Some numerical calculations have been done which permit the deduction of many properties of the synchrotron oscillation problem. For the presentation of the numerical results, it is useful to review the formulation framework to which the results are to be fitted. These are worked out for an arbitrary circular accelerator. The algebra woud have to be modified slightly to include straight sections but the numerical results are still useful.

Preliminary data are enclosed in Tables I, II, II, IV, V, and VI. Tables I to V are data for round nickel tubes in a vertical and inclined (45°) position. Table VI contains some preliminary data for nickel rectangular channels (0.060" and 0.050" spacings) in a vertical position.

A series of measurements was performed to investigate the gamma ray spectra, in the region from about 100 kev to about 3 Mev, resulting from the capture of thermal neutrons in a number of elements. The purpose of the experiment was to supplement the high energy capture gamma ray data in order to remove some of the ambiguities from the proposed energy level schemes and to obtain information for the Shielding Group of Brookhaven National Laboratory on elements normally found in reactors.

A working definition of homeostasis is the following: the sum total of the processes which maintain a steady level of various substances or functions within a living baby. Our own concern will be with the homeostasis of trace metals. I will begin with a slide which shows the total body concentration of various metals, including "trace" ones. Only metallic constituents which play a role in the maintenance of the body's structure and function are shown. The essential trace metals among them are represented by black bars. Iron is both black and white. Indeed, if one excludes the fixed sequestered iron of myoglobin and of hemoglobin, one is left with a trace fraction of iron about which I will be talking later on. Note that the scale is logarithmic, indicating that the concentrations of essential metals in the body fall off sharply and smoothly.

Recent measurements of the pion-proton total cross section, taken with small statistical errors, have shown the existence of two new maxima in the momentum range between 2 and 3 BeV/c. Measurements of comparable statistical accuracy, covering the momentum range from 2.5 to 8 BeV/c are reported in the present paper. In addition to the total cross sections for π± mesons on protons, their total cross sections on deuterons have also been determined. Some data were also taken on the total cross sections for K+ mesons on protons and deuterons and for K- mesons on protons.

Tissue from etiolated or partially etiolated Pisum seedlings is widely used in work on growth substances and light responses. However, in the authors' experience growth under the conditions commonly employed is frequently irregular, and often affords little or no satisfactory experimental material. Although the literature records little evidence of such difficulties, personal communication with many investigators leaves no doubt they are widespread.

In the analysis of the effect of ionizing radiation on living systems, the problem is complicated by the interaction of one part of the system with other parts. If an entire mouse is subjected to radiation, only a few of the most radiosensitive organs, the "weak links," react to the insult and essentially limit the size of the dose delivered since there is little to be learned from irradiating a dead mouse. Thus an insensitive organ like muscle will not respond at all to a total body dose. Likewise, every organ is composed of several different kinds of cells, and the most radiosensitive cells in the organ will determine the reaction observed.

Data on the mitotic indices of human bone marrow cells were reported in the first paper of this series, and theoretical considerations on the applicability and limitations of the index in determining kinetic parameters were discussed. In the present paper an attempt is made to compute time parameters of normal bone marrow cell proliferation from the data presented in the first paper.

Previous investigations that the pancreas is a radioresistant organ. Ivy in 1924 noted the presence of a fibrotic atrophic pancreas in a dog which had received one erythema dose to the epigastrium. Fisher in 1923 reported that four to five erythema doses delivered in a single application caused complete disappearance of the irradiated pancreatic remnant in about two months. These dogs died because of uncontrolled diabetes. One dog that received four erythema doses (possibly 200 r) was sacrificed after five months. At autopsy the irradiated pancreas had disappeared, but 275 mgm of regenerated pancreas were found at the base of the main duct and 100 mgm at the base of the accessory duct. Leven in 1933 implanted radon seeds into the pancreas. Dosages varied from 528 to 1584 millicurie hours. At postmorten the pancreas surrounding the seeds demonstrated fibrous atropy and foci of necrosis. The islets appeared normal but were relatively larger in size. Rauch in 1952 reported that dogs given 200 r in air over the pancreas on alternate days until a total of 1600 r was received failed to show any histological changes after two months. Lushbaugh and Spalding and Lushbaugh reported that over 1500 r of whole-body …

Our earlier in vitro studies have suggested that malignant tumors may not produce new cells more rapidly than normal cells are produced in the "steady state" equilibrium. Obviously tumors of all typed represent a diversion from "steady state" production with a net gain in mass of tissue. However, the increase in mass is not necessarily constant and may fluctuate in the natural history of the disorder. DNA labeling with tritiated thymidine had made it possible to characterize normal "steady state" hemopoietic growth parameters. We therefore thought it mandatory to extend these techniques to the study of growth rates of human leukemic cells. Also, since current therapy is more or less closely tied to a concept of unrestrained rapid growth, which we in part have begun to question, it appeared wise to look back at the historical development of knowledge about tumor growth. The existence of tumors in man has been known for millenia.

