pinecone/core-2020-05-10-deduplication huggingface dataset:
A charcoal-rich horizon at Ø69, Greenland : evidence for vegetation burning during the Norse landnám?

It is often assumed that the colonisation of Greenland by Norse settlers in c. A.D. 985 had a sudden and dramatic effect on the environment, involving substantial vegetation clearance and environmental degradation. Consequently, it has been argued that charcoal-rich horizons, visible in many sections in Greenland, represent the initial burning of the vegetation by Norse farmers to create land suitable for agriculture. In this study a charcoal-rich layer, visible in a modern drainage ditch beside the Norse farm of Ø69, was analysed using archaeobotany, sedimentary analysis and radiocarbon dating to test the date and formation processes of the horizon. It is demonstrated that the charcoal-rich layer at Ø69 was not derived from in situ vegetation burning in the 10th century and concluded that the layer was probably formed by the addition of midden material to the infields around Ø69 in the 13th and 14th centuries cal AD, perhaps as part of a soil amendment strategy. It is argued that caution must be exercised when interpreting charcoal-rich horizons as time-specific chronological markers in palaeoenvironmental sequences in Greenland
WASP-64 b and WASP-72 b : two new transiting highly irradiated giant planets

We report the discovery by the WASP transit survey of two new highly irradiated giant planets. WASP-64 b is slightly more massive (1.271 +/- 0.068 M-Jup) and larger (1.271 +/- 0.039 R-Jup) than Jupiter, and is in very-short (a = 0.02648 +/- 0.00024 AU, P = 1.5732918 +/- 0.0000015 days) circular orbit around a V = 12.3 G7-type dwarf (1.004 +/- 0.028 M-circle dot, 1.058 +/- 0.025 R-circle dot, T-eff = 5500 +/- 150 K). Its size is typical of hot Jupiters with similar masses. WASP-72 b has also a mass a bit higher than Jupiter's (1.461(-0.056)(+0.059) M-Jup) and orbits very close (0.03708 +/- 0.00050 AU, P = 2.2167421 +/- 0.0000081 days) to a bright (V = 9.6) and moderately evolved F7-type star (1.386 +/- 0.055 M-circle dot, 1.98 +/- 0.24 R-circle dot, T-eff = 6250 +/- 100 K). Despite its extreme irradiation (similar to 5.5 x 10(9) erg s(-1) cm(-2)), WASP-72 b has a moderate size (1.27 +/- 0.20 R-Jup) that could suggest a significant enrichment in heavy elements. Nevertheless, the errors on its physical parameters are still too high to draw any strong inference on its internal structure or its possible peculiarity.Publisher PDFPeer reviewe
Emergency department visits due to vertebral fractures in the Netherlands, 1986-2008: Steep increase in the oldest old, strong association with falls

Background: Vertebral fractures are a common consequence of osteoporosis in older persons. With the ageing of the population, numbers are expected to rise. Objective: To determine trends in health care demand due to vertebral fracture related emergency department (ED) visits and hospitalizations in the older Dutch population. Design and setting: Secular trend analysis of vertebral fracture related ED visits between 1986 and 2008, using the Dutch Injury Surveillance System. All ED visits with a primary diagnosis of a vertebral fracture in persons aged ≥65 years were extracted from this database. Main outcome measure: Numbers, age-specific and age-adjusted incidence rates (per 100,000 population) of ED visits and hospitalization rates due to vertebral fractures in the older Dutch population were calculated for each year of the study. Results: The total number of ED visits due to a vertebral fracture increased from 913 in 1986 to 2502 in 2008 (174% increase). The majority of fractures were caused by a low-energetic fall incident (83%). The overall age-adjusted incidence rate increased from 51.6 per 100,000 population in 1986 to 103.6 in 2008. Incidence rates increased with age and were higher in females than in males. The hospitalization rate remained stable at about 50-55%, in both females and males. Conclusion: Vertebral fracture related ED visits and hospitalizations are increasing rapidly in the older Dutch population, especially in the oldest-old. Most vertebral fractures were associated with falls. These findings indicate that a pro-active approach in the diagnosis and treatment of osteoporosis and in the prevention of falls in both men and women is warranted
Alcohol consumption in young adults: the role of multisensory imagery

