bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-conjugate QCD
Authors: Anber Mohamed M.
Published: October 2019

Abstract

We carry out a systematic study of SU(6) Yang-Mills theory endowed with fermions in the adjoint and 3-index antisymmetric mixed-representation. The fermion bilinear in the 3-index antisymmetric representation vanishes identically, which leads to interesting new phenomena. We first study the theory on a small circle, i.e., on

$$ {\mathrm{\mathbb{R}}}^3\times {\mathbbm{S}}_L^1 $$

ℝ
3

×

S
L
1

, employing symmetry-twisted boundary conditions and semi-classical techniques. We find that the ground state is 3-fold degenerate, which can be explained as a consequence of a 1-form/0-form mixed ’t Hooft anomaly. In addition, the theory may admit massless bosonic and fermionic degrees of freedom, depending on the number of flavors, and confines the electric probes in the infrared. Empowered by ’t Hooft anomaly matching conditions along with the 2-loop β-function, we further examine the possible infrared symmetry realizations on ℝ4 for various number of adjoint and 3-index antisymmetric fermions. The infrared theory is either a conformal field theory, which is expected for a large number of flavors, or it is confining with or without chiral symmetry breaking. In a few cases, we are able to give enough evidence for adiabatic continuity between the small- and large-circle limits.
Importance of generalized μτ symmetry and its CP extension on neutrino mixing and leptogenesis
Authors: Samanta Rome , Sinha Roopam , Ghosal Ambar
Published: October 2019

Abstract

Within the framework of residual symmetry, two ℤ
2 type associate μτ inter- change symmetries robustly constrain the Dirac CP phase δ in a model independent way. Both of them predict simultaneous maximality of δ and the atmospheric mixing angle θ
23. We show how these well known correlations will be changed if we generalize the μτ in- terchange symmetry to a μτ mixing symmetry. In particular, we show that the stringent condition of simultaneous maximality could be relaxed even with a very small departure from the exact μτ interchange. In addition, the present neutrino data on δ and θ
23 can be explained better by the mixing symmetry. After discussing the impact of the μτ mix- ing in some realistic neutrino mass models, we show how the proposed mixing could be realized with two simultaneous CP transformations which also lead to novel and testable correlations between δ and the mixing angles θij . Next we discuss in particular, the ‘three flavour regime’ of leptogenesis within the CP extended framework and show, unlike the ordinary CP extended μτ interchange symmetry, a resonant leptogenesis is possible due the generalization of μτ interchange to the μτ mixing and the resulting baryon asymmetry always requires a nonmaximal θ
23 owing to the fact that the baryon to photon ratio ηB vanishes in the exact limit of θ
23 = π/4. This is one of the robust predictions of this frame- work. The CP extended μτ mixing is also a novel example of a low energy effective model that provides an important insight to the off-diagonal terms of the flavour coupling matrix which have usually been neglected in literature to compute the final baryon asymmetry, in particular in the models with flavour symmetries.
Multi-quark colour decompositions from unitarity
Authors: Ochirov Alexander , Page Ben
Published: October 2019

Abstract

Any loop QCD amplitude at full colour is constructed from kinematic and gauge-group building blocks. In a unitarity-based on-shell framework, both objects can be reconstructed from their respective counterparts in tree-level amplitudes. This procedure is at its most powerful when aligned with flexible colour decompositions of tree-level QCD amplitudes. In this note we derive such decompositions for amplitudes with an arbitrary number of quarks and gluons from the same principle that is used to bootstrap kinematics— unitarity factorisation. In the process we formulate new multi-quark bases and provide closed-form expressions for the new decompositions. We then elaborate upon their application in colour decompositions of loop multi-quark amplitudes.
Leptogenesis in the Neutrino Option
Authors: Brivio I. , Moffat K. , Pascoli S. , Petcov S.T. , Turner J.
Published: October 2019

Abstract

We examine the compatibility between the Neutrino Option, in which the electroweak scale is generated by PeV mass type I seesaw Majorana neutrinos, and leptogenesis. We find the Neutrino Option is consistent with resonant leptogenesis. Working within the minimal seesaw scenario with two heavy Majorana neutrinos N
1, 2, which form a pseudo-Dirac pair, we explore the viable parameter space. We find that the Neutrino Option and successful leptogenesis are compatible in the cases of a neutrino mass spectrum with normal (inverted) ordering for 1.2 × 106 < M(GeV) < 8.8 × 106(2.4 × 106 < M(GeV) < 7.4 × 106), with M = (M
1 + M
2)/2 and M
1, 2 the masses of N
1, 2. Successful leptogenesis requires that ∆M/M ≡ (M
2 − M
1)/M ∼ 10−8. We further show that leptogenesis can produce the baryon asymmetry of the Universe within the Neutrino Option scenario when the requisite CP violation in leptogenesis is provided exclusively by the Dirac or Majorana low energy CP violation phases of the PMNS matrix.
Hypercharged naturalness
Authors: Serra Javi , Stelzl Stefan , Torre Riccardo , Weiler Andreas
Published: October 2019

