614 research outputs found

    Segregation patterns of Neurospora chromosome ends: mapping chromosome tips.

    Get PDF
    Segregation patterns of Neurospora chromosome ends: mapping chromosome tips

    Segregation patterns of Neurospora chromosome ends: mapping chromosome tips.

    Get PDF
    Segregation patterns of Neurospora chromosome ends: mapping chromosome tips

    Atherosclerosis of the ascending aorta is a predictor of renal dysfunction after cardiac operations

    Get PDF
    AbstractObjectives: Renal dysfunction occurring after cardiac operations has been attributed to various factors, but the importance of an atherosclerotic thoracic aorta has not been previously evaluated. The purpose of this study was to identify predictors of postoperative renal dysfunction (50% or more increase from preoperative values) and to evaluate the importance of atherosclerosis of the ascending aorta as a predictor of this complication. Methods: Nine hundred seventy-eight consecutive patients, 50 years of age and older with normal preoperative renal function (serum creatinine level of 1.5 mg/dL or less), who were scheduled to undergo cardiac surgery were prospectively evaluated. Atherosclerosis of the ascending aorta was assessed during the operation (with epiaortic ultrasound), and patients were divided into 3 groups according to its severity (normal-to-mild, moderate, and severe). Results: Univariate predictors of renal dysfunction at postoperative day 1 were atherosclerosis of the ascending aorta (P < .045) and postoperative low cardiac output (P = .05); at postoperative day 6 they were atherosclerosis of the ascending aorta (P < .0001), postoperative low cardiac output (P < .0001), advanced age (P = .001), decreased preoperative left ventricular function (P = .01), and female gender (P = .03). Multivariate analysis showed that atherosclerosis of the ascending aorta (odds ratio, 3.06; P = .04) was the only independent predictor of postoperative renal dysfunction at day 1 and that postoperative low cardiac output (odds ratio, 4.83; P < .0001), atherosclerosis of the ascending aorta (odds ratio, 2.13; P = .0006), and preoperative left ventricular dysfunction (odds ratio, 1.48; P = .028) were independent predictors of postoperative renal dysfunction at day 6. Conclusions: An atherosclerotic ascending aorta is an important predictor of postoperative renal dysfunction, possibly because atheroembolism to the kidneys occurs in the perioperative period (ie, during surgical manipulation of an atherosclerotic aorta) or because the diseased aorta may be a marker of widespread atherosclerotic disease that may predispose to perioperative renal dysfunction. (J Thorac Cardiovasc Surg 1999;117:111-6

    Independent individual addressing of multiple neutral atom qubits with a MEMS beam steering system

    Full text link
    We demonstrate a scalable approach to addressing multiple atomic qubits for use in quantum information processing. Individually trapped 87Rb atoms in a linear array are selectively manipulated with a single laser guided by a MEMS beam steering system. Single qubit oscillations are shown on multiple sites at frequencies of ~3.5 MHz with negligible crosstalk to neighboring sites. Switching times between the central atom and its closest neighbor were measured to be 6-7 us while moving between the central atom and an atom two trap sites away took 10-14 us.Comment: 9 pages, 3 figure

    Dynamical differential equations compatible with rational qKZ equations

    Full text link
    For the Lie algebra glNgl_N we introduce a system of differential operators called the dynamical operators. We prove that the dynamical differential operators commute with the glNgl_N rational quantized Knizhnik-Zamolodchikov difference operators. We describe the transformations of the dynamical operators under the natural action of the glNgl_N Weyl group.Comment: 7 pages, AmsLaTe

    Quantum W-algebras and Elliptic Algebras

    Full text link
    We define quantum W-algebras generalizing the results of Reshetikhin and the second author, and Shiraishi-Kubo-Awata-Odake. The quantum W-algebra associated to sl_N is an associative algebra depending on two parameters. For special values of parameters it becomes the ordinary W-algebra of sl_N, or the q-deformed classical W-algebra of sl_N. We construct free field realizations of the quantum W-algebras and the screening currents. We also point out some interesting elliptic structures arising in these algebras. In particular, we show that the screening currents satisfy elliptic analogues of the Drinfeld relations in U_q(n^).Comment: 26 pages, AMSLATE

    Online Embeddings

    Get PDF
    13th International Workshop, APPROX 2010, and 14th International Workshop, RANDOM 2010, Barcelona, Spain, September 1-3, 2010. ProceedingsWe initiate the study of on-line metric embeddings. In such an embedding we are given a sequence of n points X = x [subscript 1],...,x [subscript n] one by one, from a metric space M = (X,D). Our goal is to compute a low-distortion embedding of M into some host space, which has to be constructed in an on-line fashion, so that the image of each x i depends only on x [subscript 1],...,x [subscript i] . We prove several results translating existing embeddings to the on-line setting, for the case of embedding into ℓ [subscript p] spaces, and into distributions over ultrametrics

    Survey of anesthesiologists on anesthetic maintenance techniques and total intravenous anesthesia for endoscopic sinus surgery

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154490/1/alr22500.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154490/2/alr22500_am.pd

    Almost-Euclidean subspaces of â„“1N\ell_1^N via tensor products: a simple approach to randomness reduction

    Get PDF
    It has been known since 1970's that the N-dimensional ℓ1\ell_1-space contains nearly Euclidean subspaces whose dimension is Ω(N)\Omega(N). However, proofs of existence of such subspaces were probabilistic, hence non-constructive, which made the results not-quite-suitable for subsequently discovered applications to high-dimensional nearest neighbor search, error-correcting codes over the reals, compressive sensing and other computational problems. In this paper we present a "low-tech" scheme which, for any a>0a > 0, allows to exhibit nearly Euclidean Ω(N)\Omega(N)-dimensional subspaces of ℓ1N\ell_1^N while using only NaN^a random bits. Our results extend and complement (particularly) recent work by Guruswami-Lee-Wigderson. Characteristic features of our approach include (1) simplicity (we use only tensor products) and (2) yielding "almost Euclidean" subspaces with arbitrarily small distortions.Comment: 11 pages; title change, abstract and references added, other minor change
    • …
    corecore