Thermal reference points as an index for monitoring body temperature in marine mammals

BACKGROUND Monitoring body temperature is essential in veterinary care as minor variations may indicate dysfunction. Rectal temperature is widely used as a proxy for body temperature, but measuring it requires special equipment, training or restraining, and it potentially stresses animals. Infrared thermography is an alternative that reduces handling stress, is safer for technicians and works well for untrained animals. This study analysed thermal reference points in five marine mammal species: bottlenose dolphin (Tursiops truncatus); beluga whale (Delphinapterus leucas); Patagonian sea lion (Otaria flavescens); harbour seal (Phoca vitulina); and Pacific walrus (Odobenus rosmarus divergens). RESULTS The thermogram analysis revealed that the internal blowhole mucosa temperature is the most reliable indicator of body temperature in cetaceans. The temperatures taken during voluntary breathing with a camera held perpendicularly were practically identical to the rectal temperature in bottlenose dolphins and were only 1 °C lower than the rectal temperature in beluga whales. In pinnipeds, eye temperature appears the best parameter for temperature control. In these animals, the average times required for temperatures to stabilise after hauling out, and the average steady-state temperature values, differed according to species: Patagonian sea lions, 10 min, 31.13 °C; harbour seals, 10 min, 32.27 °C; Pacific walruses, 5 min, 29.93 °C. CONCLUSIONS The best thermographic and most stable reference points for monitoring body temperature in marine mammals are open blowhole in cetaceans and eyes in pinnipeds.

Principales puntos de convergencia entre las escuelas hegemónicas de teoría económica y sociológica desde la Ilustración escocesa hasta nuestros días

This research aims to show the main points of convergence between hegemonic schools of economic and sociological theory from the Scottish Enlightenment until today. To this end, on the one hand, we set three basic families of economic thought (the mainstream, the Austrian school and Marxism); and, on the other, we divide the history of sociology in five major generations (pioneers, founders, institutionalizers, compilers and constructivist). Subsequently, we set five historical periods as reference to our respective chapters and compare, within each of them, the theoretical contributions from these two areas. Thus, in the first chapter, called "the liberal parenthesis", we consider the relationship between the classical school of economics and the pioneers and founders of sociology. In the second, entitled "the social question" we analyze, on the one hand, the theoretical consistency of both the neoclassical school, as Austrian, with the principles defended by the institutionalizers of sociology; and, on the other, the influence of Karl Marx, as founder of sociology and classical economist, in the work of Soviet revolutionary theorists. In chapter three, called the "new industrial state", we demonstrate the theoretical proximity between both Keynesianism and the Austrian school of economics, with the doctrine defended by the generation of compilers in sociology. The fourth chapter, entitled "second industrial divide", refers to the similarities between the theoretical contributions of the monetarist Chicago school and the Austrian school with sociological constructivism. Finally, chapter five, the "global market", shows that the two hegemonic schools in economics, "integrated model", and sociology, "analytical sociology", are composed of the same three schools of thought: the rational choice, the neo-institutionalism and network approach. Thus, we can conclude that, if we look at their respective areas of influence, during this historical period occurs an manifest agreement between the theoretical contributions from the economic and sociological fields.