20,003 research outputs found

    A 94-GHz Frequency Modulation Continuous Wave Radar Imaging and Motion Compensation

    Get PDF
    A compact and lightweight synthetic aperture radar (SAR) that can be loaded on a miniature unmanned aerial vehicle (UAV) was recently developed. The higher the frequency is, the smaller is the antenna size and the microwave characteristics are improved. Thus, a high frequency is favorable for miniaturization and weight reduction. In this chapter, a method of obtaining a radar image through a 94-GHz frequency modulation continuous wave (FMCW) radar is proposed. In addition, a method of motion compensation is described, and the W-band SAR image after motion compensation is confirmed. This kind of SAR imaging can provide geographic information and characteristics of extreme environments, disaster scenes, and information on sites where human access is difficult

    Injury Risk Estimation Expertise Assessing the ACL Injury Risk Estimation Quiz

    Get PDF
    Background: Available methods for screening anterior cruciate ligament (ACL) injury risk are effective but limited in application as they generally rely on expensive and time-consuming biomechanical movement analysis. A potential efficient alternative to biomechanical screening is skilled movement analysis via visual inspection (ie, having experts estimate injury risk factors based on observations of athletes’ movements). Purpose: To develop a brief, valid psychometric assessment of ACL injury risk factor estimation skill: the ACL Injury Risk Estimation Quiz (ACL-IQ). Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: A total of 660 individuals participated in various stages of the study, including athletes, physicians, physical therapists, athletic trainers, exercise science researchers/students, and members of the general public in the United States. The ACL-IQ was fully computerized and made available online (www.ACL-IQ.org). Item sampling/reduction, reliability analysis, cross-validation, and convergent/discriminant validity analysis were conducted to optimize the efficiency and validity of the assessment. Results: Psychometric optimization techniques identified a short (mean time, 2 min 24 s), robust, 5-item assessment with high reliability (test-retest: r = 0.90) and consistent discriminability (average difference of exercise science professionals vs general population: Cohen d = 1.98). Exercise science professionals and general population individuals scored 74% and 53% correct, respectively. Convergent and discriminant validity was demonstrated. Scores on the ACL-IQ were most associated with ACL knowledge and various cue utilities and were least associated with domain-general spatial/decision-making ability, personality, or other demographic variables. Overall, 23% of the total sample (40% exercise science professionals; 6% general population) performed better than or equal to the ACL nomogram. Conclusion: This study presents the results of a systematic approach to assess individual differences in ACL injury risk factor estimation skill; the assessment approach is efficient (ie, it can be completed in\3 min) and psychometrically robust. The results provide evidence that some individuals have the ability to visually estimate ACL injury risk factors more accurately than other instrument-based ACL risk estimation methods (ie, ACL nomogram). The ACL-IQ provides the foundation for assessing the efficacy of observational ACL injury risk factor assessment (ie, does simple skilled visual inspection reduce ACL injuries?). It also provides a representative task environment that can be used to increase our understanding of the perceptual-cognitive mechanisms underlying observational movement analysis and to improve injury risk assessment performance

    LYVE1 Marks the Divergence of Yolk Sac Definitive Hemogenic Endothelium from the Primitive Erythroid Lineage.

    Get PDF
    The contribution of the different waves and sites of developmental hematopoiesis to fetal and adult blood production remains unclear. Here, we identify lymphatic vessel endothelial hyaluronan receptor-1 (LYVE1) as a marker of yolk sac (YS) endothelium and definitive hematopoietic stem and progenitor cells (HSPCs). Endothelium in mid-gestation YS and vitelline vessels, but not the dorsal aorta and placenta, were labeled by Lyve1-Cre. Most YS HSPCs and erythro-myeloid progenitors were Lyve1-Cre lineage traced, but primitive erythroid cells were not, suggesting that they represent distinct lineages. Fetal liver (FL) and adult HSPCs showed 35%-40% Lyve1-Cre marking. Analysis of circulation-deficient Ncx1-/- concepti identified the YS as a major source of Lyve1-Cre labeled HSPCs. FL proerythroblast marking was extensive at embryonic day (E) 11.5-13.5, but decreased to hematopoietic stem cell (HSC) levels by E16.5, suggesting that HSCs from multiple sources became responsible for erythropoiesis. Lyve1-Cre thus marks the divergence between YS primitive and definitive hematopoiesis and provides a tool for targeting YS definitive hematopoiesis and FL colonization

