The method, published in the May 4 issue of Nature Nanotechnology, enables more precise shaping of microchip components than what is possible with current technology. More precise component shapes could help manufacturers build smaller and better microchips, the key to more powerful computers and other devices.

“We are able to achieve a precision and improvement far beyond what was previously thought achievable,” said electrical engineer Stephen Chou, the Joseph C. Elgin Professor of Engineering, who developed the method along with graduate student Qiangfei Xia. Chou’s lab has previously pioneered a number of innovative chip making techniques, including a revolutionary method for making nanometer-scale patterns using imprinting.

Microchips work best when the structures fabricated on them are straight, thin and tall. Rough edges and other defects can degrade or even ruin chip performance in most applications. In integrated circuits, for instance, such flaws could cause current to leak and voltage to fluctuate. In optic devices, they could interfere with the transmission of light. In biological devices, they could impede the flow of DNA and other biomaterials.

“These chip defects pose serious roadblocks to future advances in many industries,” Chou said.

To deal with this problem, researchers try to improve the process used to make the microchips. However, Chou said such an approach works only to a point; eventually chip makers will run up against fundamental physical limits of current manufacturing techniques. In particular, the electrons and photons that are used like chisels to carve out the microscopic features on a chip always have some random behavior. This effect becomes pronounced at very small scales and limits the accuracy of component shapes.

“What we propose instead is a paradigm shift: Rather than struggle to improve fabrication methods, we could simply fix the defects after fabrication,” said Chou. ???And fixing the defects could be automatic — a process of self-perfection.???

Chou’s method, termed Self-Perfection by Liquefaction (SPEL), achieves this by melting the structures on a chip momentarily, and guiding the resulting flow of liquid so that it re-solidifies into the desired shapes. This is possible because natural forces acting on the molten structures, such as surface tension — the force that allows some insects to walk on water — smooth the structures into geometrically more accurate shapes. Lines, for instance, become straighter, and dots become rounder.

Simple melting by direct heating has previously been shown to smooth out the defects in plastic structures. This process can’t be applied to a microchip, for two reasons. First, the key structures on a chip are not made of plastic, which melts at temperatures close to the boiling point of water, but from semiconductors and metals, which have much higher melting points. Heating the chip to such temperatures would melt not just the structures, but nearly everything else on the chip. Secondly, the melting process would widen the structures and round off their top and side surfaces, all of which would be detrimental to the chip.

Chou’s team overcame the first obstacle by using a light pulse from so-called excimer laser, similar to those used in laser eye surgery, because it heats only a very thin surface layer of a material and causes no damage to the structures underneath. The researchers carefully designed the pulse so that it would melt only semiconductor and metal structures, and not damage other parts of the chip. The structures need to be melted for only a fraction of a millionth of a second, because molten metal and semiconductors can flow as easily as water and have high surface tension, which allows them to change shapes very quickly.

To overcome the second obstacle, Chou’s team placed a plate on top of the melting structures to guide the flow of liquid. The plate prevents a molten structure from widening, and keeps its top flat and sides vertical, Chou said. In one experiment, it made the edges of 70 nanometer-wide chromium lines more than five times smoother. The resulting line smoothness was far more precise than what semiconductor researchers believe to be attainable with existing technology.

The conventional approach to fixing chip defects is to measure the exact shape of each defect, and provide a correction precisely tailored to it — a slow and expensive process, Chou said. In contrast, Chou’s guided melting process fixes all defects on a chip in a single quick and inexpensive step. “Regardless of the shape of each defect, it always gets fixed precisely and with no need for individual shape measurement or tailored correction,” Chou said.

One of the big surprises from this work is observed when the guiding plate is placed not in direct contact with the molten structures, but at a distance above it. In this situation, the liquid material from the structures rises up and reaches the plate by itself, causing line structures to become taller and narrower — both highly desirable outcomes from a chip design perspective.

