scholarly journals The Function of the Calciferous Glands of Earthworms

1936 ◽  
Vol 13 (3) ◽  
pp. 279-297
Author(s):  
JAMES D. ROBERTSON
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Lumbricus Terrestris ◽  
Ion Concentration ◽  
Isolated Cells ◽  
Hydrogen Ion Concentration ◽  
Feeding Experiments ◽  
Series Of Experiments ◽  
The Common ◽  
Metabolic Carbon

1. In the Lumbricidae the secretion of the calciferous glands consists mainly of calcium carbonate, the percentage of carbonate in the calcite concretions being 95-97 per cent. 2. Feeding experiments indicate that the calcium of the secretion can be derived from the common inorganic salts such as the carbonate, sulphate, phosphate, oxalate, chloride, and nitrate, and also from pear leaves. 3. Measurements of the hydrogen-ion concentration of the gut, soil, and castings of specimens of Lumbricus terrestris show that the tendency of the cast to be more neutral than the soil is due to the secretions of the gut as a whole, and not to the secretion of the calciferous glands. 4. The optimum pH's of two of the main intestinal enzymes have been measured. Amylase has an optimum at pH 6·8-7·0, and lipase at pH 6·4-6·6 and 7·3-7·7 depending on the substrate. 5. The amount of carbon dioxide bound as carbonate by the glands was measured in a series of experiments with earthworms kept in different calcium salts. The percentage of carbon dioxide excreted as carbonate never exceeded 10 per cent, of the total metabolic carbon dioxide. 6. Absorption of iron saccharate injected into worms took place occasionally, in groups of adjacent cells in the intestine and in isolated cells in the calciferous glands. 7. The true function of the calciferous glands is excretion, calcium carbonate being passed into the gut as crystals of calcite which are chemically inactive in the gut.

scholarly journals Chloroform extraction of trace nutrients as oxinates from soil extracts for spectrographic analysis

1960 ◽  
Vol 32 (1) ◽  
pp. 223-228
Author(s):  
Osmo Mäkitie
Keyword(s):  
Trace Metals ◽  
Chloroform Solution ◽  
Soil Extract ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Spectrographic Analysis ◽  
Hydrogen Ion Concentration ◽  
Soil Extracts ◽  
Copper Manganese ◽  
The Common

The experiments show that under these conditions the common trace nutrients, cobalt, copper, manganese, molybdenum and zinc are sufficiently completely extracted as chelates by shaking the soil extract with oxine-chloroform solution. The hydrogen ion concentration of the extract and the concentration of oxine in chloroform have decisive effects on the extractability. Using the reported and discussed procedure it is possible to separate the common trace metals from the major soil extract constituents, especially for spectrographic analysis.

Sympatho-Adrenal Stimulation by Carbon Dioxide and the Inhibitory Effect of Carbonic Acid on Epinephrine Response

1956 ◽  
Vol 187 (2) ◽  
pp. 341-346 ◽  
Author(s):  
S. M. Tenney
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Acid ◽  
Test Dose ◽  
Smooth Muscle Contraction ◽  
Inhibitory Effect ◽  
Ion Concentration ◽  
Assay Method ◽  
Stimulant Effect ◽  
Hydrogen Ion Concentration ◽  
Catechol Amine

Carbon dioxide serves as a potent stimulus to increase the titer of circulating sympatho-adrenal catechol amines in the cat. Using the denervated nictitating membrane as an assay method the CO2 threshold for adrenal stimulus was determined to be about 15% concentration in alvcolar air. Adrenalectomy decreased by 60% the catechol amine titer initiated by 30% CO2, but hepatectomy was ineffective. The stimulant effect of CO2 in this action was specific and was not dependent on the change in hydrogen ion concentration. The spinal cat was almost as responsive as the normal to CO2 stimulus, but if the cord was destroyed only a very low catechol amine concentration could be detected with comparable stimulus. In the intact cat much of the inhibition of response to administered epinephrine by CO2 is more apparent than real, because the CO2 itself serves as a stimulus to raise the endogeneous epinephrine titer and each subsequently administered test dose of epinephrine was then examined against a background of hormone action. Because of the alinear shape of the epinephrine dose-response curve this can be misinterpreted as ‘inhibition.’ There was however, a direct CO2 inhibition of epinephrine-induced smooth muscle contraction which was most apparent in the range 3–15% alveolar CO2. Sympathetically innervated and denervated structures were inhibited to the same degree.

scholarly journals REGULATION OF THE HYDROGEN ION CONCENTRATION AND ITS RELATION TO METABOLISM AND RESPIRATION IN THE STARFISH

1926 ◽  
Vol 10 (2) ◽  
pp. 345-358 ◽  
Author(s):  
Laurence Irving
Keyword(s):  
Carbon Dioxide ◽  
Sea Water ◽  
Carbon Dioxide Production ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Coelomic Fluid ◽  
Vital Function ◽  
Hydrogen Ion Concentration ◽  
Optimum Ph ◽  
Patiria Miniata

The normal reaction of the cœlomic fluid in Patiria miniata and Asterias ochraceus is pH 7.6, and of the cæca, 6.7, compared with sea water at 8.3, all without salt error correction. A medium at pH 6.7–7.0 is optimum for the cæca for ciliary survival and digestion of protein, and is maintained by carbon dioxide production. The optimum pH found for carbon dioxide production is a true one for the effect of hydrogen ion concentration on the tissue. It does not represent an elimination gradient for carbon dioxide. Because the normal excised cæca maintain a definite hydrogen ion concentration and change their internal environment toward that as an optimum during life, there exists a regulatory process which is an important vital function.

