Post-Depositional Biodegradation Processes of Pollutants on Glacier Surfaces

Glaciers are important fresh-water reservoirs for our planet. Although they are often located at high elevations or in remote areas, glacial ecosystems are not pristine, as many pollutants can undergo long-range atmospheric transport and be deposited on glacier surface, where they can be stored for long periods of time, and then be released into the down-valley ecosystems. Understanding the dynamics of these pollutants in glaciers is therefore important for assessing their environmental fate. To this aim, it is important to study cryoconite holes, small ponds filled with water and with a layer of sediment, the cryoconite, at the bottom, which occur on the surface of most glaciers. Indeed, these environments are hotspots of biodiversity on glacier surface as they host metabolically active bacterial communities that include generalist taxa able to degrade pollutants. In this work, we aim to review the studies that have already investigated pollutant (e.g., chlorpyrifos and polychlorinated-biphenyls (PCBs)) degradation in cryoconite holes and other supraglacial environmental matrices. These studies have revealed that bacteria play a significant role in pollutant degradation in these habitats and can be positively selected in contaminated environments. We will also provide indication for future research in this field

Euclid Space Mission: building the sky survey

The Euclid space mission proposes to survey 15000 square degrees of the extragalactic sky during 6 years, with a step-and-stare technique. The scheduling of observation sequences is driven by the primary scientific objectives, spacecraft constraints, calibration requirements and physical properties of the sky. We present the current reference implementation of the Euclid survey and on-going work on survey optimization.Comment: to appear in Proceedings IAU Symposium No. 306, "Statistical Challenges in 21st Century Cosmology", A.F. Heavens, J.-L. Starck & A. Krone-Martins, ed

Quality of Life, Wishes, and Needs in Women with Gestational Diabetes: Italian DAWN Pregnancy Study

The DAWN (Diabetes Attitudes, Wishes and Needs) study is a survey promoted by the International Diabetes Federation to recognize the perceptions and attitudes of people suffering from diabetes mellitus. In this context, we evaluated the quality of life of Italian and immigrant women with gestational diabetes mellitus (GDM). Information was gathered using a structured questionnaire for patients' self-compilation. In a 3-month period, a 51-item questionnaire was submitted to 198 Italians and 88 immigrants (from 27 different foreign nationalities). Italian women were older and had higher education than the immigrants. 60% of the Italians and 38% of the immigrants had a family history of diabetes mellitus. In both groups, the diagnosis of GDM caused anxiety; one-third of women feared their child could contract diabetes at delivery and/or have congenital malformations. Some women had trouble in following treatment regimens: the major concern being dietary advice and blood glucose testing. Most women were satisfied (34%) or highly satisfied (60%) with the quality of care, although the degree of cooperation between diabetes specialists and gynaecologists was considered sometimes unsatisfactory. In order to optimize maternal and foetal outcomes, educational projects and improved communication between patients and the healthcare provider team are recommended

Changing patterns in HIV-1 non-B clade prevalence and diversity in Italy over three decades

n/

Bacterial communities of cryoconite holes of a temperate alpine glacier show both seasonal trends and year-to-year variability

Cryoconite holes are small depressions of the glacier surface filled with melting water and with a wind-blown debris on the bottom. These environments are considered hot spots of biodiversity and biological activities on glaciers and host communities dominated by bacteria. Most of the studies on cryoconite holes assume that their communities are stable. However, evidence of seasonal variation in cryoconite hole ecological communities exists. We investigated the variation of the bacterial communities of cryoconite holes of Forni Glacier (Central Italian Alps) during the melting seasons (July-September) 2013 and 2016, for which samples at three and five time-points, respectively were available. Bacterial communities were characterized by high-throughput Illumina sequencing of the hypervariable V5'V6 regions of 16S rRNA gene, while meteorological data were obtained by an automatic weather station. We found consistent trends in bacterial communities, which shifted from cyanobacteria-dominated communities in July to communities dominated by heterotrophic orders in late August and September. Temperature seems also to affect seasonal dynamics of communities. We also compared bacterial communities at the beginning of the melting season across 4 years (2012, 2013, 2015 and 2016) and found significant year-to-year variability. Cryoconite hole communities on temperate glaciers are therefore not temporally stable

The VIMOS Public Extragalactic Redshift Survey (VIPERS). Never mind the gaps: comparing techniques to restore homogeneous sky coverage

