Results 1 to 10 of about 15,772 (216)
On a Cluster of Nebulae in Hydra [PDF]
Proceedings of the National Academy of Sciences, 1941 Clusters of nebulae are the largest known aggregations of matter which possess definite individual characteristics. In preparation of a theoretical study of the large scale distribution of matter in the universe we propose to analyze some simple structural features of a number of clusters of nebulae.
F. Zwicky
openaire +6 more sources
The Astronomical Journal, 2008 14 pages, 6 figures, 6 ...
Garrett T. Elliott +3 more
openaire +3 more sources
Logical Methods in Computer Science, 2020 The recursive path ordering is an established and crucial tool in term rewriting to prove termination. We revisit its presentation by means of some simple rules on trees (or corresponding terms) equipped with a 'star' as control symbol, signifying a command to make that tree (or term) smaller in the order being defined.
Roy Overbeek +2 more
openaire +6 more sources
The Biological Bulletin, 1997 Embryogenesis in hydra includes a variable period of dormancy; and this period, as well as subsequent stages through hatching, takes place within a thick cuticle that hinders observation. Thus, although the early stages of development have been well-characterized qualitatively, the middle and later stages are only poorly understood.
C. L. Littlefield +3 more
openaire +4 more sources
American Zoologist, 1982 SYNOPSIS. Pieces of hydra tissue of various sizes and shapes were cut from the body columns of adult hydra and allowed to regenerate. The proportions of the resulting animals were determined first by counting cells in the head and body, and secondly by measuring the structures directly using an ocular micrometer. Head-body proportions were found to be
Hans R. Bode, Patricia Macauley Bode
openaire +2 more sources
Annals and Magazine of Natural History, 1878 (1878). Reproduction of Hydra. Annals and Magazine of Natural History: Vol. 2, No. 10, pp. 351-352.
openaire +3 more sources
Aluminium Deposition in Hydras
Folia Biologica, 2009 The aim of this research was to explore, compare and explain the appearance, purpose and possible distribution of aluminium depositions in symbiotic and aposymbiotic hydra species. Al deposition in treated hydras appeared pink as single and multiple aluminium depositions or as clusters in the shape of globular or spot-like structures inside the ...
Goran Kovačević +2 more
openaire +3 more sources
Hydra and the Evolution of Apoptosis [PDF]
Integrative and Comparative Biology, 2005 Programmed cell death occurs in most, if not all life forms. It is used to sculpt tissue during embryogenesis, to remove damaged cells, to protect against pathogen infection and to regulate cell numbers and tissue homeostasis. In animals cell death often occurs by a morphologically and biochemically conserved process called apoptosis.
Angelika Böttger +5 more
openaire +3 more sources
Nature, 1925 THE following observation was made by Mr. J. T. Wadsworth, the steward of the zoological laboratory in the University of Manchester.
openaire +2 more sources