Probing the flexibility of the DsbA oxidoreductase from Vibrio cholerae - a 15N -1H heteronuclear NMR relaxation analysis of oxidised and reduced forms of DsbA

We have determined the structure of the reduced form of the DsbA oxidoreductase from Vibrio cholerae. The reduced structure shows a high level of similarity to the crystal structure of the oxidized form and is typical of this class of enzyme containing a thioredoxin domain with an inserted α-helical domain. Proteolytic and thermal stability measurements show that the reduced form of DsbA is considerably more stable than the oxidized form. NMR relaxation data have been collected and analyzed using a model-free approach to probe the dynamics of the reduced and oxidized states of DsbA. Akaike's information criteria have been applied both in the selection of the model-free models and the diffusion tensors that describe the global motions of each redox form. Analysis of the dynamics reveals that the oxidized protein shows increased disorder on the pico- to nanosecond and micro- to millisecond timescale. Many significant changes in dynamics are located either close to the active site or at the insertion points between the domains. In addition, analysis of the diffusion data shows there is a clear difference in the degree of interdomain movement between oxidized and reduced DsbA with the oxidized form being the more rigid. Principal components analysis has been employed to indicate possible concerted movements in the DsbA structure, which suggests that the modeled interdomain motions affect the catalytic cleft of the enzyme. Taken together, these data provide compelling evidence of a role for dynamics in the catalytic cycle of DsbA.

Six year follow-up of students who participated in a school-based physical activity interventions : a longitudinal cohort study

Background
The purpose of this paper was to evaluate the long-term impact of a childhood motor skill intervention on adolescent motor skills and physical activity.

Methods
In 2006, we undertook a follow-up of motor skill proficiency (catch, kick, throw, vertical jump, side gallop) and physical activity in adolescents who had participated in a one-year primary school intervention Move It Groove It (MIGI) in 2000. Logistic regression models were analysed for each skill to determine whether the probability of children in the intervention group achieving mastery or near mastery was either maintained or had increased in subsequent years, relative to controls. In these models the main predictor variable was intervention status, with adjustment for gender, grade, and skill level in 2000. A general linear model, controlling for gender and grade, examined whether former intervention students spent more time in moderate-to-vigorous physical activity at follow-up than control students.

Results
Half (52%, n = 481) of the 928 MIGI participants were located in 28 schools, with 276 (57%) assessed. 52% were female, 58% in Grade 10, 40% in Grade 11 and 54% were former intervention students. At follow-up, intervention students had improved their catch ability relative to controls and were five times more likely to be able to catch: ORcatch = 5.51, CI (1.95 – 15.55), but had lost their advantage in the throw and kick: ORthrow = .43, CI (.23 – .82), ORkick = .39, CI (.20 – .78). For the other skills, intervention students appeared to maintain their advantage: ORjump = 1.14, CI (.56 – 2.34), ORgallop = 1.24, CI (.55 – 2.79). Intervention students were no more active at follow-up.

Conclusion
Six years after the 12-month MIGI intervention, whilst intervention students had increased their advantage relative to controls in one skill, and appeared to maintain their advantage in two, they lost their advantage in two skills and were no more active than controls at follow up. More longitudinal research is needed to explore whether gains in motor skill proficiency in children can be sustained and to determine the intervention characteristics that translate to subsequent physical activity.

Childhood motor skill proficiency as a predictor of adolescent physical activity

Purpose
Cross-sectional evidence has demonstrated the importance of motor skill proficiency to physical activity participation, but it is unknown whether skill proficiency predicts subsequent physical activity.

Methods
In 2000, children's proficiency in object control (kick, catch, throw) and locomotor (hop, side gallop, vertical jump) skills were assessed in a school intervention. In 2006/07, the physical activity of former participants was assessed using the Australian Physical Activity Recall Questionnaire. Linear regressions examined relationships between the reported time adolescents spent participating in moderate-to-vigorous or organized physical activity and their childhood skill proficiency, controlling for gender and school grade. A logistic regression examined the probability of participating in vigorous activity.

