pinecone/core-2020-05-10-deduplication huggingface dataset:
Supply chain risk management – I: Conceptualization, framework and planning process

Supply chain risk management (SCRM) is an interdisciplinary emerging area of research crossing over operations management, finance and marketing, among other disciplines. Conceptualization of SCRM is argued in reference to previous studies on risk identification, risk assessment, supply chain vulnerabilities and risk management approaches used. A SCRM framework is then developed based on taxonomies defined for risk events and risk management approaches. In line with this framework, a risk management planning process is proposed with an illustrative example
Identification of distinct nisin leader peptide regions that determine interactions with the modification enzymes NisB and NisC.

01.04.14 KB. Ok to add published version to spiral, OA paperNisin is the most prominent and applied bacteriocin that serves as a model for class I lantibiotics. The nisin leader peptide importantly determines interactions between precursor nisin and its modification enzymes NisB and NisC that mature nisin posttranslationally. NisB dehydrates serines and threonines, while NisC catalyzes the subsequent coupling of the formed dehydroamino acids to form lanthionines. Currently, little is known about how the nisin leader interacts with NisB and even less is known about its interactions with NisC. To investigate the nisin leader peptide requirements for functional interaction with the modification enzymes NisB and NisC, we systematically replaced six regions, of 2-4 amino acids each, with all-alanine regions. By performing NisB and NisC co-purification studies with these mutant leader peptides, we demonstrate that the nisin leader regions STKD(-22-19), FNLD(-18-15) and PR(-2-1) importantly contribute to the interactions of precursor nisin with both NisB and NisC, whereas the nisin leader region LVSV(-14-11) additionally contributes to the interaction of precursor nisin with NisC
U–Pb dating of cements in Mesozoic ammonites

Dating sedimentary carbonates using the U-Pb method can help improve the Phanerozoic timescale. Using a novel combination of laser-ablation, multi-collector, inductively-coupled-plasma, mass-spectrometry (LA–MC–ICP–MS) and thermal ionization multi-collector mass spectrometry (TIMS), U-Pb numerical ages were obtained on early-diagenetic calcite cements in Jurassic ammonites in which concentrations of U range from 0.47 to 5.3 ppm.\ud
\ud
The calcite cements of two ammonites, IS1 and IS2, from the uppermost Bifrons Zone of the Toarcian (179–180 Ma) of the UK, gave TIMS-normalized LA U–Pb dates of 164.9 ± 5.3 Ma and 166.7 ± 4.8 Ma respectively. Normalizing LA–ICP–MC–MS data to an in-house calcite standard gave a more precise date of 165.5 ± 3.3 Ma for IS1 cement. An unzoned ammonite, SS2, of Bajocian age (168–170 Ma) yield a TIMS-normalized LA U–Pb age of 158.8 ± 4.3 Ma for its early-diagenetic cement. Both the combined LA–MC–ICP–MS and TIMS approach, and the use of a calcite laser ablation standard can result in accurate ages of cements with uncertainties of 2–3% (2σ). The later, however, is more efficient and precise. These U-Pb dates of cements are 10 to 20 Myr younger than the numerical ages of the biostratigraphic intervals from which the ammonites derive. The U-Pb dates are taken to represent the time at which the aragonite shell of the ammonite inverted to calcite and released its U to precipitate in a late-diagenetic alteration of early-diagenetic fringing cements.\ud
\ud
Concentrations of U and Pb in a range of other pristine biogenic carbonates were found too low (U < 0.01 ppm) for meaningful dating using laser ablation method.\u
On the degree and half degree principle for symmetric polynomials

In this note we aim to give a new, elementary proof of a statement that was
first proved by Timofte. It says that a symmetric real polynomial $F$ of degree
$d$ in $n$ variables is positive on $\R^n$ (on $\R^{n}_{\geq 0}$) if and only
if it is so on the subset of points with at most $\max\{\lfloor d/2\rfloor,2\}$
distinct components. We deduce Timofte's original statement as a corollary of a
slightly more general statement on symmetric optimization problems. The idea we
are using to prove this statement is to relate it to a linear optimization
problem in the orbit space. The fact that for the case of the symmetric group
$S_n$ this can be viewed as a question on normalized univariate real
polynomials with only real roots allows us to conclude the theorems in a very
elementary way. We hope that the methods presented here will make it possible
to derive similar statements also in the case of other groups.Comment: (v2) revision based on suggestions by refere
Non-resonant New Physics in Top Pair Production at Hadron Colliders

