bluuebunny/crossref_metadata_2025 huggingface dataset:
Higgs compositeness in Sp(2N) gauge theories – Determining the low-energy constants with lattice calculations
Authors: Bennett Ed , Ki Hong Deog , Lee Jong-Wan , David Lin C.-J. , Lucini Biagio , Piai Maurizio , Vadacchino Davide
Published: March 2018

As a first step towards a quantitative understanding of the SU(4)/Sp(4) composite Higgs model through lattice calculations, we discuss the low energy effective field theory resulting from the SU(4) → Sp(4) global symmetry breaking pattern. We then consider an Sp(4) gauge theory with two Dirac fermion flavours in the fundamental representation on a lattice, which provides a concrete example of the microscopic realisation of the SU(4)/Sp(4) composite Higgs model. For this system, we outline a programme of numerical simulations aiming at the determination of the low-energy constants of the effective field theory and we test the method on the quenched theory. We also report early results from dynamical simulations, focussing on the phase structure of the lattice theory and a calculation of the lowest-lying meson spectrum at coarse lattice spacing.
Higgs compositeness in Sp(2N) gauge theories — Resymplecticisation, scale setting and topology
Authors: Bennett Ed , Ki Hong Deog , Lee Jong-Wan , David Lin C.-J. , Lucini Biagio , Piai Maurizio , Vadacchino Davide
Published: March 2018

As part of an ongoing programme to study Sp(2N) gauge theories as potential realisations of composite Higgs models, we consider the case of Sp(4) on the lattice, both as a pure gauge theory, and with two Dirac fermion flavors in the fundamental representation. In order to compare results between these two cases and maintain control of lattice artefacts, we make use of the gradient flow to set the scale of the simulations. We present some technical aspects of the simulations, including preliminary results for the scale setting in the two cases and results for the topological charge history.
Higgs compositeness in Sp(2N) gauge theories — The pure gauge model
Authors: Bennett Ed , Ki Hong Deog , Lee Jong-Wan , David Lin C.-J. , Lucini Biagio , Piai Maurizio , Vadacchino Davide
Published: March 2018

As a first step in the study of Sp(2N) composite Higgs models, we obtained a set of novel numerical results for the pure gauge Sp(4) lattice theory in 3+1 space-time dimensions. Results for the continuum extrapolations of the string tension and the glueball mass spectrum are presented and their values are compared with the same quantities in neighbouring SU(N) models.
Spectroscopy of four-dimensional N = 1 supersymmetric SU(3) Yang-Mills theory
Authors: Steinhauser Marc , Sternbeck André , Wellegehausen Björn , Wipf Andreas
Published: March 2018

Supersymmetric gauge theories are an important building block for extensions of the standard model. As a first step towards Super-QCD we investigate the pure gauge sector with gluons and gluinos on the lattice, in particular the low energy mass spectrum: meson-like gluinoballs, gluino-glueballs and pure glueballs. We report on some first calculations performed with clover improved Wilson fermions on rather small lattices. The supersymmetric continuum limit and particle masses are discussed and compared to predictions from effective field theory.
Can a Linear Sigma Model Describe Walking Gauge Theories at Low Energies?
Authors: Gasbarro Andrew
Published: March 2018

In recent years, many investigations of confining Yang Mills gauge theories near the edge of the conformal window have been carried out using lattice techniques. These studies have revealed that the spectrum of hadrons in nearly conformal ("walking") gauge theories differs significantly from the QCD spectrum. In particular, a light singlet scalar appears in the spectrum which is nearly degenerate with the PNGBs at the lightest currently accessible quark masses. This state is a viable candidate for a composite Higgs boson. Presently, an acceptable effective field theory (EFT) description of the light states in walking theories has not been established. Such an EFT would be useful for performing chiral extrapolations of lattice data and for serving as a bridge between lattice calculations and phenomenology. It has been shown that the chiral Lagrangian fails to describe the IR dynamics of a theory near the edge of the conformal window. Here we assess a linear sigma model as an alternate EFT description by performing explicit chiral fits to lattice data. In a combined fit to the Goldstone (pion) mass and decay constant, a tree level linear sigma model has a Χ2/d.o.f. = 0.5 compared to Χ2/d.o.f. = 29.6 from fitting nextto-leading order chiral perturbation theory. When the 0++ (σ) mass is included in the fit, Χ2/d.o.f. = 4.9. We remark on future directions for providing better fits to the σ mass.
Simulations of QCD and QED with C* boundary conditions
Authors: Hansen Martin , Lucini Biagio , Patella Agostino , Tantalo Nazario
Published: March 2018

We present exploratory results from dynamical simulations of QCD in isolation, as well as QCD coupled to QED, with C* boundary conditions. In finite volume, the use of C* boundary conditions allows for a gauge invariant and local formulation of QED without zero modes. In particular we show that the simulations reproduce known results and that masses of charged mesons can be extracted in a completely gauge invariant way. For the simulations we use a modified version of the HiRep code. The primary features of the simulation code are presented and we discuss some details regarding the implementation of C* boundary conditions and the simulated lattice action.

