21 resultados para RECENT COMMON ANCESTRY

em Deakin Research Online - Australia


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There has hitherto been little research into evolutionary and taxonomic relationships amongst species of the freshwater prawn genus Macrobrachium Bate across its global distribution. Previous work by the authors demonstrated that the endemic Australian species did not evolve from a single ancestral lineage. To examine whether other regional Macrobrachium faunas also reflect this pattern of multiple origins, the phylogeny of 30 Macrobrachium species from Asia, Central/South America and Australia was inferred from mitochondrial 16S rRNA sequences. Phylogenetic relationships demonstrate that, despite some evidence for regional diversification, Australia, Asia and South America clearly contain Macrobrachium species that do not share a common ancestry, suggesting that large-scale dispersal has been a major feature of the evolutionary history of the genus. The evolution of abbreviated larval development (ALD), associated with the transition from an estuarine into a purely freshwater lifecycle, was also mapped onto the phylogeny and was shown to be a relatively homoplasious trait and not taxonomically informative. Other taxonomic issues, as well as the evolutionary origins of Macrobrachium, are also discussed.

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The right of minors to make medical treatment decisions is an issue that is not explicitly addressed in the legislation of most Australian jurisdictions. While recent common law decisions allow competent minors to consent to treatment, current legislation in Victoria does not provide adequate guidelines on how competence is to be measured. It is also unclear whether the duty of confidentiality is extended to competent minors. The current study explored general practitioners' competence and confidentiality decisions with a hypothetical 14-year-old patient who requests the oral contraceptive pill (OCP). Questionnaires were sent to 1,000 Victorian general practitioners, 305 of whom responded. General practitioners were asked to determine whether "Liz" was competent to request the OCP, and whether they would maintain her confidentiality. A total of 81% of respondents found the patient competent, while 91% would have maintained her confidentiality. Results indicate that the majority of general practitioners used rationales that generally did not conform to current legal principles when making competence and confidentiality determinations regarding this patient.

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Mitochondrial sequence data is often used to reconstruct the demographic history of Pleistocene populations in an effort to understand how species have responded to past climate change events. However, departures from neutral equilibrium conditions can confound evolutionary inference in species with structured populations or those that have experienced periods of population expansion or decline. Selection can affect patterns of mitochondrial DNA variation and variable mutation rates among mitochondrial genes can compromise inferences drawn from single markers. We investigated the contribution of these factors to patterns of mitochondrial variation and estimates of time to most recent common ancestor (TMRCA) for two clades in a co-operatively breeding avian species, the white-browed babbler Pomatostomus superciliosus. Both the protein-coding ND3 gene and hypervariable domain I control region sequences showed departures from neutral expectations within the superciliosus clade, and a two-fold difference in TMRCA estimates. Bayesian phylogenetic analysis provided evidence of departure from a strict clock model of molecular evolution in domain I, leading to an over-estimation of TMRCA for the superciliosus clade at this marker. Our results suggest mitochondrial studies that attempt to reconstruct Pleistocene demographic histories should rigorously evaluate data for departures from neutral equilibrium expectations, including variation in evolutionary rates across multiple markers. Failure to do so can lead to serious errors in the estimation of evolutionary parameters and subsequent demographic inferences concerning the role of climate as a driver of evolutionary change. These effects may be especially pronounced in species with complex social structures occupying heterogeneous environments. We propose that environmentally driven differences in social structure may explain observed differences in evolutionary rate of domain I sequences, resulting from longer than expected retention times for matriarchal lineages in the superciliosus clade.

