518 research outputs found
Group and individual differences in the neural representation of described and experienced risk
Beam Test of a Segmented Foil SEM Grid
A prototype Secondary-electron Emission Monitor (SEM) was installed in the 8
GeV proton transport line for the MiniBooNE experiment at Fermilab. The SEM is
a segmented grid made with 5 um Ti foils, intended for use in the 120 GeV NuMI
beam at Fermilab. Similar to previous workers, we found that the full
collection of the secondary electron signal requires a bias voltage to draw the
ejected electrons cleanly off the foils, and this effect is more pronounced at
larger beam intensity. The beam centroid and width resolutions of the SEM were
measured at beam widths of 3, 7, and 8 mm, and compared to calculations.
Extrapolating the data from this beam test, we expect a centroid and width
resolutions of 20um and 25 um, respectively, in the NuMI beam which has 1 mm
spot size.Comment: submitted to Nucl. Instr. Meth.
Two-parameter neutrino mass matrices with two texture zeros
We reanalyse Majorana-neutrino mass matrices M_nu with two texture zeros, by
searching for viable hybrid textures in which the non-zero matrix elements of
M_nu have simple ratios. Referring to the classification scheme of Frampton,
Glashow and Marfatia, we find that the mass matrix denoted by A1 allows the
ratios (M_nu)_{mu mu} : (Mnu)_{tau tau} = 1:1 and (M_nu)_{e tau} : (Mnu)_{mu
tau} = 1:2. There are analogous ratios for texture A2. With these two hybrid
textures, one obtains, for instance, good agreement with the data if one
computes the three mixing angles in terms of the experimentally determined
mass-squared differences Delta m^2_21 and Delta m^2_31. We could not find
viable hybrid textures based on mass matrices different from those of cases A1
and A2.Comment: 10 pages, no figures, minor changes, some references adde
High-Throughput Omics Technologies: Potential Tools for the Investigation of Influences of EMF on Biological Systems
The mode of action of a huge amount of agents on biological systems is still unknown. One example where more questions than answers exist is covered by the term electromagnetic fields (EMF). Use of wireless communication, e.g. mobile phones, has been escalated in the last few years. Due to this fact, a lot of discussions dealt with health consequences of EMF emitted by these devices and led to an increased investigation of their effects to biological systems, mainly by using traditional methods. Omics technologies have the advantage to contain methods for investigations on DNA-, RNA- and protein level as well as changes in the metabolism
Fine-tuning and naturalness issues in the two-zero neutrino mass textures
In this paper we analyze the compatibility of two-zero neutrino Majorana
textures with the recent experimental data. Differently from previous works, we
use the experimental data to fix the values of the non-vanishing mass matrix
entries and study in detail the correlations and degree of fine-tuning among
them, which is also a measure of how naturally a given texture is able to
describe all neutrino data. This information is then used to expand the
textures in powers of the Cabibbo angle; extracting random O(1) coefficients,
we show that only in few cases such textures reproduce the mixing parameters in
their 3 sigma ranges.Comment: 13 pages, 14 figures. Version to appear in NP
The perception of touch and the ventral somatosensory pathway
Preusser et al. use MRI-based lesion-symptom mapping to confirm the causal role of a ventral pathway in the perception of touch. This pathway originates downstream of the postcentral gyrus in the parietal operculum, passes the insula and the putamen, before terminating in white matter projections extending to inferior lateral prefrontal corte
Penetration of alkali atoms throughout graphene membrane: theoretical modeling
Theoretical studies of penetration of various alkali atoms (Li, Na, Rb, Cs)
throughout graphene membrane grown on silicon carbide substrate are reported
and compared with recent experimental results. Results of first principles
modeling demonstrate rather low (about 0.8 eV) energy barrier for the formation
of temporary defects in carbon layer required for the penetration of Li at high
concentration of adatoms, higher (about 2 eV) barrier for Na, and barriers
above 4 eV for Rb and Cs. Experiments prove migration of lithium adatoms from
graphene surface to the buffer layer and SiC substrate at room temperature,
sodium at 100{\deg}C and impenetrability of graphene membrane for Rb and Cs.
Differences between epitaxial and free standing graphene for the penetration of
alkali ions are also discussed.Comment: 16 pages, 3 figure, accepted to Nanoscal
Identification of {HNRNPK} as Regulator of Hepatitis {C} Virus Particle Production
Hepatitis C virus (HCV) is a major cause of chronic liver disease affecting around 130 million people worldwide. While great progress has been made to define the principle steps of the viral life cycle, detailed knowledge how HCV interacts with its host cells is still limited. To overcome this limitation we conducted a comprehensive whole-virus RNA interference-based screen and identified 40 host dependency and 16 host restriction factors involved in HCV entry/replication or assembly/release. Of these factors, heterogeneous nuclear ribonucleoprotein K (HNRNPK) was found to suppress HCV particle production without affecting viral RNA replication. This suppression of virus production was specific to HCV, independent from assembly competence and genotype, and not found with the related Dengue virus. By using a knock-down rescue approach we identified the domains within HNRNPK required for suppression of HCV particle production. Importantly, HNRNPK was found to interact specifically with HCV RNA and this interaction was impaired by mutations that also reduced the ability to suppress HCV particle production. Finally, we found that in HCV-infected cells, subcellular distribution of HNRNPK was altered; the protein was recruited to sites in close proximity of lipid droplets and colocalized with core protein as well as HCV plus-strand RNA, which was not the case with HNRNPK variants unable to suppress HCV virion formation. These results suggest that HNRNPK might determine efficiency of HCV particle production by limiting the availability of viral RNA for incorporation into virions. This study adds a new function to HNRNPK that acts as central hub in the replication cycle of multiple other viruses
Flavor Violating Higgs Decays
We study a class of nonstandard interactions of the newly discovered 125 GeV
Higgs-like resonance that are especially interesting probes of new physics:
flavor violating Higgs couplings to leptons and quarks. These interaction can
arise in many frameworks of new physics at the electroweak scale such as two
Higgs doublet models, extra dimensions, or models of compositeness. We rederive
constraints on flavor violating Higgs couplings using data on rare decays,
electric and magnetic dipole moments, and meson oscillations. We confirm that
flavor violating Higgs boson decays to leptons can be sizeable with, e.g., h ->
tau mu and h -> tau e branching ratios of order 10% perfectly allowed by low
energy constraints. We estimate the current LHC limits on h -> tau mu and h ->
tau e decays by recasting existing searches for the SM Higgs in the tau-tau
channel and find that these bounds are already stronger than those from rare
tau decays. We also show that these limits can be improved significantly with
dedicated searches and we outline a possible search strategy. Flavor violating
Higgs decays therefore present an opportunity for discovery of new physics
which in some cases may be easier to access experimentally than flavor
conserving deviations from the Standard Model Higgs framework.Comment: 39 pages, 12 figures, 3 tables; v2: Improved referencing, updated mu
-> 3e bounds to include large loop contributions, corrected single top
constraints; conclusions unchanged; matches version to be published in JHEP;
v3: included 2-loop contributions in mu -> e conversion, improved discussion
of tau -> 3 mu and of EDM constraints on FV top-Higgs couplings; conclusions
unchange
Proceedings of the 2nd Workshop on Flavor Symmetries and Consequences in Accelerators and Cosmology (FLASY12)
These are the proceedings of the 2nd Workshop on Flavor Symmetries and
Consequences in Accelerators and Cosmology, held 30 June 2012 - 4 July 2012,
Dortmund, Germany.Comment: Order 400 pages, several figures including the group picture v2:
corrected author list and contributio
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