Later On

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Archive for the ‘Science’ Category

The explanation for the dress color

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One thing the dress-color disagreement does make clear: color, like beauty, is not in the object but in the beholder—specifically, color (and beauty) are an experience belonging to the beholder. We often try to place attributes totally in the object when in fact they are experiences in the subject: “Does fried liver have a good taste?” (or “Does cilantro have a good taste?”) reads as though the taste is in the object, but quite clearly it is not: the same object (fried liver or cilantro) can taste very good indeed and quite foul to others, with the object unchanged.

So when we talk about the color “of the dress,” we are really talking about subjective experiences, which naturally enough vary as the subject varies.

But New Scientist has an explanation that may be of interest.

Written by LeisureGuy

1 March 2015 at 1:32 pm

Posted in Science

Black Death in Europe: It wasn’t the rats, it was gerbils (but rats helped)

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Extremely interesting article by Elizabeth Kolbert in the New Yorker:

The black rat—also known as the ship rat, the roof rat, and the house rat—is actually gray. It has large ears and a tail that’s longer than its body. The black rat (Rattus rattus) probably evolved in tropical Asia, and then was spread around the world by humans—first by the Romans and later by European colonists. According to Juliet Clutton-Brock, the author of “A Natural History of Domesticated Mammals,” it has been blamed for causing “a greater number of deaths in the human species than any natural catastrophe or war.” But perhaps the rat has gotten a bad rap?

A paper published the other day in the Proceedings of the National Academy of Sciences, which quickly made headlines all around the world, argues that the prevailing theory of how the Black Death spread is unfair to rats. Really, the authors of the study contend, the animal responsible was a Central Asian species like the great gerbil. (Great gerbils are only distantly related to the fuzzy rodents that American kids keep as pets, though they may look a lot alike to parents.)

The authors of the study were trying to address one of the mysteries about the Black Death. Why, after killing something like twenty-five million people in Europe in the mid-fourteenth century, did outbreaks of plague keep flaring up and then dying down again? (The Great Plague of London, in the mid-seventeenth century, killed roughly a fifth of the city’s population.) The prevailing theory is—or was—that bacteria responsible for the plague, Yersinia pestis, lived on Europe’s black-rat population. The rats transmitted the bacteria to fleas, which, episodically, transmitted them to humans. But the scientists who conducted the PNAS study concluded that there were no “permanent plague reservoirs in medieval Europe.”

Instead, they posit, the plague bacterium kept being reintroduced to Europe from Asia, where it lived on the native rodent populations. They came to this conclusion after comparing tree-ring records from Europe and Asia with records of plague outbreaks. What they found was that plague seemed to show up at port cities in Europe several years after climate conditions favored a burst of population growth among rodents in Central Asia. (This theory does not completely exonerate black rats, as they would still have helped their Asian rodent brethren spread the disease once it reached Europe.)

“We show that, wherever there were good conditions for gerbils and fleas in Central Asia, some years later the bacteria shows up in harbor cities in Europe and then spreads across the continent,” one of the authors of the study, Nils Christian Stenseth, a biologist at the University of Oslo, told the BBC.

Plague is no longer a worry in Europe, although there are still occasional outbreaks in other parts of the globe. What’s perhaps the most important insight from the study has little to do with Yersinia pestis or giant gerbils. It’s that climate and human health are, in significant though often roundabout ways, related. As the climate changes, this has important—and, at the same time, hard to predict—implications.

The list of diseases (and disease vectors) that could potentially be affected by climate change is a long and various one. It includes tick-borne diseases, such as Lyme disease, and mosquito-borne diseases—dengue fever, West Nile virus, malaria. It also includes waterborne diseases, such as cholera, and fungal diseases, such as valley fever. An upcoming issue of Philosophical Transactions B, a journal of Britain’s Royal Society, is wholly devoted to the subject of “climate change and vector-borne disease.”

Rising temperatures may already be contributing to the spread of some diseases, like . . .

Continue reading.

You may recall that Dana Perino, Press Secretary to George W. Bush, assured us that global warming would reduce illnesses overall because winters would not be so severe. I wonder if she is helping out with this research.

Written by LeisureGuy

28 February 2015 at 2:26 pm

Disappointing news: Plastics are NOT being recycled

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And I’ve been so good about putting all our plastics into the recycling bin. See this disappointing article.

Written by LeisureGuy

28 February 2015 at 12:07 pm

Posted in Business, Environment

Good news for Greece, and how to argue with unreasonable people

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Paul Krugman has a couple of good things today. For one, he explains why the 4-month extension is good news for Greece. And for another, he explains how to engage with people who are not open to reason:

When I was a young economist trying to build a career, I lived — or thought I lived — in a world in which ideas and those who championed them met in relatively open intellectual combat. Of course there were people who clung to their prejudices, of course style sometimes trumped substance. But I believed that by and large better ideas tended to prevail: if your model of trade flows or exchange rate fluctuations tracked the data better than someone else’s, or resolved puzzles that other models couldn’t, you could expect it to be taken up by many if not most researchers in the field.

