233 research outputs found
Damage distribution and seismological model of the November 24, 2004, Salo' (Northern Italy) earthquake
The West side of lake of Garda, in Northern Italy, was struck by a ML=5.2 earthquake on
November 24, 2004. The felt area is rather large (from Venice to Milan) and the damaged area
consists of 66 municipalities, with a number of homeless of about 2200 and estimated direct
damages of 215 millions of euros. Most of the damaged structures are old masonry buildings and
churches, while there were almost no damage to reinforced concrete structures. The observed
distribution of macroseismic intensity shows a strong azimuthal dependence, with high intensity
level in a 10x10 km2 area located SW to the epicentre and rather large dispersion of values
(ranging from V to VII-VIII) in the first 10 km epicentral distance.
Taking into account the vulnerability level of the damaged structures and the features of the
geological formations, we tried to explain the observed damage distribution in terms of finite fault
properties of the source, despite the moderate magnitude of the event.
Thus we hypothesised a fault geometry from seismotectonic considerations and we simulated the
event by a high frequency simulation technique (Deterministic Stochastic Method, DSM). The
synthetic ground motion parameters were converted into intensity values by empirical
relationships and local geological conditions were considered to explain some discrepancies
between simulated and observed intensities. It was possible to adequately reproduce both the
observed distribution of macroseismic intensity and the ground motion recorded by an
accelerometric station located at about 13 km epicentral distance
La difesa dai terremoti in Lombardia: stato dell’arte e prospettive
L’INGV (http://www.mi.ingv.it/) svolge in Lombardia ricerche nel campo della mitigazione del rischio sismico, mediante studi mirati al miglioramento delle conoscenze sulla storia sismica, sul modello strutturale legato al regime tettonico in atto e alla definizione del moto del suolo atteso. Accanto alle indagini necessarie alla caratterizzazione sismogenetica e dei possibili effetti dello scuotimento sismico, si pone l’attività di monitoraggio sismico, che la Sezione di Milano-Pavia espleta mediante la rete accelerometrica (RAIS, http://rais.mi.ingv.it/) che consta di 20 postazioni distribuite in prevalenza sul territorio regionale.
In un recente lavoro di sintesi - di studi pluriennali su fonti storiche e di revisioni critiche di materiali pubblicati - si è tentato di colmare l’evidente carenza conoscitiva sulle caratteristiche della sismicità storica dell’area lombarda. Tale carenza è particolarmente evidente se si rapportano le informazioni oggi disponibili sui terremoti del passato in quest’area con quelle relative al settore veneto-friulano. La regione analizzata, compresa tra il bacino del fiume Adda e il Lago di Garda, è stata caratterizzata da alcuni terremoti con Mw>5.5 (es., 1117, Veronese; 1222, Brescia; 1901, Salò) e vari eventi con Mw compresa fra 4.8 e 5.5 (es., 1065, Brescia; 1396, Monza; 1642, Bergamo). Per molti degli eventi sismici fino al 1700 le informazioni sono desumibili soltanto da scarse fonti storiche. La determinazione epicentrale e l’attribuzione della magnitudo per tali eventi sono da considerarsi, pertanto, con una certa cautela al fine di definire le caratteristiche sismiche del territorio. I terremoti del 1117 e del 1222, in tale contesto, rappresentano un’eccezione rispetto ai dati generalmente disponibili. E tuttavia vari problemi tuttora aperti rendono assai difficile l’utilizzo della distribuzione del danno attribuibile a questi eventi nella prospettiva di un’affidabile parametrizzazione.
Le indagini geologico-strutturali e di geologia del Quaternario, finalizzate a definire un quadro strutturale compatibile con il regime tettonico in atto, sono necessarie per giustificare la storia sismica e, in sostanza, per definire il comportamento sismogenetico della regione. Le geometrie dei sistemi di faglia attivi alpini sono ora sufficientemente noti. Le conoscenze permettono di formulare ipotesi sismotettoniche relative all’origine dei terremoti dell’area gardesana e del Bresciano. In via di definizione sono invece le geometrie dei fronti appenninici, cui sono attribuibili i terremoti al di sopra della soglia nel settore padano. Le ricerche attuali sono altresì indirizzate ad una migliore caratterizzazione del complesso settore compreso tra la parte meridionale del Lago di Garda (area di Sirmione), Verona e Mantova, all’interno del quale potrebbe collocarsi l’area epicentrale del terremoto del 1117 (o una delle aree epicentrali, qualora si considerasse questo evento come rappresentato da una sequenza sismica).
