905 resultados para Methods : Statistical


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Mesenchymal stromal cells (MSC) with similar properties to bone marrow derived mesenchymal stromal cells (BM-MSC) have recently been grown from the limbus of the human cornea. We presently contribute to this novel area of research by evaluating methods for culturing human limbal MSC (L-MSC). Methods: Four basic strategies are compared: serum-supplemented medium (10% foetal bovine serum; FBS), standard serum-free medium supplemented with B-27, epidermal growth factor, and fibroblast growth factor 2, or one of two commercial serum-free media including Defined Keratinocyte Serum Free Medium (Invitrogen), and MesenCult-XF (Stem Cell Technologies). The phenotype of resulting cultures was examined using photography, flow cytometry (for CD34, CD45, CD73, CD90, CD105, CD141, CD271), immunocytochemistry (α-sma), differentiation assays (osteogenesis, adipogenesis, chrondrogenesis), and co-culture experiments with human limbal epithelial (HLE) cells. Results: While all techniques supported to varying degrees establishment of cultures, sustained growth and serial propagation was only achieved in 10% FBS medium or MesenCult-XF medium. Cultures established in 10% FBS medium were 70-80% CD34-/CD45-/CD90+/CD73+/CD105+, approximately 25% α-sma+, and displayed multi-potency. Cultures established in MesenCult-XF were >95% CD34-/CD45-/CD90+/CD73+/CD105+, 40% CD141+, rarely expressed α-sma, and displayed multi-potency. L-MSC supported growth of HLE cells, with the largest epithelial islands being observed in the presence of MesenCult-XF-grown L-MSC. All HLE cultures supported by L-MSC widely expressed the progenitor cell marker ∆Np63, along with the corneal differentiation marker cytokeratin 3. Conclusions: We conclude that MesenCult-XF® is a superior culture system for L-MSC, but further studies are required to explore the significance of CD141 expression in these cells.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Most studies of in vitro fertilisation (IVF) outcomes use cycle-based data and fail to account for women who use repeated IVF cycles. The objective of this study was to examine the association between the number of eggs collected (EC) and the percentage fertilised normally, and women’s self-reported medical, personal and social histories. This study involved a crosssectional survey of infertile women (aged 27-46 years) recruited from four privately-owned fertility clinics located in major cities of Australia. Regression modeling was used to estimate the mean EC and mean percentage of eggs fertilised normally: adjusted for age at EC. Appropriate statistical methods were used to take account of repeated IVF cycles by the same women. Among 121 participants who returned the survey and completed 286 IVF cycles, the mean age at EC was 35.2 years (SD 4.5). Women’s age at EC was strongly associated with the number of EC: <30 years, 11.7 EC; 30.0-< 35 years, 10.6 EC; 35.0-<40.0 years, 7.3 EC; 40.0+ years, 8.1 EC; p<.0001. Prolonged use of oral contraceptives was associated with lower numbers of EC: never used, 14.6 EC; 0-2 years, 11.7 EC; 3-5 years, 8.5 EC; 6þ years, 8.2 EC; p=.04. Polycystic ovary syndrome (PCOS) was associated with more EC: have PCOS, 11.5 EC; no, 8.3 EC; p=.01. Occupational exposures may be detrimental to normal fertilisation: professional roles, 58.8%; trade and service roles, 51.8%; manual and other roles, 63.3%; p=.02. In conclusion, women’s age remains the most significant characteristic associated with EC but not the percentage of eggs fertilised normally.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The performance of techniques for evaluating multivariate volatility forecasts are not yet as well understood as their univariate counterparts. This paper aims to evaluate the efficacy of a range of traditional statistical-based methods for multivariate forecast evaluation together with methods based on underlying considerations of economic theory. It is found that a statistical-based method based on likelihood theory and an economic loss function based on portfolio variance are the most effective means of identifying optimal forecasts of conditional covariance matrices.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background On-site wastewater treatment system (OWTS) siting, design and management has traditionally been based on site specific conditions with little regard to the surrounding environment or the cumulative effect of other systems in the environment. The general approach has been to apply the same framework of standards and regulations to all sites equally, regardless of the sensitivity, or lack thereof, to the receiving environment. Consequently, this has led to the continuing poor performance and failure of on-site systems, resulting in environmental and public health consequences. As a result, there is increasing realisation that more scientifically robust evaluations in regard to site assessment and the underlying ground conditions are needed. Risk-based approaches to on-site system siting, design and management are considered the most appropriate means of improvement to the current standards and codes for on-site wastewater treatment systems. The Project Research in relation to this project was undertaken within the Gold Coast City Council region, the major focus being the semi-urban, rural residential and hinterland areas of the city that are not serviced by centralised treatment systems. The Gold Coast has over 15,000 on-site systems in use, with approximately 66% being common septic tank-subsurface dispersal systems. A recent study evaluating the performance of these systems within the Gold Coast area showed approximately 90% were not meeting the specified guidelines for effluent treatment and dispersal. The main focus of this research was to