bluuebunny/crossref_metadata_2025 huggingface dataset:
Localization and measurement method of continuous casting slab model based on binocular vision
Authors: Fang Jianzhong , Xu Sixiang , Yang Yu , Wang Yang
Published: August 2019

As the corner points of continuous casting slab model are not obvious, the traditional feature points detection methods cannot detect the effective feature points, so these methods cannot complete the localization and measurement of continuous casting slab model. A binocular vision localization and measurement method based on edges fitting was proposed. The acquired photos of continuous casting slab model were preprocessed including de‐distortion and stereo correction. And then the Canny operator and Zernike moment were used to detect the subpixel points of the model edges. These subpixel points that have been obtained were clustered and fitted, and the intersection points of fitting curves were calculated. Finally, using the fundamental matrix to match the intersection points, and the parallax information was obtained to locate the slab model. The experiment shows that the average measurement error of model is 1.31%, which can meet the precision requirements of production.
Ambulatory urodynamics in clinical practice: A single centre experience
Authors: Cantu Hector , Sharaf Ala'a , Bevan Wendy , Hassine Anna , Hashim Hashim
Published: August 2019

Objectives

To assess the additional value of ambulatory urodynamics (AUDS) monitoring in the management of patients with unexplained lower urinary tract symptoms.

Methods

A retrospective review of the urodynamic data at a tertiary referral center between January 2006 and December 2018. During this period 12,123 urodynamic studies were conducted; 430 patients were arranged to have AUDS monitoring because their symptoms were not reproduced with either standard or video urodynamics (UDS).

Results

A total of 391 patients were included, (360 females, 31 males). Symptoms were reproduced in 74% of cases. The most common AUDS finding was detrusor overactivity with or without incontinence, followed by urodynamic stress incontinence. In 75.7% of the patients, the additional information from AUDS resulted in a change to patient management.

Conclusions

Additional UDS findings were made in the majority of patients who underwent AUDS. This helped in setting a new treatment plan for the bothersome urinary findings. AUDS monitoring is a useful additional diagnostic tool and can help to guide patient management where symptoms are not explained by standard or video UDS.
Analysis of distance‐based protein structure prediction by deep learning in CASP13
Authors: Xu Jinbo , Wang Sheng
Published: August 2019

This paper reports the CASP13 results of distance‐based contact prediction, threading, and folding methods implemented in three RaptorX servers, which are built upon the powerful deep convolutional residual neural network (ResNet) method initiated by us for contact prediction in CASP12. On the 32 CASP13 FM (free‐modeling) targets with a median multiple sequence alignment (MSA) depth of 36, RaptorX yielded the best contact prediction among 46 groups and almost the best 3D structure modeling among all server groups without time‐consuming conformation sampling. In particular, RaptorX achieved top L/5, L/2, and L long‐range contact precision of 70%, 58%, and 45%, respectively, and predicted correct folds (TMscore > 0.5) for 18 of 32 targets. Further, RaptorX predicted correct folds for all FM targets with >300 residues (T0950‐D1, T0969‐D1, and T1000‐D2) and generated the best 3D models for T0950‐D1 and T0969‐D1 among all groups. This CASP13 test confirms our previous findings: (a) predicted distance is more useful than contacts for both template‐based and free modeling; and (b) structure modeling may be improved by integrating template and coevolutionary information via deep learning. This paper will discuss progress we have made since CASP12, the strength and weakness of our methods, and why deep learning performed much better in CASP13.
Vertical β‐Ga2O3 Schottky Barrier Diodes with Enhanced Breakdown Voltage and High Switching Performance
Authors: Lu Xing , Zhang Xu , Jiang Huaxing , Zou Xinbo , Lau Kei May , Wang Gang
Published: August 2019

Herein, vertical Schottky barrier diodes (SBDs) based on a bulk β‐Ga2O3 substrate are developed. The devices feature an ion‐implanted planar edge termination (ET) structure, which can effectively smoothen the electric field peak and reduce the electric field crowding at the Schottky junction edge. Greatly enhanced reverse blocking characteristics including ≈103× lower reverse leakage current and 1.5× higher breakdown voltage (VB) are achieved, whereas good forward conduction such as a reasonably high on‐state current density and near‐unity ideality factor is maintained. In addition, the switching performance of the fabricated vertical β‐Ga2O3 SBDs is investigated using a double‐pulse test circuit. When switching from an on‐state current of 350 mA to a reverse‐blocking voltage of −100 V, the vertical β‐Ga2O3 SBDs exhibit fast reverse recovery with a reverse recovery time (trr) of ≈14.1 ns and reverse recovery charge (Qrr) of ≈0.34 nC, outperforming the Si fast recovery diode (FRD) of similar ratings. The results indicate a great promise of vertical β‐Ga2O3 SBDs for high‐voltage fast switching applications.
Modulated Metal–Insulator Transition Behaviors in Vanadium Dioxide Nanowires with an Artificial Oxidized Domain
Authors: Wei Wei , Huang Tiantian , Wang Shuxia , Luo Wenjin , Zhang Tianning , Hu Weida , Chen Xin , Dai Ning
Published: August 2019

