Fixing design bugs and wrong wire connections in computer chips after they’ve been fabricated in silicon is a tedious, trial-and-error process that often costs companies millions of dollars and months of time-to-market.
According to ScienceDaily, engineering researchers at the University of Michigan say it doesn’t have to be that way. They’ve developed a new technology to automate “post-silicon debugging.“
“Today’s silicon technology has reached such levels of small-scale fabrication and of sheer complexity that it is almost impossible to produce computer chips that work correctly under all scenarios,“ said Valeria Bertacco, assistant professor of electrical engineering and computer science and co-investigator in the new technology. “Almost all manufacturers must produce several prototypes of a given design before they attain a working chip.“
FogClear, as the new method is called, uses puzzle-solving search algorithms to diagnose problems early on and automatically adjust the blueprint for the chip. It reduces parts of the process from days to hours.
“Practically all complicated chips have bugs and finding all bugs is intractable,“ said Igor Markov, associate professor of computer science and electrical engineering and another of FogClear’s developers. “It’s a paradox. Today, manufacturers are producing chips that must work for almost all applications, from e-mail to chess, but they cannot be validated for every possible condition. It’s physically impossible.“
In the current system, a chip design is first validated in simulations. Then a draft is cast in silicon, and this first prototype undergoes additional verification with more realistic applications. If a bug is detected at this stage, an engineer must narrow down the cause of the problem and then craft a fix that does not disrupt the delicate balance of all other components of the system. This can take several days. Engineers then produce new prototypes incorporating all the fixes. This process repeats until they arrive at a prototype that is free of bugs. For modern chips, the process of making sure a chip is free of bugs takes as much time as production.
“Bugs found post-silicon are often very difficult to diagnose and repair because it is difficult to monitor and control the signals that are buried inside a silicon die, or chip. Up until now engineers have handled post-silicon debugging more as an art than a science,“ said Kai-Hui Chang, a recent doctoral graduate who will present a paper on FogClear at the upcoming International Conference on Computer-Aided Design.
FogClear automates this debugging process. The computer-aided design tool can catch subtle errors that several months of simulations would still miss. Some bugs might take days or weeks before causing any miscomputation, and they might only do so under very rare circumstances, such as operating at high temperature. The new application searches for and finds the simplest way to fix a bug, the one that has the least impact on the working parts of the chip. The solution usually requires reconnecting certain wires, and does not affect transistors.

The list of health benefits to children who were breast-fed as babies is growing, with research unveiled on Monday showing they are more likely as adults to have higher levels of ’good’ cholesterol.
According to HealthDay, numerous studies have shown babies whose mothers breast-fed them enjoy health advantages over formula-fed babies. These include fewer ear, stomach or intestinal infections, digestive problems, skin diseases and allergies, and less likelihood of developing high blood pressure, diabetes and obesity.
Now, a study presented at an American Heart Association meeting found that breast-fed babies are better off in two important heart disease risk factors as adults than bottle-fed babies--levels of “good“ HDL cholesterol and body mass index.
The study looked at 962 people, average age 41, taking part in the long-running Framingham Heart Study centered on Framingham, Massachusetts. About a quarter of the children were breast-fed for at least a month as babies.
Those who were breast-fed were 55 percent more likely to have high average levels of high-density lipoprotein, or HDL, cholesterol in adulthood than low levels.
Those who were breast-fed on average had a lower body mass index, or BMI, as adults--26.1 compared to 26.9 for the bottle-fed counterparts. Adults with a BMI above 25 are considered overweight and at higher risk for heart disease.
Having a higher HDL is considered protective against cardiovascular disease like stroke and heart attack. People with a lower BMI also are have a risk for cardiovascular disease.
These cholesterol and BMI differences were modest but significant, according to Dr. Nisha Parikh of Beth Israel Deaconess Medical Center in Boston, who led the study.
“The results are intriguing in that they point to this concept that early nutrition or early environmental exposures may affect long-term health,“ Parikh said in an interview.
Breast-feeding was not associated with benefits in other heart disease risk factors that the researchers examined, including total cholesterol and blood pressure.
The mothers of all the people tracked in the research were also part of the Framingham study.

Over-the-counter painkillers such as aspirin and ibuprofen can reduce the risk of Parkinson's disease.

