296 research outputs found
Pinch-off syndrome ou syndrome de la Pince Costo-Claviculaire Ă propos de deux cas
La chambre Ă cathĂ©ter implantable est un outil essentiel tout le long de la maladie cancĂ©reuse. Cependant, son utilisation expose Ă des complications qui peuvent ĂȘtre grave. La rupture du cathĂ©ter de la chambre implantable retrouvĂ©e dans lâabord veineux sousclavier, secondaire le plus souvent au syndrome de la pince costo-claviculaire ou pinch off qui se produit lorsque le cathĂ©ter est comprimĂ© entre la clavicule et la premiĂšre cĂŽte. Nous rapportons deux cas de pinch-off syndrome pour Ă©valuer lâapproche diagnostique et thĂ©rapeutique de cette complication
PhĂ©ochromocytome de dĂ©couverte fortuite (Ă propos dâun cas)
Nous rapportons un cas inhabituel dâincidentalome surrĂ©nalien compliquĂ© dâun Ă©tat de choc aprĂšs surrĂ©nalectomie lors dâune intervention pour nĂ©oplasie du bas rectum ; qui sâest avĂ©rĂ© ĂȘtre un phĂ©ochromocytome. Ainsi, cette observation montre la nĂ©cessitĂ© dâune exploration hormonale systĂ©matique de tout incidentalome surrĂ©nalien , afin d'Ă©viter tout incident pouvant ĂȘtre fatal
Self-Stabilizing Byzantine Resilient Topology Discovery and Message Delivery
Traditional Byzantine resilient algorithms use vertex disjoint paths to ensure message delivery in the presence of up to f Byzantine nodes. The question of how these paths are identified is related to the fundamental problem of topology discovery. Distributed algorithms for topology discovery cope with a never ending task, dealing with frequent changes in the network topology and unpredictable transient faults. Therefore, algorithms for topology discovery should be self-stabilizing to ensure convergence of the topology information following any such unpredictable sequence of events. We present the first such algorithm that can cope with Byzantine nodes. Starting in an arbitrary global state, and in the presence of f Byzantine nodes, each node is eventually aware of all the other non-Byzantine nodes and their connecting communication links. Using the topology information, nodes can, for example, route messages across the network and deliver messages from one end user to another. We present the first deterministic, cryptographic-assumptions-free, self-stabilizing, Byzantine-resilient algorithms for network topology discovery and end-to-end message delivery. We also consider the task of r-neighborhood discovery for the case in which and the degree of nodes are bounded by constants. The use of r-neighborhood discovery facilitates polynomial time, communication and space solutions for the above tasks. The obtained algorithms can be used to authenticate parties, in particular during the establishment of private secrets, thus forming public key schemes that are resistant to man-in-the-middle attacks of the compromised Byzantine nodes. A polynomial and efficient end-to-end algorithm that is based on the established private secrets can be employed in between periodical re-establishments of the secrets
Plasma Transport in Saturn's LowâLatitude Ionosphere: Cassini Data
An edited version of this paper was published by AGU. Copyright 2019 American Geophysical Union.In 2017 the Cassini Orbiter made the first in situ measurements of the upper atmosphere and ionosphere of Saturn. The Ion and Neutral Mass Spectrometer in its ion mode measured densities of light ion species (H+, H2+, H3+, and He+), and the Radio and Plasma Wave Science instrument measured electron densities. During proximal orbit 287 (denoted P287), Cassini reached down to an altitude of about 3,000 km above the 1 bar atmospheric pressure level. The topside ionosphere plasma densities measured for P287 were consistent with ionospheric measurements during other proximal orbits. Spacecraft potentials were measured by the Radio and Plasma Wave Science Langmuir probe and are typically about negative 0.3 V. Also, for this one orbit, Ion and Neutral Mass Spectrometer was operated in an instrument mode allowing the energies of incident H+ ions to be measured. H+ is the major ion species in the topside ionosphere. Ion flow speeds relative to Saturn's atmosphere were determined. In the southern hemisphere, including near closest approach, the measured ion speeds were close to zero relative to Saturn's corotating atmosphere, but for northern latitudes, southward ion flow of about 3 km/s was observed. One possible interpretation is that the ring shadowing of the southern hemisphere sets up an interhemispheric plasma pressure gradient driving this flow
Saturnâs near-equatorial ionospheric conductivities from in situ measurements
Cassiniâs Grand Finale orbits provided for the first time in-situ measurements of Saturnâs topside ionosphere. We present the Pedersen and Hall conductivities of the top near-equatorial dayside ionosphere, derived from the in-situ measurements by the Cassini Radio and Wave Plasma Science Langmuir Probe, the Ion and Neutral Mass Spectrometer and the fluxgate magnetometer. The Pedersen and Hall conductivities are constrained to at least 10â»â”â10â»âŽ S/m at (or close to) the ionospheric peak, a factor 10â100 higher than estimated previously. We show that this is due to the presence of dusty plasma in the near-equatorial ionosphere. We also show the conductive ionospheric region to be extensive, with thickness of 300â800âkm. Furthermore, our results suggest a temporal variation (decrease) of the plasma densities, mean ion masses and consequently the conductivities from orbit 288 to 292
Fractional Derivative as Fractional Power of Derivative
Definitions of fractional derivatives as fractional powers of derivative
operators are suggested. The Taylor series and Fourier series are used to
define fractional power of self-adjoint derivative operator. The Fourier
integrals and Weyl quantization procedure are applied to derive the definition
of fractional derivative operator. Fractional generalization of concept of
stability is considered.Comment: 20 pages, LaTe
Author Correction: The genetic legacy of continental scale admixture in Indian Austroasiatic speakers
This Article contains errors in the Methods section, under subsection âSamples collection and genotypingâ
Electron Density Distributions in Saturn's Ionosphere
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.Between 26 April and 15 September 2017, Cassini executed 23 highly inclined Grand Finale orbits through a new frontier for space exploration, the narrow region between Saturn and the D Ring, providing the first opportunity for obtaining in situ ionospheric measurements. During the Grand Finale orbits, the Radio and Plasma Wave Science instrument observed broadband whistler mode emissions and narrowband upper hybrid frequency emissions. Using known wave propagation characteristics of these two plasma wave modes, the electron density is derived over a broad range of ionospheric latitudes and altitudes. A twoâpart exponential scale height model is fitted to the electron density measurements. The model yields a doubleâlayered ionosphere with plasma scale heights of 545/575 km for the northern/southern hemispheres below 4,500 km and plasma scale heights of 4,780/2,360 km for the northern/southern hemispheres above 4,500 km. The interpretation of these layers involves the interaction between the rings and the ionosphere
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