Validity and reliability of measures of television viewing time and other non-occupational sedentary behaviour of adults : a review

Time spent in non-occupational sedentary behaviours (particularly television viewing time) is associated with excess adiposity and an increased risk of metabolic disorders among adults; however, there are no reviews of the validity and reliability of assessing these behaviours. This paper aims to document measures used to assess adults' time spent in leisure-time sedentary behaviours and to review the evidence on their reliability and validity. Medline, CINAHL and Psych INFO databases and reference lists from published papers were searched to identify studies in which leisure-time sedentary behaviours had been measured in adults. Sixty papers reporting measurement of at least one type of leisure-time sedentary behaviour were identified. Television viewing time was the most commonly measured sedentary behaviour. The main method of data collection was by questionnaire. Nine studies examined reliability and three examined validity for the questionnaire method of data collection. Test–retest reliabilities were predominantly moderate to high, but the validity studies reported large differences in correlations of self-completion questionnaire data with the various referent measures used. To strengthen future epidemiological and health behaviour studies, the development of reliable and valid self-report instruments that cover the full range of leisure-time sedentary behaviour is a priority.

Sedentary lifestyle as a risk factor for low back pain : a systematic review

Objectives To review systematically studies examining the association between sedentary lifestyle and low back pain (LBP) using a comprehensive definition of sedentary behaviour including prolonged sitting both at work and during leisure time.

Methods Journal articles published between 1998 and 2006 were obtained by searching computerized bibliographical databases. Quality assessment of studies employing a cohort or case–control design was performed to assess the strength of the evidence.

Results Using pre-determined keywords, we identified 1,778 titles of which 1,391 were considered irrelevant. Then, 20 of the remaining 387 publications were scrutinized for full review after an examination of all the 387 abstracts. Finally, 15 studies (10 prospective cohorts and 5 case–controls) were included in the methodological quality assessment, of which 8 (6 cohorts and 2 case–controls; 53%) were classified as high-quality studies. One high-quality cohort study reported a positive association, between LBP and sitting at work only; all other studies reported no significant associations. Hence, there was limited evidence to demonstrate that sedentary behaviour is a risk factor for developing LBP.

Conclusions The present review confirms that sedentary lifestyle by itself is not associated with LBP.

Effect of a low-resource-intensive lifestyle modification program incorporating gymnasium-based and home-based resistance training on type 2 diabetes risk in Australian adults

OBJECTIVE--The purpose of this study was to assess the effectiveness of a low-resource-intensive lifestyle modification program incorporating resistance training and to compare a gymnasium-based with a home-based resistance training program on diabetes diagnosis status and risk.

RESEARCH DESIGN AND METHODS--A quasi-experimental two-group study was undertaken with 122 participants with diabetes risk factors; 36.9% had impaired glucose tolerance (1GT) or impaired fasting glucose (IFG) at baseline. The intervention included a 6-week group self-management education program, a gymnasium-based or home-based 12-week resistance training program, and a 34-week maintenance program. Fasting plasma glucose (FPG) and 2-h plasma glucose, blood lipids, blood pressure, body composition, physical activity, and diet were assessed at baseline and week 52.

RESULTS--Mean 2-h plasma glucose and FPG fell by 0.34 mmol/1 (95% CI--0.60 to--0.08) and 0.15 mmol/l (-0.23 to -0.07), respectively. The proportion of participants with IFG or IGT decreased from 36.9 to 23.0% (P = 0.006). Mean weight loss was 4.07 kg (-4.99 to -3.15). The only significant difference between resistance training groups was a greater reduction in systolic blood pressure for the gymnasium-based group (P = 0.008).

CONCLUSIONS--This intervention significantly improved diabetes diagnostic status and reduced diabetes risk to a degree comparable to that of other low-resource-intensive lifestyle modification programs and more intensive interventions applied to individuals with IGT. The effects of home-based and gymnasium-based resistance training did not differ significantly.