We use top quark pair production as a probe of top-philic non-resonant new
physics. Following a low energy effective field theory approach, we calculate
several key observables in top quark pair production at hadron colliders (e.g.,
total cross section, ttbar invariant mass distribution, forward-backward
asymmetry, spin correlations) including the interference of the Standard Model
with dimension-six operators. We determine the LHC reach in probing new physics
after having taken into account the Tevatron constraints. In particular, we
show that the gluon fusion process gg -> ttbar which remains largely
unconstrained at the Tevatron is affected by only one top-philic dimension-six
operator, the chromo-magnetic moment of the top quark. This operator can be
further constrained by the LHC data as soon as a precision of about 20% is
reached for the total ttbar cross-section. While our approach is general and
model-independent, it is particularly relevant to models of Higgs and top
compositeness, which we consider in detail, also in connection with ttbar ttbar
and ttbar bbbar production.Comment: 34 pages, 15 figures. v2: clarifications and references added,
  published version (JHEP
Design of effective kernels for spectroscopy and molecular transport:
  time-dependent current-density-functional theory

Time-dependent current-density-functional theory (TDCDFT) provides an in
principle exact scheme to calculate efficiently response functions for a very
broad range of applications. However, the lack of approximations valid for a
range of parameters met in experimental conditions has so far delayed its
extensive use in inhomogeneous systems. On the other side, in many-body
perturbation theory (MBPT) accurate approximations are available, but at a
price of a higher computational cost. In the present work the possibility of
combining the advantages of both approaches is exploited. In this way an exact
equation for the exchange-correlation kernel of TDCDFT is obtained, which opens
the way for a systematic improvement of the approximations adopted in practical
applications. Finally, an approximate kernel for an efficient calculation of
spectra of solids and molecular conductances is suggested and its validity
discussed
Periodic Riemannian manifold with preassigned gaps in spectrum of
  Laplace-Beltrami operator

It is known (E.L. Green (1997), O. Post (2003)) that for an arbitrary
$m\in\mathbb{N}$ one can construct a periodic non-compact Riemannian manifold
$M$ with at least $m$ gaps in the spectrum of the corresponding
Laplace-Beltrami operator $-\Delta_M$. In this work we want not only to produce
a new type of periodic manifolds with spectral gaps but also to control the
edges of these gaps. The main result of the paper is as follows: for arbitrary
pairwise disjoint intervals $(\a_j,\b_j)\subset[0,\infty)$, $j=1,...,m$
($m\in\mathbb{N}$), for an arbitrarily small $\delta>0$ and for an arbitrarily
large $L>0$ we construct a periodic non-compact Riemannian manifold $M$ with at
least $m$ gaps in the spectrum of the operator $-\Delta_{M}$, moreover the
edges of the first $m$ gaps belong to $\delta$-neighbourhoods of the edges of
the intervals $(\a_j,\b_j)$, while the remaining gaps (if any) are located
outside the interval $[0,L]$.Comment: 30 pages, 2 Figures; Journal of Differential Equations (2012
Bifurcation Boundary Conditions for Switching DC-DC Converters Under
  Constant On-Time Control

Sampled-data analysis and harmonic balance analysis are applied to analyze
switching DC-DC converters under constant on-time control. Design-oriented
boundary conditions for the period-doubling bifurcation and the saddle-node
bifurcation are derived. The required ramp slope to avoid the bifurcations and
the assigned pole locations associated with the ramp are also derived. The
derived boundary conditions are more general and accurate than those recently
obtained. Those recently obtained boundary conditions become special cases
under the general modeling approach presented in this paper. Different analyses
give different perspectives on the system dynamics and complement each other.
Under the sampled-data analysis, the boundary conditions are expressed in terms
of signal slopes and the ramp slope. Under the harmonic balance analysis, the
boundary conditions are expressed in terms of signal harmonics. The derived
boundary conditions are useful for a designer to design a converter to avoid
the occurrence of the period-doubling bifurcation and the saddle-node
bifurcation.Comment: Submitted to International Journal of Circuit Theory and Applications
  on August 10, 2011; Manuscript ID: CTA-11-016
Dynamically-Stabilized Pores in Bilayer Membranes

