978 resultados para 312.275
Resumo:
A focused library based on the marine natural products polyandrocarpamines A (1) and B (2) has been designed and synthesised using parallel solution-phase chemistry. In silico physicochemical property calculations were performed on synthetic candidates in order to optimise the library for drug discovery and chemical biology. A library of ten 2-aminoimidazolone products (3–12) was prepared by coupling glycocyamidine and a variety of aldehydes using a one-step stereoselective aldol condensation reaction under microwave conditions. All analogues were characterised by NMR, UV, IR and MS. The library was evaluated for cytotoxicity towards the prostate cancer cell lines, LNCaP, PC-3 and 22Rv1.
Resumo:
In this article, we analyse bifurcations from stationary stable spots to travelling spots in a planar three-component FitzHugh-Nagumo system that was proposed previously as a phenomenological model of gas-discharge systems. By combining formal analyses, center-manifold reductions, and detailed numerical continuation studies, we show that, in the parameter regime under consideration, the stationary spot destabilizes either through its zeroth Fourier mode in a Hopf bifurcation or through its first Fourier mode in a pitchfork or drift bifurcation, whilst the remaining Fourier modes appear to create only secondary bifurcations. Pitchfork bifurcations result in travelling spots, and we derive criteria for the criticality of these bifurcations. Our main finding is that supercritical drift bifurcations, leading to stable travelling spots, arise in this model, which does not seem possible for its two-component version.
Resumo:
Background: Depression and alcohol misuse are among the most prevalent diagnoses in suicide fatalities. The risk posed by these disorders is exacerbated when they co-occur. Limited research has evaluated the effectiveness of common depression and alcohol treatments for the reduction of suicide vulnerability in individuals experiencing comorbidity. Methods: Participants with depressive symptoms and hazardous alcohol use were selected from two randomised controlled trials. They had received either a brief (1 session) intervention, or depression-focused cognitive behaviour therapy (CBT), alcohol-focused CBT, therapist-delivered integrated CBT, computer-delivered integrated CBT or person-centred therapy (PCT) over a 10-week period. Suicidal ideation, hopelessness, depression severity and alcohol consumption were assessed at baseline and 12-month follow-up. Results: Three hundred three participants were assessed at baseline and 12 months. Both suicidal ideation and hopelessness were associated with higher severity of depressive symptoms, but not with alcohol consumption. Suicidal ideation did not improve significantly at follow-up, with no differences between treatment conditions. Improvements in hopelessness differed between treatment conditions; hopelessness improved more in the CBT conditions compared to PCT and in single-focused CBT compared to integrated CBT. Limitations: Low retention rates may have impacted on the reliability of our findings. Combining data from two studies may have resulted in heterogeneity of samples between conditions. Conclusions: CBT appears to be associated with reductions in hopelessness in people with co-occurring depression and alcohol misuse, even when it is not the focus of treatment. Less consistent results were observed for suicidal ideation. Establishing specific procedures or therapeutic content for clinicians to monitor these outcomes may result in better management of individuals with higher vulnerability for suicide.
Resumo:
The prevalence of psychological maladjustment in homeless adolescents (n = 54) was compared to control group (n 58) in Brisbane, Australia using the Youth Self-Report Scale [1]. Overall, 74% of the homeless group and 22.4% of the control group scored within the clinical range on one or more of the clinical subscales. There was considerable diversity of symptomatology in the homeless group. Less than half of the homeless group were within the clinical range on both the delinquent subscale and the thought disorder subscale. Depressive, Aggressive and Somatic Complaints were also prevalent. The study challenges preconceived notions of simple relationship between adolescent homelessness and delinquency, and draws attention to the psychological needs of this group of adolescents.
Resumo:
Contrary to what many practitioners believe, current generation contact lenses are easy to fit, are well tolerated, provide superior vision, are physiologically compatible with the anterior ocular structures, cause few serious complications and are cost effective. These factors will be explored with examples of advancements that have occurred in contact lens practice over the past two decades. Consideration will also be given to the role of optometrists, the contact lens industry and educational institutions in promoting contact lenses as an alternative form of vision correction.
Resumo:
There is a dearth of preventative programs that enhance the Australian culturally and linguistically diverse (CALD) adults’ resilience to cope with the acculturation process. This article introduces the reader to the BRiTA Futures for Adults and Parents, a culture and language sensitive program for the CALD. The conceptual framework and the development process are described. The manualised program consisting of one introductory and eight intervention modules is presented. A training program is also developed to train facilitators, who can deliver the program in English or other languages. Preliminary trials indicated that the program was received well by the consumers. A block mode, instead of the traditional weekly sessions, appeared to be more practical for the small population for which it was trialled. Implications and future directions are discussed.
