32 research outputs found
Portrait of Hugh MacDiarmid
No full textA commissioned installation/portrait as one of the programme of public events at the National Galleries of Scotland/Royal Scottish Academy collaborative opus Ages of Wonder: Scotland’s Art 1540 to Now exhibition at the RSA. I was invited to ‘bring my studio’ into the building and create an artwork during the run of the exhibition in public view. The finished installation was marked with a public event in the Gallery with Calum Colvin and author James Robertson on 1/1/18. Subsequently the printed and framed photographic portrait was debuted at the RSA Annual Exhibition 2018, which was convened and curated by Colvin and included a number of guest artists who were invited to explore the links between poetry and visual art. This included a programme of public artist/poet talks. The portrait subsequently won the City of Glasgow College Purchase Prize
Multiple sets of solutions for harmonic elimination PWM bipolar waveforms: Analysis and experimental verification
No full textMultiple sets of solutions for the selective harmonic elimination pulse-width modulation method for inverter control exist. These sets present an independent solution to the same problem but further investigation reveals that certain sets may offer an improved overall harmonic performance. In this paper, a minimization method is discussed as a way to obtain these multiple sets of switching angles. A simple distortion harmonic factor that takes into account the first two most significant harmonics present in the generated waveform is considered in order to evaluate the performance of each set. The bipolar waveform is thoroughly analyzed and two cases are considered; single-phase patterns which eliminate all odd harmonics and three-phase counterparts which eliminate only the nontriplen odd harmonics from the line-to-neutral pattern but such harmonics are naturally eliminated from the line-to-line waveform. Experimental results support the theoretical considerations reported in the paper
Nixon's “full-speech”: imaginary and symbolic registers of communication
No full textCommunicative interchanges play a foundational role in establishing the social. This being said, communicative behaviour can also lead to stalemates and conflict in which demands of recognition outweigh the prospect of hearing or saying anything beyond what is thought to be known. This paper foregrounds a dimension of communication often neglected by approaches prioritizing mass communications and new media technologies, namely the psychical and inter-subjective aspects of communicative exchange. More directly, this paper introduces and develops a Lacanian psychoanalytic theory of two interlinked registers of communicative behaviour. The first of these is the imaginary: the domain of one-to-one inter-subjectivity and behaviour that serves the ego and functions to consolidate the images subjects use to substantiate themselves. The second - far more disturbing and unpredictable - is the symbolic. It links the subject to a trans-subjective order of truth, it provides them with a set of socio-symbolic co-ordinates, and it ties them into a variety of roles and social contracts. In an elaboration of these two registers, illustrated by brief reference to Nixon’s admission of guilt in his interviews with David Frost, I pay particular attention to both the potentially transformative symbolic aspect of communicative behaviours and the ever-present prospect that such relations will ossify into imaginary impasses of mis-knowing (méconnaissance) and aggressive rivalry
Coming clean: understanding and mitigating optical contamination and laser induced damage in advanced LIGO
No full textThe cleanliness of optical surfaces is of great concern as the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) project transitions from installation to operation at full power. More particulates than expected were observed on and near the core optics as a result of assembly and installation work, prompting a re-evaluation of longheld contamination control practices. Even low particulate levels can potentially damage the fused silica optics and reduce overall interferometer sensitivity. These risks are mitigated from a combination of the following approaches: quantifying the extent of the contamination, identifying its sources, improving practices to reduce the generation of particulates, introducing a non-contact in-situ cleaning technique for suspended optics in air, qualifying cleanliness levels against induced damage, and developing methods for remotely measuring and cleaning suspended optics under vacuum. While significant progress has been made in understanding and mitigating contamination, and thus, protecting the optics from losses and damage, there is still more work to be done to reach ultimate performance requirements
Coming clean: understanding and mitigating optical contamination and laser induced damage in advanced LIGO
No full text
Amassing Jacobitiana: The Amulree Jacobite Collection
No full textThe Amulree Jacobite collection has rested in the University of Stirling's library archives, practically unexplored following its bequeathal to the institution almost four decades ago. This article discusses its author, his antiquarian and authorial legacy and his fascinating collection of Jacobite-related material culture
Thromboelastometry and Platelet Function during Acclimatization to High Altitude
No full textInteraction between hypoxia and coagulation is important given the increased risk of thrombotic diseases in chronically hypoxic patients who reside at sea level and in residents at high altitude. Hypoxia alters the proteome of platelets favouring a prothrombotic phenotype, but studies of activation and consumption of specific coagulation factors in hypoxic humans have yielded conflicting results. We tested blood from 63 healthy lowland volunteers acclimatizing to high altitude (5,200 m) using thromboelastometry and assays of platelet function to examine the effects of hypoxia on haemostasis. Using data from two separate cohorts of patients following identical ascent profiles, we detected a significant delay in clot formation, but increased clot strength by day 7 at 5,200 m. The latter finding may be accounted for by the significant rise in platelet count and fibrinogen concentration that occurred during acclimatization. Platelet function assays revealed evidence of platelet hyper-reactivity, with shortened PFA-100 closure times and increased platelet aggregation in response to adenosine diphosphate. Post-expedition results were consistent with the normalization of coagulation following descent to sea level. These robust findings indicate that hypoxia increases platelet reactivity and, with the exception of the paradoxical delay in thromboelastometry clotting time, suggest a prothrombotic phenotype at altitude. Further work to elucidate the mechanism of platelet activation in hypoxia will be important and could impact upon the management of patients with acute or chronic hypoxic respiratory diseases who are at risk of thrombotic events.
