654 resultados para Total evidence
Resumo:
In recent years the development and use of crash prediction models for roadway safety analyses have received substantial attention. These models, also known as safety performance functions (SPFs), relate the expected crash frequency of roadway elements (intersections, road segments, on-ramps) to traffic volumes and other geometric and operational characteristics. A commonly practiced approach for applying intersection SPFs is to assume that crash types occur in fixed proportions (e.g., rear-end crashes make up 20% of crashes, angle crashes 35%, and so forth) and then apply these fixed proportions to crash totals to estimate crash frequencies by type. As demonstrated in this paper, such a practice makes questionable assumptions and results in considerable error in estimating crash proportions. Through the use of rudimentary SPFs based solely on the annual average daily traffic (AADT) of major and minor roads, the homogeneity-in-proportions assumption is shown not to hold across AADT, because crash proportions vary as a function of both major and minor road AADT. For example, with minor road AADT of 400 vehicles per day, the proportion of intersecting-direction crashes decreases from about 50% with 2,000 major road AADT to about 15% with 82,000 AADT. Same-direction crashes increase from about 15% to 55% for the same comparison. The homogeneity-in-proportions assumption should be abandoned, and crash type models should be used to predict crash frequency by crash type. SPFs that use additional geometric variables would only exacerbate the problem quantified here. Comparison of models for different crash types using additional geometric variables remains the subject of future research.
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This review evaluated the strength of the evidence for a causal relationship between physical activity (PA) and colorectal cancer (CRC). A systematic review of databases through February 2008 was conducted to identify studies that assessed the association between total or recreational PA and incidence or mortality of CRC (including CRC, rectal cancer, colon cancer, and proximal or distal colon cancer). Studies were evaluated for significant associations between PA and risk of CRC endpoints and for evidence of dose–response relationships in the highest quality studies. Twenty cohort studies were evaluated; 11 were high-quality. Fifty percent of all studies and 64%of highest quality studies reported at least one significant association between PA and risk of a CRC endpoint (Po0.05).However, only 28%of all analyses (31% of analyses of highest quality studies) were significant (Po0.05). Only 40% of analyses of highest quality studies resulted in a significant P for trend (Po0.05); however, a non-significant inverse linear association between PA and colon cancer riskwas apparent.Heterogeneity in the evidence from all studies and from the highest quality studies was evident. Evidence from cohort studies is not sufficient to claim a convincing relationship exists between PA and CRC risk.
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On-board mass (OBM) monitoring devices on heavy vehicles (HVs) have been tested in a national programme jointly by Transport Certification Australia Limited and the National Transport Commission. The tests were for, amongst other parameters, accuracy and tamper-evidence. The latter by deliberately tampering with the signals from OBM primary transducers during the tests. The OBM feasibility team is analysing dynamic data recorded at the primary transducers of OBM systems to determine if it can be used to detect tamper events. Tamper-evidence of current OBM systems needs to be determined if jurisdictions are to have confidence in specifying OBM for HVs as part of regulatory schemes. An algorithm has been developed to detect tamper events. The results of its application are detailed here.
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It is increasingly understood that learning and thus innovation often occurs via highly interactive, iterative, network-based processes. Simultaneously, economic development policy is increasingly focused on small and medium-sized enterprises (SMEs) as a means of generating growth, creating a clear research issue in terms of the roles and interactions of government policy, universities, and other sources of knowledge, SMEs, and the creation and dissemination of innovation. This paper analyses the contribution of a range of actors in an SME innovation creation and dissemination framework, reviewing the role of various institutions therein, exploring the contribution of cross-locality networks, and identifying the mechanisms required to operationalise such a framework. Bivariate and multivariate (regression) techniques are employed to investigate both innovation and growth outcomes in relation to these structures; data are derived from the survey responses of over 450 SMEs in the UK. Results are complex and dependent upon the nature of institutions involved, the type of knowledge sought, and the spatial level of the linkages in place but overall highlight the value of cross-locality networks, network governance structures, and certain spillover effects from universities. In general, we find less support for the factors predicting SME growth outcomes than is the case for innovation. Finally, we outline an agenda for further research in the area.
