383 research outputs found
Background level of heavy-metals soil concentrations in an industrial area of Basilicata Region (Southern Italy)
In the framework of Basilicata region air quality monitoring, we are investigating the industrial area of Melfi town. This area has been chosen as test site to evaluate the environmental impact of anthropic activities on a rather unpolluted agricultural area. In this paper we discuss the procedure to characterize the background level of heavy-metals soil concentrations. The topsoil bioavailable fraction of eight elements (Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) has been collected in two annual surveys (1993 and 1994) on a georeferenced grid, translated in GIS informative layer. Statistical analysis of spatial and temporal patterns is shown in detail
Background level of heavy-metals soil concentrations in an industrial area of Basilicata Region (Southern Italy)
In the framework of Basilicata region air quality monitoring, we are investigating the industrial area of Melfi town. This area has been chosen as test site to evaluate the environmental impact of anthropic activities on a rather unpolluted agricultural area. In this paper we discuss the procedure to characterize the background level of heavy-metals soil concentrations. The topsoil bioavailable fraction of eight elements (Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) has been collected in two annual surveys (1993 and 1994) on a georeferenced grid, translated in GIS informative layer. Statistical analysis of spatial and temporal patterns is shown in detail
The LD Adolescent and the Sat
School personnel can help LD students prepare for the SAT in a variety of ways.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66543/2/10.1177_105345128502000402.pd
Time dynamics of background noise in geoelectrical and geochemical signals: an application in a seismic area of Southern Italy
We analyse geoelectrical and geochemical time series jointly measured by means of a multiparametric automatic station close to an anomalous fluid emission in Val d’Agri (Basilicata, Italy). The investigated area is located on Southern Apennine chain that in past and recent years was interested by destructive earthquakes. After a complete
pre-processing of time series, we analyse the fluctuations triggered by the seasonal cycles and focus our attention on the possible link between geoelectrical and geochemical signals. In order to extract quantitative dynamical information from experimental time series, we detect scaling laws in power spectra that are typical fingerprints of fractional Brownian processes. After this analysis, the problem of the identification of extreme events in the time series has been approached. We consider significant anomalous patterns only when more consecutive values are above/below a fixed threshold in almost two of the time series jointly measured. We give the first preliminary results about the comparison between anomalous patterns detected in geoelectrical and geochemical parameters and the local seismic activity and, finally, analyse the implications with the earthquake prediction problem
Optically variable active galactic nuclei in the 3 yr VST survey of the COSMOS field
The analysis of the variability of active galactic nuclei (AGNs) at different
wavelengths and the study of possible correlations among different spectral
windows are nowadays a major field of inquiry. Optical variability has been
largely used to identify AGNs in multivisit surveys. The strength of a
selection based on optical variability lies in the chance to analyze data from
surveys of large sky areas by ground-based telescopes. However the
effectiveness of optical variability selection, with respect to other
multiwavelength techniques, has been poorly studied down to the depth expected
from next generation surveys. Here we present the results of our r-band
analysis of a sample of 299 optically variable AGN candidates in the VST survey
of the COSMOS field, counting 54 visits spread over three observing seasons
spanning > 3 yr. This dataset is > 3 times larger in size than the one
presented in our previous analysis (De Cicco et al. 2015), and the observing
baseline is ~8 times longer. We push towards deeper magnitudes (r(AB) ~23.5
mag) compared to past studies; we make wide use of ancillary multiwavelength
catalogs in order to confirm the nature of our AGN candidates, and constrain
the accuracy of the method based on spectroscopic and photometric diagnostics.
