M. Ă— giganteus. Changes in photosynthesis (Asat), carbohydrate composition and the expression of target transcripts were observed following chilling-shock. After 4 d the decline in leaf elongation rate (LER) in the different genotypes was measured.
Results
Following chilling-shock the greatest decline in Asat was observed in M. sacchariflorus and one M. sinensis genotype. Carbohydrate concentrations increased in all genotypes following chilling but to a lesser extent in M. sacchariflorus. Two stress inducible genes were most highly expressed in the genotypes that experienced the greatest declines in Asat and LER. Miscanthus × giganteus retained the highest Asat and was unique in exhibiting no decline in LER following transfer to 12 °C.
Conclusions
Miscanthus Ă— giganteus exhibits a superior tolerance to chilling shock than other genotypes of Miscanthus. The absence of sucrose accumulation in M. sacchariflorus during chilling-shock suggests an impairment in enzyme function. A candidate transcription factor, MsCBF3, is most highly expressed in the most sensitive genotypes and may be a suitable molecular marker for predicting chilling sensitivity
Coopetition: cooperation among competitors to enhance applied research and drive innovation in elite sport
Anti-metastatic Inhibitors of Lysyl Oxidase (LOX): Design and Structure-Activity Relationships
Lysyl oxidase (LOX) is a secreted copper-dependent amine oxidase that crosslinks collagens and elastin in the extracellular matrix (ECM) and is a critical mediator of tumor growth and metastatic spread. LOX is a target for cancer therapy and thus the search for therapeutic agents against LOX has been widely sought. We report herein the medicinal chemistry discovery of a series of LOX inhibitors bearing an aminomethylenethiophene (AMT) scaffold. High throughput screening (HTS) provided the initial hits. Structure-activity relationship (SAR) studies led to the discovery of AMT inhibitors with sub-micromolar half maximal inhibitory concentrations (IC50) in a LOX enzyme activity assay. Further SAR optimisation yielded the orally bioavailable LOX inhibitor CCT365623 with good anti-LOX potency, selectivity, pharmacokinetic properties, as well as anti-metastatic efficacy
flowLearn: Fast and precise identification and quality checking of cell populations in flow cytometry
Lux M, Brinkman RR, Chauve C, et al. flowLearn: Fast and precise identification and quality checking of cell populations in flow cytometry. Bioinformatics. 2018;34(13):2245-2253.Motivation
Identification of cell populations in flow cytometry is a critical part of the analysis and lays the groundwork for many applications and research discovery. The current paradigm of manual analysis is time consuming and subjective. A common goal of users is to replace manual analysis with automated methods that replicate their results. Supervised tools provide the best performance in such a use case, however they require fine parameterization to obtain the best results. Hence, there is a strong need for methods that are fast to setup, accurate and interpretable.
Results
flowLearn is a semi-supervised approach for the quality-checked identification of cell populations. Using a very small number of manually gated samples, through density alignments it is able to predict gates on other samples with high accuracy and speed. On two state-of-the-art data sets, our tool achieves median(F1)-measures exceeding 0.99 for 31%, and 0.90 for 80% of all analyzed populations. Furthermore, users can directly interpret and adjust automated gates on new sample files to iteratively improve the initial training
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