Dissertations / Theses on the topic 'Medical microbiology not elsewhere classified'

This thesis described the research carried out on the development of a novel hardwired tactile sensing system tailored for the application of a next generation of surgical robotic and clinical devices, namely a steerable endoscope with tactile feedback, and a surface plate for patient posture and balance. Two case studies are examined. The first is a one-dimensional sensor for the steerable endoscope retrieving shape and 'touch' information. The second is a two-dimensional surface which interprets the three-dimensional motion of a contacting moving load. This research can be used to retrieve information from a distributive tactile sensing surface of a different configuration, and can interpret dynamic and static disturbances. This novel approach to sensing has the potential to discriminate contact and palpation in minimal invasive surgery (MIS) tools, and posture and balance in patients. The hardwired technology uses an embedded system based on Field Programmable Gate Arrays (FPGA) as the platform to perform the sensory signal processing part in real time. High speed robust operation is an advantage from this system leading to versatile application involving dynamic real time interpretation as described in this research. In this research the sensory signal processing uses neural networks to derive information from input pattern from the contacting surface. Three neural network architectures namely single, multiple and cascaded were introduced in an attempt to find the optimum solution for discrimination of the contacting outputs. These architectures were modelled and implemented into the FPGA. With the recent introduction of modern digital design flows and synthesis tools that essentially take a high-level sensory processing behaviour specification for a design, fast prototyping of the neural network function can be achieved easily. This thesis outlines the challenge of the implementations and verifications of the performances.

Understanding public attitudes towards using animals for medical experimentation and the issues that cause public concern is of importance scientifically, economically and ethically. Although national opinion poll data appear to provide enough evidence to propose the hypothesis that 'the majority of people in Britain support animal research' it is clear from reviewing the literature that the attitudes of young people have not been adequately explored. Furthermore, the ethical considerations and scientific understanding underpinning such attitudes are also poorly understood. It is also clear that we have little comprehension of how ethnic minority groups in our society view animal experimentation (AE). The aim of this study is therefore to acquire a contemporary, comprehensive understanding of young people's perceptions of AL This is pursued by means of a custom made questionnaire that also seeks to explore knowledge/understanding and values/belief systems within a cross-cultural context. Qualitative aspects of the study, both verbal and pictorial, enrich the quantitative data generated, allowing a unique insight into how young people articulate their attitudes towards AE. The findings from this study reveal that young people hold a diverse array of attitudes towards AE. Their support is dependent on animal species, which for non-Islamic respondents appears to be based on traditional Western considerations of phylogenic hierarchy. For Islamic respondents, however, attitudes towards certain animals diverge from this phylogenic classification, being driven instead perhaps by traditional cultural relationships with animals. Cross-cultural differences of how animals are viewed were also apparent when value typologies were measured. Scales to assess the human-animal bond and instrumental attitudes towards animals demonstrate that Islamic respondents have a less emotional attachment to animals, viewing them more instrumentally. The human-animal relationship scales reveal no such differences. Young people appear to have a poor knowledge base regarding issues surrounding AE and have a negative image of animal welfare within research facilities. These perceptions correlate with attitudes towards AE and hence suggest that there is a need for greater communication between scientists and lay people regarding this issue. When compared with other scales measuring instrumental uses of animals, Islamic respondents supported AE to a lesser extent than might have been expected, which may reflect a lower level of general medical understanding. Gaining a greater understanding of young people's perceptions of AE is not only important in its own right but may also be of general benefit in the arena of public understanding of science. The recommendations from this study therefore suggest routes to strengthen scientific communication in regard to the issue of AB that might also be applicable to more general areas of science.

"In this study, the performance of a flat plate photocatalytic reactor for degrading and mineralising storm and wastewater pollutants is investigated. This research aims to lay the groundwork for the performance of the flat plate photocatalytic reactor using computational fluid dynamics (CFD) simulation as a first step. Then an extensive study is performed to evaluate the role of mixing and turbulence promoters in the photocatalytic reactor to improve its design to meet the needs of a prototype photocatalytic reactor. The CFD simulation results are validated with experimentally measured data under various flow conditions. The experimentally measured velocity and benzoic acid concentration was found to be in good agreement with the results of the simulation. The results showed that the model can accurately predict the velocity and the outlet concentration of benzoic acid for various hydrodynamic conditions. Using various turbulence sub-models, the flow profile in the flat plate reactor was simulated for various flow conditions. No discernible variation on the flow profiles was observed regardless of the turbulence models tested. Furthermore, the performance of the reactor for the degradation of phenol as a model pollutant was predicted which was observed to decrease with increased flow rates"--Abstract.

