986 resultados para 344.04192
Resumo:
In the present study, we propose a theoretical graph procedure to investigate multiple pathways in brain functional networks. By taking into account all the possible paths consisting of h links between the nodes pairs of the network, we measured the global network redundancy R (h) as the number of parallel paths and the global network permeability P (h) as the probability to get connected. We used this procedure to investigate the structural and dynamical changes in the cortical networks estimated from a dataset of high-resolution EEG signals in a group of spinal cord injured (SCI) patients during the attempt of foot movement. In the light of a statistical contrast with a healthy population, the permeability index P (h) of the SCI networks increased significantly (P < 0.01) in the Theta frequency band (3-6 Hz) for distances h ranging from 2 to 4. On the contrary, no significant differences were found between the two populations for the redundancy index R (h) . The most significant changes in the brain functional network of SCI patients occurred mainly in the lower spectral contents. These changes were related to an improved propagation of communication between the closest cortical areas rather than to a different level of redundancy. This evidence strengthens the hypothesis of the need for a higher functional interaction among the closest ROIs as a mechanism to compensate the lack of feedback from the peripheral nerves to the sensomotor areas.
Resumo:
We discuss potential caveats when estimating topologies of 3D brain networks from surface recordings. It is virtually impossible to record activity from all single neurons in the brain and one has to rely on techniques that measure average activity at sparsely located (non-invasive) recording sites Effects of this spatial sampling in relation to structural network measures like centrality and assortativity were analyzed using multivariate classifiers A simplified model of 3D brain connectivity incorporating both short- and long-range connections served for testing. To mimic M/EEG recordings we sampled this model via non-overlapping regions and weighted nodes and connections according to their proximity to the recording sites We used various complex network models for reference and tried to classify sampled versions of the ""brain-like"" network as one of these archetypes It was found that sampled networks may substantially deviate in topology from the respective original networks for small sample sizes For experimental studies this may imply that surface recordings can yield network structures that might not agree with its generating 3D network. (C) 2010 Elsevier Inc All rights reserved
Resumo:
The Guarguaraz Complex, in western Argentina, comprises a metasedimentary assemblage, associated with mafic sills and ultramafic bodies intruded by basaltic dikes, which are interpreted as Ordovician dismembered ophiolites. Two kinds of dikes are recognized, a group associated with the metasediments and the other ophiolite-related. Both have N-MORB signatures, with epsilon(Nd) between +3.5 and +8.2, indicating a depleted source, and Grenville model ages between 0.99 and 1.62 Ga. A whole-rock Sm-Nd isochron yielded an age of 655 +/- 76 Ma for these mafic rocks, which is compatible with cianobacteria and acritarchae recognized in the clastic metasedimentary platform sequences, that indicate a Neoproterozoic (Vendian)-Cambrian age of deposition. The Guarguaraz metasedimentary-ophiolitic complex represents, therefore, a remnant of an oceanic basin developed to the west of the Grenville-aged Cuyania terrane during the Neoproterozoic. The southernmost extension of these metasedimentary sequences in Cordon del Portillo might represent part of this platform and not fragments of the Chilenia terrane. An extensional event related to the fragmentation of Rodinia is represented by the mafic and ultramafic rocks. The Devonian docking of Chilenia emplaced remnants of ocean floor and slices of the Cuyania terrane (Las Yaretas Gneisses) in tectonic contact with the Neoproterozoic metasediments, marking the Devonian western border of Gondwana. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
The occurrences of imperial topaz in the Antonio Pereira mine, Ouro Preto, Minas Gerais, are associated with the metamorphic carbonate rocks of the Minas Supergroup. The crystals have densities varying from 3.46 to 3.58. The parameters of the unitary cells obtained were: 4.658 to 4.663 angstrom (ao), 8.823 to 8.832 angstrom (b(o)), 8.382 to 8.389 angstrom (c(o)), and 344.65 to 345.46 angstrom 3 (V). The refraction indices presented the following variations: 1.622 to 1.630 (nX), 1.624 to 1.632 (nY), 1.633 to 1.640 (nZ), and 0.008 to 0.011 (B). These properties are coherent with the low fluorine contents obtained (16,48%/17,05wt%). Infrared spectroscopy and microthermometry showed that the fluid inclusions, which represent the mineralizing fluids, are formed by H(2)O (with Ca(2+), Mg(2+) and Na(+)), and CO(2) +/- CH(4). The minimal trapping T-P conditions of 290/320 degrees C and 2,349/2,497bar were obtained for the primary fluid inclusions. The pseudo-secondary fluid inclusions were trapped at conditions of lower temperatures and variable pressures, during the deformation process under local alternating states of stress. The microthermometric studies, the structural analysis and the fluorine contents suggest that the mineralized veins were formed from hydrothermal fluids originated during the Brasiliano tectono-metamorphic event.
