Endovenous laser ablation: the role of intraluminal blood

AbstractObjectiveIn this histological study, the role of the intraluminal blood during endovenous laser ablation was assessed.MethodsIn 12 goats, 24 lateral saphenous veins were treated with a 1500-nm diode laser. Four goats were treated in an anti-Trendelenburg position (group 1). The next four goats were treated in a Trendelenburg position (group 2) and the remaining four goats in the Trendelenburg position with additional injection of tumescent liquid (group 3). Postoperatively, the veins were removed after 1 week and sent for histological examination. We measured the number of perforations. Vein wall necrosis and the perivenous tissue destruction were quantified using a graded scale.ResultsThe ‘calculated total vein wall destruction’ was significantly higher in the third group (81.83%), as compared with groups one (61.25%) (p < 0.001) and two (65.92%) (p < 0.001). All three groups showed a significant difference in the perivenous tissue destruction scale (p < 0.001) with the lowest score occurring in the third group. Vein wall perforations were significantly more frequent in groups one and two as compared with the third group (T-test respectively p < 0.001, p = 0.02).ConclusionA higher intraluminal blood volume results in reduced total vein wall destruction. Injection of tumescent liquid prevents the perivenous tissue destruction and minimises the number of perforations

Iterative disaggregation for a class of lumpable discrete-time stochastic automata networks

Cataloged from PDF version of article.Stochastic automata networks (SANs) have been developed and used in the last 15 years as a modeling formalism for large systems that can be decomposed into loosely connected components. In this work, we concentrate on the not so much emphasized discrete-time SANs. First, we remodel and extend an SAN that arises in wireless communications. Second, for an SAN with functional transitions, we derive conditions for a special case of ordinary lumpability in which aggregation is done automaton by automaton. Finally, for this class of lumpable discrete-time SANs we devise an efficient aggregation–iterative disaggregation algorithm and demonstrate its performance on the SAN model of interest. © 2002 Elsevier Science B.V. All rights reserved

Lumpable continuous-time stochastic automata networks

Cataloged from PDF version of article.The generator matrix of a continuous-time stochastic automata network (SAN) is a sum of tensor products of smaller matrices, which may have entries that are functions of the global state space. This paper specifies easy to check conditions for a class of ordinarily lumpable partitionings of the generator of a continuous-time SAN in which aggregation is performed automaton by automaton. When there exists a lumpable partitioning induced by the tensor representation of the generator, it is shown that an efficient aggregation-iterative disaggregation algorithm may be employed to compute the steady-state distribution. The results of experiments with two SAN models show that the proposed algorithm performs better than the highly competitive block Gauss-Seidel in terms of both the number of iterations and the time to converge to the solution. © 2002 Elsevier Science B.V. All rights reserved

BDGS: A Scalable Big Data Generator Suite in Big Data Benchmarking

Data generation is a key issue in big data benchmarking that aims to generate application-specific data sets to meet the 4V requirements of big data. Specifically, big data generators need to generate scalable data (Volume) of different types (Variety) under controllable generation rates (Velocity) while keeping the important characteristics of raw data (Veracity). This gives rise to various new challenges about how we design generators efficiently and successfully. To date, most existing techniques can only generate limited types of data and support specific big data systems such as Hadoop. Hence we develop a tool, called Big Data Generator Suite (BDGS), to efficiently generate scalable big data while employing data models derived from real data to preserve data veracity. The effectiveness of BDGS is demonstrated by developing six data generators covering three representative data types (structured, semi-structured and unstructured) and three data sources (text, graph, and table data)

Controlled atmosphere bench-scale calorimetry revisited

International audienceThe standard Cone Calorimeter has been designed with an "open configuration", allowing for testing of specimens through use of freely driven room air for combustion. For testing specimens in oxygen depleted atmospheres or in fuel rich combustion a modified apparatus working under controlled atmosphere can be used. To our Knowledge there is very few publications describing the use of such modified cone calorimeters and providing data regarding the effect of ventilation on the fire properties. In the open literature it was reported end of the 1990's that substantial burning can occurred outside the test chamber when such a device is used, the amount of oxygen available to combustion exceeding the amount that was fed to the combustion chamber. In such a case (leading to post-buming outside the test chamber), it has been proposed to correct the experimental data by replacing the oxygen mass feeding rate by the actual rate of oxygen consumption. This paper analyses the proposed correction, and suggests that this might not be fully satisfactory by comparison to data obtained in another bench scale calorimeter with controlled atmosphere. The capacity of a Cone Calorimeter fitted with a controlled atmosphere device will be more in depth investigated in a new research project starting in 2007

EL TURISMO EN ESPACIO RURAL EN FRANCIA

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;El turismo Rural se presenta como modelo de cuanto significa el desequilibrio campociudad. Es una nueva actividad a la que se le exige que corrija un doble desequilibrio: el abandono del campo y la sobrecarga de las playas. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Se plantea la penetración del turismo rural en Francia a través de dos vías diferentes: una espontánea y difusa y otra voluntaria y organizada. Tras el análisis de la oferta del turismo rural francés se presenta su modelo y las disfuncionalidades que se observan.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Le tourisme vert est présenté comme modèle de ce que signifie le déséquilibre campagneville. C’est une nouvelle activité à laquelle on exige la correction d’un double déséquilibre: L’abandon de la campagne et le gonflement des plages. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;La pénétration du tourisme vert en France est projetée à travers deux voies differentes: l’une spontanée et diffuse, l’autre volontaire et organisée. Après l’analyse de l’offre du tourisme vert français, on présente le modèle et les disfonctionnalités qui sont aperçues

A roadmap for the design of four-terminal spin valves and the extraction of spin diffusion length

Graphene is a promising substrate for future spintronics devices owing to its remarkable electronic mobility and low spin-orbit coupling. Hanle precession in spin valve devices is commonly used to evaluate the spin diffusion and spin lifetime properties. In this work, we demonstrate that this method is no longer accurate when the distance between inner and outer electrodes is smaller than six times the spin diffusion length, leading to errors as large as 50% for the calculations of the spin figures of merit of graphene. We suggest simple but efficient approaches to circumvent this limitation by addressing a revised version of the Hanle fit function. Complementarily, we provide clear guidelines for the design of four-terminal spin valves able to yield flawless estimations of the spin lifetime and the spin diffusion coefficient.Comment: 7 pages, 5 figure

Ueber 9-Phenyladenin

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