7440 research outputs found
Sort by
Explaining imperfect ant mimicry
No full textTheoretical thesis.Bibliography: pages 56-64.1. Can developmental constraints, multiple models or relaxed selection explain imperfect mimicry? -- 2. Mimicry in motion: can behaviour compensate for poor morphological mimicry?Many species have evolved to mimic unprofitable models in order to avoid attack by predators. Mimics are most likely to deceive predators if they resemble their models very accurately, so the existence of many poor mimics is a puzzle. Currently, there is no shortage of hypotheses to explain the persistence of poor mimicry, but comparative evidence supporting them is largely lacking. In this study, I first review the literature regarding imperfect mimicry hypotheses and evidence, then address several hypotheses using ant mimics as study subjects. Ants are avoided by many predators, and ant mimics are widespread, abundant and diverse, making them effective subjects for mimicry studies. Utilising morphometric analysis to quantify body shapes and statistical analysis of walking trajectories as a measure of behavioural mimicry, the accuracy and variation of mimicry in ant-mimicking spiders is compared with that of ant-mimicking insects, and used to assess several imperfect mimicry hypotheses. We find some evidence that poor visual mimicry in spiders may result from developmental constraints, but no evidence that selection is relaxed for smaller mimics. Additionally, ant-like walking neither reinforces nor compensates for visual mimetic accuracy.1 online resource (64 pages : illustrations, map
Molecular mechanisms of nutrient uptake in marine microbial ecosystems
No full textTheoretical thesis.Bibliography: pages 52-61Chapter 1. Introduction -- Chapter 2. Experimental design, materials and methods -- Chapter 3. Expression, purification, and characterisation of cynobacterial PBPs -- Chapter 4. DiscussionUnicellular cyanobacteria are highly diverse, abundant and ubiquitous in the global oceans. Investigating the range and magnitude of organic compound transport in these organisms will help define pathways of energy and nutrient cycling in marine ecosystems.ABC membrane transport systems utilise a periplasmic binding protein (PBP) to confer substrate specificity. These PBPs are thus ideal targets to study the ecological significance of predicted amino acid transporters. Twelve PBPs were investigated that group into three orthologous gene clusters with putative ligands: branched-chain amino acids;carbohydrates and amino acids; or amino acids, based on homology predictions.A high-throughput recombinant expression strategy enabled a protein from each cluster to be successfully heterologously expressed and purified. Differential scanning fluorimetry (DSF) analysis revealed that "SW840" binds a broad range of amino acids, aspredicted. "SC634" on the other hand was found to bind with formate and formaldehyde, not the predicted ligand of branched-chain amino acids.This work provides important evidence of the specific ligand binding characteristics for each transporter. Future work to elucidate the cellular fate of these compounds is proposed. The ability of cyanobacteria, often considered to be obligatory phototrophs, tosalvage organic compounds may provide a competitive advantage in marine ecosystems.1 online resource (vi, 64 pages) illustration
Primary EFL teachers' oral corrective feedback in Vietnam: beliefs and practices
No full textTheoretical thesis.Bibliography: pages 66-75.Chapter 1. Introduction -- Chapter 2. Literature review -- Chapter 3. Methodology -- Chapter 4. Results -- Chapter 5. Discussion -- Chapter 6. Conclusions -- References -- Appendices.This study explores teachers’ beliefs and practices about oral corrective feedback in English as a foreign language (EFL) classrooms in primary schools in Vietnam. It is an interesting context to explore teacher cognition and practice because many teachers were actually trained as secondary teachers, but they are currently teaching at primary schools. The study was conducted at 6 public primary schools in a small city in Vietnam. The data consist of interviews with 6 teachers and 24 classroom observations.The study shows that these teachers endorsed the benefits of oral corrective feedback, and they claimed to use prompts to elicit learner repair. They nominated teaching experience as the main factor shaping their beliefs and practices about oral corrective feedback.These claims were partially consistent with their classroom practices, but more incongruence was found. In accordance with their claims, these teachers normally used delayed feedback, and