Differences in Narrative Language in Evaluations of Medical Students by Gender and Under-represented Minority Status.

BACKGROUND: In varied educational settings, narrative evaluations have revealed systematic and deleterious differences in language describing women and those underrepresented in their fields. In medicine, limited qualitative studies show differences in narrative language by gender and under-represented minority (URM) status. OBJECTIVE: To identify and enumerate text descriptors in a database of medical student evaluations using natural language processing, and identify differences by gender and URM status in descriptions. DESIGN: An observational study of core clerkship evaluations of third-year medical students, including data on student gender, URM status, clerkship grade, and specialty. PARTICIPANTS: A total of 87,922 clerkship evaluations from core clinical rotations at two medical schools in different geographic areas. MAIN MEASURES: We employed natural language processing to identify differences in the text of evaluations for women compared to men and for URM compared to non-URM students. KEY RESULTS: We found that of the ten most common words, such as "energetic" and "dependable," none differed by gender or URM status. Of the 37 words that differed by gender, 62% represented personal attributes, such as "lovely" appearing more frequently in evaluations of women (p < 0.001), while 19% represented competency-related behaviors, such as "scientific" appearing more frequently in evaluations of men (p < 0.001). Of the 53 words that differed by URM status, 30% represented personal attributes, such as "pleasant" appearing more frequently in evaluations of URM students (p < 0.001), and 28% represented competency-related behaviors, such as "knowledgeable" appearing more frequently in evaluations of non-URM students (p < 0.001). CONCLUSIONS: Many words and phrases reflected students' personal attributes rather than competency-related behaviors, suggesting a gap in implementing competency-based evaluation of students. We observed a significant difference in narrative evaluations associated with gender and URM status, even among students receiving the same grade. This finding raises concern for implicit bias in narrative evaluation, consistent with prior studies, and suggests opportunities for improvement.

Sublimation of GeTe nanowires and evidence of its size effect studied by in situ TEM.

We report sublimation of crystalline GeTe nanowires at elevated temperatures in vacuum imaged by in situ transmission electron microscopy. The GeTe nanowires exhibit significant melting point suppression in the presence of Au contamination. A nanosized effusion cell is formed by coating the GeTe core with a SiO(2) shell, where the core can be evaporated or sublimated from the open end of the shell at high temperatures. By measuring the speed of the moving interface between the condensed and vapor phases, we determined the vaporization coefficient of these nanowires to be greater than or equal to approximately 10(-3) over a wide range of temperatures. At the final stage of the nanowire vaporization, the material loss occurs at a higher rate, which is evidence of a higher vaporization coefficient for nanosized GeTe. This in situ technique offers a quantitative method of investigating phase transition dynamics and kinetics of nanomaterials, an important topic for designing nanoscale devices to be operated at high temperatures such as phase change memory.

Effects of quantum confinement on the doping limit of semiconductor nanowires.

We have calculated the effects of quantum confinement on maximum achievable free carrier concentrations in semiconductor nanowires. Our calculations are based on the amphoteric defect model, which describes the thermodynamic doping limit in semiconductors in terms of the compensation of external dopants by native defects. We find that the generation of amphoteric native defects strongly limits maximum achievable carrier concentrations for nanowires with small widths where quantum confinement is appreciable. The magnitude of this effect in a given material is found to be determined by two material properties: the effective mass of the free carriers, and the position of the conduction (n-type) or valence band (p-type) edge on the absolute energy scale. These results offer a simple, predictive guideline for designing nanostructure devices and contacts where high doping levels are needed.