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The assumption of the constancy of the Weibull distribution parameters with variations in gauge length was tested for SiC-on-carbon and sapphire filaments. Surface damage was superimposed on the gauge length variations to investigate the effect of the additional flaw spectrum on the gauge length conclusions. The results have demonstrated that, even when failure is due to a single flaw spectrum, the Weibull mparameter is not constant over a gauge length range of 40 times the shortest length. When failure is due to overlapping flaw distributions the possibility of extrapolations assuming constant Weibull parameters is even more remote. The constant gauge length data was used in a modified form of the Poisson distribution proposed by Phoenix to compare to the extrapolative ability of the Weibull distribution. Very little difference in accuracy was found with the former approach being marginally better.

A theoretical analysis of selected problems related to aging in contemporary society and thoir implication for professional services to the aged are presented. Expansion of social work curricula to include gerontological content, the use of group process, and the application of videotape techniques are suggested as possible means of alleviating these problems.

The number (produced) ofLα-photons produced by electron-bombardment in a thick target of tungsten per incident electron has been measured absolutely with the Ross-filter method and relatively with the crystal-spectrometer method in the energyregion up to the 3.6 times theLIII-ionization energy . The result can be presented in the following empirical form: (produced)=4π·ŧ·(U0−1)n with ŧ=0.52·10−4±5% andn=1.44±0.02 . Out of this the number ofLIII-ionizations per electron which is slowed down to the energy within the target, has been evaluated. The computation of out of the elementary process by usingBethe's non-relativistic formulae for totalLIII-ionization cross sectionQL and energy loss-dE/ds is in full agreement with experiment in the region 20<3.6, if the constants in are chosen as follows: . By comparison of this result for with the corresponding value ofbK in the totalK-ionization cross-sectionQK for copper (bK=0.35·2.26) it is concluded that is considerably higher than predicted by theory.

Summary: Tissues and cells from various life stages and ages ofAnopheles quadrimaculatus were cultured in several media. Pupal tissue maintained in Schneider's (1) medium was the most successful system. These cells remained viable for 210 days. Xix morphologically distinguishable cell types were observed: spherical cells, two type of neuronlike cells, musclelike cells, epithelial-like cells, and polymorphic cells.

IRRADIATION within the ultraviolet (190.0–380.0 nm) range is an effective means of virus inactivation. We report the effects of short exposures of ultraviolet light at 320.0 nm on Autographa californica(Lepidoptera) nuclear polyhedrosis virus. In this case, ultraviolet light has an activating effect on the virus produced in vitro.

CULTURED mammalian cells are finding increasing use as a basis for conducting physiological and biochemical investigation outside the organism. Insect cell lines have originated from primary explants of embryonic tissue or tissues from larval and pupal stages of the donor. Cells from primary explants of embryonic tissue from the fruit fly, Drosophila melanogaster; the mosquito, Aedes aegypti; leaf hoppers, Agallia constricta and A. quadripunctata; and cockroaches, Periplaneta americana and Blabera fusca, continued to multiply and were subcultured1–4. Primary cultures of larval tissues from, the silkworm, Bombyx mori; the rice stem borer, Chilo suppressalis; and mosquitoes, Aedes aegypti, A. albopictus and Anopheles stephensi, were subcultured and developed into cell lines5–11. Cells originating from pupal ovaries of the moth, Antheraea eucalypti, have also been established as a cell line12. This article reports the first successful establishment of a cell line derived from adult tissue of the cabbage looper, Trichoplusia ni.

AMBRUS1has described an in vitro assay for fibrinolytic enzymes and has correlated his results with the therapeutic effectiveness of the preparations tested. Both the fibrinogen and thrombin used in this assay must be free or nearly free of profibrinolysin in order to distinguish between fibrinolysin and profibrinolysin activator activity.