    Role of sea ice on satellite-observed chlorophyll-a concentration variations during spring bloom in the East/Japan sea

    Get PDF
    The relationship between the spring bloom along the Primorye coast and the sea ice of the Tatarskiy Strait in the northern region of the East/Japan Sea, a semi-enclosed marginal sea in the North Pacific, was investigated using the ten-year SeaWiFS chlorophyll-a concentration data and DMSP/SSMI sea ice concentration data from 1998 to 2007. Year-to-year variations in the chlorophyll-a concentrations in the spring were positively correlated with those of the sea ice concentrations in the Tatarskiy Strait in the previous winter with a correlation coefficient of 0.77. Abrupt increases in nutrients, essential for the spring bloom in the upper ocean during spring, were supplied from sea ice-melted waters. Time series of vertical distributions of the nutrients indicated that phosphate concentrations were extremely elevated in the upper ocean (less than 100 m) without any connection to high concentrations in the deep waters below. The water mass from sea ice provided preferable conditions for the spring bloom through changes in the vertical stratification structure of the water columns. Along-coast ratios of stability parameters between two neighboring months clearly showed the rapid progression of the generation of a shallow pycnocline due to fresh water originating from sea ice. This study addressed the importance of the physical environment for biogeochemical processes in semi-enclosed marginal seas affected by local sea ice. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.1166Ysciescopu

    Nonperturbative Tests of Three-Dimensional Dualities

    Get PDF
    We test several conjectural dualities between strongly coupled superconformal field theories in three dimensions by computing their exact partition functions on a three-sphere as a function of Fayet-Iliopoulos and mass parameters. The calculation is carried out using localization of the path integral and the matrix model previously derived for superconformal N = 2 gauge theories. We verify that the partition functions of quiver theories related by mirror symmetry agree provided the mass parameters and the Fayet-Iliopoulos parameters are exchanged, as predicted. We carry out a similar calculation for the mirror of N = 8 super-Yang-Mills theory and show that its partition function agrees with that of the ABJM theory at unit Chern-Simons level. This provides a nonperturbative test of the conjectural equivalence of the two theories in the conformal limit

    Quand les patients enseignent l’empathie aux Ă©tudiants : une revue systĂ©matique des interventions visant Ă  promouvoir l’empathie chez les Ă©tudiants en mĂ©decine

