43 research outputs found
Effectiveness of probiotics in the prevention of carious lesions during treatment with fixed orthodontic appliances.
A Methodological Tool to Assess Erosion Susceptibility of High Coastal Sectors: Case Studies from Campania Region (Southern Italy)
High coastal sectors constitute the most widespread coastal environment and, under the present accelerated sea-level rise scenario, are suffering huge impacts in terms of erosion. The aim of this paper is the proposal of a new methodological approach for the assessment of their susceptibility to erosive processes. The method is based on the combination of two matrices, i.e., a matrix considering the main physical elements (essentially morphological and geotechnical characteristics) that determine the proneness to erosion of a specific high coastal sector, and a forcing matrix, which describes the forcing agents affecting the considered sector. Firstly, several variables were selected to construct each one of the two matrices according to existing studies and, in a second step, they were interpolated to obtain the susceptibility matrix (CSIx). The approach was applied to Procida Island and Cilento promontory, both located in southern Italy. Results obtained were validated by comparing them with cliff retreat data obtained by means of aerial photographs and satellite images. The analysis shows that the greater part of the analyzed high coastal sectors belongs to the high-susceptibility class due to the combination of adverse morphological, geotechnical and forcing characteristics. Such sectors can be considered "hotspots" that require an increase in monitoring programs and, at places, urgent protective actions
Metodo diagnostico ELISA applicabile all'allergia respiratoria da polline di Cupressus arizonica
Coastal vs volcanic processes: Procida Island as a case of complex morpho-evolutive response
The island of Procida (Gulf of Naples, Italy) is a site of considerable importance from a historical, cultural, and landscape point of view. The island is located along a volcanic active area in the mid-Tyrrhenian and owes its formation to several explosive eruptions started more than 70 ka BP. Presently, the entire perimeter of the island is bordered by cliffs, often articulated in an alternation of headlands and coves, sometimes with shallow sandy beaches at the base (pocket beaches). However, the presence of different orders of submarine terraced surfaces represents a significant clue to coastal response to former sea-level stands.This paper aims at reconstructing the main coastal changes that occurred in the area during the Holocene mainly driven by the interaction between the post-glacial sea-level rise, vertical ground movements (VGMs) of volcano-tectonic origin, and wave action. The coastal sector was investigated using a multi-techniques approach including direct and indirect methods, in order to obtain a detailed geomorphological characterization of the whole study area. In particular, data from direct coastal surveys were integrated with photo-interpretation of areal and satellite photos, morphometric analysis of high-resolution DTMs from Lidar and bathymetric data, interpretation of morpho-acoustic data, archaeological, geomorphological and geological sea-level markers. The geomorphological analysis of this multidisciplinary dataset resulted in the detection of the main morphological elements interpreted as evidence of ancient seascapes. In particular, three orders of paleo-shore platforms were mapped in the underwater sector, allowing the evaluation of as many phases of relative sea-level stand, at-23.2 m,-11.2 m, and -4.2 m MSL dated at approximately 4.0, 2.0, and 1.0 ka BP. These coastal landforms were interpreted as the main consequence of a seacliff retreat, exacerbated by volcano-tectonic intermittent subsidence that favoured their poly-cyclic formation. However, the integration between the geomorphological and meteo-marine analysis allowed discriminating differentiated cliff backwearing responses between the western and eastern coastal sectors of the island, due to a prevailing occurrence of storms from the south-western sector. The proposed methodological approach focused on a multi-temporal geomorphological analysis applied to a multi-modal dataset, aims to comprehensive reconstruct the coastal response of a volcanic high rocky coast to the complex interaction between endogenous and exogenous forcing factors during the Holocene
Cytotoxic effects of the mycotoxin beauvericin to human cell lines of myeloid origin
Abstract
Beauvericin, a cyclic hexadepsipeptide of potential importance to the health of humans and domestic animals, has been reported to exert
cytotoxic effects on several mammalian cell types and to induce apoptosis.We investigated the cytotoxicity of this compound to two human
cell lines of myeloid origin: the monocytic lymphoma cells U-937 and the promyelocytic leukemia cells HL-60. In some experiments
HL-60 cells partially differentiated towards the eosinophilic phenotype were also used.
Cultures of U-937 cells and HL-60 cells in stationary phase were exposed to beauvericin at concentrations ranging from 100nM to
300M for periods of time of 4 and 24 h, respectively. The effects of beauvericin on cell viability were assessed by the Trypan blue
exclusion method. In another set of experiments, performed with U-937 cells, the mycotoxin was included in the culture medium at
passaging, in order to assess its possible effects on cell growth.
Viability of both U-937 cells and HL-60 cells was not affected by beauvericin at concentrations up to 3M, after 4 h exposure, whereas
a steady decline was seen at higher concentrations. Similarly, after an exposure time of 24 h, a decline in viability was observed in cultures
exposed to beauvericin at a concentration of 10M or higher. Thus, 50% cytotoxic concentrations at 24 h of¡«=
30M and¡«=
15M were
estimated for U-937 cells and HL-60 cells, respectively.
Similar experiments were performed with cultures of HL-60 cells partially differentiated towards the eosinophilic phenotype, revealing
that, in 4 h exposure experiments (but not in 24 h experiments), the viability of these cultures underwent a significantly less pronounced
decline, in comparison to undifferentiated HL-60 cultures. Interestingly, when U-937 cells were allowed to proliferate in the presence of
the mycotoxin, included in the culture medium at passaging, a substantial cytotoxicity was observed at lower concentrations, compared
with prevalently resting, stationary phase cultures. Accordingly, a definite inhibition of the proliferative capability of the cells was detected.
The information provided by this work may be useful in selecting appropriate myeloid cell models for the development of biossays
aimed at detecting beauvericin (and, possibly, other mycotoxins) in foods and other commodities.
. 2003 Elsevier Ltd. All rights reserved