Little is known about the subjective experience of alcohol desire and craving in young people. Descriptions of alcohol urges continue to be extensively used in the everyday lexicon of young, non-dependent drinkers. Elaborated Intrusion (EI) Theory contends that imagery is central to craving and desires, and predicts that alcohol-related imagery will be associated with greater frequency and amount of drinking. This study involved 1535 age stratified 18-25. year olds who completed an alcohol-related survey that included the Imagery scale of the Alcohol Craving Experience (ACE) questionnaire. Imagery items predicted 12-16% of the variance in concurrent alcohol consumption. Higher total Imagery subscale scores were linearly associated with greater drinking frequency and lower self-efficacy for moderate drinking. Interference with alcohol imagery may have promise as a preventive or early intervention target in young people
Green-Schwarz, Nambu-Goto Actions, and Cayley's Hyperdeterminant

It has been recently shown that Nambu-Goto action can be re-expressed in
terms of Cayley's hyperdeterminant with the manifest SL(2,R) X SL(2,R) X
SL(2,R) symmetry. In the present paper, we show that the same feature is shared
by Green-Schwarz sigma-model for N=2 superstring whose target space-time is
D=2+2. When its zweibein field is eliminated from the action, it contains the
Nambu-Goto action which is nothing but the square root of Cayley's
hyperdeterminant of the pull-back in superspace \sqrt{\hyperdet(\Pi_{i
\a\Dot\a})} manifestly invariant under SL(2,R) X SL(2,R) X SL(2,R). The target
space-time D=2+2 can accommodate self-dual supersymmetric Yang-Mills theory.
Our action has also fermionic kappa-symmetry, satisfying the criterion for its
light-cone equivalence to Neveu-Schwarz-Ramond formulation for N=2 superstring.Comment: 14 pages, no figure
The june 2008 flare of Markarian 421 from optical to TeV energies\ud

We present optical, X-ray, high-energy ((sic) 30 GeV) and very high energy ((sic) 100 GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 and June 23. A high-energy gamma-ray signal was detected by AGILE with root TS = 4.5 between June 9 and 15, with F(E > 100 MeV) = 42(-12)(+14) x 10(-8) photons cm(-2) s(-1). This flaring state is brighter than the average flux observed by EGRET by a factor of similar to 3, but still consistent with the highest EGRET flux. In hard X-rays (20-60 keV) SuperAGILE resolved a five-day flare (June 9-15) peaking at similar to 55 mCrab. SuperAGILE, RXTE/ASM and Swift/BAT data show a correlated flaring structure between soft and hard X-rays. Hints of the same flaring behavior are also detected in the simultaneous optical data provided by the GASP-WEBT. A Swift/XRT observation near the flaring maximum revealed the highest 2-10 keV flux ever observed from this source, of 2.6 x 10(-9) erg cm(-2) s(-1) (i.e. > 100 mCrab). A peak synchrotron energy of similar to 3 keV was derived, higher than typical values of similar to 0.5-1 keV. VHE observations with MAGIC and VERITAS between June 6 and 8 showed the flux peaking in a bright state, well correlated with the X-rays. This extraordinary set of simultaneous data, covering a 12-decade spectral range, allowed for a deep analysis of the spectral energy distribution as well as of correlated light curves. The gamma-ray flare can be interpreted within the framework of the synchrotron self-Compton model in terms of a rapid acceleration of leptons in the jet.\u
SU(2) Dirac-Yang-Mills quantum mechanics of spatially constant quark and
  gluon fields

The quantum mechanics of spatially constant SU(2) Yang-Mills- and
Dirac-fields minimally coupled to each other is investigated as the strong
coupling limit of 2-color-QCD. Using a canonical transformation of the quark
and gluon fields, which Abelianises the Gauss law constraints to be
implemented, the corresponding unconstrained Hamiltonian and total angular
momentum are derived. In the same way as this reduces the colored spin-1 gluons
to unconstrained colorless spin-0 and spin-2 gluons, it reduces the colored
spin-1/2 quarks to unconstrained colorless spin-0 and spin-1 quarks. These
however continue to satisfy anti-commutation relations and hence the
Pauli-exclusion principle. The obtained unconstrained Hamiltonian is then
rewritten into a form, which separates the rotational from the scalar degrees
of freedom. In this form the low-energy spectrum can be obtained with high
accuracy. As an illustrative example, the spin-0 energy-spectrum of the
quark-gluon system is calculated for massless quarks of one flavor. It is
found, that only for the case of 4 reduced quarks (half-filling) satisfying the
boundary condition of particle-antiparticle C-symmetry, states with energy
lower than for the pure-gluon case are obtained. These are the groundstate,
with an energy about 20% lower than for the pure-gluon case and the formation
of a quark condensate, and the sigma-antisigma excitation with an energy about
a fifth of that of the first glueball excitation.Comment: Tab.1 and Fig.1 updated, accepted for publication in Physics Letters
Nearly K\"ahler heterotic compactifications with fermion condensates

