904 research outputs found
Citizenship rights for immigrants. National political processes and cross-national convergence in Western Europe, 1980–2008
Immigrant citizenship rights in the nation-state reference both theories of cross-national convergence and the resilience of national political processes. This article investigates European countries' attribution of rights to immigrants: Have these rights become more inclusive and more similar across countries? Are they affected by EU membership, the role of the judiciary, the party in power, the size of the immigrant electorate, or pressure exerted by anti-immigrant parties? Original data on 10 European countries, 1980-2008, reveal no evidence for cross-national convergence. Rights tended to become more inclusive until 2002, but stagnated afterward. Electoral changes drive these trends: growth of the immigrant electorate led to expansion, but countermobilization by right-wing parties slowed or reversed liberalizations. These electoral mechanisms are in turn shaped by long-standing policy traditions, leading to strong path dependence and the reproduction of preexisting cross-national differences. © 2012 by The University of Chicago. All rights reserved
The nature of GRB-selected submillimeter galaxies: hot and young
We present detailed fits of the spectral energy distributions (SEDs) of four
submillimeter (submm) galaxies selected by the presence of a gamma-ray burst
(GRB) event (GRBs 980703, 000210, 000418 and 010222). These faint ~3 mJy submm
emitters at redshift ~1 are characterized by an unusual combination of long-
and short-wavelength properties, namely enhanced submm and/or radio emission
combined with optical faintness and blue colors. We exclude an active galactic
nucleus as the source of long-wavelength emission. From the SED fits we
conclude that the four galaxies are young (ages <2 Gyr), highly starforming
(star formation rates ~150 MSun/yr), low-mass (stellar masses ~10^10 MSun) and
dusty (dust masses ~3x10^8 MSun). Their high dust temperatures (Td>45 K)
indicate that GRB host galaxies are hotter, younger, and less massive
counterparts to submm-selected galaxies detected so far. Future facilities like
Herschel, JCMT/SCUBA-2 and ALMA will test this hypothesis enabling measurement
of dust temperatures of fainter GRB-selected galaxies.Comment: 9 pages, 2 figures, submitted to ApJ, for SED templates, see
http://archive.dark-cosmology.dk
Identification of Biodiversity and Other Forest Attributes for Sustainable Forest Management: Siberian Forest Case Study
This paper attempts to identify characteristics of biodiversity and other (forest) ecosystem conditions that are considered essential for a description of ecosystem functioning and development of sustainable forest management practices in the Siberian forests. This is accomplished through an analysis of net primary production of phytomass (NPP) which acts as a proxy for ecosystem functioning. Rough Sets (RS) analysis is applied to study the Siberian ecoregions classified into compact and cohesive NPP performance classes. Through a heuristic procedure, a reduced set of attributes is generated for a NPP classification problem. In order to interpret relationships between various forest characteristics, so-called "interesting rules" are generated on a basis of reduced problem description. These "interesting rules" provide means to draw conclusions in the form of knowledge statements about functioning of the Siberian forests
An improved direct colorimetric method for the quantitative analysis of urinary hippuric acid as an index of toluene exposure
An improved direct colorimetric method for determining the concentration of urinary hippuric acid as an index of toluene exposure was described. One tenth ml of urine was diluted with 0.4 ml 0.01 M phosphate buffer H 6.9 and mixed with 0.5 ml pyridine. The mixture was layered on 0.2 ml benzenesulfonyl chloride. The reaction was started by mixing for one min with a mechanical shaker. The colored solution was allowed to stand for 30 min, diluted with 5 ml ethanol, and absorbance measured at 410 nm within 30 min after the dilution. The coefficient of variation of this method was 6% and the recovery 103% when urine contains about 0.2-0.5 mg hippuric acid per ml of urine. The concentration was linear up to 2.0 mg per ml hippuric acid in a specimen.</p
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Learning the preferences of physicians for the organization of result lists of medical evidence articles
Objectives
Despite many clinical decision support systems (CDSSs) being rated as highly usable, CDSSs have not been widely adopted in clinical practice. We posit that there are factors aside from usability that impact adoption of CDSSs; in particular we are interested in the role played by MDs intrinsic motivation to use computer-based support. Our research aim is to investigate the relationship between usability and intrinsic motivation in order to learn about adoption of CDSS in clinical practice.
