2,025 research outputs found
Sashimi plots: Quantitative visualization of RNA sequencing read alignments
We introduce Sashimi plots, a quantitative multi-sample visualization of mRNA
sequencing reads aligned to gene annotations. Sashimi plots are made using
alignments (stored in the SAM/BAM format) and gene model annotations (in GFF
format), which can be custom-made by the user or obtained from databases such
as Ensembl or UCSC. We describe two implementations of Sashimi plots: (1) a
stand-alone command line implementation aimed at making customizable
publication quality figures, and (2) an implementation built into the
Integrated Genome Viewer (IGV) browser, which enables rapid and dynamic
creation of Sashimi plots for any genomic region of interest, suitable for
exploratory analysis of alternatively spliced regions of the transcriptome.
Isoform expression estimates outputted by the MISO program can be optionally
plotted along with Sashimi plots. Sashimi plots can be used to quickly screen
differentially spliced exons along genomic regions of interest and can be used
in publication quality figures. The Sashimi plot software and documentation is
available from: http://genes.mit.edu/burgelab/miso/docs/sashimi.htmlComment: 2 figure
Galaxy cluster rotation revealed in the MACSIS simulations with the kinetic Sunyaev-Zeldovich effect
The kinetic Sunyaev-Zeldovich (kSZ) effect has now become a clear target for
ongoing and future studies of the cosmic microwave background (CMB) and
cosmology. Aside from the bulk cluster motion, internal motions also lead to a
kSZ signal. In this work, we study the rotational kSZ effect caused by coherent
large-scale motions of the cluster medium using cluster hydrodynamic
cosmological simulations. To utilise the rotational kSZ as a cosmological
probe, simulations offer some of the most comprehensive data sets that can
inform the modeling of this signal. In this work, we use the MACSIS data set to
specifically investigate the rotational kSZ effect in massive clusters. Based
on these models, we test stacking approaches and estimate the amplitude of the
combined signal with varying mass, dynamical state, redshift and map-alignment
geometry. We find that the dark matter, galaxy and gas spins are generally
misaligned, an effect that can cause a sub-optimal estimation of the rotational
kSZ effect when based on galaxy catalogues. Furthermore, we provide
halo-spin-mass scaling relations that can be used to build a statistical model
of the rotational kSZ. The rotational kSZ contribution, which is largest in
massive unrelaxed clusters (100 K), could be relevant to studies
of higher-order CMB temperature signals, such as the moving lens effect. The
limited mass range of the MACSIS sample strongly motivates an extended
investigation of the rotational kSZ effect in large-volume simulations to
refine the modelling, particularly towards lower mass and higher redshift, and
provide forecasts for upcoming cosmological CMB experiments (e.g. Simons
Observatory, SKA-2) and X-ray observations (e.g. \textit{Athena}/X-IFU).Comment: Submitted to Monthly Notices of the Royal Astronomical Society.
Comments and discussions are welcome. Data and codes can be found at
https://github.com/edoaltamura/macsis-cosmosi
Introduction to the Special Issue on Pricing, Financing, Regulating Transport Infrastructures and Services
Uncertainty quantification methods for neural networks pattern recognition
On-line monitoring techniques have attracted increasing attention as a promising strategy for improving safety, maintaining availability and reducing the cost of operation and maintenance. In particular, pattern recognition tools such as artificial neural networks are today largely adopted for sensor validation, plant component monitoring, system control, and fault-diagnostics based on the data acquired during operation. However, classic artificial neural networks do not provide an error context for the model response, whose robustness remains thus difficult to estimate. Indeed, experimental data generally exhibit a time/space-varying behaviour and are hence characterized by an intrinsic level of uncertainty that unavoidably affects the performance of the tools adopted and undermines the accuracy of the analysis. For this reason, the propagation of the uncertainty and the quantification of the so called margins of uncertainty in output are crucial in making risk-informed decision. The current study presents a comparison between two different approaches for the quantification of uncertainty in artificial neural networks. The first technique presented is based on the error estimation by a series association scheme, the second approach couples Bayesian model selection technique and model averaging into a unified framework. The efficiency of these two approaches are analysed in terms of their computational cost and predictive performance, through their application to a nuclear power plant fault diagnosis system
An approach for arsenic in a contaminated soil: Speciation, fractionation, extraction and effluent decontamination
Strong anisotropy in surface kinetic roughening: analysis and experiments
We report an experimental assessment of surface kinetic roughening properties
that are anisotropic in space. Working for two specific instances of silicon
surfaces irradiated by ion-beam sputtering under diverse conditions (with and
without concurrent metallic impurity codeposition), we verify the predictions
and consistency of a recently proposed scaling Ansatz for surface observables
like the two-dimensional (2D) height Power Spectral Density (PSD). In contrast
with other formulations, this Ansatz is naturally tailored to the study of
two-dimensional surfaces, and allows to readily explore the implications of
anisotropic scaling for other observables, such as real-space correlation
functions and PSD functions for 1D profiles of the surface. Our results confirm
that there are indeed actual experimental systems whose kinetic roughening is
strongly anisotropic, as consistently described by this scaling analysis. In
the light of our work, some types of experimental measurements are seen to be
more affected by issues like finite space resolution effects, etc. that may
hinder a clear-cut assessment of strongly anisotropic scaling in the present
and other practical contexts
New experimental limit on the Pauli Exclusion Principle violation by electrons
The Pauli Exclusion Principle (PEP) is one of the basic principles of modern
physics and, even if there are no compelling reasons to doubt its validity, it
is still debated today because an intuitive, elementary explanation is still
missing, and because of its unique stand among the basic symmetries of physics.
The present paper reports a new limit on the probability that PEP is violated
by electrons, in a search for a shifted K line in copper: the presence
of this line in the soft X-ray copper fluorescence would signal a transition to
a ground state already occupied by 2 electrons. The obtained value, , improves the existing limit by almost two
orders of magnitude.Comment: submitted to Phys. Lett.
On right-angled polygons in hyperbolic space
We study oriented right-angled polygons in hyperbolic spaces of arbitrary dimensions, that is, finite sequences (S0,S1,âŠ,Spâ1) of oriented geodesics in the hyperbolic space HHn+2 such that consecutive sides are orthogonal. It was previously shown by Delgove and Retailleau (Ann Fac Sci Toulouse Math 23(5):1049â1061, 2014. https://doi.org/10.5802/afst.1435) that three quaternionic parameters define a right- angled hexagon in the 5-dimensional hyperbolic space. We generalise this method to right-angled polygons with an arbitrary number of sides pâ„5 in a hyperbolic space of arbitrary dimension
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