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Purpose: To undertake rigorous psychometric testing of the newly developed contemporary work environment measure (the Brisbane Practice Environment Measure [B-PEM]) using exploratory factor analysis and confirmatory factor analysis. Methods: Content validity of the 33-item measure was established by a panel of experts. Initial testing involved 195 nursing staff using principal component factor analysis with varimax rotation (orthogonal) and Cronbach's alpha coefficients. Confirmatory factor analysis was conducted using data from a further 983 nursing staff. Results: Principal component factor analysis yielded a four-factor solution with eigenvalues greater than 1 that explained 52.53% of the variance. These factors were then verified using confirmatory factor analysis. Goodness-of-fit indices showed an acceptable fit overall with the full model, explaining 21% to 73% of the variance. Deletion of items took place throughout the evolution of the instrument, resulting in a 26-item, four-factor measure called the Brisbane Practice Environment Measure-Tested. Conclusions: The B-PEM has undergone rigorous psychometric testing, providing evidence of internal consistency and goodness-of-fit indices within acceptable ranges. The measure can be utilised as a subscale or total score reflective of a contemporary nursing work environment. Clinical Relevance: An up-to-date instrument to measure practice environment may be useful for nursing leaders to monitor the workplace and to assist in identifying areas for improvement, facilitating greater job satisfaction and retention.
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Many South East Asian cities have experienced substantial physical, economic and social transformations during the past several decades. The rapid pace of globalisation and economic restructuring has resulted in these cities receiving the full impact of urbanisation pressures. In an attempt to ease these pressures, cities such as Singapore, Hong Kong and Kuala Lumpur have advocated growth management approaches focussing especially on urban infrastructure sustainability. These approaches aim to achieve triple bottom line sustainability by balancing economic and social development, and environmental protection. This chapter evaluates three Asia-Pacific city cases, Singapore, Hong Kong and Kuala Lumpur, and assesses their experiences in managing their urban forms and infrastructure whilst promoting sustainable patterns of urban development.
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This paper presents early results from a pilot project which aims to investigate the relationship between proprietary structure of small and medium- sized Italian family firms and their owners’ orientation towards a “business evaluation process”. Evidence from many studies point out the importance of family business in a worldwide economic environment: in Italy 93% of the businesses are represented by family firms; 98% of them have less than 50 employees (Italian Association of Family Firms, 2004) so we judged family SMEs as a relevant field of investigation. In this study we assume a broad definition of family business as “a firm whose control (50% of shares or voting rights) is closely held by the members of the same family” (Corbetta,1995). “Business evaluation process” is intended here both as “continuous evaluation process” (which is the expression of a well developed managerial attitude) or as an “immediate valuation” (i.e. in the case of new shareholder’s entrance, share exchange among siblings, etc). We set two hypotheses to be tested in this paper: the first is “quantitative” and aims to verify whether the number of owners (independent variable) in a family firm is positively correlated to the business evaluation process. If a family firm is led by only one subject, it is more likely that personal values, culture and feelings may affect his choices more than “purely economic opportunities”; so there is less concern about monitoring economic performance or about the economic value of the firm. As the shareholders’ number increases, economic aspects in managing the firm grow in importance over the personal values and "value orientation" acquires a central role. The second hypothesis investigates if and to what extent the presence of “non- family members” among the owners affects their orientation to the business evaluation process. The “Cramer’s V” test has been used to test the hypotheses; both were not confirmed from these early results; next steps will lead to make an inferential analysis on a representative sample of the population.
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Background: Many studies have illustrated that ambient air pollution negatively impacts on health. However, little evidence is available for the effects of air pollution on cardiovascular mortality (CVM) in Tianjin, China. Also, no study has examined which strata length for the time-stratified case–crossover analysis gives estimates that most closely match the estimates from time series analysis. Objectives: The purpose of this study was to estimate the effects of air pollutants on CVM in Tianjin, China, and compare time-stratified case–crossover and time series analyses. Method: A time-stratified case–crossover and generalized additive model (time series) were applied to examine the impact of air pollution on CVM from 2005 to 2007. Four time-stratified case–crossover analyses were used by varying the stratum length (Calendar month, 28, 21 or 14 days). Jackknifing was used to compare the methods. Residual analysis was used to check whether the models fitted well. Results: Both case–crossover and time series analyses show that air pollutants (PM10, SO2 and NO2) were positively associated with CVM. The estimates from the time-stratified case–crossover varied greatly with changing strata length. The estimates from the time series analyses varied slightly with changing degrees of freedom per year for time. The residuals from the time series analyses had less autocorrelation than those from the case–crossover analyses indicating a better fit. Conclusion: Air pollution was associated with an increased risk of CVM in Tianjin, China. Time series analyses performed better than the time-stratified case–crossover analyses in terms of residual checking.
