my serendipities

Apr 16

Two Simon Fraser University psychologists have made a brain-related discovery that could revolutionize doctors’ perception and treatment of attention-deficit disorders. This discovery opens up the possibility that environmental and/or genetic factors may hinder or suppress a specific brain activity that the researchers have identified as helping us prevent distraction.

This is the first study to reveal our brains rely on an active suppression mechanism to avoid being distracted by salient irrelevant information when we want to focus on a particular item or task.

"Distraction is a leading cause of injury and death in driving and other high-stakes environments," notes McDonald, the study’s senior author. "There are individual differences in the ability to deal with distraction. New electronic products are designed to grab attention. Suppressing such signals takes effort, and sometimes people can’t seem to do it.

"Moreover, disorders associated with attention deficits, such as ADHD and schizophrenia, may turn out to be due to difficulties in suppressing irrelevant objects rather than difficulty selecting relevant ones."

The researchers are now turning their attention to understanding how we deal with distraction. They’re looking at when and why we can’t suppress potentially distracting objects, whether some of us are better at doing so and why that is the case.

"There’s evidence that attentional abilities decline with age and that women are better than men at certain visual attentional tasks," says Gaspar, the study’s first author.

” — Scientists discover brain’s anti-distraction system

It’s a hard pill to swallow, but if you’re over 24 years of age you’ve already reached your peak in terms of your cognitive motor performance, according to a new Simon Fraser University study. SFU’s Joe Thompson, a psychology doctoral student, associate professor Mark Blair, Thompson’s thesis supervisor, and Andrew Henrey, a statistics and actuarial science doctoral student, deliver the news in a just-published PLOS ONE Journal paper. In one of the first social science experiments to rest on big data, the trio investigates when we start to experience an age-related decline in our cognitive motor skills and how we compensate for that.

"After around 24 years of age, players show slowing in a measure of cognitive speed that is known to be important for performance," explains Thompson, the lead author of the study, which is his thesis. "This cognitive performance decline is present even at higher levels of skill."

But there’s a silver lining in this earlier-than-expected slippery slope into old age. “Our research tells a new story about human development,” says Thompson.

"Older players, though slower, seem to compensate by employing simpler strategies and using the game’s interface more efficiently than younger players, enabling them to retain their skill, despite cognitive motor-speed loss."

For example, older players more readily use short cut and sophisticated command keys to compensate for declining speed in executing real time decisions.

The findings, says Thompson, suggest “that our cognitive-motor capacities are not stable across our adulthood, but are constantly in flux, and that our day-to-day performance is a result of the constant interplay between change and adaptation.”

” — We’re over the hill at 24, study says — ScienceDaily

Apr 15

Researchers in the UK have developed a technique to culture universal type-O blood from stem cells. It’s the first time scientists have manufactured blood to the appropriate quality and safety standards for transfusion into a human being. It’s a breakthrough that could eventually end blood shortages in emergencies.

During the process, red blood cells are cultured from induced pluripotent stems cells. These are cells that have been extracted from humans and then “rewound” into stem cells. Biochemical conditions similar to what happens inside the human body facilitate the conversion of these undifferentiated cells into viable red blood cells — the rare universal blood type O.

” — Soon We May Be Mass Producing Human Blood

“It may sound far-fetched, but scientists are attempting to build a human heart with a 3-D printer. Ultimately, the goal is to create a new heart for a patient with their own cells that could be transplanted. It is an ambitious project to first, make a heart and then get it to work in a patient, and it could be years—perhaps decades—before a 3-D printed heart would ever be put in a person. The technology, though, is not all that futuristic: Researchers have already used 3-D printers to make splints, valves and even a human ear. So far, the University of Louisville team has printed human heart valves and small veins with cells, and they can construct some other parts with other methods, said Stuart Williams, a cell biologist leading the project. They have also successfully tested the tiny blood vessels in mice and other small animals, he said. Williams believes they can print parts and assemble an entire heart in three to five years. The finished product would be called the “bioficial heart”—a blend of natural and artificial.” — Scientists try 3-D printer to build human heart

Apr 12

Thousands of consumer products—including cosmetics, sunscreens, and clothing—contain nanoparticles added by manufacturers to improve texture, kill microbes, or enhance shelf life, among other purposes. However, several studies have shown that some of these engineered nanoparticles can be toxic to cells. A new study from MIT and the Harvard School of Public Health (HSPH) suggests that certain nanoparticles can also harm DNA.

The researchers found that zinc oxide nanoparticles, often used in sunscreen to block ultraviolet rays, significantly damage DNA. Nanoscale silver, which has been added to toys, toothpaste, clothing, and other products for its antimicrobial properties, also produces substantial DNA damage, they found.

The findings, published in a recent issue of the journal ACS Nano, relied on a high-speed screening technology to analyze DNA damage. This approach makes it possible to study nanoparticles’ potential hazards at a much faster rate and larger scale than previously possible.

The Food and Drug Administration does not require manufacturers to test nanoscale additives for a given material if the bulk material has already been shown to be safe. However, there is evidence that the nanoparticle form of some of these materials may be unsafe: Due to their immensely small size, these materials may exhibit different physical, chemical, and biological properties, and penetrate cells more easily.

"The problem is that if a nanoparticle is made out of something that’s deemed a safe material, it’s typically considered safe. There are people out there who are concerned, but it’s a tough battle because once these things go into production, it’s very hard to undo," Engelward says.

The researchers focused on five types of engineered nanoparticles—silver, zinc oxide, iron oxide, cerium oxide, and silicon dioxide (also known as amorphous silica)—that are used industrially. Some of these nanomaterials can produce free radicals called reactive oxygen species, which can alter DNA. Once these particles get into the body, they may accumulate in tissues, causing more damage.

Until now, most studies of nanoparticle toxicity have focused on cell survival after exposure. Very few have examined genotoxicity, or the ability to damage DNA—a phenomenon that may not necessarily kill a cell, but one that can lead to cancerous mutations if the damage is not repaired.

Zinc oxide and silver produced the greatest DNA damage in both cell lines. At a concentration of 10 micrograms per milliliter—a dose not high enough to kill all of the cells—these generated a large number of single-stranded DNA breaks.

Silicon dioxide, which is commonly added during food and drug production, generated very low levels of DNA damage. Iron oxide and cerium oxide also showed low genotoxicity.

"The biggest challenge we have as people concerned with exposure biology is deciding when is something dangerous and when is it not, based on the dose level. At low levels, probably these things are fine," Engelward says. "The question is: At what level does it become problematic, and how long will it take for us to notice?"

One of the areas of greatest concern is occupational exposure to nanoparticles, the researchers say. Children and fetuses are also potentially at greater risk because their cells divide more often, making them more vulnerable to DNA damage.

” — Some nanoparticles commonly added to consumer products can significantly damage DNA