Non-response bias in estimates of prevalence of club-based sport participation from an Australian national physical activity, recreation and sport survey.

BACKGROUND: An estimate of the prevalence of an activity derived from a sample survey is potentially subject to non-response bias, whereby people not involved in the activity are less likely to respond than those involved. Quantifying the extent of non-response bias is generally difficult, since it involves estimating differences between respondents for whom data is directly available from the survey, and non-respondents, for whom data is generally not directly or readily available. However, in the case of the Australian Exercise Recreation and Sport Survey (ERASS), comparative "gold standard" benchmarks exist for some aspects of the survey, in the form of state sporting association (SSA) registration databases, each of which purports to constitute a complete enumeration of club-based players of a particular sport. METHODS: ERASS estimates of the prevalence of participation in four major club-based team sports in the Australian state of Victoria in the year 2010 were compared with prevalences based on numbers of registered participants in the corresponding SSA databases. Comparisons were made for the adult population as a whole (ERASS scope being 15+ years of age), and for strata defined by age and geographical region. Because three of the four sports investigated are strongly sex-specific, no sex breakdowns were conducted. In each case the proportion of ERASS respondents reporting participation, with associated confidence limits, was compared with the corresponding SSA count expressed as a proportion of the population, to form an ERASS/SSA prevalence ratio with associated confidence limits. RESULTS: The 24 ERASS/SSA ratios ranged from 1.72 to 7.80. Most ratios lay in the range 2 to 3. The lower 95% confidence bound for the ratio was greater than 1.0 in 23 out of 24 cases. CONCLUSIONS: ERASS estimates of prevalence of these particular aspects of sport participation were higher than SSA estimates, to statistically significant degrees. The effect sizes (i.e. the discrepancies represented by the ratios) were large enough to be of great practical importance. It is conjectured that non-response bias is the most likely explanation for the discrepancies.

The influence of a Healthy Welcoming Environment on participation in club sport by adolescent girls: a longitudinal study.

BACKGROUND: This study investigated the perceived influence of a Healthy Welcoming Environment (HWE) on participation in sports clubs among adolescent girls, and how these perceptions changed longitudinally. HWE was defined in terms of a set of health promotion policies advocated by a health promotion foundation as the basis of sport club health promotion practice to promote structural reform in state sporting organisations and their affiliated associations and clubs. These included sports injury prevention, smoke-free, responsible serving of alcohol, sun protection, healthy eating, and welcoming and inclusive environments. METHODS: Year 7 and 11 female students from metropolitan (n = 17) and non-metropolitan secondary schools (n = 14) in Australia were invited to participate in three annual surveys. These surveys collected information about current or past membership of a sports club and the influence of HWEs on their decision to participate (or not) in a sports club. RESULTS: Year 7 (n = 328; 74.5%) and Year 11 (n = 112; 25.5%) female students completed all three waves (19.6% response rate; 82.7 and 74.0% retention rate). Most agreed that characteristics of HWEs were a positive influence on their participation in sports clubs, except those relating to alcohol and Sunsmart. Welcoming factors had consistent high agreement among respondents. Alcohol and friendliness factors of the club were regarded as being positively influential by higher percentages of non-metropolitan than metropolitan respondents. CONCLUSIONS: Welcoming factors were the most positive influences on decisions to participate in sports clubs. These factors may be important in reducing barriers to sport participation. Strategies supporting the social environment within sports clubs should be prioritised.

Trends in body image of adolescent females in metropolitan and non-metropolitan regions: a longitudinal study.

BACKGROUND: Body dissatisfaction is associated with a range of adverse outcomes, including impaired psychological health, low physical activity and disordered eating. This longitudinal study used the Factors Influencing Transitions in Girls' Active Leisure and Sport (FITGALS) dataset to examine trends in body image of adolescent females. Specifically, the study examined satisfaction with body size, physical appearance and dieting behaviour for two cohorts at transitional life phases in two geographic regions longitudinally over a 3-year period. METHODS: A sample of 732 adolescent females in Grade 7 (n = 489, 66.8 %) and Grade 11 (n = 243, 33.2 %) at randomly selected Australian metropolitan and non-metropolitan secondary schools responded to a questionnaire in three successive years from 2008 to 2010. Participants reported perceptions about their body size and physical appearance and whether they were, or ought to be, on a diet. The data were analysed using a series of longitudinal logistic regression models. RESULTS: Dieting and dissatisfaction with body size significantly increased over time and more so for older than younger girls. Region significantly moderated the effect of grade level regarding dissatisfaction with body size but not dieting. In non-metropolitan regions, those in the younger cohort were significantly more likely to be dissatisfied with their body size than the older cohort; whereas in metropolitan regions, those in the older cohort were significantly more likely to be dissatisfied with their body size than the younger cohort. Adolescent female's perceptions of their appearance were unchanged over time, region and grade level. CONCLUSIONS: Differences across time, region and grade level were found among adolescent females on body size and dieting behaviour, but not physical appearance. Adolescent females experience early and increasing body size dissatisfaction and dieting as they age, but stable perceptions of physical appearance. Age and geographic region are important considerations for the timing and targeting of interventions to address body image concerns. Further investigation of regional differences in body image perceptions and factors that affect these is warranted. The findings of this study highlight the ongoing need for strategies during adolescence to promote a healthy appreciation of body size and appearance.