An ABC approach to assessing the risk of violence at triage

There is evidence to suggest that the incidence of violent behaviour in the emergency department by patients toward staff is on the rise. As part of the process of determining urgency, triage nurses must assess the risk of violence at point of entry. The risk of violence, that is, behaviour that either involves a threat of physical or psychological harm to one's self or to others, is considered a critical predictor of urgency in mental health triage. A rapid violence risk assessment strategy will be described which can be utilised in emergency department triage.

Education or regulation : managing behaviour change in the AFL

Amid the increasing commodification of sports, the off-field practices of elite performers are the source of considerable public scrutiny. Barely a week goes by when we do not hear about elite male sports stars behaving badly. Of course, when elite sportsman behave badly they not only tarnish their own reputations, they bring disrepute to their club and sport. To this end, there is a growing industry awareness of the need to manage and develop professional sporting identities via a variety of education and training processes.

This paper reports on research undertaken into the professional development activities of AFL footballers, and how they are organised, supported and practiced. Drawing on extensive interview data, the research reveals a number of tensions and contradictions between the aspirations of different players, their coaches and mentors, and a range of competing industry practices and processes. In the paper we explore the possibilities for modifying behaviours and attitudes via risk management practices that centre on the provision of compulsory educational seminars and workshops. Drawing on Foucault's later work on the care of the Self we focus on the ways in which new expectations of a professional footballing identity are being constructed and managed.

Conservation ecology and breeding biology of the white-browed treecreeper, Climacteris affinis