Methods
Following the evaluation of a CDSS, 19 MDs completed a 2 part questionnaire about their intrinsic motivation to use computer-based support in general and the usability of the evaluated CDSS.
Results
The analysis of MDs motivation to use computer-based support demonstrated that MDs are comfortable using computer-based support and in general find using it quite easy (a motivation rating of 0.66 on a (0, 1) scale was computed). However MDs also reported a perceived lack of competence associated with a lack of prior experience using technology in practice, which results in pressure and tension. The considered CDSS scored highly on all usability dimensions and a usability rating of 0.74 was recorded. The examination of the relationship between motivation and usability suggested that users who were motivated to use computer-based support experienced better usability than those who reported low levels of motivation.
Conclusions
Our small case study suggests that an important factor supplementing the usability of CDSSs is intrinsic motivation to use computer-based support in general. We posit that the lack of such a measure thus far in CDSS evaluation may to some extent explain seeming MD satisfaction with CDSSs on one hand, but their limited adoption on the other. We recommend that clinical managers responsible for deploying CDSS should invest in training MDs to use technology underlying computer-based support applications instead of focusing only on the features of the specific CDSS to be deployed
Another short-burst host galaxy with an optically obscured high star formation rate: The case of GRB 071227
We report on radio continuum observations of the host galaxy of the short
gamma-ray burst 071227 (z=0.381) with the Australia Telescope Compact Array
(ATCA). We detect the galaxy in the 5.5 GHz band with an integrated flux
density of Fnu = 43 +/- 11 microJy, corresponding to an unobscured
star-formation rate (SFR) of about 24 Msun/yr, forty times higher than what was
found from optical emission lines. Among the ~30 well-identified and studied
host galaxies of short bursts this is the third case where the host is found to
undergo an episode of intense star formation. This suggests that a fraction of
all short-burst progenitors hosted in star-forming galaxies could be physically
related to recent star formation activity, implying a relatively short merger
time scale.Comment: 6 pages, ApJ, accepted for publicatio
Dust attenuation in 2<z<3 star-forming galaxies from deep ALMA observations of the Hubble Ultra Deep Field
17 pages, 7 figures, accepted version to be published in MNRASWe present the results of a new study of the relationship between infrared excess (IRX ≡ L IR/L UV), ultraviolet (UV) spectral slope (β) and stellar mass at redshifts 2 < z < 3, based on a deep Atacama Large Millimeter Array (ALMA) 1.3-mm continuum mosaic of the Hubble Ultra Deep Field. Excluding the most heavily obscured sources, we use a stacking analysis to show that z ≃ 2.5 star-forming galaxies in the mass range 9.25 ≤ log(M*/M ⊙) ≤ 10.75 are fully consistent with the IRX-β relation expected for a relatively grey attenuation curve, similar to the commonly adopted Calzetti law. Based on a large, mass-complete sample of 2 ≤ z ≤ 3 star-forming galaxies drawn frommultiple surveys, we proceed to derive a new empirical relationship between β and stellar mass, making it possible to predict UV attenuation (A1600) and IRX as a function of stellar mass, for any assumed attenuation law. Once again, we find that z ≃ 2.5 star-forming galaxies follow A1600-M* and IRX-M* relations consistent with a relatively grey attenuation law, and find no compelling evidence that star-forming galaxies at this epoch follow a reddening law as steep as the Small Magellanic Cloud (SMC) extinction curve. In fact, we use a simple simulation to demonstrate that previous determinations of the IRX-β relation may have been biased towards low values of IRX at red values of β, mimicking the signature expected for an SMC-like dust law. We show that this provides a plausible mechanism for reconciling apparently contradictory results in the literature and that, based on typical measurement uncertainties, stellar mass provides a cleaner prediction of UV attenuation than β. Although the situation at lower stellar masses remains uncertain, we conclude that for 2 < z < 3 star-forming galaxies with log(M*/M ⊙) ≥ 9.75, both the IRX-β and IRX-M* relations are well described by a Calzetti-like attenuation law.Peer reviewe
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