pinecone/core-2020-05-10-deduplication huggingface dataset:
Reconstruction of changes in the Weddell Sea sector of the Antarctic Ice Sheet since the Last Glacial Maximum

The Weddell Sea sector is one of the main formation sites for Antarctic Bottom Water and an outlet for about one fifth of Antarctica's continental ice volume. Over the last few decades, studies on glacial–geological records in this sector have provided conflicting reconstructions of changes in ice-sheet extent and ice-sheet thickness since the Last Glacial Maximum (LGM at ca 23–19 calibrated kiloyears before present, cal ka BP). Terrestrial geomorphological records and exposure ages obtained from rocks in the hinterland of the Weddell Sea, ice-sheet thickness constraints from ice cores and some radiocarbon dates on offshore sediments were interpreted to indicate no significant ice thickening and locally restricted grounding-line advance at the LGM. Other marine geological and geophysical studies concluded that subglacial bedforms mapped on the Weddell Sea continental shelf, subglacial deposits and sediments over-compacted by overriding ice recovered in cores, and the few available radiocarbon ages from marine sediments are consistent with major ice-sheet advance at the LGM. Reflecting the geological interpretations, different ice-sheet models have reconstructed conflicting LGM ice-sheet configurations for the Weddell Sea sector. Consequently, the estimated contributions of ice-sheet build-up in the Weddell Sea sector to the LGM sea-level low-stand of ∼130 m vary considerably.\ud
\ud
In this paper, we summarise and review the geological records of past ice-sheet margins and past ice-sheet elevations in the Weddell Sea sector. We compile marine and terrestrial chronological data constraining former ice-sheet size, thereby highlighting different levels of certainty, and present two alternative scenarios of the LGM ice-sheet configuration, including time-slice reconstructions for post-LGM grounding-line retreat. Moreover, we discuss consistencies and possible reasons for inconsistencies between the various reconstructions and propose objectives for future research. The aim of our study is to provide two alternative interpretations of glacial–geological datasets on Antarctic Ice-Sheet History for the Weddell Sea sector, which can be utilised to test and improve numerical ice-sheet models
Is Youth Unemployment Really the Major Worry?

Youth unemployment is seen nowadays as one of the most severe problems in Europe. The leaders of the European Union (EU) devoted a whole summit to the issue in July 2013. The problem seems fierce not only because jobless\ud
youth is expensive for the society – EUR 153 billion or 1.2% of the GDP in the EU in 2011 – but also because it affects the future of it. If an increasing part of the new generation begins its adult life with the feeling of being unnecessary and having no chance to integrate into the mainstream society, the future will be burdened with more and more inexperienced and disappointed people with all the consequences of this. Therefore, the mitigation of youth\ud
unemployment is of the utmost importance. To be successful, however, we have to understand the magnitude and the roots of the situation
The 2010 very high energy gamma-ray flare and 10 years of multi-wavelength observations of M 87\ud

The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3-6) x 10(9) M-circle dot) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz Very Long Baseline Array, VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of tau(rise)(d) = (1.69 +/- 0.30) days and tau(decay)(d) = (0.611 +/- 0.080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (similar to day), peak fluxes (Phi(>0.35 TeV) similar or equal to (1-3) x 10(-11) photons cm(-2) s(-1)), and VHE spectra. VLBA radio observations of 43 GHz of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken similar to 3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core (flux increased by factor similar to 2; variability timescale <2 days). The long-term (2001-2010) multi-wavelength (MWL) light curve of M 87, spanning from radio to VHE and including data from Hubble Space Telescope, Liverpool Telescope, Very Large Array, and European VLBI Network, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified. In the outer kiloparsec jet region, in particular in HST-1, no enhanced MWL activity was detected in 2008 and 2010, disfavoring it as the origin of the VHE flares during these years. Shortly after two of the three flares (2008 and 2010), the X-ray core was observed to be at a higher flux level than its characteristic range (determined from more than 60 monitoring observations: 2002-2009). In 2005, the strong flux dominance of HST-1 could have suppressed the detection of such a feature. Published models for VHE gamma-ray emission from M 87 are reviewed in the light of the new data.\u
STAR Barrel Electromagnetic Calorimeter Absolute Calibration Using
  "Minimum Ionizing Particles" from Collisions at RHIC

The procedure for the STAR Barrel Electromagnetic Calorimeter (BEMC) absolute
calibrations, using penetrating charged particle hits (MIP-hits) from physics
events at RHIC, is presented. Its systematic and statistical errors are
evaluated. It is shown that, using this technique, the equalization and
transfer of the absolute scale from the test beam can be done to a percent
level accuracy in a reasonable amount of time for the entire STAR BEMC.
MIP-hits would also be an effective tool for continuously monitoring the
variations of the BEMC tower's gains, virtually without interference to STAR's
main physics program. The method does not rely on simulations for anything
other than geometric and some other small corrections, and also for estimations
of the systematic errors. It directly transfers measured test beam responses to
operations at RHIC.Comment: 19 pages, 7 figures, Accepted to NIM-
Electroweak Corrections to the Deacy $H^+\to W^+h$ in the Minimal
  Supersymmetric Model

