Life Lines by Dr. Dolittle

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Diet and Exercise

Sex differences in eating after exercise

Diet and exercise are regarded as the most effective means to maintain weight as well as lose weight. But, there’s sometimes a catch as their effectiveness varies between individuals. Moreover, many people find it really difficult to keep the weight off. Researchers think this may happen in part because the body adapts to weight loss by increasing appetite and decreasing energy expenditure. Here is where exercise, in particular, is thought […]

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Avian red blood cells produce hydrogen sulfide to maintain cell integrity and longevity

Birds have strange red blood cells, at least in comparison to mammals. While they both are responsible for transporting oxygen molecules throughout the body, avian red blood cells have mitochondria and a nucleus. Mammalian red blood cells, on the other hand, are missing a nucleus as well as organelles. By eliminating these structures, mammalian red blood cells are able to carry more oxygen molecules and fold more easily to fit […]

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Hypoxia improves exercise duration

Speaking of hypoxia, a new study published in Physiological Reports examined how training for 2 weeks under 18% hypoxia impacts muscles of Thoroughbred horses. Unlike humans, these horses do not increase production of red blood cells to enhance oxygen transport throughout the body under hypoxic conditions. This difference led researchers to speculate that the horses had other ways of adapting to exercise.   In the new study, horses were trained […]

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Physiology of diving animals: how do they deal with hypoxia?

Dr. Jose Pablo Vazquez-Medina (pictured at right), a comparative physiologist at the University of California – Berkeley, was scheduled to present several ongoing studies from his lab at the Experimental Biology conference last month. Dr. Vazquez-Medina is a member of the Comparative and Evolutionary Physiology section of the American Physiological Society. Although the conference was cancelled due to Covid-19, Dr. Vazquez-Medina has agreed to share his research with us.   […]

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Seagulls pick up on human cues to find food

Have you ever experienced seagulls seemingly begging for food from you? It is not your imagination. A new study finds that seagulls really do prefer foods that have been handled by humans. The study conducted Madeleine Goumas (University of Exeter, UK) examined whether seagulls picked up on cues from humans or were simply looking for food. While standing about 8 meters away from herring gulls, the team placed two plastic-wrapped […]

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Developing Pacific molluscs produce their own carbohydrates

Animals that develop within an egg, must rely on the egg yolk for nutrition for healthy development. While we have known that proteins and fats in the egg are important for development, the role of carbohydrates in the development of molluscs is a bit vague. A new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology examined the role of carbohydrates in the development of Pacific […]

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Why pigs and people absorb more sugar from their diet than fish

Researchers at the University of Saskatchewan in Canada compared how pigs and fish absorb glucose (i.e. sugar) from the diet. They did this by measuring how well glucose moves across the intestinal wall. Their findings appear in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology.  Transport of dietary glucose from the gut to the blood is facilitated by glucose transporters that pick up glucose and move it […]

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