"The main aim of this project was to develop and optimise a thin-film fixed-bed reactor (TFFBR) in a pilot-scale system of solar energy to inactivate aquaculture pathogens and other microbes present in water."--Abstract.

The poultry industry has rapidly grown in the last few years with a focus in improving growth and productivity of broiler chickens, with performance assessed on measures such as feed conversion ratio, body weight gain and good immunity. The incorporation of antibiotics and feed additives in poultry diets, have been implemented for years to ensure the maintenance of poultry health with a focus on the control and reduction of zoonotic pathogens. In the last few years, however, key issues surrounding the antimicrobial resistance of antibiotics have urged for alternative supplementations. Nanoparticles (NPs) of silver and other metals have been heavily used in the poultry industry to improve the growth and performance of birds. Whilst successful, metal NPs exhibited higher toxicity at the higher surface to volume ratio, especially with the use of silver. This study proposes the use of NPs of essential metals and natural compounds to safely deliver nutrients, resulting in positive impacts on health and productivity with little to no toxic effects. Selenium is an essential mineral, required for the proper functioning of the immunity and is an important element in the first cell line of defence in the body. The work described in this thesis explores the ability of selenium NPs to improve the health and growth of broiler chickens by modulating their gut microbiome and metabolome, without the toxic effects observed with silver. Selenium NPs were synthesised using a simple chemical reduction method and a full characterisation was performed, assessing the physicochemical properties of the NP. Selenium NPs were then compared in an animal trial against two commonly used selenium additives in the poultry industry, sodium selenite (inorganic selenium) and selenomethionine (organic selenium). The performance of the birds was assessed based on body weight gain, the gut microbial composition and metabolite production. The toxicity of NPs was further investigated by quantifying selenium concentration in various tissues, along with a detailed histopathological assessment. Results show selenium NPs completely altered the gut microbial ecology at high concentration, with a strong correlation observed between Faecalibacterium prausnitzii abundance and increasing concentration of selenium NPs. Selenium NPs additionally increased villus height/crypt ratio associated with enhanced absorption in the small intestine and an overall increase of healthy colonic metabolites. Finally, an in vitro study demonstrated the ability of selenium NPs to reduce emerging pathogenic Enterococcus cecorum species. This thesis demonstrates the prospective ability of selenium NPs as alternatives to antibiotics and bulk supplementation, resulting in an improvement of health and performance of broiler chickens in the poultry industry.

Free-living amoebae (FLA) are an assemblage of heterotrophic, eukaryotic organisms, which survive in a range of specialised and extreme environments worldwide. A few, namely Naegleria fowleri, pathogenic Acanthamoeba spp. and Balamuthia mandrillaris may occasionally become parasites of humans and produce life and sight-threatening diseases that are difficult to treat effectively. This thesis presents the findings of a 12-month survey of 3 natural and 3 man-made water-bodies in the Rockhampton area. It was undertaken to determine if these thermophilic FLA were present in readily recoverable quantities using the samplevolumes detailed in this study thereby reflecting high population densities which could pose a potential health hazard to humans using these water bodies recreationally." -- abstract. Free-living amoebae (FLA) are an assemblage of heterotrophic, eukaryotic organisms, which survive in a range of specialised and extreme environments worldwide. A few, namely Naegleriafowleri, pathogenic Acanthamoeba spp. and Balamuthia mandrillaris may occasionally become parasites of humans and produce life and sight-threatening diseases that are difficult to treat effectively.This thesis presents the findings of a 12-month survey of 3 natural and 3 manmade water-bodies in the Rockhampton area. It was undertaken to determine if these thermophilic FLA were present in readily recoverable quantities using the sample volumes detailed in this study thereby reflecting high population densities which could pose a potential health hazard to humans using these water bodies recreationally. Thennophilic FLA were recovered from all sites with the majority being isolated in the warmer months of spring and summer. In addition, culture dynamics and desiccation experiments were conducted to study the response of FLA to laboratory manipulation of parameters that included food supply and the effects of prolonged desiccation with the objective being to predict survivability of FLA populations in response to changing environmental conditions. Food supply experiments showed that N. fowleri would survive as dormant cysts after consuming a finite food supply. Desiccation experiments conducted at 22°C showed that all of the five species of thermophilic FLA would survive to 14 weeks. This thesis demonstrated that thermophilic FLA are a common component of the microbiota of freshwater bodies in Rockhampton's tropical environment.