Zhelev and Needham have recently created large, quasi-stable pores in
artificial lipid bilayer vesicles [Biochim. Biophys. Acta 1147 (1993) 89].
Initially created by electroporation, the pores remain open for up to several
seconds before quickly snapping shut. This result is surprising in light of the
large line tension for holes in bilayer membranes and the rapid time scale for
closure of large pores. We show how pores can be dynamically stabilized via a
new feedback mechanism. We also explain quantitatively the observed sudden pore
closure as a tangent bifurcation. Finally we show how Zhelev and Needham's
experiment can be used to measure accurately the pore line tension, an
important material parameter. For their SOPC/CHOL mixture we obtain a line
tension of 2.6 10^{-6} erg/cm.Comment: 7 pages RevTeX, 3 included eps figures (published version).
  Postscript also available at http://dept.physics.upenn.edu/~moro
Neutrinos Associated With Cosmic Rays of Top-Down Origin

Top-down models of cosmic rays produce more neutrinos than photons and more
photons than protons. In these models, we reevaluate the fluxes of neutrinos
associated with the highest energy cosmic rays in light of mounting evidence
that they are protons and not gamma rays. While proton dominance at EeV
energies can possibly be achieved by efficient absorption of the dominant
high-energy photon flux on universal and galactic photon and magnetic
background fields, we show that the associated neutrino flux is inevitably
increased to a level where it should be within reach of operating experiments
such as AMANDA II, RICE and AGASA. In future neutrino telescopes, tens to a
hundred, rather than a few neutrinos per kilometer squared per year, may be
detected above 1 PeV.Comment: 16 pages, 4 figure
Vibrational transition moments of CH$_4$ from first principles

A new nine-dimensional (9D), \textit{ab initio} electric dipole moment
surface (DMS) of methane in its ground electronic state is presented. The DMS
is computed using an explicitly correlated coupled cluster CCSD(T)-F12 method
in conjunction with an F12-optimized correlation consistent basis set of the
TZ-family. A symmetrized molecular bond representation is used to parameterise
the 9D DMS in terms of sixth-order polynomials. Vibrational transition moments
as well as band intensities for a large number of IR-active vibrational bands
of $^{12}$CH$_4$ are computed by vibrationally averaging the \textit{ab initio}
dipole moment components. The vibrational wavefunctions required for these
averages are computed variationally using the program TROVE and a new
`spectroscopic' $^{12}$CH$_4$ potential energy surface. The new DMS will be
used to produce a hot line list for $^{12}$CH$_4$.Comment: J. Molec. Spectrosc. (submitted
Dispelling the N^3 myth for the Kt jet-finder

At high-energy colliders, jets of hadrons are the observable counterparts of
the perturbative concepts of quarks and gluons. Good procedures for identifying
jets are central to experimental analyses and comparisons with theory. The Kt
family of successive recombination jet finders has been widely advocated
because of its conceptual simplicity and flexibility and its unique ability to
approximately reconstruct the partonic branching sequence in an event. Until
now however, it had been believed that for an ensemble of N particles the
algorithmic complexity of the Kt jet finder scaled as N^3, a severe issue in
the high multiplicity environments of LHC and heavy-ion colliders. We here show
that the computationally complex part of Kt jet-clustering can be reduced to
two-dimensional nearest neighbour location for a dynamic set of points.
Borrowing techniques developed for this extensively studied problem in
computational geometry, Kt jet-finding can then be performed in N ln N time.
Code based on these ideas is found to run faster than all other jet finders in
current use.Comment: 11 pages, 3 figures; v2, to appear in Phys.Lett.B, includes an extra
  section briefly discussing the issues of jet areas and pileup subtraction,
  and also the Cambridge/Aachen jet finde
TNOs are Cool: A Survey of the Transneptunian Region XI: A Herschel-PACS
  view of 16 Centaurs

