Relationship between processing, surface energy and bulk properties of ultrafine silk particles

Silk particles of different sizes and shapes were produced by milling and interactions with a series of polar and non-polar gaseous probes were investigated using an inverse gas chromatography technique. The surface energy of all silk materials is mostly determined by long range dispersive interactions such as van der Waals forces. The surface energy increases and surface energy heterogeneity widens after milling. All samples have amphoteric surfaces and the concentration of acidic groups increases after milling while the surfaces remain predominantly basic. We also examined powder compression and flow behaviours using a rheometer. Increase in surface energy, surface area, and static charges in sub-micron air jet milled particles contributed to their aggregation and therefore improved flowability. However they collapse under large pressures and form highly cohesive powder. Alkaline hydrolysis resulted in more crystalline fibres which on milling produced particles with higher density, lower surface energy and improved flowability. The compressibility, bulk density and cohesion of the powders depend on the surface energy as well as on particle size, surface area, aggregation state and the testing conditions, notably the consolidated and unconsolidated states. The study has helped in understanding how surface energy and flowability of particles can be changed via different fabrication approaches.

Relationship between body mass index and the use of healthcare services in Australia

Objective: To examine the relationship between body mass index (BMI) and the use of medical and preventive health services. Research Methods and Procedures: This study involved secondary analysis of weighted data from the Australian 1995 National Health Survey. The study was a population survey designed to obtain national benchmark information about a range of health-related issues. Data were available from 17,033 men and 17,174 women, 20 years or age. BMI, based on self-reported weight and height, was analyzed in relation to the use of medical services and preventive health services. Results: A positive relationship was found between BMI and medical service use, such as medication use, visits to hospital accident and emergency departments (for women only); doctor visits, visits to a hospital outpatient clinics; and visits to other health professionals (for women only). A negative relationship was found in women between BMI and preventive health services. Underweight women were found to be significantly less likely to have Papanicolaou smear tests, breast examinations, and mammograms. Discussion: This research shows that people who fall outside the healthy weight range are more likely to use a range of medical services. Given that the BMI of industrialized populations appears to be increasing, this has important ramifications for health service planning and reinforces the need for obesity prevention strategies at a population level.

Social factors and obesity: an investigation of the role of health behaviours

OBJECTIVES: This study evaluated a behavioural model of the relation between social factors and obesity, in which differences in body mass index (BMI) across sociodemographic groups were hypothesized to be attributable to social group differences in health behaviours affecting energy expenditure (physical activity, diet and alcohol consumption and weight control).

METHODS: A total of 8667 adults who participated in the 1995 Australian National Health and Nutrition Surveys provided data on a range of health factors including objectively measured height and weight, health behaviours, and social factors including family status, employment status, housing situation and migration status.

RESULTS: Social factors remained significant predictors of BMI after controlling for all health behaviours. Neither social factors alone, nor health behaviours alone, adequately explained the variance in BMI. Gender-specific interactions were found between social factors and individual health behaviours.

CONCLUSIONS: These results suggest that social factors moderate the relation between BMI and weight-related behaviours, and that the mechanisms underlying sociodemographic group differences in obesity may vary among men and women. Additional factors are likely to act in conjunction with current health behaviours to explain variation in obesity prevalence across sociodemographic groups.

Association of genetic vatiation within UBL5 with phenotypes of metabolic syndrome

The BEACON gene was initially identified using the differential display polymerase chain reaction on hypothalamic mRNA samples collected from lean and obese Psammomys obesus, a polygenic animal model of obesity. Hypothalamic BEACON gene expression was positively correlated with percentage of body fat, and intracerebroventricular infusion of the Beacon protein resulted in a dose-dependent increase in food intake and body weight. The human homolog of BEACON, UBL5, is located on chromosome 19p in a region previously linked to quantitative traits related to obesity. Our previous studies showed a statistically significant association between UBL5 sequence variation and several obesity- and diabetes-related quantitative physiological measures in Asian Indian and Micronesian cohorts. Here we undertake a replication study in a Mexican American cohort where the original linkage signal was first detected. We exhaustively resequenced the complete gene plus the putative promoter region for genetic variation in 55 individuals and identified five single nucleotide polymorphisms (SNPs), one of which was novel. These SNPs were genotyped in a Mexican American cohort of 900 individuals from 40 families. Using a quantitative trait linkage disequilibrium test, we found significant associations between UBL5 genetic variants and waist-to-hip ratio (p = 0.027), and the circulating concentrations of insulin (p = 0.018) and total cholesterol (p = 0.023) in fasted individuals. These data are consistent with our earlier published studies and further support a functional role for the UBL5 gene in influencing physiological traits that underpin the development of metabolic syndrome.

