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 Decade: 1950-1959
Minutes of MTA Progress Meeting Held December 5, 1950

Minutes of MTA Progress Meeting Held December 5, 1950

Date: October 5, 1950
Creator: Ball, Russell H.
Description: No abstract provided.
Contributing Partner: UNT Libraries Government Documents Department
The Relation of Quantum Requirement in Photosynthesis toRespiration

The Relation of Quantum Requirement in Photosynthesis toRespiration

Date: January 21, 1955
Creator: Bassham, James A.; Shibata, Kazuo & Calvin, M.
Description: 1. The r a t e s of photosynthesis and subsequent respiration of Chlorella pyrenoidosa were measured using an oxygen analyzer (sensitive to paramagnetism). The energy absorbed during the photosynthesis periods was determined and the quantum requirement was calculated. 2. Dark respiration r a t e was found to depend on the r a t e of light absorption during the period of photosynthesis, and increased with increasing photosynthesis rate. 3 . The quantum requirement, corrected for respiration, varied from 4. 9 ( a t a ratio of photosynthesis to respiration of 1.4) to 6. 9 (at a r a t i o of 12). Both uncorrected and corrected quantum requirements approach an experimental value of 7. 4 a t high light intensity. 4. The lower quantum requirement obtained a t low light intensity is believed to be due to a relatively greater importance of contribution of energy from respiration t o photosynthesis. An expression i s derived for the relation between this contribution and the enhancement of dark respiration due to the level of photosynthesis to which the plants a r e conditioned. 5. Attempts to obtain the blue -light stimulation of photosynthesis with algae photosynthesizing in r e ...
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High Energy Physics

High Energy Physics

Date: January 1, 1955
Creator: McMillan, Edwin M.
Description: Without a little further explanation the title of this article may not convey a definite meaning to all readers, so I would like to start by pointing out that ''high energy'' refers to the energy of individual bombarding particles used to produce nuclear disintegrations, and not to situations where a large aggregate amount of energy is involved, as in an atomic power plant. The next question might be, when is energy considered ''high?'' To discuss this, we need a scale for measuring particle energies, and some feeling for the meaning of magnitudes on this scale. The basic scale unit is the ''electron volt'', which is the amount of energy acquired by a particle bearing an electric charge equal to that of an electron, when it falls through an electrical potential difference of one volt. This unit is rather small for use in nuclear physics, so a million electron volts, abbreviated ''MeV'', is the commonly used unit.
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The Nonphotosynthetic Fixation of Carbon Dioxide by ThreeMicro-Organisms

The Nonphotosynthetic Fixation of Carbon Dioxide by ThreeMicro-Organisms

Date: July 1, 1958
Creator: Holm-Hansen, O.; Moses, V. & Calvin, M.
Description: Studies by Lynch and Calvin (1952,1953) have established the nature of the compounds incorporating C{sup 14} nonphotosynthetically from C{sup 14}O{sub 2} in thirteen microorganisms: a yeast, a protozoan, two water moulds, one slime mould, three algae, three bacteria, and the green flagellate Euglena Gracilis. With the exception of H. gracilis, and of Lactobacillus cassi which fixed no detectable amounts of carbon dioxide, all these organisms fixed carbon dioxide into amino and organic acids derived from the tricarboxylic acid cycle, and into a few other compounds in individual cases (tyrosine, phenylalanine, polysaccharides [probably glucose polymers], acetic acid and butyric acid). The authors concluded that the presence of C{sup 14} in almost all these compounds could be accounted for by the carboxylation of pyruvate to yield oxalacetic or malic acids, followed by transaminase reactions. In E. gracilis, however, considerable quantities of activity also appeared in phosphorylated compounds in the dark, especially in the sugar monophosphates, phosphoglyceric acid, and phosphoenolpyruvic acid. Only with this organisms was a kinetic study performed to determine the identity and degree of labeling of the compounds containing C{sup 14} after varying periods of time. It was not stated definitely by which route carbon dioxide entered the photosynthetic intermediates, ...
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The Nurture of Creative Science and the Men who Make It