Population levels of sport participation: implications for sport policy.

BACKGROUND: Participation in sport can contribute to health-enhancing levels of leisure-time physical activity. There are recent reports that participation in sport in Australia is decreasing. However, these studies are limited to ages 15 years and over. METHODS: This study integrates sports club membership data from five popular team sports and investigates sport participation across the lifespan (4-100 years) by sex and region (metropolitan/non-metropolitan). RESULTS: Overall participant numbers per annum increased from 414,167 in 2010 to 465,403 in 2012 corresponding to a rise in the proportion of Victorian's participating in these sports from 7.5 % in 2010 to 8.3 % in 2012. The highest proportion of participants was in the 10-14 year age range, with participation rates of 36 % in 2010 and 40 % in 2012. There was a considerably lower participation rate in the 15-19 year age group compared to the 10-14 age group, in all three years studied, and the decline continued progressively with increasing age. Male and female age profiles of participation were generally similar in shape, but the female peak at age 10-14 was sharper than for the males, and conversely there were very few 4 year old female participants. Participation rates were generally higher in non-metropolitan than metropolitan areas; the difference increased with increasing age from 4 to 34 years, then steadily declined, reaching parity at around 60 years of age. CONCLUSIONS: It is a positive sign that participation in these popular sports increased by over 50,000 participants from 2010 to 2012. Large proportions of the population aged 5-14 participate in club based sport. Participation rates decline sharply in late adolescence, particularly for females, and while this may not be a concern from a broad health perspective so long as they transition into other forms of physical activity, it is certainly a matter of concern for the sport sector. It is recommended that sport policy places a higher priority on grass-roots participation and that sporting organisations are supported to prioritise the retention issues occurring during adolescence, particularly for females so as to maximise the potential for sport to maintain its positive contribution to population wellbeing.

The contribution of sport participation to overall health enhancing physical activity levels in Australia: a population-based study.

BACKGROUND: The contribution of sport to overall health-enhancing leisure-time physical activity (HELPA) in adults is not well understood. The aim was to examine this in a national sample of Australians aged 15+ years, and to extend this examination to other ostensibly sport-associated activities. METHODS: The 2010 Exercise, Recreation and Sport Survey (ERASS) was conducted by telephone interview in four quarterly waves. Data from this survey were analysed to categorise leisure-time physical activity (LTPA) as HELPA or non-HELPA, and to categorise HELPA activities and sessions of HELPA activity by setting and frequency. The contribution of sport to HELPA was estimated, both directly through activities and settings classified as sport per se, and indirectly through other fitness activities ostensibly related to preparation for sport and enhancement of sport performance. RESULTS: Of 21,602 respondents, 82 % reported some LTPA in the 12 months prior to the survey. In aggregate, respondents reported 37,020 activity types in the previous 12 months, of which 94 % were HELPA. Of HELPA activities, 71 % were non-organised, 11 % were organised but not sport club-based, and 18 % were sport club-based. Of all sport activities, 52 % were HELPA. Of sport HELPA, 33 % was sport club-based and 78 % was undertaken ≥12 times/year. Sport club members were significantly more likely to have participated in running, but significantly less likely to have participated in walking or aerobics/fitness training, than non-club members. CONCLUSIONS: Club sport participation contributes considerably to LTPA at health enhancing levels. Health promotion policies, and more specifically physical activity policies, should emphasize the role of sport in enhancing health. Sport policy should recognise the health-promoting role of community-based sport in addition to the current predominant focus on elite pathways.

A comparison of rat SPECT images obtained using (99m)Tc derived from 99Mo produced by an electron accelerator with that from a reactor.

