Posts tagged science
Articles and news from the latest research reports.
Bioengineers Introduce ‘Bi-Fi’ — The Biological ‘Internet’
If you were a bacterium, the virus M13 might seem innocuous enough. It insinuates more than it invades, setting up shop like a freeloading houseguest, not a killer. Once inside it makes itself at home, eating your food, texting indiscriminately. Recently, however, bioengineers at Stanford University have given M13 a bit of a makeover.
The researchers, Monica Ortiz, a doctoral candidate in bioengineering, and Drew Endy, PhD, an assistant professor of bioengineering, have parasitized the parasite and harnessed M13’s key attributes — its non-lethality and its ability to package and broadcast arbitrary DNA strands — to create what might be termed the biological Internet, or “Bi-Fi.” Their findings were published online Sept. 7 in the Journal of Biological Engineering
Using the virus, Ortiz and Endy have created a biological mechanism to send genetic messages from cell to cell. The system greatly increases the complexity and amount of data that can be communicated between cells and could lead to greater control of biological functions within cell communities. The advance could prove a boon to bioengineers looking to create complex, multicellular communities that work in concert to accomplish important biological functions.
Pill for healthy ageing ‘available within a generation’
Dame Linda Partridge, a geneticist at University College London, claimed drugs will soon be available which can lower the risk of diseases like cancer and dementia by tackling the root cause – age itself.
Rather than promising immortality, taking the drugs from middle age or earlier could dramatically shorten the period of illness and frailty that we typically experience before we die.
Speaking at the EMBO life sciences meeting in Nice, France this week Dame Linda said several existing drugs have already been shown to have unexpected and welcome side effects, such as aspirin which reduces the risk of cancer.
Other therapies will be produced that mimic the effects of a severely restricted diet, which animal studies suggest can protect against a host of age-related conditions including heart disease and diabetes, she said.
Speaking after her keynote lecture, she told The Daily Telegraph: “One obvious approach in trying to deal with the very rapidly increasing incidence of age related diseases is to tackle the underlying aging process itself, because it is the major risk factor.
Benzodiazepine use and risk of dementia: prospective population based study
Objective To evaluate the association between use of benzodiazepines and incident dementia.
Design Prospective, population based study.
Setting PAQUID study, France.
Participants 1063 men and women (mean age 78.2 years) who were free of dementia and did not start taking benzodiazepines until at least the third year of follow-up.
Main outcome measures Incident dementia, confirmed by a neurologist.
Results During a 15 year follow-up, 253 incident cases of dementia were confirmed. New use of benzodiazepines was associated with an increased risk of dementia (multivariable adjusted hazard ratio 1.60, 95% confidence interval 1.08 to 2.38). Sensitivity analysis considering the existence of depressive symptoms showed a similar association (hazard ratio 1.62, 1.08 to 2.43). A secondary analysis pooled cohorts of participants who started benzodiazepines during follow-up and evaluated the association with incident dementia. The pooled hazard ratio across the five cohorts of new benzodiazepine users was 1.46 (1.10 to 1.94). Results of a complementary nested case-control study showed that ever use of benzodiazepines was associated with an approximately 50% increase in the risk of dementia (adjusted odds ratio 1.55, 1.24 to 1.95) compared with never users. The results were similar in past users (odds ratio 1.56, 1.23 to 1.98) and recent users (1.48, 0.83 to 2.63) but reached significance only for past users.
Conclusions In this prospective population based study, new use of benzodiazepines was associated with increased risk of dementia. The result was robust in pooled analyses across cohorts of new users of benzodiazepines throughout the study and in a complementary case-control study. Considering the extent to which benzodiazepines are prescribed and the number of potential adverse effects of this drug class in the general population, indiscriminate widespread use should be cautioned against.
New Treatments May Help Restore Speech Lost to Aphasia
Most people know the frustration of having a word on the “tip of your tongue” that they simply can’t remember. But that passing nuisance can be an everyday occurrence for someone with aphasia, a communication disorder caused by a stroke or other brain damage that impairs the ability to process language.