The White-browed Treecreeper Climacteris affinis is one of many woodland-dependent birds that are at risk from the encroachment of human-dominated land-uses into natural landscapes. The White-browed Treecreeper inhabits semi-arid woodlands in north-west Victoria, Australia, a vegetation community that has undergone extreme modification in the last century due to the expansion of agriculture in the region. Extant woodlands represent only 10% of the original woodland cover in the region, and are highly fragmented and disturbed in many districts. Thus, the survival of the White-browed Treecreeper may depend on active management. However, current knowledge of the ecology and biology of this species is virtually non-existent, and inadequate for informed and effective conservation actions. The aim of this thesis is to redress this situation and provide the ecological basis for sound conservation management of the species. The thesis consists of two parts: an investigation of habitat use at three spatial scales and a study of the social organization, nesting requirements, breeding behaviour and reproductive success of a population of White-browed Treecreepers. Fifty-six patches of remnant woodland in north-west Victoria were surveyed to determine the factors affecting the occurrence of the White-browed Treecreeper at the regional scale. It was detected in 16 patches, and was largely confined to two core districts - Yarrara and, Wyperfeld (Pine Plains). The floristic composition of the dominant tree species was an important determinant of patch occupancy, with the results providing quantitative support for the previously suspected affinity for Belah Casuarina pauper and Slender Cypress-pine Callitris gracilis — Buloke Allocasuarina luehmannii woodlands. However, the absence of the White-browed Treecreeper from several districts was due to factors other than a lack of appropriate habitat. Demographic isolation - the distance from the focal patch to the nearest population of the White-browed Treecreeper - was the most important variable in explaining variation in patch occupancy. Patches isolated from other treecreeper populations by more than 8.3 km in landscapes of non-preferred native vegetation, and 3 km in agricultural landscapes, were unlikely to support the White-browed Treecreeper. The impact of habitat loss and fragmentation on the capacity of individuals to move through the landscape (i.e. functional connectivity) is considered in relation to disruption to dispersal and migration, and the potential collapse of local metapopulations. Habitat use was then examined in a network of patches and linear strips of Belah woodland embedded in a predominantly cultivated landscape. A minimum area of 18.5 ha of Belah woodland was identified as the most important criterion for patch occupancy at the local scale. This landscape appeared to be permeable to movement by the White-browed Treecreeper, facilitated by the extensive network of linear habitat, and clusters of small to medium fragments. The third scale of habitat use investigated the frequency of use of 1-ha plots within tracts of occupied woodland. It is important to discriminate between habitat traits that operate at the population level, and those that act as proximate cues for habitat selection by individuals. Woodlands that have high tree density, extensive cover of low-stature shrubs, abundant lichen, a complex vertical structure, and relatively low cover of grass and herbs are likely to support larger populations of the White-browed Treecreeper. However, individuals appeared to be using tree dominance (positive) and tall shrub cover (negative) as proximate environmental stimuli for habitat selectivity. A relatively high cover of ground lichen, which probably reflects a ground layer with low disturbance and high structural complexity, was also a reliable indicator of habitat use. Predictive models were developed which could be used to plan vegetation management to enhance habitat for the White-browed Treecreeper. The results of the regional, landscape and patch-scale investigations emphasise that factors operating at multiple spatial scales influence the suitability of remnant vegetation as habitat for the White-browed Treecreeper. The White-browed Treecreeper is typical of many small Australian passerines in that it has high annual survival, small clutches, a long breeding season, multiple broods and relatively low reproductive rates. Reproductive effort is adjusted through the number of clutches laid rather than clutch size. They occupy relatively large, all-purpose territories throughout the year. However, unlike many group territorial birds, territory size was not related to the number of occupants. The White-browed Treecreeper nests in tree hollows. They select hollows with a southerly orientation where possible, and prefer hollows that were higher from the ground. At Yarrara, there was considerable spatial variation in hollow abundance that, in concert with territorial constraints, restricted the actual availability of hollows to less than the absolute abundance of hollows. Thus, the availability of suitable hollows may limit reproductive productivity in some territories, although the magnitude of this constraint on overall population growth is predicted to be small. However, lack of recruitment of hollow-bearing trees would increase the potential for hollow availability to limit population growth. This prospect is particularly relevant in grazed remnants and those outside the reserve system. Facultative cooperative breeding was confirmed, with groups formed through male philopatry. Consequently, natal dispersal is female-biased, although there was no skew in the sex ratio of the fledglings or the general adult population. Helpers were observed performing all activities associated with parenting except copulation and brooding. Cooperatively breeding groups enjoyed higher fledgling productivity than simple pairs, after statistically accounting for territory and parental quality. However, the difference reflected increased productivity in the 1999-breeding season only, when climatic conditions were more favourable than in 1998. Breeding commenced earlier in 1999, and all breeding units were more likely to attempt a second brood. However, only breeders with helpers were successful in fledging second brood young, and it was this difference that accounted for the overall discrepancy in productivity. The key mechanism for increased success in cooperative groups was a reduction hi the interval between first and second broods, facilitated by compensatory reductions in the level of care to the first brood. Thus, females with helpers probably achieved significant energetic savings during this period, which enabled them to re-lay sooner. Furthermore, they were able to recommence nesting when the fledglings from the first brood were younger because there were more adults to feed the dependent juveniles. The current utility, and possible evolutionary pathways, of cooperative breeding is examined from the perspective of both breeders and helpers. Breeders benefit through enhanced fledgling productivity in good breeding conditions and a reduction in the burden of parental care, which may impart significant energetic savings. Further, breeders may facilitate philopatry as a means for ensuring a minimum level of reproductive success. Helpers benefit through an increase in their inclusive fitness in the absence of opportunities for independent breeding (i.e. ecological constraints) and access to breeding vacancies in the natal or adjacent territories (i.e. benefits of philopatry). However, the majority of breeding unit-years comprised unassisted breeders, which suggests that pairs are selectively favoured under certain environmental or demographic conditions.

