Nonlinear Localization in Metamaterials

Metamaterials, i.e., artificially structured ("synthetic") media comprising weakly coupled discrete elements, exhibit extraordinary properties and they hold a great promise for novel applications including super-resolution imaging, cloaking, hyperlensing, and optical transformation. Nonlinearity adds a new degree of freedom for metamaterial design that allows for tuneability and multistability, properties that may offer altogether new functionalities and electromagnetic characteristics. The combination of discreteness and nonlinearity may lead to intrinsic localization of the type of discrete breather in metallic, SQUID-based, and ${\cal PT}-$symmetric metamaterials. We review recent results demonstrating the generic appearance of breather excitations in these systems resulting from power-balance between intrinsic losses and input power, either by proper initialization or by purely dynamical procedures. Breather properties peculiar to each particular system are identified and discussed. Recent progress in the fabrication of low-loss, active and superconducting metamaterials, makes the experimental observation of breathers in principle possible with the proposed dynamical procedures.Comment: 19 pages, 14 figures, Invited (Review) Chapte

How Schools Affect Student Well-Being: A Cross-Cultural Approach in 35 OECD Countries

A common approach for measuring the effectiveness of an education system or a school is the estimation of the impact that school interventions have on students’ academic performance. However, the latest trends aim to extend the focus beyond students’ acquisition of knowledge and skills, and to consider aspects such as well-being in the academic context. For this reason, the 2015 edition of the international assessment system Programme for International Student Assessment (PISA) incorporated a new tool aimed at evaluating the socio-emotional variables related to the well-being of students. It is based on a definition focused on the five dimensions proposed in the PISA theoretical framework: cognitive, psychological, social, physical, and material. The main purpose of this study is to identify the well-being components that significantly affect student academic performance and to estimate the magnitude of school effects on the wellbeing of students in OECD countries, the school effect being understood as the ability of schools to increase subjective student well-being. To achieve this goal, we analyzed the responses of 248,620 students from 35 OECD countries to PISA 2015 questionnaires. Specifically, we considered non-cognitive variables in the questionnaires and student performance in science. The results indicated that the cognitive well-being dimension, composed of enjoyment of science, self-efficacy, and instrumental motivation, as well as test anxiety all had a consistent relationship with student performance across countries. In addition, the school effect, estimated through a two-level hierarchical linear model, in terms of student well-being was systematically low. While the school effect accounted for approximately 25% of the variance in the results for the cognitive dimension, only 5–9% of variance in well-being indicators was attributable to it. This suggests that the influence of school on student welfare is weak, and the effect is similar across countries. The present study contributes to the general discussion currently underway about the definition of well-being and the connection between well-being and achievement. The results highlighted two complementary concerns: there is a clear need to promote socioemotional education in schools, and it is important to develop a rigorous framework for well-being assessment. The implications of the results and proposals for future studies are discussed.Spain Ministry of Science, Innovation and Universities PSI2017-85724-P2E Estudios, Evaluaciones e Investigacion, S.

Hydrogen Sulfide Protects against Chemical Hypoxia-Induced Cytotoxicity and Inflammation in HaCaT Cells through Inhibition of ROS/NF-κB/COX-2 Pathway

Hydrogen sulfide (H2S) has been shown to protect against oxidative stress injury and inflammation in various hypoxia-induced insult models. However, it remains unknown whether H2S protects human skin keratinocytes (HaCaT cells) against chemical hypoxia-induced damage. In the current study, HaCaT cells were treated with cobalt chloride (CoCl2), a well known hypoxia mimetic agent, to establish a chemical hypoxia-induced cell injury model. Our findings showed that pretreatment of HaCaT cells with NaHS (a donor of H2S) for 30 min before exposure to CoCl2 for 24 h significantly attenuated CoCl2-induced injuries and inflammatory responses, evidenced by increases in cell viability and GSH level and decreases in ROS generation and secretions of IL-1β, IL-6 and IL-8. In addition, pretreatment with NaHS markedly reduced CoCl2-induced COX-2 overexpression and PGE2 secretion as well as intranuclear NF-κB p65 subunit accumulation (the central step of NF-κB activation). Similar to the protective effect of H2S, both NS-398 (a selective COX-2 inhibitor) and PDTC (a selective NF-κB inhibitor) depressed not only CoCl2-induced cytotoxicity, but also the secretions of IL-1β, IL-6 and IL-8. Importantly, PDTC obviously attenuated overexpression of COX-2 induced by CoCl2. Notably, NAC, a ROS scavenger, conferred a similar protective effect of H2S against CoCl2-induced insults and inflammatory responses. Taken together, the findings of the present study have demonstrated for the first time that H2S protects HaCaT cells against CoCl2-induced injuries and inflammatory responses through inhibition of ROS-activated NF-κB/COX-2 pathway

