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.

Biofuels use Could Worsen Global Warming

Biofuels use could worsen warming (site broke link so link removed)

The biofuels themselves produce less greenhouse gases than fossil fuels, but not nearly enough to offset the carbon dioxide that is released when land is cleared and plowed up to produce crops, the studies said. Carbon dioxide is one of the leading contributors to global warming.

One of the studies released Thursday by the journal Science estimated that ethanol would nearly double the greenhouse emissions over a 30-year period if the impact of land conversion is taken into account.

Surprising New Diabetes Data

But these measures are only surrogates for disease. And in many cases, the connection between “better” numbers and better health is tenuous. In the case of cholesterol, many people won’t see a health benefit from lower numbers.

Now comes yet another sobering reminder that lowering a surrogate marker doesn’t necessarily bring better health. On Feb. 6, the National Institutes of Health announced it was halting a key trial for diabetes. Researchers had hoped the trial, dubbed ACCORD (Action to Control Cardiovascular Risk in Diabetes), would show that more aggressive lowering of blood sugar would significantly reduce deaths. Instead, the opposite happened. More people in the intensive treatment group died than in the group getting standard care. “A thorough review of the data shows that the medical treatment strategy of intensively reducing blood sugar below current clinical guidelines causes harm in these…patients,” says Dr. Elizabeth Nabel, director of the National Heart, Lung & Blood Institute.

Scientific study often results in less than clear conclusions, especially in complex systems. There is great difficulty understanding what is actually going on, what interactions are present, what factors are significant, etc.. One of the great problems with the low level of scientific literacy in the USA is so many people think science is about simple absolute truth.

Scientific inquiry, especially related to health care, must attempt to gain insights from confusing signals. To gain scientific literacy one must understand basics concepts, like data is a proxy for what you aim to understand. To understand yourself you need to accept that science is not math. For a long time we are going to have to do our best to build up our understanding of human health (and other complex systems) as best we can. We need to be able to sort out what are solid conclusion, what are guesses, what seem like reasonable explanation and what level of confidence we can have in statements.

It is not enough to learn facts we need to be able to think scientifically and comprehend the subtleties surrounding the advances in scientific understanding. Some criticize newspapers and popular science for providing too simplistic a view of new scientific knowledge. While this can be a problem I really see the problem much more serious if people read obviously overly simplistic articles and don’t understand that it is just scratching the surface. The reader needs to take responsibility too. I enjoy many great articles that gloss over many of the details but provide a quick view of intriguing new breakthroughs.

Cancer Killing Ideas From Honeybees

Honeybee Weapon in War on Cancer

No, researchers haven’t found a beehive-based cure (though major royal jelly, the wondrous protein concoction that turns lowly workers into queens, may have anti-cancer properties.) But bee colonies experience their own type of cancer, and maybe human researchers can learn from their victories.
…
Like Amdam said, it’s not clear how the honeybees won. Perhaps the successful colonies produced bees adapted to noticing the intruder; perhaps it produced individual bees whose interactions caused some sort of superorganism-wide shift. And maybe when we figure that out, we’ll have some fresh ideas for fighting cancer — maybe not for tweaking our own cells, but for customized nanomolecule cancer hunters.

A New Epoch – Anthropocene

Has Earth entered a new epoch?

Geologists wonder if they should add a new epoch to the geological time scale. They call it the Anthropocene – the epoch when, for the first time in Earth’s history, humans have become a predominant geophysical force. Naming such a new epoch would also recognize that humans now share responsibility with natural forces for the state of our planet’s ecological environment.

Geologists have been using the term informally for at least half a decade. Now members of the Stratigraphy Commission of the Geological Society of London have laid out the case for giving the term official scientific status.

They make a good point I think.

BBC In Our Time Science Podcast Archive

BBC In Our Time Science Podcast Archive including: Plate Tectonics – the day the Earth moved, Genetic Mutation – the error-strewn secrets of life, The Fibonacci Sequence – the numbers in nature, Antimatter – where has it all gone?, Gravitational Waves – a new window on the universe. Great stuff. This is the type of stuff that makes the internet so great. It is wonderful the amount of great science and engineering resources are online.

Nature Recreation Declining

Glacier National Park photo by John Hunter

Photo looking north across Lake McDonald from my Village Inn balcony in Glacier National Park, by John Hunter.

