Shocks in the Quiet Solar Photosphere: A Rather Common Occurrence

We present observations of the quiet solar photosphere in the \ion{Fe}{1} lines at 6302 \AA where at least four different spatial locations exhibit upwards-directed supersonic flows. These upflows can only be detected in the circular polarization profiles as a double-peaked structure in the blue lobe of both \ion{Fe}{1} lines. We have detected cases of either magnetic polarity in the data. The polarization signals associated with the upflows are very weak, which is probably why they had not been seen before in this type of observations. We propose that the observed flows are the signature of aborted convective collapse, similar to the case reported by \citeN{BRRHC+01}. Our data indicates that this phenomenon occurs frequently in the quiet Sun, which means that many magnetic elements (although the fraction is still unknown) are destroyed even before they are formed completely. The spectral signatures of supersonic upflows reported here are probably present in most spectro-polarimetric observations of sufficient signal-to-noise and spatial resolution.Comment: ApJ Letters, submitte

Designing Web-enabled services to provide damage estimation maps caused by natural hazards

The availability of building stock inventory data and demographic information is an important requirement for risk assessment studies when attempting to predict and estimate losses due to natural hazards such as earthquakes, storms, floods or tsunamis. The better this information is provided, the more accurate are predictions on damage to structures and lifelines and the better can expected impacts on the population be estimated. When a disaster strikes, a map is often one of the first requirements for answering questions related to location, casualties and damage zones caused by the event. Maps of appropriate scale that represent relative and absolute damage distributions may be of great importance for rescuing lives and properties, and for providing relief. However, this type of maps is often difficult to obtain during the first hours or even days after the occurrence of a natural disaster. The Open Geospatial Consortium Web Services (OWS) Specifications enable access to datasets and services using shared, distributed and interoperable environments through web-enabled services. In this paper we propose the use of OWS in view of these advantages as a possible solution for issues related to suitable dataset acquisition for risk assessment studies. The design of web-enabled services was carried out using the municipality of Managua (Nicaragua) and the development of damage and loss estimation maps caused by earthquakes as a first case study. Four organizations located in different places are involved in this proposal and connected through web services, each one with a specific role

The Spitzer South Pole Telescope Deep Field Survey: Linking galaxies and halos at z=1.5

We present an analysis of the clustering of high-redshift galaxies in the recently completed 94 deg$^2$ Spitzer-SPT Deep Field survey. Applying flux and color cuts to the mid-infrared photometry efficiently selects galaxies at $z\sim1.5$ in the stellar mass range $10^{10}-10^{11}M_\odot$, making this sample the largest used so far to study such a distant population. We measure the angular correlation function in different flux-limited samples at scales $>6^{\prime \prime}$ (corresponding to physical distances $>0.05$ Mpc) and thereby map the one- and two-halo contributions to the clustering. We fit halo occupation distributions and determine how the central galaxy's stellar mass and satellite occupation depend on the halo mass. We measure a prominent peak in the stellar-to-halo mass ratio at a halo mass of $\log(M_{\rm halo} / M_\odot) = 12.44\pm0.08$, 4.5 times higher than the $z=0$ value. This supports the idea of an evolving mass threshold above which star formation is quenched. We estimate the large-scale bias in the range $b_g=2-4$ and the satellite fraction to be $f_\mathrm{sat}\sim0.2$, showing a clear evolution compared to $z=0$. We also find that, above a given stellar mass limit, the fraction of galaxies that are in similar mass pairs is higher at $z=1.5$ than at $z=0$. In addition, we measure that this fraction mildly increases with the stellar mass limit at $z=1.5$, which is the opposite of the behavior seen at low-redshift.Comment: 32 pages, 22 figures. Published in MNRA

BEC-BCS crossover in a cold and magnetized two color NJL model

The BEC-BCS crossover for a NJL model with diquark interactions is studied in the presence of an external magnetic field. Particular attention is paid to different regularization schemes used in the literature. A thorough comparison of results is performed for the case of a cold and magnetized two-color NJL model. According to our results, the critical chemical potential for the BEC transition exhibits a clear inverse magnetic catalysis effect for magnetic fields in the range $1 \lesssim eB/m_\pi^2 \lesssim 20$. As for the BEC-BCS crossover, the corresponding critical chemical potential is very weakly sensitive to magnetic fields up to $eB \sim 9\ m_\pi^2$, showing a much smaller inverse magnetic catalysis as compared to the BEC transition, and displays a strong magnetic catalysis from this point on.Comment: 15 pages, 8 figures; v2 PRD versio

A Synthetic Stellar Polarization Atlas from 400 to 1000 nm

% context heading (optional) {With the development of new polarimeters for large telescopes, the spectro-polarimetric study of astrophysical bodies is becoming feasible and, indeed, more frequent. In particular, this is permitting the observational study of stellar magnetic fields} % aims heading (mandatory) {With the aim to optimize and interpret this kind of observations, we have produced a spectral atlas of circular polarization in a grid of stellar atmospheric models with effective temperatures between 3500 and 10000 K, surface gravities $\log(g)=3.5-5$, metallicities between 10$^{-2}$ and 1, and magnetic field strengths of 100, 1000 and 5000~G} % methods heading (mandatory) {We have computed the emergent Stokes $I$ and $V$ flux spectra in LTE of more than 10$^5$ spectral lines} % results heading (mandatory) {The atlas and several numerical tools are available in electronic format and may be downloaded from http://download.hao.ucar.edu/pub/PSA/. In this paper we review and discuss some of its most relevant features, such as which spectral regions and individual lines harbor the strongest signals, what are interesting lines to observe, how to disentangle field strength from filling factor, etc.}Comment: To appear in A&

Surtos com elevada mortalidade em Equinos no Estado de Pernambuco

Surtos de enfermidades com alta mortalidade em equinos são raros no nordeste brasileiro, estando usualmente associados com processos tóxicos ou infecciosos. No presente trabalho são descritos os aspectos epidemiológicos, clínicopatológicos e laboratoriais de quatro surtos entre os anos de 2008 e 2011, nos quais os animais desenvolveram sinaisdigestivos (cólica, duodeno-jejunite), neurológicos (estupor, flacidez da cauda e disfagia) e em outros sistemas em menor ocorrência em quatro municípios da Zona-da-Mata pernambucana. Semelhantes condições ambientais e de manejo alimentar, especialmente sobre o volumoso foram observadas. Tratamento sintomático instituído foi ineficaz na maioriados casos. A análise global dos achados sugere o diagnóstico presuntivo de tóxi-infecção por Clostridium botulinum, mas outras bactérias do gênero podem estar envolvidas

Characterization of enamel surface after orthodontic brackets debonding: an in vitro study

Poster presented at the SPMicros Congress “Microscopy in Research” - XLVII Annual Congress of the Portuguese Society for Microscopy. Egas Moniz, Monte de Caparica, 9-10 December 2013PEst-OE/CTM-UI0084/2011 grant (Fundação para a Ciência e a Tecnologia

Characterization of enamel surface after orthodontic brackets debonding: an in vitro study

Abstract of the poster presented at the SPMicros Congress “Microscopy in Research” - XLVII Annual Congress of the Portuguese Society for Microscopy. Egas Moniz, Monte de Caparica, 9-10 December 2013.PEst-OE/CTM-UI0084/2011 grant (Fundação para a Ciência e a Tecnologia