pinecone/core-2020-05-10-deduplication huggingface dataset:
M31 Pixel Lensing PLAN Campaign: MACHO Lensing and Self Lensing Signals

We present the final analysis of the observational campaign carried out by
the PLAN (Pixel Lensing Andromeda) collaboration to detect a dark matter signal
in form of MACHOs through the microlensing effect. The campaign consists of
about 1 month/year observations carried out during 4 years (2007-2010) at the
1.5m Cassini telescope in Loiano ("Astronomical Observatory of BOLOGNA", OAB)
plus 10 days of data taken in 2010 at the 2m Himalayan Chandra Telescope (HCT)
monitoring the central part of M31 (two fields of about 13'x12.6'). We
establish a fully automated pipeline for the search and the characterization of
microlensing flux variations: as a result we detect 3 microlensing candidates.
We evaluate the expected signal through a full Monte Carlo simulation of the
experiment completed by an analysis of the detection efficiency of our
pipeline. We consider both "self lensing" and "MACHO lensing" lens populations,
given by M31 stars and dark matter halo MACHOs, in the M31 and the Milky Way
(MW), respectively. The total number of events is compatible with the expected
self-lensing rate. Specifically, we evaluate an expected signal of about 2
self-lensing events. As for MACHO lensing, for full 0.5 (0.01) solar mass MACHO
halos, our prediction is for about 4 (7) events. The comparatively small number
of expected MACHO versus self lensing events, together with the small number
statistics at disposal, do not enable us to put strong constraints on that
population. Rather, the hypothesis, suggested by a previous analysis, on the
MACHO nature of OAB-07-N2, one of the microlensing candidates, translates into
a sizeable lower limit for the halo mass fraction in form of the would be MACHO
population, f, of about 15% for 0.5 solar mass MACHOs
First-principles calculation of the effect of stress on the chemical activity of graphene

Graphene layers are stable, hard, and relatively inert. We study how tensile stress affects sigma and pi bonds and the resulting change in the chemical activity. Stress affects more strongly pi bonds that can become chemically active and bind to adsorbed species more strongly. Upon stretch, single C bonds are activated in a geometry mixing 120 and 90 degrees, an intermediate state between sp2 and sp3 bonding. We use ab initio density functional theory to study the adsorption of hydrogen on large clusters and two-dimensional periodic models for graphene. The influence of the exchange-correlation functional on the adsorption energy is discussed.Peer reviewe
Linking collisional and accretionary orogens during Rodinia assembly and breakup : implications for models of supercontinent cycles

We acknowledge support from our respective funding agencies (NERC grant NE/J021822/1, and NSERC Canada).Periodic assembly and dispersal of continental fragments has been a characteristic of the solid Earth for much of its history. Geodynamic drivers of this cyclic activity are inferred to be either top-down processes related to near surface lithospheric stresses at plate boundaries or bottom-up processes related to mantle convection and, in particular, mantle plumes, or some combination of the two. Analysis of the geological history of Rodinian crustal blocks suggests that internal rifting and breakup of the supercontinent were linked to the initiation of subduction and development of accretionary orogens around its periphery. Thus, breakup was a top-down instigated process. The locus of convergence was initially around north-eastern and northern Laurentia in the early Neoproterozoic before extending to outboard of Amazonia and Africa, including Avalonia–Cadomia, and arcs outboard of Siberia and eastern to northern Baltica in the mid-Neoproterozoic (∼760 Ma). The duration of subduction around the periphery of Rodinia coincides with the interval of lithospheric extension within the supercontinent, including the opening of the proto-Pacific at ca. 760 Ma and the commencement of rifting in east Laurentia. Final development of passive margin successions around Laurentia, Baltica and Siberia was not completed until the late Neoproterozoic to early Paleozoic (ca. 570–530 Ma), which corresponds with the termination of convergent plate interactions that gave rise to Gondwana and the consequent relocation of subduction zones to the periphery of this supercontinent. The temporal link between external subduction and internal extension suggests that breakup was initiated by a top-down process driven by accretionary tectonics along the periphery of the supercontinent. Plume-related magmatism may be present at specific times and in specific places during breakup but is not the prime driving force. Comparison of the Rodinia record of continental assembly and dispersal with that for Nuna, Gondwana and Pangea suggests grouping into two supercycles in which Nuna and Gondwana underwent only partial or no break-up phase prior to their incorporation into Rodinia and Pangea respectively. It was only after this final phase of assembly that the supercontinents then underwent full dispersal.Publisher PDFPeer reviewe
Yang-Mills beta-function from a large-distance expansion of the Schrödinger functional.