Uno dei settori regionali con maggiore frequenza di eventi sismici è l’area gardesana occidentale, per questo motivo la rete di monitoraggio presenta una notevole densità di postazioni nel Bresciano e se ne è pianificato l’addensamento nel Veronese. Nel corso del 2007, la rete ha consentito la registrazione di 516 forme d’onda relative a 28 eventi locali e regionali (di cui una decina localizzati nell’area citata) con magnitudo da 1.3 a 4.2, di cui sono stati calcolati i parametri di interesse ingegneristico. L’analisi delle registrazioni ha permesso di ricavare informazioni utili per il calcolo di scenari di scuotimento. Un esempio di taali applicazioni è rappresentato dallo scenario realizzato utilizzando come terremoto di riferimento l'evento del 24 Novembre 2004 (M 5.2)
Pan-European ground-motion prediction equations for the average horizontal component of PGA, PGV, and 5 %-damped PSA at spectral periods up to 3.0 s using the RESORCE dataset
This article presents a set of Ground-Motion Prediction Equations (GMPEs) for Europe and the Middle East, derived from the RESORCE strong motion data bank, following a standard regression approach. The parametric GMPEs are derived for the peak ground acceleration, peak ground velocity, and 5 %-damped pseudo-absolute acceleration response spectra computed over 23 periods between 0.02 and 3 s, considering the average horizontal-component ground-motions. The GMPEs are valid for distances less than 300 km, hypocentral depth up to 35 km and over the magnitude range 4–7.6. Two metrics for the source-to-station distance (i.e. Joyner-Boore and hypocentral) are considered. The selected dataset is composed by 2,126 recordings (at a period of 0.1 s) related to 365 earthquakes, that includes strong-motion data from 697 stations.The EC8 soil classification (four classes from A to D) discriminates recording sites and four classes (normal, reverse, strike-slip, and unspecified) describe the style of faulting. A subset which contains only stations with measured Vs30 and earthquakes with specified focal mechanism (1,224 records from 345 stations and 255 earthquakes) is used to test of the accuracy of the median prediction and the variability associated to the broader data set. A random effect regression scheme is applied and bootstrap analyses are performed to estimate the 95 % confidence levels for the parameters. The total standard deviation sigma is decomposed into between-events and within-event components, and the site-to-site component is evaluated as well. The results show that the largest contribution to the total sigma is coming from the within-event component. When analyzing the residual distributions, no significant trends are observed that can be ascribed to the earthquake type (mainshock-aftershock classification) or to the non-linear site effects. The proposed GMPEs have lower median values than global models at short periods and large distances, while are consistent with global models at long periods (T>1) s. Consistency is found with two regional models developed for Turkey and Italy, as the considered dataset is dominated by waveforms recorded in these regions
Ground motion models for Molise region (Southern Italy)
On October 31st and November 1st, 2002 two moderate earthquakes of moment magnitude Mw=5.7 (INGV-Harvard European-Mediterranean Regional Centroid-Moment tensor project) occurred in southern Italy. After the mainshocks, felt in many municipalities of the Molise and Puglia region, a strong motion and a seismic temporary network were installed in the epicentral area and surrounding regions. The strong motion network was composed by 9 stations, integrating the accelerometers of the permanent Rete Accelerometrica Nazionale (RAN network), and operated until December 2003. The strong motion data set is composed by 195 recordings from 51 earthquakes (2.5<Ml<5.4) recorded by 29 accelerometers (Dipartimento della Protezione Civile et al., 2004). In addition to the strong motion network, several Italian research institutions (Istituto Nazionale di Geofisica e Vulcanologia, INGV; Istituto Nazionale di Oceanografia e Geofisica, INOGS; Dipartimento per lo studio del Territorio e delle sue Risorse, University of Genoa, Dip.Te.Ris) installed a temporary regional network, composed by 35 seismic stations. This network aimed at monitoring and studying the evolution in time and space of the seismic sequence. More than 1900 aftershocks were recorded in the period November 1st - December 5th, 2002 (Chiarabba et al., 2005).
