912 resultados para Prof Michael ten Hompel
Resumo:
The sky is falling because the much-vaunted mining ‘boom’ is heading for ‘bust’. The fear-mongering by politicians, the industry and the media has begun in earnest. On ABC TV's 7:30 program on 22 August 2012, Federal Opposition Leader Tony Abbott blamed the Minerals Resource Rent Tax and the Carbon Tax for making ‘a bad investment environment much, much worse’ for the mining industry. The following day, Australia's Resources and Energy Minister Martin Ferguson told us on ABC radio that ‘the resources boom is over’. This must be true because, remember, we were warned to ‘Get ready for the end of the boom’ (David Uren, Economics Editor for The Australian 19 May 2012) due to the ‘Australian resource boom losing steam’ (David Winning & Robb M. Stewart, Wall Street Journal 21 August 2012). Besides, there is ‘unarguable evidence’ that Australia's production costs are ‘too expensive’ and ‘too uncompetitive’: mining magnate Gina Rinehart said so in a YouTube video placed on the Sydney Mining Club's website on 5 September 2012. Can this really be so? What is happening to the mining boom and to the people who depend upon it?
Resumo:
Purpose. To evaluate the use of optical coherence tomography (OCT) to assess the effect of different soft contact lenses on corneoscleral morphology. Methods. Ten subjects had anterior segment OCT B-scans taken in the morning and again after six hours of soft contact lens wear. For each subject, three different contact lenses were used in the right eye on non-consecutive days, including a hydrogel sphere, a silicone hydrogel sphere and a silicone hydrogel toric. After image registration and layer segmentation, analyses were performed of the first hyper-reflective layer (HRL), the epithelial basement membrane (EBL) and the epithelial thickness (HRL to EBL). A root mean square difference (RMSD) of the layer profiles and the thickness change between the morning and afternoon measurements, was used to assess the effect of the contact lens on the corneoscleral morphology. Results. The soft contact lenses had a statistically significant effect on the morphology of the anterior segment layers (p <0.001). The average amounts of change for the three lenses (average RMSD values) for the corneal region were lower (3.93±1.95 µm for the HRL and 4.02±2.14 µm for the EBL) than those measured in the limbal/scleral region (11.24±6.21 µm for the HRL and 12.61±6.42 µm for the EBL). Similarly, averaged across the three lenses, the RMSD in epithelial thickness was lower in the cornea (2.84±0.84 µm) than the limbal/scleral (5.47±1.71 µm) region. Post-hoc analysis showed that ocular surface changes were significantly smaller with the silicone hydrogel sphere lens than both the silicone hydrogel toric (p<0.005) and hydrogel sphere (p<0.02) for the combined HRL and EBL data. Conclusions. In this preliminary study, we have shown that soft contact lenses can produce small but significant changes in the morphology of the limbal/scleral region and that OCT technology is useful in assessing these changes. The clinical significance of these changes is yet to be determined.
Resumo:
The time course of elongation and recovery of axial length associated with a 30 minute accommodative task was studied using optical low coherence reflectometry in a population of young adult myopic (n = 37) and emmetropic (n = 22) subjects. Ten of the 59 subjects were excluded from analysis either due to inconsistent accommodative response, or incomplete anterior biometry data. Those subjects with valid data (n = 49) were found to exhibit a significant axial elongation immediately following the commencement of a 30 minute, 4 D accommodation task, which was sustained for the duration of the task, and ¬was evident to a lesser extent immediately following task cessation. During the accommodation task, on average, the myopic subjects exhibited 22 ± 34 µm, and the emmetropic subjects 6 ± 22 µm of axial elongation, however the differences in axial elongation between the myopic and emmetropic subjects were not statistically significant (p = 0.136). Immediately following the completion of the task, the myopic subjects still exhibited an axial elongation (mean magnitude 12 ± 28 µm), that was significantly greater (p < 0.05) than the changes in axial length observed in the emmetropic subjects (mean change -3 ± 16 µm). Axial length had returned to baseline levels 10 minutes after completion of the accommodation task. The time for recovery from accommodation-induced axial elongation was greater in myopes, which may reflect differences in the biomechanical properties of the globe associated with refractive error. Changes in subfoveal choroidal thickness were able to be measured in 37 of the 59 subjects, and a small amount of choroidal thinning was observed during the accommodation task that was statistically significant in the myopic subjects (p < 0.05). These subfoveal choroidal changes could account for some but not all of the increased axial length during accommodation.
