2,641 research outputs found
Finding bright <i>z</i> ≥ 6.6 Ly <i>α</i> emitters with lensing: prospects for <i>Euclid</i>
We model the Ly luminosity function to estimate the
number of lensed high Ly emitters that may be detected by the
Euclid Deep Survey. To span the whole range of possible predictions we exploit
two Ly luminosity function models and two strong gravitational lensing
models from the literature. We show that the planned Euclid Deep Survey
observing 40 deg over the 920-1850 nm wavelength range down to a flux limit
of erg scm will enable us to find
between and deg lensed Ly emitters at depending on the adopted Ly luminosity function and strong
gravitational lensing model. The obvious [OII], [OIII] and H
contaminants of the Ly lensed population will be identified with the
help of Euclid's spectral resolving power, while the SKA will enable the
identification of the interloper population of H emitters. By combining
Euclid and the SKA, we will thus be able to identify, for the first time, a
sample of to lensed Ly emitters at .Comment: Accepted for publication in MNRAS on 20 June 2017. (NEW: Amended
Latex
Evaluation of the phosphomannose isomerase-based selection system for gene transfer in grape
The suitability of the PMI-based system for efficient gene transfer in grape was assessed on V. vinifera ‘Brachetto’ and ‘Chardonnay’ and the rootstock '110 Richter'. The effect of mannose on non-transformed tissues was evaluated during a long culture period in the crucial stages of morphogenesis from callus to plantlet. Grape tissues of the genotypes used were affected by mannose as the carbohydrate source, damage, however, appeared after extremely long culture times. In addition, plantlets were regenerated from embryogenic calli after co-culture with Agrobacterium LBA 4404 carrying the manA gene in the PMI-GUS-Intron plasmid based on the pNOV2819 vector by Syngenta (Positech® system). Plants recovered after selection in the presence of mannose were found to be non-transgenic for the manA gene. Accordingly, PMI seems to be an unsuitable alternative to traditional marker gene selection for successful gene transfer in grape.
Costs associated with the management of waste from healthcare facilities: an analysis at national and site level
Given rising spend on the provision of healthcare services, the sustainable management of waste from healthcare facilities is increasingly becoming a focus as a means of reducing public health risks and financial costs. Using data on per capita healthcare spend at the national level, as well as a case study of a hospital in Italy, this study examined the relationship between trends in waste generation and the associated costs of managing the waste. At the national level, healthcare spend as a percentage of gross domestic product positively correlated with waste arisings. At the site level, waste generation and type were linked to department type and clinical performance, with the top three highest generating departments of hazardous healthcare waste being anaesthetics (5.96 kg day-1 bed-1), paediatric and intensive care (3.37 kg day-1 bed-1) and gastroenterology-digestive endoscopy (3.09 kg day-1 bed-1). Annual overall waste management costs were US2.36 kg-1, with the management of the hazardous fraction of the waste being highest at $US3,707,939. In Italy, reduction in both waste arisings and the associated costs could be realised through various means, including improved waste segregation, and linking the TARI tax to waste generation
The Stripe 82 1-2 GHz Very Large Array Snapshot Survey: Multiwavelength Counterparts
We have combined spectrosopic and photometric data from the Sloan Digital Sky
Survey (SDSS) with GHz radio observations, conducted as part of the
Stripe 82 GHz Snapshot Survey using the Karl G. Jansky Very Large Array
(VLA), which covers sq degrees, to a flux limit of 88 Jy rms.