Preprint: CP3-Origins-2017-046 DNRF90, CERN-TH-2017-214
Single flavour filtering for RHMC in BQCD
Authors: Kamleh Waseem , Haar Taylor , Nakamura Yoshifumi , Zanotti James M.
Published: March 2018

Filtering algorithms for two degenerate quark flavours have advanced to the point that, in 2+1 flavour simulations, the cost of the strange quark is significant compared with the light quarks. This makes efficient filtering algorithms for single flavour actions highly desirable, in particular when considering 1+1+1 flavour simulations for QED+QCD. Here we discuss methods for filtering the RHMC algorithm that are implemented within BQCD, an open-source Fortran program for Hybrid Monte Carlo simulations.
Portable LQCD Monte Carlo code using OpenACC
Authors: Bonati Claudio , Calore Enrico , Coscetti Simone , D’Elia Massimo , Mesiti Michele , Negro Francesco , Fabio Schifano Sebastiano , Silvi Giorgio , Tripiccione Raffaele
Published: March 2018

Varying from multi-core CPU processors to many-core GPUs, the present scenario of HPC architectures is extremely heterogeneous. In this context, code portability is increasingly important for easy maintainability of applications; this is relevant in scientific computing where code changes are numerous and frequent. In this talk we present the design and optimization of a state-of-the-art production level LQCD Monte Carlo application, using the OpenACC directives model. OpenACC aims to abstract parallel programming to a descriptive level, where programmers do not need to specify the mapping of the code on the target machine. We describe the OpenACC implementation and show that the same code is able to target different architectures, including state-of-the-art CPUs and GPUs.
Plasmon mass scale and quantum fluctuations of classical fields on a real time lattice
Authors: Kurkela Aleksi , Lappi Tuomas , Peuron Jarkko
Published: March 2018

Classical real-time lattice simulations play an important role in understanding non-equilibrium phenomena in gauge theories and are used in particular to model the prethermal evolution of heavy-ion collisions. Above the Debye scale the classical Yang-Mills (CYM) theory can be matched smoothly to kinetic theory. First we study the limits of the quasiparticle picture of the CYM fields by determining the plasmon mass of the system using 3 different methods. Then we argue that one needs a numerical calculation of a system of classical gauge fields and small linearized fluctuations, which correspond to quantum fluctuations, in a way that keeps the separation between the two manifest. We demonstrate and test an implementation of an algorithm with the linearized fluctuation showing that the linearization indeed works and that the Gauss’s law is conserved.
Truncation of lattice N = 4 super Yang-Mills
Authors: Giedt Joel , Catterall Simon , Jha Raghav Govind
Published: March 2018

In twisted and orbifold formulations of lattice N = 4 super Yang-Mills, the gauge group is necessarily U(1) × SU(N), in order to be consistent with the exact scalar supersymmetry Q. In the classical continuum limit of the theory, where one expands the link fields around a point in the moduli space and sends the lattice spacing to zero, the diagonal U(1) modes decouple from the SU(N) sector, and give an uninteresting free theory. However, lattice artifacts (described by irrelevant operators according to naive power-counting) couple the two sectors, so removing the U(1) modes is a delicate issue. We describe how this truncation to an SU(N) gauge theory can be obtained in a systematic way, with violations of Q that fall off as powers of 1=N2. We are able to achieve this while retaining exact SU(N) lattice gauge symmetry at all N, and provide both theoretical arguments and numerical evidence for the 1=N2 suppression of Q violation.
4D N = 1 SYM supercurrent on the lattice in terms of the gradient flow
Authors: Hieda Kenji , Kasai Aya , Makino Hiroki , Suzuki Hiroshi
Published: March 2018

The gradient flow [1–5] gives rise to a versatile method to construct renor-malized composite operators in a regularization-independent manner. By adopting this method, the authors of Refs. [6–9] obtained the expression of Noether currents on the lattice in the cases where the associated symmetries are broken by lattice regularization. We apply the same method to the Noether current associated with supersymmetry, i.e., the supercurrent. We consider the 4D N = 1 super Yang–Mills theory and calculate the renormalized supercurrent in the one-loop level in the Wess–Zumino gauge. We then re-express this supercurrent in terms of the flowed gauge and flowed gaugino fields [10].
Loop-TNR analysis of CP(1) model with theta term
Authors: Kawauchi Hikaru , Takeda Shinji
Published: March 2018

The phase structure of the two dimensional lattice CP(1) model in the presence of the θ term is analyzed by tensor network methods. The tensor renormalization group, which is a standard renormalization method of tensor networks, is used for the regions θ = 0 and θ ≠ 0. Loop-TNR, which is more suitable for the analysis of near criticality, is also implemented for the region θ = 0. The application of Loop-TNR for the region θ ≠ 0 is left for future work.
On a modification method of Lefschetz thimbles
Authors: Tsutsui Shoichiro , Doi Takahiro M.
Published: March 2018

The QCD at finite density is not well understood yet, where standard Monte Carlo simulation suffers from the sign problem. In order to overcome the sign problem, the method of Lefschetz thimble has been explored. Basically, the original sign problem can be less severe in a complexified theory due to the constancy of the imaginary part of an action on each thimble. However, global phase factors assigned on each thimble still remain. Their interference is not negligible in a situation where a large number of thimbles contribute to the partition function, and this could also lead to a sign problem. In this study, we propose a method to resolve this problem by modifying the structure of Lefschetz thimbles such that only a single thimble is relevant to the partition function. It can be shown that observables measured in the original and modified theories are connected by a simple identity. We exemplify that our method works well in a toy model.
Satisfying positivity requirement in the Beyond Complex Langevin approach
Authors: Wyrzykowski Adam , Ruba Błażej Ruba
Published: March 2018

