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Biomedical subjects

J J Dwyer

Publications and source records attributed to J J Dwyer.

8 recordsLinked to original sources
PubMed1999

Self-efficacy and participation in vigorous physical activity by high school students.

The relationship between physical activity self-efficacy and participation in vigorous physical activity by high school students is examined in this article. Self-efficacy is hypothesized to be positively related to participation in three settings (physical education class, other school-related activities, and outside of school). The effects of age, gender, perceived barriers, and actual barriers are also examined. The sample consists of 1,041 grade 9 and 11 students from a large Metropolitan Toronto school board. Factors derived from a previous (factor) analysis were used to examine the effects of self-efficacy, perceived barriers, and life strain (an actual barrier). The results of multiple regression analysis indicate that physical activity self-efficacy, despite external barriers (but not internal barriers), is predictive of physical activity participation in the hypothesized direction. Other results show consistent age and gender effects on physical activity participation and some support for the hypothesized relationship between perceived barriers and participation.

Adolescent↗
PubMed1998

Internal structure of a measure of self-efficacy in physical activity among high school students.

The preliminary development of a measure of self-efficacy to participate in vigorous physical activity when confronted with specific perceived barriers to physical activity is described. Measures used in previous research ([Hofstetter, C.R., Hovell, M.F., Sallis, J.F., 1990a. Social learning correlates of exercise self-efficacy: Early experiences with physical activity, Social Science and Medicine, 31, 1169-1176.]; [Hofstetter, C.R., Sallis, J.F., Hovell, M.F., 1990b. Some health dimensions of self-efficacy: Analysis of theoretical specificity, Social Science and Medicine, 31, 1051-1056.]; [Reynolds, K.D., Killen, J.D., Bryson, M.S., Maron, D.J., Taylor, C.B., Maccoby, N., Farquhar, J.W., 1990. Psychosocial predictors of physical activity in adolescents, Preventive Medicine, 19, 541-551.]; [Sallis, J.F., Pinski, R.B., Grossman, R.M., Patterson, T.L., Nader, P.R., 1988. The development of self-efficacy scales for health-related diet and exercise behaviors, Health Education Research, 3, 283-292.]) were adapted and original items were developed. The 20-item measure has a 5-point Likert format ranging from not at all confident (1) to very confident (5). An earlier pilot study of 200 secondary school students showed that the measure was free of social desirability. The data were derived from a survey of 1041 secondary school students from a Metropolitan Toronto board of education. Principal component analysis (PCA) with oblique rotation of the data yielded two factors: self-efficacy to overcome external barriers and self-efficacy to overcome internal barriers. The 12-item external barriers subscale had a coefficient alpha of 0.88 and the 8-item internal barriers subscale had a coefficient alpha of 0.87. The subscales significantly correlated with the frequency of participation in vigorous physical activity. In summary, the results provide some support for the internal consistency reliability, construct validity, criterion validity, and discriminant validity of the measure. Though further psychometric research is warranted, the self-efficacy measure shows promise for physical activity research.

Adolescent↗
PubMed1997

Experimental measurement of the effective dielectric in the hydrophobic core of a protein.

The dielectric inside a protein is a key physical determinant of the magnitude of electrostatic interactions in proteins. We have measured this dielectric phenomenologically, in terms of the dielectric that needs to be used with the Born equation in order to reproduce the observed pKa shifts induced by burial of an ionizable group in the hydrophobic core of a protein. Mutants of staphylococcal nuclease with a buried lysine residue at position 66 were engineered for this purpose. The pKa values of buried lysines were measured by difference potentiometry. The extent of coupling between the pKa and the global stability of the protein was evaluated by measuring pKa values in hyperstable forms of nuclease engineered to be 3.3 or 6.5 kcal mol-1 more stable than the wild type. The crystallographic structure of one mutant was determined to describe the environment of the buried lysine. The dielectrics that were measured range from 10 to 12. Published pKa values of buried ionizable residues in other proteins were analyzed in a similar fashion and the dielectrics obtained from these values are consistent with the ones measured in nuclease. These results argue strongly against the prevalent use of dielectrics of 4 or lower to describe the dielectric effect inside a protein in structure-based calculations of electrostatic energies with continuum dielectric models.

Proteins↗
PubMed1986

Personality status of wrestlers of varying abilities as measured by a sport specific version of a personality inventory.

The purpose of the study was to examine the relationship between personality and ability in wrestling. A wrestling-specific version of the Jackson Personality Inventory (JPI-W) was constructed and compared to the parent JPI. Wrestlers were categorized as qualifiers (N = 46) or nonqualifiers (N = 52) on the basis of an ability classification scheme which involved the previous year's performance at specified tournaments. These two groups were then examined for differences on eight JPI scales (anxiety, energy level, interpersonal affect, organization, risk taking, self esteem, social participation, and tolerance), eight corresponding JPI-W scales, wrestling age category (senior, junior, and juvenile), and wrestling experience. The results indicated that in comparison to nonqualifiers, qualifiers had significantly greater wrestling experience and higher self esteem as measured by the JPI-W.

Adolescent↗
PubMedDate not supplied

Staff survey of organizational structure and process for a Public Health Department.

A survey of 227 North York Public Health Department (NYPHD) staff provided their perspective on the organizational structure. They perceived that (a) the departmental and divisional organizational structures are effective for program delivery, (b) the Central Resources structure and divisional and departmental reporting structures are moderately effective for program delivery, (c) the decentralized office structure is an advantage for service delivery but less so for administration and intra-division and inter-division communication, (d) the mandatory program structure involves low to moderate interdisciplinary teamwork and moderately impacts service delivery, (e) intra-division and management-staff communication are fair but inter-division and office communication are between poor and fair, (f) education, research, and service are moderately integrated, and (g) the divisional and departmental work atmospheres are a little positive. Management perceived greater participation in program planning, more frequent communication with other divisions, a number of education and research opportunities from various divisions/units, and more management recognition than front line staff did.

Attitude of Health Personnel↗
PubMedDate not supplied

Using a program logic model that focuses on performance measurement to develop a program.

A program logic model is used to make a program ready for an evaluation. It diagrammatically shows the relationships between the objectives of the program, program activities, indicators, and resources. This article describes an expanded logic model that has a greater focus on measurement of program performance. The expanded logic model specifies both outcome and process indicators, whereas other logic models only show service delivery indicators. Also, this article describes how the expanded logic model was used to develop a bicycle safety program. A workgroup established program boundaries and reviewed documents early in the process of developing the logic model. The workgroup developed the logic model which was subsequently reviewed by other stakeholders. The workgroup continually assessed the plausibility of the logic model. Challenges and advantages in using the logic model are discussed.

Accidents, Traffic↗
PubMedDate not supplied

Effectiveness of public health interventions in food safety: a systematic review.

PURPOSE: To summarize evidence on the effectiveness of public health interventions regarding food safety at restaurants, institutions, homes and other community-based settings. METHOD: This systematic review of published and unpublished studies involved a comprehensive literature search, screening for relevance, quality assessment of relevant studies, data extraction and synthesis. RESULTS: The interventions identified in 15 studies included in this review were grouped into three categories: inspections, food handler training, and community-based education. The evidence suggests that: routine inspection (at least once per year) of food service premises is effective in reducing the risk of foodborne illness; food handler training can improve the knowledge and practices of food handlers; and selected community-based education programs can increase public knowledge of food safety. DISCUSSION: There is some evidence for the effectiveness of multiple public health interventions on food safety. Future research needs include evaluation of HACCP and community-based education programs.

Food Contamination↗