Spontaneous symmetry breaking, and strings defects in hypercomplex gauge field theories

Inspired by the appearance of split-complex structures in the dimensional reduction of string theory, and in the theories emerging as byproducts, we study the hyper-complex formulation of Abelian gauge field theories, by incorporating a new complex unit to the usual complex one. The hypercomplex version of the traditional Mexican hat potential associated with the $U(1)$ gauge field theory, corresponds to a {\it hybrid} potential with two real components, and with $U(1)\times SO(1,1)$ as symmetry group. Each component corresponds to a deformation of the hat potential, with the appearance of a new degenerate vacuum. Hypercomplex electrodynamics will show novel properties, such as the spontaneous symmetry breaking scenarios with running masses for the vectorial and scalar Higgs fields, and the Aharonov-Bohm type strings defects as exact solutions; these topological defects may be detected only by quantum interference of charged particles through gauge invariant loop integrals. In a particular limit, the {\it hyperbolic} electrodynamics does not admit topological defects associated with continuous symmetriesComment: 40 page

Strong, lightweight, and recoverable three-dimensional ceramic nanolattices

Ceramics have some of the highest strength- and stiffness-to-weight ratios of any material but are suboptimal for use as structural materials because of their brittleness and sensitivity to flaws. We demonstrate the creation of structural metamaterials composed of nanoscale ceramics that are simultaneously ultralight, strong, and energy-absorbing and can recover their original shape after compressions in excess of 50% strain. Hollow-tube alumina nanolattices were fabricated using two-photon lithography, atomic layer deposition, and oxygen plasma etching. Structures were made with wall thicknesses of 5 to 60 nanometers and densities of 6.3 to 258 kilograms per cubic meter. Compression experiments revealed that optimizing the wall thickness-to-radius ratio of the tubes can suppress brittle fracture in the constituent solid in favor of elastic shell buckling, resulting in ductile-like deformation and recoverability

INTUBACI 3N OROTRAQUEAL CON AIRTRAQ VERSUS LARINGOSCOPIA CONVENCIONAL EN PACIENTES CON OBESIDAD TIPO I PROGRAMADOS PARA CIRUG\ucdA ELECTIVA.

El presente estudio tuvo como objetivo comparar la eficacia de la intubaci\uf3n orotraqueal con laringoscopia Airtraq versus laringoscopia convencional en pacientes con obesidad tipo I programados para cirug\ueda electiva. Se realiz\uf3 un estudio tipo ensayo cl\uednico controlado simple ciego, la muestra estuvo conformada por 55 pacientes distribuidos aleatoriamente en 25 pacientes intubados con laringoscopio Airtraq y 30 intubados con laringoscopio Macintosh. El promedio de edad fue de 31,73 \ub1 7,07 a\uf1os, con predominio del sexo femenino, con \uedndice de masa corporal promedio de 31.06\ub12,56 para el grupo de Airtraq y de 33,1\ub12,43 para el grupo de Macintosh. La cirug\ueda m\ue1s frecuente en ambos grupos fue la Colecistectom\ueda Laparosc\uf3pica, clasificaci\uf3n de Mallampati grado II. El tiempo de intubaci\uf3n promedio fue de 17,97\ub113,04 minutos para pacientes que utilizaron Airtraq y 13,04\ub11,19 minutos para el grupo de Macintosh. La necesidad de asistencia para la intubaci\uf3n endotraqueal fue por retracci\uf3n del labio (36,7%) y alineaci\uf3n manual de la glotis (3,3%) para los pacientes con Macintosh. Del grupo de Airtraq\uae 28% requiri\uf3 de 2 intentos. No se observaron variaciones en los par\ue1metros hemodin\ue1micos en los diferentes momentos y 16,7% present\uf3 lesi\uf3n de v\ueda a\ue9rea como complicaci\uf3n en el grupo Macintosh. Para el \uedndice de intubaci\uf3n dif\uedcil se report\uf3 68% y 63,3% como f\ue1cil para los grupos Airtraq\uae y Macintosh respectivamente. En conclusi\uf3n, ambos laringoscopio representa una herramienta a \ufatil para los pacientes obesos; sin embargo, el resultado final depender\ue1 de las caracter\uedsticas del paciente, la disponibilidad de equipos, y la destreza y habilidades del operador.PALABRAS CLAVES DEL AUTOR: V\ueda a\ue9rea. Obesidad. Cirug\ueda ambulatoria. (DeCS: Bireme, Lilasc).ABSTRACTOROTRACHEAL INTUBATION WITH AIRTRAQ VERSUS CONVENTIONAL LARYNGOSCOPY IN OBESE TYPE I PATIENTS SCHEDULED FOR ELECTIVE SURGERY. The objective of this study was to compare the efficiency in orotracheal intubation using Airtraq versus conventional laryngoscopy in obese type I patients scheduled for elective surgery. A single blind controlled clinical trial study was conducted, the sample was comprised of 55 patients randomly distributed in 25 patients using Airtraq laryngoscope and 30 using McIntosh laryngoscope. The mean age was 31.73 \ub1 7.07 years, female gender was predominant; the average body mass index was 31.06\ub12.56 for the Airtraq group and 33.1\ub12.43 for the McIntosh group. Additionally the most frequent surgery performed in both groups was laparoscopic cholecystectomy and Mallampati classification was Grade II. Average intubation time was 17.97\ub113.04 minutes for patients who used Airtraq and 13, 04\ub11, 19 minutes for the Macintosh group. The need for assistance for endotracheal intubation was by retraction of the lip (36.7%) and manual alignment of the glottis (3.3%) for patients with Macintosh. At the same time, 28% of the Airtraq group required 2 attempts. There were no variations in hemodynamic parameters at any stage and 16.7% had injury of the airways as a complication in the Macintosh group. The difficult intubation rate reported was 68% and 63.3%, respectively, in both Airtraq and Macintosh groups. In conclusion, both laryngoscopes represent a useful tool for obese patients; however, the final result will depend on the characteristics of the patient, equipment availability, and the dexterity and skill of the operator.KEY WORDS: Airway. Obesity. Ambulatory Surgical Procedures. (DeCS: NLM, Pubmed).<br