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Planning to reach a goal is an essential capability for rational agents. In general, a goal specifies a condition to be achieved at the end of the plan execution. In this article, we introduce nondeterministic planning for extended reachability goals (i.e., goals that also specify a condition to be preserved during the plan execution). We show that, when this kind of goal is considered, the temporal logic CTL turns out to be inadequate to formalize plan synthesis and plan validation algorithms. This is mainly due to the fact that the CTL`s semantics cannot discern among the various actions that produce state transitions. To overcome this limitation, we propose a new temporal logic called alpha-CTL. Then, based on this new logic, we implement a planner capable of synthesizing reliable plans for extended reachability goals, as a side effect of model checking.
Resumo:
In this work we discuss the problem of smooth and analytic regularity for hyperfunction solutions to linear partial differential equations with analytic coefficients. In particular we show that some well known ""sum of squares"" operators, which satisfy Hormander`s condition and consequently are hypoelliptic, admit hyperfunction solutions that are not smooth (in particular they are not distributions).
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CCSD(T) with a series of correlation consistent basis up to quadruple-zeta is used to investigate the structures, vibrational spectra, relative stability, heats of formation, and barrier to isomerization of S=SBr2 and BrSSBr. It represents the most accurate and detailed characterization of these molecules to date. We show that the frequency mode at 302 cm(-1), detected in various studies and assigned to impurities by some authors, and to the anti-symmetric SBr stretch in BrSSBr by others, thus in fact corresponds to the anti-symmetric SBr stretch in the elusive S=SBr2 species; it thus corroborates and complements an earlier partial IR spectra study attributable to S=SBr2. Including corrections for relativistic and core-valence correlation effects, we also predict 26.33 (12.74) kcal/mol for Delta H-f (298.15 K) of S=SBr2 (BrSSBr). For the S=SBr2 -> BrSSBr reaction, our best estimates for the Gibbs free energy and the enthalpy of the reaction at 298.15 K are -13.71 and -13.44 kcal/mol, respectively. For a value of Delta G(#) equal to 23.52 kcal/mol, we estimate a TST rate constant, at 298.15 K, of 3.57 x 10(-5) s(-1). (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
In this work a series of tetrakis complexes C[Tm(acac)(4)] where C(+) = Li(+) Na(+) and K(+) countercations and acac = acetylacetonate ligand were synthesized and characterized for photoluminescence investigation The relevant aspect is that these complexes are water-free in the first coordination sphere The emission spectra of the tetrakis Tm(3+)-complexes present narrow bands characteristic of the (1)G(4)->(3)H(6) (479 nm) (1)G(4)->(3)F(4) (650 nm) and (1)G(4) ->(3)H(5) (779 nm) transitions of the Tm(3+) ion with the blue emission color at 479 nm as the most prominent one The lifetime values (tau) of the emitting (1)G(4) level of the C[Tm(acac)(4)] complexes were 344 360 and 400 ns for the Li(+) Na(+) and K(+) countercations respectively showing an increasing linear behavior versus the ionic radius of the alkaline ion An efficient intramolecular energy transfer process from the triplet state (T) of the ligands to the emitting (1)G(4) state of the Tm(3+) ion is observed This fact together with the absence of water molecules in first coordination sphere allows these tetrakis Tm(3+)-complexes to act as efficient blue light conversion molecular devices (c) 2010 Elsevier B V All rights reserved
Resumo:
