UNLABELLED • PREMISE OF THE STUDY Although ultraviolet radiation (UV) is known to have negative effects on plant growth, there has been no direct evidence that plants growing at higher elevations are more severely affected by ultraviolet-B (UV-B) radiation, which is known to increase with elevation. We examined damage to DNA, a primary target of UV-B, in the widespread species Polygonum sacha...

Ultraviolet (UV) signals are used in female mate choice in numerous taxa; however, the role of UV signals in male contests remains relatively unexplored. We experimentally reduced throat UV of free-ranging lizards (Platysaurus broadleyi) to test whether UV acts as a signal of fighting ability during male contests. We found that UV-reduced males were more likely to be challenged than control mal...

Net photosynthesis, growth, and ultraviolet (UV) radiation absorbance were determined for the first leaf of Cucurbita pepo L. exposed to two levels of UV-B irradiation and a UV-B radiation-free control treatment. Absorbance by extracted flavonoid pigments and other UV-B radiation-absorbing compounds from the first leaves increased with time and level of UV-B radiation impinging on leaf surfaces...

Increases in the terrestrial levels of ultraviolet-B (UV-B) radiation (280 to 320 nm) due to diminished stratospheric ozone have prompted an investigation of the protective mechanisms that contribute to UV-B tolerance in plants. In response to UV-B stress, flowering plants produce a variety of UV-absorptive secondary products derived from phenylalanine. Arabidopsis mutants with defects in the s...

abstractin the last step of desolvation method for preparation of albumin nanoparticles, glutaraldehyde (ga) is added to stabilize the newly formed nanoparticles. due to undesirable effects of ga, the objective of this study was to evaluate alternative methods of crosslinking including ultraviolet (uv) irradiation, adding of glucose and combination of both methods. the nanoparticles were prepar...

PURPOSE The purpose was to develop suitable in vitro methods to detect ocular epithelial cell damage when exposed to UV radiation, in an effort to evaluate UV-absorbing ophthalmic biomaterials. METHODS Human corneal epithelial cells (HCEC), lens epithelial cells (HLEC), and retinal pigment epithelial cells (ARPE-19) were cultured and Ultraviolet A/Ultraviolet B (UVA/UVB) blocking filters and ...

This work addresses the issue as to whether ultraviolet radiation of wavelengths longer than 200 nm can break Si-CH3 bonds in porous low-k dielectrics. To resolve this issue, porous SiCOH films (k = 2.3) were exposed to 4.9 eV (254 nm) ultraviolet (UV) radiation in both air and vacuum for 1 hour. Using Fourier Transform Infrared (FTIR) spectroscopy, the chemical structures of the dielectric fil...

Ultraviolet radiation-induced cataract has been believed to be associated with degradation of cellular components. We report that, in cultured human lens epithelial cells, UV radiation analogous to H2O2 treatment down-regulates desmosomal protein desmoglein-2. UV radiation induces generation of reactive oxygen species and transiently activates epidermal growth factor receptor, which in turn ind...

Seedlings of two late-successional tropical rainforest tree species, Tetragastris panamensis (Engler) O. Kuntze and Calophyllum longifolium (Willd.), were field grown for 3-4 months at an open site near Panama City (9 degrees N), Panama, under plastic films that either transmitted or excluded most solar UV-B radiation. Experiments were designed to test whether leaves developing under bright sun...

Enhanced hydrophobic bond-strength can be achieved by exposing prime grade silicon wafers to ultraviolet (UV) light and heat prior to bonding. The following independent variables were explored: platen temperature, UV exposure time, oxygen containing versus non-oxygen containing (nitrogen only) bonding atmosphere, and annealing temperature. The results suggest exposure to UV can be used as an ac...