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Stock repurchases (or share buy-backs) have become increasingly popular among Australian companies. One of the main aims of announcing a stock repurchase by a listed company is signalling the market that its shares are currently underpriced. When market reacts to the signal, price of the shares is expected to increase immediately after the announcement. While there are several ways of repurchasing shares, 'on-market buy-backs' is the most popular method of stock repurchases in Australia. Australian listed companies have announced more than two hundred on-market share buy-backs over the past three years. The aim of this paper is to examine the information signalling effects of these on-market buy-back announcements. If the signal is considered positively (negatively) by the market, the price of the repurchasing company's shares should increase (decrease) immediately after the announcement. If there is no information content in the announcement, the price will remain the same. In this study, signalling effect of share buy-back announcements was examined using most recent Australian data. The total population of on-market buy-back announcements during the period from January 1, 2000 to March 10, 2003 was included. The abnormal market return over the short-run (announcement day and 9 trading days centred on the announcement date) was computed using the All Ordinaries Accumulation Index as the reference portfolio. The daily Abnormal Returns (AR) and Cumulative Abnormal Returns (CAR) during the event period were computed. The results strongly support the information-signalling hypothesis of share buy..backs. Australian market generally considers announcement of on~market share repurchases as signalling of insider information that shares are currently underpriced.

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Over the past decade Australian theatre has seen an increased profile for works written and created by Indigenous artists. This paper looks at the development of Indigenous theatre in Australia and considers how increased mainstream production opportunities have facilitated this expansion of Indigenous theatre practice. Based on the textual analysis of a number of key works, this paper looks at the development of the one-person show as the dominant genre for Indigenous theatre practices, and investigates the relationship between autobiography and the celebration of ‘otherness’. This study argues that this theatre work represents a shift away from conventional representations of Aboriginality towards a more self-determined expression of political identity.

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Stomatin, originally identified as a major protein of the human erythrocyte membrane, is widely expressed in various tissues. Orthologues are found in vertebrates, invertebrates, plants, and microorganisms. Related proteins exhibit a common core structure, termed the prohibitin (PHB) domain, with varying extensions. Stomatin has an unusual topology, similar to caveolin-1, with a hydrophobic domain embedded at the cytoplasmic side of the membrane. Additional anchoring is provided by palmitoylation and the membrane affinity of the PHB domain. Stomatin associates with cholesterol-rich microdomains (lipid rafts), forms oligomers, and thereby displays a scaffolding function by generating large protein-lipid complexes. It regulates the activity of various membrane proteins by reversibly recruiting them to lipid rafts. This mechanism of regulation has been shown for GLUT-1 and may also apply for ion channels. Stomatin is located at the plasma membrane, particularly in microvilli, in endocytic and exocytic vesicles, and cytoplasmic granules. Stomatin-carrying endosomes are highly dynamic and interact with lipid droplets suggesting a role in intracellular lipid transport. This subcellular distribution and the caveolin-like protein structure suggest important membrane organizing functions for stomatin. A general picture emerges now that cell membranes contain cholesterol-rich domains that are generated and regulated by scaffolding proteins like caveolins, stomatins, and flotillin/reggie proteins.

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In this paper we analyze per capita incomes of the G7 countries using the common cycles test developed by Vahid and Engle (Journal of Applied Econometrics, 8:341–360, 1993) and extended by Hecq et al. (Oxford Bulletin of Economics and Statistics, 62:511–532, 2000; Econometric Reviews, 21:273–307, 2002) and the common trend test developed by Johansen (Journal of Economic Dynamics and Control, 12:231–254, 1988). Our main contribution is that we impose the common cycle and common trend restrictions in decomposing the innovations into permanent and transitory components. Our main finding is permanent shocks explain the bulk of the variations in incomes for the G7 countries over short time horizons, and is in sharp contrast to the bulk of the recent literature. We attribute this to the greater forecasting accuracy achieved, which we later confirm through performing a post sample forecasting exercise, from the variance decomposition analysis.

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Recent thinking on globalization places risk at the centre of contemporary life. Yet what if our perception of risk is misplaced? What if the greatest risk is not terrorism itself but the conditions that allow terrorism to flourish? This fascinating book illustrates that elevated perceptions of terrorism-related risks are having a deleterious impact on many societies, exacerbating feelings of exclusion among individuals and groups. Via their exploration of various societies, the expert contributors show that as a causal factor of terrorism, social exclusion can be remedied by inclusive, participatory and deliberative measures. They prescribe a recalibration of counter-terrorism policies to unite rather than divide multicultural societies.