Abstract

We present an exceptional twin-Higgs model with the minimal symmetry structure for an exact implementation of twin parity along with custodial symmetry. Twin particles are mirrors of the Standard Model yet they carry hypercharge, while the photon is identified with its twin. We thoroughly explore the phenomenological signatures of hypercharged naturalness: long-lived charged particles; a colorless twin top with electric charge 2/3 that once pair-produced, bounds via twin-color interactions and can annihilate to dileptons or a Higgs plus a photon or a Z; and glueballs produced from Higgs decays and twin-quarkonium annihilation that either decay displaced or are stable on collider scales and eventually decay to diphotons. Prospects for detection of these signatures are also discussed.
Longitudinal sound and diffusion in holographic massive gravity
Authors: Ammon Martin , Baggioli Matteo , Gray Séan , Grieninger Sebastian
Published: October 2019

Abstract

We consider a simple class of holographic massive gravity models for which the dual field theories break translational invariance spontaneously. We study, in detail, the longitudinal sector of the quasi-normal modes at zero charge density. We identify three hydrodynamic modes in this sector: a pair of sound modes and one diffusion mode. We numerically compute the dispersion relations of the hydrodynamic modes. The obtained speed and the attenuation of the sound modes are in agreement with the hydrodynamic predictions. On the contrary, we surprisingly find disagreement in the case of the diffusive mode; its diffusion constant extracted from the quasi-normal mode data does not agree with the expectations from hydrodynamics. We confirm our numerical results using ana- lytic tools in the decoupling limit and we comment on some possible reasons behind the disagreement. Finally, we extend the analysis of the collective longitudinal modes beyond the hydrodynamic limit by displaying the dynamics of the higher quasi-normal modes at large frequencies and momenta.
Higher spin de Sitter Hilbert space
Authors: Anninos Dionysios , Denef Frederik , Monten Ruben , Sun Zimo
Published: October 2019

Abstract

We propose a complete microscopic definition of the Hilbert space of minimal higher spin de Sitter quantum gravity and its Hartle-Hawking vacuum state. The funda- mental degrees of freedom are 2N bosonic fields living on the future conformal boundary, where N is proportional to the de Sitter horizon entropy. The vacuum state is normalizable. The model agrees in perturbation theory with expectations from a previously proposed dS- CFT description in terms of a fermionic Sp(N) model, but it goes beyond this, both in its conceptual scope and in its computational power. In particular it resolves the apparent pathologies affecting the Sp(N) model, and it provides an exact formula for late time vac- uum correlation functions. We illustrate this by computing probabilities for arbitrarily large field excursions, and by giving fully explicit examples of vacuum 3- and 4-point functions. We discuss bulk reconstruction and show the perturbative bulk QFT canonical commuta- tions relations can be reproduced from the fundamental operator algebra, but only up to a minimal error term ∼ e−O(N ), and only if the operators are coarse grained in such a way that the number of accessible “pixels” is less than O(N ). Independent of this, we show that upon gauging the higher spin symmetry group, one is left with 2N physical degrees of freedom, and that all gauge invariant quantities can be computed by a 2N × 2N matrix model. This suggests a concrete realization of the idea of cosmological complementarity.
Quasinormal modes of supersymmetric microstate geometries from the D1-D5 CFT
Authors: Chakrabarty Bidisha , Ghosh Debodirna , Virmani Amitabh
Published: October 2019

Abstract

We revisit the study of the probe scalar quasinormal modes of a class of three- charge super- symmetric microstate geometries. We compute the real and imaginary parts of the quasinormal modes and show that in the parameter range when the geometries have large AdS region, the spectrum is precisely reproduced from a D1-D5 orbifold CFT analysis. The spectrum includes the slow decaying modes pointed out by Eperon, Reall, and Santos. We analyse in detail the nature of the quasinormal modes by studying the scalar wavefunction. We show that these modes correspond to slow leakage of excitation from AdS throat to infinity.
On explicit formulae of LMOV invariants
Authors: Zhu Shengmao
Published: October 2019

Abstract

We started a program to study the open string integrality invariants (LMOV invariants) for toric Calabi-Yau 3-folds with Aganagic-Vafa brane (AV-brane) several years ago. This paper is devoted to the case of resolved conifold with one out AV-brane in any integer framingτ, which is the largeNduality of Chern-Simons theory for a framed unknot with integer framingτinS3. By using the methods from string dualities, we compute several explicit formulae of the corresponding LMOV invariants for this special model, whose integrality properties have been proved in a separated paper [56].
Search for the Electric Dipole Moment and anomalous magnetic moment of the tau lepton at tau factories
Authors: Chen Xin , Wu Yongcheng
Published: October 2019

