I have used theHipparcos Input Catalogue, together with Kurucz model stellar atmospheres and information on the strength of the interstellar extinction, to create a model of the expected intensity and spectral distribution of the local interstellar ultraviolet radiation field, under various assumptions concerning the albedo a of the interstellar grains. (This ultraviolet radiation field is of p...

Cells from a region on the posterior margin of the developing avian limb bud (the polarizing region) can signal positional information to responding anterior cells. Polarizing activity may be assayed by disaggregation of the tissue into single cells, followed by reaggregation and grafting of cell pellet. This method enables treatments of the cells while in single-cell suspension. The effects of...

During sporulation, Clostridium botulinum 33A developed resistance to ultraviolet and gamma rays about 2 hr prior to its development of heat resistance. During germination, loss of resistance to heat, ultraviolet radiation, and gamma radiation occurred essentially simultaneously.

background compact fluorescent lamp (cfl) is a developed fluorescent lamp type designed to saving energy. cfls can cause an increased health risk to humans due to the ultraviolet radiation. objectives the current study aimed to assess the ultraviolet radiation emitted from compact fluorescent lamps in highly used iranian brands. materials and methods this experimental study was conducted on 16 ...

Sunlight emits a spectrum of electromagnetic radiation that includes ultraviolet, visible, and infrared wavelengths. It is widely accepted that the ultraviolet radiation (UVR) component is responsible for the mutagenic and carcinogenic effects of sunlight. UVR is further subdivided into three wavelength ranges: UVC (100-280 nm), UVB (280-315 nm) and UVA (315-400 nm) and each of these induce dif...

Several investigators have reported that white light will counteract the effects produced in lower organisms exposed to ultraviolet light. Whitaker (14) has observed that the inhibitory effects of ul traviolet on fucus eggs could be counteracted by white light. Kelner (6)-has demonstrated spectac ular recoveries of various micro-organisms in activated with ultraviolet. Blum and Matthews (3) hav...