347 research outputs found
Dataset in support of the Southampton doctoral thesis 'The boatbuilding tradition of the Aegean during the Late Neolithic – Early Bronze Age periods. Typological classification, digital reconstruction and seakeeping assessment'
No full textDataset in support of the Southampton doctoral thesis 'The boatbuilding tradition of the Aegean during the Late Neolithic – Early Bronze Age periods. Typological classification, digital reconstruction and seakeeping assessment' Appendix D - Resistance data and Appendix C - Stability data.
This dataset is focused on two appendices:
Appendix D - Resistance data. D.1 Resistance data produced by the author via MAXSURF Resistance for this thesis.
Appendix C - Stability data
C1. Stability data – STIX and ISO criteria, produced by the author via MAXSURF Stability software for his thesis
This research was funded by Southampton Marine and Maritime Institute (SMMI), Vice-Chancellor's Scholarship, Greek Archaeological Committee UK (GACUK)
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Epigenetic chromatin modifiers in barley: IV. The study of barley Polycomb group (PcG) genes during seed development and in response to external ABA
No full textAbstract Background Epigenetic phenomena have been associated with the regulation of active and silent chromatin states achieved by modifications of chromatin structure through DNA methylation, and histone post-translational modifications. The latter is accomplished, in part, through the action of PcG (Polycomb group) protein complexes which methylate nucleosomal histone tails at specific sites, ultimately leading to chromatin compaction and gene silencing. Different PcG complex variants operating during different developmental stages have been described in plants. In particular, the so-called FIE/MEA/FIS2 complex governs the expression of genes important in embryo and endosperm development in Arabidopsis. In our effort to understand the epigenetic mechanisms regulating seed development in barley (Hordeum vulgare), an agronomically important monocot plant cultivated for its endosperm, we set out to characterize the genes encoding barley PcG proteins. Results Four barley PcG gene homologues, named HvFIE, HvE(Z), HvSu(z)12a, and HvSu(z)12b were identified and structurally and phylogenetically characterized. The corresponding genes HvFIE, HvE(Z), HvSu(z)12a, and HvSu(z)12b were mapped onto barley chromosomes 7H, 4H, 2H and 5H, respectively. Expression analysis of the PcG genes revealed significant differences in gene expression among tissues and seed developmental stages and between barley cultivars with varying seed size. Furthermore, HvFIE and HvE(Z) gene expression was responsive to the abiotic stress-related hormone abscisic acid (ABA) known to be involved in seed maturation, dormancy and germination. Conclusion This study reports the first characterization of the PcG homologues, HvFIE, HvE(Z), HvSu(z)12a and HvSu(z)12b in barley. All genes co-localized with known chromosomal regions responsible for malting quality related traits, suggesting that they might be used for developing molecular markers to be applied in marker assisted selection. The PcG differential expression pattern in different tissues and seed developmental stages as well as in two barley cultivars with different seed size is suggestive of a role for these genes in barley seed development. HvFIE and HvE(Z) were also found to be induced by the plant hormone ABA implying an association with ABA-mediated processes during seed development, germination and stress response.</p
Causal deep learning on images
No full textUnderstanding cause-effect relationships is paramount in data-driven decision-making. Causality offers tools to investigate how systems react to interventions, such as predicting outcomes following treatments. Quantifying intervention effects enables actionable, robust decisions, even with confounding factors. However, foundational causality studies focus on low-dimensional data and linear relationships. Deriving causal insights from high-dimensional and unstructured data, like images, audio, text, or genomics, remains challenging due to the complexity of these relationships. Conversely, deep learning has shown success in predictive tasks over high-dimensional data. Deep learning uses multiple layers of neural networks to process information. Traditional deep learning does not understand causal relationships, resulting in failure modes due to biases and domain shifts.
This thesis merges concepts from causality and deep learning to overcome the main weaknesses of each field. The aim is to facilitate robust decision-making using high-dimensional and unstructured data. We divide causal deep learning into three main areas of research: (1) causal reasoning, analysing system reactions to interventions with known variable relationships; (2) causal discovery, identifying these relationships given a set of variables; and (3) causal representation learning, utilising causal techniques to enhance deep representations. The main contributions involve using neural networks trained via the score of distributions (or denoising diffusion) for processing high-dimensional variables.
