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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
861

The photodynamic effect on micro-organisms found on packaging materials

Zerdin, Katherine, University of Western Sydney, College of Health and Science, School of Natural Sciences January 2008 (has links)
Many types of foods are sterilised and packaged aseptically to maximise their shelf life and ensure that they are safe for consumption. However, if even a few micro-organisms survive these treatments, the quality and/or safety of the food can be seriously compromised. Therefore, packaging materials that can actively participate in the process of inactivating micro-organisms have a potentially important role in protecting the quality and safety of packaged foods. The aim of this project is to explore the effectiveness of the photodynamic effect as a method of inactivating micro-organisms on the surface of packaging materials. Photodynamic action occurs when a photosensitiser molecule absorbs light in the presence of oxygen, leading to the formation of reactive oxygen species such as singlet oxygen, superoxide radicals, or other free radicals; these species are known to inactivate cells. Medical uses of photodynamic action have been studied extensively, usually in applications where the reactive oxygen species are produced intracellularly. However, very little research has been conducted to investigate the efficacy of extra-cellularly generated reactive oxygen species on the viability of micro-organisms, and accordingly this research project investigated the possibility that this approach might be used for inactivating micro-organisms on packaging materials. The results of this study indicate that singlet oxygen may be produced at the surface of polymer films that contain selected photosensitisers, resulting in the oxidation of known singlet-oxygen acceptors to form endoperoxides. This provides evidence that singlet-oxygen mediated reactions can occur at the surface of a sensitising film. It is likely that cell destruction is caused by singlet-oxygen, rather than involving other activated species. It was further shown that the photodynamically generated singlet-oxygen can inactivate micro-organisms (extra-cellularly) on the surface of a polymeric material. The study included examples from each genus of micro-organisms that are of concern to the food and packaging industry, including: Gram-negative bacteria (Escherichia coli); Gram-positive bacteria (Bacillus cereus), both vegetative cells and endospores; yeast (Saccharomyces cerevisiae), and mould (Fusarium oxysporium.) Results indicate that the photodynamic effect causes a substantial reduction in viable cell numbers for vegetative cells and spores (both bacterial and fungal) that have been inoculated onto a plastic surface containing the photosensitiser, anthraquinone,. The results show that an increase in the amount of reactive oxygen species produced by photodynamic action increases the inactivation rate of the micro-organisms. The micro-organisms investigated were susceptible to photodynamic action to varying extents. In conclusion, the results demonstrate that control of microbial populations on the surface of polymeric films (used in food packaging) is achievable using photodynamic action produced from polymers, based on the reported amounts of micro-organisms found on food packaging materials. / Master of Science (Hons)
862

