Search results for "HRES"
showing 10 items of 695 documents
Skin innervation at different depths correlates with small fibre function but not with pain in neuropathic pain patients
2012
Background: Neuropathy can lead not only to impaired function but also to sensory sensitization. We aimed to link reduced skin nerve fibre density in different levels to layer-specific functional impairment in neuropathic pain patients and tried to identify pain-specific functional and structural markers. Methods: In 12 healthy controls and 36 patients with neuropathic pain, we assessed clinical characteristics, thermal thresholds (quantitative sensory testing) and electrically induced pain and axon reflex erythema. At the most painful sites and at intra-individual control sites, skin biopsies were taken and innervation densities in the different skin layers were assessed. Moreover, neurona…
Local Extinction of Dragonfly and Damselfly Populations in Low- and High-Quality Habitat Patches
2010
Understanding the risk of extinction of a single population is an important problem in both theoretical and applied ecology. Local extinction risk depends on several factors, including population size, demographic or environmental stochasticity, natural catastrophe, or the loss of genetic diversity. The probability of local extinction may also be higher in low-quality sink habitats than in high-quality source habitats. We tested this hypothesis by comparing local extinction rates of 15 species of Odonata (dragonflies and damselflies) between 1930-1975 and 1995-2003 in central Finland. Local extinction rates were higher in low-quality than in high-quality habitats. Nevertheless, for the thre…
Airborne Measurements of Contrail Ice Properties—Dependence on Temperature and Humidity
2021
The largest share in the climate impact of aviation results from cirrus clouds. Here, the dependence of microphysical contrail ice properties and extinction on temperature and humidity is investigated. Contrail measurements were performed at various altitudes during the 2018 ECLIF II/NDMAX campaign with the NASA DC-8 chasing the DLR A320. Ice number concentrations and contrail extinction coefficients are largest at altitudes near 9.5 km, typical for short- and medium-range air traffic. At higher altitudes near 11.5 km, low ambient water vapor concentrations lead to smaller contrail particle sizes and lower extinction coefficients. In addition, contrails were detected below 8.2 km near the S…
Epidemic spreading and aging in temporal networks with memory
2018
Time-varying network topologies can deeply influence dynamical processes mediated by them. Memory effects in the pattern of interactions among individuals are also known to affect how diffusive and spreading phenomena take place. In this paper we analyze the combined effect of these two ingredients on epidemic dynamics on networks. We study the susceptible-infected-susceptible (SIS) and the susceptible-infected-removed (SIR) models on the recently introduced activity-driven networks with memory. By means of an activity-based mean-field approach we derive, in the long time limit, analytical predictions for the epidemic threshold as a function of the parameters describing the distribution of …
Security of public key cryptosystems based on Chebyshev Polynomials
2004
Chebyshev polynomials have been recently proposed for designing public-key systems. Indeed, they enjoy some nice chaotic properties, which seem to be suitable for use in Cryptography. Moreover, they satisfy a semi-group property, which makes possible implementing a trapdoor mechanism. In this paper we study a public key cryptosystem based on such polynomials, which provides both encryption and digital signature. The cryptosystem works on real numbers and is quite efficient. Unfortunately, from our analysis it comes up that it is not secure. We describe an attack which permits to recover the corresponding plaintext from a given ciphertext. The same attack can be applied to produce forgeries …
Thresholding projection estimators in functional linear models
2008
We consider the problem of estimating the regression function in functional linear regression models by proposing a new type of projection estimators which combine dimension reduction and thresholding. The introduction of a threshold rule allows to get consistency under broad assumptions as well as minimax rates of convergence under additional regularity hypotheses. We also consider the particular case of Sobolev spaces generated by the trigonometric basis which permits to get easily mean squared error of prediction as well as estimators of the derivatives of the regression function. We prove these estimators are minimax and rates of convergence are given for some particular cases.
Liquid-phase alkali-doping of individual carbon nanotube field-effect transistors observed in real-time
2011
The carbon nanotube (CNT) is known to be very sensitive to changes in its surrounding environment. Our study is on the effects of mild, liquid-phase alkali-doping on electronic transport in individual CNTs. We find clear and consistent reversal from p- to n-type behavior, with all seven investigated CNT field-effect transistors (FETs) retaining a similar ON/OFF ratio and subthreshold slope. We have also measured the realtime electronic response during liquid-phase doping, and demonstrate detection of alkali cations with a signal response that ranges over more than three orders of magnitude. The doping is fully reversible upon exposure to oxygen, and the doping cycle is repeatable. We also c…
Factors affecting flavor perception in space: Does the spacecraft environment influence food intake by astronauts?
2020
International audience; The intention to send a crewed mission to Mars involves a huge amount of planning to ensure a safe and successful mission. Providing adequate amounts of food for the crew is a major task, but 20 years of feeding astronauts on the International Space Station (ISS) have resulted in a good knowledge base. A crucial observation from the ISS is that astronauts typically consume only 80% of their daily calorie requirements when in space. This is despite daily exercise regimes that keep energy usage at very similar levels to those found on Earth. This calorie deficit seems to have little effect on astronauts who spend up to 12 months on the ISS, but given that a mission to …
Semi-automated and interactive segmentation of contrast-enhancing masses on breast DCE-MRI using spatial fuzzy clustering
2022
Abstract Multiparametric Magnetic Resonance Imaging (MRI) is the most sensitive imaging modality for breast cancer detection and is increasingly playing a key role in lesion characterization. In this context, accurate and reliable quantification of the shape and extent of breast cancer is crucial in clinical research environments. Since conventional lesion delineation procedures are still mostly manual, automated segmentation approaches can improve this time-consuming and operator-dependent task by annotating the regions of interest in a reproducible manner. In this work, a semi-automated and interactive approach based on the spatial Fuzzy C-Means (sFCM) algorithm is proposed, used to segme…
A heuristic fuzzy algorithm for assessing and managing tourism sustainability
2019
“Smartness” and “sustainability” are gaining growing attention from both practitioners and policy makers. “Smartness” and “sustainability” assessments are of crucial importance for directing, in a systemic perspective, the decision-making process toward sustainability and smart growth objectives. Sustainability assessment is a major challenge due to the multidisciplinary aspects involved that make the evaluation process complex and hinder the effectiveness of available monitoring tools. To achieve the assessment objective, we introduce an enhanced fuzzy logic-based framework for handling the inherent uncertainty and vagueness of the involved variables: we apply our approach to Italy, and we…