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Observations and analysis of a 63-year-old reinforced concrete promenade railing exposed to the North Sea
No full textDespite being exposed to the harsh sea-spray environment of the North Sea at Arbroath, Scotland, for over 63 years, many of the reinforced concrete precast beam elements of the 1·5 km long promenade railing are still in very good condition and show little evidence of reinforcement corrosion. In contrast, railing replacements constructed in about 1968 and in 1993 are almost all badly cracked as a result of extensive corrosion of the longitudinal reinforcement. This is despite the newer concrete appearing to be of better quality than the 1943 concrete. Statistics for maximum crack width for each of the three populations, based on measurements made in 2004 and in 2006, are presented. In situ and laboratory measurements show that the 1943 concrete appears to have high permeability but it also shows high electrical resistivity. Chloride penetration measurements show the 1943 and 1993 concretes to have similar chloride profiles and similar chloride concentrations at the reinforcement bars. This is inconsistent with the 1943 beams showing much less reinforcement corrosion than their later replacements and casts doubt on the conventional practice for durability design focusing on reducing concrete permeability through denser concretes or greater cover
Cell cycle-dependent repetitive Ca²⁺ waves induced by a cytosolic sperm extract in mature ascidian eggs mimic those observed at fertilization
No full textSperm-triggered Ca²⁺ oscillations occur throughout the animal kingdom. The mechanism sperm use to trigger Ca²⁺ oscillations at fertilization has not been resolved in any egg. The temporal, spatial and regulatory characteristics of the Ca²⁺ oscillations during fertilization in ascidians offer a unique advantage over other systems for determining the mechanism of fertilization. For example, sperm trigger two phases of Ca²⁺ oscillations that are all waves in ascidians. The first of these Ca²⁺ waves begins at the point of sperm-egg fusion while a second phase of Ca²⁺ waves originates at a vegetal protrusion termed the contraction pole. In addition, cyclin B1-dependent kinase activity provides a form of positive feedback, maintaining the second phase of Ca²⁺ waves during meiosis and thereby ensuring meiotic exit. We therefore prepared cytosolic ascidian sperm extracts or MonoQ-fractionated ascidian sperm extracts from this urochordate to investigate if a Ca²⁺-releasing sperm-borne factor was responsible for egg activation. Spatially, ascidian sperm extract induced repetitive Ca²⁺ waves that mimicked the spatial pattern displayed during fertilization: all the second-phase Ca²⁺ waves originated at a vegetal protrusion termed the contraction pole (thus mimicking fertilisation). We also demonstrated that ascidian sperm extract-induced Ca²⁺ oscillations were maintained when CDK activity was elevated and MAP kinase activity was low, as found previously for spermtriggered Ca²⁺ oscillations. As would be predicted, large doses of ascidian sperm extract injected into prophasestage oocytes, lacking CDK activity, failed to induce any Ca²⁺ release even though they responded to microinjection of the Ca²⁺-releasing second messenger inositol 1,4,5-trisphosphate. Finally, since the Ca²⁺-releasing activity from Mono-Q fractionated ascidian sperm extract eluted predominantly as one fraction, this may imply that one factor is responsible for the Ca²⁺-releasing activity. These data support a model of egg activation whereby the sperm introduces a Ca²⁺-releasing cytosolic factor into the egg. We demonstrated that ascidian sperm contain a protein factor(s) that is regulated by the egg CDK activity and can trigger all the Ca²⁺ waves observed at fertilization with a spatial pattern that mimics those initiated by sperm
Consistency in Ground Potential Rise estimation utilizing Fall of Potential method data
No full textAnalyzing Fall of Potential (FOP) test data from a grounding system current injection test is the prevalent method used to determine Ground Potential Rise (GPR). Achievable tolerance in analyzing near ideal FOP results using recognized and alternative methods were assessed previously, whereas this paper investigates distortions by buried metallic systems, such as leaky cables and pipelines, based on both simulated and field data. To work correctly with "real" data, pre-conditioning FOP data may be necessary; removing "outliers" due to real world "pathologies" in the earthing system. Applying several "cost" functions to the methods created by the combination of conditioning schemes and FOP response models produced a significant number of estimation methods. To determine the most consistent estimation methods a methodology was developed which assessed all identified methods by comparing the estimates produced with the simulation result. This allowed the most consistent and accurate GPR estimation methods to be identified
