899,343 research outputs found
Web Science is Growing Up: interdisciplinary insights and a maturing community at WebSci ’11
ACM Web Science 2011, which ran from 14 – 17 June in Koblenz, Germany, is one of the more interdisciplinary ACM conferences: unlike ACM WWW, which focuses on infrastructure, standards and development, Web Science concerns the Web as an unfolding process. It examines the Web and our society, including politics, economics and law
ACM sheaves on the double plane
The goal of this paper is to start a study of aCM and Ulrich sheaves on
non-integral projective varieties. We show that any aCM vector bundle of rank
two on the double plane is a direct sum of line bundles. As a by-product, any
aCM vector bundle of rank two on a sufficiently high dimensional quadric
hypersurface also splits. We consider aCM and Ulrich vector bundles on a
multiple hyperplanes and prove the existence of such bundles that do not split,
if the multiple hyperplane is linearly embedded into a sufficiently high
dimensional projective space. Then we restrict our attention to the double
plane and give a classification of aCM sheaves of rank at most on the
double plane and describe the family of isomorphism classes of them.Comment: 33 pages; Major changes in Section 3, 4 and 7; several typos
corrected; Comments welcom
ACM bundles on del Pezzo surfaces
ACM rank 1 bundles on del Pezzo surfaces are classified in terms of the
rational normal curves that they contain. A complete list of ACM line bundles
is provided. Moreover, for any del Pezzo surface of degree less or equal
than six and for any we construct a family of dimension of
non-isomorphic simple ACM bundles of rank on
Sudden Death and Left Ventricular Involvement in Arrhythmogenic Cardiomyopathy
BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is an inherited heart muscle disorder characterized by myocardial fibrofatty replacement and an increased risk of sudden cardiac death (SCD). Originally described as a right ventricular disease, ACM is increasingly recognized as a biventricular entity. We evaluated pathological, genetic, and clinical associations in a large SCD cohort. METHODS: We investigated 5205 consecutive cases of SCD referred to a national cardiac pathology center between 1994 and 2018. Hearts and tissue blocks were examined by expert cardiac pathologists. After comprehensive histological evaluation, 202 cases (4%) were diagnosed with ACM. Of these, 15 (7%) were diagnosed antemortem with dilated cardiomyopathy (n=8) or ACM (n=7). Previous symptoms, medical history, circumstances of death, and participation in competitive sport were recorded. Postmortem genetic testing was undertaken in 24 of 202 (12%). Rare genetic variants were classified according to American College of Medical Genetics and Genomics criteria. RESULTS: Of 202 ACM decedents (35.4±13.2 years; 82% male), no previous cardiac symptoms were reported in 157 (78%). Forty-one decedents (41/202; 20%) had been participants in competitive sport. The adjusted odds of dying during physical exertion were higher in men than in women (odds ratio, 4.58; 95% CI, 1.54-13.68; P=0.006) and in competitive athletes in comparison with nonathletes (odds ratio, 16.62; 95% CI, 5.39-51.24; P<0.001). None of the decedents with an antemortem diagnosis of dilated cardiomyopathy fulfilled definite 2010 Task Force criteria. The macroscopic appearance of the heart was normal in 40 of 202 (20%) cases. There was left ventricular histopathologic involvement in 176 of 202 (87%). Isolated right ventricular disease was seen in 13%, isolated left ventricular disease in 17%, and biventricular involvement in 70%. Among whole hearts, the most common areas of fibrofatty infiltration were the left ventricular posterobasal (68%) and anterolateral walls (58%). Postmortem genetic testing yielded pathogenic variants in ACM-related genes in 6 of 24 (25%) decedents. CONCLUSIONS: SCD attributable to ACM affects men predominantly, most commonly occurring during exertion in athletic individuals in the absence of previous reported cardiac symptoms. Left ventricular involvement is observed in the vast majority of SCD cases diagnosed with ACM at autopsy. Current Task Force criteria may fail to diagnose biventricular ACM before death
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