1,002 research outputs found

    Effects of Motion Pattern Characteristics on the Perception of Visual Acceleration

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    The ability to perceive visual motion is one that we use every day to perform goal-directed activities, such as intercepting or avoiding objects. As objects and observers rarely move at constant velocities, it is important to be able to detect changes in velocity. However, little attention has been paid to how we perceive visual acceleration in the literature. This thesis explored the influence of real world-relevant motion pattern characteristics on visual acceleration perception. Observers rarely see object motion with an unlimited field of view, and therefore we first examined how physically constraining the horizontal distance over which a stimulus can move affects the ability to detect and pursue horizontal acceleration and deceleration at different average velocities. Results indicated that detection improves and smooth pursuit worsens as average velocity increases. Moreover, both improve as the horizontal aperture size increases. Given our asymmetrical experience with the frequency and relevance of upward compared to downward events due to gravity, we then investigated whether acceleration and deceleration detection vary as a function of vertical direction. We also tested whether the effects of aperture size on detection and pursuit persist on the vertical axis. Our data suggested that detection is better for downward than upward motion, and both detection and smooth pursuit improve as the vertical aperture size increases. Considering that we tend to see translation as well as more complex motion patterns outside the laboratory, we subsequently explored whether acceleration and deceleration detection vary between horizontal translation and radial optic flow, which is similar to the motion we see when moving forward or backward while looking straight ahead. We found that detection is better for radial than horizontal motion, although direction within each pattern type has no effect. Finally, we verified that sensitivity to the presence of acceleration is uniform across the optic flow field, regardless of radial direction. In summary, although we detect acceleration and deceleration similarly across a wide range of conditions, overall perception appears to be affected by the unique characteristics of the motion pattern

    Visual Acceleration Perception for Simple and Complex Motion Patterns.

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    Humans are able to judge whether a target is accelerating in many viewing contexts, but it is an open question how the motion pattern per se affects visual acceleration perception. We measured acceleration and deceleration detection using patterns of random dots with horizontal (simpler) or radial motion (more visually complex). The results suggest that we detect acceleration better when viewing radial optic flow than horizontal translation. However, the direction within each type of pattern has no effect on performance and observers detect acceleration and deceleration similarly within each condition. We conclude that sensitivity to the presence of acceleration is generally higher for more complex patterns, regardless of the direction within each type of pattern or the sign of acceleration

    Effect of Driving Experience on Change Detection Based on Target Relevance and Size

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    Earlier studies that investigated the effects of driving experience and target safety relevance on change detection have produced conflicting results. Using a flicker change detection task to investigate the effect of driving experience on the ability to detect changes in objects that vary in safety relevance and size, the present study attempted to clarify some controversies by addressing three important methodological issues. The data showed that experienced drivers exhibited more efficient selection strategies than novice drivers and thus may have more spare resources to analyze less relevant objects in the driving environment. Selection strategies for relevant information appear to be sensitive to object size whereas selection of irrelevant information is downgraded comparatively and unaffected by size. Findings are discussed as they relate to theoretical and practical implications

    Antibody response to a third SARS-CoV-2 vaccine dose in recipients of an allogeneic haematopoietic cell transplantation

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    Allogeneic haematopoietic cell transplantation (allo-HCT) recipients show impaired antibody (Ab) response to a standard two-dose vaccination against severe acute respiratory syndrome coronavirus-2 and currently a third dose is recommended as part of the primary vaccination regimen. By assessing Ab titres 1 month after a third mRNA vaccine dose in 74 allo-HCT recipients we show sufficient neutralisation activity in 77% of the patients. Discontinuation of immunosuppression before the third vaccine led to serological responses in 50% of low responders to two vaccinations. Identifying factors that might contribute to better vaccine responses in allo-HCT recipients is critical to optimise current vaccination strategies. Keywords: allogeneic haematopoietic cell transplantation; severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2); vaccine respons

    Mid-term changes in cognitive functions in patients with atrial fibrillation: a longitudinal analysis of the Swiss-AF cohort.

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    BACKGROUND Longitudinal association studies of atrial fibrillation (AF) and cognitive functions have shown an unclear role of AF-type and often differ in methodological aspects. We therefore aim to investigate longitudinal changes in cognitive functions in association with AF-type (non-paroxysmal vs. paroxysmal) and comorbidities in the Swiss-AF cohort. METHODS Seven cognitive measures were administered up to five times between 2014 and 2022. Age-education standardized scores were calculated and association between longitudinal change in scores and baseline AF-type investigated using linear mixed-effects models. Associations between AF-type and time to cognitive drop, an observed score of at least one standard deviation below individual's age-education standardized cognitive scores at baseline, were studied using Cox proportional hazard models of each cognitive test, censoring patients at their last measurement. Models were adjusted for baseline covariates. RESULTS 2,415 AF patients (mean age 73.2 years; 1,080 paroxysmal, 1,335 non-paroxysmal AF) participated in this Swiss multicenter prospective cohort study. Mean cognitive scores increased longitudinally (median follow-up 3.97 years). Non-paroxysmal AF patients showed smaller longitudinal increases in Digit Symbol Substitution Test (DSST), Cognitive Construct Score (CoCo)and Trail Making Test part B (TMT-B) scores vs. paroxysmal AF patients. Diabetes, history of stroke/TIA and depression were associated with worse performance on all cognitive tests. No differences in time to cognitive drop were observed between AF-types in any cognitive test. CONCLUSION This study indicated preserved cognitive functioning in AF patients, best explained by practice effects. Smaller practice effects were found in non-paroxysmal AF patients in the DSST, TMT-B and the CoCo and could indicate a marker of subtle cognitive decline. As diabetes, history of stroke/TIA and depression-but not AF-type-were associated with cognitive drop, more attention should be given to risk factors and underlying mechanisms of AF

