REAL-TIME ELASTOGRAPHY IN THE ASSESSMENT OF LIVER FIBROSIS: A REVIEW OF QUALITATIVE AND SEMI-QUANTITATIVE METHODS FOR ELASTOGRAM ANALYSIS

Despite its invasiveness, liver biopsy is still considered the gold standard for the assessment of hepatic fibrosis. Non-invasive ultrasound-based techniques are increasingly employed to assess parenchymal stiffness and the progression of chronic diffuse liver diseases. Real-time elastography is a rapidly evolving technique that can reveal the elastic properties of tissues. This review examines qualitative and semi-quantitative methods developed for analysis of real-time liver elastograms, to estimate parenchymal stiffness and, indirectly, the stage of fibrosis. Qualitative analysis is the most immediate approach for elastogram analysis, but this method increases intra- and inter-observervariability,whichisseenasamajorlimitationofreal-timeelastography.Semi-quantitativemethods include analysis of the histogram derived from color-coded maps, as well as calculation of the elastic ratio and fibrosis index. (E-mail: [email protected]) 2014 World Federation for Ultrasound in Medicine & Biology

Extreme Rainfall in the Mediterranean: What Can We Learn from Observations?

Abstract Flash floods induced by extreme rainfall events represent one of the most life-threatening phenomena in the Mediterranean. While their catastrophic ground effects are well documented by postevent surveys, the extreme rainfall events that generate them are still difficult to observe properly. Being able to collect observations of such events will help scientists to better understand and model these phenomena. The recent flash floods that hit the Liguria region (Italy) between the end of October and beginning of November 2011 give us the opportunity to use the measurements available from a large number of sensors, both ground based and spaceborne, to characterize these events. In this paper, the authors analyze the role of the key ingredients (e.g., unstable air masses, moist low-level jets, steep orography, and a slow-evolving synoptic pattern) for severe rainfall processes over complex orography. For the two Ligurian events, this role has been analyzed through the available observations (e.g., Meteosat Second Generation, Moderate Resolution Imaging Spectroradiometer, the Italian Radar Network mosaic, and the Italian rain gauge network observations). The authors then address the possible role of sea–atmosphere interactions and propose a characterization of these events in terms of their predictability

Towards A Grid Infrastructure For Hydro-Meteorological Research

The Distributed Research Infrastructure for Hydro-Meteorological Study (DRIHMS) is a coordinatedaction co-funded by the European Commission. DRIHMS analyzes the main issuesthat arise when designing and setting up a pan-European Grid-based e-Infrastructure for researchactivities in the hydrologic and meteorological fields. The main outcome of the projectis represented first by a set of Grid usage patterns to support innovative hydro-meteorologicalresearch activities, and second by the implications that such patterns define for a dedicatedGrid infrastructure and the respective Grid architecture

GFM Product User Manual

This Product User Manual (PUM) is the reference document for all end-users and stakeholders of the new Global Food Monitoring (GFM) product of the Copernicus Emergency Management Service (CEMS). The PUM provides all of the basic information to enable the proper and effective use of the GFM product and associated data output layers. This manual includes a description of the functions and capabilities of the GFM product, its applications and alternative modes of operation, and step-by-step guidance on the procedures for accessing and using the GFM product

Severe floods predictive ability: A proxy based probabilistic assessment of the Italian early warning system

In compliance with the national legal framework, the regional offices (CFDs) of the Italian Civil Protection Department have the daily duty to issue warn- ings to the local population on the account of the weather and hydrology- related impacts, predicted by forecast models and refined through their exper- tise and experience: this composite of objective (model) and subjective (ana- lyst) assessments are both contributing to the actual colour-coded warning system. Given its hybrid nature, it is of paramount importance to evaluate the predictive ability of the warning decision-making process as a whole. To this end, this study compares the return period T of the occurred flood (estimated through an hydrological model fed with observations) to the warning level that was issued. The novelty of this approach is that, by applying this methodology extensively in space and time, the probability curves of the variable T for each warning level are computed, allowing to evaluate the consistency between the warnings and the actual (estimated) severity of the event. As results suggest, the national early warning system is proven to be overall reliable for most cases, though very fine scale events (e.g., severe, localised, short-lived thunder- storms) are still an open challenge

Design and preliminary analysis of a framework for integrating real and virtual instrumentation within a grid infrastructure

Access to and control of instrumentation was fundamentally part of the original Grid vision. However, the recent trend has emphasized the access to computational resources and storage, neglecting two aspects, namely, access to instruments, as well as the usability of a system becoming more and more complex. Currently, many public-funded efforts are ongoing in order to enhance citizens' lifestyle, in which the Grid plays a role: in this perspective, the overall system must be easy to utilize, being an effective tool also for educational purposes. Besides, integrating instrumentation within the Grid infrastructure poses another issue, specifically, what has to be integrated within the Grid and what has to interact, remaining decoupled from the system for performance and cost reasons. This paper introduces a framework to integrate instrumentation and aggregate it within the Grid infrastructure. In addition, it could be used for providing instrument-oriented services to the Grid infrastructure and for building laboratory experiences. Then, the paper will give some hints for the effective deployment of the proposed architecture, using as a rule of thumb, the development of a framework easy to integrate, extend and utilize

