Fermion confinement via Quantum Walks in 2D+1 and 3D+1 spacetime

We analyze the properties of a two and three dimensional quantum walk that are inspired by the idea of a brane-world model put forward by Rubakov and Shaposhnikov [1]. In that model, particles are dynamically confined on the brane due to the interaction with a scalar field. We translated this model into an alternate quantum walk with a coin that depends on the external field, with a dependence which mimics a domain wall solution. As in the original model, fermions (in our case, the walker), become localized in one of the dimensions, not from the action of a random noise on the lattice (as in the case of Anderson localization), but from a regular dependence in space. On the other hand, the resulting quantum walk can move freely along the "ordinary" dimension.Comment: 5 pages, 6 figure

One Man\u27s Pregnancy Story

Pregnancy is a challenging time for anyone. For LGBTQ people there are unique obstacles that make it especially difficult to navigate a medical system that was not built for them. Finn Schubert is trans and six months pregnant. He’s loving the experience but stressed by insurance claim denials, concerns for his safety, and medical incompetence. This capstone project includes a 20-minute documentary, text, and a photo essay

A CMOS Mixed Mode Non-Linear Processing Unit for Adaptive Sensor Conditioning in Portable Smart Systems

This paper presents the architecture of a novel non-linear digitally programmable analog unit for sensor output conditioning in battery-operated smart systems. Designed in an 180nm 1.8V standard CMOS technology, by properly setting the 6-bit registers in the arithmetic unit, the voltage inputs are weighted before being processed by a non-linear circuit. Thus, a processing system consisting of a set of these devices suitably tuned and interconnected can be applied to condition a non-linear sensor, improving its behavior both in linearity and operating range, while reducing the effects of cross sensitivity. The robustness of the digital weight tuning is tested simulating a chip-on-the-loop training using a Levenberg-Marquardt-based algorithm. Electric simulations of the proposed unit and the results of its application in a complete neural network-based processing system to improve the linear operating range of a thermistor are presented

A Fully-Integrated CMOS LDO Regulator for Battery-Operated On-Chip Measurement Systems

This paper presents a fully-integrated 0.18 mu m CMOS low drop-out (LDO) regulator designed to drive on-chip low power frontend sensor nodes. The proposed LDO is based on a simple telescopic amplifier stage with internal cascode compensation driving a PMOS pass-device, providing a high precision 1.8 V output voltage for input voltages from 3.6 V to 1.92 V up to a 50 mA load current with only 22 mu A quiescent current. Line and load regulation are respectively better than 0.017 mV/V and 0.003 mV/mA, while recovery times are below 4 mu s over a (-40 degrees C, 120 degrees C) temperature span

Optical sensors based on polymeric nanofibers layers created by electrospinning

Porous materials have become ideal candidates for the creation of optical sensors that are able to reach extremely high sensitivities, due to both the possibility to infiltrate the target substances on them and to their large surface-to-volume ratio. In this work, we present a new alternative for the creation of porous optical sensors based on the use of polymeric nanofibers (NFs) layers fabricated by electrospinning. Polyamide 6 (PA6) NFs layers with average diameters lower than 30 nm and high porosities have been used for the creation of Fabry-Pérot optical sensing structures, which have shown an experimental sensitivity up to 1060 nm/RIU (refractive index unit). This high sensitivity, together with the low production cost and the possibility to be manufactured over large areas, make NFs-based structures a very promising candidate for the development of low-cost and high performance optical sensors