We revisit AdS_4 heterotic compactifications on nearly K\"ahler manifolds in
the presence of H-flux and certain fermion condensates. Unlike previous
studies, we do not assume the vanishing of the supersymmetry variations.
Instead we determine the full equations of motion originating from the
ten-dimensional action, and subsequently we provide explicit solutions to them
on nearly K\"ahler manifolds at first order in alpha'. The Bianchi identity is
also taken into account in order to guarantee the absence of all anomalies. In
the presence of H-flux, which is identified with the torsion of the internal
space, as well as of fermion condensates in the gaugino and dilatino sectors,
new solutions are determined. These solutions provide a full classification of
consistent backgrounds of heterotic supergravity under our assumptions. All the
new solutions are non-supersymmetric, while previously known supersymmetric
ones are recovered too. Our results indicate that fully consistent
(supersymmetric or not) heterotic vacua on nearly K\"ahler manifolds are
scarce, even on AdS_4, and they can be completely classified.Comment: 1+17 pages, 1 figure; v2: remark and two references added, published
  versio
An all-sky optical catalogue of radio / X-ray sources

We present an all-sky catalogue that aligns and overlays the ROSAT HRI, RASS,
PSPC and WGA X-ray catalogues and the NVSS, FIRST and SUMSS radio catalogues
onto the optical APM and USNO-A catalogues. Objects presented are those
APM/USNO-A optical objects which are calculated with >= 40% confidence to be
associated with radio/X-ray detections, or which are identified as known QSOs,
AGN or BL Lacs, totalling 501,761 objects in all, including 48,285 QSOs and
21,498 double radio lobe detections. For each radio/X-ray associated optical
object we display the calculated percentage probabilities of its being a QSO,
galaxy, star, or erroneous radio/X-ray association, plus any identification
from the literature. The catalogue includes 86,009 objects which were not
previously identified and which we list as being 40% to >99% likely to be a
QSO. As a byproduct of the construction of this catalogue, we are able to list
comprehensive ROSAT field shifts as determined by our whole-sky likelihood
algorithm, and also plate-by-plate photometric recalibration of the complete
APM and USNO-A2.0 optical catalogues, significantly improving accuracy for
objects of >15 mag. The catalogue is available wholly and in subsets at
http://quasars.org/qorg-data.htmComment: 33 pages, accepted for A&A (first 6 pages only for print version).
  Some figures reduced in quality: full-quality PDF at
  http://www.quasars.org/qorg-paper.pd
The role of nitrogen related defects in high-k dielectric oxides:
  Density functional studies

Using ab initio density functional total energy and molecular dynamics
simulations, we study the effects of various forms of nitrogen post deposition
anneal (PDA) on the electric properties of hafnia in the context of its
application as a gate dielectric in field effect transistors (FET). We consider
the atomic structure and energetics of nitrogen containing defects which can be
formed during the PDA in various N-based ambients: N2, N+2, N, NH3, NO, N2O. We
analyse the role of such defects in fixed charge accumulation, electron
trapping and in the growth of the interface SiOx layer. We find that nitrogen
anneal of the oxides leads to an effective immobilization of native defects
such as oxygen vacancies and interstitial oxygen ions, which may inhibit growth
of silica layer. Nitrogen in any form effectively incorporates into the
pre-existing oxygen vacancies and, therefore may decrease the concentration of
shallow electron traps. However, nitrogen in any form is unlikely to
significantly reduce the fixed charge in the dielectric.Comment: 14 pages, 8 figures, 6 tables. Submitted to Journal of Applied
  Physic
Probing the sp^2 dependence of elastic moduli in ultrahard diamond films