Correlated vanadium dioxide (VO2) has shown promises in functional materials and advanced electronic devices with outstanding metal–insulator transition (MIT). The manipulations of MIT and structural phase transition in correlated oxides are among the major challenges in both fundamental science and technological applications. Herein, the modulation of MIT behaviors in one VO2 nanowire with an artificial oxidized domain induced by selected‐area chemical nanoengineering is described. The formation of an artificial oxidized domain enables to suppress MIT and stabilize the insulating phase above the MIT temperature of pristine VO2 nanowires, which leads to an enhanced MIT hysteresis and temperature. The creation of artificial domains and the modulation of MIT in correlated oxide nanowires help to both investigate the essential physics behind correlated nanomaterials and fabricate nanoscale multifunctional devices.
Microwave‐assisted acid hydrolysis for whole‐bone proteomics and paleoproteomics
Authors: Colleary Caitlin , Little Nicole C. , Cleland Timothy P.
Published: August 2019

Rationale

Whole‐bone proteomic analyses rely on lengthy sample preparation including demineralization and digestion to break bone down into peptides to recover using mass spectrometry. However, microwave‐assisted acid hydrolysis, a technique used in proteomic analyses of other soft tissues and cells, will combine both demineralization and digestion and only take minutes.

Methods

To test microwave‐assisted hydrolysis on whole moose bone, we microwaved five concentrations of acetic and formic acids (15%, 12.5%, 10%, 7.5% and 5%) for three times (10, 20 and 30 min) at 140°C using an ETHOS UP high performance microwave digestion system. Peptides were injected and separated using Thermo BioBasic C18 columns and detected with an LTQ Orbitrap Velos mass spectrometer. We searched the raw data on PEAKS 8.5 against the white‐tailed deer database.

Results

Formic acid hydrolysis led to the most complete digestion, and therefore the highest number of peptide spectrum matches, more protein groups and better sequence coverage for collagenous proteins. However, for the formic acid samples there is a tradeoff with digestion completeness and a higher incidence of in vitro modifications (i.e. formylation) that are not induced using acetic acid. Acetic acid has greater cleavage specificity and higher sequence coverage for non‐collagenous proteins.

Conclusions

Depending on the goals of analysis, there are benefits and drawbacks to using both acetic acid and formic acid. Overall, microwave‐assisted acid hydrolysis was successful in demineralizing and digesting bone fragments to considerably speed up the preparation for bottom‐up proteomics analysis.
The influence of sample matrix on the accuracy of nitrite N and O isotope ratio analyses with the azide method
Authors: Granger Julie , Boshers Danielle S. , Böhlke John K. , Yu Dan , Chen Nengwang , Tobias Craig R.
Published: August 2019

Rationale

The isotope ratios of nitrogen (15N/14N) and oxygen (18O/16O) in nitrite (NO2−) can be measured by conversion of the nitrite into nitrous oxide (N2O) with azide, followed by mass spectrometric analysis of N2O by gas chromatography isotope ratio mass spectrometry (GC/IRMS). While applying this method to brackish samples, we noticed that the N and O isotope ratio measurements of NO2− are highly sensitive to sample salinity and to the pH at which samples are preserved.

Methods

We investigated the influence of sample salinity and sample preservation pH on the N and O isotope ratios of the N2O produced from the reaction of NO2− with azide. The N2O isotope ratios were measured by GC/IRMS.

Results

Under the experimental reaction conditions, the conversion of NO2− into N2O was less complete in lower salinity solutions, resulting in respective N and O isotopic offsets of +2.5‰ and −14.0‰ compared with seawater solutions. Differences in salinity were also associated with differences in the fraction of O atoms exchanged between NO2− and water during the reaction. Similarly, aqueous NO2− samples preserved at elevated pH values resulted in the incomplete conversion of NO2− into N2O by azide, and consequent pH‐dependent isotopic offsets, as well as differences in the fraction of O atoms exchanged with water. The addition of sodium chloride to the reaction matrix of samples and standards largely mitigated salinity‐dependent isotopic offsets in the N2O product, and nearly homogenized the fraction of O atom exchange among samples of different salinity. A test of the hypobromite–azide method to measure N isotope ratios of ammonium by conversion into NO2− then N2O revealed no influence of sample salinity on the N isotope ratios of the N2O product.

Conclusions

We outline recommendations to mitigate potential matrix effects among samples and standards, to improve the accuracy of N and O isotope ratios in NO2− measured with the azide method.
Capillary-resident EphA7+ pericytes are multipotent cells with anti-ischemic effects through capillary formation
Authors: Yoshida Yuri , Kabara Maki , Kano Kohei , Horiuchi Kiwamu , Hayasaka Taiki , Tomita Yui , Takehara Naofumi , Minoshima Akiho , Aonuma Tatsuya , Maruyama Keisuke , Nakagawa Naoki , Azuma Nobuyoshi , Hasebe Naoyuki , Kawabe Jun-ichi
Published: August 2019

The presence of pericytes (PCs) with multipotency and broad distribution along capillary suggests that microvasculature plays a role not only as a duct for blood fluid transport but also as a stem cell niche that contributes to tissue maintenance and regeneration. The lack of an appropriate marker for multipotent PCs still limits our understanding of their pathophysiological roles. We identified the novel marker EphA7 to detect multipotent PCs using microarray analysis of an immortalized PC library. PCs were isolated from microvessels of mouse subcutaneous adipose tissues, then EphA7+ PCs called capillary stem cells (CapSCs) were separated from EphA7− control PCs (ctPCs) using fluorescence-activated cell sorting system. CapSCs had highly multipotency that enabled them to differentiate into mesenchymal and neuronal lineages compared with ctPCs. CapSCs also differentiated into endothelial cells and PCs to form capillary-like structures by themselves. Transplantation of CapSCs into ischemic tissues significantly improved blood flow recovery in hind limb ischemia mouse model due to vascular formation compared with that of ctPCs and adipose stromal cells. These data demonstrate that EphA7 identifies a subpopulation of multipotent PCs that have high angiogenesis and regenerative potency and are an attractive target for regenerative therapies.