pronunciation errors were the most frequent feedback target. Contrary to their stated beliefs, the teachers used more reformulations than prompts, limiting learner repair. The linguistic patterns of these teachers’ feedback are different from the expected standard expressions. This suggests that the teachers’ problematic classroom discourse skills led to such a mismatch.These findings can be a valuable reference for in-service Vietnamese primary EFL teachers to reflect on their own beliefs and practices about oral corrective feedback. This study suggests that professional development programmes for such teachers incorporate workshops on classroom skills of corrective feedback. Further studies measuring the impact of teacher English proficiency and pedagogical skills on the effectiveness of corrective feedback are needed.Mode of access: World wide web1 online resource (vii, 133 pages) table
Archaeology of logos
No full textTheoretical thesis.Bibliography: pages 61-62.The thesis aims to examine the Ancient Greek heritage and its echoes in the works of Edmund Husserl and Maurice Merleau-Ponty, I undertake this inquiry by focusing on the issue raised by Husserl in his later writings, of the historicity of rationality, and by tracing the legacy of core concepts, such as logos, physis, arche and telos. The first part critically reconstructs the arguments behind Husserl’s teleological characterisation of European humanity. The second part studies the development of a post-Husserlian project in the work of Merleau-Ponty. I focus especially on his account of Husserl’s Origin of Geometry, and the related sections in Eye and Mind, and The Visible and The Invisible. I try to defend the suggestion that key features of Merleau-Ponty’s post-Husserlian project come into sharper relief if they are read within a framework that relates his thinking to Pre-Socratic themes, notably through his novel use of some of the key concepts mentioned above.Mode of access: World wide web1 online resource (62 pages
Analysis of electricity supply data
No full textEmpirical thesis.Bibliography: pages 89-91.1. Introduction -- 2. Current approaches to NILM and background information -- 3. State changes in power space and power transient features -- 4. Technologies and hardware used -- 5. NILM system design and implementation -- 6. Testing and discussion -- 7. Conclusions and future work -- 8. Abbreviations -- Appendix -- Bibliography.Determining the power consumption and switiching times of a building or households connected loads and appliances is crucial for energy analysis and optimisation, which is increasingly becoming more relevant in today's society due to the implementation of renewable technologies and soaring energy prices. This project looks to analyse current techniques for determining electrical load characteristics from an aggregate electrical source such as a building's electrical mains. In this project a test and simulation setup is constructed. Using a non-intrusive power metering device aggregate electrical power data is collected and analysed using the techniques explored to determine individual load characteristics and to autonomously determine when individual loads are switched on and off. This is done so that individual appliances' power consumption can be estimated, or appliance switching times used for automation purposes.Mode of access: World wide web.1 online resource (xvii, 91 pages diagrams, graphs, tables
New perspectives for dating Egyptian false doors and funerary stelae of the First Intermediate Period
No full textTheoretical thesis.Bibliography: pages 226-268.Volume 1, Part 1, Studying First Intermediate Period false doors and stelae -- Introduction -- Previous scholarship -- Survey of the First Intermediate Period -- Part 2, Dating the material -- Dating First Intermediate Period false doors and stelae -- Hybrid false door-stelae -- Wedjat-eyes -- 'Killing of the glyphs' -- Owner holding a bow and arrows -- Writing of the 'revered one' -- Summary and conclusions -- Bibliography -- Volume 2, Appendices and plates.The First Intermediate Period is the modern name used by scholars to describe the intervening period between the Old and Middle Kingdoms. Poorly defined in absolute chronological terms, the First Intermediate Period is typically dismissed as a period of disunity and decline given it was the first time in Egyptian history when there was a collapse in central kingship and a shift in administration from the Memphite capital to the provinces. In order to help cast new light on the First Intermediate Period, therefore, this study focuses on the dating of 612 Egyptian false doors