The structural and elastic properties of diamond nanocomposites and
ultrananocrystalline diamond films (UNCD) are investigated using both empirical
potentials and tight binding schemes. We find that both materials are extremely
hard, but their superb diamondlike properties are limited by their sp^2
component. In diamond composites, the sp^2 atoms are found in the matrix and
far from the interface with the inclusion, and they are responsible for the
softening of the material. In UNCD, the sp^2 atoms are located in the grain
boundaries. They offer relaxation mechanisms which relieve the strain but, on
the other hand, impose deformations that lead to softening. The higher the sp^2
component the less rigid these materials are.Comment: 10 pages, 3 figures. to appear in Diamond and Relarted Material
Managing network congestion with a Kohonen-based RED queue

The behaviour of the TCP AIMD algorithm is known to cause queue length
oscillations when congestion occurs at a router output link. Indeed, due to
these queueing variations, end-to-end applications experience large delay
jitter. Many studies have proposed efficient Active Queue Management (AQM)
mechanisms in order to reduce queue oscillations and stabilize the queue
length. These AQM are mostly improvements of the Random Early Detection (RED)
model. Unfortunately, these enhancements do not react in a similar manner for
various network conditions and are strongly sensitive to their initial setting
parameters. Although this paper proposes a solution to overcome the
difficulties of setting these parameters by using a Kohonen neural network
model, another goal of this study is to investigate whether cognitive
intelligence could be placed in the core network to solve such stability
problem. In our context, we use results from the neural network area to
demonstrate that our proposal, named Kohonen-RED (KRED), enables a stable queue
length without complex parameters setting and passive measurements.Comment: 8 pages, 9 figure
Interconnection Effects in Multiparticle Production from WW Events at
  LEP

Interactions between the products of the hadronic decays of different Ws in
WW pair events can occur at several stages: from the colour rearrangement
between the quarks coming from the primary branching, to the gluon exchange
during the parton cascade, to the mixing of identical pions due to
Bose-Einstein correlations. Besides the intrinsic interest of their study
related to the understanding of the multiparticle production mechanisms, these
phenomena can affect the ultimate accuracy in the W mass measurement by LEP 2.
The status of the experimental analysis on interconnection effects between W
pairs hadronically decaying is reviewed in this paper.Comment: 10 pages, 7 figures. To be published in Proc. XXVII International
  Symposium on Multiparticle Dynamics; Laboratori Nazionali di Frascati (Roma),
  September 199
The neutrino charge radius is a physical observable

We present a method which allows, at least in principle, the direct
extraction of the gauge-invariant and process-independent neutrino charge
radius (NCR) from experiments. Under special kinematic conditions, the
judicious combination of neutrino and anti-neutrino forward differential
cross-sections allows the exclusion of all target-dependent contributions, such
as gauge-independent box-graphs, not related to the NCR. We show that the
remaining contributions contain universal, renormalization group invariant
combinations, such as the electroweak effective charge and the running mixing
angle, which must be also separated out. By considering the appropriate number
of independent experiments we show that one may systematically eliminate these
universal terms, and finally express the NCR entirely in terms of physical
cross-sections. Even though the kinematic conditions and the required precision
may render the proposed experiments unfeasible, at the conceptual level the
analysis presented here allows for the promotion of the NCR into a genuine
physical observable.Comment: 34 pages, 5 figure
Mixed tensor susceptibility of the QCD vacuum from effective quark-quark
  interactions

We calculate the mixed tensor susceptibility of QCD vacuum in the framework
of the global color symmetry model. In our calculation, the functional
integration over gluon fields can be performed and the gluonic vacuum
observable can be expressed in terms of the quark operators and the gluon
propagator. The mixed tensor susceptibility was obtained with the subtraction
of the perturbative contribution which is evaluated by the Wigner solution of
the quark gap equation. Using several different effective quark-quark
interaction models, we find the values of the mixed tensor susceptibility are
very small.Comment: 12 page
Higgs xi-inflation for the 125-126 GeV Higgs: a two-loop analysis

