330 research outputs found

    Extending Spatial Boundaries Through Sculpture Practice: An Exploratory Study of the Influence of a 3D Digital and Technological Context on Sculpture Installation Art

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    In sculpture practice, artists are challenged by a 3D digital medium within which digital data intangibility also embeds a tangible form. The focus of this study is to understand how a 3D technological context extends spatial and medium boundaries in sculpture practice and affects artists’ conceptual and practical approaches to the creative process. The study explores the sculptors’ relation to space, time, and the medium inside a gravity-free spatial context, which proposes a re-defined concept-process relationship. The research methods include a Research Creation experiential mode of inquiry and a case study interview approach. The Research Creation project documents the artist-researcher as sculptor’s conceptual investigations (which are focused on environmental concepts). The main sculpture installation work, Vulnerable: The Salmon Project, conveys a concept of memory and proposes a visual metaphor of the vulnerability of the living condition. The data collection method is informed by the artist-researcher’s creative exploration guided by an experiential learning of 3D scanning, in-depth investigations into the structure of digital objects, and applied knowledge of 3D modelling and rapid prototyping processes. The case study focuses on three professional sculptors: Kiki Smith, Evan Penny, and Trevor Gould. The artist-researcher presents an interpretation of how the artists’ conceptual explorations, professional backgrounds, and experience play a role in the way they approach 3D technology in their creative process. This research examines how artists engage with a digital medium and the ways in which it influences their visual language and artwork aesthetics. The research outcomes indicate that explorative and innovative perspectives lead to a convergence of digital mediums. Artists experience a medium that encourages the crossing over from 2D to 3D. Collaboration, or a shared knowledge approach, stimulates creative freedom inside a 3D software environment. This research contributes to a deeper understanding of artists’ interactions with extended spatial dimensions and a digital medium through which technology becomes a way of engaging, perceiving, sensing, and experiencing creativity

    Seeing but not perceiving: Inattentional Blindness as a Cause of Missed Cues in the General Practice (GP) Consultation

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    AbstractBackground: It is well known that healthcare professionals, including GPs, frequently fail to respond to cues made by their patients. A possible explanation for this behaviour is that the phenomenon of IB could lead to a failure to observe the cue, rather than a deliberate choice to ignore it. This study sought to explore that possibility, and to consider whether GP trainees are more susceptible to IB than GP trainers.Methods: The research was a case study involving two groups of participants - GP trainees and GP trainers from a localised GP Training Scheme. Actors were used to record a video of a pre-defined GP consultation involving a patient affected by headaches, who gave two significant cues which were not responded to in the video. Participants observed the video while being asked to focus on the diagnosis and management of the patient’s headaches, following which they completed a questionnaire, including questions about the cues. Results: Cues were missed by 24-53% of participants, suggesting a high rate of IB within the GP consultation. Unexpected findings included the recording by some participants of false observations from the video. There was no significant difference between trainers and trainees in the rates of IB.Conclusion: IB appears to be a real and significant phenomenon within the GP consultation, and is likely to have important implications for patient care. More research is needed to confirm these findings, establish IB rates as a cause of missed cues among healthcare professionals and evaluate possible interventions to reduce susceptibility to IB

    Comparative Dissociation of Peptide Polyanions by Electron Impact and Photo-Induced Electron Detachment

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    We compare product-ion mass spectra produced by electron detachment dissociation (EDD) and electron photodetachment dissociation (EPD) of multi-deprotonated peptides on a Fourier transform and a linear ion trap mass spectrometer, respectively. Both methods, EDD and EPD, involve the electron emission-induced formation of a radical oxidized species from a multi-deprotonated precursor peptide. Product-ion mass spectra display mainly fragment ions resulting from backbone cleavages of Cα–C bond ruptures yielding a and x ions. Fragment ions originating from N–Cα backbone bond cleavages are also observed, in particular by EPD. Although EDD and EPD methods involve the generation of a charge-reduced radical anion intermediate by electron emission, the product ion abundance distributions are drastically different. Both processes seem to be triggered by the location and the recombination of radicals (both neutral and cation radicals). Therefore, EPD product ions are predominantly formed near tryptophan and histidine residues, whereas in EDD the negative charge solvation sites on the backbone seem to be the most favorable for the nearby bond dissociation