The problem of finding a positive distribution, which corresponds to a given complex density, is studied. By the requirement that the moments of the positive distribution and of the complex density are equal, one can reduce the problem to solving the matching conditions. These conditions are a set of quadratic equations, thus Groebner basis method was used to find its solutions when it is restricted to a few lowest-order moments. For a Gaussian complex density, these approximate solutions are compared with the exact solution, that is known in this special case.
Instanton-dyon ensembles reproduce deconfinement and chiral
restoration phase transitions
Authors: Shuryak Edward
Published: March 2018

Paradigm shift in gauge topology at finite temperatures, from the instantons to their constituents – instanton-dyons – has recently lead to studies of their ensembles and very significant advances. Like instantons, they have fermionic zero modes, and their collectivization at suffciently high density explains the chiral symmetry breaking transition. Unlike instantons, these objects have electric and magnetic charges. Simulations of the instanton-dyon ensembles have demonstrated that their back reaction on the Polyakov line modifies its potential and generates the deconfinement phase transition. For the Nc = 2 gauge theory the transition is second order, for QCD-like theory with Nc = 2 and two light quark flavors Nf = 2 both transitions are weak crossovers at happening at about the same condition. Introduction of quark-flavor-dependent periodicity phases (imaginary chemical potentials) leads to drastic changes in both transitions. In particulaly, in the so called Z(Nc) – QCD model the deconfinement transforms to strong first order transition, while the chiral condensate does not disappear at all. The talk will also cover more detailed studies of correlations between the dyons, effective eta’ mass and other screening masses.
On the zero-crossing of the three-gluon Green’s function from lattice simulations
Authors: Athenodorou Andreas , Boucaud Philippe , de Soto Feliciano , Rodríguez-Quintero José , Zafeiropoulos Savvas
Published: March 2018

We report on some efforts recently made in order to gain a better understanding of some IR properties of the 3-point gluon Green’s function by exploiting results from large-volume quenched lattice simulations. These lattice results have been obtained by using both tree-level Symanzik and the standard Wilson action, in the aim of assessing the possible impact of effects presumably resulting from a particular choice for the discretization of the action. The main resulting feature is the existence of a negative log-aritmic divergence at zero-momentum, which pulls the 3-gluon form factors down at low momenta and, consequently, yields a zero-crossing at a given deep IR momentum. The results can be correctly explained by analyzing the relevant Dyson-Schwinger equations and appropriate truncation schemes.
|Vus| determination from inclusive strange tau decay and lattice HVP
Authors: Boyle Peter , Hudspith Renwick James , Izubuchi Taku , Jüttner Andreas , Lehner Christoph , Lewis Randy , Maltman Kim , Ohki Hiroshi , Portelli Antonin , Spraggs Matthew
Published: March 2018

We propose and apply a novel approach to determining |Vus| which uses inclusive strange hadronic tau decay data and hadronic vacuum polarization functions (HVPs) computed on the lattice. The experimental and lattice data are related through dispersion relations which employ a class of weight functions having poles at space-like momentum. Implementing this approach using lattice data generated by the RBC/UKQCD collaboration, we show examples of weight functions which strongly suppress spectral integral contributions from the region where experimental data either have large uncertainties or do not exist while at the same time allowing accurate determinations of relevant lattice HVPs. Our result for |Vus| is in good agreement with determinations from K physics and 3-family CKM unitarity. The advantages of the new approach over the conventional sum rule analysis will be discussed.
Semileptonic B-meson decays to light pseudoscalar mesons on the HISQ ensembles
Authors: Gelzer Zechariah , Bernard C. , Tar C. De , El-Khadra AX , Gámiz E. , Gottlieb Steven , Kronfeld Andreas S. , Liu Yuzhi , Meurice Y. , Simone J.N. , Toussaint D. , Water R.S. Van de , Zhou R.
Published: March 2018

We report the status of an ongoing lattice-QCD calculation of form factors for exclusive semileptonic decays of B mesons with both charged currents (B → πlv, Bs → Klv) and neutral currents (B → πl+l-, B → Kl+l-). The results are important for constraining or revealing physics beyond the Standard Model. This work uses MILC’s (2+1 + 1)-flavor ensembles with the HISQ action for the sea and light valence quarks and the clover action in the Fermilab interpretation for the b quark. Simulations are carried out at three lattice spacings down to 0.088 fm, with both physical and unphysical sea-quark masses. We present preliminary results for correlation-function fits.
HQET form factors for Bs → Klv decays beyond leading order
Authors: Banerjee Debasish , Koren Mateusz , Simma Hubert , Sommer Rainer
Published: March 2018

