Search results for "erosion"
showing 10 items of 637 documents
Biocrusts and catchment asymmetry in Tabernas Desert (Almeria, Spain)
2022
Abstract Catchment asymmetry is a fairly frequent phenomenon on a global scale but the main causes leading to its formation are still not well understood. Where the intervention of structural or tectonic causes is not relevant, asymmetry seems to result from differential erosion between opposite slopes that flow into the same channel, which is frequently associated with contrasted biocrust and/or vegetation covers. Biocrusts are known to be important surface stabilizing agents. However, their geomorphological consequences at the landscape scale are little known. In this study we combined field measurements with digital elevation models and image analysis to determine whether catchment asymm…
A regional analysis of the effects of largest events on soil erosion
2012
A large amount of geomorphic work is caused by a small number of extreme events that are mainly responsible for the time compression of geomorphic processes. The classic approach defines extreme events by their magnitude and they are quantified by certain deviation from a central value. Alternatively, we define extreme events as the largest events sorted by rank, whatever their absolute magnitude. In this case, events with equal rank from two different sites can be responsible for different magnitudes of geomorphic work, e.g., the amount of erosion. The new approach applied to soil erosion is that, whatever the magnitude of soil eroded, erosion is a time compressed process and the percentag…
Dental and periodontal lesions in patients with gastro-oesophageal reflux disease.
2003
Dental erosion has been considered an extraesophageal manifestation of gastro-oesophageal reflux disease, but few reports have studied the relationship between this disease and other periodontal or dental lesions. The aim of this study was to investigate the prevalence of dental and periodontal lesions in patients with gastro-oesophageal reflux disease.A total of 253 subjects were prospectively studied between April 1998 and May 2000. Two study groups were established: 181 patients with gastro-oesophageal reflux disease and 72 healthy volunteers. Clinical assessment, including body mass index and consumption of tobacco and alcohol, was performed in all subjects, as well as a dental and peri…
Prolonged in vitro exposure to white wines enhances the erosive damage on human permanent teeth compared with red wines.
2009
Abstract The aim of this in vitro study was to determine and compare the erosive potentials of red and white wines, exerted on enamel surfaces prepared from extracted human permanent teeth. European wines (50 red, 50 white wines) from different regions were purchased, and the pH values were measured. Eight wines with different pH values were selected. Enamel samples with an average surface area of 25 mm 2 were prepared from 25 extracted permanent teeth from male and female patients aged 40 to 65 years and incubated with wines for up to 24 hours; the amounts of released calcium were determined colorimetrically, and mean surface roughness was measured with a profilometer. A quantitative eleme…
Franceschetti Hereditary Recurrent Corneal Erosion
2011
To describe new affected individuals of Franceschetti's original pedigree of hereditary recurrent erosion and to classify a unique entity called Franceschetti corneal dystrophy.Observational case series.Slit-lamp examination of 10 affected individuals was conducted. Biomicroscopic examinations were supplemented by peripheral corneal biopsy in 1 affected patient with corneal haze. Tissue was processed for light and electron microscopy and immunohistochemistry was performed. DNA analysis was carried out in 12 affected and 3 nonaffected family members.All affected individuals suffered from severe ocular pain in the first decade of life, attributable to recurrent corneal erosions. Six adult pat…
Lattice Corneal Dystrophy Type 1
2014
PURPOSE To evaluate the question whether lattice corneal dystrophy type 1 (LCD1) is of epithelial or stromal origin. METHODS The landmark of advanced LCD1 shows central superficial haze and paracentral stromal lattice lines. In 16 eyes of 8 affected individuals of 2 families, a penetrating keratoplasty was performed. The follow-up was 8 to 16 years after penetrating keratoplasty. Slit-lamp documentation of the patients was evaluated in direct and indirect illumination with dilated pupil to assess the horizontal and vertical pattern of new deposits on the corneal graft. Three affected patients of 2 families are demonstrated in detail. A DNA analysis was performed. RESULTS Gene identification…
Complications following the use of alloplastic materials in urogynecological surgery
2011
Abstract Study design 118 patients, who were admitted from 2005 to 2008 to our department due to complications following mesh implantation, were included in a retrospective survey. We investigated patient symptoms, findings and subsequent patient management. There was a re-evaluation of symptoms in a follow-up eight weeks after the revision procedure. Data from our urogynecological file archive were used. Results The main complaints were de novo urgency, pain and recurrent urinary tract infections. The main findings were mesh erosion and infections including abscess formations and osteomyelitis. Before being admitted to our department, 42 patients (35.6%) had already undergone at least one …
Gully erosion susceptibility assessment by means of GIS-based logistic regression: A case of Sicily (Italy)
2014
article i nfo Article history: This research aims at characterizing susceptibility conditions to gully erosion by means of GIS and multivariate statistical analysis. The study area is a 9.5 km 2 river catchment in central-northern Sicily, where agriculture ac- tivities are limited by intense erosion. By means of field surveys and interpretation of aerial images, we prepared a digitalmap of thespatial distribution of 260 gulliesinthestudy area.Inaddition,fromavailable thematicmaps, a 5 m cell size digital elevation model and field checks, we derived 27 environmental attributes that describe the variability of lithology, land use, topography and road position. These attributes were selected f…
SW—Soil and Water
2002
Abstract Recent research has directed attention to the size distribution of eroded material because of its influence on deposition mechanics and in carrying capacity of pollutant materials. At first, in this paper the relationship between aggregate breakdown mechanism and erosion processes is briefly reviewed. Then the link between the clay enrichment ratio and the sediment delivery ratio at morphological unit scale is investigated. For 129 soil samples well distributed over the Sicilian Sparacia basin, the values for the experimental clay enrichment ratio calculated by the measured ultimate grain-size distributions are compared with the theoretical clay enrichment ratio values obtained by …
Updated measurements in vineyards improves accuracy of soil erosion rates
2018
All rights reserved. Vineyards have proven to be one of the most degraded agricultural ecosystems due to very high erosion rates, which are typically measured at fine temporal and spatial scales. Long-term soil erosion measures are rare, but this information may be indispensable for a proper understanding of the vineyard soil system, landscape evolution, and crop production. The stock unearthing method (SUM) is a common topographical measurement technique developed to assess long-term erosion rates. The reliance of the SUM has been questioned and should be replaced by an improved measurement technique. In this paper, we demonstrate the added value (improved accurate, low cost, and faster th…