32151 research outputs found
Sort by
Understanding state weakness in the Middle East and North Africa
No full textA macro overview of state formation in the Middle East that explores the paradox that highly resilient regimes and weak states coexist in much of the area. It deploys historical sociological approaches to state formation including the notion of degrees of statehood; and the origins of weak statehood in the export of the Westphalian state from the core manifested in territory-identity incongruence, economic dependency, the protection of weak states from absorption and telescoped developmental challenges. It explores the causes of variations within the region in degrees of statehood and the dominant trajectory of a bell shaped curve over time in which the agency of regime builders and changing world structural conditions have both mattered for degrees of statehood. Finally, the state weakening and partial failure attendant on the Arab uprisings is explored
From whole bodies to single cells : a guide to transcriptomic approaches for ecology and evolutionary biology
Get PDFFunding: The authors were assisted by a Special Topics Network (STN) grant from the European Society for Evolutionary Biology (ESEB) to facilitate networking of the European Drosophila Population Genomics consortium (DrosEU; https://droseu.net/). SG and NP are supported by a Deutsche Forschungsgemeinschaft grant (GR 4495/4-1, PO 1648/7-1, PO 1648/4-1). MGR is supported by Natural Environment Research Council, UK (NE/V001566/1). CS is supported by the Austrian Science Funds (P32935, P33734, W1225). TF is supported by the Swiss National Science Foundation (310030_219283, FZEB-0-214654, 31003A-182262). JG is supported by grant PID2020-115874GB-I00 funded by MCIN/AEI/10.13039/501100011033 and from grant 2021 SGR 00417 funded by Departament de Recerca i Universitats, Generalitat de Catalunya. MK was supported by the grant 322980 from The Research Council of Finland.RNA sequencing (RNAseq) methodology has experienced a burst of technological developments in the last decade, which has opened up opportunities for studying the mechanisms of adaptation to environmental factors at both the organismal and cellular level. Selecting the most suitable experimental approach for specific research questions and model systems can, however, be a challenge and researchers in ecology and evolution are commonly faced with the choice of whether to study gene expression variation in whole bodies, specific tissues, and/or single cells. A wide range of sometimes polarised opinions exists over which approach is best. Here, we highlight the advantages and disadvantages of each of these approaches to provide a guide to help researchers make informed decisions and maximise the power of their study. Using illustrative examples of various ecological and evolutionary research questions, we guide the readers through the different RNAseq approaches and help them identify the most suitable design for their own projects.Peer reviewe
Pubertal timing and mental health. Understanding social and genetic determinants
Get PDFBackground: Previous research has found associations between poor mental health and early puberty (EP). Genetically informed studies provide conflicting evidence on whether the association between mental health and EP is transient / confounded by variables like Body Mass Index (BMI).
Methods: The thesis is based on two large studies: a) The International Health Behaviour in School-Aged Children Study, providing cross-sectional evidence on pubertal timing and life circumstances in 36 countries and regions; b) The Avon Longitudinal Study on Parents and Children with longitudinal and genetic data on puberty and psychiatric impairment. The thesis relies on longitudinal and auto- regressive modelling, genetic correlations, Mendelian Randomization, as well as cross-cultural associations to elucidate the research question.
Results: 1) The study verifies the so-called “Stepfather-effect” which is measurable on a cross-cultural level (girls in families with stepfathers experience earlier puberty). However, some of these differences can be explained by differences in BMI and lifestyle between different families. 2) It is shown that there is no evidence for prepubertal psychiatric impairment caused by early puberty. Mendelian Randomization suggests a peripubertal, but no prepubertal effect in girls. 3) Genetic correlations reveal no genetic overlap of EP with mental health, but with BMI and socioeconomic traits; 4) Cross-culturally, EP is related to higher life expectancy and an overall lower burden of disease for psychiatric disorders. Overall, EP in girls is more prevalent in the lower socioeconomic strata mainly in English-speaking and Northern European countries.
