551 research outputs found
Canonical analysis based on scatter matrices.
In this paper, the influence functions and limiting distributions of the canonical correlations and coefficients based on affine equivariant scatter matrices are developed for elliptically symmetric distributions. General formulas for limiting variances and covariances of the canonical correlations and canonical vectors based on scatter matrices are obtained. Also the use of the so called shape matrices in canonical analysis is investigated. The scatter and shape matrices based on the affine equivariant Sign Covariance Matrix as well as the Tyler's shape matrix are considered in more detail. Their finite sample and limiting efficiencies are compared to those of the Minimum Covariance Determinant estimator and S-estimates through theoretical and simulation studies. The theory is illustrated by an example.Canonical correlations; Canonical variables; Canonical vectors; Covariance; Covariance determinant estimator; Determinant estimator; Distribution; Efficiency; Estimator; Functions; Influence function; Matrix; Scatter; Shape matrix; Sign covariance mix; Simulation; Studies; Theory; Tyler's estimate;
Isomeric states close to doubly magic Sn studied with JYFLTRAP
The double Penning trap mass spectrometer JYFLTRAP has been employed to
measure masses and excitation energies for isomers in Cd,
Cd, Cd and Te, for isomers in In and
In, and for isomers in Sn and Sb. These first
direct mass measurements of the Cd and In isomers reveal deviations to the
excitation energies based on results from beta-decay experiments and yield new
information on neutron- and proton-hole states close to Sn. A new
excitation energy of 144(4) keV has been determined for Cd. A good
agreement with the precisely known excitation energies of Cd,
Sn, and Sb has been found.Comment: 10 pages, 6 figures, submitted to Phys. Rev.
Canonical analysis based on scatter matrices.
In this paper, the influence functions and limiting distributions of the canonical correlations and coefficients based on affine equivariant scatter matrices are developed for elliptically symmetric distributions. General formulas for limiting variances and covariances of the canonical correlations and canonical vectors based on scatter matrices are obtained. Also the use of the so-called shape matrices in canonical analysis is investigated. The scatter and shape matrices based on the affine equivariant Sign Covariance Matrix as well as the Tyler's shape matrix serve as examples. Their finite sample and limiting efficiencies are compared to those of the Minimum Covariance Determinant estimators and S-estimator through theoretical and simulation studies. The theory is illustrated by an example.Canonical correlations; Canonical variables; Canonical vectors; Covariance; Covariance determinant estimator; Determinant estimator; Distribution; Efficiency; Estimator; Functions; Influence function; Matrix; Principal components; Scatter; Shape matrix; Sign; Sign covariance mix; Simulation; Studies; Theory; Tyler's estimate; Variance;
Q_EC values of the Superallowed beta-Emitters 10-C, 34-Ar, 38-Ca and 46-V
The Q_EC values of the superallowed beta+ emitters 10-C, 34-Ar, 38-Ca and
46-V have been measured with a Penning-trap mass spectrometer to be 3648.12(8),
6061.83(8), 6612.12(7) and 7052.44(10) keV, respectively. All four values are
substantially improved in precision over previous results.Comment: 9 pages, 7 figures, 5 table
Precision mass measurements of radioactive nuclei at JYFLTRAP
The Penning trap mass spectrometer JYFLTRAP was used to measure the atomic
masses of radioactive nuclei with an uncertainty better than 10 keV. The atomic
masses of the neutron-deficient nuclei around the N = Z line were measured to
improve the understanding of the rp-process path and the SbSnTe cycle.
Furthermore, the masses of the neutron-rich gallium (Z = 31) to palladium (Z =
46) nuclei have been measured. The physics impacts on the nuclear structure and
the r-process paths are reviewed. A better understanding of the nuclear
deformation is presented by studying the pairing energy around A = 100.Comment: 4 pages and 4 figures, RNB7 conf. pro
The impact of RNA sequence library construction protocols on transcriptomic profiling of leukemia
Background: RNA sequencing (RNA-seq) has become an indispensable tool to identify disease associated transcriptional profiles and determine the molecular underpinnings of diseases. However, the broad adaptation of the methodology into the clinic is still hampered by inconsistent results from different RNA-seq protocols and involves further evaluation of its analytical reliability using patient samples. Here, we applied two commonly used RNA-seq library preparation protocols to samples from acute leukemia patients to understand how poly-A-tailed mRNA selection (PA) and ribo-depletion (RD) based RNA-seq library preparation protocols affect gene fusion detection, variant calling, and gene expression profiling. Results: Overall, the protocols produced similar results with consistent outcomes. Nevertheless, the PA protocol was more efficient in quantifying expression of leukemia marker genes and showed better performance in the expression-based classification of leukemia. Independent qRT-PCR experiments verified that the PA protocol better represented total RNA compared to the RD protocol. In contrast, the RD protocol detected a higher number of non-coding RNA features and had better alignment efficiency. The RD protocol also recovered more known fusion-gene events, although variability was seen in fusion gene predictions. Conclusion: The overall findings provide a framework for the use of RNA-seq in a precision medicine setting with limited number of samples and suggest that selection of the library preparation protocol should be based on the objectives of the analysis.Peer reviewe
Mass measurements in the vicinity of the doubly-magic waiting point 56Ni
Masses of 56,57Fe, 53Co^m, 53,56Co, 55,56,57Ni, 57,58Cu, and 59,60Zn have
been determined with the JYFLTRAP Penning trap mass spectrometer at IGISOL with
a precision of dm/m \le 3 x 10^{-8}. The QEC values for 53Co, 55Ni, 56Ni, 57Cu,
58Cu, and 59Zn have been measured directly with a typical precision of better
than 0.7 keV and Coulomb displacement energies have been determined. The Q
values for proton captures on 55Co, 56Ni, 58Cu, and 59Cu have been measured
directly. The precision of the proton-capture Q value for 56Ni(p,gamma)57Cu,
Q(p,gamma) = 689.69(51) keV, crucial for astrophysical rp-process calculations,
has been improved by a factor of 37. The excitation energy of the proton
emitting spin-gap isomer 53Co^m has been measured precisely, Ex = 3174.3(10)
keV, and a Coulomb energy difference of 133.9(10) keV for the 19/2- state has
been obtained. Except for 53Co, the mass values have been adjusted within a
network of 17 frequency ratio measurements between 13 nuclides which allowed
also a determination of the reference masses 55Co, 58Ni, and 59Cu.Comment: 14 pages, 13 figures, submitted to Phys. Rev.
Precision mass measurements on neutron-rich rare-earth isotopes at JYFLTRAP - reduced neutron pairing and implications for the -process calculations
The rare-earth peak in the -process abundance pattern depends sensitively
on both the astrophysical conditions and subtle changes in nuclear structure in
the region. This work takes an important step elucidating the nuclear structure
and reducing the uncertainties in -process calculations via precise atomic
mass measurements at the JYFLTRAP double Penning trap. Nd, Pm,
Sm, and Gd have been measured for the first time and the
precisions for Nd, Pm, Eu, Gd, and
Tb have been improved considerably. Nuclear structure has been probed
via two-neutron separation energies and neutron pairing energy metrics
. The data do not support the existence of a subshell closure at .
Neutron pairing has been found to be weaker than predicted by theoretical mass
models. The impact on the calculated -process abundances has been studied.
Substantial changes resulting in a smoother abundance distribution and a better
agreement with the solar -process abundances are observed.Comment: 8 pages, 4 figures, accepted for publication in Physical Review
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