In this paper some studies on enzyme properties which are believed to be pertinent to antibodies will be discussed. The particular studies chosen are; (a) the evidence that residues far removed from each other in the sequence play vital roles at the active site; (b) indications on the size of the active site; and (c) evidence for flexibility at the active site. Since the relation between enzyme and antibody is of primary interest an attempt will be made to emphasize the fundamental conclusions derived from the observations and to evaluate critically the deductions on structure and function which derive from these conclusions.

The sexual reproductive ability of a forest exposed to low level ionizing radiation is dependent on the sensitivity of primordial differentiation, meiotic processes leading to the formation of gametes, fusion of the gametes, and subsequent growth of the sporophytic generations. In this report it was shown that the initiation of reproductive primordia in Pinus rigida, Quercus ilicifolia, Quercus alba and Quercus coccinea is not unusually sensitive to irradiation. Trees which had been severely damaged by chronic low level ionizing radiation (4 to 12 r/20 hr day) were able to differentiate floral structures and produce viable seed. However, flower phenology was retarded, and pronounced morphological aberrations were present. It is suggested that this delay may be the result of a reduction of endogenous growth substances.

Ionizing radiation is useful to plant breeders in obtaining mutations beneficial from an economic point of view. This report, however, concerns our basic knowledge of radiation: attention is here directed to some effects of low level radiation on the R₁ progeny. Approximately one third of the land area of the United States is covered by forest; thus, forest trees form an important component of our natural wealth. It is therefore our obligation to know how these forests will react to low level ionizing radiation. Although this type of radiation might accompany atomic explosions, its effects may not be evident for a number of years.

The propagation of clonal varieties of some orchids is at times exasperatingly slow and occasionally an almost futile effort. Clonal multiplication is generally confined to dividing mature plants and to starting plants from pseudobulbs. There is, of course, the specialized technique for obtaining Phalaenopsis plantlets from the aseptic culture of inflorescence nodes, but this is basically the same thing as propagating plants from pseudobulbs. In certain cases it is highly desirable to rapidly multiply certain clones of orchids. Awarded varieties could thereby be dispersed with great rapidity where now it may take decades for some clones to became fairly common. Commercial flower production would be very much enhanced if certain desirable clones could be multiplied ad infinitum within a short time. Orchid flower production could then be placed more on a par with many of the other cut flowers and the clonal peculiarities of some of the current hybrids could be pampered instead of ignored. This paper describes a tissue culture method for the rapid propagation of Cymbidium clones

The potassium-argon age of the Sikhote Alin iron meteorite has been determined. The value is 1.7 + 0.2 x 10⁹ years. Previous lead data suggest an age of 4.6 x 10⁹ years . The date of solidification may be the sum of these two ages.

In order to perform the various experiments with a bubble chamber, a high intensity flash tube is used. This report briefly describes the power supplies designed and constructed to power these lamps.

The power supplies designed and constructed to power high intensity flash tubes used in bubble chamber experiments are briefly described and are accompanied by a schematic diagram of the layout. (D.C.W.)

The analyzer can be operated either internally or externally. The 10 ma germanium discriminator is quiescently biased to 8.5 ma in its low-voltage state. An input signal current of 3.5 ma or more triggers it to its high voltage state. This triggers the oscillator. The oscillator signal is buffered and mixed in the bridge modulator with the reference radiofrequency signal from the cyclotron. The low-frequency beat note from the bridge modulator is squared up and passed to the beat zero univibrator which generates 0.7 mu sec signals each time the beat note passes through zero from positive to negative. The trailing edge of the beat zero univibrator is employed to terminate the time-of-flight measurement and to control the servo measurement. Drawings are included. (M.C.G.)

The object of this report is to acquaint the operator with the operational and technical aspects of the beam current integrator as well as the theory of the system operation. The design and operation of a beam current integrator are described, and the theory of operation is discussed. The instrument has two channels. The console channel is designed to measure the accumulation of charge received by a target during a period of a day no matter what the range used in the experimenter's channel. An analysis indicated that this unit will measure the accumulation of charge by a target to an accuracy of 0.1215% assuming that the constant error due to shorting the integrating capacitor is accounted for. The instrument is ranged to handle from 0.5 to 500 mu a of beam current. (M.C.G.)

A digital-to-analog converter is described which is a part of a system that converts punched-tape digital data to analog data in a series of points drawn by an x-y plotter. The converter is designed to plot accurately tapes that contain information other than coded numerical coordinates. Operation of the converter is also described along with format requirements and power supplies. (J.R.D.)

Most existing electron synchrotrons use betatron start for initial acceleration of the particles. The subsequent synchrotron acceleration is then performed with a nearly constant radio-frequency. Investigation of the effect of turn-on rate and initial energy spread is made mathematically. Several advantages are seen for such a technique. (D.C.W.)

The efficiency of multiple traversal targets is defined as the probability that a proton dies by making a nuclear collision in the target rather than by hitting the limit of the synchrotron aperture. The efficiencies of Be, Al, Cu, and Pb targets are shown for 15 and 30-Bev protons in the Brooknaven AGS. Beryllium was found to be the most efficient. (M.C.G.)