For slowly varying fields the Yang-Mills Schrödinger functional can be expanded in terms of local functionals. We show how analyticity in a complex scale parameter enables the Schrödinger functional for arbitrarily varying fields to be reconstructed from this expansion. We also construct the form of the Schrödinger equation that determines the coefficients. Solving this in powers of the coupling reproduces the results of the ‘standard’ perturbative solution of the functional Schrödinger equation which we also describe. In particular the usual result for the beta-function is obtained illustrating how analyticity enables the effects of rapidly varying fields to be computed from the behaviour of slowly varying ones
The vacuum functional at large distances.

For fields that vary slowly on the scale of the lightest mass the logarithm of the vacuum functional can be expanded as a sum of local functionals, however, this does not satisfy the obvious form of the Schrödinger equation. For ϕ4 theory we construct the appropriate equation that this expansion does satisfy. This reduces the eigenvalue problem for the Hamiltonian to a set of algebraic equations. We suggest two approaches to their solution. The first is equivalent to the usual semi-classical expansion whilst the other is a new scheme that may also be applied to theories that are classically massless but in which mass is generated quantum mechanically
Pseudorapidity and transverse-momentum distributions of charged
  particles in proton-proton collisions at $\mathbf{\sqrt{\textit s}}$ = 13 TeV

The pseudorapidity ($\eta$) and transverse-momentum ($p_{\rm T}$)
distributions of charged particles produced in proton-proton collisions are
measured at the centre-of-mass energy $\sqrt{s}$ = 13 TeV. The pseudorapidity
distribution in $|\eta|<$ 1.8 is reported for inelastic events and for events
with at least one charged particle in $|\eta|<$ 1. The pseudorapidity density
of charged particles produced in the pseudorapidity region $|\eta|<$ 0.5 is
5.31 $\pm$ 0.18 and 6.46 $\pm$ 0.19 for the two event classes, respectively.
The transverse-momentum distribution of charged particles is measured in the
range 0.15 $<$ $p_{\rm T}$ $<$ 20 GeV/c and $|\eta|<$ 0.8 for events with at
least one charged particle in $|\eta|<$ 1. The correlation between transverse
momentum and particle multiplicity is also investigated by studying the
evolution of the spectra with event multiplicity. The results are compared with
calculations from PYTHIA and EPOS Monte Carlo generators.Comment: 19 pages, 5 figures, 1 table, authors from page 14, published
  version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/192
Theory of electrons, holes and excitons in GaAs polytype quantum dots

Single and multi-band (Burt-Foreman) k.p Hamiltonians for GaAs crystal phase
quantum dots are developed and used to assess ongoing experimental activity on
the role of such factors as quantum confinement, spontaneous polarization,
valence band mixing and exciton Coulomb interaction. Spontaneous polarization
is found to be a dominating term. Together with the control of dot thickness
[Vainorious Nano Lett. 15, 2652 (2015)] it enables wide exciton wavelength and
lifetime tunability. Several new phenomena are predicted for small diameter
dots [Loitsch et al. Adv. Mater. 27, 2195 (2015)], including non-heavy hole
ground state, strong hole spin admixture and a type-II to type-I exciton
transition, which can be used to improve the absorption strength and reduce the
radiative lifetime of GaAs polytypes
Open string multi-branched and Kahler potentials