The unified velocity-acceleration data set has been considered to derive ground motion models for peak ground acceleration and peak ground velocity for both maximum horizontal and vertical components. The results obtained for the Molise area have been compared with the attenuation pattern of the Umbria-Marche region (central Italy), that was recently investigated by Bindi et al. (2006). The remarkable differences observed indicate the need of a regional attenuation relation for the area and the need of further investigations, to better identify the role of source characteristics, anelastic and geometric attenuation and site effects in the evaluation of peak ground motion values
What can we learn from the January 2012 Northern Italy earthquakes?
This note focuses on the ground motion recorded during the recent moderate earthquakes
occurred in the central part of Northern Italy (panel 1), a region characterized by low seismicity.
For this area the Italian seismic hazard map (Stucchi et al., 2011) assigns a maximum horizontal
acceleration (rock site) up to 0.2 g (10% probability of exceedance in 50 yrs). In the last 4 years,
the region was struck by 9 earthquakes in the magnitude range 4≤Mw≤5.0, with the three largest
located in the Northern Apennines (Mw 4.9 and 5.0 Parma events, December 2008 and January
2012) and in the Po plain (Mw 4.9 Reggio Emila event of January 2012). We analyze the strongmotion
data (distance < 300 km) from these events recorded by stations belonging to the INGV
(RAIS, http://rais.mi.ingv.it; RSNC http://iside.rm.ingv.it) and DPC (RAN, www.protezionecivile.it;
http://itaca.mi.ingv.it).
The 2008 and 2012 Parma events, both characterized by reverse focal mechanisms
(http://cnt.rm.ingv.it/), have depths of 27 and 60 km respectively. The deep event produced a
maximum peak ground acceleration (PGA) of 97 cm/s2 at Novellara (NVL, EC8 C class) station (70
km from the epicenter). The 25th January 2012 event (depth of 34 km) produced a maximum PGA
of 114 cm/s2 at Sorbolo (SRP) station (7 km from the epicenter).
Preliminary analyses show:
1) a peculiar ground-motion attenuation of the deep Parma event with respect to the shallow one.
In panel 2, the PGAs for the two Parma events are plotted as a function of hypocentral distance
and compared to the global ground motion prediction equation (GMPE) calibrated by Cauzzi and
Faccioli (2008) using events with depth < 30 km. The different distance-decay of PGA for the deep
event (blue for A class of EC8 and red for B and C classes, CEN 2003) is evident, in particular for
distance up to 100 km. On the other hand, the PGAs of the 2008 Parma crustal event (grey) are
well explained by this GMPE.
In panel 3, the PGAs for the deep 2012 event, grouped for EC8 classes, are compared to the
national GMPE calibrated by Bindi et al. (2011) using crustal events and epicentral distance. Also
in this case, the GMPE underestimates the PGAs up to 200 km. Although most of the class C sites
(red) show the largest PGAs, the underestimation cannot be completely ascribed to site effects.
The large PGAs from the Parma deep event, with respect to the shallow one, could be explained in
terms of source effects (e.g. large stress drop values enhancing the high-frequency radiation). In
addition, as explained by Castro et al. (2008), the different attenuation in the lower and upper crust
could explain the large PGAs recorded for the 2012 deep event.
2) seismic amplification at Po Plain sites:
In panel 4, the PGAs of the January 25th, Mw 4.9, Reggio Emilia event are plotted as a function of
the epicentral distance, together with the Bindi et al. (2011) GMPE. In general, the largest
amplitudes occur at the Po plain sites (red), suggesting possible peculiar site response. An overall
increase of the PGAs is observed around 100km, in agreement with the results of Bragato et al.
(2011) that studied the regional influence of Moho S-wave reflections in the area.
An example of site response is shown in panel 5, considering TREG (class C) and ZEN8 (class A)
stations (panel 5a), located at 88 km from the Reggio Emila epicentre. The rotational standard
spectral ratio (panel 5b) for 10 s of S wave shows polarized amplifications around 2 Hz, detected
also at others Po plain sites (not reported), as well as amplification on the vertical component.