and funerary stelae from the reigns of King Pepy II to Nebhepetre Mentuhotep II. It does this through the application of five architectural, iconographic and palaeographic dating criteria, in the context of other material culture, to show how it might be possible to establish a dating typology – one which can serve as a new chronological benchmark for dating other objects and events of the Period. The thesis is arranged into two Volumes: Volume One presents the purpose of the study, defines the key terms, discusses the research problems and methodology and holistically assesses the corpus of material in terms of its frequency and distribution. It also critically appraises the existing literature and provides a clear historical overview. This is followed by the main dating analysis whereby each of thefive dating criteria are discussed in detail, including: (1) the hybrid false door-stelae; (2) the wedjat-eyes motif; (3) the ‘killing of the glyphs’ (including the mutilation of the viper sign and the phonetic writing of Anubis); (4) the owner holding a bow and sheaf of arrows and, (5) the writing of the epithet the ‘revered one’. Volume Two presents the complete corpus of First Intermediate Period false doors and stelae employed in the study, as well as some further appendices and select coloured plates. Two main outcomes can be concluded from the study: 1. That a relative dating typology can be established for particular groupings of First Intermediate Period false doors and stelae based on some of the dating criteria applied here and; 2. The application of the abovementioned criteria can reveal new ways of understanding and interpreting the cultural, religious, social and political landscapes of the First Intermediate Period, in particular the Theban-Herakleopolitan wars.1 online resource (xxvi, 651 pages
Superstition, sin and subversion: maritime culture in Constantinople and port cities of the East in Late Antiquity and Early Byzantium
No full textTheoretical thesis.Bibliography: pages 272-303.Introduction -- 1. The maritime world of Constantinople and the Eastern Roman Empire -- 2. On the fringes of society: the men who sailed the seas of Byzantium -- 3. Perception versus reality: the maritime community of outsiders -- 4. Superstition: religion, ritual and belief in the maritime community -- 5. Sin: the (anti-)social life of the maritime crowd and the lower-class leisure industry -- 6. Subversion: the role of the maritime crowd in social, political and religious unrest -- Conclusion.The importance of sea-going trade to the Late Antique economy is widely recognised in scholarship, yet the people associated with this trade and its social impact are often overlooked. The sea played a significant social and cultural role in the lives, traditions and psyche of those living in and around the Mediterranean and Black Sea regions. In large port cities like Constantinople and Alexandria, the maritime community must have had a substantial effect on everyday life, culture and social dynamics. This thesis examines the people and professions which comprised maritime society. It looks at leisure establishments such as taverns, theatres, baths and brothels, and at those who worked in them, servicing mariners when they were onshore. Civil and maritime legislation, literary sources and archaeological evidence are investigated to conduct a sociological study of maritime society, its associated culture, and its influence on general society in the fourth to seventh centuries. The idea that members of the maritime community were collectively viewed as outsiders on the periphery of society is explored. So too is the role of sailors and sea-merchants in lower-class leisure culture in urban centres. Distinguishing features of maritime sub-culture are considered, including seafaring superstitions, traditions and practices. The role of maritime society in episodes of unrest is also investigated. Mariners provided strong-arm support for religious and political leaders, displayed a natural propensity for trouble, and were the perfect recruits for a range of uprisings. Importantly, the maritime community also facilitated communication networks that enabled institutions like the Church and circus factions to function as successful empire-wide organisations. Maritime sub-culture may have been an undesirable element of society, yet it was a significant one. It helped to shape the nature of Late Antique and Early Byzantine society and culture; even in Constantinople, the Queen of Cities.1 online resource (303 pages : illustrations, maps
Bank's justice in CSR disclosure practices: does the religion of Islam matter?
