(n.) One of the Diatomaceae, a family of minute unicellular Algae having a siliceous covering of great delicacy, each individual multiplying by spontaneous division. By some authors diatoms are called Bacillariae, but this word is not in general use.
(n.) A particle or atom endowed with the vital principle.
Example Sentences:
(1) The cytoplasmic and chloroplast ribosomes from the marine diatom Cylindrotheca fusiformis were isolated and characterized.
(2) The concentration of acetate in the interstitial water fell from about 100 microM (immediately after sedimentation of the spring diatom bloom) to a relatively constant value of about 20 microM in late summer, during which acetate utilization appeared to be balanced by production.
(3) The affinity of the diatom for glucose was greater than that shown by the bacterium, but the Km for glucose transport, 1.5x10-5M was too high to allow effective removal of glucose at in situ concentrations.
(4) We have cloned and sequenced a 5200 base restriction fragment and an overlapping 3100 base fragment of the large single copy region of the chloroplast genome of the diatom Odontella sinensis, which hybridized to several ATPase gene probes.
(5) The material consisted of 285 successive drownings, which were subject to autopsy at the Helsinki University Department of Forensic Medicine between 1978 and 1986 and for whom diatom analysis was carried out.
(6) Substituting size-fractionated silica particles for diatoms (the fossilized cell walls of unicellular algae) allowed for the purification of microgram amounts of genomic DNA, plasmid DNA, and rRNA from cell-rich sources, as exemplified for pathogenic gram-negative bacteria.
(7) In diatom and yeast spindles, elongation of the spindle in anaphase (anaphase B) may be explained by microtubule assembly at polar microtubule ends in the spindle mid-zone and sliding of the antiparallel microtubules from the opposite poles.
(8) Cells of the diatom Cyclotella meneghiniana were exposed in a closed system to 0.245 ppm 1,2,3-trichlorobenzene.
(9) Cells of the diatom Cyclotella meneghiniana were exposed in a closed system to 0.245 ppm 1,3,5-trichlorobenzene.
(10) Extracted diatom DNA separates into two bands in CsCl-Hoechst 33258 dye gradients.
(11) Quinones constituting the electron transfer systems in a marine unicellular diatom, Phaeodactylum tricornutum, were isolated and identified chromatographically.
(12) A new sulfonolipid has been isolated from a non-photosynthetic diatom, Nitzschia alba, by thin-layer and column chromatography on silicic acid, and characterized by 35S-labeling, mobility on thin-layer chromatography, infrared and NMR spectroscopy and products of hydrolysis, as a ceramide sulfonic acid (N-acyl sphingosine-1-sulfonic acid).
(13) Among eukaryotes, red algae emerged first; and, later, thraustochytrids (a Proctista group), ascomycetes (yeast), green plants (green algae and land plants), "yellow algae" (brown algae, diatoms, and chrysophyte algae), basidiomycetes (mushrooms and rusts), slime- and water molds, various protozoans, and animals emerged, approximately in that order.
(14) The spindle of the colonial diatom Fragilaria contains two distinct sets of spindle microtubules (MTs): (a) MTs comprising the central spindle, which is composed of two half-spindles interdigitated to form a region of "overlap"; (b) MTs which radiate laterally from the poles.
(15) The conformation of berchemolide was calculated by MNDO (modified neglect of diatomic overlap).
(16) Usually algal populations change from a dominance of diatoms and green algae to dominance by blue-green algae.
(17) But it seems to have stuck.” The following year, Crutzen and Eugene Stoermer – an American diatom specialist who had been using the term informally since the 1980s – jointly published an article proposing that the Anthropocene should be considered a new Earth epoch, on the grounds that “mankind will remain a major geological force for many millennia, maybe millions of years to come”.
(18) The particles are surfaces for the attachment of diatoms and hydroids.
(19) Mitotic spindles isolated from the diatom Stephanopyxis turris consist of two half-spindles of closely interdigitating microtubules that slide relative to one another in the presence of ATP, reinitiating spindle elongation (anaphase B) in vitro.
(20) We describe here a simple procedure for isolating diatom spindles which are capable of anaphase spindle elongation in vitro.
Rotifer
Definition:
(n.) One of the Rotifera. See Illust. in Appendix.
Example Sentences:
(1) Lifespan is strongly correlated (0.7009) with the length of the reproductive period in the rotifer Asplanchna brightwelli.
(2) Two possible mechanisms are discussed to explain these results: (1) cortisone stabilization of lysosomal membranes, or (2) recognition of cortisone as a hormone capable of altering resource allocation by the rotifers.
(3) The rate of lipid peroxidation (LP) was measured in rotifers reared under conditions of continuous darkness (D:D), dietary restriction, vitamin E supplementation, or elevated temperatures.
(4) They show the same buoyant density as chitin and also as the chitin-containing layers of rotifer egg-shells.
(5) The rotifer Asplanchna releases into its environment a water-soluble, nondialyzable, pronase-sensitive factor which causes uncleaved eggs of another rotifer, Brachionus calyciflorus, to develop into individuals with a pair of long, movable spines which neither their mothers nor the unaffected controls have.
(6) The jaws (trophi) of the rotifer Brachionus plicatilis are soluble in strong acids but are resistant to long treatments by strong alkali.
(7) Both high and low temperatures increased rotifer sensitivity to reference toxicants.
(8) To account for the mechanism of this unusual and novel effect it is proposed that these compounds interact with the anesthetic binding site of the rotifer cholinoceptor ionophore in the open state.
(9) It was shown by means of radiolabelling with 45 calcium that the rate of calcium accumulation in chelation-treated rotifers was markedly lower than in the untreated controls.
(10) Cortisone at 100 and 200 microM concentrations produced a significant increase in both life span and reproduction in the rotifer Asplanchna brightwelli.
(11) Extensions of life-span and reproductive period were achieved in the rotifer Mytilina brevispina var redunca by regular brief immersions in solutions of one of the following chelating agents, sodium citrate, sodium tartrate, EDTA, and EGTA.
(12) A number of compounds showing general anesthetic action in the rotifer Brachionus calyciflorus were investigated in the presence of acetylcholine.
(13) In the summer of 1982-1983 it was observed an impairment on the daily cercarial harvests which was related to ambient temperature increase, and the presence of rotifers in the aquaria water.
(14) The magnitude of cannibalism in this rotifer may be dependent upon a complex suite of heterogeneous predator-prey interactions and greatly affected by shifting densities and distributions of different clones and female morphotypes.
(15) No response was observed when rotifers were exposed to aluminum chloride, mercury chloride, pentachlorophenol, sodium arsenite, sodium azide, sodium dodecyl sulfate, or zinc chloride.
(16) Examples are provided, derived from populations having rather different lifespans such as rotifers, flies, rats and horses.
(17) Furthermore, significant quantities of calcium, which increased throughout the life-span, were withdrawn from rotifers at chelation.
(18) The rotifer Asplanchna brightwelli shows a continuous decline in swimming activity through the course of its 5-day life span.
(19) The presence of acetylcholine in the culture medium was found to result in egg retention in the bdelloid rotifer Philodina acuticornis in a dose-dependent fashion, with no other discernible physiological effect.
(20) The results of this study indicate that levels of the SOR and lipid peroxides are coupled to rotifer life-span and that activation of phospholipase A2 may contribute to the elevation of these agents in older animals.