A rapid cell counting method utilising acridine orange as a novel discriminating marker for both cultured astrocytes and microglia

Cell culture analyses of growth, morphology and apoptosis commonly require counting of different cell types stained with antibodies to discriminate between them. Previously, we reported the use of l-Leucine methyl ester (l-LME) to prepare purified cultures of type 1 astrocytes with minimal microglia, and staining by GFAP and CD antibodies, respectively. Here, we demonstrate a novel use of acridine orange (AO) for rapid discrimination between these cell types using fluorescence microscopy. AO accumulates in the lysosomes and also binds strongly to nuclear DNA and cytoplasmic/nucleolar RNA. Microglia may contain abundant lysosomes due to known roles in homeostasis and immune response. AO staining of lysosomes was tested at a range of concentrations, and 2.5 μg/mL was most suitable. In agreement with previous reports, microglia treated with AO showed very intense yellow, orange or red granular cytoplasmic staining of lysosomes. Microglia contain a substantially higher number of lysosomes than astrocytes, which have a variable amount. We measured the microglia population at 5.14 ± 0.50% in mixed cultures. Thus, these results show AO is a novel discriminatory marker, as microglia were easily observed and counted in clumps on top of the monolayer of astrocytes, providing a rapid alternative to time-consuming and costly antibody-based assays.

Why models are advantageous to learning science

Models are used routinely in science classes to help explain scientific concepts; however, students are often unaware of the role, limitations and purpose of the particular model being used. This study investigated Grade 8-11 students’ views on models in science and used these results to propose a framework to show how models are involved in learning. The results show that students’ understanding of the role of models in learning science improved in later grades and that many students were able to distinguish the purpose of scientific models from teaching models. The results are used to identify the criteria students use to classify models and to support pedagogical approaches of using models in teaching science.

Annual variation in the distribution of summer snowdrifts in the Kosciuszko alpine area, Australia, and its effect on the composition and structure of alpine vegetation

Australian alpine ecosystems are expected to diminish in extent as global warming intensifies. Alpine vegetation patterns are influenced by the duration of snow cover including the presence of snowdrifts in summer, but there is little quantitative information on landscape-scale relationships between vegetation patterns and the frequency of occurrence of persistent summer snowdrifts in the Australian alps. We mapped annual changes in summer snowdrifts in the Kosciuszko alpine region, Australia, from Landsat TM images and modelled the frequency of occurrence of persistent summer snowdrifts from long-term records (1954–2003) of winter snow depth. We then compared vegetation composition and structure among four classes that differed in the frequency of occurrence of persistent summer snowdrifts. We found a curvilinear relationship between annual winter snow depth and the area occupied by persistent snowdrifts in the following summer (r²=0.9756). Only 21 ha (0.42% of study area) was predicted to have supported summer snowdrifts in 80% of the past 50 years, while 440 ha supported persistent summer snow in 10% of years. Mean cover and species richness of vascular plants declined significantly, and species composition varied significantly, as the frequency of summer snow persistence increased. Cushion plants and rushes were most abundant where summer snowdrifts occurred most frequently, and shrubs, grasses and sedges were most abundant in areas that did not support snowdrifts in summer. The results demonstrate strong regional relationships between vegetation composition and structure and the frequency of occurrence of persistent summer snowdrifts. Reductions in winter snow depth due to global warming are expected to lead to substantial reductions in the extent of persistent summer snowdrifts. As a consequence, shrubs, grasses and sedges are predicted to expand at the expense of cushion plants and rushes, reducing landscape vegetation diversity. Fortunately, few vascular plant species (e.g. Ranunculus niphophilus) appear to be totally restricted to areas where summer snow occurs most frequently. The results from this study highlight potential indicator species that could be monitored to assess the effects of global warming on Australian alpine environments.

Encouraging governments to enhance the happiness of their nation : Step 1: understand subjective wellbeing

This article considers the issue of facilitating policies that enhance population happiness. An impediment to such action is the failure of most policy makers to understand that subjective wellbeing can be measured and understood within the framework of science. Additionally, they fail to realize that enhancing the subjective wellbeing of populations enhances not only the functioning of individuals but that of the population as a whole. A framework for understanding calls on the Theory of Subjective Wellbeing Homeostasis and data from the Australian Unity Wellbeing Index. This Index has been used to monitor the subjective wellbeing of the Australian population over the 6-year period 2001–2006. The article begins by a description of the subjective wellbeing construct and the theory that it is homeostatically managed. The operation of homeostasis makes very determined predictions as to the kinds of relationships that should be found in association with various environmental challenges and resources. These predictions will be examined in the light of the data from our surveys and the benefits of population happiness will be discussed. Finally, consideration will be given as to and how such understanding may be conveyed to politicians, in order to assist the development of policies aimed at enhancing the level of happiness in society.

