Life Lines by Dr. Dolittle

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Diet and Exercise

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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Caffeine and memory…wait what was I saying?

Personally, I would have a hard time functioning in the morning without coffee. I think many people might agree as caffeine is the most widely consumed psychoactive stimulant worldwide.  The stimulant effects of caffeine are attributed to its ability to bind to and inhibit adenosine receptors in the body, resulting in increased excitation of neurons: Long term potentiation (LTP) refers to an increase in the strength of connections formed between […]

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Very high intensity exercise: hovering

I just read an interesting review published in Physiology of flight energetics and fuel use in nectar feeding hummingbirds and bats. While flight is considered pretty high intensity exercise, hovering flight is even more demanding. Hummingbirds and nectar feeding bats are really tiny and thus have very high metabolisms to maintain body heat. Some of these animals are also migratory, which is an even greater energy demand. Remarkably, they sustain […]

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Chronic stress causes muscle loss

Researchers have known that chronic stress has many negative health effects that can impair normal growth. The impact of stress on skeletal muscle specifically is less understood. For this reason, researchers at Universidad Andres Bello in Chile explored the effects of stress induced by overcrowding in fine flounders (Paralichthys adspersus). Their results were published this month in American Journal of Physiology – Regulatory, Integrative and Comparative Physiology.  After just four weeks of […]

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How Ossabaw Island swine are helping us understand obesity and diabetes

         Ossabaw Island off the coast of Georgia (United States) is home to feral swine brought over by early Spanish explorers. In relative isolation on the island, with the exception of the introduction of a Hampshire pig, the Ossabaw pigs have become genetically distinct from those living on the mainland. Ossabaw pigs are prone to obesity and are the only miniature pigs known to develop type 2 […]

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Importance of diet to the physiology of farm-raised fish

Image of a fish farm by Vera Kratochvil [Public domain], via Wikimedia Commons Fish farming, i.e. aquaculture, has increased about 6.2% between the years 2000-2012, according to the Food and Agriculture Organization of the United Nations. Fish farms are highly dependent on fish meal as well as fish oil as nutrients for the growing fish. Although rates of farming have increased, the supply of fish meal and oil are predicted […]

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Passing gas

Many children (and adults) find humor in flatulence. If you count yourself among these individuals, then a new book written by zoologist Dani Rabaiotti and ecologist Nick Caruso, coming out in April 2018, is a must-read. The book examines which animals truly pass gas and is aptly titled, “Does it Fart?” No longer will you be limited to only blaming it on the dog or cat. Although you will not […]

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Health risks of being social

When I think of rainbow trout, the first image that comes to mind is usually something like this: In the wild, they look more like this: …not as appetizing, but a lot more fascinating.  When salmonid fish like rainbow trout are in environments with limited food or space, they form social hierarchies. In one study of limited food availability, Grobler et al., found that when they placed 4 rainbow trout […]

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Man catches rare warm-blooded fish

This past weekend a man caught a very rare fish, called an opah (aka moonfish), off the coast of Ocean City, Maryland. What makes this fish so rare is that it is the only known warm-blooded fish. In fact, they are able to keep their whole body about 5 degrees Celsius above the water they swim in. Other fish lose heat generated from muscle movements to the environment as the […]

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Fasting as a survival strategy in animals

Although female northern elephant seals only typically deliver one pup, females will sometimes nurse offspring from other mothers as in this photo by Brocken Inaglory via Wikimedia commons. A situation like this would result in less milk available to each nursing pup. I just read an interesting paper published in Physiology. Animals periodically undergo periods of food deprivation such as during hibernation, mating, molting and migration. During these period of […]

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