Monday 5-15-06

The pain of waiting for pain

Few people enjoy the anticipation of a painful experience, but some people are willing to suffer worse pain sooner rather than linger in a state of dread. It turns out that they are not simply more anxious or fearful than others; there is a biological difference in people who suffer from the mere knowledge of future pain.

Neural activity in the section of the brain that processes pain increases in people who can't stand waiting for pain. Severe dread, in other words, is a form of pain that comes from simply thinking about upcoming pain.

Wednesday 5-10-06

Sense-able network

Physicists have come up with an answer to the mystery of how human senses can span a wide range of inputs, from very subtle to very powerful, when sensory nerve cells have a small dynamic range.

The answer has to do with the way nerve cells are networked. Interactions among sensory nerve cells provide the wide dynamic range necessary to allow us to see faint stars and the blazing sun, and to detect that subtle hint of tobacco in a glass of cabernet sauvignon while being able to withstand, more or less, the stench of rotting garbage.

Wednesday 4-12-06

Toward implantable sensors

Highlights from the Body Sensor Networks 2006 workshop at MIT last week:

A computer vision system from the MIT Media Lab uses tiny wearable cameras to read facial expressions in order to determine if someone is paying attention, bored, confused, in disagreement, or concentrating. The researchers are working with an autism center to use the system as a "social-emotional prosthetic" to help people with autism communicate. [Update: see Face Reader Bridges Autism Gap on Wired News.]

A lightweight body sensor from Imperial College London monitors patients at home for complications after surgery. The system is designed to allow physicians to spot complications before patients recognize that something is wrong, making it possible to address complications sooner and reduce the associated health and economic costs.

A coin-size device from Thermo Life Energy Corporation converts body heat into electricity to power wearable health monitors and implantable medical devices. The thermoelectric power generator removes the need for batteries, which need to be recharged or replaced.

An EKG-in-a-shirt from the Franhofer Institute in Germany uses embroidered conductive yarn to connect electrodes, power supply and computer processor. The wearable EKG is more practical for monitoring patients in daily life than bulkier EKG systems with wires.

An unobtrusive vital signs monitor from Motorola is designed to keep an eye on emergency workers. The monitor's electrodes and other components are carried in a loose-fitting harness. Previous monitors required electrodes to be tightly fastened to the body, potentially hindering firefighters and other first responders.

A sensor-cell phone combination from Microsoft Research remotely monitors patients in real time. A clinical study showed that the system identified people with sleep apnea by monitoring them as they slept at home.

A smart dental prosthesis from the University of Leuven in the Netherlands incorporates a pressure sensor. The device vibrates to warn wearers when they overload it.

Wednesday 4-5-06

Kurzweil keynote

Ray Kurzweil laid out his vision of rapidly accelerating technological development at a keynote speech at the Life Sciences Conference in Boston this week. The material came largely from his most recent book, The Singularity Is Near: When Humans Transcend Biology. The highlights:

Paradigm shifts are doubling in frequency.
Computers with the power to simulate the human brain should arrive around 2013.
Simulations will eventually surpass animal models (i.e. lab mice, etc.) for medical research and drug discovery.
You will be able to download instructions from the Internet to reprogram artificial white blood cells in your body to combat specific diseases.

And by 2029:

1,000 dollars worth of computing power will equal 1,000 times the power of the human brain.
We will have reverse engineered the brain.
A computer will pass the Turing test.
Nanobots will provide nonsurgical neural implants that will expand human intelligence and allow for full-immersion virtual reality from inside the nervous system.

Thursday 3-16-06

DNA nanotech made easy

Scientists have produced two-dimensional patterns from DNA for several years, but the process is complicated and the yields are often low. A researcher from the California Institute of Technology has found a simple way to arrange DNA into just about any pattern that can be formed from 200 dots.

The technique, dubbed scaffolded DNA origami, uses short "staple" strands of DNA to fix a 7,000-letter-long virus DNA strand into a particular pattern. The choice of staple strands determines the pattern, and a software program identifies the staple strands needed to form a given design.

DNA origami can be used to place protein molecules in particular patterns to study how they interact, and to produce templates for nanoelectronic devices.

These false color atomic microscope images show a map of the Americas made of DNA and a DNA hexagon pattern, each 50 times smaller than a red blood cell. More information is on the researcher's site.

Sunday 3-12-06

Loneliness trumps exercise

Scientists have established that social isolation is bad for physical and emotional health. Most of these studies focus on how social isolation makes bad health conditions worse.

A study of rats' brains shows that social isolation also diminishes the positive effects of healthy behavior. When rats are housed together, running causes new brain cells to grow. Rats housed alone show slower neuron growth, and when the rats are also put under stress the neuron growth stops.

While this study shows the importance of social ties, it doesn't mean that working out alone is bad for you.

Friday 2-24-06

In hot water

A look at the climate during the age of the dinosaurs shows that global warming could be worse than scientists have predicted.

At the end of the dinosaurs' reign on earth, there was three to six times as much carbon dioxide in the atmosphere as today. An analysis of fossilized shells of marine microorganisms from the Cretaceous period shows an ocean temperature range 9 to 14 degrees Celsius higher than today's temperatures.

However, plugging those carbon dioxide levels into climate models gives ocean temperatures 2 to 8 degrees lower than the shell data. The discrepancy between the models and the data suggests that the models are missing something.

If prehistory is a guide, we're in for a future that's even warmer than climate models predict, with even stronger storms and even more agricultural disruption.

Thursday 2-16-06

Don't think about it

The advice to "sleep on it" is gaining scientific credibility.

A study of consumer decision-making has found that, in some cases, making decisions without attention to the choices produces better results.

For simple choices, attention does result in better decisions. But as choices become more complicated the quality of a decision decreases. This is because the capacity of conscious awareness is limited, forcing the mind to focus on a few attributes to the exclusion of others. Unconscious decision-making, however, is unaffected by choice complexity.

The study looked at consumer decision-making for simple items, like towels, and complex items, like cars. Subjects who were distracted before being forced to make a decision about complex items did better than subjects who were allowed to deliberate.

So sleeping on a decision, or otherwise taking your mind off it, will not only lower your stress level, it will give you better results, too.

Monday 2-13-06

Slick touch

Here's a cool demonstration of the potential of touchscreen technology, close to the level of the user interface in the movie Minority Report. The interaction techniques are not new, but taken together and combined with the New York University researchers' high-speed, high-resolution multiple-contact touchscreen the effect is impressive. Be sure to watch the video, and be sure to watch past the initial hyper-paint-program eye candy.

Friday 2-10-06

Nifty new tech

Highlights from this year's DEMO new and emerging technology conference:

A collection of handheld projector technologies from Digislide Holdings.

Feature-heavy voice-over-IP home phone service from My People.

Next generation videoconferencing software from VSee Lab, which lists user interface guru Terry Winograd as a technical adviser.

A wearable cellphone/music player from ZinkKat.

Friday 2-3-06

Mega fishfinder

Fish populations are in decline, largely due to overfishing. But getting accurate assessments is challenging, which has made conservation efforts all the more difficult. Traditional sonar scans of fish populations are produced by ships towing sonar gear, resulting in very slow scan lines that produce spotty data.

A new sonar technique promises to change that. The method produces instantaneous wide area scans that can track populations of millions of fish over tens of kilometers of ocean. In addition to opening the way to accurate populations surveys, the technique is giving biologists a better view of fish population dynamics and group behavior.

Friday 1-27-06

Green growing

Sustainable agriculture practices, which meet the food needs of a population with minimal environmental impact, sound like a good idea. A new study backs this up with hard data.

The study of 286 sustainable agriculture projects in 57 developing countries, including Thailand, Sri Lanka, China and Mexico, found that, in addition to improving environmental conditions, sustainable agriculture increased crop yields by an average of 79 percent.

The farm projects used less water and packed away more carbon from the atmosphere than unsustainable methods. Seventy-seven percent of projects tracking pesticide use increased yields 42 percent while reducing pesticide use by 71 percent.

Previous research has documented negative impacts on the environment and human health from industrial agriculture.