Long-term observations of reinforcement corrosion for concrete elements exposed to the North Sea
No full textThere are some 1000 reinforced concrete pre-cast beam elements that have been exposed since 1943 to a harsh sea-spray environment immediately adjacent the North Sea at Arbroath, Scotland. Most (>90%) show no obvious signs of reinforcement corrosion. However, the few elements that were replaced, in about 1968 and in 1993, have nearly all resulted in severe longitudinal cracking and extensive reinforcement corrosion, despite the later concretes being superficially of better quality than the original 1943 concrete. This paper will report statistics for maximum crack width for each of the three concrete populations, based on measurements made in 2004 and in 2006, as well as in-situ and laboratory measurements that indicate the 1943 concrete shows contradictory properties, having both high permeability and high electrical resistivity. Also, the 1943 and 1993 concretes were found to have similar chloride profiles and similar chloride concentrations at the reinforcement bars, which, again, is inconsistent with the 1943 elements showing much less reinforcement corrosion than their later replacements. These observations, and some other un-reported cases in the literature, cast doubt on the conventional notion that durable reinforced concrete structures requires reduced concrete permeability, denser concretes or greater cover
Reconceptualising the philosophical foundations of health education with respect to the impact of food technology on human health
No full textIn recent years a considerable literature has accumulated to establish that western society is confronting a monumental crisis in health care. In the thesis that follows we shall see that the nature
of the growing crisis is multifaceted and includes scientific, socio-cultural and philosophical dimensions, all of which figure prominently in the way in which we educate people of all ages for
health. My aim in the first part of the thesis will be to explore and reflect upon a number of these facets, with an aim to showing that the epistemological framework they presuppose represents a
valuable but incomplete understanding of newly emerging health problems which are themselves, partly the outcome of the highly technologised societies in which we live.
Once this preliminary objective of the thesis has been completed, I shall contend in Part II of the thesis that one area of crisis which remains insufficiently understood is the relationship between food and nutrition. I deliberately use the word relationship between food and nutrition, because the traditional emphasis of such concerns within the context of health has focused primarily on nutrition, largely in the quantitative sense of encouraging people to obtain enough vitamins, minerals, proteins, carbohydrates and fats required to keep them healthy. My contention is that without broadening the discussion to encompass the relationship between food and nutrition, the answers we give to the quantitative questions are inevitably myopic and limited.
My goal in the third and final part of this thesis will be to make clear that in light of the importance of the connection we have with our food and recent developments made in the philosophy of quantum mechanics, an exciting new discipline is emerging which Professor Ronald S. Laura has called the ‘Metaphysics of Food’. As part of my elaboration of this area, I shall weave together strands of insight from the research of Professor Laura and Dr. Masaru Emoto, two major
pioneers in advancing this field of knowledge.
Professor Laura’s theory of ‘participatory consciousness', drawn from his elaboration of quantum entanglement and his theory of ‘empathetic epistemology’ provides a fruitful conceptual framework, I shall argue, for the philosophical elucidation of Emoto’s research on the metaphysics of vii water. Using the confluent theoretical interpretative heuristics of Laura and Emoto, my objective will
be to argue that in principle, the foods we eat can themselves be impacted favourably or adversely in health terms by entanglements of consciousness which in turn affect our own health in subtle but
important ways.
