The in vivo emission spectra of sixteen species of Jamaican fireflies and four species of American fireflies have been measured with a photoelectric recording spectrometer. A simple technique of stimulation with ethyl acetate vapor was found to elicit bright continuous emission over a period of several minutes. Although the luciferin-luciferase cross-reactions were positive in all cases tested,...

Leading-twist distribution amplitudes (DAs) of light mesons like π, ρ etc. describe the leading nonperturbative hadronic contributions to exclusive QCD reactions at large energy transfer, for instance electromagnetic form factors. They also enter B decay amplitudes described in QCD factorisation, in particular nonleptonic two-body decays. Being nonperturbative quantities, DAs cannot be calculat...

We try to improve the accuracy of eccentric photorefraction by taking more information into account than just the size and tilt of the crescent. Based on Gaussian optics and the assumption of an isotropic scattering retina, a theoretical analysis of the light-intensity distribution in the pupils of astigmatic eyes is presented. The method is applied to different photorefractor setups (point lig...

The rapid worldwide evolution of LEDs as light sources has brought new challenges, which means that new methods are needed and new algorithms have to be developed. Since the majority of LED luminaries are of the multi-source type, established methods for the design of light engines cannot be used in the design of LED light engines. This is because in the latter case what is involved is not just...

We propose a new method for analysis of the sampling and reconstruction conditions of real and complex signals by use of the Wigner domain. It is shown that the Wigner domain may provide a better understanding of the sampling process than the traditional Fourier domain. For example, it explains how certain non-bandlimited complex functions can be sampled and perfectly reconstructed. On the basi...

under the contemporary scenario of global climate change and increasing coastal eutrophication, baseline studies of phytoplankton diversity and distribution in relation to habitat conditions constitute the first approach to evaluate potential shifts at the base of the food webs. here we present data of phytoplankton species composition and environmental variables in winter 2006 in a temperate ...

beyond its quantity, natural light has unique properties used intelligently in iranian historical architecture in order to transfer spiritual concepts. religious buildings are a good context for re-reading of light concept. due to its valuable place in iranian-islamic belief as well as its direct relationship with wisdom and philosophy, the qualitative presence of light in architecture, aimed a...

We identify a neglected source of information in the 3D texture in images of articulated surfaces. The texture is especially noticeable near the terminator of the body shadow. We provide a very simple model that allows us to describe the 3D texture contrast in detail. Experiments involving the data from the Curet database, laboratory observations, and informal snapshots reveal that the observat...