Discussion: The study contradicts an “accentuation hypothesis” that prepubertal differences in psychopathology accentuate after puberty, because in girls they are not present pre-pubertally and in boys they diminish over time. The thesis makes a case for understanding pubertal timing as a socioeconomic variable because of its strong association with BMI. To be informative, studies need to disentangle the biological from the socioeconomic signal
Cultivating Englishness : national identity in Middle English romance
No full textThis thesis examines the role of Middle English romance in the construction of English national identity. While nations and nationalism are often considered to have emerged in the modern period, recent years have witnessed an increasing interest in the study of medieval literature as evidence of a sense of national identity. I argue that Middle English romances participated in nation formation as a space of ‘symbolic cultivation’, i.e. the creation and cultivation of distinct myths, traditions and symbols that form the cultural core of modern nations. The first four chapters examine romances belonging to the ‘Matter of England’ group: Richard Coer de Lion, Sir Beves of Hampton, Havelok the Dane, and King Horn. The fifth chapter investigates an Arthurian romance, Sir Gawain and the Carle of Carlisle. Finally, the last section of the thesis examines The Bruce, a poem in Early Scots, as a point of comparison. I argue that the romances were often involved in a complex process of identity assertion that questioned the nature and limits of Englishness, reflecting the social and political concerns of the period
Leveraging foundation models for enhanced detection of colorectal cancer biomarkers in small datasets
Get PDFFunding: This work is supported in part by the Industrial Centre for AI Research in Digital Diagnostics (iCAIRD) which is funded by Innovate UK on behalf of UK Research and Innovation (UKRI) (project number 104690)Colorectal cancer is the second leading cause of cancer death worldwide. Its high incidence and mortality rate highlight the critical role of advanced diagnostics and early detection methods. Advancements in computational pathology can significantly enhance diagnostic precision and treatment personalisation, ultimately improving patient outcomes. Hospitals and labs globally are transitioning toward routine whole slide image (WSI) digitisation. This digitisation process generates large volumes of data, offering an opportunity to enhance diagnostic capabilities through the use of machine learning techniques such as weakly supervised learning and self supervised learning (SSL). This study evaluates the performance of state-of-the-art self-supervised learning (SSL) feature extractor foundation models—CTransPath, Phikon, and UNI—against a pretrained ResNet-50, which serves as a benchmark. Our Transformer network analyses these feature vectors, focusing on their efficacy in predicting key colorectal cancer biomarkers within a small dataset containing 423 WSIs with only 8% of cases exhibiting mismatch repair (MMR) deficiency. The CTransPath model achieved the highest validation AUROC of 0.9466 for MMR classification but exhibited a test AUROC of 0.6880, demonstrating significant variability. In contrast, the UNI model demonstrated greater consistency and robustness, achieving a test AUROC of 0.7136, which additionally represents a 6.3% improvement over ResNet-50’s test AUROC of 0.6709. The results highlight the feasibility of using advanced machine learning models with smaller, sparsely annotated datasets, though the variability noted in some models underscores the challenges at the edge of data scarcity. Code and experimental framework available at https://github.com/CraigMyles/SurGen-CRC-Arena
TESS hunt for young and maturing exoplanets (THYME). X. A two-planet system in the 210 Myr MELANGE-5 association
