6,364 research outputs found
Geostatistics as a tool to improve the natural background level definition: An application in groundwater
The Natural Background Level (NBL), suggested by UE BRIDGE project, is suited for spatially distributed datasets
providing a regional value that could be higher than the Threshold Value (TV) set by every country. In hydrogeochemically
dis-homogeneous areas, the use of a unique regional NBL, higher than TV, could arise problems
to distinguish between natural occurrences and anthropogenic contaminant sources. Hence, the goal of this
study is to improve the NBL definition employing a geostatistical approach, which reconstructs the contaminant
spatial structure accounting geochemical and hydrogeological relationships. This integrated mapping is fundamental
to evaluate the contaminant's distribution impact on the NBL, giving indications to improve it. We decided
to test this method on the Drainage Basin of Venice Lagoon (DBVL, NE Italy), where the existing NBL is seven
times higher than the TV. This area is notoriously affected by naturally occurring arsenic contamination. An available
geochemical dataset collected by 50 piezometers was used to reconstruct the spatial distribution of arsenic
in the densely populated area of the DBVL. A cokriging approachwas applied exploiting the geochemical relationships
among As, Fe andNH4+. The obtained spatial predictions of arsenic concentrationswere divided into three
different zones: i) areas with an As concentration lower than the TV, ii) areas with an As concentration between
the TV and the median of the values higher than the TV, and iii) areas with an As concentration higher than the
median. Following the BRIDGE suggestions, where enough samples were available, the 90th percentile for each
zone was calculated to obtain a local NBL (LNBL). Differently from the original NBL, this local value gives more
detailed water quality information accounting the hydrogeological and geochemical setting, and contaminant
spatial variation. Hence, the LNBL could give more indications about the distinction between natural occurrence
and anthropogenic contamination
Smoking, Not COPD, as the Disease
Comment on
Clinical Significance of Symptoms in Smokers with Preserved Pulmonary Function. [N Engl J Med. 2016]
Clinical and Radiologic Disease in Smokers With Normal Spirometry. [JAMA Intern Med. 2015
M-theory on AdS_4xM^{111}: the complete Osp(2|4)xSU(3)xSU(2) spectrum from harmonic analysis
We reconsider the Kaluza Klein compactifications of D=11 supergravity on
AdS_4x(G/H)_7 manifolds that were classified in the eighties, in the modern
perspective of AdS_4/CFT_3 correspondence. We focus on one of the three N=2
cases: (G/H)_7=M^{111}=SU(3)xSU(2)xU(1)/SU(2)xU(1)'xU(1)''. Relying on the
systematic use of the harmonic analysis techniques developed in the eighties by
one of us (P. Fre') with R. D'Auria, we derive the complete spectrum of long,
short and massless Osp(2|4)xSU(3)xSU(2) unitary irreducible representations
obtained in this compactification. Our result also provides a general scheme
for the other N=2 compactifications. Furthermore, it is a necessary comparison
term in the AdS_4/CFT_3 correspondence: the complete AdS/CFT match of the
spectra that we obtain will provide a much more stringent proof of the AdS/CFT
correspondence than in the S^7 case, since the structure of the superconformal
field theory on the M2-brane world volume must be such as to reproduce, at the
level of composite operators, the flavor group representations, the conformal
dimensions and the hypercharges that we obtain in the present article. The
investigation of the match is left to future publications. Here we provide an
exhaustive construction of the Kaluza Klein side of our spectroscopy.Comment: 65 page
An example of aquifer heterogeneity simulation to modeling well-head protection areas
Groundwater management requires the definition of Well-Head Protection Areas (WHPA) for water supply wells. Italian law uses geometrical, chronological and hydrogeological criteria for WHPA identification, providing a groundwater travel time of 60 days for the definition of the Zone of Travel (ZOT). An exhaustive ZOT delineation must involve numerical modeling of groundwater flow together with simulation of the advective component of the transport process. In this context, the spatial variability of hydrogeological and transport parameters has to be critically estimated during numerical modeling implementation.
In the present article, geostatistical simulation using a transition probability approach and groundwater numerical modeling were performed to delineate WHPAs for several supply wells in the middle Venetian Plain, taking into account the lithologic heterogeneity of the aquifer. The transition probability approach for the lithologic data was developed by T-PROGS software, while MODDLOW-2005 and PEST-ASP were used, respectively, to reproduce and calibrate site-specific hydraulic head data. Finally, a backward particle tracking analysis was performed with MODPATH to outline the 60-day ZOT
Chronic disease in the elderly: back to the future of internal medicine.