Friday 1-20-06

Pigs in space

Although the latest news on tipping points is about global warming, it looks like we have another pollution-related tipping point to contend with -- artificial debris in Earth orbit.

A study by NASA scientists shows that if no spacecraft were launched after December 2004, collisions among satellites, rocket parts and fragments thereof -- numbering more than 9,000 -- will produce more fragments, adding objects in low Earth orbit. These new objects will roughly equal the number of objects that fall out of orbit, keeping the population constant until 2055. After that, the population will increase. Of course, spacecraft have been launched since December 2004, and the 21st century is being heralded as the dawn of the commercial space era.

The U.S. military's Space Surveillance Network tracks these objects. According to their Web site, 84 percent of space debris is at altitudes of 800 kilometers and higher, well above where the space shuttle flies and where the nascent space tourism industry is likely to operate.

Still, given that the risk to satellites and manned spacecraft from collisions is increasing, the NASA scientists argue that we need to begin removing space junk. The problem is, there is no economically viable method of cleaning up the Earth orbit.

Maybe a space ecotourism venture is in order -- see space and help restore it to its natural state.

Warming threatens sea life

It looks like the very foundation of the ocean ecosystem -- phytoplankton -- is at risk from global warming. A study shows that the upward flow of nutrients that sustains the tiny sea plants will diminish as the planet heats up. The kicker is that phytoplankton absorb carbon dioxide, helping oceans draw the greenhouse gas out of the atmosphere, so less phytoplankton means more global warming.

Friday 1-13-06

Tiny teachers

Teaching doesn't necessarily require a large brain.

Scientists from the University of Bristol in England have documented teaching behavior in a species of ant. Temnothorax albipennis uses tandem running -- leading one another to food -- as a means of passing along valuable information within a colony.

Most ants use broadcast techniques like pheromone trails to transmit information about food sources from one ant to many ants.

In contrast, Temnothorax albipennis's teaching behavior uses tandem running patterns to communicate food source information from one ant to another.

A following ant taps a lead ant's rear legs and abdomen with its antennae to let the lead ant know that it is there. The lead ant, which knows the location of a food source, slows down when it no longer feels the tapping to allow the following ant to catch up, and it waits while the following ant periodically circles around to figure out where it is via landmarks.

The teaching behavior evolved because, even though the lead ants are slowed down in returning to food sources, passing along the food source's location benefits the entire colony.

The broadcast techniques work well for larger ant colonies; the one-to-one teaching technique, however, turns out to be better for the smaller Temnothorax albipennis colonies.

And you can't beat those class sizes.

Friday 1-6-06

Dangerous thoughts ahead

The Web site Edge -- that online collection of thoughts from the best and brightest minds of the English-speaking world of science and technology -- has posted its annual question: What is your dangerous idea?

The 119 responses range from politically dangerous to politically incorrect, scientifically insightful to scientifically heretical, and emotionally satisfying to emotionally repulsive.

Here are some that caught my eye:

The evidence that tribal peoples often damage their environments and make war.
- Jared Diamond

The fight against global warming is lost
- Paul Davies

Let's all stop beating Basil's car
- Richard Dawkins

What the physics of the 20th century says about the world might in fact be true
- Carlo Rovelli

The world may fundamentally be inexplicable
- Lawrence Krauss

After several generations of living in the computer culture, simulation will become fully naturalized. Authenticity in the traditional sense loses its value, a vestige of another time.
- Sherry Turkle

The quick-thinking zombies inside us
- Andy Clark

The End of Insight
- Steven Strogatz

Bacteria are us
- Lynn Margulis

Open Source Currency
- Douglas Rushkoff

A universal grammar of [mental] life
- Marc D. Hauser

Democracy may be on its way out
- Haim Harari

The self is a conceptual chimera
- John Allen Paulos

Friday 12-23-05

The world is your farm

Agriculture is a dominant force in the global environment, but scientists are still getting a handle on the details.

Researchers from the University of Wisconsin are using satellite and census data to fill in the gaps. They have started to produce maps of cropland and pastureland that provide both a global view and regional details of the human impact on the landscape.

Cropland covers 18 million square kilometers -- an area the size of South America. Cropland and pastureland cover a third of the landscape worldwide. The researchers' database will eventually include 150 individual crops. Preliminary results show an increased deforestation of Argentina and Brazil fueled by the expanding soybean crop, which is driven by demand from China.

The data is needed to help find ways of sustainably producing food.

Friday 12-16-05

Morphing bubbles

Although bubbles wobble, they always settle down to a perfectly spherical shape thanks to surface tension. But it doesn't have to be this way.

Harvard University researchers have found that coating bubbles with tiny particles counters surface tension, allowing bubbles to hold non-spherical shapes. The effect works regardless of the gases that make up the bubbles or the sizes and compositions of the particles.

The researchers made flattened bubbles, doughnut-shaped bubbles and elongated irregularly-shaped bubbles.

I wonder how long it will take toy manufacturers to adapt the technique to soap bubbles. Let's hope they use environmentally-friendly particles.

Sunday 12-11-05

Humor divides brains by gender

When you see a cartoon that makes you laugh, exactly what is going on in your brain?

Different things, depending on your gender, according to a study that used functional magnetic resonance imaging (MRI) scans to compare brain activity in males and females as they judged cartoons funny or not funny.

Although the sexes tended to find the same cartoons funny, the way they processed information to come to the same conclusions was somewhat different.

When subjects of either sex saw something funny the temporal-occipital junction and temporal pole, used for semantic knowledge and incongruency detection, and the inferior frontal gyrus, which is probably used to process language, tended to require increased blood flow to process the information.

In addition, however, females showed more activity in the left prefrontal cortex, which implies more language-based decoding, and in the mesolimbic regions, including the nucleus accumbens, which have to do with psychological rewards. As the humor level increases, the gender differences in nucleus accumbens activation increases.

At the same time, male subjects took about same amount of time determining that a cartoon was funny or not funny, while females were faster at determining that a cartoon was not funny.

According to the researchers, the processing differences may have to do with what the subjects expect. That females are less likely to expect a punch line may make them faster at determining that a cartoon is not funny. At the same time, the more unexpected the punch line, the more activity in the part of the brain that includes prediction error.

Uncovering information about how the brain processes humor may point to better diagnostic and therapeutic approaches to clinical depression.

Saturday 12-3-05

Ocean of trouble

We may see the dire consequences of global warming sooner rather than later.

A study by the UK's National Oceanography Centre shows that the Atlantic Ocean circulation pattern that keeps Europe warmer than it would otherwise be given its place on the globe is slowing and showing signs of breaking down.

The Atlantic meridianal overturning, also called the Atlantic thermohaline circulation , brings warm Gulfstream water to the UK, Scandinavia and Iceland. The warm water flows near the surface where it warms the atmosphere. As the water cools its sinks and flows southward. Global warming is increasingly melting the ice and snow in Greenland and the polar region, which is increasing the amount of fresh water in the North Atlantic. This decreases the density of the cold ocean water, which interferes with the sinking current.

The study shows a 30 percent decrease in this Atlantic circulation pattern. Paleoclimatic records show that the circulation can stop abruptly -- in as little as a decade -- and that it has severe consequences for the climate. An analysis of a possible shutdown of the circulation shows that the average temperature in Europe could decrease by as much as 10 degrees Celsius and that global vegetation growth could decrease by five percent for a century.

So if global warming can make things colder, doesn't that balance things out? The overall trend is toward a warmer planet with an increase in extreme weather events and greater extremes in regional climate variations. The potential new Little Ice Age in Europe and eastern North America is one of those variations.

Friday 11-18-05

Adding can subtract distractions

It is conventional wisdom that it is difficult to carry out two tasks at the same time. A study has showed that this is not always true. In fact, in some cases, doing two things at once can help concentration. It all depends on how different the tasks are.

The keys to concentration are working memory and attention.

The study showed that when two tasks use different working memory resources in terms of verbal, color and spatial processing, there's very little interference. This implies that each of the systems has an independent attentional capacity in the brain.

The study also showed that doing two tasks at once can actually benefit attention. The key is taking on a second task that requires different working memory resources from the ones used by the first task but that overlap with the resources taken up by potential distractions.