Longitudinal evaluation of a risk-factor model for adolescent suicidality

This research developed two best-fitting structural equation models of risk factors for adolescent depression and suicidality: a core model, which included parenting factors, gender, depression, and suicidality, and an extended model, which also encompassed personality traits (Introversion and Impulsivity) and mood factors (Anxiety and Anger). Further, this research investigated the consistency of model fit across time (Le., 1 month & 12 months) and samples, and explored the effectiveness of the ReachOut! Internet site as a psychoeducational prevention strategy for adolescent depression and suicidality. Gender, age, and location differences were also explored. Participants were 185 Year-9 students and 93 Year-10 students aged 14 - 16 years, from seven secondary schools in regional and rural Victoria. Students were given a survey which included the Parental Bonding Instrument (Parker, Tupling, & Brown, 1979), the Millon Adolescent Personality Inventory (Millon, Green, & Meagher, 1982), the Profile of Mood States Inventory (McNair & Lorr, 1964), items on suicidal behaviour including some questions from the Revised Adolescent Suicide Questionnaire (Pearce & Martin, 1994), and questions on loss and general demographics. Results supported an indirect model of risk factors, with family factors directly influencing personality factors, which in turn influenced mood factors, including depression, which then influenced suicidality. At the theoretical level, results supported Attachment Theory (Bowlby, 1969), demonstrating that perceived parenting styles that are warm and not overly controlling are more conducive to an adolescent's emotional well-being than are parenting styles that are cold and controlling. Further, results supported Millon's theory of personality (1981), demonstrating that parenting style influences a child's personality. Short-term intervention effects from the internet site were a decrease in Introversion for the full sample, and decreased Inhibition and Suicidality for a high-risk subgroup. Long-term age effects were decreased Inhibition and increased Anxiety for the fall sample. There was also a probable intervention effect for Depression for the high-risk subgroup. No location differences for the risk factors were found between regional and rural areas.