    Get PDF
    Background: Despite growing emphasis on empathic care, numerous studies demonstrate diminishing empathy in medical students. Involving patient educators in medical curricula may be a solution. Therefore, we conducted a systematic review to evaluate patient-involved interventions that promote empathy among medical students.  Method: A literature search of MEDLINE, Embase, PsycINFO, and ERIC databases was performed using the keywords “empathy,” “medical student,” and their synonyms. Results were independently screened in duplicate. Conflicts were resolved by group consensus. All English studies describing interventions that promote empathy in medical students engaging patient educators were included. Relevant data was extracted and summarized. Results: 1467 studies were screened. 14 studies were included, of which 10 were pilot studies. Studies included patient involved interventions such as storytelling (5/14), shadowing patients (3/14), recorded videos (3/14), or combinations of methods (3/14). Qualitative measurements of empathy included written feedback and group discussions. Quantitative measurements included validated scales measuring empathy. All studies demonstrated increase in empathy among medical students. Participants reported satisfaction with training and patients reported being proud of giving back by training future physicians. Conclusion: Interventions engaging patient educators were shown to have a positive impact on medical student empathy. Furthermore, patient-led education was shown to increase medical student understanding of subject and knowledge retention while empowering patients. Further implementation of patient-involved education is an important step forward in patient-partnered care and may identify additional advantages of patient engagement in medical education.Contexte : MalgrĂ© l’importance grandissante accordĂ©e Ă  l’empathie dans les soins de santĂ©, de nombreuses Ă©tudes dĂ©montrent une diminution de l’empathie chez les Ă©tudiants en mĂ©decine. La participation de patients Ă©ducateurs dans les programmes d’études mĂ©dicales pourrait ĂȘtre une solution. Nous avons donc rĂ©alisĂ© une revue systĂ©matique pour Ă©valuer les interventions qui visent Ă  promouvoir l’empathie chez les Ă©tudiants et qui font participer des patients. MĂ©thode : Nous avons effectuĂ© une recherche dans les bases de donnĂ©es MEDLINE, Embase, PsycINFO et ERIC en utilisant les mots-clĂ©s « empathie », « étudiant en mĂ©decine » et leurs synonymes. Les rĂ©sultats ont Ă©tĂ© examinĂ©s de maniĂšre indĂ©pendante et en double. Les conflits ont Ă©tĂ© rĂ©solus par consensus de groupe. Toutes les Ă©tudes en anglais dĂ©crivant des interventions visant Ă  promouvoir l’empathie chez les Ă©tudiants en mĂ©decine avec la participation de patients Ă©ducateurs ont Ă©tĂ© incluses. Les donnĂ©es pertinentes ont Ă©tĂ© extraites et rĂ©sumĂ©es. RĂ©sultats : Des 1467 études examinĂ©es, 14 ont Ă©tĂ© incluses, dont 10 études pilotes. Les interventions avec des patients mentionnĂ©es dans les Ă©tudes comprenaient des rĂ©cits (5/14), l’observation des patients (3/14), des vidĂ©os enregistrĂ©es (3/14) ou des combinaisons de mĂ©thodes (3/14). Les mesures qualitatives de l’empathie comprenaient des commentaires Ă©crits et des discussions de groupe. Les mesures quantitatives Ă©taient des Ă©chelles validĂ©es mesurant l’empathie. Toutes les Ă©tudes indiquent une augmentation de l’empathie chez les Ă©tudiants en mĂ©decine. Les participants se disent satisfaits de la formation et les patients dĂ©clarent ĂȘtre fiers de redonner aux soignants en contribuant Ă  former les futurs mĂ©decins. Conclusion : Les interventions faisant appel Ă  des patients Ă©ducateurs ont eu un effet positif sur le dĂ©veloppement de l’empathie des Ă©tudiants en mĂ©decine. En outre, il a Ă©tĂ© dĂ©montrĂ© que la participation de patients dans la formation augmentait la comprĂ©hension du sujet et la rĂ©tention des connaissances par les Ă©tudiants en mĂ©decine tout en responsabilisant les patients. La gĂ©nĂ©ralisation de l’intervention des patients dans l’éducation constitue une avancĂ©e importante dans les soins en partenariat avec le patient et pourrait rĂ©vĂ©ler d’autres avantages de la participation des patients dans l’éducation mĂ©dicale

    Supersymmetry enhancement by monopole operators

    Get PDF
    We describe a method which allows one to study hidden symmetries in a large class of strongly coupled supersymmetric gauge theories in three dimensions. We apply this method to the ABJM theory and to the infrared limit of N=4 SQCD with adjoint and fundamental matter. We show that the U(N) ABJM model with Chern-Simons level k=1 or k=2 has hidden N=8 supersymmetry. Hidden supersymmetry is also shown to occur in N=4 d=3 SQCD with one fundamental and one adjoint hypermultiplet. The latter theory, as well as the U(N) ABJM theory at k=1, are shown to have a decoupled free sector. This provides evidence that both models are dual to the infrared limit of N=8 U(N) super-Yang-Mills theory.Comment: 29 pages, late
    • 

    corecore