4,857 research outputs found
A note on the stratification by automorphisms of smooth plane curves of genus 6
In this note, we give a so-called representative classification for the
strata by automorphism group of smooth -plane curves of genus ,
where is a fixed separable closure of a field of characteristic
or . We start with a classification already obtained by the
first author and we use standard techniques.
Interestingly, in the way to get these families for the different strata, we
find two remarkable phenomenons that did not appear before. One is the
existence of a non -dimensional final stratum of plane curves. At a first
sight it may sound odd, but we will see that this is a normal situation for
higher degrees and we will give a explanation for it.
We explicitly describe representative families for all strata, except for the
stratum with automorphism group . Here we find the
second difference with the lower genus cases where the previous techniques do
not fully work. Fortunately, we are still able to prove the existence of such
family by applying a version of Luroth's theorem in dimension
The Picard Group of Brauer-Severi Varieties
In this note we provide explicit generators of the Picard groups of cyclic
Brauer-Severi varieties defined over the base field. In particular, for all
Brauer-Severi surfaces. To produce these generators we use the Twisting Theory
for smooth plane curves
Connecting blazars with ultra high energy cosmic rays and astrophysical neutrinos
We present a strong hint of a connection between high energy -ray
emitting blazars, very high energy neutrinos, and ultra high energy cosmic
rays. We first identify potential hadronic sources by filtering -ray
emitters %from existing catalogs that are in spatial coincidence with the high
energy neutrinos detected by IceCube. The neutrino filtered -ray
emitters are then correlated with the ultra high energy cosmic rays from the
Pierre Auger Observatory and the Telescope Array by scanning in -ray
flux () and angular separation () between sources and
cosmic rays. A maximal excess of 80 cosmic rays (42.5 expected) is found at
from the neutrino filtered -ray emitters
selected from the second hard {\it Fermi}-LAT catalogue (2FHL) and for
.
The probability for this to happen is , which translates to
after compensation for all the considered trials. No
excess of cosmic rays is instead observed for the complement sample of
-ray emitters (i.e. not in spatial connection with IceCube neutrinos).
A likelihood ratio test comparing the connection between the neutrino filtered
and the complement source samples with the cosmic rays favours a connection
between neutrino filtered emitters and cosmic rays with a probability of
( after compensation for all the considered
trials. The neutrino filtered -ray sources that make up the cosmic rays
excess are blazars of the high synchrotron peak type. More statistics is needed
to further investigate these sources as candidate cosmic ray and neutrino
emitters.Comment: Accepted for publication in MNRAS, added one figure (redshift
distribution), new IceCube data, and penalty factor for subsets within single
catalogue
EZH2 Single Nucleotide Variants (SNVs): Diagnostic and Prognostic Role in 10 Solid Tumor Types
The enhancer of zeste homolog 2 (EZH2) gene encodes a histone methyltransferase that is a catalytic subunit of the Polycomb repressive complex 2 (PRC2) group of proteins that act to repress gene expression. The EZH2 locus is rarely mutated in solid tumors and there is no comprehensive study of EZH2 single nucleotide variants (SNVs) associated with cancer susceptibility, prognosis and response to therapy. Here, for the first time, we review the functional roles of EZH2 DNA variants and propose a putative etiological role in 10 various solid tumors including: esophageal, hepatocellular, oral, urothelial, colorectal, lung and gastric cancers. In particular, we found that the C allele of the EZH2 variant rs3757441 is associated with increased EZH2 RNA expression and poorer prognosis (advanced stage) in at least two malignancies such as colorectal and hepatocellular carcinoma. This suggests that the C allele may be a functional risk variant in multiple malignant tumors. We therefore propose that the rs3757441 single nucleotide variant (SNV) be genotyped and real-time PCR assays be performed in large cohort studies in order to confirm this preliminary finding that could be useful for clinical practice
- …