Recent shortages of molybdenum-99 ((99)Mo) have led to an examination of alternate production methods that could contribute to a more robust supply. An electron accelerator and the photoneutron reaction were used to produce (99)Mo from which technetium-99m ((99m)Tc) is extracted. SPECT images of rat anatomy obtained using the accelerator-produced (99m)Tc with those obtained using (99m)Tc from a commercial generator were compared. Disks of (100)Mo were irradiated with x-rays produced by a 35 MeV electron beam to generate about 1110 MBq (30 mCi) of (99)Mo per disk. After target dissolution, a NorthStar ARSII unit was used to separate the (99m)Tc, which was subsequently used to tag pharmaceuticals suitable for cardiac and bone imaging. SPECT images were acquired for three rats and compared to images for the same three rats obtained using (99m)Tc from a standard reactor (99)Mo generator. The efficiency of (99)Mo-(99m)Tc separation was typically greater than 90%. This study demonstrated the delivery of (99m)Tc from the end of beam to the end user of approximately 30 h. Images obtained using the heart and bone scanning agents using reactor and linac-produced (99m)Tc were comparable. High-power electron accelerators are an attractive option for producing (99)Mo on a national scale.

Transition in participation in sport and unstructured physical activity for rural living adolescent girls.

Physical activity (PA) is important for lifelong health; however, participation is lower in rural compared with metropolitan areas and declines during adolescence, particularly for girls. It is likely that this decline is related to the number of life transitions that occur during adolescence. This qualitative study examined the views of active rural living girls regarding the factors affecting their sport and PA participation, using the socioecological model. Twenty-seven girls aged 16-17 from four schools participated in semi-structured focus group discussions. Content and thematic analysis was conducted from verbatim transcripts using NVivo. The girls enjoyed involvement in community club sport with friends and they reported living in communities where participation in sport was a major form of social interaction. However, the desire to succeed educationally was a critical factor affecting their participation in sport and PA and influenced their movement from structured club sport to more flexible, but socially isolated individual activities. It is recommended that future longitudinal research should track rural living adolescent females as they complete secondary school, in order to better understand the influence of educational priorities upon sport and PA participation and to identify practical strategies for both schools and community organizations to foster continuing participation throughout this crucial period of life transition.

Development of body oxygen stores in harbor seals: effects of age, mass, and body composition.

Harbor seal pups are highly precocial and can swim and dive at birth. Such behavioral maturity suggests that they may be born with mature body oxygen stores or that stores develop quickly during the nursing period. To test this hypothesis, we compared the blood and muscle oxygen stores of harbor seal pups, yearlings, and adults. We found that pups had smaller oxygen stores than adults (neonates 57%, weaned pups 75%, and yearlings 90% those of adults), largely because neonatal myoglobin concentrations were low (1.6+/-0.2 g% vs. 3.8+/-0.3 g% for adults) and changed little during the nursing period. In contrast, blood oxygen stores were relatively mature, with nursing pups having hematocrit (55%+/-0.2%), hemoglobin (21.7+/-0.4 g%), and blood volume (12.3+/-0.5 mL/kg) only slightly lower than the corresponding values for adults (57%+/-0.2%, 23.8+/-0.3 g %, and 15.0+/-0.5 mL/kg). Because neonatal pups had relatively high metabolic rates (11.0 mL O2/kg min), their calculated aerobic dive limit was less than 50% that of adults. These results suggest that harbor seals' early aquatic activity is primarily supported by rapid development of blood, with immature muscle oxygen stores and elevated use rates limiting aerobic diving ability.

Contaminant loads and hematological correlates in the harbor seal (Phoca vitulina) of San Francisco Bay, California.

An expanding body of research indicates that exposure to contaminants may impact marine mammal health, thus possibly contributing to population declines. The harbor seal population of the San Francisco Bay (SFB), California, has suffered habitat loss and degradation, including decades of environmental contamination. To explore the possibility of contaminant-induced health alterations in this population, blood levels of polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and polybrominated diphenyl ethers (PBDEs) were quantified in free-ranging seals; relationships between contaminant exposure and several key hematological parameters were examined; and PCB levels in the present study were compared with levels determined in SFB seals a decade earlier. PCB residues in harbor seal blood decreased during the past decade, but remained at levels great enough that adverse reproductive and immunological effects might be expected. Main results included a positive association between leukocyte counts and PBDEs, PCBs, and DDE in seals, and an inverse relationship between red blood cell count and PBDEs. Although not necessarily pathologic, these responses may serve as sentinel indications of contaminant-induced alterations in harbor seals of SFB, which, in individuals with relatively high contaminant burdens, might include increased rates of infection and anemia.

An analysis of the forces required to drag sheep over various surfaces.

