81 research outputs found
Alternatives to Outdoor Daylight Illumination for Photodynamic Therapy—Use of Greenhouses and Artificial Light Sources
Daylight-mediated photodynamic therapy (daylight PDT) is a simple and pain free treatment of actinic keratoses. Weather conditions may not always allow daylight PDT outdoors. We compared the spectrum of five different lamp candidates for indoor “daylight PDT” and investigated their ability to photobleach protoporphyrin IX (PpIX). Furthermore, we measured the amount of PpIX activating daylight available in a glass greenhouse, which can be an alternative when it is uncomfortable for patients to be outdoors. The lamps investigated were: halogen lamps (overhead and slide projector), white light-emitting diode (LED) lamp, red LED panel and lamps used for conventional PDT. Four of the five light sources were able to photobleach PpIX completely. For halogen light and the red LED lamp, 5000 lux could photobleach PpIX whereas 12,000 lux were needed for the white LED lamp. Furthermore, the greenhouse was suitable for daylight PDT since the effect of solar light is lowered only by 25%. In conclusion, we found four of the five light sources and the greenhouse usable for indoor daylight PDT. The greenhouse is beneficial when the weather outside is rainy or windy. Only insignificant ultraviolet B radiation (UVB) radiation passes through the greenhouse glass, so sun protection is not needed
Modeling Atmospheric Turbulence via Rapid Distortion Theory: Spectral Tensor of Velocity and Buoyancy
Abstract
A spectral tensor model is presented for turbulent fluctuations of wind velocity components and temperature, assuming uniform vertical gradients in mean temperature and mean wind speed. The model is built upon rapid distortion theory (RDT) following studies by Mann and by Hanazaki and Hunt, using the eddy lifetime parameterization of Mann to make the model stationary. The buoyant spectral tensor model is driven via five parameters: the viscous dissipation rate ε, length scale of energy-containing eddies L, a turbulence anisotropy parameter , gradient Richardson number (Ri) representing the local atmospheric stability, and the rate of destruction of temperature variance . Model output includes velocity and temperature spectra and associated cospectra, including those of longitudinal and vertical temperature fluxes. The model also produces two-point statistics, such as coherences and phases of velocity components and temperature. The statistics of uniformly sheared and stratified turbulence from the model are compared with atmospheric observations taken from the Horizontal Array Turbulence Study (HATS) field program, and model results fit observed one-dimensional spectra quite well. For highly unstable stratification, however, the model has deficiencies at low wavenumbers that limit its prediction of longitudinal velocity component spectra at scales on the order of 0.6 km. The model predicts coherences well for horizontal separations but overestimates vertical coherence with increasing separation. Finally, it is shown that the RDT output can deviate from Monin–Obukhov similarity theory.</jats:p
Best practice for restoration of stone reefs in Denmark (codes of conduct) 2013
This report includes recommendations for all phases of a boulder reef restoration project. The document includes an initial identification of relevant objectives for restoration, public involvement and identifies possible sources of relevant historic information as well as risks to be considered. A set of specific biological and environmental objectives that can influence the choice of design of the new reef structure is also presented. The report also includes a set of recommendations for the construction phase, requirements for safety navigation when the restoration work is finalized and presents suggestions for monitoring and management effort
Group size dynamics of the endangered mountain nyala (Tragelaphus buxtoni) in protected areas of the Arsi and Ahmar Mountains, Ethiopia
As an adaptive biological trait, group size may offer a useful metric for monitoring the welfare of wildlife species affected by their environmental surroundings. Here, we examine the drivers that cause variation in group size of the endangered mountain nyala (Tragelaphus buxtoni), including a range of natural ecological factors as well as the density of livestock. For this purpose, we collected data along transect lines during both wet and dry seasons focusing on the hitherto poorly studied populations in the Arsi Mountains National Park, Munessa-Kuke Controlled Hunting Area and Muktar Mountain Forest Reserve, which are managed for multiple use of a variety of natural resources. We found group sizes to be an average of 6.3, 4.4 and 4.1 individuals in the Arsi Mountains, Munessa-Kuke and Muktar Mountain study areas, respectively, and a combination of livestock density and habitat visibility explained as much as 74% of the variation in group size. We propose that whereas group size increases with forage availability (as measured by Normalized Difference Vegetation Index -NDVI) and in open habitats (probably due to a switch in antipredator strategy), the presence of livestock also has an independent, negative impact on group size because of the associated disturbance. The findings contribute to understanding the environmental drivers of variation in group size in social antelopes, particularly highlighting the need to improve livestock management to help conservation of species at risk
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