960 resultados para Serial-correlation common features
Resumo:
La noción de la transición como "matriz" de nuestro tiempo presente, como mito fundador de la España contemporánea es, hoy, uno de los puntos fundamentales de los debates culturales más recientes de nuestro país. Si consideramos el proceso de cambio político de la transición a la democracia como el punto de partida del proyecto democrático español aún vigente, el surgimiento de una serie de novelas centradas en el mismo resulta tan sintomático como oportuno. Por ello, en este artículo tratamos de interrogar las condiciones en las que ha aparecido esta serie de novelas, sus presupuestos comunes y los distintos núcleos de discusión a los que apuntan. Desde el análisis de la producción de una serie de autores nacidos entre la década de los sesenta y los setenta, y en concreto de la novela El jardín colgante (2012) esbozaremos, a grandes rasgos, la problemática generacional que la vuelta al debate sobre la transición supone en el contexto de la España contemporánea.
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El presente trabajo enfoca la región del Nordeste Argentino como un conjunto de provincias que presentan una realidad compleja, distinguidas por una serie de rasgos comunes que las unifican como región y permiten examinar sus principales problemáticas y potencialidades. El análisis selecciona y jerarquiza ciertos aspectos de la cuestión, de modo de brindar una perspectiva centrada en los aspectos estratégicos para el desarrollo regional
Resumo:
La noción de la transición como "matriz" de nuestro tiempo presente, como mito fundador de la España contemporánea es, hoy, uno de los puntos fundamentales de los debates culturales más recientes de nuestro país. Si consideramos el proceso de cambio político de la transición a la democracia como el punto de partida del proyecto democrático español aún vigente, el surgimiento de una serie de novelas centradas en el mismo resulta tan sintomático como oportuno. Por ello, en este artículo tratamos de interrogar las condiciones en las que ha aparecido esta serie de novelas, sus presupuestos comunes y los distintos núcleos de discusión a los que apuntan. Desde el análisis de la producción de una serie de autores nacidos entre la década de los sesenta y los setenta, y en concreto de la novela El jardín colgante (2012) esbozaremos, a grandes rasgos, la problemática generacional que la vuelta al debate sobre la transición supone en el contexto de la España contemporánea.
Resumo:
This paper is conducting a comparative analysis of the development of securities markets in nine Asian economies: Korea, Taiwan, Hong Kong, Singapore, Malaysia, Thailand, Indonesia, the Philippines, and China. This study focuses on two aspects: the history and institutional development of securities market, such as legal systems, payment systems, etc. From the analyses, this paper reveals several common features of the development of securities markets in nine Asian economies. First, most economies had an informal capital market in the early period of their history. Second, the background of the foundation of their official markets was influenced by experiences of colonization. Third, most governments recognized the importance of the capital market for economic development and had a positive attitude in promoting the market. Fourth, statistics clearly showed that most economies experienced several booms in their capital market from the late 1980s.
Origin and patterns of distribution of trace elements in street dust. Unleaded petrol and urban lead
Resumo:
The elemental composition, patterns of distribution and possible sources of street dust are not common to all urban environments, but vary according to the peculiarities of each city. The common features and dissimilarities in the origin and nature of street dust were investigated through a series of studies in two widely different cities, Madrid (Spain) and Oslo (Norway), between 1990 and 1994. The most comprehensive sampling campaign was carried out in the Norwegian capital during the summer of 1994. An area of 14 km2, covering most of downtown Oslo and some residential districts to the north of the city, was divided into 1 km2 mapping units, and 16 sampling increments of approximately 150 g were collected from streets and roads in each of them. The fraction below 100 μm was acid-digested and analysed by ICP-MS. Statistical analyses of the results suggest that chemical elements in street dust can be classified into three groups: “urban” elements (Ba, Cd, Co, Cu, Mg, Pb, Sb, Ti, Zn), “natural” elements (Al, Ga, La, Mn, Na, Sr, Th, Y) and elements of a mixed origin or which have undergone geochemical changes from their original sources (Ca, Cs, Fe, Mo, Ni, Rb, Sr, U). Soil resuspension and/or mobilisation appears to be the most important source of “natural” elements, while “urban” elements originate primarily from traffic and from the weathering and corrosion of building materials. The data for Pb seem to prove that the gradual shift from leaded to unleaded petrol as fuel for automobiles has resulted in an almost proportional reduction in the concentration of Pb in dust particles under 100 μm. This fact and the spatial distribution of Pb in the city strongly suggest that lead sources other than traffic (i.e. lead accumulated in urban soil over the years) may contribute as much lead, if not more, to urban street dust.
