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Similar Variability (similar + variability)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Prosthetic Valve Dysfunction Presenting as Intermittent Acute Aortic Regurgitation

ECHOCARDIOGRAPHY, Issue 8 2008
Dali Fan M.D., Ph.D.
We describe the case of a 43 year old man with a history of aortic stenosis, for which he had undergone aortic valve replacement in 1991 with a 25-mm Medtronic Hall prosthesis. He presented with several acute episodes of dyspnea and flash pulmonary edema. Transthoracic and transesophageal echocardiography performed to evaluate prosthetic valve function revealed evidence of "intermittent" episodes of AI, documented on color M-mode flow mapping to have a variable duration of diastolic flow (early vs. pandiastolic) across the left ventricular outflow tract and the pulse wave Doppler in the descending thoracic aorta showed similar variability in the duration of diastolic flow reversal. [source]

Introduction of a Nuclear Marker for Phylogenetic Analysis of Nepenthaceae

PLANT BIOLOGY, Issue 6 2006
H. Meimberg
Abstract: Nepenthaceae, the pitcher plants of the Old World tropics show a remarkable diversity in SE Asia, especially on the islands of Borneo and Sumatra. This region is considered as a secondary center of diversity. Sequence analysis of the cpDNA trnK intron supports this hypothesis showing the species of the Malay Archipelago as neighbour group to the isolated species from Sri Lanka, the Seychelles, and Madagascar. Based on phylogenetic reconstructions an origin of recent Nepenthaceae in the Indian subcontinent is assumed. A recent investigation focused on a non-plastid, translocated copy of the trnK intron has revealed an incongruence to tree topology based on the cpDNA trnK intron. Although the translocated copy emerged as insufficient for phylogenetic reconstruction of Nepenthaceae some taxa showed, contrary to the cpDNA dataset, relatively high distances to the rest of the taxa. These results indicated that the phylogeny of the trnK intron could not reflect true phylogenetic relationships. We investigated the peptide transferase 1 (PTR1), to develop a phylogenetic marker that is based on a nuclear low copy gene in Nepenthes. All sequences obtained were probably functional, indicated by the ratio of point mutations of the single codon positions in exon and intron regions. Comparative analysis showed that this locus is of similar variability as the cpDNA trnK intron and, contrary to the translocated copy of trnK, potential useful for phylogenetic reconstruction. While in parts congruent to the plastid trnK intron phylogeny, a higher divergence of some sequences in PRT1 and in the previously reported, non cpDNA dataset indicates that remnants of an older species stock persisted east of Wallace's line and on the Sunda Shelf. This suggests that plastid haplotypes existing today in the main distribution center of the Nepenthaceae could be descendants of more recently dispersed lineages that had been transmitted to an old species stock. [source]

Asymmetric volatility of basis and the theory of storage

THE JOURNAL OF FUTURES MARKETS, Issue 4 2005
Andre H. Gao
The theory of storage states that the marginal convenience yield on inventory falls at a decreasing rate as inventory increases. Previous literature has tested this hypothesis using the so-called "direct test" approach, which employs a direct measurement of inventory levels, or the "indirect test" approach, which examines the relative variation of spot and futures prices and the relative variation of negative basis to positive basis as alternative proxies for inventory levels. The rationale behind the indirect test is based on the hypothesis that futures prices are less variable than spot prices when inventory is low, and have similar variability when inventory is high. The authors propose a "unified test" of the theory of storage that incorporates aspects of both direct and indirect tests in an ARMAX-asymmetric GARCH model framework. © 2005 Wiley Periodicals, Inc. Jrl Fut Mark 25:399,418, 2005 [source]

Are All Trauma Centers Created Equally?

ACADEMIC EMERGENCY MEDICINE, Issue 7 2010
A Statewide Analysis
ACADEMIC EMERGENCY MEDICINE 2010; 17:701,708 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, Prior work has shown differences in mortality at different levels of trauma centers (TCs). There are limited data comparing mortality of equivalently verified TCs. This study sought to assess the potential differences in mortality as well as discharge destination (discharge to home vs. to a rehabilitation center or skilled nursing facility) across Level I TCs in the state of Ohio. Methods:, This was a retrospective, multicenter, statewide analysis of a state trauma registry of American College of Surgeons (ACS)-verified Level I TCs from 2003 to 2006. All adult (>15 years) patients transferred from the scene to one of the 10 Level I TCs throughout the state were included (n = 16,849). Multivariable logistic regression models were developed to assess for differences in mortality, keeping each TC as a fixed-effect term and adjusting for patient demographics, injury severity, mechanism of injury, and emergency medical services and emergency department procedures. Outcomes included in-hospital mortality and discharge destination (home vs. rehabilitation center or skilled nursing facility). Adjusted odds ratios (ORs) for each TC were also calculated. Results:, Considerable variability existed in unadjusted mortality between the centers, from 3.8% (95% confidence interval [CI] = 3.7% to 3.9%) to 24.2% (95% CI = 24.1% to 24.3%), despite similar patient characteristics and injury severity. Adjusted mortality had similar variability as well, ranging from an OR of 0.93 (95% CI = 0.47 to 1.84) to an OR of 6.02 (95% CI= 3.70 to 9.79). Similar results were seen with the secondary outcomes (discharge destination). Conclusions:, There is considerable variability in the mortality of injured patients at Level I TCs in the state of Ohio. The patient differences or care processes responsible for this variation should be explored. [source]