(n.) A mollusk having a shell consisting of two lateral plates or valves joined together by an elastic ligament at the hinge, which is usually strengthened by prominences called teeth. The shell is closed by the contraction of two transverse muscles attached to the inner surface, as in the clam, -- or by one, as in the oyster. See Mollusca.
(n.) A pericarp in which the seed case opens or splits into two parts or valves.
(a.) Having two shells or valves which open and shut, as the oyster and certain seed vessels.
Example Sentences:
(1) Start your exploring at Bearreraig Bay, where, if you are lucky, you may find belemnites, ammonites and bivalves.
(2) To compare biochemical differences between bivalves with and without endosymbiotic chemoautotrophic bacteria, specimens of Solemya velum, a bivalve species known to contain bacterial endosymbionts, and the symbiont-free soft-shelled clam Mya arenaria, were collected from the same subtidal reducing sediments during October and November 1988.
(3) We have demonstrated that M. edulis, a marine bivalve mollusc, reacts to the vertebrate monokines interleukin-1, -6 and TNF.
(4) Total neutral and acidic glycosphingolipids were prepared from whole tissues of the sea-water bivalve, Meretrix lusoria, and the former preparation was further fractionated into subgroups by silicic acid column chromatography.
(5) The development of microparticulate food particles for marine suspension-feeders is discussed with respect to the difficulties of nutrient delivery in the aquatic environment and to feeding and digestion in crustacea and bivalve molluscs.
(6) Attempts to introduce infectious or foreign material into oysters and other bivalve mollusks usually involve force or trauma because of immediate, prolonged adduction of the tightly closing valves.
(7) This observation, together with the finding that the oyster shell has a strong affinity for virus, suggests that surface properties, rather than size, are the principal factors governing the accumulation of viruses by filter-feeding marine bivalves.
(8) Chromatin organization in the sperm of the bivalve mollusks results from the interaction between a discrete number of protamine-like proteins (PL) and DNA.
(9) There was the doll's house-sized two-pronged fork, and the bivalves themselves, pale and ivory against the silvered shell.
(10) Infectious pancreatic necrosis virus of fish, infectious bursal disease virus of chickens, Tellina virus and oyster virus of bivalve molluscs, and drosophila X virus of Drosophila melanogaster are naked icosahedral viruses with an electron microscopic diameter of 58 to 60 nm.
(11) The control measures consisted of the prohibition of the harvest and sale of all bivalve mollusks as well as a public warning to avoid the consumption of such shellfish.
(12) The ultrastructural morphology of peripheral neurons and associated structures in the bivalve mollusc.
(13) In 6 male baboons, the left kidney was bivalved and repaired using a fibrin adhesive (group A) or conventional suturing (group B).
(14) There are various types of photoproteins: the photoproteins of coelenterates, ctenophores and radiolarians require Ca2+ to trigger their luminescence; the photoproteins of the bivalve Pholas and of the scale worm appear to involve superoxide radicals and O2 in their light-emitting reactions; the photoprotein of euphausiid shrimps emits light only in the presence of a special fluorescent compound; the photoprotein of the millipede Luminodesmus, the only known example of terrestrial origin, requires ATP and Mg2+ to emit light.
(15) Most progress is being made in relation to lethal blood mutant neoplasms in Drosophila, leukaemias of farmed salmonids among the fishes, and among shellfish, the hemic sarcomas of bivalves.
(16) Distribution of MlOse4Cer and MlXOse5Cer in various bivalve and snail glycolipid extracts were screened in thin-layer immunobinding assays by using this purified specific antibody.
(17) In the haemolymph of the Tridacnid bivalve clams anti-galactans occur which do not have only glycosubstance precipitating and cell agglutinating properties, but also show mitogenic activity with respect to the blast transformation of human peripheral lymphocytes.
(18) The pericardial glands of three bivalve molluscs are composed of convoluted epithelium that appears as pouches on the auricles of Mytilus and as tubules in the connective tissue at the anterior-lateral sides of the pericardial cavity of Mercenaria and Anodonta.
