1,140 research outputs found
An operational flash-flood forecasting chain applied to the test cases of the EU project HYDROPTIMET
International audience The application of a flash-flood prediction chain, developed by CIMA, to some testcases for the Tanaro river basin in the framework of the EU project HYDROPTIMET is presented here. The components of the CIMA chain are: forecast rainfall depths, a stochastic downscaling procedure and a hydrological model. Different meteorological Limited Area Models (LAMs) provide the rainfall input to the hydrological component. The flash-flood prediction chain is run both in a deterministic and in a probabilistic configuration. The sensitivity of forecasting chain performances to different LAMs providing rainfall forecasts is discussed. The results of the application show how the probabilistic forecasting system can give, especially in the case of convective events, a valuable contribution in addressing the uncertainty at different spatio-temporal scales involved in the flash flood forecasting problem in small and medium basins with complex orography
Application of statistical analysis to estimate the costal hazard. A case study in Liguria region
Liguria Region is totally exposed to the action of the sea storms and too the natural evolution of the profile of the shoreline. The modification along the time of the shape of the shoreface is measured from the official administrative and technical offices of the Liguria Region and Italian Environmental Ministry, this information is available in shape format starting from 1944.
The phenomenon of coastal flood produces a direct damage represented by the loss of soil and an indirect damage correlated to the impact on tourism activity, social aspects, and damage to heritage buildings. In recent years another type of damage source must be considered, and this is the phenomenon of the increasing of the mean sea water level, known as Sea Level Rise (SLR). It is necessary to introduce this phenomenon in the hazard analysis and this is a direct and known consequence of the climate change.
Results from the hazard index encompass both the relative magnitude of erosion and/or coastal flooding, and the probability that these hazards may occur based on the distribution of the index using different scenarios. The paper analyzes a Liguria case study in which the effects of SLR is particularly critical in terms of heritage and economic and social activities hazar
AUMENTO DEGLI INDICI DI CITOLISI EPATICA NEI SOGGETTI CON INFEZIONE DA HIV CHE AVVIANO LA PRIMA LINEA DI TRATTAMENTO ANTIRETROVIRALE: STUDIO OSSERVAZIONALE DI COORTE
Obiettivi: Valutare l'incidenza e i fattori di rischio per il rialzo degli enzimi di citolisi epatica (liver enzyme elevation, LEE) nei pazienti che iniziano una terapia antiretrovirale di prima linea (ART) nella coorte osservazionale prospettica ICONA.
Pazienti e metodi: sono stati selezionati per lo studio 6575 pazienti naive alla ART, che hanno iniziato, tra giugno 2009 e dicembre 2017, un regime terapeutico costituito da 2 inibitori nucleosidici della trascrittasi inversa (NRTI) associati ad un inibitore della proteasi potenziato (PI/b) N=2436 (37.1%), ad un inibitore non nucleosidico della trascrittasi inversa (NNRTI) N=2384 (36.3%), o ad un inibitore dell'integrasi (INSTI) N=755 (26.7%). La presenza di co-infezione da parte del virus dell\u2019HBV (HBsAg positivit\ue0) o dell\u2019HCV (HCV-RNA positivit\ue0) \ue8 stata rilevata nel 3.9% e nel 5.8% della popolazione dello studio. I LEE sono stati definiti come aumento di ALT o AST di 65 2.5 x ULN (limite superiore della normale) per i pazienti con valori di base nei limiti della norma o 65 2.5 x il valore basale, per i pazienti con valori di base >ULN. L'analisi di regressione Cox inverse probability weighted \ue8 stata utilizzata per calcolare gli hazard ratio (HR) ed i relativi intervalli di confidenza al 95% (95%CI) per LEE, sulla base del regime terapeutico di prima linea utilizzato e delle caratteristiche basali dei partecipanti allo studio.
Risultati: Durante un follow-up complessivo di 20722 anni di osservazione, si sono verificati 183 casi di LEE. Dopo l'aggiustamento per i principali fattori confondenti, il rischio di LEE \ue8 risultato significativamente ridotto nei pazienti trattati con INSTI rispetto a coloro che ricevevano NNRTI (HR 0.46, 95%CI 0.25-0.86), con una significativa riduzione del rischio nel gruppo di pazienti trattati con raltegravir (HR 0.11, 95%CI 0.02-0.84, utilizzando la classe degli NNRTI come riferimento). L'HR per LEE \ue8 risultato significativamente pi\uf9 elevato nei soggetti con co-infezione da HBV o HCV, nei pazienti con infezione da HIV scarsamente controllata e in quelli che hanno contratto l'HIV attraverso la trasmissione omosessuale.