Results
Of 481 original participants located, 297 (62%) consented and 276 (57%) were surveyed. All were in secondary school with females comprising 52% (144). Adolescent time in moderate-to-vigorous and organized activity was positively associated with childhood object control proficiency. Respective models accounted for 12.7% (p = .001), and 18.2% of the variation (p = .003). Object control proficient children became adolescents with a 10% to 20% higher chance of vigorous activity participation.

Conclusions
Object control proficient children were more likely to become active adolescents. Motor skill development should be a key strategy in childhood interventions aiming to promote long-term physical activity.

Associations between the physical and social environment and depressive symptomology among Australian adolescents

Depression is a significant public health issue among Australian adolescents. A number of family, school and community level factors have been identified as important determinants of adolescent's health and well-being, including depression. This study examines associations between measures of the social and physical environment and adolescent mental health, specifically depressive symptomotology using data from the Healthy Neighbourhoods study, a large observational study carried out in 231 Australian schools stratified by socioeconomic quartiles and urban/non-urban geography, which focuses on adolescent health and well-being. Participants were 8256 year 6 and 8
students (48% male), aged 11-16 years (M = 11.6, SD = 0.8 years) from schools across Victoria,Queensland and Western Australia who completed a comprehensive on-line survey. Data collected included the Short Mood and Feeling Questionnaire (SMFQL a tool for assessing depressive symptomotology in adolescents. Results showed that the mean total depression score (possible range 0-26 with total scores;:: 8 used as the cutoff for depression symptomotology) was 6.4 (SD = 5.9), with scores for females (M = 6.8, SD = 6.3) higher than those for males (M = 5.9, SD = 5.5), and scores for year 8 students (M = 6.7,SD = 6.1) higher than those for year 6 students (M = 6.2, SD = 5.8) (p < .001). Greater access to sporting and play equipment, local parks, and more functional neighbourhoods for walking and jogging reduced the odds for depressive symptomotology (p < .05L while increased levels of abandoned homes, and higher levels of fighting within the neighbourhood, and fewer scout/guide clubs, local teams to play sport, and adults in the neighbourhood to talk with, as well as reduced neighbourhood safety increased the odds for depressive symptomotology (p < .05). These findings support the important role of physical and social environments in influencing adolescent health and well-being. Modifications to particular aspects of these environments at the community level may assist in providing adolescents some protection from depression.

Skills, strategies, sport and social responsibility : reconnecting physical education

Physical education is one of the more difficult subjects in the curriculum for generalist classroom teachers in primary schools to incorporate confidently into their teaching. In many primary schools, the generalist classroom teacher defers to a physical education specialist. This situation has both positive and negative features. In this context, this study brings together several prominent models of physical education teaching in an approach that enables the curriculum to be encountered through the interests of the children. This approach offers a generalist teacher, through appropriate professional development, a means for delivering a high-quality physical education programme, and also complements the repertoire of the specialist physical education teacher at both primary and secondary school levels.

Game-centred models and teaching in culturally diverse settings

This presentation draws on the observations and experiences that we, as teacher educators, have had using Teaching Games for Understanding (TGfU) as a pedagogical tool with generalist pre-service teachers in two different sites: Malaysia and Australia. TGfU is a game-centred pedagogy in which students learn the „Why‟ of game playing before the „How‟ of the skills associated with the game. This concept is based on a student-centred approach to learning. The benefit of this pedagogy to generalist teachers is the notion that they are not required to be a master of many sports. This narrative relates the observations and experiences of teacher educators of Malaysian and Australian generalist pre-service teachers confronted with teaching and learning TGfU for the first time in their culturally specific contexts. The two key issues arising from teaching the TGfU model were: the disparity in the cohorts‟ experiences arising from institutionalised conceptions by the pre-service teachers of what and how learning occurs in physical education; and the pre-service teachers‟ difficulty with implementing the TGfU model in a practical situation. Crossing the cultural divide for the Malaysian and Australian pre-service teachers required them to explore more fully the range of approaches to teaching and to recognise a more student-centred approach as a valid and authentic tool. As both teachers and observers of this process, our intention was to examine the two cohorts‟ learning and subsequent teaching with the aim of developing better understandings of the challenges when teaching TGfU in tertiary settings.

