Secondary emission of nanocrystalline zinc oxide

The Raman and photoluminescence (PL) spectra of nanocrystalline zinc oxide produced by mechanochemical synthesis were measured using a pulsed nitrogen laser (337.1 nm) and xenon lamp (360 nm) as excitation sources in PL measurements and a cw Nd:YAG laser in Raman measurements. PL was observed in the range 400–800 nm. The Raman spectrum of nanocrystalline (90 nm) ZnO was compared to that of coarsegrained ZnO. The Raman bands of nanocrystalline zinc oxide were found to be shifted to lower frequencies and broadened. Laser radiation was shown to cause local heating of zinc oxide up to 1000 K, resulting in photoinduced formation of zinc nanoclusters. Mixtures of zinc oxide and sodium chloride powders are heated to substantially lower temperatures. Under nitrogen laser excitation, the green PL band (535 nm), characteristic of bulk ZnO, is shifted to longer wavelengths by 85 nm. The results are interpreted in terms of light confinement in zinc oxide microclusters consisting of large number of nanocrystallites. The photoinduced processes in question may be a viable approach to producing metal-insulator structures in globular photonic crystals, opals, filled with zinc oxide.

Laboratory and non-laboratory-based risk prevention models for secondary prevention of cardiovascular disease : the LIPID study

Aims : The aims of this study were to examine whether risk prediction models for recurrent cardiovascular disease (CVD) events have prognostic value, and to particularly examine the performance of those models based on non-laboratory data. We also aimed to construct a risk chart based on the risk factors that showed the strongest relationship with CVD.

Methods and results : Cox proportional hazards models were used to calculate a risk score for each recurrent event in a CVD patient who was enrolled in a very large randomized controlled clinical trial. Patients were then classified into groups according to quintiles of their risk score. These risk models were validated by calibration and discrimination analyses based on data from patients recruited in New Zealand for the same study. Non-laboratory-based risk factors, such as age, sex, body mass index, smoking status, angina grade, history of myocardial infarction, revascularization, stroke, diabetes or hypertension and treatment with pravastatin, were found to be significantly associated with the risk of developing a recurrent CVD event. Patients who were classified into the medium and high-risk groups had two-fold and four-fold the risk of developing a CVD event compared with those in the low-risk group, respectively. The risk prediction models also fitted New Zealand data well after recalibration.

Conclusion : A simpler non-laboratory-based risk prediction model performed equally as well as the more comprehensive laboratory-based risk prediction models. The risk chart based on the further simplified Score Model may provide a useful tool for clinical cardiologists to assess an individual patient's risk for recurrent CVD events.

Using everyday experiences in teaching secondary mathematics in Malawi : possibilities and constraints for change

Proponents of socially and culturally oriented mathematics education have argued that teaching approaches which value and connect with the learner's prior knowledge and everyday experience are more likely to promote active, meaningful, relevant and liberatory learning than approaches which rely on transmission and abstract presentation of mathematical content. In Malawi, proposals to reform the outdated secondary mathematics curriculum have been made with the aim of aligning mathematics instruction with the social and political changes in the current Malawian society. Using a case study approach, this study investigated the extent to which everyday experiences could be used as a vehicle for changing the learning and teaching of secondary mathematics in Malawi. The study was collaborative, taking place over a period of five months in severely overcrowded and poorly resourced classes in two schools. It involved three mathematics teachers in a cycle of planning and teaching mathematics lessons based on the use of everyday experiences, and observation of and reflection on these lessons, in order to document the effects of using everyday experiences on student learning and teachers' teaching practices. The data was collected through student questionnaires; classroom observations and fieldnotes; interviews and reflective meetings with teachers; and informal meetings with key education officials in Malawi. Mathematics examination results from students involved in this study and a corresponding group from the previous year were collected. A reflective and critical approach was adopted in the interpretation and discussion of the data. Teachers' participation in this study resulted in heightened awareness of their teaching roles and the value of linking school mathematics with everyday experience. The study also shows that students found mathematics interesting and important to learn despite their lack of success in it. In addition, the study documented a number of constraints to change in mathematics instruction such as teachers' focus on mathematics content and examination requirements, and students' resistance to inquiry learning. It also recorded possibilities and barriers to collaboration both between teachers and researchers, and teachers themselves. The findings of this study are timely since they could serve to inform the reform of the Malawian secondary mathematics curriculum currently being undertaken, which began without a critical examination of the classroom conditions necessary to accommodate a socio-politically relevant mathematics education.

