851 resultados para Initial adhesions
Resumo:
This study evaluates three versions of the Wayfinding Effectiveness Scale (WES), developed to differentiate problems of wayfinding and wandering behavior of community-residing elders with dementia (EWD), in 266 dyads (EWD and caregiver) recruited from Alzheimer's Association chapters. Factor analyses yield a five-factor solution (explained variance = 62.6%): complex wayfinding goals, analytic strategies, global strategies, simple wayfinding goals, and being stimulus bound. Overall, internal consistencies are high: WES (.94-.95), and subscales are stable across all versions. Testretest reliability is acceptable for the overall WES and two subscales (complex and simple wayfinding goals) for the care recipient current behavior version. Construct validity is supported by the pattern of correlations among subscales and analyses of variance (ANOVAs) showing significant differences among the care recipient (current vs. prior behavior) and caregiver versions overall and for all subscales. Results support the WES as a valid and reliable measure of wayfinding effectiveness in persons with dementia.
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Objective: The global implementation of oral random roadside drug testing is relatively limited, and correspondingly, the literature that focuses on the effectiveness of this intervention is scant. This study aims to provide a preliminary indication of the impact of roadside drug testing in Queensland. Methods: A sample of Queensland motorists’ (N= 922) completed a self-report questionnaire to investigate their drug driving behaviour, as well as examine the perceived affect of legal sanctions (certainty, severity and swiftness) and knowledge of the countermeasure on their subsequent offending behaviour. Results: Analysis of the collected data revealed that approximately 20% of participants reported drug driving at least once in the last six months. Overall, there was considerable variability in respondent’s perceptions regarding the certainty, severity and swiftness of legal sanctions associated with the testing regime and a considerable proportion remained unaware of testing practices. In regards to predicting those who intended to drug driving again in the future, perceptions of apprehension certainty, more specifically low certainty of apprehension, were significantly associated with self-reported intentions to offend. Additionally, self-reported recent drug driving activity and frequent drug consumption were also identified as significant predictors, which indicates that in the current context, past behaviour is a prominent predictor of future behaviour. To a lesser extent, awareness of testing practices was a significant predictor of intending not to drug drive in the future. Conclusion: The results indicate that drug driving is relatively prevalent on Queensland roads, and a number of factors may influence such behaviour. Additionally, while the roadside testing initiative is beginning to have a deterrent impact, its success will likely be linked with targeted intelligence-led implementation in order to increase apprehension levels as well as the general deterrent effect.
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The Australian construction industry is characterized as being a competitive and risky business environment due to lack of cooperation, insufficient trust, ineffective communication and adversarial relationships which are likely lead to poor project performance. Relational contracting (RC) is advocated by literature as an innovative approach to improve the procurement process in the construction industry. Various studies have collectively added to the current knowledge of known RC norms, but there seem to be little effort on investigating the determinants of RC and its impact on project outcomes. In such circumstances, there is lack of evidence and explanation on the manner on how these issues lead to different performance. Simultaneously, the New Engineering Contract (NEC) that embraced the concept of RC is seen as a modern way of contracting and also considered as one of the best approaches to the perennial problem of improving adversarial relationships within the industry. The reality of practice of RC in Australia is investigated through the lens of the NEC. A synthesis of literature views on the concept, processes and tools of RC is first conducted to develop the framework of RC. A case study approach is proposed for an in-depth analysis to explore the critical issues addressed by RC in relation to project performance. Understanding the realities of RC will assist stakeholders in the construction industry with their investment in RC.
