PubMed Health⌕ Search

Biomedical subjects

C Heffernan

Publications and source records attributed to C Heffernan.

7 recordsLinked to original sources
PubMed2000

Optimum pinch grips in the handling of dies.

Handling roller-press dies has caused numerous work-related musculoskeletal disorders in the leather industry. The dies are quite large (0.61 x 0.30 m), heavy (3.5 kg) and are difficult to handle because of the large pinch span requirements (up to 16 cm). The purpose of this study was to determine the optimum pinch span and optimum crossbar angulation to minimize die handling forces. Five-finger pulp-pinch forces were measured on five males and five females with a force-sensitive-resistor instrumented glove while handling a simulated adjustable die. Maximum pinch forces occurred at pinch spans between 1.27 and 3.81 cm, with average female strengths being 57% of average male pinch strengths. Minimum pinch forces to hold the die occurred at a 45 degrees angulation and increased linearly as the angle approached 90 degrees or the normal vertical orientation. The simplest solution to redesigning the dies is to: (1) decrease the distance between the braces to less than 4 cm and (2) slant the braces at 45 degrees.

Ergonomics↗
PubMed1997

Changes in gravity influence rat postnatal motor system development: from simulation to space flight.

Our research examines the role of the environment in postnatal nervous system development. Recently we have been studying the effects of changes in gravity on the motor system of rats from postnatal day (P) 2 to 31 using kinematic analysis of swimming, walking, and righting reflexes. Using the tail suspension model of weightlessness we identified sensitive and critical periods of motor system development corresponding to the time during which a motor skill is first achieved. Motor performance in suspended animals was marked by slow swimming, walking, and air-righting, all of which were characterized by hindlimb extension. (Walton et al, Neurosci. 52,763,1992). The critical periods identified in these studies contributed to determining the age of animals for a small payload, NIH.R3. This 9-day mission (STS-72) included 2 litters at P5, P7, or P15 at launch. The P7-16 and P15-24 groups were studied post-flight. On the landing day (R+0) surface righting, swimming and walking were slower in flight compared to control animals. Differences were more marked in the younger animals and the hindlimbs were more affected than the forelimbs with marked, prolonged extension of, at least, the ankle joint angle. Readaptation to 1G was slower in the P7-16 group with righting reflexes adapting first, walking last. We have shown that gravity is an important factor in postnatal nervous system development and that its affect depends on the age of the animal, duration of the perturbation, and the motor function studied.

Animals↗
PubMed1996

Haida perspectives on living with non-insulin-dependent diabetes.

OBJECTIVE: To understand the experience of Haida people living with non-insulin-dependent diabetes mellitus (NIDDM), in order to provide a basis for a culturally sensitive community-based approach to managing NIDDM. DESIGN: Qualitative study using grounded theory. SETTING: The villages of Skidegate and Old Massett in Haida Gwaii (Queen Charlotte Islands), British Columbia. PARTICIPANTS: Nine focus groups met at the beginning and six at the end of the project. The focus groups had 8 to 12 members each and roughly the same number of men and women overall. The groups included people with diabetes, family members of people with diabetes, community leaders and elders. FINDINGS: Conceptual findings related to the participants' views on the impact of NIDDM on their lives, their views on what life was like before the effects of NIDDM were felt and their beliefs about the prevention and treatment of NIDDM. Six themes recurred in the discussions: fear; grief and loss; the loss of and desire to regain control; food and eating; physical and personal strength; and traditional ways. CONCLUSIONS: Insights into the illness experience of different cultural groups can inform program development and the creation of culturally sensitive health care interventions.

Adult↗
PubMed1975

The sialic acid and carbohydrate content and the synthesis of glycoprotein from radioactive precursors by tissues of the normal and diseases upper intestinal tract.

The sialic acid and total hexose content of perorally obtained mucosal biopsies have been determined. Gastric mucosa has a higher content of sialic acid/mg protein and a lower content of total hexoses/mg protein than does jejunal mucosa. There were no differences chemically between gastric biopsies from subjects with or without peptic ulcers. Neither were there any differences between normal jejunal mucosa and jejunal mucosa from patients with untreated or treated coeliac disease. The studies of the incorporation of radioactive glucose into glycoprotein using all these tissues indicate that bacteria make a major in vitro contribution. This method is not suitable for study of de novo synthesis in either gastric or jejunal mucosa. Results are presented which suggest that bacteria may normally be present within the mucous layer of the stomach.

Adult↗