The points discussed above should to be interpreted as a warning for future applications dealing
with ground motion estimation in the aftermath of an earthquake in this area (e.g. ShakeMap
calculation): currently used GMPEs, based on different events and sites characteristics could lead
to significant bias in the final results
Comparison of topical tacrolimus 0.1 % in pectin ointment with clobetasol 0.5% ointment in adults with moderate to severe desquamative gingivitis: A 4-week, randomized, double-blind clinical trial.
BACKGROUND: Desquamative gingivitis (DG) is a clinical condition characterized by red, painful, glazed, and friable gingiva, which might be a manifestation of some autoimmune mucocutaneous diseases. The time from the development of initial signs of DG to diagnosis can vary from months to years. Based on a literature search, no data concerning patients with DG without signs of autoimmune disease were available.
OBJECTIVE: The aim of this trial was to compare the efficacy and tolerability of monotherapy with topical tacrolimus 0.1% in pectin ointment versus clobetasol propionate 0.5% ointment in adults affected by DG.
METHODS: This randomized, double-blind clinical trial was conducted at the Dipartimento di Medicina Clinica e Sperimentale, Universita di Verona, Verona, Italy. Patients aged > or =18 years were selected using the department's electronic medical records based on a clinical diagnosis of moderate to severe DG. After a 2-week washout period, patients were randomly assigned to receive 2 mL of tacrolimus 0.1% in pectin (equivalent to 0.2 mg of tacrolimus) or 2 mL of clobetasol propionate 0.5% ointment (equivalent to 1 mg of clobetasol) QD for 4 weeks. Evaluations were performed before treatment (baseline), after the treatment period (week 4), and at 2 follow-up visits at weeks 6 and 8. The signs of DG (ie, erythema [atrophy] and desquamation [erosions/ulceration]) were quantified by a blinded investigator using a calculated score based on their surface extension, using a drawing in which the areas of various zones of the mouth were indicated as a percentage of the whole oral mucosa. Severity of erythema and desquamation was rated on a 4-point scale (0 = absent; 1 = involvement of 15% [severe]). The primary end point was the number of patients who achieved remission (severity score of 0) in either sign; the secondary end point was the proportions of patients achieving improvement (severity score of 0 or 1) in either sign. Before and after treatment, we measured the serum concentrations of tacrolimus and its metabolites with an immunoenzymatic assay kit. Tolerability was assessed using hematology, biochemistry, urinalysis, measurements of systolic/diastolic blood pressure and heart rate, patient interview, and spontaneous reporting.
RESULTS: A total of 24 patients (18 women, 6 men; all white of Italian origin; age range, 21-65 years; 12 patients per treatment group) were enrolled in the study. In the tacrolimus group, 11 (91.7%) patients achieved remission of erythema and/or desquamation at weeks 4 and 6; at week 8, these rates were 9 (75.0%) and 8 (66.7%), respectively; none of the patients in the clobetasol group achieved remission of either sign at any time point (all, P < 0.001). At weeks 4, 6, and 8, significantly greater proportions of patients treated with tacrolimus had improved erythema and desquamation compared with those treated with clobetasol (all, P < 0.001). At week 4, all patients had undetectable serum tacrolimus concentrations (<1.5 microg/L). Six (50.0%) patients in the tacrolimus group reported a mild oral burning sensation, and 6 (50.0%) patients in the clobetasol group reported mild mouth dryness. No other adverse events were reported.