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Background: Bone healing is sensitive to the initial mechanical conditions with tissue differentiation being determined within days of trauma. Whilst axial compression is regarded as stimulatory, the role of interfragmentary shear is controversial. The purpose of this study was to determine how the initial mechanical conditions produced by interfragmentary shear and torsion differ from those produced by axial compressive movements. ----- ----- Methods: The finite element method was used to estimate the strain, pressure and fluid flow in the early callus tissue produced by the different modes of interfragmentary movement found in vivo. Additionally, tissue formation was predicted according to three principally different mechanobiological theories. ----- ----- Findings: Large interfragmentary shear movements produced comparable strains and less fluid flow and pressure than moderate axial interfragmentary movements. Additionally, combined axial and shear movements did not result in overall increases in the strains and the strain magnitudes were similar to those produced by axial movements alone. Only when axial movements where applied did the non-distortional component of the pressure–deformation theory influence the initial tissue predictions. ----- ----- Interpretation: This study found that the mechanical stimuli generated by interfragmentary shear and torsion differed from those produced by axial interfragmentary movements. The initial tissue formation as predicted by the mechanobiological theories was dominated by the deformation stimulus.
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Fracture healing is influenced by fixation stability and experimental evidence suggests that the initial mechanical conditions may determine the healing outcome. We hypothesised that mechanical conditions influence not only the healing outcome, but also the early phase of fracture healing. Additionally, it was hypothesised that decreased fixation stability characterised by an increased shear interfragmentary movement results in a delay in healing. Sixty-four sheep underwent a mid-shaft tibial osteotomy which was treated with either a rigid or a semi-rigid external fixator. Animals were sacrificed at 2, 3, 6 and 9 weeks postoperatively and the fracture callus was analysed using radiological, biomechanical and histological techniques. The tibia treated with semi-rigid fixation showed inferior callus stiffness and quality after 6 weeks. At 9 weeks, the calluses were no longer distinguishable in their mechanical competence. The calluses at 9 weeks produced under rigid fixation were smaller and consisted of a reduced fibrous tissue component. These results demonstrate that the callus formation over the course of healing differed both morphologically and in the rate of development. In this study, we provide evidence that the course of healing is influenced by the initial fixation stability. The semi-rigid fixator did not result in delayed healing, but a less optimal healing path was taken. An upper limit of stability required for successful healing remains unknown, however a limit by which healing is less optimal has been determined.
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There is a growing desire for boards of nonprofits to deliver better governance to the organizations they control. Consequently, self-evaluation has become an important tool for nonprofit boards to meet these expectations and demonstrate that they are discharging their responsibilities effectively. This article describes initial results aimed at developing a psychometrically sound, survey-based board evaluation instrument, based on the Team Development Survey (TDS), that assesses the team attributes of an organization’s board. Our results indicate that while constructs applicable to teams generally appear to apply to boards, there are also important differences. We highlight how a perception of board objective clarity, appropriate skills mix, resource availability, and psychological safety were positively and significantly associated with measures of board, management and organizational performance.
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Commencing 13 March 2000, the Corporate Law Economic Reform Program Act 1999 (Cth) introduced changes to the regulation of corporate fundraising in Australia. In particular, it effected a reduction in the litigation risk associated with initial public offering prospectus disclosure.We find that the change is associated with a reduction in forecast frequency and an increase in forecast value relevance, but not with forecast error or bias. These results confirm previous findings that changes in litigation risk affect the level but not the quality of disclosure. They also suggest that the reforms’ objectives of reducing fundraising costs while improving investor protection, have been achieved.
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Background: Potyviruses are found world wide, are spread by probing aphids and cause considerable crop damage. Potyvirus is one of the two largest plant virus genera and contains about 15% of all named plant virus species. When and why did the potyviruses become so numerous? Here we answer the first question and discuss the other. Methods and Findings: We have inferred the phylogenies of the partial coat protein gene sequences of about 50 potyviruses, and studied in detail the phylogenies of some using various methods and evolutionary models. Their phylogenies have been calibrated using historical isolation and outbreak events: the plum pox virus epidemic which swept through Europe in the 20th century, incursions of potyviruses into Australia after agriculture was established by European colonists, the likely transport of cowpea aphid-borne mosaic virus in cowpea seed from Africa to the Americas with the 16th century slave trade and the similar transport of papaya ringspot virus from India to the Americas. Conclusions/Significance: Our studies indicate that the partial coat protein genes of potyviruses have an evolutionary rate of about 1.1561024 nucleotide substitutions/site/year, and the initial radiation of the potyviruses occurred only about 6,600 years ago, and hence coincided with the dawn of agriculture. We discuss the ways in which agriculture may have triggered the prehistoric emergence of potyviruses and fostered their speciation.
