948 resultados para Machines à vecteurs supports
Resumo:
The Self-regulation Skills Interview (SRSI) is a clinical tool designed to measure a range of metacognitive skills essential for rehabilitation planning, monitoring an individual's progress, and evaluating the outcome of treatment interventions. The results of the present study indicated that the SRSI has sound interrater reliability and test-retest reliability. A principle components analysis revealed three SRSI factors: Awareness, Readiness to Change, and Strategy Behavior. A comparison between a group of 61 participants with acquired brain injury (ABI) and a group of 43 non-brain-injured participants indicated that the participants with ABI had significantly lower levels of Awareness and Strategy Behavior, but that level of Readiness to Change was not significantly different between the two groups. The significant relationship observed between the SRSI factors and measures of neuropsychological functioning confirmed the concurrent validity of the scale and supports the value of the SRSI for post-acute assessment.
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The chondroitin sulfate proteoglycans neurocan and phosphacan are believed to modulate neurite outgrowth by binding to cell adhesion molecules, tenascin, and the differentiation factors heparin-binding growth-associated molecule and amphoterin. To assess the role of these chondroitin sulfate proteoglycans in the olfactory system, we describe here their expression patterns during both embryonic and postnatal development in the mouse. Immunoreactivity for neurocan was first detected in primary olfactory neurons at embryonic day 11.5 (E11.5). Neurocan was expressed by primary olfactory axons as they extended toward the rostral pole of the telencephalon as well as by their arbors in glomeruli after they contacted the olfactory bulb. The role of neurocan was examined by growing olfactory neurons on an extracellular matrix substrate containing neurocan or on extracellular matrix in the presence of soluble neurocan. In both cases, neurocan strongly promoted neurite outgrowth. These results suggest that neurocan supports the growth of primary olfactory axons through the extracellular matrix as they project to the olfactory bulb during development. Phosphacan, unlike neurocan, was present within the mesenchyme surrounding the E11.5 and E12.5 nasal cavity. This expression decreased at E13.5, concomitant with a transient appearance of phosphacan in nerve fascicles. Within the embryonic olfactory bulb, phosphacan was localised to the external and internal plexiform layers. However, during early postnatal development phosphacan was concentrated in the glomerular layer. These results suggest that phosphacan may play a role in delineating the pathway of growing olfactory axons as well as defining the laminar organization of the bulb. Together, the spatiotemporal expression patterns of neurocan and phosphacan indicate that these chondroitin sulfate proteoglycans have diverse in situ roles, which are dependent on context-specific interactions with extracellular and cell adhesion molecules within the developing olfactory nerve pathway. (C) 2000 Wiley-Liss, Inc.
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Catalytic reforming of methane with carbon dioxide was studied in a fixed-bed reactor using unpromoted and promoted Ni/gamma-Al2O3 catalysts. The effects of promoters, such as alkali metal oxide (Na2O), alkaline-earth metal oxides (MgO, CaO) and rare-earth metal oxides (La2O3, CeO2), on the catalytic activity and stability in terms of coking resistance and coke reactivity were systematically examined. CaO-, La2O3- and CeO2-promoted Ni/gamma-Al2O3 catalysts exhibited higher stability whereas MgO- and Na2O-promoted catalysts demonstrated lower activity and significant deactivation. Metal-oxide promoters (Na2O, MgO, La2O3, and CeO2) suppressed the carbon deposition, primarily due to the enhanced basicities of the supports and highly reactive carbon species formed during the reaction. In contrast, CaO increased the carbon deposition; however, it promoted the carbon reactivity. (C) 2000 Society of Chemical Industry.
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Objective: To determine whether electromyographic (EMG) onsets of vastus medialis obliquus (VMO) and vastus lateralis (VL) are altered in the presence of patellofemoral pain syndrome (PFPS) during the functional task of stair stepping. Design: Cross-sectional. Setting: University laboratory. Patients: Thirty-three subjects with PFPS and 33 asymptomatic controls. Interventions: Subjects ascended and descended a set of stairs-2 steps, each 20-cm high-at usual stair-stepping pace. EMG readings of VMO and VL taken on middle stair during step up (concentric contraction) and step down (eccentric contraction). Main Outcome Measures: Relative difference in onset of surface EMG activity of VMO compared with VL during a stair-stepping task. EMG onsets were determined by using a computer algorithm and were verified visually. Results: In the PFPS population, the EMG onset of VL occurred before that of VMO in both the step up and step down phases of the stair-stepping task (p < .05). In contrast, no such differences occurred in the onsets of EMG activity of VMO and VL in either phase of the task for the control subjects. Conclusion: This finding supports the hypothesized relationship between changes in the timings of activity of the vastimuscles and PFPS. This finding provides theoretical rationale to support physiotherapy treatment commonly used in the management of PFPs.