Significance statement The present study characterizes the multipotency of pericyte populations isolated from mammalian capillaries using a novel genetic marker, EphA7. It is shown that this marker can be used to isolate living cells and that EphA7+ pericytes, termed capillary stem cells (CapSCs), have capillary formation by themselves and cross-germ layer plasticity to differentiate into mesenchymal and neuronal lineages, indicating its potential use in both disease models and regenerative therapies.
Gastropods from the Jurassic neptunian sills of Rocca Busambra (north‐western Sicily, Italy): Patellogastropoda, Pleurotomarioidea, Scissurelloidea, Fissurelloidea and Eucycloidea
Authors: Szabó János , Conti Maria Alessandra , Monari Stefano , Wendt Jobst
Published: August 2019

The gastropods from Jurassic neptunian sills of Rocca Busambra (Sicily, Italy) represent an extraordinary assemblage for richness and extremely high degree of novelty, consisting of about 250 species (two‐thirds of which are new) of 20 superfamilies. A total of 38 species and 18 genera of Lottioidea, Pleurotomarioidea, Scissurelloidea, Fissurelloidea and Eucycloidea are described. Of these, 30 species and 9 genera are new, namely Ramusatomaria nuda gen. et sp. nov., Trapanimaria gattoi gen. et sp. nov., Trapanimaria nicolosiensis gen. et sp. nov., Trapanimaria? pallinii gen. et sp. nov., Trochotomaria conoidea sp. nov., Trochotomaria polymorpha sp. nov., Laevitomaria babalusciae sp. nov., Pyrgotrochus vorosi sp. nov., Auritoma lenticula gen. et sp. nov., Busambrella fasciata gen. et sp. nov., Emarginula (Emarginula) burgioi sp. nov., Emarginula (Tauschia) acutidens sp. nov., Propeucyclus sicanus gen. et sp. nov., Propeucyclus obesus gen. et sp. nov., Propeucyclus? semireticulatus gen. et sp. nov., Eucyclomphalus? marenostrum sp. nov., Toronyella lineata gen. et sp. nov., Toronyella margaritata gen. et sp. nov., Zarnglaffia polygonalis sp. nov., Zarnglaffia palermitana sp. nov., Ambercyclus cratisculptus sp. nov., Elymicyclus alternatus gen. et sp. nov., Elymicyclus ietumensis gen. et sp. nov., Elymicyclus martae gen. et sp. nov., Elymicyclus garibaldii gen. et sp. nov., Jurassiscala sturanii gen. et sp. nov., Jurassiscala? tenuiretis gen. et sp. nov., Fischeriella sicula sp. nov., Retimusina poseidoni gen. et sp. nov. and Retimusina? tritoni sp. nov. The new scissurelloidean family Auritomidae fam. nov. is erected. A palaeobiogeographical analysis indicates close relationships with coeval faunas from condensed pelagic carbonates of the central region of western Tethys.
Modular fluxes, elliptic genera, and weak gravity conjectures in four dimensions
Authors: Lee Seung-Joo , Lerche Wolfgang , Weigand Timo
Published: August 2019

Abstract

We analyse the Weak Gravity Conjecture for chiral four-dimensional F-theory compactifications withN= 1 supersymmetry. Extending our previous work on nearly tensionless heterotic strings in six dimensions, we show that under certain assumptions a tower of asymptotically massless states arises in the limit of vanishing coupling of a U(1) gauge symmetry coupled to gravity. This tower contains super-extremal states whose charge-to-mass ratios are larger than those of certain extremal dilatonic Reissner-Nordström black holes, precisely as required by the Weak Gravity Conjecture. Unlike in six dimensions, the tower of super-extremal states does not always populate a charge sub-lattice.

The main tool for our analysis is the elliptic genus of the emergent heterotic string in the chiralN= 1 supersymmetric effective theories. This also governs situations where the heterotic string is non-perturbative. We show how it can be computed in terms of BPS invariants on elliptic four-folds, by making use of various dualities and mirror symmetry. Compared to six dimensions, the geometry of the relevant elliptically fibered four-folds is substantially richer than that of the three-folds, and we classify the possibilities for obtaining critical, nearly tensionless heterotic strings. We find that the (quasi-)modular properties of the elliptic genus crucially depend on the choice of flux background. Our general results are illustrated in a detailed example.
Constructing $$ \mathcal{N} $$ = 4 Coulomb branch superamplitudes
Authors: Herderschee Aidan , Koren Seth , Trott Timothy
Published: August 2019

Abstract

We study scattering amplitudes of massive BPS states on the Coulomb branch of 4d

$$ \mathcal{N} $$

N

= 4 super-Yang-Mills, utilising a little group covariant on-shell superspace for massive particles. Super-BCFW recursion for massive amplitudes is constructed and its validity is proven for all Coulomb branch superamplitudes. We then determine the exact three-particle superamplitudes for massive states. These ingredients allow us to explicitly compute the four- and five-particle superamplitudes, which is the first non-trivial usage of BCFW recursion for amplitudes with entirely massive external states. The manifest little group covariance helps clarify both the role of special kinematic properties of BPS states and the organizational structures of the superamplitudes.
BPS wilson loops in generic conformal $$ \mathcal{N} $$ = 2 SU(N) SYM theories
Authors: Billò M. , Galvagno F. , Lerda A.
Published: August 2019

