While our data do not permit us to state the exact locus or mode of action of ultraviolet radiation in the Arbacia egg, certain general conclusions may be reached. The amount of delay of cleavage of these eggs is determined by two principal factors: (1) The extent of an effect, resulting from photochemical action induced by ultraviolet radiation, which is reversible in a biological sense, the r...

HE cytogenetic interest in ultraviolet radiation resides in the hope T that the qualitatively discriminating nature of this type of radiant energy will yield still further evidence as to the structure and behavior of the hereditary mechanism. It is now known that ultraviolet, like X-rays, can produce gene mutations and chromosomal changes; it is likewise known that, unlike X-rays, ultraviolet i...

Effects of eutrophication on arsenic speciation were studied in eutrophic Lake Kiba and mesotrophic Lake Biwa, Japan. By combining hydride generation atomic absorption spectrometry with ultraviolet irradiation, inorganic, methyl and ultraviolet-labile fractions of arsenic were determined. In both Lakes, inorganic species (As(V+III)) dominated over other forms of arsenic all the year round. Most...

Any reduction in global mean near-surface temperature due to a future decline in solar activity is likely to be a small fraction of projected anthropogenic warming. However, variability in ultraviolet solar irradiance is linked to modulation of the Arctic and North Atlantic Oscillations, suggesting the potential for larger regional surface climate effects. Here, we explore possible impacts thro...

The sun protection factor (SPF) has widely been used to evaluate the protective value of sunscreens. However, SPF only reflects the effectiveness of the sunscreen to protect against acute sunburn which is mainly due to ultraviolet B (UVB) radiation. The deleterious effects of UVB are well known and UVB was believed in the past to be the spectrum responsible for the damages arising from ultravio...

The power of the energy radiated from any material is dependent on the temperature. For example, the sun with the temperature of 6,000°C at the surface and ~15,000,000°C at the depths radiates the radio-magnetic ray with from the weak to the strong energy. The radiomagnetic ray with strong energy is absorbed before the arrives at the surface of the earth. But, if a human bathe in the ultraviole...

Rare-earth-doped laser materials show strong prospects for quantum information storage and processing, as well as for biological imaging, due to their high-Q 4f↔4f optical transitions. However, the inability to optically detect single rare-earth dopants has prevented these materials from reaching their full potential. Here we detect a single photostable Pr(3+) ion in yttrium aluminium garnet na...

Far Ultraviolet Spectroscopic Explorer (FUSE ) observations of the bright binary system Capella (α Aurigae; G1 III + G8 III) reveal a rich emission line spectrum containing neutral and ionic species, among them H i, O i, C iii, Ovi, Svi, Nev and Nevi. In addition the Fexviii 974.85 Å line, formed at temperatures of ≈ 6 × 10 K, is detected. Whereas the chromospheric and transition region emissio...