1000 resultados para Ciência e tecnologia informáticas


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Background: The present work aims at the application of the decision theory to radiological image quality control ( QC) in diagnostic routine. The main problem addressed in the framework of decision theory is to accept or reject a film lot of a radiology service. The probability of each decision of a determined set of variables was obtained from the selected films. Methods: Based on a radiology service routine a decision probability function was determined for each considered group of combination characteristics. These characteristics were related to the film quality control. These parameters were also framed in a set of 8 possibilities, resulting in 256 possible decision rules. In order to determine a general utility application function to access the decision risk, we have used a simple unique parameter called r. The payoffs chosen were: diagnostic's result (correct/incorrect), cost (high/low), and patient satisfaction (yes/no) resulting in eight possible combinations. Results: Depending on the value of r, more or less risk will occur related to the decision-making. The utility function was evaluated in order to determine the probability of a decision. The decision was made with patients or administrators' opinions from a radiology service center. Conclusion: The model is a formal quantitative approach to make a decision related to the medical imaging quality, providing an instrument to discriminate what is really necessary to accept or reject a film or a film lot. The method presented herein can help to access the risk level of an incorrect radiological diagnosis decision.

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Papillomaviruses have been reported to be very difficult to grow in cell culture. Also, there are no descriptions of cell cultures from lesions of bovine cutaneous papillomatosis, with identification of different bovine papilloma virus (BPV) DNA sequences. In the present report, we describe primary cell cultures from samples of cutaneous lesions (warts). We investigated the simultaneous presence of different BPV DNA sequences, comparing the original lesion to different passages of the cell cultures and to peripheral blood. BPV 1, 2 and 4 DNA sequences were found in lesion samples, and respective cell cultures and peripheral blood, supporting our previous hypothesis of the possible activity of these sequences in different samples and now also showing how they can be maintained in different passages of cell cultures.

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We investigate the quantum integrability of the Landau-Lifshitz (LL) model and solve the long-standing problem of finding the local quantum Hamiltonian for the arbitrary n-particle sector. The particular difficulty of the LL model quantization, which arises due to the ill-defined operator product, is dealt with by simultaneously regularizing the operator product and constructing the self-adjoint extensions of a very particular structure. The diagonalizibility difficulties of the Hamiltonian of the LL model, due to the highly singular nature of the quantum-mechanical Hamiltonian, are also resolved in our method for the arbitrary n-particle sector. We explicitly demonstrate the consistency of our construction with the quantum inverse scattering method due to Sklyanin [Lett. Math. Phys. 15, 357 (1988)] and give a prescription to systematically construct the general solution, which explains and generalizes the puzzling results of Sklyanin for the particular two-particle sector case. Moreover, we demonstrate the S-matrix factorization and show that it is a consequence of the discontinuity conditions on the functions involved in the construction of the self-adjoint extensions.

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The importance of interface effects for organic devices has long been recognized, but getting detailed knowledge of the extent of such effects remains a major challenge because of the difficulty in distinguishing from bulk effects. This paper addresses the interface effects on the emission efficiency of poly(p-phenylene vinylene) (PPV), by producing layer-by-layer (LBL) films of PPV alternated with dodecylbenzenesulfonate. Films with thickness varying from similar to 15 to 225 nm had the structural defects controlled empirically by converting the films at two temperatures, 110 and 230 degrees C, while the optical properties were characterized by using optical absorption, photoluminescence (PL), and photoluminescence excitation spectra. Blueshifts in the absorption and PL spectra for LBL films with less than 25 bilayers (<40-50 nm) pointed to a larger number of PPV segments with low conjugation degree, regardless of the conversion temperature. For these thin films, the mean free-path for diffusion of photoexcited carriers decreased, and energy transfer may have been hampered owing to the low mobility of the excited carriers. The emission efficiency was then found to depend on the concentration of structural defects, i.e., on the conversion temperature. For thick films with more than 25 bilayers, on the other hand, the PL signal did not depend on the PPV conversion temperature. We also checked that the interface effects were not caused by waveguiding properties of the excited light. Overall, the electronic states at the interface were more localized, and this applied to film thickness of up to 40-50 nm. Because this is a typical film thickness in devices, the implication from the findings here is that interface phenomena should be a primary concern for the design of any organic device. (C) 2011 American Institute of Physics. [doi:10.1063/1.3622143]

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We describe the measurement of the depth of maximum, X(max), of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10(18) eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106 +/- 35-21) g/cm(2)/decade below 10(18.24) +/- (0.05) eV, and d24 +/- 3 g/cm(2)/ecade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm(2). The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

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Searching lead compounds for new antituberculosis drugs, the activity of synthetic sulfonamides and sulfonyl-hydrazones were assayed for their potential inhibitory activity towards a protein tyrosine phosphatase from Mycobacterium tuberculosis - PtpB. Four sulfonyl-hydrazones N-phenylmaleimide derivatives were active (compounds 14, 15, 19 and 21), and the inhibition of PtpB was found to be competitive with respect to the substrate p-nitrophenyl phosphate. Structure-based molecular docking simulations were performed and indicated that the new inhibitor candidates showed similar binding modes, filling the hydrophobic pocket of the protein by the establishment of van der Waals contacts, thereby contributing significantly to the complex stability.

