A new unit root test with two structural breaks in level and slope at unknown time

In this paper, we propose a new augmented Dickey–Fuller-type test for unit roots which accounts for
two structural breaks. We consider two different specifications: (a) two breaks in the level of a trending data series and (b) two breaks in the level and slope of a trending data series. The breaks whose time of occurrence is assumed to be unknown are modeled as innovational outliers and thus take effect gradually. Using Monte Carlo simulations, we showthat our proposed test has correct size, stable power, and identifies the structural breaks accurately.

Differences in physical activity during school recess

BACKGROUND: School recess provides a daily opportunity for physical activity engagement. The purpose of this study was to examine physical activity levels during recess by gender, ethnicity, and grade, and establish the contribution of recess to daily school physical activity levels.
METHODS: Two hundred and ten children (45% boys) from grades 3 to 6 in 4 elementary schools had their physical activity during school quantified using uni-axial accelerometry every 5 seconds for 5 consecutive school days. Data were collected in fall 2009. The proportion of time spent engaged in physical activity during daily school recess was determined using existing age-appropriate cutpoints. The relative contribution of recess to school day physical activity was also determined.
RESULTS: Boys were more active than girls during recess. Girls engaged in more sedentary activity than boys. No main effects for ethnicity were observed. Children in grades 3 and 5 were more active than children in grades 4 and 6. Recess contributed 17.9% and 15.5% toward boys’ and girls’ school day moderate-to-vigorous physical activity, respectively.
CONCLUSION: Children engaged in physical activity during recess, though interventions may be needed to increase the intensity of activity in this context.

Supporting ICT based pedagogies in science in rural school settings

Recent research has demonstrated a significant disadvantage for rural teachers in a variety of aspects of ICT use. This context provides a backdrop for two professional learning programs designed to support ICT-based pedagogies in teaching science in Victorian rural primary and secondary schools. In both programs the school-based workshops initiated a community of learners supported with online web-presence. One program used an intensive five-day workshop focused on developing teachers’ knowledge, pedagogical expertise and leadership skills in embedding ICT into classroom practice. The second program provided a one-day workshop focused on integrating ICT skills in teaching science. Factors that affected the uptake of ICT included the considerable diversity in ICT availability and use, teacher competence, lack of support in schools, and online support. To redress rural disadvantage in ICT use, school commitment and focused leadership were identified as central to programs that supported and developed teacher skills and pedagogies over time.

University dreams start in primary school

Up to 40 per cent of first-year undergraduates first consider university in primary school.

The finding, as part of a large-scale survey of 55,000 students in 55 institutions, has given universities quantitative evidence for the first time that young students are highly receptive to the notion of attending university.

Creating a dialogue across time in Athens : the new Acropolis museum and the Parthenon

A visit to the New Acropolis Museum in Athens, Greece, in late June 2010 set in train a number of questions and inspired a research project to begin to unravel something of the complex relationship between ancient and modern architecture on the Athenian Acropolis. Research was guided by the question: how does the contemporary museum, designed by Swiss born architect Bernard Tschumi in collaboration with local Greek architect Michalis Photiadis relate to the ancient Acropolis and the fifth century BC Parthenon, whose sculptures it was to house? A critical literature review was augmented by design analysis and field experience. This paper documents the resulting critical thematic investigations of the Parthenon, the Acropolis and the New Museum through siting, materiality and light, alignment, visual connections, through exploitation of the unique Attic light, orchestrated movement and considered juxtapositions. Research has revealed that Tschumi’s deliberate strategy of creating a dialogue between his building and the ancient monuments holds the key to his design intent, to creatively exploring contemporary architecture at the edge of such a physically and culturally dominant ancient plateau.

Arresting the decline in senior school chemistry

Enrolments in Australian Year 11 and year 12 chemistry are declining. In 1992, 23% of Australian year 12 students studied chemistry, decreasing to 18% in 2010. For science as a whole, the decrease is even more dramatic, from 94% to 51%. The decrease is slowing, but is continuing.
How should we respond to the report? Firstly, we should realise that it is not all gloom and doom. Secondly, education is not solely the responsibility of curriculum authorities and teachers. Each RACI member can communicate, inform and generally educate the wider community about the excitement and value of chemical science. Just a couple of hours of your time is not a panacea, but it can still make long-lasting impacts and affect career choices: even the largest beach consists of tiny individual grains of sand.

A cross-sectional study of the individual, social, and built environmental correlates of pedometer based physical activity among elementary school children

