808 research outputs found
Pyrcca: Regularized Kernel Canonical Correlation Analysis in Python and Its Applications to Neuroimaging
Canonical correlation analysis (CCA) is a valuable method for interpreting
cross-covariance across related datasets of different dimensionality. There are
many potential applications of CCA to neuroimaging data analysis. For instance,
CCA can be used for finding functional similarities across fMRI datasets
collected from multiple subjects without resampling individual datasets to a
template anatomy. In this paper, we introduce Pyrcca, an open-source Python
module for executing CCA between two or more datasets. Pyrcca can be used to
implement CCA with or without regularization, and with or without linear or a
Gaussian kernelization of the datasets. We demonstrate an application of CCA
implemented with Pyrcca to neuroimaging data analysis. We use CCA to find a
data-driven set of functional response patterns that are similar across
individual subjects in a natural movie experiment. We then demonstrate how this
set of response patterns discovered by CCA can be used to accurately predict
subject responses to novel natural movie stimuli
Impact ionization fronts in Si diodes: Numerical evidence of superfast propagation due to nonlocalized preionization
We present numerical evidence of a novel propagation mode for superfast
impact ionization fronts in high-voltage Si -- structures. In
nonlinear dynamics terms, this mode corresponds to a pulled front propagating
into an unstable state in the regime of nonlocalized initial conditions. Before
the front starts to travel, field-ehanced emission of electrons from deep-level
impurities preionizes initially depleted base creating spatially nonuniform
free carriers profile. Impact ionization takes place in the whole high-field
region. We find two ionizing fronts that propagate in opposite directions with
velocities up to 10 times higher than the saturated drift velocity.Comment: 3 pages, 4 figure
Reducing the distortion in thin-sheet structures made from high-strength steel based on CAE-welded joint analysis
High competition in the field of mechanical engineering requires the manufacture of lightweight thin-sheet structures made of high-strength steels ensuring the geometry of a certain accuracy. Supporting a given geometry is achievable by improving methods to reduce residual deformations. Therefore, the purpose of the investigation is to reduce the distortion based on the analysis of the influence of clamping rigidity on the stress-strain state of the assembly using computer simulation by the finite element method. The result of the study is a clamping model that allows to adjust the level of residual stresses and deformations, confirmed experimentally. © 2019 IOP Publishing Ltd.Foundation for Assistance to Small Innovative Enterprises in Science and Technology, FASIE: 11995GU/2017The present study was supported by FASIE Grant №11995GU/2017. This work was done within the state order of IMP UB RAS on the subject “Laser”
USING OF LONG ACTION ERYTHROPOES STIMULATED AGENTS FOR TREATMENT OF ANEMIA IN PATIENTS WITH CHRONIC KIDNEY DISEASES V D ST
the article describes approaches to cost optimization of anemia treatment in CKD–VDst. patients by comparison of costs in phase correction and support treatment with long action ESA in patients on HD and HDF.
Aims. To reveal the influence of HD and HDF to summary dozes of ESA in anemia treatment, to reveal the influence of different long action ESA to hemoglobin variability and find connection between HD, HDF and ESA type to cost of ESA using.
Materials and methods. There were 14 patients on HD and 14 on HDF. All patients were treated with dialysis 3 time per week, session duration was 4,5–5 hours. eKt/У were 1,39±0,06 in HDF group and 1,29±0,07 in HD group. Mean hemoglobin was 98,3±2,46 g/l in HDF group and 92,76±2,46 g/l in HD group. In correction phase we used pegylated erythropoietin–p in both groups before achievement target hemoglobin 110 g/l, then was support phase ofanemia treatment during 6 months with hemoglobin target 100g/l to 120 g/l. Next 6 months patients were switched to darbepoetin alfa.
Results. It is investigated optimization of anemia correction with long action ESP in patients on HD and HDF. It is revealed a tendency to decrease treatment cost with pegylated erythropoietin–p compared to darbepoetin alfa (1965,13±250,69 vs 2117,39±147,59 Gr/mth) and HDF group compared HD group with pegylated erythropoietin–p (1983,9±345,9 vs 1950,69±367,1 Gr/mth). Treatment with darbepoetin alfa associated with higher hemoglobin variability compared with pegylated erythropoietin–p.
Conclusion. The result of our investigation lead to prove some hope to optimization of anemia treatment in patients with CKD Vst. On hemodialysis, but to have statistically reliability we need lager patients groups
Response of the solar atmosphere to magnetic field evolution in a coronal hole region
Methods. We study an equatorial CH observed simultaneously by HINODE and
STEREO on July 27, 2007. The HINODE/SP maps are adopted to derive the physical
parameters of the photosphere and to research the magnetic field evolution and
distribution. The G band and Ca II H images with high tempo-spatial resolution
from HINODE/BFI and the multi-wavelength data from STEREO/EUVI are utilized to
study the corresponding atmospheric response of different overlying layers.
