Particle size analysis of lamb meat: Effect of homogenization speed, comparison with myofibrillar fragmentation index and its relationship with shear force.

The impact of homogenization speed on Particle Size (PS) results was examined using samples from the M.longissimus thoracis et lumborum (LL) of 40 lambs. One gram duplicate samples from meat aged for 1 and 5days were homogenized at five different speeds; 11,000, 13,000, 16,000, 19,000 and 22,000rpm. In addition to this LL samples from 30 different lamb carcases also aged for 1 and 5days were used to study the comparison between PS and myofibrillar fragmentation index (MFI) values. In this case, 1g duplicate samples (n=30) were homogenized at 16,000rpm and the other half (0.5g samples) at 11,000rpm (n=30). The homogenates were then subjected to respective combinations of treatments which included either PS analysis or the determination of MFI, both with or without three cycles of centrifugation. All 140 samples of LL included 65g blocks for subsequent shear force (SF) testing. Homogenization at 16,000rpm provided the greatest ability to detect ageing differences for particle size between samples aged for 1 and 5days. Particle size at the 25% quantile provided the best result for detecting differences due to ageing. It was observed that as ageing increased the mean PS decreased and was significantly (P<0.001) less for 5days aged samples compared to 1day aged samples, while MFI values significantly increased (P<0.001) as ageing period increased. When comparing the PS and MFI methods it became apparent that, as opposed to the MFI method, there was a greater coefficient of variation for the PS method which warranted a quality assurance system. Given this requirement and examination of the mean, standard deviation and the 25% quantile for PS data it was concluded that three cycles of centrifugation were not necessary and this also applied to the MFI method. There were significant correlations (P<0.001) within the same lamb loin sample aged for a given period between mean MFI and mean PS (-0.53), mean MFI and mean SF (-0.38) and mean PS and mean SF (0.23). It was concluded that PS analysis offers significant potential for streamlining determination of myofibrillar degradation when samples are measured after homogenization at 16,000rpm with no centrifugation.

Daily energy expenditure in free-living children: comparison of heart-rate monitoring with the doubly labeled water (2H2(18)O) method.

Total energy expenditure (TEE) was measured simultaneously in 36 free-living children aged 7, 9, 12, and 15 y over 10-15 d by the doubly labeled water (DLW) method and for 2-3 separate days by heart-rate (HR) monitoring. The 95% confidence limits of agreement (mean difference +/- 2SD) were -1.99 to +1.44 MJ/d. HR TEE discrepancies ranged from -16.7% to +18.8% with 23 values lying within +/- 10% of DLW TEE estimates. Boys and girls spent 462 +/- 108 and 318 +/- 120 min/d, respectively, in total physical activity (P less than 0.01). Time spent in moderate and vigorous physical activity (MVPA) was 68 +/- 37 min/d by younger children (7-9 y) and 34 +/- 24 min/d by older children (12-15 y) (P less than 0.001). Younger boys engaged in MVPA (91 +/- 33 min/d) and vigorous physical activity (VPA) (35 +/- 15 min/d) significantly longer than younger girls (MVPA, 39 +/- 16 min/d, P less than 0.001; VPA, 10 +/- 4 min/d, P less than 0.01) as did older boys (MVPA, 52 +/- 21 min/d; VPA, 30 +/- 18 min/d) compared with older girls (MVPA, 15 +/- 10 min/d; VPA, 8 +/- 5 min/d). HR monitoring provides a close estimation of the TEE of population groups and objective assessment of associated patterns of physical activity.

Psychometric testing of the reduced Laffrey Health Conception Scale.

PURPOSE: Laffrey's Health Conception Scale (LHCS), an instrument designed to measure personal definitions of health, was reduced with the intent of creating a useful yet less cumbersome version of the LHCS. DESIGN: The original form of the LHCS was tested in a preliminary study, and results were used as a basis for the reduction of the instrument. The original clinical and new overall wellness subscales were subsequently tested with a larger population of manufacturing plant workers. SETTING: One chemical plant and three Midwestern manufacturing plants. SUBJECTS: The sample for the preliminary study comprised 94 chemical plant workers. For the larger study, the sample comprised 892 subjects; because this instrument was part of a larger questionnaire to identify predictors of workers' use of hearing protection, only those workers who spent some part of their work time in areas of the plant which required hearing protection use were eligible to participate. MEASURES: The original LHCS was used in the preliminary study. The reduced LHCS was used in the larger study and psychometrically evaluated. RESULTS: The reduced LHCS accounted for 51% of the variance in definition of health; all but one item had loaded on one of the two factors with a loading of .41 or greater. The revised LHCS demonstrated excellent internal consistency. Two distinct factors, the clinical subscale and the overall wellness subscale, were isolated. CONCLUSIONS: The researchers recommend the reduced LHCS be used for assessing subjects' definition of health; the reduced instrument requires fewer items, and therefore less time, to measure individuals' definitions of health with excellent reliability.