The Nurture of Creative Science and the Men who Make It

Date: May 1, 1958
Creator: Calvin, Melvin
Description: This report describes the development of work that began as an investigation of photosynthesis and that continues in this direction, but which has as a new product some entirely strngly results. Photosynthesis, the process upon which all life on earth today is ultimately dependent, achieves the conversion of electromagnetic energy from the sun into chemical energy in the form of plant material by the reduction of CO{sub 2} from the atmosphere with the liberation of O{sub 2} to the atmosphere. It has been possible to describe in some detail the way in which the plant accomplishes the reduction of carbon dioxide, using radioactive carbon as a tracer. The status of the present knowledge, and how they attained it, together with some prospectus of the future and what we can look forward to, is the principal theme of this discussion.
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Photosynthesis (The Path of Carbon in Photosynthesis and thePrimary Quantum Conversion Act of Photosynthesis)

Photosynthesis (The Path of Carbon in Photosynthesis and thePrimary Quantum Conversion Act of Photosynthesis)

Date: November 22, 1952
Creator: Calvin, Melvin
Description: This constitutes a review of the path of carbon in photosynthesis as it has been elaborated through the summer of 1952, with particular attention focused on those aspects of carbon metabolism and i t s variation which have led to some direct information regarding the primary quantum conversion act. An introduction to the arguments which have been adduced in support of the idea that chlorophyll i s a physical sensitizer handing i t s excitation on to thioctic acid, a compound containing a strained 1, 2 -dithiolcyclopentane ring, i s given.
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Notes on Quadrupole Focusing

Notes on Quadrupole Focusing

Date: February 9, 1956
Creator: McMillan, Edwin M.
Description: No abstract prepared.
Contributing Partner: UNT Libraries Government Documents Department
The Path of Carbon in Photosynthesis. XVI. Kinetic Relationshipsof the Intermediates in Steady State Photosynthesis

The Path of Carbon in Photosynthesis. XVI. Kinetic Relationshipsof the Intermediates in Steady State Photosynthesis

Date: June 5, 1952
Creator: Benson, A.A.; Kawaguchi, S.; Hayes, P. & Calvin, M.
Description: A kinetic study of the accumulation of C{sup 14} in the intermediates of steady state photosynthesis in C{sup 14}O{sub 2} provides information regarding the sequence of reactions involved. The work described applied the radio-chromatographic technique for analysis of the labeled early products. The simultaneous carboxylation reaction resulting in malic acid as well as phosphoglycerate is demonstrated in experiments at high light intensity. A comparison of radioactivities in a number of phosphorylated sugars as a function of time reveals concurrent synthesis of fructose and sedoheptulose phosphates followed by that of ribulose phosphates and later by that of glucose phosphates. The possibility that the cleavage of C{sub 4} compounds to C{sub 2} carbon dioxide acceptors may involve C{sub 7} and C{sub 5} sugars and evidence for this mechanism is presented.
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Observation of Antiprotons

Observation of Antiprotons

Date: October 19, 1955
Creator: Chamberlain, Owen; Segre, Emilio; Wiegand, Clyde & Ypsilantis,Thomas
Description: One of the striking features of Dirac's theory of the electron was the appearance of solutions to his equations which required the existence of an antiparticle, later identified as the positron.
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The Path of Carbon in Photosynthesis. XVIII The Identification ofNucleotide Coenzymes

The Path of Carbon in Photosynthesis. XVIII The Identification ofNucleotide Coenzymes

