Magellan LDSS3 emission confirmation of galaxies hosting metal-rich Lyman-alpha absorption systems

Using the Low Dispersion Survey Spectrograph 3 at the Magellan II Clay Telescope, we target {candidate absorption host galaxies} detected in deep optical imaging {(reaching limiting apparent magnitudes of 23.0-26.5 in $g, r, i,$ and $z$ filters) in the fields of three QSOs, each of which shows the presence of high metallicity, high $N_{\rm HI}$ absorption systems in their spectra (Q0826-2230: $z_{abs}$=0.9110, Q1323-0021: $z_{abs}=0.7160$, Q1436-0051: $z_{abs}=0.7377, 0.9281$). We confirm three host galaxies {at redshifts 0.7387, 0.7401, and 0.9286} for two of the Lyman-$\alpha$ absorption systems (one with two galaxies interacting). For these systems, we are able to determine the star formation rates (SFRs); impact parameters (from previous imaging detections); the velocity shift between the absorption and emission redshifts; and, for one system, also the emission metallicity.} Based on previous photometry, we find these galaxies have L$>$L$^{\ast}$. The [O II] SFRs for these galaxies are in the range $11-25$ M$_{\odot}$ yr$^{-1}$ {(uncorrected for dust)}, while the impact parameters lie in the range $35-54$ kpc. {Despite the fact that we have confirmed galaxies at 50 kpc from the QSO, no gradient in metallicity is indicated between the absorption metallicity along the QSO line of sight and the emission line metallicity in the galaxies.} We confirm the anti-correlation between impact parameter and $N_{\rm HI}$ from the literature. We also report the emission redshift of five other galaxies: three at $z_{em}>z_{QSO}$, and two (L$<$L$^{\ast}$) at $z_{em}<z_{QSO}$ not corresponding to any known absorption systems.Comment: 14 pages, 7 figures, 4 tables, accepted to MNRA

Fundamental constraints on particle tracking with optical tweezers

A general quantum limit to the sensitivity of particle position measurements is derived following the simple principle of the Heisenberg microscope. The value of this limit is calculated for particles in the Rayleigh and Mie scattering regimes, and with parameters which are relevant to optical tweezers experiments. The minimum power required to observe the zero-point motion of a levitating bead is also calculated, with the optimal particle diameter always smaller than the wavelength. We show that recent optical tweezers experiments are within two orders of magnitude of quantum limited sensitivity, suggesting that quantum optical resources may soon play an important role in high sensitivity tracking applications

The Strange Tale of Wesley and Florence Garrison: Racial Crosscurrents of the Postwar Florida Republican Party

For the first two thirds of the 20th Century, the Republican Party of Florida had a well-deserved reputation for being quiet, weak, and ineffectual. The Democratic Party dominated electoral politics so completely that some counties in the panhandle and north central Florida prided themselves on having no registered Republicans. Yet at the 1952 state Republican convention, held in the sleepy college town of Gainesville, the participants acted as if their meeting mattered. A group of upstarts led by Miami real estate developers Wesley and Florence Garrison, a couple some regarded as reformers and some regarded as rabblerousers, commandeered the front row of seating and refused to allow the state executive committee to take their positions on stage. After the Alachua County sheriff restored order, the Garrisons and their supporters made their presence known by repeatedly interrupting the opening roll call with chants of contest and communist, and slamming their chair legs loudly against the tile floor. At issue was the party\u27s decision to abandon the primary election and select its delegates to the Republican national convention without participation from rank and file party members, a choice the Garrisons vehemently opposed. Despite the repeated distractions, however, the state party went on with its agenda and appointed a delegate slate that excluded the Gamsons and their allies

Experiment towards continuous-variable entanglement swapping: Highly correlated four-partite quantum state

We present a protocol for performing entanglement swapping with intense pulsed beams. In a first step, the generation of amplitude correlations between two systems that have never interacted directly is demonstrated. This is verified in direct detection with electronic modulation of the detected photocurrents. The measured correlations are better than expected from a classical reconstruction scheme. In the entanglement swapping process, a four--partite entangled state is generated. We prove experimentally that the amplitudes of the four optical modes are quantum correlated 3 dB below shot noise, which is due to the potential four--party entanglement.Comment: 9 pages, 10 figures, update of references 9 and 10; minor inconsistency in notation removed; format for units in the figures change

Household Transmission of Rotavirus in a Community with Rotavirus Vaccination in Quininde, Ecuador

Background: We studied the transmission of rotavirus infection in households in peri-urban Ecuador in the vaccination era. Methods: Stool samples were collected from household contacts of child rotavirus cases, diarrhea controls and healthy controls following presentation of the index child to health facilities. Rotavirus infection status of contacts was determined by RT-qPCR. We examined factors associated with transmissibility (index-case characteristics) and susceptibility (householdcontact characteristics). Results: Amongst cases, diarrhea controls and healthy control household contacts, infection attack rates (iAR) were 55%, 8% and 2%, (n = 137, 130, 137) respectively. iARs were higher from index cases with vomiting, and amongst siblings. Disease ARs were higher when the index child was ,18 months and had vomiting, with household contact ,10 years and those sharing a room with the index case being more susceptible. We found no evidence of asymptomatic infections leading to disease transmission. Conclusion: Transmission rates of rotavirus are high in households with an infected child, while background infections are rare. We have identified factors associated with transmission (vomiting/young age of index case) and susceptibility (young age/sharing a room/being a sibling of the index case). Vaccination may lead to indirect benefits by averting episodes or reducing symptoms in vaccinees

