Category Archives: Science

500 Year Floods

Why you can get ‘500 year floods’ two years in a row by Anne Jefferson:

Flood probabilities are based on historical records of stream discharge. Let’s use the Iowa River at Marengo, Iowa as an example. It reached a record discharge of 46,600 cubic feet per second* (1320 m3/s) on 12 June. That flow was estimated to have a 500 year recurrence interval, based on 51 years of peak flow records
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When you are extrapolating beyond your data by an order of magnitude, the highest points in the dataset start to have a lot of leverage. Let’s imagine that there’s another big flood on the Iowa River next year and we do the same analysis. Now our dataset has 52 points, with the highest being the flood of 2008. When that point is included in the analysis, a discharge of 46,600 cubic feet per second* (1320 m3/s) has a recurrence interval of <150 years (>0.6%). It’s still a darn big flow, but it doesn’t sound quite so biblical anymore.
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Urbanization and the adding of impervious surface is one cause of increasing flood peaks, but in Iowa, a more likely culprit is agricultural.

This post is a good explanation that the 500 year flood idea is just way of saying .2% probability (that some people confuse as meaning it can only happen every 500 years). But I actually am more interested in the other factor which is how much estimation is in “500 year prediction.” We don’t have 500 years of data. And the conditions today (I believe) are much more likely to create extreme conditions. So taking comfort in 500 year (.2%), or even 100 year (1% probability) flood “predictions” is dangerous.

It would seem to me, in fact, actually having a 500 year flood actually increases the odds for it happening again (because the data now includes that case which had not been included before). It doesn’t actually increase the likelihood of it happening but the predictions we make are based on the data we have (so given that it happens our previous 500 year prediction is questionable). With a coin toss we know the odds are 50%, getting 3 heads in a row doesn’t convince us that our prediction was bad. And therefore the previous record of heads or tails in the coin toss have no predictive value.

I can’t see why we would think that for floods. With the new data showing a flood, (it seems to me) most any model is likely to show an increased risk (and pretty substantial I would think) of it happening again in the next 100 years (especially in any area with substantial human construction – where conditions could well be very different than it was for our data that is 20, 40… years old). And if we are entering a period of more extreme weather then that will likely be a factor too…

The comments on the original blog post make some interesting points too – don’t miss those.

Magnetic Movie

Magnetic Movie from Semiconductor on Vimeo

Magnetic Movie was shot in NASA’s Space Sciences Laboratories at UC Berkeley for Chanel 4 in association with the Arts Council of England.

In Magnetic Movie, Semiconductor have taken the magnificent scientific visualisations of the sun and solar winds conducted at the Space Sciences Laboratory and Semiconducted them. Ruth Jarman and Joe Gerhardt of Semiconductor were artists-in-residence at SSL. Combining their in-house lab culture experience with formidable artistic instincts in sound, animation and programming, they have created a magnetic magnum opus in nuce, a tour de force of a massive invisible force brought down to human scale, and a “very most beautiful thing.”

Magnetic Movie is the aquavit, something not precisely scientific but grants us an uncanny experience of geophysical and cosmological forces.

Cool video: I must admit I am confused at how extensive the artistic license taken with the animation is.

How Prozac Sent Science Inquiry Off Track

I post often on examples of scientific inquiry in action. I think it is an important way to see how science works while searching for answers. The process is not a simple one, but after a solution is found it can often be presented as obvious. But while trying to find answers it is quite difficult.

How Prozac sent the science of depression in the wrong direction

But the success of Prozac hasn’t simply transformed the treatment of depression: it has also transformed the science of depression. For decades, researchers struggled to identify the underlying cause of depression, and patients were forced to endure a series of ineffective treatments. But then came Prozac. Like many other antidepressants, Prozac increases the brain’s supply of serotonin, a neurotransmitter. The drug’s effectiveness inspired an elegant theory, known as the chemical hypothesis: Sadness is simply a lack of chemical happiness. The little blue pills cheer us up because they give the brain what it has been missing.

There’s only one problem with this theory of depression: it’s almost certainly wrong, or at the very least woefully incomplete. Experiments have since shown that lowering people’s serotonin levels does not make them depressed, nor does it does not make them depressed, nor does it worsen their symptoms if they are already depressed.
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In this sense, Prozac is simply a bottled version of other activities that have a similar effect, such as physical exercise.
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It is jarring to think of depression in terms of atrophied brain cells, rather than an altered emotional state. It is called “depression,” after all. Yet these scientists argue that the name conceals the fundamental nature of the illness, in which the building blocks of the brain – neurons – start to crumble. This leads, over time, to the shrinking of certain brain structures, like the hippocampus, which the brain needs to function normally.