Investigation into the diffusion of innovation in technical and further education : implementing e-mail through action research

This research project examined the diffusion of change within one Victorian TAFE Institute by engaging action research to facilitate implementation of e-mail technology. The theoretical framework involving the concepts of technology innovation and action research was enhanced with the aid of Rogers's (1983) model of the diffusion of the innovation process. Political and cultural factors made up the initiation phase of innovation, enabling the research to concentrate on the implementation phase of e-mail Roger's (1983) model also provided adopter categories that related to the findings of a Computer Attitude Survey that was conducted at The School of Mines and Industries Ballarat (SMB), now the University of Ballarat—TAFE Division since amalgamation on 1st January 1998. Despite management rhetoric about the need to utilise e-mail, Institute teaching staff lacked individual computers in their work areas and most were waiting to become connected to the Internet as late as 1997. According to the action research reports, many staff were resistant to the new e-mail facilities despite having access to personal computers whose numbers doubled annually. The action research project became focussed when action researchers realised that e-mail workshop training was ineffective and that staff required improved access. Improvement to processes within education through collaborative action research had earlier been achieved (McTaggart 1994), and this project actively engaged practitioners to facilitate decentralised e-mail training in the workplace through the action research spiral of planning, acting, observing and reflecting, before replanning. The action researchers * task was to find ways to improve the diffusion of e-mail throughout the Institute and to develop theoretical constructs. My research task was to determine whether action research could successfully facilitate e-mail throughout the Institute. A rich literature existed about technology use in education, technology teaching, gender issues, less about computerphobia, and none about 'e-mailphobia \ It seemed appropriate to pursue the issue of e-mailphobia since it was marginalised, or ignored in the literature. The major political and cultural influences on the technologising of SMB and e-mail introduction were complex, making it impossible to ascertain the relative degrees of influence held by Federal and State Governments, SMB's leadership or the local community, Nonetheless, with the implementation of e-mail, traditional ways were challenged as SMB's culture changed. E-mail training was identified as a staff professional development activity that had been largely unsuccessful. Action research is critical collaborative inquiry by reflective practitioners who are accountable for making the results of their inquiry public and who are self-evaluating of their practice while engaging participative problem-solving and continuing professional development (Zuber-Skerritt 1992, 1993). Action research was the methodology employed in researching e-mail implementation into SMB because it involved collaborative inquiry with colleagues as reflective practitioners. Thoughtful questions could best be explored using deconstructivist philosophy, in asking about the noise of silence, which issues were not addressed, what were the contradictions and who was being marginalised with e-mail usage within SMB. Reviewing literature on action research was complicated by its broad definition and by the variability of research (King & Lonnquist 1992), and yet action research as a research methodology was well represented in educational research literature, and provided a systematic and recognisable way for practitioners to conduct their research. On the basis of this study, it could be stated that action research facilitated the diffusion of e-mail technology into one TAFE Institute, despite the process being disappointingly slow. While the process in establishing the action research group was problematic, action researchers showed that a window of opportunity existed for decentralised diffusion of e-mail training,in preference to bureaucratically motivated 'workshops. Eight major findings, grouped under two broad headings were identified: the process of diffusion (planning, nature of the process, culture, politics) and outcomes of diffusion (categorising, e-mailphobia, the survey device and technology in education). The findings indicated that staff had little experience with e-mail and appeared not to recognise its benefits. While 54.1% did not agree that electronic means could be the preferred way to receive Institute memost some 13.7% admitted to problems with using the voice answering service on telephones. Some 43.3% thought e-mail would not improve their connectedness (how they related) to the Institute. A small percentage of staff had trouble with telephone voice-mail and a number of these were anxious computer users. Individualised tuition and peer support proved helpful to individual staff whom action researchers believed to be 'at risk', as determined from the results of a Computer Attitude Survey. An instructional strategy that fostered the development of self-regulation and peer support was valuable, but there was no measure of the effects of this action research program, other than in qualitative terms. Nevertheless, action research gave space to reflect on the nature of the underlying processes in adopting e-mail. Challenges faced by TAFE action researchers are integrally affected by the values within TAFE, which change constantly and have recently been extensive enough to be considered as a 'new paradigm'. The influence of competition policy, the training reform agenda and technologisation of training have challenged traditional TAFE values. Action research reported that many staff had little immediate professional reason to use e-mail Theoretical answers were submerged beneath practical professional concerns, which related back to how much time teachers had and whether they could benefit from e-mail. A need for the development of principles for the sound educational uses of e-mail increases with the internationalisation of education and an increasing awareness of cultural differences. The implications for conducting action research in TAFE are addressed under the two broad issues of power and pedagogy. Issues of power included gaining access, management's inability to overcome staff resistance to technology, changing TAFE values and using technology for conducting action research. Pedagogical issues included the recognition of educational above technological issues and training staff in action research. Finally, seventeen steps are suggested to overcome power and pedagogical impediments to the conduct of action research within TAFE. This action research project has provided greater insight into the difficulties of successfully introducing one culture-specific technology into one TAFE Institute. TAFE Institutes need to encourage more action research into their operations, and it is only then that -we can expect to answer the unanswered questions raised in this research project.

