Human papillomavirus prevalence, viral load and pre-cancerous lesions of the cervix in women initiating highly active antiretroviral therapy in South Africa : a cross-sectional study

Background Cervical cancer and infection with human immunodeficiency virus (HIV) are both important public health problems in South Africa (SA). The aim of this study was to determine the prevalence of cervical squamous intraepithelial lesions (SILs), high-risk human papillomavirus (HR-HPV), HPV viral load and HPV genotypes in HIV positive women initiating anti-retroviral (ARV) therapy. Methods A cross-sectional survey was conducted at an anti-retroviral (ARV) treatment clinic in Cape Town, SA in 2007. Cervical specimens were taken for cytological analysis and HPV testing. The Digene Hybrid Capture 2 (HC2) test was used to detect HR-HPV. Relative light units (RLU) were used as a measure of HPV viral load. HPV types were determined using the Roche Linear Array HPV Genotyping test. Crude associations with abnormal cytology were tested and multiple logistic regression was used to determine independent risk factors for abnormal cytology. Results The median age of the 109 participants was 31 years, the median CD4 count was 125/mm3, 66.3% had an abnormal Pap smear, the HR-HPV prevalence was 78.9% (Digene), the median HPV viral load was 181.1 RLU (HC2 positive samples only) and 78.4% had multiple genotypes. Among women with abnormal smears the most prevalent HR-HPV types were HPV types 16, 58 and 51, all with a prevalence of 28.5%. On univariate analysis HR-HPV, multiple HPV types and HPV viral load were significantly associated with the presence of low and high-grade SILs (LSIL/HSIL). The multivariate logistic regression showed that HPV viral load was associated with an increased odds of LSIL/HSIL, odds ratio of 10.7 (95% CI 2.0 – 57.7) for those that were HC2 positive and had a viral load of ≤ 181.1 RLU (the median HPV viral load), and 33.8 (95% CI 6.4 – 178.9) for those that were HC2 positive with a HPV viral load > 181.1 RLU. Conclusion Women initiating ARVs have a high prevalence of abnormal Pap smears and HR-HPV. Our results underscore the need for locally relevant, rigorous screening protocols for the increasing numbers of women accessing ARV therapy so that the benefits of ARVs are not partially offset by an excess risk in cervical cancer.

In vitro physical stimulation of tissue-engineered and native cartilage

Because of the limited availability of donor cartilage for resurfacing defects in articular surfaces, there is tremendous interest in the in vitro bioengineering of cartilage replacements for clinical applications. However, attaining mechanical properties in engineered cartilaginous constructs that approach those of native cartilage has not been previously achieved when constructs are cultured under free-swelling conditions. One approach toward stimulating the development of constructs that are mechanically more robust is to expose them to physical environments that are similar, in certain ways, to those encountered by native cartilage. This is a strategy motivated by observations in numerous short-term experiments that certain mechanical signals are potent stimulators of cartilage metabolism. On the other hand, excess mechanical loading can have a deleterious effect on cartilage. Culture conditions that include a physical stimulation component are made possible by the use of specialized bioreactors. This chapter addresses some of the issues involved in using bioreactors as integral components of cartilage tissue engineering and in studying the physical regulation of cartilage. We first consider the generation of cartilaginous constructs in vitro. Next we describe the rationale and design of bioreactors that can impart either mechanical deformation or fluid-induced mechanical signals.

Interstellar titanium-oxides in interplanetary dust

Interstellar gas abundances (Clayton et al., 1986) suggest that titanium may be bound up in dust and indeed, excess titanium in carbonaceous chondrites is attributed to mixing of interstellar and Solar System materials (Morton, 1974). Fine-grained chondritic interplanetary dust particles (lOPs) of cometary origin are relatively pristine early Solar System materials (Mackinnon and Rietmeijer, 1987; Rietmeijer, 1987) and show chemical and mineralogical signatures related to a pre-solar or nebular origin. For example, large OtH ratios suggest a presolar or interstellar dust component in some chondritic lOPs(Mackinnon and Rietmeijer, 1987). Ti/Si ratios (normalized to bulk CI) in lOPs and carbonaceous chondrite matrices exceed solar abundances but are similar to dust from comet Halley (Jessberger et al., 1987). The Ti-distribution in chondritic lOPs shows major, small-scale « 0.1 urn) variations (Flynn et al., 1978) consistent with heterogeneously distributed Ti-bearingphases. Analytical electron microscope (AEM) studies, in fact, have identified platey grains of Ti-metal, Ti407 and Ti s09 in two different lOPs (Mackinnon and Rietmeijer, 1987). The occurrence of Ti407 was related in situ low-temperature aqueous alteration and therefore implied the presence of BaTi03 (Rietmeijer and Mackinnon, 1984). Yet, the presence ofTis09 in an lOp which shows no evidence of aqueous alteration (Rietmeijer.and McKay, 1986) requires a different interpretation. The distribution of Ti-oxides in chondritic lOPs were investigated with ultra-microtomed thin sections of fluffy chondri tic lOP U2011*B (lSC allocation U2011C2) using a lEOL 2000FX AEM operating at an accelerating voltage of 200kV and with an attached Tracor Northern TN5500 energy dispersive spectrometer.

