pinecone/core-2020-05-10-deduplication huggingface dataset:
Boundary conditions as constraints

A new method to compute the symplectic structure of a quantum field theory
with non trivial boundary conditions is proposed. Following the suggestion in
\cite{ho:gnus, ardalan}, we regard that the boundary conditions are second
class constraints in the sense of the Dirac's method. However, we show that
this proposal is more useful if we consider an inverse of the Holographic map
between a theory defined in the boundary to another with constraints but
without boundary.Comment: 18 pages, references adde
Correlation lengths and $E_{8}$ mass spectrum of the dilute $A_{3}$ lattice model

The exact perturbation approach is used to derive the elementary correlation lengths $\xi_i$ and related mass gaps $m_i$ of the two-dimensional dilute A_L lattice model in regimes 1 and 2 for L odd from the Bethe Ansatz solution. In regime 2 the A_3 model is the E_8 lattice realisation of the two-dimensional Ising model in a magnetic field at T=T_c. The calculations for the A_3 model in regime 2 start from the eight thermodynamically significant string types found in previous numerical studies. These string types are seen to be consistent in the ordered high field limit. The eight masses obtained reduce with the approach to criticality to the E_8 masses predicted by Zamolodchikov, thus providing a further direct lattice determination of the E_8 mass spectrum
Localized Beampipe Heating due to $e^{-}$ Capture and Nuclear Excitation in Heavy Ion Colliders

At heavy ion colliders, two major sources of beam loss are expected to be $e^+e^-$ production, where the $e^-$ is bound to one of the nuclei, and photonuclear excitation and decay via neutron emission. Both processes alter the ions charged to mass ratio by well defined amounts, creating beams of particles with altered magnetic rigidity. These beams will deposit their energy in a localized region of the accelerator, causing localized heating, The size of the target region depends on the collider optics. For medium and heavy ions, at design luminosity at the Large Hadron Collider, local heating may be more than an order of magnitude higher than expected. This could cause magnet quenches if the local cooling is inadequate. The altered-rigidity beams will also produce localized radiation damage. The beams could also be extracted and used for fixed target experiments
Uraltsev Sum Rule in Bakamjian-Thomas Quark Models

We show that the sum rule recently proved by Uraltsev in the heavy quark limit of QCD holds in relativistic quark models \`a la Bakamjian and Thomas, that were already shown to satisfy Isgur-Wise scaling and Bjorken sum rule. This new sum rule provides a {\it rationale} for the lower bound of the slope of the elastic IW function $\rho^2 \geq {3 \over 4}$ obtained within the BT formalism some years ago. Uraltsev sum rule suggests an inequality $|\tau_{3/2}(1)| > |\tau_{1/2}(1)|$. This difference is interpreted in the BT formalism as due to the Wigner rotation of the light quark spin, independently of a possible LS force. In BT models, the sum rule convergence is very fast, the $n = 0$ state giving the essential contribution in most of the phenomenological potential models. We underline that there is a serious problem, in the heavy quark limit of QCD, between theory and experiment for the decays $B \to D^*_{0,1}(broad) \ell \nu$, independently of any model calculation
$S$-Duality and the Calabi-Yau Interpretation of the $N = 4$ to $N = 2$
  Flow

The action of the $S$-duality $Sl(2,Z)$ group on the moduli of the Calabi-Yau
manifold $W\IP^{12}_{11226}$ appearing in the rank two dual pair $(K^{3}\times
T^{2}/W\IP^{12}_{11226})$ is defined by interpreting the $N\!=\!4$ to $N\!=\!2$
flow, for $SU(2)$ supersymmetric Yang-Mills, in terms of the Calabi-Yau moduli.
The different singularity loci are mapped in a one to one way, and the
($N\!=\!2$ limit/point particle limit) is obtained in both cases by the same
type of blow up. Moreover, it is shown that the $S$-duality group permutes the
different singularity loci of the moduli of $W\IP^{12}_{11226}$. We study the
transformation under $S$-duality of the Calabi-Yau Yukawa couplings.Comment: 14 pages, Latex, 2 eps files. Comments, one more figure and
  references adde
Nonadiabatic polaronic superconductivity in MgB2 and cuprates