Numerous studies on the effects of radiation on the central nervous system used traditional pathomorphological changes as parameters of radiosensitivity, but pathogenesis and mechanisms of radiation injury to the nervous tissue are still little understood. Furthermore, the great discrepancy of dose requirement leading to physiological responses and on the other hand to pathomorphological changes in the central nervous system is not satisfactorily explained.

It has been known for many years that bone growth may be retarded by relatively large doses of therapeutic radiation. Similar doses of radiation have also shown retarded growth in animals. More recently, reports of studies of Japanese children exposed to the Atomic Bomb Detentions at Hiroshima and Nagasaki and Marshallese children exposed to radiation in the fallout accident of 1954 have indicated some impairment in their growth and development, possibly related to radiation exposure. Since the doses of radiation received by these children were lower than would be expected to produce retardation of bone growth by direct irradiation, it was considered that indirect mechanisms might play a part. This preliminary report summarizes investigations of possible indirect effects of X-irradiation in bone growth in rats.

Encysted Trichinella spiralis larvae incorporated carbon-14 from mice fed diets containing C14 -labeled glycerine and DL-alanine. In general, a higher level of C14 activity (C14 per gram of dry tissue) was found in muscle larvae than in muscle tissue. The presence of encysted Trichinella larvae in the muscles of 56-day and 180-day infected mice did not alter incorporation of C14 from these amino acids into infected muscle protein when compared with noninfected muscle. These experiments were extended to include the aromatic amino acids, DL-tyrosine and DL-tryptophan.

Seven lysogenic strains - three of Rhizobium Leguminosarum and four of R-trifolii - were identified among a total of 54 strains from these two species and R. phascoli. The R. leguminosarum strain may be multiply lysogenic; two of them also produce lethal agents resembling bacteriocins in their effects. Lysogeny was confirmed by standard criteria of UV-inducibility, self-immunity, and reproductive ability. Lysogenic conversion involving symbiotic characteristics was not observed. A minimum of six different temperate phage were identified. The host range includes strains of the above three rhizobial species, but not of R. mclilotii. Variation in host specificity of some phage following host passage is under investigation.

The following cells were operated at 820°C: [equations not transcribed] where the over-all reaction in each cell is simply the transfer of NaCl from pure NaCl to the mixtures of the right hand compartment. The porcelain acts as a pure sodium ion conductor in these cells. The relative partial molar free energy of mixing for sodium chloride, FMNaCl, is given by [equation not transcribed] where E is the EMF of the cell. Results are given over the entire composition range in each system and compared with previous measurements from other sources. Other thermodynamic quantities are calculated from the results. Experiments using a H2, HCl mixture in place of Cl2 are discussed, as well as the extension of the measurements to other systems.

Previous attempts by the present authors to compare the behavior of orally administered vitamin B12 with that of injected material have been inconclusive. Thus, 30 days after administration to normal humans, 0.19% of a tracer amount (0.5 μg) of injected radioactive vitamin B12 is excreted per day; and in an independent study, the eventual daily output was found to be 0.23% of a 3 μg dose. By contrast the total excretion rate of normal vitamin B12 from body stores appears to be only ≈0.03% per day. Such a divergence may result from incomplete mixing of radioactive vitamin B12 and body stores of the vitamin. Alternatively it may actually reflect the functioning of different compartments attending the several modes of administration involved. The possibility of degradation or transformation of vitamin within tissues and organs must also be considered.

The aim of this series of experiments was to evaluate the existence of abscopal effects of irradiation. No attempt was made towards the elucidation of mechanisms. Very early in the history of radiological research it was noticed radiation produces both local and general effects involving the entire body. Gauss and Lembcke introduced the term "Roentgenkater" (radiation sickness). They ascribed these "General Effects" to the circulation of toxic substances released from cells that disintegrated following irradiation.