    Eikonal phase retrieval: Unleashing the fourth generation sources potential for enhanced propagation based tomography on biological samples

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    The evolution of synchrotrons towards higher brilliance beams has increased the possible sample-to-detector propagation distances for which the source confusion circle does not lead to geometrical blurring. This makes it possible to push near-field propagation driven phase contrast enhancement to the limit, revealing low contrast features which would otherwise remain hidden under an excessive noise-to-signal ratio. Until today this possibility was hindered, in most objects of scientific interest, by the simultaneous presence of strong phase gradient regions and low contrast features. The strong gradients, when enhanced with the now possible long propagation distances, induce such strong phase effects that the linearisation assumptions of current state-of-the-art single-distance phase retrieval filters are broken, and the resulting image quality is jeopardized. Our work provides an innovative algorithm which efficiently performs the phase retrieval task over the entire near-field range, producing images of exceptional quality for mixed objects

    Deep Learning for Vascular Segmentation and Applications in Phase Contrast Tomography Imaging

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    Automated blood vessel segmentation is vital for biomedical imaging, as vessel changes indicate many pathologies. Still, precise segmentation is difficult due to the complexity of vascular structures, anatomical variations across patients, the scarcity of annotated public datasets, and the quality of images. We present a thorough literature review, highlighting the state of machine learning techniques across diverse organs. Our goal is to provide a foundation on the topic and identify a robust baseline model for application to vascular segmentation in a new imaging modality, Hierarchical Phase Contrast Tomography (HiP CT). Introduced in 2020 at the European Synchrotron Radiation Facility, HiP CT enables 3D imaging of complete organs at an unprecedented resolution of ca. 20mm per voxel, with the capability for localized zooms in selected regions down to 1mm per voxel without sectioning. We have created a training dataset with double annotator validated vascular data from three kidneys imaged with HiP CT in the context of the Human Organ Atlas Project. Finally, utilising the nnU Net model, we conduct experiments to assess the models performance on both familiar and unseen samples, employing vessel specific metrics. Our results show that while segmentations yielded reasonably high scores such as clDice values ranging from 0.82 to 0.88, certain errors persisted. Large vessels that collapsed due to the lack of hydrostatic pressure (HiP CT is an ex vivo technique) were segmented poorly. Moreover, decreased connectivity in finer vessels and higher segmentation errors at vessel boundaries were observed. Such errors obstruct the understanding of the structures by interrupting vascular tree connectivity. Through our review and outputs, we aim to set a benchmark for subsequent model evaluations using various modalities, especially with the HiP CT imaging database

    Systematic review and meta-analysis of maintenance of physical activity behaviour change in cancer survivors.

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    BACKGROUND: Physical activity can improve health and wellbeing after cancer and may reduce cancer recurrence and mortality. To achieve such long-term benefits cancer survivors must be habitually active. This review evaluates the effectiveness of interventions in supporting maintenance of physical activity behaviour change among adults diagnosed with cancer and explores which intervention components and contextual features are associated with effectiveness. METHODS: Relevant randomised controlled trials (RCTs) were identified by a search of Ovid Medline, Ovid Embase and PsychINFO. Trials including adults diagnosed with cancer, assessed an intervention targeting physical activity and reported physical activity behaviour at baseline and ≥ 3 months post-intervention were included. The behaviour change technique (BCT) taxonomy was used to identify intervention components and the Template for Intervention Description and Replication to capture contextual features. Random effect meta-analysis explored between and within group differences in physical activity behaviour. Standardised mean differences (SMD) describe effect size. RESULTS: Twenty seven RCTs were included, 19 were pooled in meta-analyses. Interventions were effective at changing long-term behaviour; SMD in moderate to vigorous physical activity (MVPA) between groups 0.25; 95% CI = 0.16-0.35. Within-group pre-post intervention analysis yielded a mean increase of 27.48 (95% CI = 11.48-43.49) mins/wk. of MVPA in control groups and 65.30 (95% CI = 45.59-85.01) mins/wk. of MVPA in intervention groups. Ineffective interventions tended to include older populations with existing physical limitations, had fewer contacts with participants, were less likely to include a supervised element or the BCTs of 'action planning', 'graded tasks' and 'social support (unspecified)'. Included studies were biased towards inclusion of younger, female, well-educated and white populations who were already engaging in some physical activity. CONCLUSIONS: Existing interventions are effective in achieving modest increases in physical activity at least 3 months post-intervention completion. Small improvements were also evident in control groups suggesting low-intensity interventions may be sufficient in promoting small changes in behaviour that last beyond intervention completion. However, study samples are not representative of typical cancer populations. Interventions should consider a stepped-care approach, providing more intensive support for older people with physical limitations and others less likely to engage in these interventions