We compute semi-leptonic Bs decay form factors using Heavy Quark Effective Theory on the lattice. To obtain good control of the 1 /mb expansion, one has to take into account not only the leading static order but also the terms arising at O (1/mb): kinetic, spin and current insertions. We show results for these terms calculated through the ratio method, using our prior results for the static order. After combining them with non-perturbative HQET parameters they can be continuum-extrapolated to give the QCD form factor correct up to O (1/[see formula in PDF]) corrections and without O (αs(mb)n) corrections.
Renormalization of Supersymmetric QCD on the Lattice
Authors: Costa Marios , Panagopoulos Haralambos
Published: March 2018

We perform a pilot study of the perturbative renormalization of a Supersymmetric gauge theory with matter fields on the lattice. As a specific example, we consider Supersymmetric N=1 QCD (SQCD). We study the self-energies of all particles which appear in this theory, as well as the renormalization of the coupling constant. To this end we compute, perturbatively to one-loop, the relevant two-point and three-point Green’s functions using both dimensional and lattice regularizations. Our lattice formulation involves theWilson discretization for the gluino and quark fields; for gluons we employ the Wilson gauge action; for scalar fields (squarks) we use naive discretization. The gauge group that we consider is SU(Nc), while the number of colors, Nc, the number of flavors, Nf, and the gauge parameter, α, are left unspecified. We obtain analytic expressions for the renormalization factors of the coupling constant (Zg) and of the quark (ZΨ), gluon (Zu), gluino (Zλ), squark (ZA±), and ghost (Zc) fields on the lattice. We also compute the critical values of the gluino, quark and squark masses. Finally, we address the mixing which occurs among squark degrees of freedom beyond tree level: we calculate the corresponding mixing matrix which is necessary in order to disentangle the components of the squark field via an additional finite renormalization.
Proton mass decomposition
Authors: Yang Yi-Bo , Chen Ying , Draper Terrence , Liang Jian , Liu Keh-Fei
Published: March 2018

We report the results on the proton mass decomposition and also on the related quark and glue momentum fractions. The results are based on overlap valence fermions on four ensembles of Nf = 2 + 1 DWF configurations with three lattice spacings and volumes, and several pion masses including the physical pion mass. With 1-loop pertur-bative calculation and proper normalization of the glue operator, we find that the u, d, and s quark masses contribute 9(2)% to the proton mass. The quark energy and glue field energy contribute 31(5)% and 37(5)% respectively in the MS scheme at µ = 2 GeV. The trace anomaly gives the remaining 23(1)% contribution. The u, d, s and glue momentum fractions in the MS scheme are consistent with the global analysis at µ = 2 GeV.
Berezinskii-Kosterlitz-Thouless phase transition from lattice sine-Gordon model
Authors: Giedt Joel , Flamino James
Published: March 2018

We obtain nonperturbative results on the sine-Gordon model using the lattice field technique. In particular, we employ the Fourier accelerated hybrid Monte Carlo algorithm for our studies. We find the critical temperature of the theory based autocorrelation time, as well as the finite size scaling of the “thickness” observable used in an earlier lattice study by Hasenbusch et al.
Charmonia in moving frames
Authors: Prelovsek S. , Bali G. , Collins S. , Mohler D. , Padmanath M. , Piemonte S. , Weishaeupl S.
Published: March 2018

Lattice simulation of charmonium resonances with non-zero momentum provides additional information on the two-meson scattering matrices. However, the reduced rotational symmetry in a moving frame renders a number of states with different JP in the same lattice irreducible representation. The identification of JP for these states is particularly important, since quarkonium spectra contain a number of states with different JP in a relatively narrow energy region. Preliminary results concerning spin-identification are presented in relation to our study of charmonium resonances in flight on the Nf = 2 + 1 CLS ensembles.
Update on ɛK with lattice QCD inputs
Authors: Jang Yong-Chull , Lee Weonjong , Lee Sunkyu , Leem Jaehoon
Published: March 2018

We report updated results for ɛK, the indirect CP violation parameter in neutral kaons, which is evaluated directly from the standard model with lattice QCD inputs. We use lattice QCD inputs to fix [see formula in PDF], and mc(mc). Since Lattice 2016, the UTfit group has updated the Wolfenstein parameters in the angle-only-fit method, and the HFLAV group has also updated |Vcb|. Our results show that the evaluation of ɛK with exclusive |Vcb| (lattice QCD inputs) has 4.0σ tension with the experimental value, while that with inclusive |Vcb| (heavy quark expansion based on OPE and QCD sum rules) shows no tension.
Topological susceptibility with a single light quark flavour
Authors: Frison Julien , Kitano Ryuichiro , Yamada Norikazu
Published: March 2018

One of the historical suggestions to tackle the strong CP problem is to take the up quark mass to zero while keeping md finite. The θ angle is then supposed to become irrelevant, i.e. the topological susceptibility vanishes. However, the definition of the quark mass is scheme-dependent and identifying the mu = 0 point is not trivial, in particular with Wilson-like fermions. More specifically, up to our knowledge there is no theoretical argument guaranteeing that the topological susceptibility exactly vanishes when the PCAC mass does.

