7,277 research outputs found
Sindbis virus proteins nsP1 and nsP2 contain homology to nonstructural proteins from several RNA plant viruses
Although the genetic organization of tobacco mosaic virus (TMV) differs considerably from that of the tripartite viruses (alfalfa mosaic virus [AlMV] and brome mosaic virus [BMV]), all of these RNA plant viruses share three domains of homology among their nonstructural proteins. One such domain, common to the AlMV and BMV 2a proteins and the readthrough portion of TMV p183, is also homologous to the readthrough protein nsP4 of Sindbis virus (Haseloff et al., Proc. Natl. Acad. Sci. U.S.A. 81:4358-4362, 1984). Two more domains are conserved among the AlMV and BMV 1a proteins and TMV p126. We show here that these domains have homology with portions of the Sindbis proteins nsP1 and nsP2, respectively. These results strengthen the view that the four viruses share mechanistic similarities in their replication strategies and may be evolutionarily related. These results also suggest that either the AlMV 1a, BMV 1a, and TMV p126 proteins are multifunctional or Sindbis proteins nsP1 and nsP2 function together as subunits in a single complex
Rat Poison Kills a Pack of Eastern Coyotes, Canis latrans, in an Urban Area
We document the death of a pack of Eastern Coyotes (Canis latrans) from high levels of brodifacoum, a second generation poison that is the active ingredient in some forms of rat poison (e.g., d-Con®). The Coyotes died within a week of each other during late March/early April 2005. This incident indicates the vulnerability of wild animals to commercial over-the-counter rodenticides
Assessing effect of beat detector on detection dependent signal quality indices
Patient monitoring algorithms which use multimodal physiological waveforms are needed to reduce alarm fatigue by alarming only for physiologic events and not signal artifacts. When combining information from multiple ECG signals, computational approaches that automatically identify artifacts in ECG signals play an important role. Signal quality indices (SQIs) have been derived which can differentiate between ECG signal artifacts and normal QRS morphology. Some of these SQIs are derived using beat detections and might be affected by the beat detector used. Using ECG signals from the PhysioNet/Computing in Cardiology Challenge 2015 training set, we studied the effect of beat detector on previously reported ECG SQIs derived using beat detections. We found that, while being affected by the beat detector, some of these SQIs can predict beat detector failure. Using beat detector specific SQIs can improve the designs of robust monitoring algorithms
The Mixing Rate of the Arterial Blood Pressure Waveform Markov Chain is Correlated with Shock Index during Hemorrhage in Anesthetized Swine
Identifying the need for interventions during hemorrhage is complicated due to physiological compensation mechanisms that can stabilize vital signs until a significant amount of blood loss. Physiological systems providing compensation during hemorrhage affect the arterial blood pressure waveform through changes in dynamics and waveform morphology. We investigated the use of Markov chain analysis of the arterial blood pressure waveform to monitor physiological systems changes during hemorrhage. Continuous arterial blood pressure recordings were made on anesthetized swine (N=7) during a 5 min baseline period and during a slow hemorrhage (10 ml/kg over 30 min). Markov chain analysis was applied to 20 sec arterial blood pressure waveform segments with a sliding window. 20 ranges of arterial blood pressure were defined as states and empirical transition probability matrices were determined for each 20 sec segment. The mixing rate (2nd largest eigenvalue of the transition probability matrix) was determined for all segments. A change in the mixing rate from baseline estimates was identified during hemorrhage for each animal (median time of 13 min, ~10% estimated blood volume, with minimum and maximum times of 2 and 33 min, respectively). The mixing rate was found to have an inverse correlation with shock index for all 7 animals (median correlation coefficient of -0.95 with minimum and maximum of -0.98 and -0.58, respectively). The Markov chain mixing rate of arterial blood pressure recordings is a novel potential biomarker for monitoring and understanding physiological systems during hemorrhage
NYU-VAGC: a galaxy catalog based on new public surveys
Here we present the New York University Value-Added Galaxy Catalog
(NYU-VAGC), a catalog of local galaxies (mostly below a redshift of about 0.3)
based on a set of publicly-released surveys (including the 2dFGRS, 2MASS, PSCz,
FIRST, and RC3) matched to the Sloan Digital Sky Survey (SDSS) Data Release 2.