Abstract

Precise measurement of the Electric Dipole Moment (EDM) and anomalous magnetic moment (g-2) of particles are important tests of Beyond Standard Model (BSM) physics. It is generally believed that the tau lepton couples more strongly to BSM due to its large mass, and can be searched for at collider experiments. A new method to ap- proximately reconstruct the neutrinos from the hadronic decays of τ
−
τ
+ pairs produced at e
−
e
+ tau factories is proposed. With all final state particle momenta available, observables based on matrix elements and sensitive to BSM are calculated. It is estimated that with 50 ab−1 of data to be delivered by the Belle-II experiment, a tau EDM search with a 1-σ level precision of

$$ \left|{d}_{\tau}^{NP}\right|<2.04\times {10}^{-19}\ 10 $$

d
τ
NP

<
2.04
×

10

−
19

10

e·cm, and g-2 search with

$$ \left|{\alpha}_{\tau}^{NP}\right|<1.75\times {10}^{-5} $$

α
τ
NP

<
1.75
×

10

−
5

(1.5% of the SM prediction), can be expected when systematics are not considered. The new precision can effectively constrain BSM models with heavy mirror neutrinos. It can also constrain models containing a light scalar with mass at O(1 GeV), which can explain the current muon g-2 anomaly as well. The method in this work offers a new opportunity to search for BSM at current and future tau factories with high precision.
Systematic classification of two-loop d = 4 Dirac neutrino mass models and the Diracness-dark matter stability connection
Authors: Chuliá Salvador Centelles , Cepedello Ricardo , Peinado Eduardo , Srivastava Rahul
Published: October 2019

Abstract

We provide a complete systematic classification of all two-loop realizations of the dimension four operator for Dirac neutrino masses. Our classification is multi-layered, starting first with a classification in terms of all possible distinct two looptopologies. Then we discuss the possiblediagramsfor each topology.Model-diagramsoriginating from each diagram are then considered. The criterion forgenuinenessis also defined and discussed at length. Finally, as examples, we construct two explicit models which also serve to highlight the intimate connection between the Dirac nature of neutrinos and the stability of dark matter.
Zee model with flavor dependent global U(1) symmetry
Authors: Nomura Takaaki , Yagyu Kei
Published: October 2019

Abstract

We study a simple extension of the Zee model, in which a discrete Z
2 symmetry imposed in the original model is replaced by a global U(1) symmetry retaining the same particle content. Due to the U(1) symmetry with flavor dependent charge assignments, the lepton sector has an additional source of flavor violating Yukawa interactions with a controllable structure, while the quark sector does not at tree level. We show that current neutrino oscillation data can be explained under constraints from lepton flavor violating decays of charged leptons in a successful charge assignment of the U(1) symmetry. In such scenario, we find a characteristic pattern of lepton flavor violating decays of additional Higgs bosons, which can be a smoking gun signature at collider experiments.
A near-minimal leptoquark model for reconciling flavour anomalies and generating radiative neutrino masses
Authors: Bigaran Innes , Gargalionis John , Volkas Raymond R.
Published: October 2019

Abstract

We introduce two scalar leptoquarks, the SU(2)
L
isosinglet denoted ϕ ∼ (3
,
1
, −1/3) and the isotriplet φ ∼ (3
,
3
, −1/3), to explain observed deviations from the standard model in semi-leptonic B-meson decays. We explore the regions of parameter space in which this model accommodates the persistent tensions in the decay observables R

D
(∗), R

K
(∗) , and angular observables in b → sμμ transitions. Additionally, we exploit the role of these exotics in existing models for one-loop neutrino mass generation derived from ∆L = 2 effective operators. Introducing the vector-like quark χ ∼ (3
,
2
, −5/6) necessary for lepton-number violation, we consider the contribution of both leptoquarks to the generation of radiative neutrino mass. We find that constraints permit simultaneously accommodating the flavour anomalies while also explaining the relative smallness of neutrino mass without the need for cancellation between leptoquark contributions. A characteristic prediction of our model is a rate of muon-electron conversion in nuclei fixed by the anoma- lies in b → sμμ and neutrino mass; the COMET and Mu2e experiments will thus test and potentially falsify our scenario. The model also predicts signatures that will be tested at the LHC and Belle II.
Rank-one flavor violation and B-meson anomalies
Authors: Gherardi Valerio , Marzocca David , Nardecchia Marco , Romanino Andrea
Published: October 2019

Abstract

We assume that the quark-flavor coefficients matrix of the semileptonic operators addressing the neutral-current B-meson anomalies has rank-one, i.e. it can be described by a single vector in quark-flavor space. By correlating the observed anomalies to other flavor and high-p

T
observables, we constrain its possible directions and we show that a large region of the parameter space of this framework will be explored by flavor data from the NA62, KOTO, LHCb and Belle II experiments.
Emergent/composite axions
Authors: Anastasopoulos P. , Betzios P. , Bianchi M. , Consoli D. , Kiritsis E.
Published: October 2019

Abstract

Hidden theories coupled to the SM may provide emergent axions, that are composites/bound-states of the hidden fields. This is motivated by paradigms emerging from the AdS/CFT correspondence but it is a more general phenomenon. We explore the general setup and find that UV-sourced interactions of instanton densities give rise to emergent axions in the IR. We study the general properties of such axions and argue that they are generically different from both fundamental and composite axions that have been studied so far.
Topological AdS/CFT and the Ω deformation
Authors: Genolini Pietro Benetti , Richmond Paul
Published: October 2019

Abstract

In this note, we define a holographic dual to four-dimensional superconformal field theories formulated on arbitrary Riemannian manifolds equipped with a Killing vector. Moreover, assuming smoothness of the bulk solution, we study the variation of the holographically renormalized supergravity action in the class of metrics on the boundary four-manifold with a prescribed isometry.
String field theory as world-sheet UV regulator
Authors: Sen Ashoke
Published: October 2019

