منابع مشابه
Phylogeny and evolution of glass sponges (porifera, hexactinellida).
Reconstructing the phylogeny of sponges (Porifera) is one of the remaining challenges to resolve the metazoan Tree of Life and is a prerequisite for understanding early animal evolution. Molecular phylogenetic analyses for two of the three extant classes of the phylum, Demospongiae and Calcarea, are largely incongruent with traditional classifications, most likely because of a paucity of inform...
متن کاملSponges
reference taxon for studying metazoan origins. Like a living time capsule, they may allow us to infer the genome content and cell biology of the unicellular progenitors of Metazoa. For example, comparing choanoflagellate and metazoan genomes will reveal the minimal genetic toolkit of the first metazoan. Pilot studies of choanoflagellate expressed genes have already uncovered homologs of a remar...
متن کاملSuper sponges.
The localisation of tumour deposits by a 131 1 labelled monoclonal antibody to carcinoembryonic antigen (CEA) has been evaluated in 24 patients with primary gastric, oesophageal and colorectal cancer and in 26 patients with clinically suspected recurrent gastric and colorectal cancer. Seventeen of 20 primary sites and 6/15 associated secondary sites were correctly identified by external scannin...
متن کاملSponges for Generalized Morphology
Mathematical morphology has traditionally been grounded in lattice theory. For non-scalar data lattices often prove too restrictive, however. In this paper we present a more general alternative, sponges, that still allows useful definitions of various properties and concepts from morphological theory. It turns out that some of the existing work on “pseudo-morphology” for non-scalar data can in ...
متن کاملPorifera: The Sponges
Found at all depths and latitudes, sponges are among the most ubiquitous of marine organisms. With the advent of modern laboratory and field techniques (e.g., electron microscopy, histochemistry, the development of molecular biology and biochemistry, and the use of SCUBA for collection purposes) our knowledge of sponge biology has mushroomed (see reviews by Fell, 1974; Bergquist et al., 1979). ...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1899
ISSN: 0036-8733
DOI: 10.1038/scientificamerican02041899-75