Most birds have visual sensitivity to ultraviolet (UV) wavelengths, and this sensitivity appears to play a role in their colour vision. Artificial lighting is normally deficient in UV wavelengths. Hence, there may be welfare implications for captive birds kept under such lighting. We investigated whether the absence of UV wavelengths during rearing adversely affects Japanese quail (Coturnix coturnix japonica). We also investigated the short-term effect of switching from UV-containing to UV-deficient lighting, and vice versa. Stress was assessed by monitoring behaviour and plasma corticosterone levels. We did not detect any significant difference in these variables between birds reared either with or without UV. We conclude that rearing quail in an absence of UV does not appear to have a significant impact on their welfare, as measured using these indicators.

The welfare of laboratory rats and mice is sought to be optimised through adjustment of a variety of environmental factors, including light intensity and photoperiodicity. However, the fact that rodents are able to perceive ultraviolet (UV) light tends to be ignored. The importance of being able — as a rodent — to utilise this part of the visual spectrum has not been studied in great detail, but suggestions, based on the evolutionary success of this trait, indicate that the deprivation of ultraviolet light in mice and rats could perhaps impact negatively on the welfare of these animals. Further research into the importance of having a UV light source available to rats and mice should be encouraged.

Losses of picloram (4-amino-3,5,6-trichloropicolinic acid) in water exposed to sunlight ranged from 50 to 80% after 1 days' exposure (14 h sunlight) and 95% or more after 4 days exposure (56 h of sunlight) at four locations in Southern Arizona. Samples exposed at the highest elevation (2800 m) consistently lost picloram more quickly than samples at the lower elevations. Dry, recrystallized picloram losses were 11, 47, and 67% after 1, 2, and 4 days of sunlight exposure, respectively. At the same times, picloram losses in water were 65, 89, and 99%, respectively. These results indicate that photodecomposition is an important factor for the use and residue longevity of picloram on high-altitude rangelands of the western United States.

We present a summary of the scientific objectives, payload and mission profile of the Space Weather & Ultraviolet Solar Variability Microsatellite Mission (SWUSV) proposed to CNES and ESA (small mission).

We investigate the advantages of imaging solar filaments and prominences in Lyman-Alpha, coupled to H-Alpha on ground, to develop more reliable precursors indicators for large flares, several hours before their occurrence.

A system for illuminating a sample in situ with visible and ultraviolet light inside a transmission electron microscope was devised to study photocatalysts. There are many mechanical and optical factors that must be considered when designing and building such a system. Some of the restrictions posed by the electron microscope column are significant, and care must be taken not to degrade the microscope's electron-optical performance or to unduly restrict the other capabilities of the microscope. We discuss the nature of the design considerations, as well as the practical implementation and characterization of a solution. The system that has been added to an environmental transmission electron microscope includes a high brightness broadband light source with optical filters, a fiber to guide the light to the sample, and a mechanism for precisely aligning the fiber tip.

The measurement of near-infrared (NIR) cathodoluminescence (CL) with sufficient sensitivity to allow full spectral mapping has been investigated through the application of optimized grating spectrometers that allow the ultraviolet (UV), visible, and NIR CL spectra to be measured simultaneously. Two optical spectrometers have been integrated into an electron microprobe, allowing simultaneous collection of hyperspectral CL (UV-NIR), characteristic X-rays, and electron signals. Combined hyperspectral CL spectra collected from two natural apatite (Ca5[PO4]3[OH,F]) samples from Wilberforce (Ontario, Canada) and Durango (Mexico) were qualitatively analyzed to identify the emission centers and then deconvoluted pixel-by-pixel using least-squares fitting to produce a series of ion-resolved CL intensity maps. Preliminary investigation of apatite has shown strong NIR emissions associated primarily with the rare-earth element Nd. Details of growth and alteration were revealed in the NIR that were not discernable with electron-induced X-ray mapping. Intense emission centers from Nd3+ and Sm3+ were observed in the spectra from both apatites, along with minor emissions from other 3+ rare-earth elements. Quantitative electron probe microanalysis was performed on points within the mapped area of the Durango apatite to produce a calibration line relating cathodoluminescent intensity of the fitted peak centered at 1,073 nm (1.156 eV) to the Nd concentration.