Abstract

Even at tree level, the first quantized string theory suffers from apparent short distance singularities associated with collision of vertex operators that prevent us from straightforward numerical computation of various quantities. Examples include string theory S-matrix for generic external momenta and computation of the spectrum of string theory under a marginal deformation of the world-sheet theory. The former requires us to define the S-matrix via analytic continuation or as limits of contour integrals in complexified moduli space, while the latter requires us to use an ultraviolet cut-off at intermediate steps. In contrast, string field theory does not suffer from such divergences. In this paper we show how string field theory can be used to generate an explicit algorithm for computing tree level amplitudes in any string theory that does not suffer from any short distance divergence from integration over the world-sheet variables. We also use string field theory to compute second order mass shift of string states under a marginal deformation without having to use any cut-off at intermediate steps. We carry out the analysis in a broad class of string field theories, thereby making it manifest that the final results are independent of the extra data that go into the formulation of string field theory. We also comment on the generalization of this analysis to higher genus amplitudes.
QCD axion on hilltop by a phase shift of π.
Authors: Takahashi Fuminobu , Yin Wen
Published: October 2019

Abstract

We show that the initial misalignment angle of the QCD axion (or axion-like particles) can be set very close to π, if the QCD axion has a mixing with another heavy axion which induces the phase shift ≈ π after inflation. In the simplest case, the heavy axion plays the role of the inflaton, and we call such inflation as “πnflation”. The basic idea was first proposed by Daido and the present authors in ref. [1] in 2017 and more recently discussed in ref. [2]. We show that the QCD axion with a decay constant f

a
 ≳ 3 × 109 GeV can explain dark matter by the πnflation mechanism. A large fraction of the parameter region has an overlap with the projected sensitivity of ORGAN, MADMAX, TOORAD and IAXO. We also study implications for the effective neutrino species and isocurvature perturbations. The πnflation can provide an initial condition for the hilltop inflation in the axion landscape, and in a certain set-up, a chain of the hilltop inflation may take place.
Generalizations of the Pontryagin and Husain-Kuchař actions to manifolds with boundary
Authors: Barbero G. J. Fernando , Díaz Bogar , Margalef-Bentabol Juan , Villaseñor Eduardo J.S.
Published: October 2019

Abstract

In this paper we study a family of generalizations of the Pontryagin and Husain-Kuchǎr actions on manifolds with boundary. In some cases, they describe well- known models — either at the boundary or in the bulk — such as 3-dimensional Euclidean general relativity with a cosmological constant or the Husain-Kuchǎr model. We will use Hamiltonian methods in order to disentangle the physical and dynamical content of the systems that we discuss here. This will be done by relying on a geometric implementation of the Dirac algorithm in the presence of boundaries recently proposed by the authors.
Dual gravitational charges and soft theorems
Authors: Godazgar Hadi , Godazgar Mahdi , Pope C. N.
Published: October 2019

Abstract

We consider the consequences of the dual gravitational charges for the phase space of radiating modes, and find that they imply a new soft NUT theorem. In particular, we argue that the existence of these new charges removes the need for imposing boundary conditions at spacelike infinity that would otherwise preclude the existence of NUT charges.
Gluing two affine Yangians of 𝔤𝔩1
Authors: Li Wei , Longhi Pietro
Published: October 2019

Abstract

We construct a four-parameter family of affine Yangian algebras by gluing two copies of the affine Yangian of 𝔤𝔩1. Our construction allows for gluing operators with arbitrary (integer or half integer) conformal dimension and arbitrary (bosonic or fermionic) statistics, which is related to the relative framing. The resulting family of algebras is a two-parameter generalization of the

$$ \mathcal{N} $$

N

= 2 affine Yangian, which is isomorphic to the universal enveloping algebra of 𝔲 (1)⊕ 𝒲

$$ {}_{\infty}^{\mathcal{N}=2}\left[\lambda \right] $$

∞

N
=
2

λ

. All algebras that we construct have natural representations in terms of “twin plane partitions”, a pair of plane partitions appropriately joined along one common leg. We observe that the geometry of twin plane partitions, which determines the algebra, bears striking similarities to the geometry of certain toric Calabi-Yau threefolds.
$$ \mathcal{N} $$ = (8, 0) AdS vacua of three-dimensional supergravity
Authors: Deger Nihat Sadik , Eloy Camille , Samtleben Henning
Published: October 2019

Abstract

We give a classification of fully supersymmetric chiral

$$ \mathcal{N} $$

N

= (8, 0) AdS3 vacua in general three-dimensional half-maximal gauged supergravities coupled to matter. These theories exhibit a wealth of supersymmetric vacua with background isometries given by the supergroups OSp(8|2, ℝ), F(4), SU(4|1, 1), and OSp(4
∗

|4), respectively. We identify the associated embedding tensors and the structure of the associated gauge groups. We furthermore compute the mass spectra around these vacua. As an off-spin we include results for a number of

$$ \mathcal{N} $$

N

= (7, 0) vacua with supergroups OSp(7|2, ℝ) and G(3), respectively. We also comment on their possible higher-dimensional uplifts.
Cluster adjacency for m = 2 Yangian invariants
Authors: Łukowski Tomasz , Parisi Matteo , Spradlin Marcus , Volovich Anastasia
Published: October 2019