Get PDFFunding: P.C.T. was supported by an NSF Graduate Research Fellowship (DGE-1650116), the NC Space Grant Graduate Research Fellowship, the Zonta International Amelia Earhart Fellowship, and the Jack Kent Cooke Foundation Graduate Scholarship. A.W.M. was supported by grants from the NSF CAREER program (AST-2143763) and NASA’s exoplanet research program (XRP 80NSSC21K0393). M.G.B. was supported by an NSF Graduate Research Fellowship (DGE2040435) and the NC Space Grant Graduate Research Fellowship. F.J.P. acknowledges financial support from the grant CEX2021-001131-S funded by MCIN/AEI/ 10.13039/ 501100011033 and through projects PID2019-109522GB-C52 and PID2022-137241NB-C43. This research also received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 803193/BEBOP) and from the Science and Technology Facilities Council (STFC; grant No. ST/S00193X/1). The postdoctoral fellowship of K.B. is funded by F.R.S.-FNRS grant T.0109.20 and by the Francqui Foundation. K.A.C. acknowledges support from the TESS mission via subaward s3449 from MIT. M.K. acknowledges support from the MIT Kavli Institute as a Juan Carlos Torres Fellow. This publication benefits from the support of the French Community of Belgium in the context of the FRIA Doctoral Grant awarded to M.T.Young (<500 Myr) planets are critical to studying how planets form and evolve. Among these young planetary systems, multiplanet configurations are particularly useful, as they provide a means to control for variables within a system. Here, we report the discovery and characterization of a young planetary system, TOI-1224. We show that the planet host resides within a young population we denote as MELANGE-5. By employing a range of age-dating methods—isochrone fitting, lithium abundance analysis, gyrochronology, and Gaia excess variability—we estimate the age of MELANGE-5 to be 210 ± 27 Myr. MELANGE-5 is situated in close proximity to previously identified younger (80–110 Myr) associations, Crius 221 and Theia 424/Volans-Carina, motivating further work to map out the group boundaries. In addition to a planet candidate detected by the TESS pipeline and alerted as a TESS object of interest, TOI-1224 b, we identify a second planet, TOI-1224 c, using custom search tools optimized for young stars (Notch and LOCoR). We find that the planets are 2.10 ± 0.09 R⊕ and 2.88 ± 0.10 R⊕ and orbit their host star every 4.18 and 17.95 days, respectively. With their bright (K = 9.1 mag), small (R* = 0.44 R⊙), and cool (Teff = 3326 K) host star, these planets represent excellent candidates for atmospheric characterization with JWST.Peer reviewe
Associate/dissociate : allusive and elusive care in Veronica Ryan’s sculpture
Get PDFFunding: Research for this article has been supported by AHRC/UKRI fellowship AH/S004750/1.Reflecting on the experience of curating Veronica Ryan’s work for the 2021 exhibition Life Support: Forms of Care in Art and Activism at Glasgow Women’s Library, this essay contextualizes the artist’s recent sculptures in relation to the theories, philosophies, and ethics of care that have recently gained increasing prominence in artistic and curatorial practice. Drawing on the philosopher Virginia Held’s understanding of care as inherently intersubjective, it proposes that Ryan’s sculptures model a comparable understanding of caring relations through their associative yet ultimately elusive operations. Ryan is recognized for her use of abstracted organic forms, particularly seeds, pods, husks, and fruits. Since moving to New York from Britain in 1990 and developing a career between the two countries, Ryan has engaged with industrial and mass-produced receptacles, molds, and packing materials, an interest which has expanded to include fishing wire, plastic bottles, and take-away food containers, alongside textiles. Yet, although many of these elements remain identifiable, the resulting works delight in category confusion between organic and prefabricated, instigating uncanny textural effects that engender perceptual uncertainty. Their chains of allusion resist singular, fixed meanings, generating a continual back and forth of association and dissociation that constitutes a sustained meditation on care’s relational complexity.Peer reviewe
Monte Carlo simulation of intraoperative photodynamic therapy for glioblastoma : investigating dosimetric parameters and treatment efficacy
No full textThis thesis looks at using Monte Carlo radiative transfer (MCRT) to simulate the path and effect of light as it travels through biological tissue.
The increase in light-based skin treatments and medical technology has resulted in a need for detailed information on the penetration depth of light into skin. A 6-layer skin model is developed to simulate the propagation of light from 200 nm - 1000 nm into skin with Fitzpatrick photo-type I. The effect of varying stratum corneum thickness and light incident angle is investigated before looking at the lateral spread of a laser beam incident on the skins surface.
