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Posts Tagged ‘science

[LINK] “Wooly Mammoth Genes Inserted into Elephant Cells”

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The Dragon’s Tales linked last week to this Discovery News report suggesting that the resurrection of the mammoth may not be too far off.

Researchers from Harvard University have successfully inserted genes from a woolly mammoth into living cells from an Asian elephant, the extinct giant’s closest remaining relative.

Harvard geneticist George Church used DNA from Arctic permafrost woolly mammoth samples to copy 14 mammoth genes — emphasizing those related to its chilly lifestyle.

“We prioritized genes associated with cold resistance including hairiness, ear size, subcutaneous fat and, especially, hemoglobin,” Church told The Sunday Times.

Then, using a kind of DNA cut/paste system called CRISPR (clustered regularly interspaced short palindromic repeat), Church dropped the genes into Asian elephant skin cells.

The result? A petri dish of elephant cells functioning normally with mammoth DNA in them, marking the first time mammoth genes have been on the job since the creature went extinct some 4,000 years ago, as Sarah Fecht, from Popular Science, noted.

Written by Randy McDonald

March 30, 2015 at 10:42 pm

[LINK] On the oddity of Nova Vulpeculae 1670, aka CK Vulpeculae

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National Geographic‘s Nadia Drake reports on how recent reanalyses of an obscure seventeenth-century nova points to early astronomers’ observation of something very unusual.

For decades, scientists thought the explosion was a classical nova, a stellar outburst that’s less catastrophic than a supernova. But a new look at the remnant left behind by the explosion reveals a more violent history, astronomers report Monday in Nature. Now called CK Vulpeculae, the explosion was what’s called a red transient, produced when two stars violently collide.

Red transients are thought to be a relatively rare type of stellar smashup; based on the chemical elements produced in the collision, this one appears to have been particularly violent, possibly even head-on, says study author Tomasz Kaminski, of the European Southern Observatory.

In 1670, a new star appeared in the sky. Located near the head of Cygnus the Swan, the guest star was first spotted in June. It stuck around through the summer but faded in the fall.

In March 1671, the star reappeared—and over that summer, it shone brighter than ever before. Astronomers of the time, including lunar cartographer Hevelius and Giovanni Domenico Cassini (the namesake of NASA’s Saturn-exploring Cassini spacecraft), kept track of the star’s light until it vanished that October. It made one more feeble appearance in 1672 before disappearing for good.

At the time, astronomers didn’t know what they were looking at. “There would still have been controversy as to whether the nova was in the starry realms or in the Earth’s atmosphere,” says Owen Gingerich, professor emeritus of astronomy and the history of science at the Harvard-Smithsonian Center for Astrophysics.

Written by Randy McDonald

March 27, 2015 at 11:08 pm

[BLOG] Some Wednesday links

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  • Gerry Canavan produces his own compendium of interesting links.
  • Centauri Dreams speculates about the colours indicative of extraterrestrial life, and ecologies.
  • Crooked Timber takes a look at Northern Ireland and the legacies of past violence.
  • The Dragon’s Tales reports on a hominid fossil that may indicate a much greater diversity in our ancestral gene pool than we thought.
  • A Fistful of Euros’ Edward Hugh wonders when the European Central Bank will start to taper interest rates.
  • The Frailest Thing warns that the promises of tech giants to free people from the shackles of the past should be seen critically.
  • On St. Patrick’s Day, Joe. My. God. and Michael in Norfolk both note the extent to which attitudes towards GLBT people in Ireland have changed.
  • Lawyers, Guns and Money wonders about the good sense of going off of anti-depressants.
  • Marginal Revolution’s Tyler Cowen proclaims Scarborough to be one of the world’s best food cities.
  • Savage Minds makes the case for anthropologists to aid the post-cyclone people of Vanuatu.
  • Spacing interviews the NDP’s Thomas Mulcair on urban issues.
  • The Volokh Conspiracy’s David Bernstein is unhappy at the consequences for Israel of Netanyahu’s reelection, while Lawyers, Guns and Money looks at income disparities in Israel.
  • Window on Eurasia argues that high inequality and low social mobility in Russia will doom the country, notes the potential for water-driven conflict in Central Asia, and notes Russian interest in acquiring more slots of Muslim pilgrims after Crimea’s annexation.

