Flight Initiation Distance Differs Between Populations of Western Fence Lizards (Sceloporus occidentalis) at a Rural and an Urban Site

Abstract.—Flight initiation distance (FID) is the distance to which a predator is permitted to approach before the prey initiates flight behavior. This can be influenced by factors including predator density and distance to cover. We measured flight initiation distances in two populations of Western fence lizards (Sceloporus occidentalis), one in a rural and one in an urban environment. Lizards at the rural site initiated flight at significantly longer distances than those at the urban site. These results support the prediction that lizard behavior can be influenced by differences in human exposure and predator recognition in their environments. Lizards develop tolerance to humans in urban areas in order to maximize fitness by reserving energy and utilizing resources for longer periods of time. The findings from this study demonstrate that researchers should be aware of differences in human exposure between populations of study animals and should choose study sites appropriately when designing FID studies

Ariel - Volume 1 Number 3

Copyright 1969 Arie

A Theoretical and Experimental Analysis of a Self-contained R-290 Refrigeration Unit Applied to a Glass Door Reach-in Supermarket Display Case

This paper presents a theoretical and experimental analysis of a self-contained variable speed R290 refrigeration unit applied to a typical 1.25m long two-glass-door reach-in supermarket display case, originally designed to run on an integrated R404a single speed refrigeration unit. A semi-empirical mathematical model was put forward to predict system energy consumption and cabinet psychometrics as a function of environmental conditions (ambient temperature and relative humidity), compressor model (single-speed, variable-speed and compressor displacement), refrigerant fluid (R290 and R404a) and geometry (heat exchangers overall heat transfer coefficient). One energy consumption test was performed at 32°C ambient temperature and used to calibrate components overall heat transfer coefficients. The model validation was then performed by using the calibrated model to predict the system energy consumption at 27°C ambient temperature. A good agreement between experimental and numerical results was found with errors lower than 1% and 3% on energy consumption and compressor running time ratio respectively. Finally, the model was applied to predict annual energy consumption for two units (R290 self-contained and R404a integrated) as a function of the monthly average ambient temperatures for Joinville, Santa Catarina, Brazil. The simulation results indicate an annual energy consumption saving up to 30% when a self-contained R290 variable speed hermetic refrigeration unit is applied to a cabinet originally designed for an integrated R404a single speed compressor refrigeration unit

Previsión de crisis epilépticas usando transformada wavelet y correlación cruzada

Este artículo describe la detección de actividad precrisis mediante la aplicación de la correlación cruzada junto con la transformada Wavelet. La transformada Wavelet es aplicada a los datos EEG puros para la reducción y pre-procesamiento de las señales. Esta técnica de extracción de características provee las señales simplificadas para ser procesadas por medio de la técnica de correlación cruzada. El análisis ha sido realizado con un grupo de datos tanto precrisis como intercrisis, (incluyendo crisis agudas inducidas y crisis espontáneas recurrentes), con el fin de determinar su sensitividad y especificidad (tasa de falsas predicciones). Son determinados, adicionalmente, el período de ocurrencia de crisis y el horizonte de previsión de crisis