8,171 research outputs found

    Data Analysis Techniques for Fan Performance in Highly-Distorted Flows from Boundary Layer Ingesting Inlets

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    The design of a unique distortion-tolerant fan for a high-bypass ratio boundary-layer ingesting propulsion system has been completed and a rig constructed and tested in the NASA Glenn 8x6 wind tunnel. Processing the data from the experiment presented some interesting challenges because of the complexity of the experimental setup and the flow through the test rig. The experiment was run in three phases, each of which employed a unique complement of inlet throat and fan face instrumentation to avoid the blockage that would have resulted from simultaneously installing all of the rakes. The measurement from the individual test points were subsequently combined to compute the overall stage performance. A CFD model of the experiment was used to gain understanding of the flow field and to test some of the techniques proposed for interpolating and extrapolating the measurements into regions where measurements were not made. This capability became extremely useful when it was discovered that there was an unexpected total temperature distortion in the tunnel. The CFD model was modified by inserting a total temperature profile at the upstream boundary that mimicked the measured distortion where measurements were available and that CFD solution was used to investigate methods to infer the complete total temperature field at the fan face

    Critical orientations for humanising health sciences education in South Africa

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    In this article, the authors make a case for the ’humanisation' and ’decolonisation' of health sciences curricula in South Africa, using integration as a guiding framework. Integration refers to an education that is built on a consolidated conceptual framework that includes and equally values the natural or biomedical sciences as well as the humanities, arts and social sciences, respecting that all of this knowledge has value for the practice of healthcare. An integrated curriculum goes beyond add-on or elective courses in the humanities and social sciences. It is a curriculum that includes previously marginalised sources of knowledge (challenging knowledge hierarchies and decolonising curricula); addresses an appropriate intellectual self-image in health sciences education (challenging the image of the health professional); promotes understanding of history and social context, centring issues of inclusion, access and social justice (cultivating a social ethic) and finally, focuses on care and relatedness as an essential aspect of clinical work (embedding relatedness in practice). The article offers a brief historical overview of challenges in health and health sciences education in South Africa since 1994, followed by a discussion of contemporary developments in critical health sciences pedagogies and the medical and health humanities in South Africa. It then draws on examples from South Africa to outline how these four critical orientations or competencies might be applied in practice, to educate health professionals that can meet the challenges of health and healthcare in contemporary South Africa

    A Taxonomy of Arts Interventions for People With Dementia

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    Background and Objectives The current evidence base for the arts and dementia has several limitations relating to the description, explanation, communication, and simplification of arts interventions. Research addressing these challenges must be multidisciplinary, taking account of humanities and science perspectives. Consequently, this research aimed to produce a taxonomy, or classification, of arts interventions for people with dementia as a contribution to this growing field. Research Design and Methods This research was underpinned by taxonomy and realist methodology. Taxonomy, the science of classification, produces a common language to name, define, and describe the world around us. Realist theory explains how interventions “work” and produce their effects. The main findings in this paper were generated from a case study and a Delphi study. Results An arts and dementia taxonomy of 12 dimensions was developed: Art Form, Artistic elements, Artistic focus, Artistic materials, Arts activity, Arts approaches, Arts facilitators, Arts location, Competencies, Complementary arts, Intervention context, Principles. Discussion and Implications Arts interventions can be classified according to their contexts, mechanisms, and outcomes. A range of stakeholders could benefit from the taxonomy, including people with dementia, artists, practitioners, carers, care staff, funders, commissioners, researchers, and academics. Language relating to the arts and dementia can be adapted depending on the audience. This is a foundational model requiring further development within the arts and dementia community

    Improved u′g′r′i′z′u'g'r'i'z' to UBVRCICUBVR_CI_C Transformation Equations for Main Sequence Stars

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    We report improved transformation equations between the u′g′r′i′z′u'g'r'i'z' and UBVRCICUBVR_CI_C photometric systems. Although the details of the transformations depend on luminosity class, we find a typical rms scatter on the order of 0.001 magnitude if the sample is limited to main sequence stars. Furthermore, we find an accurate transformation requires complex, multi-color dependencies for the bluer bandpasses. Results for giant stars will be reported in a subsequent paper.Comment: 7 pages, 8 figure

    New optical and near-infrared Surface Brightness Fluctuations models. A primary distance indicator ranging from Globular Clusters to distant galaxies?