The Measurement of Threats to Patient Safety in Australian General Practice

Makeham, Meredith Anne Blatt January 2008 (has links)
Doctor of Philosophy(PhD) / The importance of better understanding error and safety in the community setting is widely accepted, with recent calls to promote efforts and improve resources in this area of research (Jacobson, Elwyn et al. 2003). The measurement of patient safety events in primary care is a relatively under-researched area and it is well recognized that there are large gaps in the research describing patient safety in ambulatory settings (Hammons, Piland et al. 2003). Attitudes towards embracing safety event measurement have improved in recent years, however there remains a substantial amount of work to be done before common standards can be recommended, despite recent calls in the scientific literature for national and international systems (Runciman, Williamson et al. 2006). This thesis describes the Threats to Australian Patient Safety (TAPS) study, which aimed to create a secure anonymous web-based error reporting system suited to the Australian general practice setting, and then describe and quantify the errors reported by a representative random sample of Australian general practitioners. The study was made possible with the support of funding from a National Health and Medical Research Council project grant, and also gained support from NSW Health and the Commonwealth Department of Health and Aging in the form of granting qualified privilege and providing essential Medicare data under legal instrument. The study methodology involved the development of a database management system which created an electronic method for managing and analysing a wide variety of vii features related to large numbers of anonymously reported errors from Australian general practice. A representative random sample of 84 general practitioners (GPs) from New South Wales (NSW) participated in the study, with over 400 errors reported in a 12 month period. The key messages arising from the TAPS study were: • GPs embraced anonymous patient safety event reporting using a secure website, with the majority of study participants making reports • New findings from this study on the incidence of reported error in general practice were published in the scientific literature, which will help guide the design of future error reporting systems • A new taxonomy to describe reported error from GPs was developed as part of this study and published in the scientific literature, with the view of allowing future self-coding of reported patient safety events by GPs The TAPS study presented the first calculations known worldwide of the incidence of reported error in a general practice setting using a representative random sample of general practitioners. It was found that if an anonymous, secure, web-based reporting system was provided, approximately 2 errors were reported by general practitioners per 1000 patients seen per year (Makeham, Kidd et al. 2006). In addition, the study created a simple descriptive general practice based error taxonomy, entitled the TAPS taxonomy (see Appendix 10) (Makeham, Stromer et al. 2007), and was the first study to test the reproducibility of the application of such a viii tool using a group of general practitioners. The TAPS taxonomy developed as part of this study was found to have a good level of inter-coder agreement. With respect to the underlying causes of errors, the TAPS study found that the majority of reported patient safety events were errors related to the processes of health care (70%), rather than errors related to the knowledge and skills of health professionals (30%). Most errors reported in the TAPS study had the direct involvement of a patient (93% of error reports). Overall the reporting general practitioners were very familiar with these patients, who were on average 52 years old, and more often female (56%). Around one quarter of the errors reported was associated with patients being harmed. Reports containing events related to processes of health care were associated less with harm than those containing events related to the knowledge and skills of health professionals. The patients in errors associated with patient harm reported in the TAPS study were on average older than patients in reports where no harm was known to have occurred (58 years versus 50 years respectively). There was no statistically significant difference found between these groups with respect to gender or ethnicity, including people from Non-English speaking backgrounds or Aboriginal and Torres Strait Islander (ATSI) peoples, although the association with the latter group approached statistical significance. ix Cases of patient death were reported in 8 of 415 errors reported in the TAPS study (2%), and more often involved events relating to the knowledge and skills of health professionals than events relating to the processes of health care compared to reports not involving a known patient death. In support of suggestions in the scientific literature about the importance of anonymity as a feature of an error reporting system, a feedback interview found that an anonymous reporting system was a factor which made participants more likely to report error events, with two thirds of participants agreeing that anonymity made them more likely to participate in reporting. The majority of participants found the reporting process easy to undertake, and took approximately 6 minutes to send a report. The study provided a self directed learning educational activity for participating general practitioners that was approved for 30 group 1 Quality Assurance and Continuing Education points by the Royal Australian College of General Practitioners (RACGP). An important practical outcome of the TAPS study was that it highlighted a systematic error relating to immunisation failures with meningococcal vaccines which was reported to relevant organisations including NSW Health, the RACGP and the manufacturer involved, which was addressed with educational materials for GPs being distributed and communication in Australian Family Physician. x There are further analyses that could be undertaken using the TAPS data to improve our understanding of the errors reported, such as further statistical analyses using techniques such as building a model with multiple regression to determine significant factors that contribute to different error types. This work was beyond the scope of the TAPS study aims, but is part of further research recommendations. In addition, future studies should address aspects of patient safety and reported error that it would not be possible to capture from the perspective of the reporting GP. Rather than one taxonomy which describes the reported errors from the GP’s perspective in the way that the TAPS taxonomy does, it may be useful to develop a series of interlinked taxonomies that are directed to the needs of differing constituencies, such as the organisation providing health funds or the health insurer, the health regulators and legislators, and the patients or their significant others. The assessment of potential and actual harms sustained by patients involved in reported errors is a further area of patient safety research that is difficult to comprehensively assess, and existing reporting systems in the literature, whilst addressing this from the reporter’s perspective, require further work to improve the accuracy by which harm is measured and correlated with other data sets such as those managed by health insurers, and the experiences of people who are the subject of the reports. The TAPS study presents a number of new findings about the nature of error and threats to patient safety that arise in the Australian health care environment, reported by a representative sample of general practitioners, and it is hoped that these will be xi useful to all stakeholders in the health care setting, from clinicians, through to policy makers, and most importantly the patients who are the subject of the potentially preventable harms and near misses that are highlighted in this thesis
863