Excluding areas masked by bright stars, the photometric sample covers 3514
square degrees and the spectroscopic sample covers 2627 square degrees (with
about 85% completeness). Earlier, proprietary versions of this catalog have
formed the basis of many SDSS investigations of the power spectrum, correlation
function, and luminosity function of galaxies. We calculate and compile derived
quantities (for example, K-corrections and structural parameters for galaxies).
The SDSS catalog presented here is photometrically recalibrated, reducing
systematic calibration errors across the sky from about 2% to about 1%. We
include an explicit description of the geometry of the catalog, including all
imaging and targeting information as a function of sky position. Finally, we
have performed eyeball quality checks on a large number of objects in the
catalog in order to flag deblending and other errors. This catalog is
complementary to the SDSS Archive Servers, in that NYU-VAGC's calibration,
geometrical description, and conveniently small size are specifically designed
for studying galaxy properties and large-scale structure statistics using the
SDSS spectroscopic catalog.Comment: accepted by AJ; full resolution version available at
http://sdss.physics.nyu.edu/vagc/va_paper.ps; data files available at
http://sdss.physics.nyu.edu/vagc
Calculation of surface tension via area sampling
We examine the performance of several molecular simulation techniques aimed
at evaluation of the surface tension through its thermodynamic definition. For
all methods explored, the surface tension is calculated by approximating the
change in Helmholtz free energy associated with a change in interfacial area
through simulation of a liquid slab at constant particle number, volume, and
temperature. The methods explored fall within three general classes:
free-energy perturbation, the Bennett acceptance-ratio scheme, and the expanded
ensemble technique. Calculations are performed for both the truncated
Lennard-Jones and square-well fluids at select temperatures spaced along their
respective liquid-vapor saturation lines. Overall, we find that Bennett and
expanded ensemble approaches provide the best combination of accuracy and
precision. All of the methods, when applied using sufficiently small area
perturbation, generate equivalent results for the Lennard-Jones fluid. However,
single-stage free-energy-perturbation methods and the closely related test-area
technique recently introduced by Gloor et al. [J. Chem. Phys. 123, 134703
(2005)], generate surface tension values for the square-well fluid that are not
consistent with those obtained from the more robust expanded ensemble and
Bennett approaches, regardless of the size of the area perturbation.
Single-stage perturbation methods fail also for the Lennard-Jones system when
applied using large area perturbations. Here an analysis of phase-space overlap
produces a quantitative explanation of the observed inaccuracy, and shows that
the satisfactory results obtained in these cases from the test-area method
arise from a cancellation of errors that cannot be expected in general.Comment: 28 pages, 7 figures, to appear in J. Chem. Phys. (07 Nov 2007 issue
The Claims Culture: A Taxonomy of Industry Attitudes
This paper presents an analysis of a familiar aspect of construction industry culture that we have dubbed 'the claims culture'. This is a culture of contract administration that lays a strong emphasis on the planning and management of claims. The principal elements of the analysis are two sets of distinctions. The first comprises economic and occupational orders, referring to two kinds of control that are exercised over the construction process; predicated respectively on economic ownership and occupational competence. The second refers to contrasting attitudes towards relationships and problem solving within these orders: respectively 'distributive' and 'integrative'. The concepts of economic and occupational order entail further sub-categories. The various attitudes associated with these categories and sub-categories are described. They are assessed as to their consequences for change initiatives in the industry
ECGlib: Library for Processing Electrocardiograms
Abstract To facilitate evaluation of ECGs in the FDA ECG Warehouse, public databases and clinical trials we have developed a C++ library for processing ECGs (ECGlib). ECGlib has a modular design, and is capable of handling files stored in many different formats, e.g. ISHNE, Physionet and FDA HL7. Moreover, ECGlib provides functions to do standard ECG signal processing, such as noise removal, QRS detection, classification, median beat creation and ECG waveform delineation. The performance of the different components of ECGlib has been evaluated using publicly available databases from Physionet (MIT-BIH and QTDB). The performance of ECGlib processing methodologies is comparable to state-of-the-art methods. We have also developed a MATLAB/Octave interface for ECGlib and are working on an interface for Python, R and Julia. Lastly, ECGlib comes with a set of command line tools that utilize parallel processing to quickly enable researchers to process large databases. We believe frameworks such as the one described can be used to facilitate research of ECG signals and we are working on making the library publicly available under an open source license
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