Synchrotron radiation x-ray topography and defect selective etching analysis of threading dislocations in GaN

The crystal quality of bulk GaN crystals is continuously improving due to advances in GaN growth techniques. Defect characterization of the GaN substrates by conventional methods is impeded by the very low dislocation density and a large scale defect analysis method is needed. White beam synchrotron radiation x-ray topography (SR-XRT) is a rapid and non-destructive technique for dislocation analysis on a large scale. In this study, the defect structure of an ammonothermal c-plane GaN substrate was recorded using SR-XRT and the image contrast caused by the dislocation induced microstrain was simulated. The simulations and experimental observations agree excellently and the SR-XRT image contrasts of mixed and screw dislocations were determined. Apart from a few exceptions, defect selective etching measurements were shown to correspond one to one with the SR-XRT results.Peer reviewe

Symmetries and reversing symmetries of toral automorphisms

Toral automorphisms, represented by unimodular integer matrices, are investigated with respect to their symmetries and reversing symmetries. We characterize the symmetry groups of GL(n,Z) matrices with simple spectrum through their connection with unit groups in orders of algebraic number fields. For the question of reversibility, we derive necessary conditions in terms of the characteristic polynomial and the polynomial invariants. We also briefly discuss extensions to (reversing) symmetries within affine transformations, to PGL(n,Z) matrices, and to the more general setting of integer matrices beyond the unimodular ones.Comment: 34 page

The Sloan Digital Sky Survey Quasar Lens Search. IV. Statistical Lens Sample from the Fifth Data Release

We present the second report of our systematic search for strongly lensed quasars from the data of the Sloan Digital Sky Survey (SDSS). From extensive follow-up observations of 136 candidate objects, we find 36 lenses in the full sample of 77,429 spectroscopically confirmed quasars in the SDSS Data Release 5. We then define a complete sample of 19 lenses, including 11 from our previous search in the SDSS Data Release 3, from the sample of 36,287 quasars with i<19.1 in the redshift range 0.6<z<2.2, where we require the lenses to have image separations of 1"<\theta<20" and i-band magnitude differences between the two images smaller than 1.25 mag. Among the 19 lensed quasars, 3 have quadruple-image configurations, while the remaining 16 show double images. This lens sample constrains the cosmological constant to be \Omega_\Lambda=0.84^{+0.06}_{-0.08}(stat.)^{+0.09}_{-0.07}(syst.) assuming a flat universe, which is in good agreement with other cosmological observations. We also report the discoveries of 7 binary quasars with separations ranging from 1.1" to 16.6", which are identified in the course of our lens survey. This study concludes the construction of our statistical lens sample in the full SDSS-I data set.Comment: 37 pages, 2 figures and 5 tables, accepted to A

A hazard analysis method for systematic identification of safety requirements for user interface software in medical devices

© Springer International Publishing AG (outside the US) 2017. Formal methods technologies have the potential to verify the usability and safety of user interface (UI) software design in medical devices, enabling significant reductions in use errors and consequential safety incidents with such devices. This however depends on comprehensive and verifiable safety requirements to leverage these techniques for detecting and preventing flaws in UI software that can induce use errors. This paper presents a hazard analysis method that extends Leveson’s System Theoretic Process Analysis (STPA) with a comprehensive set of causal factor categories, so as to provide developers with clear guidelines for systematic identification of use-related hazards associated with medical devices, their causes embedded in UI software design, and safety requirements for mitigating such hazards. The method is evaluated with a case study on the Gantry-2 radiation therapy system, which demonstrates that (1) as compared to standard STPA, our method allowed us to identify more UI software design issues likely to cause use-related hazards; and (2) the identified UI software design issues facilitated the definition of precise, verifiable safety requirements for UI software, which could be readily formalized in verification tools such as Prototype Verification System (PVS).- U.S. Food and Drug Administration(NORTE-01-0145-FEDER-000016)Sandy Weininger (FDA), Scott Thiel (Navigant Consulting, Inc.), Michelle Jump (Stryker), Stefania Gnesi (ISTI/CNR) and the CHI+MED team (www.chi-med.ac.uk) provided useful feedback and inputs. Paolo Masci’s work is supported by the North Portugal Regional Operational Programme (NORTE 2020) under the PORTUGAL 2020 Partnership Agreement, and by the European Regional Development Fund (ERDF) within Project “NORTE-01-0145-FEDER-000016”.info:eu-repo/semantics/publishedVersio

Evaluation of formal IDEs for human-machine interface design and analysis: the case of CIRCUS and PVSio-web

Critical human-machine interfaces are present in many systems including avionics systems and medical devices. Use error is a concern in these systems both in terms of hardware panels and input devices, and the software that drives the interfaces. Guaranteeing safe usability, in terms of buttons, knobs and displays is now a key element in the overall safety of the system. New integrated development environments (IDEs) based on formal methods technologies have been developed by the research community to support the design and analysis of high-confidence human-machine interfaces. To date, little work has focused on the comparison of these particular types of formal IDEs. This paper compares and evaluates two state-of-the-art toolkits: CIRCUS, a model-based development and analysis tool based on Petri net extensions, and PVSio-web, a prototyping toolkit based on the PVS theorem proving system.This work is partially supported by: Project NORTE-01-0145-FEDER-000016, financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) PhD scholarship