CONTRIBUTION TO THE STUDY OF THE PRECIPITATION OF CARBONATES, BORATES, SILICATES AND ARSENATES

1941 ◽  
Vol 19b (8) ◽  
pp. 179-204 ◽  
Author(s):  
Paul E. Gagnon ◽  
Louis Cloutier ◽  
R. Martineau
Keyword(s):  
Liquid Medium ◽  
Room Temperature ◽  
The Other ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Molar Ratio ◽  
Hydrogen Ion Concentration ◽  
Basic Carbonate ◽  
Series Of Experiments ◽  
Cobalt And Nickel

A study was made of the precipitation, at room temperature, of the carbonates of cadmium, cobalt, and nickel, of the chromate of beryllium, of the borates of zinc, of the silicates of copper and of the arsenates of lead. A rapid-mixing apparatus that insured that the precipitations took place in homogeneous liquid medium was used. In each series of experiments, the concentration of one reacting solution was kept constant and that of the other systematically varied. The values of the molar ratio of oxides, CdO/CO2 for example, in the precipitates were found by analysis. If they remained constant with different concentrations of reactants, a definite compound was indicated. The normal cadmium carbonate was obtained. Three definite basic compounds, not described in the literature, were prepared: a definite basic carbonate of cobalt, 5CoCO3∙Co(OH)2, and two definite basic arsenates of lead, 4Pb3(AsO4)2∙Pb(OH)2 and 9Pb3(AsO4)2∙Pb(OH)2. Dilead arsenate, PbHAsO4, was easily precipitated, but trilead arsenate, Pb3(AsO4)2, only under very specific conditions. The other precipitates were all mixtures. The influence of the hydrogen ion concentration of the solutions on the composition of the precipitates formed was determined.

scholarly journals Pore Filling Effect of Forced Carbonation Reactions Using Carbon Dioxide Nanobubbles

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4343
Author(s):  
Jihoon Kim ◽  
Ryoma Kitagaki ◽  
Heesup Choi
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solution ◽  
Surface Modification ◽  
Calcium Carbonate ◽  
Pore Filling ◽  
Concrete Repair ◽  
Mortar Specimen ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Series Of Experiments

Various methods for repairing and modifying concrete surfaces have been proposed and applied to improve the durability of existing concrete structures. Surface modification through forced carbonation is a method of densification that forms calcium carbonate in the pores on the surface of concrete to improve its durability. In this study, to evaluate the applicability of this surface modification method to existing buildings, a series of experiments was conducted in which mortar specimens were repeatedly immersed in a carbon dioxide nanobubble aqueous solution. By evaluating the weight change and absorption rate, it was determined that the higher the water/cement ratio of the mortar specimen, the higher the pore filling effect owing to immersion in the carbon dioxide nanobubble aqueous solution. In addition, the effect of clogged pores generated by the precipitation of calcium carbonate was confirmed, and it was found that the higher the water/cement ratio of the mortar specimen, the higher the pore filling effect due to clogging. We believe that our findings contribute to the development of research and construction practices associated with concrete repair and restoration.

Ventilatory response to fixed acid evaluated by ‘iso-Pco2’ technique

1959 ◽  
Vol 14 (4) ◽  
pp. 557-561 ◽  
Author(s):  
Dario B. Domizi ◽  
John F. Perkins ◽  
Joan S. Byrne
Keyword(s):  
Carbon Dioxide ◽  
Ventilatory Response ◽  
Carbon Dioxide Tension ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Control Value ◽  
Anesthetized Dogs ◽  
Increased Sensitivity ◽  
Small Increments ◽  
Fixed Acid

In order to avoid changes in a second stimulus to ventilation, i.e. carbon dioxide, while measuring the response to fixed acid, a technique was utilized whereby alveolar carbon dioxide tension (PaCOCO2) could be held constant. This technique includes continuous recording of PaCOCO2 with an infrared type analyzer and addition of sufficient CO2 to the inspired air to keep PaCOCO2 at its control value (near 40 mm Hg). The response of anesthetized dogs to infusion of 0.5 m HCl was measured when the PaCOCO2 was held at the control value and also at various other levels. Other experiments measured the effect of CO2 when it was not allowed to change arterial hydrogen ion concentration [H+]. It was found that both these substances are potent respiratory stimuli and that their effects may be considered essentially separate and additive, as suggested by Gray. The experiments also demonstrated a slightly increased sensitivity to CO2 at increased arterial [H+], but this effect was not found necessary to explain the response to acid. Responses to successive small increments in PaCOCO2 failed to reveal any ‘threshold,’ even with CO2 tensions as low as 15 mm during acidosis. Submitted on December 29, 1958

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