[LINK] On the possible extensive water oceans of early Mars

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The New York Times‘ Marc Kaufman reported on the controversial new suggestion, described in the new Science paper “Strong water isotopic anomalies in the martian atmosphere: Probing current and ancient reservoirs”.

After six years of planetary observations, scientists at NASA say they have found convincing new evidence that ancient Mars had an ocean.

It was probably the size of the Arctic Ocean, larger than previously estimated, the researchers reported on Thursday. The body of water spread across the low-lying plain of the planet’s northern hemisphere for millions of years, they said.

If confirmed, the findings would add significantly to scientists’ understanding of the planet’s history and lend new weight to the view that ancient Mars had everything needed for life to emerge.

“The existence of a northern ocean has been debated for decades, but this is the first time we have such a strong collection of data from around the globe,” said Michael Mumma, principal investigator at NASA’s Goddard Center for Astrobiology and an author of the report, published in the journal Science. “Our results tell us there had to be a northern ocean.”

But other experts said the question was hardly resolved. The ocean remains “a hypothesis,” said Ashwin Vasavada, project scientist of the Curiosity rover mission at the Jet Propulsion Laboratory in Pasadena, Calif.

The Guardian‘s Ian Sample explained the scientists’ methodology.

The scientists used the Keck II telescope and Nasa’s Infrared Telescope Facility, both in Hawaii, and the ESO’s Very Large Telescope in Chile, to make maps of the Martian atmosphere over six years. They looked specifically at how different forms of water molecules in the Martian air varied from place to place over the changing seasons.

Martian water, like that on Earth, contains standard water molecules, made from two hydrogen atoms and one oxygen atom, and another form of water made with a heavy isotope of hydrogen called deuterium. On Mars, water containing normal hydrogen is lost to space over time, but the heavier form is left behind.

When normal water is lost on Mars, the concentration of deuterium in water left behind goes up. The process can be used to infer how much water there used to be on the planet. The higher the concentration of deuterium, the more water has been lost.

The infrared maps show that water near the Martian ice caps is enriched with deuterium. The high concentration means that Mars must have lost a vast amount of water in the past, equivalent to more than six times that now locked up in the planet’s frozen ice caps.

The scientists calculate that the amount of water was enough to create a global ocean that covered the entire surface of Mars to a depth of 137m. But Mars was probably never completely submerged. Based on the Martian terrain today, the scientists believe the water pooled into a much deeper ocean in the low-lying northern plains, creating an ocean that covered nearly a fifth of the planet’s surface. The Atlantic, by comparison, covers about 17% of Earth’s surface.

“Ultimately we can conclude this idea of an ocean covering 20% of the planet which opens the idea of habitability and the evolution of life on the planet,” said Geronimo Villanueva, the first author on the study.

The Vastitas Borealis, the deep and level northern-hemispheric plain, has long been thought of as a possible ancient ocean bed.

The science can be challenged on multiple grounds. For example, are scientists correct in their judgement of Mars’ ancient hydrogen/deuterium ratios? It could go either way if they are wrong. Regardless, this has implications for ancient–and even current?–life on the Red Planet.

Written by Randy McDonald

March 5, 2015 at 11:17 pm

[LINK] “Real Paleo Diet: Early Hominids Ate Just About Everything”

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At IFL Science, Ken Sayers notes that, far from cleaving to the paleo diet in vogue now, early hominids have a diverse omnivorous diet.

Reconstructions of human evolution are prone to simple, overly-tidy scenarios. Our ancestors, for example, stood on two legs to look over tall grass, or began to speak because, well, they finally had something to say. Like much of our understanding of early hominid behavior, the imagined diet of our ancestors has also been over-simplified.

Take the trendy Paleo Diet which draws inspiration from how people lived during the Paleolithic or Stone Age that ran from roughly 2.6 million to 10,000 years ago. It encourages practitioners to give up the fruits of modern culinary progress – such as dairy, agricultural products and processed foods – and start living a pseudo-hunter-gatherer lifestyle, something like Lon Chaney Jr. in the film One Million BC. Adherents recommend a very specific “ancestral” menu, replete with certain percentages of energy from carbohydrates, proteins and fats, and suggested levels of physical activity. These prescriptions are drawn mainly from observations of modern humans who live at least a partial hunter-gatherer existence.