Although the articulation of the pedagogic implications of this insight would be beyond the remit of this Master Thesis, a conceptual foundation will have been laid here upon which a new edifice for further research at the doctoral level can be built
Effectiveness of mindfulness interventions for parents of children and adolescents diagnosed with chronic conditions: a systematic review and meta-analysis
No full textThe ongoing stress associated with managing a child's chronic condition often results in compromised mental health and quality of life for parents. Mindfulness and Acceptance-based intervention (MAIs). MAIs are increasingly being suggested as potential means to alleviate these adverse effects. Despite the growing body of research, no previous studies have systematically synthesized the evidence supporting the benefits of MAIs for parents of children and adolescents diagnosed with chronic conditions. To address this gap, this study presents a comprehensive systematic review and meta-analysis assessing the effectiveness of MAIs in enhancing parental mental well-being in this population. Peer-reviewed journal articles of mindfulness interventions delivered to parents of children and adolescents (birth to 18 years of age) diagnosed with a chronic condition were eligible for inclusion. Following the PRISMA guidelines for systematic reviews, we electronically searched PsycINFO, MEDLINE, Scopus, CINAHL, Psychological and Behavioral Sciences Collection as well as undertaking hand searches, which resulted in the inclusion of twenty-two studies published between 2006 and 2023. These studies collectively analysed 1,463 parents of children with chronic health conditions. The Joanna Briggs Institute Critical Appraisal checklists were used to assess the methodological quality of included articles. The results suggest that when compared to a control condition, mindfulness-based and Acceptance and Commitment Therapy (ACT) based interventions were effective in decreasing parental stress and depression. However, there was no significant effect on reducing anxiety. Based on these findings, we discussed considerations for implementing interventions and identified areas which warrant further research
The phytoremediation of PFAS contaminated soil using Cannabis sativa L. (hemp) plants
No full textPoly and Per-fluoroalkyl substances (PFAS) are a class of persistent organic pollutants (POPs) that pose a significant threat to the health of communities and ecological systems. They are released into soil and water systems as a consequence of their use in Aqueous Fire Fighting Foams (AFF), as waste from plastics or semiconductor manufacturing and as leachate from PFAS-contaminated landfill. PFAS do not fully decay naturally. Current soil remediation techniques are ill-equipped to remediate the large volumes of soil currently impacted by PFAS. Plants have long been used to remediate heavy metals and other POPs, however the ability for plants to remediate PFAS contaminated soil is poorly understood. While a large catalogue of plants have been investigated for their ability to remediate PFAS, Cannabis sativa is underrepresented in the literature. The effect of growth duration and the concomitant changes to plant physiology on PFAS uptake into plants and removal from soil is also poorly understood. Any potential temporal effects on PFAS uptake will be investigated in both individual plant components and in the contaminated soil. The soil will be investigated at each time point using multi-point sampling to develop a complete PFAS concentration profile. It was found that the uptake of PFAS into plants occurred over two distinct phases, rapid uptake during vegetative growth and a slowed uptake during flowering. Potentially as a result of this, young male plants accumulated more than young female plants and vice versa for mature plants. Soil was found to contain less PFAS the longer plants were allowed to grow and despite the distance from the main root mass, PFAS concentration was lowest at the edge of the pots. PFAS removal being independent of root access, highlighted phytoremediation’s potential in large area applications. These results have demonstrated the importance of plant mass, rapid vegetative growth and gender ratio in C.sativa phytoremediation. It has also further improved our understanding of how PFAS migrates through soil during phytoremediation
Magnetic Resonance Imaging (MRI) only radiation therapy treatment planning for complex pelvic cancers
No full textRadiation oncology has a history of utilising advanced technology to improve the accuracy and efficiency of radiation treatments. As treatment techniques in radiation oncology progress, the need for greater visualisation of treatment and normal tissue structures is increased. Due to the improved tissue contrast and functional imaging capabilities, Magnetic Resonance Imaging (MRI) is becoming an increasingly favoured imaging modality, aiding in the advancement of radiation therapy treatments. MRI provides a greater visualisation of soft tissue targets and organs at risk (OAR) structures, as well as providing biological information on the target structures, far beyond what conventional computed tomography (CT) affords in radiation therapy treatment planning. An MRI-only workflow would be beneficial in the radiation therapy treatment planning process to reduce the errors associated with a multi-modal workflow. A