1,306 research outputs found
CP nonconservation in the leptonic sector
In this paper we use an exact method to impose unitarity on moduli of
neutrino PMNS matrix recently determined, and show how one could obtain
information on CP nonconservation from a limited experimental information. One
suggests a novel type of global fit by expressing all theoretical quantities in
terms of convention independent parameters: the Jarlskog invariant and the
moduli , able to resolve the positivity problem of .
In this way the fit will directly provide a value for , and if it is
different from zero it will prove the existence of CP violation in the
available experimental data. If the best fit result, , from M.
Maltoni {\em et al}, [New J.Phys. {\bf 6} (2004) 122] is confirmed, it will
imply a new physics in the leptonic sector
Heterologous expression screens in Nicotiana benthamiana identify a candidate effector of the wheat Yellow Rust Pathogen that associates with processing bodies
Rust fungal pathogens of wheat (Triticum spp.) affect crop yields worldwide. The molecular mechanisms underlying the virulence of these pathogens remain elusive, due to the limited availability of suitable molecular genetic research tools. Notably, the inability to perform high-throughput analyses of candidate virulence proteins (also known as effectors) impairs progress. We previously established a pipeline for the fast-forward screens of rust fungal candidate effectors in the model plant Nicotiana benthamiana. This pipeline involves selecting candidate effectors in silico and performing cell biology and protein-protein interaction assays in planta to gain insight into the putative functions of candidate effectors. In this study, we used this pipeline to identify and characterize sixteen candidate effectors from the wheat yellow rust fungal pathogen Puccinia striiformis f sp tritici. Nine candidate effectors targeted a specific plant subcellular compartment or protein complex, providing valuable information on their putative functions in plant cells. One candidate effector, PST02549, accumulated in processing bodies (P-bodies), protein complexes involved in mRNA decapping, degradation, and storage. PST02549 also associates with the P-body-resident ENHANCER OF mRNA DECAPPING PROTEIN 4 (EDC4) from N. benthamiana and wheat. We propose that P-bodies are a novel plant cell compartment targeted by pathogen effectors
Chandra Detection of the Forward and Reverse Shocks in Cassiopeia-A
We report the localization of the forward and reversed shock fronts in the
young supernova remnant Cas-A using X-ray data obtained with the Chandra
Observatory. High resolution X-ray maps resolve a previously unseen X-ray
feature encompassing the extremity of the remnant. This feature consists of
thin, tangential wisps of emission bordering the outer edge of the thermal
X-ray and radio remnant, forming a circular rim, approx. 2.7 in radius. Radio
images show a sharp rise in brightness at this X-ray rim, along with a large
jump in the synchrotron polarization angle. These characteristics suggest that
these wisps are the previously unresolved signature of the forward, or outer,
shock. Similarly, we identify the sharp rise in emissivity of the bright shell
for both the radio and X-ray line emission associated with the reverse shock.
The derived ratio of the averaged forward and reverse shock radii of approx.
3:2 constrains the remnant to have swept up roughly the same amount of mass as
was ejected; this suggests that Cas-A is just entering the Sedov phase.
Comparison of the X-ray spectra from the two shock regions shows that the
equivalent widths of prominent emission lines are significantly lower exterior
to the bright shell, as expected if they are respectively identified with the
shocked circumstellar material and shocked ejecta. Furthermore, the spectrum of
the outer rim itself is dominated by power-law emission, likely the counterpart
of the non-thermal component previously seen at energies above 10 keV.Comment: 7 pages with 5 figures, LaTex, emulateapj.sty. To appear in the
Astrophysical Journal Letter
GotEnzymes: an extensive database of enzyme parameter predictions
Enzyme parameters are essential for quantitatively understanding, modelling, and engineering cells. However, experimental measurements cover only a small fraction of known enzyme-compound pairs in model organisms, much less in other organisms. Artificial intelligence (Al) techniques have accelerated the pace of exploring enzyme properties by predicting these in a high-throughput manner. Here, we present GotEnzymes, an extensive database with enzyme parameter predictions by Al approaches, which is publicly available at https://metabolicatlas.org/gotenzymes for interactive web exploration and programmatic access. The first release of this data resource contains predicted turnover numbers of over 25.7 million enzyme-compound pairs across 8099 organisms. We believe that GotEnzymes, with the readily-predicted enzyme parameters, would bring a speed boost to biological research covering both experimental and computational fields that involve working with candidate enzymes
Finite-level systems, Hermitian operators, isometries, and a novel parameterization of Stiefel and Grassmann manifolds
In this paper we obtain a description of the Hermitian operators acting on
the Hilbert space \C^n, description which gives a complete solution to the
over parameterization problem. More precisely we provide an explicit
parameterization of arbitrary -dimensional operators, operators that may be
considered either as Hamiltonians, or density matrices for finite-level quantum
systems. It is shown that the spectral multiplicities are encoded in a flag
unitary matrix obtained as an ordered product of special unitary matrices, each
one generated by a complex -dimensional unit vector, . As a
byproduct, an alternative and simple parameterization of Stiefel and Grassmann
manifolds is obtained.Comment: 21 page
PDS 144: the first confirmed Herbig Ae-Herbig Ae wide binary
PDS 144 is a pair of Herbig Ae stars that are separated by 5.'' 35 on the sky. It has previously been shown to have an A2Ve Herbig Ae star viewed at 83 degrees inclination as its northern member and an A5Ve Herbig Ae star as its southern member. Direct imagery revealed a disk occulting PDS 144 N-the first edge-on disk observed around a Herbig Ae star. The lack of an obvious disk in direct imagery suggested PDS 144 S might be viewed face-on or not physically associated with PDS 144 N. Multi-epoch Hubble Space Telescope imagery of PDS 144 with a 5 year baseline demonstrates PDS 144 N & S are comoving and have a common proper motion with TYC 6782-878-1. TYC 6782-878-1 has previously been identified as a member of Upper Sco sub-association A at d = 145 +/- 2 pc with an age of 5-10 Myr. Ground-based imagery reveals jets and a string of Herbig-Haro knots extending 13' (possibly further) which are aligned to within 7 degrees +/- 6 degrees on the sky. By combining proper motion data and the absence of a dark mid-plane with radial velocity data, we measure the inclination of PDS 144 S to be i = 73 degrees +/- 7 degrees. The radial velocity of the jets from PDS 144 N & S indicates they, and therefore their disks, are misaligned by 25 degrees +/- 9 degrees. This degree of misalignment is similar to that seen in T Tauri wide binaries.Peer reviewe
Supernova Remnants in the Magellanic Clouds III: An X-ray Atlas of LMC Supernova Remnants
We have used archival ROSAT data to present X-ray images of thirty-one
supernova remnants (SNRs) in the Large Magellanic Cloud (LMC). We have
classified these remnants according to their X-ray morphologies, into the
categories of Shell-Type, Diffuse Face, Centrally Brightened, Point-Source
Dominated, and Irregular. We suggest possible causes of the X-ray emission for
each category, and for individual features of some of the SNRs.Comment: 27 pages, 6 figures (9 figure files). To appear in the Supplement
Series of the Astrophysical Journal, August 1999 Vol. 123 #
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