Conclusioni: Nel nostro studio, l'utilizzo di INSTI riduce del 54% il rischio di LEE rispetto ad altri regimi. Questo dato potrebbe essere particolarmente importante per la scelta dell'ART in pazienti con fattori di rischio per tossicit\ue0 epatica come le co-infezioni HCV e HBV
Remote Sensing-Based Methodology for the Quick Update of the Assessment of the Population Exposed to Natural Hazards
The assessment of the number of people exposed to natural hazards, especially in countries with strong urban growth, is difficult to be updated at the same rate as land use develops. This paper presents a remote sensing-based procedure for quickly updating the assessment of the population exposed to natural hazards. A relationship between satellite nightlights intensity and urbanization density from global available cartography is first assessed when all data are available. This is used to extrapolate urbanization data at different time steps, updating exposure each time new nightlights intensity maps are available. To test the reliability of the proposed methodology, the number of people exposed to riverine flood in Italy is assessed, deriving a probabilistic relationship between DMSP nightlights intensity and urbanization density from the GUF database for the year 2011. People exposed to riverine flood are assessed crossing the population distributed on the derived urbanization density with flood hazard zones provided by ISPRA. The validation against reliable exposures derived from ISTAT data shows good agreement. The possibility to update exposure maps with a higher refresh rate makes this approach particularly suitable for applications in developing countries, where urbanization and population densities may change at a sub-yearly time scale
Rationale for an association between PD1 checkpoint inhibition and therapeutic vaccination against HIV
The pathogenesis of HIV immunodeficiency is mainly dependent on the cytopatic effects exerted by the virus against infected CD4+ T cells. However, CD4+ T cell loss cannot be the only pathogenic factor since severe opportunistic infections may develop in HIV infected patients with normal CD4+ T cell counts and since the recent START study indicated that absolute CD4+ T cell counts are not predictive for AIDS and non-AIDS events. Recently our group demonstrated that CD8+CD28-CD127lowCD39+ regulatory T lymphocytes, previously found highly concentrated within tumor microenvironment, circulate with elevated frequency in the peripheral blood of HIV infected patients. Here, we show that these cells, that at least in part are HIV specific, express the PD1 immune checkpoint. Based on these evidences and considerations, in this Perspective article we speculate on the opportunity to treat HIV infected patients with anti-PD1 immune checkpoint inhibitors as a way to counteract the T regulatory cell compartment and to unleash virus-specific immune responses. In order to potentiate the immune responses against HIV we also propose the potential utility to associate immune checkpoint inhibition with HIV-specific therapeutic vaccination, reminiscent of what currently applied in oncologic protocols. We suggest that such an innovative strategy could permit drug-sparing regimens and, perhaps, lead to eradication of the infection in some patients
Effects of propagation conditions on radar beam-ground interaction: impact on data quality
International audienceA large part of the research in the radar meteorology is devoted to the evaluation of the radar data quality and to the radar data processing. Even when, a set of absolute quality indexes can be produced (like as ground clutter presence, beam blockage rate, distance from radar, etc.), the final product quality has to be determined as a function of the task and of all the processing steps. In this paper the emphasis lies on the estimate of the rainfall at the ground level taking extra care for the correction for ground clutter and beam blockage, that are two main problems affecting radar reflectivity data in complex orography. In this work a combined algorithm is presented that avoids and/or corrects for these two effects. To achieve this existing methods are modified and integrated with the analysis of radar signal propagation in different atmospheric conditions. The atmospheric refractivity profile is retrieved from the nearest in space and time radiosounding. This measured profile is then used to define the `dynamic map' used as a declutter base-field. Then beam blockage correction is applied to the data at the scan elevations computed from this map. Two case studies are used to illustrate the proposed algorithm. One is a summer event with anomalous propagation conditions and the other one is a winter event. The new algorithm is compared to a previous method of clutter removal based only on static maps of clear air and vertical reflectivity continuity test. The improvement in rain estimate is evaluated applying statistical analysis and using rain gauges data. The better scores are related mostly to the ``optimum" choice of the elevation maps, introduced by the more accurate description of the signal propagation. Finally, a data quality indicator is introduced as an output of this scheme. This indicator has been obtained from the general scheme, which takes into account all radar data processing steps
3DVAR assimilation of SSM/I data over the sea for the IOP2b MAP case
International audienceData assimilation by 3DVAR of data from the Special Sensor Microwave/Imager (SSM/I) has been performed to study the IOP2b case (19-21 September 1999) of the Mesoscale Alpine Programme (MAP). Only data over the sea surface are used to avoid the contamination of the surface emissivity. Moreover, the rainy data are filtered out because the assimilation algorithm of 3DVAR does not take into account the scattering processes. SSM/I data are assimilated in two different ways: as Brightness Temperature directly, or as Precipitable Water and surface wind speed retrieved from the Brightness Temperature. The effect of the thinning of the observations has been studied and a set of sensitivity test cases has been carried out; the one by one removal of the SSM/I frequencies from the initial dataset allows to evaluate their impact on the Initial Conditions. A few experiments are performed using these new Initial Conditions to initialize the MM5 (PSU/NCAR) model. The results show that the assimilation of the retrieved quantities, i.e. Precipitable Water and surface wind speed, does not produces large improvement in the Initial Conditions. Vice versa, the assimilation of the Brightness temperatures produces a large variability of the Initial Conditions. The forecast experiments show that the model is very sensitive to the 22GHz and 37GHz frequencies
Applicability of a forecasting chain in a different morphological environment in Italy
International audienceThe operational meteo-hydrological forecasting chain of the Liguria Region (NW Italy) is applied to a different morphoclimatic environment, such as the Emilia Romagna Region (N Italy). Modification to the chain, both in models and in procedures, are introduced to overcome problems related to medium dimension catchments (A?1000km2), characterized by complex altimetry profiles and antropical interventions along the river. The main feature of the original operational procedure, that is the probabilistic approach, is maintained. Hydraulic hazard reduction through artificial reservoirs management is exploited with reference to a specific event occurred on the Reno basin (Emilia Romagna Region)
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