Applying the health promotion model to development of a worksite intervention.

INTRODUCTION: Consistent use of hearing protection devices (HPDs) decreases noise-induced hearing loss, however, many workers do not use them consistently. Past research has supported the need to use a conceptual framework to understand behaviors and guide intervention programs; however, few reports have specified a process to translate a conceptual model into an intervention. PURPOSE: The strongest predictors from the Health Promotion Model were used to design a training program to increase HPD use among construction workers. SUBJECTS/SETTING: Carpenters (n = 118), operating engineers (n = 109), and plumber/pipefitters (n = 129) in the Midwest were recruited to participate in the study. DESIGN: Written questionnaires including scales measuring the components of the Health Promotion Model were completed in classroom settings at worker trade group meetings. MEASURES: All items from scales predicting HPD use were reviewed to determine the basis for the content of a program to promote the use of HPDs. Three selection criteria were developed: (1) correlation with use of hearing protection (at least .20), (2) amenability to change, and (3) room for improvement (mean score not at ceiling). RESULTS: Linear regression and Pearson's correlation were used to assess the components of the model as predictors of HPD use. Five predictors had statistically significant regression coefficients: perceived noise exposure, self-efficacy, value of use, barriers to use, and modeling of use of hearing protection. Using items meeting the selection criteria, a 20-minute videotape with written handouts was developed as the core of an intervention. A clearly defined practice session was also incorporated in the training intervention. CONCLUSION: Determining salient factors for worker populations and specific protective equipment prior to designing an intervention is essential. These predictors provided the basis for a training program that addressed the specific needs of construction workers. Results of tests of the effectiveness of the program will be available in the near future.

Conducting worksite research: methodological issues and suggested approaches.

1. With increasing national concern about adult health and reducing health care costs, more research about these issues is being carried out in the worksite. 2. The worksite generates a variety of complications that may not be present in many other research settings; these include management policies, plant regulations, and management/labor relations. 3. The researchers review issues related to conducting research at the worksite and, based on their experience in this setting, make recommendations for resolving these issues.

Work force diversity. Implications for occupational health nursing.

1. Increasing work force diversity is reflected in the Healthy People 2010 goal to eliminate health disparities. 2. At the organization level, a framework of cultural competence defines the developmental process toward cultural proficiency. 3. Strategies are suggested for organizations and nurses to engage in cultural competence.

The impact of supplementing lambs with algae on growth, meat traits and oxidative status.

The current study examined the effect of supplementing lambs with algae. Forty, three month old lambs were allocated to receive a control ration based on oats and lupins (n=20) or the control ration with DHA-Gold™ algae (~2% of the ration, n=20). These lambs came from dams previously fed a ration based on either silage (high in omega-3) or oats and cottonseed meal (OCSM: high in omega-6) at joining (dam nutrition, DN). Lamb performance, carcase weight and GR fat content were not affected by treatment diet (control vs algae) or DN (silage vs OSCM). Health claimable omega-3 fatty acids (EPA+DHA) were significantly greater in the LL of lambs fed algae (125±6mg/100g meat) compared to those not fed algae (43±6mg/100g meat) and this effect was mediated by DN. Supplementing with algae high in DHA provides a means of improving an aspect of the health status of lamb meat.

The interrelationship between sensory tenderness and shear force measured by the G2 Tenderometer and a Lloyd texture analyser fitted with a Warner-Bratzler head.

A comparison of peak shear force results for a Lloyd texture analyser fitted with a Warner Bratzler type of shearing head and a G2 Tenderometer was undertaken using sheep meat. The G2 is a new version of the Tenderometer that uses an electric linear motor to compress the sample, but still retains the blunt wedge-shaped "tooth". Analysis of sheep meat samples (n=121) revealed that the average G2 Tenderometer shear force results were approximately 1.2 times those for the Lloyd based on the following model; Lloyd=1.561 Tenderometer(0.84). Both instruments explained low amounts of the variation (less than 20%) in the sensory traits tenderness and overall liking. The high values for the sensory traits indicate that a wider range of samples, including samples with lower sensory scores, is required to develop robust threshold estimates so that either instrument could be use as an auditing instrument for the processing industry.

Examination of the effect of ageing and temperature at rigor on colour stability of lamb meat.

A study of factors (ageing period, rigor temperature and vitamin E level) impacting on the colour stability of lamb m. longissimus thoracis et lumborum (LL) during 3 days of simulated retail display was undertaken. The LL were taken from 84 lambs from 3 slaughters. Slices of LL were measured fresh (24h post-mortem) or after ageing for 5 days in vacuum packaging. The oxy/met ratio (630/580 nm), declined with display time, and increased with increasing temperature at pH6.0. Redness (a*) values also declined with display time and a reduction in redness values was observed as LL pH at 24h post-mortem and/or pH at 18°C increased. There was no effect of ageing period or vitamin E level on the oxy/met ratio or a* values when the vitamin E level averaged 3.76 mg/kg LL. These results suggest that maximising vitamin E levels in lambs and achieving a moderate rate of pH decline will optimise colour stability irrespective of ageing period.