Changing bodies, changing discourses : women's experiences of early menopause

Early menopause has been constructed by discourses of biological determinism as an untimely, but natural, failure of the female body. Medical discourses in particular have interpreted early menopause as a congenital irregularity and a rare anomaly of menopause at midlife. In this thesis I challenge the notion that early menopause is an innate imperfection related only to women’s age. I propose that early menopause is dependent upon the cultural interpretations of individual women and is constituted through the mercurial and multiple discourses of women who have this embodied experience. Moreover, I reveal that early menopause is a contemporary condition and that its location in history is inextricably bound to discourses of risk, naturalism and the self. Further I make the assumption that having an early menopause both affects and is an effect of women’s fertility, sexuality and subjectivity. I have drawn upon a broad range of sources to provide a sociological analysis of early menopause. Literature on early menopause is dominated by positivist discourses, yet many alternate discourses negotiate these influential constructions. I suggest here that the perception of early menopause as a natural fault is merely a construction by medical discourses and does not incorporate the dynamic discourses of early-menopausal women. Moreover, the restriction of early menopause to a genetic female failure excludes the majority of women who have an early menopause through iatrogenisis. This omission occurs through the failure of positivist discourses to accommodate diversity in discourses. Recent sociological and feminist studies have vindicated menopausal women. They have reconstructed menopause through notions of embodiment and have removed the veil of negativity used by the medical sciences to contain menopausal women (Komesaroff, Rothfield and Daly 1997). The visibility of menopausal women, however, remains connected to age. Menopause has been created as a predictable consequence of aging and as such has come to be synonymous with middle age. Nowadays, even men are said to experience menopause at midlife (Carruthers 1996). But early menopause is constituted within the discourses of women who have this experience. Medico-scientific discourses, based upon theories of genetic inevitability, disregard this perspective. Consequently early menopause is subsumed by naturalistic discourses that relate menopause to midlife. Such restraint reflects the unease created by menopause that does not coincide with prescribed life stages. Women's experiences of their changing bodies are largely unheard. Thus, women who have an early menopause are faced with a chasm of ‘cultural non-recognition’ (Fraser 1997). Conjointly with this discursive repression early-menopausal women face social imbalances that are transacted as both cause and consequence of early menopause. In particular the contemporary creation of early menopause is bound to the social and historical location of women as a group. Women are exploited by the institution of medicine, ‘exposure to environmental toxicity’ (Fraser 1997: 11) and commercialization as causes of early menopause. Yet the corporeal effects of practices of risk avoidance (Beck 1993), social practices (Shilling 1993) and Western consumerism (Lupton 1994) fail to be recognized. I address these problematics through a poststructural and feminist critique that assumes moments of commonality among women, while at the same time recognizes shifting and multiple differences (Nicholson 1999). I suggest here that early menopause falls into cultural misrecognition in Fraser's (1997) terms and argue that it is united concurrently with the gender injustice of androcentrism (Fraser 1997: 21). Fraser (1997: 16) suggests that it is only by relating these dual problematics that we are able to make sense of current dilemmas. Thus I have critiqued early menopause through a connection between individual embodied experiences of early menopause and early menopause as a modern phenomenon that is specific to women. I have attempted to unravel these arguments that simultaneously call to ‘... abolish gender differentiation and to valorize gender specificity’ (Fraser 1997: 21) while at the same time acknowledging their interconnectedness. An approach of merely combining women’s discourses with overarching social issues would be inadequate as not only do these problematics intersect but they also can be opposed. As Fraser (1997: 25) notes with her theory, redressing one aspect of cultural or social analysis can further imbalance another. For instance making visible the diversity and uniqueness of individual experiences of early menopause could detract from acknowledging the contemporary construction of early menopause through social inequality. Crucial to this understanding is a destabilizing of the binary construction of differences between the sexes that makes way for a reconstruction of early menopause through ‘sexual slippage’ (Matus 1995). In this thesis I look for a subtlety between the particular and the collective that views early menopause as concurrently a singular and changeable experience as well as imbedded in social practice. I suggest that these concepts are entwined as interactive effects of early menopause. Thus I have analyzed the bivalent problematics of the embodiment and social location of early menopause as imbricated, dynamic and unending discourses. From this perspective I reviewed the literature that was available on early menopause. In Chapter One I look to descriptions of early menopause and note that it has disappeared into a conglomeration of disparate, mostly medical, discourses that are contradictory. Nevertheless medical discourses offer ‘conclusive’ definitions of early menopause that are based on naturalistic views of the body (Shilling 1994). The determinants used are inconsistent and do not include women's discourses of early menopause. Thus, dominant medical discourses obscure women’s embodied experiences of early menopause and ignore the contemporary causes of early menopause. In Chapter Two I examine the causes of early menopause as a way of explaining the disparity between medical discourses and my anecdotal observations of early menopause as a fairly common contemporary occurrence. The relatively recent escalation in gynaecological surgery, especially hysterectomy, appears to account almost single-handedly for early menopause as a current phenomenon. Moreover, the extraordinary number of women who have their uterus removed at hysterectomy can be interpreted as a modern implementation of ancient anxieties. Women's sexuality has been constructed throughout history as problematic and this unease has been translated through women's bodies as dangerous and in need of control (Greer 1992). Thus social concerns which have evolved historically have emerged through the representation of a woman's uterus as an unseen, dark and mysterious risk (Beck 1993). Medical discourses define this risk and are able to negate the so-called dangers of women's sexuality through the surgical removal of their organs. Widespread negotiation of medical discourses is apparent, as hysterectomy in the modern Western world is the most common of all surgical operations (Hufnagel 1989). It is overwhelmingly the most common cause of early menopause as well. I examine also the historical condemnation of infertile women and how this anxiety has been transposed to the modern world through the commercialization of reproduction. Transactions of this social unease can cause early menopause. For instance the medical technology of in-vitro fertilization (I.V.F.) has been offered as a panacea for the infertility of early menopause but, paradoxically, can cause early menopause as well. Conception through technology has been normalized as a viable option for women who are unable to conceive and understandings of I.V.F. have moved into everyday discourse. Medical discourses have constructed fertility as a saleable item and infertile women expect that they can purchase this merchandise. Human eggs have become lucrative commodities that now are available in the market place. Egg ‘donation’ for I.V.F. programs can hasten the attrition rate of eggs and can cause early menopause in some pre-menopausal women (Rowland 1992: 24). Even the recycling of a woman’s uterus supposedly has become a possibility through the transferring of this ‘used’ organ at hysterectomy to a recipient woman who can use the other woman’s uterus as a ‘gestational garage’ (Rogers 1998). In this way women have been disembodied as