Tired of dying : fatigue and stress in long distance road transport

McKinnon, Peter Laurence, University of Western Sydney, College of Social and Health Sciences, School of Nursing, Family and Community Health January 2004 (has links)
In this thesis, the author has drawn on a large body of international research and his own surveys, interviews and experience to examine the interrelated issues of Fatigue and Stress in the long distance sector of the Australian road transport industry. Two major Australian studies are studied in some detail: House of Representatives Standing Committee on Communications, Transport and the Arts: Beyond the Midnight Oil, Report into an Inquiry into Managing Fatigue in Transport, Parliament of the Commonwealth of Australia October 2000 (The Neville Report) and Quinlan, Michael, Report of an Inquiry into Safety in the Long Haul Sector of the Road Trucking Industry, Motor Accident Authority of NSW, Nov 2001 and the United States of America: Belzer, Michael H., Sweatshop on Wheels: Winners and Losers in Trucking Deregulation, Oxford University Press, New York, 2000, has direct relevance to this study, especially as it relates to the underlying causes of much of the fatigue and stress suffered by long distance drivers. An extensive literature review was undertaken to help form an understanding of the issues and developments relating to workplace fatigue and stress, in several different settings, including the military, aviation and general industry. The author has surveyed a number of long distance drivers and interviewed managers and others linked to this industry, analysed their responses and reported on the findings. Since the commencement of this study, several significant changes have occurred in the relevant legislation and its application, and where possible these have been incorporated into the study / Master of Science (Hons)
864

Radioisotope laboratory safety auditing, compliance and associated problems in NSW

Bartolo, William Charles Francis, Safety Science, Faculty of Science, UNSW January 2007 (has links)
This thesis reports on the modification of the "Safecode" computer-program to monitor the safety of radio-isotope laboratories, and its application to 24 compliance audits in NSW during the period 1999 to 2006. Additionally, an attempt was made to predict the level of risk to persons working within those laboratories. Based on the current NSW radiation control legislation and the relevant Australian Standards a comprehensive audit checklist was developed for this project. Each safety requirement in those documents was used to develop a question, resulting in 187 questions in the checklist. The questions were grouped into the following seven Topic Elements: Licensing and Registration; Radiation Safety Administration; Personal and Area Monitoring; Dose Limit Compliance; Documentation/Records; RSO/RSC Qualifications and Duties; and Facilities. A novel feature was the allocation of "weighting factors" to individual questions and Elements. The computer program facilitated analysis of data and provided output in spreadsheet and graphical form. .The on-site physical audits were conducted using the project check-list, and were supplemented by discussions with the client's representative. The results showed significant variation between sites with overall compliance scores ranging from 37% to 94%. The reasons for this large variation stem from differences in local management regime; the appointment of an RSO at one site; variation in the extent of adoption of relevant codes of practice; and legislative weaknesses. Further analysis of the data presented legal, advisory and combined scores for each Element for each site; and variations over time. The graphic displays of the results were appreciated by client management. The formula developed to predict risk, based on the physical parameters alone, showed little relationship to the total audit scores. Statistical analysis of the two data groups by correlation coefficient confirmed this general finding. Development of the formula however served to indicate deficiencies in the Question Set, and the importance of human factors in achieving a high degree of safety.
865

