pinecone/core-2020-05-10-deduplication huggingface dataset:
Neutron–proton effective mass splitting in neutron-rich matter at normal density from analyzing nucleon–nucleus scattering data within an isospin dependent optical model

The neutron–proton effective mass splitting in asymmetric nucleonic matter of isospin asymmetry δ and normal density is found to be mn−p⁎≡(mn⁎−mp⁎)/m=(0.41±0.15)δ from analyzing globally 1088 sets of reaction and angular differential cross sections of proton elastic scattering on 130 targets with beam energies from 0.783 MeV to 200 MeV, and 1161 sets of data of neutron elastic scattering on 104 targets with beam energies from 0.05 MeV to 200 MeV within an isospin dependent non-relativistic optical potential model. It sets a useful reference for testing model predictions on the momentum dependence of the nucleon isovector potential necessary for understanding novel structures and reactions of rare isotopes
Time- and Spacelike Nucleon Electromagnetic Form Factors beyond
  Relativistic Constituent Quark Models

For the first time, a phenomenological analysis of the experimental
electromagnetic form factors of the nucleon, both in the timelike and spacelike
regions, is performed by taking into account the effects of nonvalence
components in the nucleon state, within a light-front framework. Our model,
based on suitable Ansatzes for the nucleon Bethe-Salpeter amplitude and a
microscopic version of the well-known Vector Meson Dominance model, has only
four free parameters (determined by the spacelike data with $\chi^2/datum \sim
1.7$), and yields a nice description of the experimental electromagnetic form
factors in the physical region in the range $-30 (GeV/c)^2 < q^2 < 20
(GeV/c)^2$, except for the neutron one in the timelike region. Valuable
information can be gained in the timelike region on possible missing Vector
Mesons around $q^2 \sim 4.5 (GeV/c)^2$ and $q^2 \sim 8.0 (GeV/c)^2
Search for new phenomena in events with three or more charged leptons in pp collisions at TeV with the ATLAS detector

A generic search for anomalous production of events with at least three charged leptons is presented. The data sample consists of pp collisions at \( \sqrt{s}=8 \) TeV collected in 2012 by the ATLAS experiment at the CERN Large Hadron Collider, and corresponds to an integrated luminosity of 20.3 fb−1. Events are required to have at least three selected lepton candidates, at least two of which must be electrons or muons, while the third may be a hadronically decaying tau. Selected events are categorized based on their lepton flavour content and signal regions are constructed using several kinematic variables of interest. No significant deviations from Standard Model predictions are observed. Model-independent upper limits on contributions from beyond the Standard Model phenomena are provided for each signal region, along with prescription to re-interpret the limits for any model. Constraints are also placed on models predicting doubly charged Higgs bosons and excited leptons. For doubly charged Higgs bosons decaying to eτ or μτ, lower limits on the mass are set at 400 GeV at 95% confidence level. For excited leptons, constraints are provided as functions of both the mass of the excited state and the compositeness scale Λ, with the strongest mass constraints arising in regions where the mass equals Λ. In such scenarios, lower mass limits are set at 3.0 TeV for excited electrons and muons, 2.5 TeV for excited taus, and 1.6 TeV for every excited-neutrino flavour.<p>ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1007/JHEP08(2015)138</p
Differential top-antitop cross-section measurements as a function of observables constructed from final-state particles using pp collisions at root s=7 TeV in the ATLAS detector

Various differential cross-sections are measured in top-quark pair (t (t) over bar) events produced in proton-proton collisions at a centre-of-mass energy of root s = 7 TeV at the LHC with the ATLAS detector. These differential cross-sections are presented in a data set corresponding to an integrated luminosity of 4.6 fb(-1). The differential cross-sections are presented in terms of kinematic variables, such as momentum, rapidity and invariant mass, of a top-quark proxy referred to as the pseudo-top-quark as well as the pseudo-top-quark pair system. The dependence of the measurement on theoretical models is minimal. The measurements are performed on tt events in the lepton+jets channel, requiring exactly one charged lepton and at least four jets with at least two of them tagged as originating from a b-quark. The hadronic and leptonic pseudo-top-quarks are defined via the leptonic or hadronic decay mode of the W boson produced by the top-quark decay in events with a single charged lepton. Differential cross-section measurements of the pseudo-top-quark variables are compared with several Monte Carlo models that implement next-to-leading order or leading-order multi-leg matrix-element calculations.<p>ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1007/JHEP06(2015)100</p
Single-molecule observation of the ligand-induced population shift of rhodopsin, a g-protein-coupled receptor.

