Category Archives: Students

Items for students and others, interested in learning about science and engineering and the application of science in our lives. We post many of the general interest items here.

Using Bacteria to Power Microscopic Machines

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory and Northwestern University have discovered that common bacteria can turn microgears when suspended in a solution, providing insights for designs of bio-inspired dynamically adaptive materials for energy.

“The ability to harness and control the power of bacterial motion is an important requirement for further development of hybrid biomechanical systems driven by microorganisms,” said Argonne physicist and principal investigator Igor Aronson. “In this system, the gears are a million times more massive than the bacteria.”

A few hundred bacteria work together in order to turn the gear. When multiple gears are placed in the solution with the spokes connected as in a clock, the bacteria will turn both gears in opposite directions, causing the gears to rotate in synchrony—even for long stretches of time.

“There exists a wide gap between man-made hard materials and living tissues; biological materials, unlike steel or plastics, are ‘alive,'” Aronson said. “Our discovery demonstrates how microscopic swimming agents, such as bacteria or man-made nanorobots, in combination with hard materials, can constitute a ‘smart material’ which can dynamically alter its microstructures, repair damage, or power microdevices.”

Surprise Shrimp Under Antarctic Ice

A three-inch long Lyssianasid amphipod found 600 feet beneath the Ross Ice Shelf stars in a recent popular webcast (see below). NASA scientists were using a borehole camera to look back up towards the ice surface when they spotted this pinkish-orange creature swimming beneath the ice.

Stacy Kim of Moss Landing Marine Laboratory was the first biologist to see the video and immediately recognized it as a Lyssianasid amphipod. It was about 3 inches long and Stacy concluded that this meant there was quite an extensive biological community under the ice here – even 20 miles from open water.

Next steps for Google’s Experimental Fiber Network

Think big with a gig: Google’s experimental fiber

Universal, ultra high-speed Internet access will make all this and more possible. We’ve urged the FCC to look at new and creative ways to get there in its National Broadband Plan – and today we’re announcing an experiment of our own.
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We’re planning to build and test ultra high-speed broadband networks in a small number of trial locations across the United States. We’ll deliver Internet speeds more than 100 times faster than what most Americans have access to today with 1 gigabit per second, fiber-to-the-home connections. We plan to offer service at a competitive price to at least 50,000 and potentially up to 500,000 people.

Next steps for our experimental fiber network

So what’s next? Over the coming months, we’ll be reviewing the responses to determine where to build. As we narrow down our choices, we’ll be conducting site visits, meeting with local officials and consulting with third-party organizations. Based on a rigorous review of the data, we will announce our target community or communities by the end of the year.

Of course, we’re not going to be able to build in every interested community — our plan is to reach a total of at least 50,000 and potentially up to 500,000 people with this experiment. Wherever we decide to build, we hope to learn lessons that will help improve Internet access everywhere.

This is another great idea from Google. Not only to push forward the much poorer internet connectivity those in the USA have than other countries but it will hopefully lead to some real engineering breakthroughs. And it is a smart move to increase Google’s potential income – a better internet experience (for users) will likely help Google quite a bit.

Researchers Find High-Fructose Corn Syrup Results in More Weight Gain

A Princeton University research team has demonstrated that rats with access to high-fructose corn syrup gained significantly more weight than those with access to table sugar, even when their overall caloric intake was the same. In addition to causing significant weight gain in lab animals, long-term consumption of high-fructose corn syrup also led to abnormal increases in body fat, especially in the abdomen, and a rise in circulating blood fats called triglycerides

Photo of Princeton University research team, including (from left) undergraduate Elyse Powell, psychology professor Bart Hoebel, visiting research associate Nicole Avena and graduate student Miriam Bocarsly, by Denise Applewhite

The first study showed that male rats given water sweetened with high-fructose corn syrup in addition to a standard diet of rat chow gained much more weight than male rats that received water sweetened with table sugar, or sucrose, in conjunction with the standard diet. The concentration of sugar in the sucrose solution was the same as is found in some commercial soft drinks, while the high-fructose corn syrup solution was half as concentrated as most sodas.

The second experiment — the first long-term study of the effects of high-fructose corn syrup consumption on obesity in lab animals — monitored weight gain, body fat and triglyceride levels in rats with access to high-fructose corn syrup over a period of six months. Compared to animals eating only rat chow, rats on a diet rich in high-fructose corn syrup showed characteristic signs of a dangerous condition known in humans as the metabolic syndrome, including abnormal weight gain, significant increases in circulating triglycerides and augmented fat deposition, especially visceral fat around the belly. Male rats in particular ballooned in size: Animals with access to high-fructose corn syrup gained 48 percent more weight than those eating a normal diet. In humans, this would be equivalent to a 200-pound man gaining 96 pounds.

“These rats aren’t just getting fat; they’re demonstrating characteristics of obesity, including substantial increases in abdominal fat and circulating triglycerides,” said Princeton graduate student Miriam Bocarsly. “In humans, these same characteristics are known risk factors for high blood pressure, coronary artery disease, cancer and diabetes.” In addition to Hoebel and Bocarsly, the research team included Princeton undergraduate Elyse Powell and visiting research associate Nicole Avena, who was affiliated with Rockefeller University during the study and is now on the faculty at the University of Florida. The Princeton researchers note that they do not know yet why high-fructose corn syrup fed to rats in their study generated more triglycerides, and more body fat that resulted in obesity.