The research presented here analyses and compares textual narratives generated within policy, scholarly and popular media to discern how the sexuality or intimacy needs of people categorised as ‘learning disabled’ have been historically and more recently managed in Australia and the United Kingdom. The research uses a modified critical discourse analytical approach which, in order to clarify the distinct role of power in the construction of discourses of sexuality, is mediated by the more recent ideas of progressive phronesis offered by Flyvbjerg (1998a; 2001). The analysis identifies three broad stages in the historical development of the discourses about the sexuality of learning disabled people. The first phase was prior to the 1800s, when these people were labelled non-derogatorily as ‘idiots’, and perceived as childlike, innocent and asexual. The second stage was in the 1800s when, with the emergence of scientific rationality and medicalisation, so-called idiots became medicalised and categorised as ‘feeble-minded’ or ‘moral imbeciles’. This thesis demonstrates that, during this period, an emphasis on sexual self-denial, anxieties about venereal disease and non-procreative erotic pleasure helped to inform discourses of eugenics and learning disabled people became perceived as a sexual threat to the society. This underpinned policies of sexual control through institutionalisation, gender segregation and sterilisation. The third period in the development of discourses relating to the sexuality of learning disabled people paralleled the ‘sexual revolution’ of the late- 1900s and the move towards deinstitutionalisation and human rights. This analysis shows that, although the principle of ‘sexual freedom’ was ostensibly incorporated in modern policy discourse, the sexuality of learning disabled people continues to be influenced by significant barriers of sexual intolerance, demonstrated by continuing practices of sexual segregation, sterilisation, criminal labelling and imprisonment. The analysis indicates that a discourse of sexuality, which has legitimised the control and management of learning disabled people in varying forms since the Enlightenment, continues to be encountered in policy and popular narratives. Robust sexuality awareness and education programs for carers of these people, and society in general, are necessary so that intimacy and/or sexual desires are accepted as a normal need for all human beings.

Background; Peripherally inserted central catheters (PICC) are increasing in popularity in healthcare systems around the world. Positive patient satisfaction and clear fiscal savings combined with perceived low insertion and post insertion complication rates when compared to other options have secured the popularity of PICC in health care systems around the world. However little quality evidence is available to PICC inserters with regards to the safest catheter choice in order to produce the lowest levels of post insertion complications both in general adult populations as well as specific patient groups. Research question; Is the make of the PICC catheter (silicone or polyurethane) selected by nurse inserters a primary influence in patients experiencing post insertion complications? Data Analysis- Descriptive statistics were used to present demographic findings in both phases of the study. Phase One results were graphically portrayed, while Phase Two data was entered into the computer program SPSS (version 24). For Phase Two comparisons of post insertion complication rates and varying factors of both PICC type were analysed with Pearson chi test, categorical regression, two sample independent t-test, nonparametric binomial test and ANOVA. Methods; To address this research question a two phase study guided by the Gearing framework was undertaken in a Medical Imaging department of a large public hospital in Far North Queensland, Australia. The Gearing framework is a retrospective chart audit research design that comprises nine steps including: conception of the research, literature review, proposal development, data abstraction, development of protocols for data abstraction, chart audit tool, sample, ethical considerations and pilot. Phase One of the study comprised steps 1 and 2 in the Gearing framework. Consistent with the Gearing framework the literature review is presented as systematic review, and forms part of the data collection process. Phase Two encompassed steps 3 to 9 of the Gearing framework and the chart audit process. Using the tool developed in steps 1 to 9 a total of 379 charts were accessed and data recorded on 295 of these on a secure electronic device. Data collected included; demographic data, patient status, reason for insertion and reason for removal of PICC. Results; Phase One, the systematic literature review, found a large variance in reported post insertion complications from 8 to 50% of all PICC inserted. Both silicone and polyurethane PICC showed similar overall rates of post insertion complication however with closer examination strengths and weaknesses in each PICC type were noted. These finding were used to inform Phase Two of the study. Of the 295 PICC insertions included in Phase Two, 141 were silicone PICC and 154 polyurethane PICC. Various patient groups were contained within the sample including: inpatient (142), outpatient (80) and transitional (73). Reason for requiring a PICC identified 102 oncology patients, 164 requiring intravenous antibiotics and 29 requiring other types medications. Reasons for removal of catheter varied from no complication/ completion of therapy (67.8%), infection (11.2%), migration (5.8%), deceased (4.7%), occlusion (3.7%), thrombus (2.7%), breakage (2.7%), phlebitis (0.3%) and upgrade to triple lumen catheter (0.3%). Overall the number of lumens the PICC contained (p=.001) was shown to be a predictor of removal due to post insertion complications. Categorical regression showed that oncology, not the catheter type, (Beta 0.253, p=.083), to be the strongest predictor of complications. Conclusions; PICC remain a safe and reliable form of medium to long-term intravenous access across PICC types, patient groups and for all patient types. The greatest predictors of post insertion complications were number of lumens and oncology patient groups. The emerging trend of health facilities to transition inpatients to outpatients in the community with PICC insitu was shown to be a safe practice with similar post insertion complication levels to inpatients.

