Experimental studies have shown that parasites can reduce host density and even drive host population to extinction. Existing mathematical models for parasite-host interactions, while can address the host density reduction scenario, fail to explain such deterministic extinction phenomena. In order to understand the parasite induced host extinction, Ebert et al. (2000) formulated a plausible but...

We present the generation of quantum-correlated photon pairs and subsequent pump rejection across two silicon-on-insulator photonic integrated circuits. Incoherently cascaded lattice filters are used to provide over 100 dB pass-band to stop-band contrast with no additional external filtering. Photon pairs generated in a microring resonator are successfully separated from the input pump, confirm...

The effect of the finite extinction ratio of an electro-optic modulator (EOM) on the Brillouin frequency measurement of a distributed Brillouin-based fiber optic sensor is studied. An EOM with a finite extinction ratio limits the application of Brillouin optical time domain analysis in a distributed Brillouin-based fiber optic sensor. This results in confusion in specifying the location of the ...

Isolated photosynthetic reaction center from the bacterium Rhodospirillum rubrum was extracted with acetone-methanol. Its main pigments were identified as bacteriochlorophyll, bacteriopheophytin, and spirilloxanthin. The extinction coefficients of these pigments in acetone-methanol were determined. Quantitative spectroscopic analysis of the dry acetone-methanol extracts indicated a bacteriochlo...

We investigate the systematic variation of the [OII]λ3727/Hα flux line ratio as a function of various galaxy properties, i.e., luminosity, metallicity, reddening, and excitation state, for a sample of 1 124 emission-line galaxies, with a mean redshift z ∼ 0.06, drawn from the Two Degree Field Galaxy Redshift Survey. The mean observed and extinction-corrected emission-line flux ratios agree well...

Lidars are ideal for mapping the spatial distribution of aerosol concentrations, however efforts to convert the lidar measurements into estimates of the aerosol extinction or scattering coefficient are usually complicated. The difficulties arise from the uncertainty in the aerosol backscatter-to-extinction ratio and the lidar calibration. In marine conditions with little absorption, the aerosol...

The results of an investigation of the performance of a time-division-addressed fiber-optic gas-sensor array by means of wavelength modulation of a distributed-feedback (DFB) laser are reported. The system performance is found to be severely limited by the extinction ratio of the optical switch used for pulse amplitude modulation. Formulas that relate the cross-talk level to the extinction rati...

A study on aerosol extinction-to-backscatter ratio with combination of micro-pulse lidar and MODIS over Hong Kong Q. S. He, C. C. Li, J. T. Mao, and A. K. H. Lau Department of Atmospheric Science, School of Physics, Peking University, Beijing, China The Institute for the Environment, the Hong Kong University of Science and Technology, Hong Kong, China Received: 29 November 2005 – Accepted: 1 Fe...

It is widely understood that the costs and benefits of mating can affect the fecundity and survival of individuals. Sexual conflict may have profound consequences for populations as a result of the negative effects it causes males and females to have on one another's fitness. Here we present a model describing the evolution of sexual conflict, in which males inflict a direct cost on female fitn...

We report experimental and theoretical verification of the nature and position of multiple interference points of visible light transmitted through the valve of the centric diatom species Coscinodiscus granii. Furthermore, by coupling the transmitted light into an optical fiber and moving the diatom valve between constructive and destructive interference points, an extinction ratio of 20 dB is ...