Resumo:
Background Migraine is a brain disorder affecting ∼12% of the Caucasian population. Genes involved in neurological, vascular, and hormonal pathways have all been implicated in predisposing individuals to developing migraine. The migraineur presents with disabling head pain and varying symptoms of nausea, emesis, photophobia, phonophobia, and occasionally visual sensory disturbances. Biochemical and genetic studies have demonstrated dysfunction of neurotransmitters: serotonin, dopamine, and glutamate in migraine susceptibility. Glutamate mediates the transmission of excitatory signals in the mammalian central nervous system that affect normal brain function including cognition, memory and learning. The aim of this study was to investigate polymorphisms in the GRIA2 and GRIA4 genes, which encode subunits of the ionotropic AMPA receptor for association in an Australian Caucasian population. Methods Genotypes for each polymorphism were determined using high resolution melt analysis and the RFLP method. Results Statistical analysis showed no association between migraine and the GRIA2 and GRIA4 polymorphisms investigated. Conclusions Although the results of this study showed no significant association between the tested GRIA gene variants and migraine in our Australian Caucasian population further investigation of other components of the glutamatergic system may help to elucidate if there is a relationship between glutamatergic dysfunction and migraine.
Resumo:
Objectives: To examine factors associated with the uptake of i) long-acting reversible, ii) permanent and iii) traditional contraceptive methods among Australian women. Methods: Participants in the Australian Longitudinal Study on Women's Health born in 1973–78 reported on their contraceptive use at three surveys: 2003, 2006 and 2009. The participants were 5,849 women aged 25–30 in 2003 randomly sampled from Medicare. The main outcome measure was current contraceptive method at age 28–33 years categorised as long-acting reversible methods (implant, IUD, injection), permanent (tubal ligation, vasectomy), and traditional methods (oral contraceptive pills, condoms, withdrawal, safe period). Results: Compared to women living in major cities, women in inner regional areas were more likely to use long-acting (OR=1.26, 95%CI 1.03–1.55) or permanent methods (OR=1.43, 95%CI 1.17–1.76). Women living in outer regional/remote areas were more likely than women living in cities to use long-acting (OR=1.65, 95%CI 1.31–2.08) or permanent methods (OR=1.69, 95%CI 1.43–2.14). Conclusions: Location of residence is an important factor in women's choices about long-acting and permanent contraception in addition to the number and age of their children. Implications: Further research is needed to understand the role of geographical location in women's access to contraceptive options in Australia.
Resumo:
An alternative learning approach for destructive testing of structural specimens in civil engineering is explored by using a remote laboratory experimentation method. The remote laboratory approach focuses on overcoming the constraints in the hands-on experimentation without compromising the understanding of the students on the concepts and mechanics of reinforced concrete structures. The goal of this study is to evaluate whether or not the remote laboratory experimentation approach can become a standard in civil engineering teaching. The teaching activity using remote-laboratory experimentation is presented here and the outcomes of this activity are outlined. The experience and feedback gathered from this study are used to improve the remote-laboratory experimentation approach in future years to other aspects of civil engineering where destructive testing is essential.
Resumo:
Improved public awareness of the environment and available technologies will continue to highlight the importance of sustainable housing in the coming years. Despite this potential, the majority of new housing development in Australia is still “project homes” with few tangible sustainability measures. Stakeholders tend to have different perceptions and priorities on sustainability. To promote the uptake of sustainable housing products, a study of the critical issues affecting the implementation of sustainable housing is necessary. This research investigates multiple factors that may influence key stakeholders’ decision-making towards sustainable housing adoption. Drawing insights from combined questionnaire and interview studies, 12 critical factors and their interrelationships are identified based on professional views in the Australian housing industry. The mutual influences, or driving force and dependency, of these factors are further investigated via Interpretive Structural Modelling (ISM) to distinguish those requiring prominent and immediate attention. A hierarchical model is developed to help key stakeholders prioritise actions when implementing sustainable housing.
Resumo:
A method is proposed to describe force or compound muscle action potential (CMAP) trace data collected in an electromyography study for motor unit number estimation (MUNE). Experimental data was collected using incre- mental stimulation at multiple durations. However, stimulus information, vital for alternate MUNE methods, is not comparable for multiple duration data and therefore previous methods of MUNE (Ridall et al., 2006, 2007) cannot be used with any reliability. Hypothesised ring combinations of motor units are mod- elled using a multiplicative factor and Bayesian P-spline formulation. The model describes the process for force and CMAP in a meaningful way.