The objective of research is to develop a computer simulation modeltoprovide a means to effectively and efficiently reduce medication errors associated with points of distribution sitesby identifying and manipulating screeners with a high probability of generating errors.Points of distribution sites are used to rapidly distribute chemoprophylaxis to a large population in response to a pandemic event or a bioterrorism attack. Because of the nature of therapid response, points of distribution sites require the use of peer-trained helpers who volunteer their services.The implications are that peer-trained helperscould have a variety of experience or education levels. Thesefactors increase the risk of medical errors. Reducing medical errors is accomplished through changing the means in which healthcare providers are trained and focusing on a team approach to healthcare delivery. Computer simulations have been used in the past to identify sources of inefficiency and potential of error. Data for the model werecollected over the course of two semesters. Of the 349 data points collected from the first semester, only 137 data points were usable for the purposes of modelbuilding. When the experiment was conducted again for the second semester, similar results werefound. The control simulation was run 20 times with each screener generating errors with a probability of 0.101 following a Bernoulli distribution. The variable simulation was run 30 times with each screener generating the same probability of errors; however, the researcher identified the screeners generating the errors and immediately stopped them from processing additional agents once they reached five errors. An ANOVA was conducted on the percent errors generated from each simulation run. The results of the ANOVA showedsignificant difference between individuals within the groups. A simulation model wasbuilttoreflect the differences in medical error rates between screeners. By comparing the results of the simulation as the screeners are manipulated in the system, the model can be used to show how medical errors can be reduced in points of distribution sites

Total knee arthroplasty (TKA) has proven successful in treating symptomatic arthritis of the knee. Since its development, many and varied outcome measures have been developed to assess outcome. None have been accepted as the universal standard, although some are widely used. Many measures have no data regarding validity, reliability or responsiveness. There is little guidance or consensus in the literature as to which should be used in clinical practice, research or audit. In addition, there is limited research assessing the relationship between subjective clinical outcome scores, patient perceived reports and objective measures such as the timed up and go test (TUG), knee laxity and muscle strength. Establishing relationships between self report and objective measures may aid clinicians in developing more appropriate interventions. Twenty four patients underwent unilateral TKA and were assessed a mean of 27.5 (SD 11.7) months after surgery. Assessment included four patient reported scores (Knee Outcomes and Osteoarthritis Score, Oxford Knee Score, American Knee Society Score and Short Form 12) and three objective outcome scores (knee laxity, quadriceps muscle strength and timed up and go test (TUG). Significant (<0.05) correlations were demonstrated between the four patient reported scores (r=0.410- 0.786) except the MCS portion of the SF12 (r=0.286-0.483). The TUG was the only objective outcome measure to demonstrate a statistically significant (p=0.0001-0.005) correlation with subjective knee outcome scores (OKS, KOOS and 4 items of the KOOS) (r=--0.557 to -0.770). A patient's ability to walk at a certain pace is correlated with patient satisfaction after TKA. There were no 4 observed correlations between knee laxity or quadriceps muscle strength with the four subjective knee scores. Therefore for a comprehensive assessment of outcome after TKA, use of a combination of objective and subjective outcome measures is recommended, as they measure different aspects of outcome.

"The effect of temperature, pH, presence of inorganic ions and organic matter in water stored for 24 h in a copper water storage vessel was studied and enumeration was carried out under normal aerobic conditions and conditions designed to neutralise reactive oxygen species by the addition of 0.5% w/v sodium pyruvate and incubation in an anaerobic jar containing an anaerobic gas pack to encourage fermentative metabolism... The present study demonstrated complete inactivation of Salmonella Typhimurium, Salmonella Typhi and Vibrio cholerae by storage in a copper vessel for 24 h... The results of the present study highlight the significance of using copper as an antibacterial agent against common water-borne pathogens in reducing the risk of incidence of infections from contaminated water"--Abstract.