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Coating anatase TiO2 onto three different particle supports, activated carbon (AC), gamma -alumina (Al2O3) and silica gel (SiO2), by chemical vapor deposition (CVD) was studied. The effect of the CVD synthesis conditions on the loading rate of anatase TiO2 was investigated. It was found that introducing water vapor during CVD or adsorbing water before CVD was crucial to obtain anatase TiO2 on the surface of the particle supports. The evaporation temperature of precursor, deposition temperature in the reactor, flow rate of carrier gas, and the length of coating time were also important parameters to obtain more uniform and repeatable TiO2 coating. High inflow precursor concentration, high CVD reactor temperature and long coating time tended to cause block problem. Coating TiO2 onto small particles by CVD involved both chemical vapor deposition and particle deposition. It was believed that the latter was the reason for the block problem. In addition, the mechanism of CVD process in this study included two parts, pyrolysis and hydrolysis, and one of them was dominant in the CVD process under different synthesis route. Among the three types of materials, silica gel, with higher surface hydroxyl groups and macropore surface area, was found to be the most efficient support in terms of both anatase TiO2 coating and photocatalytic reaction. (C) 2001 Elsevier Science B.V. All rights reserved.
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From an experiment in which corals are transplanted between two depths on a Panamanian coral reef, Baker1 infers that bleaching may sometimes help reef corals to survive environmental change. Although Baker's results hint at further mechanisms by which reef-building corals may acclimatize to changing light conditions, we do not consider that the evidence supports his inference.
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The objective of he article is to research the dynamic capacities developed and used by WEG in its internationalization process and to explain how these capacities help the company defends and supports competitive advantage. The article presents an exploratory study of the internationalization process of WEG in Argentina and China. This article has as analysis approach the dynamic capacities, contributes to the literature of international management in two aspects. First, it adds the analytical look of the internationalization based on dynamic capacities that are still well restricted. Second, when working the dynamic capacities as central element of the analysis of the internationalization process, it Proposes one framework of integrative analysis of the economic and behavioral theories that are used to explain the process of companies`-internationalization, although they are dealt independently and sometimes antagonistic way. The result shows as the dynamic capacities are articulated in the base of WEG in its process of internationalization for Argentina and the subsequent movement for China. The developed dynamic capacities in Argentina were acquired for the Brazilian headquarter and could have been applied in the process of internationalization for China. However, a more complex organizational structure cannot be identified where the inter-subsidiary relationships could share dynamic capacities as proposed in framework.
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We introduced a spectral clustering algorithm based on the bipartite graph model for the Manufacturing Cell Formation problem in [Oliveira S, Ribeiro JFF, Seok SC. A spectral clustering algorithm for manufacturing cell formation. Computers and Industrial Engineering. 2007 [submitted for publication]]. It constructs two similarity matrices; one for parts and one for machines. The algorithm executes a spectral clustering algorithm on each separately to find families of parts and cells of machines. The similarity measure in the approach utilized limited information between parts and between machines. This paper reviews several well-known similarity measures which have been used for Group Technology. Computational clustering results are compared by various performance measures. (C) 2008 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.
Resumo:
A graph clustering algorithm constructs groups of closely related parts and machines separately. After they are matched for the least intercell moves, a refining process runs on the initial cell formation to decrease the number of intercell moves. A simple modification of this main approach can deal with some practical constraints, such as the popular constraint of bounding the maximum number of machines in a cell. Our approach makes a big improvement in the computational time. More importantly, improvement is seen in the number of intercell moves when the computational results were compared with best known solutions from the literature. (C) 2009 Elsevier Ltd. All rights reserved.
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Exponential and sigmoidal functions have been suggested to describe the bulk density profiles of crusts. The present work aims to evaluate these conceptual models using high resolution X-radiography. Repacked seedbeds from two soil materials, air-dried or prewetted by capillary rise, were subjected to simulated rain, which resulted in three types of structural crusts, namely, slaking, infilling, and coalescing. Bulk density distributions with depth were generated using high-resolution (70 mum), calibrated X-ray images of slices from the resin-impregnated crusted seedbeds. The bulk density decreased progressively with depth, which supports the suggestion that a crust should be considered as a nonuniform layer. For the slaking and the coalescing crusts, the exponential function underestimated the strong change in bulk density across the morphologically defined transition between the crust and the underlying material; the sigmoidal function provided a better description. Neither of these crust models effectively described the shape of the bulk density profiles through the whole seedbed. Below the infilling and slaking crusts, bulk density increased linearly with depth as a result of slumping. In the coalescing crusted seedbed, the whole seedbed uniformly collapsed and most of the bulk density change within the crust could be ascribed to slumping (0.33 g cm(-3)) rather than to crusting (0.12 g cm(-3)). Finally, (i) X-radiography appears as a unique tool to generate high resolution bulk density profiles and (ii) in structural crusts, bulk density profiles could be modeled using the existing exponential and sigmoidal crusting models, provided a slumping model would be coupled.