    Evaluation of the tuberculin skin test and the interferon-γ release assay for TB screening in French healthcare workers

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    <p>Abstract</p> <p>Introduction</p> <p>Using French cut-offs for the Tuberculin Skin Test (TST), results of the TST were compared with the results of an Interferon-γ Release Assay (IGRA) in Healthcare Workers (HCW) after contact to AFB-positive TB patients.</p> <p>Methods</p> <p>Between May 2006 and May 2007, a total of 148 HCWs of the University Hospital in Nantes, France were tested simultaneously with IGRA und TST. A TST was considered to indicate recent latent TB infection (LTBI) if an increase of >10 mm or if TST ≥ 15 mm for those with no previous TST result was observed. For those with a positive TST, chest X-ray was performed and preventive chemotherapy was offered.</p> <p>Results</p> <p>All HCWs were BCG-vaccinated. The IGRA was positive in 18.9% and TST ≥ 10 mm was observed in 65.5%. A recent LTBI was believed to be highly probable in 30.4% following TST. Agreement between IGRA and TST was low (kappa 0.041). In 10 (16.7%) out of 60 HCWs who needed chest X-ray following TST the IGRA was positive. In 9 (20%) out of 45 HCWs to whom preventive chemotherapy was offered following TST the IGRA was positive. Of those considered TST-negative following the French guidelines, 20.5% were IGRA-positive. In a two-step strategy - positive TST verified by IGRA - 18 out of 28 (64.3%) IGRA-positive HCWs would not have been detected using French guidelines for TST interpretation.</p> <p>Conclusion</p> <p>The introduction of IGRA in contact tracings of BCG-vaccinated HCWs reduces X-rays and preventive chemotherapies. Increasing the cut-off for a positive TST does not seem to be helpful to overcome the effect of BCG vaccination on TST.</p

    Luminance-polarity distribution across the symmetry axis affects the electrophysiological response to symmetry

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    Electrophysiological studies of symmetry have found a difference wave termed the Sustained Posterior Negativity (SPN) related to the presence of symmetry. Yet the extent to which the SPN is modulated by luminance-polarity and colour content is unknown. Here we examine how luminance-polarity distribution across the symmetry axis, grouping by luminance polarity, and the number of colours in the stimuli, modulate the SPN. Stimuli were dot patterns arranged either symmetrically or quasi-randomly. There were several arrangements: &rsquo;segregated&rsquo;-symmetric dots were of one polarity and random dots of the other; &lsquo;unsegregated&rsquo;-symmetric dots were of both polarities in equal proportions; &lsquo;anti-symmetric&rsquo;-dots were of opposite polarity across the symmetry axis; &lsquo;polarity-grouped anti-symmetric&rsquo;-as anti-symmetric but with half the pattern of one polarity and the other opposite; multi-colour symmetric patterns made of either two, three and four colours. We found that the SPN is: reduced by the amount of position-symmetry, sensitive to luminance-polarity mismatch across the symmetry axis and not modulated by the number of colours in the stimuli. Our results show that the sustained nature of the SPN coincides with the late onset of a topographic microstate sensitive to symmetry. These findings emphasise the importance of not only position symmetry, but also luminance polarity matching across the symmetry axis
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