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1.
Tor Strömgren 《Coral reefs (Online)》1987,6(1):43-47
Series of apices of Acropora pulchra from an intertidal reef at Phuket, Thailand, were grown at different depths in the sea, and the length growth was monitored at 12–24 h intervals with laser diffraction. The growth rates of actively growing apices were normally distributed and showed a high variability, with an average coefficient of variation of 58%. There was a highly significant difference in average growth rate between adjacent colonies. A significant linear relationship was found between irradiance and length growth, with a saturating level at 300–400 Wm-2. At 1000 Wm-2 length growth was significantly reduced. Under normal daylight conditions, day and night growth rates were equal. 相似文献
2.
Bicarbonate/chloride antiport in Vero cells: I. Evidence for both sodium-linked and sodium-independent exchange 总被引:2,自引:0,他引:2
Tor Inge Tnnessen Jannikke Ludt Kirsten Sandvig Sjur Olsnes 《Journal of cellular physiology》1987,132(2):183-191
The effect of bicarbonate on the ability of cells to regulate the internal pH after acid and alkali loads was studied. In the presence of Na+, the normalization of the internal pH after acid loads occurred more rapidly in the presence than in the absence of bicarbonate. DIDS (4,4'-diisothiocyano-2,2'-stilbene-disulfonic acid) strongly inhibited the pH increase, whereas amiloride inhibited it to a lesser extent. The Na+-linked, bicarbonate-dependent pHi increase after an acid load was strongly reduced in cells depleted of Cl-. When cells were transferred to gluconate or mannitol balanced buffers containing bicarbonate, there was a rapid alkalinization of the cytosol, apparently due to influx of bicarbonate induced by chloride efflux. When the internal pH was below 7.0, the pH increase was much more rapid in the presence than in the absence of Na+, whereas at higher internal pH, there was no measurable effect of Na+. The ability of the cells to reduce the internal pH after an alkali load was increased in the presence of bicarbonate. The data indicate that both Na+-linked and Na+-independent bicarbonate/chloride exchange occur in Vero cells. 相似文献
3.
Summary The opioidergic, sympathetic and neuropeptide Y-positive innervation of the sphincter of Oddi (common bile duct sphincter and pancreatic duct sphincter), as well as other segments of the extrahepatic biliary tree was studied in the monkey by use of immunohistochemistry. Methionine-enkephalin-positive nerves were seen to innervate the smooth muscle of all portions of the sphincter of Oddi and also local ganglion cells. No methionine-enkephalin-positive nerves could be detected in the common bile duct, pancreatic duct or gallbladder. Tyrosine hydroxylase-positive nerves occurred between smooth muscle bundles and also ran to local ganglion cells as well as along the common bile duct. Neuropeptide Y-positive nerves were observed within smooth muscle of the sphincter of Oddi (all portions), common bile duct, pancreatic duct and gallbladder. No evidence of any differential innervation of the pancreatic duct and common bile duct sphincters could be detected with these markers. 相似文献
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5.
Steinar Solberg Tor Larsen Leif Jørgensen 《In vitro cellular & developmental biology. Plant》1985,21(11):612-616
Summary This study examined whether nonconfluent endothelial cell cultures reacted differently than confluent ones toward thrombin-stimulated
platelets or a heparinized salt solution. The adherence to the endothelial cell cultures of51Cr-labeled human platelets stimulated at different thrombin concentrations was studied. There was significantly higher adherence
of stimulated platelets to nonconfluent cultures compared with confluent ones. This was confirmed by scanning electron microscopy,
which also revealed a tendency for the platelets to adhere at the cell periphery. Electron microscopy also showed that thrombin-stimulated
platelets induced endothelial cell contraction. Part of the peripheral endothelial cell surface toward the bottom of the culture
dish was inverted, facing the lumen of the dish. This phenomenon was particularly seen in nonconfluent cultures. When51Cr-labeled endothelial cultures were incubated with a mildly injurious fluid as heparinized sodium acetate and 20% serum,
at 20° C for 30 min, the nonconfluent cultures showed significantly more cell detachment and release of51Cr than the confluent ones. We conclude that under the conditions of the present experiments there are differences in the
reactivity of confluent and nonconfluent endothelial cell cultures. These differences probably reflect biological dissimilarities.
In experiments where properties of cultured endothelium are studied, care should be taken that the degree of confluency is
standardized. 相似文献
6.
Prof. Dr. Tor G. Karling 《Zoomorphology》1969,65(2):202-208
A specimen of Ethmorhynchus anophthalmus Meixner 1938 contains a complex of supernumerary genital organs in front of the pharynx. The phenomenon elucidates some traits in the morphogenesis of the atrial organs.
Abkürzungen in den Abbildungen At Atrium genitale - Bu Bursa - Ci Cirrus des Kopulationsorganes - Dc Ductus communis - Ho Hoden - Ke Keimstock - Kop Kopulationsorgan - Ph Pharynx - R Rüssel - Sa Samenblase 相似文献
Abkürzungen in den Abbildungen At Atrium genitale - Bu Bursa - Ci Cirrus des Kopulationsorganes - Dc Ductus communis - Ho Hoden - Ke Keimstock - Kop Kopulationsorgan - Ph Pharynx - R Rüssel - Sa Samenblase 相似文献
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Effects of acid wastes from titanium dioxide production on biomass and species richness of benthic algae 总被引:1,自引:1,他引:0
Titanium dioxide wastes are suspected to be toxic to rocky shore communities in an estuary in southeast Norway. An experimental project lasting two years examined whether titanium dioxide wastes affected recolonization by rocky shore organisms. The experiments were performed in situ in six tanks (each with 9 m3 brackish water) at two different levels of salinity. Three different concentrations of industrial waste water were used. The growth season in 1986 was dry and sunny compared to 1987, causing reduction of growth on exposed granite chips compared to controls. At the two highest waste concentrations in the tanks, Fucus serratus was observed with necrotic tissue both years, and in 1986 benthic diatoms were scarce. 相似文献
10.
Tor Strömgren 《Journal of experimental marine biology and ecology》1980,43(2):107-119
The increase in length of Pelvetia canaliculata (L.) Dec. et Thur., Fucus spiralis L., F. vesiculosus L., F. serratus L., and Ascophyllym nodosum (L.) Le Jolis was measured in various concentrations of lead, cadmium, and mercury during a period of 9–10 days. Concentration ranges of the three metals were 45 2600 μg 1, 1.5 1040 μg 1 and 0.9 1250 μg 1, respectively.Significant reductions of growth rate compared with the controls were observed at ? 810 μg 1 of lead, ? 450 μg/l of cadmium, and ? 10 μg/l of mercury, and regressions of growth reduction on log concentration were indicated.Growth was significantly enhanced in Pelvetia canaliculata and Ascophyllum nodosum when exposed to cadmium, and in this case there was a significant regression of growth iincrease on log concentration. The growth of Pelvetia canaliculata was also enhanced at all concentrations of lead. 相似文献