major hurdle to the implementation of MRI in radiation therapy treatment planning, is the requirement for electron density and mass density attenuation information for dose calculation by the radiation therapy planning software. The grey scale units of the CT scan directly relate to the electron and mass density of the tissues, while the grey scale units of the MRI relate to the magnetic properties of the tissues. Therefore, in order to supersede the current application of CT and to utilise MRI solely for radiation therapy treatment planning, the electron density and mass density values of the tissues need to be estimated from the MRI scan. This process involves creating a synthetic CT (sCT) scan from the MRI scan, for treatment dose calculations. This thesis aimed to extend the application of previously successful sCT generation techniques, by applying to a wider pelvic treatment population, and a male and female cohort to accommodate MRI-only planning for a greater number of patients and treatment sites in the pelvic region. sCT generation methods applied to the same cohort of patients and assessed for dosimetric and anatomical accuracy. The work also aimed to apply a commercially available model of sCT generation for analysis, and to improve the dosimetric results using a derived density curve. This thesis extended the image guidance considerations for this cohort of patients, to validate the use of MRI for treatment image guidance. Collectively this body of work investigates the application of sCT creation for MRI only treatment planning for cancers of the pelvic region. This thesis addresses the research gaps of current studies which are limited to specific tumour regions, small cohort sizes, omission of the female population and provides a direct comparison of sCT techniques on the same population. This body of work builds on this MRI only planning concept to also address the use of the planning scan for daily treatment guidance
Natural versus anthropogenic sources of channel sand and fine gravel following integrated logging in the Letts Creek Catchment, NSW
No full textIntegrated logging immediately before a large storm in February 1992 caused extensive erosion of a feeder road in compartment 588/2 of Yambulla State Forest that allegedly supplied large amounts of sand and fine gravel to the downstream river channel where pools were supposedly infilled. However, most sediment eroded on the feeder road was actually stored on slopes and in filter strips before reaching channels. Subsequent soil conservation works rehabilitated the worst-eroded areas and they are still functioning effectively today. There is no direct connection of sand and fine gravel between the general harvest area and downstream channels because of many intervening sediment discontinuities, such as ponds, drainage lines, filter strips and floodouts. The catastrophic flood of February 1971 was the largest for at least the last 50 y in the Towamba catchment and caused substantial widening of lower Letts Creek and Wog Wog River. It also reorganised channel-spanning boulder steps on upper Letts Creek and a tributary in and immediately downstream of compartment 588/2, and may have caused gully erosion on the tributary of Letts Creek. Bank erosion supplied the sand and fine gravel in the river
bed of these headwater channels. A cluster of large floods between 1988 and 1992 exacerbated bank erosion in the two channels draining the logged compartment and infilled pools
Rationalization of quantitative tooth surface loss data for epidemiological research
No full textRecent UK National Surveys have revealed a high prevalence of tooth surface loss (TSL) because of erosion in Children and Adolescents. Although digital surface mapping and surface matching techniques may be used to quantify its progression with time, reporting TSL of individuals as a function of either mean depth loss or volume loss, this can be inadequate when transferred for epidemiological analysis. For example, a tooth displaying multiple regions of depth loss may deserve to be distinguished from a tooth with a single localised area of erosion, although the total volume change may be the same. A potential solution, explored here, is to use both the quantitative wear data and colour coded surface representation plots generated by such methods to arrive at a single categorical wear score [1 (≤5% of surface exhibits TSL) to 5 (≥51% of surface exhibits TSL)]. Two examiners independently categorized, on two separate occasions, the TSL of 53 maxillary incisors (26 subjects observed at baseline and 9 months). Their performance was assessed for intra- and inter-examiner agreement by; (i) calculating the percentage of agreement, (ii) a Wilcoxon matched-pairs signed rank test. Thereafter, in cases of disagreement a consensus score was allocated and a regression analysis of this versus the numerically derived percentage of the surface that had undergone change was carried out. Intra- and inter-examiner agreement was 100 and 88·7% respectively and for the inter-examiner comparison P = 0·0456. The categorical scores and the quantitative wear data correlated linearly (R = 0·82). It is concluded that the method used to rationalize the quantitative TSL data is both reproducible and reflects the quantitative data. Its use should be helpful in epidemiological TSL studies but continued vigilance is required in cases of examiner disagreement