Abstract

We classify the rational Yangian invariants of the m = 2 toy model of

$$ \mathcal{N} $$

N

= 4 Yang-Mills theory in terms of generalised triangles inside the amplituhedron

$$ {\mathcal{A}}_{n,k}^{(2)} $$

A

n
,
k

2

. We enumerate and provide an explicit formula for all invariants for any number of particles n and any helicity degree k. Each invariant manifestly satisfies cluster adjacency with respect to the Gr(2, n) cluster algebra.
Axion clockworks from heterotic M-theory: the QCD-axion and its ultra-light companion
Authors: Im Sang Hui , Nilles Hans Peter , Olechowski Marek
Published: October 2019

Abstract

A previously discussed clockwork mechanism within heterotic M-theory is applied to its axion landscape. We identify a unique candidate for a QCD-axion with a decay constant in the preferred “axion window” around 1011 GeV. It is accompanied by at least one ultra-light axion that couples predominantly to hidden sector gauge groups.
Pseudoscalar quarkonium+γ production at NLL+NLO accuracy
Authors: Chung Hee Sok , Ee June-Haak , Kang Daekyoung , Kim U-Rae , Lee Jungil , Wang Xiang-Peng
Published: October 2019

Abstract

We consider the exclusive pseudoscalar heavy-quarkonium (η

b, c
) production in association with a photon at future lepton colliders where the collider energies of O(102) GeV are far greater than the quarkonium mass. At these energies, the logarithm of mass to collision energy becomes increasingly large hence its resummation becomes particularly important. By making use of the light-cone-distribution factorization formula, we resum the logarithms up to next-to-leading-logarithmic accuracy (NLL) that corresponds to order-α

s
accuracy. We combine the resummed result with a known fixed-order result at next-to-leading order (NLO) such that both resummed-logarithmic terms and non-logarithmic terms are included at the same order in α

s
. This allowed us to provide reliable predictions at accuracies of order α

s
ranging from relatively low energies near quarkonium mass to the collider energies of O(102) GeV. We also include the leading relativistic corrections resummed at leading-logarithmic accuracy. Our prediction at the Belle energy is comparable with fixed-order predictions in literatures while it shows a large deviation from a recent Belle’s upper limit by about 4 σ. Finally, we make predictions for the energies of future Z - and Higgs factories.
Three-loop form factors for Higgs boson pair production in the large top mass limit
Authors: Davies Joshua , Steinhauser Matthias
Published: October 2019

Abstract

We consider the virtual corrections to Higgs boson pair production at next-to- next-to-leading order, in the large top quark mass limit. We compute five expansion terms for the box-type form factors and eight expansion terms for the triangle form factor, which serve as useful input for the construction of approximations. We present analytic results for the form factors in the soft-virtual approximation.

From a technical point of view the calculation is quite challenging since huge intermediate expressions are produced. We describe our methods and optimizations to overcome these difficulties, which might be useful for other calculations.
Determinants of the spatial distribution of exporters in regions: the role of ownership
Authors: Nazarczuk Jarosław M. , Umiński Stanisław , Brodzicki Tomasz
Published: October 2019

Spatial distribution of exporters only recently has attracted the attention of researchers, while the location of economic activity as such has been subject of profound analysis for a long time. Regions have become more open and thus vulnerable to external shocks. Nevertheless, the increase in the number of exporters in the population of firms is one of the top priorities of regions’ economic policy agenda, as it improves competitiveness and overall productivity. Literature overview shows an important gap, which is insufficient consideration of the role of ownership, as regards the determinants of the spatial distribution of exporters. The study identifies the differences between the determinants of spatial location of foreign-owned exporters (FOEs) and domestic-owned exporters (DOEs), in particular the role of metropolis, the proximity to infrastructure and the consequences of historical factors and thus the path dependency. The FOEs and DOEs differ in their location preferences. In particular, our results indicate that FOEs pay more attention to proximity to infrastructure and are more susceptible to the presence of agglomeration externalities in the vicinity of metropolitan areas. In addition, historical factors affect the spatial distribution of exporters, especially if the interaction of path dependency and infrastructure endowment is introduced.
Optimization of cutting conditions using artificial neural networks and the Edgeworth-Pareto method for CNC face-milling operations on high-strength grade-H steel
Authors: Abbas Adel Taha , Pimenov Danil Yurievich , Erdakov Ivan Nikolaevich , Mikolajczyk Tadeusz , Soliman Mahmoud Sayed , El Rayes Magdy Mostafa
Published: October 2019