Rhodopsin is a G-protein-coupled receptor, in which retinal chromophore acts as inverse-agonist or agonist depending on its configuration and protonation state. Photostimulation of rhodopsin results in a pH-dependent equilibrium between the active state (Meta-II) and its inactive precursor (Meta-I). Here, we monitored conformational changes of rhodopsin using a fluorescent probe Alexa594 at the cytoplasmic surface, which shows fluorescence increase upon the generation of active state, by single-molecule measurements. The fluorescence intensity of a single photoactivated rhodopsin molecule alternated between two states. Interestingly, such a fluorescence alternation was also observed for ligand-free rhodopsin (opsin), but not for dark-state rhodopsin. In addition, the pH-dependences of Meta-I/Meta-II equilibrium estimated by fluorescence measurements deviated notably from estimates based on absorption spectra, indicating that both Meta-I and Meta-II are mixtures of two conformers. Our observations indicate that rhodopsin molecules intrinsically adopt both active and inactive conformations, and the ligand retinal shifts the conformational equilibrium. These findings provide dynamical insights into the activation mechanisms of G-protein-coupled receptors
Tilt measurements at Vulcano Island

A network of tiltmeters has been operational on Vulcano Island for numerous years. At present, the network comprises five functioning borehole stations, four of which are installed at 8-10 m and allow recording very stable, high precision signals with very low noise.
We report observations over the last 12 years that illustrate impulsive variations linked to seismicity and long-term (several years) trends in the signals. We suggest a relationship between tilt changes correlated to the strongest regional seismic events and site acceleration; long-term tilt variations analyzed in combination with other ground deformation data seem to represent the evidence of a contraction of the La Fossa cone.
We also analyzed how the tilt device has the capability to detect possible magma migrations; we considered previous studies that have imaged spatially well-defined levels of magma accumulation beneath La Fossa, and Vulcanello; we concluded that the Vulcano tilt network should be capable of detecting the upward migration of small magma volumes. 
Finally, we show that no evidence of changes are visible on tilt signals during anomalous degassing episodes (linked to a building up input of magmatic fluids) at the La Fossa thereby evidencing that no magma migration occurred during such events
Highly eccentric hip-hop solutions of the 2N-body problem

We show the existence of families of hip-hop solutions in the equal-mass 2N-body\ud
problem which are close to highly eccentric planar elliptic homographic motions of 2N\ud
bodies plus small perpendicular non-harmonic oscillations. By introducing a parameter Є, the homographic motion and the small amplitude oscillations can be uncoupled\ud
into a purely Keplerian homographic motion of  fixed period and a vertical oscillation described by a Hill type equation. Small changes in the eccentricity induce large\ud
variations in the period of the perpendicular oscillation and give rise, via a Bolzano argument, to resonant periodic solutions of the uncoupled system in a rotating frame. For small Є ≠ 0, the topological transversality persists and Brouwer's fixed point theorem shows the existence of this kind of solutions in the full system.Postprint (author’s final draft
Nickel nanocatalyst exsolution from (La,Sr) (Cr,M, Ni)O3 (M=Mn, Fe) perovskites for the fuel oxidation layer of Oxygen Transport Membranes

Funding: EPSRC: EP/K015540/1, Royal Society: WRMA 2012/R2, Praxair.La0.75Sr0.25Cr0.5Mn0.5O3 (LSCM) and La0.75Sr0.25Cr0.5Fe0.5O3 (LSCF) perovskites with partial substitution of the B-site by 5mol% of Ni were synthesized and characterized for the fuel oxidation layer of Oxygen Transport Membranes (OTMs). X-ray diffraction showed that single phase compounds were obtained at 1300oC. LSCM exhibits a rhombohedral structure and LSCF an orthorhombic structure. Both materials retain their structures, after doping the B site with Ni, with small changes on the unit cell parameters. Thermal analysis under reducing conditions was used to investigate the reducibility of these perovskites up to 900oC, which appears to be enhanced by doping with Ni. The formation of Ni nanoparticles (30-50nm) on the LSCM-Ni and LSCF-Ni grains was observed by scanning electron microscopy, after reducing the samples in 5% H2/Ar at 900oC, indicating possible enhanced catalytic activity and potential benefits for the development of the OTMs. DC Conductivity measurements conducted under a redox cycle, indicate that LSCFNi presents a better redox stability than LSCMNi.Publisher PDFPeer reviewe
New constraints on the mid-IR EBL from the HESS discovery of VHE γ-rays from 1ES 0229+200

