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Biomedical subjects

V C Smith

Publications and source records attributed to V C Smith.

At least 127 records · Page 7Linked to original sources

Chromatic two-pulse resolution with and without luminance transients.

Two-pulse discrimination thresholds determined for homochromatic pulses presented as luminance increments or decrements are invariant with wavelength. Wavelength does affect two-pulse temporal resolution if chromatic pulses are presented in hue substitution, matched in luminance (with flicker photometry) to an achromatic background field. For relatively long pulses, the wavelength effect resembles trichromatic saturation discrimination, with poorest temporal resolution at 570 nm. For shorter pulses, temporal resolution for hue substitution stimuli appears related to saturation discrimination under conditions of artificial tritanopia. Under conditions of hue substitution, short-wavelength pulses yield good temporal resolution.

Color↗

Growth promotion by homocysteic acid.

Homocysteic acid, H03SCH2CH2CHNH2CO2H, promotes growth of hypophysectomized rats, assayed by observation of increased thickness of epiphyseal cartilage of the tibia and by observation of tail growth. Doses of homocysteic acid as low as 1 microgram per day for 4 days in the tibia assay and 2.5 milligrams per kilogram per day for 5 weeks in the tail assay were effective in promoting growth. Serum somatomedin activity, determined by the porcine cartilage disk assay, was also increased by homocysteic acid. These findings relate an area of sulfur amino acid metabolism to the physiological action of growth hormone, accelerated growth in homocystinuria, initiation of arteriosclerosis, and control of cellular growth.

Animals↗

Effect of field size on red--green color mixture equations.

Red-green color mixture equations were measured in 10 color-normal observers for fields of view varying from 30' to 10 degrees. The G/R mixture decreases continuously as field size is increased. The data are consistent with the interpretation that the cone visual photopigments decrease exponentially in effective optical density as the field size is increased.

Adult↗

Recruitment and progress of minority medical school entrants 1970-1972.

This is a report on a national study of minority group applicants and entrants to the 1970, 1971, and 1972 entering classes of U.S. medical colleges. The aim of the investigation was to further understanding of the factors involved in attempting to increase minority representation in education for the practice of medicine. Data from the Association of American Medical Colleges are used to examine characteristics of successful and unsuccessful minority applicants to medical school. Socieconomic, personal, institutiona, and geographical factors that relate to the recruitment and progress of minority students in medicine are analyzed and evaluated. Differences between Caucasian and minority group students affecting admissions, retention, and promotion are documented. The investigators also compare the projections of a 1970 AAMC task force report with actual occurrences in the national effort to expand educational opportunities in medicine for blacks and other underrepresented minority students (that is, American Indians, Mexican Americans, and mainland Puerto Ricans). This comparison shows substantial progress toward the projected figures but a need for renewed commitment if they are to be reached. Suggestions are offered for improving the recruitment and progress of minority medical school entrants by such means as the AAMC Simulated Minority Admissions Exercises and by ongoing programs at individual medical schools. The study also yielded such pertinent findings as the following: 1. Confirmation that the racial characterizations self-reported by medical school applicants have a high degree of accuracy and an increasing degree of completeness. 2. An encouraging increase in the number of black premedical students who will potentially apply for the medical school classes entering in 1976 and 1977. 3. Growth in the enrollment of low-income medical students, most of it explained by the increase in the numbers of minority group members who have been admitted in recent years. 4. More mobility among blacks than Caucasians with regard to attending medical schools in other than their region of legal residence. 5. A higher proportion of women, of older, and of married students among minority medical school matriculants than among Caucasian matriculants. 6. A slightly higher medical school retention rate for Caucasians than for students from underrepresented minority groups, possibly explained in part by the greater diversity in the socioeconomic and educational backgrounds of the latter. 7. A positive relationship for blacks between the size of undergraduate college attended and successful completion of the first year of medical school.

Black or African American↗