We will present our recent progresses on the empirical check of this property using Nf = 1 + 2 flavours of clover fermions, where the lightest fermion is tuned very close to [see formula in PDF] and the mass of the other two is kept of the order of magnitude of the physical ms. This choice is indeed expected to amplify any unknown non-perturbative effect caused by mu ≠ md. The simulation is repeated for several βs and those results, although preliminary, give a hint about what happens in the continuum limit.
Alternatives to the stochastic “noise vector” approach
Authors: de Forcrand Philippe , Jäger Benjamin
Published: March 2018

Several important observables, like the quark condensate and the Taylor coefficients of the expansion of the QCD pressure with respect to the chemical potential, are based on the trace of the inverse Dirac operator and of its powers. Such traces are traditionally estimated with “noise vectors” sandwiching the operator. We explore alternative approaches based on polynomial approximations of the inverse Dirac operator.
SU(3) Yang Mills theory at small distances and fine lattices
Authors: Husung Nikolai , Koren Mateusz , Krah Philipp , Sommer Rainer
Published: March 2018

We investigate the SU(3) Yang Mills theory at small gradient flow time and at short distances. Lattice spacings down to a = 0.015 fm are simulated with open boundary conditions to allow topology to flow in and out. We study the behaviour of the action density E(t) close to the boundaries, the feasibility of the small flow-time expansion and the extraction of the Λ-parameter from the static force at small distances. For the latter, significant deviations from the 4-loop perturbative β-function are visible at α ≈ 0.2. We still can extrapolate to extract roΛ.
Verification of real-time WSA−ENLIL+Cone simulations of CME arrival-time at the CCMC from 2010 to 2016
Authors: Wold Alexandra M. , Mays M. Leila , Taktakishvili Aleksandre , Jian Lan K. , Odstrcil Dusan , MacNeice Peter
Published: March 2018

The Wang-Sheeley-Arge (WSA)−ENLIL+Cone model is used extensively in space weather operations world-wide to model coronal mass ejection (CME) propagation. As such, it is important to assess its performance. We present validation results of the WSA−ENLIL+Cone model installed at the Community Coordinated Modeling Center (CCMC) and executed in real-time by the CCMC space weather team. CCMC uses the WSA−ENLIL+Cone model to predict CME arrivals at NASA missions throughout the inner heliosphere. In this work we compare model predicted CME arrival-times to in situ interplanetary coronal mass ejection leading edge measurements at Solar TErrestrial RElations Observatory-Ahead (STEREO-A), Solar TErrestrial RElations Observatory-Behind (STEREO-B), and Earth (Wind and ACE) for simulations completed between March 2010 and December 2016 (over 1,800 CMEs). We report hit, miss, false alarm, and correct rejection statistics for all three locations. For all predicted CME arrivals, the hit rate is 0.5, and the false alarm rate is 0.1. For the 273 events where the CME was predicted to arrive at Earth, STEREO-A, or STEREO-B, and was actually observed (hit event), the mean absolute arrival-time prediction error was 10.4 ± 0.9 h, with a tendency to early prediction error of −4.0 h. We show the dependence of the arrival-time error on CME input parameters. We also explore the impact of the multi-spacecraft observations used to initialize the model CME inputs by comparing model verification results before and after the STEREO-B communication loss (since September 2014) and STEREO-A sidelobe operations (August 2014–December 2015). There is an increase of 1.7 h in the CME arrival time error during single, or limited two-viewpoint periods, compared to the three-spacecraft viewpoint period. This trend would apply to a future space weather mission at L5 or L4 as another coronagraph viewpoint to reduce CME arrival time errors compared to a single L1 viewpoint.
Acute Cellular Rejection: Is It Still Relevant?
Authors: Koutsokera Angela , Levy Liran , Pal Prodipto , Orchanian-Cheff Ani , Martinu Tereza
Published: March 2018

Despite significant progress in the field of transplant immunology, acute cellular rejection (ACR) remains a very frequent complication after lung transplantation (LTx), with almost 30% of LTx recipients experiencing at least one episode of treated ACR during the first year of follow-up. Most episodes respond to the first-line immunosuppressive treatment and are rarely a direct cause of death. However, the association of ACR with later adverse outcomes, such as chronic lung allograft dysfunction, bronchial stricture, and infectious complications associated with the intensification of immunosuppression, negatively impacts long-term survival. The burden imposed on patients and health-care resources is even higher in cases of refractory or recurrent ACR, which accelerates lung function decline. Although important laboratory and clinical research conducted over the last two decades has improved our understanding of the mechanisms underlying ACR, there are still many uncertainties about the risk factors for ACR, the optimal monitoring strategies, and the prediction of long-term outcomes. These knowledge gaps contribute to the large variability in clinical practice among LTx centers, which renders multicenter studies of ACR challenging. In this review, we summarize current evidence on the epidemiology, pathogenesis, and risk factors of ACR. We describe diagnostic and therapeutic approaches that are currently used in the clinical practice and also review promising diagnostic tools that are under investigation. Associations between ACR and other adverse outcomes of LTx are examined. Finally, within each topic of discussion, we highlight the main areas of controversy and opportunities for future research.
Fungal Infections Complicating Lung Transplantation
Authors: Clark Nina , Weigt S. , Fishbein Michael , Kubak Bernard , Belperio John , Lynch Joseph
Published: March 2018