Erratum to: Thromboelastometry and platelet function during acclimatisation to high altitude (doi: 10.1160/TH17-02-0138) http://eprints.whiterose.ac.uk/129510/
In the Original Article by Rocke et al. “Thromboelastometry and platelet function during acclimatization to high altitude” (Thromb Haemost 2018; 118: 063-071) after publication of the article it has come to the corresponding author's attention that an author was inadvertently omitted from the manuscript. The author, Martin MacInnis, made a significant contribution to: 1. initiating the coagulation research that led to the manuscript, 2. designing the research protocol and performing the initial data analysis, 3. recruiting volunteers, writing applications for ethical approval and making other logistical arrangements that were necessary to complete the study. Martin MacInnis has read and approved the published version of the manuscript. Furthermore, a middle initial was added to the updated list (Shona E. Main) and misspelling of Elizabeth Horn's surname was corrected. The amended author list is as above. https://doi.org
The association between life course socioeconomic position and life satisfaction in different welfare states:European comparative study of individuals in early old age
No full textBACKGROUND: whether socioeconomic position over the life course influences the wellbeing of older people similarly in different societies is not known.OBJECTIVE: to investigate the magnitude of socioeconomic inequalities in life satisfaction among individuals in early old age and the influence of the welfare state regime on the associations. Design: comparative study using data from Wave 2 and SHARELIFE, the retrospective Wave of the Survey of Health, Ageing, and Retirement in Europe (SHARE), collected during 2006-07 and 2008-09, respectively.SETTING: thirteen European countries representing four welfare regimes (Southern, Scandinavian, Post-communist and Bismarckian).SUBJECTS: a total of 17,697 individuals aged 50-75 years.METHODS: slope indices of inequality (SIIs) were calculated for the association between life course socioeconomic position (measured by the number of books in childhood, education level and current wealth) and life satisfaction. Single level linear regression models stratified by welfare regime and multilevel regression models, containing interaction terms between socioeconomic position and welfare regime type, were calculated.RESULTS: socioeconomic inequalities in life satisfaction were present in all welfare regimes. Educational inequalities in life satisfaction were narrowest in Scandinavian and Bismarckian regimes among both genders. Post-communist and Southern countries experienced both lower life satisfaction and larger socioeconomic inequalities in life satisfaction, using most measures of socioeconomic position. Current wealth was associated with large inequalities in life satisfaction across all regimes.CONCLUSIONS: Scandinavian and Bismarckian countries exhibited narrower socioeconomic inequalities in life satisfaction. This suggests that more generous welfare states help to produce a more equitable distribution of wellbeing among older people.</p
Data accompanying: "Snow persistence lowers and delays peak NDVI, the vegetation index that underpins Arctic greening analyses"
No full textThis dataset contains multispectral orthomosaics generated from repeat drone imagery captured during a single growing season at one Arctic and one sub-Arctic tundra site. The orthomosaics are used to calculate the persistence of fine scale snow cover in: Hoad et al. (in press) - Snow persistence lowers and delays peak NDVI, the vegetation index that underpins Arctic greening analyses All code to analyse and visualise this data can be found in the following GitHub repository: https://github.com/calumhoad/snowpersistence Data summary: This dataset contains an orthomosaic for each date where a drone survey was conducted at three tundra plots: Blæsedalen (BL), Kluane Low (KL) and Kluane High (KH). The Blæsedalen data were captured using the integrated sensor aboard a DJI Mavic 3 Multispectral and the Kluane data were captured using a SAL Engineering MAIA-S2 sensor. For more information on methdology, please refer to our Environmental Research Letters article and supplementary materials. The imagery for each plot is listed below: Blæsedalen (BL): 2023-07-02 2023-07-12 2023-07-18 2023-07-26 Kluane Low (KL): 2022-06-29 2022-07-05 2022-07-18 2022-08-01 2022-08-14 Kluane High (KH): 2022-07-09 2022-07-19 2022-07-29 2022-08-04 2022-08-13 To replicate analyses from the manuscript: Clone the GitHub repository before downloading this data, then place the contents of each subfolder from the dataset into the following folders of the GitHub repo: For Blæsedalen files: data/uav/orthomosaics/m3m/5cm For Kluane Low files: data/uav/orthomosaics/maia/kluane-low/5cm For Kluane High files: data/uav/orthomosaics/maia/kluane-high/5cm Cite as: Hoad, C., Myers-Smith, I.H., Kerby, J.T., Colesie, C. and Assmann, J.J., (in press). Snow persistence lowers