Resumo:
Hematopoietic stem cell (HSC) transplant is a well established curative therapy for some hematological malignancies. However, achieving adequate supply of HSC from some donor tissues can limit both its application and ultimate efficacy. The theory that this limitation could be overcome by expanding the HSC population before transplantation has motivated numerous laboratories to develop ex vivo expansion processes. Pioneering work in this field utilized stromal cells as support cells in cocultures with HSC to mimic the HSC niche. We hypothesized that through translation of this classic coculture system to a three-dimensional (3D) structure we could better replicate the niche environment and in turn enhance HSC expansion. Herein we describe a novel high-throughput 3D coculture system where murine-derived HSC can be cocultured with mesenchymal stem/stromal cells (MSC) in 3D microaggregates—which we term “micromarrows.” Micromarrows were formed using surface modified microwells and their ability to support HSC expansion was compared to classic two-dimensional (2D) cocultures. While both 2D and 3D systems provide only a modest total cell expansion in the minimally supplemented medium, the micromarrow system supported the expansion of approximately twice as many HSC candidates as the 2D controls. Histology revealed that at day 7, the majority of bound hematopoietic cells reside in the outer layers of the aggregate. Quantitative polymerase chain reaction demonstrates that MSC maintained in 3D aggregates express significantly higher levels of key hematopoietic niche factors relative to their 2D equivalents. Thus, we propose that the micromarrow platform represents a promising first step toward a high-throughput HSC 3D coculture system that may enable in vitro HSC niche recapitulation and subsequent extensive in vitro HSC self-renewal.
Resumo:
Context: The benefits of high serum levels of 25-hydroxyvitamin D [25(OH)D] are unclear. Trials are needed to establish an appropriate evidence base. Objective: We plan to conduct a large-scale trial of vitamin D supplementation for the reduction of cancer incidence and overall mortality and report here the methods and results of a pilot trial established to inform its design. Design: Pilot D-Health was a randomized trial carried out in a general community setting with 12 months intervention and follow-up. Participants: Participants were 60- to 84-yr-old residents of one of the four eastern Australian states who did not have any vitamin D-related disorders and who were not taking more than 400 IU supplementary vitamin D per day. A total of 644 participants were randomized, and 615 completed the study (two persons withdrew because of nonserious adverse events). Interventions: The interventions were monthly doses of placebo or 30,000 or 60,000 IU vitamin D3. Main Outcomes: The main outcomes were the recruitment rate and changes in serum 25(OH)D. Results: Ten percent of those approached were recruited. At baseline, the mean 25(OH)D was 42 nmol/liter in all three study arms. The mean change in 25(OH)D in the placebo group was 0.12 nmol/liter, compared with changes of 22 and 36 nmol/liter in the 30,000- and 60,000-IU groups, respectively. Conclusions: The D-Health pilot has shown that a large trial is feasible in Australia and that a dose of 2000 IU/d will be needed to ensure that a large proportion of the population reaches the target serum 25(OH)D level. Copyright © 2012 by The Endocrine Society.
Resumo:
Immigration has played an important role in the historical development of Australia. Thus, it is no surprise that a large body of empirical work has developed, which focuses upon how migrants fare in the land of opportunity. Much of the literature is comparatively recent, i.e. the last ten years or so, encouraged by the advent of public availability of Australian crosssection micro data. Several different aspects of migrant welfare have been addressed, with major emphasis being placed upon earnings and unemployment experience. For recent examples see Haig (1980), Stromback (1984), Chiswick and Miller (1985), Tran-Nam and Nevile (1988) and Beggs and Chapman (1988). The present paper contributes to the literature by providing additional empirical evidence on the native/migrant earnings differential. The data utilised are from the rather neglected Australian Bureau of Statistics, ABS Special Supplementary Survey No.4. 1982, otherwise known as the Family Survey. The paper also examines the importance of distinguishing between the wage and salary sector and the self-employment sector when discussing native/migrant differentials. Separate earnings equations for the two labour market groups are estimated and the native/migrant earnings differential is broken down by employment status. This is a novel application in the Australian context and provides some insight into the earnings of the selfemployed, a group that despite its size (around 20 per cent of the labour force) is frequently ignored by economic research. Most previous empirical research fails to examine the effect of employment status on earnings. Stromback (1984) includes a dummy variable representing self-employment status in an earnings equation estimated over a pooled sample of paid and self-employed workers. The variable is found to be highly significant, which leads Stromback to question the efficacy of including the self-employed in the estimation sample. The suggestion is that part of self-employed earnings represent a return to non-human capital investment, i.e. investments in machinery, buildings etc, the structural determinants of earnings differ significantly from those for