Structural characterisation of kaolinite : NaCl intercalate and its derivatives

Kaolinite:NaCl intercalates with basal layer dimensions of 0.95 and 1.25 nm have been prepared by direct reaction of saturated aqueous NaCl solution with well-crystallized source clay KGa-1. The intercalates and their thermal decomposition products have been studied by XRD, solid-state 23Na, 27Al, and 29Si MAS NMR, and FTIR. Intercalate yield is enhanced by dry grinding of kaolinite with NaCl prior to intercalation. The layered structure survives dehydroxylation of the kaolinite at 500°–600°C and persists to above 800°C with a resultant tetrahedral aluminosilicate framework. Excess NaCl can be readily removed by rinsing with water, producing an XRD ‘amorphous’ material. Upon heating at 900°C this material converts to a well-crystallized framework aluminosilicate closely related to low-camegieite, NaAlSiO4, some 350°C below its stability field. Reaction mechanisms are discussed and structural models proposed for each of these novel materials.

Balls up : the converse blank canvas project

Research background: For decades the Chuck Taylor All Star basketball shoe (first designed in 1921 by Converse, an American shoe company), has been an iconic item of fashion apparel, particularly for the youth oriented market - as a form of self expression and identify, adolescents have for generations been customising their Converse sneakers to create innovative and unique footwear. Although originally developed purely for sport, sneakers gradually crossed over into fashion and the majority of athletic shoes are now purchased for street fashion or leisure wear. Artisan Gallery (Brisbane), in conjunction with the exhibition Reboot: Function, Fashion and the Sneaker, a history of the sneaker, selected 20 designers to customise and re-design the classic Converse Chuck Taylor All Stars shoe and in doing so highlighted the diversity of forms possible for creative outcomes. As Artisan Gallery Curator Kirsten Fitzpatrick states “the ‘sports show’, designed to coincide with the Olympics, is also about exploring the sneaker as a platform for creativity... and (one) of the more bazaar creations was Dean Brough's deconstructed shoes to make men’s underwear.” The exhibition ran from 21 June – 16 August 2012: http://artisan-ideaskillproduct.blogspot.com.au/2012/06/converse-blank-canvas-project.html Research question: Even though the sneaker is a fashion item, it still is fundamentally used for foot protection and historically was aligned to ball sports, principally Basketball - as a fashion designers/practitioner how can I connect (in a whimsical manner) this history of usage for ball sports to the sneaker and re-design and re-use all the physical elements of the shoe to produce a unique wearable item of clothing - the selected medium for this challenge and experimentation was the classic archetypal men’s white boxer shorts. Artisan Statement BALLS UP - The Converse Sneaker, it’s almost impossible to imagine a better rounded item to maintain peak performance for all types of ball sports. Gentlemen, your other most precious balls also deserve this level of comfort and support to sustain the hard times – the Converse Boxer, balls up, bats out, get ready to play hard. Research contribution: The project highlighted some of the unique and diverse creative manifestations that are possible from the classic sneaker. From a fashion practitioners’ perspective, the design outcomes (men’s boxer short made from converse sneakers) demonstrated the strong association to iconic fashion apparel, and recognised the connection to wearability and comfort that is requisite in both footwear and men’s underwear. Research significance: The exhibition was viewed by in excess of 1000 people and generated exceptional media coverage and public exposure/impact. As Artisan Gallery Curator Kirsten Fitzpatrick states “20 of Brisbane's best designers were given the opportunity to customise their own Converse Sneakers, with The Converse Blank Canvas Project.” And to be selected in this category demonstrates the calibre of importance for design prominence.

