Phase behavior and crystallization in blends of a low molecular weight polyethylene-block-poly(ethylene oxide) diblock copolymer and poly(hydroxyether of bisphenol A)

The phase behavior, morphology and crystallization in blends of a low-molecular-weight (Mn = 1400) double-crystalline polyethylene-block-poly(ethylene oxide) (PE-PEO) diblock copolymer with poly(hydroxyether of bisphenol A) (PH) were investigated by differential scanning calorimetry, transmission electron microscopy and small-angle X-ray scattering. The symmetric PE-PEO diblock copolymer consists of a PH-miscible PEO block and a PH-immiscible PE block. However, PH only exhibits partial miscibility with the PEO block of the copolymer in the PH/PE-PEO blends; both macrophase and microphase separations took place. There existed two macrophases in the PH/PE-PEO blends, i.e., a PH-rich phase and a PE-PEO copolymer-rich phase. The PE block of the copolymer in the blends exhibited fractionated crystallization behavior by homogeneous nucleation. There appeared three crystallization exotherms related to the crystallization of the PE block within three different microenvironments in the PH/PE-PEO blends.

Do clinicians know how to use pulse oximetry? A literature review and clinical implications

Pulse oximerry has become one of the most commonly used tools in the clinical environment for assessing patients' oxygenation status. It is employed almost continuously in critical care areas and frequently in the general ward environment. Although it is a much better tool for determining hypoxia than the human eye, its use is limited if clinicians do not understand relevant physiological principles, such as the oxyhaemoglobin dissociation curve and the inherent limitations of the device. Furthermore, the risk for compromised patient safety is significant if clinicians fail to recognise the potential for false or erroneous readings. This paper explores the research which has examined clinicians' comprehension of pulse oximetry. Fourteen studies examining clinicians' knowledge of pulse oximerry were reviewed. These studies revealed significant knowledge deficits about pulse oximerry amongst nurses, doctors and allied health professionals, all of whom used this technology frequently. Alarmingly, those lacking an adequate understanding of pulse oximerry included senior, experienced clinicians. The studies were limited by their use of convenience sampling and small sample sizes. Further research is needed to better understand the significance of this problem and to examine how principles of pulse oximerry are taught to nurses and other health professionals at the undergraduate and postgraduate levels. Educators and clinicians alike must ensure that a safe level of knowledge for the use of pulse oximerry is maintained in order to ensure that patient outcomes are not compromised.

Phase behavior, crystallization, and hierarchical nanostructures in self-organized thermoset blends of epoxy resin and amphiphilic poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) triblock copolymers

Nanostructured thermoset blends of bisphenol A-type epoxy resin (ER) and amphiphilic poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers were successfully prepared. Two samples of PEO-PPO-PEO triblock copolymer with different ethylene oxide (EO) contents, denoted as EO30 with 30 wt % EO content and EO80 with 80 wt % EO content, were used to form the self-organized thermoset blends of varying compositions using 4,4'-methylenedianiline (MDA) as curing agent. The phase behavior, crystallization, and morphology were investigated by differential scanning calorimetry (DSC), transmission electron microscopy (TEM), atomic force microscopy (AFM), and small-angle X-ray scattering (SAXS). It was found that macroscopic phase separation took place in the MDA-cured ER/EO30 blends containing 60-80 wt % EO30 triblock copolymer. The MDA-cured ER/EO30 blends with EO30 content up to 50 wt % do not show macroscopic phase separation but exhibit nanostructures on the order of 10-30 nm as revealed by both the TEM and SAXS studies. The AFM study further shows that the ER/EO30 blend at some composition displays structural inhomogeneity at two different nanoscales and is hierarchically nanostructured. The spherical PPO domains with an average size of about 10 nm are uniformly dispersed in the 80/20 ER/EO30 blend; meanwhile, a structural inhomogeneity on the order of 50-200 nm is observed. The ER/EO80 blends are not macroscopically phase-separated over the entire composition range because of the much higher PEO content of the EO80 triblock copolymer. However, the ER/EO80 blends show composition-dependent nanostructures on the order of 10-100 nm. The 80/20 ER/EO80 blend displays hierarchical structures at two different nanoscales, i.e., a bicontinuous microphase structure on the order of about 100 nm and spherical domains of 10-20 nm in diameter uniformly dispersed in both the continuous microphases. The blends with 60 wt % and higher EO80 content are completely volume-filled with spherulites. Bundles of PEO lamellae with spacing of 20-30 nm interwoven with a microphase structure on the order of about 100 nm are revealed by AFM study for the 30/70 ER/EO80 blend.