A non-minimal coupling xi of the Standard Model Higgs field to gravity can
give rise to inflation, but large xi is required and thus leads to a violation
of perturbative unitarity at Mp/xi, which is well below the inflationary scale
Mp/sqrt(xi). We re-examine this claim for a Higgs mass in the range 125-126 GeV
for which lambda_eff(mu) runs to very small values near the Planck scale and
can significantly reduce the value of xi required for inflation. Using the
two-loop renormalization group equations and effective potential for Higgs
xi-inflation, we find that familiar inflationary solutions can have a
non-minimal coupling as small as xi ~ 400 without the potential developing a
second minimum. We also find a new observationally allowed region of Higgs
xi-inflation with xi ~ 90 and distinct inflationary predictions, including an
observable level of the tensor-to-scalar ratio r.Comment: 25 pages, 4 figures. v2: Discussion clarified and references added.
  Suppressed Goldstone boson masses for prescription I and two-loop beta
  function for xi now used. Results modified slightly. v3: Matches published
  versio
Search for baryon number violation in top-quark decays

A search for baryon number violation (BNV) in top-quark decays is performed
using pp collisions produced by the LHC at sqrt(s) = 8 TeV. The top-quark decay
considered in this search results in one light lepton (muon or electron), two
jets, but no neutrino in the final state. Data used for the analysis were
collected by the CMS detector and correspond to an integrated luminosity of
19.5 inverse femtobarns. The event selection is optimized for top quarks
produced in pairs, with one undergoing the BNV decay and the other the standard
model hadronic decay to three jets. No significant excess of events over the
expected yield from standard model processes is observed. The upper limits at
95% confidence level on the branching fraction of the BNV top-quark decay are
calculated to be 0.0016 and 0.0017 for the muon and the electron channels,
respectively. Assuming lepton universality, an upper limit of 0.0015 results
from the combination of the two channels. These limits are the first that have
been obtained on a BNV process involving the top quark.Comment: Replaced with published version. Added journal reference and DO
First $\pi K$ atom lifetime and $\pi K$ scattering length measurements

The results of a search for hydrogen-like atoms consisting of
$\pi^{\mp}K^{\pm}$ mesons are presented. Evidence for $\pi K$ atom production
by 24 GeV/c protons from CERN PS interacting with a nickel target has been seen
in terms of characteristic $\pi K$ pairs from their breakup in the same target
($178 \pm 49$) and from Coulomb final state interaction ($653 \pm 42$). Using
these results the analysis yields a first value for the $\pi K$ atom lifetime
of $\tau=(2.5_{-1.8}^{+3.0})$ fs and a first model-independent measurement of
the S-wave isospin-odd $\pi K$ scattering length
$\left|a_0^-\right|=\frac{1}{3}\left|a_{1/2}-a_{3/2}\right|=
\left(0.11_{-0.04}^{+0.09} \right)M_{\pi}^{-1}$ ($a_I$ for isospin $I$).Comment: 14 pages, 8 figure
Isomonodromy, Painlev\'e Transcendents and Scattering off of Black Holes

We apply the method of isomonodromy to study the scattering of a generic
Kerr-NUT-(A)dS black hole. For generic values of the charges, the problem is
related to the connection problem of the Painlev\'e VI transcendent. We review
a few facts about Painlev\'e VI, Garnier systems and the Hamiltonian structure
of flat connections in the Riemann sphere. We then outline a method for
computing the scattering amplitudes based on Hamilton-Jacobi structure of
Painlev\'e, and discuss the implications of the generic result to black hole
complementarity.Comment: 40 pages, 4 figures, JHEP styl
Infinite Matrix Product States for long range SU(N) spin models

We construct 1D and 2D long-range SU(N) spin models as parent Hamiltonians
associated with infinite matrix product states. The latter are constructed from
correlators of primary fields in the SU(N) level 1 WZW model. Since the
resulting groundstates are of Gutzwiller-Jastrow type, our models can be
regarded as lattice discretizations of fractional quantum Hall systems. We then
focus on two specific types of 1D spin chains with spins located on the unit
circle, a uniform and an alternating arrangement. For an equidistant
distribution of identical spins we establish an explicit connection to the
SU(N) Haldane-Shastry model, thereby proving that the model is critical and
described by a SU(N) level 1 WZW model. In contrast, while turning out to be
critical as well, the alternating model can only be treated numerically. Our
numerical results rely on a reformulation of the original problem in terms of
loop models.Comment: 37 pages, 6 figure