Comparison Of Different Intervals Research Articles

Effects of a past contest on the future winning probability in a hyper‐aggressive fruit fly

AbstractIn various animal taxa, prior experience of contests influences the consequences of subsequent contests. A well‐known example is the winner and loser effects, in which winners have a higher winning probability, whereas losers become more likely to lose in the subsequent contests. Previous studies have suggested that the intensity of past contests also affects the future winning probability in two ways: modulating the extent of the winner–loser effect or decreasing the winning probability of both winners and losers. However, the number of studies that investigated the effect of both the contest outcome and intensity has been limited. Here, we analyzed the effect of past fighting experience in a hyper‐aggressive fruit fly Drosophila prolongata to ask (1) whether the winner–loser effect exists in this species and (2) how the contest intensity influences the subsequent winning probability. To disentangle the multiple factors affecting the winning probability, we employed the experimental design involving both body size manipulation and the comparison of different intervals between the two contests. The results did not support the existence of the winner–loser effect: both winners and losers of the first contest showed decreased winning probability in the second contest. With a short interval (2 h), contest intensity negatively influenced the winning probability in winners, though the significance level of its effect was marginally above the statistical threshold. In contrast, contest intensity had no effect in losers. Notably, contest intensity positively correlated with the winning probability after the longer interval (1 d) in both winners and losers, suggesting that it reflects the intrinsic fighting potential of individuals. The possible mechanisms underlying the observed results were discussed. Our study illustrates the transient influence of past contests other than the winner–loser effect.

ESTIMATING SUSPENDED SEDIMENT BY ARTIFICIAL NEURAL NETWORK (ANN), DECISION TREES (DT) AND SEDIMENT RATING CURVE (SRC) MODELS (CASE STUDY: LORESTAN PROVINCE, IRAN)

The aim of this study was to estimate suspended sediment by the ANN model, DT with CART algorithm and different types of SRC, in ten stations from the Lorestan Province of Iran. The results showed that the accuracy of ANN with Levenberg-Marquardt back propagation algorithm is more than the two other models, especially in high discharges. Comparison of different intervals in models showed that running models with monthly data, resulted in smaller error and better estimated results. Moreover, results showed that using Minimum Variance Unbiased Estimator (MVUE) bias correction factor modified the SRC results, especially in monthly time steps in almost all stations. Hence, it can be said that if because of advantages such as simplicity, SRC models are preferred, it is better that MSRC (modified sediment rating curve) is used in monthly period.

Pilot in vitro toxicity study of 5-ALA and Photofrin in microvascular endothelial cell cultures.

Complicated hemangiomas are unique problems in which intervention with the proper laser can be an ideal solution. In this study we evaluated the toxicity of 5-Aminolevulinic acid (5-ALA) and Photofrin using in vitro models. The in vitro toxicity of 5-ALA and Photofrin was examined in a microvascular endothelial cell (MEC) culture system. The measurement of the percentage of MEC killed by various drug concentration using fluorescence viability assay. MEC incubated with 5-ALA at various concentrations for evaluation of dark toxicity showed less than a 50% cell kill. A comparison of different intervals of subcultured MEC showed that the early subculture (3 days after primary culture) is more vulnerable than later subculture (7 days after). Cells treated with Photofrin at various concentrations exhibited less than 50% cell kill (dark toxicity). The comparison of different intervals of subculture (3 days and 7 days after primary culture) showed a result similar to that of 5-ALA. All controls showed 0% cell kill. In conclusion, both 5-ALA and Photofrin are capable of destroying human microvascular endothelial cells in vitro. Drug concentrations and the power density for photodynamic therapy should be considered and will be included in our subsequent studies.

Some aspects of animal photoperiodism.

Many animals have the ability to distinguish between daily cycles of light and darkness that differ in length. This photoperiodic process is clearly one of time measurement since, in effect, it involves the comparison of different intervals of time. The mechanism that controls it can therefore be regarded as a clock of a particular type, namely an interval timer. Although seasonal reactions to day length are common enough, information on the location and mode of operation of the clock is only available for a few groups, among which birds and anthropods are particularly prominent.