Resumo:
The derivative nonlinear Schrodinger DNLS equation, describing propagation of circularly polarized Alfven waves of finite amplitude in a cold plasma, is truncated to explore the coherent, weakly nonlinear, cubic coupling of three waves near resonance, one wave being linearly unstable and the other waves damped. In a reduced three-wave model equal dampings of daughter waves, three-dimensional flow for two wave amplitudes and one relative phase, no matter how small the growth rate of the unstable wave there exists a parametric domain with the flow exhibiting chaotic relaxation oscillations that are absent for zero growth rate. This hard transition in phase-space behavior occurs for left-hand LH polarized waves, paralleling the known fact that only LH time-harmonic solutions of the DNLS equation are modulationally unstable, with damping less than about unstable wave frequency 2/4 x ion cyclotron frequency. The structural stability of the transition was explored by going into a fully 3-wave model different dampings of daughter waves,four-dimensional flow; both models differ in significant phase-space features but keep common features essential for the transition.
Resumo:
Nowadays, Software Product Line (SPL) engineering [1] has been widely-adopted in software development due to the significant improvements that has provided, such as reducing cost and time-to-market and providing flexibility to respond to planned changes [2]. SPL takes advantage of common features among the products of a family through the systematic reuse of the core-assets and the effective management of variabilities across the products. SPL features are realized at the architectural level in product-line architecture (PLA) models. Therefore, suitable modeling and specification techniques are required to model variability. In fact, architectural variability modeling has become a challenge for SPLE due to the fact that PLA modeling requires not only modeling variability at the level of the external architecture configuration (see [3,4] literature reviews), but also at the level of internal specification of components [5]. In addition, PLA modeling requires preserving the traceability between features and PLAs. Finally, it is important to take into account that PLA modeling should guide architects in modeling the PLA core assets and variability, and in deriving the customized products. To deal with these needs, we present in this demonstration the FPLA Modeling Framework.
Resumo:
In the current uncertain context that affects both the world economy and the energy sector, with the rapid increase in the prices of oil and gas and the very unstable political situation that affects some of the largest raw materials’ producers, there is a need for developing efficient and powerful quantitative tools that allow to model and forecast fossil fuel prices, CO2 emission allowances prices as well as electricity prices. This will improve decision making for all the agents involved in energy issues. Although there are papers focused on modelling fossil fuel prices, CO2 prices and electricity prices, the literature is scarce on attempts to consider all of them together. This paper focuses on both building a multivariate model for the aforementioned prices and comparing its results with those of univariate ones, in terms of prediction accuracy (univariate and multivariate models are compared for a large span of days, all in the first 4 months in 2011) as well as extracting common features in the volatilities of the prices of all these relevant magnitudes. The common features in volatility are extracted by means of a conditionally heteroskedastic dynamic factor model which allows to solve the curse of dimensionality problem that commonly arises when estimating multivariate GARCH models. Additionally, the common volatility factors obtained are useful for improving the forecasting intervals and have a nice economical interpretation. Besides, the results obtained and methodology proposed can be useful as a starting point for risk management or portfolio optimization under uncertainty in the current context of energy markets.