An investigation of scale economies and quality issues in the teaching and management of large subjects

Many in the tertiary education system have had concerns with the issues surrounding the teaching of large classes, including teaching quality and whether there are effective learning outcomes for students. An issue closely related to quality is the cost of providing an efficacious education system. It is a common perception that large classes are economical to run and small subjects are not. As with any complex issue there are several perspectives that could be utilised, the needs of the institution, the teaching staff, the community or the students, and whether or not these needs are being met.

This study aims to assess whether universities are meeting the needs of students in large marketing classes. For this purpose the study investigates the application of selfdetermination theory and psychological needs satisfaction. The basic needs scale, comprising of three constructs; Control, Competence and Caring was adapted and used to evaluate students' perception of an introductory marketing subject.

The study used a multi-method approach consisting of a literature review, a qualitative phase involving in-depth interviews and focus groups. A survey of 366 students who had undertaken an introductory level marketing subject in a large class format was also conducted. The results show that the psychological needs satisfaction of many students are not being fully realised. It was also found that marketing degree students enjoyed the challenges and were more stimulated by the subject (than students in other degree streams). The higher achieving students enjoyed the challenge of the subject more than the lower achieving students. The implications of these findings and suggestions for
further investigation are discussed.

Herbert Spencer in the suburbs? Class, politics, ideology and the Australian petty-bourgeoisie in the Howard years

A dominant trope of media commentary after the 2004 federal election was the rise of blue-collar self-employment and small business and its negative impact on Labor electoral support. In this paper I examine the evidence on the growth of self-employment and small business in Australia since the 1980s and the political consequences of this growth. I consider why the growth of self-employment and small business has been overstated by many observers, and the emergence of a right-wing anti-capitalism in the critique of the dependence of wage-labour. Although the growth of self-employment and small business has been overstated it is a real phenomenon. I extract the rational kernel from the largely ill-informed commentary on this issue and place contemporary debates about self-employment in a historical and global context. I consider why the self-employed and small business were once seen as natural allies of the working-class in a populist coalition but why they are now identified by commentators as hostile to class politics.

Smoking cessation programs in pregnancy: systematically addressing development, implementation, women's concerns and effectiveness

Objectives:  To increase a review's relevance to practitioners and service users and identify the implications for systematic review methodology. Methods:  A systematic review of the effects of smoking cessation programmes implemented during pregnancy integrated process indicators and the views of maternity service users and health promotion specialists. Additional qualitative data were extracted systematically from included randomised control trials (RCTs) to determine whether the design of interventions and conclusions arising from their evaluation related to the views of service users. On completing the review we reflected on the types of observational and qualitative research it drew on, where this research was incorporated into the review, and its added value. Results:   Incorporating process indicators into the review revealed: 1) problems with implementation and transplantation of some interventions and 2) studies with more stringent quality criteria and process evaluations demonstrated greater impact (weighted mean difference in smoking). Pregnant smokers were rarely involved in the design or evaluation of the interventions. Prior observational and qualitative studies and small scale consultations influenced the criteria by which the effectiveness of the interventions were judged, and revealed to what extent these criteria are adopted in practice.
Conclusions:   Systematically abstracting data about the development and delivery of interventions revealed gaps that might be filled by the active involvement of service users.

Optimal lag-length choice in stable and unstable VAR models under situations of homoscedasticity and ARCH

The performance of different information criteria - namely Akaike, corrected Akaike (AICC), Schwarz-Bayesian (SBC), and Hannan-Quinn - is investigated so as to choose the optimal lag length in stable and unstable vector autoregressive (VAR) models both when autoregressive conditional heteroscedasticity (ARCH) is present and when it is not. The investigation covers both large and small sample sizes. The Monte Carlo simulation results show that SBC has relatively better performance in lag-choice accuracy in many situations. It is also generally the least sensitive to ARCH regardless of stability or instability of the VAR model, especially in large sample sizes. These appealing properties of SBC make it the optimal criterion for choosing lag length in many situations, especially in the case of financial data, which are usually characterized by occasional periods of high volatility. SBC also has the best forecasting abilities in the majority of situations in which we vary sample size, stability, variance structure (ARCH or not), and forecast horizon (one period or five). frequently, AICC also has good lag-choosing and forecasting properties. However, when ARCH is present, the five-period forecast performance of all criteria in all situations worsens.