Spatial modelling of population health screening : the role of accessibility in predicting expected patient flows

This paper describes a generalised linear mixed model (GLMM) approach for understanding spatial patterns of participation in population health screening, in the presence of multiple screening facilities. The models presented have dual focus, namely the prediction of expected patient flows from regions to services and relative rates of participation by region- service combination, with both outputs having meaningful implications for the monitoring of current service uptake and provision. The novelty of this paper lies with the former focus, and an approach for distributing expected participation by region based on proximity to services is proposed. The modelling of relative rates of participation is achieved through the combination of different random effects, as a means of assigning excess participation to different sources. The methodology is applied to participation data collected from a government-funded mammography program in Brisbane, Australia.

Does fundamental indexation lead to better risk-adjusted returns? New evidence from Australian Securities Exchange

We investigate the claims of superiority of fundamental indexation strategy over capitalisation-weighted indexation by using data for Australian Securities Exchange (ASX) listed stocks. Whilst our results are in line with the outperformance observed in other geographical markets, we find that the excess returns from fundamental indexation in Australian market are much higher. On a rolling 5-year basis, the fundamental index always outperforms the capitalisation-weighted index. Our results suggest that superior performance of fundamental indexation could not be entirely attributed to value, size, or momentum effects. The outperformance persists even after adjusting for slightly higher transaction costs related to turnover.

Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990–2010 : a systematic analysis for the Global Burden of Disease Study 2010

Background Non-fatal health outcomes from diseases and injuries are a crucial consideration in the promotion and monitoring of individual and population health. The Global Burden of Disease (GBD) studies done in 1990 and 2000 have been the only studies to quantify non-fatal health outcomes across an exhaustive set of disorders at the global and regional level. Neither effort quantified uncertainty in prevalence or years lived with disability (YLDs). Methods Of the 291 diseases and injuries in the GBD cause list, 289 cause disability. For 1160 sequelae of the 289 diseases and injuries, we undertook a systematic analysis of prevalence, incidence, remission, duration, and excess mortality. Sources included published studies, case notification, population-based cancer registries, other disease registries, antenatal clinic serosurveillance, hospital discharge data, ambulatory care data, household surveys, other surveys, and cohort studies. For most sequelae, we used a Bayesian meta-regression method, DisMod-MR, designed to address key limitations in descriptive epidemiological data, including missing data, inconsistency, and large methodological variation between data sources. For some disorders, we used natural history models, geospatial models, back-calculation models (models calculating incidence from population mortality rates and case fatality), or registration completeness models (models adjusting for incomplete registration with health-system access and other covariates). Disability weights for 220 unique health states were used to capture the severity of health loss. YLDs by cause at age, sex, country, and year levels were adjusted for comorbidity with simulation methods. We included uncertainty estimates at all stages of the analysis. Findings Global prevalence for all ages combined in 2010 across the 1160 sequelae ranged from fewer than one case per 1 million people to 350 000 cases per 1 million people. Prevalence and severity of health loss were weakly correlated (correlation coefficient −0·37). In 2010, there were 777 million YLDs from all causes, up from 583 million in 1990. The main contributors to global YLDs were mental and behavioural disorders, musculoskeletal disorders, and diabetes or endocrine diseases. The leading specific causes of YLDs were much the same in 2010 as they were in 1990: low back pain, major depressive disorder, iron-deficiency anaemia, neck pain, chronic obstructive pulmonary disease, anxiety disorders, migraine, diabetes, and falls. Age-specific prevalence of YLDs increased with age in all regions and has decreased slightly from 1990 to 2010. Regional patterns of the leading causes of YLDs were more similar compared with years of life lost due to premature mortality. Neglected tropical diseases, HIV/AIDS, tuberculosis, malaria, and anaemia were important causes of YLDs in sub-Saharan Africa. Interpretation Rates of YLDs per 100 000 people have remained largely constant over time but rise steadily with age. Population growth and ageing have increased YLD numbers and crude rates over the past two decades. Prevalences of the most common causes of YLDs, such as mental and behavioural disorders and musculoskeletal disorders, have not decreased. Health systems will need to address the needs of the rising numbers of individuals with a range of disorders that largely cause disability but not mortality. Quantification of the burden of non-fatal health outcomes will be crucial to understand how well health systems are responding to these challenges. Effective and affordable strategies to deal with this rising burden are an urgent priority for health systems in most parts of the world. Funding Bill & Melinda Gates Foundation.