It has been established by chromosome marker studies, histochemical, immunological, and cytological methods that the hemopoietic tissues of animals exposed to lethal doses of whole-body irradiation can be repopulated by transfused autologous, homologous or heterologous bone marrow cells. However, the morphology of the cell responsible for the regeneration of hematopoietic activity in the various hemopoietic organs has not been identified. It has been shown that the bone marrow contains the cell or cells capable of regenerating all types of hemopoietic tissues. In order to identify transfused cells, one must have a label which persists through successive divisions. Odell and Smith labeled the donors with S35 methionin and were thus able to follow the accumulation of the donor marrow cells in the recipients lungs and subsequently their releases to the bone marrow and spleen. However, this compound has a relatively rapid turnover in the labeled cells and thus a relatively limited capability of serial studies to observe mitosis and differentiation. Tritiated thymidine is ideal for this purpose since it is incorporated solely into DNA and is diluted only by mitosis. In addition the high resolution with tritium makes it certain that one is observing nuclear labeling. Bond et al. have studied …

The mode of dissolution of magnesium in molten magnesium chloride contacted with Mg-Pb alloys was studied at 750°C using anodic chronopotentiometry. An inert tantalum anode was used to determine relative amounts of magnesium dissolved in its chloride as a function of magnesium activity in the alloy. According to the law of mass action a linear dependence of magnesium solubility on a Mg indicates Mg2Cl2 as the reaction product and a parabolic dependence indicates MgCl. It was found that the amount of magnesium dissolved in its chloride was directly proportional to the magnesium activity in the metal phase, i.e., a linear dependence, indicating Mg2Cl2 as the subhalide species. Due to the corrosive nature of the Mg-MgCl2 system a special apparatus was used so that only the inert metals tantalum and molybdenum came in contact with the melt. Purification procedures and conditions for proper equilibration and measurement were established and are reported. The basic equation of chronopotentiometry, [equation not transcribed], was found to hold and at given magnesium activities the product [unintelligible] did not vary with the current, indicating the validity of the analytical technique.

This paper will first note briefly the place and status of radiobiotopical investigations with fast neutrons. The monoenergetic (fast) neutron technique employed at this laboratory will be then described and results of studies with various criteria-of-effect in the mouse will be reviewed. Finally, certain general patterns of response for these systems will be pointed out as functions of neutron energy.

The problem to be discussed originates in our interest in the diagnosis and treatment of brain tumors. It has been established by others that some positron-emitting radioactive isotopes, in particular Arsenic-74 and Copper-64, can be causal to localize in brain tumors and thus to serve as agents for locating the tumors. Although other kinds of radioisotopes have also been used successfully in locating tumors, positron emitters have some especially attractive features. Their use is based on the principle that a positron, or positively charged electron, is a form of "anti-matter," and when it encounters an ordinary negatively charged electron both are annihilated, giving rise to two gamma rays that are emitted in opposite directions. Such an event is detectable through the use of coincidence counting. The data for which the method of analysis is to be discussed in the present paper is generated by a device using the coincidence counting method with multiple detectors in an arrangement potentially suitable for three-dimensional localization of brain tumors.

Kalanchoe seedlings were exposed to 330 r/20 hrs/day from a Co60 source. Samples were harvested weekly. No new leaves were produced after initial exposure to irradiation. Mitosis in the apical meristem appears to have been suppressed. However, the axillary meristem and the cambium continue their activity. This results in a much broadened stem tip with enlarged cells, supported by a stout internode in which cell size has remained relatively normal but cell number has increased. After about 26 days of exposure, meristematic activity in the shoot apex region appears to resume. This results in the formation of growth centers which can give rise to leaves or malformed structures. The original phyllotaxy is not recovered. It is suggested that this resumption of growth may be an instance of adaptation to irradiation.

Production cross sections and angular distributions of Λ and K° particles produced by 11.4 Bev/c π" mesons in hydrogen have been measured. A systematic investigation was made of all two-body decays of unstable neutral particles. No events inconsistent with γ, Λ, or K° were found. Production cross sections, angular distributions and effective mass distributions of π mesons produced in 4-prong events were also measured. No evidence for dominance of any high mass multi-pion resonance was found. Both the pion production and strange particle production reactions demonstrated peripheral characteristics in that the baryon was strongly peaked backward in the center of mass. The average transverse momentum was observed to be a monotonically increasing function of mass. The experimental total interaction cross section was 25.3 ± 1.5 mb. The effect of the pion-nucleon T ' 3/2 isobar was clearly observed.

Since 1940 it has been known that extra salt (i.e. sodium chloride) facilitated the development of experimental hypertension induced by various sterols; subsequently hypertension was induced by desoxycorticosterone acetate plus sodium chloride; then hypertension was produced by using hypertonic saline as the sole source of liquid; and finally, in 1953, Menesly and his associates reported that chronic ingestion of excess dietary salt alone would produce hypertension in rats. Furthermore, in conformity with general pharmacologic experience relating dose response to successive increments of a drug, as the average daily salt intake increased, the average systolic, blood pressure increased.