paid employees. Tran-Nam and Nevile (1988) deal with differences between paid employees and the selfemployed by deleting the latter from their sample. However, deleting the self-employed from the estimation sample may lead to bias in the OLS estimation method (see Heckman 1979). The desirable properties of OLS are dependent upon estimation on a random sample. Thus, the 'Ran-Nam and Nevile results are likely to suffer from bias unless individuals are randomly allocated between self-employment and paid employment. The current analysis extends Tran-Nam and Nevile (1988) by explicitly treating the choice of paid employment versus self-employment as being endogenously determined. This allows an explicit test for the appropriateness of deleting self-employed workers from the sample. Earnings equations that are corrected for sample selection are estimated for both natives and migrants in the paid employee sector. The Heckman (1979) two-step estimator is employed. The paper is divided into five major sections. The next section presents the econometric model incorporating the specification of the earnings generating process together with an explicit model determining an individual's employment status. In Section 111 the data are described. Section IV draws together the main econometric results of the paper. First, the probit estimates of the labour market status equation are documented. This is followed by presentation and discussion of the Heckman two-stage estimates of the earnings specification for both native and migrant Australians. Separate earnings equations are estimated for paid employees and the self-employed. Section V documents estimates of the nativelmigrant earnings differential for both categories of employees. To aid comparison with earlier work, the Oaxaca decomposition of the earnings differential for paid-employees is carried out for both the simple OLS regression results as well as the parameter estimates corrected for sample selection effects. These differentials are interpreted and compared with previous Australian findings. A short section concludes the paper.
Resumo:
The Flightless Cormorant Phalacrocorax harrisi is restricted to c. 400 km of the western coastline of the Galápagos archipelago coinciding with the local occurrence of seasonal upwelling of oceanic currents. Individuals frequently make more than one breeding attempt per year, usually change mates, and when juveniles are raised, females desert them to the further care of their mates who complete the rearing alone. Here we report data from a ten-year historical study of a colony stretching c.2 km along the coast-line and representing c. 12% of the total population of the species. The number of clutches laid and juveniles fledged were linked to the occurrence of cold water in off-shore foraging grounds. Most Flightless Cormorants have attachments to local stretches of coastline several hundred metres long. However, a few birds travelled many kilometres, including between colonies, sometimes over open sea. We show that males invest more in nest-building and feeding of the offspring than their mates, and we relate this to the (presumed) in-bred nature of the colony and to male and female reproductive strategies. Our data validate a published demographic model of the species (Valle 1995).
Resumo:
This study examined the effect of 20 weeks resistance training on a range of serum hormones and inflammatory markers at rest, and following acute bouts of exercise in prostate cancer patients undergoing androgen deprivation. Ten patients exercised twice weekly at high intensity for several upper and lower-body muscle groups. Neither testosterone nor prostate-specific antigen changed at rest or following an acute bout of exercise. However, serum growth hormone (GH), dehydroepiandrosterone (DHEA), interleukin-6, tumor necrosis factor-alpha and differential blood leukocyte counts increased (P < 0.05) following acute exercise. Resistance exercise does not appear to compromise testosterone suppression, and acute elevations in serum GH and DHEA may partly underlie improvements observed in physical function.
Resumo:
Qualitative Health Psychology aims to contribute to the debate about the nature of psychology and of science through ‘an examination of the role of qualitative research within health psychology’ (p. 3). The editors, in bringing together contributors from the UK, Ireland, Canada, Brazil, New Zealand and Australia, have compiled a text that reflects different uses of qualitative health research in diverse social and cultural contexts. Structured into three parts, the book encompasses key theoretical and methodological issues in qualitative research in its attempt to encourage broad epistemological debate within health psychology.
Resumo:
This thesis provides an overview of the Sri Lankan civil war with a view to identifying some of the factors that contributed to the dispute between the Sri Lankan government and the Liberation Tigers of Tamil Eelam. It adopts a multi-causal explanation of the conflict by reference to the theories of social power developed by Michael Mann. The conflict has been variously described as an ethnic or political conflict, or has been characterised as a determined by a number of interacting factors (including colonialism, ethnicity, religion, economy, politics and globalisation). Mann’s four-dimensional model of social power is deployed to analyse the causal relationships, together with their inter-connections, which clarify the origins of the dispute. It argues that Mann’s theoretical framework helps to highlight some of the interconnected elements that contributed to the conflict.