The effectiveness of physical activity interventions for the treatment of overweight and obesity and type 2 diabetes

This review summarises current evidence relating to the effectiveness of physical activity (PA) interventions for treating overweight and obesity and type 2 diabetes. Interventions to increase PA for the treatment of overweight and obesity in both children and adults have primarily consisted of health education and behaviour modification strategies in clinical settings or with selected families or individuals. Although evidence is limited, strategies to reduce sedentary behaviours appear to have potential for reducing obesity among children and adolescents. Among adults, strategies that combine diet and PA are more effective than PA strategies alone. Combined lifestyle strategies are most successful for maintained weight loss, although most programs are unsuccessful in producing long-term changes. There is little evidence about compliance to prescribed behaviour changes or the factors that promote or hinder compliance to lifestyle changes. Limited evidence suggests that continued professional contact and self-help groups can help sustain weight loss. Most of the interventions for the treatment of type 2 diabetes have been conducted in clinical settings and have typically required the use of extensive resources. Evidence suggests that interventions can lead to small but clinically meaningful improvements in glycaemic control, even in the absence of weight loss. A recent study demonstrated that a multifactorial intervention (diet, PA and pharmaceutical) can reduce the risk of diabetes complications in individuals with type 2 diabetes. Nevertheless, there is little evidence about the effectiveness of community-based interventions in producing long-term changes in glycaemic control and reduced mortality in people with type 2 diabetes.

Professional standards for physical education teachers' professional development : technology for performance?

Background: The widespread and diverse models of professional standards for teaching raise questions with respect to the need to provide teachers with a pathway for continuing professional development balanced with the public nature of surveillance and accountability that may accompany standards. Ways of understanding technologies of power in relation to standards for
teaching gives us a new language and, in turn, new questions about the standards agenda in the physical education profession.
Purpose: To analyse how one health and physical education (HPE) teacher worked with Education Queensland’s (EQ) professional standards for teaching within the broader context of teacher professional development and renewal.
Participants and setting: An experienced HPE teacher working in an urban secondary school was the ‘case’ for this article. Tim was the only experienced HPE teacher within the larger pilot study of 220 selected teachers from the volunteer pool across the state.
Data collection: The case-study data comprised two in-depth interviews conducted by the first author, field notes from workshops (first author), teacher diaries and work samples, notes from focus groups of which Tim was a member, and electronic communications with peers by Tim
during the course of the evaluation.
Findings: Tim was supportive of the teaching standards while they did not have a strong evaluative dimension associated with technologies of power. He found the self-regulation associated with his reflective practices professionally rewarding rather than being formalised within a prescribed
professional development framework.
Conclusion: Tim’s positive response to the professional standards for teaching was typical of the broader pilot cohort. The concept of governmentality provided a useful framework to help map how the standards for teaching were received, regardless of teacher specialisation or experience.
We suggest that it is not until the standards regimes are talked about within the discourses of
power (e.g. codification for career progression, certification for professional development imperatives) that we can understand patterns of acceptance and resistance by teachers to policies
that seek to shape their performance.

Can we skill and activate children through primary school physical education lessons? "Move it Groove it" - a collaborative health promotion intervention

Background: Physical education (PE) lessons are an ideal setting to improve child fundamental movement skills (FMSs) and increase physical activity (PA) for optimal health. Despite this, few studies have assessed the potential to do both simultaneously. The “Move It Groove It” primary school intervention in New South Wales, Australia, had this opportunity.