Computer Numerical Control (CNC) face milling is commonly used to manufacture products from high-strength grade-H steel in both the automotive and the construction industry. The various milling operations for these components have key performance indicators: accuracy, surface roughness (Ra), and machining time for removal of a unit volume min/cm3 (Tm). The specified surface roughness values for machining each component is achieved based on the prototype specifications. However, poor adherence to specifications can result in the rejection of the machined parts, implying extra production costs and raw material wastage. An algorithm using an artificial neural network (ANN) with the Edgeworth-Pareto method is presented in this paper to optimize the cutting parameter in CNC face-milling operations. The set of parameters are adjusted to improve surface roughness and minimal unit-volume material removal rates, thereby reducing production costs and improving accuracy. An ANN algorithm is designed in Matlab, based on a 3–10-1 Multi-Layer Perceptron (MLP), which predicts the Ra of the workpiece surface to an accuracy of ± 5.78% within the range of the experimental angular spindle speed, feed rate, and cutting depth. An unprecedented Pareto frontier for Ra and Tm was obtained for the finished grade-H steel workpiece using an ANN algorithm that was then used to determine optimized cutting conditions. Depending on the production objective, one or the other of two sets of optimum machining conditions can be used: the first one sets a minimum cutting power, while the other sets a maximum Tm with a slight increase (under 5%) in milling costs.
Correction to: Chemometric tools for the authentication of cod liveroil based on nuclear magnetic resonance and infrared spectroscopy data
Authors: Giese Editha , Rohn Sascha , Fritsche Jan
Published: October 2019

The article Chemometric tools for the authentication of cod liver oil based on nuclear magnetic resonance and infrared spectroscopy data, written by Editha Giese, Sascha Rohn and Jan Fritsche.
Conservation process of archaeological waterlogged wood studied by spectroscopy and gradient NMR methods
Authors: Kowalczuk Joanna , Rachocki Adam , Broda Magdalena , Mazela Bartłomiej , Ormondroyd Graham A. , Tritt-Goc Jadwiga
Published: October 2019

The properties of methyltrimethoxysilane-treated, waterlogged archeological elm wood were studied by magnetic resonance imaging and nuclear magnetic resonance (NMR) methods. The spatially resolved proton density images, spin–spin relaxation profiles, proton NMR spectra, and self-diffusion coefficients of the preservative agents were measured during drying. The resolution of the data allowed for the differentiation between the early and late wood areas of the elm wood and determination of the shrinkage of the sample in the tangential and radial directions, and it showed the different dynamics of methyltrimethoxysilane (MTMS) in the lumen cells of both early and late woods. The NMR spectra indicated that the MTMS, after rapid evaporation of ethanol, is bound to the wood. Identical measurements were also taken for the archeological elm wood treated with polyethylene glycol (PEG) and for an untreated wood sample. From the results, it can be concluded that MTMS showed significantly higher stability against shrinkage when compared to PEG. Therefore, it may be considered as an alternative preservative for archeological wood.
Optimal EPO dosing in hemodialysis patients using a non-linear model predictive control approach
Authors: Rogg S. , Fuertinger D. H. , Volkwein S. , Kappel F. , Kotanko P.
Published: October 2019

Anemia management with erythropoiesis stimulating agents is a challenging task in hemodialysis patients since their response to treatment varies highly. In general, it is difficult to achieve and maintain the predefined hemoglobin (Hgb) target levels in clinical practice. The aim of this study is to develop a fully personalizable controller scheme to stabilize Hgb levels within a narrow target window while keeping drug doses low to mitigate side effects. First in-silico results of this framework are presented in this paper. Based on a model of erythropoiesis we formulate a non-linear model predictive control (NMPC) algorithm for the individualized optimization of epoetin alfa (EPO) doses. Previous to this work, model parameters were estimated for individual patients using clinical data. The optimal control problem is formulated for a continuous drug administration. This is currently a hypothetical form of drug administration for EPO as it would require a programmable EPO pump similar to insulin pumps used to treat patients with diabetes mellitus. In each step of the NMPC method the open-loop problem is solved with a projected quasi-Newton method. The controller is successfully tested in-silico on several patient parameter sets. An appropriate control is feasible in the tested patients under the assumption that the controlled quantity is measured regularly and that continuous EPO administration is adjusted on a daily, weekly or monthly basis. Further, the controller satisfactorily handles the following challenging problems in simulations: bleedings, missed administrations and dosing errors.
Redo surgery with longitudinal resection for dilated bowel in Hirschsprung disease: an illustrative case series
Authors: Roorda Daniëlle , Surridge Tessa J. , Visschers Ruben G. J. , Derikx Joep P. M. , van Heurn L. W. Ernest
Published: October 2019

Purpose

Patients with Hirschsprung disease (HD) can have persistent obstructive symptoms after resection of the aganglionic segment. If obstructive symptoms are treated inadequately, this may lead to recurrent faecal stasis and impaction, and may result in severe distension of the bowel. A permanently distended bowel which not responds to conservative treatment may be an indication for redo surgery. The aim of this study is to describe our experiences and the short-term results of a novel technique: longitudinal antimesenteric resection with a longitudinal anastomosis.

Methods

We reviewed the medical records of our three patients who underwent longitudinal resection of severe distended bowel. This technique aims to improve defecation by improving faecal passage and is characterized by resection of the antimesenteric side of the distended intestinal segment, followed by plication with a longitudinal anastomosis. In this paper, this novel technique is described in detail, as well as short-term outcomes.