Some occupational health and safety hazards associated with sheep shearing are related to shearing shed design. One aspect is the floor of the catching pen, from which sheep are caught and dragged to the shearing workstation. Floors can be constructed from various materials, and may be level or gently sloping. An experiment was conducted using eight experienced shearers as participants to measure the force exerted by a shearer when dragging a sheep. Results showed that significant changes in mean dragging force occurred with changes in both surface texture and slope. The mean dragging forces for different floor textures and slopes ranged from 359 N (36.6 kg) to 423N (43.2 kg), and were close to the maximum acceptable limits for pulling forces for the most capable of males. The best floor tested was a floor sloped at 1:10 constructed of timber battens oriented parallel to the path of the drag, which resulted in a mean dragging force 63.6N (15%) lower than the worst combination.

Immunohistochemical evidence for estrogen receptors in meibomian glands.

PURPOSE: To look for sex hormone receptor distribution in three structures contributing to the normal human tear film: the conjunctiva, the accessory lacrimal glands, and the meibomian glands. DESIGN: An immunohistochemical study. TISSUES AND CONTROLS: Forty-one upper eyelid specimens were collected from 15 male and 26 female patients (age range, 1.5-85 years) during blepharoptosis surgery via posterior tarsoconjunctival mullerectomy (Fasanella-Servat or Gavaris). In addition, control sections of histologically normal breast, prostate, and skin tissue were obtained. METHODS: Immunohistochemical staining using mouse monoclonal antibodies against estrogen, progesterone, and androgen receptors was performed on all tissues and controls. Quantitation of the receptors was performed and expressed as percentage nuclear positivity. Specimens were divided into three groups based on the age of the patient: <12 years (n = 9); 18-55 years (n = 1); >55 years (n = 12). RESULTS: Forty-one specimens contained conjunctiva. All were negative for estrogen, progesterone, and androgen receptors. Twenty-four specimens contained accessory lacrimal glands of Wolfring. All were negative for the three receptors. Twenty-two specimens contained meibomian glands. All were positive for estrogen receptors; one was positive for progesterone receptors and one for androgen receptors. Using Minitab statistical software (Minitab Inc. State College, PA), analysis of variation revealed no statistical difference between sexes or between age groups studied. The sebaceous glands of skin were uniformly positive for androgen receptors. Sebaceous glands of the face and scalp (3 of the 15 skin samples) were also positive for estrogen receptors. CONCLUSIONS: Estrogen receptors are present in the meibomian glands of the upper eyelid. Unlike sebaceous glands elsewhere on the skin, the meibomian glands lack androgen receptors. Estrogen receptors may play a role in modulation of the lipid layer of the tear film, and their activity may be linked to meibomian gland dysfunction and dry eye syndrome.

Characterization of adrenergic receptors in the accessory lacrimal glands of the upper eyelid.

PURPOSE: To identify the histologic location as well as the exact subtype of adrenergic receptors in the accessory lacrimal glands of the upper eyelid. METHODS: Upper eyelid specimens were collected from 19 patients undergoing routine blepharoptosis correction via a posterior tarsoconjunctival mullerectomy. Immunohistochemical staining using polyclonal antibodies against human alpha 1, alpha 2, beta 1, and beta 2 receptors was performed on all specimens. RESULTS: beta 1 receptors were the predominant adrenergic receptor subtype in the glands of Wolfring. CONCLUSIONS: The presence of beta 1 receptors in the accessory lacrimal glands of the upper eyelid may suggest a possible role for selective beta 1 agonists in the treatment of keratitis sicca.

Distribution of adrenergic receptor subtypes in the retractor muscles of the upper eyelid.

PURPOSE: To identify adrenergic receptor subtypes and their relative distribution in the retractor muscles of the upper eyelid, the levator palpebrae superioris, and the Müller muscle. The pattern of distribution of these receptors in the Müller muscle was further compared in patients with dysthyroid eyelid retraction and in normal subjects. METHODS: Müller muscle specimens were collected from 19 patients undergoing ptosis correction and from 8 patients undergoing repair of dysthyroid eyelid retraction. Immunohistochemical staining for alpha 1-, alpha 2-, beta 1-, and beta 2-adrenergic receptors was performed using antihuman rabbit polyclonal antibodies. RESULTS: alpha 2-Adrenergic receptors were the predominant subtype in the Müller muscle, and beta 1-adrenergic receptors were the predominant subtype in the levator muscle. There was no significant difference in the staining pattern between specimens collected from patients with dysthyroid eyelid retraction and those from normal subjects. CONCLUSIONS: The interaction between the alpha 2 and beta 1 receptors in the upper eyelid retractor muscles may be important in the control of the upper eyelid position and may contribute to the development of dysthyroid eyelid retraction. Specific alpha 2 antagonists could be developed and may be effective pharmacologic agents for the treatment of eyelid retraction.

