Building a Better Dead Body Detector | Discoblog

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graveIt was just like an Easter egg hunt, except instead of eggs, two researchers hid dead rats. Some rats waited three inches underground. Others sat in the open. The duo also buried empty boxes–for comparison. By the end of their study, Thomas J. Bruno and Tara M. Lovestead were expert deceased rodent-hunters, and may have developed a tool to help law enforcement find buried human bodies.

Bruno and Lovestead are chemists at the National Institute of Standards and Technology. Their body-finding tool has an aluminum needle, slightly thicker than a human hair, which they used to prick grave soil for samples from underground air pockets. Back in the lab, they sorted through those samples for rotting flesh gases, in particular one called ninhydrin-reactive nitrogen.

They found that five week-old bodies gave off the most ninhydrin-reactive nitrogen, but that they could detect the gas even after twenty weeks. Their test is an improvement on more expensive means for finding dead bodies, because the device works at room temperature (previously analysis required an ultra-cold device). It also uses a chemical already available on a crime scene–forensics teams use ninhydrin reagent to pick up latent fingerprints.

Though this initial study only uncovered rat bodies under soil, Bruno said that the device might even detect a human body buried under a concrete slab (after drilling a one-eighth-inch hole). A seemingly particular scenario, but for crime show and mafia movie enthusiasts an understandable one.

Check out DISCOVER’s new TV show, Joe Genius.

Related content:
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Discoblog: How Long Would It Take a Physics Lecture to Actually Kill You?
Discoblog: DNA Test Solves the Mystery of Copernicus’s Remains
Discoblog: Decapitated, Lion-Chewed Remains = Ancient Gladiator Graveyard

Image: flickr / Jay Malone


New study clinches it: the Earth is warming up | Bad Astronomy

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For quite some time now, the evidence that the Earth is warming up has been piling up. Study after study has shown this, and that’s why the vast majority of scientists agree on it.

And now, to pile on even more, a large NOAA study has been released reiterating this fact:

The 2009 State of the Climate report released today draws on data for 10 key climate indicators that all point to the same finding: the scientific evidence that our world is warming is unmistakable. More than 300 scientists from 160 research groups in 48 countries contributed to the report, which confirms that the past decade was the warmest on record and that the Earth has been growing warmer over the last 50 years.

They looked at multiple indicators for temperatures, including sea levels, air temperature over land, air temperature over water, the sea surface temperatures, and more. All of them — all of them — indicate the Earth is warming.

warmingindicators

I have little to add to the science or conclusions of this, since I’ve said it so many times here on the blog (see Related Posts at the bottom for more info). But what I will mention are some of the headlines I’m seeing. CBC News said, "Global warming signs unmistakable" and had a video saying it was "undeniable". Slashdot had it as "Global warming undeniable, report says" as well. You can find many others.

That’s not correct. Of course this report is deniable. That’s what deniers do: deny. And we’ll be hearing from them in the comments below, have no doubts.

Mind you, I am distinguishing, as I always do, between deniers and skeptics. Those are two very different things. I am, quite literally, a skeptic of global warming. I do think it’s happening, but that’s because that’s what the evidence is telling me. If good, solid evidence came along that contradicted that, I would a) look at it, and b) assess it, and c) if it’s incontrovertible then I would change my mind. But I haven’t seen that evidence. Note again I mean evidence that overturns the consensus, not evidence that simply weakens it. A good, broad theory does need occasional modification (like the Big Bang model has added pieces like inflation, dark matter, and dark energy) but it takes a boatload of evidence to overturn. That evidence doesn’t exist.

But to deny means to ignore the evidence, or twist it, spin it, cherry-pick it, distort it. Studies like the one above are critical, but they will be dismissed by the deniers and their acolytes. We need to keep hammering away at the deniers, and make sure we get as much press — more — than they do. Because this is real, it’s happening, and all the denialists with their fingers in their ears cannot change that. All they can do at this point is make it worse.

Always remember, this is the denialists’ mascot:

lalalala_ottercanthearyou

Related posts:

- Two posts about denialism: climate change and otherwise
- Stepping off the narrow path of reality
- Global warming emails: followup
- Climategate’s death rattle


You are what you eat – how your diet defines you in trillions of ways | Not Exactly Rocket Science

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Gutbacteria

We depend on a special organ to digest the food we eat and you won’t find it in any anatomy textbook. It’s the ‘microbiome’ – a set of trillions of bacteria living inside your intestines that outnumber your own cells by ten to one. We depend on them. They wield genes that allow them to break down molecules in our food that we can’t digest ourselves. And we’re starting to realise that this secret society within our bowels has a membership roster that changes depending on what we eat.

