433 research outputs found
Decentralized planning for self-adaptation in multi-cloud environment
The runtime management of Internet of Things (IoT) oriented applications deployed in multi-clouds is a complex issue due to the highly heterogeneous and dynamic execution environment. To effectively cope with such an environment, the cross-layer and multi-cloud effects should be taken into account and a decentralized self-adaptation is a promising solution to maintain and evolve the applications for quality assurance. An important issue to be tackled towards realizing this solution is the uncertainty effect of the adaptation, which may cause negative impact to the other layers or even clouds. In this paper, we tackle such an issue from the planning perspective, since an inappropriate planning strategy can fail the adaptation outcome. Therefore, we present an architectural model for decentralized self-adaptation to support the cross-layer and multi-cloud environment. We also propose a planning model and method to enable the decentralized decision making. The planning is formulated as a Reinforcement Learning problem and solved using the Q-learning algorithm. Through simulation experiments, we conduct a study to assess the effectiveness and sensitivity of the proposed planning approach. The results show that our approach can potentially reduce the negative impact on the cross-layer and multi-cloud environment
Gas Geochemistry and Fractionation Processes in Florina Basin, Greece
Florina Basin is located in northern Greece, close to Mount Voras where the volcanic activity of Late Messinian age began. In the area, many CO2-rich gas emissions are present as a bubbling free-phase in groundwater (both springs and wells) and soil gases. Volcanism along with the geological and geodynamic regime of the basin, created the ideal conditions for CO2 accumulation in vertically stacked reservoirs. One of these, industrially exploited by the company Air Liquide Greece, produces 30,000 t/a of CO2. Results show that CO2 concentrations in the gases of Florina can arrive up to 99.8% and are mostly above 90%. Moreover, C-isotope composition (-2.1 to + 0.3 h vs. VPDB) indicates a mixed mantle-limestone origin for CO2, while He isotope composition (R/RA from 0.21 to 1.20) shows a prevailing crustal origin with an up to 15% mantle contribution. Helium and methane, with concentrations spanning over three orders of magnitude, show a positive correlation and a consequent high variability of He/CO2 and CH4/CO2 ratios. This variability can be attributed to the interaction of the uprising gases with groundwater that chemically fractionates them due to their different solubility. Based on the CO2, CH4 and He concentrations, gas samples collected in the basin can be divided in 3 groups: a) deep reservoir gases, b) enriched in less soluble gases and c) depleted in less soluble gases. The first group consists of gas samples collected at the Air Liquide extraction wells, which tap a 300m deep reservoir. This group can be considered as the least affected by fractionation processes due to interaction with groundwater. The gases of the second group due to their interaction with shallower unsaturated aquifers, become progressively enriched in less soluble gases (He and CH4). Finally, the third group represents residual gas phases after extensive degassing of the groundwater during its hydrological pathway
Weight filtration on the cohomology of complex analytic spaces
We extend Deligne's weight filtration to the integer cohomology of complex
analytic spaces (endowed with an equivalence class of compactifications). In
general, the weight filtration that we obtain is not part of a mixed Hodge
structure. Our purely geometric proof is based on cubical descent for
resolution of singularities and Poincar\'e-Verdier duality. Using similar
techniques, we introduce the singularity filtration on the cohomology of
compactificable analytic spaces. This is a new and natural analytic invariant
which does not depend on the equivalence class of compactifications and is
related to the weight filtration.Comment: examples added + minor correction
Carbon dixide emission in Italy: Shallow crustal sources or subduction related fluid recycling?
Anomalous non-volcanic CO2 release in central and
southern Italy has been highlighted by ten years of detailed
investigations on Earth degassing processes. Two regional
degassing structures are located in the Tyrrhenian sector
where more then 200 emissions of CO2 are located and has
been recently included in the first web based catalogue of
degassing sites (http://googas.ov.ingv.it). The total amount of
CO2 released by the two structures were evaluated to be >
2×1011 mol a-1 ( >10% of the estimated global volcanic CO2
emission). The anomalous flux of CO2 suddenly disappears in
the Apennine in correspondence of a narrow band where most
of the Italian seismicity concentrates. Here, at depth, the gas
accumulates in crustal traps generating CO2 overpressurised
reservoirs. These overpressured structures are, in our opinion,
one of the main cause of Apennine earthquake activation
processes. The results of these investigations suggested that
Earth degassing in Italy may have an active primary role in the
geodynamics of the region. What is the origin of gas? The
large extension of the degassing structures and petrologic data
suggested that the main source of gas is a mantle
metasomatised by the fluids produced in the subdacted slabs.