(19) Four biotypes and five antigenic types of bacteria, pathogenic for the larvae of five species of bivalve mollusks, were isolated and described in some detail.
(20) Laboratory toxicity tests performed on the bivalve Cerastoderma edule submitted to sublethal concentrations of paper mill effluent revealed significant decreases of adenylate energy charge (AEC), and changes in the total adenylate pool were observed in a 24-hr period even for the lowest concentration of pollutant tested.
Velum
Definition:
(n.) Curtain or covering; -- applied to various membranous partitions, especially to the soft palate. See under Palate.
(n.) See Veil, n., 3 (b).
(n.) A thin membrane surrounding the sporocarps of quillworts Isoetes).
(n.) A veil-like organ or part.
(n.) The circular membrane that partially incloses the space beneath the umbrella of hydroid medusae.
(n.) A delicate funnel-like membrane around the flagellum of certain Infusoria. See Illust. a of Protozoa.
Example Sentences:
(1) MRI revealed cranium bifida and agenesis of anterior medullar velum.
(2) To compare biochemical differences between bivalves with and without endosymbiotic chemoautotrophic bacteria, specimens of Solemya velum, a bivalve species known to contain bacterial endosymbionts, and the symbiont-free soft-shelled clam Mya arenaria, were collected from the same subtidal reducing sediments during October and November 1988.
(3) The Z-plasties facilitate effective dissection and redirection of the palatal muscles to produce an overlapping muscle sling and lengthen the velum without using tissue from the hard palate, which permits hard palate closure without pushback or lateral relaxing incisions.
(4) We now report that, compared to controls, rats with acute EAE exhibit fewer detectable mast cells in their dura mater and velum interpositum.
(5) The superior medullary velum was not recognized in 10 cases and the corpus medullare in 5.
(6) Its efficacy is generally accepted, and its use, especially in cases of obstructive sleep apnea syndrome, is the only treatment of the palatal velum at present practiced.
(7) The axons originate in dorsal dendrites, run dorsally along the border of the gray matter and pierce the velum medullare on the contralateral side.
(8) While coughing the movement of the velum is purely passive because of the exspirational thrust.
(9) The velopharyngeal closure patterns can be grouped into five categories according to the manner of the velum and lateral pharyngeal wall movements.
(10) Few 5-HT nerve terminals occurred only on the roof of the fourth ventricle (velum medullare, lamina epithelialis of the tela chorioidea), and the surface of the choroid plexus epithelia was devoid of such nerves.
(11) The inferior medullary velum and tela choroidea were removed intact from the fourth ventricle, post-osmicated, dehydrated, critical point dried, coated with palladium-gold and examined in a Cambridge Stereoscan S4 scanning electron microscope.
(12) The clinical presentation, radiological findings, and surgical management of two cases of meningioma arising from the velum interpositum without dural attachment are described.
(13) The delta 13C and delta 15N ratios of the amino acids are very similar to the isotope ratios previously found in both the endosymbionts and whole tissues of S. velum.
(14) Five patients evaluated via multi-view videofluoroscopy were found to have incongruous movements between the velum and lateral aspects of the pharyngeal walls.
(15) They are lined on the inside towards the distal part of the velum by thin epithelium and towards the proximal part by ciliated sensory cells.
(16) The cerebellum, the beginning of which was already noted at stages 13 and 14, consists of (1) a rostral part that arises from the alar plate of the isthmic segment and will form the superior medullary velum and part of the corpus cerebelli; and (2) a caudal part that develops from rhombomere 1.
(17) The measuring principle is described and the movements of the velum during speech production are demonstrated in cleft palate patients with different speech results.
(18) In individuals without pharyngeal flap surgery the velum was displaced in the anterior direction and its position could be influenced by the pushback of the mandible.
(19) In addition to this permanement neurogenous myoclonus, there are also rhythmical contractions of the velum, usually considered to be psychogenous.
(20) The second procedure is for use after exeresis involving all or almost all of the soft palate and a half of the posterior pharyngeal wall, and makes use of velum palatinum reconstruction.