Date: January 19, 1953
Creator: Buchanan, J.G.; Lynch, V.H.; Benson, A.A.; Calvin, M. & Bradley,D.F.
Description: The radioactive compounds to be observed when algae or green leaves are allowed to photosynthesize in C{sup 14}O{sub 2} for short periods are almost all phosphorylated derivatives of sugars. Of these, phosphate esters of trioses, sedoheptulose and fructose are the first to incorporate C{sup 14} followed closely by ribulose diphosphate, glucose-6-phosphate and a phosphate of mannose. It has been noted, in earlier papers of this series, that on radiograms of the products of photosynthesis, a dark area appeared in a position occupied by no known sugar phosphate and which gave glucose on acid hydrolysis or on treatment with a phosphatase preparation. This has hitherto been referred to as an 'unknown glucose phosphate'. It was found that this substance was more labile to acid than glucose-l-phosphate, itself a readily hydrolysable phosphate, and furthermore that other labile glucose derivatives were formed as intermediates during the acid hydrolysis. Accumulation of labeled glucose in this area precedes that in sucrose and suggests its synthetic relationship to sucrose phosphate synthesis.
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Action and Emission Spectra of the Luminescence of Green PlantMaterials

Action and Emission Spectra of the Luminescence of Green PlantMaterials

Date: December 29, 1957
Creator: Tollin, G.; Fujimori, E. & Calvin, Melvin
Description: The action and emission spectra of the delayed light emission from Chlorella, Nostoc, and spinach chloroplasts have been measured. The action spectra for Chlorella and for spinach chloroplasts are quite similar to the absorption spectra of these materials. The action spectrum for Nostoc, on the other hand, shows a relatively low activity for chlorophyll and carotenoids and a high activity for phycocyanin. The emission spectra of these materials demonstrates that the luminescence is the result of a transition between the first excited singlet state and the ground state of chlorophyll. Low-temperature studies suggest that the triplet state of chlorophyll is not involved at all in the luminescence of spinach chloroplasts. There is some indication that part of the light emitted from Nostoc is due to a phycocyanin transition.
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Reduction of Carbon Dioxide inAqueous Solutions by IonizingRadiation

Reduction of Carbon Dioxide inAqueous Solutions by IonizingRadiation

Date: March 13, 1951
Creator: Garrison, W.M.; Morrison, D.C.; Hamilton, J.G.; Benson, A.A. & Calvin, M.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Q and Zs for 1/10 Scale Gravity

Q and Zs for 1/10 Scale Gravity

Date: October 23, 1950
Creator: Sewell, D.
Description: No abstract prepared.
Contributing Partner: UNT Libraries Government Documents Department
The Chelate Process, VI. Process flow involving o-dichlorobenzeneas the solvent for TTA

The Chelate Process, VI. Process flow involving o-dichlorobenzeneas the solvent for TTA

Date: January 1, 1951
Creator: Davis Jr., M.W.; Hicks, T.E. & Vermeulen, T.
Description: Comparative studies of a series of halogenated solvents, as carriers for TTA in the chelate process for plutonium extraction, indicate that ortho-dichlorobenzene most nearly satisfies the requirements that are set forth. A complete process design is presented for use with this solvent, and flow data and equipment capacities are given for dissolver solution and for uranium-free fission product solution as alternate feeds to the process. Vertical mixer-settlers are recommended as the contractors, although pulsed columns or packed columns are also believed to be suitable. The size of such units is estimated from the best available rate and equilibrium data, and the effects of several operating variable are considered.
Contributing Partner: UNT Libraries Government Documents Department
K Interactions in Hydrogen

K Interactions in Hydrogen

Date: November 14, 1956
Creator: Alvarez, Luis W.; Bradner, Hugh; Falk-Vairant, Paul; Gow, J.Donald; Rosenfeld, Arthur H.; Solmitz, Frank T. et al.
Description: No abstract prepared.
Contributing Partner: UNT Libraries Government Documents Department
The Photosynthetic Cycle and Respiration: Ligh-DarkTransients