These changes take place across both space and time. Different cultures around the world have starkly contrasting diets and their gut bacteria are different too. As we grow older, we eat increasingly diverse foods, from the milk of infancy to the complex menus of adulthood. As our palate changes, so do our gut bacteria.

It all starts from the moment we’re born, when we inherit our first microbiome from our mums – a zeroeth birthday present that give us the digestive abilities that we need from day one. These first colonists are laden with genes for digesting milk proteins, allowing babies to make full use of their only source of nourishment.

But breast milk isn’t just a meal for baby, but for baby’s first gut bacteria. After lactose and fat, the third most common ingredients in breast milk are small sugar molecules called ‘oligosaccharides’. Gut bacteria thrive on these and Angela Zivkovic from the University of California, Davis thinks that they evolved as part of breast milk, to selectively feed the right bacteria in a baby’s bowels.

Breast milk contains over 200 types of oligosaccharides. They’re part of a baby’s immune system by acting as decoys for disease-causing bacteria. They look like molecules on the surface of human cells, which infectious bacteria recognise and stick to. By presenting alternative targets, the oligosaccharides divert these bacteria away from actual cells.

But they also feed helpful bacteria just as they distract harmful ones. The bifidiobacteria, which are common in the guts of breast-fed infants, have a preference for milk oligosaccharides, and some species can survive on these molecules alone. So when mum suckles her infant, she’s looking after both her baby and its partners-in-digestion.

Of course, babies are eventually weaned off milk and as they move to solid foods, their guts are the sites of tumultuous change. Jeremy Koenig from Cornell University studied these shifts by tracking the gut bacteria of one specific baby for its first 2.5 years. Koenig had the unenviable task of collecting over 60 samples from the baby’s soiled diapers. As the child grew up, the bacteria in his guts became gradually more diverse, but the roster went through four bigger shifts all associated with big life events – getting fever, starting on solid foods, taking antibiotic treatments, and shifting from breast milk to cow milk.

With each change, the baby’s microbiome started wielding different genetic tools. His first group were rife with genes for digesting milk proteins. Just before he was weaned on solid food, his microbiome started activating genes that break down the complex sugars and starches in plant food. It was already prepared for the arrival of peas and other table food. And when he actually started eating these foods, the bacteria changed even further to include more members of the Bacteroidetes, a family that specialises in digesting plant molecules.

In the baby’s second year, when he started scoffing increasingly complex foods, the abilities of his microbiome diversified again. They started activating genes that can use carbohydrates effectively, produce vitamins, and break down unusual and diverse chemicals. Koenig thinks that things settle down at this point and the make-up of our bacterial cartel becomes relatively stable. Even after an antibiotic assault, the same species bounce back in the same numbers. But once again, the food we eat determines which species set up shop in the first place.

Burkina_Faso

Carlotta de Filippo compared the gut bacteria of 14 children from a village in Burkina Faso with those of 14 children in Florence, Italy. The African children came from families of subsistence farmers and their menus were mostly vegetarian. The eat little in the way of fat or animal protein and their diet is heavy in fibre, starch and plant carbohydrates. By contrast, the Italian kids ate a typical Western diet, high in animal protein, sugar, starch and fat and low in fibre. They ate about half as much fibre as their African peers and about 50% more calories.

These differences are reflected in their bowels. The bacterial community in the African guts were dominated by those plant-digesting specialists, the Bacteroidetes. They probably helped the children to break down the tough fibres that they eat and extract more energy from their meals. Meanwhile, the Italian bowels were dominated by another group, the Firmicutes, which are generally more common in obese people compared to lean ones.

Of course, diet is just one of many traits that separate children from Italy and Burkina Faso, including genes, hygiene and climate. But the youngest babies in de Filippo’s sample show that diet wields by far the greatest influence on the microbiome. The toddlers, unlike their older peers, all ate the same food – breast milk – and as a result, their microbiomes were very similar to one another’s, despite the gulf of differences between their cultures. It’s only at the point of weaning when their diets diverged that their gut communities did too.

The African children also had a greater diversity of gut bacteria, which probably hitch a ride into their bodies via their food. In Europe, generic, uncontaminated food presents a blockade to bacteria from the outside world, which means that Western gut communities have become gentrified. They lack genetic diversity, and they have few ways of increasing it.

This is bad news, for bacteria from the outside world provide a reservoir of useful genes that could help the microbiome to adapt to unusual diets. The fibre-digesting abilities of the Burkina Faso children are probably one example of this. A more striking one was discovered just last year: Japanese gut bacteria have borrowed genes from an oceanic species, which allow them to digest carbohydrates in seaweed. Western diets hold back this evolutionary potential.