Background: Children who participate in regular physical activity obtain health benefits. Preliminary pedometerbased cut-points representing sufficient levels of physical activity among youth have been established; however limited evidence regarding correlates of achieving these cut-points exists. The purpose of this study was to identify correlates of pedometer-based cut-points among elementary school-aged children.
Method: A cross-section of children in grades 5-7 (10-12 years of age) were randomly selected from the most (n = 13) and least (n = 12) ‘walkable’ public elementary schools (Perth, Western Australia), stratified by socioeconomic status. Children (n = 1480; response rate = 56.6%) and parents (n = 1332; response rate = 88.8%) completed a survey, and steps were collected from children using pedometers. Pedometer data were categorized to reflect the sex-specific pedometer-based cut-points of ≥15000 steps/day for boys and ≥12000 steps/day for girls. Associations between socio-demographic characteristics, sedentary and active leisure-time behavior, independent mobility, active transportation and built environmental variables - collected from the child and parent surveys - and meeting pedometer-based cut-points were estimated (odds ratios: OR) using generalized estimating equations.
Results: Overall 927 children participated in all components of the study and provided complete data. On average, children took 11407 ± 3136 steps/day (boys: 12270 ± 3350 vs. girls: 10681 ± 2745 steps/day; p < 0.001) and 25.9% (boys: 19.1 vs. girls: 31.6%; p < 0.001) achieved the pedometer-based cut-points. After adjusting for all other variables and school clustering, meeting the pedometer-based cut-points was negatively associated (p < 0.05) with being male (OR = 0.42), parent self-reported number of different destinations in the neighborhood (OR 0.93), and a friend’s (OR 0.62) or relative’s (OR 0.44, boys only) house being at least a 10-minute walk from home. Achieving the pedometer-based cut-points was positively associated with participating in screen-time < 2 hours/day (OR 1.88), not being driven to school (OR 1.48), attending a school located in a high SES neighborhood (OR 1.33), the average number of steps among children within the respondent’s grade (for each 500 step/day increase: OR 1.29), and living further than a 10-minute walk from a relative’s house (OR 1.69, girls only).
Conclusions: Comprehensive multi-level interventions that reduce screen-time, encourage active travel to/from school and foster a physically active classroom culture might encourage more physical activity among children.

How is active transport associated with children's and adolescents' physical activity over time?

Background : As few longitudinal studies have examined how active transport is associated with physical activity among children and adolescents over time, and how active transport tracks through childhood and adolescence, it is important to understand whether physically active children retain their activity patterns through adolescence. This study aimed to examine (a) tracking of active transport and of moderate-to-vigorous physical activity (MVPA) across childhood and adolescence in two age cohorts; and (b) associations between active transport and MVPA at three distinct time-points, over five years.

Methods : This longitudinal study of two cohorts aged 5-6 years (n = 134) and 10-12 years (n = 201) at baseline (T1), in Melbourne, Australia, gathered follow-up data at three (T2) and five years (T3). Walking/cycling to local destinations was survey-reported; while MVPA was recorded using accelerometers and mean time spent daily in MVPA on week days and on weekends was computed. Tracking of these behaviours was examined over five years using General Estimating Equations. Linear regression analyses were performed to examine associations between active transport and MVPA at each time-point.

Results : Active transport tracked moderately among children (boys, bs = 0.36; girls, bs = 0.51) but not among adolescents. Physical activity tracked moderately (bs value range: 0.33-0.55) for both cohorts. Active transport was not associated with children’s MVPA at any time-point, but was associated with adolescent boys’ MVPA on week days at T1 (B = 1.37 (95% CI: 0.15, 2.59)), at T2 (B = 1.27 (95% CI: 0.03, 2.51)) and at T3 (B = 0.74 (95% CI: 0.01, 1.47)), and with adolescent girls’ MVPA on week days (B = 0.40 (95% CI: 0.04, 0.76)) and on weekends (B = 0.54 (95% CI:0.16, 0.93)) at T3 only.

Conclusion : Active transport was associated only with boys’ MVPA during early adolescence and with boys’ and girls’ MVPA during late adolescence. While active transport should be encouraged among all school-aged children, it may provide an important source of habitual physical activity for adolescent girls, in particular, among whom low and declining physical activity levels have been reported world-wide.

Changing teaching practice using a school improvement cycle

This paper discusses the actions, strategies and responses of teachers during their involvement with a short cycle school improvement model in four schools. The school improvement cycles are designed to build the leadership of principals to support teachers at an individual level through a web of decision making and practices. In these cycles, teachers are both more supported and more accountable for implementing changed classroom practices in order to bring about improved student outcomes. T he school improvement model follows a pattern of decision making and negotiation across and between layers of leadership within the network and the school, but for improvement to occur at the level of the student, the teacher’s pedagogical practices need to be r(e)negotiated to ensure that teaching practice meet the needs of the students.
However, evaluating teacher practice is risky business. Teachers can say, and believe, that their practices are providing the best for their students, but this is an area of uncertainty. Using a number of strategies including observation of teacher meetings, teacher interviews and video capture, the research will investigate the issue of how directives for change are translated into classroom practice. The observation of meetings of teachers will provide an indication of the type of change required and the proposed strategies. Video-capture, which is followed by teacher interviews, will provide further information about changing teaching practice.
With teacher permission, students in the research will also view the video snippets to indicate what particular pedagogy was instrumental in their learning, providing substantial feedback to the teacher on what works best for that cohort of students at that time. Teachers will be provided with the opportunity to reflect on and learn from their practice, using video-capture as a self-reflective tool. Teachers can employ video capture as a strategy to assess their management of students, their pedagogical approaches, teaching strategies and student responses and is an emerging area of research of interest to teachers and teacher educators (e.g. Seidel, Sturmer, Blomberg, Kobarg, Schwindt, 2011). The paper will provide examples of changed teacher practice through vignettes of a number of schools, teachers and classrooms and will explore the methodological reflexivity associated with this dual role of the research: to evaluate, and to support improvement.

