10.15.08

Eyeing the Biological Clock

Posted in Biology at the University of Virginia, Body Clock, Jacob Canon, Nocturnin, Sleep, The Oscar Show, UVa College of Arts & Sciences, University of Virginia, biology, circadian rhythms, metabolism, nervous system, neurophysiology, physical health, physiology, sensory inputs, stress, visual processing at 11:04 am by Jacob Canon

In today’s show, adapted from an article written by Fariss Samarrai,  Senior News Officer for the Office of Public Affairs, we will look at a team of UVa researchers who have discovered a switching mechanism in the eye that plays a key role in regulating the sleep/wake cycles in mammals.

Biologists at the University of Virginia have discovered a switching mechanism in the eye that plays a key role in regulating the sleep/wake cycles in mammals.  The new finding demonstrates that light receptor cells in the eye are central to setting the rhythms of the brain’s primary timekeeper, the suprachiasmatic nuclei, which regulates activity and rest cycles. The finding appears in the current issue of the Proceedings of the National Academy of Sciences.

Susan Doyle, a research scientist at U.Va. and the study’s lead investigator said, “The finding is significant because it changes our understanding of how light input from the eye can affect activity and sleep patterns.”

Funded by the National Institute of Mental Health, Doyle conducted her research with colleagues Tomoko Yoshikawa, a visiting scholar from Japan, and UVa undergraduate student Holly Hillson, in the laboratory of Michael Menaker, a leading researcher in the study of circadian rhythms.

Biological clocks are the body’s complex network of internal oscillators that regulate daily activity/rest cycles and other important aspects of physiology, including body temperature, heart rate and food intake.

The investigators did this by both reducing the intensity of light given to normal mice and also creating a mutated line of mice with reduced light sensitivity in their eyes, which rendered them fully active in the day but inactive at night, a complete reversal of the normal activity/rest cycles of mice.

The researchers discovered that they could reverse the “temporal niche” of mice—meaning that the animals’ activity phase could be switched from their normal nocturnality, or night activity, to being diurnal, or day active.

Doyle said, “This suggests that we have discovered an additional mechanism for regulating nocturnity and diurnity that is located in the light input pathways of the eye.  The significance of this research for humans is that it could ultimately lead to new treatments for sleep disorders, perhaps even eye drops that would target neural pathways to the brain’s central timekeeper.”

An estimated one in six people in the United States suffer from sleep disorders, including insomnia and excessive sleepiness. And as the U.S. population ages, a growing number of people are developing visual impairments that can result in sleep disorders.

Besides sleep disorders, research in this field may eventually help treat the negative effects of shift work, aging and jet lag. Doyle said, “Currently, one in 28 Americans age 40 and over suffer from blindness or low vision, and this number is estimated to double in the next 15 years.  Our discovery of the switching mechanism in the eye has direct relevance with respect to the eventual development of therapies to treat circadian and sleep disorders in the visually impaired.”

You’ve been listening to the Oscar Show, I’m Jacob Canon. Join us next week when we look at the University of Virginia’s Kath Weston and the journey that led to her new book, Traveling Light: On the Road with America’s Poor.

Permalink Comments

09.03.08

Energy Efficient Smart Climate Controls

Posted in Energy, The Oscar Show, UVa College of Arts & Sciences, University of Virginia, climate, efficiency, electricity, environmental conditions, fuel costs, sensory inputs, technology, visual processing at 11:04 am by Jacob Canon

In today’s show, adapted from an article written by Brevy Cannon, general assignment writer for UVa’s Office of Public Affairs, we discuss the research of Ron Williams, a professor of electrical and computer engineering, and his teams research of how to make more intelligent climate control systems, to aid in energy efficiency.

It’s not a new energy-saving concept to turn down your thermostat at night, or leave your air conditioner off when no one is home. A research team plans to take that concept to the next level by using automated sensors and sophisticated software to enable heating and cooling systems to respond to the number of occupants in a room at any given time.

The research team, which recently won a new UVa Collaborative Sustainable Energy Seed Grant worth about $30,000 to investigate how to make more intelligent climate control systems, includes Ron Williams, a professor of electrical and computer engineering, fellow electrical and computer engineer Paxton Marshall, John Quale, an assistant professor of architecture and director of UVa’s ongoing ecoMOD project, which involves studies of the energy efficiency of modular housing prototypes, and Cheryl Gomez, UVa’s director of utilities.

Williams said, “The volume of outside air that must be heated or cooled when 20 people are in a room is double that needed for 10, opening the possibility of significant energy savings from a climate control system that can respond to occupancy.” The most cost-effective measures to ensure adequate energy supplies and reduce greenhouse gas emissions come from energy conservation rather than new energy technologies.

Williams went on to say, “the idea of “intelligent building control” has been around since the 1970s. Only in recent years have computers and networking technology become so powerful and inexpensive that they could potentially be widely implemented in buildings at costs that could be justified in energy savings. Because the overall electric supply system is only about 33 percent efficient from fuel to end use, a one-unit reduction in consumption saves three units of new energy supply.