“The authors demonstrate improved edge roughness and dramatically altered aspect ratios in nanoscale features,” said Donald Tennant, director of operations at the NanoScale Science and Technology Facility at Cornell University. The techniques “may be a way forward when nanofabricators bump up against the limits of lithography and pattern transfer,” he said.

Next, Chou’s group plans to demonstrate this technique on large (8-inch) wafers. Several leading semiconductor manufacturers have expressed keen interest in the technique, Chou said.

[Steven Schultz @ Princeton University Engineering School]

“People concerned with the effects of gas prices were significantly less attentive on the job, less excited about going to work, less passionate and conscientious and more tense,” Hochwarter said. “These people also reported more ‘blues’ on the job. Employees were simply unable to detach themselves from the stress caused by escalating gas prices as they walked through the doors at work.”

Hochwarter gleaned the information by surveying more than 800 full-time employees this spring when gas prices hovered at about $3.50 per gallon. All of the people surveyed work in a wide range of occupations, primarily in the southeastern United States. All drove personal transportation to work and had an average commute of 15 miles each way.

Survey respondents said gas prices were foremost on their mind, including a disgruntled factory worker who wrote, “I spend more time at work trying to figure out what I need to give up to keep gas in my tank than thinking about how to do my job.”

Hochwarter’s research will be submitted for publication later this summer. Among his findings:

• 52 percent have reconsidered taking vacations or other recreational activities

• 45 percent have had to cut back on debt-reduction payments, such as credit card payments
• Nearly 30 percent considered the consequences of going without basics including food, clothing and medicine
• 45 percent report that the escalating gas prices have “caused them to fall behind financially”
• 39 percent agreed with the statement “Gas prices have decreased my standard of living”
• About 33 percent — or one in three — said they would quit their job for a comparable one nearer to home

Hochwarter’s discussions with employees confirm the study’s results. Many employees report that gas prices rank as the No. 1 water-cooler discussion topic, ahead of family, sports or work, he said. He found little difference in responses among different ages, gender, work tenure and occupations.

“Several employees said they simply could not escape the media onslaught of bad news regarding the future of gas prices, and many reported their financial futures were looking bleaker and bleaker,” Hochwarter said.

As gas prices rise, so does the stress. Consider the words of Sandy, a medical records clerk: “The more it goes up, the more behind I get. If gas goes up to $5 or $6 a gallon, I just don’t know what I’ll do.”

[Wayne Hochwarter @ Florida State University]

Among the most important and complex molecules in the human body, sugars control not just metabolism but also how cells communicate with one another. Graduating senior Jeffery Martin has put his basic knowledge of sugars to exceptional use by creating a lab-on-a-chip device that builds complex, highly specialized sugar molecules, mimicking one of the most important cellular structures in the human body — the Golgi Apparatus.

“Almost completely independently he has been able to come closer than researchers with decades more experience to creating an artificial Golgi,” said Robert Linhardt, the Ann and John H. Broadbent Jr. ‘59 Senior Constellation Professor of Biocatalysis and Metabolic Engineering at Rensselaer and Martin’s adviser. “He saw a problem in the drug discovery process and almost instantly devised a way to solve it.”

Cells build sugars in a cellular organelle known as the Golgi Apparatus. Under a microscope, the Golgi looks similar to a stack of pancakes. The strange-looking organelle finishes the process of protein synthesis by decorating the proteins with highly specialized arrangements of sugars. The final sugar-coated molecule is then sent out into the cell to aid in cell communication and to help determine the cell’s function in the body.

Martin’s artificial Golgi functions in a surprisingly similar way to the natural Golgi, but he gives the ancient organelle a very high-tech makeover. His chip looks similar to a miniature checker board where sugars, enzymes, and other basic cell materials are suspended in water and can be transported and mixed by applying electric currents to the destination squares on the checker board. Through this process sugars can be built in an automated fashion where they are exposed to a variety of enzymes found in the natural Golgi. The resulting sugars can then be tested on living cells either on the chip or in the lab to determine their effects. With the chip’s ability to process many combinations of sugars and enzymes, it could help researchers quickly uncover new sugar-based drugs, according to Martin.