We consider type II string compactifications on Calabi-Yau orientifolds with
fluxes and D-branes, and analyse the F-term scalar potential that
simultaneously involves closed and open string modes. In type IIA models with
D6-branes such potential can be directly computed by integrating out Minkowski
three-forms. The result shows a multi-branched structure along the space of
lifted open string moduli, in which discrete shifts in special Lagrangian and
Wilson line deformations are compensated by changes in the RR flux quanta. The
same sort of discrete shift symmetries are present in the superpotential and
constrain the Kahler potential. As for the latter, inclusion of open string
moduli breaks the factorisation between complex structure and Kahler moduli
spaces. Nevertheless, the 4d Kahler metrics display a set of interesting
relations that allow to rederive the scalar potential analytically. Similar
results hold for type IIB flux compactifications with D7-brane Wilson lines.Comment: 60 pages, one figure. v2 minor corrections and references adde
Degeneracy between $\theta_{23}$ octant and neutrino non-standard
  interactions at DUNE

We expound in detail the degeneracy between the octant of $\theta_{23}$ and
flavor-changing neutral-current non-standard interactions (NSI's) in neutrino
propagation, considering the Deep Underground Neutrino Experiment (DUNE) as a
case study. In the presence of such NSI parameters involving the $e-\mu$
($\varepsilon_{e\mu}$) and $e-\tau$ ($\varepsilon_{e\tau}$) flavors, the
$\nu_\mu \to \nu_e$ and $\bar\nu_\mu \to \bar\nu_e$ appearance probabilities in
long-baseline experiments acquire an additional interference term, which
depends on one new dynamical CP-phase $\phi_{e\mu/e\tau}$. This term sums up
with the well-known interference term related to the standard CP-phase $\delta$
creating a source of confusion in the determination of the octant of
$\theta_{23}$. We show that for values of the NSI coupling (taken one
at-a-time) as small as $few\,\%$ (relative to the Fermi coupling constant
$G_{\mathrm F}$), and for unfavorable combinations of the two CP-phases
$\delta$ and $\phi_{e\mu/e\tau}$, the discovery potential of the octant of
$\theta_{23}$ gets completely lost.Comment: 11 pages, 5 pdf figures. Minor changes in the text. New references
  added. Accepted in Physics Letters
Double scattering production of two positron-electron pairs in
  ultraperipheral heavy-ion collisions

We present first measurable predictions for electromagnetic (two-photon)
double scattering production of two positron-electron pairs in ultraperipheral
heavy-ion collisions at LHC. Measureable cross sections are obtained with
realistic cuts on electron/positron (pseudo)rapidities and transverse momenta
for the ALICE and ATLAS or CMS experiments. The predictions for total and
differential cross sections are presented. We show also two-dimensional
distributions in rapidities of the opposite-sign (from the same or different
subcollisions) and of the same-sign ($e^+ e^+$ or $e^- e^-$) electrons and in
rapidity distance between them. Expected number of events are presented and
discussed. Our calculations strongly suggest that relevant measurements with
the help of ATLAS, CMS and ALICE detectors are possible in a near future.Comment: 10 pages, 6 figure
Carotenoids are essential for the assembly of cyanobacterial photosynthetic complexes.

In photosynthetic organisms, carotenoids (carotenes and xanthophylls) are important for light harvesting, photoprotection and structural stability of a variety of pigment-protein complexes. Here, we investigated the consequences of altered carotenoid composition for the functional organization of photosynthetic  complexes in wild-type and various mutant strains of the cyanobacterium Synechocystis sp. PCC 6803. Although it is generally accepted that xanthophylls do not play a role in cyanobacterial photosynthesis in low-light conditions, we have found that the absence of xanthophylls leads to reduced oligomerization of photosystems I and II. This is remarkable because these complexes do not bind xanthophylls. Oligomerization is even more disturbed in crtH mutant cells, which  show limited carotenoid synthesis; in these cells also the phycobilisomes are distorted despite the fact that these extramembranous light-harvesting complexes  do not contain carotenoids. The number of phycocyanin rods connected to the phycobilisome core is strongly reduced leading to high amounts of unattached phycocyanin units. In the absence of carotenoids the overall organization of the  thylakoid membranes is disturbed: Photosystem II is not formed, photosystem I hardly oligomerizes and the assembly of phycobilisomes remains incomplete. These  data underline the importance of carotenoids in the structural and functional organization of the cyanobacterial photosynthetic machinery
Search for the direct production of charginos, neutralinos and staus in final states with at least two hadronically decaying taus and missing transverse momentum in pp collisions at root s=8 TeVwith the ATLAS detecto