Centaurs are the transitional population between trans-Neptunian objects
(TNOs) and Jupiter-family comets. For this reason it is possible to access the
smaller ones, which is more difficult to do with the TNO population. The goal
of this work is to characterize a set of 16 Centaurs in terms of their size,
albedo, and thermal properties. We study the correlations, for a more extended
sample obtained from the literature, of diameter, albedo, orbital parameters,
and spectral slopes. We performed three-band photometric observations using
Herschel-PACS and used a consistent method for the data reduction and aperture
photometry of this sample to obtain monochromatic flux densities at 70, 100,
and 160 $\mu$m. Additionally, we used Spitzer-MIPS flux densities at 24 and 70
$\mu$m when available. We also included in our Centaur sample scattered disk
objects (SDOs), a dynamical family of TNOS, using results previously published
by our team, and some Centaurs observed only with the Spitzer/MIPS instrument.
We have determined new radiometric sizes and albedos of 16 Centaurs. The first
conclusion is that the albedos of Centaur objects are not correlated with their
orbital parameters. Similarly, there is no correlation between diameter and
orbital parameters. Most of the objects in our sample are dark (pv < 7%) and
most of them are small (D < 120km). However, there is no correlation between
albedo and diameter, in particular for the group of the small objects as albedo
values are homogeneously distributed between 4 to 16%. The correlation with the
color of the objects showed that red objects are all small (mean diameter 65
km), while the gray ones span a wide range of sizes (mean diameter 120 km).
Moreover, the gray objects tend to be darker, with a mean albedo of 5.6%,
compared with a mean of 8.5% (ranging from 5 to 15%) for the red objects.Comment: 16 pages, 7 figures. accepted at A&A. in pres
Towards large r from [p,q]-inflation

The recent discovery of B-mode polarizations in the CMB by the BICEP2
collaboration motivates the study of large-field inflation models which can
naturally lead to significant tensor-to-scalar ratios. A class of such models
in string theory are axion monodromy models, where the shift symmetry of an
axion is broken by some branes. In type IIB string theory such models so far
utilized NS5 branes which lead to a linear potential with an induced
tensor-to-scalar ratio of $r \sim 0.07$. In this short note we study a
modification of the scenario to include [p,q] 7-branes and show that this leads
to an enhanced tensor-to-scalar ratio $r \sim 0.14$. Unlike 5-branes, 7-branes
are in-principle compatible with supersymmetry, however we find that an
implementation of the inflationary scenario requires an explicit breaking of
supersymmetry by the 7-branes during inflation. This leads to similar
challenges as in 5-brane models. We discuss the relation to high-scale
supersymmetry breaking after inflation.Comment: 8 pp; v2: references added, typos correcte
A Revised Scheme to Compute Horizontal Covariances in an Oceanographic
  3D-VAR Assimilation System

We propose an improvement of an oceanographic three dimensional variational
assimilation scheme (3D-VAR), named OceanVar, by introducing a recursive filter
(RF) with the third order of accuracy (3rd-RF), instead of a RF with first
order of accuracy (1st-RF), to approximate horizontal Gaussian covariances. An
advantage of the proposed scheme is that the CPU's time can be substantially
reduced with benefits on the large scale applications. Experiments estimating
the impact of 3rd-RF are performed by assimilating oceanographic data in two
realistic oceanographic applications. The results evince benefits in terms of
assimilation process computational time, accuracy of the Gaussian correlation
modeling, and show that the 3rd-RF is a suitable tool for operational data
assimilation.Comment: 26 page
Differential cross section measurements for the production of a W boson
  in association with jets in proton-proton collisions at sqrt(s) = 7 TeV

Measurements are reported of differential cross sections for the production
of a W boson, which decays into a muon and a neutrino, in association with
jets, as a function of several variables, including the transverse momenta (pt)
and pseudorapidities of the four leading jets, the scalar sum of jet transverse
momenta (HT), and the difference in azimuthal angle between the directions of
each jet and the muon. The data sample of pp collisions at a centre-of-mass
energy of 7 TeV was collected with the CMS detector at the LHC and corresponds
to an integrated luminosity of 5.0 inverse femtobarns. The measured cross
sections are compared to predictions from Monte Carlo generators, MADGRAPH +
PYTHIA and SHERPA, and to next-to-leading-order calculations from BLACKHAT +
SHERPA. The differential cross sections are found to be in agreement with the
predictions, apart from the pt distributions of the leading jets at high pt
values, the distributions of the HT at high-HT and low jet multiplicity, and
the distribution of the difference in azimuthal angle between the leading jet
and the muon at low values.Comment: Replaced with published version. Added journal reference and DO
Modelling CO emission from hydrodynamic simulations of nearby spirals,
  starbursting mergers, and high-redshift galaxies