The Photosynthetic Cycle and Respiration: Ligh-DarkTransients

Date: March 1, 1956
Creator: Bassham, James A.; Shibata, Kazuo; Steenberg, Kjell; Bourdon,Jean & Calvin, M.
Description: Studies of the transient changes in radiocarbon found in various photosynthetic and respiratory intermediates in Scenedesmus, which result when changing from a condition of steady-state photosynthesis in the light to dark and then back to light again, indicate the following metabolic mechanisms: (a) The carboxylation step in the carbon-reduction cycle of photosynthesis results in the formation of two molecules of 3-PGA from one RuDP molecule, one CO{sub 2}, and one H{sub 2}O: (b) This carboxylation reaction proceeds for about thirty seconds in the dark after the light is turned off and its rate is proportional to the falling concentration of RuDP, and stops when the latter concentration falls to zero. (c) Turning off the light results in the transfer of radiocarbon from PGA to citric acid, and glutamic acid, whereas turning on the light results in a decrease in radiocarbon in citric acid. These results provide new evidence for the theory that the oxidation of pyruvic acid to acetyl CoA and CO{sub 2} with a subsequent condensation of acetyl CoA with oxaloacetic acid to give citric acid is blocked in the light by reduction of a cofactor, which may be thioctic acid, required for pyruvic acid oxidation. (d) These transients ...
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Small Angle Neutron-Proton Scattering at 90 MEV

Small Angle Neutron-Proton Scattering at 90 MEV

Date: February 4, 1954
Creator: Chamberlain, Owen & Easley, James W.
Description: No abstract prepared.
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The Path of Carbon in Photosynthesis. XVII. Phosphorus Compoundsas Intermediates in Photosynthesis

The Path of Carbon in Photosynthesis. XVII. Phosphorus Compoundsas Intermediates in Photosynthesis

Date: July 8, 1952
Creator: Buchanan, J.G.; Bassham, J.A.; Benson, A.A.; Bradley, D.F.; Calvin, M.; Daus, L.L. et al.
Description: Studies of carbon dioxide fixation in green plants using the C{sup 14} isotope have shown that in very short times phosphoglyceric acid contains most of the radioactivity. The tracer is present almost entirely in the carboxyl group. The importance of organic phosphates in the subsequent metabolism of phosphoglyceric acid can be seen from the accompanying photographs.
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The Velocity-Selecting Cerenkov Counter

The Velocity-Selecting Cerenkov Counter

Date: April 17, 1956
Creator: Chamberlain, Owen & Weigand, Clyde
Description: None
Contributing Partner: UNT Libraries Government Documents Department
A Survey of the Rates and Products of Short-Term Photosynthesis inPlants of 9 Phyla

A Survey of the Rates and Products of Short-Term Photosynthesis inPlants of 9 Phyla

Date: May 1, 1954
Creator: Calvin, M.; Norris, R.E. & Norris, Louisa
Description: The conclusions of this paper are: (1) Short-term photosynthetic experiments using C{sup 14}O{sub 2} and paper chromatography were performed with 27 different plants representing nine phyla: Schizophyta (Schizophyceae), Euglenophyta, Chlorophyta, Charophyta, Chrysophyta, Rhodophyta, Bryophyta, Pteridophyta, and Spermatophyta. (2) There is a remarkable uniformity in the types of ethanol-soluble compounds which became radioactive in the entire group of plants used. The amounts of the different compounds varied considerably percentage-wise among the various plants as would be expected because of their inherent metabolic differences and the variations in their physiological states induced by experimental conditions. (3) Sucrose became radioactive in very different amounts in two major groupings of plants: (a) those containing only photosynthetic tissue and (b) those containing non-photosynthetic tissue as well. The amount of radioactive sucrose in the former group was much lower than that in the latter. (4) An unidentified compound became radioactive in appreciable amounts in two of the blue-green algae, but was radioactive in very small amounts or not visible at all on the chromatograms of all other plants.
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Energy Conversion in Photosynthetic Processes

