Effect of destruction of the frontal and parietal regions of the neocortex on the ability of dogs to solve extrapolation problems

Parietoectomized dogs (n = 8), like intact ones (n = 102), are able to extrapolate the direction of the movement of an alimentary stimulus when presented with a complex task variant. In this they differ from animals with a prefrontal lobectomy (n = 10) in which, according to the authors' previous data (1971), the ability to elementary rational activity in Krushinsky extrapolation test (1977), is impaired.     

Effects of delta sleep-inducing peptide on the intercentral integration during experimental epilepsy

In free behavior experiments on cats it has been shown, that the intraperitoneal injection of delta-sleep-inducing peptide (100 mg/kg) may change organization of the pathology integration-epileptic discharges did not spread all the structures simultaneously. The slow-waves were registered in central medium of the thalamus and nucl. caudati. The epileptic discharges were registered first in visual and auditory cortex, hippocampus. After that they were observed in the motor cortex, nucl. caudati and centrum medianum of the thalamus.     

Strategies and methodology of marine diodiversity studies

This paper reviews major global and regional international approaches to inventory and monitoring of biological diversity. The current strategy of studying marine biodiversity is outlined. We also discuss the methodology of marine biota inventory at the regional level within the framework of the long-term biodiversity studies in the West and North Pacific Ocean that are undertaken by the international institutions Census of Marine Life, DIWPA, and NaGISA. The paper also contains data on the biological diversity of Russian Far East seas.     

Symmetry of priapulids (Priapulida). 2. Symmetry of larvae

Larvae of priapulids are characterized by radial symmetry evident from both external and internal characters of the introvert and lorica. The bilaterality appears as a result of a combination of several radial symmetries: pentaradial symmetry of the teeth, octaradial symmetry of the primary scalids, 25-radial symmetry of scalids, biradial symmetry of the neck, and biradial and decaradial symmetry of the trunk. Internal radiality is exhibited by musculature and the circumpharyngeal nerve ring. Internal bilaterality is evident from the position of the ventral nerve cord and excretory elements. Externally, the bilaterality is determined by the position of the anal tubulus and two shortened midventral rows of scalids bordering the ventral nerve cord. The lorical elements define the biradial symmetry that is missing in adult priapulids. The radial symmetry of larvae is a secondary appearance considered an evolutionary adaptation to a lifestyle within the three-dimensional environment of the benthic sediment.     

Ultrastructure of Microvillar Coelomocytes from the Trunk Coelom of Thysanocardia nigra Ikeda, 1904 (Sipuncula) from the Sea of Japan

This research is part of a study on the ultrastructure of coelomocytes and cellular complexes from the body cavity of sipunculans. New free-swimming elements called microvillar cells in the trunk coelom of Thysanocardia nigra Ikeda, 1904 are examined using transmission electron microscopy. The cell harbors a giant vesicle filled with a fibrous matrix and rosettes of minute osmiophilous granules. The nucleus is peripheral, and a few cell organelles are situated between the cell membrane and the vesicular membrane. The cell membrane bears numerous microvilli with enlarged apical points. Numerous small microvillar vesicles swimming in the coelomic fluid separate from the microvillar cells. The functional morphology of coelomocytes and cellular complexes is discussed.Original Russian Text Copyright © 2005 by Biologiya Morya, Maiorova, Adrianov.     

Current problems in marine biodiversity studies

This paper deals with a discussion of terminology and six proposed levels of biodiversity. Recent data and estimates were used to compare species and taxonomic diversity of terrestrial, freshwater, and marine organisms. About 1.5 million terrestrial species and 320000 aquatic species are hitherto known. In spite of a long history of research, only about 280000 marine species have been discovered, of which 180000 species are invertebrates. Of 33 metazoan phyla, 31 are found in the sea, 13 of these being exclusively marine. Seventeen metazoan phyla contain freshwater species, and only 11 phyla comprise terrestrial animals. Two phyla (freshwater Micrognathozoa and terrestrial Onychophora) possess no marine species. In this paper, we review the assessment reports on marine biological diversity in coral reefs, coastal ecosystems, macrobenthos, and meiofauna. Recent data on the number of known species are listed for each metazoan phylum; the number of anticipated new species to be discovered is estimated. Deep-sea macrobenthos are believed to comprise about 25 million species; meiofauna seems to be composed of 20 to 30 million species, ten million of whom are marine nematodes. Hypotheses are discussed that can account for the high species diversity of deep-sea macrobenthos and meiofauna.