125 research outputs found
Coulomb-driven flow of a dielectric liquid subject to charge injection by a sharp electrode
Injection of charge by a sharp electrode into a surrounding dielectric liquid leads to Coulomb forces
that set the liquid into motion. An analysis is presented of this motion in a small region around the
edge of the electrode, which determines the injected current as a function of the far electric potential
seen by this region. By using an injection law appropriate for nonpolar liquids, the analysis predicts
an electric current that increases first exponentially and then as the power 7
3 of the harmonic part of
the electric potential, sometimes with a range of multiplicity in betweenMinisterio de Ciencia e Innovación PB95-0008
Polynomial characteristic sets for DFA identification
[EN] We study the order in Grammatical Inference algorithms, and its influence on the polynomial (with respect to the data) identification of languages. This work is motivated by recent results on the polynomial convergence of data-driven grammatical inference algorithms. In this paper, we prove a sufficient condition that assures the existence of a characteristic sample whose size is polynomial with respect to the minimum DFA of the target language. © 2012 Elsevier B.V. All rights reserved.Work partially supported by the Spanish Ministerio de Economia y Competitividad under research project TIN2011-28260-C03-01 and Universidad Politecnica de Valencia grant PAID-2019-06-2011.García Gómez, P.; López Rodríguez, D.; Vázquez-De-Parga Andrade, M. (2012). Polynomial characteristic sets for DFA identification. Theoretical Computer Science. 448:41-46. https://doi.org/10.1016/j.tcs.2012.04.042S414644
Pos procesado de imágenes diagnósticas
El sistema de pos procesamiento de imágenes radiológicas es el conjunto de técnicas
que operan sobre la presentación digital de una imagen u objeto en el cuerpo humano. Para
obtener estas imágenes se emplea un procedimiento que consta de un equipo convencional de
rayos X y un procesamiento digital. En general, las técnicas de procesamiento de imágenes son
aplicadas cuando resulta necesario realzar o modificar una imagen para mejorar su apariencia o
para destacar algún aspecto de la información contenida en las mismas.
El objetivo de este trabajo es analizar las técnicas del pos procesado en la radiología
convencional para obtener imágenes diagnósticas de mayor calidad, a través realizar una
investigación de documentos relacionados con el post procesado de la imagen diagnóstica que
nos brinde información relevante, especificar las ventajas y desventajas y finalmente revisar
distintas tecnologías de adquisición de imagen diagnósticas como la radiología convencional,
digital, medicina nuclear, ultrasonidos, tomografía computarizada y resonancia magnética y sus
diferentes tipos de post procesado.
De esta manera la radiología ha evolucionado favorablemente tanto para el médico
como para el paciente y para las instituciones de salud.The radiological image post-processing system is the set of techniques that operate on
the digital presentation of an image or object in the human body. To obtain these images, a
procedure is used that consists of conventional X-ray equipment and digital processing. In
general, processing techniques Images are applied when it is necessary to enhance or modify an
image to improve its appearance or to highlight some aspect of the information contained
therein.
The objective of this work is to analyze post-processing techniques in conventional
radiology to obtain higher quality diagnostic images, through researching documents related to
post-processing of diagnostic images that provide us with relevant information, specify the
advantages and disadvantages and finally review different diagnostic image acquisition
technologies such as digital conventional radiology, nuclear medicine, ultrasound, computed
tomography and nuclear magnetic resonance and their different types of post processing.