This article was submitted for publication in the journal Physica C: Superconductivity\ud
[© Elsevier] with the title 'Nonadiabatic superconductivity in MgB2 and cuprates'. The definitive version is available at: http://dx.doi.org/10.1016/S0921-4534(01)01095-4.The Fermi energy, EF, of newly discovered high-Tc superconductor MgB2 and cuprates is estimated from the measured London penetration depth using a parameter-free expression. EF of MgB2 and more than 30 lanthanum, yttrium and mercury-based cuprates appears to be about or below 100 meV, depending on doping. There is every evidence that the remarkable low value of EF and the strong coupling of carriers with high-frequency phonons is the cause of high Tc in all newly discovered superconductors. Taking into account that the carriers mainly reside on oxygen in cuprates, on boron in magnesium-diborade, and on carbon in doped fullerenes, these superconductors form what is essentially nonadiabatic `metallic' oxygen, boron and carbon, respectively. The boron isotope effect on the carrier mass in magnesium-diboride similar to the oxygen isotope effect on the supercarrier mass observed by Guo-meng Zhao et al. in cuprates is predicted
Assisting natural forest regeneration in Northern Ethiopia: one measure is not enough

Management strategies aimed at rehabilitating degraded and cleared forests often rely on temporary or permanent exclusion of herbivores (wild animals, livestock or both).  But in many cases, this simple management technique is not sufficient to induce ecosystem restoration: many negative effects keep the ecosystem in a suboptimal, low biomass state.  The presence of such stable states requires restoration measures to act on multiple stress factors simultaneously.&#xd;&#xa;&#xd;&#xa;Compensating for all limiting factors is neither practically nor economically feasible.  But detailed knowledge about the autoecology of tree species &#x2013; i.e. their site requirements, regeneration strategies and recruitment dynamics &#x2013; may be used to tailor management to the most pertinent problems.  Here we illustrate this approach with results from forest restoration experiments in grazing exclosures in northern Ethiopia using African wild olive (_Olea europaea_ ssp. _cuspidata_) as a representative Afromontane climax species.&#xd;&#xa;&#xd;&#xa;The recruitment of African wild olive is affected by seed limitation, restricted seed dispersal and germination and survival limitation.  The exclusion of grazing animals as a single measure to restore forest is not enough.  Degraded grazing land moves into a state dominated by persistent shrubs, arresting forest succession and discouraging local stakeholders.  Direct sowing or planting of seedlings in fertile patches under selected pioneer shrubs, however, may help to overcome this form of bush encroachment, in particular during years with an above-average rainfall.&#xd;&#xa
On semi-finite hexagons of order $(2, t)$ containing a subhexagon

The research in this paper was motivated by one of the most important open
problems in the theory of generalized polygons, namely the existence problem
for semi-finite thick generalized polygons. We show here that no semi-finite
generalized hexagon of order $(2,t)$ can have a subhexagon $H$ of order $2$.
Such a subhexagon is necessarily isomorphic to the split Cayley generalized
hexagon $H(2)$ or its point-line dual $H^D(2)$. In fact, the employed
techniques allow us to prove a stronger result. We show that every near hexagon
$\mathcal{S}$ of order $(2,t)$ which contains a generalized hexagon $H$ of
order $2$ as an isometrically embedded subgeometry must be finite. Moreover, if
$H \cong H^D(2)$ then $\mathcal{S}$ must also be a generalized hexagon, and
consequently isomorphic to either $H^D(2)$ or the dual twisted triality hexagon
$T(2,8)$.Comment: 21 pages; new corrected proofs of Lemmas 4.6 and 4.7; earlier proofs
  worked for generalized hexagons but not near hexagon
Phantom Space-times in Fake Supergravity