Experimental investigations on gas explosions in partially confined regions

Park, Dal Jae, Safety Science, Faculty of Science, UNSW January 2007 (has links)
The primary objectives of the described research were to examine the underlying physical phenomena occurring during flame/obstacles interactions in various chambers of low L/D ratio and to develop a new empirical equation for explosion venting. A literature review suggested that the propagating flame/obstacle interactions in enclosures with large L/D ratio (&gt 2) result in flame acceleration and subsequent pressure build-up during a gas explosion. However, the interactions in practical situations with small L/D &lt 2 were not extensively studied. In this thesis the first investigation involved the flame interaction with different single and multiple obstacles in a 1/20th model of real enclosure. Results provided the basis for flame propagation, local flame displacement speed probability density functions (pdfs), mean flame velocity and explosion pressure. The second investigation of the study involved the flame interaction with multiple bars within chambers of different L/D ratios. The results provided mean flame velocities on each stage, as a function of nondimensional time, and pressure developments as a function of L/D ratio. The final investigation is associated with gas explosion venting. The predictive ability between existing models on explosion venting and experimental results obtained in this thesis were undertaken and found to be deficient. Consequently a new empirical model for predicting explosion venting was developed. The new model was validated with experimental data published in literature.
866

Death By QT: A New Safety Challenge

Raghib, Hala, halaraghib@yahoo.com January 2007 (has links)
The HERG gene encodes for the delayed rectifier K+ channel in human cardiac tissue and contributes to the repolarization phase of the ventricular action potential. Defects in its activity underlies a cardiac disorders linked to a prolongation in the QT interval known as acquired long QT syndrome. The channel has structural properties that lead to its unintentional inhibition by various classes of drugs and is a source of drug induced cardiac toxicity. To date, no assay has been set as a standard due to variability across laboratories and the use of animals providing variable results due to differences in the ion channels involved in repolarisation. This thesis focuses on the development of testing assays for HERG using animal-free methodology. In Chapter 2, a human embryonic kidney (HEK293) cell line was cultured and transfected with the human HERG gene using animal-free methodologies. The success of the transfection was confirmed using PCR, patch clamp electrophysiology and a non-radioactive rubidium assay. Using a non-radioactive rubidium assay, drug inhibition on the transfected cell line was measured. The IC50 values obtained for a range of drugs were compared to those obtained using electrophysiological studies in the literature and there was a high correlation (r2 = 0.76). In Chapter 3, a human neuroblastoma cell line (SH-SY5Y) was tested for its validity for testing the effect of drugs on the endogenously expressed HERG K+ channel. The drug IC50 values obtained using the Rb+ assay were well correlated (r2= 0.82) with patch clamp studies in HERG transfected HEK293 cells in the literature. Clomipramine a clinically used antidepressant causes prolongation in the QT interval, however its mechanism of action on cardiac cells leading to this cardiotoxic effect is unclear. In this study, clomipramine was tested using HERG transfected HEK293 cells and the neuroblastoma cell line (SH-SY5Y) using a rubidium assay and whole cell patch clamp. Clomipramine inhibited HERG with an IC50 value of 8.35 µM and 2.18 µM in HERG transfected HEK293 cells and the neuroblastoma cell line (SH-SY5Y) using the rubidium assay respectively. Clomipramine inhibited HERG currents with an IC50 value of 0.50 µM using the patch clamp technique in HEK293 cells. The results indicate that the prolongation in the QT interval caused by clomipramine may involve HERG inhibition. The HERG K+ channel is regulated by several protein kinases including protein kinase A and protein kinase B. In Chapter 5, the specific PKC activator and phorbol ester PDA was used to study HERG regulation by PKC in HERG transfected HEK293 cells. PDA caused a reduction in HERG currents in HEK293 cells. The PKC pseudo substrate inhibitor PKC [19-36] did not inhibit the effect of PDA on HERG currents. The results of the study suggest that (1) PDA could be acting directly on the channel and inhibiting its function or (2) PDA is activating other proteins which are affecting HERG currents in the HERG transfected HEK293 cells.
867