Abstract

We consider the 1/2 BPS circular Wilson loop in a generic

$$ \mathcal{N} $$

N

= 2 SU(N) SYM theory with conformal matter content. We study its vacuum expectation value, both at finite N and in the large-N limit, using the interacting matrix model provided by localization results. We single out some families of theories for which the Wilson loop vacuum expectation values approaches the

$$ \mathcal{N} $$

N

= 4 result in the large-N limit, in agreement with the fact that they possess a simple holographic dual. At finite N and in the generic case, we explicitly compare the matrix model result with the field-theory perturbative expansion up to order g
8 for the terms proportional to the Riemann value ζ (5), finding perfect agreement. Organizing the Feynman diagrams as suggested by the structure of the matrix model turns out to be very convenient for this computation.
Electroweak pseudo-observables and Z-boson form factors at two-loop accuracy
Authors: Dubovyk Ievgen , Freitas Ayres , Gluza Janusz , Riemann Tord , Usovitsch Johann
Published: August 2019

Abstract

We present Standard Model predictions for the complete set of phenomenologically relevant electroweak precision pseudo-observables related to the Z-boson: the leptonic and bottom-quark effective weak mixing angles

$$ {\sin}^2{\theta}_{\mathrm{eff}}^{\mathrm{\ell}} $$

sin
2

θ
eff
ℓ

,

$$ {\sin}^2{\theta}_{\mathrm{eff}}^b $$

sin
2

θ
eff
b

, the Z-boson partial decay widths Γ
f
, where f indicates any charged lepton, neutrino and quark flavor (except for the top quark), as well as the total Z decay width Γ
Z
, the branching ratios R

ℓ
, R

c
, R

b
, and the hadronic cross section

$$ {\sigma}_{\mathrm{had}}^0 $$

σ
had
0

. The input parameters are the masses M
Z, M
H and m
t, and the couplings α
s, α. The scheme dependence due to the choice of M
W or its alternative G

μ
as a last input parameter is also discussed. Recent substantial technical progress in the calculation of Minkowskian massive higher-order Feynman integrals allows the calculation of the complete electroweak two-loop radiative corrections to all the observables mentioned. QCD contributions are included appropriately. Results are provided in terms of simple and convenient parameterization formulae whose coefficients have been determined from the full numerical multi-loop calculation. The size of the missing electroweak three-loop or QCD higher-order corrections is estimated. We briefly comment on the prospects for their calculation. Finally, direct predictions for the

$$ Z\overline{f}f $$

Z

f
¯

f

vector and axial-vector form-factors are given, including a discussion of separate order-by-order contributions.
Two-loop $$ \mathcal{O} $$ ($$ {\alpha}_t^2 $$) corrections to the neutral Higgs boson masses in the CP-violating NMSSM
Authors: Dao Thi Nhung , Gröber Ramona , Krause Marcel , Mühlleitner Margarete , Rzehak Heidi
Published: August 2019

Abstract

We present our calculation of the two-loop corrections of

$$ \mathcal{O} $$

O

(

$$ {\alpha}_t^2 $$

α
t
2

) to the neutral Higgs boson masses of the CP-violating Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM). The calculation is performed in the Feynman diagrammatic approach in the gaugeless limit at vanishing external momentum. We apply a mixed

$$ \overline{\mathrm{DR}} $$

DR
¯

-on-shell (OS) renormalization scheme for the NMSSM input parameters. Furthermore, we exploit a

$$ \overline{\mathrm{DR}} $$

DR
¯

as well as an OS renormalization in the top/stop sector. The corrections are implemented in the Fortran code NMSSMCALC for the calculation of the Higgs spectrum both in the CP-conserving and CP-violating NMSSM. The code also provides the Higgs boson decays including the state-of-the-art higher-order corrections. The corrections computed in this work improve the already available corrections in NMSSMCALC which are the full one-loop corrections without any approximation and the two-loop

$$ \mathcal{O} $$

O

(α

t

α

s
) corrections in the gaugeless limit and at vanishing external momentum. Depending on the chosen parameter point, we find that the O(α

t

α

s
+

$$ {\alpha}_t^2 $$

α
t
2

) corrections add about 4-7% to the one-loop mass of the SM-like Higgs boson for

$$ \overline{\mathrm{DR}} $$

DR
¯

renormalization in the top/stop sector and they reduce the mass by about 6-9% if OS renormalization is applied. For an estimate of the theoretical uncertainty we vary the renormalization scale and change the renormalization scheme and show that care has to be taken in the corresponding interpretation.
High precision determination of αs from a global fit of jet rates
Authors: Verbytskyi Andrii , Banfi Andrea , Kardos Adam , Monni Pier Francesco , Kluth Stefan , Somogyi Gábor , Szőr Zoltán , Trócsányi Zoltán , Tulipánt Zoltán , Zanderighi Giulia
Published: August 2019