Sclerosing sweat-duct carcinoma (malignant syringoma) of the upper eyelid: a patient report with immunohistochemical and ultrastructural analysis.

Sclerosing sweat-duct carcinoma or malignant syringoma is a rare eyelid tumor. The authors report the first patient with sclerosing sweat-duct carcinoma involving the upper eyelid and present its immunohistochemical and ultrastructural features. The clinical features and the histopathologic and ultrastructural findings that distinguish this tumor from its benign counterparts are discussed. Sclerosing sweat-duct carcinomas are slow growing but locally invasive neoplasms that have a propensity to recur. Wide and deep surgical excision with frozen section evaluation of margins is recommended.

Sensitivity and specificity of the diagnosis of periocular lesions by oculoplastic surgeons.

BACKGROUND: A few studies have assessed the sensitivity of ophthalmologists in diagnosing periocular lesions. However, no study has assessed their diagnostic specificity or the degree to which they overdiagnose various lesions. We performed a study to determine the sensitivity and specificity of oculoplastic surgeons' preoperative diagnoses of common and uncommon periocular lesions. METHODS: Using the patient records of four oculoplastic ophthalmologists, we reviewed all charts documenting periocular surgery in which lesions were excised and sent for biopsy. For each of 358 cases we recorded the preoperative diagnosis as listed by the surgeon and the postoperative diagnosis as reported by the pathologist. Each preoperative diagnosis was then scored as correct or incorrect. The relative number of each type of lesion was determined, and the ophthalmologists' sensitivity and specificity were calculated. RESULTS: The sensitivity and specificity for the eight most frequently lesions were (in order of frequency) basal cell carcinoma 92.1% and 81.6% respectively, papilloma 81.6% and 66.0%, cyst 66.7% and 69.7%, nevus 53.6% and 75.0%, seborrheic keratosis 27.8% and 71.4%, chalazion 93.3% and 100.0%, squamous cell carcinoma 33.3% and 55.6%, and xanthelasma 100.0% and 76.9%. The values for melanoma were 50.0% and 28.6%, for sebaceous gland carcinoma 0.0% and 100.0%, and for uncommon lesions (nonspecific inflammation, actinic keratosis, granuloma, cavernous hemangioma, folliculitis, benign sweat gland tumour, eccrine hidrocystoma and collagenous tissue) 27.8% and 57.1%. The overall accuracy in lesion identification was 70.0%. INTERPRETATION: Although ophthalmologists have excellent diagnostic sensitivity and specificity for some types of lesion, such as basal cell carcinoma and chalazion, the identification of other lesion types, such as cyst, squamous cell carcinoma and possibly melanoma and sebaceous gland carcinoma, is less optimal.

Transcanalicular removal of silastic nasolacrimal tubes.

Removal of nasolacrimal tubes is often an awkward procedure when performed transnasally, especially in children and apprehensive adults. We evaluated in a prospective fashion the transcanalicular route to retrieve nasolacrimal tubes. Overall, this technique was well tolerated by patients and easy to perform. Tube breakage during removal may be a complication.

Blastogenesis and interleukin-2 receptor expression assays in the harbor seal (Phoca vitulina).

Two in vitro functional assays were developed to evaluate mitogen-induced responses of peripheral blood mononuclear leukocytes (PBML) from free-ranging harbor seals, Phoca vitulina. Lymphocyte proliferation was measured by a standard blastogenesis assay following optimization of culture conditions including mitogen concentration, cell density, and incubation time. These optimized parameters, with the exception of incubation time, were subsequently employed to measure lymphocyte activation by analytical flow cytometry using fluorochrome-based identification of cell surface interleukin-2 receptor (IL-2r) expression. Baseline values established for free-ranging harbor seals had extensive animal variability; there was evidence that the samples were derived from a group of animals with a normal distribution. Positive correlations were observed between blastogenesis assays, and between blastogenesis and activation assays, when using pokeweed or concanavalin A as the stimulus. However, no relationship was found in the expression of the IL-2r induced by these mitogens. This result supports the contention that the two mitogens stimulate different lymphocyte subpopulations. This was observed only with the IL-2r expression assay because of its unique ability to measure the number of T lymphocytes initially activated rather than the ultimate number of progeny cells identified by blastogenesis. Both assays, used concurrently, should provide a more comprehensive representation of lymphocyte competence and serve as a measure of animal health.