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Objective Recent evidence suggests a role for diet quality in the common mental disorders depression and anxiety. We aimed to investigate the association between diet quality, dietary patterns, and the common mental disorders in Norwegian adults.

Methods
This cross-sectional study included 5731 population-based men and women aged 46 to 49 and 70 to 74 years. Habitual diet was assessed using a validated food frequency questionnaire, and mental health was measured using the Hospital Anxiety and Depression Scale.

Results After adjustments for variables including age, education, income, physical activity, smoking, and alcohol consumption, an a priori healthy diet quality score was inversely related to depression (odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.59–0.84) and anxiety (OR = 0.77, 95% CI = 0.68–0.87) in women and to depression (OR = 0.83, 95% CI = 0.70–0.99) in men. Women scoring higher on a healthy dietary pattern were less likely to be depressed (OR = 0.68, 95% CI = 0.57–0.82) or anxious (OR = 0.87, 95% CI = 0.77–0.98), whereas men were more likely to be anxious (OR = 1.19, 95% CI = 1.03–1.38). A traditional Norwegian dietary pattern was also associated with reduced depression in women (OR = 0.77, 95% CI = 0.64–0.92) and anxiety in men (OR = 0.77, 95% CI = 0.61–0.96). A western-type diet was associated with increased anxiety in men (OR = 1.27, 95% CI = 1.14–1.42) and women (OR = 1.29, 95% CI = 1.17–1.43) before final adjustment for energy intake.

Conclusions
In this study, those with better quality diets were less likely to be depressed, whereas a higher intake of processed and unhealthy foods was associated with increased anxiety.

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Background Depression often coexists with myocardial infarction (MI) and has been found to impede recovery through reduced functioning in key areas of life such as work. In an era of improved survival rates and extended working lives, we review whether depression remains a predictor of poorer work outcomes following MI by systematically reviewing literature from the past 15 years.

Methods Articles were identified using medical, health, occupational and social science databases, including PubMed, OVID, Medline, Proquest, CINAHL plus, CCOHS, SCOPUS, Web of Knowledge, and the following pre-determined criteria were applied: (i) collection of depression measures (as distinct from 'psychological distress') and work status at baseline, (ii) examination and statistical analysis of predictors of work outcomes, (iii) inclusion of cohorts with patients exhibiting symptoms consistent with Acute Coronary Syndrome (ACS), (iv) follow-up of work-specific and depression specific outcomes at minimum 6 months, (v) published in English over the past 15 years. Results from included articles were then evaluated for quality and analysed by comparing effect size.

Results Of the 12 articles meeting criteria, depression significantly predicted reduced likelihood of return to work (RTW) in the majority of studies (n = 7). Further, there was a trend suggesting that increased depression severity was associated with poorer RTW outcomes 6 to 12 months after a cardiac event. Other common significant predictors of RTW were age and patient perceptions of their illness and work performance.

Conclusion Depression is a predictor of work resumption post-MI. As work is a major component of Quality of Life (QOL), this finding has clinical, social, public health and economic implications in the modern era. Targeted depression interventions could facilitate RTW post-MI.

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Mitochondrial DNA (mtDNA) can be a powerful genetic marker for tracing origins and history of invasive populations. Here, we use mtDNA to address questions relevant to the understanding of invasion pathways of common starlings (Sturnus vulgaris) into Western Australia (WA) and discuss the utility of this marker to provide information useful to invasive species management. Mitochondrial sequence data indicate two geographically restricted genetic groups within Australia. Evidence of dispersal from genetically distinct sources outside the sampled range of starlings in Australia suggests increased vigilance by management agencies may be required to prevent further incursions from widely separated localities. Overall, genetic diversity in Australia was lower than in samples from the native range. Within Australia, genetic diversity was lowest in the most recently colonized area in the west, indicating that demographic bottlenecks have occurred in this area. Evidence of restricted dispersal between localities on the edge of the range expansion (ERE) in WA and other Australian sampling localities suggests that localized control within the ERE may be effective in preventing further range expansion. Signatures of spatial and demographic expansion are present in mismatch analyses from sampling localities located at the ERE, but neutrality indices did not support this finding, suggesting that the former may be more sensitive to recent expansion. Additionally, mismatch analyses support the presence of admixture, which is likely to have occurred pre-introduction. We compare our findings with those from a microsatellite study of the same samples and discuss how the mtDNA analyses used here offer valuable and unique insights into the invasion history of introduced species.