We calculate the $O(\alpha_{ew}m_{t(b)}^{2}/m_{W}^{2})$ and $O(\alpha_{ew}
m_{t(b)}^4/m_W^4)$ supersymmetric electroweak corrections to the process
$H^+\to W^+h$ in the Minimal Supersymmetric Model. These corrections arise from
the virtual effects of the third family quaurks (top and bottom) and squarks
(top-squark and bottom-squark). We find that for $m_{H^+}>200$GeV at low
$\tan\beta(\leq 3)$, the corrections can increase the tree-level decay widths
and the branching radios more than 20% and 40%, respectively.Comment: 20 pages, including 7 ps figure
Subleading Shape Functions and the Determination of |V_{ub}|

It is argued that the dominant subleading shape-function contributions to the
endpoint region of the charged-lepton energy spectrum in B -> X_u l nu decays
can be related in a model-independent way to an integral over the B -> X_s
gamma photon spectrum. The square root of the fraction of B -> X_u l nu events
with charged-lepton energy above E_0=2.2 GeV can be calculated with a residual
theoretical uncertainty from subleading shape-function effects that it safely
below the 10% level. These effects have therefore a minor impact on the
determination of |V_{ub}|.Comment: 8 pages, 1 figure. Final version to appear in Physics Letters B. By a
  smarter choice of weight function, m_b and lambda_1 have been eliminated from
  the final results. A paragraph has been added mentioning the potentially
  sizeable uncertainty due to duality violations and spectator-dependent
  effects. The discussion of the results obtained in refs. [7,8] has been made
  more accurat
CPT violation in entangled B0-B0bar states and the demise of flavour
  tagging

We discuss the demise of flavour tagging due to the loss of the
particle-antiparticle identity of neutral B-mesons in the
Einstein-Podolsky-Rosen correlated states. Such a situation occurs in cases
where the CPT operator is ill-defined, as happens, for example, in quantum
gravity models with induced decoherence in the matter sector. The time
evolution of the perturbed B0-B0bar initial state, as produced in B-factories,
is sufficient to generate new two-body states. For flavour specific decays at
equal times, we discuss two definite tests of the two body entanglement: (i)
search for the would-be forbidden B0 B0 and B0bar B0bar states; (ii) deviations
from the indistinguishable probability between the permuted states B0bar B0 and
B0 B0bar.Comment: 12 pages LATEX, one eps figure incorporate
Proton Decay at $M_{pl}$ and the Scale of SUSY-Breaking

It is sometimes argued that a virtue of pushing the supersymmetry breaking
scale above 1 PeV is that no particular flavor structure is required in the
soft sector in order to evade bounds on flavor-changing neutral currents.
However, without flavor structure, suppressing generic Planck-suppressed
contributions to proton decay requires even higher SUSY scales, of order
$10^{11}$ ($10^9$) GeV for degenerate (mini-split) gauginos and scalars. With
flavor structure, the question of whether proton decay or flavor symmetries are
more constraining is model-dependent, but it straightforward to find simple
models where both constraints are satisfied for much lower SUSY scales.Comment: 14 pages, 1 figure. v2: expanded discussion of alignment models in
  sec. 3. accepted for publication in JHE
126 GeV Higgs in Next-to-Minimal Universal Extra Dimensions

Discovery of a Higgs boson and precise measurements of its properties open a
new window to test physics beyond the standard model. Models with Universal
Extra Dimensions are not exception. Kaluza-Klein excitations of the standard
model particles contribute to the production and decay of the Higgs boson. In
particular, the parameters associated with third generation quarks are
constrained by Higgs data, which are relatively insensitive to other searches
often involving light quarks and leptons. We investigate implications of the
126 GeV Higgs in Next-to-Minimal Universal Extra Dimensions, and show that
boundary terms and bulk masses allow a lower compactification scale as compared
to in Minimal Universal Extra Dimensions.Comment: 12 pages, 4 figure
The higher derivative regularization and quantum corrections in ${\cal
  N}=2$ supersymmetric theories