Complementary Medicines in Hospitals - a Focus on Surgical Patients and Safety

Braun, Lesley Anne, lgbraun@bigpond.net.au January 2007 (has links)
This study aimed to determine how CMs used by surgical patients are managed in the hospital system by doctors and pharmacists and what patient and practitioner influences affect this management. Research design and method Five systematic reviews were conducted to investigate the peer-reviewed literature for information about Australians use of CM; overseas and Australian doctors and CM; surgical patients use of CM and safety information about CMs in surgery as a basis to design and conduct three surveys. Surveys of hospital doctors, pharmacists and surgical patients were used to obtain measurement of people's attitudes, perceptions, behaviours and usage of CMs. For healthcare practitioners, knowledge of complementary medicines (CMs), past training, current practice and interest in future practice of complementary therapies (CTs) and education was also investigated. Approximately 50% of surgical patients reported taking CMs in the 2 weeks prior to surgery and approximately 50% of these patients intended to continue use in hospital. The most commonly used CMs were: fish oil supplements, multivitamins, vitamin C and glucosamine supplements as well as some CMs considered to potentially increase bleeding risk or induce drug interactions. It was not uncommon for CMs to be used at the same time as prescription medicines. Most surgical patients in general self-prescribe their CMs or have them recommended by family and friends whereas medical practitioners were the main prescribers to cardiac surgery patients. Nearly 60% of patients using CMs in the 2 weeks prior to admission did not tell hospital staff about use. The main reason for non-disclosure was not being asked about use whereas fear of a negative response was rarely a concern. The most common sources of information surgery patients refer to were GPs, pharmacists and health food stores. Hospital doctors and pharmacists did not routinely refer to information sources about CMs safety. The majority of doctors and pharmacists did not routinely ask patients about CMs, or record usage information. They had little training and knowledge of the evidence of commonly used CMs and lacked confidence in dealing with CMs-related issues. Their attitude to CMs is moderately negative and many are wary of safety, efficacy and cost-effectiveness issues. The majority of practitioners considered some CTs as potentially useful, particularly acupuncture, massage and meditation whereas the medicinal CTs and chiropractic were considered potentially harmful. Most practitioners were interested in future education about CMs and CTs and some would consider practising CTs. Personal usage of CTs was low although there was substantial interest in receiving future treatment. Despite many strategically orientated initiatives developed in Australia to promote evidence based medicine (EBM) and quality use of medicines (QUM), it appears that CMs have been largely ignored and overlooked in the practice of Medicine and Pharmacy within the hospital system. Furthermore, it appears that in regards to CMs a 'don't ask, don't tell, don't know' culture exists within hospitals and that evidence based patient-centred care and concordance is not being achieved and potentially patient safety and wellbeing is being compromised.
868

HACCP-Implementering och tillsyn

Axelsson, Christer January 2008 (has links)
<p> </p><p>The food-safety legislation in Sweden were changed and updated in 1996, much because of demands from the European Union for a common legislation regarding the food-safety issues in the EU. This report discusses how the Swedish authorities are dealing with the new legislation in Sweden. Further on the report presents how the food safety officers in the municipalities in Sweden are implementing this new legislation in their daily work, especially the requirements regarding the HACCP, Hazard Analysis Control and Checkpoints. The report shows that the implementation is quite slow and that many foodsafety-officers don’t implement the legislation in the same way all over the country. In some parts of Sweden the officers demands a complete Hazard-analysisplan with Critical checkpoints while in other parts of Sweden the are not the same demands. The reason to why this is possible may be the educational differences between the food safety officers in Sweden. In some municipalities the officers are well educated about the new legislation including HACCP while other municipalities don’t afford or take the time to educate their officers. The report also shows that the knowledge of the new legislation is poor among the people who work in the food-section.</p><p> </p>
869

