肺原位腺癌手术与随访之争议解析

《WHO胸部肿瘤分类(第5版)》中的肺肿瘤分类目录把肺原位腺癌从腺癌目录中移出, 归类到腺体前驱病变。肺磨玻璃结节临床考虑原位腺癌时,如何进行临床决策更易造成偏差, 到底是随访还是手术值得思考, 过度诊疗和误诊误治同时存在。应充分理解肺原位腺癌的特性, 以较好的心态去应对, 从生物学及社会心理学两方面考虑, 不能治愈了一个肺癌, 但多了一个肺癌患者。建议在医患共同决策的前提下进行个体化方案制定, 使患者尽早回归社会, 最大可能使患者获益。

     

The shape of holes

The shape of holes can be recognized as accurately as the shape of objects (Palmer, S. E. (1999). Vision science: photons to phenomenology. Cambridge, MA: MIT Press), yet the area enclosed by a hole is a background region, and it can be demonstrated that background regions are not represented as having shape. What is therefore the shape of a hole, if any? To resolve this apparent paradox, we suggest that the shape of a hole is available indirectly from the shape of the surrounding object. We exploited the fact that observers are faster at judging the position of convex vertices than concave ones (Perception 30 (2001) 1295), and using a figural manipulation of figure/ground we found a reversal of the relative speeds when the same contours were presented as holes instead of objects. If contours were perceived as belonging to the hole rather than the surrounding object then there would have been no qualitative difference in responses to the object and hole stimuli. We conclude that the contour bounding a hole is automatically assigned to the surrounding object, and that a change in perception of a region from object to hole always drastically changes the encoded information. We discuss the many interesting aspects of holes as a subject of study in different disciplines and predict that much insight especially about shape will continue to come from holes.     

How owls structure visual information

Recent studies on perceptual organization in humans claim that the ability to represent a visual scene as a set of coherent surfaces is of central importance for visual cognition. We examined whether this surface representation hypothesis generalizes to a non-mammalian species, the barn owl (Tyto alba). Discrimination transfer combined with random-dot stimuli provided the appropriate means for a series of two behavioural experiments with the specific aims of (1) obtaining psychophysical measurements of figure–ground segmentation in the owl, and (2) determining the nature of the information involved. In experiment 1, two owls were trained to indicate the presence or absence of a central planar surface (figure) among a larger region of random dots (ground) based on differences in texture. Without additional training, the owls could make the same discrimination when figure and ground had reversed luminance, or were camouflaged by the use of uniformly textured random-dot stereograms. In the latter case, the figure stands out in depth from the ground when positional differences of the figure in two retinal images are combined (binocular disparity). In experiment 2, two new owls were trained to distinguish three-dimensional objects from holes using random-dot kinematograms. These birds could make the same discrimination when information on surface segmentation was unexpectedly switched from relative motion to half-occlusion. In the latter case, stereograms were used that provide the impression of stratified surfaces to humans by giving unpairable image features to the eyes. The ability to use image features such as texture, binocular disparity, relative motion, and half-occlusion interchangeably to determine figure–ground relationships suggests that in owls, as in humans, the structuring of the visual scene critically depends on how indirect image information (depth order, occlusion contours) is allocated between different surfaces. Electronic Publication     

Marxism after the Collapse of the Soviet Union

The article studies the implications for historical materialism of the failure of the socialist project in the Soviet Union. The author demonstrates that the said failure broadly confirms central historical materialist theses, which would have been difficult to sustain if the Russian revolution had succeeded in its goal of superseding capitalism and establishing a socialist society.     

生命进化动力之哲学思考

对生命进化的本质问题作了新的哲学思考,提出进化的本质是物种在生存的驱动下生存效率的优化过程,是原始细胞自主性与环境选择的双向过程。同时提出推动物种进化的动力在于生存资源稀缺性与物种自私性之间的矛盾和多细胞物种效率优化过程中自身的局部利益与整体利益之间的矛盾。