bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interplay of electric field and disorder in Dirac liquid silicene
Authors: Craco L. , Carara S. S. , Leoni S. 
Published: February 2021

Abstract
Layered materials with buckled structure offer a promising route to explore distinct phases of quantum matter. Using GGA + DMFT we reveal the complex interplay between perpendicular electric field and site-diagonal disorder in the Dirac liquid electronic state of silicene. The electronic structure we derive is promising in the sense that it leads to results that might explain why out-of-plane electric field plus moderate disorder can generate marginal Dirac valleys consistent with scanning tunneling spectroscopy of silicene on Ag substrates.

Graphic Abstract
Improving heavy dijet resonance searches using jet substructure at the LHC
Authors: Nayak Aruna Kumar , Rai Santosh Kumar , Samui Tousik 
Published: February 2021

AbstractThe search for new physics at high energy accelerators has been at the crossroads with very little hint of signals suggesting otherwise. The challenges at a hadronic machine such as the LHC is compounded by the fact that final states are swamped with jets which one needs to understand and unravel. A positive step in this direction would be to separate the jets in terms of their gluonic and quark identities, much in a similar spirit of distinguishing heavy quark jets from light quark jets that has helped in improving searches for both neutral and charged Higgs bosons at the LHC. In this work, we utilise this information using the jet substructure techniques to comment on possible improvements in sensitivity as well as discrimination of new resonances in the all hadronic mode that would be crucial in pinning down new physics signals at HL-LHC, HE-LHC and any future 100 TeV hadron collider.
Diphoton decay of the higgs from the Epstein–Glaser viewpoint
Authors: Duch Paweł , Dütsch Michael , Gracia-Bondía José M. 
Published: February 2021

AbstractWe revisit a nearly 10-year old controversy on the diphoton decay of the Higgs particle. To a large extent, the controversy turned around the respective merits of the regularization techniques employed. The novel aspect of our approach is thatnoregularization techniques are brought to bear: we work within the Bogoliubov–Epstein–Glaser scheme of renormalization by extension of distributions. Solving the problem actually required an expansion of this method’s toolkit, furnished in the paper.
General approach to the Lagrangian ambiguity in f(R, T) gravity
Authors: Carvalho G. A. , Rocha F. , Oliveira H. O. , Lobato R. V. 
Published: February 2021

AbstractThe f(R, T) gravity is a theory whose gravitational action depends arbitrarily on the Ricci scalar, R, and the trace of the stress–energy tensor, T; its field equations also depend on matter Lagrangian, $$\mathscr {L}_{m}$$

L
m

. In the modified theories of gravity where field equations depend on Lagrangian, there is no uniqueness on the Lagrangian definition and the dynamics of the gravitational and matter fields can be different depending on the choice performed. In this work, we have eliminated the $$\mathscr {L}_{m}$$

L
m

dependence from f(R, T) gravity field equations by generalizing the approach of Moraes in Ref. [1]. We also propose a general approach where we argue that the trace of the energy–momentum tensor must be considered an “unknown” variable of the field equations. The trace can only depend on fundamental constants and few inputs from the standard model. Our proposal resolves two limitations: first the energy–momentum tensor of the f(R, T) gravity is not the perfect fluid one; second, the Lagrangian is not well-defined. As a test of our approach we applied it to the study of the matter era in cosmology, and the theory can successfully describe a transition between a decelerated Universe to an accelerated one without the need for dark energy.
Fluid dynamics in the warp drive spacetime geometry
Authors: Santos-Pereira Osvaldo L. , Abreu Everton M. C. , Ribeiro Marcelo B. 
Published: February 2021