mechanical systems with inter-changeable body parts and the potentially detrimental consequences of these commercial transactions are ignored. In addition I show how early menopause can be caused by the connection between the self and the social structure. Women's subjectivity is constituted through the cultural discourses available to them and these discourses affect social behaviour (Lupton 1995). For instance smoking and dieting have been identified as causes of early menopause. These activities have been related to the creation of women’s bodies as hetero-sexually desirable and are endemic to young women (Evans-Young 1995). This suggests that cultural causes of early menopause are transactions of sexual politics. Yet there is a paucity of literature that acknowledges the relationship between women’s subjectivity and early menopause. Thus the second chapter exposes a link between sexual politics and causes of early menopause through women's relationships with risk, naturalism and the self. In Chapter Three I deconstruct early menopause through theoretical considerations. I rely on an overarching poststructuralism that embraces the concept of fragmented plural discourses and the subjectivity of menopausal women as a continuous process (Komesaroff 1997: 61). I have woven these variables through broad feminist critiques (Leonard 1997). Through this eclectic approach I hoped to find some loose alignment between the corporeal, ontological and embodied dimensions of early menopause. The recurring themes of sexuality, fertility and subjectivity emerge through deconstructing discourses of sexual difference as immutable and non-negotiable; exposing ‘premature ovarian failure’ as a discursive construction that censures early-menopausal women; and acknowledging the discourses of individual women as unique, diverse and dynamic. I looked to a method of exposing some of these individual discourses and in Chapter Four I describe a critical research process aimed at understanding early menopause as a lived experience. In the remaining chapters I align these ontological arguments with an analysis of the discourses of women who had experienced or were experiencing an early menopause. This section partly relieves the ‘cultural non-recognition’ of the discourses of early-menopausal women. I recorded the narratives of fifty early-menopausal women through in-depth interviews and used this empirical data to direct the study. This data provides the opportunity to understand early menopause as an assortment of embodied experiences. For instance women’s experiences of age at commencement of menopause spanned over three and half decades. They did not reflect the age specifications prescribed by medical discourses. Rather women interpreted their experiences within their own discourses and determined their menopause as early based upon the expectations of their cultural context. Many of the women experienced changes attributed to menopause at midlife. It was not these changes that were significant to early-menopausal women it was how each woman translated these changes that provided meanings of early menopause. In Chapter Five I introduce the women through a table that connects the varying experiences of each woman. This profile shows that, in the main, the women’s experiences of early menopause were unexpected. I suggest that this is due to the disparity between early-menopausal women’s experiences and the current age and social norms of menopause. By bracketing the women into cohorts patterns emerged displaying differences between women who had menopause in their teens, twenties, thirties and forties. Adolescent women had intense feelings of abnormality and despair. Women who were in their twenties were less devastated by menopause than the younger women but described their sexuality and self-identity as changing. And although some women in their thirties were shocked or dismayed to have an early menopause others were ambivalent or happy. These women also described their sexuality and self-identity through changing discourses. A number of the women who were in their forties said that they were ‘too young for the menopause’ but were far less despondent than the younger women. It seemed that the greater the distance between age norms and social norms the more negatively women responded. Age norms that determine the social norms of women's lives through a ‘biological clock’ are constructed to reflect social values. But age is a social construction that changes over time. Thus it would appear that women’s changing bodies and changing discourses of early menopause are in the process of recreating age and social norms around menopause. In Chapter Six I draw upon women’s narratives that describe a connection between early menopause and sexuality. Yet the respondents were not unified in their constructions of sexuality. For instance a number of the women rejected the containment of their sexuality as absolute and defined in terms of bi-lateral hetero-sexual opposition. The discourses of these women constructed their sexuality as continuously flexible. Some early-menopausal women described this sexual mobility as an equivocal relationship between their sexuality, reproductive capacity and female organs. Other women articulated their sexuality as vacillating, ambiguous and unrepresentative of the so-called ‘true woman’. Several felt that they were not meant to have female reproductive organs at all. Nearly one third of the women had had their uterus removed at hysterectomy and the reproductive organs of two women were rudimentary. Women’s narratives showed that the social value of fertility influences constructions of early menopause. In Chapter Seven I record the contrast between the poignant responses of women who wished to have a baby of their own and other women who resisted discourses that entwine reproductivity with being a woman. For instance some women negotiated fertility through economic discourses of consumerism with the expectation that they could purchase conception as a commodity. Other women welcomed their early menopause as freedom from contraceptive concerns and others had no interest in reproduction at all. Thus discord arose through discourses that problematize early-menopausal women as non-reproductive and discourses that value variability. In addition many of the women’s accounts constructed their subjectivity as mobile, challenging the notion that discourses of the self are immutable. Chapter Eight presents narratives which suggest that the subjectivity of many women was altered continuously by early menopause. Yet some of the women rejected the construction of their subjectivity as unfluctuating. These contradictions reflect the uncertainties of the contemporary world. Nevertheless most respondents found that the tethering of menopause to constructions of midlife was incongruous with their own experiences. Many women refused to accept the label of social redundancy attached to middle-aged women. They moved their subjectivity beyond the reproductive body to a shifting and tractable identity of the self. This thesis demonstrates that the medical construction of early menopause as a rare and natural female flaw varies from women's experiences which suggest that early menopause is common and discursively constructed. This disparity has occurred through the privilege placed upon the construction of bodies as immutable and sexually static. This privileging has obscured the multi-dimensional causes of early menopause and given preference to a mono-causal theory. By exposing the variety of causes of early menopause the medical construction of women through a universal and unalterable body of reproduction is challenged. Moreover, women's discourses of early menopause demonstrate that the medical reduction of early menopause to a spontaneous bio-chemical malfunction has ignored the volatility of women’s embodied experiences. Women experience early menopause variously and through mercurial discourses. I suggest here that women's discourses of their experiences of early menopause reflect recurring and restructuring philosophical quandaries of fertility, sexuality and subjectivity. While there can be no representative claims made from this thesis it contributes to an understanding of the embodied experiences of early menopause. It provides an understanding of the creation of early menopause through social practices and goes part way to redressing the problematics of what Fraser terms ‘cultural non-recognition’. But, more importantly, it acknowledges early menopause as a variety of experiences where women interpret their changing bodies through changing discourses.