Friday 11-11-05

Attack could overload Net

A method of exploiting the Transmission Control Protocol (TCP) could, in theory, clog large sections of the Internet, according to a report by University of Maryland researchers. The vulnerability, first uncovered six years ago, could be used to bring the world's information circulatory system to a virtual standstill, according to the report.

The CERT Coordination Center, which tracks computer and network security threats, has issued a vulnerability note about the security hole.

Transmission Control Protocol regulates the flow of data between computers on the Internet and private Internet protocol (IP) networks. The problem is an attacker could alter a receiving computer in a way that could cause a sending computer to increase its rate of transmission to the point of saturating its network connection. This could be used, for instance, to launch a denial of service attack against a Web site.

A coordinated attack by a large enough but plausible number of altered Transmission Control Protocol receivers has the potential to overload the Internet's trunk lines, according to the report.

Thursday 11-10-05

Cleaner nylon

Good news on the green chemical front.

Artificial textiles are often made using chemical processes that create chemical wastes. The two main methods of manufacturing Nylon-6, which is used to make fabrics and industrial plastics, produce waste ammonium sulfate.

Researchers from the University of Cambridge in England have worked out a way to manufacture Nylon-6 using a fairly simple and reasonably low-temperature reaction that produces no ammonium sulfate waste.

Key to the greener reaction is a type of catalyst that helped along the reaction. According to the researchers, this particular type of catalyst -- single-site heterogeneous catalysts -- could reduce chemical waste products in other reactions as well.

Friday 11-4-05

Measuring moisture

Quick -- what is the dominant greenhouse gas?

Water vapor actually traps more of the heat from Earth than any other gas in the atmosphere.

Although climate models have been predicting that a warmer climate means more water vapor in the atmosphere, which, in turn, means a warmer climate, this outcome has been hotly debated because it has been difficult to measure.

Researchers from the University of Miami, the University of Colorado, the National Oceanic and Atmospheric Administration, and Princeton University have taken a look at the empirical evidence by matching climate model simulations with real-world satellite measurements.

Like much news lately about global warming, it's not good. The study validates climate models that predict that moisture levels in the upper troposphere will double by the end of the century.

Tuesday 11-1-05

Questionable choices

How often do you miss detecting a mistake? How do you know?

Researchers from Lund University in Sweden and New York University have shown that people can regularly fail to notice the difference between a choice they made and a wrong outcome that was ostensibly based on that choice.

Worse, in the researchers' experiments people often offered pat explanations of the wrong outcome.

The experiment, designed to explore relationships among intention, choice, and introspection, involved showing 15 pairs of female faces to 120 participants and asking each participant to choose which of each pair was more attractive. Soon after choosing, participants were given the pictures they chose and asked to supply reasons for the choices. One-fifth of the time, however, participants were given the picture they did not choose.

Participants failed to notice three-quarters of the incorrect pictures, and explained their reasons behind the switched choices with specifics such as "She looks like an aunt of mine" and "She seems nicer than the other one."

The researchers have dubbed the phenomenon "choice blindness".

Tuesday 10-25-05

Boosting old brains

It looks like timing is everything in teaching an older brain new tricks.

Researchers from Miami University have shown that it's possible to make the age-related learning impairments of rabbits disappear by timing the learning to take place during theta brainwave activity.

This type of brainwave originates from the hippocampus region of the brain; previous studies have shown that the hippocampus plays a key role in learning.

The researchers' experiments involved conditioning rabbits to blink their eyes on command, but the method could potentially be used to optimize all types of learning.

Friday 10-21-05

That's how the spaghetti crumbles

Ever notice that when you bend a dry piece of spaghetti and it breaks, it usually breaks into three or more pieces rather than just two?

Didn't think so. Researchers from French National Center for Scientific Research, however, have not only noticed the phenomenon, but have also explained why spaghetti falls to pieces under pressure. They've confirmed the explanation with high-speed movies of spaghetti breaking.

It turns out that the initial fracture causes additional breaks -- they are triggered by waves traveling along the piece of spaghetti immediately after the first break.

Although the way spaghetti breaks is not in and of itself terribly important, the physics of a rod of spaghetti bears on the physics of rods of other materials like those used in buildings and bridges.

Tuesday 10-11-05

Grammar as time machine

Researchers have been able to show how early humans spread throughout Europe and Asia over the past several thousand years or so by studying changes in language vocabulary. The method has proved reliable going back only about 8,000 years, however, because it becomes impossible to differentiate between real relationships and chance resemblances that far back in time.

A new method that uses the structure of language, including sound systems and grammar, could extend this time window. It tested well in organizing the relationships of already-understood Oceanic Austronesian languages. When researchers applied the method to the Papuan languages of Melanesia they found evidence of a more than 10,000-year-old relationship.

The method shows that it might be possible to extract more information about relationships among the world's 300 or so language families.

Wednesday 10-5-05

Uphill water walkers

Walking on water is a tricky business. So is defying gravity. Some bugs can do both.

The insects and spiders that walk on water are light enough that surface tension will support their weight. The tricky part of traversing water, however, is crossing the border between liquid and land. There's a bulge, or meniscus, at the border that can be the equivalent of a slippery hill to a small insect.

Larger insects can jump over menisci, but this is not practical for insects that measure only a few millimeters.

A study shows that the millimeter-scale water-walking insects Mesovelia, Microvelia and, Pyrrhalta, or beetle larva, switch to a most unusual means of propulsion to get over these water barriers: they tap capillary forces -- the same surface-tension forces that allow water to flow up a thin tube -- to catch a sort of escalator ride.

The insects glide over menisci by pushing their front and rear legs into and then pulling up on the surface of the water while pressing down the surface of the water with their middle legs. The resulting capillary forces drags them up the slope as fast as 30 body lengths per second.

Friday 9-30-05

Seashells and CO2

There's a common thread running through news of the specifics of global warming lately -- things are turning out worse than predicted.

Today's news is no different. The increase in carbon dioxide in the atmosphere has increased the acidity and decreased the amount of calcium carbonate in ocean water. This promises to affect marine organisms including ecologically important corals and plankton that need the mineral to maintain their external skeletons.

A study tapped 13 computer models to predict the calcium carbonate concentration of the earth's oceans under a business-as-usual scenario, then immersed pteropods -- a type of ocean snail -- in water containing the level of calcium carbonate predicted for 2100. The snail's shells started dissolving within 48 hours.

The upshot is that decreased calcium carbonate concentrations are likely to start causing problems for ecosystems in surface waters of the Southern Ocean, the Arctic Ocean and subarctic Pacific Ocean within decades. Previous estimates had pegged the timing at centuries.

Tuesday 9-27-05

A-salting freshwater

The saltiness of freshwater in United States has been on the increase for several decades. A new study shows that salinity levels are starting to reach the point of serious ecological consequences.

The study shows that fresh water in the northeastern United States is becoming more salty due to a double whammy: an increase in road surfaces causes more rainwater and snowmelt to run off into streams, rivers, ponds and lakes rather than being filtered by land, and the use of salt and other deicers on roads during the winter makes this runoff saltier.

The study examined the salinization rate in Baltimore County, the Hudson River Valley, and New Hampshire's White Mountains, and found that water grew saltier over the past 30 years in all areas. During the winter some urban waterways were 25 percent as salty as seawater.

The upshot is that at this rate, surface water in the northeastern U.S. will become too salty for freshwater life or human consumption within the next century.

If you put together all the impervious surfaces -- roads and buildings -- in the continental United States, they would cover 112,610 square kilometers, an area nearly the size of Ohio. More than one million new single-family homes and more than 10,000 miles of new roads are built in the United States each year.

Between 10 and 15 million tons of salt is used on roads in the United States each winter.

Monday 9-19-05

Room temperature ice

Experiments have proved that it is possible to freeze water at room temperature using energy to trigger hydrogen to bond in the way needed for crystallization. What's more, the phenomenon uses considerably less energy than had been predicted. The catch is that this type of freezing only happens in nanoscale spaces.

The researchers were able to force ice to form in extremely narrow gaps between a gold surface and the gold tip of a scanning tunneling microscope in an electric field as low as one million volts per meter. Previous estimates had pegged the number at one billion volts per meter.