AbstractThe Alcubierre warp drive metric is a spacetime geometry featuring a spacetime distortion, called a warp bubble, where a massive particle inside it acquires global superluminal velocities, or warp speeds. This work presents solutions of the Einstein equations for the Alcubierre metric having fluid matter as gravity source. The energy–momentum tensor considered has two fluid contents, the perfect fluid and the parametrized perfect fluid (PPF), a tentative more flexible model whose aim is to explore the possibilities of warp drive solutions with positive matter density content. Santos-Pereira et al. (Eur Phys J C 80:786, 2020) already showed that the Alcubierre metric having dust as source connects this geometry to the Burgers equation, which describes shock waves moving through an inviscid fluid, but led the solutions back to vacuum. The same happened for two out of four solutions subcases for the perfect fluid. Other solutions for the perfect fluid indicate the possibility of warp drive with positive matter density, but at the cost of a complex solution for the warp drive regulating function. Regarding the PPF, solutions were also obtained indicating that warp speeds could be created with positive matter density. Weak, dominant, strong and null energy conditions were calculated for all studied subcases, being satisfied for the perfect fluid and creating constraints in the PPF quantities such that a positive matter density is also possible for creating a warp bubble. Summing up all results, energy–momentum tensors describing more complex forms of matter or field distributions generate solutions for the Einstein equations with the warp drive metric where a negative matter density might not be a strict precondition for attaining warp speeds.
Hadronic vacuum-polarization contribution to various QED observables
Authors: Karshenboim Savely G. , Shelyuto Valery A. 
Published: February 2021

Abstract
Due to precision tests of quantum electrodynamics (QED), determination of accurate values of fundamental constants, and constraints on new physics, it is important in a consistent way to evaluate a number of QED observables such as the Lamb shift in hydrogen-like atomic systems. Even in a pure leptonic case, those QED variables are in fact not pure QED ones since hadronic effects are involved through intermediate states while accounting for higher-order effects. One of them is hadronic vacuum polarization (hVP). Complex evaluations often involve a number of QED quantities, for which treatment of hVP is not consistent. The highest accuracy for a calculation of the hVP term is required for the anomalous magnetic moment of a muon. However, a standard data-driven treatment of hVP, based on a dispersion integration of experimental data on electron-positron annihilation to hadrons and some other phenomena, leads to a contradiction with the experimental value of $$a_\mu $$

a
μ

. This experimental value can be considered as an indirect determination of the hVP contribution to $$a_\mu $$

a
μ

and the scatter of theory and experiment allows one to obtain a conservative estimation of the related hVP contribution. In this paper, we derive exact and approximate relations between the leading-order (LO) hVP contributions to various observables. Using those relations, we obtain for them a consistent set of the results, based on the scatter of $$a_\mu $$

a
μ

values. While calculating the LO hVP term, we have to remember that next-to-LO (NLO) hVP corrections are often comparable with the uncertainty of the LO term. Special attention is payed to hVP contribution to simple atoms. In particular, we discuss the NLO contribution to the Lamb shift in ordinary and muonic hydrogen and other two-body atoms for $$Z\le 10$$

Z
≤
10

. We also consider the NLO contribution of the muonic vacuum polarization to the Lamb shift in hydrogen-like atoms. With the $$a_\mu $$

a
μ

puzzle unresolved, one may still require present-days values of the hVP contributions to various observable for comparison to experiment etc. the presence of contradicting values and a lack of consistency means an additional uncertainty for $$a_\mu $$

a
μ

and for key contributions to it, including the LO hVP one. We present here an estimation of such a propagated uncertainty in hVP contributions to different QED observables and recommend a consistent set of the related LO hVP contributions.

Graphic Abstract
Anomalous diffraction of matter waves with minimal quantum metasurfaces
Authors: Valagiannopoulos Constantinos 
Published: February 2021

AbstractIn the last few years, there is a huge upsurge in the number of closed deals regarding quantum technologies for materials, computing, communication and instrumentation. Such a trend has inevitably affected the research funding market; thus, large state initiatives are taken that are directly expected to drive the formulation of novel research concepts and the development of quantum device prototypes from sensors and circuitry to quantum memory and repeaters. A fundamental operation behind all these applications is the effective steering of electrons, constituting matter waves, along specific directions and with certain magnitudes, due to development of various reflective and refractive orders. The objective of this study is to optimize the simplest structure that supports such anomalous diffraction, namely a quantum metasurface comprising cylindrical rods embedded in suitable crystalline matter. Several highly-performing designs from these minimal setups are proven to work exceptionally as multiport components, employable to a variety of quantum engineering implementations.
Exploiting the wide dynamic range of silicon photomultipliers for quantum optics applications
Authors: Cassina Silvia , Allevi Alessia , Mascagna Valerio , Prest Michela , Vallazza Erik , Bondani Maria 
Published: February 2021