Prevention of body concerns and risk behaviours in adolescent boys

Overall, this thesis was designed to explore the nature of adolescent boys' body image, the effects of body image on body change strategies and psychological adjustment, and the factors that influence body image. The first study examined body image in 362 adolescent boys. Body image was considered in terms of attitudes to different body parts and attributes, including, lower, middle and upper body, as well as weight, shape and muscles. The relationships between Body Mass Index (BMI), body image, sociocultural messages, psychological adjustment and body change strategies, including strategies to decrease weight and increase muscles using food and exercise, drive for thinness, bulimic attitudes and behaviour, excessive exercise, food supplements to lose weight, increase muscles and steroids, were also investigated. Multiple regression analyses were used to examine the role of body image, sociocultural messages and psychological adjustment to predict satisfaction with different body attributes and body change strategies. The findings from study one led to the development of a program aimed at preventing the development of unhealthy attitudes and behaviours among adolescent boys. Study two involved the implementation and evaluation of this prevention program. One hundred and twenty one boys participated in the program. The program was based on social-cognitive theory, and included a focus on accepting differences and the development of self-esteem. The boys who participated in the program indicated some change in existing attitudes and showed less development of risk behaviours relative to the control group. The implications of the findings from this thesis in relation to future research, as well as the prevention of adolescent boys' body image problems are discussed.

Surface behaviour and lipid interaction of Alzheimer beta-amyloid peptide 1-42: a membrane-disrupting peptide

