Official "Science News" Thread

[ewmayer]

Originally Posted by rogue

I get a weekly newsletter via e-mail from Mensa.

First useful aspect - besides "hooking up with fellow nerds" - of that organization of which I've heard. :)

[I'm probably just jealous 'cause I never joined, and a few years post-college they stopped mailing me.]

[Uncwilly]

Originally Posted by rogue

I get a weekly newsletter via e-mail from Mensa.

Originally Posted by ewmayer

[I'm probably just jealous 'cause I never joined, and a few years post-college they stopped mailing me.]

My sentiment about Densa:
"I don't want to belong to any club that will accept people like me as a member."

[Kathegetes]

Originally Posted by cheesehead

"Earth Hums, and It's 'Loudest' in Europe, Americas"

http://news.nationalgeographic.com/n...es-coasts.html

I remember you. Didn't you find a factor for me? Do you live in Wisconsin ? Please don't tell if we can't ask such things.

[rogue]

Originally Posted by ewmayer

First useful aspect - besides "hooking up with fellow nerds" - of that organization of which I've heard. :)

[I'm probably just jealous 'cause I never joined, and a few years post-college they stopped mailing me.]

I used to be more involved when I was living in Chicago. I enjoyed monthly meetings and nights out at various eateries. Not being from Chicago and being shy, it was a way for me to get out and meet people. I made a number of friends when I was there. It was a lot of fun. I'm not very active today because I have a life , but I do enjoy the monthly national bulletin which always has word games from Richard Lederer. Both of my kids enjoy that article.

[Uncwilly]

Ewwww.
10-Inch-Long Earwax Plug Reveals Life History
Interesting though.

[ewmayer]

Originally Posted by chappy

there was only a one in ten chance of noticing. Unless you are a roman legionnaire.

Roman-legion-spun version of an old standby:

Q: Didja hear about the Roman legion which submitted a bunch of wordplay jokes to a contest?

A: They had high hopes for most of their quips making the finals, but no pun in ten did.

----------------------

Originally Posted by Uncwilly

Ewwww.
10-Inch-Long Earwax Plug Reveals Life History
Interesting though.

That gives a whole new meaning to "in one ear and out the other"...

[chappy]

Originally Posted by ewmayer

Roman-legion-spun version of an old standby:

Q: Didja hear about the Roman legion which submitted a bunch of wordplay jokes to a contest?

A: They had high hopes for most of their quips making the finals, but no pun in ten did.

----------------------

/facepalm

I had heard this worded slightly differently, it is still painful. :)

[cheesehead]

“It’s not tomorrow that you’re going to walk into your doctor’s office and they’re going to think this way,” said Dr. Lupski. “It’s going to take time.”

I'd always thought that a person normally had only one set of DNA in all body cells. Different portions of that DNA may be activated or deactivated by RNA in different parts of the body, but the same basic code was in all. I thought that the only exceptions were where chemical toxins or radiation, or stuff like that, had gotten into a particular cell and damaged/changed the DNA in that cell.

And that's what I've read in many books about DNA and genetics

(Another possible weird situation: accidental body puncture situations where someone else's DNA got mixed into some of one's cells and managed to carry on as if it were in the original person's body. And then there are now-ordinary organ transplants.)

BTW, I'm not talking about the fact that about 90% (by number, not volume) of our body cells are actually single-celled organisms that live symbiotically with us. Each of those microorganisms has DNA different from our human DNA. They help with digestion and so forth. I'm talking about more than one human genome in the human cells in one human's body.

But I now realize that I'd overlooked some other possibilities.

I was (lazily) relying on semi-magical thinking ... faith ... that "something" normally prevented any other possibility of multiple DNA genomes in one person -- that the body's immune system, or "something", would normally keep everything neat and tidy (except in really weird cases). I trusted that I could, or I could find someone else who could, explain via "normal" processes why there wouldn't be different DNA in different parts of ones body.

