Sunday, August 29, 2010

A University of Tokyo group of researchers, led by bioengineer Shoji Takeuchi, has made an electronic sensor capable of smelling gases. The sensor uses genetically engineered frog cells. Since previous sensors were not very accurate, the scientist decided to try a biological approach. The invention was revealed in a US scientific journal yesterday, and is supposed to be used to design better machines to detect polluting gases in the atmosphere.

Previous smell sensors were based on quartz rods, which vibrate when a substance binds to them. The gases are distinguished by their molar masses, which can be similar for molecules with different structure, thus relatively often triggering a false positive. Trying to find a more accurate solution, Takeuchi decided to follow an example from insect world. As he explained, “when you think about the mosquito, it is able to find people because of carbon dioxide from the human. So the mosquito has CO₂ receptors. When we can (extract) DNA (from the mosquito) we can put this DNA into the frog eggs to detect CO₂.”

Genes of several insects (the silk moth, diamondback moth and fruit fly), injected into African clawed frog Xenopus laevis eggs, allowed them to produce relatively inexpensive and useful sensors. The choice of the species was caused by their widely studied and well-understood protein expression mechanism.

The modified cells responded to three kinds of pheromones and one odourant, which have similar chemical properties. When a molecule of an odorous substance adhered to the receptor on the membrane protein, ion channels opened for a certain period of time, and a current was generated. Its magnitude was clearly different for all four tested substances, allowing to distinguish between them accurately.

The colleagues embedded the sensor into a mannequin, so that it could shake its head when a gas was detected. It was easier to observe. Pheromones and molecules with quite similar molecule structure produced clearly distinguishable reaction, with higher accuracy than other biological or human-made sensors. As the research group said, the detection sensitivity of the odor sensor is several tens of parts per billion (ppb), and it is as high as the sensitivity of an existing odor sensor that uses an oxide semiconductor. The distinctive feature of the new sensor is its capability to selectively detect some odorous substances, rather than its sensitivity. Very few false positives were possible due to the biological mechanism involved.

At normal temperature, the sensor lifetime is about 12 hours, which can be extended by putting it into a refrigerator before first use.

Shoji Takeuchi says has a great hope for research use in future, since the frog eggs are very practical for genetic engineering, and can be conveniently used to develop smell sensors for a wide range of gases. He said, “The X. laevis oocyte has high versatility for the development of chemical sensors for various odorants. We believe that a shared ability to smell might open a new relationship between man and robot. .. The research will have wide implications… If the sensor is embedded in a nursing robot, it will be able to identify certain mouth odors or body odors. Also, it can be used for detecting CO₂, air pollution, water pollution and food. It’s very important for the environment.”

Wednesday, May 23, 2012

Abdelbaset al-Megrahi has been buried in the town of Janzur, west of the Libyan capital Tripoli. He was the only individual convicted in association with the Lockerbie bombing of 1988. He died at his residence Sunday, aged 60.

The bombing of Pan Am Flight 103 from London to New York resulted in 270 fatalities, including all 259 of the airplane’s occupants and eleven individuals on the ground. 189 of those who died in the incident were US citizens. The death toll for this terrorist incident is larger than that for any other which has occurred in the United Kingdom thus far.

Abdelbaset al-Megrahi was placed on trial in May 2000 in the Netherlands alongside Al Amin Khalifah Fhimah. While Fhimah was found not guilty on all charges placed against him, al-Megrahi was found guilty of his and sentenced to at least 27 years imprisonment. Having been initially placed in HM Prison Barlinnie, al-Megrahi was transferred to Greenock in 2005.

In 2002, an appeal against his conviction was unsuccessful. Five years later, senior judges in Scotland were to review his case, but he dropped the appeal. Due to suffering from prostate cancer, he was granted a compassionate release from Scottish prison two days later.

Current UK Prime Minister David Cameron commented on his belief that al-Megrahi “should never have been released from prison” and said his death was an occasion “to remember the 270 people who lost their lives in what was an appalling terrorist act”. According to Alex Salmond, First Minister of Scotland, the investigation into the Lockerbie bombing is ongoing. Salmond also called for remembrance of those killed. Prosecutors, he said, had always thought there were others besides al-Megrahi involved in the attack.

US citizen Susan Cohen, the mother of one of those killed in the Lockerbie bombing, thought of al-Megrahi as “a mass murderer” who “deserved to die”, adding to CNN: “I feel no pity around him. He got to die with his family around him. My daughter [Theodora], at age 20, died a brutal, horrible death”. However, UK citizen Jim Swire, father of another victim of the bombing, believes al-Megrahi was not guilty. He described al-Megrahi’s death as “a sad time”, telling the BBC he was “satisfied for some years that this man was nothing to do with the murder of my daughter”.

