13,872 research outputs found
The seesaw portal in testable models of neutrino masses
A Standard Model extension with two Majorana neutrinos can explain the
measured neutrino masses and mixings, and also account for the
matter-antimatter asymmetry in a region of parameter space that could be
testable in future experiments. The testability of the model relies to some
extent on its minimality. In this paper we address the possibility that the
model might be extended by extra generic new physics which we parametrize in
terms of a low-energy effective theory. We consider the effects of the
operators of the lowest dimensionality, , and evaluate the upper bounds on
the coefficients so that the predictions of the minimal model are robust. One
of the operators gives a new production mechanism for the heavy neutrinos at
LHC via higgs decays. The higgs can decay to a pair of such neutrinos that,
being long-lived, leave a powerful signal of two displaced vertices. We
estimate the LHC reach to this process.Comment: 19 pages, 11 figure
The seesaw path to leptonic CP violation
Future experiments such as SHiP and high-intensity colliders will
have a superb sensitivity to heavy Majorana neutrinos with masses below .
We show that the measurement of the mixing to electrons and muons of one such
state could imply the discovery of leptonic CP violation in the context of
seesaw models. We quantify in the minimal model the CP discovery potential of
these future experiments, and demonstrate that a 5 CL discovery of
leptonic CP violation would be possible in a very significant fraction of
parameter space.Comment: An error has been fixed, main conclusions unchange
Surface mixing and biological activity in the four Eastern Boundary Upwelling Systems
Eastern Boundary Upwelling Systems (EBUS) are characterized by a high
productivity of plankton associated with large commercial fisheries, thus
playing key biological and socio-economical roles. The aim of this work is to
make a comparative study of these four upwelling systems focussing on their
surface stirring, using the Finite Size Lyapunov Exponents (FSLEs), and their
biological activity, based on satellite data. First, the spatial distribution
of horizontal mixing is analysed from time averages and from probability
density functions of FSLEs. Then we studied the temporal variability of surface
stirring focussing on the annual and seasonal cycle. There is a global negative
correlation between surface horizontal mixing and chlorophyll standing stocks
over the four areas. To try to better understand this inverse relationship, we
consider the vertical dimension by looking at the Ekman-transport and vertical
velocities. We suggest the possibility of a changing response of the
phytoplankton to sub/mesoscale turbulence, from a negative effect in the very
productive coastal areas to a positive one in the open ocean.Comment: 12 pages. NPG Special Issue on "Nonlinear processes in oceanic and
atmospheric flows". Open Access paper, available also at the publisher site:
http://www.nonlin-processes-geophys.net/16/557/2009
X-Ray Fluorescence Analysis of Fine Atmospheric Aerosols from a Site in Mexico City
A study was performed in the Winter of the year 2015 in a Southwestern site in the MAMC (Ciudad Universitaria), collecting PM2.5 samples with a Mini Vol. As a part of wider study focused to fully characterize aerosols at this site, an X-ray Fluorescence (XRF) spectrometer (based on an Rh X-ray tube) built to analyze environmental samples, was used to characterize the sample set. A total of 16 elements (Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb) were detected in most samples and mean concentrations were calculated. Cluster analysis was also applied to the elemental concentrations to find possible correlations among the elements
Human papillomavirus E2 regulates SRSF3 (SRp20) to promote capsid protein expression in infected differentiated keratinocytes
The human papillomavirus (HPV) life cycle is tightly linked to differentiation of the infected epithelial cell suggesting a sophisticated interplay between host cell metabolism and virus replication. Previously we demonstrated in differentiated keratinocytes in vitro and in vivo that HPV16 infection caused increased levels of the cellular SR splicing factors (SRSFs) SRSF1 (ASF/SF2), SRSF2 (SC35) and SRSF3 (SRp20). Moreover, the viral E2 transcription and replication factor that is expressed at high levels in differentiating keratinocytes could bind and control activity of the SRSF1 gene promoter. Here we reveal that E2 proteins of HPV16 and HPV31 control expression of SRSFs 1, 2 and 3 in a differentiation-dependent manner. E2 has the greatest trans-activation effect on expression of SRSF3. siRNA depletion experiments in two different models of the HPV16 life cycle (W12E and NIKS16) and one model of the HPV31 life cycle (CIN612-9E) revealed that only SRSF3 contributed significantly to regulation of late events in the virus life cycle. Increased levels of SRSF3 are required for L1 mRNA and capsid protein expression. Capsid protein expression was regulated specifically by SRSF3 and appeared independent of other SRSFs. Taken together these data suggest a significant role of the HPV E2 protein in regulating late events in the HPV life cycle through transcriptional regulation of SRSF3 expression.
IMPORTANCE Human papillomavirus replication is accomplished in concert with differentiation of the infected epithelium. Virus capsid protein expression is confined to the upper epithelial layers so as to avoid immune detection. In this study we demonstrate that the viral E2 transcription factor activates the promoter of the cellular SRSF3 RNA processing factor. SRSF3 is required for expression of the E4ÌL1 mRNA and so controls expression of the HPV L1 capsid protein. Thus we reveal a new dimension of virus-host interaction crucial for production of infectious virus. SRSF proteins are known drug targets. Therefore, this study provides an excellent basis for developing strategies to regulate capsid protein production in the infected epithelium and production of new virions
Predicting the baryon asymmetry with degenerate right-handed neutrinos
We consider the generation of a baryon asymmetry in an extension of the
Standard Model with two singlet Majorana fermions that are degenerate above the
electroweak phase transition. The model can explain neutrino masses as well as
the observed matter-antimatter asymmetry, for masses of the heavy singlets
below the electroweak scale. The only physical CP violating phases in the model
are those in the PMNS mixing matrix, i.e. the Dirac phase and a Majorana phase
that enter light neutrino observables. We present an accurate analytic
approximation for the baryon asymmetry in terms of CP flavour invariants, and
derive the correlations with neutrino observables. We demonstrate that the
measurement of CP violation in neutrino oscillations as well as the mixings of
the heavy neutral leptons with the electron, muon and tau flavours suffice to
pin down the matter-antimatter asymmetry from laboratory measurements.Comment: 29 + 4 pages, 9 figures. Includes a comparison to the non-degenerate
scenario. Matches published version in JHE
ANALYTICS AND DATA SCIENCE APPLIED TO THE TRAJECTORY OUTLIER DETECTION
Nowadays, logistics for transportation and distribution of merchandise are a key element to increase the competitiveness of companies. However, the election of alternative routes outside the panned routes causes the logistic companies to provide a poor-quality service, with units that endanger the appropriate deliver of merchandise and impacting negatively the way in which the supply chain works. This paper aims to develop a module that allows the processing, analysis and deployment of satellite information oriented to the pattern analysis, to find anomalies in the paths of the operators by implementing the algorithm TODS, to be able to help in the decision making. The experimental results show that the algorithm detects optimally the abnormal routes using historical data as a base
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