We discuss phantom metrics admitting Killing spinors in fake N=2, D=4
supergravity coupled to vector multiplets. The Abelian U(1) gauge fields in the
fake theory have kinetic terms with the wrong sign. We solve the Killing spinor
equations for the standard and fake theories in a unified fashion by
introducing a parameter which distinguishes between the two theories. The
solutions found are fully determined in terms of algebraic conditions, the
so-called stabilisation equations, in which the symplectic sections are related
to a set of functions. These functions are harmonic in the case of the standard
supergravity theory and satisfy the wave-equation in flat (2+1)-space-time in
the fake theory. Explicit examples are given for the minimal models with
quadratic prepotentials.Comment: 11 page
Importance Sampling Variance Reduction for the Fokker-Planck Rarefied
  Gas Particle Method

Models and methods that are able to accurately and efficiently predict the
flows of low-speed rarefied gases are in high demand, due to the increasing
ability to manufacture devices at micro and nano scales. One such model and
method is a Fokker-Planck approximation to the Boltzmann equation, which can be
solved numerically by a stochastic particle method. The stochastic nature of
this method leads to noisy estimates of the thermodynamic quantities one wishes
to sample when the signal is small in comparison to the thermal velocity of the
gas. Recently, Gorji et al have proposed a method which is able to greatly
reduce the variance of the estimators, by creating a correlated stochastic
process which acts as a control variate for the noisy estimates. However, there
are potential difficulties involved when the geometry of the problem is
complex, as the method requires the density to be solved for independently.
  Importance sampling is a variance reduction technique that has already been
shown to successfully reduce the noise in direct simulation Monte Carlo
calculations. In this paper we propose an importance sampling method for the
Fokker-Planck stochastic particle scheme. The method requires minimal change to
the original algorithm, and dramatically reduces the variance of the estimates.
We test the importance sampling scheme on a homogeneous relaxation, planar
Couette flow and a lid-driven-cavity flow, and find that our method is able to
greatly reduce the noise of estimated quantities. Significantly, we find that
as the characteristic speed of the flow decreases, the variance of the noisy
estimators becomes independent of the characteristic speed
WASP-80b : a gas giant transiting a cool dwarf

We report the discovery of a planet transiting the star WASP-80 (1SWASP J201240.26-020838.2; 2MASS J20124017-0208391; TYC 5165-481-1; BPM 80815; V = 11.9, K = 8.4). Our analysis shows this is a 0.55 ± 0.04 Mjup, 0.95 ± 0.03 Rjup gas giant on a circular 3.07 day orbit around a star with a spectral type between K7V and M0V. This system produces one of the largest transit depths so far reported, making it a worthwhile target for transmission spectroscopy. We find a large discrepancy between the vsini inferred from stellar line broadening and the observed amplitude of the Rossiter-McLaughlin effect. This can be understood either by an orbital plane nearly perpendicular to the stellar spin or by an additional, unaccounted for source of broadening.Publisher PDFPeer reviewe
Making implicit practice explicit: How do upper secondary teachers describe their reading comprehension strategies instruction?

This study examined the activation of teachers’ tacit knowledge of reading comprehension strategy instruction as part of a teacher professional development course. Although studies have examined professional development courses that inform teachers about research-based knowledge, there has not been much research on courses activating teachers’ tacit knowledge, as is the case with the present study. This qualitative study analyzed 21 upper secondary teachers’ instructional design; which strategies they promoted, how these differed across subjects, how their instruction was made explicit through professional development, and how the course contributed to the activation of tacit knowledge. This study demonstrated teacher learning over time, where implicit practices were made explicit through written narratives and increased metacognitive awareness
Month of birth and risk of multiple sclerosis: confoundingand adjustments

A month of birth effect on multiple sclerosis (MS) risk has been reported from different countries. Recent critics have suggested that this finding is caused by confounding and that adequately adjusting for year and place of birth would markedly reduce this effect. All inhabitants in Norway are registered in the Norwegian Population Registry (Statistics Norway), making this an ideal area for performing adjusted analyses. Using the entire Norwegian population born between 1930 and 1979 (n = 2,899,260), we calculated the excess between observed and expected number of births for each month for 6649 Norwegian MS patients, 5711 mothers, 5247 fathers, and 8956 unaffected siblings. The analyses were adjusted for year of birth and place of birth according to the 19 counties in Norway. An unadjusted analysis revealed 13% fewer MS births than expected in February (P = 0.0015; Bonferroni corrected P = 0.018), 10% more in April (P = 0.0083; Bonferroni corrected P = 0.0996) and 15% more in December (P = 0.00058; Bonferroni corrected P = 0.007). Adjustments for both year and place of birth significantly altered our results for February and December, but even after these adjustments there were still 10% more MS births than expected in April (P = 0.00796; Bonferroni corrected P = 0.096). MS patients had a higher incidence of April births than their siblings (Fisher-exact test; P = 0.011), mothers (Fisher-exact test; P = 0.004), and fathers (Fisher-exact test; P = 0.011) without MS. Adjustments for confounding significantly affected our results. However, even after adjustments, there appears to be a persistent higher than expected frequency of April births in the MS population
High resolution spectral characteristics of the Earth-ionosphere cavity resonances