Engineering Mosquitoes to be Flying Vaccinators

Mosquitoes Engineered Into Flying Vaccinators by Emily Singer

Researchers in Japan have transformed mosquitoes into vaccine-carrying syringes by genetically engineering the insects to express the vaccine for leishmaniasis–a parasitic disease transmitted by the sandfly–in their saliva. According to a study in Insect Molecular Biology, mice bitten by these mosquitoes produced antibodies against the parasite. It’s not yet clear whether the immune response was strong enough to protect against infection.

“Following bites, protective immune responses are induced, just like a conventional vaccination but with no pain and no cost,” said lead researcher Shigeto Yoshida, from the Jichi Medical University in JapanYoshida, in a press release from the journal. “What’s more continuous exposure to bites will maintain high levels of protective immunity, through natural boosting, for a life time. So the insect shifts from being a pest to being beneficial.”

Researchers consider the project more of a proof of principle experiment than a viable public health option, at least for now.

Very cool.

Invisible Worlds: Fastest Thing on the Planet

Fun with Fungi.

Statistical Errors in Medical Studies

I have written about statistics, and various traps people often fall into when examining data before (Statistics Insights for Scientists and Engineers, Data Can’t Lie – But People Can be Fooled, Correlation is Not Causation, Simpson’s Paradox). And also have posted about reasons for systemic reasons for medical studies presenting misleading results (Why Most Published Research Findings Are False, How to Deal with False Research Findings, Medical Study Integrity (or Lack Thereof), Surprising New Diabetes Data). This post collects some discussion on the topic from several blogs and studies.

HIV Vaccines, p values, and Proof by David Rind

if vaccine were no better than placebo we would expect to see a difference as large or larger than the one seen in this trial only 4 in 100 times. This is distinctly different from saying that there is a 96% chance that this result is correct, which is how many people wrongly interpret such a p value.
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So, the modestly positive result found in the trial must be weighed against our prior belief that such a vaccine would fail. Had the vaccine been dramatically protective, giving us much stronger evidence of efficacy, our prior doubts would be more likely to give way in the face of high quality evidence of benefit.
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While the actual analysis the investigators decided to make primary would be completely appropriate had it been specified up front, it now suffers under the concern of showing marginal significance after three bites at the statistical apple; these three bites have to adversely affect our belief in the importance of that p value. And, it’s not so obvious why they would have reported this result rather than excluding those 7 patients from the per protocol analysis and making that the primary analysis; there might have been yet a fourth analysis that could have been reported had it shown that all important p value below 0.05.

How to Avoid Commonly Encountered Limitations of Published Clinical Trials by Sanjay Kaul, MD and and George A. Diamond, MD

Trials often employ composite end points that, although they enable assessment of nonfatal events and improve trial efficiency and statistical precision, entail a number of shortcomings that can potentially undermine the scientific validity of the conclusions drawn from these trials. Finally, clinical trials often employ extensive subgroup analysis. However, lack of attention to proper methods can lead to chance findings that might misinform research and result in suboptimal practice.

Why Most Published Research Findings Are False by John P. A. Ioannidis
Continue reading →

Autonomous Underwater Robot Decides on Experiment Options

Ocean robot plans experiments

the autonomous underwater vehicle (AUV) used a piece of software called “T rex”, which operates in a similar way to the software used to control Nasa’s Mars Exploration Rovers – helping them to avoid obstacles on the surface of the Red Planet.

One main difference between the two pieces of software is that for the Mars rovers, the software ran in the control centre on Earth. With this marine vehicle, it runs onboard the robotic vehicle.
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“We tell it, ‘here’s the range of tasks that we want you to perform’, and it goes off and assesses what is happening in the ocean, making decisions about how much of the range it will cover to get back the data we want.”

Researchers at MBARI used the Gulper AUV to monitor potentially harmful algal blooms.

Kim Fulton-Bennett from MBARI explained: “We used to send out a ship for a full day every few weeks to manually take these measurements. Now we just take the AUV outside the harbour and send it on its way.

“About 24 hours later, it comes back, we hoist it on board, and download the data.”

IBM Fellow Grady Booch on the Value of Engineering?

In this webcast IBM Fellow Grady Booch discusses the critical role engineering plays in moving society forward. And he explores the history of science and engineering. This interesting webcast would be a good video to show children, or anyone, to bring out the desire to study engineering and encourage them to study so they can join the many engineers shaping our world and our future.

Norway Reduces Infections by Reducing Antibiotic Use

Norway conquers infections by cutting use of antibiotics

Twenty-five years ago, Norwegians were also losing their lives to this bacteria. But Norway’s public health system fought back with an aggressive program that made it the most infection-free country in the world. A key part of that program was cutting back severely on the use of antibiotics.

Now a spate of new studies from around the world prove that Norway’s model can be replicated with extraordinary success, and public health experts are saying these deaths — 19,000 in the U.S. each year alone, more than from AIDS — are unnecessary.

“It’s a very sad situation that in some places so many are dying from this, because we have shown here in Norway that Methicillin-resistant Staphylococcus aureus [MRSA] can be controlled, and with not too much effort,” said Jan Hendrik-Binder, Oslo’s MRSA medical advisor. “But you have to take it seriously, you have to give it attention and you must not give up.”

The World Health Organization says antibiotic resistance is one of the leading public health threats on the planet. A six-month investigation by The Associated Press found overuse and misuse of medicines has led to mutations in once curable diseases like tuberculosis and malaria, making them harder and in some cases impossible to treat.

Now, in Norway’s simple solution, there’s a glimmer of hope.