Photodynamic therapy (PDT) is a light based therapy currently used or being investigated to treat many different forms of cancer. The combination of treatment light, a photosensitising drug and oxygen result in a localised toxic effect that specifically targets
cancer cells. The MCRT code is used to develop a time dependant simulation of PDT, considering the treatment light fluence rate and local concentrations of photosensitiser and oxygen. This allows different PDT protocols to be simulated and compared.
Glioblastoma (GBM) is an aggressive and difficult to treat form of brain tumour. It has a low survival rate due to the tumours highly diffusive nature, resulting in a high rate of recurrence. A recent clinical trial aimed to increase this survival time by intraoperatively treating the resection cavity with PDT at the end of resection surgery to increase the extent of resection. The MCRT/PDT simulation is used to model this protocol and investigate the effect on tumour cell kill when varying several treatment parameters such as treatment time, light power and photosensitiser concentration. Finally, a heat transport simulation is also used to investigate the effect of intraoperative PDT treatment on the temperature of the surrounding brain tissues."This work was supported by ht UK Research and Innovation (UKRI) Engineering and Physical Sciences Research Council (EPSRC) Centre for Doctoral Training in Applied Photonics (Grant No. EP/S022821/1); and the Laser Research and Therapy Fund (Grant No. SC030850)."--Fundin
Roadmap on photonic metasurfaces
Get PDFFunding: C.R. and U.L. acknowledge support through the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy via the Excellence Cluster 3D Matter Made to Order (EXC-2082/1, Grant No. 390761711). A.B.E. acknowledges support through the Cluster of Excellence PhoenixD (EXC 2122, Project ID No. 390833453). I.F.-C. and C.R. acknowledge support through the CRC Waves: Analysis and Numerics (SFB 1173, Grant No. 258734477. K.A. acknowledges funding from the Swiss National Science Foundation (Project No. PZ00P2_193221).Here we present a roadmap on Photonic metasurfaces. This document consists of a number of perspective articles on different applications, challenge areas or technologies underlying photonic metasurfaces. Each perspective will introduce the topic, present a state of the art as well as give an insight into the future direction of the subfield.Peer reviewe
A theoretical analysis of non-Markovian open system dynamics in correlated quantum materials
Get PDFGaining fine control over the behaviours of open quantum systems requires a finer understanding of the ways in which their environments impact their dynamics. While frequent approaches invoke Markovian approximations, the modern push towards picosecond quantum technologies highlights the practical need for treatments that go beyond this paradigm. In non-Markovian dynamical regimes, excitations within the environment of a system have lifetimes long enough to mediate a time-delayed self-coupling. These memory effects can lead to quantitatively distinct features in the resulting dynamics of the system, and so a precise understanding of their origin is crucial. Building upon a robust theoretical framework, we perform a systematic analysis of the dynamics of an impurity spin coupled to strongly correlated materials. As a theoretically and experimentally accessible model, we start with the Luttinger liquid, which allows us to study how strong correlations and interactions alter the response of the bath to the impurity and the resulting dynamics. Under this framework, non-Markovian behaviour emerges in the form of an initial slip prior to the spin decoherence, and we find that the signatures of spin-charge separation within the Luttinger liquid play a direct role in mediating this response. We further uncover the precise link between the strengths of interactions in modulating the rate and amplitude of this feature, which can be either greatly enhanced or suppressed. Equipped with this knowledge, we demonstrate that additional advantage can be gained out of cooling protocols that operate based on the non-Markovian dynamical response. We also consider scenarios where the massive Klein-Gordon model is an emergent theory of the bath, uncovering rich theoretical insights into the relationship between massive and massless limits via transient generalised Gibbs ensembles. Remarkably, we find that this transient regime is characterised by a massless theory with a mass-dependent effective temperature
Access Repository Dashboard
Do you manage St Andrews Research Repository? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!