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Data collected at the Pierre Auger Observatory are used to establish an upper limit on the diffuse flux of tau neutrinos in the cosmic radiation. Earth-skimming nu(tau) may interact in the Earth's crust and produce a tau lepton by means of charged-current interactions. The tau lepton may emerge from the Earth and decay in the atmosphere to produce a nearly horizontal shower with a typical signature, a persistent electromagnetic component even at very large atmospheric depths. The search procedure to select events induced by tau decays against the background of normal showers induced by cosmic rays is described. The method used to compute the exposure for a detector continuously growing with time is detailed. Systematic uncertainties in the exposure from the detector, the analysis, and the involved physics are discussed. No tau neutrino candidates have been found. For neutrinos in the energy range 2x10(17) eV < E(nu)< 2x10(19) eV, assuming a diffuse spectrum of the form E(nu)(-2), data collected between 1 January 2004 and 30 April 2008 yield a 90% confidence-level upper limit of E(nu)(2)dN(nu tau)/dE(nu)< 9x10(-8) GeV cm(-2) s(-1) sr(-1).

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The concept of constitutional dynamic chemistry (CDC) based on the control of non-covalent interactions in supramolecular structures is promising for having a large impact on nanoscience and nanotechnology if adequate nanoscale manipulation methods are used. In this study, we demonstrate that the layer-by-layer (LbL) technique may be used to produce electroactive electrodes with ITO coated by tetrasulfonated nickel phthalocyanine (NiTsPc) alternated with poly(allylamine hydrochloride) (PAH) incorporating gold nanoparticles (AuNP), in which synergy has been achieved in the interaction between the nanoparticles and NiTsPc. The catalytic activity toward hydrogen peroxide (H(2)O(2)) in multilayer films was investigated using cyclic voltammetry, where oxidation of H(2)O(2) led to increased currents in the PAH-AuNP/NiTsPc films for the electrochemical processes associated with the phthalocyanine ring and nickel at 0.52 and 0.81 V vs. SCE, respectively, while for PAH/NiTsPc films (without AuNP) only the first redox process was affected. In control experiments we found out that the catalytic activity was not solely due to the presence of AuNP, but rather to the nanoparticles inducing NiTsPc supramolecular structures that favored access to their redox sites, thus yielding strong charge transfer. The combined effects of NiTsPc and AuNP, which could only be observed in nanostructured LbL films, point to another avenue to pursue within the CDC paradigm.

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Survey of the hymenopterous parasitoids (Insecta, Hymenoptera) from the Parque Estadual da Fonte Grande, Vitória, ES, Brazil. Parasitoids Hymenoptera were collected in a trail inside the Parque Estadual da Fonte Grande (20º17'51.7''S; 40º20'13.1''W), located in an area of the Atlantic Forest, during the period of June 2000 to July 2001. A total of 4,595 specimens, belonging to 28 families, have been collected. Braconidae, Eulophidae, and Scelionidae, were the most common families, with relative abundance of 22.5%, 14.32%, and 13.12%, respectively. Sixteen families showed the relative frequency lower than 1%. A preliminary list with 47 genera of some of the families is included.

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O livro encontra-se disponível na Biblioteca Central da Universidade. Financiamento Fundação de Apoio à Ciência e Tecnologia do Espírito Santo (FAPES).