In this way, radiology has evolved favorably for both the doctor and the patient and for
health institutions
Comportamiento mecánico de mezclas de escoria vítrea de horno alto y metacaolín activadas alcalinamente: estudio estadístico = Mechanical behaviour of alkali-activated metakaolin blended pastes: statistical study
El estudio y desarrollo de cementos alternativos y más
eco-eficientes que el cemento Portland es un tema de
gran impacto a nivel científico y tecnológico. Entre esos
posibles cementos se encuentran los cementos alcalinos
que son materiales conglomerantes obtenidos por la
interacción química de materiales silico-aluminosos cálci-
cos y disoluciones fuertemente alcalinas. En el presente
trabajo se estudia el comportamiento mecánico y la com-
posición mineralógica de mezclas de escoria vítrea de
horno alto y metacaolín activadas alcalinamente con
disoluciones de NaOH. El objetivo de este estudio es
conocer cómo afectan parámetros tales como la relación
escoria/metacaolín, la concentración de la disolución
activadora y la temperatura de curado, al desarrollo re-
sistente de las mezclas. A través del estudio estadístico
realizado se ha podido establecer la influencia de cada
variable y modelizar el comportamiento resistente de
estos cementos alcalinos. Se concluye que la concentra-
ción del activador y la relación escoria/metacaolín son los
parámetros más relevantes
Adult cocaine-induced brain metabolic activation is altered in a sex-dependent manner by chronic periadolescent cannabinoid exposure in rats
[Poster] 4th European Molecular Imaging Meeting, Barcelona, Spain, May 27 - 30, 2009Cannabinoid exposure during the periadolescent period has been shown to
augment the rates of cocaine self-administration in female but not male Wistar rats. However,
how this cannabinoid history alters cocaine-induced brain activation remains unknownPublicad
Biomass-modulated fire dynamics during the last glacial-interglacial transition at the central pyrenees (Spain)
Understanding long-term fire ecology is essential for current day interpretation of ecosystem fire responses. However palaeoecology of fire is still poorly understood, especially at high-altitude mountain environments, despite the fact that these are fire-sensitive ecosystems and their resilience might be affected by changing fire regimes. We reconstruct wildfire occurrence since the Lateglacial (14.7. cal. ka BP) to the Mid-Holocene (6. cal. ka BP) and investigate the climate-fuel-fire relationships in a sedimentary sequence located at the treeline in the Central Spanish Pyrenees. Pollen, macro- and micro-charcoal were analysed for the identification of fire events (FE) in order to detect vegetation post-fire response and to define biomass-fire interactions. mean fire intervals (mfi) reduced since the Lateglacial, peaking at 9-7.7. cal. ka BP while from 7.7 to 6. cal. ka BP no fire is recorded. We hypothesise that Early Holocene maximum summer insolation, as climate forcing, and mesophyte forest expansion, as a fuel-creating factor, were responsible for accelerating fire occurrence in the Central Pyrenees treeline. We also found that fire had long-lasting negative effects on most of the treeline plant communities and that forest contraction from 7.7. cal. ka BP is likely linked to the ecosystem's threshold response to high fire frequencies.This research has been funded by the projects DINAMO (CGL2009-07992) (funding EGPF — grant ref. BES-2010-038593 and MSC), DINAMO2 (CGL2012-33063), ARAFIRE (2012 GA LC 064), GRACCIE-CONSOLIDER (CSD2007-00067). GGR was funded by the Juan de la Cierva Program (grant ref. JCI2009-04345) and JAE-Doc CSIC Program, LLM was supported by a postdoctoral MINT fellowship funded by the Institute for the Environment (Brunel University), AMC is a Ramón y Cajal fellow (ref: RYC-2008-02431), APS holds a grant funded by the Aragon Government (ref. 17030G/5423/480072/14003) and JAE holds a grant funded by the Basque Country Government (BFI-2010-5)
Caspase-1 genetic variation is not associated with Alzheimer's disease risk
BACKGROUND:
Interleukin (IL)-1beta is a potent proinflammatory cytokine markedly overexpressed in the brains of patients with Alzheimer's disease (AD), and also involved in development of atherosclerosis and coronary artery disease. Caspase-1 (CASP1), formerly called IL-1beta converting enzyme (ICE), mediates the cleavage of the inactive precursor of IL-1beta into the biologically active form. CASP1 genetic variation (G+7/in6A, rs501192) has been associated with susceptibility to myocardial infarction and cardiovascular death risk. We examined the contribution of this gene to the susceptibility for AD.
METHODS:
We examined genetic variations of CASP1 by genotyping haplotype tagging SNPs (htSNPs) (rs501192, rs556205 and rs530537) in a group of 628 Spanish AD cases and 722 controls.