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Fear relevance, the potential of a stimulus to become quickly associated with fear, is a characteristic assumed to have an evolutionary basis and to result in preferential processing. Previous research has shown that fear relevant stimuli share a number of characteristics, negative valence and preferential identification in a visual search task, for instance. The present research examined whether these two characteristics can be acquired by non-fear relevant stimuli (geometric shapes) as a result of Pavlovian fear conditioning. Two experiments employed an aversive learning paradigm with geometric shape CSs and a shock US, with stimulus ratings, affective priming and visual search performance assessed before and after acquisition and after extinction. Differential electrodermal responses, larger during CS1 than CS, were present during acquisition but not during extinction. Affective priming results suggest that the CS1 acquired negative valence during acquisition, which was lost during extinction. However, negative valence as indexed by more negative ratings for CS1 than for CS shapes seemed to survive extinction. Preferential attentional processing as indexed by faster detection of CS1 among CS shapes than vice versa on the visual search task also remained. The current research confirmed that characteristics of fear relevant stimuli can be acquired in an aversive learning episode and that they may be extinguished. This supports the proposal that fear relevance may be malleable through learning.
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The fabrication of heavy-duty printer heads involves a great deal of grinding work. Previously in the printer manufacturing industry, four grinding procedures were manually conducted in four grinding machines, respectively. The productivity of the whole grinding process was low due to the long loading time. Also, the machine floor space occupation was large because of the four separate grinding machines. The manual operation also caused inconsistent quality. This paper reports the system and process development of a highly integrated and automated high-speed grinding system for printer heads. The developed system, which is believed to be the first of its kind, not only produces printer heads of consistently good quality, but also significantly reduces the cycle time and machine floor space occupation.
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This work describes the catalytic activity of manganese and iron porphyrins, Mn and Fe(TFPP)Cl, covalently immobilized on the aminofunctionalized supports montmorillonite K-10 (MontX) and silica (SilX), where X= 1 or 2 represents the length of the organic chain (""arms"") binding the metalloporphyrin to the support. These systems were characterized by UV-vis and Electronic Paramagnetic Resonance (EPR), and they were used as catalysts in the oxidation of carbamazepine (CBZ) by the oxidants iodosylbenzene (PhIO) and hydrogen peroxide. The manganese porphyrin (MnP) catalysts proved to be efficient and selective for the epoxide, the main CBZ metabolite in natural systems. MnMont1 was an excellent catalyst when PhIO was used as oxidant, even better than the same MnP in homogeneous system. Supports bearing short ""arms"" led to the best yields. Although H2O2 is an environmentally friendly oxidant, low product yields were obtained when it was employed in CBZ oxidation. Fe(TFPP)CI immobilized on aminofunctionalized supports was not an efficient catalyst, probably due to the presence of Fe(H) species in the matrix, which led to the less reactive intermediate PFe(IV)(O). (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
Electrical or chemical stimulation of the inferior colliculus (IC) induces fear-like behaviors. More recently, consistent evidence has shown that electrical stimulation of the central nucleus of the IC supports Pavlovian conditioning and latent inhibition (Li). LI is characterized by retardation in conditioning and also by an impaired ability to ignore irrelevant stimuli, after a non-reinforced pre-exposure to the conditioned stimulus. LI has been proposed as a behavioral model of cognitive abnormalities seen in schizophrenia. The aim of the present study was to determine whether dopaminergic mechanisms in the IC are involved in LI of the conditioned emotional response (CER). To induce LI, a group of rats was pre-exposed (PE) to six tones in two sessions, while rats that were not pre-exposed (NPE) had two sessions without tone presentations. The conditioning consisted of two tone presentations to the animal, followed immediately by a foot shock. PE and NPE rats received IC microinjections of physiological saline, the dopaminergic agonist apomorphine (9.0 mu g/0.5 mu L/side), or the dopaminergic antagonist haloperidol (0.5 mu g/0.5 mu L/side) before both pre-exposure and conditioning. During the test, the PE rats that received saline or haloperidol had a lower suppression of the licking response compared to NPE rats that received vehicle or haloperidol, indicating that latent inhibition was induced. There was no significant difference in the suppression ratio in rats that received apomorphine injections into the IC, indicating reduced latent inhibition. These results suggest that dopamine-mediated mechanisms of the IC are involved in the development of LI. (C) 2008 Elsevier Inc. All rights reserved.
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Stibadocerina Alexander, a monotypic genus, includes the only known Neotropical species of the family Cylindrotomidae, S. chilensis Alexander, 1929, from South Central Chile (ca. 36 degrees 50`S-42 degrees 17`S). In this paper, Stibadocerina chilensis is redescribed and illustrated in detail. A study of wing-vein homology in the subfamily Stibadocerinae is provided, to identify the components of the reduced radial sector in Stibadocerina and related taxa. The proposed hypotheses of wing-vein homology are tested, and the systematic position of Stibadocerina is assessed through a cladistic analysis of 13 characters of the male imago, scored for exemplar species of the four genera included in the Stibadocerinae. A single most parsimonious tree supports the monophyly of the Stibadocerinae and the following relationships among its included genera: Stibadocerodes [Stibadocera (Stibadocerella + Stibadocerina)]. The subfamily includes one example of a vicariant distribution with a sister-group relationship between South Central Chilean and East Asian taxa, and supports a biogeographical interpretation of an ancestral trans-Pacific biota.