Inledning: Kvinnors sexualitet och kroppsuppfattning efter gynekologisk cancer förändras. Som barnmorskor är det viktigt att i tidigt skede medverka till och förebygga de komplikationer som dessa kvinnor drabbas av. Syfte: Syftet med studien var att göra en jämförande, detaljerad beskrivning av attraktion och sexuell lust hos kvinnor som blivit strålbehandlade mot gynekologisk cancer. Metod: En prospektiv kohortstudie med kvantitativ ansats med enkätformulär. Två kohorter har jämförts där 616 kvinnor behandlats för gynekologisk cancer samt 344 kvinnor som inte behandlats. Resultat: Kvinnorna upplever sig mindre attraktiva och att deras partner även tycker det. De hade mindre längtan efter sex och hade sex mer sällan. Flertalet talade inte med någon om sin brist på lust till sex eller om de sexuellt relaterade biverkningarna. De kände sig mindre upphetsade i en sexuell situation där tillfredsställelsen och avspänningen i samband med orgasm förändrats. Kvinnornas välbefinnande påverkades negativt och problem med avföring och gasläckage förekom. Slutsats: Upprepad information och återkoppling före, under och efter behandling mellan kvinnorna och patientansvarig barnmorska/läkare är nödvändigt. Kvinnornas upplevelse av att vara attraktiva, tankar på, längtan och lust efter sex samt ofrivillig gasavgång och avföringsträngningar är de viktigaste faktorerna att belysa för kvinnorna för att kunna förbereda och förebygga komplikationer efter gynekologisk cancer.
Resumo:
The paper is analyzing how people in late modern society characterized by de-traditionalization, use moving images as a cultural resource for the construction of meaningful subjective world views. As a theoretical concept with several dimensions, “sacralization of the self” (Woodhead & Heelas 2000: 344), is related to media theory. With a critical focus on ‘the self’, as a core aspect in contemporary media society Eric W. Rothenbuhler labels the individual self as one of “the sacred objects of modern culture” (Rothenbuhler 2006: 31).I want to emphasize the need for case studies in order to undertake a critical investigation about ‘the self’ and how consumption of fiction film is interconnected to spectator´s creation of self images, but also to understand how film engagement elicits self-reflection (Giddens 1991, Axelson 2008, Vaage 2009a). The paper make use of empirical data to illustrate and theoretically develop perspectives on how the audience uses fiction film in every-day life for the construction of the self, as well for the construction of more profound and long-lasting ideas of being part of a moral community (Brereton 2005, Jerslev 2006, Klinger 2008, Mikkola et al. 2007, Vaage 2009b). Some empirical findings support a conclusion that moving images creates a transitional space for the human mind, with the capacity of transporting the spectator from real life to fiction and back to real life again, helping the individual with an ongoing process of transforming the self, dealing with who you actually are, and who you want to become (Axelson 2008, Vaage 2009b).
Resumo:
The aim of the project is to examine the music salon in Falun as a part of the mining community and in the historical context of European salon culture. A specifc goal is to develop a deeper understanding about the salon when it comes to education and pedagogic ideas. Of a certain interest is Johan Henrik Munktell’s (1804-1861) education travelling (bildningsresor). Inspired by Mendelssohn’s music salon in Berlin and the early salons in Upp-sala he created his own salon in Grycksbo. A letter collection from J.H. Munktell to his father J.J. Munktell in 1828-30 can be considered a unique historical material, which places the salon in Falun in a continental context of culture, education and industrial pretensions. The results have potential to extend the knowledge of Nordic salon culture and how it has infuenced general pedagogy and music education.
Resumo:
Evento internacional, cujo caderno de resumos está disponível em http://www.sbece.com.br/conteudo/view?ID_CONTEUDO=865, mas os Anais estão disponíveis somente em CD rom.