The effect of a kiwi fruit based solution on meat traits in beef m. semimembranosus (topside).

The effectiveness of a kiwi fruit based solution for improving the tenderness of beef m. semimembranosus and the effect on colour stability was studied. Three treatments were applied; (1) injection with the solution, (2) injection with water and (3) no injection. All samples were packaged using a SmartShape™ prototype and aged for 1 or 14 days. There was a significant effect (P<0.001) of the kiwi fruit solution on shear force, with no difference between samples injected with water and those not injected. For compression of the samples no fixed effects were significant (P>0.05). Samples not injected (control) were the darkest (lowest L* values) with no difference between samples injected with water and those injected with kiwi fruit solution. Injected samples had lower a* (redness) values than non-injected samples. In general the samples not injected had higher ratio (630/580 nm) values indicating less formation of metmyoglobin.

Explaining the variation in the shear force of lamb meat using sarcomere length, the rate of rigor onset and pH.

The temperature when the pH=6.0 (temp@pH6) impacts on the tenderness and eating quality of sheep meat. Due to the expense, sarcomere length is not routinely measured as a variable to explain variation in shear force, but whether measures such as temp@pH6 are as useful a parameter needs to be established. Measures of rigor onset in 261 carcases, including the temp@pH6, were evaluated in this study for their ability to explain some of the variation in shear force. The results show that for 1 day aged product combinations of the temp@pH6, the pH at 18 °C and the pH at 24 h provided a larger reduction (almost double) in total shear force variation than sarcomere length alone, with pH at 24 h being the single best measure. For 5 day aged product, pH at 18 °C was the single best measure. Inclusion of sarcomere length did represent some improvement, but the marginal increase would not be cost effective.

A blood center communication plan and guideline for assisting hospitals with the implementation of the new international uniform bar code-labeling standard.

BACKGROUND: Transition to the International Society of Blood Transfusion (ISBT) bar code-labeling standard known as ISBT 128 is scheduled to begin July 1, 1997. Blood centers play a pivotal role in educating and assisting hospitals with the implementation of the new standard. A communication plan and hospital guidelines to facilitate the actual transition to ISBT 128 are integral parts of a blood center's comprehensive implementation strategy. STUDY DESIGN AND METHODS: In Phase 1, the blood center identified specific target groups within the hospitals and developed educational materials for them. A survey tool was used to identify unique hospital needs. Subsequent blood center newsletters and customer service forums included ISBT 128 updates. In Phase 2, guidelines to assist hospitals with the identification of critical elements, milestones, and target dates for the transition were developed with hospital staff input. RESULTS: Survey results on the change to ISBT 128 showed that many hospitals were unfamiliar with this change and its effects on operational issues. Various forums to disseminate information about ISBT 128 are needed to provide education and assistance to diverse groups within the hospital. CONCLUSION: A partnership approach between hospitals and the regional blood center should promote a successful transition from the current bar code symbology, American Blood Commission Codabar, to ISBT 128.

Occupational reproductive health risks.

The potentially harmful effects on women of certain workplace exposures are widely appreciated, and steps to control these have included legislative efforts such as right-to-know laws of well as corporate policies mandating selective restriction of fertile women, which are illegal under federal civil rights laws. This chapter reviews the various occupational health risks reproductive women face in the workplace but also considers the effects of other genetic, medical, social, infectious, and environmental factors which may be of even greater concern than most occupational factors.

Health-promoting lifestyles of English-speaking and Spanish-speaking Mexican-American migrant farm workers.

This study was conducted with 62 Mexican-American migrant farm workers at four different sites in northern Illinois. An established English and a newly developed pilot Spanish version of the health-promoting lifestyle profile was used. The concept of health-promoting lifestyle appeared to be culturally relevant to study participants. English-speaking migrant workers scored significantly lower than Spanish-speaking workers on the dimensions of self-actualization, exercise, and stress management. Patterns of scores among both groups were highest in self-actualization and interpersonal support, and lowest in health responsibility and exercise. Further research in health-promoting behaviors with all cultural groups and socioeconomic levels of society will contribute to achievement of the World Health Organization's goal, health for all by the year 2000.

Health-promoting lifestyles of blue-collar, skilled trade, and white-collar workers.

