Learning Objects (LOs) have evolved as a means to organize, encapsulate, and exchange reusable granules of learning material between different e-learning systems. A common problem encountered in practical situations is that conceptually coherent learning material may be distributed across several LOs, a problem which may originate in the way the material is decomposed into LOs. From a maintenan...

    Abstract   Background: Gastroenterologists are required to obtain consent before undertaking   any endoscopic examination. Published data indicate that in practice there are many deficiencies in this process. The aim of this survey was to determine the quality of information given to patients before the endoscopic procedures in Iran .   Methods: A structured questionnaire about patient's in...

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We perform event-driven molecular dynamics simulations of a system composed by uniaxial hard ellipsoids for different values of the aspect ratio and packing fraction. We compare the molecular orientational-dependent structure factors previously calculated within the Percus-Yevick approximation with the numerical results. The agreement between theoretical and numerical results is rather satisfac...

Perceptual multistability refers to cases where perception alternates between two or more interpretations of an unchanging sensory stimulus. In a first experiment we trained eight pigeons to discriminate horizontal and vertical apparent motion stimuli and then presented a multistable display. In five cases their behavior showed alternations similar to human experiments. In a second experiment w...

Single features such as line orientation and length are known to guide visual search, but relatively little is known about how multiple features combine in search. To address this question, we investigated how search for targets differing in multiple features (intensity, length, orientation) from the distracters is related to searches for targets differing in each of the individual features. We...

The Coulombic interaction in the oriented attachment growth of one-dimensional nanotubes is evaluated via a newly-derived analytical expression of the Coulombic interactions between a spherical attaching nanoparticle and a growing nanotube. The correlation between the interaction and the important growth parameters, including nanoparticle/nanotube size, aspect ratio, and nanoparticle-nanotube s...

Above a certain density threshold, suspensions of rodlike colloidal particles form system-spanning networks. Using Monte Carlo simulations, we investigate how the depletion forces caused by spherical particles affect these networks in isotropic suspensions of rods. Although the depletion forces are strongly anisotropic and favor alignment of the rods, the percolation threshold of the rods decre...

Far field X-ray grating interferometry achieves extraordinary phase sensitivity in imaging weakly absorbing samples, provided that the grating period is within the transverse coherence length of the X-ray source. Here we describe a cost-efficient process to fabricate large area, 100 nm half-pitch hard X-ray phase gratings with an aspect ratio of 32. The nanometric gratings are suitable for ordi...

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