The strength of an electric field diminishes exponentially with distance making it possible for small spaces to have high electric fields. Electric fields of one million volts per meter can be found in nanoscale electrical devices; they also form naturally in extremely small crevices in rocks, and probably in thunderclouds. A household static electric spark generates an electric field of about three million volts per meter.

Monday 9-12-05

Brown blocks white

It looks like beer and barbecue sauce that contain a certain type of caramel food coloring may pack a wallop beyond the usual food and alcohol overindulgences.

A study shows how the food coloring, 2-acetyl-4-tetrahydroxybutylimidazole (THI), suppresses the immune system. The study uncovers details of how the lymph system works and how nutrition affects the immune system, and could lead to therapies that deliberately suppress the immune system.

Previous studies had shown that the food coloring gets in the way of the migration of lymphocytes, a type of white blood cell, from the thymus gland and the lymph nodes to the lymph system and blood vessels. Lymphocytes produce antibodies that identify infectious agents like bacteria and viruses.

The new study shows that the food coloring inhibits an enzyme that degrades a key signaling molecule, causing the molecule to accumulate in lymphoid tissues, which in turn inhibits the white cells from leaving the tissues.

Friday 9-2-05

Cultural vision

It seems that people from the opposite ends of the earth tend to look at things differently.

A study examining the way American and Chinese students look at photographs that contain an obvious focal point and a complex background revealed distinct differences. The study tracked students' eye movements as they looked at pictures including a tiger in a forest and an airplane with a landscape behind it.

The American students were quicker to look at the focal point and looked at it longer, while the Chinese students made more quick glances around the rest of the picture.

There have been hints of this cultural difference before -- previous studies (1 , 2) have shown that North Americans tend toward the analytical and tend to pay more attention to focal objects, while East Asians tend toward the holistic and tend to pay more attention to context.

The difference also translated to differences in remembering the objects later. The Chinese students remembered the photographs slightly better, but the American students were better at remembering they had seen the focal object before when it was put in front of a new background.

Wednesday 8-31-05

Blink blindness

Although there are still many things that science cannot explain precisely, a research team has solved one mystery. It is now known why the human perception of the world doesn't include sudden darkness every few seconds while we blink.

Scientists discovered 20 years ago that visual sensitivity changes during blinking, but it took the advent of functional magnetic resonance imaging to work out how this happens. The MRI study suggests that activity in the parts of the brain associated with awareness of changes in a person's surroundings is suppressed during blinking.

Wednesday 8-23-05

Bone farming

Doing surgery that requires extra pieces of bone usually involves the painful process of harvesting from a patient's iliac crest, or risking immune system reactions by using materials that originate outside the patient's body.

A new technique uses a space inside the patient's body to grow new bone for use elsewhere in the body. The technique involves pumping a gel that promotes bone formation into an area between the tibia and periosteum. This area contains a layer of cells that has the potential to generate different types of tissue. In the researchers' experiments with rabbits, it took about six weeks to grow enough bone tissue to repair a bone defect.

The adult human body contains 206 bones.

Friday 8-19-05

Not your father's hurricane

If it seems like hurricanes have been more destructive in recent decades, it's because they have been, and it's not just because of the explosive growth of coastal development.

Computer models and scientific theory predict that global warming increases storm intensity. An analysis of tropical cyclones since the middle of the 20th century confirms that this is the case: the top wind speeds and the durations of tropical cyclones have increased by about 50 percent in the past 50 years.

The analysis correlates the increases in storm intensity with increases in average surface temperatures of tropical oceans.

Monday 8-15-05

Research news roundup week of August 15, 2005

Your face on my cellphone

The widespread availability of digital photography thanks to camera-equipped cellphones opens the door to all manner of humor and hijinks. Aiding and abetting wouldbe digital jokesters is software that allows users to transform photographs of faces into animated 3D models.

The software allows people to send each other short animated clips featuring talking heads complete with audio messages produced with speech synthesis technology. For example, you could take a friend's picture, convert the image of his face into a 3D model, type in embarrassing or humorous phrases, and send the resulting animation clip to his girlfriend. This type of image capture and animation technology has been around for years in laboratories. The researchers fit the software on cellphones and created an easy-to-use interface. (LiveMail: Personalized Avatars for Mobile Entertainment, presented at Mobile Systems, Applications and Services (MobiSys) 2005, Seattle, Washington, June 6-8, 2005)

All plastic radio ID tags

One of the promises -- and perils -- of radio frequency identification (RFID) tags is that when the chips can be made cheaply enough, anyone, including manufacturers and governments will be able to tag, and therefore track, everything under the sun.

Key to making them cheaply is making them entirely of plastic. A high-speed organic diode could be the last piece of the puzzle.

RFID tags don't require a power source. They are activated when a tag reader hits them with radiowaves; the radiowaves provide the power the tags need to transmit a signal back to the reader. Plastic transistors are fast enough to carry out the task of transmitting a tag's ID codes, but the rectifier, which converts alternating current produced by the reader's radio signal to the direct current needed by the tag's circuits, is another matter. The researchers' organic diode rectifier -- at 50 megahertz -- is fast enough to do so. (50 MHz rectifier based on an organic diode, Nature Materials, August, 2005)

DNA and electricity

The question of whether or not DNA molecules conduct electricity has been the subject of a hot debate stoked by conflicting experimental results. The tricky part of answering the question is it's extremely difficult to connect individual molecules to circuit testers. Because of this, past results have been all over the map.

A more accurate test shows that DNA does conduct electricity. Key to the accuracy was a way to make the DNA molecules stand up so that only one end was touching the surface, assuring that nothing was interfering with or assisting the molecules' conductance. The physics of how electricity moves through DNA remains an open question. (Direct measurement of electrical transport through single DNA molecules of complex sequence, Proceedings of the National Academy Of Sciences, August 16, 2005)

Simpler nanotube circuits

Carbon nanotubes are the object of many a researcher's vision for ultra miniaturized computer circuits. Among the many challenges to making computer chips from nanotubes, however, has been finding a way to connect millions of closely-packed nanotubes to metal electrodes to form transistors.

A group of researchers has sidestepped the problem by showing that Y-shaped carbon nanotubes act as electrical switches all by themselves, removing the need for the connections. Given a high enough voltage, the Y-shaped nanotube blocks electrical current to turn the switch off. The researchers are still working out the physics involved in the switching process. (Novel electrical switching behavior and logic in carbon nanotube Y-junctions, Nature Materials, August 14, 2005)

Friday 8-12-05

Stealth learning

Scientists understand how habit works in animals better than in humans because the strong human tendency to acquire knowledge consciously makes it more difficult to test habit in people.

A study using patients who have no capacity for acquiring knowledge consciously due to damage to the medial temporal lobe -- a part of the brain that handles perception, recognition and comprehension -- shows that humans can also learn via trial-and-error unconsciously.

The patients gradually learned to choose the correct object of a pair. The learning was truly unconscious -- although the patients learned to choose the correct object with a high degree of accuracy, they could not say why the object they chose was the right one.

Thursday 8-11-05

More melting and a mystery solved

About 26 percent of the carbon that has accumulated on earth in the past 10,000 years -- 70 billion metric tons -- has been safely locked up in the frozen expance of Western Siberia's lowland permafrost peat bogs. The permafrost area is larger than France and Germany combined.

About a year in a half ago a UCLA scientist who showed that western Siberia is a warming hot spot -- its average temperatures are increasing more than twice as fast as the average global warming -- raised an alarm. His analysis showed that if the permafrost melts it could release large amounts of carbon dioxide or methane into the atmosphere. Either scenario has the potential to speed global warming, but methane is 20 times as strong a greenhouse gas as carbon dioxide.

Scientists speculated that if the bogs dry as they warm, the methane will react with oxygen to form carbon dioxide as it is released. If the process happens more rapidly, however, the thawing bogs will release methane directly into the atmosphere.

Here's today's bad news. Researchers just back from the remote area have reported that the peat bogs are indeed melting, and the process is happening so fast that methane is bubbling directly from the thawing permafrost surface even in winter.

