The ergonomics and design of an inclusive best-fit solution to workbenches

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.In a time when the developed world, is trying to reduce the human and economic costs of musculo-skeletal disorders (MSDs), any contribution to such an endeavour would be welcome. These economic costs are estimated to be in the tens of billions of Euro in the EU countries and similarly in the USA, the cost in human pain has not been measured. It may surprise many that in spite of all the advancements in science and technology, that two generations of people, who are very significantly taller than the people of a century ago, are still working in industry and in education at benches, which have not changed, either in height or design in centuries. Some, like wheelchair users do not have the opportunity to work at a bench at all. At the outset this research project, had the primary objective of determining an ergonomic best-fit, for a broad range of users of workbenches. These included the young school going population (12-13 year olds), the senior students (16 plus years old), adults, and a cohort of surrogate wheelchair users. The research also endeavoured to determine if adolescents, who were of the same stature as adults, had the same workbench ergonomics requirements. The secondary objective, which was completely dependant on the first, was to design a bench, which would suit the ergonomic requirements of this diverse group. The research has identified the best-fit workbench heights for the total cohort, while recognising the individual differences in relation to bench height ergonomics, for each of the sub-groups tested. The findings of the research have shown, that using surrogate wheelchair users to determine ergonomic data for this type of activity is fully justified. In combining the raw data for a similar number of wheelchair users, a best-fit bench height has been confirmed at 100 mm above knee height. There are no significant differences between the ergonomic requirements for males and females at workbenches. Body part discomfort has been reduced significantly, for the wheelchair users, at the identified height and endurance has been extended. Importantly the career options for wheelchair users have been extended, empowering them to make broader career choices. The outcomes of the research relating to three groups making up the able-bodied cohort have shown that an ergonomic best-fits possible, which suits the needs of this diverse group. A height of 150 mm under elbow height has been identified as best-fit, and this reduces the discomfort considerably while extending endurance. Robust working heights have been identified, but the female working heights at workbenches, are not as robust as for the males. For all groups it has been shown that bench height has a significant effect on body part discomfort and endurance, and while there were differences in efficiency, which were not quite significant, it is suggested that working in an ergonomically compromising position must, in the long term, in addition to increasing the risk of MSDs, likely also influence productivity, and quality of work. An inclusive test-workbench has been designed and built which satisfies the ergonomic needs of the diverse user group described above

Patterns of adaptive and purifying selection in the genomes of phocid seals

Modern genomic sequencing technologies provide the opportunity to address long-standing questions in molecular evolution with empirical data. In this dissertation, I combine this new technology with advances in statistical population genetics to describe how deleterious mutations and adaptive evolution have shaped the genomic evolution of phocid seals. In Chapter 1, I model historical demographic processes using whole genome sequences of eight seal taxa: the Hawaiian monk seal, the Mediterranean monk seal, the northern elephant seal, the southern elephant seal, the Weddell seal, the grey seal, the Baltic ringed seal, and the Saimaa ringed seal. Through this, I establish that the endangered monk seal species have long-term small population sizes, as do grey seals. On the other hand, the elephant seals, Weddell seal, and ringed seals had much larger populations in the distant past. Notably, the most recent glaciation (c. 12,000-120,000 years ago) appeared to have a dramatic effect on phocid populations throughout the world. With this knowledge of historical population sizes, I test a fundamental premise of molecular evolution: that the rate of mutation accumulation will be higher in smaller populations due to less efficient purifying selection. I show that there is not a higher substitution rate or overall rate of mutation accumulation in the long-term small populations of monk seals compared to other seal species. On the contrary, overall rates of mutation accumulation appear to be lower in monk seals and grey seals, both of which show smaller long-term population sizes compared to the other species. This suggests either that the distribution of fitness effects may differ across seal species in a way that depends on population size and history. In Chapter 2, I use population genomic data and a newly developed statistical model to detect positive selection in the protein coding genes of phocid seals (monk seals, elephant seals, Weddell seals, grey seals, and ringed seals). In addition, I use a phylogenetic framework to detect parallel evolution across multiple lineages of seals, relating to traits such as polar adaptations, hypoxia tolerance during long dives, and mating behavior. I develop a new bioinformatic tool to process raw BAM files and transform them into useable input for MASS-PRF, a tool to detect selection from polymorphism and divergence data. Through these analyses, I identify thousands of genes that show positive selection across multiple seal lineages. Genes associated with immune function, sperm competition, and blubber composition show positive selection in all lineages, highlighting how complex and important these traits are in seals. In the deep-diving elephant seals, the list of positively selected genes was enriched for genes relating to cardiac muscle development and function, providing important insight into how adaptive protein evolution has helped allow these seals to survive sustained bradycardia during dives that last over an hour. Weddell seals, on the other hand, showed enrichment for genes relating to neuronal development, which may relate to molecular adaptations that allow their neurons to survive hypoxic conditions during long dives. Because MASS-PRF allows for site-specific tests of selection, I am able to show how parallel evolution in the same genes across lineages sometimes may or may not involve positive selection at the same genic site. In Chapter 3, I use the population genomic data from Chapter 2 to model the distribution of fitness effects (DFE) of segregating alleles in each population. Due to sample size issues, only parameters for the Hawaiian monk seal were confidently estimated. Using the site frequency spectrum of synonymous sites, I show that the Hawaiian monk seal has had a long-term effective population size below 5000, in agreement with the results from Chapter 1. In addition, I should that after the arrival of humans in Hawaii, the monk seal experienced a 95% decline in effective population size, in line with the current census size of fewer than 1500 individuals. Conditioning the model on the Hawaiian monk seal demographic parameters, I am able to estimate the shape of DFE in Hawaiian monk seals using the site frequency spectrum of nonsynonymous sites. I estimate a DFE for the Hawaiian monk seal that is nearly identical to the one estimated in humans. This DFE, however, is different than the one estimated for mouse, with the seal and human DFEs having a higher proportion of more strongly deleterious alleles. This pattern cannot be explained by phylogenetic relatedness or differences in phenotypic complexity, but instead is likely related to differences in effective population size. I discuss how the geometric model of evolution predicts such a shift in DFE in response to the epistatic effect of fixed deleterious mutations in smaller populations

