4,475 research outputs found
Four-Parameter white blood cell differential counting based on light scattering measurements
Measurement of the depolarized orthogonal light scattering in flow cytometry enables one to discriminate human eosinephilic granulocytes from neutrophilic granulocytes. We use this method to perform a four-parameter differential white blood cell analysis. \ud
A simple flow cytometer was built equipped with a 5-mW helium neon laser that measures simultaneously four light scattering parameters. Lymphocytes, monocytes, and granulocytes were identified by simultaneously measuring the light scattering intensity at angles between 1.0° and 2.6° and angles between 3.0° and 11.0°. Eosinophilic granulocytes were distinguished from neutrophilic granulocytes by simultaneous measurement of the orthogonal and depolarized orthogonal light scattering. \ud
Comparison of a white blood cell differentiation of 45 donors obtained by the Technicon H-6000 and our instrument revealed good correlations. The correlation coefficients (r2) found were: 0.99 for lymphocytes, 0.76 for monocytes, 0.99 for neutrophilic granulocytes, and 0.98 for eosinophilic granulocytes. The results demonstrate that reliable white blood cell differentiation of the four most clinically relevant leukocytes can be obtained by measurement of light scattering properties of unstained leukocytes
Simple modules for the partition algebra and monotone convergence of Kronecker coefficients
We construct bases of the simple modules for partition algebras which are indexed by paths in an alcove geometry. This allows us to give a concrete interpretation (and new proof) of the monotone convergence property for Kronecker coefficients using stratifications of the cell modules of the partition algebra
Image patch analysis of sunspots and active regions. II. Clustering via matrix factorization
Separating active regions that are quiet from potentially eruptive ones is a
key issue in Space Weather applications. Traditional classification schemes
such as Mount Wilson and McIntosh have been effective in relating an active
region large scale magnetic configuration to its ability to produce eruptive
events. However, their qualitative nature prevents systematic studies of an
active region's evolution for example. We introduce a new clustering of active
regions that is based on the local geometry observed in Line of Sight
magnetogram and continuum images. We use a reduced-dimension representation of
an active region that is obtained by factoring the corresponding data matrix
comprised of local image patches. Two factorizations can be compared via the
definition of appropriate metrics on the resulting factors. The distances
obtained from these metrics are then used to cluster the active regions. We
find that these metrics result in natural clusterings of active regions. The
clusterings are related to large scale descriptors of an active region such as
its size, its local magnetic field distribution, and its complexity as measured
by the Mount Wilson classification scheme. We also find that including data
focused on the neutral line of an active region can result in an increased
correspondence between our clustering results and other active region
descriptors such as the Mount Wilson classifications and the value. We
provide some recommendations for which metrics, matrix factorization
techniques, and regions of interest to use to study active regions.Comment: Accepted for publication in the Journal of Space Weather and Space
Climate (SWSC). 33 pages, 12 figure
Image patch analysis of sunspots and active regions. I. Intrinsic dimension and correlation analysis
The flare-productivity of an active region is observed to be related to its
spatial complexity. Mount Wilson or McIntosh sunspot classifications measure
such complexity but in a categorical way, and may therefore not use all the
information present in the observations. Moreover, such categorical schemes
hinder a systematic study of an active region's evolution for example. We
propose fine-scale quantitative descriptors for an active region's complexity
and relate them to the Mount Wilson classification. We analyze the local
correlation structure within continuum and magnetogram data, as well as the
cross-correlation between continuum and magnetogram data. We compute the
intrinsic dimension, partial correlation, and canonical correlation analysis
(CCA) of image patches of continuum and magnetogram active region images taken
from the SOHO-MDI instrument. We use masks of sunspots derived from continuum
as well as larger masks of magnetic active regions derived from the magnetogram
to analyze separately the core part of an active region from its surrounding
part. We find the relationship between complexity of an active region as
measured by Mount Wilson and the intrinsic dimension of its image patches.
Partial correlation patterns exhibit approximately a third-order Markov
structure. CCA reveals different patterns of correlation between continuum and
magnetogram within the sunspots and in the region surrounding the sunspots.
These results also pave the way for patch-based dictionary learning with a view
towards automatic clustering of active regions.Comment: Accepted for publication in the Journal of Space Weather and Space
Climate (SWSC). 23 pages, 11 figure
Relativistic and correlation effects on molecular properties - the interhalogens CIF, BrF, BrCI, IF, ICI and IBr
The effect of relativity on the properties of the interhalogens ClF, BrF, BrCl, IF, IBr, and IBr is studied by comparing relativistic and nonrelativistic calculations. Bond lengths, harmonic frequencies, and dissociation energies show that the bond is weakened in the relativistic formalism. Relativity increases the electric dipole moment whereas the electric quadrupole moment and dipole polarizability display an irregular behavior. The relativistic contributions to the electric dipole and quadrupole moment of the iodine containing molecules are 10%–20% of the total value, whereas the contributions in the other molecules cannot be neglected. The value of the electric quadrupole moment is dominated by the relativistic contributions
Improvements on coronal hole detection in SDO/AIA images using supervised classification
We demonstrate the use of machine learning algorithms in combination with
segmentation techniques in order to distinguish coronal holes and filaments in
SDO/AIA EUV images of the Sun. Based on two coronal hole detection techniques
(intensity-based thresholding, SPoCA), we prepared data sets of manually
labeled coronal hole and filament channel regions present on the Sun during the
time range 2011 - 2013. By mapping the extracted regions from EUV observations
onto HMI line-of-sight magnetograms we also include their magnetic
characteristics. We computed shape measures from the segmented binary maps as
well as first order and second order texture statistics from the segmented
regions in the EUV images and magnetograms. These attributes were used for data
mining investigations to identify the most performant rule to differentiate
between coronal holes and filament channels. We applied several classifiers,
namely Support Vector Machine, Linear Support Vector Machine, Decision Tree,
and Random Forest and found that all classification rules achieve good results
in general, with linear SVM providing the best performances (with a true skill
statistic of ~0.90). Additional information from magnetic field data
systematically improves the performance across all four classifiers for the
SPoCA detection. Since the calculation is inexpensive in computing time, this
approach is well suited for applications on real-time data. This study
demonstrates how a machine learning approach may help improve upon an
unsupervised feature extraction method.Comment: in press for SWS
New Developments in MadGraph/MadEvent
We here present some recent developments of MadGraph/MadEvent since the
latest published version, 4.0. These developments include: Jet matching with
Pythia parton showers for both Standard Model and Beyond the Standard Model
processes, decay chain functionality, decay width calculation and decay
simulation, process generation for the Grid, a package for calculation of
quarkonium amplitudes, calculation of Matrix Element weights for experimental
events, automatic dipole subtraction for next-to-leading order calculations,
and an interface to FeynRules, a package for automatic calculation of Feynman
rules and model files from the Lagrangian of any New Physics model.Comment: 6 pages, 3 figures. Plenary talk given at SUSY08, Seoul, South Korea,
June 2008. To appear in the proceeding
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