The upshot is that global warming is starting to trigger events that are accelerating global warming. The permafrost melt stands to double the amount of carbon put into the atmosphere by natural landmass sources. Before this news, the United Nations estimated that the planet will warm between 1.4 and 5.8 degrees Celsius from 1990 to 2100.

The research also explains what had been a puzzling contradiction. Lakes in Alaska, also a global warming hot spot, have been growing at a breakneck pace because of permafrost melt there. But Western Siberia has lost thousands of lakes in the past three decades. The apparently opposite reactions, however, are simply different stages in the same process. Initial melting increases surface water that forms lakes because the remaining permafrost prevents draining. The lakes eventually disappear when the permafrost below them melts completely.

Tuesday 8-9-05

Research news roundup week of August 8, 2005

Here's a look at the latest developments in technology research, some of which might be expanded on in a coming issue of TRN:

Cleaner hydrogen

Hydrogen is the focus of many people's hopes and dreams for weaning the world from fossil fuels. But while hydrogen itself is a clean fuel, most of the processes used to produce it are not environmentally sound. Many scientists are looking to the sun to provide a clean, renewable energy source for producing hydrogen fuel, usually by using sunlight to extract hydrogen from water. Researchers from Israel, Switzerland, France and Sweden have extended the use of sunlight to another part of the hydrogen equation; they used a giant solar oven to purify zinc, which is a catalyst in the process of extracting hydrogen from water. Their prototype solar tower, positioned at the focal point of 64 mirrors harvesting sun from the Israeli desert, heated zinc oxide ore to 1,200 degrees Celsius to produce 45 kilograms of zinc powder in one hour.

Siggraph: remote-control humans

Researchers from NTT Communication Science Laboratories in Japan have developed a way of altering a person's balance electronically. The galvanic vestibular stimulation system uses electrodes worn behind the ears to steer someone who is walking and induce a sense of acceleration in someone who is standing. Potential uses include adding a sense of G-force to virtual reality and video games. I find one of the researchers' suggested applications a little disturbing, though. They propose using the system for flow control of pedestrians. Who's going to feel comfortable giving control of his or her body to someone else or to a computer? I can't help but picture a glitch in the system that causes a city block's worth of pedestrians to lurch suddenly into the street.

Siggraph: targeted Smell-o-vision

In the late '50s and early '60s, Hollywood experimented with adding odors to movies, but pumping smelly gases into movie theaters proved unworkable. In recent years virtual reality researchers have been revisiting the notion of odor delivery to heighten sensory experience. Various research teams have developed methods of delivering targeted blasts of scented air at people's faces, but users have found the air currents distracting. Researchers from ATR Media Information Science Laboratories in Japan have refined the air cannon approach by using multiple cannons targeted so that the scented air vortex rings they emit collide with each other at a point in space, delivering odor sans wind.

Gray-haired qubits

One of the principal challenges to building unimaginably fast quantum computers is making quantum bits -- isolated particles used to store and process bits of information -- that last long enough to be useful. Survival times are usually measured in milliseconds or microseconds. Researchers from the National Institute of Standards and Technology (NIST), who have been making progress in recent years with their trapped ion quantum computing scheme, have reported that they can sustain beryllium ion qubits for more than 10 seconds, which is 50 times longer than previous systems and plenty long enough to carry out computations.

Wednesday 8-3-05

Research news roundup week of August 1, 2005

Here's a look at the latest developments in technology research, some of which might be expanded on in a coming issue of TRN:

Are barcode and hologram tags really necessary? Physicists in the UK have found that objects like paper documents, credit cards, and product packaging can be uniquely identified without any type of tag. The method uses existing microscopic imperfections on the objects to generate a unique pattern when the surface is scanned by an ordinary laser scanner.

The quest to give computers the ability to learn languages on their own, much the way humans learn language, has taken a big step forward with the development of an algorithm by researchers at Tel Aviv University and Cornell University that can suss out the structure and rules of a language without being given cues. This could not only improve natural language processing technology but also the pattern recognition systems used to sift through large amounts of data.

Scientists from Stanford University coaxed cancer cells to absorb carbon nanotubes attached to folic acid, then used an infrared laser to heat up the nanotubes in order to kill the cancer cells without harming healthy cells. Several research teams are using folic acid as a cancer-fighting Trojan horse. A newsbrief in the current issue of TRN describes a molecule that links the bait to an anticancer drug.

Scientists from Oak Ridge National Laboratory and North Carolina State University have taken pictures of a tooth that show the nanoscale structure of its proteins and crystals. This method could provide higher-resolution images of biological tissue than are currently available. They previously used a similar method to examine the structure of butterfly wings.

A program note: see how we got started and help us keep going (a short history of TRN).

Thursday 7-28-05

Soothing oil

It seems silly at first glance that sailors of old dumped barrels of oil onto the sea during a storm. A modern mathematical model of hurricanes, however, shows that the sailors knew what they were doing.

Tropical cyclones cause ocean waves to throw a spray of water droplets into the air. The droplets reduce the turbulence of the air, which allows the wind to accelerate, intensifying the storm. Coating the water's surface with oil minimizes the formation of water droplets.

Tuesday 7-26-05

Fading protection

Apologies for all the bad news on global warming lately (1, 2, 3), and further apologies for some even worse news.

A study shows that the effect of atmospheric aerosols has been counteracting global warming by a larger amount than previously thought, meaning the actual effect of a given amount of extra carbon dioxide in the atmosphere is likely to be worse than previously predicted.

Given that levels of ozone-depleting aerosols have peaked, the upshot is that climate change in the 21st century is likely to be as bad as or worse than the upper extremes of estimates by the Intergovernmental Panel on Climate Change. The most likely scenario is a rise of more than six degrees Celsius by the year 2100. This rise is so rapid that it is difficult to predict the consequences for the planet, according to the researchers.

Friday 7-22-05

Seeing red

Although people have been fascinated by and have used hypnosis for many years, it's not entirely clear exactly how it works.

Researchers looking at the way the brain manages conflict have uncovered a clue, however. They were able to use hypnosis to alter the way people looked at words, which in turn affected the way the brain resolved a classic cognitive conflict between competing word meanings and colors.

Ask a person to name the color of ink used in a printed names of a colors and you get a faster answer when the name is the same as the color than when it is not. People hypnotized and given a suggestion to interpret the printed words as gibberish, however, were able to identify the ink color in the same time regardless of the printed name.

This shows that -- in highly hypnotizable subjects anyway -- hypnosis can alter the way the brain handles visual information. The work also sheds light on how the placebo effect works.

Wednesday 7-20-05

Informative droppings

It looks like landscape corridors -- narrow strips of land that connect areas suitable for wildlife -- are quite useful. Landscape corridors are designed to help prevent plant and animal populations from becoming isolated and therefore more prone to extinction, but it has been hard to assess how well they work.

Research involving bluebird feed sprayed with fluorescent powder shows that the birds often travel near the corridors and disperse more of their seeds via droppings in the patches of habitat that are connected by corridors than in patches that are disconnected.

The researchers also used the bird data to build a model that predicts seed dispersal over larger areas.

Tuesday 7-19-05

Copying keys

Automobile ignition keys and SpeedPass devices that use the Digital Signature Transponder radio frequency identification device are no longer completely secure.

A group of researchers has shown that it is possible to spoof the devices. As proof they bought gas and started up an automobile using simulated Digital Signature Transponder devices.

The researchers spoofed the device by cracking its cipher, or method of generating secret codes, using only a rough published schematic and experimental observation of the device. They used the information to recover a Digital Signature Transponder's secret key. They then cracked the key using a specialized computer made from 16 field programmable computer chips. Once they had the key and serial number of the Digital Signature Transponder they were able to reproduce the device's output.

The Achilles heel of the device was the key length -- at a relatively weak 40 bits, it took the researchers' array of sixteen chips less than an hour to recover a given transponder key.

The researchers are scheduled to present their results at the 14th Usenix Security Symposium in Baltimore starting July 31st.