A comparative study of the osteology and myology of the cranial and cervical regions of the shrew, Blarina brevicauda, and the mole, Scalopus aquaticus.

http://deepblue.lib.umich.edu/bitstream/2027.42/56325/1/MP080.pd

Identification of sleep apnea events using discrete wavelet transform of respiration, ECG and accelerometer signals

Sleep apnea is a common sleep disorder in which patient sleep patterns are disrupted due to recurrent pauses in breathing or by instances of abnormally low breathing. Current gold standard tests for the detection of apnea events are costly and have the addition of long waiting times. This paper investigates the use of cheap and easy to use sensors for the identification of sleep apnea events. Combinations of respiration, electrocardiography (ECG) and acceleration signals were analysed. Results show that using features, formed using the discrete wavelet transform (DWT), from the ECG and acceleration signals provided the highest classification accuracy, with an F1 score of 0.914. However, the novel employment of just the accelerometer signal during classification provided a comparable F1 score of 0.879. By employing one or a combination of the analysed sensors a preliminary test for sleep apnea, prior to the requirement for gold standard testing, can be performed

Salpingectomy for ectopic pregnancy: Does length really matter?

This abstract describes a case of a tubal stump ectopic. The aetiology, presentation and management of such rare cases are described. The evidence bases for the rationale for leaving a short versus a long stump at salpingectomy is reviewed

Towards Automatic Blotch Detection for Film Restoration by Comparison of Spatio-Temporal Neighbours

In this paper, a new method of blotch detection for digitised film sequences is proposed. Due to the aging of film stocks, their poor storage and/or repeated viewing, it is estimated that approximately 50% of all films produced prior to 1950 have either been destroyed or rendered unwatchable [1,2]. To prevent their complete destruction, original film reels must be scanned into digital format; however, any defects such as blotches will be retained. By combining a variation of a linear time, contour tracing technique with a simple temporal nearest neighbour algorithm, a preliminary detection system has been created. Using component labelling of dirt and sparkle the overall performance of the completed system, in terms of time and accuracy, will compare favourably to traditional motion compensated detection methods. This small study (based on 13 film sequences) represents a significant first step towards automatic blotch detection

Development of novel advanced flow control systems on centrifugal microfluidic platforms for nucleic acid testing

In this work the development of novel flow control methods in centrifugal microfluidic systems for the nucleic acid testing are demonstrated. Nucleic acids make excellent biomarkers for the identification of numerous diseases, but their detection is a lengthy and labour intensive process. Centrifugal microfluidics has emerged as a highly useful tool in the area of biomedical diagnostics; however there are still limitations when it comes to sample preparation on these Lab-on-a-Disc systems. This is especially important in nucleic acid testing, where the main bottleneck in performing these processes on microfluidic devices is in sample preparation. Nucleic acid testing can be broken into three stages; extraction, purification and detection. To this end, this work outlines the development of two novel centrifugal routing systems for nucleic acid purification, through the integration of functional materials. The first is a solvent-selective router which integrated two solvent specific membrane valves. The capability of the system to purify total RNA with significant integrity and concentration was shown. The second system integrated multi-layer Graphene Oxide (GO) membranes into our Lab-on-a-Disc devices. Using this, two unique properties of the GO were investigated; its solvent selectivity and air impermeability. Finally, a novel, centrifugo-pneumatic scheme for solvent-selective routing of organic and aqueous flows was demonstrated. Also shown is the development of two separate extraction platforms. The first was a centrifugo-pneumatic ‘μHomogenizer’, which implements a 3-phase fluid extraction protocol of RNA. This system integrates chemical lysis and separation of the RNA containing aqueous phase and shows significant improvement over its time-consuming and labour intensive benchtop alternate. The second was the development of a mechanical lysis method that utilises a rotor stator grinding mill driven by the spindle motor. This system can be used for general lysis of a wide range of bacteria but would be of significant benefit for armoured cells

Research and development study on multimode system applications in the area of time of flight and coincidence measurements

Technical specifications for multimode digital storage device, and applications to time of flight and coincidence measurement