Photodegradation, interaction with iron oxides and bioavailability of dissolved organic matter from forested floodplain sources

Photochemical degradation of dissolved organic matter (DOM) can influence food webs by altering the availability of carbon to microbial communities, and may be particularly important following periods of high DOM input (e.g. flooding of forested floodplains). Iron oxides can facilitate these reactions, but their influence on subsequent organic products is poorly understood. Degradation experiments with billabong (= oxbow lake) water and river red gum (Eucalyptus camaldulensis) leaf leachate were conducted to assess the importance of these reactions in floodplain systems. Photochemical degradation of DOM in sunlight-irradiated quartz tubes (with and without amorphous iron oxide) was studied using gas chromatography and UV-visible spectroscopy. Photochemical reactions generated gaseous products and small organic acids. Bioavailability of billabong DOM increased following irradiation, whereas that of leaf leachate was not significantly altered. Fluorescence excitation-emission spectra suggested that the humic component of billabong organic matter was particularly susceptible to degradation, and the source of DOM influenced the changes observed. The addition of amorphous iron oxide increased rates of photochemical degradation of leachate and billabong DOM. The importance of photochemical reactions to aquatic systems will depend on the source of the DOM and its starting bioavailability, whereas inputs of freshly formed iron oxides will accelerate the processes.

Self-assembled complexes of poly(4-vinylphenol) and poly(ε-caprolactone)-block-poly(2-vinylpyridine) via competitive hydrogen bonding

Nanostructured complexes were prepared from poly(ε-caprolactone)-block-poly(2-vinylpyridine) (PCL-b-P2VP) and poly(4-vinylphenol) (PVPh) in tetrahydrofuran (THF). The phase behavior, specific interactions, and morphology were investigated using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, optical microscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). In this A-b-B/C type block copolymer/homopolymer system, both blocks of the PCL-b-P2VP block copolymer have favorable intermolecular interaction toward PVPh via hydrogen bonding, but the interaction between P2VP block and PVPh is significantly stronger than that between PCL block and PVPh. It was found that the disparity in competitive intermolecular interactions, specifically PVPh and P2VP block interact strongly whereas PVPh and PCL block interact weakly, leads to the formation of a variety of nanostructures depending on PVPh concentration. Spherical micelles of 30−40 nm in diameter were obtained in the complex with 10 wt % PVPh, followed by wormlike micelles with size in the order of 40−50 nm in the complexes with 30−60 wt % PVPh. At low PVPh concentrations, PCL interacts weakly with PVPh, whereas in the complexes containing more than 20 wt % PVPh, the PCL block began to interact considerably with PVPh, leading to the formation of composition-dependent nanostructures. The complex becomes homogeneous with PVPh content beyond 60 wt %, since a sufficient amount of PVPh is available to form hydrogen bonds with both PCL and P2VP. Finally, a model was proposed to explain the self-assembly and microphase morphology of these complexes based on the experimental results obtained. The competitive hydrogen-bonding interactions cause the self-assembly and formation of different microphase morphologies.

Vascular distribution of nitric oxide synthase and vasodilation in the Australian lungfish, Neoceratodus forsteri

The presence of nitric oxide synthase (NOS) and role of nitric oxide (NO) in vascular regulation was investigated in the Australian lungfish, Neoceratodus forsteri. No evidence was found for NOS in the endothelium of large and small blood vessels following processing for NADPH-diaphorase histochemistry. However, both NADPH-diaphorase histochemistry and neural NOS immunohistochemistry demonstrated a sparse network of nitrergic nerves in the dorsal aorta, hepatic artery, and branchial arteries, but there were no nitrergic nerves in small blood vessels in tissues. In contrast, nitrergic nerves were found in non-vascular tissues of the lung, gut and kidney. Dual-wire myography was used to determine if NO signalling occurred in the branchial artery of N. forsteri. Both SNP and SIN-1 had no effect on the pre-constricted branchial artery, but the particulate guanylyl cyclase (GC) activator, C-type natriuretic peptide, always caused vasodilation. Nicotine mediated a dilation that was not inhibited by the soluble GC inhibitor, ODQ, or the NOS inhibitor, L-NNA, but was blocked by the cyclooxygenase inhibitor, indomethacin. These data suggest that NO control of the branchial artery is lacking, but that prostaglandins could be endothelial relaxing factors in the vasculature of lungfish.