Methods: A whole school approach to implementation included establishment of school project teams, a teacher “buddy” system, project Web site, teacher training workshops, and small grants for equipment. The quasi-experimental evaluation involved 1,045 year 3 and 4 children (aged 7 to 10 years) in nine intervention and nine control rural primary schools (53% boys/47% girls). It utilised pre- and postobservational surveys of (1) mastery or near mastery levels for each of eight FMSs, (2) proportion of PE lesson time spent in moderate to vigorous PA (MVPA) and vigorous PA (VPA), and (3) teacher- and lesson-related contextual covariates. Data were analysed by hierarchical logistic multiple regression.

Results: For FMSs, overall mastery or near mastery level at baseline was 47% ranging from 22.7% for the overarm throw among girls to 75.4% for the static balance among boys. The intervention delivered substantial improvements in every FMS for both genders ranging from 7.2% to 25.7% (13 of 16 comparisons were significant). For PA level, mean MVPA at baseline was 34.7%. Baseline MVPA for boys was 38.7% and for girls was 33.2%. The intervention was associated with a nonsignificant 4.5% increase in MVPA and a significant 3.0% increase in VPA. This translates to a gain of <1 minute of MVPA per average 21-minute lesson.

Conclusions: This is the first study to show that by modifying existing PE lessons, significant improvements in FMS mastery can be gained without adversely affecting children’s MVPA and VPA. To increase PA levels, we recommend increasing the number of PE lessons per week.

Beyond the analogon; the "transfer of the referent" : the relationship between the external world experienced through culturally generated perceptual models constructed in the human mind, and the transfer of these images, via visual language, onto referen

Within 20th. Century art, the concept of the ‘normative’ image, as an attribute of things, has been challenged. As a consequence, paintings must now picture the ‘real’ world in other ways, incorporating knowledge and meaning beyond the analogon. Such descriptive representations were revealed as paradigmatic, rather than incontrovertible fact. Dependent on pre-conceived notions of stereotypicality, these descriptive images relied on surface illumination. My thesis explores images of things in the world as culturally inspired and information based. I examine paintings and sculptures of other cultures, such as black African, and other historical periods such as the Medieval, which reveal metonymously the basis for variations in representations of the ‘real’ world. The new enhanced representations which Modern artists created in their work were denigrated as deviant from the absolute ‘normative’ or regarded as distortions for purely mannerist and stylistic reasons. Postmodern research has reassessed them as multiple or extended imagings in whose facture new knowledge and human responses can be incorporated. These new forms of representation can be regarded as theoretical constructs rather than stylised depictions of appearance. In this way referents are transferred through the mind onto objects and vistas in the real world to align with our developed view of the physical world and better our understanding of humanity’s symbiotic relationship with nature.

Physical theory of organisation and consequent neural model of spatio-temporal pattern acquisition

A neurone model (the FORMON) is proposed which provides a mathematical explanation for a range of psychological phenomena and has potential in Artificial Intelligence applications. A general definition of organisation in terms of entropy and information is formulated. The concept of microcodes is introduced to describe the physical nature of organisation. Spatio-temporal pattern acquisition and processing functions attributable to individual neurones are reviewed. The criterion for self-organisation in a neurone is determined as the maximisation of mutual organisation. A feedback control system is proposed to satisfy this criterion and provide an integrated long-term memory of spatio-temporal pattern. This pattern acquisition system is shown to be applicable to dendritic pattern recognition and axonal pattern generation. Provision is also made for adaptation, short-term memory and operant learning. An electro-chemical model of transmission and processing of neural signals is outlined to provide the pattern acquisition functions of the Formon model. A transverse magnetic mode of electrotonic propagation is postulated in addition to the transverse electromagnetic mode. Configurations of the Formon are categorised in terms of possible pattern processing functions. Connective architectures are proposed as self-organising models of acquisitive semantic and syntactic networks.

