Search results for "TOPOGRAPHY"

Repeatability of whole-cornea measurements using a new swept-source optical coherence tomographer

2020

Purpose: The aim of this study was to evaluate the repeatability of several corneal parameters provided by a high-resolution swept-source optical coherence tomographer (SS-OCT). Methods: One eye from each of 74 patients was measured five times consequently using the ANTERION SS-OCT. The following corneal parameters were analyzed: average, steep and flat keratometry (K), astigmatism for anterior, posterior and total at 3-mm, average K and astigmatism at 6-mm, anterior and posterior eccentricity, higher-order aberrations (HOA) and spherical aberration ([Formula: see text]), and anterior and posterior best-fit sphere at 8-mm. The intrasubject standard deviation (Sw), coefficient of variation (…

Précipitations et relief en Afrique orientale et australe : modélisations statistiques et géostatistiques.

2008

By considering two examples in Eastern and Southern Africa, this work has two aims: a better understanding of the influence of topography on the spatial distribution of rainfall and an optimal interpolation of station rainfall data, taking into account topography. To this end, an original methodology is developped, partly derived from previous studies focusing on extratropical regions.First, a statistical model is defined. With the help of a multi-scalar decomposition of topographical information into descriptors, a multiple linear regression is performed. This model is used to better understand the relationship between rainfall and topography. In Eastern Africa, the spatial distribution of…

Soil water erosion on Mediterranean vineyards: A review

2016

Soil water erosion on cultivated lands represents a severe threat to soil resources in the world, and especially in Mediterranean areas, due to their topographic, edaphic and climatic conditions. Among the cultivated lands, vineyards deserve a particular attention because, aside representing one of the most important crops in terms of income and employment, they also have proven to be the form of agricultural use that causes one of the highest soil losses. Although the topic of soil water erosion on vineyards has been studied, it still raises uncertainties, due to the high variability of procedures for data acquisition, which consists into different scales of analysis and measurement method…

Short-Term Changes in Light Distortion in Orthokeratology Subjects

2015

Purpose. Quantifying adaptation to light distortion of subjects undergoing orthokeratology (OK) for myopia during the first month of treatment. Methods. Twenty-nine healthy volunteers (age: 22.34 ± 8.08 years) with mean spherical equivalent refractive error −2.10 ± 0.93D were evaluated at baseline and days 1, 7, 15, and 30 of OK treatment. Light distortion was determined using an experimental prototype. Corneal aberrations were derived from corneal topography for different pupil sizes. Contrast sensitivity function (CSF) was analyzed for frequencies of 1.50, 2.12, 3.00, 4.24, 6.00, 8.49, 12.00, 16.97, and 24.00 cpd under photopic conditions. Results. Average monocular values of all light di…

Scanning tunneling microscopy and spectroscopy of Mo clusters grown on TiO2(110).

2007

Molybdenum was deposited in two steps (3 eq. ML and 1 eq. ML) on the light blue rutile TiO2 10) (1 x 1) surface at room temperature, each Mo deposition cycle being followed by an annealing up to 950-1000 K. This procedure was found to lead to formation of separated clusters having a size in very wide range (1-20 nm). Scanning tunneling microscopy showed a dependence of the cluster morphology as a function of the size. The scanning tunneling spectra of Mo clusters was studied as a function of cluster dimensions and discussed in comparison with photoelectron spectroscopy results previously obtained for homogeneous Mo films. The dI/d V curves do not display the valence band structure of deposi…

A Hydrogel Derived From Decellularized Dermal Extracellular Matrix. Biomaterials

2012

The ECM of mammalian tissues has been used as a scaffold to facilitate the repair and reconstruction of numerous tissues. Such scaffolds are prepared in many forms including sheets, powders, and hydrogels. ECM hydrogels provide advantages such as injectability, the ability to fill an irregularly shaped space, and the inherent bioactivity of native matrix. However, material properties of ECM hydrogels and the effect of these properties upon cell behavior are neither well understood nor controlled. The objective of this study was to prepare and determine the structure, mechanics, and the cell response in vitro and in vivo of ECM hydrogels prepared from decellularized porcine dermis and urinar…

GLI EFFETTI DEL DISTURBO ANTROPICO SULLA TOPOGRAFIA DEL REEF A VERMETI

2011

Intertidal vermetid reefs could be affected by many human disturbances. Using a microtopography device, the authors analysed the changes induced by the accessibility on the surface topography of the reefs. Human activities seems to be able to induce a decrease in rugosity and a surface smoothing on the outer margin of the reef. These effects are proportional to the accessibility of the site.

Seismostratigraphic reconstruction of the Messinian palaeotopography across the Northern Sicily Continental Margin (NSCM) and an overlying Zanclean m…

2018

During the Messinian salinity crisis (MSC) (from 5.97 to 5.33 Ma), the Mediterranean Sea became disconnected from the world’s oceans and a fast and continuous evaporation resulted in its partial desiccation. One of the theories for the end of the MSC postulates that a large volume of Atlantic waters entered the Mediterranean Sea through the Gibraltar Strait and rapidly refilled the Mediterranean basin in an event welldocumented known as the Zanclean Flood. The pathway of the Zanclean flood during its passage from the western to the eastern Mediterranean Sea is unclear. The aim of this study is to understand the effects of the Messinian palaeotopography of the southern Tyrrhenian Sea on the …

Modeling the past and future dynamic of the vegetation patterns at catchment scale using an ecohydrological Cellular Automata model

2014

Correlation between Topographic Parameters Obtained by Back Surface Topography Based on Structured Light and Radiographic Variables in the Assessment…

2017

<sec><title>Study Design</title><p>Optical cross-sectional study.</p></sec><sec><title>Purpose</title><p>To study the correlation between asymmetry of the back (measured by means of surface topography) and deformity of the spine (quantified by the Cobb angle).</p></sec><sec><title>Overview of Literature</title><p>The Cobb angle is considered the gold standard in diagnosis and follow-up of scoliosis but does not correctly characterize the three-dimensional deformity of scoliosis. Furthermore, the exposure to ionizing radiation may cause harmful effects particularly during the growth stage, includi…