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Sigma 54 is a required factor for bacterial RNA polymerase to respond to enhancers and directs a mechanism that is a hybrid between bacterial and eukaryotic transcription. Three pathways were found that bypass the enhancer requirement in vitro. These rely on either deletion of the sigma 54 N terminus or destruction of the DNA consensus −12 promoter recognition element or altering solution conditions to favor transient DNA melting. Each of these allows unstable heparin-sensitive pre-initiation complexes to form that can be driven to transcribe in the absence of both enhancer protein and ATP β–γ hydrolysis. These disparate pathways are proposed to have a common basis in that multiple N-terminal contacts may mediate the interactions between the polymerase and the DNA region where melting originates. The results raise possibilities for common features of open complex formation by different RNA polymerases.
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Large-scale genetic screens for mutations affecting early neurogenesis of vertebrates have recently been performed with an aquarium fish, the zebrafish. Later stages of neural morphogenesis have attracted less attention in small fish species, partly because of the lack of molecular markers of developing structures that may facilitate the detection of discrete structural alterations. In this context, we report the characterization of Ol-Prx 3 (Oryzias latipes-Prx 3). This gene was isolated in the course of a large-scale screen for brain cDNAs containing a highly conserved DNA binding region, the homeobox helix-three. Sequence analysis revealed that this gene belongs to another class of homeobox genes, together with a previously isolated mouse ortholog, called OG-12 [Rovescalli, A. C., Asoh, S. & Nirenberg, M. (1996) Proc. Natl. Acad. Sci. USA 93, 10691–10696] and with the human SHOX gene [Rao, E., Weiss, B., Fukami, M., Rump, A., Niesler, B., et al. (1997) Nat. Genet. 16, 54–62], thought to be involved in the short-stature phenotype of Turner syndrome patients. These three genes exhibit a moderate level of identity in the homeobox with the other genes of the paired-related (PRX) gene family. Ol-Prx 3, as well as the PRX genes, are expressed in various cartilaginous structures of head and limbs. These genes might thus be involved in common regulatory pathways during the morphogenesis of these structures. Moreover, this paper reports a complex and monophasic pattern of Ol-Prx 3 expression in the central nervous system, which differs markedly from the patterns reported for the PRX genes, Prx 3 excluded: this gene begins to be expressed in a variety of central nervous system territories at late neurula stage. Strikingly, it remains turned on in some of the derivatives of each territory during the entire life of the fish. We hope this work will thus help identify common features for the PRX 3 family of homeobox genes.
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In human cells, hMLH1, hMLH3, hPMS1 and hPMS2 are four recognised and distinctive homologues of MutL, an essential component of the bacterial DNA mismatch repair (MMR) system. The hMLH1 protein forms three different heterodimers with one of the other MutL homologues. As a first step towards functional analysis of these molecules, we determined the interacting domains of each heterodimer and tried to understand their common features. Using a yeast two-hybrid assay, we show that these MutL homologues can form heterodimers by interacting with the same amino acid residues of hMLH1, residues 492–742. In contrast, three hMLH1 partners, hMLH3, hPMS1 and hPMS2 contain the 36 homologous amino acid residues that interact strongly with hMLH1. Contrary to the previous studies, these homologous residues reside at the N-terminal regions of three subdomains conserved in MutL homologues in many species. Interestingly, these residues in hPMS2 and hMLH3 may form coiled-coil structures as predicted by the MULTICOIL program. Furthermore, we show that there is competition for the interacting domain in hMLH1 among the three other MutL homologues. Therefore, the quantitative balance of these three MutL heterodimers may be important in their functions.
Resumo:
It is generally accepted that globular proteins fold with a hydrophobic core and a hydrophilic exterior. Might the spatial distribution of amino acid hydrophobicity exhibit common features? The hydrophobic profile detailing this distribution from the protein interior to exterior has been examined for 30 relatively diverse structures obtained from the Protein Data Bank, for 3 proteins of the 30S ribosomal subunit, and for a simple set of 14 decoys. A second-order hydrophobic moment has provided a simple measure of the spatial variation. Shapes of the calculated spatial profiles of all native structures have been found to be comparable. Consequently, profile shapes as well as particular profile features should assist in validating predicted protein structures and in discriminating between different protein-folding pathways. The spatial profiles of the 14 decoys are clearly distinguished from the profiles of their native structures.
