Life Science
dr. dolittle | September 9, 2015 Arousal of a thirteen-lined ground squirrel from hibernation. By Uncredited; Walter L. Hahn [Public domain], via Wikimedia Commons
In a new study published in the American Journal of Physiology Regulatory, Integrative and Comparative Physiology, researchers at the University of Wisconsin, La Crosse were interested in understanding how thirteen-lined ground squirrels protect their brains during arousal from hibernation. This is a period of time in which the animals experience major changes in their body temperature and increased blood flow to the brain. The researchers knew that levels of…
dr. dolittle | September 3, 2015A new study published in the Proceedings of the Royal Society B: Biological Sciences provides evidence that hummingbird tongues act like micropumps when drinking nectar. This finding is in contrast to the long-held belief that their tongues use capillary action to pull in fluids. A team of researchers from the University of Connecticut used high-speed film to capture 18 species of wild hummingbirds as they drank from special transparent feeders. They made sure to mimic wildflowers by developing feeders with similar shapes, volumes and concentrations of nectar as the real thing. What they…
dr. dolittle | September 1, 2015Answer: pregnancy.
Unlike most animals, it is the male seahorses that give birth to live young. A new study conducted at the University of Sydney and published in Molecular Biology and Evolution, found that the male seahorses not only carry out the pregnancy, they also supply nutrients to the developing embryos, including fats and calcium. The researchers suspect that these nutrients are secreted into the brood pouch where they can be absorbed by developing embryos. According to quote from study author Dr. Whittington, published in the International Business Times, "Seahorse babies get a lot…
dr. dolittle | August 19, 2015Another new study published in Nature Communications shows follows along with the prior post and shows that ancestral dogs were ambush hunters that evolved from forest dwelling animals similar to a mongoose (or a cat).
These early ancestors to dogs were ambush predators. The image shows Hesperocyon (left) and later Sunkahetanka (right). Image from Discovery News, by Mauricio Anton
An international team of researchers studied archived samples of elbows and teeth of multiple species of dogs that lived between 40 - 2 million years ago. According to a quote from …
dr. dolittle | August 18, 2015 By Noel Feans (originally posted to Flickr as Watch your back!) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
New research suggests that cats may have played a role in the extinction of about 40 species of wild dogs by simply out-hunting them and therefore consuming more food.
The study noted that dogs first appeared in North America around 40 million years ago and by 22 million years ago there were over 30 species of wild dogs. Cats arrived from Asia around 20 million years after dogs appeared. The arrival of cats was followed by decreased diversity of…
dr. dolittle | August 17, 2015 Image of baboon with offspring By RADION Imaginery / Kamil Wencel (RADION Imaginery / http://imaginery.radion.org/) [Attribution], via Wikimedia Commons
Malnutrition during pregnancy is a major global health issue that leads to restricted growth of developing fetuses making them more prone to death and disease. In fact, babies born from poorly nourished mothers are more likely to develop obesity, metabolic syndrome and cardiovascular disease as adults.
Researchers from the University of Colorado and University of Texas Health Sciences Center teamed up to examine whether the placenta can…
dr. dolittle | August 16, 2015I came across the "I Spy Physiology" blog today from the American Physiological Society. The blog focuses on physiological topics relevant to daily life. There are also a couple of comparative physiology gems in the blog that you can view using the links below:
How birds my help us understand diabetes
How research on walking stick insects may help us to understand how the brain times leg contractions to regulate walking
Pretty neat stuff!
dr. dolittle | August 4, 2015I came across this highly entertaining video of the "Top 10 Extreme Forms of Life" on YouTube:
dr. dolittle | August 3, 2015I came across this neat video from Mayo Clinic researcher Dr. Michael Romero, a comparative physiologist interested in how the kidneys work. In this video he describes discoveries made in zebrafish that relate to human kidney function:
dr. dolittle | August 2, 2015
Research published in the Journal of Experimental Biology shows that noisy humans are impacting the physiology and behaviors of dolphins and whales. To compete against man-made noises, these animals are altering the amplitude, frequency or length of their vocalizations or repeat what they need to say with the hope of being heard. Dr. Maria Holt and colleagues studied a par of bottlenose dophins vocalizing and discovered that the oxygen intake of the animals increased as they raised their voices. The team then calculated the number of additional calories the dolphins would need to ingest to…
dr. dolittle | July 29, 2015It is that time of year again to vote for your favorite "Ugliest dog". I have a feeling it will be a close contest. To pick your favorite contender, click here.