Resumo:
BACKGROUND: Epidemiologic research has demonstrated that cutaneous markers of photo-damage are associated with risk of basal cell carcinoma (BCC). However there has been no previous attempt to calculate pooled risk estimates. METHODS: We conducted a systematic review and meta-analysis after extracting relevant studies published up to January 2013 from five electronic databases. Eligible studies were those that permitted quantitative assessment of the association between histologically-confirmed BCC and actinic keratoses, solar elastosis, solar lentigines, or telangiectasia. RESULTS: Seven eligible studies were identified and summary odds ratios (OR) were calculated using both random and quality effects models. Having more than ten actinic keratoses was most strongly associated with BCC, conferring up to a 5-fold increase in risk (OR: 4.97; 95% CI: 3.26, 7.58). Other factors, including solar elastosis, solar lentigines, and telangiectasia had weaker but positive associations with BCC with ORs around 1.5. CONCLUSIONS: Markers of chronic photo-damage are positively associated with BCC. The presence of actinic keratoses was the most strongly associated with BCC of the markers examined. IMPACT: This work highlights the relatively modest association between markers of chronic ultraviolet exposure and BCC.
Resumo:
A range of authors from the risk management, crisis management, and crisis communications literature have proposed different models as a means of understanding components of crisis. A generic component of these sources has focused on preparedness practices before disturbance events and response practices during events. This paper provides a critical analysis of three key explanatory models of how crises escalate highlighting the strengths and limitations of each approach. The paper introduces an optimised conceptual model utilising components from the previous work under the four phases of pre-event, response, recovery, and post-event. Within these four phases, a ten step process is introduced that can enhance understanding of the progression of distinct stages of disturbance for different types of events. This crisis evolution framework is examined as a means to provide clarity and applicability to a range of infrastructure failure contexts and provide a path for further empirical investigation in this area.
Resumo:
Multiple Sclerosis (MS) is a central nervous system (CNS) chronic inflammatory demyelinating disease leading to various neurological disabilities. The disorder is more prevalent for women with a ratio of 3:2 female to male. Objectives: To investigate variation within the estrogen receptor 1 (ESR1) polymorphism gene in an Australian MS case-control population using two intragenic restriction fragment length polymorphisms; the G594A located in exon 8 detected with the BtgI restriction enzyme and T938C located in intron 1, detected with PvuII. One hundred and ten Australian MS patients were studied, with patients classified clinically as Relapsing Remitting MS (RR-MS), Secondary Progressive MS (SP-MS) or Primary Progressive MS (PP-MS). Also, 110 age, sex and ethnicity matched controls were investigated as a comparative group. No significant difference in the allelic distribution frequency was found between the case and control groups for the ESR1 PvuII (P = 0.50) and Btg1 (P = 0.45) marker. Our results do not support a role for these two ESR1 markers in multiple sclerosis susceptibility, however other markers within ESR1 should not be excluded for potential involvement in the disorder.
Resumo:
I grew up in academic heaven. At least for me it was. Not only was Sweden in the late 1980s paradise for any kind of empirical research, with rich and high-quality business statistics being made available to researchers without them having to sign away their lives; 70+ percent response rates achieved in mail surveys to almost any group (if you knew how to do them), and boards of directors opening their doors to more qualitatively orientated researchers to sit in during their meetings. In addition, I perceived an environment with a very high degree of academic freedom, letting me do whatever I found interesting and important. I’m sure for others it was sheer hell, with very unclear career paths and rules of the game. Career progression (something which rarely entered my mind) meant that you tried as best you could and then you put all your work – reports, books, book chapters, conference papers, maybe even published articles – in a box and had some external committee of professors look at it. If you were lucky they liked what they saw for whatever reasons their professorial wisdom dictated, and you got hired or promoted. If you were not so lucky you wouldn’t get the job or the promotion, without quite knowing why. So people could easily imagine an old boys club – whose members were themselves largely unproven in international, peer review publishing – picking whoever they wanted by whatever criteria they choose to apply. Neither the fact that assessors were external nor the presence of an appeals system might have completely appeased your suspicious and skeptical mind, considering the balance of power.