349 research outputs found
Diversity of Rainfall Thresholds for early warning of hydro-geological disasters
For early warning of disasters induced by precipitation
(such as floods and landslides), different kinds of rainfall thresholds are
adopted, which vary from each other, on the basis on adopted hypotheses. In
some cases, they represent the occurrence probability of an event (landslide
or flood), in other cases the exceedance probability of a critical value for
an assigned indicator I (a function of rainfall heights), and in further
cases they only indicate the exceeding of a prefixed percentage a critical
value for I, indicated as Icr. For each scheme, it is usual to define
three different criticality levels (ordinary, moderate and severe), which
are associated to warning levels, according to emergency plans. This work
briefly discusses different schemes of rainfall thresholds, focusing
attention on landslide prediction, with some applications to a real case
study in Calabria region (southern Italy)
A space-time generator for rainfall nowcasting: the PRAISEST model
International audienceThe paper introduces a new stochastic technique for forecasting rainfall in space-time domain: the PRAISEST Model (Prediction of Rainfall Amount Inside Storm Events: Space and Time). The model is based on the assumption that the rainfall height H accumulated on an interval ?t between the instants i?t and (i+1)?t and on a spatial cell of size ?x?y is correlated either with a variable Z, representing antecedent precipitation at the same point, either with a variable W, representing simultaneous rainfall at neighbour cells. The mathematical background is given by a joined probability density fH,W,Z (h,w,z) in which the variables have a mixed nature, that is a finite probability for null value and infinitesimal probabilities for the positive values. As study area, the Calabria region, in Southern Italy, has been selected. The region has been discretised by 10 km×10 km cell grid, according to the raingauge network density in this area. Storm events belonging to 1990?2004 period were analyzed to test performances of the PRAISEST model
Rainfall nowcasting by at site stochastic model P.R.A.I.S.E.
The paper introduces a stochastic model to forecast rainfall heights at
site: the P.R.A.I.S.E. model (Prediction of Rainfall Amount Inside Storm
Events). PRAISE is based on the assumption that the rainfall height <I>H<sub>i</I>+1</sub>
accumulated on an interval Δ<I>t</I> between the instants <I>iΔt</I> and
<I>(i+1Δt</I> is correlated with a variable <I>Z<sub>i<sup>(ν)</sup></sub></I>,
representing antecedent precipitation. The mathematical
background is given by a joined probability density <I>f<sub>H<sub>i+1</sub></sub>, Z<sub>i</sub><sup>(ν)</sup>(h<sub>i+1</sub> ,z<sub>i</sub><sup>(ν)</sup></I>) in which
the variables have a mixed nature, that is a finite probability in
correspondence to the null value and infinitesimal probabilities in
correspondence to the positive values. As study area, the Calabria region,
in Southern Italy, was selected, to test performances of the PRAISE model
Embryonic Exposure to Valproic Acid Impairs Social Predispositions of Newly-Hatched Chicks
This work was supported by a grant from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) Grant ERC-2011-ADG_20110406, Project No: 461 295517, PREMESOR to G.V. Support from Fondazione Caritro Grant Biomarker DSA [40102839] and PRIN 2015 (Neural bases of animacy detection, and their relevance to the typical and atypical development of the brain) to GV is also acknowledged
Influence of the bias-voltage on the anchoring energy for nematic liquid crystals
The influence of the bias-voltage on the anisotropic part of the nematic surface energy is analyzed. The experimental data show a strong dependence of the anchoring strength on the bias-voltage when the electrodes of the nematic cell are covered with WO3. The observed dependence can be interpreted taking into account the ions dissolved in the liquid crystal. We propose a model in which the effect of the bias-voltage is to collect the ions near the electrodes, in a surface layer whose thickness is of the order of the Debye’s screening length. The surplus of electric field due to this ions confinement gives rise to an electrostatic contribution to the total energy that can be considered as a surface energy. The proposed model is in good agreement with the experimental data. The model is used to interpret the observed independence of the anchoring strength on the bias-voltage when the indium-oxide electrode is covered with a film of polyimide, or it is without any covering. The influence of a charge emission from the electrodes under the bias voltage on the anchoring
energy is also analyzed. Possible applications of the observed phenomenon are discussed
NATURAL AND ANTHROPOGENIC RISKS: PROPOSAL FOR AN INTERDISCIPLINARY GLOSSARY
In the past few years, Italy has been ravaged by catastro-
phic events of natural or anthropogenic origin. These events
have highlighted, once again, the need to take prevention
measures in order to mitigate the damage that similar future
events could inflict on the Italian social and economic system.
As the costs of these measures might be very high, available
resources should be allocated carefully, assigning priority to
areas with the highest potential risk. Therefore, estimating the
potential damage caused by events expected both in the near
future and on a longer timescale in a reliable way might be
an important tool for pursuing an effective prevention policy.
The growing diversification and extent of urbanised areas and
economic activities make the estimation of the above effects
increasingly complex. Hence, reliance should be made on a
combination of disciplines that may be very different from or
that have often developed independently of one another over
the years. However, this combination has resulted in discre-
pancies in methodological approaches, which have impaired
the effectiveness of communication to the authorities in char-
ge of prevention policies.
This document proposes a common way through which
the scientific community may present its arguments and ex-
press its opinions about risks at the request of policymakers.
In particular, the document proposes the use of a glossary
with a view to overcoming “language” barriers among the va-
rious disciplines and defining a common lexicon.
