Critical properties of the optical field localization in a three-dimensional percolating system: Theory and experiment

We systematically study the optical field localization in an active three-dimensional (3D) disordered percolating system with light nanoemitters incorporated in percolating clusters. An essential feature of such a hybrid medium is that the clusters are combined into a fractal radiation pattern, in which light is simultaneously emitted and scattered by the disordered structures. Theoretical considerations, based on systematic 3D simulations, reveal nontrivial dynamics in the form of propagation of localized field bunches in the percolating material. We obtain the length of the field localization and dynamical properties of such states as functions of the occupation probability of the disordered clusters. A transition between the dynamical states and narrow point-like fields pinned to the emitters is found. The theoretical analysis of the fractal field properties is followed by an experimental study of the light generation by nanoemitters incorporated in the percolating clusters. The experimental results corroborate theoretical predictions.Comment: 10 pages, 14 figures, to be published Chaos, Solitons & Fractal

Geology of La Reforma caldera complex, Baja California, Mexico

A new geological map at 1:50,000 scale of La Reforma Caldera Complex has been produced applying modern survey methodologies to volcanic areas. This map aims to represent a reliable and objective tool to understand the geological evolution of the region. La Reforma Caldera Complex is a Pleistocene nested caldera located in the central part of the Baja California peninsula, Mexico. The twelve formations defined within the Quaternary volcanic record were grouped into three phases (pre-caldera, caldera, and post-caldera). The pre-caldera phase (>1.35 Ma) is characterized by scattered eruptions, mostly occurred in submarine environment. The caldera phase (1.35–0.96 Ma) groups several distinct explosive and effusive eruptions that formed the present-day caldera depression. The post caldera phase includes scattered effusive eruptions (ended at 0.28 Ma) and resurgence, characterized by several hundred meters of uplift of the central block within the caldera depression

8. EXPERIENCIAS EN EL TRATAMIENTO TÉRMICO DE ACEROS PARA ASEGURAMIENTO DE LA VALIDEZ DE LOS RESULTADOS EN DUREZA ROCKWELL C

Los laboratorios que siguen la norma ISO/IEC 17025 deben asegurar la validez de los resultados cuando ejecutan rutinariamente calibraciones y ensayos, en el caso de la dureza Rockwell, varios de los procedimientos de aseguramiento involucran el uso de materiales homogéneos, a excepción de los materiales de referencia certificados, los aceros en estado de suministro comercial presentan una no homogeneidad en la dureza bastante alta y después del tratamiento térmico comercial, esta persiste. En el presente trabajo se realiza el control de los parámetros de ciclos de tratamiento térmico para tres aceros (AISI 4140, AISI O1 y uno similar al AISI D2), con el fin de obtener una homogeneidad cercana a las estipuladas en la norma ASTM E18-19 para los rangos de dureza de la escala Rockwell C referentes a los bloques patrón. Para confirmar la homogeneidad de los tratamientos térmicos se realizaron mediciones de dureza HRC en un durómetro previamente verificado y análisis metalográficos, encontrando que la variación de temperaturas del tratamiento térmico influye en la homogeneidad de la dureza

8. EXPERIENCIAS EN EL TRATAMIENTO TÉRMICO DE ACEROS PARA ASEGURAMIENTO DE LA VALIDEZ DE LOS RESULTADOS EN DUREZA ROCKWELL C

Los laboratorios que siguen la norma ISO/IEC 17025 deben asegurar la validez de los resultados cuando ejecutan rutinariamente calibraciones y ensayos, en el caso de la dureza Rockwell, varios de los procedimientos de aseguramiento involucran el uso de materiales homogéneos, a excepción de los materiales de referencia certificados, los aceros en estado de suministro comercial presentan una no homogeneidad en la dureza bastante alta y después del tratamiento térmico comercial, esta persiste. En el presente trabajo se realiza el control de los parámetros de ciclos de tratamiento térmico para tres aceros (AISI 4140, AISI O1 y uno similar al AISI D2), con el fin de obtener una homogeneidad cercana a las estipuladas en la norma ASTM E18-19 para los rangos de dureza de la escala Rockwell C referentes a los bloques patrón. Para confirmar la homogeneidad de los tratamientos térmicos se realizaron mediciones de dureza HRC en un durómetro previamente verificado y análisis metalográficos, encontrando que la variación de temperaturas del tratamiento térmico influye en la homogeneidad de la dureza

Interaction of mumps virus V protein variants with STAT1-STAT2 heterodimer: experimental and theoretical studies

<p>Abstract</p> <p>Background</p> <p>Mumps virus V protein has the ability to inhibit the interferon-mediated antiviral response by inducing degradation of STAT proteins. Two virus variants purified from Urabe AM9 mumps virus vaccine differ in their replication and transcription efficiency in cells primed with interferon. Virus susceptibility to IFN was associated with insertion of a non-coded glycine at position 156 in the V protein (VGly) of one virus variant, whereas resistance to IFN was associated with preservation of wild-type phenotype in the V protein (VWT) of the other variant.</p> <p>Results</p> <p>VWT and VGly variants of mumps virus were cloned and sequenced from Urabe AM9 vaccine strain. VGly differs from VWT protein because it possesses an amino acid change Gln₁₀₃Pro (Pro¹⁰³) and the Gly¹⁵⁶insertion. The effect of V protein variants on components of the interferon-stimulated gene factor 3 (ISGF3), STAT1 and STAT2 proteins were experimentally tested in cervical carcinoma cell lines. Expression of VWT protein decreased STAT1 phosphorylation, whereas VGly had no inhibitory effect on either STAT1 or STAT2 phosphorylation. For theoretical analysis of the interaction between V proteins and STAT proteins, 3D structural models of VWT and VGly were predicted by comparing with simian virus 5 (SV5) V protein structure in complex with STAT1-STAT2 heterodimer. <it>In silico </it>analysis showed that VWT-STAT1-STAT2 complex occurs through the V protein Trp-motif (W¹⁷⁴, W¹⁷⁸, W¹⁸⁹) and Glu⁹⁵residue close to the Arg⁴⁰⁹and Lys⁴¹⁵of the nuclear localization signal (NLS) of STAT2, leaving exposed STAT1 Lys residues (K⁸⁵, K⁸⁷, K²⁹⁶, K⁴¹³, K⁵²⁵, K⁶⁷⁹, K⁶⁸⁵), which are susceptible to proteasome degradation. In contrast, the interaction between VGly and STAT1-STAT2 heterodimer occurs in a region far from the NLS of STAT2 without blocking of Lys residues in both STAT1 and STAT2.</p> <p>Conclusions</p> <p>Our results suggest that VWT protein of Urabe AM9 strain of mumps virus may be more efficient than VGly to inactivate both the IFN signaling pathway and antiviral response due to differences in their finest molecular interaction with STAT proteins.</p

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO