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Biomedical subjects

F L Collins

Publications and source records attributed to F L Collins.

At least 37 records · Page 2Linked to original sources
PubMed1988

Plasma concentrations of FSH, LH and progesterone in sheep immunized against an androstenedione-protein conjugate.

A significant increase in the plasma concentrations of FSH (P less than 0.05) and LH (P less than 0.001) was observed during the luteal (Days 9-11) phase but not during the subsequent cloprostenol-induced follicular phase in androstenedione-immunized ewes compared to those in control ewes. Over the same time period the geometric mean (and 95% confidence limits) androstenedione antibody titres in the immunized ewes was 1/305 (1/158, 1/590) whereas they were not detectable in the controls. In the subsequent cycle, the ovulation rates were 1.6 +/- 0.2 for the immunized ewes and 1.1 +/- 0.1 for the control ewes (P less than 0.05) and the luteal progesterone concentrations were significantly higher in the immunized ewes compared to the controls (P less than 0.01). Collectively, these results suggest that active immunization against androstenedione leads to an increase in the plasma concentrations of both FSH and LH. The results are consistent with the hypothesis that FSH plays a central role in determining the ovulation rate in sheep.

Androstenedione↗
PubMed1986

The effects of behavioral vision training on multiple aspects of visual functioning in myopic adults.

Twenty myopic adults were randomly assigned to either a behavioral visual acuity training program or to a no-treatment control group in order to assess changes in several aspects of visual behavior. Measures were obtained both pre- and posttraining for a number of variables. These included recognition and resolution visual acuity, contrast sensitivity, perceived clarity and confidence of responses, and stimulus duration. Results indicated that training subjects significantly improved on all three measures of visual acuity: recognition acuity, resolution acuity, and contrast sensitivity. Improvements in acuity were associated with significant improvements in the perceived clarity of the stimuli but not in the confidence of the subject's response. These data expand our knowledge concerning the effectiveness of behavioral training programs in improving visual acuity in myopia. The potential utility of such programs is discussed.

Behavior Therapy↗
PubMed1986

Using reinforcement and cueing to increase healthy snack food choices in preschoolers.

We examined the effects of behavioral procedures to modify the food choices of preschoolers during a snack period at school (training setting) and at home (generalization setting). In the first experiment, we evaluated the usefulness of nutrition training and a generalization programming strategy of cueing to improve healthy snacking; in the second experiment we investigated the effect of nutrition training alone. In addition, three cases are presented that illustrate individualized procedures to facilitate generalization of healthy snacking to home. Results indicated that children's healthy snack choices increased in the preschool training setting, that generalization to home was achieved only when procedures to program it were implemented, and that the best results were found when the generalization procedures were tailored to the individual child.

Child, Preschool↗
PubMed1985

Single-subject research designs for optometry.

Single-subject research designs are used extensively in the fields of education and psychology. There are many advantages of these designs over traditional group designs and they appear particularly important for applied research in optometry. An overview of the basic designs is presented. For each type of design, examples are provided that illustrate the application of this methodology to applied optometric research.

Feedback↗
PubMed1981

Behavioral contracting to improve dietary compliance in chronic renal dialysis patients.

End stage renal disease is the most severe stage of kidney failure. Hemodialysis or kidney transplants are required to insure patient survival. When dialysis treatment is used, patients experience dietary restrictions and consequently must limit fluid and food intake to compensate for the lack of kidney functioning. Two case studies are presented to demonstrate the effectiveness of behavioral procedures in improving compliance to dietary restrictions in chronic fluid overloaders. A contracting procedure between medical staff and the patients, and contingent staff praise for meeting weight standards, led to lower intersession weight gain. Continuous follow-up assessment indicated long term maintenance of treatment effects for these patients.

Aged↗
PubMed1978

Fading and feedback in the modification of visual acuity.

Two experiments assessing the modification of visual acuity by fading plus feedback procedures are presented. The training procedure involved a gradual increase of the distance myopic subjects could accurately discriminate letters requiring a minimum of 20/20 vision at approximately 23 feet. In Experiment I experimental and matched control groups of mildly to moderately myopic subjects were compared on repeated Ortho-rater examinations of visual acuity. The experimental group showed a significant improvement relative to the control group who received no training. Multiple-baseline across-stimuli designs were used in Experiment II to evaluate training effects for another group of subjects with moderate to severe myopia. Two measures of acuity were obtained. Accuracy of discrimination of letters at various preselected distances was determined each session while Ortho-rater examinations were given periodically throughout training. Changes in discrimination accuracy over sessions appeared to be related to fading for three of the four subjects, and Ortho-rater acuity changes were observed for each subject. Some short-term maintenance of improved vision was evident on both acuity measures.

Accommodation, Ocular↗