Image of the Week: Printing Blood Vessels and a Whole Lot More

In a paper published this week in the journal Advanced Materials, Dr. Shaochen Chen
demonstrated that blood vessels, which could eventually be used in artificial tissue, can be
created using a new 3D printing technique called dynamic optical projection stereolithography.   
Image courtesy: Biomedical Nanotechnology Laboratory, Chen Research Group, UC San Diego Jacobs School of Engineering

Do you have a good printer at home?  What about one that can print you a new car part, a toy, or another 3D object?  It may sound bizarre, but 3D printing (also known as additive manufacturing because a printer typically builds an object by slowly adding layers of material) is becoming more common in a wide range of contexts, including the battlefield and the medical field.

Our image of the week shows artificial blood vessels printed by researchers in the Biomeidcal Nanoengineering Lab at US San Diego.  Their technique uses light to trigger the formation of a solid 3D structure from a solution containing cells and biomolecules that are photo-sensitive (or reactive to light).  By carefully controlling the beam of light with a series of mirrors, they are able to fabricate tiny, intricate structures like those found in nature.  They believe the new process will lead to better tools for growing cells in the lab and could eventually even allow medical professionals to print tissues for regenerative medicine.

LEARN MORE
Watch an amazing video and read about another application of 3D printing that was recently in the news: a bald eagle named Beauty was given a prosthetic beak made on a 3D printer after being injured by a gunshot. (Warning: although there's a happy ending, images may not be suitable for sensitive readers and viewers.)

Read the Science Insider piece about the newly created National Additive Manufacturing Innovation Institute and the wide potential uses for and benefits of 3D printing.

Read yesterday's story in Reuters about how the business of 3D printing is starting to make its way into individual homes and garages.

The Scientific Method in Action: Advances in Weather Forecasting

Through repeated applications of the scientific method and advances
in computer modeling, weather predication has become a 
scientific endeavor and accuracy has greatly improved.   
Image courtesy: Chris Zielecki (Flickr CC)

Meteorologists often take a lot of flack when their weather predictions aren't accurate--indeed it can be very annoying to cancel a big event for a blizzard that never materializes, or worse, very dangerous if an unexpected storm comes up while you are out hiking. Despite its foibles, though, weather forecasting has come a long way from its early roots of divining celestial signs and following limericks ("red sky at night, sailors delight; red sky in morning, sailors take warning") to become a truly scientific endeavor.

As in any scientific field, uncertainty is inherent in the data that predict the path of a hurricane or separate "clear skies" from "chance of thunderstorms."  But the accuracy of weather forecasts has greatly improved over the last century,  thanks in large part to advances in computer modeling.

Early efforts to predict the weather mathematically, by people like Vilhelm Bjerknes and Lewis Fry Richardson, highlighted the need for serious computational power to begin even approaching the level of complexity found in Earth's atmosphere.  Efforts to make weather prediction scientific, and the recognition that propagating a tiny error across a series of weather calculations could have a huge cumulative impact on the results, also spawned the field of chaos theory.  Chaos theory, which includes the popular notion of "the butterfly effect," aims to understand underlying patterns of behavior in complex systems (like weather) and to quantifying the uncertainty.

Strides in the accuracy of weather prediction are an everyday example of the scientific method in action. Modern meteorologists--as well as scientists who model long-term global climate systems--still contend with uncertainty, complexity, the limits of technology, and human errors.  But through the iterative process of the scientific method (and aided by faster, more powerful computers), they are continuously fine-tuning their models and predictions.  That's good news for science and for anyone who wants to plan a picnic or avoid a lightening strike.

LEARN MORE
Venture inside one of the modern nerve centers for weather forecasting, the National Centers for Environmental Prediction, in Nate Silver's New York Times Magazine piece "The Weatherman is Not a Moron."

Learn about some of the first computer models, which were developed for weather prediction in our module Research Methods: Modeling

Read about how weather forecasting led to the rise of chaos theory in our module Data: Uncertainty, Error, and Confidence

Image of the Week: Six New Species of Millipedes Found in Musuem Collections

A male specimen of Nephopyrgodesmus eungella--one of six new
species of millipede found in leaf litter that was sitting on the shelves
of two Australian museums. Image Courtesy: Robert Mesibov (CC)

Think you have to organize an expedition to an isolated patch of wilderness or the deepest depths of the sea to find news species?  Not hardly.  This week, scientists described six new species and three new genera of millipedes that were found on the shelves of two Australian museums.  Dr. Robert Mesibov, a millipede specialist at the Queen Victoria Museum and Art Gallery, discovered the specimens among the "residue" (in this case bags full of leaf litter) from previous collecting expeditions focused mainly on beetles.  Our image of week shows one of the new species.  All six are described--and shown in beautifully creepy photographic detail--in the open access journal ZooKeys.

LEARN MORE
Find out how scientists classify and name the diversity of life on Earth, in our modules: Taxonomy I and Taxonomy II: Nomenclature.

Read about two new bat species discovered in 2009 among the Smithsonian Institution's mammal collections and a new dinosaur discovered in 2011 in Natural History Museum of London's collections.