Implantable biomedical devices have been widely used to treat a variety of diseases for many decades. If allowed by the size and form factor, batteries have been the power source of choice in implantable devices (e.g., cardiac pacemakers). Batteries are, however, still big and come in shapes that are not ideal for minimally invasive deployment. Inductive powering is another commonly used energy source in which two well-aligned coils allow a transmitter to power the implanted receiver (e.g., cochlear implants). Once the receiver coil becomes small (mm-scale), the inductive powering link becomes very inefficient and sensitive to slight misalignment between the coils. Hence, it becomes increasingly difficult to power small devices implanted deep (>5 cm) within the tissue using inductive powering. Ultrasonic powering is an attractive alternative for powering miniature devices since it can penetrate deep into the tissue, it has greater efficiency at mm-scale receiver size, it can be omni-directional, and it is more amenable to miniaturization.

In this dissertation, I describe the use of ultrasonic waves to power and control mm-scale implantable devices. After a detailed look at ultrasonic transmission link, I will discuss factors affecting the power transfer efficiency. These include the effect of receiver aspect ratio and size on the resonant frequency and factors related to acoustic and electrical matching. A 3D printed acoustic matching layer in then described. I will discuss two applications using ultrasound to power and control implantable devices. The first is a low-power on-off acoustic control scheme to reduce the standby power consumption in implantable devices. The second is an ultrasonically powered electrolytic ablator with an on-board micro-light-source for the treatment of cancer.

A focus group study was conducted to provide a base of knowledge related to the facilitators and inhibitors of appropriately trained nurses carrying the pager that notifies of the need for a medical emergency team (MET) response. The study site was in regional Queensland and seventeen Registered Nurses participated in the study. The concepts found in data progressively contributed to the development of four major themes: motivators to do the training, applying theory to practice, the MET experience and prioritising the pager. The data uncovered some information that has not previously been reported in the literature. Other findings offer support for evidence that already exists.

This thesis is a collection of the three projects I have worked on at Purdue. The first is a paper on thermoacoustic tomography involving circular integrating detectors that was published in Inverse Problems and Imaging. Results from this paper include demonstrating that the measurement operators involved are Fourier integral operators, as well as proving microlocal uniqueness in certain cases, and also stability. The second paper, submitted to the Journal of Inverse and Ill-Posed Problems, is much more of an application of sampling theory in to the specific case of thermoacoustic tomography. Results from this paper include demonstrating resolution limits imposed by sampling rates, and showing that aliasing artifacts appear in predictable locations in an image when the measurement operator is under sampled in either the time variable or space variables. We also show an application of a basic anti aliasing scheme based on averaging of data. The last project moves slightly away from microlocal analysis and considers the uniqueness in medical imaging of the restricted Radon transform in even dimensions. This is the classical interior problem, and we show a characterization of the range of the Radon transform, and from this are able to obtain a characterization of the kernel of the restricted Radon transform. We include figures throughout to illustrate results.

The story behind this research project begins in 1962 when, at age 11, I developed an eating disorder and began to keep a diary. The themes and threads that bind the story together, however, began to weave a pattern almost as soon as I was born. In early childhood, the world through my eyes comprised a small, beautiful valley adjoining the Mitchell River National Park in Victoria, Australia. I lived on a dairy farm with my parents and sister. For my first 11 years, my home had no electricity, television or Internet, but my days were full. The farm, river and adjacent bushland provided a natural outdoors playground, seeding my imagination. Indoors, on rainy days and at night by lantern-light, at the solid oak kitchen table, I would ask my mother for pen and paper and write a note or two about my day. A friendship with words was already taking hold.

Neck braces and head supports used today do not allow wearers to rotate their head while maintaining the support they need. For people with chronic muscle diseases, such as ALS, DHS, Myasthenia Gravis, and Muscular Dystrophy, this inconvenience greatly affects their quality of life in that it hinders their abilities to perform activities of daily living, such as nonverbal communication and knowing their surroundings outside without having to move their entire body. There is a need for a head support device that allows individuals with chronic muscle diseases to rotate their heads, so they may better perform daily activities of living and thus live a more fulfilling life.

The purpose of this study was to assess the basic stance of safety of a dynamic head support device that allows individuals with chronic muscle diseases to rotate their heads left and right. The assessment includes an experimental procedure that will conclude whether this device can withstand the load equivalent to an average adult’s head in a stationary position and a dynamic movement.

This research proposed a procedure that has a testing apparatus that will place a predetermined load onto the dynamic head support device to stabilize it and then continuously add weight that was checked incrementally. This load was placed on the device while it was centered and static first. The next step in this procedure is to assess whether or not the load on the device can be carried while dynamically moving on the race of the radial sliding track of the device. The data recorded from this experiment will provide the necessary information to determine whether the basic safety requirement of load capacity for a medical device such as the one in this proposed research is met.