Abstract

We present state-of-the-art extractions of the strong coupling based on N3LO+NNLL accurate predictions for the two-jet rate in the Durham clustering algorithm at e
+
e
− collisions, as well as a simultaneous fit of the two- and three-jet rates taking into account correlations between the two observables. The fits are performed on a large range of data sets collected at the LEP and PETRA colliders, with energies spanning from 35 GeV to 207 GeV. Owing to the high accuracy of the predictions used, the perturbative uncertainty is considerably smaller than that due to hadronization. Our best determination at the Z mass is α

s
(M
Z) = 0.11881 ± 0.00063(exp.) ± 0.00101(hadr.) ± 0.00045(ren.) ± 0.00034(res.), which is in agreement with the latest world average and has a comparable total uncertainty.
Displaced lepton jet signatures from self-interacting dark matter bound states
Authors: Tsai Yuhsin , Xu Tao , Yu Hai-Bo
Published: August 2019

Abstract

We study self-interacting dark matter signatures at the Large Hadron Collider. A light dark photon, mediating dark matter self-interactions, can bind dark matter particles to form a bound state when they are produced via a heavy pseduoscalar in pp collisions. The bound state can further annihilate into a pair of boosted dark photons, which subsequently decay into charged leptons through a kinetic mixing portal, resulting in striking displaced lepton jet signals. After adapting the analysis used in the ATLAS experiment, we explore the reach of the model parameters at the 13 TeV run with an integrated luminosity of 300 fb−1. For heavy dark matter, the displaced lepton jet searches can surpass traditional monojet signals in setting the lower bound on the pseduoscalar mass. If a positive signal is detected, we can probe the dark matter mass and the dark coupling constant after combining both the displaced lepton jet and monojet searches. We further show the CMS dimuon search can be sensitive to the final state radiation of the dark photon. Our results demonstrate terrestrial collider experiments complement astronomical observations of galaxies in the search of the self-interacting nature of dark matter.
(0,2) dualities and the 4-simplex
Authors: Dimofte Tudor , Paquette Natalie M.
Published: August 2019

Abstract

We propose that a simple, Lagrangian 2d

$$ \mathcal{N} $$

N

= (0, 2) duality interface between the 3d

$$ \mathcal{N} $$

N

= 2 XYZ model and 3d

$$ \mathcal{N} $$

N

= 2 SQED can be associated to the simplest triangulated 4-manifold: the 4-simplex. We then begin to flesh out a dictionary between more general triangulated 4-manifolds with boundary and 2d

$$ \mathcal{N} $$

N

= (0, 2) interfaces. In particular, we identify IR dualities of interfaces associated to local changes of 4d triangulation, governed by the (3), (2, 4), and (2, 4) Pachner moves. We check these dualities using supersymmetric half-indices. We also describe how to produce stand-alone 2d theories (as opposed to interfaces) capturing the geometry of 4-simplices and Pachner moves by making additional field-theoretic choices, and find in this context that the Pachner moves recover abelian

$$ \mathcal{N} $$

N

= (0, 2) trialities of Gadde-Gukov-Putrov. Our work provides new, explicit tools to explore the interplay between 2d dualities and 4-manifold geometry that has been developed in recent years.
Chern-Simons theory from M5-branes and calibrated M2-branes
Authors: Mezei Márk , Pufu Silviu S. , Wang Yifan
Published: August 2019

Abstract

We study a sector of the 5d maximally supersymmetric Yang-Mills theory onS5consisting of 1/8-BPS Wilson loop operators contained within a greatS3insideS5. We conjecture that these observables are described by a 3d Chern Simons theory onS3, analytically continued to a pure imaginary Chern-Simons level. Therefore, the expectation values of these 5d Wilson loops compute knot invariants. We verify this conjecture in the weakly-coupled regime from explicit Feynman diagram computations. At strong coupling, these Wilson loop operators lift to 1/8-BPS surface operators in the 6d (2,0) theory onS1×S5. Using AdS/CFT, we show that these surface operators are dual to M2-branes subject to certain calibration conditions required in order to preserve supersymmetry. We compute the renormalized action of a large class of calibrated M2-branes and obtain a perfect match with the field theory prediction. Finally, we present a derivation of the 3d Chern-Simons theory from 5d super-Yang-Mills theory using supersymmetric localization, modulo a subtle issue that we discuss.
Quantum quench in non-relativistic fermionic field theory: harmonic traps and 2d string theory
Authors: Das Sumit R. , Hampton Shaun , Liu Sinong
Published: August 2019

Abstract

We investigate a class of exactly solvable quantum quench protocols with a finite quench rate in systems of one dimensional non-relativistic fermions in external harmonic oscillator or inverted harmonic oscillator potentials, with time dependent masses and frequencies. These hamiltonians arise, respectively, in harmonic traps, and the c = 1 Matrix Model description of two dimensional string theory with time dependent string coupling. We show how the dynamics is determined by a single function of time which satisfies a generalized Ermakov-Pinney equation. The quench protocols we consider asymptote to constant masses and frequencies at early times, and cross or approach a gapless potential. In a right side up harmonic oscillator potential we determine the scaling behavior of the one point function and the entanglement entropy of a subregion by obtaining analytic approximations to the exact answers. The results are consistent with Kibble-Zurek scaling for slow quenches and with perturbation calculations for fast quenches. For cis-critical quench protocols the entanglement entropy oscillates at late times around its initial value. For end-critical protocols the entanglement entropy monotonically goes to zero inversely with time, reflecting the spread of fermions over the entire line. For the inverted harmonic oscillator potential, the dual collective field description is a scalar field in a time dependent metric and dilaton background.
Notes on the D = 11 pure spinor superparticle
Authors: Berkovits Nathan , Casali Eduardo , Guillen Max , Mason Lionel
Published: August 2019