But De Filippo thinks that the problems are bigger. An unbalanced or simplified microbiome could be damaging the health of Westerners more directly, affecting the risk of a variety of other medical conditions, including allergies, inflammatory bowel disease, bowel cancer and obesity. A diverse microbiome could also prevent more harmful species from setting up shop – indeed, and somewhat unexpectedly, food poisoning bacteria like Shigella and Escherichia were less common in the Burkinabe children than the Italian ones.

As we learn more about our bacterial partners, we might eventually find ways of influencing them to improve our health, just as breast milk appears to selectively nourish helpful species. The prospect of combating obesity, allergies or infections by inoculating people with the right bacteria might seem far-fetched but it’s already happening. In 2008, Alexander Khoruts from the University of Minnesota managed to cure a woman with a “vicious gut infection” by giving her a transplant of her husband’s gut bacteria.

A success like this is just the beginning, based on a fairly limited understanding of the microbiome. Koenig’s study demonstrates how important it is to look at gut bacteria over time while de Filippo shows that it’s equally essential to look at how they vary from place to place. This is the sort of deeper understanding that future triumphs will be built from.

References:

More on the microbiome:

If the citation link isn’t working, read why here


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Off to Lake Tahoe for “Techonomy” | The Intersection

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Lake TahoeFor the remainder of this week, I’ve signed on as a blogger for a fantastic conference that’s unfolding in Lake Tahoe called “Techonomy: A New Philosophy of Progress.” It’s a love-fest for Innovation that has just about the best list of speakers conceivable. There are many tiers, but at the top tier are people like Bill Gates, Jeff Bezos, and so on.

The Techonomy blog, where I’ll be covering the conference along with four other bloggers, is here. I’ll be crossposting here, but not giving the full content and just linking back over to Techonomy. Topics that I plan on blogging about include geoengineering, new advances in unraveling aging, and much else…


NAC Is Dissatisfied With NASA on Commercial Plans (or lack thereof)

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More Detail Sought On Commercial Crew Plan, Aviation Week

"Members of the panel's commercial space subcommittee expressed dissatisfaction with some of the information they have received from NASA managers on the agency's approach to what is known as commercial crew. Panel members complained that the agency has not been clear on just how it would use commercial vehicles to deliver astronauts to the ISS, which the panel found would make it difficult for industry to set up the kind of public-private partnerships NASA seeks. The NAC subcommittee wants a better strategy for spending the $6 billion requested for commercial crew transportation over the next five years. "We strongly feel that you need to go do this, because what we're hearing from you is all over the map," said Bret Alexander, who as chairman of the commercial space panel will ask the full NAC to endorse his subcommittee's position at the JPL meeting."

Kepler Scientists Dispute Sasselov’s Public Comments

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Kepler Science Status: Statement to Ames Center Director

"Recently there have been reports to the effect that Kepler has discovered many Earth-like planets. This is not the case. Analysis of the current Kepler data does not support the assertion that Kepler has found any Earth-like planets. Kepler is producing excellent results and is on a path to achieving all its mission requirements and actually determining the frequency of Earth-size planets, especially in habitable zones. We will announce our results when they become available and are confirmed."

NASA Contractor/Civil Service Social Media Guidelines Released

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Message to NASA Civil Service and Contractor Employees: Social Networking Tools and Web 2.0 - Appropriate Use of Web Technologies

"The use of Web 2.0 tools can significantly enhance NASA's ability to communicate with employees and the public about its mission. The purpose of this memorandum is to provide guidance to NASA civil service and contractor employees regarding the use of these Web technologies to facilitate collaboration and information sharing within NASA. These Web technologies include tools such as wikis, blogs, mash ups, web feeds (i.e., Really Simple Syndication and Rich Site Summary (RSS) feeds), social networking sites (e.g., Facebook), and forums, which are often collectively referred to as Web 2.0.

NASA Headquarters and the NASA centers are encouraged to use Web 2.0 tools. Employees implementing Web 2.0 technologies or integrating these tools into the NASA environment are responsible for posting and using content in accordance with applicable ethics, information assurance (IA) and privacy laws, regulations, and NASA policies. They also must adhere to IA, records management and privacy policy guidance. Policy regarding the appropriate use (both personal and professional) of government equipment with regards to Web 2.0 can be found in NPD 2540.1.

Using social media in a professional capacity (e.g., creating a Twitter feed for a mission) is an example of an official NASA communication. The informality and enforced brevity of such media notwithstanding, NASA personnel using Web 2.0 tools are representing the agency, and their communications must be professional and factually accurate."