The construction of a glossary requires the definition of
key terms and their mutual relations, which may become a
common legacy within a scientific and technical community.
Moreover, a glossary may help overcome possible differences
in the usage of those terms across the various disciplines, con-
sidering both consolidated uses at international level and ope-
rational practices at national level. Thus, the proposed glossa-
ry is not a mere listing of terms with their definitions. Indeed,
the meaning of the definitions depends only on the use of
the related terms in the reasoning process and in the opinions
that represent the outcome of this process. In this sense, the
construction of a glossary requires the adoption of a common
approach by the members of the scientific community involved.
The document is organised as follows. The second sec-
tion provides an overview of the rationale for a common ter-
minology and the features that it should have, explaining its
logical structure and normative purpose. Section 3 defines the
concept of risk analysis in simple terms, highlighting the pos-
sible ambiguities associated with this concept that need fur-
ther insights. Section 4 proposes a formalisation of the logical
process to be followed in carrying out assessments and ex-
pressing opinions on various risks. This section also deals, in
general terms, with the main items of information considered
and their mutual relations. Section 5 presents the glossary, i.e.
a list of terms, their definitions, and, where necessary, their
application contexts. Finally, a short list of references used in
the document is provided
Automated DBS Extraction Prior to Hilic/RP LC-MS/MS Target Screening of Drugs
This article describes a rapid LC-MS/MS target screening method based on an automated extraction of 5 mu L dried blood spots (DBS), two 5 min chromatographic runs on orthogonal phase columns (RP and Hilic) and a data dependent acquisition (DDA) of product ions spectra for the reliable identification of the detected compounds. The extraction step was performed in 2 min by using the LC autosampler itself in 96-well plates. This procedure was evaluated using 22 model compounds frequently encountered in forensic investigations, i.e., cocaine, benzodiazepines, amphetamines, opioids, antidepressants and antipsychotics. These investigations showed that even if the extraction step was reduced to a minimum, the extraction recoveries were satisfactory (median value of 40 %) and allowed for the detection of the model compounds in their therapeutic ranges, with the exception of morphine. Moreover, the use of two different chromatographic columns broadened the number of screening targets to those that behaved poorly under RP conditions, such as amphetamines or glucuronides, while keeping chromatographic gradients very short. This procedure was applied to 34 authentic post-mortem cases. It allowed the detection of 89 % of the compounds that were quantified in the routine procedures and the formal identification of 77 % of the compounds using their product ions spectra. These results were considered more than satisfactory compared to routine screening alone (GC-MS and LC-DAD, 55 % compound identification). The method described in this article is therefore a powerful approach for a fast, reliable and efficient target screening of drugs in forensic and clinical investigations
Big data managing in a landslide early warning system: Experience from a ground-based interferometric radar application
A big challenge in terms or landslide risk mitigation is represented by
increasing the resiliency of society exposed to the risk. Among the
possible strategies with which to reach this goal, there is the implementation of
early warning systems. This paper describes a procedure to improve early warning
activities in areas affected by high landslide risk, such as those
classified as critical infrastructures for their central role in society.
This research is part of the project LEWIS (Landslides Early Warning
Integrated System): An Integrated System for Landslide Monitoring, Early
Warning and Risk Mitigation along Lifelines.
LEWIS is composed of a susceptibility assessment methodology providing
information for single points and areal monitoring systems, a data
transmission network and a data collecting and processing center (DCPC),
where readings from all monitoring systems and mathematical models converge
and which sets the basis for warning and intervention activities.
The aim of this paper is to show how logistic issues linked to advanced
monitoring techniques, such as big data transfer and storing, can be dealt
with compatibly with an early warning system. Therefore, we focus on the
interaction between an areal monitoring tool (a ground-based interferometric
radar) and the DCPC. By converting complex data into ASCII strings and
through appropriate data cropping and average, and by implementing an
algorithm for line-of-sight correction, we managed to reduce the data daily
output without compromising the capability for performing
Bioderived dyes-mediated vat photopolymerization 3D printing of chitosan hydrogels for tissue engineering
The importance of 3D printable hydrogels is constantly increasing in the field of tissue engineering, due to their characteristic structure and similarity with the human body extracellular matrix (ECM). Herein, Quinizarin-based bioderived photoactive dyes were employed for the 3D printing of methacrylated chitosan by vat pho-topolymerization (VPP). Dyes are commonly needed in VPP to obtain good resolution avoiding the light scattering in the vat, here the bioderived molecules had further utility granting the printability with good resolution while acting both as photosensitizers and fillers/crosslinkers. Defined and detailed architectures in the range of millimetres were obtained with low printing times showing for the first time the possibility to obtain all-chitosan 3D structures with suspended features by Digital Light Processing (DLP), which is a form of vat photopolymerization; such a result is not achievable without the quinizarin-derived dyes. The same structures were achieved with an opti-mized concentration of poly(ethylene glycol) diacrylate, as a comparison, enhancing the resolution. For all the formulations, the important feature to obtain the gel printability (considering reactiveness, viscosity, shear thinning behaviour, mechanical properties and stability) were evaluated. The hydrogels mechanical character-ization and swelling properties were also tested and reported. Lastly, the possible application in tissue engi-neering was also evaluated through cell proliferation analysis over samples, including metabolic activity and DNA contempt assays. The use of such bioderived photoactive molecules that simultaneously act as photosensitizer enhancing the ink reactivity, as dye improving the definition of the final structures and as filler/crosslinker increasing the me-chanical stability, could represent a valuable route for the DLP printing of soft hydrogels
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