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Bresenham’s algorithm for plotting a two-dimensional line segment is elegant and efficient in its deployment of mid-point comparison and integer arithmetic. It is natural to investigate its three-dimensional extensions. In so doing, this paper uncovers the reason for little prior work. The concept of the mid-point in a unit interval generalizes to that of nearest neighbours involving a Voronoi diagram. Algorithmically, there are challenges. While a unit interval in two-dimension becomes a unit square in three-dimension, “squaring” the number of choices in Bresenham’s algorithm is shown to have difficulties. In this paper, the three-dimensional extension is based on the main idea of Bresenham’s algorithm of minimum distance between the line and the grid points. The structure of the Voronoi diagram is presented for grid points to which t...
Several of the major processes that result in N loss from soil (nitrification, ammonia volatilization, and denitrification) discriminate against ¹⁵N and fractionate the stable N isotopes, thus δ¹⁵N of ecosystem components has been suggested as an indicator of ecosystem N leakiness. This concept has been applied more successfully to native systems (primarily forest) than to managed systems where N inputs are greater and N cycling processes have potentially been modified. We analysed 210 New Zealand soils (0–100 mm depth) from different land-use systems (increasing in intensity of land use management from indigenous, to plantation forestry, pasture under drystock, pasture under dairy, and cropping) for δ¹⁵N and measures of N availability (total N, C/N, and N mineralization) to determine whether increasing intensity of land use management...
Male Wistar rats received bilateral Fimbria lesions and were postoperatively housed in either standard social conditions or in impoverished conditions (one rat per cage) for 2 weeks in experiment I, and for 7 months in experiment II. The effects of lesion and housing conditions were investigated in the Morris maze spatial orientation task. Fimbria lesions increased the latency to reach the platform during acquisition in both experiments, which indicates that functional recovery of the Morris maze impairment does not occur in 7 months time. Post-operative impoverishment for 2 weeks or for 7 months reduced the lesion induced deficit in Morris maze acquisition, while it had a more general effect in the trial without platform. Interestingly, the impoverishment effects were not more severe after 7 months, but even less easily detected. Thes...
Lack of dystrophin in mdx mice leads to muscle fibre degeneration followed by the formation of new myofibres. This degeneration—regeneration event occurs in clusters. It is accompanied by inflammation and remodelling of the intramuscular terminal nerve fibres. Since the growth-associated protein B-50/GAP-43 has been shown to be involved in axonal outgrowth and synaptic remodelling following neuronal injury, we have investigated the presence of B-50 in gastrocnemius and quadriceps muscles of mdx mice. Using immunocytochemistry we demonstrate increased presence of B-50 in terminal nerve branches at motor endplates of mdx mice, particularly in the clusters of de- and regenerating myofibres. In comparison, the control mice displayed no B-50 immunoreactivity in nerve fibres contacting motor endplates. Our findings indicate that during axona...
An alternative to the usual vierbein field in a (3 + 1)-dimensional (euclidean) space-time is proposed such that the internal index takes only three values and the external is a double: ea = −ea. In flat space-time this field reduces to the self-dual generalized Levi-Civita symbol a. Like the vierbein field, our field determines the metric field g uniquely. It can be viewed upon as the 'cube root' of the metric field. In euclidean space the internal symmetry group is SL(3). In Minkowski space, in a sense to be explained, the internal symmetry group is SU(3). The Einstein-Hilbert action takes an elegant form in terms of this new field.
The molecular composition of five brown coals from three different basins (Maestrazgo, Mequinenza and Rubielos) in Spain was investigated by flash pyrolysis-gas chromatography and flash pyrolysis-gas chromatography-mass spectrometry. In these techniques, the macromolecular material is thermally degraded in an inert atmosphere and the compounds formed are on-line separated, identified and quantified. This information provided insight into the macromolecular structure of the coals which was inaccesible by other means. The composition of the pyrolysates is described in detail with emphasis on the distributions and relative abundance of n-alkanes, n-1-alkanes, (alkyl)phenols, sulphur compounds [(alkyl)thiophenes and (alkyl)benzenes and (alkyl)naphthalenes. These compound classes represent the major pyrolysis products of the samples analyse...
Diagnosis is a basic issue of any fault-tolerance policy. Fault localization within the neural architecture is necessary to provide information for hardware reconfiguration in order to achieve system survival, possibly with reduced computational capabilities. In this paper, a comprehensive approach to architectural fault-tolerant design of neural networks is proposed and evaluated, with specific reference to concurrent high-level diagnosis and fault localization. The approach refers to the operational life of trained neural networks. Two error detection techniques are applied: on-line concurrent diagnosis with the use of data coding for error detection at neuron level and on-line compact testing for localization of the faulty neuron within the network.
An ultrasound-assisted method was used for synthesizing nanosized Pt–graphene oxide (GO)–TiO2 photocatalyst. The Pt–GO–TiO2 nanoparticles were characterized by diffused reflectance spectroscopy, X-ray diffraction, N2 BET adsorption–desorption measurements, atomic force microscopy and transmission electron microscopy. The photocatalytic and sonophotocatalytic degradation of a commonly used anionic surfactant, dodecylbenzenesulfonate (DBS), in aqueous solution was carried out using Pt–GO–TiO2 nanoparticles in order to evaluate the photocatalytic efficiency. For comparison purpose, sonolytic degradation of DBS was carried out. The Pt–GO–TiO2 catalyst degraded DBS at a higher rate than P–25 (TiO2), prepared TiO2 or GO–TiO2 photocatalysts. The mineralization of DBS was enhanced by a factor of 3 using Pt–GO–TiO2 compared to the P–25 (TiO2). ...
The paper shows the impact of privatization and liberalization on consumers in the telecommunication sector for 15 EU countries. Policy reforms are summarized by the OECD regulatory indicators (REGREF) that consider the extent of privatization, vertical disintegration, and market entry. After controlling for other country variables, first, a test of the impact of ownership and regulatory changes on consumer prices is given. In the second step, the Eurobarometer data on consumers' satisfaction about quality and prices of the telecommunication service are considered. The analysis confirms the importance of market regulation in reducing prices but minimizes the role played by privatization per se. Overall, the findings offer only mixed evidence, and somehow contradict, the hypothesis that all the reforms work in a similar way across the E...
Background: Glycated hemoglobin (HbA1c) has a key role for diagnosing diabetes and monitoring glycemic state. As recently reviewed, available data on HbA1c biological variation show marked heterogeneity. Here we experimentally revaluated these data using a well designed protocol. Methods: We took five EDTA whole blood specimens from 18 apparently healthy subjects on the same day, every two weeks for two months. Samples were stored at −80 °C until analysis and assayed in duplicate in a single run by Roche Tina-quant® Gen.2 immunoassay. Data were analyzed by the ANOVA. To assess the assay traceability to the IFCC reference method, we preliminarily carried out a correlation experiment. Results: The bias (mean±SD) of the Roche immunoassay was 0.3%±0.7%, confirming the traceability of the employed assay. No difference was found in HbA1c val...
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