Actual Interference Research Articles

Intensity Distributions in Electron Interference Phenomena Produced by an Electrostatic Bi-prism

The paper describes a model of electron interference obtained using an electrostatic bi-prism. The model is an approximation to the actual interference process, in which two diffracted waves, each representing the diffraction of electrons emerging from a single source by an opaque half-plane, are superposed in such a way that the half-planes are of opposite orientation and overlap by a distance equal to the width of the bi-prism filament. The intensity distribution in the interference pattern calculated according to the formula derived from this model is in an exact agreement with the intensity distribution found experimentally. This makes it possible to present a consistent quantitative explanation of all the special properties of the interference pattern, including intensity modulation of the fringes. The model may also serve for detailed interpretation of some interference phenomena in light optics, such as those observed with the help of Fresnel mirrors or a Fresnel bi-prism.

PRODUCTION OF A POLYSACCHARIDE BY STAPHYLOCOCCUS AUREUS. 3. ACTION OF PENICILLINS AND POLYSACCHARIDES ON ENZYMIC LYSIS.

Summary1. The resistance of S. aureus to lysis by lysozome and trypsin was abolished by exposing growing cells to subinhibitory concentrations of nafcillin. This observation, together with the results of electron microscopic studies of nafcillin-treated cells exposed to maximal enzymatic action, reflect an actual interference with cell wall synthesis. 2. Although the precise cytological action of the subinhibitory levels of the penicillins on the integrity of the cell wall is not known, the limited lytic action of lysozyme on cells treated with oxacillin and cloxacillin, as well as the resistance of these cells to further lysis by trypsin, suggest at least a quantitative difference between nafcillin and the other penicillins in the disorganization of the cell wall structure. 3. On the basis of the experiments described, evidence is presented which indicates that subinhibitory levels of nafcillin produce an alteration of cell wall structure, thereby increasing permeability and rendering the cell wall and p...

Reduction of pituitary content of ACTH by cortisone.

CORTISONE administration induces adrenocortical atrophy in experimental animals (Ingle and Kendall, 1937) and in man (Sprague et al., 1950; Wilkins et al., 1950). The mechanism of action of the steroid is in part a reduction in rate of discharge of ACTH from the adenohypophysis. However, the steroid has been reported to induce histopathological changes in the pituitary and the possibility exists that actual interference with ACTH synthesis as well as discharge occurs. The present report indicates that cortisone decreases the rate of synthesis of ACTH by the pituitary of the dog. materials and methods Three mongrel dogs were treated with cortisone, 100 mg. per day, by subcutaneous injection. One animal was treated with cortisone for 14 days, a second for 44 days and a third for 71 days. Three dogs received injections of saline and served as controls. At the end of the treatment, each dog was anesthetized with sodium pentobarbital and killed by exsanguination.

Mariposa Claim.

Treaties — Interpretation — Rules of — Rejection of Presumption against Redundancy — Interpretation of United States-Panama Claims Convention of 1926.Arbitration — Jurisdiction — Claims Arising Subsequent to Ratification of Arbitral Agreement.State Responsibility — Conditions of — Expropriation by Legislation — Necessity of Actual Interference with Possession — Arbitration — Jurisdiction — Claims Arising subsequent to Ratification of Arbitral Agreement — Treaties — Interpretation — Rules of — Presumption against Redundancy — Interpretation of the United States-Panama Claims Convention, 1926.

NICOTINIC ACID IN THE TREATMENT OF ATYPICAL PSYCHOTIC STATES

There have been reports of excellent results from the treatment of pellagrous psychoses with nicotinic acid;¹these have dealt with the more familiar mental symptoms occurring in frank or subclinical pellagra of the usual type. The present communication deals with observations made on nineteen individuals all presenting mental symptoms of somewhat similar pattern, none corresponding to the ordinary conception of pellagrous dementia. Hebetude grading into profound stupor was a feature so prominent that frontal lobe tumor was suspected in three patients, lethargic encephalitis in one and chronic subdural hematoma in a third. Delirium was present three times, agitated depression once, and one patient presented the signs of central neuritis. Signs of peripheral neuritis were not discovered, but five patients had marked deafness which disappeared under treatment; it was difficult to determine whether this transient deafness was due to failure of attention or to actual interference with the auditory mechanism.

Episiotomy and Perineal Repair

T HERE is a seeming paradox in obstetrical practice-increase in obstetrical knowledge and skill and yet no apparent corresponding drop in the maternal death rate. It has been repeatedly explained, however, that the report of death and morbidity are more accurate than formerly, and that there is still in large centers of population an inferior work being done. The accurate records and the inferior work in some localities account, in some measure, for the apparent discrepancy. It is true, however, that there is a decided change in the attitude of the public toward hospitals and that many more people than formerly are going to institutions for the lying-in period. With this increasing hospitalization of obstetrical cases there is every reason to believe that the records will show a corresponding drop in the maternal death rate. During the care of a patient a good obstetrician has in mind definite objectives: as comfortable a delivery as is compatible with safety, a well mother after delivery, and a healthy baby. Every obstetrician wishes to see his patient back in the usual routine of life with no distressing sequelae. Every woman coming to her physician wants to be well, she wants a well baby, but at the same time she wants that baby with as little pain as possible. The number of operative deliveries in hospital work is slowly increasing. Such deliveries in skilled hands will be a logical result of obstetrical advance. The usual rules in regard to interference, however, should always be observed. Actual interference will depend on the judgment and good sense of the operator. A large number of backaches and malpositions of the uterus can be avoided if

Submarine Cable Telegraphy: Influence of Interference

The design and operation of long submarine telegraph cables are affected to an important degree by extraneous electrical interference near the ends. The amount of interference in different cases is dependent upon a number of factors, some of which can only be determined by measurements made in the vicinity. The relation is first given between the amount of interference and the operating speed of the cable, assuming the interference to be sinusoidal. This is extended to include actual interference which is not sinusoidal. Since the computations with non-sinusoidal interference are too tedious for general field use, an experimental method is given which provides results which may be used directly in determinations of the effect upon cable operation. Examples are given of the computation of the response of the receiving instrument under the influence of a transient extraneous voltage, the frequency characteristic of the receiving equipment being known. Conversely, examples are given of the computation of the frequency characteristic from the results of an experimental determination of the response of the receiving instrument to a transient impressed voltage.