AbstractSilicon photomultipliers are photon-number-resolving detectors endowed with hundreds of cells enabling them to reveal high-populated quantum optical states. In this paper, we address such a goal by showing the possible acquisition strategies that can be adopted and discussing their advantages and limitations. In particular, we determine the best acquisition solution in order to properly reveal the nature, either classical or nonclassical, of mesoscopic quantum optical states.
A Chimeric GM-CSF/IL18 Receptor to Sustain CAR T-cell Function
Authors: Lange Shannon , Sand Laurens G.L. , Bell Matthew , Patil Sagar L. , Langfitt Deanna , Gottschalk Stephen 
Published: February 2021

Abstract

The inability of chimeric antigen receptor (CAR) T cells to sustain their effector function after repeated exposure to tumor cells is a major obstacle to their success in patients with solid tumors. To overcome this limitation, we designed a novel chimeric cytokine receptor to create an autocrine loop that links activation-dependent GM-CSF production by CAR T cells to IL18 receptor signaling (GM18). Expression of GM18 in CAR T cells enhanced their effector function in an antigen- and activation-dependent manner. In repeat stimulation assays, which mimic chronic antigen exposure, CAR.GM18 T cells had a significantly greater ability to expand and produce cytokines in comparison with their unmodified counterparts targeting EPHA2 or HER2. In vivo, CAR.GM18 T cells induced tumor regression at cell doses at which standard CAR T cells were ineffective in two solid tumor xenograft models. Thus, our study highlights the potential of hijacking cytokines that are physiologically secreted by T cells to bolster their antitumor activity.

Significance:
We designed a chimeric cytokine receptor (GM18) that links CAR T-cell activation to MYD88 signaling. GM18 endows CAR T cells with sustained effector function in the setting of chronic antigen exposure, resulting in potent antitumor activity in preclinical solid tumor models.
This article is highlighted in the In This Issue feature, p. 1601
Mutations in the RAS/MAPK Pathway Drive Replication Repair–Deficient Hypermutated Tumors and Confer Sensitivity to MEK Inhibition
Authors: Campbell Brittany B. , Galati Melissa A. , Stone Simone C. , Riemenschneider Alexandra N. , Edwards Melissa , Sudhaman Sumedha , Siddaway Robert , Komosa Martin , Nunes Nuno M. , Nobre Liana , Morrissy A. Sorana , Zatzman Matthew , Zapotocky Michal , Joksimovic Lazar , Kalimuthu Sangeetha N. , Samuel David , Mason Gary , Bouffet Eric , Morgenstern Daniel A. , Aronson Melyssa , Durno Carol , Malkin David , Maris John M. , Taylor Michael D. , Shlien Adam , Pugh Trevor J. , Ohashi Pamela S. , Hawkins Cynthia E. , Tabori Uri 
Published: February 2021

Abstract

The RAS/MAPK pathway is an emerging targeted pathway across a spectrum of both adult and pediatric cancers. Typically, this is associated with a single, well-characterized point mutation in an oncogene. Hypermutant tumors that harbor many somatic mutations may obscure the interpretation of such targetable genomic events. We find that replication repair–deficient (RRD) cancers, which are universally hypermutant and affect children born with RRD cancer predisposition, are enriched for RAS/MAPK mutations (P = 10−8). These mutations are not random, exist in subclones, and increase in allelic frequency over time. The RAS/MAPK pathway is activated both transcriptionally and at the protein level in patient-derived RRD tumors, and these tumors responded to MEK inhibition in vitro and in vivo. Treatment of patients with RAS/MAPK hypermutant gliomas reveals durable responses to MEK inhibition. Our observations suggest that hypermutant tumors may be addicted to oncogenic pathways, resulting in favorable response to targeted therapies.