Results

All patients had an uneventful recovery after longitudinal antimesenteric resection. During follow-up, the functional outcomes were excellent, with a large improvement of bowel function. All patients were continent for faeces, and treated with low-dose laxatives or occasional preventive irrigation in one patient. There were no more complaints of persistent constipation or soiling.

Conclusion

Longitudinal resection is a surgical redo-procedure offering large benefits for patients with Hirschsprung disease with distended bowel after primary surgery.
A different view on fine-scale population structure in Western African populations
Authors: Chaichoompu Kridsadakorn , Abegaz Fentaw , Cavadas Bruno , Fernandes Verónica , Müller-Myhsok Bertram , Pereira Luísa , Van Steen Kristel
Published: October 2019

Due to its long genetic evolutionary history, Africans exhibit more genetic variation than any other population in the world. Their genetic diversity further lends itself to subdivisions of Africans into groups of individuals with a genetic similarity of varying degrees of granularity. It remains challenging to detect fine-scale structure in a computationally efficient and meaningful way. In this paper, we present a proof-of-concept of a novel fine-scale population structure detection tool with Western African samples. These samples consist of 1396 individuals from 25 ethnic groups (two groups are African American descendants). The strategy is based on a recently developed tool called IPCAPS. IPCAPS, or Iterative Pruning to CApture Population Structure, is a genetic divisive clustering strategy that enhances iterative pruning PCA, is robust to outliers and does not require a priori computation of haplotypes. Our strategy identified in total 12 groups and 6 groups were revealed as fine-scale structure detected in the samples from Cameroon, Gambia, Mali, Southwest USA, and Barbados. Our finding helped to explain evolutionary processes in the analyzed West African samples and raise awareness for fine-scale structure resolution when conducting genome-wide association and interaction studies.
Incoherent light control through scattering media based on machine learning and its application to multiview stereo displays
Authors: Horisaki Ryoichi , Mori Yuki , Tanida Jun
Published: October 2019

In this paper, we present a method for controlling incoherent light through scattering media based on machine learning and its potential application to multiview stereo displays. The inverse function between input and output light intensity patterns through a scattering medium is regressed with a machine learning algorithm. The inverse function is used for calculating an input pattern for generating a target output pattern through a scattering medium. We demonstrate the proposed method by assuming a potential application to multiview stereo displays. This concept enables us to use a diffuser as a parallax barrier, a cylindrical lens array, or a lens array on a conventional multiview stereo display, which will contribute to a low-cost, highly functional display. A neural network is trained with a large number of pairs of displayed random patterns and their parallax images at different observation points, and then a displayed image is calculated from arbitrary parallax images using the trained neural network. In the experimental demonstration, the scattering-based multiview stereo display was composed of a diffuser and a conventional liquid crystal display, and it reproduced different handwritten characters, which were captured by a stereo camera.
Delayed gratification in New Caledonian crows and young children: influence of reward type and visibility
Authors: Miller Rachael , Frohnwieser Anna , Schiestl Martina , McCoy Dakota E. , Gray Russell D. , Taylor Alex H. , Clayton Nicola S.
Published: October 2019

Self-control underlies cognitive abilities such as decision making and future planning. Delay of gratification is a measure of self-control and involves obtaining a more valuable outcome in the future by tolerating a delay or investing a greater effort in the present. Contextual issues, such as reward visibility and type, may influence delayed gratification performance, although there has been limited comparative investigation between humans and other animals, particularly non-primate species. Here, we adapted an automated ‘rotating tray’ paradigm used previously with capuchin monkeys to test for delay of gratification ability that requires little pre-test training, where the subject must forgo an immediate, less preferred reward for a delayed, more preferred one. We tested New Caledonian crows and 3–5-year-old human children. We manipulated reward types to differ in quality or quantity (Experiments 1 and 2) as well as visibility (Experiment 2). In Experiments 1 and 2, both species performed better when the rewards varied in quality as opposed to quantity, though performed above chance in both conditions. In Experiment 1, both crows and children were able to delay gratification when both rewards were visible. In Experiment 2, 5-year-old children outperformed 3- and 4-year olds, though overall children still performed well, while the crows struggled when reward visibility was manipulated, a result which may relate to difficulties in tracking the experimenters’ hands during baiting. We discuss these findings in relation to the role of contextual issues on self-control when making species comparisons and investigating the mechanisms of self-control.
An orthotropic electro-viscoelastic model for the heart with stress-assisted diffusion
Authors: Propp Adrienne , Gizzi Alessio , Levrero-Florencio Francesc , Ruiz-Baier Ricardo
Published: October 2019

We propose and analyse the properties of a new class of models for the electromechanics of cardiac tissue. The set of governing equations consists of nonlinear elasticity using a viscoelastic and orthotropic exponential constitutive law, for both active stress and active strain formulations of active mechanics, coupled with a four-variable phenomenological model for human cardiac cell electrophysiology, which produces an accurate description of the action potential. The conductivities in the model of electric propagation are modified according to stress, inducing an additional degree of nonlinearity and anisotropy in the coupling mechanisms, and the activation model assumes a simplified stretch–calcium interaction generating active tension or active strain. The influence of the new terms in the electromechanical model is evaluated through a sensitivity analysis, and we provide numerical validation through a set of computational tests using a novel mixed-primal finite element scheme.
Economic Return on Investment of Parent Training Programmes for the Prevention of Child Externalising Behaviour Problems
Authors: Nystrand Camilla , Hultkrantz Lars , Vimefall Elin , Feldman Inna
Published: October 2019

