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Posts Tagged ‘science

[LINK] “Mystical amphibian venerated by Aztecs nears extinction”

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I saw axolotls once in the Toronto Zoo. How sad it is if they go extinct in the wild, as this Al Jazeera article suggests.

The Mexican salamander is found only in its original habitat, Xochimilco. The area contains the last remnants of a system of lakes and canals upon which the Aztec capital thrived. But Xochimilco is now a UNESCO World Heritage site at risk of being swallowed by massive urbanization and pollution in this sprawling capital of 22 million people.

The Aztecs venerated the axolotl as a god, the twin brother of their most important deity, the feathered serpent Quetzalcoatl. Axolotls have been depicted throughout the ages in Mexico, from archaeological sites to modern art. In Diego Rivera’s mural “Water, Origin of Life” (1951), an axolotl swims near a male figure’s genitals — symbolically at the center of creation.

Having the rare amphibian capacity to grow into adulthood without undergoing metamorphosis, the axolotl lives in an eternal adolescent stage. It can regenerate limbs and organs — even parts of its heart and brain — which makes it a valuable case study for scientists all over the world.

[. . .]

A recent study from the National Autonomous University of Mexico (UNAM) shows in 1998 there were 6,000 axolotls per square kilometer in Xochimilco. By 2008 that figure had plummeted to 100. And in 2014 researchers found less than one per square kilometer.

There are at least three major causes for its decline: urbanization, water pollution and the massive invasion of exotic predator fish like carp and tilapia, introduced by the Mexican government in the 1980s to help feed local communities. From the first few thousands they introduced, there are now an estimated 900 tons of fish in these canals.

Written by Randy McDonald

February 17, 2015 at 11:12 pm

[CAT] “Why Do Cats Love Boxes So Much?”

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Wired‘s Bryan Gardiner answers the question. It turns out that they really like warm places where they can hide.

Understanding the feline mind is notoriously difficult. Cats, after all, tend not to be the easiest test subjects. Still, there’s a sizable amount of behavioral research on cats who are, well, used for other kinds of research (i.e., lab cats). These studies—many of which focused on environmental enrichment—have been taking place for more than 50 years and they make one thing abundantly clear: Your fuzzy companion derives comfort and security from enclosed spaces.

This is likely true for a number of reasons, but for cats in these often stressful situations, a box or some other type of separate enclosure (within the enclosures they’re already in) can have a profound impact on both their behavior and physiology.

Ethologist1 Claudia Vinke of Utrecht University in the Netherlands is one of the latest researchers to study stress levels in shelter cats. Working with domestic cats in a Dutch animal shelter, Vinke provided hiding boxes for a group of newly arrived cats while depriving another group of them entirely. She found a significant difference in stress levels between cats that had the boxes and those that didn’t. In effect, the cats with boxes got used to their new surroundings faster, were far less stressed early on, and were more interested in interacting with humans.

It makes sense when you consider that the first reaction of nearly all cats to a stressful situation is to withdraw and hide. “Hiding is a behavioral strategy of the species to cope with environmental changes and stressors,” Vinke said in an email.

This is as true for cats in the wild as it is for those in your home. Only instead of retreating to tree tops, dens, or caves, yours may find comfort in a shoe box.

Much more at the link.

Written by Randy McDonald

February 15, 2015 at 4:58 am

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[CAT] “How do cats deal with being weightless?”

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Universe Today’s Nancy Atkinson reports.

Here’s some footage from some the Aerospace Medical Research Laboratories which include a test of the effects of weightlessness on cats in a C-131 “vomit comet” that simulates weightlessness. Best I can tell, this research was done in 1947. Think of it in the same vein as all those weird tests the early astronauts had to endure.

The text from the video: “In these experiments you can see the disorientation resulting when an animal is suddenly placed in a weightless state. Cats when dropped under normal conditions will invariably rotate their bodies longitudinally in midar and land on their feet. This automatic reflex action is almost completely lost under weightlessness.”

Written by Randy McDonald

February 15, 2015 at 4:49 am

Posted in Science, Video

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[LINK] “The Intriguing New Science That Could Change Your Mind About Rats”

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Brandon Keim’s Wired article argues that in a wide variety of ways, rats and human beings are fundamentally the same, at least in being smart social mammals. Provocative, long read.

[W]e still have much to learn about rats, and from them. Yes, there’s volume upon volume of rat research—but most of it focuses on traditional questions of basic physiology and drug responses and so forth. Few researchers have asked what rats think and feel, or how they’ve adapted to environments so very different from their ancestral home in southern Mongolia.

On this front, rats are guides to emerging questions of evolution and cognition: how cities shape the brains and behaviors of the animals within them, and whether aspects of consciousness once considered exceptional might in fact be quite common.

Foremost among these is empathy, widely considered a defining human characteristic. Yet rats may possess it too. An especially fascinating line of research, the latest installment of which was published last year in the journal eLife, suggests rats treat each other in an empathic manner. Such thoughtfulness underscores the possibility that rats are far more complicated than we’re accustomed to thinking—and that much of what’s considered sophisticated human behavior may in fact be quite simple.

