243 research outputs found
Bioagent defeat in shock driven gas flow
The problem of planar shock interaction with gas cylinders whose axis of symmetry is parallel to the plane of the shock has been well studied both experimentally and numerically, and in this case, the flow evolution driven by Richtmyer-Meshkov instability is well characterized (although, as this thesis shows, assumptions commonly made about the experimental conditions need to be carefully checked). However, for a similar oblique interaction, with the plane of the shock and the axis of the density interface being non-parallel, presently only numerical results exist. The problem of oblique shock interaction is quite interesting to study experimentally both because of a variety of relevant applications and because it adds large-scale three-dimensionality to the initial conditions. Additionally, there is a considerable interest in the problem of shock interaction with particulates, droplets, and bioagents suspended in gas. Here we describe an experimental arrangement for the studies of planar and oblique shocks and present some preliminary results
Detection of time reversibility in time series by ordinal patterns analysis
Time irreversibility is a common signature of nonlinear processes, and a
fundamental property of non-equilibrium systems driven by non-conservative
forces. A time series is said to be reversible if its statistical properties
are invariant regardless of the direction of time. Here we propose the Time
Reversibility from Ordinal Patterns method (TiROP) to assess time-reversibility
from an observed finite time series. TiROP captures the information of scalar
observations in time forward, as well as its time-reversed counterpart by means
of ordinal patterns. The method compares both underlying information contents
by quantifying its (dis)-similarity via Jensen-Shannon divergence. The
statistic is contrasted with a population of divergences coming from a set of
surrogates to unveil the temporal nature and its involved time scales. We
tested TiROP in different synthetic and real, linear and non linear time
series, juxtaposed with results from the classical Ramsey's time reversibility
test. Our results depict a novel, fast-computation, and fully data-driven
methodology to assess time-reversibility at different time scales with no
further assumptions over data. This approach adds new insights about the
current non-linear analysis techniques, and also could shed light on
determining new physiological biomarkers of high reliability and computational
efficiency.Comment: 8 pages, 5 figures, 1 tabl
A platform for glycoengineering a polyvalent pneumococcal bioconjugate vaccine using E. coli as a host
Complex networks: new trends for the analysis of brain connectivity
Today, the human brain can be studied as a whole. Electroencephalography,
magnetoencephalography, or functional magnetic resonance imaging techniques
provide functional connectivity patterns between different brain areas, and
during different pathological and cognitive neuro-dynamical states. In this
Tutorial we review novel complex networks approaches to unveil how brain
networks can efficiently manage local processing and global integration for the
transfer of information, while being at the same time capable of adapting to
satisfy changing neural demands.Comment: Tutorial paper to appear in the Int. J. Bif. Chao
Esterificação e tranesterificação de óleo de polpa de acrocomia aculeata de elevada acidez com etanol em condições supercriticas
Neste trabalho, avaliou-se a esterificação e transesterificação de óleo de polpa de Mokayá (Acrocomia aculeata) com etanol em condições supercríticas. A análise do perfil lipídico do óleo mostrou alto conteúdo de ácido oleico (C18:1). A reação para a conversão do óleo foi conduzida em reator Parr utilizando óleo de polpa de alta acidez (56 mg KOH/g) e etanol na relação molar 1:40, em condições de temperaturas elevadas (285 e 315 °C), tempos de reação de 20 e 50 min e agitação de 175 rpm. A maior conversão de óleo de polpa em ésteres etílicos foi obtida nas condições de máxima temperatura e tempo de reação.CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI
Producción de biodiesel por esterificación y transesterificación simultánea de aceite de pulpa de coco (Acrocomia aculeata) utilizando metanol y etanol en condiciones de fluido supercrítico.
El objetivo general del proyecto es contribuir al conocimiento del sistema de colecta y almacenamiento de los frutos de Acrocomia aculeata y aprovechamiento del aceite de la pulpa con miras a su utilización como materia prima para la obtención de biodiesel.CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI
The DICA Endoscopic Classification for Diverticular Disease of the Colon Shows a Significant Interobserver Agreement among Community Endoscopists: an International Study
Background & Aims: The Diverticular Inflammation and Complication Assessment (DICA) endoscopic classification of diverticulosis and diverticular disease (DD) is currently available. It scores severity of the disease as DICA 1, DICA 2 and DICA 3. Our aim was to assess the agreement on this classification in an international endoscopists community setting. Methods: A total of 96 doctors (82.9% endoscopists) independently scored a set of DD endoscopic videos. The percentages of overall agreement on DICA score and a free-marginal multirater kappa (kappa) coefficient were reported as statistical measures of interrater agreement. Results: Overall agreement in using DICA was 91.8% with a free-marginal kappa of 88% (95% CI 80-95). The overall agreement levels were: DICA 1, 85.2%; DICA 2, 96.5%; DICA 3, 99.5%. The free marginal. was: DICA 1 = 0.753, DICA 2 = 0.958, DICA 3 = 0.919. The agreement about the main endoscopic items was 83.4% (k 67%) for diverticular extension, 62.6% (k 65%) for number of diverticula for each district, 86.8% (k 82%) for presence of inflammation, and 98.5 (k 98%) for presence of complications. Conclusions: The overall interrater agreement in this study ranges from good to very good. DICA score is a simple and reproducible endoscopic scoring system for diverticulosis and DD
International Consensus on Diverticulosis and Diverticular Disease. Statements from the 3rd International Symposium on Diverticular Disease
The statements produced by the Chairmen and Speakers of the 3rd International Symposium on Diverticular Disease, held in Madrid on April 11th-13th 2019, are reported. Topics such as current and evolving concepts on the pathogenesis, the course of the disease, the news in diagnosing, hot topics in medical and surgical treatments, and finally, critical issues on the disease were reviewed by the Chairmen who proposed 39 statements graded according to level of evidence and strength of recommendation. Each topic was explored focusing on the more relevant clinical questions. The vote was conducted on a 6-point scale and consensus was defined a priori as 67% agreement of the participants. The voting group consisted of 124 physicians from 18 countries, and agreement with all statements was provided. Comments were added explaining some controversial areas
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