CONCLUSIONS: The results of this small study suggest that topical tacrolimus 0.1 % in pectin was more effective compared with clobetasol propionate 0.5% ointment in the treatment of DG. Both treatments were generally well tolerated in the population studied
Qui INGV
L’INGV, a partire dal 2006, ha iniziato una fase di potenziamento del monitoraggio accelerometrico, installando nelle aree centrali della pianura padana 22 sensori strong-motion (Rete Accelerometrica Italia Settentrionale, RAIS, http://rais.mi.ingv.it/). Dal 2008, sensori accelerometrici sono stati via via installati in 105 siti a Rete Sismica Nazionale (RSN), gestita dal Centro Nazionale Terremoti (CNT). Nel complesso le 127 stazioni accelerometriche presenti sul territorio nazionale costituiscono a tutti gli effetti la rete accelerometrica nazionale INGV. I dati acquisiti da tutte le stazioni accelerometriche sono attualmente distribuiti in tempo reale tramite il portale EIDA (European Integrated Data Archive; http://eida.rm.ingv.it/) e sono principalmente utilizzati per il calcolo delle Shakemaps a scala nazionale.
Attualmente, l’INGV sta realizzando un portale web per la distribuzione dei dati accelerometrici registrati dalle stazioni INGV, composto da 2 moduli distinti: il primo, denominato ISMD, ha lo scopo di archiviaziare e distribuire in tempo quasi reale (poche ore dopo l’evento) le forme d’onda accelerometriche in formato non corretto ed i relativi metadati ottenuti a seguito di una procedura di processamento automatico; il secondo, denominato DYNA, è una banca dati relazionale, contenente le forme d’onda di accelerazione, velocità e spostamento e gli spettri di risposta di accelerazione, ottenuti attraverso il processamento manuale dei segnali non corretti, oltre ai relativi metadati associati agli eventi sismici ed alle stazioni di registrazione
Il prototipo del portale dei dati accelerometrici INGV (Figura 1) è stato pubblicato lo scorso maggio, a seguito della sequenza sismica Emiliana
Task 4 - Garda - Deliverable D13: Scenari di scuotimento al bedrock a vari livelli di complessitĂ
Randomized placebo-controlled trial comparing desloratadine and montelukast in monotherapy and desloratadine plus montelukast in combined therapy for chronic idiopathic urticaria
BACKGROUND: H 1 -receptor antagonists are considered to be particularly effective in reducing pruritus, and they are therefore recommended as first-line treatment in patients with chronic idiopathic urticaria (CIU). Recently, antileukotriene receptors have been used in patients with CIU, either administered as monotherapy or combined with H 1 -receptor antagonists.
OBJECTIVE: We compared the clinical efficacy of 5 mg of desloratadine administered once daily either as monotherapy or combined with a leukotriene antagonist, 10 mg of montelukast daily, and 10 mg of montelukast administered daily as monotherapy for the treatment of patients affected by CIU with placebo.
METHODS: One hundred sixty patients aged 18 to 69 years (mean +/- SD, 43.9 +/- 13.4 years) with a history of moderate CIU were selected. A randomized, double-blind, double-dummy, placebo-controlled, parallel-group study design was used. Patients were treated with 5 mg of desloratadine once daily (n = 40), 10 mg of montelukast once daily (n = 40), 5 mg of desloratadine (n = 40) in the morning plus montelukast in the evening, or matched placebo (n = 40). Assessment of treatment efficacy was based on scores of daily cutaneous symptoms evaluated reflectively and instantaneously.
RESULTS: Only the group treated with desloratadine as monotherapy or as combined therapy concluded the whole study. Twenty-seven of the 40 patients in the montelukast group and 35 of the 40 patients in the placebo group discontinued the treatment. As reflective evaluation, all groups showed significant differences compared with the placebo group in terms of total symptom score, number of hives, and size of largest hive. In addition to the pruritus, only the groups treated with desloratadine as monotherapy or combined therapy showed significant differences compared with those receiving placebo, whereas there were no differences between the montelukast and placebo groups. Finally, no differences were found between the desloratadine group and the desloratadine plus montelukast group. The instantaneous evaluation demonstrated similar results regarding the desloratadine group and the desloratadine plus montelukast group versus the placebo group, whereas there were no significant differences between the group treated with montelukast alone and the placebo group for pruritus and size of largest hive. No differences were found between the group treated with desloratadine alone and the desloratadine plus montelukast group.
CONCLUSIONS: The results of this comparative study demonstrate that desloratadine is highly effective for the treatment of patients affected by CIU. In addition, the regular combined therapy of desloratadine plus montelukast does not seem to offer a substantial advantage with respect to desloratadine as monotherapy in patients affected by moderate CIU
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