The natural resonances of the Earth-ionosphere cavity at frequencies between 5 and 100 Hz have been studied since the fundamental paper by Schumann. While the gross features of the phenomena are now well understood, considerable work remains to be done on their detailed behaviour. In the present study a high resolution, data adaptive spectral technique is applied to digital electromagnetic data obtained at a moderate latitude. A particular feature of the method employed is that spectral properties become available on the same time scale as many ELF events, thus both time local and time averaged resonance features can be readily established. The technique can thus be applied to both dynamic and steady-state descriptions of the cavity's properties.\ud
\ud
For the data set considered, the technique adequately resolves the first six resonance modes on a time scale of 0.75 s. The presence of higher order modes is also indicated. The time averaged frequencies obtained are in accord with those of previous experimental determinations. When the time local properties of individual transient waveforms are examined, however, we observe a number of detailed effects which are predicted by theory. The precise spectral structure of the resonance modes appears influenced by the differing locations of the sources of transient excitation. In the case of the first order resonance mode, the properties of the cavity consistently support both singlet and doublet resonance behaviour.\u
A global spectral library to characterize the world’s soil

Soil provides ecosystem services, supports human health and habitation, stores carbon and regulates emissions of greenhouse gases. Unprecedented pressures on soil from degradation and urbanization are threatening agro-ecological balances and food security. It is important that we learn more about soil to sustainably manage and preserve it for future generations. To this end, we developed and analyzed a global soil visible–near infrared (vis–NIR) spectral library. It is currently the largest and most diverse database of its kind. We show that the information encoded in the spectra can describe soil composition and be associated to land cover and its global geographic distribution, which acts as a surrogate for global climate variability. We also show the usefulness of the global spectra for predicting soil attributes such as soil organic and inorganic carbon, clay, silt, sand and iron contents, cation exchange capacity, and pH. Using wavelets to treat the spectra, which were recorded in different laboratories using different spectrometers and methods, helped to improve the spectroscopic modelling. We found that modelling a diverse set of spectra with a machine learning algorithm can find the local relationships in the data to produce accurate predictions. The spectroscopic models that we derived are parsimonious and robust, and using them we derived a harmonized global soil attribute dataset, which might serve to facilitate research on soil at the global scale. This spectroscopic approach should help to deal with the shortage of data on soil to better understand it and to meet the growing demand for information to assess and monitor soil at scales ranging from regional to global. We hope that this work might reinvigorate our community’s discussion towards larger, more coordinated collaborations and encourage other contributions. We also hope that use of the database will deepen our understanding of soil so that we might sustainably manage it and push the research outcomes of the soil, earth and environmental sciences towards applications that we have not yet dreamed of
Protective Effect of Focal Adhesion Kinase against Skeletal Muscle Reperfusion Injury after Acute Limb Ischemia