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Initial crack widely exists in the welded members of steel bridge induced by the welding procedure or by the fatigue damage crack initiation. The behavior of crack growth with a view to fatigue damage accumulation on the tip of cracks is discussed. Fatigue life of welded components with initial crack in bridges under traffic loading is investigated. Based on existing fatigue experiment results of welded members with initial crack and the fatigue experiment results of welded bridge members under constant stress cycles, the crack would keep semi-elliptical shape with variable ratio of a/c during the crack propagation. Based on the concept of continuum damage accumulated on the tip of fatigue cracks,the fatigue damage law suitable for steel bridge members under traffic loading is modified to consider the crack growth.The virtual crack growth method and the semi-elliptical crack shape assumption are proposed in this paper to deduce a new model of fatigue crack growth rate for welded bridge members under traffic loading. And the calculated method of the stress intensity factor necessary for evaluation of the fatigue life of welded bridge members with cracks is discussed.The proposed fatigue crack growth model is then applied to calculate the crack growth and the fatigue life of existing welded members with fatigue experimental results. The fatigue crack propagation computation results show that the ratio of crack depth to the half crack surface length a/c is variable during crack propagation process and the stress cycle increases with the increase of a0/c0 with certain a0/t0 .The calculated and measured fatigue lives are generally in good agreement,at some initial conditions of cracking, for welded members widely used in steel bridges.
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BACKGROUND: Stromal signalling increases the lateral cell adhesions of prostate epithelial cells grown in 3D culture. The aim of this study was to use microarray analysis to identify significant epithelial signalling pathways and genes in this process. METHODS: Microarray analysis was used to identify genes that were differentially expressed when epithelial cells were grown in 3D Matrigel culture with stromal co-culture compared to without stroma. Two culture models were employed: primary epithelial cells (ten samples) and an epithelial cell line (three experiments). A separate microarray analysis was performed on each model system and then compared to identify tissue-relevant genes in a cell line model. RESULTS: TGF beta signalling was significantly ranked for both model systems and in both models the TGF beta signalling gene SOX4 was significantly down regulated. Analysis of all differentially expressed genes to identify genes that were common to both models found several morphology related gene clusters; actin binding (DIAPH2, FHOD3, ABLIM1, TMOD4, MYH10), GTPase activator activity (BCR, MYH10), cytoskeleton (MAP2, MYH10, TMOD4, FHOD3), protein binding (ITGA6, CD44), proteinaceous extracellular matrix (NID2, CILP2), ion channel/ ion transporter activity (CACNA1C, CACNB2, KCNH2, SLC8A1, SLC39A9) and genes associated with developmental pathways (POFUT1, FZD2, HOXA5, IRX2, FGF11, SOX4, SMARCC1). CONCLUSIONS: In 3D prostate cultures, stromal cells increase lateral epithelial cell adhesions. We show that this morphological effect is associated with gene expression changes to TGF beta signalling, cytoskeleton and anion activity.
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In this paper, we report on how peer scaffolding was used to effect change in tertiary teaching practice and academic disposition in the use of Information and Communication Technology (ICT) in Science teaching and learning. We present a small-scale case study investigating the practice of one of this paper’s authors. It is told through two salient episodes which narratively describe the scaffolding used to support a teaching experiment. This was made possible through the national Teaching Teachers for the Future Project (2011-2012) which aimed to enhance the technological pedagogical capability of pre-service teachers across Australia. The outcome was a demonstrable shift in the academic’s disposition towards the use and benefits of ICT in teaching science and an increase in skills and confidence for both the academic and his students. This study and its outcomes fit within the contemporary push to “re-imagine” the teaching of Science, and more broadly of STEM, in schools.