Resumo:
The Marine Systems Simulator (MSS) is an environment which provides the necessary resources for rapid implementation of mathematical models of marine systems with focus on control system design. The simulator targets models¡Xand provides examples ready to simulate¡Xof different floating structures and its systems performing various operations. The platform adopted for the development of MSS is Matlab/Simulink. This allows a modular simulator structure, and the possibility of distributed development. Openness and modularity of software components have been the prioritized design principles, which enables a systematic reuse of knowledge and results in efficient tools for research and education. This paper provides an overview of the structure of the MSS, its features, current accessability, and plans for future development.
Resumo:
Jackson (2005) developed a hybrid model of personality and learning, known as the learning styles profiler (LSP) which was designed to span biological, socio-cognitive, and experiential research foci of personality and learning research. The hybrid model argues that functional and dysfunctional learning outcomes can be best understood in terms of how cognitions and experiences control, discipline, and re-express the biologically based scale of sensation-seeking. In two studies with part-time workers undertaking tertiary education (N equals 137 and 58), established models of approach and avoidance from each of the three different research foci were compared with Jackson's hybrid model in their predictiveness of leadership, work, and university outcomes using self-report and supervisor ratings. Results showed that the hybrid model was generally optimal and, as hypothesized, that goal orientation was a mediator of sensation-seeking on outcomes (work performance, university performance, leader behaviours, and counterproductive work behaviour). Our studies suggest that the hybrid model has considerable promise as a predictor of work and educational outcomes as well as dysfunctional outcomes.
Resumo:
Background The behaviour of tumour cells depends on factors such as genetics and the tumour microenvironment. The latter plays a crucial role in normal mammary gland development and also in breast cancer initiation and progression. Breast cancer tissues tend to be highly desmoplastic and dense matrix as a pre-existing condition poses one of the highest risk factors for cancer development. However, matrix influence on tumour cell gene expression and behaviour such as cell migration is not fully elucidated. Results We generated high-density (HD) matrices that mimicked tumour collagen content of 20 mg/cm3 that were ~14-fold stiffer than low-density (LD) matrix of 1 mg/cm3. Live-cell imaging showed breast cancer cells utilizing cytoplasmic streaming and cell body contractility for migration within HD matrix. Cell migration was blocked in the presence of both the ROCK inhibitor, Y-27632, and the MMP inhibitor, GM6001, but not by the drugs individually. This suggests roles for ROCK1 and MMP in cell migration are complicated by compensatory mechanisms. ROCK1 expression and protein activity, were significantly upregulated in HD matrix but these were blocked by treatment with a histone deacetylase (HDAC) inhibitor, MS-275. In HD matrix, the inhibition of ROCK1 by MS-275 was indirect and relied upon protein synthesis and Notch1. Inhibition of Notch1 using pooled siRNA or DAPT abrogated the inhibition of ROCK1 by MS-275. Conclusion Increased matrix density elevates ROCK1 activity, which aids in cell migration via cell contractility. The upregulation of ROCK1 is epigenetically regulated in an indirect manner involving the repression of Notch1. This is demonstrated from inhibition of HDACs by MS-275, which caused an upregulation of Notch1 levels leading to blockade of ROCK1 expression.
Resumo:
This paper investigates the outsourcing of income tax return preparation by Australian accounting firms. It identifies the extent to which firms are currently outsourcing accounting services or considering outsourcing accounting services, with a focus on personal and business income tax return preparation. The motivations and barriers for outsourcing by Australian accounting firms are also considered in this paper. Privacy, security of client data, and the competence of the outsourcing provider's staff have been identified as risks associated with outsourcing. An expectation relating to confidentiality of client data is also examined in this paper. Statistical analysis of data collected from a random sample of Australian accounting firms using a survey questionnaire provided the empirical data for the paper. The results indicate that the majority of Australian accounting firms are either currently outsourcing or considering outsourcing accounting services, and firms are outsourcing taxation preparation both onshore and offshore. The results also indicate that firms expect the volume of outsourced work to increase in the future. In contrast to the literature identifying labour arbitrage as the primary driver for organisations choosing to outsource, this study found that the main factors considered by accounting firms in the decision to outsource were to expedite delivery of services to clients and to enable the firm to focus on core competencies. Data from this study also supports the literature which ndicates that not all tax practitioners are adhering to codes of conduct in relation to client confidentiality. Research identifying the extent to which accounting services are outsourced is limited, therefore significant contributions to the academic literature and the accounting profession are provided by this ndicates that not all tax practitioners are adhering to codes of conduct in relation to client confidentiality. Research identifying the extent to which accounting services are outsourced is limited, therefore significant contributions to the academic literature and the accounting profession are provided by this study.