ECMO : the clinician’s view

Background: Extra corporeal membrane oxygenation (ECMO) is a complex rescue therapy used to provide cardiac and/or respiratory support for critically ill patients who have failed maximal conventional medical management. ECMO is based on a modified cardiopulmonary bypass (CPB) circuit, and can provide cardiopulmonary support for up-to several months. It can be used in a veno venous configuration for isolated respiratory failure, (VV-ECMO), or in a veno arterial configuration (VA-ECMO) where support is necessary for cardiac +/- respiratory failure. The ECMO circuit consists of five main components: large bore cannulae (access cannulae) for drainage of the venous system, and return cannulae to either the venous (in VV-ECMO) or arterial (in VA ECMO) system. An oxygenator, with a vast surface area of hollow filaments, allows addition of oxygen and removal of carbon dioxide; a centrifugal blood pump allows propulsion of blood through the circuit at upto 10 L/minute; a control module and a thermoregulatory unit, which allows for exact temperature control of the extra corporeal blood. Methods: The first successful use of ECMO for ARDS in adults occurred in 1972, and its use has become more commonplace over the last 30 years, supported by the improvement in design and biocompatibility of the equipment, which has reduced the morbidity associated with this modality. Whilst the use of ECMO in neonatal population has been supported by numerous studies, the evidence upon which ECMO was integrated into adult practice was substantially less robust. Results: Recent data, including the CESAR study (Conventional Ventilatory Support versus Extra corporeal membrane oxygenation for Severe Respiratory failure) has added a degree of evidence to the role of ECMO in such a patient population. The CESAR study analysed 180 patients, and confirmed that ECMO was associated with an improved rate of survival. More recently, ECMO has been utilized in numerous situations within the critical care area, including support in high-risk percutaneous interventions in cardiac catheter lab; the operating room, emergency department, as well in specialized inter-hospital retrieval services. The increased understanding of the risk:benefit profile of ECMO, along with a reduction in morbidity associated with its use will doubtless lead to a substantial rise in the utilisation of this modality. As with all extra-corporeal circuits, ECMO opposes the basic premises of the mammalian inflammation and coagulation cascade where blood comes into foreign circulation, both these cascades are activated. Anti-coagulation is readily dealt with through use of agents such as heparin, but the inflammatory excess, whilst less macroscopically obvious, continues un-abated. Platelet consumption and neutrophil activation occur rapidly, and the clinician is faced with balancing the need of anticoagulation for the circuit, against haemostasis in an acutely bleeding patient. Alterations in pharmacokinetics may result in inadequate levels of disease modifying therapeutics, such as antibiotics, hence paradoxically delaying recovery from conditions such as pneumonia. Key elements of nutrition and the innate immune system maysimilarly be affected. Summary: This presentation will discuss the basic features of ECMO to the nonspecialist, and review the clinical conundrum faced by the team treating these most complex cases.

A comprehensive investigation of the risky driving behaviour of young novice drivers