Significance:
Tumors harboring a single RAS/MAPK driver mutation are targeted individually for therapeutic purposes. We find that in RRD hypermutant cancers, mutations in the RAS/MAPK pathway are enriched, highly expressed, and result in sensitivity to MEK inhibitors. Targeting an oncogenic pathway may provide therapeutic options for these hypermutant polyclonal cancers.
This article is highlighted in the In This Issue feature, p. 1307
Nongenetic Evolution Drives Lung Adenocarcinoma Spatial Heterogeneity and Progression
Authors: Tavernari Daniele , Battistello Elena , Dheilly Elie , Petruzzella Aaron S. , Mina Marco , Sordet-Dessimoz Jessica , Peters Solange , Krueger Thorsten , Gfeller David , Riggi Nicolo , Oricchio Elisa , Letovanec Igor , Ciriello Giovanni 
Published: February 2021

Abstract

Cancer evolution determines molecular and morphologic intratumor heterogeneity and challenges the design of effective treatments. In lung adenocarcinoma, disease progression and prognosis are associated with the appearance of morphologically diverse tumor regions, termed histologic patterns. However, the link between molecular and histologic features remains elusive. Here, we generated multiomics and spatially resolved molecular profiles of histologic patterns from primary lung adenocarcinoma, which we integrated with molecular data from &gt;2,000 patients. The transition from indolent to aggressive patterns was not driven by genetic alterations but by epigenetic and transcriptional reprogramming reshaping cancer cell identity. A signature quantifying this transition was an independent predictor of patient prognosis in multiple human cohorts. Within individual tumors, highly multiplexed protein spatial profiling revealed coexistence of immune desert, inflamed, and excluded regions, which matched histologic pattern composition. Our results provide a detailed molecular map of lung adenocarcinoma intratumor spatial heterogeneity, tracing nongenetic routes of cancer evolution.

Significance:
Lung adenocarcinomas are classified based on histologic pattern prevalence. However, individual tumors exhibit multiple patterns with unknown molecular features. We characterized nongenetic mechanisms underlying intratumor patterns and molecular markers predicting patient prognosis. Intratumor patterns determined diverse immune microenvironments, warranting their study in the context of current immunotherapies.
This article is highlighted in the In This Issue feature, p. 1307
Pharmacogenomics of the Efficacy and Safety of Colchicine in COLCOT
Authors: Dubé Marie-Pierre , Legault Marc-André , Lemaçon Audrey , Lemieux Perreault Louis-Philippe , Fouodjio René , Waters David D. , Kouz Simon , Pinto Fausto J. , Maggioni Aldo P. , Diaz Rafael , Berry Colin , Koenig Wolfgang , Lopez-Sendon Jose , Gamra Habib , Kiwan Ghassan S. , Asselin Géraldine , Provost Sylvie , Barhdadi Amina , Sun Maxine , Cossette Mariève , Blondeau Lucie , Mongrain Ian , Dubois Anick , Rhainds David , Bouabdallaoui Nadia , Samuel Michelle , de Denus Simon , L’Allier Philippe L. , Guertin Marie-Claude , Roubille François , Tardif Jean-Claude 
Published: February 2021

Background:
The randomized, placebo-controlled COLCOT (Colchicine Cardiovascular Outcomes Trial) has shown the benefits of colchicine 0.5 mg daily to lower the rate of ischemic cardiovascular events in patients with a recent myocardial infarction. Here, we conducted a post hoc pharmacogenomic study of COLCOT with the aim to identify genetic predictors of the efficacy and safety of treatment with colchicine.

Methods:
There were 1522 participants of European ancestry from the COLCOT trial available for the pharmacogenomic study of COLCOT trial. The pharmacogenomic study’s primary cardiovascular end point was defined as for the main trial, as time to first occurrence of cardiovascular death, resuscitated cardiac arrest, myocardial infarction, stroke, or urgent hospitalization for angina requiring coronary revascularization. The safety end point was time to the first report of gastrointestinal events. Patients’ DNA was genotyped using the Illumina Global Screening array followed by imputation. We performed a genome-wide association study in colchicine-treated patients.

Results:

None of the genetic variants passed the genome-wide association study significance threshold for the primary cardiovascular end point conducted in 702 patients in the colchicine arm who were compliant to medication. The genome-wide association study for gastrointestinal events was conducted in all 767 patients in the colchicine arm and found 2 significant association signals, one with lead variant rs6916345 (hazard ratio, 1.89 [95% CI, 1.52–2.35],
P
=7.41×10
−9
) in a locus which colocalizes with Crohn disease, and one with lead variant rs74795203 (hazard ratio, 2.51 [95% CI, 1.82–3.47];
P
=2.70×10
−8
), an intronic variant in gene
SEPHS1
. The interaction terms between the genetic variants and treatment with colchicine versus placebo were significant.