Resumo:
Dystrobrevin is a component of the dystrophin-associated protein complex and has been shown to interact directly with dystrophin, α1-syntrophin, and the sarcoglycan complex. The precise role of α-dystrobrevin in skeletal muscle has not yet been determined. To study α-dystrobrevin's function in skeletal muscle, we used the yeast two-hybrid approach to look for interacting proteins. Three overlapping clones were identified that encoded an intermediate filament protein we subsequently named desmuslin (DMN). Sequence analysis revealed that DMN has a short N-terminal domain, a conserved rod domain, and a long C-terminal domain, all common features of type 6 intermediate filament proteins. A positive interaction between DMN and α-dystrobrevin was confirmed with an in vitro coimmunoprecipitation assay. By Northern blot analysis, we find that DMN is expressed mainly in heart and skeletal muscle, although there is some expression in brain. Western blotting detected a 160-kDa protein in heart and skeletal muscle. Immunofluorescent microscopy localizes DMN in a stripe-like pattern in longitudinal sections and in a mosaic pattern in cross sections of skeletal muscle. Electron microscopic analysis shows DMN colocalized with desmin at the Z-lines. Subsequent coimmunoprecipitation experiments confirmed an interaction with desmin. Our findings suggest that DMN may serve as a direct linkage between the extracellular matrix and the Z-discs (through plectin) and may play an important role in maintaining muscle cell integrity.
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To evaluate the relative importance of ornithine (Orn) as a precursor in proline (Pro) synthesis, we isolated and sequenced a cDNA encoding the Orn-δ-aminotransferase (δ-OAT) from Arabidopsis thaliana. The deduced amino acid sequence showed high homology with bacterial, yeast, mammalian, and plant sequences, and the N-terminal residues exhibited several common features with a mitochondrial transit peptide. Our results show that under both salt stress and normal conditions, δ-OAT activity and mRNA in young plantlets are slightly higher than in older plants. This appears to be related to the necessity to dispose of an easy recycling product, glutamate. Analysis of the expression of the gene revealed a close association with salt stress and Pro production. In young plantlets, free Pro content, Δ1-pyrroline-5-carboxylate synthase mRNA, δ-OAT activity, and δ-OAT mRNA were all increased by salt-stress treatment. These results suggest that for A. thaliana, the Orn pathway, together with the glutamate pathway, plays an important role in Pro accumulation during osmotic stress. Conversely, in 4-week-old A. thaliana plants, although free Pro level also increased under salt-stress conditions, the δ-OAT activity appeared to be unchanged and δ-OAT mRNA was not detectable. Δ1-pyrroline-5-carboxylate synthase mRNA was still induced at a similar level. Therefore, for the adult plants the free Pro increase seemed to be due to the activity of the enzymes of the glutamate pathway.
Resumo:
2,6-Dichloroisonicotinic acid (INA) and salicylic acid (SA) are potent inducers of plant defense responses including the synthesis of pathogenesis-related (PR) proteins and the development of enhanced disease resistance. A soluble SA-binding protein has been purified from tobacco with an affinity and specificity of binding that suggest it is a SA receptor. Recently, this protein has been shown to be a catalase whose enzymatic activity is inhibited by SA binding. We have proposed that the resulting increase in intracellular levels of reactive oxygen species plays a role in the induction of defense responses such as PR protein gene expression. Here we report that INA, like SA, binds the SA-binding protein/catalase and inhibits its enzymatic activity. In fact, the dose-response curves for inhibition of catalase by these two compounds are similar. Furthermore, the ability of both INA analogues and SA derivatives to bind and inhibit tobacco catalase correlates with their biological activity to induce PR-1 gene expression and enhance resistance to tobacco mosaic virus. Comparison of the structures of INA, SA, and their analogues reveals several common features that appear to be important for biological activity. Thus, these results not only suggest that INA and SA share the same mechanism of action that involves binding and inhibition of catalase but also further indicate an important role for reactive oxygen species in the induction of certain plant defense responses. This is supported by the demonstration that INA-mediated PR-1 gene activation is suppressed by antioxidants.