Results of a search for the electroweak associated production of charginos and next-to-lightest neutralinos, pairs of charginos or pairs of tau sleptons are presented. These processes are characterised by final states with at least two hadronically decaying tau leptons, missing transverse momentum and low jet activity. The analysis is based on an integrated luminosity of 20.3 fb(-1) of proton-proton collisions at root s = 8 TeV recorded with the ATLAS experiment at the Large Hadron Collider. No significant excess is observed with respect to the predictions from Standard Model processes. Limits are set at 95% confidence level on the masses of the lighter chargino and next-to-lightest neutralino for various hypotheses for the lightest neutralino mass in simplified models. In the scenario of direct production of chargino pairs, with each chargino decaying into the lightest neutralino via an intermediate tau slepton, chargino masses up to 345 GeV are excluded for a massless lightest neutralino. For associated production of mass-degenerate charginos and next-to-lightest neutralinos, both decaying into the lightest neutralino via an intermediate tau slepton, masses up to 410 GeV are excluded for a massless lightest neutralino
Camassa-Holm type equations for axisymmetric Poiseuille pipe flows

11 pages, 4 figures, 31 references. Other author's papers can be downloaded at http://www.denys-dutykh.com/International audienceWe present a study on the nonlinear dynamics of a disturbance to the laminar state in non-rotating axisymmetric Poiseuille pipe flows. The associated Navier-Stokes equations are reduced to a set of coupled generalized Camassa-Holm type equations. These support singular inviscid travelling waves with wedge-type singularities, the so called peakons, which bifurcate from smooth solitary waves as their celerity increase. In physical space they correspond to localized toroidal vortices or vortexons. The inviscid vortexon is similar to the nonlinear neutral structures found by Walton (2011) and it may be a precursor to puffs and slugs observed at transition, since most likely it is unstable to non-axisymmetric disturbances
A unifying look at the Apostolico-Giancarlo string-matching algorithm

International audienceString matching is the problem of finding all the occurrences of a pattern in a text. We present a new method to compute the combinatorial shift function ("matching shift") of the well-known Boyer-Moore string matching algorithm. This method implies the computation of the length of the longest suffixes of the pattern ending at each position in this pattern. These values constituted an extra-preprocessing for a variant of the Boyer-Moore algorithm designed by Apostolico and Giancarlo. We give here a new presentation of this algorithm that avoids extra preprocessing together with a tight bound of 1.5n character comparisons (where n is the length of the text)
Inductive pattern-based land use/cover change models: A comparison of four software packages

International audienceLand use/cover change (LUCC), as an important factor in global change, is a topic that has recently received considerable attention in the prospective modeling domain. There are many approaches and software packages for modeling LUCC, many of them are empirical approaches based on past LUCC such as CLUES , DINAMICA EGO, CA_MARKOV and Land Change Modeler (both available in IDRISI). This study reviews the possibilities and the limits of these four modeling software packages. First, a revision of the methods and tools available for each model was performed, taking into account how the models carry out the different procedures involved in the modeling process: quantity of change estimate, change potential evaluation, spatial allocation of change, reproduction of temporal and spatial patterns, model evaluation and advanced modeling options. Additional considerations, such as flexibility and user friendliness were also taken into account. Then, the four models were applied to a virtual case study to illustrate the previous descriptions with a typical LUCC scenario that consists of four processes of change (conversion of forest to two different types of crops, crop abandonment and urban sprawl) that follow different spatial patterns and are conditioned by different drivers. The outputs were compared to assess the quantity of change estimates, the change potential and the simulated prospective maps. Finally, we discussed some basic criteria to define a " good " model
Parameter estimation in non-linear mixed effects models with SAEM algorithm: extension from ODE to PDE.

