ANESTHESIA AND ANALGESIA IN ANTARCTIC FISH: AN EXPERIMENTAL APPROACH

Foi levado a efeito em peixes antárticos um estudo sobre as ações anestésicas e/ou analgésicas de depressores centrais ketamine, fentanyl e thiopental bem como do anestésico local benzocaina. As drogas foram adicionadas à água marinha aerada nas temperaturas de 1 a 1,5oC. Ketamine (15 mg/L) e fentanyl (50 g/L) não induziram anestesia mas causaram demorada analgesia e sedação. Doses de 100 mg/L de Thiopental foram necessárias para anestesiar peixes, ou seja, em concentração 30 vezes maior do que a dose anestésica usual utilizada para mamíferos. A anestesia ocasionada nos peixes foi longa - de 3 a 4 horas - e difícil de ser controlada. Um dos peixes utilizados na experimentação permaneceu em estado de comatose por quatro dias com sobrevida. Benzocaina em doses de 100 mg/L foi eficiente para anestesiar peixes dentro de 6 a 8 minutos após a sua administração. A anestesia, neste caso, teve duração de 15 a 20 minutos acompanhada de pequena depressão respiratória. Abstract It was studied in Antarctic fishes the anesthetic and/or analgesic actions of central depressors ketamine, fentanyl and thiopental as well as the local anesthetic benzocaine. The drugs were added to aerated marine water at temperatures of 1-1.5 C. Ketamine (15 mg/L) and fentanyl (50 g/L) failed in inducing anesthesia but caused a long lasting analgesia and sedation. Thiopental was required in doses of 100 mg/L to anesthetize the fishes, that is, about 30 times higher than the usual anesthetic dose for mammals. The anesthesia was long lasting, that is, 3-4 h, and difficult to control. One fish remained in a comatose state for four days with survival. Benzocaine in doses of 100 mg/L was successful in anesthetizing the fishes within 6-8 min, anesthesia lasting for 15-20 min, with a minor respiratory depression

ANÁLISE DA POPULAÇÃO MICROBIANA EM ÁGUA DE LAVAGEM DE CARCAÇA E EM CARCAÇA BOVINA EM UM FRIGORÍFICO ABATEDOURO

O objetivo do presente trabalho foi detectar coliformes totais e fecais na água utilizada em um abatedouro de bovinos da região metropolitana de Curitiba e em swabs de carcaças bovinas. As amostras foram colhidas conforme metodologia colilert® para água de lavagem e tubos seriados e petrifilm® para swabs de carcaça. Os resultados não foram satisfatórios em 20% das amostras de água, e em 10% das análises das carcaças. Analysis of the microbial population in the water used for carcass washing and in bovine carcass at a slaugther house Abstract The main aim of the present research was to detect the total and fecal coliforms in the water used for carcass washing and in swabs from the bovine carcasses, in a slaughter house from the Metropolitan Region of Curitiba. The sampling has been processed according to the colilert® methodology for the washing water and serial tubes and petrifilm® for the carcasses swabs. Results were found unsatisfactory for 20% of the water samples and 10% of the bovine carcasses

Fatigue crack propagation in HSLA steel specimens subjected to unordered and ordered load spectra

Prediction of fatigue crack propagation in metallic structures subjected to dynamic random load spectra, containing variable overloads and underloads, is challenging because of possible retardation and acceleration effects. In this paper, fatigue crack growth behaviour under random spectrum load is investigated on ESE(T) specimens made of DNV 460 steel, which is an HSLA steel widely used in the offshore industry. A reference spectrum composed of a sequence of random loads is transferred into various reduced and ordered spectra. Reduced spectra have been defined based on a peak-valley segmentation algorithm and on the deletion of non-damaging events. Ordered spectra consist of block loading sequences determined by rainflow counting methods. Specific control software has been developed that allows to execute the K (stress intensity factor) controlled experimental program and perform on-line crack growth measurement using a material compliance method. The different spectra are compared in terms of total crack extension and retardation in crack growth rate. Algorithms for crack growth simulation have been implemented in Abaqus using both existing and adapted plastic zone models. Numerical results are critically compared to the experimental data