Now, an article has pointed out what I was overlooking. There are so many really weird cases that they're actually ordinary, and modern medical practice will have to learn to take this into account as we get more genetic medicine.

"DNA Double Take"
http://www.nytimes.com/2013/09/17/sc...uble-take.html

(with my boldface emphasis in places)

From biology class to “C.S.I.,” we are told again and again that our genome is at the heart of our identity. Read the sequences in the chromosomes of a single cell, and learn everything about a person’s genetic information — or, as 23andme, a prominent genetic testing company, says on its Web site, “The more you know about your DNA, the more you know about yourself.”

(It turns out that that last sentence is still true, but "your DNA" is not so simply cut-and-dried as it was once thought to be.)

But scientists are discovering that — to a surprising degree — we contain genetic multitudes. Not long ago, researchers had thought it was rare for the cells in a single healthy person to differ genetically in a significant way. But scientists are finding that it’s quite common for an individual to have multiple genomes. Some people, for example, have groups of cells with mutations that are not found in the rest of the body. Some have genomes that came from other people.

“There have been whispers in the matrix about this for years, even decades, but only in a very hypothetical sense,” said Alexander Urban, a geneticist at Stanford University. Even three years ago, suggesting that there was widespread genetic variation in a single body would have been met with skepticism, he said. “You would have just run against the wall.”

But a series of recent papers by Dr. Urban and others has demonstrated that those whispers were not just hypothetical. The variation in the genomes found in a single person is too large to be ignored. “We now know it’s there,” Dr. Urban said. “Now we’re mapping this new continent.”

Dr. James R. Lupski, a leading expert on the human genome at Baylor College of Medicine, wrote in a recent review in the journal Science that the existence of multiple genomes in an individual could have a tremendous impact on the practice of medicine. “It’s changed the way I think,” he said in an interview.

Scientists are finding links from multiple genomes to certain rare diseases, and now they’re beginning to investigate genetic variations to shed light on more common disorders.

Science’s changing view is also raising questions about how forensic scientists should use DNA evidence to identify people.

Egad ... maybe O.J. really didn't do it!

It’s also posing challenges for genetic counselors, who can’t assume that the genetic information from one cell can tell them about the DNA throughout a person’s body.

. . .

Yet all these powerful tests are based on the assumption that, inside our body, a genome is a genome is a genome. Scientists believed that they could look at the genome from cells taken in a cheek swab and be able to learn about the genomes of cells in the brain or the liver or anywhere else in the body.

In the mid-1900s, scientists began to get clues that this was not always true. In 1953, for example, a British woman donated a pint of blood. It turned out that some of her blood was Type O and some was Type A. The scientists who studied her concluded that she had acquired some of her blood from her twin brother in the womb, including his genomes in his blood cells.

Chimerism, as such conditions came to be known, seemed for many years to be a rarity. But “it can be commoner than we realized,” said Dr. Linda Randolph, a pediatrician at Children’s Hospital in Los Angeles who is an author of a review of chimerism published in The American Journal of Medical Genetics in July.

Twins can end up with a mixed supply of blood when they get nutrients in the womb through the same set of blood vessels. In other cases, two fertilized eggs may fuse together. These so-called embryonic chimeras may go through life blissfully unaware of their origins.

One woman discovered she was a chimera as late as age 52. In need of a kidney transplant, she was tested so that she might find a match. The results indicated that she was not the mother of two of her three biological children.

(Be careful in interpreting that. The children were from her eggs, all right.)

It turned out that she had originated from two genomes. One genome gave rise to her blood and some of her eggs; other eggs carried a separate genome.

Women can also gain genomes from their children. After a baby is born, it may leave some fetal cells behind in its mother’s body, where they can travel to different organs and be absorbed into those tissues. “It’s pretty likely that any woman who has been pregnant is a chimera,” Dr. Randolph said.

Everywhere You Look

As scientists begin to search for chimeras systematically — rather than waiting for them to turn up in puzzling medical tests — they’re finding them in a remarkably high fraction of people. In 2012, Canadian scientists performed autopsies on the brains of 59 women. They found neurons with Y chromosomes in 63 percent of them. The neurons likely developed from cells originating in their sons.