This is still true in much of economics, I believe. But in the areas that matter most given the state of the world, it’s not true at all. People who declared back in 2009 that Keynesianism was nonsense and that monetary expansion would inevitably cause runaway inflation are still saying exactly the same thing after six years of quiescent inflation and overwhelming evidence that austerity affects economies exactly the way Keynesians said it would.

And we’re not just talking about cranks without credentials; we’re talking about founders of the Shadow Open Market Committee and Nobel laureates.

Obviously this isn’t just a story about economics; it covers everything from climate science and evolution to Bill O’Reilly’s personal history. But that in itself is telling: academic economics, which still has pretenses of being an arena of open intellectual inquiry, appears to be deeply infected with politicization.

So what should those of us who really wanted to be part of what we thought this enterprise was about do? That’s the question Brad DeLong has been asking.

I see three choices: . . .

Continue reading.

Written by LeisureGuy

27 February 2015 at 3:03 pm

A 3-D map of the human genome

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This video is actually part of an article I blogged yesterday, but if you didn’t click, you should at least see this video:

Written by LeisureGuy

26 February 2015 at 5:24 pm

Posted in Science, Video

Genetic geometry

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The genome packs into the nucleus in a manner consistent with the structure of a fractal globule, shown here — a polymer state that is extraordinarily dense, but entirely unknotted.

The genome packs into the nucleus in a manner consistent with the structure of a fractal globule, shown here — a polymer state that is extraordinarily dense, but entirely unknotted.

The above image is from a fascinating article by Ivan Amato in Quanta:

The nuclei from a half-million human cells could all fit inside a single poppy seed. Yet within each and every nucleus resides genomic machinery that is incredibly vast, at least from a molecular point of view. It has billions of parts, many used to activate and silence genes — an arrangement that allows individual cells to specialize as brain cells, heart cells and some 200 other different cell types. What’s more, each cell’s genome is atwitter with millions of mobile pieces that swarm throughout the nucleus and latch on here and there to tweak the genetic program. Every so often, thegenomic machine replicates itself.

At the heart of the human genome’s Lilliputian machinery is the two meters’ worth of DNA that it takes to embody a person’s 3 billion genetic letters, or nucleotides. Stretch out all of the genomes in all of your body’s trillions of cells, says Tom Misteli, the head of the cell biology of genomes group at the National Cancer Institute in Bethesda, Md., and it would make 50 round trips to the sun. Since 1953, when James Watson and Francis Crick revealed the structure of DNA, researchers have made spectacular progress in spelling out these genetic letters. But this information-storage view reveals almost nothing about what makes specific genes turn on or off at different times, in different tissue types, at different moments in a person’s day or life.

To figure out these processes, we must understand how those genetic letters collectively spiral about, coil, pinch off into loops, aggregate into domains and globules, and otherwise assume a nucleus-wide architecture. “The beauty of DNA made people forget about the genome’s larger-scale structure,” said Job Dekker, a molecular biologist at the University of Massachusetts Medical School in Worcester who has built some of the most consequential tools for unveiling genomic geometry. “Now we are going back to studying the structure of the genome because we realize that the three-dimensional architecture of DNA will tell us how cells actually use the information. Everything in the genome only makes sense in 3-D.” . . .

Continue reading.

Written by LeisureGuy

25 February 2015 at 8:07 pm

Posted in Science

Why it’s difficult to respect the GOP: The House GOP passed a bill to forbid the EPA from getting expert advice from scientists

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Because why? Because ignorance is good, I guess. Beverly Mitchell reports at Habitat:

While everyone’s attention was focused on the Senate and the Keystone XL decision on Tuesday, some pretty shocking stuff was quietly going on in the House of Representatives. The GOP-dominated House passed a bill that effectively prevents scientists who are peer-reviewed experts in their field from providing advice — directly or indirectly — to the EPA, while at the same time allowing industry representatives with financial interests in fossil fuels to have their say. Perversely, all this is being done in the name of “transparency.”

Bill H.R. 1422, also known as the Science Advisory Board Reform Act, passed 229-191. It was sponsored by Representative Chris Stewart (R-UT), pictured. The bill changes the rules for appointing members to the Science Advisory Board (SAB), which provides scientific advice to the EPA Administrator. Among many other things, it states: “Board members may not participate in advisory activities that directly or indirectly involve review or evaluation of their own work.” This means that a scientist who had published a peer-reviewed paper on a particular topic would not be able to advise the EPA on the findings contained within that paper. That is, the very scientists who know the subject matter best would not be able to discuss it.

On Monday, the White House issued a statement indicating it would veto the bill if it passed, noting: “H.R. 1422 would negatively affect the appointment of experts and would weaken the scientific independence and integrity of the SAB.” Representative Jim McGovern (D-MA) was more blunt, telling House Republicans on Tuesday: “I get it, you don’t like science. And you don’t like science that interferes with the interests of your corporate clients. But we need science to protect public health and the environment.” . . .

Continue reading.

The bill seems to me to be simply insane. I simply cannot grasp how any serious adult would sign on to that but this is how the GOP thinks.

Written by LeisureGuy

25 February 2015 at 4:02 pm


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