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61.
This paper proposes a research direction to study the development of ‘artificial social intelligence’ of autonomous robots which should result in ‘individualized robot societies’. The approach is highly inspired by the ‘social intelligence hypothesis’, derived from the investigation of primate societies, suggesting that primate intelligence originally evolved to solve social problems and was only later extended to problems outside the social domain. We suggest that it might be a general principle in the evolution of intelligence, applicable to both natural and artificial systems. Arguments are presented why the investigation of social intelligence for artifacts is not only an interesting research issue for the study of biological principles, but may be a necessary prerequisite for those scenarios in which autonomous robots are integrated into human societies, interacting and communicating both with humans and with each other. As a starting point to study experimentally the development of robots' ‘social relationships’, the investigation of collection and use of body images by means of imitation is proposed. A specific experimental setup which we use to test the theoretical considerations is described. The paper outlines in what kind of applications and for what kind of robot group structures social intelligence might be advantageous.  相似文献   
62.
Long edge glass knives, ‘Ralph knives’, were produced in an LKB Histo KnifeMaker. The edge angles were measured by light microscopy; depending on the breaking conditions the angles varied between 12° and 58°, as measured close to the edge in the mid-portion of the knives. Hackle marks were more common in the left portion of the edge than in the middle and right portions. Some of the knives were used for cutting sections from urinary bladder tumours embedded in paraffin or in glycol methacrylate. Following microtomy the sections were allowed to stretch on a water surface; this procedure resulted in an increased width of the plastic sections, whereas the paraffin sections were not affected. The compression of the whole sections averaged 15% in the paraffin sections and 11% in the plastic sections; in both cases the compression factors were positively correlated to the angle of the knife edge. Smaller compression factors were found for the cell nuclei in the embedded tissue.  相似文献   
63.
In the subcortical auditory system of Rhinolophus rouxi, antibodies directed against the calcium-binding proteins parvalbumin, calbindin D-28k, and calretinin yield partly overlapping and partly complementary labeling patterns which are described in detail for each nucleus. The most general features of the labeling patterns are that: 1) Parvalbumin is a potent marker for large and heterogeneous populations of cells and puncta (presumed axon terminals) throughout the auditory pathway. 2) Immunostaining with the monoclonal calbindin-antiserum was typically absent or sparse in most auditory brainstem centers, but prominent in auditory nerve fibers and in cells of the medial geniculate body (MGB). 3) Calretinin label is abundant but more restricted to subsets of auditory nuclei or subpopulations of cells than parvalbumin. 4) Calcium-binding proteins are useful markers to define particular subregions or cell types in auditory nuclei: for example, i) different labeling patterns are obtained within the nuclei of the lateral lemniscus and adjacent tegmental zones; ii) in the inferior colliculus both calbindin- and calretinin-antisera yield similar regional specific staining patterns, but label different cell types; iii) subregions of the medial geniculate body have characteristic profiles of calcium-binding proteins; and iv) analyses of different nuclei showed that there is no simple common denominator for cells characterized by the expression of particular calcium-binding proteins, nor does labeling correspond in a straightforward way with specific functional systems. 5) there are profound differences between the calbindin labeling patterns seen in Rhinolophus and those in other mammals.  相似文献   
64.
Larval insect herbivores feeding externally on leaves are vulnerable to numerous and varied enemies. Larvae of the Neotropical herbivore, Chelymorpha alternans (Chrysomelidae:Cassidinae), possess shields made of cast skins and feces, which can be aimed and waved at attacking enemies. Prior work with C. alternans feeding on Merremia umbellata (Convolvulaceae) showed that shields offered protection from generalist predators, and polar compounds were implicated. This study used a ubiquitous ant predator, Azteca lacrymosa, in field bioassays to determine the chemical constitution of the defense. We confirmed that intact shields do protect larvae and that methanol-water leaching significantly reduced shield effectiveness. Liquid chromatography-mass spectrometry (LC-MS) of the methanolic shield extract revealed two peaks at 20.18 min and 21.97 min, both with a molecular ion at m/z 593.4, and a strong UV absorption around 409 nm, suggesting a porphyrin-type compound. LC-MS analysis of a commercial standard confirmed pheophorbide a (Pha) identity. C. alternans shields contained more than 100 μg Pha per shield. Shields leached with methanol-water did not deter ants. Methanol-water-leached shields enhanced with 3 μg of Pha were more deterrent than larvae with solvent-leached shields, while those with 5 μg additional Pha provided slightly less deterrence than larvae with intact shields. Solvent-leached shields with 10 μg added Pha were comparable to intact shields, even though the Pha concentration was less than 10% of its natural concentration. Our findings are the first to assign an ecological role for a chlorophyll catabolite as a deterrent in an insect defense.  相似文献   
65.