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There is a need for the development of effective universal preventive approaches to the common mental disorders, depression and anxiety, at a population level. Poor diet, physical inactivity and smoking have long been recognized as key contributors to the high prevalence noncommunicable diseases. However, there are now an increasing number of studies suggesting that the same modifiable lifestyle behaviors are also risk factors for common mental disorders. In this paper we point to the emerging data regarding lifestyle risk factors for common mental disorders, with a particular focus on and critique of the newest evidence regarding diet quality. On the basis of this most recent evidence, we consequently argue for the inclusion of depression and anxiety in the ranks of the high prevalence noncommunicable diseases influenced by habitual lifestyle practices. We believe that it is both feasible and timely to begin to develop effective, sustainable, population-level prevention initiatives for the common mental illnesses that build on the established and developing approaches to the noncommunicable somatic diseases.

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Objectives. There is evidence to suggest that immigrant groups from low- or medium-human development index countries show a significant adoption of obesogenic behaviors and experience weight gain following migration to Australia. The objective of this study is to understand the changes that Iranian immigrants experience in relation to the determinants of obesity after migration to Victoria, Australia.

Design. We conducted five focus group discussions with 33 recent Iranian immigrants. This study took an interpretive qualitative approach to data analysis using the constant comparative method.

Results. Participants discussed individual level acculturation (e.g., in diet, body size, attitudes), as well as environmental level changes (e.g., physical/structural and sociocultural) that occurred after immigration. Stress during the initial immigration transition, which affected diet and physical activity habits, was a common experience among participants. Gender and the effect of political/religious changes were also important factors. Participants' discourse largely focused on their ability and willingness to adopt positive health behaviors after migration.

Conclusion. This study provides insight into the effect of migration on the determinants of obesity among Iranian immigrants in Victoria, Australia, and offers a contrast with the existing evidence by considering the experience of a group that is generally well educated, often emigrates for reasons related to personal freedom as opposed to material deprivation, and has rates of obesity similar to high-income countries.

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Prevention strategies have made a major contribution to the considerable successes in reductions in cardiovascular disease and cancer mortality seen in recent decades. However, in the field of psychiatry, similar population-level initiatives in the prevention of common mental disorders, depression and anxiety, are noticeably lacking. This paper aims to provide a brief overview of the existing literature on the topic of the prevention of common mental disorders and a commentary regarding the way forward for prevention research and implementation.

Methods:
This commentary considers what we currently know, what we might learn from the successes and failures of those working in prevention of other high prevalence health conditions, and where we might go from here. Taking cognisance of previous preventive models, this commentary additionally explores new opportunities for preventive approaches to the common mental disorders.

Results:
The consensus from a large body of evidence supports the contention that interventions to prevent mental disorders across the lifespan can be both effective and cost-effective. However, funding for research in the area of prevention of common mental disorders is considerably lower than that for research in the areas of treatment, epidemiology and neurobiology. Thus, there is a clear imperative to direct funding towards prevention research to redress this imbalance. Future prevention interventions need to be methodologically rigorous, scalable to the population level and include economic evaluation. Evidence-based knowledge translation strategies should be developed to ensure that all stakeholders recognise preventing mental disorders as an imperative, with appropriate resources directed to this objective.

Conclusion:
There has been a recent expansion of research into potentially modifiable risk factors for depression, and it is now timely to make a concerted effort to advance the field of prevention of common mental disorders.

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 Australian Criminal Law in the Common Law Jurisdictions is a clear and comprehensive introduction to the fundamentals of criminal law. Updated throughout to reflect recent cases and legislation, the fourth edition combines clear case extracts with incisive author commentary and discussion.