Search for relativistic magnetic monopoles with five years of the ANTARES detector data

[EN] A search for magnetic monopoles using five years of data recorded with the ANTARES neutrino telescope from January 2008 to December 2012 with a total live time of 1121 days is presented. The analysis is carried out in the range b>0.6 of magnetic monopole velocities using a strategy based on run-by-run Monte Carlo simulations. No signal above the background expectation from atmospheric muons and atmospheric neutrinos is observed, and upper limits are set on the magnetic monopole flux ranging from 5.7x10-16 to 1.5x10-18 cm-2 . s-1.sr-1.The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02), Labex OCEVU (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Stichting voor Fundamenteel Onderzoek der Materie (FOM), Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS), Romania; Ministerio de Economia y Competitividad (MINECO): Plan Estatal de Investigacion (refs. FPA2015-65150-C3-1-P, -2-P and -3-P, (MINECO/FEDER)), Severo Ochoa Centre of Excellence and MultiDark Consolider (MINECO), and Prometeo and Grisolia programs (Generalitat Valenciana), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilitiesAlbert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.; Aubert, J.; Avgitas, T.... (2017). Search for relativistic magnetic monopoles with five years of the ANTARES detector data. Journal of High Energy Physics (Online). (7):1-16. https://doi.org/10.1007/JHEP07(2017)054S1167P.A.M. Dirac, Quantized Singularities in the Electromagnetic Field, Proc. Roy. Soc. Lond. A 133 (1931) 60 [ INSPIRE ].G. ’t Hooft, Magnetic Monopoles in Unified Gauge Theories, Nucl. Phys. B 79 (1974) 276 [ INSPIRE ].A.M. Polyakov, Particle Spectrum in the Quantum Field Theory, JETP Lett. 20 (1974) 194 [ INSPIRE ].G. Lazarides, C. Panagiotakopoulos and Q. Shafi, Magnetic Monopoles From Superstring Models, Phys. Rev. Lett. 58 (1987) 1707 [ INSPIRE ].Y.M. Cho and D. Maison, Monopoles in Weinberg-Salam model, Phys. Lett. B 391 (1997) 360 [ hep-th/9601028 ] [INSPIRE].Particle Data Group collaboration, C. Patrignani et al., Review of Particle Physics, Chin. Phys. C 40 (2016) 100001 [ INSPIRE ].L. Patrizii and M. Spurio, Status of Searches for Magnetic Monopoles, Ann. Rev. Nucl. Part. Sci. 65 (2015) 279 [ arXiv:1510.07125 ] [INSPIRE].ATLAS collaboration, Search for magnetic monopoles and stable particles with high electric charges in 8 TeV pp collisions with the ATLAS detector, Phys. Rev. D 93 (2016) 052009 [ arXiv:1509.08059 ] [ INSPIRE ].MoEDAL collaboration, B. Acharya et al., Search for magnetic monopoles with the MoEDAL prototype trapping detector in 8 TeV proton-proton collisions at the LHC, JHEP 08 (2016) 067 [ arXiv:1604.06645 ] [INSPIRE].MoEDAL collaboration, B. Acharya et al., Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC, Phys. Rev. Lett. 118 (2017) 061801 [ arXiv:1611.06817 ] [INSPIRE].T.W.B. Kibble, Topology of Cosmic Domains and Strings, J. Phys. A 9 (1976) 1387 [ INSPIRE ].J. Preskill, Cosmological Production of Superheavy Magnetic Monopoles, Phys. Rev. Lett. 43 (1979) 1365 [ INSPIRE ].A.H. Guth, The Inflationary Universe: A Possible Solution to the Horizon and Flatness Problems, Phys. Rev. D 23 (1981) 347 [ INSPIRE ].D. Ryu, H. Kang and P.L. Biermann, Cosmic magnetic fields in large scale filaments and sheets, Astron. Astrophys. 335 (1998) 19 [ astro-ph/9803275 ] [ INSPIRE ].E.N. Parker, The Origin of Magnetic Fields, Astrophys. J 160 (1970) 383.ANTARES collaboration, M. Ageron et al., ANTARES: the first undersea neutrino telescope, Nucl. Instrum. Meth. A 656 (2011) 11 [ arXiv:1104.1607 ] [INSPIRE].ANTARES collaboration, S. Adrian-Martinez et al., Search for Relativistic Magnetic Monopoles with the ANTARES Neutrino Telescope, Astropart. Phys. 35 (2012) 634 [ arXiv:1110.2656 ] [ INSPIRE ].IceCube collaboration, M.G. Aartsen et al., Searches for Relativistic Magnetic Monopoles in IceCube, Eur. Phys. J. C 76 (2016) 133 [ arXiv:1511.01350 ] [INSPIRE].ANTARES collaboration, J.A. Aguilar et al., The data acquisition system for the ANTARES