oxygen
dr. dolittle | October 18, 2016...in alligators at least.
Image of alligator eggs and hatchling from National Park Service.
Researchers from the University of Manchester, University of North Texas - Denton, and the Rockefeller Wildlife Refuge - Grand Chenier, Louisiana teamed up to explore the effects of exposure to low oxygen on embryonic American alligators (Alligator mississippiensis). Alligator eggs are often laid in nests where oxygen concentrations can reportedly vary between 11-20% (21% is normal atmospheric levels). This is really important as issues related to embryonic development could continue to affect…
dr. dolittle | April 6, 2016
Still going strong...here are the highlights from several sessions held on Day 4:
Drawing of Lake Whitefish by William Converse Kendall - Kendall, William Converse, b. (1909) Fishes of the Connecticut Lakes and Neighboring Waters, with Notes on the Plankton Environment, Report of the Commissioner of Fisheries, 1906-1907, Washington, DC: Government Printing Office, p. 39 Fig.1, Public Domain
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…
dr. dolittle | November 24, 2015 Image of chicken egg from Wikimedia Commons.
Turns out the egg is an important phase. A new study published this month in American Journal of Physiology - Regulatory, Integrative and Comparative Physiology looked at what happens in the egg when a chicken fetus was exposed to low oxygen (hypoxia) conditions. In mammals, this can occur as a result of maternal hypoxia, preeclampsia as well as anemia in the fetus resulting in less red blood cells that can carry oxygen. Understanding this is important as restricted fetal growth is associated with an increased risk for developing cardiovascular…
dr. dolittle | March 29, 2015
I was very impressed by the graduate and undergraduate students who presented their research at the Scholander poster competition sponsored by the Comparative and Evolutionary Physiology section of the American Physiological Society this afternoon. I am sure the winner of the competition will be very difficult to select.
Some highlights included:
Bridget Martinez, graduate student at the University of California - Merced whose research focused on hormonal changes that occur with fasting in elephant seal pups. In mammals, food deprivation leads to lower thyroid hormone concentrations, which…
dr. dolittle | June 16, 2013 Image source: AKIKO KUMAGAI & ATSUSHI MIYAWAKI as posted in Scientific American
Dr. Miyawaki from the RIKEN Brain Science Institute in Wako, Japan and colleagues have identified the first example of a muscle protein in Japanese freshwater eels (Anguilla japonica) that fluoresces under special circumstances that may lead to improved medical testing (photo above). The researchers have isolated the protein they named UnaG (after "unagi", the term for freshwater eel in Japanese). What is unique about this protein is that it fluoresces under low oxygen conditions and when it binds to…
dr. dolittle | April 23, 2013
Today's symposia included a session on "Integrative Cardiovascular and Respiratory Physiology of Non-model Organisms" as well as the August Krogh Distinguished Lecture.
This year's Krogh lecture was given by Dr. Stan Lindstedt from Northern Arizona University. Dr. Lindstedt is arguably best known for publishing work showing that the metabolic rate of an animal is negatively correlated with body mass. In other words, smaller animals have a higher metabolic rate than larger animals. Knowing that relationship could have saved Tusko the elephant from a whopping dose of LSD (1962, prior to the…
esiegel | March 17, 2013"Build a man a fire, and he'll be warm for a day. Set a man on fire, and he'll be warm for the rest of his life." -Terry Pratchett
Whether it comes from without or within, there are few things in this life that captivate our attention better than a brilliant, hot and colorful display. This weekend, have a listen to The Roots with John Legend, as they sing about
The Fire.
Deep off in the depths of space, although you won't find any stars burning a bright green color, you will find stellar remnants, or star corpses, glowing a brilliant green.
Image credit: NASA, ESA, and the Hubble Heritage…
esiegel | June 8, 2012"Building one space station for everyone was and is insane: we should have built a dozen." -Larry Niven
Here on the solid ground of the Earth, the Sun and Moon rise and set on a daily basis. During the hours where the Sun is invisible, blocked by the solid Earth, the stars twirl overhead in the great canopy of the night sky.
Image credit: Chris Luckhardt at flickr.
In the northern hemisphere, they appear to rotate around the North Star, while in the southern hemisphere, the stars appear to rotate about the South Celestial Pole. The longer you observe -- or for photography, the longer you…
milhayser | August 16, 2011
On Universe, Claire L. Evans looks back on the starry-eyed futurism of the 1970's, when Gerard O'Neill envisioned "massive colonies of human habitation in space—self-sustaining environments capable of hosting hundreds of thousands of people." These colonies, housed in spinning cylinders, "would float in space at Lagrangian points, points of stable gravitational equilibrium located along the path of the moon's orbit." Today our ambitions are a bit less grand—and perhaps we should focus on taking care of the perennial spaceship Earth. But with unlimited room to grow and plenty of solar…
edyong | December 24, 2008 Since the first living things appeared on the planet, the biggest among them have become increasingly bigger. Over 3.6 billion years of evolution, life's maximum size has shot up by 16 orders of magnitude - about 10 quadrillion times - from single cells to the massive sequoias of today (below right). And no matter what people say, size does matter.
The largest of creatures, from the blue whale to the sauropod dinosaurs, are powerful captors of the imagination, but they are big draws for scientists too. Jonathan Payne from Stamford University is one of them, and together with a large team,…
esiegel | April 7, 2008What's going to happen to all the stars in the Universe as they get older? Well, just as nothing can live forever, stars can't live forever also. Why? Because they run on fuel: burning hydrogen into helium, for example. When they run out of fuel, something's gotta give. Barbara Ryden reminds us of an excellent and appropriate quote by Dylan Thomas:
Do not go gentle into that good night.
Rage, rage against the dying of the light.
But what exactly happens to the star depends very sensitively on what the mass of the star is.
If you've got a tiny little star, less than about 40% of the mass of…