A nonautonomous nth order Lotka-Volterra system of differential equations is considered. It is shown that if the coefficients satisfy certain inequalities, then any solution with positive components at some point will have all of its last n − 1 components tend to zero, while the first one will stabilize at a certain solution of a logistic equation.

An improvement of the estimation of mineral dust longwave, direct radiative forcing is presented. It is based on recent developments that combine Sun photometer and multiwavelength lidar data to retrieve range-resolved coarseand fine-mode extinction coefficients. The forcings are calculated separately for each mode, and their sum is compared to the classical approach in which only the total ext...

A few pyrene-based fluorescent compounds were synthesized using Pd/Cu-catalyzed cross-coupling reaction. Photophysical properties of the π-conjugated pyrene derivatives were studied and the results indicate materials with high quantum efficiency and high extinction coefficient. No π stacking was observed in the crystal lattice. The molecules described here may be useful in developing sensors or...

This study examines differences in the normalized radar cross section, derived from ground-based versus spaceborne radar data. A simple homogeneous half-space model, indicates that agreement between the two improves as 1) the distance from the scatterer is increased; and/or 2) the extinction coefficient increases.

In the present work, we report studies on optical and structural phenomenon in as-deposited thin films composed of aligned nanorods of amorphous SexTe100-x (x = 3, 6, 9, and 12). In structural studies, field emission scanning electron microscopic (FESEM) images suggest that these thin films contain high yield of aligned nanorods. These nanorods show a completely amorphous nature, which is verif...

Light extinction by aerosols is due to scattering and absorption. The anthropogenic contribution is generally dominated by light scattering by sulfate particles and light absorption by elemental carbon. While real-time, in situ instrumentation for the measurement of ambient light scattering exists and is widely used (i.e., nephelometers), no such instrumentation is currently in use for the sens...

The experimental was split plot in a randomized complete block design with three replications. In this experiment, different levels of nitrogen in the main plots included four levels (0, 50, 100 and 150 N) kg.ha-1 urea and wheat varieties, including cultivars, Sepahan and SW were placed in the subplots. Results showed that nitrogen fertilizer and cultivar were significant effects on ...

Taro, Colocasia esculenta (L.) Schott, is the most important species from the Araceae family. The leaf area (LA) is important for the interception of solar radiation and for the biomass production. The light extinction coefficient (k) is related to the leaf inclination angle, leaf arrangement, regarding the Leaf Area Index (LAI), providing an indication of the plants efficiency on intercepting ...

introduction: one of the hallmark symptoms of posttraumatic stress disorder (ptsd) is the impaired extinction of traumatic memory. single prolonged stress (sps) has been suggested as an animal model of ptsd, since sps rats exhibited the impaired fear extinction. oxytocin (oxt) has been recently suggested as a potential pharmacotherapy for treatment of ptsd. in this study, using sps rats we inve...

Diffusion methods were used to investigate the fixation probability, average time until fixation and extinction, and cumulative heterozygosity and genetic variance for single mutant genes in finite populations with partial inbreeding. The critical parameters in the approximation are the coefficient of inbreeding due to nonrandom mating (F) and the effective population size (Ne), which also depe...