Neutrino Telescope, Nucl. Instrum. Meth. A 570 (2007) 107 [ astro-ph/0610029 ] [INSPIRE].D.R. Tompkins, Total energy loss and Čerenkov emission from monopoles, Phys. Rev. 138 (1965) B248.Y. Kazama, C.N. Yang and A.S. Goldhaber, Scattering of a Dirac Particle with Charge Ze by a Fixed Magnetic Monopole, Phys. Rev. D 15 (1977) 2287 [ INSPIRE ].S.P. Ahlen, Monopole Track Characteristics in Plastic Detectors, Phys. Rev. D 14 (1976) 2935 [ INSPIRE ].S.P. Ahlen, Stopping Power Formula for Magnetic Monopoles, Phys. Rev. D 17 (1978) 229 [ INSPIRE ].J. Derkaoui et al., Energy losses of magnetic monopoles and of dyons in the earth, Astropart. Phys. 9 (1998) 173 [ INSPIRE ].CERN Application Software Group, GEANT 3.21 Detector Description and Simulation Tool, CERN Program Library Long Writeup W5013 (1993).G. Carminati, A. Margiotta and M. Spurio, Atmospheric MUons from PArametric formulas: A fast GEnerator for neutrino telescopes (MUPAGE), Comput. Phys. Commun. 179 (2008) 915 [ arXiv:0802.0562 ] [INSPIRE].Y. Becherini, A. Margiotta, M. Sioli and M. Spurio, A parameterisation of single and multiple muons in the deep water or ice, Astropart. Phys. 25 (2006) 1 [ hep-ph/0507228 ] [INSPIRE].J. Brunner, ANTARES simulation tools, in proceedings of The VLVnT workshop, Amsterdam (2003), http://www.vlvnt.nl/proceedings.pdf .ANTARES collaboration, A. Margiotta, Common simulation tools for large volume neutrino detectors, Nucl. Instrum. Meth. A 725 (2013) 98 [ INSPIRE ].V. Agrawal, T.K. Gaisser, P. Lipari and T. Stanev, Atmospheric neutrino flux above 1-GeV, Phys. Rev. D 53 (1996) 1314 [ hep-ph/9509423 ] [INSPIRE].G.D. Barr, T.K. Gaisser, S. Robbins and T. Stanev, Uncertainties in Atmospheric Neutrino Fluxes, Phys. Rev. D 74 (2006) 094009 [ astro-ph/0611266 ] [INSPIRE].L. Fusco and A. Margiotta, The Run-by-Run Monte Carlo simulation for the ANTARES experiment, EPJ Web Conf. 116 (2016) 02002.ANTARES collaboration, J.A. Aguilar et al., A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope, Astropart. Phys. 34 (2011) 652 [ arXiv:1105.4116 ] [INSPIRE].ANTARES collaboration, S. Adrian-Martinez et al., Searches for Point-like and extended neutrino sources close to the Galactic Centre using the ANTARES neutrino Telescope, Astrophys. J. 786 (2014) L5 [ arXiv:1402.6182 ] [INSPIRE].G.J. Feldman and R.D. Cousins, A unified approach to the classical statistical analysis of small signals, Phys. Rev. D 57 (1998) 3873 [ physics/9711021 ] [INSPIRE].G.C. Hill and K. Rawlins, Unbiased cut selection for optimal upper limits in neutrino detectors: The model rejection potential technique, Astropart. Phys. 19 (2003) 393 [ astro-ph/0209350 ] [ INSPIRE ].ANTARES collaboration, J.A. Aguilar et al., Zenith distribution and flux of atmospheric muons measured with the 5-line ANTARES detector, Astropart. Phys. 34 (2010) 179 [ arXiv:1007.1777 ] [ INSPIRE ].ANTARES collaboration, S. Adrian-Martinez et al., Measurement of the atmospheric ν μ energy spectrum from 100 GeV to 200 TeV with the ANTARES telescope, Eur. Phys. J. C 73 (2013) 2606 [ arXiv:1308.1599 ] [INSPIRE].ANTARES collaboration, S. Adrian-Martinez et al., First Search for Point Sources of High Energy Cosmic Neutrinos with the ANTARES Neutrino Telescope, Astrophys. J. 743 (2011) L14 [ arXiv:1108.0292 ] [INSPIRE].ANTARES collaboration, P. Amram et al., The ANTARES optical module, Nucl. Instrum. Meth. A 484 (2002) 369 [ astro-ph/0112172 ] [INSPIRE].ANTARES collaboration, J.A. Aguilar et al., Transmission of light in deep sea water at the site of the ANTARES Neutrino Telescope, Astropart. Phys. 23 (2005) 131 [ astro-ph/0412126 ] [ INSPIRE ].MACRO collaboration, M. Ambrosio et al., Final results of magnetic monopole searches with the MACRO experiment, Eur. Phys. J. C 25 (2002) 511 [ hep-ex/0207020 ] [INSPIRE].BAIKAL collaboration, K. Antipin et al., Search for relativistic magnetic monopoles with the Baikal Neutrino Telescope, Astropart. Phys. 29 (2008) 366 [ INSPIRE ].KM3Net collaboration, S. Adrian-Martinez et al., Letter of intent for KM3NeT 2.0, J. Phys. G 43 (2016) 084001 [ arXiv:1601.07459 ] [INSPIRE]