Astrobiology is a relatively recent scientific field that seeks to understand the origin and dynamics of life in the Universe. Several hypotheses have been proposed to explain life in the cosmic context throughout human history, but only now, technology has allowed many of them to be tested. Laboratory experiments have been able to show how chemical elements essential to life, such as carbon, nitrogen, oxygen and hydrogen combine in biologically important compounds. Interestingly, these compounds are ubiquitous. How these compounds were combined to the point of originating cells and complex organisms is still to be unveiled by science. However, our 4.5 billion years old Solar system appeared in a 10 billion years old Universe. Thus, simple cells such as micro-organisms may have had time to form in planets older than ours or in other suitable places in the Universe. One hypothesis related to the appearance of life on Earth is called panspermia, which predicts that microbial life could have been formed in the Universe billions of years ago, travelling between planets, and inseminating units of life that could have become more complex in habitable planets such as Earth. A project designed to test the viability of extremophile micro-organisms exposed to simulated extraterrestrial environments is in progress at the Carlos Chagas Filho Institute of Biophysics (UFRJ, Brazil) to test whether microbial life could withstand inhospitable environments. Radiation-resistant (known or novel ones) micro-organisms collected from extreme terrestrial environments have been exposed (at synchrotron accelerators) to intense radiation sources simulating Solar radiation, capable of emitting radiation in a few hours equivalent to many years of accumulated doses. The results obtained in these experiments reveal an interesting possibility of the existence of microbial life beyond Earth.

We review the principles of ultraviolet (UV) irradiation, the inactivation of infectious agents by UV, and current applications for the control of microorganisms. In particular, wavelengths between 200 and 280 nm (germicidal UV) affect the double-bond stability of adjacent carbon atoms in molecules including pyrimidines, purines and flavin. Thus, UV inactivation of microorganisms results from the formation of dimers in RNA (uracil and cytosine) and DNA (thymine and cytosine). The classic application of UV irradiation is the inactivation of microorganisms in biological safety cabinets. In the food-processing industry, germicidal UV irradiation has shown potential for the surface disinfection of fresh-cut fruit and vegetables. UV treatment of water (potable and wastewater) is increasingly common because the process is effective against a wide range of microorganisms, overdose is not possible, chemical residues or by-products are avoided, and water quality is unaffected. UV has been used to reduce the concentration of airborne microorganisms in limited studies, but the technology will require further development if it is to gain wider application. For bioaerosols, the primary technical challenge is delivery of sufficient UV irradiation to large volumes of air, but the absence of UV inactivation constants for airborne pathogens under a range of environmental conditions (temperature, relative humidity) further compounds the problem.

La directive européenne 2006/25/CE, relative à l’exposition des travailleurs auxrayonnements optiques, prévoit l’évaluation des risques au poste de travail par la mesureet/ou le calcul. L’objectif de cette étude était de permettre à des organismes de contrôlede mettre en œuvre la directive en mettant à leur disposition une méthodologie simpled’évaluation des risques in situ, compatible avec leurs moyens. Cette étude a doncconsisté à faire un état du marché, acquérir quelques appareils de mesure de coûtraisonnable (radiomètres et spectroradiomètres) et ensuite évaluer leurs performances. Lesrésultats des mesures effectuées sur 5 lampes de spectres divers, à l’aide de cesappareils, ont été comparés à ceux donnés par un spectroradiomètre de laboratoire priscomme référence. De cette étude il est ressorti qu’aucun d’eux ne permet de mesurer avecune précision acceptable le rayonnement émis par des sources de différentes natures surl’ensemble du domaine spectral compris entre 180 et 3 000 nm. Les radiomètres ne sont pasadaptés à la mesure de sources émettant sur un domaine spectral étroit. Lesspectroradiomètres à simple monochromateur ou à barrettes CCD linéaires présentent quant àeux des erreurs importantes attribuables à la lumière parasite (stray light). Cependant,l’approche d’une méthode de correction de cette lumière parasite a montré qu’il étaitpossible d’améliorer la précision de ces appareils.