Modelling income group differences in the health and economic impacts of targeted food taxes and subsidies

Objective : To examine the effects, by income group, of targeted food taxes and subsidies on nutrition, health and expenditure in the UK.

Methods : A model based on consumption data and demand elasticity was constructed to predict the effects of four food taxation-subsidy regimens. Resulting changes in demand, expenditure, nutrition, cardiovascular disease (CVD) and cancer mortality were estimated.

Data : Expenditure data were taken from the Expenditure and Food Survey; estimates of price elasticities of demand for food were taken from a report based on the National Food Survey 1988–2000. Estimates of effect on CVD and cancer mortality of changing fat, salt, fruit and vegetable intake were taken from previous meta-analyses.

Results : (i) Taxing principal sources of dietary saturated fat is unlikely to reduce cardiovascular disease (CVD) or cancer mortality. (ii) Taxing ‘less healthy’ foods (defined by the WXYfm nutrient profiling model) could increase CVD and cancer deaths by 35–1300 yearly. (iii) Taxing ‘less healthy’ foods and subsidising fruits and vegetables by 17.5% could avert up to 2900 CVD and cancer deaths yearly. (iv) Taxing ‘less healthy’ foods and using all tax revenue to subsidize fruits and vegetables could avert up to 6400 CVD and cancer deaths yearly. Few obesity-related CVD deaths are averted by any of the regimens. All four regimens would be economically regressive and positive health effects will not necessarily be greater in lower-income groups where the need for dietary improvement is higher.

Conclusions : A targeted food tax combined with the appropriate subsidy on fruits and vegetables could reduce deaths from CVD and cancer.

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.

Interaction of dietary fibre, carbohydrate metabolism and diabetes in the rat

It is currently accepted that the most appropriate diet in the treatment of non-insulin-dependent diabetes mellitus "e;NIDDM"e; is high in carbohydrates, high in fibre and low in fat. Dietary fibre reduces the rate of carbohydrate absorption, which may have a beneficial effect on insulin action. Furthermore, high fibre diets also increase the amount of carbohydrates which are not absorbed from the small intestine. These malabsorbed carbohydrates are fermented by the bacterial population in the large intestine, producing short chain fatty acids "e;SCFA"e;, including propionate, which has been shown to alter liver carbohydrate metabolism. This thesis investigated the actions of slowed carbohydrate absorption and carbohydrate malabsorption in streptozotocin-induced "e;STZ"e; diabetic rats. High carbohydrate diet supplemented with guar gum, a soluble dietary fibre, fed to STZ diabetic rats improved insulin sensitivity. investigation of the alterations in the stomach and small intestine demonstrated that guar increased the viscosity of the meal in the intestine. The action of increased fermentation, producing more propionate, was investigated by supplementing propionate into the diets of STZ diabetic rats or when perfused into isolated rat livers. No changes in insulin action or liver glucose metabolism were measured. in addition, it was shown that guar gum reduces food intake in STZ diabetic rats. Mild reductions in food intake in STZ diabetic rats were shown to increase insulin action. In summary, STZ diabetic rats fed high carbohydrate, high fibre diets reductions in food consumption and slowed carbohydrate absorption are important factors which may lower blood glucose concentrations and increase insulin action. increased SCFA production is unlikely to contribute significantly to the improvements in insulin action.

Identifying and developing executive skills

This study aimed to identify those skills which, individually or in combination, contribute to a high standard of management practice by Chief Executive Officers in Australia. Based on an extensive review of the literature, a skill taxonomy was developed to reflect current research findings. Verification of this taxonomy was sought through field questionnaires and depth interviews with male and female CEOs drawn from large and small organisations in both the public and private sectors. This led to a revised skill taxonomy, with 17 skills reflecting three significant categories; understanding and interpreting the external environment understanding and mobilising the internal environment and understanding and mobilising personal resources’ Eight of the skills were identified as key differentiating skills. They are situational, contingent and interdependent They reflect the broad context in which they are applied and their interrelationships in the wider environment. The research then sought to determine how these skills were acquired or developed. The motivation and capacity for continual learning was a key factor. The most effective learning took place in a randomised, unstructured, incremental and integrative fashion. Experiences associated with breadth, diversity, challenge and with reassessing perspectives and personal paradigms were of particular significance. It was found that an ordered, structured and purposive learning approach — as implied by most existing learning models — does not necessarily enhance the acquisition of the key skills; it may well impede their development. This led to the theoretical conclusion that there are three modes of learning relevant to senior executives; instrumental learning (‘learning to do’), systemic learning (‘learning to be’) and meta-learning (‘learning to learn’). The implications are drawn out, with particular reference to the experiences and facilitative organisational environments needed for the development of systemic and meta-learning; the modes considered of most importance if senior executives are to be able to effectively respond to the organisational and environmental challenges they face.