We model the intensity of emission lines from the CO molecule, based on
hydrodynamic simulations of spirals, mergers, and high-redshift galaxies with
very high resolutions (3pc and 10^3 Msun) and detailed models for the
phase-space structure of the interstellar gas including shock heating, stellar
feedback processes and galactic winds. The simulations are analyzed with a
Large Velocity Gradient (LVG) model to compute the local emission in various
molecular lines in each resolution element, radiation transfer and opacity
effects, and the intensity emerging from galaxies, to generate synthetic
spectra for various transitions of the CO molecule. This model reproduces the
known properties of CO spectra and CO-to-H2 conversion factors in nearby
spirals and starbursting major mergers. The high excitation of CO lines in
mergers is dominated by an excess of high-density gas, and the high turbulent
velocities and compression that create this dense gas excess result in broad
linewidths and low CO intensity-to-H2 mass ratios. When applied to
high-redshift gas-rich disks galaxies, the same model predicts that their
CO-to-H2 conversion factor is almost as high as in nearby spirals, and much
higher than in starbursting mergers. High-redshift disk galaxies contain giant
star-forming clumps that host a high-excitation component associated to gas
warmed by the spatially-concentrated stellar feedback sources, although CO(1-0)
to CO(3-2) emission is overall dominated by low-excitation gas around the
densest clumps. These results overall highlight a strong dependence of CO
excitation and the CO-to-H2 conversion factor on galaxy type, even at similar
star formation rates or densities. The underlying processes are driven by the
interstellar medium structure and turbulence and its response to stellar
feedback, which depend on global galaxy structure and in turn impact the CO
emission properties.Comment: A&A in pres
Black Hole Thermodynamics and Negative Entropy in deSitter and
  Anti-deSitter Einstein-Gauss-Bonnet gravity

We investigate the charged Schwarzschild-Anti-deSitter (SAdS) BH
thermodynamics in 5d Einstein-Gauss-Bonnet gravity with electromagnetic field.
The Hawking-Page phase transitions between SAdS BH and pure AdS space are
studied. The corresponding phase diagrams (with critical line defined by GB
term coefficient and electric charge) are drawn. The possibility to account for
higher derivative Maxwell terms is mentioned.
  In frames of proposed dS/CFT correspondence it is demonstrated that brane
gravity maybe localized similarly to AdS/CFT.
  SdS BH thermodynamics in 5d Einstein and Einstein-Gauss-Bonnet gravity is
considered. The corresponding (complicated) surface counterterms are found and
used to get the conserved BH mass, free energy and entropy. The interesting
feature of of higher derivative gravity is the possibility for negative (or
zero) SdS (or SAdS) BH entropy which depends on the parameters of higher
derivative terms. We speculate that the appearence of negative entropy may
indicate a new type instability where a transition between SdS (SAdS) BH with
negative entropy to SAdS (SdS) BH with positive entropy would occur.Comment: 46 pages, Latex file, misprints corrected, reference added,
  discussion is enlarge
Remarks on the Calculations of Charged Open String Amplitudes: the
  1-loop Tadpole

In string theory, there are various physical situations where the world-sheet
fields have a shifted moding. For instance, this is the case for the twisted
closed string in Z_N orbifold or for the charged open string in a constant
electro-magnetic field. Because of this feature, it is quite challenging to
give explicit formulae describing the string interaction, even for the bosonic
case. In this note, we focus on the case of the charged open bosonic string and
construct the 1-loop tadpole which is an object generating all 1-point
functions from the annulus in the presence of an external field. In the
operator formalism, this represents one of the basic building blocks for the
construction of a general loop amplitude.Comment: 6 pages. Contribution to the proceedings of the RTN meeting ``The
  Quantum Structure of Spacetime and the Geometric Nature of Fundamental
  Interactions'', (Corfu, 13-20 September 2001
Quantum chains with a Catalan tree pattern of conserved charges: the $\delta$ = -1 XXZ model and the isotropic octonionic chain

A class of quantum chains possessing a family of local conserved charges with a Catalan tree pattern is studied. Recently, we have identified such a structure in the integrable SU(N)-invariant chains. In the present work we find sufficient conditions for the existence of a family of charges with this structure in terms of the underlying algebra. Two additional systems with a Catalan tree structure of conserved charges are found. One is the spin 1/2 XXZ model with \Delta=-1. The other is a new octonionic isotropic chain, generalizing the Heisenberg model. This system provides an interesting example of an infinite family of noncommuting local conserved quantities