40 research outputs found
Polycyclic aromatic hydrocarbons in atmospheric depositions around the Venice Lagoon
Studies have revealed the potential risks to which human health and ecosystems are exposed in the Venice Lagoon, due to the atmospheric deposition of persistent pollutants such as trace metals and organic compounds. A total of 77 atmospheric bulk deposition samples were collected monthly from April 2002 to December 2004, from three sites located in the cities of Mestre and Venice, and inside the industrial area of Porto Marghera. Samples were analyzed by HRGC/HRMS for polycyclic aromatic hydrocarbon (PAH) content. Spatial variations of atmospheric fallout were investigated, and source identification was attempted using diagnostic ratios and multivariate statistical analysis. Different conditions were recorded, with three anthropic signatures: i) industrial, mainly affected by local industrial sources and diesel engine emissions, ii) urban, mostly influenced by high traffic density, especially petrol car emissions and iii) lagoonal, characterized by dieselemissions from boat engines and oil burning, with random transport of industrial emissions
DNA Damage and Transcriptional Changes in the Gills of Mytilus galloprovincialis Exposed to Nanomolar Doses of Combined Metal Salts (Cd, Cu, Hg)
[ENG]Aiming at an integrated and mechanistic view of the early biological effects of selected metals in the marine sentinel
organism Mytilus galloprovincialis, we exposed mussels for 48 hours to 50, 100 and 200 nM solutions of equimolar Cd, Cu
and Hg salts and measured cytological and molecular biomarkers in parallel. Focusing on the mussel gills, first target of toxic
water contaminants and actively proliferating tissue, we detected significant dose-related increases of cells with micronuclei and other nuclear abnormalities in the treated mussels, with differences in the bioconcentration of the three metals determined in the mussel flesh by atomic absorption spectrometry. Gene expression profiles, determined in the same
individual gills in parallel, revealed some transcriptional changes at the 50 nM dose, and substantial increases of differentially expressed genes at the 100 and 200 nM doses, with roughly similar amounts of up- and down-regulated genes. The functional annotation of gill transcripts with consistent expression trends and significantly altered at least in one
dose point disclosed the complexity of the induced cell response. The most evident transcriptional changes concerned protein synthesis and turnover, ion homeostasis, cell cycle regulation and apoptosis, and intracellular trafficking (transcript
sequences denoting heat shock proteins, metal binding thioneins, sequestosome 1 and proteasome subunits, and GADD45 exemplify up-regulated genes while transcript sequences denoting actin, tubulins and the apoptosis inhibitor 1 exemplify
down-regulated genes). Overall, nanomolar doses of co-occurring free metal ions have induced significant structural and
functional changes in the mussel gills: the intensity of response to the stimulus measured in laboratory supports the
additional validation of molecular markers of metal exposure to be used in Mussel Watch programsWork granted by MIUR and Co.Ri.La. to PV. LV is currently supported by the FP7-KBBE-2010-4-266157 Bivalife project. Work in the laboratory of MPC is
funded by grants to consolidated research groups (ref GIC07/26-IT-393-07, Basque Government), and to the unit of formation and research (UFI ref 11/37,
University of the Basque Country) and projects Nanoretox (ref CP-FP 214478-2, UE 7th FP) and Nanocancer (ref CTM2009-13477, Spanish Ministry of Science and
Innovation
Impact of Redshift Information on Cosmological Applications with Next-Generation Radio Surveys
In this paper, we explore how the forthcoming generation of large-scale radio
continuum surveys, with the inclusion of some degree of redshift information,
can constrain cosmological parameters. By cross-matching these radio surveys
with shallow optical to near-infrared surveys, we can essentially separate the
source distribution into a low- and a high-redshift sample, thus providing a
constraint on the evolution of cosmological parameters such as those related to
dark energy. We examine two radio surveys, the Evolutionary Map of the Universe
(EMU) and the Westerbork Observations of the Deep APERTIF Northern sky (WODAN).