Lung transplantation is an increasingly utilized modality for treating advanced lung disease. However, lung transplant recipients (LTRs) experience high rates of infection-related mortality and, compared with other solid organ transplant recipients, are at increased risk of infectious complications given the intensity of immunosuppression employed, the presence of airway abnormalities after surgery and exposure of the allograft to the environment. Fungal infections, particularly mold infections, are problematic after transplantation as they are often associated with limited treatment options and poor outcomes. We describe the non-Candida fungal infections occurring in LTRs, including their epidemiology, clinical features, and treatment.
Chronic Lung Allograft Dysfunction: Evolving Concepts and Therapies
Authors: DerHovanessian Ariss , Wallace W. , Lynch Joseph , Belperio John , Weigt S.
Published: March 2018

Lung transplantation has become an established therapeutic option for a variety of end-stage lung diseases. Technical advances in graft procurement, implantation, perioperative care, immunosuppression, and posttransplant medical management have led to significant improvements in 1-year survival, but outcomes after the first year have improved minimally over the last two decades. The main limitation to better long-term survival after lung transplantation is chronic lung allograft dysfunction (CLAD). CLAD also impairs quality of life and increases the costs of medical care. Our understanding of CLAD manifestations, risk factors, and mechanisms is rapidly evolving. Recognition of different CLAD phenotypes (e.g., bronchiolitis obliterans syndrome and restrictive allograft syndrome) and the unique pathogenic mechanisms will be important for developing novel therapies. In addition to alloimmune-mediated rejection, we now recognize the importance of alloimmune-independent mechanisms of injury to the allograft. CLAD is the consequence of dysregulated repair of allograft injury. Unfortunately, currently available therapies for CLAD are usually not effective. However, the advances in knowledge, reviewed in this manuscript, should lead to novel strategies for CLAD prevention and treatment, as well as improvement in long-term outcomes after lung transplantation. We provide an overview of the evolving terminology related to CLAD, its varying clinical phenotypes and their diagnosis, natural history, pathogenesis, and potential treatments.
Homeopathy for Perennial Asthma in Adolescents: Pilot Feasibility Study Testing a Randomised Withdrawal Design
Authors: Mitchiguian Hotta Livia , de Toledo Cesar Amarilys , Martinez Edson , Demarzo Marcelo , Cardinalli Adler Ubiratan
Published: March 2018

Introduction Previous findings from a pragmatic trial suggest that usual care compared with usual care plus individualised homeopathy is not a feasible design to address homeopathic interventions for asthma.

Objective The main purpose of this article was to investigate the feasibility of the randomised withdrawal design as a strategy to assess the effectiveness of a standardised clinical–pharmaceutical homeopathic protocol (Organon.modus) on perennial asthma in adolescents.

Methods Randomised withdrawal, double-blind, parallel, placebo-controlled, 12-week study. Patients: 12 to 17 years old adolescents, with the diagnosis of perennial asthma, using inhalatory beclomethasone (plus fenoterol for wheezing episodes), who achieved 3 months of well-controlled asthma, after a variable period of individualised homeopathic treatment according to Organon.modus protocol. Setting: a secondary care medical specialist centre. Intervention: continuation with the individualised homeopathic medicine or with indistinguishable placebo during 12 weeks of beclomethasone step-down. Primary outcome: number of days of well-controlled asthma. Secondary measures: number of days of fenoterol use, number of visits to an emergency service (without hospitalisation) and percentage of patients excluded due to an exacerbation characterising a partly controlled asthma. Tolerability was assessed by Adverse Events, registered at every visit.

Results Nineteen patients were randomised to continue treatment with homeopathy and 21 with placebo. Effectiveness measures for the homeopathy and placebo groups respectively were median number of days of good clinical control: 84 versus 30 (p = 0.18); median number of days of fenoterol use per patient: 3 versus 5 (p = 0.41); visits to an emergency room: 1 versus 6 (p = 0.35); percentage of exclusion due to partly controlled asthma: 36.8% versus 71.4% (p = 0.05). Few Adverse Events were reported.

Conclusions This pilot study supports the feasibility of the double-blind randomised withdrawal design in studies investigating homeopathy on teenage asthma, when performed by specialists following a standardised clinical–pharmaceutical homeopathic protocol.

Clinical Trial Registration RBR-6XTS8Z.
Risk Factors for Neonatal Hypoxic-Ischemic Encephalopathy in the Absence of Sentinel Events
Authors: Eke Ahize , Ozen Maide , Burd Irina , Graham Ernest , Novak Christopher
Published: March 2018

Objective Hypoxic-ischemic encephalopathy (HIE) may be associated with intrapartum sentinel events or may be unexplained. We sought to identify risk factors for unexplained HIE cases and compare their morbidity and mortality to cases associated with sentinel events.

Study Design Retrospective cohort study of all neonates admitted with suspected HIE treated with whole-body hypothermia from January 2007 through July 2017. Cases of unexplained HIE were compared with those with a sentinel event.

Results A total of 223 neonates met the inclusion criteria, of which 86 (38.6%) experienced a sentinel event and 137 (61.4%) did not. Placental histopathology was performed for 28/31 (90.3%) and 48/53 (90.6%) inborn neonates with and without sentinel events, respectively. Placentas from unexplained HIE cases more often exhibited histologic chorioamnionitis (43.8% vs. 17.9%, p = 0.02) and funisitis (25% vs. 3.6%, p = 0.02). Neonatal morbidity and mortality were similar. On multivariable regression, nulliparity (odds ratio [OR], 4.11, 95% confidence interval [CI]: 1.24–13.62) and histologic funisitis (OR, 20.33, 95% CI: 1.11–373.4) remained significant.

