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Biomedical subjects

A S Ryan

Publications and source records attributed to A S Ryan.

66 records · Page 4Linked to original sources

Nutrient intake in the United States during the first 12 months of life.

Nutrient intakes of 463 infants ranging in age from 1 week to 12 months from the Nationwide Food Consumption Survey 1977-78 were evaluated according to different foods (milk and milk products, noniron-fortified formula, iron-fortified formula, infant cereal, commercial baby foods, and table foods). Breast-fed infants and infants fed a combination of cow's milk and formula were excluded. Results indicated that iron was the nutrient most often consumed in amounts less than the RDA. Infants fed a diet that included either cow's milk or noniron-fortified formula had a median iron intake less than the recommended allowance. In comparison, infants who were fed an iron-fortified formula had a median iron intake well above the RDA. The relative proportion of iron derived from different foods is discussed.

Animals↗

Differential fatness gain of low income boys and girls.

As shown in 564 girls and 553 boys followed for a period of 18 yr, long-term gain in both subscapular and triceps skinfold thickness was higher in children of lower family income level than those of higher family incomes. This differential fatness gain accounts for the socioeconomic "reversal" of fatness in the female shown in cross-sectional studies and newly extends the phenomenon to both sexes. The finding that low-income children show a greater long-term increase in fatness bears on the prevention and control of obesity.

Adipose Tissue↗

Income matched black-white hemoglobin differences after correction for low transferrin saturations.

As shown in 3321 age-matched pairs of black and white participants in the National Health and Nutrition Examination Surveys (NHANES I) the magnitude of difference in hemoglobin approximates 0.73 g/dl both before and after exclusion of low transferrin saturation values (i.e., equal to or less than 15%). These new income-matched, age-matched comparisons of individuals of the same sex provide a useful estimate of the magnitude of the hemoglobin difference between American blacks and whites.

Adolescent↗

Suggested sex and age appropriate values for "low" and "deficient" hemoglobin levels.

New values for "deficient" and "low" Hb have been calculated as the smoothed 5th and the 15th percentiles for white males and females included in the National Health and Nutrition Examination Survey (NHANES I). With separate tabulations for 18.389 white individuals contained in this data base and for 12,320 with transferrin saturation values of 16% and above, these new values have the advantage of being fully age-specific, based upon a single source of hematological data and providing quantitative definitions of "low" and "deficient."

Adolescent↗

Wear striation direction on primate teeth: a scanning electron microscope examination.

Two experimental methods were used to produce wear striations in one direction on unworn teeth. These include: (1) sliding 22 American Indian (Juntunen site, Michigan; Late Woodland) newly erupted incisors, by hand, across a flat grass surface covered with fine loose sand; and (2) using a unidirectional motor driven mechanical wear machine to draw 56 modern human dental extractions across a flat glass surface covered with silicon carbide powder of different grit sizes. A scanning electron microscope examination of individual wear striation morphology indicates that these wear striations begin with broad pits and have extending grooves that become narrower; characteristics that indicate the motion of wear. Patterns of wear striations on the worn dentitions of American Indians (Juntunen site) and the paleocene primate Phenacolemur pagei show similar characteristics and correspond to the buccal phase of mastication when the mandible is drawn upward, forward and slightly medially into centric occlusion. The data provided by this study can be used to test competing hypotheses concerning the direction of mandibular movement during mastication and food preparation.

Animals↗

A preliminary scanning electron microscope examination of wear striation direction on primate teeth.

Wear striations experimentally produced on initially unworn teeth were examined at high magnification using a scanning electron microscope. Certain characteristics of individual wear striations on these teeth indicate the direction of motion that produced them. Other striations on worn teeth of American Indians and the Paleocene primate Phenocolemur show similar characteristics and correspond to mandibular movement during mastication.

Animals↗