500 Million-year-old Stromatolite Fossil

VMNH scientists confirm discovery of 500 million-year-old fossil

Virginia Museum of Natural History scientists have confirmed that an approximately 500 million-year-old stromatolite was recently discovered at the Boxley Blue Ridge Quarry near Roanoke, Virginia. This is the first-ever intact stromatolite head found in Virginia, and is one of the largest complete “heads” in the world, at over 5 feet in diameter and weighing over 2 tons. Stromatolites are among the earliest known life forms, and are important in helping scientists understand more about environments that existed in the past.

A stromatolite is a mound produced in shallow water by mats of algae that trap mud and sand particles. Another mat grows on the trapped sediment layer and this traps another layer of sediment, growing gradually over time. Stromatolites can grow to heights of a meter or more. They are uncommon today but their fossils are among the earliest evidence for living things. The oldest stromatolites have been dated at 3.46 billion years old.

NASA Set to Test Mars Ice

UA Lander begins ice analysis:

‘Phoenix’ scraped at an ice layer buried underneath the soil in what mission scientists call the “Snow White” trench. The lander used a blade attached to its robotic arm to scrape up small piles of icy soil that each contain between two and four teaspoonfuls of material. The robotic arm will now scoop up that material and sprinkle it into the lander’s Thermal and Evolved Gas Analyzer, or TEGA. That instrument will use its ovens to “bake” the sample and “sniff” any gases it gives off (water vapor, for example), to determine its composition.

Martian Dirt Could Yield Asparagus

NASA scientists say they are “flabbergasted” to find that soil on Mars appears rich enough to grow such Earth-bound plants as asparagus.

U.S. space researchers revealed the results of their first “wet” chemical analysis of Martian dirt Thursday and said it is not as acidic as expected, appearing to have the requirements and nutrients to support life.

Measuring Protein Bond Strength with Optical Tweezers

Using a light touch to measure protein bonds

MIT researchers have developed a novel technique to measure the strength of the bonds between two protein molecules important in cell machinery: Gently tugging them apart with light beams. “It’s really giving us a molecular-level picture of what’s going on,” said Matthew Lang, an assistant professor of biological and mechanical engineering
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The researchers studied the interactions between the proteins by pinning one actin filament to a surface and controlling the motion of the second one with a beam of light. As the researchers tug on a bead attached to the second filament, the bond mediated by the actin-binding protein eventually breaks.

With this technique, the researchers can get a precise measurement of the force holding the proteins together, which is on the order of piconewtons (10^-12 newtons).

Protecting the Food Supply

A few weeks ago we posted about Tracking Down Tomato Troubles as another example of the challenges of scientific inquiry. Too often, in the rare instances that science is even discussed in the news, the presentation provides the illusion of simple obvious answers. Instead it is often a very confusing path until the answers are finally found (posts on scientific investigations in action). At which time it often seems obvious what was going on. But to get to the solutions we need dedicated and talented scientists to search for answers.

Now the CDC is saying tomatoes might not be the source of the salmonella after all: CDC investigates possible non-tomato salmonella sources.

Federal investigators retraced their steps Monday as suspicions mount that fresh unprocessed tomatoes aren’t necessarily causing the salmonella outbreak that has sickened hundreds across the USA.

Three weeks after the Food and Drug Administration warned consumers to avoid certain types of tomatoes linked to the salmonella outbreak, people are still falling ill, says Robert Tauxe with the Centers for Disease Control and Prevention. The latest numbers as of Monday afternoon were 851 cases, some of whom fell ill as recently as June 20, says Tauxe, deputy director of the CDC’s division of foodborne diseases.

The CDC launched a new round of interviews over the weekend. “We’re broadening the investigation to be sure it encompasses food items that are commonly consumed with tomatoes,” Tauxe says. If another food is found to be the culprit after tomatoes were recalled nationwide and the produce industry sustained losses of hundreds of millions of dollars, food safety experts say the public’s trust in the government’s ability to track foodborne illnesses will be shattered.

“It’s going to fundamentally rewrite how we do outbreak investigations in this country,” says Michael Osterholm of the Center for Infectious Disease Research and Policy at the University of Minnesota. “We can’t let this investigation, however it might turn out, end with just the answer of ‘What caused it?’ We need to take a very in-depth look at foodborne disease investigation as we do it today.”