Predictive ability of severe rainfall events over Catalonia for the year 2008

This paper analyses the predictive ability of quantitative precipitation forecasts (QPF) and the so-called "poor-man" rainfall probabilistic forecasts (RPF). With this aim, the full set of warnings issued by the Meteorological Service of Catalonia (SMC) for potentially-dangerous events due to severe precipitation has been analysed for the year 2008. For each of the 37 warnings, the QPFs obtained from the limited-area model MM5 have been verified against hourly precipitation data provided by the rain gauge network covering Catalonia (NE of Spain), managed by SMC. For a group of five selected case studies, a QPF comparison has been undertaken between the MM5 and COSMO-I7 limited-area models. Although MM5's predictive ability has been examined for these five cases by making use of satellite data, this paper only shows in detail the heavy precipitation event on the 9¿10 May 2008. Finally, the "poor-man" rainfall probabilistic forecasts (RPF) issued by SMC at regional scale have also been tested against hourly precipitation observations. Verification results show that for long events (>24 h) MM5 tends to overestimate total precipitation, whereas for short events (¿24 h) the model tends instead to underestimate precipitation. The analysis of the five case studies concludes that most of MM5's QPF errors are mainly triggered by very poor representation of some of its cloud microphysical species, particularly the cloud liquid water and, to a lesser degree, the water vapor. The models' performance comparison demonstrates that MM5 and COSMO-I7 are on the same level of QPF skill, at least for the intense-rainfall events dealt with in the five case studies, whilst the warnings based on RPF issued by SMC have proven fairly correct when tested against hourly observed precipitation for 6-h intervals and at a small region scale. Throughout this study, we have only dealt with (SMC-issued) warning episodes in order to analyse deterministic (MM5 and COSMO-I7) and probabilistic (SMC) rainfall forecasts; therefore we have not taken into account those episodes that might (or might not) have been missed by the official SMC warnings. Therefore, whenever we talk about "misses", it is always in relation to the deterministic LAMs' QPFs

Ensemble cloud-resolving modelling of a historic back-building mesoscale convective system over Liguria: The San Fruttuoso case of 1915

Highly localized and persistent back-building mesoscale convective systems represent one of the most dangerous flash-flood-producing storms in the north-western Mediterranean area. Substantial warming of the Mediterranean Sea in recent decades raises concerns over possible increases in frequency or intensity of these types of events as increased atmospheric temperatures generally support increases in water vapour content. However, analyses of the historical record do not provide a univocal answer, but these are likely affected by a lack of detailed observations for older events. In the present study, 20th Century Reanalysis Project initial and boundary condition data in ensemble mode are used to address the feasibility of performing cloud-resolving simulations with 1 km horizontal grid spacing of a historic extreme event that occurred over Liguria: The San Fruttuoso case of 1915. The proposed approach focuses on the ensemble Weather Research and Forecasting (WRF) model runs that show strong convergence over the Ligurian Sea (17 out of 56 members) as these runs are the ones most likely to best simulate the event. It is found that these WRF runs generally do show wind and precipitation fields that are consistent with the occurrence of highly localized and persistent back-building mesoscale convective systems, although precipitation peak amounts are underestimated. Systematic small north-westward position errors with regard to the heaviest rain and strongest convergence areas imply that the reanalysis members may not be adequately representing the amount of cool air over the Po Plain outflowing into the Ligurian Sea through the Apennines gap. Regarding the role of historical data sources, this study shows that in addition to reanalysis products, unconventional data, such as historical meteorological bulletins, newspapers, and even photographs, can be very valuable sources of knowledge in the reconstruction of past extreme events

Ensemble cloud-resolving modelling of a historic back-building mesoscale convective system over Liguria: the San Fruttuoso case of 1915

Highly localized and persistent back-building mesoscale convective systems represent one of the most dangerous flash-flood-producing storms in the north-western Mediterranean area. Substantial warming of the Mediterranean Sea in recent decades raises concerns over possible increases in frequency or intensity of these types of events as increased atmospheric temperatures generally support increases in water vapour content. However, analyses of the historical record do not provide a univocal answer, but these are likely affected by a lack of detailed observations for older events. In the present study, 20th Century Reanalysis Project initial and boundary condition data in ensemble mode are used to address the feasibility of performing cloud-resolving simulations with 1 km horizontal grid spacing of a historic extreme event that occurred over Liguria: the San Fruttuoso case of 1915. The proposed approach focuses on the ensemble Weather Research and Forecasting (WRF) model runs that show strong convergence over the Ligurian Sea (17 out of 56 members) as these runs are the ones most likely to best simulate the event. It is found that these WRF runs generally do show wind and precipitation fields that are consistent with the occurrence of highly localized and persistent back-building mesoscale convective systems, although precipitation peak amounts are underestimated. Systematic small north-westward position errors with regard to the heaviest rain and strongest convergence areas imply that the reanalysis members may not be adequately representing the amount of cool air over the Po Plain outflowing into the Ligurian Sea through the Apennines gap. Regarding the role of historical data sources, this study shows that in addition to reanalysis products, unconventional data, such as historical meteorological bulletins, newspapers, and even photographs, can be very valuable sources of knowledge in the reconstruction of past extreme events.This article is published as Parodi, Antonio, Luca Ferraris, William Gallus, Maurizio Maugeri, Luca Molini, Franco Siccardi, and Giorgio Boni. "Ensemble cloud-resolving modelling of a historic back-building mesoscale convective system over Liguria: the San Fruttuoso case of 1915." Climate of the Past 13, no. 5 (2017): 455. DOI: 10.5194/cp-13-455-2017. Posted with permission.</p