Over-the-counter painkillers such as aspirin and ibuprofen can reduce the risk of Parkinson’s disease, US researchers said.
They found that regular users of such drugs, which ease the pain of arthritis and headaches, were much less likely to have Parkinson’s than non-users or sporadic users, Reuters said.
The drugs, known as non-steroidal anti-inflammatory drugs or NSAIDS, are taken daily by millions of people.
A team from University of California Los Angeles studied 579 men and women from California, half of whom had Parkinson’s disease. They were asked if they had taken aspirin or other NSAIDs such as ibuprofen once a week or more at any point in their life for at least a month.
Those who took two or more pills a week for at least one month were considered regular users.
Acetaminophen, also known as paracetamol, is not an NSAID and does not act in the same way as aspirin, ibuprofen, naproxen and similar drugs.
The researchers found the NSAID users were less likely to have Parkinson’s, especially those using ibuprofen or other non-aspirin NSAIDs.
“Our findings suggest NSAIDs are protective against Parkinson’s disease, with a particularly strong protective effect among regular users of non-aspirin NSAIDs, especially those who reported two or more years of use,“ UCLA’s Angelika Wahner, who worked on the study, said in a statement.
“Given these results and the growing burden of Parkinson’s disease as people age, there’s a pressing need for further studies explaining why these drugs may play a protective role,“ she added.
Women who took aspirin regularly lowered their risk of Parkinson’s disease by nearly 40 percent, Wahner and colleagues reported in the journal Neurology.
“Interestingly, aspirin only benefited women. It may be that men are taking lower doses of aspirin for heart problems, while women may be using higher doses for arthritis or headache,“ Wahner said.
Epidemiologist Beate Ritz, who also worked on the study, said the drugs may prevent damaging inflammation in the brain.

Boys who watch seemingly harmless cartoons or contact sports on TV between the ages of two and five are more likely to be aggressive and disobedient later, a study showed.
“We found the more violent TV children see as preschoolers, the more likely they are to have anti-social behaviors--acting aggressively, disobeying, getting in trouble--at school age,“ said Dimitri Christakis, a lead author of the study, published in the scientific journal, Pediatrics.
“Cartoons are the main culprit,“ he told AFP.
“Most parents consider cartoons not threatening to their children because, after all, they’re not real and they’re just funny. But the truth is that preschool children don’t distinguish between fantasy and reality the way older children and adults do. To them it’s all very real.
“Precisely because cartoon violence is intended to be funny and depicts violence without real consequence--even if people get blown up, they’re black for a second and then return to
normal--it conveys the wrong messages about the effects of violence in the real world,“ Christakis said.
Neither preschool girls who watched violent programs nor children who watched non-violent or educational TV showed aggressive behavior later, the study conducted by researchers at the Seattle Children’s Hospital Research Institute found.
The researchers used data gathered in a 40-year study of 8,000 US families to review what types of programs were watched by 184 boys and 146 girls between the ages of two and five and what behaviors they displayed later.
Programs classed as violent for the study included Power Rangers, Star Wars and American football matches.
Non-violent programs included Toy Story and the Flintstones, while Sesame Street and the Magic School Bus were among the educational shows.
“It’s not just about watching TV, it’s about what children watch,“ Christakis said.
“The take-home message to parents is that they have to be very mindful of what their children watch, and if they’re careful about it, there’s no harm in selective TV viewing.
“If they’re not, there really are risks in terms of children’s behavior,“ Christakis said.

An eight-week regimen of yoga proved safe for patients with chronic heart failure and helped reduce signs of inflammation often linked with death, according to a study.
More than 5 million Americans have chronic heart failure, a long-term condition in which the heart no longer pumps blood efficiently to the body’s other organs, Reuters said.
Health problems and deaths from the disease remain high despite widespread use of effective drug and device therapies to treat the condition.
Researchers at Emory University School of Medicine in Atlanta who measured the effects of an eight-week yoga regimen on 19 heart failure patients found the exercise routine reduced markers of inflammation associated with heart failure while also improving exercise tolerance and quality of life.
“Many people believe the addition of yoga may be beneficial in cardiac rehabilitation,“ said the researchers, whose findings were presented at the annual meeting of the American Heart Association. “Furthermore, it may be that yoga has an impact on the mechanisms of action involved in the progression of heart failure.“
The study found significant differences in levels of biological markers in the blood--interleukin-6, C-reactive protein and extra-cellular superoxide dismutase--between patients who completed the yoga therapy and those who received standard medical therapy. Patients on yoga therapy completed the regimen without complications.
Patients who did yoga saw a 26 percent decrease in symptoms on a standard assessment that measures quality of life in heart failure patients, compared to a 3 percent decrease for the patients on medical therapy alone.
“Yoga is aerobic. It is not surprising, in terms of its effects on the inflammatory markers,“ said Dr. Nieca Goldberg, who prescribes both yoga and tai chi, a Chinese martial art, to her heart failure and heart attack patients.
Goldberg, a professor of medicine at New York University, said heart failure patients often have trouble with exercise due to fatigue and shortness of breath caused by the heart’s reduced pumping ability.
“What’s nice is they found not only does it reduce inflammatory markers, but it is a safe form of exercise and it improves the quality of their lives,“ Goldberg said.