However, has been also hypothesised the presence of localised
crustal source of the gas. This matter will be discussed on the
base of unpublished isotopic data of the main gas emissions
Understanding functional group and assembly dynamics in temperature responsive systems leads to design principles for enzyme responsive assemblies
Understanding the molecular rules behind the dynamics of supramolecular assemblies is fundamentally important for the rational design of responsive assemblies with tunable properties. Herein, we report that the dynamics of temperature-sensitive supramolecular assemblies is not only affected by the dehydration of oligoethylene glycol (OEG) motifs, but also by the thermally-promoted molecular motions. These counteracting features set up a dynamics transition point (DTP) that can be modulated with subtle variations in a small hydrophobic patch on the hydrophilic face of the amphiphilic assembly. Understanding the structural factors that control the dynamics of the assemblies leads to rational design of enzyme-responsive assemblies with tunable temperature responsive profiles
A Two-Phase ASP Encoding for Solving Rehabilitation Scheduling
The rehabilitation scheduling process consists of planning rehabilitation physiotherapy sessions for patients, by assigning proper operators to them in a certain time slot of a given day, taking into account several requirements and optimizations, e.g., patient’s preferences and operator’s work balancing. Being able to efficiently solve such problem is of upmost importance, in particular after the COVID-19 pandemic that significantly increased rehabilitation’s needs. In this paper, we present a solution to rehabilitation scheduling based on Answer Set Programming (ASP), which proved to be an effective tool for solving practical scheduling problems. Results of experiments performed on both synthetic and real benchmarks, the latter provided by ICS Maugeri, show the effectiveness of our solution
Diabetes influences cancer risk in patients with increased carotid atherosclerosis burden
Background and aims: Atherosclerosis and cancer share several risk factors suggesting that at least in part their pathogenesis is sustained by common mechanisms. To investigate this relation we followed a group of subjects with carotid atherosclerosis at baseline up for malignancy development.Methods and results: we carried out an observational study exploring cancer incidence (study endpoint) in subjects with known carotid atherosclerosis at baseline (n = 766) without previous cancer or carotid vascular procedures. During the follow-up (160 +/- 111 weeks) 24 cancer occurred, corresponding to an overall annual incidence rate of 0.11%. 10 diagnosis of cancer occurred in individuals with a carotid stenosis >50% (n = 90) whereas 14 in patients with a carotid stenosis <50% patients (n = 676) (p < 0.001). Respect to patients without cancer, diabetes was markedly more common in subjects with cancer diagnosis during the FU (37.3%vs75.0%, p < 0.001). After controlling for classic risk factors, carotid stenosis >50% (HR = 2.831, 95%CI = 1.034-5.714; p = 0.036) and diabetes (HR = 4.831, 95%CI = 1.506-15.501; p = 0.008) remained significantly associated with cancer diagnosis.Conclusions: to our knowledge this is the first study reporting a significant risk of cancer development in subjects with diabetes and high risk of cerebrovascular events, highlighting the need of a carefully clinical screening for cancer in diabetic patients with overt carotid atherosclerosis. (C) 2019 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved
Active Degassing of Deeply Sourced Fluids in Central Europe: New Evidences From a Geochemical Study in Serbia
We report on the results of an extensive geochemical survey of fluids released in the Vardar zone (central-western Serbia), a mega-suture zone at the boundary between Eurasia and Africa plates. Thirty-one bubbling gas samples are investigated for their chemical and isotopic compositions (He, C, Ar) and cluster into three distinct groups (CO2-dominated, N2-dominated, and CH4-dominated) based on the dominant gas species. The measured He isotope ratios range from 0.08 to 1.19 Ra (where Ra is the atmospheric ratio), and reveal for the first time the presence of a minor (<20%) but detectable regional mantle-derived component in Serbia. δ13C values range from −20.2‰ to −0.1‰ (versus PDB), with the more negative compositions observed in N2-dominated samples. The carbon-helium relationship indicates that these negative δ13C compositions could be due to isotopic fractionation processes during CO2 dissolution into groundwater. In contrast, CO2-rich samples reflect mixing between crustal and mantle-derived CO2. Our estimated mantle-derived He flux (9.0 × 109 atoms m−2 s−1) is up to 2 orders of magnitude higher than the typical fluxes in stable continental areas, suggesting a structural/tectonic setting favoring the migration of deep-mantle fluids through the crust
A shallow layer model for heavy gas dispersion from natural sources: application and hazard assessment at Caldara di Manziana, Italy.
Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached.Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached.Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached.Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached.Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached
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