891 resultados para Phylogenetic Position
Resumo:
Whilst the decision regarding defibrillator implantation in a patient with a familial sudden cardiac death syndrome is likely to be most significant for any particular individual, the clinical decision-making process itself is complex and requires interpretation and extrapolation of information from a number of different sources. This document provides recommendations for adult patients with the congenital Long QT syndromes, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy. Although these specific conditions differ in terms of clinical features and prognosis, it is possible and logical to take an approach to determining a threshold for implantable cardioveter-defibrillator implantation that is common to all of the familial sudden cardiac death syndromes based on estimates of absolute risk of sudden death. Published on behalf of the European Society of Cardiology. © The Author 2010.
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In this article, we present position indication functionality as obtained by using a retrodirective array, thereby allowing location information extraction of the position of the remote transmitter with which the retrodirective array is cooperating. This is carried out using straightforward circuitry with no requirement for complex angle of arrival algorithms, thereby giving a result in real time enabling tracking of fast moving transmitters. We show using a 10 x element retrodirective array, operating at 2.4 GHz that accuracies of far-field angle of arrival of within +/- 1 degrees over the arrays +/- 30 degrees azimuth field of view are possible. While in the near-field for angles of arrival of +/- 10 degrees it is possible to extract the position of a dipole source down to a resolution of 032 lambda. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1031-1034, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25097
Resumo:
Anew species of fossil polyplacophoran from the Danian (Lower Palaeocene) of Denmark is described from over 450 individual disarticulated plates. The polyplacophorans originate from the 'nose-chalk' in the classical Danish locality of Fakse Quarry, an unconsolidated coral limestone in which aragonitic mollusc shells are preserved through transformation into calcite. In plate architecture and sculpture, the new Danish material is similar to Recent Leptochiton spp., but differs in its underdeveloped apophyses and high dorsal elevation (height/width ca. 0.54). Cladistic analysis of 55 original shell characters coded for more than loo Recent and fossil species in the order Lepiclopleurida shows very high resolution of interspecific relationships, but does not consistently recover traditional genera or subgenera. Inter-relationships within the suborder Lepidopleurina are of particular interest as it is often considered the most 'basal' neoloricate lineage. In a local context, the presence of chitons in the faunal assemblage of Fakse contributes evidence of shallow depositional depth for at least some elements of this Palaeocene seabed, a well-studied formation of azooxanthellic coral limestones. This new record for Denmark represents a well-dated and ecologically well-understood fossil chiton with potential value for understanding the radiation of the Neotoricata.
Resumo:
The position of the earliest-derived living molluscs, the Polyplacophora ( chitons) and shell-less vermiform Aplacophora, remains highly contentious despite many morphological, developmental and molecular studies of extant organisms. These two groups are thought to represent either a basal molluscan grade or a clade (Aculifera) sister to the 'higher' molluscs (Conchifera). These incompatible hypotheses result in very different predictions about the earliest molluscs. A new cladistic analysis incorporating both Palaeozoic and extant molluscs is presented here. Our results support the monophyly of Aculifera and suggest that extant aplacophorans and polyplacophorans both derive from a disparate group of multivalved molluscs in two major clades. Reanalysis of the critical Ordovician taxon 'Helminthochiton' thraivensis shows that this animal lacks a true foot despite bearing polyplacophoran-like valves. Its position within our phylogenetic reconstruction indicates that many fossil 'polyplacophorans' in the order Palaeoloricata are likely to represent footless stem-group aplacophorans. 'H.' thraivensis and similar forms such as Acaenoplax may be morphological stepping stones between chitons and the shell-less aplacophorans. Our results imply that crown-group molluscan synapomorphies include serial repetition, the presence of a foot, a mineralized scleritome and a creeping rather than worm-like mode of life.
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This study demonstrated key resistance genes to fluroquinilones in Streptococcci isolated from sputum of people with CF. This suggests that other bacteria which are sometimes considered commensal may be a resovoir for resistance. Jse designed the study with Moore.
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We have surveyed the frequency band 218.30-263.55 GHz toward the core positions N and M and the quiescent cloud position NW in the Sgr B2 molecular cloud using the Swedish-ESO Submillimetre Telescope. In total 1730, 660, and 110 lines were detected in N, M, and NW, respectively, and 42 different molecular species were identified. The number of unidentified lines are 337, 51, and eight. Toward the N source, spectral line emission constitutes 22% of the total detected flux in the observed band, and complex organic molecules are the main contributors. Toward M, 14% of the broadband flux is caused by lines, and SO2 is here the dominant source of emission. NW is relatively poor in spectral lines and continuum. In this paper we present the spectra together with tables of suggested line identifications.
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Objectives. We examined the associations between socioeconomic position, co-occurrence of behavior-related risk factors, and the effect of these factors on the relative and absolute socioeconomic gradients in coronary heart disease.
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Bystander effects, whereby cells that are not directly exposed to ionizing radiation exhibit adverse biological effects, have been observed in a number of experimental systems. A novel stochastic model of the radiation-induced bystander effect is developed that takes account of spatial location, cell killing and repopulation. The ionizing radiation dose- and time-responses of this model are explored, and it is shown to exhibit pronounced downward curvature in the high dose-rate region, similar to that observed in many experimental systems, reviewed in the paper. It is also shown to predict the augmentation of effect after fractionated delivery of dose that has been observed in certain experimental systems. It is shown that the generally intractable solution of the full stochastic system can be considerably simplified by assumption of pairwise conditional dependence that varies exponentially over time. (C) 2004 Elsevier Ltd. All rights reserved.