See the new species of lacewing scientists in California recently found by browsing photos on Flickr.

Darwin Tunes: Scientists Examine How Consumer Choice Can Drive the Evolution of Music from Noise

Image Courtesy: Flickr User all that improbable blue (CC)

Here's an application of evolutionary theory you don't see everyday: the evolution of music by natural, make that public selection.

Researchers from the Department of Life Sciences at the Imperial College of London and the Media Interaction Group at the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan joined forces to investigate how consumer preferences--as opposed to directed artistic efforts--can affect the evolution of music.  They set out to answer some very interesting questions, including:  Is it possible to make music without a composer? If so, what kind of music is made? What limits the evolution of music?

Inspired by research on evolution in microbes and studies on how art and music develop and change in response to cultural forces, the team created "Darwin Tunes," a computer-based system for simulating natural selection within a "population" of audio clips. Darwin Tunes is powered by an algorithm that creates "digital genomes"--computer programs, which, when executed, create short loops of sound. Like a biological genome that serves as a blueprint for an organism, each digital genome specifies certain parameters--in this case things like instrumentation and note placement. The algorithm does not receive any melodies, rhythms, or other human-created sounds as inputs, so the music created by Darwin Tunes is truly computer-generated.

Running the algorithm once produces a population of 100 audio loops that go through a number of "life cycles" during the course of the experiment. Which loops get to "reproduce" and which "die off" is determined by the ratings given by a group of nearly 7,000 human listeners who use a five-point scale ranging from "I can't stand it" to "I love it." Those clips that are deemed most pleasing reproduce and those that are hard-on-the-ears go extinct. In evolutionary terms, listener ratings are the "selective pressure" acting on the population.

As with living organisms, the offspring of the audio loops differ from their parents for reasons that also mirror biological evolution.  Each audio loop in the second generation is produced by combining the genomes of two first-generation loops (akin to sexual reproduction in nature). The genomes of the second generation are also modified with new, random musical "genetic material" akin to DNA mutations in nature. Each new generation is again rated by listeners.

By repeating this process a few thousand times, the research team found that clips changed over time--moving from sound that would most aptly be called "noise" to sound that qualified as "music." The difference is easy to hear in the clips below, which contain loops produced initially by Darwin Tunes (generation zero), loops from generation 1,500, and loops from generation 3,000.


Generation Zero

Generation 1500

Generation 3000

As any musician or music lover can tell you, the qualities that make a piece of music appealing are complex. To better understand which traits were being "selected for" in the Darwin Tunes populations, the researchers looked to the emerging field of music information retrieval (MIR) technology. MIR is what allows services like Pandora and iTunes to suggest new music based on the songs already on a user's playlist. Using two MIR algorithms to analyze the various generations of clips (both those that evolved with listener input and controls that were randomly assigned ratings), the researchers identified two specific traits that were changing over time: the presence of chords commonly used in popular music and the complexity of rhythmic patterns in the music.

While these two features are clearly important, the researchers conclude that there are many other musical factors in the evolution of these clips and that additional experiments using a wider variety of MRI algorithms would be interesting. The results of the study appear in today's early online edition of the Proceedings of the National Academy of Sciences. You can listen to and rate clips by visiting the Darwin Tunes website.

For more about evolution and natural selection, browse our modules on Adaptation and Charles Darwin (and don't miss Part 2 or Part 3!).


Want to read more about the science of music? Check out the research conducted by the Pattern Analysis and Intelligent Systems Research Group at the University of Bristol. Their work to develop a mathematical equation that can predict hit songs was presented in December 2011 at the 4th International Workshop on Machine Learning and Music. Visit their Score a Hit website or download the short paper that appeared in the conference proceedings.

Video of the Week: Science (and Math) on Ice

Tonight the Los Angeles Kings and the New Jersey Devils will suit up and hit the ice for the first game of the National Hockey League (NHL) Stanley Cup Finals. The players probably won't be thinking about Newton's Laws of Motion while being checked against the glass or how they make use of kinetic and potential energy to launch that 160 kilometer per hour slapshot, but a hockey game is a fast and furious demonstration of many of the key concepts of physics.

In fact, a careful observer can see physics, statistics, geometry, and biology all at work in the rink. Even if you're not a hockey fan, the speed, power, and reaction time of NHL players is undeniably impressive, and the Science of NHL Hockey video series from the National Science Foundation and NBC Learn offers a view you can't get from the nosebleed seats. We're crowning the segment entitled "Work, Energy, and Power" our video of the week, but they are all worth a watch.



For more videos from the Science of NHL Hockey series, visit the NSF's Science360 Network.

For ideas from the National Science Teachers Association about how to incorporate these videos into lesson plans for high school and junior high students, visit NBC Learn. (Scroll down, select a lesson plan, and then click on full-screen mode to read the document.)