This idea runs contrary to notions of human exceptionality. Yet evolution teaches us that humans and other creatures share not only bodies, but brains. In that light, why wouldn’t rats care about each other? The idea also challenges us to see rats anew: Not just as vermin, or as anonymous laboratory models of some biological process, but as fellow animals.

As neurobiologist Peggy Mason, a pioneer in rat empathy research put it, “I’m perfectly happy thinking of myself as a rat with a fancy neocortex.”

Written by Randy McDonald

February 13, 2015 at 11:02 pm

[LINK] “Measles Still Kills Thousands of Children Each Year”

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The Inter Press Service’s Lyndal Williams notes that measles is still a killer.

Measles remains one of the leading causes of death for young children worldwide, even though a safe vaccine is available.

Most of the 145,700 people who died from measles in 2013 were children under the age of five, according to the World Health Organization (WHO).

However, immunisation has also saved many children from death and serious illness. The WHO estimates that 15.6 million deaths were prevented between 2000 and 2013, because of increased access to the measles vaccination.

Jos Vandelaer, prinicipal advisor on immunisations for UNICEF, the United Nations children’s agency, told IPS that the children most at risk of missing out on vaccinations are among the world’s most vulnerable and disadvantaged, including children from minority backgrounds and displaced or refugee children in temporary accommodation.

“These are the very same kids who also don’t have access to health care, to clean water, to hygiene, to school, and so on,” he said.

“So these kids face a double whammy, in that if they don’t get immunised and they fall sick their chance of getting treatment is also lower than an average kid.”

Written by Randy McDonald

February 11, 2015 at 10:58 pm

[LINK] “It Looks Like an Asteroid Strike Can’t Cause a Worldwide, Dinosaur-Killing Firestorm”

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Universe Today’s Nancy Atkinson shares the relatively good news.

For decades, scientists have debated the cause of the mass extinction that wiped out the dinosaurs and other life 65 million years ago. While the majority of researchers agree that a massive asteroid impact at Chicxulub, Mexico is the culprit, there have been some dissenters. Now, new research is questioning just a portion of the asteroid/Cretaceous-Paleogene extinction scenario. While the scientists involved in the study don’t doubt that such an asteroid impact actually happened, their research shows it is just not possible that vast global firestorms could have ravaged our planet and be the main cause of the extinction.

Researchers from the University of Exeter, University of Edinburgh and Imperial College London recreated the vast energy released from a 15-km wide asteroid slamming into Earth, which occurred around the time that dinosaurs became extinct.

They found that close to the impact site — a 180 km wide crater in Mexico — the heat pulse would have lasted for less than a minute. This intense but short-lived heat, the team says, could not have ignited live plants, challenging the idea that the impact led to global firestorms.

However, they did find that the effects of the impact would actually be worse on the other side of the planet, where less intense but longer periods of heat could have ignited live plant matter.

“By combining computer simulations of the impact with methods from engineering we have been able to recreate the enormous heat of the impact in the laboratory,” said Dr. Claire Belcher from the University of Exeter. “This has shown us that the heat was more likely to severely affect ecosystems a long distance away, such that forests in New Zealand would have had more chance of suffering major wildfires than forests in North America that were close to the impact. This flips our understanding of the effects of the impact on its head and means that palaeontologists may need to look for new clues from fossils found a long way from the impact to better understand the mass extinction event.”

Written by Randy McDonald

February 5, 2015 at 11:01 pm

[BLOG] Some Wednesday links

  • At Antipope, Harry Connolly analyzes a paragraph of Charlie Stross’ writing in detail.
  • Bad Astronomy’s Phil Plait and the Planetary Society Blog’s Casey Dreier both note NASA’s interest in sending a probe to Europa.
  • blogTO notes that Wrigley will shut down a gum-manufacturing plant in Toronto, at the cost of 400 jobs.
  • The Dragon’s Gaze links to a survey of 12 nearby red dwarf stars indicating that none of them have massive planets in close orbits.
  • The Dragon’s Tales notes India’s interest in Japan’s Soryu submarine.
  • Kieran Healy analyzes vaccination data in California, looking at rates of vaccination in different types of schools.
  • Language Hat analyzes the complexities of Gogol’s writing style.
  • Marginal Revolution looks at a debt-restructuring plan for Greece.
  • The Planetary Society Blog shares the latest images from Ceres.
  • Strange Maps looks at the distribution of federally-owned lands across the United States.
  • Transit Toronto notes the passage of a new TTC budget aiming to fix underfunding-related problems.
  • The Volokh Conspiracy considers when voters should defer to the views of scientists.
  • Window on Eurasia suggests Russia might be trying to de-Turkify Crimea, notes the non-Russian past of Siberia, and suggests that current Russian policy is a self-fulfilling prophecy of enemy-making.
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