    Perceptions of Portuguese undergraduate students about assessment: a study in five public universities

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    This paper draws upon a broader piece of research on assessment in higher education, particularly focusing on issues regarding the fairness and effectiveness of the assessment methods and their implications for the learning process. The perceptions of undergraduate students are analysed taking into account the effectiveness and fairness of both traditional and learner-centred assessment methods, as well their influence on the learning process. In total, 624 students participated in this study in five Portuguese Public Universities in different areas of knowledge and programmes. Data were collected through questionnaires. Findings suggest that assessment is seen as more effective and fairer when it is done through the use of learner-centred assessment methods rather than by traditional assessment (e.g. written tests or exams). The students also claim that they devote more time to study when assessment is performed through learner-centred assessment methods than by traditional ones. The most used assessment methods are written tests and oral presentations in group. However, differences in the programmes were identified as well as differences according to gender. Implications of the findings for assessment and for the teaching and learning process are discussed.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), Portugal. Fundos Nacionais através da FCT (Fundação para a Ciência e a Tecnologia) e cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) no âmbito do CIEC (Centro de Investigação em Estudos da Criança, da Universidade do Minho) com a referência POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio

    Proximal adductor avulsions are rarely isolated but usually involve injury to the PLAC and pectineus: Descriptive MRI findings in 145 athletes

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    Purpose The purpose of the study is to review the MRI findings in a cohort of athletes who sustained acute traumatic avulsions of the adductor longus fibrocartilaginous entheses, and to investigate related injuries namely the pyramidalis- anterior pubic ligament - adductor longus complex (PLAC). Associated muscle and soft tissue injuries were also assessed. Methods The MRIs were reviewed for a partial or complete avulsion of the adductor longus fibrocartilage, as well as continuity or separation of the adductor longus from the pyramidalis. The presence of a concurrent partial pectineus tear was noted. Demographic data was analysed. Linear and logistic regression was used to examine associations between injuries. Results The mean age was 32.5 (SD 10.9). The pyramidalis was absent in 3 of 145 patients. 85 of 145 athletes were professional and 52 competed in the football Premier League. 132 had complete avulsions and 13 partial. The adductor longus was in continuity with pyramidalis in 55 athletes, partially separated in seven and completely in 81 athletes. 48 athletes with a PLAC injury had a partial pectineus avulsion. Six types of PLAC injuries patterns were identified. Associated rectus abdominis injuries were rare and only occurred in five patients (3.5%). Conclusion The proximal adductor longus forms part of the PLAC and is rarely an isolated injury. The term PLAC injury is more appropriate term. MRI imaging should assess all the anatomical components of the PLAC post-injury, allowing recognition of the differentpatterns of injury

    OpenMS – An open-source software framework for mass spectrometry

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    <p>Abstract</p> <p>Background</p> <p>Mass spectrometry is an essential analytical technique for high-throughput analysis in proteomics and metabolomics. The development of new separation techniques, precise mass analyzers and experimental protocols is a very active field of research. This leads to more complex experimental setups yielding ever increasing amounts of data. Consequently, analysis of the data is currently often the bottleneck for experimental studies. Although software tools for many data analysis tasks are available today, they are often hard to combine with each other or not flexible enough to allow for rapid prototyping of a new analysis workflow.</p> <p>Results</p> <p>We present OpenMS, a software framework for rapid application development in mass spectrometry. OpenMS has been designed to be portable, easy-to-use and robust while offering a rich functionality ranging from basic data structures to sophisticated algorithms for data analysis. This has already been demonstrated in several studies.</p> <p>Conclusion</p> <p>OpenMS is available under the Lesser GNU Public License (LGPL) from the project website at <url>http://www.openms.de</url>.</p

    A new valuation school : Integrating diverse values of nature in resource and land use decisions

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    We are increasingly confronted with severe social and economic impacts of environmental degradation all over the world. From a valuation perspective, environmental problems and conflicts originate from trade-offs between values. The urgency and importance to integrate nature's diverse values in decisions and actions stand out more than ever. Valuation, in its broad sense of 'assigning importance', is inherently part of most decisions on natural resource and land use. Scholars from different traditions -while moving from heuristic interdisciplinary debate to applied transdisciplinary science- now acknowledge the need for combining multiple disciplines and methods to represent the diverse set of values of nature. This growing group of scientists and practitioners share the ambition to explore how combinations of ecological, socio-cultural and economic valuation tools can support real-life resource and land use decision-making. The current sustainability challenges and the ineffectiveness of single-value approaches to offer relief demonstrate that continuing along a single path is no option. We advocate for the adherence of a plural valuation culture and its establishment as a common practice, by contesting and complementing ineffective and discriminatory single-value approaches. In policy and decision contexts with a willingness to improve sustainability, integrated valuation approaches can be blended in existing processes, whereas in contexts of power asymmetries or environmental conflicts, integrated valuation can promote the inclusion of diverse values through action research and support the struggle for social and environmental justice. The special issue and this editorial synthesis paper bring together lessons from pioneer case studies and research papers, synthesizing main challenges and setting out priorities for the years to come for the field of integrated valuation.Peer reviewe
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