and delays peak NDVI, the vegetation index that underpins Arctic greening analyses. Abstract (from manuscript): Satellite imagery is critical for understanding land-surface change in the rapidly warming Arctic. Since the 1980s, studies have found positive trends in the normalised difference vegetation index (NDVI) derived from satellite imagery over the Arctic—commonly referred to as ‘Arctic greening’ and assumed to represent increased vegetation productivity. However, greening analyses use satellite imagery with pixel sizes ranging from tens to hundreds of metres and do not account for the integration of abiotic phenomena such as snow within vegetation indices. Here, we use high-resolution drone data from one Arctic and one sub-Arctic site to show that fine-scale snow persistence within satellite pixels is associated with both reduced magnitude and delayed timing of annual peak NDVI, the base metric of Arctic greening analyses. We found higher snow persistence within Sentinel-2 pixels is associated with a lower magnitude and later peak NDVI, with a mean difference in NDVI of 0.1 and seven days between high and low snow persistence pixels. These effects were stronger in NASA HLSS30 data, representative of Landsat data commonly used in greening analyses. Our findings indicate that unaccounted changes in fine-scale snow persistence may contribute to Arctic spectral greening and browning trends through either biotic responses of vegetation to snow cover or abiotic integration of snow within the estimated peak NDVI. In order to improve our understanding of Arctic land-surface change, studies should integrate very-high-resolution data to estimate the dynamics of late-season snow within coarser satellite pixels. Acknowledgements (from manuscript): We would like to thank everyone who helped with field data collection in the Canadian Yukon during 2022 and in Greenland during 2023, including Joseph Everest, Erica Zaja, Jiri Subrt, Sian Williams and Mariana García Criado. For help with drones and sensors, particular thanks go to Tom Wade at the University of Edinburgh Airborne Research and Innovation facility, and Alex Merrington, Jack Gillespie, Craig Atkins and Robbie Ramsay at the NERC Field Spectroscopy Facility. Additional thanks to Alan Hobbs, Colin Kay and Graham Mitchell from the NERC Geophysical Equipment Facility. We thank Tim Gyger for support and consultation on our statistical methods, Gwenn Flowers for the time taken to provide climate data for Kluane and Kirsten Schmidt-Pedersen for sharing her extensive knowledge of the people, plants and animals of Qeqertarsuaq, Greenland. Funding for this research was provided by NERC through a SENSE CDT studentship (NE/T00939X/1), the NERC Tundra Time project (NE/W006448/1), a 2023 UK-Greenland Arctic Bursary, a NERC Geophysical Equipment Facility loan (1152), and a NERC Field Spectroscopy Facility loan (891.0111). Additional funding was provided by a Scottish Alliance for GeoScience, Environment and Society (SAGES) small grant scheme award to Calum Hoad. We thank Kluane First Nation and Champagne and Aishihik First Nations for their permission to work on their lands. We gratefully acknowledge the people of Kalaallit Nunaat in general, and of Qeqertarsuaq in particular, for being able to conduct this research on their land. We thank Outpost Research Station and Arctic Station for logistical support. The authors acknowledge constructive comments from two anonymous reviewers, which greatly improved the manuscript. Author contributions (from manuscript): Calum G. Hoad: Conceptualisation (lead); Data curation (lead); Formal analysis (equal); Funding acquisition (equal); Investigation (lead); Methodology (lead); Project administration (lead); Resources (lead); Software (equal); Visualisation (lead); Writing – original draft (lead); Writing – review and editing (lead). Isla H. Myers-Smith: Conceptualisation (supporting); Formal analysis (supporting); Funding acquisition (equal); Methodology (supporting); Resources (supporting); Supervision (lead); Visualisation (supporting); Writing – review and editing (equal). Jeff T. Kerby: Conceptualisation (supporting); Methodology (supporting); Supervision (equal); Visualisation (supporting); Writing – review and editing (equal). Claudia Colesie: Conceptualisation (supporting); Funding acquisition (supporting); Supervision (equal); Project administration (supporting); Resources (supporting); Visualisation (supporting); Writing – review and editing (equal). Jakob J. Assmann: Conceptualisation (supporting); Data curation (supporting); Formal analysis (equal); Investigation (supporting); Methodology (supporting); Supervision (lead); Software (equal); Visualisation (supporting); Writing – original draft (supporting); Writing – review and editing (equal).Hoad, C. G., Myers-Smith, I., Kerby, J., Colesie, C., & Assmann, J. J. (2025). Data accompanying: "Snow persistence lowers and delays peak NDVI, the vegetation index that underpins Arctic greening analyses" [Data set]. Zenodo. https://doi.org/10.5281/zenodo.1481020