Honestly some of them are rather cute in their own way. I am rather partial to Rascal Deux and Icky...this will be a tough decision.
Here are a couple of contestants from the 2013 contest (images from Wikipedia):
dr. dolittle | July 27, 2015 Image of a Siberian hamster from Wikimedia Commons
Exposing Siberian hamsters (Phodopus sungorus) to shorter photoperiods (think winter) for about two months causes the animals to spontaneously undergo daily bouts of torpor during which time they decrease metabolic rate to conserve energy. New research published in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology was designed to examine whether decreases in growth hormone secretion was involved in stimulating these daily torpor episodes. By administering a chemical that inhibits growth hormone,…
dr. dolittle | July 22, 2015
New research from Dr. Scott Boback and colleagues at Dickinson College (Pennsylvania) shows that boa constrictors do not use suffocation as a primary means of killing their victims. Rather, by measuring blood pressure and heart activity of the prey, they were able to determine that the snakes restrict blood flow in their victims causing circulatory arrest and a lack of oxygen delivery to vital organs. By preventing blood flow to the brain, the victims faint within mere seconds. Dr. Boback was quoted in BBC News saying , "...an absence of blood flow will cause death more rapidly than…
dr. dolittle | July 20, 2015
If you happen to be in the Arctic this summer polar bears (Ursus maritimus) can be spotted spending their time on the sea ice or on the shore in areas where ice has melted. While it is difficult to study the physiology of bears living on the ice, it had been hypothesized that bears living on shore experience a state similar to winter hibernation in which they attempt to decrease their energy expenditure when food resources are low. However, new research published in Science shows that bears living on the ice as well as those on shore experience some decrease in activity as well as body…
dr. dolittle | July 15, 2015
Research published July 3 in the journal BMC Evolutionary Biology supports the idea that some species of spiders can catch the wind to "sail" across bodies of water, which they suggest might be why certain spiders seem to be all over the world. While some spiders were already know to catch the breeze to travel by air relatively short distances, and some are known to be aquatic, the researchers in this study were interested in examining just how well spiders could actually walk on water. So, they collected 325 wild spiders and dropped them on water to see what would happen. All of the…
dr. dolittle | July 8, 2015I came across this neat press release from the American Physiological Society which describes new research on understanding how the genes of burmese pythons are actually altered by feeding. Fascinating! The research was published in the May issue of Physiological Genomics. Here is a brief synopsis. For the full story, visit the APS website.
Yep, that's a python eating a rodent.
What is so fascinating about Burmese pythons is that their body literally is reconstructed within 3 days of eating resulting in the doubling or organ size and a 10-44 fold increase in metabolism. Then, within about…
dr. dolittle | July 2, 2015 Image of a Mexican Jay selecting peanuts from www.sci-News.com
I just listened to a neat podcast from Scientific American's Karen Hopkin in which she described a new study published in the Journal of Ornithology that suggests Mexican Jays (Aphelocoma ultramarina) pick which peanut to eat only after literally weighing their options. The researchers modified some peanuts to remove the contents. The Mexican Jays were then offered unmodified nuts along with the empty shells. Perhaps not surprisingly, the birds snubbed the empty shells. Rather, they only chose shells that contained nuts. In…
dr. dolittle | June 30, 2015
Sadly, the second herpes virus-related death occurred after this story was released at the Albuquerque BioPark. The victim was a five-year old Asian elephant named Daizy.
Source:
The Scientist
dr. dolittle | June 29, 2015 Canadian Geese. Image take near Lakeview, OR. Image from: Bureau of Land Management
A new study conducted by researchers Eric Vaillancourt and Jean-Michel Weber at the University of Ottawa examined blood sugar regulation in a bird that specialize in long distance migration, the Canada goose (Branta canadensis, image above). As referenced in the study published in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, Canadian geese migrate approximately 7,000 km on their way to the Arctic, a trip that includes non-stop flights of up to 1,000 km at a time…
dr. dolittle | June 22, 2015 A camouflaged giant Australian cuttlefish. Image from LiveScience; Credit: Sarah Zylinski, Duke University
Could you imagine artificial skin capable of quickly changing colors to communicate or hide? Scientists have been testing ways to mimic the skin of cephalopods like squid, octopuses and cuttlefish, which have a remarkable ability to change skin color and sometimes even texture to mimic their surroundings. Cephalopods have networks of chromatophores, which are cells within their skin that contain a pigment sac. Expanding these cells with the aid of muscles, makes the pigment expand…