incorporate strong scientific knowledge into an integrated risk assessment process to allow suitable management practices to be set in place to mitigate the inherent risks. To achieve this, research was undertaken focusing on three main aspects involved with the performance and management of OWTS. Firstly, an investigation into the suitability of soil for providing appropriate effluent renovation was conducted. This involved detailed soil investigations, laboratory analysis and the use of multivariate statistical methods for analysing soil information. The outcomes of these investigations were developed into a framework for assessing soil suitability for effluent renovation. This formed the basis for the assessment of OWTS siting and design risks employed in the developed risk framework. Secondly, an assessment of the environmental and public health risks was performed specifically related the release of contaminants from OWTS. This involved detailed groundwater and surface water sampling and analysis to assess the current and potential risks of contamination throughout the Gold Coast region. Additionally, the assessment of public health risk incorporated the use of bacterial source tracking methods to identify the different sources of fecal contamination within monitored regions. Antibiotic resistance pattern analysis was utilised to determine the extent of human faecal contamination, with the outcomes utilised for providing a more indicative public health assessment. Finally, the outcomes of both the soil suitability assessment and ground and surface water monitoring was utilised for the development of the integrated risk framework. The research outcomes achieved through this project enabled the primary research aims and objects to be accomplished. This in turn would enable Gold Coast City Council to provide more appropriate assessment and management guidelines based on robust scientific knowledge which will ultimately ensure that the potential environmental and public health impacts resulting from on-site wastewater treatment is minimised. As part of the implementation of suitable management strategies, a critical point monitoring program (CPM) was formulated. This entailed the identification of the key critical parameters that contribute to the characterised risks at monitored locations within the study area. The CPM will allow more direct procedures to be implemented, targeting the specific hazards at sensitive areas throughout Gold Coast region.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper describes observational research and verbal protocols methods, how these methods are applied and integrated within different contexts, and how they complement each other. The first case study focuses on nurses’ interaction during bandaging of patients’ lower legs. To maintain research rigor a triangulation approach was applied that links observations of current procedures, ‘talk-aloud’ protocol during interaction and retrospective protocol. Maps of interactions demonstrated that some nurses bandage more intuitively than others. Nurses who bandage intuitively assemble long sequences of bandaging actions while nurses who bandage less intuitively ‘focus-shift’ in between bandaging actions. Thus different levels of expertise have been identified. The second case study consists of two laboratory experiments. It focuses on analysing and comparing software and product design teams and how they approached a design problem. It is based on the observational and verbal data analysis. The coding scheme applied evolved during the analysis of the activity of each team and is identical for all teams. The structure of knowledge captured from the analysis of the design team maps of interaction is identified. The significance of this work is within its methodological approach. The maps of interaction are instrumental for understanding the activities and interactions of the people observed. By examining the maps of interaction, it is possible to draw conclusions about interactions, structure of knowledge captured and level of expertise. This research approach is transferable to other design domains. Designers will be able to transfer the interaction maps outcomes to systems and services they design.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A recent production of Nicholson’s Shadowlands at the Brisbane Powerhouse could have included two advertising lines: “Outspoken American-Jewish poet meets conservative British Oxford scholar” and “Emotive American Method trained actor meets contained British trained actor.” While the fusion of acting methodologies in intercultural acting has been discussed at length, little discussion has focussed on the juxtaposition of diverse acting styles in production in mainstream theatre. This paper explores how the permutation of American Method acting and a more traditional British conservatory acting in Crossbow’s August 2010 production of Shadowlands worked to add extra layers of meaning to the performance text. This sometimes inimical relationship between two acting styles had its beginnings in the rehearsal room and continued onstage. Audience reception to the play in post-performance discussions revealed the audience’s acute awareness of the transatlantic cultural tensions on stage. On one occasion, this resulted in a heated debate on cultural expression, continuing well after the event, during which audience members became co-performers in the cultural discourses of the play.