نتایج جستجو برای: ultraviolet radiation uvr

تعداد نتایج: 268678  

Journal: :International ophthalmology clinics 2005
Matthew S Oliva Hugh Taylor

Moderate exposure to ultraviolet radiation (UVR) from the sun is a necessary part of maintaining normal health. Ultraviolet radiation is critical for formation of VitaminD and the normal healthy growth of bones and teeth. However, excessive exposure to UVR has no health benefits and can lead to adverse consequences for the skin and eye. When the body receives excessive UVR exposure on a chronic...

2011
David M. Fields Caroline M. F. Durif Reidun M. Bjelland Steven D. Shema Anne B. Skiftesvik Howard I. Browman

UVB alters photosynthetic rate, fatty acid profiles and morphological characteristics of phytoplankton. Copepods, important grazers of primary production, select algal cells based upon their size, morphological traits, nutritional status, and motility. We investigated the grazing rates of the copepod Calanus finmarchicus on the diatom Thalassiosira weissflogii cultured under 3 levels of ultravi...

2004
Frank McArdle Lesley E Rhodes Richard AG Parslew Malcolm J Jackson

Background: Ultraviolet radiation (UVR) generates reactive oxygen species in skin that can play a role in skin damage, but reports about the photoprotective properties of oral antioxidant supplements

Journal: :Ecology letters 2012
Erin P Overholt Spencer R Hall Craig E Williamson Claire K Meikle Meghan A Duffy Carla E Cáceres

Climate change and variation in atmospheric ozone are influencing the intensity of ultraviolet radiation (UVR) reaching ecosystems. Changing UVR regimes, in turn, may alter epidemics of infectious disease. This possibility hinges on the sensitivity of epidemiologically relevant traits of host and parasite to UVR. We address this issue using a planktonic system (a zooplankton host, Daphnia denti...

Journal: :The British journal of ophthalmology 2001
J E Walsh J P Bergmanson D Wallace G Saldana H Dempsey H McEvoy L M Collum

BACKGROUND/AIMS Certain degenerative eye conditions occur predominantly nasally, at the limbal region, and are associated with solar ultraviolet radiation (UVR) induced damage. The relative contribution to the in vivo ocular flux of (a) the reflection of UVR incident on the skin of the nose onto the nasal limbus, and (b) the focusing of UVR incident on the temporal side of the cornea onto the n...

Journal: :Addiction biology 2012
Cynthia R Harrington Tracy C Beswick Michael Graves Heidi T Jacobe Thomas S Harris Shadi Kourosh Michael D Devous Bryon Adinoff

Frequent and excessive tanning persists despite a growing understanding of its associated morbidity and mortality, suggesting that ultraviolet radiation may impart rewarding effects beyond the assumed cosmetic benefits. To empirically measure putative centrally rewarding properties of ultraviolet radiation (UVR), we assessed the effects of a commercially available tanning bed upon regional cere...

2015
Presentación Carrillo Juan M. Medina-Sánchez Guillermo Herrera Cristina Durán María Segovia Dolores Cortés Soluna Salles Nathalie Korbee Félix L. Figueroa Jesús M. Mercado Christopher J. Gobler

Some of the most important effects of global change on coastal marine systems include increasing nutrient inputs and higher levels of ultraviolet radiation (UVR, 280-400 nm), which could affect primary producers, a key trophic link to the functioning of marine food webs. However, interactive effects of both factors on the phytoplankton community have not been assessed for the Mediterranean Sea....

Journal: :Journal of fish biology 2010
Y Fukunishi R Masuda Y Yamashita

Hatching success was examined under exposure to solar ultraviolet radiation (UVR) using filters to give three different light conditions [C1: UV-B, UV-A and photosynthetically active radiation (PAR), C2: UV-A and PAR, C3: PAR] in red Pagrus major and black Acanthopagrus schlegeli sea bream. Hatching rate of both species was reduced by an exposure over a 2 day period to UVR and was not significa...

2017

Solar ultraviolet radiation (UVR, 280-400 nm) is known to cause a number of detrimental effects in aquatic organisms. The area of Patagonia, which is sometimes under the influence of the Antarctic ozone “hole”, occasionally receives enhanced levels of ultraviolet B radiation (UV-B, 280-315 nm). Great efforts have been put into creating a database for UVR climatology by installing a variety of i...

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