About 1 million Americans — roughly one in every 250 — are affected by aphasia, which can also impact reading and writing skills. But how they acquire the problem and how long they’ll endure it differ from person to person, explained Ellayne Ganzfried, a speech-language pathologist and executive director of the National Aphasia Association.
"No two people with aphasia are alike because everyone’s brain responds to the injury in a different way," Ganzfried said. "About half of people who have aphasia recover quickly, within the first few days. If the symptoms of aphasia last longer than two or three months, a complete recovery is unlikely … [though] some people continue to improve over a period of years and even decades."
Strokes are the most common cause, followed by head injuries, tumors, migraines or other neurological issues. Depending on the damage to the brain regions controlling language, which are typically in the left hemisphere, the resulting aphasia can be broken into four broad categories:
- Difficulty expressing thoughts through speech or writing
- Difficulty understanding spoken or written language
- Difficulty using the correct names for objects, people, places or events
- Loss of almost all language function, with no ability to speak or understand speech.
"Processing language requires the collaboration of lots of different parts or systems of the brain," explained Karen Riedel, director of speech-language pathology at the Rusk Institute of Rehabilitation Medicine at NYU Langone Medical Center in New York City. "The whole brain ‘talks’ — the whole brain has something to do with the use of language."
Because of this, a variety of therapies are used to help people regain as much speech and language as possible. But regardless of the injury, people with aphasia have the best chances for recovery when language therapy begins immediately, Riedel said.
Because aphasia is so variable, a therapy that helps one person might not help another, she noted. Tried-and-true techniques include melodic intonation therapy, which uses melody and rhythm to help improve the ability to retrieve words, and constraint-induced therapy, which forces people to use speech over other communication methods.
But technology, Riedel said, has introduced new language-improvement techniques into the mix over the last few years that are both exciting and fun. Several apps available for iPhone or iPad involve synthetic speech that helps engage those with aphasia in yet another realm of communication.
"Our patients have much more access to different kinds of programs that are computer-based," she said. "There’s always something new around the corner."
What remains a constant concern, however, is the misunderstanding many people have of those with language difficulties and how to treat them, Ganzfried and Riedel agreed.
"Many people with aphasia will become socially isolated because of their communication difficulties, which can lead to depression," Ganzfried said. "There are also many misconceptions about aphasia, including that the person is mentally unstable or under the influence of drugs or alcohol. It’s also extremely frustrating. Imagine knowing what you want to say in your head but you can’t get the words out."
(Source: consumer.healthday.com)
Risk-Sensitivity in Bayesian Sensorimotor Integration
Information processing in the nervous system during sensorimotor tasks with inherent uncertainty has been shown to be consistent with Bayesian integration. Bayes optimal decision-makers are, however, risk-neutral in the sense that they weigh all possibilities based on prior expectation and sensory evidence when they choose the action with highest expected value. In contrast, risk-sensitive decision-makers are sensitive to model uncertainty and bias their decision-making processes when they do inference over unobserved variables. In particular, they allow deviations from their probabilistic model in cases where this model makes imprecise predictions. Here we test for risk-sensitivity in a sensorimotor integration task where subjects exhibit Bayesian information integration when they infer the position of a target from noisy sensory feedback. When introducing a cost associated with subjects’ response, we found that subjects exhibited a characteristic bias towards low cost responses when their uncertainty was high. This result is in accordance with risk-sensitive decision-making processes that allow for deviations from Bayes optimal decision-making in the face of uncertainty. Our results suggest that both Bayesian integration and risk-sensitivity are important factors to understand sensorimotor integration in a quantitative fashion.
When Your Eyes Tell Your Hands What to Think: You’re Far Less in Control of Your Brain Than You Think
You’ve probably never given much thought to the fact that picking up your cup of morning coffee presents your brain with a set of complex decisions. You need to decide how to aim your hand, grasp the handle and raise the cup to your mouth, all without spilling the contents on your lap.
A new Northwestern University study shows that, not only does your brain handle such complex decisions for you, it also hides information from you about how those decisions are made.
"Our study gives a salient example," said Yangqing ‘Lucie’ Xu, lead author of the study and a doctoral candidate in psychology at Northwestern. "When you pick up an object, your brain automatically decides how to control your muscles based on what your eyes provide about the object’s shape. When you pick up a mug by the handle with your right hand, you need to add a clockwise twist to your grip to compensate for the extra weight that you see on the left side of the mug.