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    We present new theoretical models for Surface Brightness Fluctuations (SBF) both for optical and near-infrared bands in standard ground-based and Hubble Space Telescope filter systems. Simple Stellar Population simulations are adopted. Models cover the age and metallicity ranges from t=5t=5 to 15 Gyr15~Gyr and from Z=0.0001Z=0.0001 to 0.04 respectively. Effects due to the variation of the Initial Mass Function and the stellar color-temperature relations are explored. Particular attention is devoted to very bright stars in the color-magnitude diagram and to investigate the effects of mass loss along the Red Giant Branch (RGB) and the Asymptotic Giant Branch (AGB). It is found that UU and BB bands SBF amplitudes are powerful diagnostics for the morphology of the Horizontal Branch and the Post-AGB stars population. We point out that a careful treatment of mass loss process along the RGB and AGB is fundamental in determining reliable SBF evaluations. The SBF measurements are used to give robust constraints on the evolution of AGB stars, suggesting that mass loss activity on AGB stars should be twice more efficient than on the RGB stars. Our models are able to reproduce the absolute SBF magnitudes of the Galactic Globular Clusters and of galaxies, and their integrated colors. New calibrations of absolute SBF magnitude in VV, RR, II, and KK photometric filters are provided, which appear reliable enough to directly gauge distances bypassing other distance indicators. The SBF technique is also used as stellar population tracer to derive age and metallicity of a selected sample of galaxies of known distances. Finally, {\it SBF color} versus {\it integrated color} diagrams are proposed as particularly useful in removing the well known {\it age-metallicity degeneracy} affecting our knowledge of remote stellar systems.Comment: AJ accepted, 46 pages, 21 figures, 10 tables, uses aastex.cl

    A Multi-Wavelength, Multi-Epoch Study of the Soft X-Ray Transient Prototype, V616 Mon (A0620-00)

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    We have obtained optical and infrared photometry of the soft x-ray transient prototype V616 Mon (A0620-00). From this photometry, we find a spectral type of K4 for the secondary star in the system, which is consistent with spectroscopic observations. We present J-, H-, and K-band light curves modeled with WD98 and ELC. Combining detailed, independently run models for ellipsoidal variations due to a spotted, non-spherical secondary star, and the observed ultraviolet to infrared spectral energy distribution of the system, we show that the most likely value for the orbital inclination is 40.75 +/- 3 deg. This inclination angle implies a primary black hole mass of 11.0 +/- 1.9 solar masses.Comment: 29 pages (preprint format), including 7 figures and 4 tables, accepted for publication in the Nov 2001 issue of A

    Exploring open cheminformatics approaches for categorizing per-and polyfluoroalkyl substances (PFASs)

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    Per- and polyfluoroalkyl substances (PFASs) are a large and diverse class of chemicals of great interest due to their wide commercial applicability, as well as increasing public concern regarding their adverse impacts. A common terminology for PFASs was recommended in 2011, including broad categorization and detailed naming for many PFASs with rather simple molecular structures. Recent advancements in chemical analysis have enabled identification of a wide variety of PFASs that are not covered by this common terminology. The resulting inconsistency in categorizing and naming of PFASs is preventing efficient assimilation of reported information. This article explores how a combination of expert knowledge and cheminformatics approaches could help address this challenge in a systematic manner. First, the “splitPFAS” approach was developed to systematically subdivide PFASs (for eventual categorization) following a CnF2n+1–X–R pattern into their various parts, with a particular focus on 4 PFAS categories where X is CO, SO2, CH2 and CH2CH2. Then, the open, ontology-based “ClassyFire” approach was tested for potential applicability to categorizing and naming PFASs using five scenarios of original and simplified structures based on the “splitPFAS” output. This workflow was applied to a set of 770 PFASs from the latest OECD PFAS list. While splitPFAS categorized PFASs as intended, the ClassyFire results were mixed. These results reveal that open cheminformatics approaches have the potential to assist in categorizing PFASs in a consistent manner, while much development is needed for future systematic naming of PFASs. The “splitPFAS” tool and related code are publicly available, and include options to extend this proof-of-concept to encompass further PFASs in the future

    The combined immunohistochemical expression of AMBRA1 and SQSTM1 identifies patients with poorly differentiated cutaneous squamous cell carcinoma at risk of metastasis: A proof of concept study

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    \ua9 2024 AMLo Biosciences Ltd. Journal of Cutaneous Pathology published by John Wiley & Sons Ltd.Background: Cutaneous squamous cell carcinoma (cSCC) incidence continues to increase globally with, as of yet, an unmet need for reliable prognostic biomarkers to identify patients at increased risk of metastasis. The aim of the present study was to test the prognostic potential of the combined immunohistochemical expression of the autophagy regulatory biomarkers, AMBRA1 and SQSTM1, to identify high-risk patient subsets. Methods: A retrospective cohort of 68 formalin-fixed paraffin-embedded primary cSCCs with known 5-year metastatic outcomes were subjected to automated immunohistochemical staining for AMBRA1 and SQSTM1. Digital images of stained slides were annotated to define four regions of interest: the normal and peritumoral epidermis, the tumor mass, and the tumor growth front. H-score analysis was used to semi-quantify AMBRA1 or SQSTM1 expression in each region of interest using Aperio ImageScope software, with receiver operator characteristics and Kaplan–Meier analysis used to assess prognostic potential. Results: The combined loss of expression of AMBRA1 in the tumor growth front and SQSTM1 in the peritumoral epidermis identified patients with poorly differentiated cSCCs at risk of metastasis (*p < 0.05). Conclusions: Collectively, these proof of concept data suggest loss of the combined expression of AMBRA1 in the cSCC growth front and SQSTM1 in the peritumoral epidermis as a putative prognostic biomarker for poorly differentiated cSCC
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