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Objective: The aim of this literature review is to identify the role of probiotics in the management of enteral tube feeding (ETF) diarrhoea in critically ill patients.---------- Background: Diarrhoea is a common gastrointestinal problem seen in ETF patients. The incidence of diarrhoea in tube fed patients varies from 2% to 68% across all patients. Despite extensive investigation, the pathogenesis surrounding ETF diarrhoea remains unclear. Evidence to support probiotics to manage ETF diarrhoea in critically ill patients remains sparse.---------- Method: Literature on ETF diarrhoea and probiotics in critically ill, adult patients was reviewed from 1980 to 2010. The Cochrane Library, Pubmed, Science Direct, Medline and the Cumulative Index of Nursing and Allied Health Literature (CINAHL) electronic databases were searched using specific inclusion/exclusion criteria. Key search terms used were: enteral nutrition, diarrhoea, critical illness, probiotics, probiotic species and randomised clinical control trial (RCT).---------- Results: Four RCT papers were identified with two reporting full studies, one reporting a pilot RCT and one conference abstract reporting an RCT pilot study. A trend towards a reduction in diarrhoea incidence was observed in the probiotic groups. However, mortality associated with probiotic use in some severely and critically ill patients must caution the clinician against its use.---------- Conclusion: Evidence to support probiotic use in the management of ETF diarrhoea in critically ill patients remains unclear. This paper argues that probiotics should not be administered to critically ill patients until further research has been conducted to examine the causal relationship between probiotics and mortality, irrespective of the patient's disease state or projected prophylactic benefit of probiotic administration.
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This paper investigates the research question ‘What is the effect of co-ethnic and non coethnic networking on business performance in Chinese immigrant businesses?’ The research will discuss key themes such as the extent to which Chinese immigrant entrepreneurs are embedded in co-ethnic and non co-ethnic networks and the affect of embeddedness on business performance, such as the entrepreneur’s satisfaction and business growth. Research on immigrant entrepreneurship has emerged as an important new area of inquiry within the field of entrepreneurship. The increased importance of the subject is due in part to major immigrant receiving countries, such as Australia, the United States and Canada, experiencing a high growth rate in their immigrant population. Reflecting on the existing research on immigrant entrepreneurship, it was decided to investigate the role of embeddedness on entrepreneurial business performance. This research seeks to identify the impact of embeddedness in co-ethnic and non co-ethnic networks on business performance of Chinese immigrant entrepreneurs in Australia. Chinese immigrant restaurant entrepreneurs in southeast Queensland, Australia were studied. The result expands on existing research on immigrant entrepreneurship, since the majority of immigrant entrepreneurship studies have been conducted on the United States and Canada immigrant experiences, but few have been conducted in the Australian immigrant entrepreneur context. This thesis also adds empirical testing to a research area with little empirical testing. The results indicated that embeddedness in the co-ethnic network is positively related to business performance measured by both growth and satisfaction. Embeddedness in the non co-ethnic network of the Chinese immigrant entrepreneurs in Australia did not show a similar pattern in accordance with studies conducted in the United States and Canada. This result is interesting and creates the opportunity for future research employing a comparative study.