Energy Conversion in Photosynthetic Processes

Date: March 10, 1958
Creator: Tollin, Gordon; Sogo, Power B. & Calvin, Melvin
Description: The concepts of solid-state photophysics are applied to biological materials, especially particulate matter derived from green plants. Photoinduced electron-spin resonance signals have been observed in isolated chloroplasts and other green plant materials; their growth time is not affected by reducing the temperature to -140 C. The luminescence of these materials has also been investigated under a variety of conditions. The results of these studies have been shown to be consistent with a mechanism involving the recombination of electrons and holes trapped in a quasi-crystalline lattice. Some details of such a mechanism have been proposed that suggest the mode of entry of the light energy into the photosynthetic pathway.
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Medical and Health Physics Quarterly Report October, November, andDecember, 1950

Medical and Health Physics Quarterly Report October, November, andDecember, 1950

Date: February 27, 1951
Creator: Biology, Health and
Description: A considerable volume of work was accomplished during the past three months in the tracer program, experiments being conducted with At{sup 211}, carrier-free Bi{sup 206}, carrier-free Mn{sup 52}, carrier-free Mo{sup 93,99}, Np{sup 237}, Ta{sup 182} of a fair degree of specific activity, carrier-free Sc{sup 46}, and high specific activity Tm{sup 170}.
Contributing Partner: UNT Libraries Government Documents Department
Effects of Mineral Salts on Short-Term Incorporation of CarbonDioxide in Chlorella

Effects of Mineral Salts on Short-Term Incorporation of CarbonDioxide in Chlorella

Date: July 1, 1958
Creator: Holm-Hansen, O.; Nishida, K.; Moses, V. & Calvin, M.
Description: Although the functions of the essential major elements in plant metabolism have been studied for many years, little work has been done concerning the effect of these elements during short-term incorporation of radioactive carbon dioxide. This may be of some importance as it has been the general custom during photosynthesis studies in this laboratory to suspend algae in various dilute buffer solutions or in distilled water alone assuming that the salt remaining within the cells from the time of growth in nutrient solution are sufficient in quantity for the cells not to become deficient in one or more of the essential elements during the course of the experiment. There are some indications, however, that the addition of salts to algae suspended in distilled water may have a rapid, pronounced effect on some metabolic system within the plant. Thus, Clendenning, Brown and Eyster (1956) have reported that Nostoc muscorum, if rinsed and resuspended in distilled water, loses most of its photosynthetic capacity, which can, however, be completely restored by the addition of potassium ion in concentrations no greater than a few parts per million. Also, K. Baalorud (personal communication) found that the photosynthetic rate of a marine diatom, when suspended in ...
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Spallation-Fission Competition in Heaviest Elements; Helium IonInduced Reactions in Plutonium Isotopes

Spallation-Fission Competition in Heaviest Elements; Helium IonInduced Reactions in Plutonium Isotopes

Date: June 1, 1956
Creator: Glass, Richard A.; Carr, Robert J.; Cobble, James W. & Seaborg,Glenn T.
Description: Excitation functions have been determined for the spallation and fission reactions induced in plutonium isotopes by 20 to 50 Mev helium ions. The method employed consisted of cyclotron bombardments of plutonium oxide followed by the chemical isolation and alpha or beta counting of radioactive reaction products. Formation cross sections are given where possible for the curium and americium spallation products corresponding to ({alpha},n), ({alpha},2n), ({alpha},3n), ({alpha},4n), ({alpha}5n), ({alpha},p), ({alpha},pn or d), ({alpha},p2n or t), and ({alpha},p3n) reactions in Pu{sup 238} , Pu{sup 239}, and Pu{sup 242}. Fission yield curves and fission cross sections for Pu{sup 238} and Pu{sup 239} serve to define the characteristics of the ({alpha},f) reaction for plutonium isotopes. Chemical procedures are outlined for the separation of both spallation and fission product elements in a sequence of operations performed on the entire dissolved target.
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