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Irradiation of an insulator by gamma rays can produce voltage and charge buildups near thin layers of foreign material within the insulator. Measurements have been made of the current produced as a function of atomic number and thickness of the perturbing layer. Current was also measured as a function of separation from the perturbation, as was voltage buildup within the insulator close to the perturbation.

The data indicate that these algin products are free from any deleterious substances which adversely affect health when fed at levels which are at least 10 times higher than when used in foods or pharmaceutical products. The difficulties experienced with feeding the higher levels seem to be due, at least in greater part, to the physical texture imparted to the diets fed. This should not be a problem in the commercial use of the product. The data indicate that the three algin products which were tested are wholesome.

Iritis was produced in rabbits by the intravenous injection of either primary or purified cultures from 19 to 21 patients with acute or chronic eye diseases, and in 11 of 14 controls (laboratory assistants, healthy children, and patients with arthritis and thyrotoxicosis).

Thirty angiographic examinations of transplanted kidneys were carried out in 24 patients.When the kidney function was satisfactory the angiographic appearances were characterized by a rapid passage of contrast medium, good filling of the peripheral branches, and a dense nephrographic phase with sharp delineation between the medulla and cortex.In kidneys with a reversible impairment in function the appearances were similar, although the passage time was sometimes slightly prolonged. The renal failure in these cases was probably caused by tubular necrosis or slight reversible rejection. The prognosis as to renal function was good.When the kidney function was impaired by irreversible rejection the appearances differed, showing marked prolongation of the passage time, absent filling of the peripheral branches, and low contrast density in the nephrographic phase.The angiographic examinations had no detectable adverse effects. It is concluded that angiography of the transplanted kidney is helpful to differentiation of the causes of failure of the transplant.

At the line of contact between a liquid surface and a bounding wet solid wall deformation of the surface is produced by surface tension, and this deformation gives rise to various features in the radiograph. For the interpretation of these image features a detailed analysis was performed by means of model experiments. Tubes and rods of methyl acrylate with different diameters and covered with wet sheets of porous paper were used. The tubes were partly filled with water. In some cases a rod was placed concentrically or eccentrically inside the tube. The shape of the image of the liquid surface in vertical and inclined models was examined by conventional radiographic technique and computed tomography. At the walls the surface tension resulted in formation of meniscoids. When the distance between solid walls was short enough adjacent meniscoids joined to form a discoid. The shape of the meniscoid and discoid varied with the shape and inclination of the walls. Distinct boundaries representative of the shape and position of the surface were produced only from those places where the beam was tangential to the surface. When the surface was concave towards the gas in the direction of the beam an internal boundary with a light Mach line was produced. When the surface was convex towards the gas in the direction of the beam an external boundary with a dark Mach line was produced. A boundary was straight when the surface was plane or was part of a cylindric surface. The seemingly simple form of the liquid surface gave rise to surprisingly complex boundary formations, which are analyzed in detail. The findings reported may have a variety of implications for the interpretation of clinical radiographs and may act as a key for the reconstruction of the structures reproduced.

The problem of stability in politics can be viewed from various angles. One possible approach is to regard a number of power units at different points of time and note if any change in their relationship has occurred. This raises the question about measuring political power; and some scholars will doubt the advisability of asking such a question. Hedley Bull argues that political science is in danger of being “distorted and impoverished by a fetish for measurement.” He favors a return to the classical tradition, and some of his arguments are certainly persuasive.

Repair of peripheral nerves with preserved cadaver grafts has become one of the most promising fields of modern surgery. The results of animal experimentation and clinical application appear to justify this claim. This communication is a preliminary report dealing with the clinical application of experimental work of one of us1 to 3 cases in which preserved cadaver grafts have been used to repair large defects in human peripheral nerves.To appreciate the failures of peripheral nerve surgery in the past, the pathologic anatomy of the traumatized nerve must be considered. When a nerve is severed there is considerable hemorrhage into the injured area. In the process of repair this hemorrhage is replaced by scar tissue and neuroma formation even when directly sutured. The consensus is that neuromas are largely due to the outgrowth of the proximal end of the neurons trying to find their way down the distal portion

1.The masticatory system should be regarded as a unit, since an intimate functional interaction exists between muscles, joints and teeth.2.Functional analysis is of greatest importance; in two dentitions which appear morphologically similar, the analysis may reveal quite dissimilar functional conditions which will indicate different treatment of each case.3.The effects of functional disturbances and occlusal disharmonies should be looked upon as long-term developments. The accumulative long-term effects of even minor occlusal disharmonies may lead to functional disorders of the masticatory system and contribute to breakdown of inflamed periodontal tissues.Cuspal interferences are the most important occlusal disharmonies. However, loosening of teeth may lead to defective proximal contacts. Cleaning may then become difficult and the risk of inflammation may increase. Hypofunction can also lead to accumulation of debris. Therefore, many possibilities of functional derangements exist,4.As a general rule the local treatment of the gingival tissues should be performed before any other treatment. The patient cannot be regarded as finally treated until all has been done to encourage proper mouth hygiene. Ideal results cannot always be obtained. There are cases where a compromise is forced upon the dentist.5.The dentist can render his patients excellent service by retaining their teeth through splints, bridgework and other means of occlusal rehabilitation. Naturally the hygienic condition should be the best possible and the prognosis should be carefully evaluated.6.Planning of prosthetic reconstruction work with clue regard to a long-term prognosis makes the dentist stop thinking only in terms of the single tooth or the single segment of the dentition. Instead, he is induced to think in terms of the masticatory system as a whole.