B6O is a possible candidate of superhard materials with a hardness of 45 GPa measured on single crystals. Up to now, densification of these materials was only possible at high pressure. However, recently it was found that Al2O3 can be utilized as an effective sintering additive, similar to the addition of Y2O3/Al2O3 that was used in this work. The densification behavior of the material as a function of applied pressure, its microstructure evolution, and the resulting mechanical properties were investigated. A strong dependence of the densification with increasing pressure was found. The material revealed characteristic triple junctions filled with amorphous residue composed of B2O3, Al2O3, and Y2O3, while no amorphous grain-boundary films were observed along internal interfaces. Mechanical testing revealed on average a hardness of 33 GPa, a fracture toughness of 4 MPa·m1/2, and a strength value of 520 MPa.  相似文献   
66.
67.
A new pseudoreceptor modeling method (PRPS) was applied to the refinement of a homology model of the human histamine H4 receptor (H4R), the prediction of a ligand binding site, and virtual screening. Retrieval of two new H4R ligands demonstrates the biological relevance of the pseudoreceptor model and provides a means for finding new hits and leads in the early phases of drug discovery.

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68.
To warp diffusion tensor fields accurately, tensors must be reoriented in the space to which the tensors are warped based on both the local deformation field and the orientation of the underlying fibers in the original image. Existing algorithms for warping tensors typically use forward mapping deformations in an attempt to ensure that the local deformations in the warped image remains true to the orientation of the underlying fibers; forward mapping, however, can also create ldquoseamsrdquo or gaps and consequently artifacts in the warped image by failing to define accurately the voxels in the template space where the magnitude of the deformation is large (e.g., |Jacobian| > 1). Backward mapping, in contrast, defines voxels in the template space by mapping them back to locations in the original imaging space. Backward mapping allows every voxel in the template space to be defined without the creation of seams, including voxels in which the deformation is extensive. Backward mapping, however, cannot reorient tensors in the template space because information about the directional orientation of fiber tracts is contained in the original, unwarped imaging space only, and backward mapping alone cannot transfer that information to the template space. To combine the advantages of forward and backward mapping, we propose a novel method for the spatial normalization of diffusion tensor (DT) fields that uses a bijection (a bidirectional mapping with one-to-one correspondences between image spaces) to warp DT datasets seamlessly from one imaging space to another. Once the bijection has been achieved and tensors have been correctly relocated to the template space, we can appropriately reorient tensors in the template space using a warping method based on Procrustean estimation.  相似文献   
69.
Potato is one of the world's most widely grown tuber crop, in which starch is the predominant form of carbohydrates. Potatoes can be prepared in many ways: boiled, fried or roasted. Frying and roasting potatoes at high temperatures result in an appetizing crust, but at the same time acrylamide can form. In this study, the concentrations of the acrylamide precursors, asparagine and sugars, were determined in five different Swedish-grown potato varieties, together with the acrylamide content after typical home-cooking procedures; oven-roasting of potato wedges and pan-frying of cubes of boiled potatoes. Pan-frying of boiled potato cubes resulted in higher levels of acrylamide (530-1100 microg/kg) than in the wedges (140-250 microg/kg). Blanching combined with a shorter roasting time was shown to be an efficient way of reducing the acrylamide content in roasted potato wedges, especially in the experiments performed after long-term storage, where the acrylamide content was reduced from 110-260 to 50-140 microg/kg. No correlation was found between precursor content and acrylamide content, and this finding emphasizes the need for further studies on factors affecting acrylamide formation, for example, the availability of precursors at the surface during cooking.  相似文献   
70.
A survey of benzene contamination of 451 beverage samples, using headspace sampling combined with gas chromatography and mass spectrometry (HS-GC/MS) with a quantification limit of 0.13 microg l(-1), was conducted. Artefactual benzene formation during headspace sampling was excluded by gentle heating at 50 degrees C only and adjustment of sample pH to 10. The incidence of benzene contamination in soft drinks, beverages for babies, alcopops and beer-mixed drinks was relatively low, with average concentrations below the EU drinking-water limit of 1 microg l(-1). Significantly higher concentrations were only found in carrot juice, with the highest levels in carrot juice specifically intended for infants. About 94% of 33 carrot juice for infants had detectable benzene levels, with an average concentration of 1.86 +/- 1.05 microg l(-1). Benzene contamination of beverages was significantly correlated to iron and copper concentrations, which act as catalyst in benzene formation. The formation of benzene in carrot juice was predominantly caused by a heat-induced mechanism, which explains the higher levels in infant carrot juices that are subject to higher heat-treatment to exclude microbiological contamination.  相似文献   
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