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.

Science Based Triathlete

The Making of a Olympian by Arianne Cohen

In a break with training orthodoxy, Potts and his coach have created a regimen called feedback training in which the training plan is reassessed every 24 hours based on the constant monitoring of three variables: wattage (the power Potts’s body produces), cadence (the tempo of his arm and leg movements) and heart rate. No lap times. No mileage. No grand training schedules planned months in advance. Only raw biological data. “My coach and I talk a lot about engines,” Potts says. “In auto racing, you want to put out the highest amount of power with the least amount of fuel. We do the same thing. My heart and lungs are my engine. The goal is to always increase the efficiency of the engine.”

Every night, Doane analyzes his athlete’s response to the day’s training. He’s looking for the best way to expand Potts’s aerobic capacity, power output and lactate threshold, without overtraining. If Doane sees that Potts’s heartbeat has been sluggish—say, beating 140 times per minute while Potts is trying to produce 410 watts—that means his body is struggling to recover from earlier training, so he’ll dial back the intensity of his workouts. If, on the other hand, his heart rate stays in the sweet spot around 165 while he churns through a series of 360- to 400-watt intervals, that means he’s fully recovered and ready to be pushed again. “We’ve created a feedback loop,” Doane says. In other words, Doane subjects Potts to a careful dose of punishment, and Potts’s body tells Doane, through empirical data, what he needs to do next.

Nice article. As it mentions really almost all Olympic athletes today use a great deal of science in their training.

Why ‘Licking Your Wounds’ Works

Why ‘Licking Your Wounds’ Actually Works

scientists found that histatin, a small protein in saliva previously only believed to kill bacteria was responsible for the healing.

To come to this conclusion, the researchers used epithelial cells that line the inner cheek, and cultured in dishes until the surfaces were completely covered with cells. Then they made an artificial wound in the cell layer in each dish, by scratching a small piece of the cells away.

In one dish, cells were bathed in an isotonic fluid without any additions. In the other dish, cells were bathed in human saliva. After 16 hours the scientists noticed that the saliva treated “wound” was almost completely closed. In the dish with the untreated “wound,” a substantial part of the “wound” was still open. This proved that human saliva contains a factor which accelerates wound closure of oral cells.

Because saliva is a complex liquid with many components, the next step was to identify which component was responsible for wound healing. Using various techniques the researchers split the saliva into its individual components, tested each in their wound model, and finally determined that histatin was responsible.

Awesome Robot: uBot-5

Cool video on the uBot-5 from UMass Amherst.

The uBot-5 is dynamically stable, using two wheels in a differential drive configuration for mobility. Dynamically stable robots are well suited to environments designed for humans where both a high center of mass and a small footprint are often required.

via: Pop Culture and Engineering Intersect

Toyota has long been interested in personal robot assistants. And the uBot-5, under development at UMass-Amherst, is also looking to meeting that need: Robot developed by computer scientists to assist with elder care:

Baby boomers are set to retire, and robots are ready to help, providing elder care and improving the quality of life for those in need.
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The uBOT-5 carries a Web cam, a microphone, and a touch-sensitive LCD display that acts as an interface for communication with the outside world. “Grandma can take the robot’s hand, lead it out into the garden and have a virtual visit with a grandchild who is living on the opposite coast,” says Grupen, who notes that isolation can lead to depression in the elderly.

Grupen studied developmental neurology in his quest to create a robot that could do a variety of tasks in different environments. The uBot-5’s arm motors are analogous to the muscles and joints in our own arms, and it can push itself up to a vertical position if it falls over. It has a “spinal cord” and the equivalent of an inner ear to keep it balanced on its Segway-like wheels.

Such robots have a huge market waiting for them if engineers can provide models that can be useful at the right price. The future of such efforts looks very promising.

Microbes Beneath the Sea Floor

This stuff is cool. Here is the full press release from Penn State, Microbes beneath sea floor genetically distinct

Tiny microbes beneath the sea floor, distinct from life on the Earth’s surface, may account for one-tenth of the Earth’s living biomass, according to an interdisciplinary team of researchers, but many of these minute creatures are living on a geologic timescale.

“Our first study, back in 2006, made some estimates that the cells could double every 100 to 2,000 years,” says Jennifer F. Biddle, PhD. recipient in biochemistry and former postdoctoral fellow in geosciences, Penn State. Biddle is now a postdoctoral associate at the University of North Carolina, Chapel Hill.

The researchers looked at sediment samples from a variety of depths taken off the coast of Peru at Ocean Drilling Site 1229. They report their findings in today’s (July 22) online issue of the Proceedings of the National Academy of Sciences.

“The Peruvian Margin is one of the most active surface waters in the world and lots of organic matter is continuously being deposited there,” says Christopher H. House, associate professor of geoscience. “We are interested in how the microbial world differs in the subsea floor from that in the surface waters.”

The researchers used a metagenomic approach to determine the types of microbes residing in the sediment 3 feet, 53 feet, 105 feet and 164 feet beneath the ocean floor. The use of the metagenomics, where bulk samples of sediment are sequences without separation, allows recognition of unknown organism and determination of the composition of the ecosystem.

“The results show that this subsurface environment is the most unique environment yet studied metagenomic approach known today,” says House. “The world does look very different below the sediment surface.” He notes that a small number of buried genetic fragments exist from the water above, but that a large portion of the microbes found are distinct and adapted to their dark and quiet world.