Williams has estimated that occupant-sensing technology could produce as much as a 9 percent energy savings during the heating season, but said he would be happy with even 2 to 3 percent energy savings.

To help keep down the cost of such systems, the U.Va. research team will create a sophisticated, but simple-to-customize, computer model of a building space that accounts for how the occupants and outside temperatures impact heating and cooling needs.

The team will monitor one University space, a student activity room called “The Forum” in the Observatory Hill Dining Hall, seeking to better match the amount of heating and cooling of the space to the precise number of occupants, without diminishing their perceived comfort.

Williams said, “the schedule of reservations for the room will be used as a starting point for predicting occupancy.” The team will install sensors — probably video cameras with image recognition software — to detect the comings and goings of people.

The team will correlate the occupancy data; predicted and actual, with measurements of air temperatures; inside and outside, air flows and electricity usage, to gradually improve their software model and controls.

The detecting poses several challenges, since people often come and go through the double doors in large groups and clumps, sometimes in both directions at once. Williams said, “it’s straightforward engineering, but — like the iPod — there are a lot of little problems that have to be overcome to make it all come together.I actually view this is as more of an embedded computing and information management problem rather than an energy management problem.”

Gomez said that she hopes that energy savings realized by this research can eventually be implemented more widely around Grounds. About one-third of the University’s 13.3 million square feet of space (in about 550 buildings) has been built or renovated since 1999, meaning the climate control systems are modern enough that they would benefit from intelligent building controls. In much of the rest, the heating and cooling systems are antiquated or in need of upgrades and would be largely unresponsive to short-term thermostat changes.

Gomez went on to say, “this problem has not yet been addressed aggressively, other “lower hanging fruit” offered more energy savings for lower costs, like installing fluorescent bulbs, LEDs and low-flow fixtures across Grounds… reducing climate control costs may be one of the next targets for saving energy at UVa.”

You’ve been listening to the Oscar Show, I’m Jacob Canon. Join us for our next show, when we will well discuss the research of Silvia Salinas Blemker, an assistant professor of mechanical and aerospace engineering, trying to identify reasons and mechanics of hamstring pulls.

Permalink Comments

02.06.08

Locked-In Syndrome

Posted in Cognitive Science, Jacob Canon, The Oscar Show, UVa College of Arts & Sciences, Uncategorized, University of Virginia, nuerology, physical health, physiology, sensory inputs, technology, visual processing at 12:06 pm by Jacob Canon

In today’s show, adapted from an article published on the Oscar web site written by Linda Kobert, we examine the work of Dennis Proffitt, Professor and Director of the Cognitive Science Program, whose research focuses on creating computer interfaces to help make life more bearable for patients with ALS and other diseases that are the cause of locked-in syndrome.

Up to now, the most iconic connection to Amyotrophic Lateral Sclerosis or Lou Gehrig’s disease, is the famous farewell in Yankee stadium By Mr. Gerhig. Forced to retire from baseball, the profession he loved and was best known for, he became the personification of this devastating disease.

In 2002, Peggy Chun, a popular artist was diagnosed with ALS. This debilitating neurological disorder progressively destroys a person’s motor neurons. As a victim of this incurable disease, Chun can feel, see, smell, taste, think and imagine, but she can no longer move in any way. She is, in the parlance of the medical profession, “locked-in.” ALS is the most frequent cause of locked-in syndrome, which begins with numbness in the extremities and progresses upward until all motor function disappears.

Usually the last thing you lose is eye movement,” says Dennis Proffitt, U.Va. cognitive psychologist and Commonwealth Professor of Psychology. “When you lose that, you are cognitively alert, you can think, you can feel, but you can’t move a thing. As a result, you can’t communicate in any way. It’s awful.”

Funded by the National Science Foundation, Proffitt, his colleagues at Georgia Tech and a company called Archinoetics in Hawaii are working to develop computer interfaces that may one day make life for locked-in patients more bearable.

Scientists know different parts of the brain are activated when a person performs different functions. For example, moving the left arm activates an area on the right side of the brain, the back of the brain is active with visual imagery and the frontal lobe is active when one tries to focus attention on something. Proffitt’s system simply detects whether or not a particular area of the brain is actively engaged at the time.

With this in mind, researchers are currently testing a technology that allows Chun and other locked-in patients to answer simple yes/no questions. An interface using functional near infrared imaging (fNIR) assesses activity in Broca’s area, a part of the brain where verbal working memory occurs. They strap a device, just above the left ear that projects a light beam through the skull measuring changes in blood volume and oxygenation when Broca’s area is engaged.

With the device in place, subjects are asked to count in their head when they want to activate the verbal working memory and initiate a “yes” response. When they want to say “no,” subjects think of clouds or rest or think “la la la.” It’s a process that most people can engage easily without having to spend a long time training to do it.