Conclusions:
We found 2 genomic regions associated with gastrointestinal events in patients treated with colchicine. Those findings will benefit from replication to confirm that some patients may have genetic predispositions to lower tolerability of treatment with colchicine.
Targeted Undersmoothing: Sensitivity Analysis for Sparse Estimators
Authors: Hansen Christian , Kozbur Damian , Misra Sanjog 
Published: February 2021

AbstractThis paper proposes a procedure for assessing the sensitivity of inferential conclusions for functionals of sparse high-dimensional models following model selection. The proposed procedure is called targeted undersmoothing. Functionals considered include dense functionals that may depend on many or all elements of the high-dimensional parameter vector. The sensitivity analysis is based on systematic enlargements of an initially selected model. By varying the enlargements, one can conduct sensitivity analysis about the strength of empirical conclusions to model selection mistakes. We illustrate the procedure's performance through simulation experiments and two empirical examples.
Countervailing Market Power and Hospital Competition
Authors: Barrette Eric , Gowrisankaran Gautam , Town Robert 
Published: February 2021

Abstract
While economic theories indicate that market power by downstream firms can potentially counteract market power upstream, antitrust policy is opaque as to whether to incorporate countervailing market power in merger analyses. We use detailed national claims data from the health care sector to evaluate whether countervailing insurer power does indeed limit hospitals' exercise of market power. We estimate willingness-to-pay models to evaluate hospital market power across analysis areas. We find that countervailing market power is important: a typical hospital merger would raise hospital prices 4.3% at the 25th percentile of insurer concentration but only 0.97% at the 75th percentile of insurer concentration.
Does Market Interaction Erode Moral Values?
Authors: Bartling Björn , Fehr Ernst , Özdemir Yagiz 
Published: February 2021

Abstract
The widespread use of markets leads to unprecedented material well-being in many societies. We study whether market interaction, as a side effect, erodes moral values. In an influential paper, Falk and Szech (2013) provide experimental data that seem to suggest that “market interaction erodes moral values.” Although we replicate their main treatment effect, we show that additional treatments are necessary to corroborate their conclusion. These treatments reveal that playing repeatedly, and not market interaction, causes the erosion of moral values. Our paper thus shows that neither Falk and Szech's data nor our data support the claim that markets erode morals.
Female preferences for discrete and continuous male colour expression may help reinforce colour polymorphism in a desert lizard
Authors: Glover Jenell A. , Lattanzio Matthew S. 
Published: February 2021

Abstract
Despite recognition that colour can vary continuously, colour expression in colour polymorphic species is usually treated as discrete. We conducted three experiments to evaluate the extent that discrete and continuous male coloration influenced female mating preferences in long-tailed brush lizards (Urosaurus graciosus). Each experiment provided females with a different social context: a dimorphic choice between a yellow and an orange male (coloration treated as discrete), and a choice between either two orange males or two yellow males (coloration treated as continuous variation). Females preferred orange males over yellow males in the first experiment, and the findings of our second experiment suggested that males with moderate orange coloration were most preferred. In contrast, females behaved randomly with respect to two yellow males. Our findings show that females in colour polymorphic species can evaluate both discrete and continuous aspects of morph coloration during mate assessment, which may help maintain their polymorphism.
Oman’s Trade Potentials with Indian Ocean Rim Countries
Authors: Gani Azmat , Hasim Haslifah M. , Al-Mawali Nasser 
Published: February 2021

Abstract
Oman’s regional trade flow, especially with the Indian Ocean Rim countries, is examined within a gravity model framework. The analysis is based on the generalised method of moments (GMM) estimation procedure. The findings show that Oman’s exports are strongly determined by the Indian Ocean Rim countries’ populations, gross domestic product, infrastructure, Oman’s trade policy and a common border and language. Distance is found to induce significant friction for Oman’s imports. We conclude that the Indian Ocean Rim countries are sources of active markets and provide opportunities for greater trade integration. In light of the dramatic decline in world oil prices in recent years, Oman also needs to reduce its reliance on oil earnings and intervene more aggressively in its domestic economy by diversifying its non-oil sector and concentrate more on non-oil led exports.