Evolution of the Mass-Metallicity relations in passive and star-forming galaxies from SPH-cosmological simulations

We present results from SPH-cosmological simulations, including self-consistent modelling of SN feedback and chemical evolution, of galaxies belonging to two clusters and twelve groups. We reproduce the mass-metallicity (ZM) relation of galaxies classified in two samples according to their star-forming activity, as parametrized by their sSFR, across a redshift range up to z=2. Its slope shows irrelevant evolution in the passive sample, being steeper in groups than in clusters. However, the sub-sample of high-mass passive galaxies only is characterized by a steep increase of the slope with redshift, from which it can be inferred that the bulk of the slope evolution of the ZM relation is driven by the more massive passive objects. (...ABRIDGED...) The ZM relation for the star-forming sample reveals an increasing scatter with redshift, indicating that it is still being built at early epochs. The star-forming galaxies make up a tight sequence in the SFR-M_* plane at high redshift, whose scatter increases with time alongside with the consolidation of the passive sequence. We also confirm the anti-correlation between sSFR and stellar mass, pointing at a key role of the former in determining the galaxy downsizing, as the most significant means of diagnostics of the star formation efficiency. Likewise, an anti-correlation between sSFR and metallicity can be established for the star-forming galaxies, while on the contrary more active galaxies in terms of simple SFR are also metal-richer. We discuss these results in terms of the mechanisms driving the evolution within the high- and low-mass regimes at different epochs: mergers, feedback-driven outflows and the intrinsic variation of the star formation efficiency.Comment: Emended list of author

The QUEST-La Silla AGN Variability Survey

We present the characterization and initial results from the QUEST-La Silla AGN variability survey. This is an effort to obtain well sampled optical light curves in extragalactic fields with unique multi-wavelength observations. We present photometry obtained from 2010 to 2012 in the XMM-COSMOS field, which was observed over 150 nights using the QUEST camera on the ESO-Schmidt telescope. The survey uses a broadband filter, the $Q$-band, similar to the union of the $g$ and the $r$ filters, achieving an intrinsic photometric dispersion of $0.05$ mag, and a systematic error of $0.05$ mag in the zero-point. Since some detectors of the camera show significant non-linearity, we use a linear correlation to fit the zero-points as a function of the instrumental magnitudes, thus obtaining a good correction to the non-linear behavior of these detectors. We obtain good photometry to an equivalent limiting magnitude of $r\sim 20.5$. Studying the optical variability of X-ray detected sources in the XMM-COSMOS field, we find that the survey is $\sim75-80$% complete to magnitudes $r\sim20$, and $\sim67$% complete to a magnitude $r\sim21$. The determination and parameterization of the structure function (${SF}_{norm}(\tau) = A \tau^{\gamma}$) of the variable sources shows that most BL AGN are characterized by $A > 0.1$ and $\gamma > 0.025$. It is further shown that variable NL AGN and GAL sources occupying the same parameter space in $A$ and $\gamma$ are very likely to correspond to obscured or low luminosity AGN. Our samples are, however, small, and we expect to revisit these results using larger samples with longer light curves obtained as part of our ongoing survey.Comment: Accepted for publication in Ap

Determinación por cromatografía de aminoácidos en Iridaea ciliata e lridaea laminarioides

Se estudió el contenido de aminoácidos libres y de aquellos provenientes de hidro/izados de proteínas en Iridaea ciliata e lridaea laminarioides, por cromatografía en papel y en placas de celulosa. La composición de aminoácidos en ambas algas es muy similar. Los aminoácidos glicina, alanina, arginina, ácido glutámico y ácido aspártico son los que se encuentran en mayor proporción