Aims.To investigate the very high energy (VHE: >100 GeV) $\gamma$-ray emission from the high-frequency peaked BL Lac 1ES 0229+200.\ud
Methods.Observations of 1ES 0229+200 at energies above 580 GeV were performed with the High Energy Stereoscopic System (HESS) in 2005 and 2006.\ud
Results.1ES 0229+200 is discovered by HESS to be an emitter of VHE photons. A signal is detected at the 6.6$\sigma$ level in the HESS observations (41.8 h live time). The integral flux above 580 GeV is $(9.4\pm1.5_{\rm stat}\pm1.9_{\rm syst}) \times 10^{-13}$ cm-2 s-1, corresponding to ~1.8% of the flux observed from the Crab Nebula. The data show no evidence for significant variability on any time scale. The observed spectrum is characterized by a hard power law ( $\Gamma = 2.50\pm0.19_{\rm stat}\pm0.10_{\rm syst}$) from 500 GeV to ~15 TeV.\ud
Conclusions.The high-energy range and hardness of the observed spectrum, coupled with the object's relatively large redshift ( z = 0.1396), enable the strongest constraints so far on the density of the Extragalactic Background Light (EBL) in the mid-infrared band. Assuming that the emitted spectrum is not harder than $\Gamma_{\rm int} \approx 1.5$, the HESS data support an EBL spectrum $\propto$ $\lambda^{-1}$ and density close to the lower limit from source counts measured by Spitzer, confirming the previous indications from the HEGRA data of 1ES 1426+428 (z=0.129). Irrespective of the EBL models used, the intrinsic spectrum of 1ES 0229+200 is hard, thus locating the high-energy peak of its spectral energy distribution above a few TeV.Peer-reviewedPublisher Version5354
Search for novel circulating cancer chemopreventive biomarkers of dietary rice bran intervention in Apc(Min) mice model of colorectal carcinogenesis, using proteomic and metabolic profiling strategies.

SCOPE: There is strong epidemiological evidence indicating that consumption by humans of whole-grain foods including rice bran may be associated with a low incidence of cancer, especially in the colorectum. Molecular processes associated with cancer development may be retarded by fiber consumption. Consequently, intervention with dietary fiber might be suitable as a cancer chemoprevention strategy in high-risk populations. Here, we searched for putative molecular mechanism-based efficacy biomarkers of rice fiber consumption in the plasma of mice characterized by a genetic propensity to develop gastrointestinal adenomas. The hypothesis was tested that metabolic and proteomic changes in blood reflect the chemopreventive activity of rice bran. METHODS AND RESULTS: Apc(Min) mice received diet supplemented with rice bran at 5, 15, and 30%. Blood and tissue samples were taken. Plasma was subjected to MS-based proteomic and metabolic profiling analyses as well as assessment of hematocrit values. Gastrointestinal tracts were removed and adenomas were counted and their size was measured so that total tumor burden could be calculated. The hypothesis was tested that metabolic and proteomic changes in blood reflect chemopreventive activity. CONCLUSION: Rice bran consumption reduced adenoma burden and number in a dose-related fashion when compared to controls. Metabolic profiling data demonstrated strong clustering of the groups indicating that metabolic pathways are perturbed. Proteomic analysis identified adiponectin as a molecule that was significantly altered, which may play a role in tumor suppression.The authors would like to thanks the HOPE against Cancer Foundation for funding this study. We also thank RiceBran Technologies (formerly Nutracea, Scottsdale, AR, USA) for generous support of the study. Work was also supported by a Cancer Research UK Programme grant (C325/A13101).Peer-reviewedPost-prin
Size, shape and spatial arrangement of mega-scale glacial lineations from a large and diverse dataset.

