Interocular rivalry revealed in the human cortical blind-spot representation

To understand conscious vision, scientists must elucidate how the brain selects specific visual signals for awareness. When different monocular patterns are presented to the two eyes, they rival for conscious expression such that only one monocular image is perceived at a time. Controversy surrounds whether this binocular rivalry reflects neural competition among pattern representations or monocular channels. Here we show that rivalry arises from interocular competition, using functional magnetic resonance imaging of activity in a monocular region of primary visual cortex corresponding to the blind spot. This cortical region greatly prefers stimulation of the ipsilateral eye to that of the blind-spot eye. Subjects reported their dominant percept while viewing rivalrous orthogonal gratings in the visual location corresponding to the blind spot and its surround. As predicted by interocular rivalry, the monocular blind-spot representation was activated when the ipsilateral grating became perceptually dominant and suppressed when the blind-spot grating became dominant. These responses were as large as those observed during actual alternations between the gratings, indicating that rivalry may be fully resolved in monocular visual cortex. Our findings provide the first physiological evidence, to our knowledge, that interocular competition mediates binocular rivalry, and indicate that V1 may be important in the selection and expression of conscious visual information.     

Conservation of Y-linked genes during human evolution revealed by comparative sequencing in chimpanzee

The human Y chromosome, transmitted clonally through males, contains far fewer genes than the sexually recombining autosome from which it evolved. The enormity of this evolutionary decline has led to predictions that the Y chromosome will be completely bereft of functional genes within ten million years. Although recent evidence of gene conversion within massive Y-linked palindromes runs counter to this hypothesis, most unique Y-linked genes are not situated in palindromes and have no gene conversion partners. The 'impending demise' hypothesis thus rests on understanding the degree of conservation of these genes. Here we find, by systematically comparing the DNA sequences of unique, Y-linked genes in chimpanzee and human, which diverged about six million years ago, evidence that in the human lineage, all such genes were conserved through purifying selection. In the chimpanzee lineage, by contrast, several genes have sustained inactivating mutations. Gene decay in the chimpanzee lineage might be a consequence of positive selection focused elsewhere on the Y chromosome and driven by sperm competition.     

《新规则》与《部门立卷制度》在高校奇怪践行解析

《部门立卷制度》与《新规则》是在不同层面对档案工作进行规范化管理的指导性规范文献,档案工作应该同时而且全面加以贯彻执行,然而高校并非如此践行,执行二选一的奇怪践行方式,笔者对这一做法提出质疑,从而根据高校这种怪践产生的原因提出自己独到的解决策略。     

Domain organization of human chromosomes revealed by mapping of nuclear lamina interactions

The architecture of human chromosomes in interphase nuclei is still largely unknown. Microscopy studies have indicated that specific regions of chromosomes are located in close proximity to the nuclear lamina (NL). This has led to the idea that certain genomic elements may be attached to the NL, which may contribute to the spatial organization of chromosomes inside the nucleus. However, sequences in the human genome that interact with the NL in vivo have not been identified. Here we construct a high-resolution map of the interaction sites of the entire genome with NL components in human fibroblasts. This map shows that genome-lamina interactions occur through more than 1,300 sharply defined large domains 0.1-10 megabases in size. These lamina-associated domains (LADs) are typified by low gene-expression levels, indicating that LADs represent a repressive chromatin environment. The borders of LADs are demarcated by the insulator protein CTCF, by promoters that are oriented away from LADs, or by CpG islands, suggesting possible mechanisms of LAD confinement. Taken together, these results demonstrate that the human genome is divided into large, discrete domains that are units of chromosome organization within the nucleus.     

“个体”与“集体”的双重变奏——论“山药蛋”派的农村叙事

“山药蛋”派的农村叙事在农村小说的写作史上自成一支，蕴涵在其中的个体与集体之间的关系从以土地为代表的自然和集体茏罩下的个体两方面得到了呈示。这种双重的变奏显现在“山药蛋”派的创作中．构成了一种内在的标识。     

庄子与荀子“天人观”比较

庄子与荀子的"天人观"既有一定的相通性,又有各自十分迥异的特色。庄子与荀子的"天人观"都突出了"天"的客观性,不同的是庄子最终走向"天人合一",而荀子走向"天人之分"。比较庄子与荀子的"天人观",可以看出庄子道家立场和荀子儒家立场的不同,"天人观"的差异反映出庄子与荀子思维方式的根本差异。