Young novice drivers - that is, drivers aged 16-25 years who are relatively inexperienced in driving on the road and have a novice (Learner, Provisional) driver's licence - have been overrepresented in car crash, injury and fatality statistics around the world for decades. There are numerous persistent characteristics evident in young novice driver crashes, fatalities and offences, including variables relating to the young driver themselves, broader social influences which include their passengers, the car they drive, and when and how they drive, and their risky driving behaviour in particular. Moreover, there are a range of psychosocial factors influencing the behaviour of young novice drivers, including the social influences of parents and peers, and person-related factors such as age-related factors, attitudes, and sensation seeking. Historically, a range of approaches have been developed to manage the risky driving behaviour of young novice drivers. Traditional measures predominantly relying upon education have had limited success in regulating the risky driving behaviour of the young novice driver. In contrast, interventions such as graduated driver licensing (GDL) which acknowledges young novice drivers' limitations - principally pertaining to their chronological and developmental age, and their driving inexperience - have shown to be effective in ameliorating this pervasive public health problem. In practice, GDL is a risk management tool that is designed to reduce driving at risky times (e.g., at night) or in risky driving conditions (e.g., with passengers), while still enabling novice drivers to obtain experience. In this regard, the GDL program in Queensland, Australia, was considerably enhanced in July 2007, and major additions to the program include mandated Learner practice of 100 hours recorded in a logbook, and passenger limits during night driving in the Provisional phase. Road safety researchers have also continued to consider the influential role played by the young driver's psychosocial characteristics, including psychological traits and states. In addition, whilst the majority of road safety user research is epidemiological in nature, contemporary road safety research is increasingly applying psychological and criminological theories. Importantly, such theories not only can guide young novice driver research, they can also inform the development and evaluation of countermeasures targeting their risky driving behaviour. The research is thus designed to explore the self-reported behaviours - and the personal, psychosocial, and structural influences upon the behaviours - of young novice drivers This thesis incorporates three stages of predominantly quantitative research to undertake a comprehensive investigation of the risky driving behaviour of young novices. Risky driving behaviour increases the likelihood of the young novice driver being involved in a crash which may harm themselves or other road users, and deliberate risky driving such as driving in excess of the posted speed limits is the focus of the program of research. The extant literature examining the nature of the risky behaviour of the young novice driver - and the contributing factors for this behaviour - while comprehensive, has not led to the development of a reliable instrument designed specifically to measure the risky behaviour of the young novice driver. Therefore the development and application of such a tool (the Behaviour of Young Novice Drivers Scale, or BYNDS) was foremost in the program of research. In addition to describing the driving behaviours of the young novice, a central theme of this program of research was identifying, describing, and quantifying personal, behavioural, and environmental influences upon young novice driver risky behaviour. Accordingly the 11 papers developed from the three stages of research which comprise this thesis are framed within Bandura's reciprocal determinism model which explicitly considers the reciprocal relationship between the environment, the person, and their behaviour. Stage One comprised the foundation research and operationalised quantitative and qualitative methodologies to finalise the instrument used in Stages Two and Three. The first part of Stage One involved an online survey which was completed by 761 young novice drivers who attended tertiary education institutions across Queensland. A reliable instrument for measuring the risky driving behaviour of young novices was developed (the BYNDS) and is currently being operationalised in young novice driver research in progress at the Centre for Injury Research and Prevention in Philadelphia, USA. In addition, regression analyses revealed that psychological distress influenced risky driving behaviour, and the differential influence of depression, anxiety, sensitivity to punishments and rewards, and sensation seeking propensity were explored. Path model analyses revealed that punishment sensitivity was mediated by anxiety and depression; and the influence of depression, anxiety, reward sensitivity and sensation seeking propensity were moderated by the gender of the driver. Specifically, for males, sensation seeking propensity, depression, and reward sensitivity were predictive of self-reported risky driving, whilst for females anxiety was also influential. In the second part of Stage One, 21 young novice drivers participated in individual and small group interviews. The normative influences of parents, peers, and the Police were explicated. Content analysis supported four themes of influence through punishments, rewards, and the behaviours and attitudes of parents and friends. The Police were also influential upon the risky driving behaviour of young novices. The findings of both parts of Stage One informed the research of Stage Two. Stage Two was a comprehensive investigation of the pre-Licence and Learner experiences, attitudes, and behaviours, of young novice drivers. In this stage, 1170 young novice drivers from across Queensland completed an online or paper survey exploring their experiences, behaviours and attitudes as a pre- and Learner driver. The majority of novices did not drive before they were licensed (pre-Licence driving) or as an unsupervised Learner, submitted accurate logbooks, intended to follow the road rules as a Provisional driver, and reported practicing predominantly at the end of the Learner period. The experience of Learners in the enhanced-GDL program were also examined and compared to those of Learner drivers who progressed through the former-GDL program (data collected previously by Bates, Watson, & King, 2009a). Importantly, current-GDL Learners reported significantly more driving practice and a longer Learner period, less difficulty obtaining practice, and less offence detection and crash involvement than Learners in the former-GDL program. The findings of Stage Two informed the research of Stage Three. Stage Three was a comprehensive exploration of the driving experiences, attitudes and behaviours of young novice drivers during their first six months of Provisional 1 licensure. In this stage, 390 of the 1170 young novice drivers from Stage Two completed another survey, and data collected during Stages Two and Three allowed a longitudinal investigation of self-reported risky driving behaviours, such as GDL-specific and general road rule compliance; risky behaviour such as pre-Licence driving, crash involvement and offence detection; and vehicle ownership, paying attention to Police presence, and punishment avoidance. Whilst the majority of Learner and Provisional drivers reported compliance with GDL-specific and general road rules, 33% of Learners and 50% of Provisional drivers reported speeding by 10-20 km/hr at least occasionally. Twelve percent of Learner drivers reported pre-Licence driving, and these drivers were significantly more risky as Learner and Provisional drivers. Ten percent of males and females reported being involved in a crash, and 10% of females and 18% of males had been detected for an offence, within the first six months of independent driving. Additionally, 75% of young novice drivers