Economic models to inform decision-making are gaining popularity, especially for preventive interventions. However, there are few estimates of the long-term returns to parenting interventions used to prevent mental health problems in children. Using data from a randomised controlled trial evaluating five indicated parenting interventions for parents of children aged 5–12, we modeled the economic returns resulting from reduced costs in the health care and education sector, and increased long-term productivity in a Swedish setting. Analyses done on the original trial population, and on various sized local community populations indicated positive benefit–cost ratios. Even smaller local authorities would financially break-even, thus interventions were of good value-for-money. Benefit–cost analyses of such interventions may improve the basis for resource allocation within local decision-making.
The ratio of response spectra from seismic-type free-field and building foundation vibrations: the influence of rockburst parameters and simple models of kinematic soil-structure interaction
Authors: Kuzniar Krystyna , Tatara Tadeusz
Published: October 2019

Mining-related seismicity is a significant problem in regions with the exploitation in underground mines. Despite the fact that mining tremors result from human activity and are classified as so-called paraseismic shocks, as with earthquakes, they are random events. Moreover, these rockbursts could cause significant damage to surface structures, including buildings. This paper deals with the analysis of experimentally obtained results in terms of the differences between the mine-induced vibrations described by the response spectra from the free-field near a given building and the simultaneously recorded vibrations in the building foundations. The influences of epicentral distance, mining tremor energy and the value of peak ground acceleration on the curves of free-field—foundation response spectra ratio were studied. The impact of the type of building on the transmission of response spectra from the free-field vibrations to the building foundations was also analysed for three types of apartment buildings (low-rise, medium-rise, high-rise). The usefulness of the approximate models of the phenomenon of soil-structure interaction during earthquakes proposed in the literature is also estimated in this paper in specific instances of mining tremors. Furthermore, the study presents original, simple, empirical models for the evaluation of the differences in the response spectra originating from free-field and building foundation vibrations in the mining region.
Assessment of the Laurentian Great Lakes’ hydrological conditions in a changing climate
Authors: Mailhot Edouard , Music Biljana , Nadeau Daniel F. , Frigon Anne , Turcotte Richard
Published: October 2019

A set of 28 simulations from five regional climate models are used in this study to assess the Great Lakes’ water supply from 1953 to 2100 following emissions scenarios RCP4.5 and 8.5 with a focus on bi-weekly changes in the means and extremes of hydrological variables. Models are first evaluated by comparing annual cycles of precipitation, runoff, evaporation and net basin supply (NBS) with observations. Trends in mean values are then studied for each variable using Theil-Sen’s statistical test. Changes in extreme conditions are analyzed using generalized extreme values distributions for a reference period (1971–2000) and two future periods (2041–2070 and 2071–2100). Ensemble trend results show evaporation increases of 136 and 204 mm (RCP4.5 and RCP8.5) over the Great Lakes between 1953 and 2100. Precipitation increases by 83 and 140 mm and runoff increases by 68 and 135 mm. Trends are not equally distributed throughout the year as seasonal changes differ greatly. As a result, Great Lakes net basin supply is expected to increase in winter and spring and decrease in summer. Over the entire year, NBS increases of 14 and 70 mm are projected for scenarios RCP4.5 and 8.5 respectively by the year 2100. An analysis of extreme values reveals that precipitation and NBS maxima increase by 11 to 27% and 1 to 9% respectively, while NBS minima decrease by 18 to 29% between 1971–2000 and 2041–2100.
Drones in humanitarian contexts, robot ethics, and the human–robot interaction
Authors: van Wynsberghe Aimee , Comes Tina
Published: October 2019

There are two dominant trends in the humanitarian care of 2019: the ‘technologizing of care’ and the centrality of the humanitarian principles. The concern, however, is that these two trends may conflict with one another. Faced with the growing use of drones in the humanitarian space there is need for ethical reflection to understand if this technology undermines humanitarian care. In the humanitarian space, few agree over the value of drone deployment; one school of thought believes drones can provide a utility serving those in need while another believes the large scale deployment of drones will exacerbate the already prevalent issues facing humanitarian aid providers. We suggest in this paper that the strength of the humanitarian principles approach to answer questions of aid provision can be complimented by a technology-facing approach, namely that of robot ethics. We have shown that for humanitarian actors we ought to be concerned with the risks of a loss of contextualization and de-skilling. For the beneficiary, we raise three concerns associated with the threat to the principle of humanity for this group: a loss of dignity by reducing human-to-human interactions; a threat to dignity through a lack of informational transparency; and, a threat to dignity by failing to account for the physiological and behavioral impacts of the drone on human actors. Although we acknowledge the obstacles (and dangers) associated with understanding the physiological and behavioral impacts we insist that the moral acceptability and desirability of drones in humanitarian contexts is dependent on the findings from such studies and that tailored ethical guidelines for drone deployment in humanitarian action be created to reflect the results of such studies.