Conclusion Other than nulliparity and infection which could be identified on umbilical cord examination following delivery but not on clinical assessment prior to delivery, there are no other identifiable risk factors for HIE in the absence of a sentinel event, and morbidity and mortality are similar between groups.
Mapping the Values of IoT
Authors: Nicolescu Razvan , Huth Michael , Radanliev Petar , De Roure David
Published: March 2018

We investigate the emerging meanings of “value” associated with the Internet of Things. Given the current political economy, we argue that the multiple meanings of “value” cannot be reduced to a single domain or discipline, but rather they are invariably articulated at the juxtaposition of three domains: social, economic, and technical. We analyse each of these domains and present domain challenges and cross-domain implications – drawing from an interdisciplinary literature review and gap analysis across sources from academia, business, and governments. We propose a functional model that aggregates these findings into a value-driven logic of the emerging global political economy enabled by digital technology in general and IoT in particular. These conceptual contributions highlight the critical need for an interdisciplinary understanding of the meaning of “value”, so that IoT services and products will create and sustain such concurrent meanings during their entire lifecycle, from design to consumption and retirement or recycling.
Novel strategy to implement active-space coupled-cluster methods
Authors: Rolik Zoltán , Kállay Mihály
Published: March 2018

A new approach is presented for the efficient implementation of coupled-cluster (CC) methods including higher excitations based on a molecular orbital space partitioned into active and inactive orbitals. In the new framework, the string representation of amplitudes and intermediates is used as long as it is beneficial, but the contractions are evaluated as matrix products. Using a new diagrammatic technique, the CC equations are represented in a compact form due to the string notations we introduced. As an application of these ideas, a new automated implementation of the single-reference-based multi-reference CC equations is presented for arbitrary excitation levels. The new program can be considered as an improvement over the previous implementations in many respects; e.g., diagram contributions are evaluated by efficient vectorized subroutines. Timings for test calculations for various complete active-space problems are presented. As an application of the new code, the weak interactions in the Be dimer were studied.
Dianion diagnostics in DESIREE: High-sensitivity detection of Cn2− from a sputter ion source
Authors: Chartkunchand K. C. , Stockett M. H. , Anderson E. K. , Eklund G. , Kristiansson M. K. , Kamińska M. , de Ruette N. , Blom M. , Björkhage M. , Källberg A. , Löfgren P. , Reinhed P. , Rosén S. , Simonsson A. , Zettergren H. , Schmidt H. T. , Cederquist H.
Published: March 2018

A sputter ion source with a solid graphite target has been used to produce dianions with a focus on carbon cluster dianions, Cn2−, with n = 7–24. Singly and doubly charged anions from the source were accelerated together to kinetic energies of 10 keV per atomic unit of charge and injected into one of the cryogenic (13 K) ion-beam storage rings of the Double ElectroStatic Ion Ring Experiment facility at Stockholm University. Spontaneous decay of internally hot Cn2− dianions injected into the ring yielded Cn− anions with kinetic energies of 20 keV, which were counted with a microchannel plate detector. Mass spectra produced by scanning the magnetic field of a 90° analyzing magnet on the ion injection line reflect the production of internally hot C72− – C242− dianions with lifetimes in the range of tens of microseconds to milliseconds. In spite of the high sensitivity of this method, no conclusive evidence of C62− was found while there was a clear C72− signal with the expected isotopic distribution. This is consistent with earlier experimental studies and with theoretical predictions. An upper limit is deduced for a C62− signal that is two orders-of-magnitude smaller than that for C72−. In addition, CnO2− and CnCu2− dianions were detected.
The influence of gas pressure on E↔H mode transition in argon inductively coupled plasmas
Authors: Zhang Xiao , Zhang Zhong-kai , Cao Jin-xiang , Liu Yu , Yu Peng-cheng
Published: March 2018

Considering the gas pressure and radio frequency power change, the mode transition of E↔H were investigated in inductively coupled plasmas. It can be found that the transition power has almost the same trend decreasing with gas pressure, whether it is in H mode or E mode. However, the transition density increases slowly with gas pressure from E to H mode. The transition points of E to H mode can be understood by the propagation of electromagnetic wave in the plasma, while the H to E should be illustrated by the electric field strength. Moreover, the electron density, increasing with the pressure and power, can be attributed to the multiple ionization, which changes the energy loss per electron-ion pair created. In addition, the optical emission characteristics in E and H mode is also shown. The line ratio of I750.4 and I811.5, taken as a proxy of the density of metastable state atoms, was used to illustrate the hysteresis. The 750.4 nm line intensity, which has almost the same trend with the 811.5 nm line intensity in H mode, both of them increases with power but decreases with gas pressure. The line ratio of 811.5/750.4 has a different change rule in E mode and H mode, and at the transition point of H to E, it can be one significant factor that results in the hysteresis as the gas pressure change. And compared with the 811.5 nm intensity, it seems like a similar change rule with RF power in E mode. Moreover, some emitted lines with lower rate constants don’t turn up in E mode, while can be seen in H mode because the excited state atom density increasing with the electron density.
Rate constants for proteins binding to substrates with multiple binding sites using a generalized forward flux sampling expression
Authors: Vijaykumar Adithya , ten Wolde Pieter Rein , Bolhuis Peter G.
Published: March 2018

