3,687 research outputs found
Detecting synchronization in spatially extended discrete systems by complexity measurements
The synchronization of two stochastically coupled one-dimensional cellular
automata (CA) is analyzed. It is shown that the transition to synchronization
is characterized by a dramatic increase of the statistical complexity of the
patterns generated by the difference automaton. This singular behavior is
verified to be present in several CA rules displaying complex behavior.Comment: 4 pages, 2 figures; you can also visit
http://add.unizar.es/public/100_16613/index.htm
Optimal Monetary Policy and Asset Prices: the case of Colombia
The unfolding of the 2007 world financial and economic crisis has highlighted the vulnerability of real economic activity to strong fluctuations in asset prices. Which is the optimal monetary policy in an economy like the Colombian that is exposed to swings in asset prices? What is the implication in terms of Central Bank losses when it follows a standard simple rule instead of the optimal monetary policy? To answer these questions we use a Dynamic Stochastic General Equilibrium (DSGE) model with physical capital and sticky wages for the Colombian economy and derive the optimal monetary policy. Then, we explore the dynamic effects of news about a future technology improvement which turns out ex post to be overoptimistic under the optimal policy rule and alternative specifications of simple rules and definitions of output gap.DSGE model, Optimal Monetary Policy, Asset Price boom-busts, Colombia. Classification JEL: E44, E52, E61.
Metabolic and Stress Responses in Senegalese Soles (Solea senegalensis Kaup) Fed Tryptophan Supplements: E ects of Concentration and Feeding Period
The objective of this study was to assess the impact of di erent dietary Trp concentrations on
the stress and metabolism response of juvenile Senegalese soles (Solea senegalensis). Fish (38.1 1.9 g)
were fed di erent Trp-enriched feeds (0%, 1% and 2% Trp added) for two and eight days, and later
exposed to air stress for three min. Samples were taken pre- and 1 h post-stress (condition). Plasma
cortisol, lactate, glucose and proteins were significantly a ected by the sampling time, showing higher
values at 1 h post-stress. Trp concentration in food also had significant e ects on lactate and glucose
levels. However, the feeding period did not a ect these parameters. Post-stress values were higher
than in the pre-stress condition for every plasma parameter, except for lactate in two days and 1% Trp
treatment. Nevertheless, cortisol, glucose and lactate did not vary significantly between pre- and
post-stress samplings in fish fed the 1% Trp-enriched diet for two days. The lack of variability in
cortisol response was also due to the high pre-stress value, significantly superior to pre-stress control.
The exposure time to Trp feeding did not significantly a ect any enzyme activity; however, Trp added
and condition influenced protein-related enzyme activities. In spite of decreasing stress markers,
Trp-enriched diets altered the protein metabolism
Recommendations on seismic actions on bridges
The paper describes the main features of a technical Recommendation first draft on Seismic Actions on Bridges, promoted by the Spanish Ministry of Public Works (MOPT). Although much more research is needed to clarify the seismic behaviour of the vast class of problems present in port structures the current state of the art allows at least a classificaton of subjects and the establishment of minimum requirements to guide the design. Also the use of more refined methods for specially dangerous situations needs some general guidelines that contribute to mantein the design under reasonable safety margins. The Recommendations of the Spanish MOPT are a first try in those directions
Centaurea sect. Calcitrapa (Heister ex Fabr.) DC. in the Iberian Peninsula
Se ha efectuado la revisión taxonómica de Centaurea sect. Calcitrapa (Heister ex Fabr.) DC. en la Península Ibérica. Se reconocen 3 taxones, uno de los cuales es descrito como nuevo: C. bofilliana Sennen ex Devesa & E. López. Se aporta una clave para la identificación de los taxones, así como su descripción morfológica e información sobre la distribución geográfica, apetencias ecológicas, fenología y número cromosómicoA taxonomic review of Centaurea sect. Calcitrapa (Heister ex Fabr.) DC. in the Iberian Peninsula was carried out. Three taxa are recognized and one of them is described as a new species: C. bofilliana Sennen ex Devesa & E. López. A key for the identification of taxa is made and their morphological description, geographical distribution, ecology, phenology and chromosome numbers are give
Evaluación de la calidad de los ecosistemas acuáticos a partir del modo de nutrición (IMN) de sus macroinvertebrados. Una adaptación para la educación secundaria
Tanto por las Naciones Unidas como por la Comisión Europea (COM, 1997) se insta al estudio, conservación y mejora de los sistemas acuáticos. En la Península Ibérica y hasta la fecha, los índices utilizados habitualmente para evaluar y determinar la calidad del agua basados en los macroinvertebrados tienen una aplicación restringida a los ríos, ya que, en los demás ecosistemas acuáticos (lagos, lagunas, humedales, etc.) el comportamiento de dichos índices parece que no aporta conclusiones fiables. Con el nuevo índice ecológico presentado en este trabajo, llamado “Índice del Modo de Nutrición” (IMN), se pretende evaluar la calidad de la estructura trófica de las comunidades de macroinvertebrados de todos los sistemas acuáticos continentales y acercar de manera relevante la utilización de los macroinvertebrados acuáticos en la realización de proyectos dirigidos al alumnado de enseñanza secundaria
A contribution to the karyological knowledge of the genus Centaurea L. (Asteraceae) in the Iberian Peninsula. Sect. Seridia (Juss.) DC.