We construct a new version of the higher covariant derivative regularization
for a general ${\cal N}=2$ supersymmetric gauge theory formulated in terms of
${\cal N}=1$ superfields. This regularization preserves both supersymmetries of
the classical action, namely, the invariance under the manifest ${\cal N}=1$
supersymmetry and under the second hidden on-shell supersymmetry. The
regularizing ${\cal N}=2$ supersymmetric higher derivative term is found in the
explicit form in terms of ${\cal N}=1$ superfields. Thus, ${\cal N}=2$
supersymmetry is broken only by the gauge fixing procedure. Then we analyze the
exact NSVZ $\beta$-function and prove that in the considered model its higher
loop structure is determined by the anomalous dimension of the chiral
superfield $\Phi$ in the adjoint representation which is the ${\cal N}=2$
superpartner of the gauge superfield $V$. Using the background field method we
find that this anomalous dimension is related with the anomalous dimension of
the hypermultiplet and vanishes if the effective action is invariant under
${\cal N}=2$ background supersymmetry. As a consequence, in this case the
higher loop contributions to $\beta$-function also vanish. The one-loop
renormalization structure in the considered regularization is also studied by
the explicit calculations of the one-loop renormalization constants.Comment: 26 pages, 4 figures; the version accepted for publication in Nucl.
  Phys.
Energy-pressure relation for low-dimensional gases

A particularly simple relation of proportionality between internal energy and
pressure holds for scale invariant thermodynamic systems, including classical
and quantum Bose and Fermi ideal gases. One can quantify the deviation from
such a relation by introducing the internal energy shift as the difference
between the internal energy of the system and the corresponding value for scale
invariant gases. We discuss general thermodynamic properties associated to the
scale invariance, provide criteria for which the internal energy shift density
is a bounded function of temperature. We then study the internal energy shift
and deviations from the energy-pressure proportionality in low dimensional
models of gases interpolating between the ideal Bose and the ideal Fermi gases,
focusing on the Lieb-Liniger model in 1d and on the anyonic gas in 2d. In 1d
the internal energy shift is determined from the thermodynamic Bethe ansatz
integral equations and an explicit relation for it is given at high
temperature. Our results show that the internal energy shift is positive, it
vanishes in the two limits of zero and infinite coupling (respectively the
ideal Bose and the Tonks Girardeau gas) and it has a maximum at a finite,
temperature depending, value of the coupling. Remarkably, at fixed coupling the
energy shift density saturates to a finite value for infinite temperature. In
2d we consider systems of Abelian anyons and non Abelian Chern-Simons
particles: as it can be seen also directly from a study of the virial
coefficients, in the usually considered hard-core limit the internal energy
shift vanishes and the energy is just proportional to the pressure, with the
proportionality constant being simply the area of the system. Soft-core
boundary conditions at coincident points for the two-body wavefunction
introduce a length scale, and induce a non-vanishing internal energy shift.Comment: 40 pages, 6 figures, typos corrected, references added, published
  versio
Toric Duality, Seiberg Duality and Picard-Lefschetz Transformations

Toric Duality arises as an ambiguity in computing the quiver gauge theory
living on a D3-brane which probes a toric singularity. It is reviewed how, in
simple cases Toric Duality is Seiberg Duality. The set of all Seiberg Dualities
on a single node in the quiver forms a group which is contained in a larger
group given by a set of Picard-Lefschetz transformations. This leads to
elements in the group (sometimes called fractional Seiberg Duals) which are not
Seiberg Duality on a single node, thus providing a new set of gauge theories
which flow to the same universality class in the Infra Red.Comment: 7 pages, 5 figures. Based on the talk presented by A.H. at the 35th
  International Symposium Ahrenshoop on the Theory of Elementary Particles. v2:
  two references adde
Quaternion Involutions

An involution is usually defined as a mapping that is its own inverse. In
this paper, we study quaternion involutions that have the additional properties
of distribution over addition and multiplication. We review formal axioms for
such involutions, and we show that the quaternions have an infinite number of
involutions. We show that the conjugate of a quaternion may be expressed using
three mutually perpendicular involutions. We also show that any set of three
mutually perpendicular quaternion involutions is closed under composition.
Finally, we show that projection of a vector or quaternion can be expressed
concisely using involutions
Reactive ion etching of quartz and pyrex for micro electronic applications.

The reactive ion etching of quartz and Pyrex substrates was carried out using CF4/Ar and CF4/O2 gas mixtures in a combined radio frequency (rf)/microwave (µw) plasma. It was observed that the etch rate and the surface morphology of the etched regions depended on the gas mixture (CF4/Ar or CF4/O2), the relative concentration of CF4 in the gas mixture, the rf power (and the associated self-induced bias) and microwave power. An etch rate of 95 nm/min for quartz was achieved. For samples covered with a thin metal layer, ex situ high resolution scanning electron microscopy and atomic force microscopy imaging indicated that, during etching, surface roughness is produced on the surface beneath the thin metallic mask. Near vertical sidewalls with a taper angle greater than 80° and smooth etched surfaces at the nanometric scale were fabricated by carefully controlling the etching parameters and the masking technique. A simulation of the electrostatic field distribution was carried out to understand the etching process using these masks for the fabrication of high definition features
TERT promoter mutations are highly recurrent in SHH subgroup medulloblastoma