OBJECTIVES  In cardiac muscle, ischemia reperfusion (IR) injury is attenuated by mitochondrial function, which may be upregulated by focal adhesion kinase (FAK). The aim of this study was to determine whether increased FAK levels reduced rhabdomyolysis in skeletal muscle too.  MATERIAL AND METHODS  In a translational in vivo experiment, rat lower limbs were subjected to 4 hours of ischemia followed by 24 or 72 hours of reperfusion. FAK expression was stimulated 7 days before (via somatic transfection with pCMV-driven FAK expression plasmid) and outcomes were measured against non-transfected and empty transfected controls. Slow oxidative (i.e., mitochondria-rich) and fast glycolytic (i.e., mitochondria-poor) type muscles were analyzed separately regarding rhabdomyolysis, apoptosis, and inflammation. Severity of IR injury was assessed using paired non-ischemic controls.  RESULTS  After 24 hours of reperfusion, marked rhabdomyolysis was found in non-transfected and empty plasmid-transfected fast-type glycolytic muscle, tibialis anterior. Prior transfection enhanced FAK concentration significantly (p = 0.01). Concomitantly, levels of BAX, promoting mitochondrial transition pores, were reduced sixfold (p = 0.02) together with a blunted inflammation (p = 0.01) and reduced rhabdomyolysis (p = 0.003). Slow oxidative muscle, m. soleus, reacted differently: although apoptosis was detectable after IR, rhabdomyolysis did not appear before 72 hours of reperfusion; and FAK levels were not enhanced in ischemic muscle despite transfection (p = 0.66).  CONCLUSIONS  IR-induced skeletal muscle rhabdomyolysis is a fiber type-specific phenomenon that appears to be modulated by mitochondria reserves. Stimulation of FAK may exploit these reserves constituting a potential therapeutic approach to reduce tissue loss following acute limb IR in fast-type muscle
Measurement of jet quenching with semi-inclusive hadron-jet distributions in central Pb-Pb collisions at root s(NN)=2.76 TeV

We report the measurement of a new observable of jet quenching in central Pb-Pb collisions at sNN−−−√=2.76 TeV, based on the semi-inclusive rate of charged jets recoiling from a high transverse momentum (high-p T) charged hadron trigger. Jets are measured using collinear-safe jet reconstruction with infrared cutoff for jet constituents of 0.15 GeV, for jet resolution parameters R = 0.2, 0.4 and 0.5. Underlying event background is corrected at the event-ensemble level, without imposing bias on the jet population. Recoil jet spectra are reported in the range 20 &lt; p T, jet ch  &lt; 100 GeV. Reference distributions for pp collisions at s√=2.76 TeV are calculated using Monte Carlo and NLO pQCD methods, which are validated by comparing with measurements in pp collisions at s√=7 TeV. The recoil jet yield in central Pb-Pb collisions is found to be suppressed relative to that in pp collisions. No significant medium-induced broadening of the intra-jet energy profile is observed within 0.5 radians relative to the recoil jet axis. The angular distribution of the recoil jet yield relative to the trigger axis is found to be similar in central Pb-Pb and pp collisions, with no significant medium-induced acoplanarity observed. Large-angle jet deflection, which may provide a direct probe of the nature of the quasi-particles in hot QCD matter, is explored
Decay constants of pseudoscalar D -mesons in lattice QCD with domain-wall fermion

We present the first study of the masses and decay constants of the pseudoscalar D mesons in two flavors lattice QCD with domain-wall fermion. The gauge ensembles are generated on the 243×48 lattice with the extent Ns=16 in the fifth dimension, and the plaquette gauge action at β=6.10 , for three sea-quark masses with corresponding pion masses in the range 260–475 MeV. We compute the point-to-point quark propagators, and measure the time-correlation functions of the pseudoscalar and vector mesons. The inverse lattice spacing is determined by the Wilson flow, while the strange and the charm quark masses by the masses of the vector mesons ϕ(1020) and J/ψ(3097) respectively. Using heavy meson chiral perturbation theory (HMChPT) to extrapolate to the physical pion mass, we obtain fD=202.3(2.2)(2.6) MeV and fDs=258.7(1.1)(2.9) MeV
Topological defect with nonzero Hopf invariant in Yang–Mills–Higgs model

We propose a topological defect or instanton solution with nonzero Hopf invariant to the 3+1D non-Abelian gauge theory coupled with scalar fields. This solution, which we call Hopf defect, represents a spacetime event that makes a 2 π rotation of vacuum manifold of the monopole. Although the action of this Hopf defect is logarithmically divergent, it may still give relevant contributions in a finite-sized system. Since the Chern–Simons term for the unbroken U(1) gauge field may appear in the low energy effective theory, the Hopf defect may possibly generate a phase factor change for the monopoles