[Abridged] Non-uniform sampling and gaps in sky coverage are common in galaxy redshift surveys, but these effects can degrade galaxy counts-in-cells and density estimates. We carry out a comparison of methods that aim to fill the gaps to correct for the systematic effects. Our study is motivated by the analysis of the VIMOS Extragalactic Redshift Survey (VIPERS), a flux-limited survey (i<22.5) based on one-pass observations with VIMOS, with gaps covering 25% of the surveyed area and a mean sampling rate of 35%. Our findings are applicable to other surveys with similar observing strategies. We compare 1) two algorithms based on photometric redshift, that assign redshifts to galaxies based on the spectroscopic redshifts of the nearest neighbours, 2) two Bayesian methods, the Wiener filter and the Poisson-Lognormal filter. Using galaxy mock catalogues we quantify the accuracy of the counts-in-cells measurements on scales of R=5 and 8 Mpc/h after applying each of these methods. We also study how they perform to account for spectroscopic redshift error and inhomogeneous and sparse sampling rate. We find that in VIPERS the errors in counts-in-cells measurements on R<10 Mpc/h scales are dominated by the sparseness of the sample. All methods underpredict by 20-35% the counts at high densities. This systematic bias is of the same order as random errors. No method outperforms the others. Random and systematic errors decrease for larger cells. We show that it is possible to separate the lowest and highest densities on scales of 5 Mpc/h at redshifts 0.5<z<1.1, over a large volume such as in VIPERS survey. This is vital for the characterisation of cosmic variance and rare populations (e.g, brightest galaxies) in environmental studies at these redshifts.Comment: 17 pages, 13 figures, accepted for publication in A&A (revised version after minor revision and language editing

1.65 micron H-band Surface Photometry of Galaxies. X: Structural and Dynamical Properties of Elliptical Galaxies

We analyse the structural and dynamical properties of a sample of 324 nearby elliptical and dwarf elliptical galaxies observed during an extensive NIR survey in H-band (1.65 micron). The Fundamental Plane (FP) is determined and a significant tilt is assessed. The origins of such a tilt are investigated by means of a spherically symmetric, isotropic pressure supported dynamical model relying on the observed surface brightness profiles. The systematic variation of the shape coefficient converting the measured central velocity dispersion $sigma_0$ into the virial rms velocity $sigma_{rms}$ is found to be the main cause of the tilt, due to aperture effects. Moreover the ratio between the dynamical mass $M_{dyn}$ and the total H-band luminosity $L_H$ turns out to be roughly constant along the luminosity sequence of ellipticals: H-band luminosity is therefore a reliable and cheap estimator of the dynamical mass of the Es.Comment: 28 pages, 6 figures, accepted for publication on Ap

The VIMOS Public Extragalactic Redshift Survey (VIPERS). Exploring the dependence of the three-point correlation function on stellar mass and luminosity at 0.5<z<1.1

The three-point correlation function (3PCF) is a powerful probe to investigate the clustering of matter in the Universe in a complementary way with respect to lower-order statistics, providing additional information with respect to the two-point correlation function and allowing us to shed light on biasing, nonlinear processes, and deviations from Gaussian statistics. In this paper, we analyse the first data release of the VIMOS Public Extragalactic Redshift Survey (VIPERS), determining the dependence of the three-point correlation function on luminosity and stellar mass at $z=[0.5,1.1]$. We exploit the VIPERS Public Data Release 1, consisting of more than 50,000 galaxies with B-band magnitudes in the range $-21.6\lesssim M_{\rm B}-5\log(h)\lesssim-19.9$ and stellar masses in the range $9.8\lesssim\log(M_\star[h^{-2}\,M_\odot])\lesssim 10.7$. We measure both the connected 3PCF and the reduced 3PCF in redshift space, probing different configurations and scales, in the range $2.5<r\,$[Mpc/h]$<20$. We find a significant dependence of the reduced 3PCF on scales and triangle shapes, with stronger anisotropy at larger scales ($r\sim10$ Mpc/h) and an almost flat trend at smaller scales, $r\sim2.5$ Mpc/h. Massive and luminous galaxies present a larger connected 3PCF, while the reduced 3PCF is remarkably insensitive to magnitude and stellar masses in the range we explored. These trends, already observed at low redshifts, are confirmed for the first time to be still valid up to $z=1.1$, providing support to the hierarchical scenario for which massive and bright systems are expected to be more clustered. The possibility of using the measured 3PCF to provide independent constraints on the linear galaxy bias $b$ has also been explored, showing promising results in agreement with other probes.Comment: 12 pages, 11 figures, 2 tables, accepted for publication in A&

Euclid space mission: a cosmological challenge for the next 15 years

Euclid is the next ESA mission devoted to cosmology. It aims at observing most of the extragalactic sky, studying both gravitational lensing and clustering over $\sim$15,000 square degrees. The mission is expected to be launched in year 2020 and to last six years. The sheer amount of data of different kinds, the variety of (un)known systematic effects and the complexity of measures require efforts both in sophisticated simulations and techniques of data analysis. We review the mission main characteristics, some aspects of the the survey and highlight some of the areas of interest to this meetingComment: to appear in Proceedings IAU Symposium No. 306, 2014, "Statistical Challenges in 21st Century Cosmology", A.F. Heavens, J.-L. Starck & A. Krone-Martins, ed