reported owning their own car within six months of gaining their Provisional driver's licence. Vehicle owners reported significantly shorter Learner periods and more risky driving exposure as a Provisional driver. Paying attention to Police presence on the roads appeared normative for young novice drivers: 91% of Learners and 72% of Provisional drivers reported paying attention. Provisional drivers also reported they actively avoided the Police: 25% of males and 13% of females; 23% of rural drivers and 15% of urban drivers. Stage Three also allowed the refinement of the risky behaviour measurement tool (BYNDS) created in Stage One; the original reliable 44-item instrument was refined to a similarly reliable 36-item instrument. A longitudinal exploration of the influence of anxiety, depression, sensation seeking propensity and reward sensitivity upon the risky behaviour of the Provisional driver was also undertaken using data collected in Stages Two and Three. Consistent with the research of Stage One, structural equation modeling revealed anxiety, reward sensitivity and sensation seeking propensity predicted self-reported risky driving behaviour. Again, gender was a moderator, with only reward sensitivity predicting risky driving for males. A measurement model of Akers' social learning theory (SLT) was developed containing six subscales operationalising the four constructs of differential association, imitation, personal attitudes, and differential reinforcement, and the influence of parents and peers was captured within the items in a number of these constructs. Analyses exploring the nature and extent of the psychosocial influences of personal characteristics (step 1), Akers' SLT (step 2), and elements of the prototype/willingness model (PWM) (step 3) upon self-reported speeding by the Provisional driver in a hierarchical multiple regression model found the following significant predictors: gender (male), car ownership (own car), reward sensitivity (greater sensitivity), depression (greater depression), personal attitudes (more risky attitudes), and speeding (more speeding) as a Learner. The research findings have considerable implications for road safety researchers, policy-makers, mental health professionals and medical practitioners alike. A broad range of issues need to be considered when developing, implementing and evaluating interventions for both the intentional and unintentional risky driving behaviours of interest. While a variety of interventions have been historically utilised, including education, enforcement, rehabilitation and incentives, caution is warranted. A multi-faceted approach to improving novice road safety is more likely to be effective, and new and existing countermeasures should capitalise on the potential of parents, peers and Police to be a positive influence upon the risky behaviour of young novice drivers. However, the efficacy of some interventions remains undetermined at this time. Notwithstanding this caveat, countermeasures such as augmenting and strengthening Queensland's GDL program and targeting parents and adolescents particularly warrant further attention. The findings of the research program suggest that Queensland's current-GDL can be strengthened by increasing compliance of young novice drivers with existing conditions and restrictions. The rates of speeding reported by the young Learner driver are particularly alarming for a number of reasons. The Learner is inexperienced in driving, and travelling in excess of speed limits places them at greater risk as they are also inexperienced in detecting and responding appropriately to driving hazards. In addition, the Learner period should provide the foundation for a safe lifetime driving career, enabling the development and reinforcement of non-risky driving habits. Learners who sped reported speeding by greater margins, and at greater frequencies, when they were able to drive independently. Other strategies could also be considered to enhance Queensland's GDL program, addressing both the pre-Licence adolescent and their parents. Options that warrant further investigation to determine their likely effectiveness include screening and treatment of novice drivers by mental health professionals and/or medical practitioners; and general social skills training. Considering the self-reported pre-licence driving of the young novice driver, targeted education of parents may need to occur before their child obtains a Learner licence. It is noteworthy that those participants who reported risky driving during the Learner phase also were more likely to report risky driving behaviour during the Provisional phase; therefore it appears vital that the development of safe driving habits is encouraged from the beginning of the novice period. General education of parents and young novice drivers should inform them of the considerably-increased likelihood of risky driving behaviour, crashes and offences associated with having unlimited access to a vehicle in the early stages of intermediate licensure. Importantly, parents frequently purchase the car that is used by the Provisional driver, who typically lives at home with their parents, and therefore parents are ideally positioned to monitor the journeys of their young novice driver during this early stage of independent driving. Parents are pivotal in the development of their driving child: they are models who are imitated and are sources of attitudes, expectancies, rewards and punishments; and they provide the most driving instruction for the Learner. High rates of self-reported speeding by Learners suggests that GDL programs specifically consider the nature of supervision during the Learner period, encouraging supervisors to be vigilant to compliance with general and GDL-specific road rules, and especially driving in excess of speed limit. Attitudes towards driving are formed before the adolescent reaches the age when they can be legally licensed. Young novice drivers with risky personal attitudes towards driving reported more risky driving behaviour, suggesting that countermeasures should target such attitudes and that such interventions might be implemented before the adolescent is licensed. The risky behaviours and attitudes of friends were also found to be influential, and given that young novice drivers tend to carry their friends as their passengers, a group intervention such as provided in a school class context may prove more effective. Social skills interventions that encourage the novice to resist the negative influences of their friends and their peer passengers, and to not imitate the risky driving behaviour of their friends, may also be effective. The punishments and rewards anticipated from and administered by friends were also found to influence the self-reported risky behaviour of the young novice driver; therefore young persons could be encouraged to sanction the risky, and to reward the non-risky, driving of their novice friends. Adolescent health programs and related initiatives need to more specifically consider the risks associated with driving. Young novice drivers are also adolescents, a developmental period associated with depression and anxiety. Depression, anxiety, and sensation seeking propensity were found to be predictive of risky driving; therefore interventions targeting psychological distress, whilst discouraging the expression of sensation seeking propensity whilst driving, warrant development and trialing. In addition, given that reward sensitivity was also predictive, a scheme which rewards novice drivers for safe driving behaviour - rather than rewarding the novice through emotional and instrumental rewards for risky driving behaviour - requires further investigation. The Police were also influential in the risky driving behaviour of young novices. Young novice drivers who had been detected for an offence, and then avoided punishment, reacted differentially, with some drivers appearing to become less risky after the encounter, whilst for others their risky behaviour appeared to be reinforced and therefore was more likely to be performed again. Such drivers saw t