Scientists have known for years that certain sugars can serve as extremely beneficial therapeutics for humans. One well-known example is heparin, which is among the most widely used drugs in the world. Heparin is formed naturally in the Golgi organelle in cells of the human body as well as in other animals like pigs. Heparin acts as an anticoagulant preventing blood clots, which makes it a good therapeutic for heart, stroke, and dialysis patients.

The main source of heparin is currently the intestines of foreign livestock and, as recent news reports highlight, the risk of contamination from such sources is high. So researchers are working around the clock to develop a safer, man-made alternative to the drug that will prevent outside contamination. A synthetic alternative would build the sugar from scratch, helping eliminate the possibility of contamination he explained.

“I am very grateful to have the privilege of working with Dr. Linhardt who has discovered the recipe to make fully synthetic heparin,” Martin said. “Because we know the recipe, I am going to use it as a model to test the device. If our artificial Golgi can build fully functional heparin, we can then use the artificial organelle to produce many different sugar variants by altering the combination of enzymes used to synthesize them. Another great thing about these devices is that they are of microscale size, so that if needed we could fill an entire room with them to increase throughput for drug discovery.”

There are millions of possible sugar combinations that can be formed and scientists currently only know the function of very few of them like heparin. “Since it is known that these types of sugars play a part in many important biological processes such as cell growth, cell differentiation, blood coagulation, and viral defense mechanisms, we feel that that this artificial Golgi will help our team to develop a next generation of sugar-based drugs, known as glycotheraputics,” Martin said. “We are going to start making new combinations and we simply don’t know what we are going to find. We could find a sugar whose signal blocks the spread of cancer cells or initiates the differentiation of stem cells. We just don’t know.”

Martin, a Barry M. Goldwater Scholar and native of the small town of Boylston, Mass., is graduating from Rensselaer on May 17, 2008 with a nearly perfect GPA. He plans to continue on at Rensselaer as a graduate student, working with Linhardt to test and further develop his artificial Golgi.

[Gabrielle DeMarco @ Rensselaer Polytechnic Institute]

The new study is led by Lothar Stramma from the Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel, Germany, and is co-authored by Janet Sprintall, a physical oceanographer at Scripps Oceanography and others. The researchers found through analysis of a database of ocean oxygen measurements that levels in tropical oceans at a depth of 300 to 700 meters (985 to 2,300 feet) have declined during the past 50 years. The ecological impacts of this increase could have substantial biological and economical consequences.

“We found the largest reduction in a depth of 300 to 700 meters (985 to 2,300 feet) in the tropical northeast Atlantic, whereas the changes in the eastern Indian Ocean were much less pronounced,” said Stramma. “Whether or not these observed changes in oxygen can be attributed to global warming alone is still unresolved. The reduction in oxygen may also be caused by natural processes on shorter time scales.”

Sprintall said the oxygen-poor areas have the potential to move into coastal areas via currents that flow from the mid-depth tropical oceans, where the oxygen changes were observed, and along the west coast of continents.

“The width of the low-oxygen zone is expanding deeper but also shoaling toward the ocean surface,” said Sprintall, a specialist in observing changes of fluxes in ocean properties such as heat distribution.

Sprintall contributed data to the study gathered during recent cruises undertaken as part of the Climate Variability and Predictability (CLIVAR) program, a long-running study operated by the World Climate Research Programme that seeks to understand climate through ocean-atmosphere interactions.

The study, “Expanding Oxygen-Minimum Zones in the Tropical Oceans,” appears in the May 2 edition of the journal Science. The research team includes Stramma, Sprintall, NOAA scientist Gregory Johnson, and Volker Mohrholz from the Institute for Baltic Sea Research in Warnem??nde, Germany.

The team selected ocean regions for which they could obtain the greatest amount of data to document the decline in oxygen. Some of the more recent data came from oxygen sensors which have been added to about 150 of the profiling floats used in Argo, a worldwide network of sensors that track basic ocean conditions such as temperature and salinity. There are more than 3,000 Argo floats operating in the world’s oceans, and Sprintall said the quality of the data gathered by the Argo floats suggests that more units in the network should be outfitted with oxygen sensors.