A crucial advantage is their combined potential to provide a deep, full-sky
survey. The surveys used for the cross-identifications are SkyMapper and SDSS,
for the southern and northern skies, respectively. We concentrate on the galaxy
clustering angular power spectrum as our benchmark observable, and find that
the possibility of including such low redshift information yields major
improvements in the determination of cosmological parameters. With this
approach, and provided a good knowledge of the galaxy bias evolution, we are
able to put strict constraints on the dark energy parameters, i.e.
w_0=-0.9+/-0.041 and w_a=-0.24+/-0.13, with type Ia supernovae and CMB priors
(with a one-parameter bias in this case); this corresponds to a Figure of Merit
(FoM) > 600, which is twice better than what is obtained by using only the
cross-identified sources and greater than four time better than the case
without any redshift information at all.Comment: 12 pages, 6 figures, 6 tables; accepted for publication in MNRA
Cosmology from HI galaxy surveys with the SKA
The Square Kilometer Array (SKA) has the potential to produce galaxy redshift surveys which
will be competitive with other state of the art cosmological experiments in the next decade. In this
chapter we summarise what capabilities the first and the second phases of the SKA will be able
to achieve in its current state of design. We summarise the different cosmological experiments
which are outlined in further detail in other chapters of this Science Book. The SKA will be
able to produce competitive Baryonic Oscillation (BAOs) measurements in both its phases. The
first phase of the SKA will provide similar measurements in optical and IR experiments with
completely different systematic effects whereas the second phase being transformational in terms
of its statistical power. The SKA will produce very accurate Redshift Space Distortions (RSD)
measurements, being superior to other experiments at lower redshifts, due to the large number
of galaxies. Cross correlations of the galaxy redshift data from the SKA with radio continuum
surveys and optical surveys will provide extremely good calibration of photometric redshifts as
well as extremely good bounds on modifications of gravity. Basing on a Principle Component
Analysis (PCA) approach, we find that the SKA will be able to provide competitive constraint
on dark energy and modified gravity models. Due to the large area covered the SKA it will be a
transformational experiment in measuring physics from the largest scales such as non-Gaussian
signals. Finally, the SKA might produce the first real time measurement of the redshift
drift. The SKA will be a transformational machine for cosmology as it grows from an early Phase
1 to its full power
Cosmology on the Largest Scales with the SKA
Advancing Astrophysics with the Square Kilometre Array
June 8-13, 2014
Giardini Naxos, ItalyThe study of the Universe on ultra-large scales is one of the major science cases for the Square
Kilometre Array (SKA). The SKA will be able to probe a vast volume of the cosmos, thus representing
a unique instrument, amongst next-generation cosmological experiments, for scrutinising
the Universe’s properties on the largest cosmic scales. Probing cosmic structures on extremely
large scales will have many advantages. For instance, the growth of perturbations is well understood
for those modes, since it falls fully within the linear régime. Also, such scales are unaffected
by the poorly understood feedback of baryonic physics. On ultra-large cosmic scales, two key effects
become significant: primordial non-Gaussianity and relativistic corrections to cosmological
observables. Moreover, if late-time acceleration is driven not by dark energy but by modifications
to general relativity, then such modifications should become apparent near and above the horizon
scale. As a result, the SKA is forecast to deliver transformational constraints on non-Gaussianity
and to probe gravity on super-horizon scales for the first time
Cosmology on the Largest Scales with the SKA
The study of the Universe on ultra-large scales is one of the major science cases for the Square
Kilometre Array (SKA). The SKA will be able to probe a vast volume of the cosmos, thus representing
a unique instrument, amongst next-generation cosmological experiments, for scrutinising
the Universe’s properties on the largest cosmic scales. Probing cosmic structures on extremely
large scales will have many advantages. For instance, the growth of perturbations is well understood
for those modes, since it falls fully within the linear régime. Also, such scales are unaffected
by the poorly understood feedback of baryonic physics. On ultra-large cosmic scales, two key effects
become significant: primordial non-Gaussianity and relativistic corrections to cosmological
observables. Moreover, if late-time acceleration is driven not by dark energy but by modifications
to general relativity, then such modifications should become apparent near and above the horizon
scale. As a result, the SKA is forecast to deliver transformational constraints on non-Gaussianity
and to probe gravity on super-horizon scales for the first time