The health-promoting lifestyles of blue-collar, skilled trade, and white-collar workers were examined. Specific purposes included determining differences in health-promoting behaviors, especially according to worker category, as well as ethnic identification, age, gender, education, and marital status. A convenience sample of 638 workers in a midwestern automotive components plant completed the Health-Promoting Lifestyle Profile (HPLP) and demographics questionnaire. In a multivariate analysis of variance (MANOVA) including all demographic variables, significant differences were found in the mean scores on subscales of the HPLP by job category (2 subscales), age (3), gender (2), and education (4). Prior to including education in the MANOVA, significant differences were found by job category on 5 subscales of the HPLP. The effects of education eliminated the majority of the effects of job category.

Predictors of hearing protection use among workers: implications for training programs.

In this study, we used the conceptual Health Promotion Model to identify predictors of hearing protection use among blue-collar workers (N = 504). The strongest predictors were self-efficacy, benefits, value, and barriers. Items in the barriers scale were most strongly correlated with use and had the greatest potential for change. Therefore, items from this scale are being used as the primary basis for development of a training intervention program.

Suppression of ventricular arrhythmias after coronary artery ligation by pinacidil, a vasodilator drug.

Pinacidil, a new vasodilator compound, has been shown to lower blood pressure in animals and humans by a direct vasodilator effect. We have studied the effects of pinacidil on experimental cardiac arrhythmias in dogs. Pinacidil did not exhibit antiarrhythmic activity on ouabain-induced arrhythmias. In contrast, verapamil had minor antiarrhythmic activity on the ouabain arrhythmia, restoring sinus rhythm in one-third of the dogs studied. Pinacidil suppressed the arrhythmia present 22-24 h after coronary artery ligation at doses which produced a significant reduction in mean arterial pressure. The antiarrhythmic action of pinacidil was not modified by pretreatment with propranolol but appeared to be blunted by the infusion of the alpha-agonist, phenylephrine. Other hypotensive agents, hydralazine and sodium nitroprusside, although producing similar reductions in mean arterial pressure to pinacidil, did not exhibit a consistent antiarrhythmic action in dogs 22-24 h after coronary artery ligation. The calcium antagonist verapamil did not display antiarrhythmic activity on this model. The mechanisms by which pinacidil exerted an antiarrhythmic action have not yet been elucidated. The results of the present study suggest that further studies with pinacidil on myocardial infarct size, myocardial perfusion, and experimental cardiac arrhythmias would be advantageous.

Investigation into mechanism of lack of reflex tachycardia in response to hypotensive action of indoramin in dogs.

In animals and man, the selective alpha 1-adrenoceptor antagonist indoramin reduces arterial pressure without increasing heart rate. We studied this mechanism of absence of reflex tachycardia in anaesthetised dogs. Indoramin reduced (p less than 0.05) arterial pressure with no reflex increase in heart rate, whereas phenoxybenzamine reduced (p less than 0.05) pressure but increased (p less than 0.05) heart rate. Atropine and propranolol pretreatment, vagotomy and division of the cardio-accelerator nerve did not prevent the reduction (p less than 0.05) in arterial pressure and heart rate seen with indoramin. Mexiletine, a drug which has membrane-stabilising activity, had no effect on heart rate or arterial pressure. Mexiletine and indoramin did not affect the increases in heart rate produced by stimulation of the cardio-accelerator nerve. Indoramin reduced (p less than 0.05) the increases in heart rate and arterial pressure produced by bilateral carotid occlusion, and potentiated the arterial pressure reduction but attenuated the heart rate response to intravenous isoprenaline. It also reduced (nonsignificantly) the responses to intravenous noradrenaline and phenylethylamine but had no effect on the arterial pressure and heart rate responses to bilateral central vagal stimulation. We conclude that the absence of the reflex tachycardia with hypotensive doses of indoramin does not result from the myocardial membrane-stabilising action of indoramin or from alteration in sympathetic and parasympathetic activity, but may occur partly from a reduction in baroreceptor sensitivity.

Use of hearing protection and perceptions of noise exposure and hearing loss among construction workers.

The purpose of this study was to describe construction workers' use of hearing protection devices (HPDs) and determine their perceptions of noise exposure and hearing loss. Operating engineers, carpenters, and plumbers/pipe fitters in the Midwest (n = 400) completed a written questionnaire regarding their use of HPDs and their perceptions of noise exposure and hearing loss. Subjects were recruited through their trade union groups. Mean reported use of HPDs and mean perceived noise exposure were compared across trade groups. Bivariate and multivariate analysis techniques were used to assess relationships between use of HPDs and trade category, education, age, years of employment, noise exposure, and hearing loss. Bivariate analyses identified significant differences in mean use of HPDs by age, years of employment, and trade group. Multivariate logistic regression assessing the independent effects of these variables found significant differences only by trade group. Results indicate a need for significant improvement in all three trade groups' use of HPDs, and suggest a need to consider use and exposure levels, demographics, and trade group membership in designing hearing conservation programs.