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this paper is to report on a methods research project investigating the evaluation of diverse teaching practice in Higher Education. The research method is a single site case study of an Australian university with data collected through published documents, surveys, interviews and focus groups. This project provides evidence of the wide variety of evaluation practice and diverse teaching practice across the university. This breadth identifies the need for greater flexibility of evaluation processes, tools and support to assist teaching staff to evaluate their diverse teaching practice. The employment opportunities for academics benchmark the university nationally and position the case study in the field. Finally this reaffirms the institutional responsibility for services to support teaching staff in an ongoing manner.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Every day inboxes are being flooded with invitations to invest money in overseas schemes, notifications of overseas lottery wins and inheritances, as well as emails from banks and other institutions asking for customers to confirm information about their identity and account details. While these requests may seem outrageous, many believe the request to be true and respond, through the sending of money or personal details. This can have devastating consequences, financially, emotionally and physically. While enforcement action is important, greater success is likely to come in the area of prevention, which avoids victim losses in the first place. Considerable victim support is also required by victims who have suffered significant losses, in trying to get their lives back on track. This project examined fraud prevention strategies and support services for victims of online fraud across the United Kingdom, United States of America and Canada. While much work has already been undertaken in Queensland, there is considerable room for improvement and a great deal can be learnt from these overseas jurisdictions. There are several examples of innovative and effective responses, particularly in the area of victim support, that are highlighted throughout this report. It is advocated that Australia can continue to improve its position regarding the prevention and support of online fraud victims, by applying the knowledge and expertise learnt overseas to a local context.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose: The prevalence of refractive errors in children has been extensively researched. Comparisons between studies can, however, be compromised because of differences between accommodation control methods and techniques used for measuring refractive error. The aim of this study was to compare spherical refractive error results obtained at baseline and using two different accommodation control methods – extended optical fogging and cycloplegia, for two measurement techniques – autorefraction and retinoscopy. Methods: Participants comprised twenty-five school children aged between 6 and 13 years (mean age: 9.52 ± 2.06 years). The refractive error of one eye was measured at baseline and again under two different accommodation control conditions: extended optical fogging (+2.00DS for 20 minutes) and cycloplegia (1% cyclopentolate). Autorefraction and retinoscopy were both used to measure most plus spherical power for each condition. Results: A significant interaction was demonstrated between measurement technique and accommodation control method (p = 0.036), with significant differences in spherical power evident between accommodation control methods for each of the measurement techniques (p < 0.005). For retinoscopy, refractive errors were significantly more positive for cycloplegia compared to optical fogging, which were in turn significantly more positive than baseline, while for autorefraction, there were significant differences between cycloplegia and extended optical fogging and between cycloplegia and baseline only. Conclusions: Determination of refractive error under cycloplegia elicits more plus than using extended optical fogging as a method to relax accommodation. These findings support the use of cycloplegic refraction compared with extended optical fogging as a means of controlling accommodation for population based refractive error studies in children.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

IT-supported field data management benefits on-site construction management by improving accessibility to the information and promoting efficient communication between project team members. However, most of on-site safety inspections still heavily rely on subjective judgment and manual reporting processes and thus observers’ experiences often determine the quality of risk identification and control. This study aims to develop a methodology to efficiently retrieve safety-related information so that the safety inspectors can easily access to the relevant site safety information for safer decision making. The proposed methodology consists of three stages: (1) development of a comprehensive safety database which contains information of risk factors, accident types, impact of accidents and safety regulations; (2) identification of relationships among different risk factors based on statistical analysis methods; and (3) user-specified information retrieval using data mining techniques for safety management. This paper presents an overall methodology and preliminary results of the first stage research conducted with 101 accident investigation reports.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The gross overrepresentation of Indigenous peoples in prison populations suggests that sentencing may be a discriminatory process. Using findings from recent (1991–2011) multivariate statistical sentencing analyses from the United States, Canada, and Australia, we review the 3 key hypotheses advanced as plausible explanations for baseline sentencing discrepancies between Indigenous and non-Indigenous adult criminal defendants: (a) differential involvement, (b) negative discrimination, and (c) positive discrimination. Overall, the prior research shows strong support for the differential involvement thesis and some support for the discrimination theses (positive and negative). We argue that where discrimination is found, it may be explained by the lack of a more complete set of control variables in researchers’ multivariate models and/or differing political and social contexts.