Sustainability in online communities of practice : the case study of a group of Secondary School Educators in Victoria

This paper reports on Information Technology (IT) secondary school educators in Victoria and their involvement in an online community of practice. It examined the social effects of the online mailing list technology on their participation and factors that influenced their collaboration with other colleagues. In mapping these elements, the motivations of educators and the effects on online communities of practice can be distilled and then used to build and sustain other architectures of participation. It was found that mailing list subscribers seem to trade a currency of support, thoughts, ideas and answers, which helped them in their day-to-day teaching. Online communities of practice provide a convenient way to keep up professional networks while continuing to stay abreast with subject specific knowledge and skills. The findings of this case study may be generalised to other educational mailing lists to guide designers and managers and inspire educators to join and ultimately benefit from these text based online environments.

Living improvement : a case study of a secondary school in England

Schools in England are being urged to personalize the curriculum and make school experiences more responsive to all students. We report on an evaluation project which investigated innovation in teaching and learning in a successful secondary school in the north of England. Data were gathered from a sample of teaching staff, a questionnaire to all students, lesson and meeting observations, and meetings with the governing body and parents: the student-guided evaluation canvassed recent and planned changes to the structure and experience of teaching and learning. This article illuminates how one school is breaking the ‘traditional schooling rules’ that limit improvement and how in doing so it is developing new insights about the nature and process of improvement. We show how staff and students have been engaged in the change process, and focus in particular on analysing the interplay between improvement as a plan, a practice and a lived experience.

Fostering meaningful learning by using word problems in post-secondary mathematics

This research is a case study of action research investigating the effects of using word problems with Chinese Malaysian post-secondary students studying mathematics as an enabling science. A variety of word problems, a discussion method, reflective and peer learning, specific values in mathematics, and relevant socio-cultural and language issues were explored.

Factors influencing the impact of secondary exposure to trauma

The research found significant relationships between secondary exposure to client trauma and symptoms associated with secondary traumatic stress and vicarious trauma in a sample of community mental health clinicians. The research supports developmental conceptualisations of the relationships between these constructs and burnout, and identifies potential individual vulnerability and protective factors. The portfolio explores the impact of childhood maltreatment from an attachment theory perspective. Four clinical cases are presented illustrating the clinical relevance of the impact of childhood maltreatment and attachment disturbance, and the complexities associated with current attachment classification systems and differential diagnosis.

Secondary students

Results indicated: Literacy programs provided optimal learning environments for access, participation and outcomes, reconnecting marginalised students to education; students were able to determine their preferred reading methods and educational pathways; students could negotiate work requirements, learned to be optimistic through creative pedagogies and built solid relationships through improved social skills.

The relationship between primary and secondary control and eating behaviour

Two studies were conducted investigating Australian women's management of their life goals. Although engagement with goals was generally positive for psychological well-being, the propensity to disengage from appearance-related goals was beneficial for body image and protective against disordered eating, suggesting strategies for promoting goal disengagement in women with eating disordered behaviour. The portfolio presents four case studies reviewing empirical research demonstrating the efficacy of adjuvant psychological therapy in relieving psychological distress in cancer patients.

Reengaging 'at-risk' youth in secondary education

A psychosocial study suggesting how 'at-risk' youth may reengage in secondary education. There are four outcomes: first, recognize identity work as key to understanding youth; second, progressively include youth in decision making; third, empower youth through collegial dialogue; finally, share creation of and responsibilities for content, process, assessment and evaluation.