Insufficient sleep can negatively affect preteens’ metabolism as well as their exercise and eating habits, causing them to get fat, researchers reported.
Children aged 9 to 12 who slept less than nine hours a night were more likely to gain weight than their more rested peers, according to researchers at the University of Michigan’s Center for Human Growth and Development, BBC said.
“Many children aren’t getting enough sleep, and that lack of sleep may not only be making them moody or preventing them from being alert and ready to learn at school, it may also be leading to a higher risk of being overweight,“ said Dr. Julie Lumeng, primary author of the report.
In elementary school, children should be getting 10 to 12 hours of sleep a night, according to the National Sleep Foundation.
In a statement released by the school, Lumeng said well-rested children may be more energetic and more likely to go out and play, rather than lying around watching TV. Tired children may seek out food when they become irritable or moody, she added.
But what may be more significant is the effect sleep has on the secretion of hormones that regulate fat storage, appetite and glucose metabolism, she said. Not enough sleep can change carbohydrate metabolism and cause impaired glucose tolerance, which can affect weight, she added.
Her report was published in the November issue of “Pediatrics,“ the journal of the American Academy of Pediatrics.
The findings were based on an analysis of sleep patterns and other data from a government survey of 785 children aged 9 to 12. Eighteen percent were overweight by the time they reached the sixth grade.
The 12-year-olds who slept less than nine hours a night were more likely to be overweight than those who slept more, and those who got less sleep at age 9 were more likely to be overweight three years later, the study found.

This artist's conception shows two white dwarf stars spiraling in toward each other until they collide.

Astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have found that a supernova discovered last year was formed when two white dwarf stars collided. The white dwarfs were siblings orbiting each other. They slowly spiraled inward until they merged, touching off a titanic explosion. CfA observations show the strongest evidence yet of what was, until now, a purely theoretical mechanism for creating a supernova.
“This finding shows that nature may be richer than we suspected, with more than one way to make a white dwarf explode,“ said Harvard graduate student and first author Malcolm Hicken, Astronomy.com said.
Astronomers characterize an observed supernova based on whether its spectrum shows evidence of hydrogen (Type II) or not (Type I). In Type II, a massive, short-lived star undergoes core collapse and explodes. In the conventional picture for Type Ia, the most common supernovae lacking hydrogen, a white dwarf star collects gas from a companion star until it undergoes catastrophic nuclear fusion and blasts itself apart.
The new find, supernova 2006gz, was classified as a Type Ia due to the lack of hydrogen and other characteristics. However, an analysis combining CfA data with measurements from The Ohio State University suggested that SN 2006gz was unusual and deserved a closer look.
Most importantly, SN 2006gz showed the strongest spectral signature of unburned carbon ever seen. Merging white dwarfs are expected to have carbon outside their densest regions. The powerful explosion from the inside then should push off the outmost carbon-rich layers.
The spectrum of SN 2006gz also showed evidence for compressed layers of silicon. Silicon was created during the explosion and then compressed by a shock wave that rebounded from the surrounding layers of carbon and oxygen. Computer models for merging white dwarfs predict both the carbon and silicon spectral signatures.
Additionally, SN 2006gz was brighter than expected, indicating that its progenitor exceeded the 1.4 solar mass Chandrasekhar limit--the upper bound for a single white dwarf. Only one other potential example of a super-Chandrasekhar supernova has been seen: SN 2003fg. While observations of that event were suggestive, the data from SN 2006gz are much stronger.
“Our case is different. Although 2006gz is also extra bright, the chemistry we see, particularly unburned carbon, is well observed and very unusual,“ said Harvard astronomer Robert Kirshner, a member of the discovery team.
In addition to providing the first example of a new way to make supernovae, SN 2006gz holds implications for the field of cosmology. Type Ia supernovae typically have a narrow spread in brightness, which makes them useful as “standard candles“ for calculating cosmic distances. It was the study of Type Ia supernovae that led to the discovery of dark energy, the mysterious force causing the expansion of the universe to accelerate.
If Type Ia supernovae are more varied than previously expected, then astronomers must be extra cautious when using them to study the cosmos.
“Supernova 2006gz stands out from normal Type Ia objects and wouldn’t be included in cosmology studies,“ commented Hicken. “But we have to be careful not to mistake a double white dwarf explosion for a single white dwarf blast. SN 2006gz was easy to recognize, but there may be less clear-cut cases.“