6,653 research outputs found
Fast Genome-Wide QTL Analysis Using Mendel
Pedigree GWAS (Option 29) in the current version of the Mendel software is an
optimized subroutine for performing large scale genome-wide QTL analysis. This
analysis (a) works for random sample data, pedigree data, or a mix of both, (b)
is highly efficient in both run time and memory requirement, (c) accommodates
both univariate and multivariate traits, (d) works for autosomal and x-linked
loci, (e) correctly deals with missing data in traits, covariates, and
genotypes, (f) allows for covariate adjustment and constraints among
parameters, (g) uses either theoretical or SNP-based empirical kinship matrix
for additive polygenic effects, (h) allows extra variance components such as
dominant polygenic effects and household effects, (i) detects and reports
outlier individuals and pedigrees, and (j) allows for robust estimation via the
-distribution. The current paper assesses these capabilities on the genetics
analysis workshop 19 (GAW19) sequencing data. We analyzed simulated and real
phenotypes for both family and random sample data sets. For instance, when
jointly testing the 8 longitudinally measured systolic blood pressure (SBP) and
diastolic blood pressure (DBP) traits, it takes Mendel 78 minutes on a standard
laptop computer to read, quality check, and analyze a data set with 849
individuals and 8.3 million SNPs. Genome-wide eQTL analysis of 20,643
expression traits on 641 individuals with 8.3 million SNPs takes 30 hours using
20 parallel runs on a cluster. Mendel is freely available at
\url{http://www.genetics.ucla.edu/software}
A quantum model for the magnetic multi-valued recording
We have proposed a quantum model for the magnetic multi-valued recording in
this paper. The hysteresis loops of the two-dimensional systems with randomly
distributed magnetic atoms have been studied by the quantum theory developed
previously. The method has been proved to be exact in this case. We find that
the single-ion anisotropies and the densities of the magnetic atoms are mainly
responsible for the hysterisis loops. Only if the magnetic atoms contained by
the systems are of different (not uniform) anistropies and their density is
low, there may be more sharp steps in the hysteresis loops. Such materials can
be used as the recording media for the so-called magnetic multi-valued
recording. Our result explained the experimental results qualitativly.Comment: 10 pages containing one Table. Latex formatted. 5 figures: those who
are interested please contact the authors requiring the figures. Submitted to
J. Magn. Magn. Mater. . Email address: [email protected]
Regional economic status inference from information flow and talent mobility
Novel data has been leveraged to estimate socioeconomic status in a timely
manner, however, direct comparison on the use of social relations and talent
movements remains rare. In this letter, we estimate the regional economic
status based on the structural features of the two networks. One is the online
information flow network built on the following relations on social media, and
the other is the offline talent mobility network built on the anonymized resume
data of job seekers with higher education. We find that while the structural
features of both networks are relevant to economic status, the talent mobility
network in a relatively smaller size exhibits a stronger predictive power for
the gross domestic product (GDP). In particular, a composite index of
structural features can explain up to about 84% of the variance in GDP. The
result suggests future socioeconomic studies to pay more attention to the
cost-effective talent mobility data.Comment: 7 pages, 5 figures, 2 table
Lacing topological orders in two dimensions: exactly solvable models for Kitaev's sixteen-fold way
A family of two-dimensional (2D) spin-1/2 models have been constructed to
realize Kitaev's sixteen-fold way of anyon theories. Defining a one-dimensional
(1D) path through all the lattice sites, and performing the Jordan-Wigner
transformation with the help of the 1D path, we find that such a spin-1/2 model
is equivalent to a model with species of Majorana fermions coupled to a
static gauge field. Here each specie of Majorana fermions gives
rise to an energy band that carries a Chern number , yielding a
total Chern number . It has been shown that the ground states
are three (four)-fold topologically degenerate on a torus, when is an odd
(even) number. These exactly solvable models can be achieved by quantum
simulations.Comment: 20 pages, 9 figure
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