Abstract

The D = 11 pure spinor superparticle has been shown to describe linearized D = 11supergravityinamanifestlycovariantway. Anumberofauthorshaveproposedthat its correlation functions be used to compute amplitudes. The use of the scalar structure of the eleven-dimensional pure spinor top cohomology introduces a natural measure for computing such correlation functions. This prescription requires the construction of ghost number one and zero vertex operators. In these notes, we construct explicitly a ghost number one vertex operator but show the incompatibiliy of a ghost number zero vertex operator satisfying a standard descent equation for D = 11 supergravity.
The Effect of Die Bearing Geometry on Surface Recrystallization During Extrusion of an Al-Mg-Si-Mn Alloy
Authors: Mahmoodkhani Y. , Chen J. , Wells M. A. , Poole W. J. , Parson N. C.
Published: August 2019

The formation of large surface grains known as peripheral coarse grains (PCG) is an undesirable feature commonly observed in extruded medium-strength Al-Mg-Si alloys produced for many applications including automotive. The objective of this study was to evaluate factors contributing to the formation of PCG layers, particularly the die bearing geometry, with the goal of developing strategies to eliminate or reduce this phenomenon. This was accomplished using a combination of extrusion trials and finite element method simulations to characterize the role of die bearing geometry on the formation of surface microstructure during the extrusion of an Al-Mg-Si-Mn alloy. The extrusion trials were conducted using two die bearing geometries, (i) a zero bearing die and (ii) a choke die using an extrusion temperature of 480 °C and ram velocities of 20 to 30 mm/s. Axisymmetric extrusion was conducted with an extrusion ratio of 16.5. During the extrusion trials, partially extruded billets were extracted from the extrusion press and water quenched in order to follow the evolution of the surface microstructure for the different bearing geometries. In addition, ram motion was arrested in the middle of the extruded length, held for 5 seconds and then resumed to investigate the role of changing the deformation conditions of the surface on the extruded microstructure. Optical microscopy and electron back-scattered scanning diffraction (EBSD) were used to quantify the microstructure and crystallographic texture of the extrudates and partially extruded billets at different spatial locations. A finite element (FE) mathematical model using the commercial software package DEFORM 2D was also developed to simulate the extrusion process so that loads, temperatures, and material flow patterns could be predicted. The FE model was used to track material flow streamlines close to the surface. Specific locations along these streamlines were then selected for EBSD analysis on the partially extruded billets. The results indicate that the major factor affecting the formation of the PCG layer is the local stored energy of the near surface material which in turn is a function of the details of the die bearing geometry.
New Biharmonic Functions on the Compact Lie Groups $$\mathbf{SO}(n)$$, $$\mathbf{SU}(n)$$, $$\mathbf{Sp}(n)$$
Authors: Gudmundsson Sigmundur , Siffert Anna
Published: August 2019

We develop a new scheme for the construction of explicit complex-valued proper biharmonic functions on Riemannian Lie groups. We exploit this and manufacture many infinite series of uncountable families of new solutions on the special unitary group $$\mathbf{SU}(n)$$

SU
(
n
)

. We then show that the special orthogonal group $$\mathbf{SO}(n)$$

SO
(
n
)

and the quaternionic unitary group $$\mathbf{Sp}(n)$$

Sp
(
n
)

fall into the scheme. As a by-product we obtain new harmonic morphisms on these groups. All the constructed maps are defined on open and dense subsets of the corresponding spaces.
Spacelike Mean Curvature Flow
Authors: Lambert Ben , Lotay Jason D.
Published: August 2019

We prove long-time existence and convergence results for spacelike solutions to mean curvature flow in the pseudo-Euclidean space$$\mathbb {R}^{n,m}$$Rn,m, which are entire or defined on bounded domains and satisfying Neumann or Dirichlet boundary conditions. As an application, we prove long-time existence and convergence of the$${{\,\mathrm{G}\,}}_2$$G2-Laplacian flow in cases related to coassociative fibrations.
Organic petrography, Rock–Eval pyrolysis and biomarker geochemistry of Maastrichtian Gombe Formation, Gongola Basin, Nigeria
Authors: Jimoh Ayoola Y. , Ojo Olusola J. , Akande Samuel O.
Published: August 2019

The Maastrichtian Gombe Formation is located within one of the inland basins of Nigeria (Gongola Basin). Surface and borehole samples of coal and interbedded shale of this formation were evaluated to determine the organic matter richness, quality, maturity, source and depositional environment through organic geochemical techniques such as total organic carbon (TOC) determination, Rock–Eval pyrolysis, chromatography and organic petrography. The genetic potential and average TOC value of the coals, shales and coaly shales are 38.03 wt%, 3.14 wt% and 12.1 wt%, respectively, indicating moderate-to-good source potential. HIs are less than 200 mgHC/gTOC for all the samples indicating Type III kerogen for most of the samples (gas prone) and plant contributions from terrestrial sources. The source rocks were characterized by high molecular weight n-alkanes which range from C10–C41 in the coals and C9–C41 in the shales. The n-alkanes distributions in the coals maximize at C29 indicating terrestrial sourced organic matter, while the shales maximize at C16 and C29 indicating mixed sources. Pr/Ph of the coals and shales ranges from (2.15–3.51) to (0.95–2.37), respectively, suggesting fluvio-deltaic deltaic and coastal swamp depositional environments. The predominance of pristane over phytane suggests humic origin of the organic matter. The sterane/hopane values (< 0.6) indicate incorporation of bacterial inputs commonly associated with terrigenous organic matter in the coals. The CPI is greater than unity, Tmax is generally < 435 °C and vitrinite reflectance less than 0.55 Ro for most of the samples and suggest the samples are of low maturity status to expel liquid hydrocarbon.
One-dimensional model of turbulent flow of non-Newtonian drilling mud in non-prismatic channels
Authors: Welahettige Prasanna , Lundberg Joachim , Bjerketvedt Dag , Lie Bernt , Vaagsaether Knut
Published: August 2019