But from a scientific standpoint, these kinds of simple characterizations of our ancestors’ behavior generally don’t add up. Recently, fellow anthropologist C. Owen Lovejoy and I took a close look at this crucial question in human behavioral evolution: the origins of hominid diet. We focused on the earliest phase of hominid evolution from roughly 6 to 1.6 million years ago, both before and after the first use of modified stone tools. This time frame includes, in order of appearance, the hominids Ardipithecus and Australopithecus, and the earliest members of our own genus, the comparatively brainy Homo. None of these were modern humans, which appeared much later, but rather our distant forerunners.

We examined the fossil, chemical and archaeological evidence, and also closely considered the foraging behavior of living animals. Why is this crucial? Observing animals in nature for even an hour will provide a ready answer: almost all of what an organism does on a daily basis is simply related to staying alive; that includes activities such as feeding, avoiding predators and setting itself up to reproduce. That’s the evolutionary way.

[. . .]

Researchers Tom Hatley and John Kappelman noted in 1980 that hominids have bunodont – low, with rounded cusps – back teeth that show much in common with bears and pigs. If you’ve watched these animals forage, you know they’ll eat just about anything: tubers, fruits, leafy materials and twigs, invertebrates, honey and vertebrate animals, whether scavenged or hunted. The percentage contribution of each food type to the diet will depend (you guessed it) on the energetic value of specific foods in specific habitats, at specific times of year. Evidence from the entirety of human evolution suggests that our ancestors, and even we as modern humans, are just as omnivorous.

Written by Randy McDonald

March 2, 2015 at 10:18 pm

[LINK] “Most HIV Infections Come From Undiagnosed or Untreated People: Study”

U.S. News and World Report is one news source of many sharing news of a recent study suggesting that the overwhelming majority of HIV transissions in the United States–nearly 92%–are a consequence of untreated people passing the virus on.

If an American becomes infected with HIV, chances are he or she contracted the virus from someone who didn’t know they were infected or wasn’t getting proper treatment.

That’s the message of a new U.S. study, which found that undiagnosed and untreated people with HIV may be responsible for more than nine out of 10 new infections.

The findings “highlight the community-wide prevention benefits of expanding HIV diagnosis and treatment in the United States,” a team led by Dr. Jacek Skarbinski, of the U.S. Centers for Disease Control and Prevention, wrote in the report.

Looking at 2009 data, Skarbinski’s team said that about 45,000 new cases of HIV were transmitted that year, adding to the total of more than 1.1 million Americans who were already living with HIV, the virus that causes AIDS.

Using national databases, the investigators estimated that more than 18 percent of that total remained undiagnosed, while another 45 percent were aware of their status but were not getting medical care.

Only about one-quarter of HIV-infected Americans had managed to get their viral status under control by using the current standard of care known as antiretroviral therapy, the researchers found. These drugs can lower an HIV patient’s viral load to undetectable levels.

Science Daily goes into greater detail and links to the study.

Written by Randy McDonald

February 25, 2015 at 11:31 pm

Posted in Science

Tagged with , , , ,

[BLOG] Some Tuesday links

  • blogTO notes that loads of new streetcars should arrive this year for the TTC.
  • The Dragon’s Gaze links to one paper examining the impact of colliding stellar winds in a close binary on habitable planets, links to another examining how habitable planets gets their water, and wonders about the insights provided by the HR 8799 planetary system into water delivery.
  • The Dragon’s Tales links to a paper arguing that Enceladus’ subsurface ocean is made of alkaline soda water.
  • Joe. My. God. notes a claim by some British scientists that it may be possible, with foreseeable genetic engineering, to create children with two same-sex parents.
  • Languages of the World’s Asya Perelstvaig looks into what Broca’s area of the brain actually means for human language.
  • Marginal Revolution notes that the woman-dominated area of health care is a growth area for middle-class employment in the United States.
  • Otto Pohl notes that yesterday was the 71st anniversary of the deportation of the Chechens and the Ingush.
  • pollotenchegg maps industrial production in Ukraine.
  • Will Baird argues at The Power and the Money that the Minsk Accord is crumbling and examines the reasons for Chinese support of Russia.
  • Spacing Toronto’s John Lorinc worries about corporate sponsorship of ice rinks.
  • Torontoist notes that Massey Hall has begun its renovations.
  • Towleroad notes a Texan legislator who wants to make it illegal for trans people to use public washrooms.
  • Transit Toronto observes that the Union-Pearson Express is undergoing test runs.
  • Window on Eurasia worries about the potential for a minority of Russians in Latvia’s eastern Latgale province to start trouble.
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