25 research outputs found
Synchronization of coupled limit cycles
A unified approach for analyzing synchronization in coupled systems of
autonomous differential equations is presented in this work. Through a careful
analysis of the variational equation of the coupled system we establish a
sufficient condition for synchronization in terms of the geometric properties
of the local limit cycles and the coupling operator. This result applies to a
large class of differential equation models in physics and biology. The
stability analysis is complemented with a discussion of numerical simulations
of a compartmental model of a neuron.Comment: Journal of Nonlinear Science, accepte
Physical properties of FeSeTe single crystals grown under different conditions
We report on structural, magnetic, conductivity, and thermodynamic studies of
FeSeTe single crystals grown by self-flux and Bridgman methods.
The samples were prepared from starting materials of different purity at
various temperatures and cooling rates. The lowest values of the susceptibility
in the normal state, the highest transition temperature of 14.5 K, and
the largest heat-capacity anomaly at were obtained for pure (oxygen-free)
samples. The critical current density of A/cm (at 2
K) achieved in pure samples is attributed to intrinsic inhomogeneity due to
disorder at the cation and anion sites. The impure samples show increased
up to A/cm due to additional pinning centers of
FeO. The upper critical field of kOe is estimated
from the resistivity study in magnetic fields parallel to the \emph{c}-axis.
The anisotropy of the upper critical field reaches a value at . Extremely low values of the residual Sommerfeld coefficient for pure
samples indicate a high volume fraction of the superconducting phase (up to
97%). The electronic contribution to the specific heat in the superconducting
state is well described within a single-band BCS model with a temperature
dependent gap K. A broad cusp-like anomaly in the electronic
specific heat of samples with suppressed bulk superconductivity is ascribed to
a splitting of the ground state of the interstitial Fe ions. This
contribution is fully suppressed in the ordered state in samples with bulk
superconductivity.Comment: 11 pages, 11 figures, 3 table
Magnetic Fields, Relativistic Particles, and Shock Waves in Cluster Outskirts
It is only now, with low-frequency radio telescopes, long exposures with
high-resolution X-ray satellites and gamma-ray telescopes, that we are
beginning to learn about the physics in the periphery of galaxy clusters. In
the coming years, Sunyaev-Zeldovich telescopes are going to deliver further
great insights into the plasma physics of these special regions in the
Universe. The last years have already shown tremendous progress with detections
of shocks, estimates of magnetic field strengths and constraints on the
particle acceleration efficiency. X-ray observations have revealed shock fronts
in cluster outskirts which have allowed inferences about the microphysical
structure of shocks fronts in such extreme environments. The best indications
for magnetic fields and relativistic particles in cluster outskirts come from
observations of so-called radio relics, which are megaparsec-sized regions of
radio emission from the edges of galaxy clusters. As these are difficult to
detect due to their low surface brightness, only few of these objects are
known. But they have provided unprecedented evidence for the acceleration of
relativistic particles at shock fronts and the existence of muG strength fields
as far out as the virial radius of clusters. In this review we summarise the
observational and theoretical state of our knowledge of magnetic fields,
relativistic particles and shocks in cluster outskirts.Comment: 34 pages, to be published in Space Science Review
Correcting palindromes in long reads after whole-genome amplification
Background: Next-generation sequencing requires sufficient DNA to be available. If limited, whole-genome amplification is applied to generate additional amounts of DNA. Such amplification often results in many chimeric DNA fragments, in particular artificial palindromic sequences, which limit the usefulness of long sequencing reads. Results: Here, we present Pacasus, a tool for correcting such errors. Two datasets show that it markedly improves read mapping and de novo assembly, yielding results similar to these that would be obtained with non-amplified DNA. Conclusions: With Pacasus long-read technologies become available for sequencing targets with very small amounts of DNA, such as single cells or even single chromosomes
Whole-genome amplification (WGA) create specific chimeric fragments, which consist mainly of palindrome sequences. We developed the tool Pacasus to detect and correct these palindromic sequences in long reads, for example from PacBio and Nanopore
Next-generation sequencing requires sufficient DNA to be available. If limited, whole-genome amplification is applied to generate additional amounts of DNA. Such amplification often results in many chimeric DNA fragments, in particular artificial palindromic sequences, which limit the usefulness long reads from technologies such as PacBio and Oxford Nanopore unusable for further analysis. We developed Pacasus, a tool for correcting such errors in long reads. With Pacasus long-read technologies become readily available for sequencing targets with very small amounts of DNA
Whole-genome amplification (WGA) create specific chimeric fragments, which consist mainly of palindrome sequences. We developed the tool Pacasus to detect and correct these palindromic sequences in long reads, for example from PacBio and Nanopore
Next-generation sequencing requires sufficient DNA to be available. If limited, whole-genome amplification is applied to generate additional amounts of DNA. Such amplification often results in many chimeric DNA fragments, in particular artificial palindromic sequences, which limit the usefulness long reads from technologies such as PacBio and Oxford Nanopore unusable for further analysis. We developed Pacasus, a tool for correcting such errors in long reads. With Pacasus long-read technologies become readily available for sequencing targets with very small amounts of DNA
Correcting palindromes in long reads after whole-genome amplification
Background: Next-generation sequencing requires sufficient DNA to be available. If limited, whole-genome amplification is applied to generate additional amounts of DNA. Such amplification often results in many chimeric DNA fragments, in particular artificial palindromic sequences, which limit the usefulness of long sequencing reads. Results: Here, we present Pacasus, a tool for correcting such errors. Two datasets show that it markedly improves read mapping and de novo assembly, yielding results similar to these that would be obtained with non-amplified DNA. Conclusions: With Pacasus long-read technologies become available for sequencing targets with very small amounts of DNA, such as single cells or even single chromosomes