990 resultados para Historical present


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This paper analyses the representations of the body present in contemporary science-fiction literature and film. Using theoretical concepts by Althusser, Foucault and Haraway, the text establishes first a typology of cybernetic organisms in contemporary culture and reviews its presence and ideological implications in films like Robocop (1987), Johny Mnemonic (1995) or Matrix (1999). The paper argues for a self-conscience as political and historical subjects in order to avoid falling into a fallacious cyberandroginy that reinforces phallogocentric power structures.

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Empirical studies have shown little evidence to support the presence of all unit roots present in the $^{\Delta_4}$ filter in quarterly seasonal time series. This paper analyses the performance of the Hylleberg, Engle, Granger and Yoo (1990) (HEGY) procedure when the roots under the null are not all present. We exploit the Vector of Quarters representation and cointegration relationship between the quarters when factors $(1-L),(1+L),\bigg(1+L^2\bigg),\bigg(1-L^2\bigg) y \bigg(1+L+L^2+L^3\bigg)$ are a source of nonstationarity in a process in order to obtain the distribution of tests of the HEGY procedure when the underlying processes have a root at the zero, Nyquist frequency, two complex conjugates of frequency $^{\pi/2}$ and two combinations of the previous cases. We show both theoretically and through a Monte-Carlo analysis that the t-ratios $^{t_{{\hat\pi}_1}}$ and $^{t_{{\hat\pi}_2}}$ and the F-type tests used in the HEGY procedure have the same distribution as under the null of a seasonal random walk when the root(s) is/are present, although this is not the case for the t-ratio tests associated with unit roots at frequency $^{\pi/2}$.

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Empirical studies have shown little evidence to support the presence of all unit roots present in the $^{\Delta_4}$ filter in quarterly seasonal time series. This paper analyses the performance of the Hylleberg, Engle, Granger and Yoo (1990) (HEGY) procedure when the roots under the null are not all present. We exploit the Vector of Quarters representation and cointegration relationship between the quarters when factors $(1-L),(1+L),\bigg(1+L^2\bigg),\bigg(1-L^2\bigg) y \bigg(1+L+L^2+L^3\bigg)$ are a source of nonstationarity in a process in order to obtain the distribution of tests of the HEGY procedure when the underlying processes have a root at the zero, Nyquist frequency, two complex conjugates of frequency $^{\pi/2}$ and two combinations of the previous cases. We show both theoretically and through a Monte-Carlo analysis that the t-ratios $^{t_{{\hat\pi}_1}}$ and $^{t_{{\hat\pi}_2}}$ and the F-type tests used in the HEGY procedure have the same distribution as under the null of a seasonal random walk when the root(s) is/are present, although this is not the case for the t-ratio tests associated with unit roots at frequency $^{\pi/2}$.

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The distribution of mitochondrial control region-sequence polymorphism was investigated in 15 populations of Crocidura russula along an altitudinal gradient in western Switzerland. High-altitude populations are smaller, sparser and appear to undergo frequent bottlenecks. Accordingly, they showed a loss of rare haplotypes, but unexpectedly, were less differentiated than lowland populations. Furthermore, the major haplotypes segregated significantly with altitude. The results were inconsistent with a simple model of drift and dispersal. They suggested instead a role for historical patterns of colonization, or, alternatively, present-day selective forces acting on one of the mitochondrial genes involved in metabolic pathways.

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The last decade has presented studies providing evidence for astrocytic exocytosis of glutamate potentiating nerve signals. To make further investigations into this astrocytic attribute we investigated the localization of the vesicular glutamate transporter 1 (VGLUT1) in small processes of astrocytes close to glutamatergic terminals in frontal cortex, striatum, molecular layer of hippocampus and stratum radiatum of hippocampus. According to the importance of VGLUT1 in glutamate exocytosis the presence of VGLUT1 in astrocytic processes indicates the ability to exocytose glutamate. METHODS: For qualitative analysis we used immunoflourescence histochemistry. Sections from rat frontal cortex, striatum, molecular layer of hippocampus and stratum radiatum of hippocampus were labeled with antibodies against glutamine synthetase (an astrocytic marker) and VGLUT1. Z-stacks of 4.5-5 lm obtained by confocal microscopy from each section were deconvolved and 3D reconstructed in Amira. Small astrocytic processes were analysed for the presence of VGLUT1 inside the processes. The quantitative analysis was done by immunogold labeling. Ultrathin sections from each brain region were labeled for GLT (an astrocytic marker) and VGLUT1. Pictures obtained by electron microscopy were analysed and the point density (gold particles/nm2) for VGLUT1 in astrocytic processes was measured. RESULTS: Using confocal 3D reconstructions we were qualitatively able to identify VGLUT1 within small processes of astrocytes in all four brain regions. Reflecting our qualitative findings the electron microscopical immunogold quantifications showed a significant density of gold particles signaling VGLUT1 in astrocytic processes in all four brain regions. CONCLUSION: We extend the results of previous studies on glutamate release from astrocytes, which have focused on the hippocampus, proposing that astrocytic exocytosis of glutamate is a global phenomenon in the brain.