One-dimensional model of non-Newtonian turbulent flow in a non-prismatic channel is challenging due to the difficulty of accurately accounting for flow properties in the 1-D model. In this study, we model the 1-D Saint–Venant system of shallow water equations for water-based drilling mud (non-Newtonian) in open Venturi channels for steady and transient conditions. Numerically, the friction force acting on a fluid in a control volume can be subdivided, in the 1-D drilling mud modelling and shallow water equations, into two terms: external friction and internal friction. External friction is due to the wall boundary effect. Internal friction is due to the non-Newtonian viscous effect. The internal friction term can be modelled using pure non-Newtonian viscosity models, and the external friction term using Newtonian wall friction models. Experiments were carried out using a water-based drilling fluid in an open Venturi channel. Density, viscosity, flow depth, and flow rate were experimentally measured. The developed approach used to solve the 1-D non-Newtonian turbulence model in this study can be used for flow estimation in oil well return flow.
Self‐compassion as mediator between coping and social anxiety in late adolescence: A longitudinal analysis
Authors: Ștefan Catrinel A.
Published: August 2019

Introduction

Previous research uncovered that self‐compassion is related to coping strategies elicited during stressful situations, and might also contribute to less biased perceptions of social situations. Hence, the current study's objective was to investigate longitudinally the mediator role of self‐compassion in the relation between coping and social anxiety in late adolescence, with emphasis on the first months of adjustment to college life.

Methods

The sample included 63 first‐year students (75% women) from Romania with a mean age of 18.76 years. They filled out the Coping Orientation to Problems Experienced Inventory at Time 1 (beginning of the first semester), as well as the Self‐Compassion Scale‐Short Form and the Leibowitz Social Anxiety Scale‐Short Form at both T1 and Time 2 (3 months after the baseline assessment).

Results

The results of the mediation analyses showed that both approach and avoidant coping at T1 exhibited a significant indirect effect on social anxiety levels at T2 through self‐compassion measured at T2 controlling for the effects of gender, self‐compassion and social anxiety at T1. These findings suggested that approach coping increases the likelihood of more compassionate views of oneself, which are likely to contribute to less social anxiety; conversely, avoidant coping decreases self‐compassionate attitudes, which in turn increase social anxiety symptoms.

Conclusions

These results provided added evidence to the fact that during the transition from adolescence to adulthood, teaching college students a more self‐accepting and kind perspective on one's imperfections could play a significant role in preventing and treating social anxiety.
Key factors for the assessment of mobility in advanced dementia: A consensus approach
Authors: Van Ooteghem Karen , Musselman Kristin E. , Mansfield Avril , Gold David , Marcil Meghan N. , Keren Ron , Tartaglia Maria Carmela , Flint Alastair J. , Iaboni Andrea
Published: August 2019

Introduction

Loss of mobility is common in advanced dementia and has important negative consequences related to fall risk, loss of independence, and lack of participation in meaningful activities. The causes of decline are multifactorial, including disease‐specific changes in motor function, behavior, and cognition. To optimize clinical management of mobility, there is a need to better characterize capacity for safe and independent mobility. This study aimed to identify key factors that impact on mobility in dementia.

Methods

Expert input was gathered using a modified Delphi consensus approach. The primary criterion for participation was specialist knowledge in mobility or dementia, either as a clinician or a researcher. Participants rated elements of mobility for importance and feasibility of assessment in advanced dementia and prioritized items for inclusion in a mobility staging tool. Descriptive statistics and qualitative content analysis were used to summarize responses.

Results

Thirty‐six experts completed the first survey with an 80% retention rate over three rounds. One‐third of 61 items reached consensus for being both important and feasible to assess, representing five categories of elements. Items reaching agreement for a staging tool included walking, parkinsonism, gait, impulsivity, fall history, agitation, transfers, and posture control.

Discussion

This study highlights the need for a multidimensional, dementia‐specific approach to mobility assessment. Results have implications for development of assessment methods and management guidelines to support the clinical care of mobility impairment in people with dementia.
In Quest of Calibration Density and Consistency in Hydrologic Modeling: Distributed Parameter Calibration against Streamflow Characteristics
Authors: Yang Yuan , Pan Ming , Beck Hylke E. , Fisher Colby K. , Beighley R. Edward , Kao Shih‐Chieh , Hong Yang , Wood Eric F.
Published: August 2019