We also perform tests aimed at assessing the relevance of dense sampling in
view of future wide-field surveys. We demonstrate that the method allows the
selection of high-purity (> 86%) samples. We take advantage of the longer
observing baseline to achieve great improvement in the completeness of our
sample with respect to X-ray and spectroscopically confirmed samples of AGNs
(59%, vs. ~15% in our previous work), as well as in the completeness of
unobscured and obscured AGNs. The effectiveness of the method confirms the
importance to develop future, more refined techniques for the automated
analysis of larger datasets.Comment: 21 pages, 10 figures; accepted for publication in A&
Optimizing Cadences with Realistic Light Curve Filtering for Serendipitous Kilonova Discovery with Vera Rubin Observatory
Current and future optical and near-infrared wide-field surveys have the potential of finding kilonovae, the optical and infrared counterparts to neutron star mergers, independently of gravitational-wave or high-energy gamma-ray burst triggers. The ability to discover fast and faint transients such as kilonovae largely depends on the area observed, the depth of those observations, the number of re-visits per field in a given time frame, and the filters adopted by the survey; it also depends on the ability to perform rapid follow-up observations to confirm the nature of the transients. In this work, we assess kilonova detectability in existing simulations of the LSST strategy for the Vera C. Rubin Wide Fast Deep survey, with focus on comparing rolling to baseline cadences. Although currently available cadences can enable the detection of more than 300 kilonovae out to 1400 Mpc over the ten-year survey, we can expect only 3-32 kilonovae similar to GW170817 to be recognizable as fast-evolving transients. We also explore the detectability of kilonovae over the plausible parameter space, focusing on viewing angle and ejecta masses. We find that observations in redder izy bands are crucial for identification of nearby (within 300 Mpc) kilonovae that could be spectroscopically classified more easily than more distant sources. Rubin's potential for serendipitous kilonova discovery could be increased by gain of efficiency with the employment of individual 30s exposures (as opposed to 2x15s snap pairs), with the addition of red-band observations coupled with same-night observations in g- or r-bands, and possibly with further development of a new rolling-cadence strategy
Three-Dimensional Myocardial Perfusion Maps by Contrast Echocardiography
We evaluated the clinical applicability of a system for three-dimensional (3-D) display of a perfusion map following myocardial contrast echocardiography (MCE). The system was used in 12 patients (9 males and 3 females, mean age 52 ± 10 years) undergoing interventional treatment of chronic total coronary occlusion. In each patient three standard apical views were acquired at baseline with sonicated IopamidolR injections into the left coronary artery (LCA) and into the right coronary artery (RCA). Following successful recanalization of the occluded artery MCE was repeated. The patients tolerated the procedure well. Acquisition of three standard apical views provided sufficient information for the reconstruction of 3-D perfusion maps containing the 16 standard left ventricular (LV) segments. Side-by-side display of the perfusion maps obtained following LCA and RCA echocontrast injections allowed us to classify the myocardial segments (192) into three groups: (1) those supplied by one major artery (124); (2) those supplied by collaterals from contralateral or both major arteries (58); and (3) segments supplied by none of the major arteries (10). Decreased opacification was observed in 50 segme
Wavelet analysis as a tool to characteriseand remove environmental noisefrom self-potential time series
Multiresolution wavelet analysis of self-potential signals and rainfall levels is performed for extracting fluctuations
in electrical signals, which might be addressed to meteorological variability. In the time-scale domain of the wavelet transform, rain data are used as markers to single out those wavelet coefficients of the electric signal which can be considered relevant to the environmental disturbance. Then these coefficients are filtered out
and the signal is recovered by anti-transforming the retained coefficients. Such methodological approach might
be applied to characterise unwanted environmental noise. It also can be considered as a practical technique to
remove noise that can hamper the correct assessment and use of electrical techniques for the monitoring of geophysical phenomena
Reports of Negative Interactions with Healthcare Providers among Transgender, Nonbinary, and Gender-Expansive People assigned Female at Birth in the United States: Results from an Online, Cross-Sectional Survey
Over one million people in the United States are transgender, nonbinary, or gender expansive (TGE). TGE individuals, particularly those who have pursued gender-affirming care, often need to disclose their identities in the process of seeking healthcare. Unfortunately, TGE individuals often report negative experiences with healthcare providers (HCPs). We conducted a cross-sectional online survey of 1684 TGE people assigned female or intersex at birth in the United States to evaluate the quality of their healthcare experiences. Most respondents (70.1%, n = 1180) reported at least one negative interaction with an HCP in the past year, ranging from an unsolicited harmful opinion about gender identity to physical attacks and abuse. In an adjusted logistic regression model, those who had pursued gender-affirming medical care (51.9% of the sample, n = 874) had 8.1 times the odds (95% CI: 4.1-17.1) of reporting any negative interaction with an HCP in the past year, compared to those who had not pursued gender-affirming care, and tended to report a higher number of such negative interactions. These findings suggest that HCPs are failing to create safe, high-quality care interactions for TGE populations. Improving care quality and reducing bias is crucial for improving the health and well-being of TGE people
The VMC Survey -- XXXV. Model fitting of LMC Cepheid light curves
We present the results of the light curve model fitting technique applied to
optical and near-infrared photometric data for a sample of 18 Classical
Cepheids (11 fundamentals and 7 first overtones) in the Large Magellanic Cloud
(LMC). We use optical photometry from the OGLE III database and near--infrared
photometry obtained by the European Southern bservatory public survey "VISTA
near--infrared survey of the Magellanic Clouds system". Iso--periodic nonlinear
convective model sequences have been computed for each selected Cepheid in
order to reproduce the multi--filter light curve amplitudes and shape details.
The inferred individual distances provide an intrinsic weighted mean value for
the LMC distance modulus of mag with a standard deviation of 0.13
mag. We derive also the Period--Radius, the Period--Luminosity and the
Period--Wesenheit relations that are consistent with similar relations in the
literature. The intrinsic masses and luminosities of the best--fitting models
show that all the investigated pulsators are brighter than the redictions of
the canonical evolutionary mass--luminosity relation, suggesting a significant
efficiency of non--canonical phenomena, such as overshooting, mass loss and/or
rotation.Comment: 14 pages, 10 figures, MNRAS accepte
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