Sunday 7-10-05

Serial and parallel

Since the first attempt to give a robot some visual sense of the world, it has been obvious that biological vision can be quite sophisticated. One running debate has been how the brain crunches information gathered by the eyes when scanning a scene for objects like food. Does it use serial techniques -- look at each object to see if it carries a series of traits like yellow color, banana size range, and easy reach -- or parallel processing techniques -- do a quick scan to highlight all the yellow vegetation, then check the other traits against this list?

Researchers working with monkeys have found that the answer is both. The visual cortex is complicated -- the neurons in monkeys' brains use a mix of serial and parallel mechanisms to identify objects.

In addition to advancing the science of vision, the work could help improve computer vision systems for medical and security applications.

Friday 7-8-05

Plant storms

It looks like plants responding to climate change can, in turn, affect the climate.

A study has shown that vegetation response to global warming can affect the severity and frequency of extreme weather events like storms and heat waves. The study shows that in certain places changes in vegetation and the resulting changes in atmosphere-vegetation feedback will make for more or fewer extreme events, depending on the region.

The bad news is it looks like the places where vegetation changes will mitigate extreme weather events will be limited to less populated high elevations like the high Sierra Nevada mountains, while in lower areas, including much of the western United States, the changes are likely to make things worse. According to the researchers' climate models, the effect could double the number of extremely hot days in semi-arid areas like the California coast.

Tuesday 7-5-05

Hydrogen's health advantage

Help is on the way -- potentially -- for rising gasoline prices, the rising global temperature and rising health problems due to particulate matter from vehicle exhaust.

According to a recent study, converting all U.S. vehicles to fuel cell that use hydrogen produced by wind and/or natural gas would lead to fuel costs of between $1.12 and $3.20 per gallon in the U.S.; at the same time, the switch would save between 3,700 and 6,400 lives per year. Using more wind vs. natural gas would benefit the climate more, according to the study.

Saturday 6-25-05

Bird talk isn't cheap

Research is increasingly showing that birds are not so bird-brained. Scientists have known for some time that bird communications are fairly rich.

A new study shows that chickadee warning calls about predators include information like the type of predator and how much of a danger it poses. The study showed that the warning calls have a higher level of complexity and sophistication than previously believed.

One of the chickadee's calls sounds like the bird's name -- chick-a-dee. The birds use this call to indicate a perched bird of prey, and the number of extra dee's at the end of a call designates the degree of risk -- the more dee's the bigger the problem. The predator information allows the chickadees -- and often other species of small birds -- to gather in an appropriate size group to mob the predator and drive it away.

I'm hoping the people remaking Alfred Hitchcock's classic The Birds will bear this in mind.

Friday 6-17-05

Visual discipline

It looks like what you see can be influenced by your mental state.

A collaboration between Tibetan Buddhist monks and neuroscientists has shown that meditation can influence sight.

The study contrasted 76 Tibetan Buddhist monks with 1,000 people who were not experienced in meditation. It used the visual phenomenon of perceptual rivalry, which occurs when the brain is confronted with an image and that can be seen in two different ways or with separate images for each eye. The effect is responsible for motion-induced blindness.

The study, which used head-mounted displays to induce perceptual rivalry, showed that monks who performed one of three types of meditation had considerably slower rates of alternation between images than non-meditators. One-point meditation, in which the meditator concentrates on a single object to focus the mind, was particularly effective at diminishing perceptual rivalry. Three monks were able to hold their perceptions completely stable during a five-minute meditation period.

Tuesday 6-14-05

I feel your pain

It looks like empathy is more than skin deep.

A study shows that empathy for physical pain in other people can be physical. When a study subject saw a particular muscle being pricked by a needle on another person, the same muscle on the subject reacted in a similar way as the muscle that was pricked. The subject didn't actually feel pain, but the sensory system of the muscle was provoked, or excited, in the same way, showing that empathy extends beyond emotion to the neural processing signals of muscles. The more painful the pinpricking appeared to the subjects, the stronger the response in their own muscles.

The researchers speculate that the phenomenon is a necessary condition for people to learn culture-specific reactions to pain.

Friday 6-10-05

Dolphin culture

One of the hallmarks of human intelligence is the use of tools, and one of the keys to human success is the ability to pass learned behavior from generation to generation.

It looks like dolphins are capable of these types of behaviors as well. A group of wild dolphins in Western Australia uses sponges to forage for food. The shark bay bottlenose dolphins break marine sponges from the ocean floor and wear them on their snouts to probe into the seabed for fish.

The behavior is not just environmental, because only some of the dolphins in the area use sponges. When researchers analyzed DNA from 13 sponging dolphins and 172 non-sponging dolphins, they found that the behavior is not a genetic trait, but the sponging dolphins are genetically related. Of 22 dolphins observed using sponges for foraging, only one was male. This all suggests that the behavior is part of a material culture that is passed mostly from mother to daughter and that the behavior came from a single "Sponging Eve."

The research sheds more light on the relationships between tool use, intelligence and culture in animals, and how they might have emerged in early humans.


Wednesday 6-8-05

Step lively

A design student has concocted a shoe insole and base-station system that records the number of steps a child takes and translates that to time allowed watching television. The suggested activity-to-TV-time ratio for children: 1,200 to 1,500 steps for two hours. The base station connects to a television and turns the television off once the exercise credit runs out.

This is just one of several efforts to make exercise a part of everyday life despite a developed-world lifestyle that makes it easy to do very little. One of our favorites is a bicycle generator that turns your pedaling into electricity. You can go even further along this track with pedal-powered washing machines, water pumps, grain mills and blenders.

The next question is how long it will take for health clubs to become energy self-sufficient. It's not a new idea 1 2 3.

Monday 6-6-05

Water in the air

Water gets around. It's also pretty influential.

The hydrologic cycle -- or flow of liquid water across the earth -- has been altered by humans since crop irrigation began about 6,000 years ago, and is well-considered by weather models.

Less is known about the cycle of water vapor. Researchers comparing land use today with prehuman times showed that deforestation has decreased the flow of water vapor from land by about the same amount as irrigation has increased it. However, rather than simply canceling each other out, the two forces can change regional patterns of water vapor flow considerably. They can trigger, for instance, disruptions in the Asian monsoon system.

On average, 0.001 percent of the Earth's water is in the atmosphere at any one time

Wednesday 5-25-05

Pinpointing pollution

A new technique makes it possible to pinpoint pollution sources by observing the effect pollution has on a river and reconstructing what happened. Key to the technique was the solution to a math problem -- a one-dimensional linear advection-dispersion-reaction equation.

The technique involves sampling pollutants at two points in a river over time to model the evolution of the contamination. One sample point is up river from the source and the other downriver. The method first determines the state of the river at the time the spill ended and then traces the spill to its origin.

Despite the 57-year-old Clean Water Act, water pollution in the U.S. remains a big problem. According to the EPA, "some 40% of surveyed rivers aren't suitable for the uses (recreation, supporting fish and wildlife, etc.) for which States have designated them."

Monday 5-23-05

Influential words

It looks like the perception of a smell can be strongly influenced by words. Subjects rating the smell of cheddar cheese found it significantly more unpleasant when it was labeled body odor. What's more, magnetic resonance imaging during the test showed that when the odor was labeled cheddar cheese, blood flow increased to a region of the brain that processes olfactory information; cheddar cheese smells labeled body odor, however, did not increase the blood flow. This shows that words can either evoke imaginary smells or affect the way the brain processes smells.

At the same time, researchers have found the answer to a long-standing cognitive psychology question: do we unconsciously process the meaning of words slipped subliminally into our consciousnesses. It looks like we do: researchers have shown that the brain responds differently to subliminal words that are threatening vs. nonthreatening.

Previous research showed that subliminal words can condition our perceptions of consciously perceived words.

Though claims for the power of subliminal advertising have yet to be verified, these experiments show that there is more to unconscious thought than scientists previously believed.

Monday 5-16-05

Dissecting the House

A network is a series of objects that are linked in some way. There are networks everywhere -- the Internet, predator-prey relationships, social relationships, and even political relationships.

A study shows that analyzing relationships among committees and subcommittees in the U.S. House of Representatives is enough to reveal the intrinsic hierarchical structure within the House as a whole. The researchers showed that it is possible to plot political and organizational relationships between committees in the House using the committee and subcommittee analysis plus a similar analysis of roll-call votes.