Observational astronomy began in Padova four hunderd years ago, when Galileo Galilei pointed a newly invented instrument towards Jupiter. After only one week of observations he discovered four moons circling Jupiter. In the intervening four centuries, technical progress in instrumentation and novel observational approaches have revealed much about the connection between these Medicean moons with Jupiter, none more revealing than the auroral emissions. In this paper we review observations of ultraviolet aurora made by earth-orbitting spacecraft as well as those that flew by the Jovian system.

Poultry, unlike humans, have a fourth retinal cone that allows them to see in the UVA part of ultraviolet radiation. This ocular function is principally used by poultry to modify various behavioural functions such as feeding, peer recognition, mate selection, mating activity, and social encounters. Retinally perceived UVA controls the release of melatonin in the pineal gland of dark-adapted birds. Ultraviolet radiation has shorter wavelengths than visible light, and, as a result, is unable to penetrate to the hypothalamus to induce a photosexual response; UV is thus minimally involved in avian reproductive function. UVA and UVB have anti-rachitic properties which catalyse the synthesis of vitamin D3 from 7-dehydroxycholesterol in the skin of feet and legs, a function that prevents rickets, minimises the incidence of tibial dyschondroplasia, and normalises growth and bone ash in young birds fed diets deficient in vitamin D3; surprisingly, there is sufficient UVA in white fluorescent light to produce these benefits. UVC from the sun is filtered out by the atmosphere's ozone layer, so does not occur in sunlight, but artificially produced UVC has germicidal properties and has been shown to protect domestic fowl from aerogenic viral infections, however, vaccination has made this property superfluous to the modern poultry industry. Recently, the introduction of lamps that emit both visible light and UV has made the provision of UVA to poultry a practical proposition, and so it is opportune that the responses of poultry to UV radiation are reviewed and its relevance to modern poultry production assessed.

The mid-ultraviolet is an important diagnostic region due to its sensitivity to the hottest stars of a stellar population. Sources of mid-UV flux include main sequence turn-off stars, the basic clocks of stellar evolution, and also blue horizontal branch stars and blue stragglers. We describe some observed trends in mid-UV colors and spectral indices.

The abundance derivation of heavy r-elements may provide a better understanding of the r-process, and the determination of several reference r-elements should allow a better determination of the star's age. The spatial ultraviolet (UV) region presents a large number of lines of heavy elements, and in some cases such as Bi, Pt, Au, detectable lines are only available in the UV. The extreme “r-process star” CS 31082-001 ([Fe/H] = −2.9) was observed in the spatial UV in order to determine abundances of the heavy elements, using STIS on board HST.

Gamma-ray bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. The gamma radiation from a burst within a few kiloparsecs would quickly deplete much of the Earth's protective ozone layer, allowing an increase in solar ultraviolet radiation reaching the surface. This radiation is harmful to life, damaging DNA and causing sunburn. In addition, NO2 produced in the atmosphere would cause a decrease in visible sunlight reaching the surface and could cause global cooling. Nitric acid rain could stress portions of the biosphere, but the increased nitrate deposition could be helpful to land plants. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of GRBs delivering a range of fluences, at various latitudes, at the equinoxes and solstices, and at different times of day. We have estimated DNA damage levels caused by increased solar UVB radiation, reduction in solar visible light due to NO2 opacity, and deposition of nitrates through rainout of HNO3. In this paper we give a concise review of this work and discuss current and future work on extending and improving our estimates of the terrestrial impact of a GRB.

