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In this paper, we review McCulloch's legacy, from his early work in neurophysiology, and its relationship to his philosophical quest for an 'experimental epistemology' to his role in the cybernetics movement during the 1940s and 1950s and his contributions to the development of computer science and communication theory. There are three parts in chronological sequence. First, the period up to his work at Yale University with Dusser de Barenne, where he concentrated on the experimental study of the functional organization of sensory cortex. Second, the time of his Psychiatric Chair at the University of Chicago and the organization of the Macy Foundation Conferences. To this period corresponds the genesis and publication of the most influential and quoted work by McCulloch and Pitts: A Logical Calculus of the Ideas Immanent in Neurons Activity. Third, the period of his research activity at the Massachussetts Institute of Technology where he, Lettvin, Maturana and Pitts produced epochmaking papers on epistemological neurophysiology, the modelling of the reticular formation and other work with da Fonseca and Moreno-Díaz. We finally refer to the International Conference that took place in McCulloch's memory at the 25th anniversary of his death. Our main conclusion is that McCulloch's writings are still a source of inspiration from neurophysiology to artificial intelligence and robotics.  相似文献   

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Karl Höfler 《Protoplasma》1959,50(2):189-197
Ohne Zusammenfassung  相似文献   

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《Ibis》1959,101(2):137-152
The breeding season on the Santa Elena peninsula in S.W. Ecuador is described on the basis of 1761 nests found in the four years 1955 to 1958. The environment and climate are outlined—a cool, dry season from about May to November and a warm, variable wet season from December to April, when alone rain may fall. It is shown that each year the general breeding season is closely correlated with the rainfall. The peak of breeding varies from year to year by at least a month and its length from about six weeks to three and a half months.
Although all species for which there are enough data, are stimulated to breed after important falls of rain, most of those species of small land-birds which are completely resident, attempt to nest before the rain and often continue for some time afterwards. Some specific differences, between seed- and insect-eating finches, seem to be adaptations to food supply and the availability of nest sites and building material. Such evidence as there is suggests that raptors, waders and waterfowl also nest in the wet season (often late), rather than in the dry season. (Unfortunately herons and sea-birds do not nest in the area.)
Annual differences in the amount of breeding by the same species are thought not to be entirely due to differences in weather between years.
It is suggested that the late (August-September) breeding in the Galápagos Islands described by Lack (1950) and the apparent dry-season nesting of raptors, waders and waterfowl there might be found to be linked with variable or abnormally wet weather, if records of rainfall from the islands were available.  相似文献   

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Fourteen compounds were isolated from Cremanthodium brunneo-pilosum, including two steroids (1 and 14), five sesquiterpenoids (2–6), six flavonoids (7–12) and one isoflavone (13). Graveolide (2) was obtained from a plant for the first time. 5,7-Dihydroxy-3,6,3′,4′-tetramethoxy-flavone (9), centaureidin (10) and tectoridin (13) have not been isolated from the family Compositae. The chemotaxonomic data support the relationship between this species and others in the family Compositae.  相似文献   

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THE BREEDING OF SOME S.W. ECUADORIAN BIRDS   总被引:1,自引:0,他引:1  
《Ibis》1960,102(3):349-382
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桂西和黔南中三叠世珊瑚   总被引:1,自引:0,他引:1  
文内描述中三叠世安尼阶(Anisian)珊瑚化石分别采自桂西田阳板纳组和黔南贵阳青岩青岩组。板纳组珊瑚群中建立Pentasmilia guangxiensisgen.etsp.nov.,该新属种有5条第一周期原生隔片甚至有5条第二周期后生隔片,以此不同于有6条第一周期原生隔片和有6条第二周期后生隔片的石珊瑚类(scleractinians)的珊瑚。产于板纳组的另一新属种Radiophyllia astylatusgen.etsp.nov.,其隔片的排列格式与前人归纳的隔片周期插入示意图甚似,但它却发生在中生代最早期(Anisian)珊瑚的骸体内。文中还对青岩组的Pamiroseris silesiaca作了重新描述。  相似文献   

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Although New Zealand separated from Gondwana during the late Cretaceous (80 million years ago) it shares strong floristic affinities with other Southern Hemisphere landmasses. For 150 years, biogeographers have debated whether these similarities reflect the ancient Gondwanan connection or subsequent dispersal events. Molecular phylogenies are providing new insights into the history of Southern Hemisphere plant groups. These studies show that many plant lineages are recent arrivals in New Zealand, diversifying rapidly and then travelling to other Southern Hemisphere landmasses.  相似文献   

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