Neutrophil activation, antioxidant supplements and exercise-induced oxidative stress

Neutrophils produce free radicals known as reactive oxygen species (ROS), which assist in the clearance of damaged host tissue. Tissue damage may occur during exercise due to muscle damage, thermal stress and ischaemia/reperfusion. When produced in excess, neutrophil-derived ROS may overwhelm the body's endogenous antioxidant defence mechanisms, and this can lead to oxidative stress. There is increasing evidence for links between oxidative stress and a variety of pathological disorders such as cardiovascular diseases, cancer, chronic inflammatory diseases and post-ischaemic organ injury. A small number of studies have investigated whether there is a link between neutrophil activation and oxidative stress during exercise. In this review, we have summarised the findings of these studies. Exercise promotes the release of neutrophils into the circulation, and some evidence suggests that neutrophils mobilised after exercise have an enhanced capacity to generate some forms of ROS when stimulated in vitro. Neutrophil activation during exercise may challenge endogenous antioxidant defence mechanisms, but does not appear to increase lipid markers of oxidative stress to any significant degree, at least in the circulation. Antioxidant supplements such as N-acetylcysteine are effective at attenuating increases in the capacity of neutrophils to generate ROS when stimulated in vitro, whereas vitamin E reduces tissue infiltration of neutrophils during exercise. Free radicals generated during intense exercise may lead to DNA damage in leukocytes, but it is unknown if this damage is the result of neutrophil activation. Exercise enhances the expression of inducible haem (heme)-oxygenase (HO-1) in neutrophils after exercise, however, it is uncertain whether oxidative stress is the stimulus for this response.

Measurement error of rearfoot kinematics during running between a 100Hz and 30Hz camera

Background: Measurement accuracy is critical for biomechanical gait assessment. Very few studies have determined the accuracy of common clinical rearfoot variables between cameras with different collection frequencies. Research question: What is the measurement error for common rearfoot gait parameters when using a standard 30Hz digital camera compared to 100Hz camera? Type of study: Descriptive. Methods: 100 footfalls were recorded from 10 subjects ( 10 footfalls per subject) running on a treadmill at 2.68m/s. A high-speed digital timer, accurate within 1ms served as an external reference. Markers were placed along the vertical axis of the heel counter and the long axis of the shank. 2D coordinates for the four markers were determined from heel strike to heel lift. Variables of interest included time of heel strike (THS), time of heel lift (THL), time to maximum eversion (TMax), and maximum rearfoot eversion angle (EvMax). Results: THS difference was 29.77ms (+/- 8.77), THL difference was 35.64ms (+/- 6.85), and TMax difference was 16.50ms (+/- 2.54). These temporal values represent a difference equal to 11.9%, 14.3%, and 6.6% of the stance phase of running gait, respectively. EvMax difference was 1.02 degrees (+/- 0.46). Conclusions: A 30Hz camera is accurate, compared to a high-frequency camera, in determining TMax and EvMax during a clinical gait analysis. However, relatively large differences, in excess of 12% of the stance phase of gait, for THS and THL variables were measured.