Telomerase reverse transcriptase (TERT) promoter mutations were recently shown to drive telomerase activity in various cancer types, including medulloblastoma. However, the clinical and biological implications of TERT mutations in medulloblastoma have not been described. Hence, we sought to describe these mutations and their impact in a subgroup-specific manner. We analyzed the TERT promoter by direct sequencing and genotyping in 466 medulloblastomas. The mutational distributions were determined according to subgroup affiliation, demographics, and clinical, prognostic, and molecular features. Integrated genomics approaches were used to identify specific somatic copy number alterations in TERT promoter-mutated and wild-type tumors. Overall, TERT promoter mutations were identified in 21 % of medulloblastomas. Strikingly, the highest frequencies of TERT mutations were observed in SHH (83 %; 55/66) and WNT (31 %; 4/13) medulloblastomas derived from adult patients. Group 3 and Group 4 harbored this alteration in <5 % of cases and showed no association with increased patient age. The prognostic implications of these mutations were highly subgroup-specific. TERT mutations identified a subset with good and poor prognosis in SHH and Group 4 tumors, respectively. Monosomy 6 was mostly restricted to WNT tumors without TERT mutations. Hallmark SHH focal copy number aberrations and chromosome 10q deletion were mutually exclusive with TERT mutations within SHH tumors. TERT promoter mutations are the most common recurrent somatic point mutation in medulloblastoma, and are very highly enriched in adult SHH and WNT tumors. TERT mutations define a subset of SHH medulloblastoma with distinct demographics, cytogenetics, and outcomes. Electronic supplementary material The online version of this article (doi:10.1007/s00401-013-1198-2) contains supplementary material, which is available to authorized users
Transition state trajectory stability determines barrier crossing rates
  in chemical reactions induced by time-dependent oscillating fields

When a chemical reaction is driven by an external field, the transition state
that the system must pass through as it changes from reactant to product -for
example, an energy barrier- becomes time-dependent. We show that for periodic
forcing the rate of barrier crossing can be determined through stability
analysis of the non-autonomous transition state. Specifically, strong agreement
is observed between the difference in the Floquet exponents describing
stability of the transition state trajectory, which defines a recrossing-free
dividing surface [G. T. Craven, T. Bartsch, and R. Hernandez, Phys. Rev. E 89,
040801(R) (2014)], and the rates calculated by simulation of ensembles of
trajectories. This result opens the possibility to extract rates directly from
the intrinsic stability of the transition state, even when it is
time-dependent, without requiring a numerically-expensive simulation of the
long-time dynamics of a large ensemble of trajectories
Generative models of the human connectome

The human connectome represents a network map of the brain's wiring diagram
and the pattern into which its connections are organized is thought to play an
important role in cognitive function. The generative rules that shape the
topology of the human connectome remain incompletely understood. Earlier work
in model organisms has suggested that wiring rules based on geometric
relationships (distance) can account for many but likely not all topological
features. Here we systematically explore a family of generative models of the
human connectome that yield synthetic networks designed according to different
wiring rules combining geometric and a broad range of topological factors. We
find that a combination of geometric constraints with a homophilic attachment
mechanism can create synthetic networks that closely match many topological
characteristics of individual human connectomes, including features that were
not included in the optimization of the generative model itself. We use these
models to investigate a lifespan dataset and show that, with age, the model
parameters undergo progressive changes, suggesting a rebalancing of the
generative factors underlying the connectome across the lifespan.Comment: 38 pages, 5 figures + 19 supplemental figures, 1 tabl
Foraging mode switching : the importance of prey distribution and foraging currency

A.D.H. was supported by the European Research Council (Advanced Grant 250209 to Alasdair Houston), a College for Life Sciences Fellowship at the Wissenschaftskolleg zu Berlin, and a NERC Independent Research FellowshipNE/L011921/1.Foraging methods are highly variable, but can be grouped into two modes: searching and ambush. While research has focused on the functioning of each mode, the question of how animals choose which to use has been largely neglected. Here we consider a forager that exploits prey that are patchily distributed in space and time. This forager can either sit and wait for prey to appear or search for prey, which is more likely to result in encounters with prey but costs more energy and/or exposes the forager to greater predation risk. The currency that natural selection appears to have optimized will be determined by the additional costs of searching and whether there is a risk of starvation. We therefore compare the predictions of models based on currencies that consider only energy and predation risk to state-dependent models in which energy reserves are used to trade off predation rate, starvation rate and investment in growth. The choice of currency qualitatively affects how mode should change when prey abundance and prey patchiness increase. We show how differing prey distributions can explain variation in effects of experimentally increasing prey abundance. Our work has several implications for the study of foraging mode, population dynamics and the methods used to assess population size.Publisher PDFPeer reviewe