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The mud crab (Scylla spp.) aquaculture industry has expanded rapidly in recent years in many countries in the Indo - West Pacific (IWP) region as an alternative to marine shrimp culture because of significant disease outbreaks and associated failures of many shrimp culture industries in the region. Currently, practices used to produce and manage breeding crabs in hatcheries may compromise levels of genetic diversity, ultimately compromising growth rates, disease resistance and stock productivity. Therefore, to avoid “genetic pollution” and its harmful effects and to promote further development of mud crab aquaculture and fisheries in a sustainable way, a greater understanding of the genetic attributes of wild and cultured mud crab stocks is required. Application of these results can provide benefits for managing wild and cultured Asian mud crab populations for multiple purposes including for commercial production, recreation and conservation and to increase profitability and sustainability of newly emerging crab culture industries. Phylogeographic patterns and the genetic structure of Asian mud crab populations across the IWP were assessed to determine if they were concordant with those of other widespread taxa possessing pelagic larvae of relatively long duration. A 597 bp fragment of the mitochondrial DNA COI gene was amplified and screened for variation in a total of 297 individuals of S. paramamosain from six sampling sites across the species’ natural geographical distribution in the IWP and 36 unique haplotypes were identified. Haplotype diversities per site ranged from 0.516 to 0.879. Nucleotide diversity estimates among haplotypes were 0.11% – 0.48%. Maximum divergence observed among S. paramamosain samples was 1.533% and samples formed essentially a single monophyletic group as no obvious clades were related to geographical location of sites. A weak positive relationship was observed however, between genetic distance and geographical distance among sites. Microsatellite markers were then used to assess contemporary gene flow and population structure in Asian mud crab populations sampled across their natural distribution in the IWP. Eight microsatellite loci were screened in sampled S. paramamosain populations and all showed high allelic diversity at all loci in sampled populations. In total, 344 individuals were analysed, and 304 microsatellite alleles were found across the 8 loci. The mean number of alleles per locus at each site ranged from 20.75 to 28.25. Mean allelic richness per site varied from 17.2 to 18.9. All sites showed high levels of heterozygosity as average expected heterozygosities for all loci ranged from 0.917 – 0.953 while mean observed heterozygosity ranged from 0.916 – 0.959. Allele diversities were similar at all sites and across all loci. The results did not show any evidence for major differences in allele frequencies among sites and patterns of allele frequencies were very similar in all populations across all loci. Estimates of population differentiation (FST) were relatively low and most probably largely reflect intra – individual variation for very highly variable loci. Results from nDNA analysis showed evidence for only very limited population genetic structure among sampled S. paramamosain, and a positive and significant association for genetic and geographical distance among sample sites. Microsatellite markers were then employed to determine if adequate levels of genetic diversity has been captured in crab hatcheries for the breeding cycle. The results showed that all microsatellite loci were polymorphic in hatchery samples. Culture populations were in general, highly genetically depauperate, compared with comparable wild populations, with only 3 to 8 alleles recorded for the same loci set per population. In contrast, very high numbers of alleles per locus were found in reference wild S. paramamosain populations, which ranged from 18 to 46 alleles per locus per population. In general, this translates into a 3 to 10 fold decline in mean allelic richness per locus in all culture stocks compared with wild reference counterparts. Furthermore, most loci in all cultured S. paramamosain samples showed departures from HWE equilibrium. Allele frequencies were very different in culture samples from that present in comparable wild reference samples and this in particular, was reflected in a large decline in allele diversity per locus. The pattern observed was best explained by significant impacts of breeding practices employed in hatcheries rather than natural differentiation among wild populations used as the source of brood stock. Recognition of current problems and management strategies for the species both for the medium and long-term development of the new culture industry are discussed. The priority research to be undertaken over the medium term for S. paramamosain should be to close the life cycle fully to allow individuals to be bred on demand and their offspring equalised to control broodstock reproductive contributions. Establishing a broodstock register and pedigree mating system will be required before any selection program is implemented. This will ensure that sufficient genetic variation will be available to allow genetic gains to be sustainably achieved in a future stock improvement program. A fundamental starting point to improve hatchery practices will be to encourage farmers and hatchery managers to spawn more females in their hatcheries as it will increase background genetic diversity in culture stocks. Combining crablet cohorts from multiple hatcheries into a single cohort for supply to farmers or rotation of breeding females regularly in hatcheries will help to address immediate genetic diversity problems in culture stocks. Application of these results can provide benefits for managing wild and cultured Asian mud crab populations more efficiently. Over the long-term, application of data on genetic diversity in wild and cultured stocks of Asian mud crab will contribute to development of sustainable and productive culture industries in Vietnam and other countries in the IWP and can contribute towards conservation of wild genetic resources.
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Abstract This paper uses a case study to identify the impact of a Queensland parliamentary committee on policy. In 2003, the Travelsafe Committee undertook two inquiries investigating young driver and rider issues. In 2007, the Queensland Parliament passed legislation that provided the power to make regulations that changed the graduated driver licensing laws in Queensland. The analysis of the second reading speeches for this bill suggests that parliamentary committees can help set the agenda for government policy. The role of the Travelsafe Committee in this process was recognised by both government and non-government members of Parliament and by those that had been, or were currently, members of the committee and by those that had no membership experience of the Travelsafe Committee prior to the debate of the legislation. This paper suggests that in order for committees to successfully participate in policy work they need to have strong ideas, work to a consistently high standard and the chair needs to be dedicated to the work of the committee. This case study indicates the importance of parliamentary committees in the policy work of a parliament.
