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Tag Archive for ‘oxygen’

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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First ever recording of heart rate in free swimming blue whales

While we are on the topic of whales, I found additional research published in the Proceedings of the National Academy of Sciences USA on these animals and how their hearts function that I find fascinating. Talk about extreme physiology! Researchers from Stanford University were able to attach surface electrodes to blue whales using suction cups. This allowed them to measure – for the first time – how heart rate changes during […]

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How some fish may compensate for low environmental oxygen

     Adult fish rely on gills to extract oxygen from the surrounding water. Larval fish, on the other hand, do not have well-developed gills and instead rely primarily on gas exchange across their skin.      In a new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, researchers examined whether larval fish could use their pectoral fins to increase the flow of water […]

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Adults are better adapted to survive without oxygen

Adult fruit flies (Drosophila melanogaster) are more tolerant of environments devoid of oxygen than their larvae. In fact, they are able to survive up to 12 hours without oxygen by becoming paralyzed, which enables them to dramatically reduce metabolism and the need for oxygen. In contrast, Drosophila larvae expend a lot of energy trying to escape and are only able to tolerate a couple of hours without oxygen. This is surprising […]

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Importance and dangers of oxygen for air-breathing animals

Although oxygen is essential for air-breathing species and allowed for the evolution of multicellular organisms, it is also a dangerous molecule that can lead to cellular toxicity through the generation of reactive oxygen species (ROS). However, it is important to point out that cellular ROS also play several physiological roles in the body. I just read an interesting review article published in Physiological Reviews that explored natural oxygen delivery and availability […]

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Compromising fish

Here’s something to think about. How do fish optimize gas exchange in their gills to efficiently take up oxygen (favoring large, thin, permeable membranes) while at the same time limiting water and ion movement across the surface? If they reduce surface area, then oxygen transfer will be limited, but ions and water transfer will be optimized. What is a fish to do? A new review article published in Physiology discussed how […]

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Environmental impact on physiology

Several of the comparative physiology posters and talks presented at the Experimental Biology conference today focused on the impact of environmental changes on the physiology of animals. Here are some highlights: Rachel Heuer, a postdoctoral fellow at the University of Miami working with Dr. Martin Grosell, examined the effects of crude oil on heart function in mahi-mahi. As the Deepwater Horizon spill occurred when these fish were spawning, it is […]

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Comparative Physiology @ Experimental Biology

I am printing my posters and planning my schedule for the 2018 Experimental Biology conference, which starts this weekend. This is no doubt the highlight of my year! I am looking forward to the comparative physiology sessions. Judging from the program, I think this is going to be a really exciting conference! This year’s August Krogh Distinguished Lectureship will be given by Dr. Stanley Hillman from Portland State University who […]

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Experimental Biology 2016 – Day 4

Still going strong…here are the highlights from several sessions held on Day 4: John Eme (California State University, San Marcos) presented data testing the effects of varying temperatures mimicking overwintering conditions on embryonic development of Lake whitefish. He found that indeed exposure to variable incubation temperatures between 2-8 deg C resulted in increased mortality. Moreover, the embryos hatched earlier and were smaller than animals exposed to constant temperatures. Nariman Hossein-Javaheri et al., (University […]

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Experimental Biology 2016 – August Krogh Distinguished Lecturer: Dr. Jon Harrison

This year’s August Krogh Distinguished lecture, the highest award given to an accomplished Comparative Physiologist from the Comparative and Evolutionary Physiology section of the American Physiological Society was awarded to Dr. Jon Harrison, Arizona State University. Dr. Harrison gave an outstanding seminar in which he reviewed some of his major research discoveries. His work has included examining how insects tolerate various temperatures and how changes in the levels of atmospheric […]

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