Image of the Week: Solar Eclipse Dazzles

This past Sunday, observers in and parts of Southeast Asia and North America witnessed an annular solar eclipse--an arrangement in which the moon shades out most but not all of the sun, leaving a bright ring around the dark lunar form. Although Earth-bound viewers couldn't look at the eclipse directly with naked eyes, the Hinode spacecraft snapped some dazzling shots, including the one below. Hinode, a joint venture between NASA and the Japan Aerospace Exploration Agency (JAXA), is cruising in low-Earth orbit to help scientists study the sun's magnetic field and energy releases.

A picture of the annular solar eclipse on May 20, 2012, captured by the Hinode spacecraft.
Image Courtesy: NASA Goddard Space Flight Center

To see more images of the eclipse and the wild shadows it created, visit the 2012 Annular Solar Eclipse Group on Flickr.

Then tell us: did you witness the eclipse? Where were you, and how did you view it?

Video: Virtual Tour of Vesta Asteroid with Data from NASA's Dawn Spacecraft

Call it a giant asteroid. Call is a planetoid. Scientists call it Vesta--a 300 mile wide celestial body in the asteroid belt between Mars and Jupiter that, in some ways, bares a striking resemblance to a rocky planet like Earth. NASA's Dawn spacecraft has been orbiting Vesta since July 2011 collecting data and taking photographs.

Last week, scientists released a bevy of images and information about Vesta, including data confirming that Vesta is indeed structured like a planet with an iron core and that it separated into layers (crust, mantle, etc.) as it formed. (For more information about the structure of our own planet, see our module on Earth's Structure.) Vesta's topography is also quite varied, exhibiting landslides, craters, and a mountain twice the height of Mt. Everest. Using data from Dawn, NASA's Jet Propulsion Laboratory created this ethereal virtual tour of Vesta's surface.

Video Courtesy: NASA Jet Propulsion Laboratory California Institute of Technology

For more information, check out NASA's Dawn news page or some of the widespread media coverage from the New York Times, Nature, and the LA Times, among others.

Next Generation Science Standards Open for Public Comment through June 1

Among other things, the Next Generation Science
Standards aim to emphasize the process and practice of
science.   Photo Courtesy: Argonne National Laboratory (CC)

Today, a draft of the Next Generation Science Standards was released for a three-week public comment period. The new Standards are based on the National Research Council’s (NRC) Framework for K–12 Science Education and are the first update since the original National Science Education Standards were released in 1996.

Among other things, the new Standards are intended to place a broader emphasis on the process and practice of the scientific enterprise. This is highlighted by the fact that the very first Dimension of the Framework on which the Standards are based is entitled Practices, and is meant to describe how scientists work. This is an ambitious and long-overdue goal, and we are excited to see more emphasis placed on it.

Over the past decades, science education has migrated away from teaching about science and has migrated towards conveying facts and figures. As Bruce Alberts, editor of the journal Science has said, “Rather than learning how to think scientifically, students are generally being told about science and asked to remember facts.”

There are many reasons proposed to explain this migration—an emphasis on standardized test performance, lack of specialized teacher preparation, etc. But probably the most reasonable of these explanations is the fact that science textbooks fail to describe the scientific process and instead present science as a series of facts and predetermined endpoints.

In his landmark book, The Structure of Scientific Revolutions, published almost 50 years ago today, Thomas Kuhn wrote:

Textbooks thus begin by truncating the scientist’s sense of his discipline’s history and then proceed to supply a substitute for what they have eliminated. …Yet the textbook-driven tradition in which scientists come to sense their participation is one that, in fact, never existed.

To educate students about science, we need to present the discipline as it is practiced, not as a series of inevitable facts discovered by fate.

In 2006, we began an initiative to develop a series of modules that expressly describe the Process of Science. This initiative—possibly better described as an ongoing journey—has been both incredibly rewarding and at times slightly maddening. As the core authors of the Process content, Anne Egger and I have invested thousands of hours into researching these ideas, writing about them, editing, rewriting, and eventually launching these to the public.

Writing some of these modules was relatively straightforward. For example, there is an extensive literature underscoring the concept of Scientific Ethics, and there are well defined ideas about how a scientific Experiment differs from a Comparative study. However, there is less written about many other core ideas underscoring scientific practice such as how and why individual scientists collaborate, how subjectivity affects data interpretation, and how error and uncertainty in data are quantified and expressed. Still other concepts that need explaining, such as “What is the Scientific Method?” or “How does scientific knowledge differ from other types of knowledge?” are sometimes defined by scientists in the same way Supreme Court Justice Potter Stewart defined pornography in 1964: “I know it when I see it.”

In fact, Nobel laureate Sir Peter Medawar once said, “Ask a scientist what he conceives the scientific method to be and he adopts an expression that is at once solemn and shifty-eyed: solemn, because he feels he ought to declare an opinion; shifty-eyed because he is wondering how to conceal the fact that he has no opinion to declare.”

We hope that the Next Generation Science Standards will help catalyze a shift back towards teaching about science as it is practiced. In the meantime, please join us in reviewing the new Standards and submitting comments to make sure they emphasize the practices used by scientists.  Comments are due by June 1.

Need help getting started?  The National Science Teachers Association has created a “study guide” for organizing a group discussion, including questions to consider for each section of the new standards (see page 11).