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Rede é o nome dado para se referenciar qualquer forma que seja composta por linhas interligadas por pontos, sendo assim essa denominação é utilizada para participar de nomes e conceitos em diversas área do conhecimento. Na geografia isso não ocorre de forma diferente. As redes geográficas são a denominação dada as ligações feitas no espaço articuladas por pontos, notadamente são usadas para se fazer referência a redes materiais, mas podem ser mais imateriais ou abstratas a depender do objeto de pesquisa e do adjetivo adotado. A noção de redes urbanas nasceu vinculada aos objetos materiais, entretanto com a evolução da técnica passou a abranger objetos cada vez mais virtuais. As redes urbanas são compostas pelo conjunto de cidades, cada qual com sua centralidade representadas por pontos ou nós na rede, e pelas ligações entre elas, rodovias, hidrovias, infovias etc. As cidades que compõem a rede, por mais semelhanças que possam ter entre si, tem diferentes tipos e graus de centralidade, de poder de atração de pessoas, de recursos; sendo uma região de influência singular, que muda de tempos em tempos, face a evolução do território onde se insere. Tanto as centralidades quanto as redes de urbanas estão em constante mudança, necessitando sempre de atualização tornando o estudo das redes e das centralidades uma questão sempre nova; em especial quando considerado um território tão vasto e complexo como o brasileiro. Neste trabalho relatamos os resultados do estudo das especificidades da centralidade da cidade de Viçosa, que está localizada no interior do estado de Minas Gerais, Brasil. Este estudo fez uso de dados numéricos, fotográficos e cartográficos coletados em diversos momentos da evolução do município e da região onde este se insere, que revelaram as mudanças de qualidade e de intensidade na centralidade dessa cidade, hoje tipificada como média ou intermediária, inserida na rede urbana mineira. No período compreendido entre os anos de 1850 e 1930, Viçosa passou de uma inexpressiva localidade rural, a importante centro de produção de café, galgando ganhos políticos nesse período. Seguiu-se um período de menor pujança, por cerca de setenta anos, para depois, na virada do século XX para XXI, ressurgi como uma localidade especializada em oferecer serviços, notadamente vinculados ao ensino superior e à produção de ciência e tecnologia. Essa nova centralidade, ao contrário do que muitas vezes ocorre, não foi fruto nem de um recurso natural inerente ao território e nem, tão pouco, pela atuação de grandes grupos capitalistas. Foi galgado principalmente pela atuação do Estado que construiu ali as bases de uma especialização funcional, através da implantação de uma universidade pública.

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O presente trabalho visa estudar a ferramenta de comunicação interna de uma instituição pública de educação- um informativo digital, por meio da avaliação dos atributos necessários para que uma notícia seja divulgada neste veículo. Dessa maneira, se busca criar um documento com um elenco de valores-notícia que norteiem a seleção, produção e divulgação de notícias no informativo digital e, assim, contribuir para a melhoria da comunicação interna na organização. A avaliação das matérias e a criação deste documento utilizarão como referencial os valores-notícia já utilizados no jornalismo para definir o que é notícia.

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Tissue engineering applications rely on scaffolds that during its service life, either for in-vivo or in vitro applications, are under mechanical solicitations. The variation of the mechanical condition of the scaffold is strongly relevant for cell culture and has been scarcely addressed. Fatigue life cycle of poly-ε-caprolactone, PCL, scaffolds with and without fibrin as filler of the pore structure were characterized both dry and immersed in liquid water. It is observed that the there is a strong increase from 100 to 500 in the number of loading cycles before collapse in the samples tested in immersed conditions due to the more uniform stress distributions within the samples, the fibrin loading playing a minor role in the mechanical performance of the scaffolds

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This paper proposes a wireless EEG acquisition platform based on Open Multimedia Architecture Platform (OMAP) embedded system. A high-impedance active dry electrode was tested for improving the scalp- electrode interface. It was used the sigma-delta ADS1298 analog-to-digital converter, and developed a “kernelspace” character driver to manage the communications between the converter unit and the OMAP’s ARM core. The acquired EEG signal data is processed by a “userspace” application, which accesses the driver’s memory, saves the data to a SD-card and transmits them through a wireless TCP/IP-socket to a PC. The electrodes were tested through the alpha wave replacement phenomenon. The experimental results presented the expected alpha rhythm (8-13 Hz) reactiveness to the eyes opening task. The driver spends about 725 μs to acquire and store the data samples. The application takes about 244 μs to get the data from the driver and 1.4 ms to save it in the SD-card. A WiFi throughput of 12.8Mbps was measured which results in a transmission time of 5 ms for 512 kb of data. The embedded system consumes about 200 mAh when wireless off and 400 mAh when it is on. The system exhibits a reliable performance to record EEG signals and transmit them wirelessly. Besides the microcontroller-based architectures, the proposed platform demonstrates that powerful ARM processors running embedded operating systems can be programmed with real-time constrains at the kernel level in order to control hardware, while maintaining their parallel processing abilities in high level software applications.

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É possível encontrar nos mercados de valores mobiliários e/ou outros instrumentos financeiros e/ou nas chamadas bolsas de valores - éticas concretas, reais e definidas? Pensamos que sim. Os fundos éticos são apenas uma das espécies de fundos. Abstract: You can find in the securities markets and / or other financial instruments and / or in so-called exchanges - concrete ethical, real and defined? We think so. Ethical funds are only one species of funds.