Development of material models to predict the crashworthiness of tubes

Metallic tubes have been extensively studied for their crashworthiness as they closely resemble automotive crash rails. Recently, the demand to produce light weight yet safer vehicles has led to the need to understand the behaviour of novel materials such as composites, metallic foams and sandwich structures durign a crash. This paper presents a method to predict the crashworthiness of structural components using material modes. The material factors that most affect the crushing response are determined and quantified by developing and validating the crushing of a square tube model in Abaqus. The inputs from the model are used to construct a simple, physically realistic constitutive model and new test methods for predicting the material behaviour at high strain rates using low test speeds. These material models enable a designer to predict the crash behaviour of a structure without the need to perform extensive physical tests, thus reducing the time and cost of development.

Design and degradation modelling through artificial neural networks

Automotive is one of the major manufacturing industries in Australia that requires extensive reliability test for the components used in vehicles. To achieve a shorter time-to-market and a highly reliable product while reducing the amount of physical prototyping, there is a growing need for better understanding on the effect that the design parameters have on the degradation of the product. This paper presents comprehensive descriptions of applying Artificial Neural Network (ANN) to capture the relationships between design and degradation. Consequently, two models of different practical significance are created as the result of the work. The vision of the models is to be used by the testers and designers as a guideline in design evaluation, so that time-consuming and expensive iterations of the product developmental cycle can be reduced substantially. The degradation of the folding force of a mechanical system is used to illustrate our approach.

Associations of residential density with adolescents’ physical activity in a rapidly urbanizing area of mainland China

In the context of recent social and economic transitions in China, lack of physical activity among adolescents is an emerging health risk, particularly so in rapidly expanding urban areas. Evidence from Western countries suggests that built environment attributes can influence the physical activity participation of young people, but whether or not this is the case for China is unknown. We recruited high school students from ten urban districts in Nanjing, Mainland China (n=2,375; mean age=13.9± 1.0 years old; 46% boys; survey response rate=89%). The outcome variable was selfreported recreational physical activity time; the primary explanatory variable was the residential density of the urban districts. Analysis was conducted using mixed-effects logistic regression models. After adjustment for potential confounding variables, including sedentary behavior and green space, there was a consistent and graduated association between residential density and physical activity; residential density was significantly negatively associated with recreational physical activity time for students from the higher tertile of residential density (OR; 95% CI=0.64; 0.42 to 0.97) compared to those from the lower tertile. The direction and magnitude of the negative association between residential density and physical activity was similar for boys and girls. It should be a public health priority to identify the particular urban environment attributes that can encourage and support young people’s participation in physical activity.

Relationships between maturity status, physical activity and physical self-perceptions in primary school children

The aim of this study was to examine the influence of maturity status on primary school children's physical activity and physical self-perceptions. Altogether, 175 children (97 girls, 78 boys) aged 10.6 ± 0.3 years completed the Children and Youth Physical Self-Perception Profile and wore an ActiGraph accelerometer for five consecutive days to assess moderate-to-vigorous physical activity. Anthropometric measures were completed to estimate maturity status. A two-level, multi-level analysis was used to assess the influence of maturity status on moderate-to-vigorous physical activity and physical self-perceptions. Boys performed more moderate-to-vigorous physical activity than girls (P < 0.0001), but when the effect of maturity status was controlled the difference was reduced (P = 0.02). Significant differences between the sexes were also observed for physical self-perception sub-domains (boys > girls, P = 0.02 to 0.0001). When maturity status was added to the model, significant differences were no longer apparent for each sub-domain, with the exception of perceived strength. Significant interactions between gender and maturity status revealed that boys' physical self-perceptions improved with more advanced maturity status, whereas girls' self-perceptions decreased (P = 0.07 to 0.002). Significant differences between the sexes in moderate-to-vigorous physical activity and some domains of physical self-perceptions were reduced or no longer evident when the effect of maturity status was controlled. Maturity status may differentially influence boys' and girls' physical self-perceptions.