Search results for " Dual"
showing 10 items of 154 documents
Evapotranspiration from an Olive Orchard using Remote Sensing-Based Dual Crop Coefficient Approach
2013
A remote sensing-based approach to estimate actual evapotranspiration (ET) was tested in an area covered by olive trees and characterized by Mediterranean climate. The methodology is a modified version of the standard FAO-56 dual crop coefficient procedure, in which the crop potential transpiration, T p, is obtained by directly applying the Penman-Monteith (PM) equation with actual canopy characteristics (i.e., leaf area index, albedo and canopy height) derived from optical remote sensing data. Due to the minimum requirement of in-situ ancillary inputs, the methodology is suitable also for applications on large areas where the use of tabled crop coefficient values become problematic, due to…
Impact of comorbidities on the severity of chronic hepatitis B at presentation.
2011
AIM: To evaluate the clinical relevance of each cofactor on clinical presentation of chronic hepatitis B. METHODS: Out of 1366 hepatitis B surface antigen (HBsAg) positive subjects consecutively observed in 79 Italian hospitals, 53 (4.3%) showed as the only cofactor hepatitis D virus (HDV) infection [hepatitis B virus (HBV)/HDV group], 130 (9.5%) hepatitis C virus (HCV) (group HBV/HCV), 6 (0.4%) human immunodeficiency virus (HIV) (group HBV/HIV), 138 (10.2%) alcohol abuse (group HBV/alcohol); 109 (8.0%) subjects had at least two cofactors and 924 were in the cofactor-free (CF) group. RESULTS: Compared with patients in group CF those in group HBV/alcohol were older and more frequently had ci…
Dual-Energy CT Material Density Iodine Quantification for Distinguishing Vascular From Nonvascular Renal Lesions: Normalization Reduces Intermanufact…
2019
OBJECTIVE. The purpose of this study was to determine whether a single, uniform normalized iodine threshold reduces variability and enables reliable differentiation between vascular and nonvascular renal lesions independent of the dual-energy CT (DECT) platform used. MATERIALS AND METHODS. In this retrospective, HIPAA-compliant, institutional review board-approved study, 247 patients (156 men, 91 women; mean age ± SD, 67 ± 12 years old) with 263 renal lesions (193 nonvascular, 70 vascular) underwent unenhanced single- energy and contrast-enhanced DECT scans. One hundred and six nonvascular and 38 vascular lesions were scanned on two dual-source DECT (dsDECT) scanners, and 87 nonvascular and…
Virtual Unenhanced Images at Dual-Energy CT: Influence on Renal Lesion Characterization
2019
Background Dual-energy (DE) CT allows reconstruction of virtual noncontrast (VNC) images from a single-phase contrast agent-enhanced examination, potentially reducing the need for multiphasic CT to characterize renal lesions. However, data regarding diagnostic performance of VNC images for the characterization of renal lesions are limited. Purpose To determine whether renal mass CT performed by using VNC images allows for reliable identification of renal lesions and differentiation of contrast-enhanced from unenhanced lesions, compared with unenhanced images. Materials and Methods This is a retrospective study of 293 patients (105 women [mean age, 65 years; age range, 18-91 years] and 188 m…
Efficacy of single-source rapid kV-switching dual-energy CT for characterization of non-uric acid renal stones: a prospective ex vivo study using ant…
2019
Purpose To investigate the accuracy of rapid kV-switching single-source dual-energy computed tomography (rsDECT) for prediction of classes of non-uric-acid stones. Materials and methods Non-uric-acid renal stones retrieved via percutaneous nephrolithotomy were prospectively collected between January 2017 and February 2018 in a single institution. Only stones >= 5 mm and with pure composition (i.e., >= 80% composed of one component) were included. Stone composition was determined using Fourier Transform Infrared Spectroscopy. The stones were scanned in 32-cm-wide anthropomorphic whole-body phantom using rsDECT. The effective atomic number (Zeff), the attenuation at 40 keV (HU40), 70 ke…
Assessment of maximal handgrip strength: How many attempts are needed?
2017
BACKGROUND: Handgrip strength (HGS) is used to identify individuals with low muscle strength (dynapenia). The influence of the number of attempts on maximal HGS is not yet known and may differ depending on age and health status. This study aimed to assess how many attempts of HGS are required to obtain maximal HGS.METHODS: Three cohorts (939 individuals) differing in age and health status were included. HGS was assessed three times and explored as continuous and dichotomous variable. Paired t-test, intraclass correlation coefficients (ICC) and Bland-Altman analysis were used to test reproducibility of HGS. The number of individuals with misclassified dynapenia at attempts 1 and 2 with respe…
Imaging of sarcopenia.
2016
Sarcopenia is currently considered a geriatric syndrome increasing in older people. The consequences of sarcopenia – in terms of impaired mobility, limited self-sufficiency and disability – have been amply demonstrated, increasing the need to develop methods to identify muscle mass loss as early as possible. Although sarcopenia involves a reduction in both muscle mass and function, loss of muscle mass remains the essential criterion for diagnosing this condition in daily practice. Computed tomography and magnetic resonance imaging represent the gold standard for studying body composition, and can identify quantitative and qualitative changes in muscle mass. These techniques are costly, time…
Introduction to General Duality Theory for Multi-Objective Optimization
1992
This is intended as a comprehensive introduction to the duality theory for vector optimization recently developed by C. Malivert and the present author [3]. It refers to arbitrarily given classes of mappings (dual elements) and extends the general duality theory proposed for scalar optimization by E. Balder, S. Kurcyusz and the present author [1] and P. Lindberg.
Indigenismo y migracionismo. Aspectos de la neolitización en la fachada oriental de la Península Ibérica
1996
This paper discusses various aspects on the origins of the Neolithic in the Iberian Peninsula. The dual model is proposed as an alternative to the dichotomy of demie (migrationist) and non-demic (indigenist) explanations. The application of this model in eastern Spain offers an opportunity to evaluate its potential to account for diversity in processes associated with the origins of food production and their spatial organisation.
Topological Dual Systems for Spaces of Vector Measure p-Integrable Functions
2016
[EN] We show a Dvoretzky-Rogers type theorem for the adapted version of the q-summing operators to the topology of the convergence of the vector valued integrals on Banach function spaces. In the pursuit of this objective we prove that the mere summability of the identity map does not guarantee that the space has to be finite dimensional, contrary to the classical case. Some local compactness assumptions on the unit balls are required. Our results open the door to new convergence theorems and tools regarding summability of series of integrable functions and approximation in function spaces, since we may find infinite dimensional spaces in which convergence of the integrals, our vector value…