Elderly people are often affected by two or more chronic diseases, more frequently cardiovascular diseases, chronic respiratory diseases, metabolic syndrome and cancer. Thesemost frequent chronic diseases share largely preventable risk factors, the most important being smoking and obesity, and may be linked to chronic systemic inflammation. Coexistingchronic diseases affect the course of the primary disease and alter the efficacyand safety of its management. Current clinical practice is dominated by the "singledisease"approach, which has major limitations, and there is increasing evidence that a patient-oriented approach that takes into account the several co-existing components of chronic disease is required. This "change of concept" implies the need for medical specialists to extend their expertise to broader diagnostic and treatment approaches that are traditionally the purview of internal medicine. This new approach also requires a differentapproach to clinical research and teaching, followed by extensive rewriting of medical textbooks and remodelling of teaching curricula to reflect the complexity of the patient affected by chronic diseases
Assessing transmissivity from specific capacity in an alluvial aquifer in the middle Venetian plain (NE Italy)
Defining aquifer permeability distribution accurately over large areas is often debated in hydrogeology. The operational efforts to calculate hydraulic conductivity with classical aquifer tests are significant; however, accurate knowledge of permeability areal distribution is fundamental both from a hydrogeological and a modeling standpoint. This paper presents an empirical relationship between the transmissivity (T) and the specific capacity (SC) values obtained from experimental aquifer and well tests. All experimental values were obtained from 50 mm wells in middle Venetian plain artesian gravel aquifers. Many other authors have presented empirical relationships between T and SC, but most are related to fissured/karst aquifers, and only a few concern alluvial porous aquifers. Analysis of the T vs. SC relationship standardized residuals shows that a linear relationship produces statistically significant normal residuals compared with an exponential relationship
Second resonance of the Higgs field: more signals from the LHC experiments
It has been proposed that, beside the known resonance with mass 125
GeV, the Higgs field might exhibit a second resonance with a larger mass
GeV which,
however, would couple to longitudinal W's with the same typical strength as the
low-mass state at GeV and thus represent a relatively narrow resonance.
Looking for evidences in the LHC data, from two analyses published in 2021 by
ATLAS (searching for heavy resonances decaying into final states with 4 charged
leptons or with photon pairs) we have found combined indications for a new
resonance of mass 680 (15) GeV and total width
45 (15) GeV. More recent results by CMS (searching
for heavy resonances decaying into a pair of h(125) Higgs bosons or looking for
high-mass photon pairs produced in pp-diffractive scattering) also show
definite excesses pointing toward a new resonance of mass 660(30) GeV. However, beside the agreement with the predicted mass range,
a clean indication derives from the ATLAS 4-lepton data which reproduce to high
accuracy the expected correlation between resonating peak cross section
and the ratio . This
correlation is mainly determined by the lower mass 125 GeV and supports
the view that the known and the new heavy resonance are two different
excitations of the same Higgs field by effectively eliminating the spin-zero
vs. spin-2 ambiguity in the interpretation of the heavy state. The overall
statistical evidence might now be above the traditional 5-sigma discovery
threshold because, when comparing with a definite theoretical prediction as in
our case, local excesses should maintain intact their statistical significance
and not be downgraded by the so called "look-elsewhere" effect.Comment: 14 pages, 4 figures, 4 table
Acute exacerbations of chronic obstructive pulmonary disease provide a unique opportunity to take care of patients
Exacerbation of chronic obstructive pulmonary disease (ECOPD) identifies the acute phase of COPD. The COPD patient is often frail and elderly with concomitant chronic diseases. This requires the physician not only looks at specific symptoms or organs, but to consider the patient in all his or her complexity. \ua9Copyright B. Begh\ue9 et al., 2013 Licensee PAGEPress
Persistent asthma hospitalizations and deaths require a national asthma prevention plan.
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Subsoil geostatistical modeling as tool for hydrogeological modeling: transitional probability approach applied upon a heterogeneous site
Hydrogeological modeling, 3D simulation, Venice lagoon, reactive transport numerical mode
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