RESULTS:
There were no differences in the genotypic, allelic or haplotypic distributions between cases and controls in the overall analysis or after stratification by age, gender or APOE epsilon4 allele.
CONCLUSION:
Our negative findings in the Spanish population argue against the hypothesis that CASP1 genetic variations are causally related to AD risk
Chronic cannabinoid administration to periadolescent rats modulates the metabolic response to acute cocaine in the adult brain
Purpose: To analyze brain metabolic response to acute cocaine in male and female Wistar rats
with or without a history of cannabinoid exposure during periadolescence.
Procedures: The synthetic cannabinoid agonist CP 55,940 (CP) or its vehicle (VH), were
administered to male and female rats during periadolescence. When these animals reached
adulthood, saline and cocaine-induced changes in 2-deoxy-2-[18F]fluoro D glucose (FDG)
uptake were studied by positron emission tomography.
Results: The baseline (post-saline) metabolism in the septal nuclei was higher in CP-females
than in VH-females, although septal metabolism was lower in CP-females after cocaine,
reaching similar values to those of VH-females at baseline. Cocaine did not affect metabolism in
VH-females. Periadolescent cannabinoid treatment did not influence baseline metabolism in
males although cocaine reduced the FDG uptake in the dorsal striatum of males that received
the VH but not CP.
Conclusions: These results suggest that cannabinoids during periadolescence modify baseline
and cocaine-evoked brain metabolism in a sex-dependent manner. In the case of CP-females,
the involvement of septal metabolic alterations in their susceptibility to the rewarding effects of
cocaine should be further investigated.This work was supported by grants from the Ministerio de Educación y Ciencia (Grants nº SAF2004-08148 and SAF2007-064890); Ministerio de Sanidad y Consumo (Grants RD06/ 00170029 of Instituto de Salud Carlos III, PNSD 2004 2007 and 2008 2010); Dirección General de Investigación de la Comunidad de Madrid (Grant S-SAL/0261/2006, I+D CANNAB-CM Consortium); and UNED (Plan de Promoción de la Investigación) to EA, and grants from the “Ministerio de Ciencia y Tecnología” (TEC2004-07052-C02-01/TCM), “Ministerio de Sanidad y Consumo” (CIBER CB06/01/0079, PNSD 2007 2010, FIS CP08/00017), “Ministerio de Industria” (CENIT program) and “Fundación de Investigación Médica Mutua Madrileña” (2007 2010 and 2008 2011) to MD.Publicad
Epistasis between intracellular cholesterol trafficking-related genes (NPC1 and ABCA1) and Alzheimer's disease risk
Aberrant cholesterol metabolism has been implicated in Alzheimer´s disease (AD). Recent findings have suggested an interaction of Niemann-Pick C1 (NPC1) and ATP-binding cassette transporter A1 (ABCA1) proteins in intracellular cholesterol transport and in maintaining cell cholesterol balance. Underexpression of NPC1 in concert with underexpression of ABCA1 would result in increased cholesterol accumulation and increased AD risk. We examined a functional polymorphism in the ABCA1 promoter region (−477, rs2422493), and four NPC1 polymorphisms in exon 6 (rs18050810), intron 20 (rs4800488), intron 22 (rs2236707), and intron 24 (rs2510344) capturing 85% of genetic variability in Hap Map CEU population, in a group of 631 Spanish AD patients and 731 controls. Subjects carrying both the ABCA1 (−477) TT genotype and the NPC1 (exon 6) GG genotype (OR = 1.89; 95% CI 1.04-3.41), NPC1 (intron 20) AA genotype (OR = 2.05; 95% CI 1.26-3.33), NPC1 (intron 22) AA genotype (OR = 2.05; 95% CI 1.18-3.58), or NPC1 (intron 24) GG genotype (OR = 1.89; 95% CI 1.16-3.07) had a higher risk of developing AD than subjects without these risk genotypes. Testing for epistatic interaction between genes in the pathway of cholesterol metabolism might be useful for predicting AD risk
- …