In The International Journal of Cancer in August, Eugen Dhimolea of the Dana-Farber Cancer Institute in Boston and colleagues reported that male cells can also infiltrate breast tissue. When they looked for Y chromosomes in samples of breast tissue, they found it in 56 percent of the women they investigated.

. . .

Benign Differences

The latest findings make it clear that mosaicism is quite common — even in healthy cells.

. . .

Moving Cautiously

Medical researchers aren’t the only scientists interested in our multitudes of personal genomes. So are forensic scientists. When they attempt to identify criminals or murder victims by matching DNA, they want to avoid being misled by the variety of genomes inside a single person.

Last year, for example, forensic scientists at the Washington State Patrol Crime Laboratory Division described how a saliva sample and a sperm sample from the same suspect in a sexual assault case didn’t match.

. . .

For genetic counselors helping clients make sense of DNA tests, our many genomes pose more serious challenges. ...

. . .

[xilman]

Originally Posted by cheesehead

I'd always thought that a person normally had only one set of DNA in all body cells. Different portions of that DNA may be activated or deactivated by RNA in different parts of the body, but the same basic code was in all. I thought that the only exceptions were where chemical toxins or radiation, or stuff like that, had gotten into a particular cell and damaged/changed the DNA in that cell.

And that's what I've read in many books about DNA and genetics

Fascinating! Thanks for drawing it to my attention.

It has long been known that some plants are genetic mosaics, the canonical example being the common European oak tree, Quercus robur. There are sound evolutionary reasons why this may be so. Plants, by and large, have difficulty running away from predators and need to evolve other mechanisms whether chemical or mechanical or otherwise. If you're a large plant, being a genetic mosaic means that you may survive a predator which kills only part of you. I had not read of the same phenomenon being widespread in animals.

[ewmayer]

Originally Posted by xilman

Fascinating! Thanks for drawing it to my attention.

It has long been known that some plants are genetic mosaics, the canonical example being the common European oak tree, Quercus robur. There are sound evolutionary reasons why this may be so. Plants, by and large, have difficulty running away from predators and need to evolve other mechanisms whether chemical or mechanical or otherwise. If you're a large plant, being a genetic mosaic means that you may survive a predator which kills only part of you. I had not read of the same phenomenon being widespread in animals.

If one thinks about the rampant "genomic promiscuity" at work in the evolution-from-replicating-molecules of the first cells as we know them today, it makes sense that chimerism should be common, if not ubiquitous (MtDNA may be an "evolved form" of such). It has apparently been widely thought - in a self-fulfilling sort of way - that "higher organisms" had "cleaned up their act" in this respect. Another form of vanity disguised as scientific assumption bites the dust.

------------------------

Colorado rainfall one for the ages, Weather Service says: (Reuters) - The downpour that inundated parts of Colorado this month was a once-in-a-millennium event for those areas, according to an analysis by the National Weather Service.

Reptile fossil found in Alaska may be newly discovered species: ANCHORAGE, Alaska (Reuters) - The fossil of a sea reptile found two years ago in Alaska may be that of a previously unknown species, a scientist who was part of a team that discovered and excavated the remains said on Wednesday.

[kladner]

Originally Posted by ewmayer

.....
------------------------

Colorado rainfall one for the ages, Weather Service says: (Reuters) - The downpour that inundated parts of Colorado this month was a once-in-a-millennium event for those areas, according to an analysis by the National Weather Service.

I hope at least some of it was on the Western slope and replenishes Lake Meade. Most of what I've heard about has been on the East.

Reptile fossil found in Alaska may be newly discovered species

: ANCHORAGE, Alaska (Reuters) - The fossil of a sea reptile found two years ago in Alaska may be that of a previously unknown species, a scientist who was part of a team that discovered and excavated the remains said on Wednesday.

Dang! Not even a drawing?