International audienceParameter estimation in non linear mixed effects models requires a large number of evaluations of the model to study. For ordinary differential equations, the overall computation time remains reasonable. However when the model itself is complex (for instance when it is a set of partial differential equations) it may be time consuming to evaluate it for a single set of parameters. The procedures of population parametrization (for instance using SAEM algorithms) are then very long and in some cases impossible to do within a reasonable time. We propose here a very simple methodology which may accelerate population parametrization of complex models, including partial differential equations models. We illustrate our method on the classical KPP equation
v4, v5, v6, v7: nonlinear hydrodynamic response versus LHC data

7 pages and 3 figuresInternational audienceHigher harmonics of anisotropic flow ($v_n$ with $n\ge 4$) in heavy-ion collisions can be measured either with respect to their own plane, or with respect to a plane constructed using lower-order harmonics. We explain how such measurements are related to event-plane correlations. We show that CMS data on $v_4$ and $v_6$ are compatible with ATLAS data on event-plane correlations. If one assumes that higher harmonics are the superposition of non-linear and linear responses, then the linear and non-linear parts can be isolated under fairly general assumptions. By combining analyses of higher harmonics with analyses of $v_2$ and $v_3$, one can eliminate the uncertainty from initial conditions and define quantities that only involve nonlinear hydrodynamic response coefficients. Experimental data on $v_4$, $v_5$ and $v_6$ are in good agreement with hydrodynamic calculations. We argue that $v_7$ can be measured with respect to elliptic and triangular flow. We present predictions for $v_7$ versus centrality in Pb-Pb collisions at the LHC
Gluconeogenic Signals Regulate Iron Homeostasis via Hepcidin in Mice.

Hepatic gluconeogenesis provides fuel during starvation, and is abnormally induced in obese individuals or those\ud
with diabetes. Common metabolic disorders associated with active gluconeogenesis and insulin resistance (obesity,\ud
metabolic syndrome, diabetes, and nonalcoholic fatty liver disease) have been associated with alterations in iron\ud
homeostasis that disrupt insulin sensitivity and promote disease progression. We investigated whether gluconeogenic\ud
signals directly control Hepcidin, an important regulator of iron homeostasis, in starving mice (a model of persistently\ud
activated gluconeogenesis and insulin resistance).|We investigated hepatic regulation of Hepcidin expression in\ud
C57BL/6Crl, 129S2/SvPas, BALB/c, and wild-type and Creb3l3-/- null mice. Mice were fed a standard, iron-balanced\ud
chow diet or an iron-deficient diet for 9 days before death, or for 7 days before a 24- to 48-hour starvation period;\ud
liver and spleen tissues then were collected and analyzed by quantitative reverse-transcription polymerase chain\ud
reaction and immunoblot analyses. Serum levels of iron, hemoglobin, Hepcidin, and glucose also were measured. We\ud
analyzed human hepatoma (HepG2) cells and mouse primary hepatocytes to study transcriptional control of Hamp\ud
(the gene that encodes Hepcidin) in response to gluconeogenic stimuli using small interfering RNA, luciferase\ud
promoter, and chromatin immunoprecipitation analyses.|Starvation led to increased transcription of encodes\ud
phosphoenolpyruvate carboxykinase 1 (a protein involved in gluconeogenesis) in livers of mice, increased levels of\ud
Hepcidin, and degradation of Ferroportin, compared with nonstarved mice. These changes resulted in hypoferremia\ud
and iron retention in liver tissue. Livers of starved mice also had increased levels of Ppargc1a messenger RNA and\ud
Creb3l3 messenger RNA, which encode a transcriptional co-activator involved in energy metabolism and a liverspecific\ud
transcription factor, respectively. Glucagon and a cyclic adenosine monophosphate analog increased promoter\ud
activity and transcription of Hamp in cultured liver cells; levels of Hamp were reduced after administration of small\ud
interfering RNAs against Ppargc1a and Creb3l3. PPARGC1A and CREB3L3 bound the Hamp promoter to activate its\ud
transcription in response to a cyclic adenosine monophosphate analog. Creb3l3-/- mice did not up-regulate Hamp or\ud
become hypoferremic during starvation.|We identified a link between glucose and iron homeostasis, showing that\ud
Hepcidin is a gluconeogenic sensor in mice during starvation. This response is involved in hepatic metabolic adaptation\ud
to increased energy demands; it preserves tissue iron for vital activities during food withdrawal, but can cause\ud
excessive iron retention and hypoferremia in disorders with persistently activated gluconeogenesis and insulin\ud
resistance