Is the neighbourhood environment associated with sedentary behaviour outside of school hours among children?

Background Little is known about neighbourhood environments and children’s sedentary behaviour outside school hours.
Purpose This study aims to examine the associations between public open spaces (POS), parent perceptions of the neighbourhood and children’s sedentary behaviours.
Methods Parents reported their child’s television viewing and computer/electronic game time and their perceptions of the physical and social neighbourhood. Children’s sedentary
time was objectively assessed. The closest POS was audited.
Results Cross-sectionally, living near a POS with a water feature and greater parental satisfactionwith POS quality were negatively associated with computer/e-games; greater POS area was negatively associated with TV viewing. Longitudinally, living in a cul-de-sac and greater satisfaction with POS quality were negatively associated with computer/e-games and TV viewing, respectively. Awalking path in the POS was positively associated with computer/e-games.
Conclusion Neighbourhood features appear to positively and negatively influence children’s sedentary behaviours, highlighting the complexity of urban planning on behaviour. Further age- and context-specific studies are required.

A comparison of the classification of disparate malware collected in different time periods

It has been argued that an anti-virus strategy based on malware collected at a certain date, will not work at a later date because malware evolves rapidly and an anti-virus engine is faced with a completely new type of executable not as amenable to detection as the first was. In this paper, we test this idea by collecting two sets of malware, the first from 2002 to 2007, the second from 2009 to 2010 to determine how well the anti-virus strategy we developed based on the earlier set [14] will do on the later set. This anti-virus strategy integrates dynamic and static features extracted from the executables to classify malware by distinguishing between families. The resulting classification accuracies are very close for both datasets, with a difference of only 5.4%, the older malware being more accurately classified than the newer malware. This leads us to conjecture that current anti-virus strategies can indeed be modified to deal effectively with new malware.

Increasing children’s physical activity : individual, social, and environmental factors associated with walking to and from school

Background. Efforts to increase the prevalence of children’s active school transport require evidence to inform the development of comprehensive interventions. This study used a multilevel ecological framework to investigate individual, social, and environmental factors associated with walking to and from school among elementary school-aged children, stratified by gender.
Method. Boys aged 10 to 13 years (n = 617) and girls aged 9 to 13 years (n = 681) attending 25 Australian primary schools located in high or low walkable neighborhoods completed a 1-week travel diary and a parent/child questionnaire on travel habits and attitudes.
Results. Boys were more likely (odds ratio [OR] = 3.37; p < .05) to walk if their school neighborhood had high connectivity and low traffic and less likely to walk if they had to cross a busy road (OR = 0.49; p < .05). For girls, confidence in their ability to walk to or from school without an adult (OR = 2.03), school encouragement (OR = 2.43), scheduling commitments (OR = 0.41), and parent-perceived convenience of driving (OR = 0.24) were significantly associated (p < .05) with walking. Irrespective of gender and proximity to school, child-perceived convenience of walking (boys OR = 2.17 and girls OR = 1.84) and preference to walk to school (child perceived, boys OR = 5.57, girls OR = 1.84 and parent perceived, boys OR = 2.82, girls OR = 1.90) were consistently associated (p < .05) with walking to and from school.
Conclusion. Although there are gender differences in factors influencing children walking to and from school, proximity to school, the safety of the route, and family time constraints are consistent correlates. These need to be addressed if more children are to be encouraged to walk to and from school.

Five-year changes in school recess and lunchtime and the contribution to children’s daily physical activity

Objective To investigate the longitudinal changes in children's recess and lunchtime physical activity levels and in the contribution of recess and lunchtime to daily physical activity levels over 5 years among 5–6- and 10–12-year olds.

Methods Data were drawn from two longitudinal studies that were conducted in metropolitan Melbourne, Australia. Boys and girls (n=2782) aged 5–6 years and 10–12 years participated in baseline (T0) measures. Physical activity (n=2490) was measured every 60 s for eight consecutive days using hip-mounted accelerometry. Subsequent measurements were taken at 3-year (T1; n=773) and 5-year (T2; n=634) follow-up. Physical activity intensities were derived using age-adjusted cut-points. Sedentary time was defined as 100 counts/min. Longitudinal data were analysed using three-level (time, child, school) multilevel analyses, stratified by sex and cohort, and adjusted for potential confounding variables.

Results Significant decreases in recess and lunchtime moderate and vigorous physical activity were observed (p<0.001), with larger decreases occurring in the older cohort. Associated increases were observed in sedentary time over time (p<0.01). Although the contribution of recess to daily moderate intensity physical activity increased in the younger cohort over time (p<0.001), significant decreases were observed in the older cohort (p<0.001).

Conclusion Physical activity levels during recess and lunchtime decreased in both cohorts over time. Decreases in the contribution of recess and lunchtime to older children's daily physical activity were also observed. Interventions are needed in both primary and secondary schools to promote physical activity levels during recess and lunchtime, particularly during the early years of secondary school.