Amyloid aggregates, found in patients that suffer from Alzheimer's disease, are composed of fibril-forming peptides in a β-sheet conformation. One of the most abundant components in amyloid aggregates is the β-amyloid peptide 1–42 (Aβ 1–42). Membrane alterations may proceed to cell death by either an oxidative stress mechanism, caused by the peptide and synergized by transition metal ions, or through formation of ion channels by peptide interfacial self-aggregation. Here we demonstrate that Langmuir films of Aβ 1–42, either in pure form or mixed with lipids, develop stable monomolecular arrays with a high surface stability. By using micropipette aspiration technique and confocal microscopy we show that Aβ 1–42 induces a strong membrane destabilization in giant unilamellar vesicles composed of palmitoyloleoyl-phosphatidylcholine, sphingomyelin, and cholesterol, lowering the critical tension of vesicle rupture. Additionally, Aβ 1–42 triggers the induction of a sequential leakage of low- and high-molecular-weight markers trapped inside the giant unilamellar vesicles, but preserving the vesicle shape. Consequently, the Aβ 1–42 sequence confers particular molecular properties to the peptide that, in turn, influence supramolecular properties associated to membranes that may result in toxicity, including: 1), an ability of the peptide to strongly associate with the membrane; 2), a reduction of lateral membrane cohesive forces; and 3), a capacity to break the transbilayer gradient and puncture sealed vesicles.

Media reports of heroin overdose spates: public health messages, moral panics or risk advertisements?

This article reports on an investigation of the public health utility of media messages concerning spates (temporal clusters) of heroin-related overdose (HOD) from the perspective of some injecting drug users (IDUs). In-depth qualitative interviews were carried out with a convenience sample of 60 IDUs, in the setting of two Needle and Syringe Programs in an Australian regional city (Geelong) between April and May 2000. Very few interviewees reported that they had personally experienced a spate of overdoses. None of the interviewees reported communicating the existence of a killer batch to other IDUs. No interviewees reported having changed either their injecting practices or the amount of heroin they used following such a media alert. Indeed, a substantial minority of the interviewees reported seeking out these stronger batches and participant narratives illustrate that, for a substantial group of interviewees, the media reporting of a hypothetical 'killer batch' of heroin may have implications for their drug-seeking and health-related behaviour. It was found that the accuracy of information available to IDUs is mixed and that the flow of information within this social network was slow. Findings demonstrate that media reporting of killer batches of heroin has little value as a public health strategy and provide an example of how some activities that are proposed as public health measures may in fact have the opposite effect.

Scapegoating, self-confidence and risk comparison : the functionality of risk neutralisation and lay epidemiology by injecting drug users

This paper investigates the competing rationalities of scientific and lay epidemiology and how the tension between the two impacts on the efficacy of health promotion messages for injecting drug users (IDUs). It proposes that behaviours, which may be difficult to understand when viewed at an individual level, are, in fact, rational within particular cultural contexts. The study used qualitative semi-structured interviews with 60 heroin users. A number of different types of risk neutralisation were observed in this group of interviewees, including: scapegoating, self-confidence and risk comparison. Interviewees commonly used lay epidemiology to justify and rationalise their risk neutralisation strategies. The paper provides concrete examples of the ways in which this group of IDUs neutralise risk through the use of these strategies. The findings illustrate how many of the psychological constructs surrounding the perception of risk which focus on individual behaviour are fundamentally simplistic and often unhelpful in understanding the behaviours of this group of people. It is concluded that some ‘risk’ behaviours are often functional and rational within the context of prohibitionist drug policies which create an environment in which the IDU often has little real agency to reduce the risks associated with their drug use.

Investigation of the interaction between risk types in the outsourcing of the information technology function

Describes a new theory of behaviour of risks in an information technology (IT) outsourcing exercise. A framework developed during the study allows practioners and managers to allay anxieties about managing uncertainty from risks that manifest when multiple parties interact over long periods of time in this environment.

Electrochemical behaviour of the pyrethroid insecticides

A systematic study is made of the electrochemical reduction and oxidation of eighteen pyrethroid insecticides and six model compounds. In addition the electrochemical oxidation of an insecticide synergist and the reduction of an insect repellent is studied. Oxidation and reduction mechanisms were partially or fully assigned for the the electrochemical reactions. The results indicate the presence of two oxidation sites common to the majority of pyrethroids. Specific sites of electrochemical reduction are observed for a number of pyrethroids. The electrochemical respones may be applied to the selective determination of a number pf pyrethroids synergists and repellents in commercial formulations without the requirement of pyrethroids, synergists and repellents in commerical formulations without the requirement for extensive sample preparation or the use of a separation technique.