Keith's note: An example of the implications of this policy: those of you who have Twitter accounts that you use to relay information about NASA can no longer block people from following you. You need to be open and transparent about the information you relay as a NASA employee (civil servant and contractor). If you cannot refrain from Twittering about both personal and work-related stuff then a remarkably simple solution is to get another Twitter account for your personal use.

Critical ISS EVA Now Planned For Friday

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Down to the Wire for Station Repair Spacewalks, CBS

"NASA astronauts and engineers are refining plans for two spacewalks by astronauts Douglas Wheelock and Tracy Caldwell Dyson to replace a large ammonia pump module that shut down Saturday, knocking out one of the International Space Station's two cooling loops. The astronauts hope to carry out the first spacewalk Friday morning, starting at 6:55 a.m. EDT, and a second excursion Monday to finish the job, one of the so-called "big 14" on a list of critical components that require spacewalk repair if problems crop up. NASA managers initially targeted Thursday for the first spacewalk and Sunday for the second, but decided late Monday they needed more time to review procedures."

International Space Station Repair Spacewalk Planned for Friday

"NASA has decided to wait until Friday to conduct a spacewalk to replace a failed ammonia pump module on the International Space Station. Mission managers, program managers, flight controllers, engineers, astronauts and spacewalk experts made the decision Monday evening after continuing to analyze and refine engineering requirements, and reviewing the results of an underwater practice session."

Static Kill and the Replaying Video

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Here is a diagram of the layout of the well leak site from The Oil Drum.

Layout around Deepwater/BP oil well site

The “static kill” procedure reportedly began today, attempting to kill the leaking BP oil well for good.   It’s hard to know whether what we are being told is correct however, because BP has lied to us in the past, and we know now that BP is running the underwater video in loops.  This has been observed by several people.  The rerunning of the video was observed by ‘oil industry expert’ Bob Cavnar, and he reported it tonight on Countdown.    See video here.  Have we ever been sure the video provided by BP was live?

“Based on the results of the injectivity test, BP started pumping drilling mud today at 21:00 (UK) and 15:00 (CDT) as part of the static kill operations. All operations are being carried out with the guidance and approval of the National Incident Commander.”  (See another video here.)

Why they are approaching this with a static kill procedure is something of a mystery. The static kill is coming at the problem via the capping stack at the top of the well again, as opposed to using only the relief wells.  They are also back to using the toxic drilling mud again, which is not normal mud at all.

“…the mud contains ethylene glycol, a highly toxic chemical commonly used in anti-freeze, and caustic soda, a compound more commonly known as lye that is is also toxic. . . . . BP dumped tens of thousands of gallons of the sludge into the well as part of the failed “top-kill” attempt in May, most of which ended up in the ocean.”

Read more about the mud at Mother Jones. Are  they using the same drilling mud in this “static kill” procedure?  There is no reason to believe they are not.  It seems like the EPA can’t tell BP to do anything, including poisoning our land, our water, and our wildlife.  I guess we should feel lucky that BP even felt like stopping the leak at all.

The relief wells, we are told by Thad Allen, will now be used for a “bottom kill”.  Bob Cavnar believes that primarily attacking the well from the top again is a mistake.  Even if the top kill seems to be successful, he feels that we will not be sure the well is stopped on the bottom unless the relief wells are used.

Why aren’t the relief wells being used as the primary well kill method,  after we heard from BP for months that the relief wells are the only way to stop the leak for good?

We may only know the answers to these things several months from now.  One relief well is only about 4 feet from its target.  Meanwhile, there have been some holdups in getting the final “kill” started, but apparently it has begun.  The problem is that at this [...]

Nano-Energy Workshop on September 13-14

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Sessions and discussions will explore how a wide range of nanotechnology disciplines across chemistry, materials, electrical engineering, physics and photonics are being explored to address the need to improve today's energy efficiencies and even tap into new sources of energy production.

Two innovative LMU projects in physics receive EU funding

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Two junior researchers at Ludwig-Maximilians-University (LMU) Munich have been awarded prestigious Starting Grants by the European Research Council (ERC). Professor Dieter Braun and Professor Philip Tinnefeld, both members of the Faculty of Physics, will each receive research funding in the amount of some 1.5 million Euros over the next five years.

Compact microscope a marvel

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A compact microscope invented at Rice University is proving its potential to impact global health. This portable, battery-operated fluorescence microscope, which costs $240, stacks up nicely against devices that retail for as much as $40,000 in diagnosing signs of tuberculosis.