Communication and Networking Techniques for Traffic Safety Systems

Chisalita, Ioan January 2006 (has links)
<p>Accident statistics indicate that every year a significant number of casualties and extensive property losses occur due to traffic accidents. Consequently, efforts are directed towards developing passive and active safety systems that help reduce the severity of crashes, or prevent vehicles from colliding with one another. To develop these systems, technologies such as sensor systems, computer vision and vehicular communication have been proposed. Safety vehicular communication is defined as the exchange of data between vehicles with the goal of providing in-vehicle safety systems with enough information to permit detection of traffic dangers. Inter-vehicle communication is a key safety technology, especially as a complement to other technologies such as radar, as the information it provides cannot be gathered in any other way. However, due to the specifics of the traffic environment, the design of efficient safety communication systems poses a series of major technical challenges.</p><p>In this thesis we focus on the design and development of a safety communication system that provides support for active safety systems such as collision warning and collision avoidance. We begin by providing a method for designing the support system for active safety systems. Within our study, we investigate different safety aspects of traffic situations. For performing traffic investigations, we have developed ECAM, a temporal reasoning system for modeling and analyzing accident scenarios.</p><p>Next, we focus on the communication system design. We investigate approaches that can be applied to implement safety vehicular communication, as well as design aspects of such systems, including networking techniques and transmission procedures. We then propose a new solution for vehicular communication in the form of a distributed communication protocol that allows the vehicles to organize themselves in virtual clusters according to their common interest in traffic safety. To disseminate the information used for organizing the network and for assessing dangers in traffic, we develop an anonymous context-based broadcast protocol. This protocol requires the receivers to determine whether they are the intended destination for sent messages based on knowledge about their current situation in traffic. This communication system is then augmented with a reactive operation mode, where warnings can be issued and forwarded by vehicles. A vehicular communication platform that provides an implementation framework for the communication system, and integrates it within a vehicle, is also proposed. Experiments have been conducted, under various conditions, to test communication performance and the system’s ability to reduce accidents. The results indicate that that the proposed communication system can efficiently provide the exchange of safety information between vehicles.</p>
870

Out-of-service criteria for commercial vehicles : evaluation of accident data in relation to vehicle criteria

Miller, Stanley Glade 03 May 1996 (has links)
The Commercial Vehicle Safety Alliance (CVSA) is an association of industry representatives, and state, territorial, provincial, and federal government officials in the United States, Canada, and Mexico. The CVSA's goal is to improve commercial vehicle safety. The CVSA concentrates its safety focus on three areas; driver, vehicle, and hazardous materials. Since 1981, the CVSA has developed a set of criteria for each of the three areas that define conditions which are so unsafe that a truck and/or driver should not be allowed to operate. These criteria are known as out of service (OOS) criteria. To check the compliance of motor carriers with the CVSA criteria, a series of road side inspections is conducted by state and local governments. If the driver and/or vehicle are found in violation of the CVSA OOS criteria, they are placed "out of service" until the conditions are completely remedied. Due to criteria growth, the CVSA wanted to examine the OOS criteria in the vehicle and hazardous materials areas. This study, focused on the vehicle portion of the OOS criteria, attempted to correlate commercial vehicle defects to commercial vehicle accidents. For a major portion of this project, actual accident reports from six states of the United States were evaluated. The states and reports were selected via a stratified two stage cluster sampling system. The results were used to form estimates of the proportion and number of commercial vehicle accidents in the United States with a mechanical defect as a contributing factor. In addition to the accident report sampling, other sources were used to establish a correlation between vehicle defects and commercial vehicle accidents. They include literature, national databases, and post-crash inspections. Results from this study show that approximately 4.6% of all commercial vehicle accidents have a mechanical defect as a factor contributing to the accident. Of these, brakes (1.66%), tires (0.45%), couplings (0.38%), load securement (0.37%), and wheels (0.33%) accounted for the majority. A comparison was also made between the OSU study results and the information gathered from other sources. A cost factor was also used to rank the accidents. The sampled accidents accrued $22.7 million in damage to people and property. The underlying assumption is vehicle defects that are strongly represented in accidents and accident damage estimates should have a strong representation in the out-of-service criteria. / Graduation date: 1997

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