HST FOC spectroscopy of the NLR of NGC 4151. I. Gas kinematics

We present the results from a detailed kinematic analysis of both ground-based, and Hubble Space Telescope/Faint Object Camera long-slit spectroscopy at sub-arcsec spatial resolution, of the narrow-line region of NGC 4151. In agreement with previous work, the extended emission gas (R > 4") is found to be in normal rotation in the galactic plane, a behaviour that we were able to trace even across the nuclear region, where the gas is strongly disturbed by the interaction with the radio jet, and connects smoothly with the large scale rotation defined by the neutral gas emission. The HST data, at 0.029" spatial resolution, allow us for the first time to truly isolate the kinematic behaviour of the individual clouds in the inner narrow-line region. We find that, underlying the perturbations introduced by the radio ejecta, the general velocity field can still be well represented by planar rotation down to a radius of ~ 0.5" (30 pc), distance at which the rotation curve has its turnover. The most striking result that emerges from our analysis is that the galaxy potential derived fitting the rotation curve changes from a "dark halo" at the ENLR distances to dominated by the central mass concentration in the NLR, with an almost Keplerian fall-off in the 1"< R < 4" interval. The observed velocity of the gas at 0.5" implies a mass of M ~ 10E9 M(sol) within the inner 60 pc. The presence of a turnover in the rotation curve indicates that this central mass concentration is extended. The first measured velocity point (outside the region saturated by the nucleus) would imply an enclosed mass of ~ 5E7 M(sol) within R ~ 0.15" (10 pc) which represents an upper limit to any nuclear point mass.Comment: 30 pages (aaspp4.sty), 14 figures. Fig. 1, 2 and 4 available by anonymous FTP at 143.54.2.51 (cd /pub/winge) as GIF files; or upon request to [email protected]. Accepted for publication in the Astrophysical Journal (part 1

Near-Infrared and Star-forming properties of Local Luminous Infrared Galaxies

We use HST NICMOS continuum and Pa-alpha observations to study the near-infrared and star-formation properties of a representative sample of 30 local (d ~ 35-75Mpc) luminous infrared galaxies (LIRGs, infrared 8-1000um luminosities of L_IR=11-11.9[Lsun]). The data provide spatial resolutions of 25-50pc and cover the central ~3.3-7.1kpc regions of these galaxies. About half of the LIRGs show compact (~1-2kpc) Pa-alpha emission with a high surface brightness in the form of nuclear emission, rings, and mini-spirals. The rest of the sample show Pa-alpha emission along the disk and the spiral arms extending over scales of 3-7kpc and larger. About half of the sample contains HII regions with H-alpha luminosities significantly higher than those observed in normal galaxies. There is a linear empirical relationship between the mid-IR 24um and hydrogen recombination (extinction-corrected Pa-alpha) luminosity for these LIRGs, and the HII regions in the central part of M51. This relation holds over more than four decades in luminosity suggesting that the mid-IR emission is a good tracer of the star formation rate (SFR). Analogous to the widely used relation between the SFR and total IR luminosity of Kennicutt (1998), we derive an empirical calibration of the SFR in terms of the monochromatic 24um luminosity that can be used for luminous, dusty galaxies.Comment: Accepted for publication in ApJ. Contact first author for high qualitity version of figure

Associations of Acculturation With Self-Report and Objective Physical Activity and Sedentary Behaviors Among Latinas

Background. Less than 50% of Latinas meet physical activity (PA) recommendations. Acculturation is a complex cultural phenomenon that may influence health behaviors, but associations between acculturation and Latinas’ activity and sedentary levels are unclear. Aim. To examine associations of acculturation with Latinas’ domain-specific and total PA as well as sedentary time. Method. We analyzed baseline data collected between 2011 and 2013 among 410 Latinas (18-65 years) from a PA promotion intervention in San Diego, CA (Fe en Acción/Faith in Action). Participants wore an accelerometer to assess moderate-to-vigorous PA (MVPA) and sedentary time and completed a survey assessing domain-specific PA, sociodemographics, and acculturation as measured by length of residence in the United States and the Bidimensional Acculturation Scale (BAS) for Hispanics. Higher acculturation was defined as longer residence in the United States or being either assimilated or bicultural as per scores on the Hispanic and Anglo domains of the BAS. Results. Based on weekly averages from the accelerometer, Latinas spent 103 minutes in MVPA and 76% of total activity in sedentary time. Only 32% met MVPA recommendations via self-reported leisure-time and transportation PA. Longer residence in the United States was inversely associated with reporting any transportation or occupational PA and meeting MVPA recommendations. Assimilated/bicultural Latinas had significantly less accelerometer-based total MVPA and higher sedentary time than their lower acculturated counterparts. Conclusions. Overall, higher acculturation, based on either measure, was related to less activity. Our findings suggest interventions tailored to the acculturation levels of Latinas are needed to help reduce disparities in Latinas’ PA and sedentary behaviors

Lavados por aspiración colonoscópica para el perfil metataxonómico mucoso de las alteraciones del tracto gastrointestinal asociadas a la espondiloartritis