"We showed that the use of this visual information is so powerful and automatic that we cannot turn it off. When people see an object weighted in one direction, they actually can’t help but ‘feel’ the weight in that direction, even when they know that we’re tricking them," Xu said.
The Marketplace in Your Brain: Neuroscientists have found brain cells that compute value. Why are economists ignoring them?
In 2003, amid the coastal greenery of the Winnetu Oceanside Resort, on Martha’s Vineyard, a group of about 20 scholars gathered to kick-start a new discipline. They fell, broadly, into two groups: neuroscientists and economists. What they came to talk about was a collaboration between the two fields, which a few researchers had started to call “neuroeconomics.” Insights about brain anatomy, combined with economic models of neurons in action, could produce new insights into how people make decisions about money and life.
A photo taken during one of those sun-dappled days captures the group posed and smiling around a giant chess set on the resort lawn. Pawns were about two feet tall, kings and queens about four feet. Informally, the neuroscientists began to play the black pieces. The economists began to play white.
Today, nearly a decade later, a few black pawns have moved down the board. But the white pieces have stayed put. “I would say that neuroeconomics is about 90 percent neuroscience and 10 percent economists,” says Colin F. Camerer, a professor of behavioral finance and economics at the California Institute of Technology and one of the prime movers in the new field. “We’ve taken a lot of mathematical models from economics to help describe what we see happening in the brain. But economists have been a lot slower to use any of our ideas.”
Scientists announce new treatment for type II diabetes
According to the World Health Organization, there are currently 347 million diabetics worldwide, with 90 percent of those people having type II diabetes specifically. It occurs when fat accumulates in places such as muscles, blood vessels and the heart, causing the cells in those areas to no longer be sufficiently responsive to insulin. This insulin resistance, in turn, causes blood glucose levels to rise to dangerous levels. Ultimately, it can result in things such as heart disease, strokes, blindness, kidney failure, and amputations. Fortunately, however, an international team of scientists has just announced a new way of treating the disease.
Currently, one of the main ways of treating type II diabetes involves switching the patient to a healthier diet and increasing the amount of exercise they get – the disease is most often caused by obesity. Additionally, oral medication can be used to increase insulin production and the body’s sensitivity to it, or to decrease glucose production. For approximately 30 percent of patients, however, such medication ceases to be effective after a few years, and they end up having to receive regular insulin injections.
The new treatment focuses on VEGF-B, a protein within the body that affects how fat is transported and stored. Using an antibody/drug known as 2H10, the scientists were able to block the signaling of VEGF-B in mice and rats, which subsequently kept fat from accumulating in the “wrong” areas of the animals – namely their muscles, blood vessels and hearts.
Deaf girl fitted with bionic ear speaks her first word
Evie was born profoundly deaf but it was not until she was 16 months old that tests revealed she had no hearing nerves, meaning an auditory brainstem implant - or bionic ear - was her only chance of ever hearing.
The 23-month-old has Oculo-Auriculo-Vertebral Syndrome (OAV), a very rare condition with no known cause, which affects the eyes, ears and spine.
Robots paint hotel guests’ sleep patterns
Global hotel chain Ibis is transforming the nightly tosses and turns of its guests into works of modern art, painted by robots.
"Our masterpiece is to make your sleep a true work of art," the promotional video gushes, after putting a far more interesting point to viewers: "What does sleep look like?" To find out, the budget chain is installing thin grids covered in 80 heat, pressure and sound sensors on mattresses in select guestrooms, kicking off on 13 October in Paris. Data gathered by the sensors will be fed wirelessly throughout the night to the studio, where it is then fed through an algorithm that converts information on a guest’s movement, sound and temperature into colour and movement.
This video shows the robot, much like an assembly line arm, reacting in sequence, tracing acrylic paints onto a black canvas in a visual and physical interpretation of sleep cycles and patterns.
Only 40 participants can take part — anyone who wants to try it out can enter a competition on the Ibis Facebook page. When the project is wrapped up in Novemeber there will be an online gallery of the artworks and guests will get an original to take home.