Proffitt said, “it was hard for us to think of something we could ask a person to do — something easy to control, something you can turn on and off — that we could measure in this way. What we came up with was sub-vocal speech … talking to yourself. You could be counting, or you could be reciting a poem. We couldn’t tell the difference. We have no idea what you’re doing. We just know the kind of thing you’re doing.”

He stresses, “It’s not reading your thoughts, we can’t do that.”

Proffitt admitted, “at this time the system is primitive, but it’s a start. Right now it’s an on/off switch. What we want to do is to get continuous control so the person is not just activating … Not just ‘yes’ or ‘no,’ but small to large, continuous control within some range. If we could achieve that in the next few years, that would be a huge improvement in what we will be able to do with the technology.”

For the half million people in the world with locked-in syndrome, having the ability to communicate, even in this primitive fashion, can make the difference between suffering in silence and a meaningful life.

But Peggy Chun isn’t waiting for the technology to evolve. This future icon of the human spirit refuses to be shut down. She uses the system now as a tool for creativity. With the sensor in place over her left ear, the artist activates Broca’s area to select shades from a palette that show up on a computer screen as horizontal gradations of color. She calls it “brain art,” and it may be simple, but it’s selling like hotcakes.

You’ve been listening to the Oscar Show, I’m Jacob Canon. Join us next week when our topic will be the research of Jared Harris, assistant professor at the University of Virginia’s Darden School of Business concerning business ethics and strategy, as he looks to answer the questions, “What motivates a company to cook the books? And, what happens to businesses that get caught committing financial fraud?”

Permalink Comments

12.13.07

Inside the brain of crayfish

Posted in Biology at the University of Virginia, DeForest Mellon, The Oscar Show, University of Virginia, biology, brain, crustaceans, evolution, nervous system, neurophysiology, sensory inputs, visual processing at 11:37 am by Jacob Canon

Today’s show, from an article published on the Oscar web site written by Fariss Samarrai, we examine lobsters and other crustaceans. What most people think of as food, is being utilized by UVa biology professor DeForest Mellon in his research of how the brain detects, integrates and uses co-joined yet dissimilar sensory inputs.

Imagine you are on a voyage to the bottom of the sea, or simply looking along the bottom of a clear stream observing lobsters or crayfish waving their antennae. Looking closer, you see them feeling around with their legs and flicking their antennules — the small, paired sets of miniature feelers at the top of their heads between the long antennae. While the long antennae are used for getting a physical feel of an area, such as the contours of a crevice, the smaller antennules are there to both help the creature smell and also to sense motion in the water that could indicate the presence of food, a mate or danger. The legs also have receptors that detect chemical signatures, preferably those emanating from a nice hunk of dead fish.

“They constantly flick their antennules,” says DeForest Mellon, a University of Virginia biology professor, “it is doing two things that are processed simultaneously in the brain as he flicks: smelling the water, and also sensing motion in the water, which can indicate the presence of food or other things of interest.” Mellon said, “I’m interested in understanding how these senses are combined and interpreted in the brain of these animals. My question is how does the brain detect, integrate and use these co-joined but dissimilar sensory inputs?”

“We taste food by a combination of senses, taste, aroma, texture and how good that dish looks. This complex process of brain processing is not much different with crustaceans, though their brains are much simpler, which makes them a great study model,” Mellon says. Mellon and other neurophysiology researchers commonly use crustaceans to try to gain basic understanding of the nervous systems of creatures in general. Extrapolating what they find to gain a basic understanding of the much more complex human brain.

Mellon says, “due to the large-sized nerve cells of invertebrates, we can conveniently and practically examine these systems that are largely the same among all creatures, and antennule flicking can serve as a practical model that helps us understand how two or more senses work together in the brain.”

Mellon has been investigating sensory systems for half a century, since his grad school days at Johns Hopkins University. And he’s still learning. Recently Mellon perused the research in the field — his own and that of many other scientists — of the past 45 years or so and published a review of the literature in the August 2007 issue of The Biological Bulletin.

What he’s found is that there is still much to be understood. “It’s fertile ground for ongoing research,” he said. “The size of an area of the brain devoted to a particular sense gives us a good idea of how an animal perceives the world. About 40 percent of a crustacean’s brain is devoted to the sense of smell. This shows how important detecting odors are to the animal.” “Crayfish and lobsters are generally solitary creatures, inhabiting an aquatic environment that is often dark, and they need that highly acute sense of smell.”Humans, by contrast, have less than 1 percent by volume of the brain devoted to interpreting smells, but about 30 percent of the human brain is concerned with visual processing.

Mellon said, “I have always been fascinated by the diversity of animal types and their equally diverse behaviors. Both are genetically based. And through often very subtle adoption of genetic variations in different animals, evolution has arrived at different solutions to common survival problems. This behavioral diversity and the variants in nervous system organization account for why I remain fascinated with biology.”

Permalink Comments