Abdelbaset al-Megrahi has consistently denied responsibility for the attack. In his final recorded interview in December 2011, he insisted he was “an innocent man” who was “about to die and I ask now to be left in peace with my family.” His brother Mohammed al-Megrahi claimed “[t]here never was exact proof” and said al-Megrahi’s “pain is over now – he is with God”.

Monday, August 15, 2005

Oregon State University (OSU) animal researchers in conjunction with the U.S. Department of Agriculture‘s (USDA) Dubois, Idaho-based Sheep Experiment Station released a report on an OSU-USDA study which was initiated in 1995 after breeders asked the government to determine why some rams bought as breeding studs showed no interest in females. The researchers are working under a $2.8 million grant from the National Institutes of Health in hopes of developing a test which can determine the likelihood of a ram being female-oriented before it is sold as a stud.

By studying difference in the animal’s brains after slaughter, the study also showed what could be a biological determiner for what makes a ram male-oriented instead of female-oriented sexually. The scientists’ results showed that the anterior preoptic area of the rams’ hypothalamus was 50 percent smaller in male-oriented rams as opposed to female oriented rams. A 1991 study of human brains of AIDS victims showed a similar hypothalamus size difference between gay and heterosexual men.

The sheep researchers postulate that low levels of aromatase hormones in the brain of a developing male sheep fetus may have kept the brain from fully masculinizing, leading to sexually male-oriented rams.

“This lends further support to the idea that homosexuality has biological underpinnings,” Charles Roselli, a professor of physiology and pharmacology, said in an interview with the Corvallis Gazette-Times.

Professor Stormshak believes that “understanding sexual drives and the continuum of sexual behavior could possibly help explain the scientific basis of sexual assault [and] put an end to assertions that homosexuality is a lifestyle choice.”

Thursday, December 22, 2005

Striking New York City transit workers will return to their jobs in 12-24 hours under an agreement reached today. While no final contract agreement has been reached, transit work will resume as negotiations continue. At 2:40 pm EST, the TWU board voted to end the strike. By 3:00 pm, the TWU Local 100 website had posted a notice to workers to return to work.

Mediator Richard Curreri announced the union is “taking steps” to immediately restore transportation to the city. “We have requested the leadership of the TWU to take the actions necessary to direct its membership to immediately return to work and they have agreed to take such actions,” Mr. Curreri told reporters.

Thirty-four thousand Transport Workers Union Local 100 members walked off the job December 20 after working months without a contract when negotiations broke down over disagreements concerning pensions, health benefits, and pay. Agreement had nearly been reached, but just a few hours before a strike deadline, the Metropolitan Transport Authority’s chairman, Peter S. Kalikow, made an unexpected demand, requiring that all new transit workers increase the contribution to pensions from the present 2 percent of their wages to 6 percent, which upset the union members. Roger Toussaint, president of Transport Workers Union Local 100, stated “Were it not for the pension piece we would not be on strike.” and summed up the whole conflict as “a fight over dignity and respect on the job, a concept that is very alien to the MTA. Transit workers are tired of being underappreciated and disrespected.”

The strike has affected an estimated 7 million commuters in the city over three days, which is about 21 million person-days in total. New York’s 34,000 bus and subway workers are affected by the difficulty of their everyday working conditions and health standards for a total of about 10 million person-days per year.

Sunday, August 21, 2005

A robotic system at Stanford Medical Center was used to perform a laparoscopic gastric bypass surgery successfully with a theoretically similar rate of complications to that seen in standard operations. However, as there were only 10 people in the experimental group (and another 10 in the control group), this is not a statistically significant sample.

If this surgical procedure is as successful in large-scale studies, it may lead the way for the use of robotic surgery in even more delicate procedures, such as heart surgery. Note that this is not a fully automated system, as a human doctor controls the operation via remote control. Laparoscopic gastric bypass surgery is a treatment for obesity.

There were concerns that doctors, in the future, might only be trained in the remote control procedure. Ronald G. Latimer, M.D., of Santa Barbara, CA, warned “The fact that surgeons may have to open the patient or might actually need to revert to standard laparoscopic techniques demands that this basic training be a requirement before a robot is purchased. Robots do malfunction, so a backup system is imperative. We should not be seduced to buy this instrument to train surgeons if they are not able to do the primary operations themselves.”

There are precedents for just such a problem occurring. A previous “new technology”, the electrocardiogram (ECG), has lead to a lack of basic education on the older technology, the stethoscope. As a result, many heart conditions now go undiagnosed, especially in children and others who rarely undergo an ECG procedure.

Friday, March 30, 2007

Israeli firm Environmental Energy Resources (EER) has announced that it has developed a new technology, plasma gasification melting technology (PGM), to safely dispose of low- and medium-level nuclear waste. Extremely high temperatures are used to turn the waste into a mildly radioactive glass-like substance, which can be used as a building material. The process also releases an extremely hot mixture of gases that can be used to power steam turbines, generating electricity. The company claims that 70% of this electricity is used to drive the PGM process, while 30% is available as exportable energy.