5,292 research outputs found
Molecular detection of parasites (Trematoda, Digenea: Bucephalidae and Monorchiidae) in the European flat oyster Ostrea edulis (Mollusca: Bivalvia)
Members of the globally distributed bivalve family Ostreidae (oysters) have a significant role in marine ecosystems and include species of high economic importance. In this work, we report the occurrence of digenean parasites of the families Bucephalidae (Prosorhynchoides sp.) and Monorchiidae (Postmonorchis sp.) in Mediterranean native populations of Ostrea edulis (but not in the introduced Magallana gigas). Molecular detection was based on DNA sequencing of the ribosomal intergenic spacer 2 (ITS2) marker. The importance of detecting the presence of overlooked digenean parasites in Mediterranean oysters is discussed. © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Time trend occurrence of duodenal intraepithelial lymphocytosis and celiac disease in an open access endoscopic population
Background: Duodenal intraepithelial lymphocytosis (DIL) is a histological finding characterized by the increase of intraepithelial CD3T-lymphocytes over the normal value without villous atrophy, mostly associated to coeliac disease (CD), Helicobacter pylori (Hp) gastritis and autoimmune diseases. Objective: To assess the occurrence of DIL, CD and Hp gastritis in an endoscopic population over a 13 year period. Methods: From 2003 to 2015 we included adult patients who consecutively underwent oesophago-gastro-duodenoscopy (OGD) with duodenal biopsies assessing the overall and annual occurrence of DIL and CD and the prevalence of Hp gastritis. Results: 160 (2.3%) patients with DIL and 275 (3.9%) with CD were detected among 7001 patients. CD occurrence was higher from 2003 to 2011, while since 2012 DIL occurrence gradually increased significantly compared to CD (p = 0.03). DIL patients were more frequently female (p = 0.0006) and underwent OGD more frequently for dyspepsia (p = 0.002) and for indications not related to gastrointestinal symptoms than CD patients (p = 0.0003). Hp gastritis occurred similarly in CD and DIL patients but the latter had higher frequency of atrophic body gastritis (p = 0.005). Conclusions: DIL is a condition increasing in the general endoscopic population mainly diagnosed by chance. Concomitant gastric histological evaluation is able in one third of DIL patients to identify associated possible causes of DIL, such as Hp and atrophic gastritis
The seismic microzonation of level 3 of Sant’Agata Fossili (northern Italy) based on a multidisciplinary approach.
In this paper the results of a detailed seismic microzonation, performed at Sant’Agata Fossili (Piemonte region, northern Italy) are presented. We study the local seismic response of this small village using a level 3, that is the most accurate level following the Italian code of seismic microzonation. The activity steps consist in a gradual widening of knowledge of the different aspects of the amplification phenomena. A multidisciplinary approach has been performed to obtain the local seismic response: including a study of local geology, geophysical and geotechnical characterization of the lithologies, and numerical and experimental analyses. We finally compare the obtained elastic response spectra to the prescribed spectra of the Italian Building Code (in Italian: Norme Tecniche per le Costruzioni). Our results show the geologic and geophysical differences of the subsoil, that produce different local seismic response in terms of amplification factors and acceleration response spectra.PublishedS01893T. Pericolosità sismica e contributo alla definizione del rischio5T. Sorveglianza sismica e operatività post-terremotoJCR Journalope
Assessment of ground-motion amplification in the Fucino Basin (Central Italy) through seismic data
The Fucino basin (Central Italy) is one of the largest intermountain alluvial plain in the Appennines range. It has
a tectonic origin related to the presence of important systems of faults located in its northern and eastern edges.
Some of these faults are still active and capable of generating strong seismic events as the January 13th 1915 Ms
7.0 Avezzano earthquake (about 30000 casualties). Site effects related to the soft soils filling the basin can be very
important also taking into account the presence of historical villages located at the edges of the basin and new
settlements developed in the area.
In this paper we show the preliminary results of a seismic network installed in the Fucino area in order to collect
information about site amplification effects and geometry of the basin. A lake occupied the Fucino basin for many
thousands of years and it was completely drained at the end of the 19th century.
We analyze ambient seismic vibrations and recordings of about 150 local earthquakes mainly related to the seismic
sequence of the April 6th 2009 Mw 6.3 L’Aquila event. Moreover the strongest events of L’Aquila sequence were
analyzed at the three strong-motion permanent stations operating in the area. Using standard spectral techniques
we investigate the variation of resonance frequencies within the basin. The ground motion recorded in the
Fucino plain is mainly characterized by strong energy at low-frequencies (f < 1 Hz) affecting both horizontal and
vertical components. This is particularly evident for stations deployed in correspondence of very thick deposits
of sedimentary filling, where a significant increase of ground-motion amplitude and duration is caused by locally
generated surface waves. The amplification at low-frequencies (< 1 Hz) on the horizontal components can reach
up a factor of 10 in comparison to nearby stiff sites. However, we found evidences of seismic amplification
phenomena also for stiff sites surrounding the basin, including stations of the Italian strong motion network. The
independent geological information, the shallow shear-velocity profiles available for the basin can be combined
with resonance frequencies of the sites for deriving representative geological sections to be used as base for future
numerical 2D-3D modeling of the seismic wave propagation in the basin. Seismic modeling can be important to
reduce the seismic hazard in the area
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