Conventional basin‐by‐basin approaches to calibrate hydrologic models are limited to gauged basins and typically result in spatially discontinuous parameter fields. Moreover, the consequent low calibration density in space falls seriously behind the need from present‐day applications like high resolution river hydrodynamic modeling. In this study we calibrated three key parameters of the Variable Infiltration Capacity (VIC) model at every 1/8° grid‐cell using machine learning‐based maps of four streamflow characteristics for the conterminous United States (CONUS), with a total of 52,663 grid‐cells. This new calibration approach, as an alternative to parameter regionalization, applied to ungauged regions too. A key difference made here is that we tried to regionalize physical variables (streamflow characteristics) instead of model parameters whose behavior may often be less well understood. The resulting parameter fields no longer presented any spatial discontinuities and the patterns corresponded well with climate characteristics, such as aridity and runoff ratio. The calibrated parameters were evaluated against observed streamflow from 704/648 (calibration/validation period) small‐to‐medium‐sized catchments used to derive the streamflow characteristics, 3941/3809 (calibration/validation period) small‐to‐medium‐sized catchments not used to derive the streamflow characteristics as well as five large basins. Comparisons indicated marked improvements in bias and Nash‐Sutcliffe efficiency. Model performance was still poor in arid and semiarid regions, which is mostly due to both model structural and forcing deficiencies. Although the performance gain was limited by the relative small number of parameters to calibrate, the study and results here served as a proof‐of‐concept for a new promising approach for fine‐scale hydrologic model calibrations.
Spectral Analysis of River Resistance and Aquifer Diffusivity in a River‐Confined Aquifer System
Authors: Wang Jun‐Zhi , Wörman Anders
Published: August 2019

Hydraulic connections between a river and an adjacent aquifer are controlled by the river resistance and aquifer diffusivity. In this paper, we derive a spectral solution linking the power spectrum of river stage fluctuations to that of the hydraulic head of a confined aquifer by means of a physical scaling factor. The physical scaling factor represents an algebraic expression of the river resistance and aquifer diffusivity and is included in an exact spectral solution derived herein. Statistical measures of the aquifer diffusivity and river resistance are provided by fitting the solution versus observed groundwater hydraulic head obtained at several distances and/or frequencies. At a study site in the middle reach of the Yangtze River and downstream of the Three Gorges Dam in China, we find systematic damping of the hydraulic head variations with distance from the river, which follows a fractal pattern driven by the river stage. In general, the estimated parameters are consistent with results reported in the literature, which supports the validity of the proposed spectral approach, although the paper discusses advantages and limitations due to application conditions.
Six New Satellites Watch the Atmosphere over Earth’s Equator
Authors: Anthes Richard , Schreiner William
Published: August 2019

The FORMOSAT-7/COSMIC-2 constellation, launched this June, will provide the most accurate data yet on tropical weather, climate, and space weather.
Projected Changes in Permafrost Active Layer Thickness Over the Qinghai‐Tibet Plateau Under Climate Change
Authors: Zhao Dongsheng , Wu Shaohong
Published: August 2019

Climate warming would increase the active layer thickness (ALT) of permafrost, which can cause changes in the hydrological cycle, ecological processes, and carbon flux in cold regions. However, changes in permafrost ALT due to climate warming remain poorly quantified, which limits our understanding of environmental change in cold regions. In this study, the Lund‐Postam‐Jena dynamic vegetation model is coupled to the Kudryavtsev model to examine changes in permafrost ALT on the Qinghai‐Tibet Plateau (QTP) under climate change scenarios based on the representative concentration pathways (RCPs). The results suggest that the permafrost ALT on the QTP would exhibit a significant increasing trend under the climate change scenarios, and a large increment of ALT may occur in the northwestern QTP. In the near‐term (2011–2040), the change in ALT on the QTP is different under the RCP2.6, RCP4.5, RCP6.0, and RCP8.5 emissions scenarios, with an increment of 5–30 cm. In the mid‐term (2041–2070), ALT would deepen further with an obvious reduction in permafrost area, while the increase in ALT decreases from south to north. In the long‐term (2071–2099), the average increment of ALT would be greater than 30 cm under the RCP4.5, RCP6.0, and RCP8.5 scenarios, and the increment in ALT increases from south to north, with a remarkable retreat in permafrost area from south to north.
Drivers of Low Instream Large Wood Retention and Imprints of Wood Mobility in Mountain Nonperennial Streams of a Mediterranean Semiarid Environment
Authors: Galia T. , Horáček M. , Macurová T. , Škarpich V.
Published: August 2019

The majority of research on instream large wood (LW) focuses on perennial streams in temperate zones, and much less is known about wood distribution and its driving factors in other environments, such as semiarid bioclimatic regions. In this study, we sought to predict LW retention by assessing reach‐scale variables to infer the influence of external factors on the presence of LW in 37 independent reaches of ephemeral and intermittent streams draining a mountain range in a Mediterranean semiarid environment (Lefka Ori Mountains, Crete, Greece). In addition, we focused on LW pieces that had been mobilized by fluvial transport to find links between wood mobility and the external reach‐scale characteristics of this environment. Markedly low average LW frequency (6.5 LW/100 m) and volume (9.06 m3/ha) were observed in the studied reaches in comparison with streams draining other bioclimatic regions. Only one complex general linear model was found to predict LW volume (including valley confinement and basal area of coniferous trees), and five explanatory variables (elevation as a proxy of annual precipitation, valley type, valley confinement index, basal area of coniferous trees, and basal area of all trees) were significant in separated models predicting LW volume. Only two variables (valley floor width and the basal area of broadleaf trees) were significant in separated models for prediction of LW frequency. The mobilized LW in the studied streams tends to be stored as individual, dispersed pieces rather than in jams, likely due to overall low LW abundance which effectively prevents clustering of wood.