Mega-scale glacial lineations (MSGLs) are a characteristic landform on ice stream beds. Solving the puzzle of their formation is key to understanding how ice interacts with its bed and how this, in turn, influences the dynamics of ice streams. However, a comprehensive and detailed characterization of this landform's size, shape and spatial arrangement, which might serve to test and refine formational theories, is largely lacking. This paper presents a detailed morphometric analysis and comparison of 4043 MSGLs from eight palaeo-ice stream settings: three offshore (Norway and Antarctica), four onshore (Canada), and one from under a modern ice stream in West Antarctica. The length of MSGLs is lower than previously suggested (mode 1000–2000 m; median 2892 m), and they initiate and terminate at various locations on an ice stream bed. Their spatial arrangement reveals a pattern that is characterized by an exceptional parallel conformity (80% of all mapped MSGLs have an azimuth within 5° from the mean values), and a fairly constant lateral spacing (mode 200–300 m; median 330 m), which we interpret as an indication that MSGLs are a spatially self-organized phenomenon. Results show that size, shape and spatial arrangement of MSGLs are consistent both within and also generally between different ice stream beds. We suggest this results from a common mechanism of formation, which is largely insensitive to local factors. Although the elongation of MSGLs (mode 6–8; median 12.2) is typically higher than features described as drumlins, these values and those of their width (mode 100–200 m; median 268 m) overlap, which suggests the two landforms are part of a morphological continuum and may share a similar origin. We compare their morphometry with explicit predictions made by the groove-ploughing and rilling instability theories of MSGL formation. Although the latter was most compatible, neither is fully supported by observation
Jet multiplicity in the proto-binary system NGC1333-IRAS4A. The detailed
  CALYPSO IRAM-PdBI view

Owing to the paucity of sub-arcsecond (sub)mm observations required to probe
the innermost regions of newly forming protostars, several fundamental
questions are still being debated, such as the existence and coevality of close
multiple systems. We study the physical and chemical properties of the jets and
protostellar sources in the NGC1333-IRAS4A proto-binary system using continuum
emission and molecular tracers of shocked gas. We observed NGC1333-IRAS4A in
the SiO(6-5), SO(6_5-5_4), and CO(2-1) lines and the continuum emission at 1.3,
1.4, and 3 mm using the IRAM Plateau de Bure Interferometer in the framework of
the CALYPSO large program. We clearly disentangle for the first time the
outflow emission from the two sources A1 and A2. The two protostellar jets have
very different properties: the A1 jet is faster, has a short dynamical
timescale (<10^3 yr), and is associated with H2 shocked emission, whereas the
A2 jet, which dominates the large-scale emission, is associated with diffuse
emission, bends, and emits at slower velocities. The observed bending of the A2
jet is consistent with the change of propagation direction observed at large
scale and suggests jet precession on very short timescales (~200-600 yr). In
addition, a chemically rich spectrum with emission from several COMs (e.g.
HCOOH, CH3OCHO, CH3OCH3) is only detected towards A2. Finally, very
high-velocity shocked emission (~50 km s^-1) is observed along the A1 jet. An
LTE analysis shows that SiO, SO, and H2CO abundances in the gas phase are
enhanced up to (3-4)x10^{-7}, (1.4-1.7)x10^{-6}, and (3-7.9)x10^{-7},
respectively. The intrinsic different properties of the jets and driving
sources in NGC1333-IRAS4A suggest different evolutionary stages for the two
protostars, with A1 being younger than A2, in a very early stage of star
formation previous to the hot-corino phase.Comment: Accepted for publication in Astronomy & Astrophysic
High level implementation of geometric multigrid solvers for finite
  element problems: applications in atmospheric modelling