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Mixed methods research is the use of qualitative and quantitative methods in the same study to gain a more rounded and holistic understanding of the phenomena under investigation. This type of research approach is gaining popularity in the nursing literature as a way to understand the complexity of nursing care and as a means to enhance evidenced-based practice. This paper introduces nephrology nurses to mixed methods research, its terminology and application to nephrology nursing. Five common mixed methods designs will be described highlighting the purposes, strengths and weaknesses of each design. Examples of mixed methods research will be given to illustrate the wide application of mixed methods research to nursing and its usefulness in nephrology nursing research.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The authors present a qualitative and quantitative comparison of various similarity measures that form the kernel of common area-based stereo-matching systems. The authors compare classical difference and correlation measures as well as nonparametric measures based on the rank and census transforms for a number of outdoor images. For robotic applications, important considerations include robustness to image defects such as intensity variation and noise, the number of false matches, and computational complexity. In the absence of ground truth data, the authors compare the matching techniques based on the percentage of matches that pass the left-right consistency test. The authors also evaluate the discriminatory power of several match validity measures that are reported in the literature for eliminating false matches and for estimating match confidence. For guidance applications, it is essential to have and estimate of confidence in the three-dimensional points generated by stereo vision. Finally, a new validity measure, the rank constraint, is introduced that is capable of resolving ambiguous matches for rank transform-based matching.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aim: Competency standards support a range of professional activities including the accreditation of university courses. Reviewing these standards is essential to ensure universities continue to produce well equipped graduates, who can meet the challenge of changing workforce requirements. This paper has two aims: a) to provide an overview of the methodological approaches utilised for compilation and review of the Competency Standards for Dietetics and b) to evaluate the Dietitians Association of Australia’s Competency Standards and capture emerging and contemporary dietetic practice. Methods: A literature review of the methods used to develop Competency Standards for dietitians in Australia, including entry level, advanced level and DAA Fellow competencies and other specific areas of competency, such as public health nutrition and nutrition education is outlined and compared to other allied health professions. The mixed methods methodology used in the most recent review is described in more detail. Results: The history of Dietetic Competency Standards development and review in Australia is compared to dietetic Competency Standards internationally and within other health professions in Australia. The political context in which these standards have been developed in Australia and which has determined their format is also discussed. The results of the most recent Competency Standards review are reported to highlight emerging practice in Australia. Conclusion: The mixed methods approach used in this review provides rich data about contemporary dietetic practice. Our view supports a planned review of all Competency Standards to ensure practice informs education and credentialling and we recommend the Dietitians Association of Australia consider this in future

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Nutritional status in people with Parkinson’s disease (PD) has previously been assessed in a number of ways including BMI, % weight loss and the Mini-Nutritional Assessment(MNA). The symptoms of the disease and the side effects of medication used to manage them result in a number of nutrition impact symptoms that can negatively influence intake. These include chewing and swallowing difficulties, lack of appetite, nausea, and taste and smell changes, among others. Community-dwelling people with PD, aged >18 years, were recruited (n=97, 61 M, 36 F). The Patient-Generated Subjective Global Assessment(PG-SGA) and (MNA) were used to assess nutritional status. Weight, height, mid-arm circumference(MAC) and calf circumference were measured. Based on SGA, 16(16.5%) were moderately malnourished (SGA B) while none were severely malnourished (SGA C). The MNA identified 2(2.0%) as malnourished and 22(22.7%) as at risk of malnutrition. Mean MNA scores were different between the three groups,F(2,37)=7.30,p<.05 but not different between SGA B (21.0(2.9)) and MNA at risk (21.8(1.4)) participants. MAC and calf circumference were also different between the three groups,F(2,37)=5.51,p<.05 and F(2,37)=15.33,p<.05 but not between the SGA B (26.2(4.2), 33.3(2.8)) and MNA at risk (28.4(5.6), 36.4(4.7)) participants. The MNA results are similar to other PD studies using MNA where prevalence of malnutrition was between 0-2% with 20-33% at risk of malnutrition. In this population, the PG-SGA may be more sensitive to assessing malnutrition where nutrition impact symptoms influence intake. With society’s increasing body size, it might also be more appropriate as it does not rely on MAC and calf circumference measures.