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Changes in stride characteristics and gait rhythmicity characterize gait in Parkinson's disease and are widely believed to contribute to falls in this population. However, few studies have examined gait in PD patients who fall. This study reports on the complexities of walking in PD patients who reported falling during a 12-month follow-up. Forty-nine patients clinically diagnosed with idiopathic PD and 34 controls had their gait assessed using three-dimensional motion analysis. Of the PD patients, 32 (65%) reported at least one fall during the follow-up compared with 17 (50%) controls. The results showed that PD patients had increased stride timing variability, reduced arm swing and walked with a more stooped posture than controls. Additionally, PD fallers took shorter strides, walked slower, spent more time in double-support, had poorer gait stability ratios and did not project their center of mass as far forward of their base of support when compared with controls. These stride changes were accompanied by a reduced range of angular motion for the hip and knee joints. Relative to walking velocity, PD fallers had increased mediolateral head motion compared with PD nonfallers and controls. Therefore, head motion could exceed “normal” limits, if patients increased their walking speed to match healthy individuals. This could be a limiting factor for improving gait in PD and emphasizes the importance of clinically assessing gait to facilitate the early identification of PD patients with a higher risk of falling.
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The number of Australian children requiring foster care due to abuse and neglect is increasing at a faster rate than suitable carers can be recruited. Currently increased numbers of foster children are presenting with higher care needs. Evidence suggests carers with a higher education could contribute to placement stability and ultimately provide more positive outcomes for this group of children. This paper explores the level of interest by tertiary educated persons toward a model of fostering for children with higher needs. Using a descriptive survey methodology, a convenience sample of 644 university undergraduate and postgraduate students within faculties of health sciences, and education, arts and social sciences was employed. Psychology students in the 17-26 year old age group showed greatest interest in a professional foster care model and this was statistically significant (p=0.002 955 CI .000-.010) when compared to other health professionals and other age groups. Education students held the highest interest in general fostering although not statistically significant. When these survey results were extrapolated to the total number of health professionals in Australia there could be 8,385 potential recruits for a model professional foster care. Focused campaigns are required to source professional as recruits to fostering with the benefit of servicing the placement needs of higher care needs children and contributing to general foster care resources.
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Background: Young motorists engaging in anti-social and often dangerous driving manoeuvres (which is often referred to as “hooning” within Australia) is an increasing road safety problem. While anecdotal evidence suggests that such behaviour is positively linked with crash involvement, researchers have yet to examine whether younger drivers who deliberately break road rules and drive in an erratic manner (usually with peers) are in fact over represented in crash statistics. This paper outlines research that aimed to identify the characteristics of individuals most likely to engaging in hooning behaviours, as well as examine the frequency of such driving behaviours and if such activity is linked with self-reported crash involvement.---------- Methods: A total of 717 young drivers in Queensland voluntarily completed a questionnaire to investigate their driving behaviour and crash history.---------- Results: Quantitative analysis of the data revealed that almost half the sample reported engaging in some form of “hooning” behaviour at least once in their lifetime, although only 4% indicated heavy participation in the behaviour e.g., >50 times. Street racing was the most common activity reported by participants followed by “drifting” and then “burnouts”. Logistic regression analysis indicated that being younger and a male was predictive of reporting such anti-social driving behaviours, and importantly, a trend was identified between such behaviour and self-reported crash involvement.---------- Conclusions: This research provides preliminary evidence that younger male drivers are more likely to engage in dangerous driving behaviours, which ultimately may prove to increase their overall risk of becoming involved in a crash. This paper will further outline the study findings in regards to current enforcement efforts to deter such driving activity as well as provide direction for future research efforts in this area.---------- Research highlights: ► The self-reported driving behaviours of 717 younger Queensland drivers were examined to investigate the relationship between deliberately breaking road rules and self-reported crash involvement. ► Younger male drivers were most likely to engage in such aberrant driving behaviours and a trend was identified between such behaviour and self-reported crash involvement.