El estudio de la microbiota del tracto GI de pacientes con espondiloartritis (SpA) se ha centrado en el análisis de muestras de heces, que retratan principalmente la microbiota luminal. El objetivo de este estudio era determinar la contribución de la microbiota de la mucosa y la microbiota luminal a la disbiosis intestinal en la espondiloartritis, utilizando lavados por aspiración colonoscópica (LAC), una alternativa reciente para los estudios regionales del tracto gastrointestinal. Se analizaron 59 CAL (de colon sigmoide e íleon distal), y 41 muestras de heces, de 32 pacientes con SpA y 7 individuos sanos, utilizando perfiles metataxonómicos dirigidos al gen 16S rRNA. Se halló una alta prevalencia de manifestaciones del tracto gastrointestinal entre los pacientes con SpA (65,3%). El perfil metataxonómico confirmó que las muestras de CAL del tracto GI inferior (colon o íleon) presentaban un bacterioma distintivo e indiferenciado, distinto del encontrado en las muestras de heces o en el inicio del tracto GI (cavidad oral [OC]). Las muestras del tracto gastrointestinal inferior y las heces de los pacientes con EI mostraron un comportamiento similar al de la microbiota del grupo con EII, con una riqueza y diversidad microbianas reducidas, en comparación con los controles sanos. Curiosamente, se observó un aumento de los taxones proinflamatorios en los pacientes con EI, como la familia Enterobacteriaceae (principalmente en el íleon), Succinivibrio spp. y Prevotella stercorea. Por el contrario, los pacientes con EA presentaron una disminución significativa de los productores de AGCC Coprococcus catus y Eubacterium biforme. Nuestros datos apoyan el valor de las muestras de CAL para el estudio regional del tracto gastrointestinal y aportan información sobre los posibles "taxones perturbadores" implicados en los trastornos asociados al tracto gastrointestinal observados en los pacientes con SpA.he study of the GI-tract microbiota of spondylarthritis (SpA) patients has focused on the analysis of feces samples, that picture mostly the luminal microbiota. The aim of this study was to determine the contribution of mucosal and luminal microbiome to the gut dysbiosis in SpA, using colonoscopy aspiration lavages (CAL), a recent alternative for regional studies of the GI-tract. We analyzed 59 CAL (from sigmoid colon and distal ileum), and 41 feces samples, from 32 SpA patients and 7 healthy individuals, using 16S rRNA gene-targeted metataxonomic profiling. It was found high prevalence of GI-tract manifestations among SpA patients (65.3%). Metataxonomic profiling, confirmed CAL samples from the lower GI tract (colon or ileum) presented a distinctive and undifferentiated bacteriome and separate from that found in feces’ samples or in the beginning of the GI tract (oral cavity (OC)). Lower GI-tract samples and feces of SpA patients exhibited similar behavior to the microbiota of IBD group with reduced microbial richness and diversity, comparing to the healthy controls. Interestingly, it was found increase in proinflammatory taxa in SpA patients, such as Enterobacteriaceae family (mostly in the ileum), Succinivibrio spp. and Prevotella stercorea. Conversely, SpA patients presented significant decrease in the SCFA producers Coprococcus catus and Eubacterium biforme. Our data support the value of CAL samples for the regional study of GI-tract and contribute with information of potential “disruptor taxa” involved in the GI-tract associated disorders observed in SpA patients

Stellar Population gradients in galaxy discs from the CALIFA survey

While studies of gas-phase metallicity gradients in disc galaxies are common, very little has been done in the acquisition of stellar abundance gradients in the same regions. We present here a comparative study of the stellar metallicity and age distributions in a sample of 62 nearly face-on, spiral galaxies with and without bars, using data from the CALIFA survey. We measure the slopes of the gradients and study their relation with other properties of the galaxies. We find that the mean stellar age and metallicity gradients in the disc are shallow and negative. Furthermore, when normalized to the effective radius of the disc, the slope of the stellar population gradients does not correlate with the mass or with the morphological type of the galaxies. Contrary to this, the values of both age and metallicity at $\sim$2.5 scale-lengths correlate with the central velocity dispersion in a similar manner to the central values of the bulges, although bulges show, on average, older ages and higher metallicities than the discs. One of the goals of the present paper is to test the theoretical prediction that non-linear coupling between the bar and the spiral arms is an efficient mechanism for producing radial migrations across significant distances within discs. The process of radial migration should flatten the stellar metallicity gradient with time and, therefore, we would expect flatter stellar metallicity gradients in barred galaxies. However, we do not find any difference in the metallicity or age gradients in galaxies with without bars. We discuss possible scenarios that can lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&