Cross-matching the radio source components with optical data via
visual inspection results in a final sample of cross-matched objects,
of which have spectroscopic redshifts and objects have
photometric redshifts. Three previously undiscovered Giant Radio Galaxies
(GRGs) were found during the cross-matching process, which would have been
missed using automated techniques. For the objects with spectroscopy we
separate radio-loud Active Galactic Nuclei (AGN) and star-forming galaxies
(SFGs) using three diagnostics and then further divide our radio-loud AGN into
the HERG and LERG populations. A control matched sample of HERGs and LERGs,
matched on stellar mass, redshift and radio luminosity, reveals that the host
galaxies of LERGs are redder and more concentrated than HERGs. By combining
with near-infrared data, we demonstrate that LERGs also follow a tight
relationship. These results imply the LERG population are hosted by population
of massive, passively evolving early-type galaxies. We go on to show that
HERGs, LERGs, QSOs and star-forming galaxies in our sample all reside in
different regions of a WISE colour-colour diagram. This cross-matched sample
bridges the gap between previous `wide but shallow' and `deep but narrow'
samples and will be useful for a number of future investigations.Comment: 17 pages, 19 figures. Resubmitted to MNRAS after the initial comment
Digital threats to democracy: comparative lessons and possible remedies
We introduce a special issue that collects eight articles, comprising research from twenty-three countries and four continents on the sources, impact on citizens, and possible remedies to various digital threats to democracy, ranging from disinformation to hate speech to state interference with online freedoms. We set these contributions against the backdrop of a profound change in how scholars think about the implications of digital media for democracy. From the utopianism that prevailed from the 1990s until the early 2010s, the post-2016 reckoning has led to a change in the kinds of questions scholars ask, with the focus gradually shifting to investigations of the threats, rather than the benefits, of the Internet. The eight contributions presented in this special issue employ a variety of disciplinary approaches and methods, often comparing different countries, to address some of the most pressing questions on how the Internet can hinder the feasibility and well-functioning of democracy around the world. We conclude by setting out three challenges for future research on digital media and politics: a growing but still partial understanding of the extent and impact of the main digital threats to democracy; the risk that the dominant approaches become overly pessimistic, or founded on weak normative grounds; and the risk that research overemphasizes direct and short-term implications of digital threats on individuals and specific groups at the expense of indirect and medium-term effects on collective norms and expectations of behavior
SR-FTIR microscopy for the study of residues on Palaeolithic stone tools: Looking for a methodological protocol
In this paper, we use SR-FTIR microscopy to analyse residues identified on seven
lithic artefacts from the Evolved Epigravettian layer 9c2 of the cave site of Grotta Paglicci
(Apulia, southern Italy). Synchrotron radiation, thanks to its properties that particularly increase
the sensitivity of FTIR microscopy, allows the analysis of samples of microscopic size and the
characterisation of even highly degraded compounds, such as the residues of materials worked
by Palaeolithic stone tools or complex compounds used for hafting. This pilot study has been
carried out in the framework of a project concerning the reconstruction of hunting technologies
between the Middle and Upper Palaeolithic. The preliminary results allowed us to focus on the
issues of our methodological approach and to show the potential of the SR-FTIR microscopy for
the analysis of residues on lithic implements
Evolution of the far-infrared luminosity functions in the Spitzer Wide-area Infrared Extragalactic Legacy Survey
We present new observational determination of the evolution of the rest-frame
70 and 160 micron and total infrared (TIR) galaxy luminosity functions (LFs)
using 70 micron data from the Spitzer Wide-area Infrared Extragalactic Legacy
Survey (SWIRE). The LFs were constructed for sources with spectroscopic
redshifts only in the XMM-LSS and Lockman Hole fields from the SWIRE
photometric redshift catalogue. The 70 micron and TIR LFs were constructed in
the redshift range 0<z<1.2 and the 160 micron LF was constructed in the
redshift range 0<z<0.5 using a parametric Bayesian and the vmax methods. We
assume in our models, that the faint-end power-law index of the LF does not
evolve with redshifts. We find the the double power-law model is a better
representation of the IR LF than the more commonly used power-law and Gaussian
model. We model the evolution of the FIR LFs as a function of redshift where
where the characteristic luminosity, evolve as
\propto(1+z)^{\alpha_\textsc{l}}. The rest-frame 70 micron LF shows a strong
luminosity evolution out to z=1.2 with alpha_l=3.41^{+0.18}_{-0.25}. The
rest-frame 160 micron LF also showed rapid luminosity evolution with
alpha_l=5.53^{+0.28}_{-0.23} out to z=0.5. The rate of evolution in luminosity
is consistent with values estimated from previous studies using data from IRAS,
ISO and Spitzer. The TIR LF evolves in luminosity with
alpha_l=3.82^{+0.28}_{-0.16} which is in agreement with previous results from
Spitzer 24 micron which find strong luminosity evolution. By integrating the LF
we calculated the co-moving IR luminosity density out to z=1.2, which confirm
the rapid evolution in number density of LIRGs and ULIRGs which contribute
~68^{+10}_{-07} % to the co-moving star formation rate density at z=1.2. Our
results based on 70 micron data confirms that the bulk of the star formation at
z=1 takes place in dust obscured objects.Comment: 17 pages, 14 figure
Accidental exposure to politics on social media as online participation equalizer in Germany, Italy, and the United Kingdom
We assess whether and how accidental exposure to political information on social
media contributes to citizens\u2019 online political participation in comparative perspective.
Based on three online surveys of samples representative of German, Italian, and British
Internet users in the aftermath of the 2014 European Parliament elections, we find that
accidental exposure to political information on social media is positively and significantly
correlated with online participation in all three countries, particularly so in Germany
where overall levels of participation were lower. We also find that interest in politics
moderates this relationship so that the correlation is stronger among the less interested
than among the highly interested. These findings suggest that inadvertent encounters
with political content on social media are likely to reduce the gap in online engagement
between citizens with high and low interest in politics, potentially broadening the range
of voices that make themselves heard
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