We apply our methods to medical imaging where possible. In healthcare, understanding high-dimensional causal relationships is vital. Our techniques enable lesion localisation in brain scans, creating synthetic images without biases, understanding causal structures in high-dimensional datasets, and learning of causally ordered latent spaces. This thesis merges causality with deep learning, unlocking robust decision-making for high-dimensional data
Aging of Asphalt Symposium: Delft, the Netherlands September 17th 2014
No full textTechnical specifications for the asphalt concrete properties are developed to be able to specify mixtures that will perform well in pavement applications. Being able to identify and determine properties related to pavement performance in practice is crucial for both road authorities and contractors, since it allows for design and risk management by determining design life times and reliability. However, the properties of Asphalt Concrete (AC) change over its lifetime and since most pavement layers last for a decade or more these changes are crucial in determining the performance in practice.For many of the standard materials the effect of aging is implicitly dealt with in the safety factors that also account for other effects such as the variation rest periods/healing and variations in traffic and weather in the design methods and specifications. Rapid changes in the materials used (increasing percentages reclaimed asphalt, bio‐bitumen, rejuvenators, waste materials) and in theproduction of both bitumen (new refining methods resulting in different composition of bitumen) and asphalt concrete itself (warm mix asphalt, porous asphalt concrete, rubber asphalt mixtures) lead to increased uncertainty in the effects of aging. As a result, the uncertainties in pavement performance increase, which means the prediction of maintenance and the necessary budgets is getting more inaccurate.In order to maintain the ability to reliably design and maintain pavements and determine the most cost‐effective solutions for a given situation, a better understanding of the aging processes and objective methods to take into account aging effects on material properties is needed. This need is widely recognized, in the USA the Mechanical Empirical Design Guide takes aging into account through aging tests on the bitumen used and in Europe CEN TC227 works on establishing a method to assess the aging sensitivity of asphalt mixtures. This symposium aimed at combining the existing information and insights from ongoing research into recommendations that will allow thedevelopment of methods to determine aging sensitivity and the impact on pavement performance, facilitate the exchange of obtained data and stimulate further developments The resulting recommendations are: Do make long term aging sensitivity of binders part of the bitumen standards and take the results from the aging sensitivity of binders into consideration when assessing AC properties.Be aware that RTFOT testing only gives an indication of the sensitivity of a penetration grade binder to aging during hot mix production and construction, it doesn’t work for hard grades, PMB’s or warm mixes. Because of the many variables involved, developing one test method to characterise aging sensitivity seems improbable. However, PAV aging is both practical and, if tests at various conditions are carried out, able to give kinematic properties. A PAV protocol for testing at two temperatures and time intervals could provide practical characterisation information forthe short term and enable model development and validation on the long term. RCAT and other aging procedures could also be used in this sense, but considering the availability of equipment and the wide spread experience, PAV is the best candidate to allow the rapid development of international experience with the approach.Based on the current standards and the work presented during the symposium, PAV tests at 90 and 100 degrees Celsius and 20 and 40 hours, respectively, are suggested. The low values for temperature and duration are based on the current standards and fit both the USA and CEN procedure, while research shows that after 40 hours at 100 degrees the chemical (FTIR) and rheological (DSR) properties of laboratory aged and field samples were similar (Section6.5 and 8.5). At 100oC the temperature is low enough so that the effect of secondary reactions is negligible. As such, these conditions are appropriate for kinetic expressions for in service pavement performance. For high temperature processes and possibly also for repeated recycling (very long term) more sophisticated methods are needed. Set‐up and maintain field monitoring of temperature and UV radiation in various climate zones, as well as regular sampling over time and height to keep checking the predicted changes (from both tests and models), versus the actual changes in properties order to ensure reliability of the data as well as the applicability for pavement performance prediction. In setting up field tests, it is important to get both the composition of the virgin bitumen and the composition after mixing, transport and placement in the pavement. Thesecompositions provide the starting points from both the material and pavement structure point of view and can be used to assess the development of aging products over time. There is a lot of discussion about the impact of binder recovery methods on the observed composition, so until it is proven that this does not have an influence, for comparisons the same recovery method should be used. Set up a coordination and support action on AC‐Aging to continue to exchange information and experiences, both in research and in construction projects. develop an IR testing protocol, to facilitate the exchange of results and information. Compare the bitumen composition that is found through various recovery methods toestablish if there is an effect and if so, develop a procedure to address this. To further understanding of aging, a Round Robin test on the differences in test conditions between US and EU, allowing better access to each other’s data and knowledge would be seful. When developing aging tests for AC, it would be useful to look at the US experience. As long as there is no fundamentally correct method for assessing the aging, it would be preferable to standardize it as much as possible in order to allow cooperation and exchange of data.Pavement Engineerin
Τhe Role of a Gibberellin 20-Oxidase Gene in Fruit Development in Pepper (Capsicum annuum)
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Ageing Behavior of Porous and Dense Asphalt Mixtures in the Field
No full textBitumen ageing is one of the principal factors causing the deterioration of asphalt pavements. As bitumen ages, the pavement loses its ability to relax stresses during loading/unloading and thermal cooling process, thus the risk of cracking increases. Oxidation and ultraviolet (UV) radiation are believed to be the main factors that can cause bitumen ageing during pavement service life. The aim of this study is to evaluate the mechanical behavior of porous and dense asphalt pavements during field ageing. Pavement test sections were constructed in 2014 and are being exposed to actual environmental conditions since then. To investigate the effect of UV radiation on ageing, UV reflective glass-plates were utilized to cover part of the pavement surface. To study the evolution of the pavements’ mechanical properties, asphalt cores were collected from the test sections periodically (at one-year intervals). The changes in the stiffness modulus of the mixtures were determined via cyclic indirect tensile tests. The results show that the effect of mineral aggregate packing, and hence of air-void distribution and connectivity, on the ageing sensitivity (both thermal and UV ageing sensitivity) of the pavements with time was found to be significant, as the changes of the stiffness of the porous mixtures were greater than that of dense mixtures.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Pavement Engineerin
Crumb rubber modified bitumen: Experimental characterization and modelling
No full textA sustainable pavement, which can minimize environmental impacts through the reduction of energy consumption, natural resources and associated emissions while meeting all performance conditions and standards, is in urgent need to combat the climate change. The current scenario of depleting crude oil, reduced quarry zones, and stringent environmental regulations has driven the use of waste materials and by-products in pavement applications. The utilization of crumb rubber from scrap tires for bitumen modification has become a common engineering practice since last century...Pavement Engineerin
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