The implementation of efficient multigrid preconditioners for elliptic
partial differential equations (PDEs) is a challenge due to the complexity of
the resulting algorithms and corresponding computer code. For sophisticated
finite element discretisations on unstructured grids an efficient
implementation can be very time consuming and requires the programmer to have
in-depth knowledge of the mathematical theory, parallel computing and
optimisation techniques on manycore CPUs. In this paper we show how the
development of bespoke multigrid preconditioners can be simplified
significantly by using a framework which allows the expression of the each
component of the algorithm at the correct abstraction level. Our approach (1)
allows the expression of the finite element problem in a language which is
close to the mathematical formulation of the problem, (2) guarantees the
automatic generation and efficient execution of parallel optimised low-level
computer code and (3) is flexible enough to support different abstraction
levels and give the programmer control over details of the preconditioner. We
use the composable abstractions of the Firedrake/PyOP2 package to demonstrate
the efficiency of this approach for the solution of strongly anisotropic PDEs
in atmospheric modelling. The weak formulation of the PDE is expressed in
Unified Form Language (UFL) and the lower PyOP2 abstraction layer allows the
manual design of computational kernels for a bespoke geometric multigrid
preconditioner. We compare the performance of this preconditioner to a
single-level method and hypre's BoomerAMG algorithm. The Firedrake/PyOP2 code
is inherently parallel and we present a detailed performance analysis for a
single node (24 cores) on the ARCHER supercomputer. Our implementation utilises
a significant fraction of the available memory bandwidth and shows very good
weak scaling on up to 6,144 compute cores.Comment: 22 pages, 5 figures, 9 tables. Submitted to JC
New Relations for Einstein-Yang-Mills Amplitudes

We obtain new relations between Einstein-Yang-Mills (EYM) amplitudes
involving N gauge bosons plus a single graviton and pure Yang-Mills amplitudes
involving N gauge bosons plus one additional vector boson inserted in a way
typical for a gauge boson of a "spectator" group commuting with the group
associated to original N gauge bosons. We show that such EYM amplitudes satisfy
U(1) decoupling relations similar to Kleiss-Kuijf relations for Yang-Mills
amplitudes. We consider a D-brane embedding of EYM amplitudes in the framework
of disk amplitudes involving open and closed strings. A new set of monodromy
relations is derived for mixed open-closed amplitudes with one closed string
inserted on the disk world-sheet and a number of open strings at the boundary.
These relations allow expressing the latter in terms of pure open string
amplitudes and, in the field-theory limit, they yield the U(1) decoupling
relations for EYM amplitudes.Comment: 15 pages, harvmac, 3 figure
The plant cytoskeleton, NET3C, and VAP27 mediate the link between the plasma membrane and endoplasmic reticulum

The cortical endoplasmic reticulum (ER) network in plants is a highly dynamic structure, and it contacts the plasma membrane (PM) at ER-PM anchor/contact sites. These sites are known to be essential for communication between the ER and PM for lipid transport, calcium influx, and ER morphology in mammalian and fungal cells. The nature of these contact sites is unknown in plants, and here, we have identified a complex that forms this bridge. This complex includes (1) NET3C, which belongs to a plant-specific superfamily (NET) of actin-binding proteins, (2) VAP27, a plant homolog of the yeast Scs2 ER-PM contact site protein, and (3) the actin and microtubule networks. We demonstrate that NET3C and VAP27 localize to puncta at the PM and that NET3C and VAP27 form homodimers/oligomers and together form complexes with actin and microtubules. We show that F-actin modulates the turnover of NET3C at these puncta and microtubules regulate the exchange of VAP27 at the same sites. Based on these data, we propose a model for the structure of the plant ER-PM contact sites.Biotechnology and Biological Sciences Research Council (BBSRC)Leverhulme trus
Improved imputation quality of low-frequency and rare variants in European samples using the 'Genome of the Netherlands'

Although genome-wide association studies (GWAS) have identified many common variants associated with complex traits, low-frequency and rare variants have not been interrogated in a comprehensive manner. Imputation from dense reference panels, such as the 1000 Genomes Project (1000G), enables testing of ungenotyped variants for association. Here we present the results of imputation using a large, new population-specific panel: the Genome of The Netherlands (GoNL). We benchmarked the performance of the 1000G and GoNL reference sets by comparing imputation genotypes with 'true' genotypes typed on ImmunoChip in three European populations (Dutch, British, and Italian). GoNL showed significant improvement in the imputation quality for rare variants (MAF 0.05-0.5%) compared with 1000G. In Dutch samples, the mean observed Pearson correlation, r 2, increased from 0.61 to 0.71. We also saw improved imputation accuracy for other European populations (in the British samples, r 2 improved from 0.58 to 0.65, and in the Italians from 0.43 to 0.47). A combined reference set comprising 1000G and GoNL improved the imputation of rare variants even further. The Italian samples benefitted the most from this combined reference (the mean r 2 increased from 0.47 to 0.50). We conclude that the creation of a large population-specific reference is advantageous for imputing rare variants and that a combined reference panel across multiple populations yields the best imputation results