Maintenance of polarization of polarized protons in a linear accelerator is known to be feasible. Circular accelerators present a different problem, and the investigation of the interaction of orbit dynamics and particle polarization in general is undertaken. The equation of motion of the spin vector of a charged particle in a magnetic field as formulated by Bargmann, Michel, and Telegdi is utilized in the study of depolarization for several accelerators. High values of depolarization are obtained, and means for avoiding such depolarization are suggested. (D.C.W.)

An investigation was made of Cosmotron intensity versus time through the entire time interval from the beginning of injection to the completion of r-f capture. The induction electrode signal was used for the instantaneous measurement of beam intensity. Oscilloscope displays of the signal were photographed and traced. Base lines were filled in on the tracings and the area of the pulses measured with a polar planimeter. It was found that the relation losses of beam intensity increase with injection intensity (total injected charge), and that most of the losses take place in the time interval between the end of injection and the completion of the first synchrotron oscillation

Use of the Smith chart in studying stub tuners is demonstrated. Several properties of the tuners are shown, and charts for various wave length spacings, tuning trajectories, and admittances are included.

Technique used in deriving values of the linac ball tuner settings to produce various fields is discussed briefly, and tables showing ball tuner change numbers and values used in making up the ball tuner change numbers are given.

This report describes the design procedure for a reflectometer or directional coupler to replace the probe part of the D07-1020 assembly used at the Brookhaven Alternating Gradient Synchrotron linac. Mathematical treatment and diagrams of various reflectometers are included.

Two methods for measuring target efficiencies are briefly discussed. The second method puts an upper bound on the efficiency and permits observation of instantaneous efficiency, thereby aiding location of losses. Measurements agree well with conventional radiochemical values.

The G-values for the formation of H₂ and CH₄ in the Co60 gamma radiolysis of the xylene isomers and ethylbenzene were compared. The presence of iodine does not affect GH2, but reduces GCH4 a limiting value. For p-xylene, GH2 and the unscavengeable CH₄ yield are independent of temperature from 20 to 110 deg C, whereas the total CH₄ yield increases six-fold over this range. The H₂ and CH₄ yields are greatly reduced in the solid state, and in the liquids state benzene shows a protective effect on the yields of both gases. The formation of CH₄ and C₂ -hydrocarbons was compared with the C6 -and C7 - products for p- xylene and ethylbenzene, and isomerization is shown to occur to a negligible extent. The production of high-molecular-weight products was measured for the xylenes, and is independent of dose rate and temperature for liquid p-xylene, but is decreased in the solid state. The results are qualitatively consistent with the reactions of radicals and excited molecules.

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.

A brief overview of a study on the effect of 5-fluoroucil (FU) on chloroplast formation in Euglena,

Ever since the hydrolysis of ATP by myosin was discovered the mechanism of this reaction has been a subject of intensive research. In some way the energy of the phosphate bond must be transferred to muscle protein so that chemical energy can be transformed into mechanical work. Formation of a phosphoryl-myosin intermediate has been suggested by many workers but evidence for such an intermediate has been elusive. ADP-32-ATP exchanges gave negative results and no P32-labeled myosin, other than that absorbed by non-covalent forces, has yet been identified with the hydrolysis reaction

Human iron metabolism has been extensively studied in the past twenty-five years with the radioisotopes iron⁵⁵ and iron⁵⁹. Before the availability of the whole body counter, however, iron absorption studies were performed by the indirect methods of fecal assay of unabsorbed radioiron, and estimation of red cell incorporation of absorbed tracer. The few long-term excretion studies performed required numerous assumptions, since human iron excretion was less well understood. Whole body counting provides a simple and accurate method of measuring the total body retention of administrative tracer iron⁵⁹, thus making absorption and subsequent excretion determinations possible with a single radioiron study. The energetic gamma emissions of iron⁵⁹ permit ready external detection with small quantities of isotope, Normal radioiron distribution is uniform throughout the circulating red cell mass and thus minimize geometry influences on the counting efficiency, 0nly the 45.1 day half-life of iron⁵⁹ limits long term iron turnover studies. Measurements of iron⁵⁹ absorption and long-term body turnover have been under way at Brookhaven National Laboratory for over two years. The present paper outlines some of the results of these studies, and discusses some implications of the method.

The biological effects of various doses of radiation in plants are reviewed. Data are reported from a study of the effects of gamma radiation on a terrestrial ecosystem in which oak and pine are the principal tree species. Exposure rates around a 9500-C Cs¹³⁷ source varied from several thousand r/day within a few meters to about 2 r/day at 130 m delivered during a 20-hr day. Measurements were made of changes in the populations of species which formed the ecosystem, the rates of fixation, paths of energy movement through the system, differences in radiosensitivity among the plant species, and radiation effects on host-parasite relations. Results are discussed from the standpoint of the results of contamination of the environment with radioactive debris.