To predict the response of a biochemical system, knowledge of the intrinsic and effective rate constants of proteins is crucial. The experimentally accessible effective rate constant for association can be decomposed in a diffusion-limited rate at which proteins come into contact and an intrinsic association rate at which the proteins in contact truly bind. Reversely, when dissociating, bound proteins first separate into a contact pair with an intrinsic dissociation rate, before moving away by diffusion. While microscopic expressions exist that enable the calculation of the intrinsic and effective rate constants by conducting a single rare event simulation of the protein dissociation reaction, these expressions are only valid when the substrate has just one binding site. If the substrate has multiple binding sites, a bound enzyme can, besides dissociating into the bulk, also hop to another binding site. Calculating transition rate constants between multiple states with forward flux sampling requires a generalized rate expression. We present this expression here and use it to derive explicit expressions for all intrinsic and effective rate constants involving binding to multiple states, including rebinding. We illustrate our approach by computing the intrinsic and effective association, dissociation, and hopping rate constants for a system in which a patchy particle model enzyme binds to a substrate with two binding sites. We find that these rate constants increase as a function of the rotational diffusion constant of the particles. The hopping rate constant decreases as a function of the distance between the binding sites. Finally, we find that blocking one of the binding sites enhances both association and dissociation rate constants. Our approach and results are important for understanding and modeling association reactions in enzyme-substrate systems and other patchy particle systems and open the way for large multiscale simulations of such systems.
Reversible phase-change behavior in two-dimensional antimony telluride (Sb2Te3) nanosheets
Authors: Jacobs-Gedrim Robin B. , Murphy Michael T. , Yang Fan , Jain Nikhil , Shanmugam Mariyappan , Song Eui Sang , Kandel Yudhister , Hesamaddin Parham , Yu Hong Yu , Anantram M. P. , Janes David B. , Yu Bin
Published: March 2018

Potential two-dimensional (2D) van der Waals crystals with mechanical flexibility, transparency, and low cost are viable material platforms for future nanodevices. Resistive switching behavior in 2D layered Sb2Te3 nanosheets is demonstrated. Nearly three orders of magnitude switch in sheet resistance were realized for more than 20 cycles. The observed hysteretic behavior is due to the change between crystalline and amorphous phases under a melt-quench-recrystallization mechanism. More importantly, the energy required to amorphize the nanosheets decreases exponentially with layer thickness reduction. It is expected that scaling to the ultimate two-dimensional limit in chalcogenide nanosheet-based phase change devices may meet or even exceed the energy efficiency of neurobiological architectures.
The effect of skin moisture on the density distribution of OH and O close to the skin surface
Authors: Wu F. , Li J. , Liu F. , Zhou X. , Lu X.
Published: March 2018

OH radicals and O atoms are believed to be two of the most important reactive species in various biomedical applications of atmospheric pressure plasma jets. In this study, the effect of the skin moisture on the density distribution of OH and O close to the surface of the ex vivo pig skin is investigated by using laser-induced fluorescence technology. The skin moistures used in this study are 20%, 40%, 60%, and 80%, respectively. The experiment results indicate that, at a gas flow rate of 0.5 L/min, when the skin moisture is increased, the OH density close to the skin surface increases, while the O density decreases. On the other hand, when the gas flow rate is increased to 1 L/min, the OH density close to the skin surface is less sensitive with the moisture of the skin surface. Besides, when the skin moisture is 80%, the OH density increases with the increase in the concentration of H2O in the working gas and it reaches its maximum 7.9 × 1013 cm−3 when the concentration of H2O in the working gas is about 500 ppm. The OH density starts to decrease while the H2O concentration in the working gas keeps increasing. On the order hand, the O density shows a maximum 7.4 × 1014 cm−3 when the gas flow rate is 0.5 L/min with no O2 added and the skin moisture is 20%. But, when the gas flow rate is increased to about 1 to 2 L/min, the O density achieves its maximum when 0.5% of O2 is added to the working gas. The possible reasons for these observations are discussed.
Numerical study of droplet evaporation in an acoustic levitator
Authors: Bänsch Eberhard , Götz Michael
Published: March 2018

We present a finite element method for the simulation of all relevant processes of the evaporation of a liquid droplet suspended in an acoustic levitation device. The mathematical model and the numerical implementation take into account heat and mass transfer across the interface between the liquid and gaseous phase and the influence of acoustic streaming on this process, as well as the displacement and deformation of the droplet due to acoustic radiation pressure. We apply this numerical method to several theoretical and experimental examples and compare our results with the well-known d2-law for the evaporation of spherical droplets and with theoretical predictions for the acoustic streaming velocity. We study the influence of acoustic streaming on the distribution of water vapor and temperature in the levitation device, with special attention to the vapor distribution in the emerging toroidal vortices. We also compare the evaporation rate of a droplet with and without acoustic streaming, as well as the evaporation rates in dependence of different temperatures and sound pressure levels. Finally, a simple model of protein inactivation due to heat damage is considered and studied for different evaporation settings and their respective influence on protein damage.