Results. We explore an emerging dipole locating at the CH boundary. Mini-scale
arch filaments (AFs) accompanying the emerging dipole were observed with the Ca
II H line. During the separation of the dipolar footpoints, three AFs appeared
and expanded in turn. The first AF divided into two segments in its late stage,
while the second and third AFs erupted in their late stages. The lifetimes of
these three AFs are 4, 6, 10 minutes, and the two intervals between the three
divisions or eruptions are 18 and 12 minutes, respectively. We display an
example of mixed-polarity flux emergence of IN fields within the CH and present
the corresponding chromospheric response. With the increase of the integrated
magnetic flux, the brightness of the Ca II H images exhibits an increasing
trend. We also study magnetic flux cancellations of NT fields locating at the
CH boundary and present the obvious chromospheric and coronal response. We
notice that the brighter regions seen in the 171 A images are relevant to the
interacting magnetic elements. By examining the magnetic NT and IN elements and
the response of different atmospheric layers, we obtain good positive linear
correlations between the NT magnetic flux densities and the brightness of both
G band (correlation coefficient 0.85) and Ca II H (correlation coefficient
0.58).Comment: 9 pages, 9 figures. A&A, in pres
First LIGO search for gravitational wave bursts from cosmic (super)strings
We report on a matched-filter search for gravitational wave bursts from
cosmic string cusps using LIGO data from the fourth science run (S4) which took
place in February and March 2005. No gravitational waves were detected in 14.9
days of data from times when all three LIGO detectors were operating. We
interpret the result in terms of a frequentist upper limit on the rate of
gravitational wave bursts and use the limits on the rate to constrain the
parameter space (string tension, reconnection probability, and loop sizes) of
cosmic string models.Comment: 11 pages, 3 figures. Replaced with version submitted to PR
Characteristics of undernourished older medical patients and the identification of predictors for undernutrition status
<p>Abstract</p> <p>Background</p> <p>Undernutrition among older people is a continuing source of concern, particularly among acutely hospitalized patients. The purpose of the current study is to compare malnourished elderly patients with those at nutritional risk and identify factors contributing to the variability between the groups.</p> <p>Methods</p> <p>The study was carried out at the Soroka University Medical Center in the south of Israel. From September 2003 through December 2004, all patients 65 years-of-age or older admitted to any of the internal medicine departments, were screened within 72 hours of admission to determine nutritional status using the short version of the Mini Nutritional Assessment (MNA-SF). Patients at nutritional risk were entered the study and were divided into malnourished or 'at risk' based on the full version of the MNA. Data regarding medical, nutritional, functional, and emotional status were obtained by trained interviewers.</p> <p>Results</p> <p>Two hundred fifty-nine elderly patients, 43.6% men, participated in the study; 18.5% were identified as malnourished and 81.5% were at risk for malnutrition according to the MNA. The malnourished group was less educated, had a higher depression score and lower cognitive and physical functioning. Higher prevalence of chewing problems, nausea, and vomiting was detected among malnourished patients. There was no difference between the groups in health status indicators except for subjective health evaluation which was poorer among the malnourished group. Lower dietary score indicating lower intake of vegetables fruits and fluid, poor appetite and difficulties in eating distinguished between malnourished and at-risk populations with the highest sensitivity and specificity as compare with the anthropometric, global, and self-assessment of nutritional status parts of the MNA. In a multivariate analysis, lower cognitive function, education <12 years and chewing problems were all risk factors for malnutrition.</p> <p>Conclusion</p> <p>Our study indicates that low food consumption as well as poor appetite and chewing problems are associated with the development of malnutrition. Given the critical importance of nutritional status in the hospitalized elderly, further intervention trials are required to determine the best intervention strategies to overcome these problems.</p
Stacked Search for Gravitational Waves from the 2006 SGR 1900+14 Storm
We present the results of a LIGO search for short-duration gravitational
waves (GWs) associated with the 2006 March 29 SGR 1900+14 storm. A new search
method is used, "stacking'' the GW data around the times of individual
soft-gamma bursts in the storm to enhance sensitivity for models in which
multiple bursts are accompanied by GW emission. We assume that variation in the
time difference between burst electromagnetic emission and potential burst GW
emission is small relative to the GW signal duration, and we time-align GW
excess power time-frequency tilings containing individual burst triggers to
their corresponding electromagnetic emissions. We use two GW emission models in
our search: a fluence-weighted model and a flat (unweighted) model for the most
electromagnetically energetic bursts. We find no evidence of GWs associated
with either model. Model-dependent GW strain, isotropic GW emission energy
E_GW, and \gamma = E_GW / E_EM upper limits are estimated using a variety of
assumed waveforms. The stacking method allows us to set the most stringent
model-dependent limits on transient GW strain published to date. We find E_GW
upper limit estimates (at a nominal distance of 10 kpc) of between 2x10^45 erg
and 6x10^50 erg depending on waveform type. These limits are an order of
magnitude lower than upper limits published previously for this storm and
overlap with the range of electromagnetic energies emitted in SGR giant flares.Comment: 7 pages, 3 figure
Searching for gravitational waves from known pulsars
We present upper limits on the amplitude of gravitational waves from 28
isolated pulsars using data from the second science run of LIGO. The results
are also expressed as a constraint on the pulsars' equatorial ellipticities. We
discuss a new way of presenting such ellipticity upper limits that takes
account of the uncertainties of the pulsar moment of inertia. We also extend
our previous method to search for known pulsars in binary systems, of which
there are about 80 in the sensitive frequency range of LIGO and GEO 600.Comment: Accepted by CQG for the proceeding of GWDAW9, 7 pages, 2 figure
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