Se da a conocer el número cromosómico de 10 taxones del género Centaurea pertenecientes a la sección Seridia (Juss.) DC. presentes en la Península Ibérica. En el caso de Centaurea lusitanica var. crassifolia P. Silva, C. aspera subsp. stenophylla (Dufour) Nyman y C. barrasii Pau se trata, al parecer, del primer recuento. El número diploide 2n = 22 es el más frecuente en el grupo estudiado, mientras que el nivel tetraploide 2n = 44 sólo se ha detectado en C. seridis L. y C. sphaerocephala L.A karyological study of taxa of genus Centaurea L. sect. Seridia (Juss.) DC. in the Iberian Peninsula is reported. We have studied 10 taxa and the reports for 3 of them are given for the first time: Centaurea lusitanica var. crassifolia P. Silva, C. aspera subsp. stenophylla (Dufour) Nyman and C. barrasii Pau. Diploid number 2n = 22 is the most frequent whereas tetraploid level 2n = 44 has been found only in C. seridis L. and C. sphaerocephala L
A method to discern complexity in two-dimensional patterns generated by coupled map lattices
Complex patterns generated by the time evolution of a one-dimensional
digitalized coupled map lattice are quantitatively analyzed. A method for
discerning complexity among the different patterns is implemented. The
quantitative results indicate two zones in parameter space where the dynamics
shows the most complex patterns. These zones are located on the two edges of an
absorbent region where the system displays spatio-temporal intermittency.Comment: 3 pages, 3 figures; some information about the authors:
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Telomere length in patients with gestational Diabetes Mellitus and normoglycemic pregnant women: a systematic review and meta-analysis
We performed a systematic review and meta-analysis of studies assessing telomere length in blood leukocytes or mononuclear cells in women with gestational diabetes mellitus (GDM) and normoglycemic pregnant women (NPW) and their infants. The review protocol was registered in PROSPERO (CRD42022300950). Searches were conducted in PubMed, Embase, LILACS, CNKI, and Wang Fang, from inception through November 2022. The primary outcomes were maternal and offspring telomere length. The Newcastle-Ottawa Scale was used to assess the quality of included studies. Random-effect meta-analyses were applied to estimate standardized mean differences (SMDs) and their 95% confidence interval (CI). The meta-analysis of four studies showed no significant maternal telomere length difference (SMD = −0.80, 95% CI: −1.66, 0.05) in women with GDM compared to NPW. In the sensibility analysis omitting one study with a small sample of women, the telomere length becomes significantly reduced in women with GDM (SMD = −1.10, 95% CI: −2.18, −0.02). GDM patients had increased glucose (SMD = 0.28, 95% CI: 0.09, 0.46) and glycosylated hemoglobin than NPW (SMD = 0.62, 95% CI: 0.23, 1.01) while total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides did not display differences between women with and without GDM. There was no significant difference in cord blood telomere length in offspring from women with GDM and NPW (SMD = 0.11, 95% CI: −0.52, 0.30). Cord blood insulin levels (SMD = 0.59, 95% CI: 0.33, 0.85) and birthweight (SMD = 0.59, 95% CI: 0.39, 0.79) were higher in offspring from pregnant women with GDM than in those from NPW. There were no significant differences in maternal and offspring telomere length between pregnancies with and without GDM
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