Search for heavy lepton partners of neutrinos in proton-proton collisions in the context of the type III seesaw mechanism

This is the Pre-print version of the Article. The official publishe version can be accessed from the link below - Copyright @ 2012 ElsevierA search is presented in proton–proton collisions at sqrt(s) = 7TeV for fermionic triplet states expected in type III seesaw models. The search is performed using final states with three isolated charged leptons and an imbalance in transverse momentum. The data, collected with the CMS detector at the LHC, correspond to an integrated luminosity of 4.9 fb−1. No excess of events is observed above the background predicted by the standard model, and the results are interpreted in terms of limits on production cross sections and masses of the heavy partners of the neutrinos in type III seesaw models. Depending on the considered scenarios, lower limits are obtained on the mass of the heavy partner of the neutrino that range from 180 to 210 GeV. These are the first limits on the production of type III seesaw fermionic triplet states reported by an experiment at the LHC.This study is spported by the BMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MEYS (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MSI (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MON, RosAtom, RAS and RFBR (Russia); MSTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEP, IPST and NECTEC (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie programme and the European Research Council (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation a la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the Ministry of Education, Youth and Sports (MEYS) of Czech Republic; the Council of Science and Industrial Research, India; the Compagnia di San Paolo (Torino); and the HOMING PLUS programme of Foundation for Polish Science, cofinanced from European Union, Regional Development Fund

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Search for charged Higgs bosons in the H±→tbH^{\pm} \rightarrow tb decay channel in pppp collisions at s=8\sqrt{s}=8 TeV using the ATLAS detector

Charged Higgs bosons heavier than the top quark and decaying via H ± → tb are searched for in proton-proton collisions measured with the ATLAS experiment at √s=8 TeV corresponding to an integrated luminosity of 20.3fb−1. The production of a charged Higgs boson in association with a top quark, gb → tH ±, is explored in the mass range 200 to 600 GeV using multi-jet final states with one electron or muon. In order to separate the signal from the Standard Model background, analysis techniques combining several kinematic variables are employed. An excess of events above the background-only hypothesis is observed across a wide mass range, amounting to up to 2.4 standard deviations. Upper limits are set on the gb → tH ± production cross section times the branching fraction BR(H ± → tb). Additionally, the complementary s-channel production, qq ′ → H ±, is investigated through a reinterpretation of W ′ → tb searches in ATLAS. Final states with one electron or muon are relevant for H ± masses from 0.4 to 2.0 TeV, whereas the all-hadronic final state covers the range 1.5 to 3.0 TeV. In these search channels, no significant excesses from the predictions of the Standard Model are observed, and upper limits are placed on the qq ′ → H ± production cross section times the branching fraction BR(H ± → tb)