Many of the connections found by the analysis were expected. Sets of subcommittees under a larger committee share many of the same members.

Some connections, however, were unusually strong. For example, the nine-member Select Committee on Homeland Security has an unusually strong connection with the 13-member Rules Committee, which decides how the body conducts business and therefore what legislation is considered by other committees and the full House. The homeland security committee is also strongly connected to the seven-member Legislative and Budget Process Subcommittee of the Rules Committee.

These unusually strong connections, in the researchers words, "strongly suggest" that some committees are stacked rather than determined at random. Each party's caucus elects members to committees.

Further references:
An analysis of four theories on the origin of congressional committees.
Thomas, the Library of Congress' database of all things congressional.
An explanation of how committees work, from Thomas.

Friday 5-13-05

Cancer-fighting herb detailed

Western researchers have made derivatives of the active ingredient of a traditional Chinese herbal treatment and showed that they strongly inhibit cell signaling in cancer cells.

Previous research had showed that Indirubin -- the active ingredient in the herb Qing Dai used in traditional Chinese medicine in an herbal blend for treating leukemia -- blocks the cell cycle. A hallmark of cancer is that cancer cells lack the normal mechanisms for controlling cell replication.

The new research shows that derivatives of Indirubin inhibited the activity of Stat3 in breast cancer and prostate cancer cell lines. Stat3 is a protein that promotes cell survival and replication. Stat3 is constantly activated in many types of cancer cells.

Tuesday 5-10-05

How happy equals healthy

Given that stress is bad for you, the happier you are the healthier you are. Studies have long shown that happier people live longer. Scientists are now getting down to the nitty-gritty of why this is.

Researchers looking at the psychobiological connection between happiness and health problems have showed that people who report more everyday happiness are healthier as measured by lower levels of the stress hormone cortisol, which is related to Type II diabetes and hypertension, lower levels of plasma fibrinogen, a protein implicated in heart disease, and lower heart rates.

The researchers showed that this is the case even when subjects were in psychological distress, which indicates that happiness leads to healthier biological processes. So the connection between health and happiness seems to go both ways healthier people are generally happier (though not always) and happier people are healthier.

Friday 5-6-05

Cancer checkpoints

A pair of recent papers has advanced the understanding of cancer by showing how cells, in most cases, head off the condition. The human body contains trillions of cells, that replicate and make copying mistakes at a rate of one per hundred thousand cell divisions. Given the very large number of cells we have and the potential for mistakes that lead to cancer, it's clear that cells have some method of preventing cancer from propagating.

Cells have mechanisms to recognize and repair DNA damage, and if the damage cannot be repaired, cell death is triggered.

One paper showed that the uncontrolled cell division that marks cancer upsets the DNA process, making mistakes more common, which trips the mechanisms that recognize and repair DNA damage and trigger cell death.

Another paper from that shows that gene mutations that disrupt the DNA repair process are associated with cancer.

Monday 5-2-05

Hibernation for all?

Suspended animation -- a mainstay of science fiction -- may not be so far-fetched after all.

Researchers have found a way to put mice into a suspended animation-like state. Mice in this state took fewer than 10 breaths per minute rather than the usual 120 and had core body temperatures as low as 11 degrees Celsius, down from the usual 37.

The trick to putting mice into deep sleep is having them breathe air containing hydrogen sulfide, a chemical animals naturally produce, probably to help regulate body temperature and metabolic activity. Hydrogen sulfide disrupts the body's natural energy process.

Mice put under for as long as six hours returned to normal when the hydrogen sulfide was removed from their air supply.

The state is similar to hibernation, torpor and estivation, and could be tapped for humans undergoing surgery.

Trap makers

Researchers have discovered a society that methodically gathers and farms special materials for the purpose of constructing traps for unsuspecting travelers.

The traps have a distinctly medieval quality: they consist of a woven fiber platform pitted with holes. Members of the society lie beneath the platform; when a victim bumbles into the trap, they spring up through the holes. Some of them stretch the victim's limbs across the platform while others move in for the kill.

This devious behavior comes from a species of ant that feeds on much larger insects: they construct the traps from hairs gathered from the stem of the plant they live in, and reinforce them using fungus the ants raise in their colonies.

Friday 4-29-05

Everyday toxins

There's news on the chemical front from two common household areas.

A large-scale survey of scientific studies has shed light on a serious problem with a common plastic used in hard clear plastic baby bottles, food containers, toys including pacifiers, and a dental sealant. Polycarbonate plastics are among the plastics labeled "7" for recycling purposes.

A chemical used to manufacture products from polycarbonate is extremely harmful in very low doses, according to an eight-year old study now backed by the survey of 125 studies on the low-dose effects of bisphenol-A.

The studies show that Bisphenol-A (BPA) acts as an estrogen mimic; it adversely affects reproduction, the immune system, learning and the brain. Studies also link the chemical to behavioral changes and an increased chance for some cancers.

The survey showed that after the initial study raised a red flag eight years ago, the chemical industry conducted 11 studies and independent scientists conducted of 105 studies; all 11 of industry researchers' studies found no evidence of harm, while 95 of the independent results showed ill effects.

The California legislature is considering a bill to ban bisphenol-A in products made for children three years and younger.

At the same time, research has shown that antimicrobial products including antimicrobial soaps are also bad for larger organisms.

The researchers found that the combination of chlorinated water and Triclosan produces chloroform. Triclosan is the antimicrobial ingredient used in antimicrobial dish and hand soap, toothpaste, cosmetics, deodorants, medical implants, kitchen tiles, children's toys, cutting boards, hot tubs and clothing.

Chloroform has been linked with human bladder cancers and miscarriages and is classified as a probable human carcinogen by the Environmental Protection Agency. Most cities add chlorine to tap water to kill bacteria.

The research also suggests that in the presence of sunlight, the reaction could also produce chlorinated dioxins, which are toxic.

Further resources:
Home page
of University of Missouri researcher Frederick vom Saal, who carried out the low-dose bisphenol-A survey.
News story
from the journal Environmental Science and Technology about the antimicrobial soap research.

Tuesday 4-26-05

Seeing how you think

It will be a long time, if ever, before anyone will be able to tap into anyone else's internal dialogue, but scientists are beginning to read minds. Researchers working with brain scan equipment are quickly uncovering clues about how we think.

One group monitored the brain activity of people playing an investor/trustee game to identify a neural signal in the caudate nucleus (image) that indicates a person's intention to trust the other player.

Another group confirmed that the ventrolateral prefrontal cortex has to do with planning to move a hand or other limb.

A third group made simultaneous recordings of the activity of as many as 250 individual neurons in the hippocampus regions of live mice to find patterns, or basic coding units, within the activity that have to do with how memories are stored.

And a pair of research groups have shown that brain scans can be decoded to discover what a person has seen.

The first group trained a computer program to recognize differences in brain activity depending on the orientation of parallel sets of stripes a person is looking at. The second group showed that it was possible to decipher subliminal information that the person does not consciously know about.

This last finding is a bit eerie. Using a person's brain activity readings to determine what image was flashed quickly on the screen in front of that person's eyes turned out to be more accurate than the person's recollection of the event. When a pair of images were flashed quickly enough, the people only recalled seeing the second one, but the researchers were able to use the brain activity to identify the first image.

Wednesday 4-20-05

Weird fields and beyond

The results from MIT's annual Weird Fields contest are in. The competitors -- students taking the undergraduate course Introduction to Electricity and Magnetism -- plug mathematical expressions describing electromagnetic fields into a computer program that renders the field visually. The winner is the student whose mathematical expression produces the most striking electromagnetic field image.

Clockwise from top left:
winner, George Zaidan
first runner-up, Dan Yuan
second runner-up, Brian Malley

The winning images from this year and last year are also on display at the MIT Museum.

You can also do the coursework to learn how to use the simulator and produce your own weird fields images.

Here's a brief tour of other sites that display some of science's many beautiful and intriguing images:

Science Magazine and the National Science Foundation's Science and Engineering Visualization Challenge
The Wellcome Trust's Sciart 2004
MIT research scientist and photographer Felice Frankel
The Science Photo Library
Novartis Pharmaceuticals and The Daily Telegraph's Visions of Science contest


Wednesday 4-13-05

Damage done

There's more bad news on the human-damage-to-the-earth front.