No full textEmpirical thesis.Bibliography: pages 55-62.Chapter One. Introduction -- Chapter Two. Literature review, theoretical framework and hypotheses development -- Chapter Three. Methodology -- Chapter Four. Results and discussions -- Chapter Five. Conclusion, implications, contributions, limitations and future research -- References -- Appendix.Using content analysis, this study aims to empirically investigate the extent to which Islamic banks and Islamic Windows practice corporate social reporting (CSR) disclosure implied by Shari'ah principles from an Islamic society's perspective. Islamic banks are independent banks founded on Shari'ah principles and offer Islamic products and services, while Islamic Windows are a separate department of conventional banks providing Islamic products and services to society due to increased worldwide demand. Specifically, the study compares the extent of these disclosure practices between Islamic banks and Islamic Windows. It further compares the extent of CSR disclosure practices in a cross-cultural context between Islamic banks in Pakistan and conventional banks in Australia to identify whether Islam influences CSR disclosure practices of Islamic banks. CSR disclosures are measured using Ethical Identity Index (EII) and consider only disclosed information in annual reports rather than other reporting instruments. By incorporating Neo-institutional theory (NIT), this study provides insights into whether Islamic banks are seeking legitimacy through CSR disclosure practices in a country where Islamic ethical values as informal institutions have a significant influence on operational activities. The findings suggest that Islamic Windows are disclosing less compared to Islamic banks regarding social and ethical issues, which may risk their corporate and ethical reputation. Moreover, the results reveal that Islamic banks are not communicating any more CSR information than conventional banks, suggesting that Islam does not influence their business practices. The results will assist in understanding disclosure practices by Islamic banks and Islamic Windows in a distinctive social-cultural context where Islam is the dominant religion and influences CSR disclosure practices.Mode of access: World wide web1 online resource (73 pages) table
Investigating the impact of dietary fibre on the gut microbiota
No full textEmpirical thesis.Includes bibliographical references.Chapter 1. Introduction -- Chapter 2. Fibre supplements derived from sugarcane stem, wheat dextrin and psyllium husk have different in vitro effects on the gut microbiota -- Chapter 3. Effect of fibre supplementation on high fat diet-induced changes in the mouse gut microbiota -- Chapter 4. Effect of weekly overnight fasting and fibre supplementation on the gut microbiota of mice fed a high fat diet -- Chapter 5. Cereal products derived from wheat, sorghum, rice and oats alter the infant gut microbiota in vitro -- Chapter 6. Conclusions and future directions -- Appendices.Diets low in complex polysaccharides have been shown to perturb the gut microbiota-host relationship, and thus impact host health. As evidence supporting this hypothesis continues to grow, therapeutic modulation of the gut microbiota through supplementation of complex polysaccharides for preventing or treating diseases has gained significant scientific and commercial interest. Several supplements in the form of dietary fibre or prebiotics are marketed commercially for this purpose. However, only limited work has been conducted to scientifically evaluate the ability of these products to alter the gut microbiota and improve host health.In this work, we investigated the impact of commercially available dietary fibre and cereal products on the gut microbiota and metabolite production. We used an in vitro adult digestive and gut microbiota model system and a high fat diet fed mouse model to examine the effect of dietary fibre supplementation on the gut microbiota, metabolites and host physiology. Using an in vitro infant digestive and gut microbiota model system we investigated the impact of cereal products on the infant gut microbiota and metabolites.Our results demonstrated significant shifts in the overall gut microbiota community structure upon addition of each product. The abundance of various bacterial taxa associated with fibre digestion and anti-inflammatory capabilities increased with fibre additions. However, the specific nature of the alterations was product-dependent. Fibre supplementation in mice ameliorated high fat diet-induced changes in the abundance of specific gut bacteria, whilst no significant changes in the glucose clearance or body weight were observed. Further, we demonstrated significant differences in the gut microbiota response to a high fat diet and fibre supplementation upon weekly overnight fasting in mice. The product-dependent impact on the gut microbiota and metabolites highlights the need for stringent scientific evaluation of commercial fibre products for their effect on the gut microbiota and host physiology.Mode of access: World wide web1 online resource (xxi, 250 pages) illustrations (some colour
Nano-scale Raman thermometry of diamond
No full textTheoretical thesis.Bibliography: pages 47-54.1. Introduction -- 2. Raman thermometry -- 3. Methodology -- 4. Raman thermometry with diamond -- 5. Outlook.Raman spectroscopy is well established over a broad range of interdisciplinary applications, which include optical imaging, crystallographic probing, spectroscopy and thermometry. The basis of this thesis is Raman thermometry with nanodiamond, i.e. nano-scale diamond crystals, and its application for characterising integrated transistor circuits. Firstly, an extensive review of Raman scattering, spectroscopy, thermometry and diamond properties is developed. Then, attention is focused on the experimental implementation of Raman thermometry with bulk and 250 nm diamond crystals. As an initial experimental step and under well-controlled conditions, the temperature dependence of the Raman line shift and width is characterised. In a second step, a preliminary measurement on a real semiconductor chip is carried out. The results open up a path towards the practical and robust implementation of a nanoscale temperature sensor for device characterisation.1 online resource (vii, 54 pages) colour illustration