Do people still care about nature

Nature recreation worldwide — from camping, hunting and fishing to park visitation — has declined sharply since the 1980s
…
The study examines data from the United States, Japan and Spain on everything from backpacking to duck hunting…that correlated a decline in visits to U.S. National Parks with an increase in television, video game and Internet use.
…
The decline in some nature use seems to be accelerating, such as U.S. state park and national forest visits, as well as fishing. Others show a more steady decline, such as U.S. and Japanese national park visits and U.S. Bureau of Public Lands visits. Most reliable long-term per capita visitation measures of nature recreation peaked between 1981 and 1991. They’ve declined about 1.2 percent per year since then, and have declined a total of between 18 percent and 25 percent.
…
Other research shows that the time children spend in nature — particularly the activities we looked at in this study – determines their environmental awareness as adults. We recently wrote a review paper looking at this phenomenon as well as at the effects of videophilia on childhood development. These effects are substantial and include obesity, attentional disorders, lack of socialization and poor academic performance.

I must say I am surprised by this. My visits to national parks have led me to believe the attendance was increasing but that seems to be wrong. The National Parks Service has a simple web tool to view visits to US national parks by year. Go visit great parks, here are some photos from my trips: Grand Teton National Park, Rocky Mountain National Park, Shenandoah National Park and Grand Canyon National Park.

Energy-Efficient Microchip

Team develops energy-efficient microchip

The key to the improvement in energy efficiency was to find ways of making the circuits on the chip work at a voltage level much lower than usual, Chandrakasan explains. While most current chips operate at around one volt, the new design works at just 0.3 volts.

Reducing the operating voltage, however, is not as simple as it might sound, because existing microchips have been optimized for many years to operate at the higher standard-voltage level. “Memory and logic circuits have to be redesigned to operate at very low power supply voltages,” Chandrakasan says.

One key to the new design, he says, was to build a high-efficiency DC-to-DC converter–which reduces the voltage to the lower level–right on the same chip, reducing the number of separate components. The redesigned memory and logic, along with the DC-to-DC converter, are all integrated to realize a complete system-on-a-chip solution.

One of the biggest problems the team had to overcome was the variability that occurs in typical chip manufacturing. At lower voltage levels, variations and imperfections in the silicon chip become more problematic. “Designing the chip to minimize its vulnerability to such variations is a big part of our strategy,” Chandrakasan says. “So far the new chip is a proof of concept. Commercial applications could become available “in five years, maybe even sooner, in a number of exciting areas”

The World’s Hottest Chili

The World’s Hottest Chili:

The standard measure for such things is the Scoville Heat Unit, or SHU, named after Wilbur Lincoln Scoville, a chemist who in 1912 developed a method of assessing the heat given off by capsaicin, the active ingredient in chili peppers. JalapeÃ±o peppers measure about 5,000 SHUs. The bhut jolokia tops a million.
…
Food scientists speculate that hot chilies have an unexpected side effect that boosts their popularity. A publication of the Brooklyn Botanical Garden in New York described it this way: “When capsaicin comes into contact with the nerve endings in the tongue and mouth, pain messengers, called neurotransmitters, are sent to the brain in a panic. The brain, mistakenly perceiving that the body is in big trouble, responds by turning on the waterworks to douse the flames. The mouth salivates, the nose runs and the upper body breaks into a sweat. The heart beats faster and the natural painkiller endorphin is secreted. In other words, you get a buzz.”

Water: Supercool and Strange

Supercool, and Strange

As liquids go, water is a radical nonconformist—differing from other liquids in dozens of ways (see the latest count at www.lsbu.ac.uk/water/anmlies). Most famous among water’s peculiarities is its density at low temperatures. While other liquids contract and get denser as they cool toward their freezing points, water stops contracting and starts to expand. That’s why ice floats and frozen pipes burst.
…
Water gets even weirder at colder temperatures, where it can exist as a liquid in a supercooled state well below its ordinary freezing point. Recent evidence suggests that supercooled water splits its personality into two distinct phases—another oddity unseen in other liquids. And last year, water surprised scientists yet again, when they found that at –63 degrees Celsius, supercooled water’s weird behavior returns to “normal.”

The Decoy Effect

The Decoy Effect, or How to Win an Election

The human brain, however, always seeks simple answers. Enter the third candidate. Huber told some people there was also a choice of a four-star restaurant that was farther away than the five-star option. People now gravitated toward the five-star choice, since it was better and closer than the third candidate. (The three-star restaurant was closer, but not as good as the new candidate.)

Another group was given a different third candidate, a two-star restaurant halfway between the first two. Many people now chose the three-star restaurant, because it beat the new option on convenience and quality. (The five-star restaurant outdid this third candidate on only one measure, quality.)

What the decoy effect basically shows is that when people cannot decide between two front-runners, they use the third candidate as a sort of measuring stick. If one front-runner looks much better than the third candidate, people gravitate toward that front-runner. Third candidates, in other words, can make a complicated decision feel simple.