The researchers, who included Biddle; House; Stephan C. Schuster, associate professor; and Jean E. Brenchley, professor, biochemistry and molecular biology, Penn State; and Sorel Fitz-Gibbon, assistant research molecular biologist at the Center for Astrobiology, UCLA, found that a large percentage of the microbes were Archaea, single-celled organisms that look like Bacteria but are different on the metabolic and genetic levels. The percentage of Archaea increases with depth so that at 164 feet below the sea floor, perhaps 90 percent of the microbes are Archaea. The total number of organisms decreases with depth, but there are lots of cells, perhaps as many as 1,600 million cells in each cubic inch.
Continue reading →

Science and the Excitement, the Mystery and the Awe of a Flower

Pleasure of Finding Things Out by Richard P. Feynman is a great explanation of how scientists think: “The science knowledge only adds to the excitement, the mystery and the awe of a flower”

I did post on this before. Related book: Classic Feynman: All the Adventures of a Curious Character.

Pseudogap and Superconductivity

MIT physicists shed light on key superconductivity riddle

Hudson’s team is focusing on the state of matter that exists at temperatures just above the temperature at which materials start to superconduct. This state, known as the pseudogap, is poorly understood, but physicists have long believed that characterizing the pseudogap is important to understanding superconductivity.

In their latest work, published online on July 6 in Nature Physics, they suggest that the pseudogap is not a precursor to superconductivity, as has been theorized, but a competing state. If that is true, it could completely change the way physicists look at superconductivity, said Hudson.

“Now, if you want to explain high-temperature superconductivity and you believe the pseudogap is a precursor, you need to explain both. If it turns out that it is a competing state, you can instead focus more on superconductivity,” he said.

DNA Passed to Descendants Changed by Your Life

How your behaviour can change your children’s DNA

Until recently that would also have been the opinion of most scientists. Genes, it was thought, were highly resilient. Even if people did wreck their own DNA through bad diet, smoking and getting fat, that damage was unlikely to be passed to future generations.

Now, however, those assumptions are being re-examined. At the heart of this revolution is a simple but controversial idea: that DNA can be modified or imprinted with the experiences of your parents and grandparents.

According to this new science, known as epigenetics, your ancestors’ diet, smoking habits, exposure to pollutants and levels of obesity could be affecting you today. In turn, your lifestyle could affect your children and grandchildren.
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If we drink heavily, take drugs, get fat or wait too long to reproduce, then epigenetics might start tying up some of the wrong genes and loosening the bonds on others. Sometimes those changes will affect sperm and egg cells.

It seems to me this area is still far from having conclusive proof. But it is another great example of scientists seeking to improve our knowledge of how things work.

Leopard Bests Crocodile

Leopard savaging a crocodile caught on camera:

A series of incredible pictures taken at a South African game reserve document the first known time that a leopard has taken on and defeated one of the fearsome reptiles. The photographs were taken by Hal Brindley, an American wildlife photographer, who was supposed to be taking pictures of hippos from his car in the Kruger National Park.

The giant cat raced out of cover provided by scrub and bushes to surprise the crocodile, which was swimming nearby. A terrible and bloody struggle ensued. Eventually, onlookers were amazed to see the leopard drag the crocodile from the water as the reptile fought back.

Eventually the big cat was able to sit on top of the reptile and suffocate it. In the past, there have been reports of crocodiles killing leopards, but this is believed to the first time that the reverse scenario has been observed.

Fixing the World on $2 a Day

MIT’s Guru of Low-Tech Engineering Fixes the World on $2 a Day

The charcoal project is the responsibility of Mary Hong, a 19-year-old branching out beyond her aerospace major this semester. She and the other students, coincidentally all women, are enrolled in Smith’s D-Lab, a course that is becoming quietly famous beyond the MIT campus in Cambridge, Mass. The D is for development, design and dissemination; last fall, more than 100 students applied for about 30 slots. To prepare for their field work, D-Lab students live for a week in Cambridge on $2 per day. (Smith joins in.) Right now, eight more D-Lab teams are plying jungle rivers, hiking goat trails and hailing chicken buses in seven additional countries—Brazil, Honduras, Ghana, Tanzania, Zambia, India and China. In Smith’s view, even harsh aspects of Third World travel have their benefits. “If you get a good bout of diarrhea from a waterborne disease,” she says, “you really understand what it means to have access to clean drinking water.”
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Despite their simplicity, Smith’s creations made her a minor celebrity at MIT, and in 2000 she became the first woman to win the $30,000 Lemelson-MIT Student Prize. The same year, she began teaching full time at the university. It was nearly 30 years since German economist E.F. Schumacher had published Small is Beautiful: Economics as if People Mattered, the book credited with launching the appropriate technology movement. Schumacher argued that many of the infrastructure projects funded by the World Bank and other organizations hadn’t improved lives on the village level. “He rightly and aptly pointed out that big solutions don’t fit for villages. You have to make it small,”

Finding the Host Genes Viruses Require

Flu-infected fly cells reveal dependencies of the virus

The new study is important because it demonstrates a rapid-fire technique for identifying host factors such as proteins and carbohydrates that a virus commandeers to successfully infect a cell. By exposing the virus’s dependencies, the Wisconsin team has uncovered a target-rich environment for influenza drug developers.
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By working in fly cells, the Wisconsin team was able to deploy a technique to rapidly and selectively silence thousands of genes to see which were used by the flu virus. Screening a library of some 13,000 genes, the group identified more than 100 whose suppression in fly cells hindered the virus’s ability to successfully take over the cell and make new viruses.