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The public library movement f the early twentieth century was a national phenomenon, in which Iowa, along with its neighboring states, played a prominent role. In 1900, the Iowa Library Commission noted 48 free public libraries in the state. Today there are approximately 500, in towns ranging in size from Beaman, with a population of 222, the Des Moines, the state capitol. Iowans took enthusiastic advantage of Andre Carnegie's library philanthropy. In 1919, the Carnegie Corporation stopped funding libraries, 101 building has been erected in Iowa with Carnegie funds. Iowa place fourth among the states in terms of the number of communities obtaining Carnegie buildings, fifth in dollar appropriation per one hundred population and eighth in the total amount of money given by Carnegie to a state. These figures provide some measure by which interest in popular education among Iowans of the period can be judged. Today these early libraries, often the most distinctive public libraries in small or medium-sized towns, are physical foci in the townscapes of their communities and centers for a variety of educational and social activities. This survey was initiated by the Division of Historic Preservation in 1977. It grew out of the need to provide a framework within which libraries could be evaluated for National Register action. Several libraries (Des Moines, Grinnell, Eagle Grove, Carroll) has been recent candidates for the Register. There was every indication that enthusiasm for old library buildings was increasing and that more nominations could be expected in the future. The attrition rate among early library buildings was (and is) growing. Most libraries were built on limited budgets (Carnegie did not squander his money) and, despite the fact that future expansion was usually a conscious consideration in their design, they are rapidly becoming obsolete, due to expanding collections and changing styles of librarianship. If the protection of the threatened with demolition or alteration, action needed to be taken.

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This booklet takes a look at the role trees and woodlands play in the development of Iowa's history. It identifies the individual and groups of trees that have historical significance in the state.

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In recent years historical research seems to be the State Historical Society's main function, although it was formed with the principal functions of collection, preservation and exhibition. Now, instead of simply attempting to make the largest possible collection of historical materials in one place, this society will now endeavor to compile, publish and distribute accurate and scientific historical literature. The book also lists publications, information on the library and on membership.

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Historical Summary of Travel, Crashes, Fatalities, and Rates 1970 – 2009, produced by Iowa Department of Transportation.

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Historical Summary of Travel, Crashes, Fatalities, and Rates 2001 – 2009, produced by Iowa Department of Transportation.

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Socrates' serene attitude before his death -although this is questioned-, as described by Xenophon in his Apologia Socratis becomes for the playwright Rodolf Sirera a useful reference in an effort to reflect boldly on the limits of theatrical fiction in another clear example of the Classical Tradition, including that derived from Baroque Tragedy. However, in this case, it is judged severely to make us more conscious of the risk of turning life into a mere theatrical performance and human beings into actors and actresses in a play they did not write.

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Understanding the relative importance of historical and environmental processes in the structure and composition of communities is one of the longest quests in ecological research. Increasingly, researchers are relying on the functional and phylogenetic β-diversity of natural communities to provide concise explanations on the mechanistic basis of community assembly and the drivers of trait variation among species. The present study investigated how plant functional and phylogenetic β-diversity change along key environmental and spatial gradients in the Western Swiss Alps. Methods Using the quadratic diversity measure based on six functional traits: specific leaf area (SLA), leaf dry matter content (LDMC), plant height (H), leaf carbon content (C), leaf nitrogen content (N), and leaf carbon to nitrogen content (C/N) alongside a species-resolved phylogenetic tree, we relate variations in climate, spatial geographic, land use and soil gradients to plant functional and phylogenetic turnover in mountain communities of the Western Swiss Alps. Important findings Our study highlights two main points. First, climate and land use factors play an important role in mountain plant community turnover. Second, the overlap between plant functional and phylogenetic turnover along these gradients correlates with the low phylogenetic signal in traits, suggesting that in mountain landscapes, trait lability is likely an important factor in driving plant community assembly. Overall, we demonstrate the importance of climate and land use factors in plant functional and phylogenetic community turnover, and provide valuable complementary insights into understanding patterns of β-diversity along several ecological gradients.