Springtime ozone depletion over Antarctica has been observed for over a decade. Associated with ozone depletion is an increase in the levels of biologically harmful ultraviolet-B (UV-B) that reach the earth's surface, a situation that has prompted much controversy about the ecological effects of this atmospheric phenomenon on Antarctic ecosystems. A major hindrance to assessing the ecological impact is lack of appropriate data on Antarctic systems before the present ozone depletion cycle began. In addition, certain physical features of the Antarctic environment (clouds, snow and ice) and the UV-B photobiology (repair processes and protective strategies) of endemic species can alter the potential biological effects of this environmental stress in, as yet, undetermined ways. Increases in incident UV levels will most likely result in changes in the taxonomic structure of communities. The effects of these changes on net productivity and trophic dynamics cannot be accurately assessed without quantifying ambient doeses of UV and characterizing the UV photobiology of individual species. Both the physical features of the springtime environment and the biological responses of endemic species must be considered in future research efforts to evaluate the biological consequences of the Antarctic ozone hole.

Acute ultraviolet (UV) irradiation of normal human skin results in several clinical effects, including sunburn inflammation (erythema) and tanning, histological changes such as thickening of the epidermis, and local or systemic immunosuppression. Chronic UV irradiation leads to photoaging, sustained immunosuppression and photocarcinogenesis. Photocarcinogenesis involves the accumulation of genetic changes, as well as immune system modulation, and ultimately leads to the development of skin cancers. Recent advances in molecular and cellular biology have clarified the mechanisms of photocarcinogenesis, including the formation of DNA photoproducts, DNA repair, the mutation of proto-oncogenes and tumour suppressor genes, and UV-induced immunosuppression. Further investigation and a better understanding of photocarcinogenesis are critical to the development of effective prevention and intervention strategies for human skin cancer.

Hf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Murine cones contain two opsins in the same cone, one ultraviolet (UV) and the other middle-wavelength sensitive (M). A long-wavelength flash only affecting M-opsin suppresses the cone electroretinogram (ERG) produced by light absorption of UV-cone opsin raising the hypothesis that activation of M-cone opsin suppresses UV-cone opsin responses in the same cone. Here we show that pharmacologic blockade of synaptic transmission in the superfused murine retina, which eliminates interaction from second-order neurons, fails to prevent suppression of the UV-opsin driven pathway by long-wavelength stimuli. This proves that the antagonism must be occurring in the same cone, co-expressing both opsins. Our results show that UV-opsin suppression successively ceases in presence of the M-opsin activating background light, which implies that cone light adaptation is controlled at the opsin stage, before activation of transducin. It also reveals the time course of a transient desensitization of cones due to post-opsin factors in the transduction cascade.

Recent physiological experiments support behavioral and morphological evidence for a fourth type of cone in the turtle retina, maximally sensitive in the ultraviolet (UV). This cone type has not yet been included in the models proposed for connectivity between cones and horizontal cells. In this study, we examined the inputs of UV, S, M, and L cones to horizontal cells. We used the high-resolution Dynamic Constant Response Method to measure the spectral sensitivity of horizontal cells without background light and after adaptation to UV, blue (B), green (G), and red (R) light. We concluded the following: (1) Tetrachromatic input to a Y/B horizontal cell was identified. The spectral-sensitivity curves of the cell in three of the adaptation conditions were well represented by L-, M-, and S-cone functions. Adaptation to blue light revealed a peak at 372 nm, the same wavelength location as that determined behaviorally in the turtle. A porphyropsin template could be closely fitted to the sensitivity band in that region, strong evidence for input from a UV cone. (2) The spectral-sensitivity functions of R/G horizontal cells were well represented by the L- and M-cone functions. There was no indication of UV- or S-cone inputs into these cells. (3) The spectral sensitivities of the monophasic horizontal cells were dominated by the L cone. However, the shape of the spectral-sensitivity function depended on the background wavelength, indicating secondary M-cone input. Connectivity models of the outer retina that predict input from all cone types are supported by the finding of tetrachromatic input into Y/B horizontal cells. In contrast, we did not find tetrachromatic input to R/G and monophasic horizontal cells. Chromatic adaptation revealed the spectral-sensitivity function of the turtle UV cone peaking at 372 nm.