I am inclined to believe the FDA is not enough focused on food safety. Perhaps we are not funding it enough, but we sure are spending tons of money on something so I can’t believe more money needs to be spent. Maybe just fewer bills passed (that the politicians don’t even bother to read) with favors to special interests instead of funding to support science and food safety. Or perhaps we are funding enough (though I am skeptical of this contention) and we just are not allowing food safety to get in the way of what special interests want (so we fund plenty for FDA to have managed this much better, to have systems in place that would provide better evidence but they are either prevented from doing so or failed to do so). I am inclined to believe special interests have more sway in agencies like (NASA, EPA, FDA…) than the public good and scientific openness – which is very sad. And, it seems to me, politicians have overwhelmingly chosen not to support more science in places like FDA, CDC, NIH… while increasing federal spending in other areas dramatically.

Refrigeration Without Electricity

Lack of electricity is a serious problem for vaccines and medicines that need to be cooled. It is hard to imagine that this is a problem, living in the USA, but this is still a problem today. As readers of this blog notice I really like appropriate technology solutions that provide real quality of life enhancements for hundreds of millions of people (which undoubtedly is influence by my father).

Fold.it – the Protein Folding Game

Foldit is a revolutionary new computer game enabling you to contribute to important scientific research. This is another awesome combination of technology, distributed problem solving, science education…

Essentially the game works by allowing the person to make some decisions then the computer runs through some processes to determine the result of those decisions. It seems the human insight of what might work provides an advantage to computers trying to calculate solutions on their own. Then the results are compared to the other individuals working on the same protein folding problem and the efforts are ranked.

This level of interaction is very cool. SETI@home, Rosetta@home and the like are useful tools to tap the computing resources of millions on the internet. But the use of human expertise really makes fold.it special. And you can’t help but learn by playing. In addition, if you are successful you can gain some scientific credit for your participation in new discoveries.

The site includes some excellent educational material on proteins and related material. What is a protein:

Proteins are the workhorses in every cell of every living thing. Your body is made up of trillions of cells, of all different kinds: muscle cells, brain cells, blood cells, and more. Inside those cells, proteins are allowing your body to do what it does: break down food to power your muscles, send signals through your brain that control the body, and transport nutrients through your blood. Proteins come in thousands of different varieties, but they all have a lot in common. For instance, they’re made of the same stuff: every protein consists of a long chain of joined-together amino acids.
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structure specifies the function of the protein. For example, a protein that breaks down glucose so the cell can use the energy stored in the sugar will have a shape that recognizes the glucose and binds to it (like a lock and key) and chemically reactive amino acids that will react with the glucose and break it down to release the energy.
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Proteins are involved in almost all of the processes going on inside your body: they break down food to power your muscles, send signals through your brain that control the body, and transport nutrients through your blood. Many proteins act as enzymes, meaning they catalyze (speed up) chemical reactions that wouldn’t take place otherwise. But other proteins power muscle contractions, or act as chemical messages inside the body, or hundreds of other things.

Continue reading →

Physicist Swimming Revolution

A Revolution That Began With a Kick by Amy Shipley:

The answer, they say, cannot lie solely in the latest high-tech swimsuits introduced amid a swirl of controversy this winter, because the world-record smashing began at last year’s world championships — long before the newest of the newfangled apparel came out.

Swimmers, coaches and scientists say it is impossible to pinpoint one explanation. They cite many contributing factors, ranging from professional training groups that have sprouted across the United States to greater access to underwater cameras and other advanced technology.

But some say the most significant breakthrough has been a revival of a swimming maneuver developed more than 70 years ago by one of the physicists who worked on the atomic bomb.

Though utilized for decades, the underwater dolphin kick had not been fully exploited by the swimming mainstream until Olympic megastar Michael Phelps and a few other stars began polishing it — and crushing other swimmers with it — in recent years.

Very interesting and another example of how good ideas are often ignored for a long time.

The underwater dolphin kick attracted the interest of swimming innovators as early as the 1930s. The late Volney C. Wilson explored its possibilities before diving into later work on nuclear fission and the atomic bomb, according to David Schrader, a research professor at Marquette University who is Wilson’s biographer.

Schrader said Wilson, an alternate on the 1932 Olympic water polo team who studied fish propulsion at a Chicago aquarium, claimed to have shown the kick to Johnny Weissmuller, a training mate at the Illinois Athletic Club. “Weissmuller reproduced it perfectly, but was not impressed by it,” said Schrader in a phone interview, recalling a conversation with Wilson.
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One of the first swimmers to turn heads with the underwater dolphin kick was David Berkoff, a Harvard graduate who became known for the “Berkoff Blastoff.” In 1988, Berkoff set several world records in the 100 backstroke by dolphin-kicking for 35 meters underwater at the start of the race.

Which goes to show you that you can gain advantages just by using the information that is available – your own innovation is not the only way to get ahead. Just doing a better job of adapting what others learn to your challenges can be very rewarding.