According to a study by the Millennium Ecosystem Assessment, humans have, in the past 50 years polluted or over-exploited two-thirds of the ecological systems life depends on, including air and water. The study, the most wide-ranging look at the planet's life-support systems to date, was coordinated by the United Nations Environment Programme, and carried out by 1,360 experts from organizations including United Nations agencies United Nations Foundation, United Nations Development Programme and United Nations Educational, Scientific and Cultural Organization, and the World Health Organization, the Smithsonian National Museum of Natural History, the Chinese Academy of Sciences, Stanford University, the University of Wisconsin, the University of Cambridge, and the University of Oxford.

The damage is mostly due to human demand for food, fresh water, timber, fiber and fuel, and includes deforestation, nitrogen runoff, and global warming. The strain on earth's resources has sparked a substantial and largely irreversible loss in biological diversity and is responsible for triggering abrupt changes like the collapse of fisheries.

The study pointed to changes that could limit the damage: changes in consumption patterns, better education, new technology and higher prices for exploiting ecosystems.

The study estimated that many ecosystems retain more value if maintained.

A wetland in Canada, for instance is worth $6,000 a hectare if it is able to support plants and animals, filter pollution, store water and act as a human recreation site. When converted to farmland the same hectare is worth $2,000. Similarly, a Thai mangrove worth $1,000 a hectare drops to $200 a hectare as a shrimp farm.

Wednesday 4-6-05


Blue-green neurotoxin

Here's yet another thing to worry about -- pond scum.

Researchers have found that species of all five major types of cyanobacteria, or blue green algae, produce a toxin that has been associated with several types of neurodegenerative diseases, including Alzheimer's. Ninety-five percent of the 30 different genre of cyanobacteria the researchers studied produced the neurotoxin -N-methylamino-L-alanine (BMAA), according to the study.

Cyanobacteria are abundant and ancient organisms. Algal blooms are fueled by various sources of pollution, including sewage and fertilisers, and by higher water temperatures caused by global warming.






Monday 4-4-05

Eating the seed corn

It looks like funding for basic research is in decline.

Association for Computing Machinery President David Patterson, in an April 2005 letter to members, pointed out that funding from the Defense Advanced Research Projects Agency (DARPA) to the four most highly rated U.S. computer science departments has dropped sharply over the last five years: the University of California at Berkeley received 38 percent less funding in 2004 than 1999, Carnegie Mellon University 41 percent less, the Massachusetts Institute of Technology 54 percent less, and Stanford University 46 percent less.

This comes at a time when industry-funded long-term research and development is also sparse, according to Patterson. "The world has changed since the heady days of the 1970s that laid the foundation of 20th-century [information technology]," he wrote. "While the industry has expanded dramatically, and many IT companies spend billions on research and development, little is for long-term research... many of the newer companies that expanded IT... do not make any significant investment in research and development that looks forward more than one product cycle."

Over the past few years TRN reporters have received many unsolicited comments about the lack of funding for basic research. Earlier this year, Penn State University electrical engineering and materials science and engineering professor Craig Grimes' added the following comment after answering a reporter's question about how soon practical implementations of his research could be technically possible:

"If you look at the... administration's funding for the hydrogen economy, it's a classic example of the trickle down theory. By the time the funding trickles down to the people doing research there isn't much to speak of. Maybe 5 minutes worth of our nation's Iraq adventure."

The 2005 fiscal year budget for the federal Hydrogen Fuel Initiative is $227 million, of which the Department of Energy awarded $75 million in research grants. The U.S. military is spending about 1,000 times that -- $5.8 billion per month -- in Iraq and Afghanistan. The DOE research grants work out to just under 10 hours, or just under half a day, of the war costs.

Grimes' research team is using nanotechnology techniques to construct a material that uses energy from the sun to extract hydrogen fuel from water (See Nanotubes crank out hydrogen).

Basic computer science research has paved the way for many technologies in common use today, including the graphical user interface, the Internet, and search engines.

To get a sense of the scope and types of basic and applied computer science projects funded by DARPA, search the TRN archive for "DARPA" and "computer science". You get 235 stories from the last five years. The same search in Google Scholar turns up 18,200 research papers. A quick scan of the Google results shows that about 80 percent of these are DARPA-funded computer science research projects.

Other resources: story about computer science research funding decline in the the April 2nd New York Times. Slashdot discussion of the issue.

Tuesday 3-22-05

Swelling seas

Research data about climate change is coming in thick and fast, and the news is not good for land animals. It is clear that ocean warming and sea level rise lag behind climate warming, but it has been difficult to predict the details of this complex system. A pair of studies from the National Center for Atmospheric Research show that there is a 300 year lag between atmospheric changes and ocean changes.

Scientists used a pair of complex global climate models run on supercomputers to show that even if greenhouse gas atmospheric levels had been stabilized in the year 2000 the global average temperature would increase by half a degree Celsius in the next hundred years -- the same increase as that over the last century. Worse, the increase in sea level would double to 11 centimeters due just to thermal effects -- warmer water taking up more space. The separate effects of melting glaciers would increase the sea level rise by about the same amount. The model showed the global average temperature stabilizing around the year 2100, but, due to the ocean lag, water continuing to expand for the next 200 years.

When the scientists ran the models assuming the world's current greenhouse gas emissions were to continue the global temperature increased between 2 and 6 Celsius and the thermal effect sea level rise averaged 25 centimeters per century.

An earlier report from the Intergovernmental Panel on climate change estimates that the business-as-usual global warming scenario will increase the sea level by 18 centimeters by 2030 and 44 centimeters by 2070.

National Oceanic and Atmospheric Administration (NOAA) researchers organize the physical effects of sea level rise into 5 categories: inundation of full-line areas, erosion of beaches and bluffs, salt intrusion into aquifers and surface waters, higher water tables, and increased flooding and storm damage.

Here are some related facts:

    Beach erosion happens two orders of magnitude faster than the rate of sea level rise.
    A rise of 50 centimeters would put somewhere between 3,300 and 7,000 square miles of the United States underwater, double its floodplain, and inundate half its wetlands.
    About 100 million people live on land that is one meter or less above sea level.
    About 40 percent of the world's population live within 100 kilometers of the coast.

It looks like the political lag on global warming will be costly.

The National Center for Atmospheric Research press release provides more details about the climate models and supercomputers used in the studies.

Monday 3-14-05

Born to talk

Providing more evidence that the human brain is primed for language, researchers have described a sign language that emerged spontaneously among deaf Bedouins in the Negev Desert in Israel. Within one generation the language evolved a consistent grammar. The grammar -- in particular word order -- is different enough from nearby languages to indicate that it developed independently.

If humans have an innate grammar, Broca's area, which is associated with speech and language understanding, is a likely source.

Tuesday 3-1-05

Weighty matters

Scientists from the U.S., Britain and France have proposed that the kilogram, a random measure officially represented by a cylinder of metal housed at the Bureau International des Poids et Mesures near Paris, be replaced by a more precise measure based on natural phenomena like a quantity of light or atoms.

The proposal has precedence -- the other six of the seven basic units of the international measurement system are defined by natural phenomena. The second, for instance, is defined as 9,192,631,770 cesium atom oscillations, while the meter is defined as the distance light travels in a vacuum in a 299,792,458th of a second. In contrast to these unchanging definitions that can theoretically be measured anywhere, the kilogram cylinder, a physical object available only a single physical location, is subject to slight mass changes due to contamination or surface loss.

In other precision-measurement news, physicists, engineers and statisticians at the National Institute of Standards and Technology are nearing the end of a four-year effort to provide standard rulers for the extremely small. The rulers use the spacing of atoms within silicon crystals to measure the dimensions of structures as tiny as the individual logic gates of microprocessors. The new rulers are accurate to within 2 nanometers -- about the span of 20 hydrogen atoms.

At the same time, NIST is aiming even smaller with an atomic force microscope calibration tool designed to be as accurate as 0.4 nanometers.





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