Lisa Levin, a biological oceanographer at Scripps Oceanography who studies oxygen-minimum zones that intercept the seafloor, said an expansion of oxygen-minimum zones in the oceans could lead to diminished biodiversity and to the expanded distributions of organisms that have adapted to live in hypoxic, or oxygen-poor waters.

“I think it’s uncharted territory,” said Levin, who was not affiliated with the study. “Thicker oxygen minimum zones could affect nutrient cycling, predator-prey relationships and plankton migrations. Where the expanding oxygen-minimum zones impinge on continental margins, we could see huge ecosystem changes.”

[Rob Monroe and Mario Aguilera @ UC San Diego]

Frasier Crane and his brother, Niles, both practiced psychiatry on their popular NBC sitcom “Frasier.” Mob boss Tony Soprano had his therapist on HBO’s hit show “The Sopranos.” And HBO has even made therapy the focus of two recent shows — “Tell Me You Love Me” and “In Treatment.”

But all of these TV portrayals may actually make viewers less likely to seek psychological services themselves. That’s according to a new study by three Iowa State University psychologists.

ISU psychology professors David Vogel and Douglas Gentile collaborated with graduate student Scott Kaplan on the study of 369 Iowa State students. It explored how exposure to television shows may contribute to negative perceptions about psychological services that can lead to lower intentions to seek such services. They produced a paper titled “The Influence of Television on Willingness to Seek Therapy,” which was published in the March issue of the Journal of Clinical Psychology, a professional journal.

Unflattering portrayals of mental health professionals

Kaplan has conducted a related content analysis on television portrayals of mental health professionals. It found that they’re not favorable.

“Generally, it seems like therapists are portrayed unethically — like sleeping with the client, or implanting false memories, or talking about their clients outside the session,” Vogel said. “These are things that almost never happen with real therapists, but on a show — because they’re probably more exciting — they happen more frequently.”

“Therapists also often are portrayed as buffoons,” Gentile said. “That’s either by being the jokester, like Frasier, or by being the butt of jokes. In either case, these are not positive portrayals. They do not show the skill, expertise and ethics of professional therapists.”

But it’s not just the portrayal of the therapists that may be keeping people out of therapy. It’s also the portrayal of those who seek counseling on TV.

“If you examine the portrayal of the clients, it’s probably as bad or worse,” Vogel said. “So why would you seek therapy if you believe you’re going to be perceived negatively and you’re going to see someone who’s incompetent and not able to help you?”

Because dramas and comedies are the two types of shows that often portray psychologists and psychotherapy, the ISU psychologists asked respondents how often they watched TV comedy and drama shows. They also asked them to assess perceptions of the stigma associated with seeking professional help, attitudes toward therapy, their intentions to seek therapy for psychological and interpersonal concerns, and their feelings of depression.

TV ties to therapy stigma

The study found a positive correlation between viewers’ exposure to comedy and drama shows and their perceptions of stigma associated with seeking professional help. This stigma was then related to lower willingness to seek professional mental health services.

“One of the things that’s important to note about this particular study is that we showed that TV exposure was related to your perceptions of the stigma associated with seeking help, which has been found to be one of the main factors found from inhibiting people from seeking that help,” Vogel said. “So you perceive that yourself, and other people, would be crazy to go (to therapy).”

That’s a problem for those people who could really benefit from professional mental health services. According to Vogel, the most recent studies in the mental health field have found that about half of population experiences a situation in their lives where psychological therapy could be helpful — about 20 percent in a single year. But in a given year, only about 10 percent of the people who could benefit from therapy will seek help from a psychologist or other mental health professional.

“Mental health services are already vastly underutilized, and this cultural stigma is part of the reason,” Gentile said. “And this study suggests that this cultural stigma exists partly because of the way that psychologists and their patients are portrayed on television.”

[Mike Ferlazzo @ Iowa State University]