Due to the role leaf phenolics in defending against ultraviolet B (UVB) under previously controlled conditions, we hypothesize that ultraviolet radiation (UVR) could be a primary factor driving the variation in leaf phenolics in plants over a large geographic scale. We measured leaf total phenolics, ultraviolet-absorbing compounds (UVAC), and corresponding leaf N, P, and specific leaf area (SLA...

Cataract is the leading cause of blindness in the world (1). The World Health Organization defines cataract as a clouding of the lens of the eye which impedes the transfer of light. Cataract is a multi-factorial disease associated with diabetes, smoking, ultraviolet radiation (UVR), alcohol, ionizing radiation, steroids and hypertension. There is strong experimental (2-4) and epidemiological ev...

In Western countries, ultraviolet (UV)-induced skin cancer has been studied extensively regarding the high incidence of skin cancers in the white population; however, for people of color, cataracts are the main public health issue in relation to increased ambient ultraviolet radiation (UVR). To our knowledge, few studies have been conducted examining the relationship between cataracts and ambie...

This study was conducted to explore the involvement of DNA damage in the suppression of contact hypersensitivity (CHS) by UV irradiation. The opossum, Monodelphis domestica, was used because cells of these marsupials have an enzyme that is activated by visible light (photoreactivating enzyme) and repairs ultraviolet radiation (UVR)-induced pyrimidine dimers in DNA. A single dose of 1,500 J/m2 o...

Human skin, especially the epidermis, contains several major solar ultraviolet-radiation- (UVR-) absorbing endogenous chromophores including DNA, urocanic acid, amino acids, melanins and their precursors and metabolites. The lack of solubility of melanins prevents their absorption spectra being defined by routine techniques. Indirect spectroscopic methods show that their spectral properties dep...

Vitamin D can be synthesized following exposure to ultraviolet radiation (UVR), ingested in the diet or provided through oral supplementation. The medical literature frequently states that humans obtain most of their vitamin D from sunshine and that UVR exposure is essential to maintain vitamin D levels. A systematic review was conducted to determine the requirement for UVR in maintaining adequ...

In this study we report the response of net community production (NCP) of plankton communities in the Arctic surface waters exposure to natural ultraviolet radiation (UVR) conditions. A possible bias in previous measurements performed using borosilicate glass bottles (opaque to most UVR) can underestimate NCP. Here we show that 77% of the sampled communities suffer, on average, 38.5% of net inc...

The direct harmful effects of ultraviolet radiation (UVR) on benthic and planktonic organisms have been well studied in aquatic systems. Less clear, however, is how UVR might affect aquatic communities through its effects on trophic interactions. The focus of this study was twofold: first, to examine the direct effect of UVR on benthic invertebrates and epilithon, the rock-dwelling matrix of al...

Chronic exposure to ultraviolet radiation (UVR) is linked to the development of cutaneous squamous cell carcinoma (SCC), a non-melanoma form of skin cancer that can metastasize. Tumor necrosis factor-alpha (TNFα), a pro-inflammatory cytokine, is linked to UVR-induced development of SCC. To find clues about the mechanisms by which TNFα may promote UVR-induced development of SCC, we investigated ...