The Select Committee Report on Obesity (2004): The significant omission of parental views of their children's eating

Many studies have reported increasing levels of obesity and overweight in children. Recent policy developments have examined a range of influences on children's eating habits but have left largely unexamined the role of parents in general and mothers in particular. In this study we examined mothers’ understandings of healthy eating and of their influence on their children's eating patterns. Semi-structured interviews were conducted with nine mothers of children aged between 4 and 12 years of age. Interviewees displayed knowledge of recommended eating practices for their children but distinguished this knowledge from actual eating practices. Avoidance of negative social perceptions, pleasure in eating and opportunities for fast food were regarded as more important than eating in accordance with recommended nutritional guidelines. Moreover, the food choices made were viewed as positive alternatives to eating based on nutritional balance. These views pose a challenge for policy initiatives to address obesity and excess weight in children. Future initiatives should have increased regard for the everyday contexts within which children's eating patterns are understood and justified.

Construct Redundancy in Process Modeling Grammars: Improving the Explanatory Power of Ontological Analysis

Conceptual modelling supports developers and users of information systems in areas of documentation, analysis or system redesign. The ongoing interest in the modelling of business processes has led to a variety of different grammars, raising the question of the quality of these grammars for modelling. An established way of evaluating the quality of a modelling grammar is by means of an ontological analysis, which can determine the extent to which grammars contain construct deficit, overload, excess or redundancy. While several studies have shown the relevance of most of these criteria, predictions about construct redundancy have yielded inconsistent results in the past, with some studies suggesting that redundancy may even be beneficial for modelling in practice. In this paper we seek to contribute to clarifying the concept of construct redundancy by introducing a revision to the ontological analysis method. Based on the concept of inheritance we propose an approach that distinguishes between specialized and distinct construct redundancy. We demonstrate the potential explanatory power of the revised method by reviewing and clarifying previous results found in the literature.

Are we missing opportunities? Understanding health behaviours associated with overweight in pregnancy

While maternal obesity, excess pregnancy weight gain and lifestyle behaviours are associated with future overweight for both mothers and babies, there is limited research on how best to intervene. An evidence base that identifies behavioural influences is crucial to the development of effective interventions. This thesis aims to gain an understanding of maternal behavioural outcomes of healthy eating, physical activity and gestational weight gain (GWG), the psychosocial influences on these and to examine differences according to pre-pregnancy weight status. The New Beginnings Healthy Mothers and Babies Study was a prospective observational study using the PRECEDE-PROCEED model of health promotion planning as a framework. A consecutive sample of 715 women was recruited. Height and weight were measured and women completed questionnaires at approximately 16 and 36 weeks gestation. This thesis presents three chapters of original research across four study domains. While healthy eating was widely regarded as important during pregnancy and had become more so, there was more variability in attitudes towards physical activity. Ninety-two percent of participants achieved the maximum knowledge score relating to the influence of nutrition on pregnancy. However, 8% and 36% respectively knew how many serves of fruit and vegetables should be consumed daily. Six percent of participants met the recommendations for fruit consumption, 4% achieved the recommended vegetable intake and 44% achieved sufficient physical activity. There were few differences between healthy and overweight women for measures of physical activity and healthy eating. Many predisposing, reinforcing and enabling factors with a positive influence on health behaviours were lower in women commencing pregnancy overweight and those factors with a negative influence on health behaviours were higher when compared to healthy weight women. Some of these antecedents to health behaviours that were different according to prepregnancy weight status were associated with diet quality and physical activity. While self efficacy was consistently associated with diet quality and physical activity for both weight groups, other associations between specific predisposing, reinforcing and enabling factors differed with behaviour and weight status group. These results highlight the complexity of supporting behaviour change in a one-size-fits-all approach. Sixty-four percent of participants gained weight outside of recommendations. Compared to healthy weight women, those women who were already overweight at the beginning of pregnancy were more likely to gain too much weight (30% vs 56%, p<0.001). Only 35% of participants reported their correct recommended weight gain. Excess GWG was associated with few predisposing factors, however, these were not consistent between prepregnancy weight status groups. Less than 50% of women reported sometimes/usually/always receiving advice from health professionals relating to healthy eating, physical activity or GWG. These results indicate that there are opportunities to improve the advice and support provided by health care professionals in the antenatal period. Evidence from this PhD research suggests that there is a need for effective prevention and management of excess weight in pregnancy. Effective management of this problem is likely to require a multidisciplinary approach with multi-level strategies. Importantly, the strategies may need to be tailored according to pre-pregnancy weight status. Collectively, the evidence derived from this thesis suggests that opportunities to support healthy lifestyles and prevent future overweight are being missed during pregnancy.