Diet and habitat of the powerful owl (Ninox strenua) living near Melbourne

The diet of Powerful Owls (Ninox strenua) living at Christmas Hills, 35km north-east of Melbourne was examined by analysis of 686 regurgitated pellets collected over two years. An aid was also developed to help identify potential mammalian prey species based on hair and skeletal characteristics. The following features were found to be most useful in distinguishing between the three species of arboreal marsupials - Common Ringtail Possum (Pseudocheirus peregrinus), Common Brushtail Possum (Trichosurus vulpecula) and Sugar Glider (Petaurus breviceps): - Cross-sectional width of primary guard hairs. - The size and shape of the nasal, frontal, parietal and squamosal bones of the skull. - Dentition. The size and shape of the upper incisor, canine and premolar teeth. The size and shape of the lower incisor and premolar teeth. - The size of the humerus. The Sugar Glider has a much smaller humerus than that of the Common Ringtail Possum and the Common Brushtail Possum. In the Common Brushtail Possum the entepicondyle ends in a very sharp point but the Common Ringtail Possum this point is not as sharp. - The Common Ringtail Possum’s femur has a very prominent trochanter which projects further than that in the Common Brushtail Possum. The femur of the Sugar Glider is distinguished by having a very large depression between the condyle and the trochanter. - The Common Brushtail Possum’s scapula has a narrower lower blade (relative to length) than that in the Common Ringtail Possum. The scapula of the Sugar Glider is smaller in size than that of the other two possums.The pelvic girdle Of the Common Brushtail Possum has a much wider ischium than those of the Common Brushtail Possum and the Sugar Glider. The ilium of the Sugar is much narrower and smaller than that of the other two possums Mammalian prey was found in 89%, insects in 13% and birds in 10% of the pellets. Of the mammals, Common Ringtail Possums occurred most frequently in the pellets over the year. There was no seasonal difference in the frequency of occurrence of Common Ringtail Possums and Sugar Gliders in pellets. However, Common Brushtail Possums were more likely to be taken in spring than in the other seasons. More adult Common Ringtail Possums were taken as prey than were other age classes over the year, except in summer when high numbers of young were consumed by the owls. The habitat of the Powerful Owl was examined by ground surveys and spotlight surveys in sixteen sites within the Warrandyte-Kinglake Nature Conservation Link. Four categories of survey sites were chosen with the following features. Category A - Sites with a dense understorey of shrubs and small trees, as well as many old trees (>10/ha) which might be suitable for nest hollows. Category B - Sites which lacked a dense understorey of shrubs and small trees and containing few or no old trees suitable for nest hollows. Category C - Sites with a dense understorey of shrubs and small trees but containing few or no old trees suitable for nest hollows. Category D - Sites which lacked a dense understorey of shrubs and small trees but having old trees (>10/ha) which might be suitable for nest hollows. High prey densities strongly correlated with the presence of hollows at these sites. In the light of the results, management recommendations were made for the future conservation of the Powerful Owls living at Christmas Hills. The following recommendations were particularly important: 1. Cleared or semi - cleared land within the Warrandyte Kinglake Nature Conservation Link be revegetated using indigenous species of eucalypts and waffles in order to provide a contiguous native forest corridor for the movement of possums and gliders between the Yarra River Valley and the Kinglake Plateau. 2. Continued planting of Eucalyptus spp. and Acacia spp. in the forested areas of the Warrandyte-Kinglake Nature Conservation Link. 3. Continued protection of healthy living trees to provide a continuous supply of hollow trees. 4. No falling of dead standing trees for firewood collecting as these can provide nest hollows for prey species of the Powerful Owl.