Can dietary lipid source circadian alternation improve omega-3 deposition in rainbow trout?

With the salmonid industry currently exploiting the vast majority of globally available fish oil, there is the need to optimise fish oil utilisation by increasing its efficiency in terms of transferring the health-promoting long chain omega-3 fatty acids (n−3 LC-PUFA) into farmed fish flesh. The aim of this study was to evaluate if dietary fatty acid deposition is affected by the time of feeding, and hence identify possible innovative feeding strategies towardsmore efficient use of dietary fish oil. Over a period of 12 weeks, three diets with different lipid sources, canola oil (CO), fish oil (FO) or a 50/50 blend of the two oils (Mix), were alternated daily and fed to rainbow trout (Oncorhynchus mykiss). Six treatments were administered to fish, reference treatment (REF, continuously fed FO), control treatment (CT, continuously fed Mix), am canola oil ration (amCOR), pm canola oil ration (pmCOR), am canola oil satiation (amCOS) and pm canola oil satiation (pmCOS). Fish received either the CO diet in the am or pm feeds and received the FO diet at the opposite time. A significant increase in growth and feed consumption was noted in the pmCOS treatment. Fillet fatty acid profile was modified by associated feeding schedules and was generally reflective of dietary fatty acid profile. No significant increases in n−3 LCPUFA deposition were observed. However, both linoleic acid (18:2n−6) and α-linolenic acid (18:3n−3) contents were significantly higher in pmCOR compared to amCOR and CT. The results of the present study suggest the existence of cyclical circadian patterns in fatty acid deposition in rainbow trout.

Influences on preschool children's physical activity

This study explored mothers' perceptions of influences on preschoolers' physical activity. Six semistructured focus groups with 23 mothers were conducted across a range of socioeconomic position locations. Mothers identified 4 key areas of influence: child fundamentals (eg, sex, personality), parent power (eg, rules, support), people to share with (eg, peers, adults), and places and things (eg, physical environments, toys). No substantial differences in themes were identified among socioeconomic position groups. Influences on preschoolers' physical activity are multidimensional, multifactorial, and support the use of ecological models to conceptualize and understand the influencing factors. Associations among factors influencing preschoolers' physical activity should be further investigated through quantitative research.

Ultraviolet-sensitive vision in long-lived birds

Long-term exposure to ultraviolet (UV) light generates substantial damage, and in mammals, visual sensitivity to UV is restricted to short-lived diurnal rodents and certain marsupials. In humans, the cornea and lens absorb all UV-A and most of the terrestrial UV-B radiation, preventing the reactive and damaging shorter wavelengths from reaching the retina. This is not the case in certain species of long-lived diurnal birds, which possess UV-sensitive (UVS) visual pigments, maximally sensitive below 400 nm. The Order Psittaciformes contains some of the longest lived bird species, and the two species examined so far have been shown to possess UVS pigments. The objective of this study was to investigate the prevalence of UVS pigments across long-lived parrots, macaws and cockatoos, and therefore assess whether they need to cope with the accumulated effects of exposure to UV-A and UV-B over a long period of time. Sequences from the SWS1 opsin gene revealed that all 14 species investigated possess a key substitution that has been shown to determine a UVS pigment. Furthermore, in vitro regeneration data, and lens transparency, corroborate the molecular findings of UV sensitivity. Our findings thus support the claim that the Psittaciformes are the only avian Order in which UVS pigments are ubiquitous, and indicate that these long-lived birds have UV sensitivity, despite the risks of photodamage.

Garden & landscape heritage:a crisis of tangible & intangible comprehension and curatorship

The cultural landscape of George Town, Penang, Malaysia, embraces the historic enclave of George Town as well as a range of other significant colonial vestiges adjacent to the entrépôt. Many of these landscapes cannot be isolated from the énclave as they are integral to and part of its cultural mosaic and character. Perhaps the most important are the Penang Hill hill-station landscape and the 'Waterfall‘ Botanic Gardens. The latter is an under-valued 'garden of the empire‘—a garden that significantly underpinned the development and historical and botanical stature of the Singapore Botanic Gardens.This paper reviews the cultural significance of colonial botanic gardens as they were established around the world during the scientific explosion of the late 1800s. It addresses their position within World Heritage listings, and considers the role, significance and importance of the 'Waterfall‘ Botanic Gardens within this context, within the concept of 'cultural landscapes‘, and critiques its absence from the recent World Heritage Listing of the colonial enclaves of Georgetown and Meleka in Malaysia.