New Study Reveals How the Brain Recognizes Speech Sounds

January 30, 2014. Francisco researchers are reporting a detailed account of how speech sounds are identified by the human brain, offering an unprecedented insight into the basis of human language.

The finding, they said, may add to our understanding of language disorders, including dyslexia.

Scientists have known for some time the location in the brain where speech sounds are interpreted, but little has been discovered about how this process works.

The UCSF team reports that the brain does not respond to the individual sound segments known as phonemes – such as the b sound in “boy” – but is instead exquisitely tuned to detect simpler elements, which are known to linguists as “features.”

This organization may give listeners an important advantage in interpreting speech, the researchers said, since the articulation of phonemes varies considerably across speakers, and even in individual speakers over time.

The work may add to our understanding of reading disorders, in which printed words are imperfectly mapped onto speech sounds. But because speech and language are a defining human behavior, the findings are significant in their own right, said UCSF neurosurgeon and neuroscientist Edward F. Chang, MD, senior author of the new study.

“This is a very an intriguing glimpse into speech processing,” said Chang, associate professor of neurological surgery and physiology. “The brain regions where speech is processed in the brain had been identified, but no one has really known how that processing happens.”

Breaking Down Speech into Acoustic Features

Although we usually find it effortless to understand other people when they speak, parsing the speech stream is an impressive perceptual feat.

Speech is a highly complex and variable acoustic signal, and our ability to instantaneously break that signal down into individual phonemes and then build those segments back up into words, sentences and meaning is a remarkable capability.

The previous studies have analyzed brain responses to just a few natural or synthesized speech sounds, but the new research employed spoken natural sentences containing the complete inventory of phonemes in the English language.

To capture the very rapid brain changes involved in processing speech, the UCSF scientists gathered their data from neural recording devices that were placed directly on the surface of the brains of six patients as part of their epilepsy surgery.

 The patients listened to a collection of 500 unique English sentences spoken by 400 different people while the researchers recorded from a brain area called the superior temporal gyrus (STG; also known as Wernicke’s area), which previous research has shown to be involved in speech perception. The utterances contained multiple instances of every English speech sound.

Many researchers have presumed that brain cells in the STG would respond to phonemes. But the researchers found instead that regions of the STG are tuned to respond to even more elemental acoustic features that reference the particular way that speech sounds are generated from the vocal tract. “These regions are spread out over the STG,” said Nima Mesgarani (PhD, who was a postdoctoral fellow in Chang’s laboratory.) “As a result, when we hear someone talk, different areas in the brain ‘light up’ as we hear the stream of different speech elements.”

Reference:

News Reported the Journal 'SCIENCE EXPRESS'

SLU Researchers Study Therapy to Relieve Sickle Cell Pain

Saint Louis University researchers are studying whether ReoPro® (abciximab), a drug currently given to heart patients undergoing angioplasties to open blocked arteries, also could help children and young adults who have severe pain from sickle cell disease.

Sickle cell crises occur when clots form in the small blood vessels, preventing blood from flowing freely to organs. Healthy red blood cells are shaped like flexible donuts and can fold to easily wiggle through the smallest blood vessels. Red blood cells in patients who have sickle cell disease are misshaped, crescent-like cells with sharp edges that get caught inside blood vessel walls and pile up to create blockages.

Much like an accident that impedes traffic on the road where it happened and on secondary feeder roads, sickle cell crises cause a second blood vessel blockage when red blood cells and platelets (small blood cells that stop bleeding) stick to the lining of the blood vessel walls.

"It's like there's a traffic accident and a quarter mile down the road, you slow down again. Right now, we don't have anything that directly targets that secondary blockage," Ferguson said. "These traffic pile ups can decrease blood flow and can damage the organ on the other side, such as the spleen, eyes or lungs."

Ferguson, who is the study chair, said the research could represent a new approach to treating sickle cell crisis. He is leading a study that examines whether or not ReoPro could reduce the length of time patients who are having a sickle cell pain crisis spend in the hospital.

"As far as I know, no one has targeted the increased stickiness of both platelets and red blood cells in the context of a crisis," Ferguson said. "We hope our research will tell us more about treating the disease and potentially open an avenue of research and drug development."

Scientists from SLU (Center for World Health and Medicine) reviewed medical literature that identified the mechanism of action used by ReoPro as potentially promising in treating sickle cell crises because it attacks blockages in blood flow on two fronts. They then approached Ferguson about conducting the research, said Peter Ruminski, executive director of the center.

"ReoPro hits both of those proteins that affect the stickiness of platelets and the flow of red blood cells through the walls of the blood vessels. Our research will help us find out if medications that have similar properties can be effective against sickle cell disease," Ruminski said.

The Center for World Health and Medicine brokered the research project, which is the first clinical trial to come out of its work.

While ReoPro has been approved by the Food and Drug Administration to prevent clotting during angioplasty procedures, it has not been studied as a treatment for sickle cell disease. Janssen Biotech, Inc., the company that discovered and developed ReoPro, is donating the medication and providing funding for the study.

Ferguson is recruiting 100 patients who are between ages 5 and 25 for the double-blind randomized trial. Within 16 hours of being hospitalized for a sickle cell pain crisis, half will receive the investigational medicine and half a placebo. All will receive the standard of care, which includes pain medication, while they are in the hospital and released.

Researchers will track how long the volunteers remain in the hospital. Those in the study will be discharged from the hospital once their pain can be controlled by oral medications, provided they have no other medical problems. They will have a follow up visit with their hematologist a week to 10 days after leaving the hospital, which is routine care for those who have suffered a sickle cell crisis.

Sickle cell disease occurs in about one in 400 people of African descent and one in 4,000 Hispanics, affecting between 80,000 and 100,000 Americans. It varies in severity, with some people having significant pain from multiple crises. Typically, those who have sickle cell disease live to be in their 50s.

Reference:

Nancy Solomon

314.977.8017

As the article presented by Saint Louis University.

Herschel Telescope Detects Water on Dwarf Planet

January 22, 2014Scientists using the Herschel space observatory have made the first definitive detection of water vapor on the largest and roundest object in the asteroid belt, Ceres.

Plumes of water vapor are thought to shoot up periodically from Ceres when portions of its icy surface warm slightly. Ceres is classified as a dwarf planet, a solar system body bigger than an asteroid and smaller than a planet.

Herschel is a European Space Agency (ESA) mission with important NASA contributions.

How the immune system fights off malaria findings by MIT's Scientists

Throughout history malaria has proved to be a significant threat to human health. Between 300 and 500 million clinical cases occur each year worldwide, approximately 2 million of which are fatal, primarily in children. The vast majority of malaria-related deaths are due to infection with Plasmodium falciparum; P. vivax causes severe febrile illness but is rarely fatal.
Now, a team of scientists has identified a key host defense mechanism.
A team led by MIT researchers has developed a strain of mice that mimics many of the features of the human immune system and can be infected with the most common human form of the malaria parasite. Using this strain, the researchers have already identified a key host defense mechanism, and they believe it should lead to many more useful discoveries.

To generate these cells, the researchers deliver human hematopoietic stem cells, along with cytokines that help them mature into B and T cells, natural killer (NK) cells, and macrophages- all critical components of the immune system.These mice have already proven useful to study other diseases, such as dengue fever.

“Human malaria studies have been hampered by a lack of animal models,” says Jianzhu Chen, the Ivan R. Cottrell Professor of Immunology, {a member of MIT’s Koch Institute for Integrative Cancer Research, and the lead principal investigator of the Infectious Disease Interdisciplinary Research Group at the Singapore-MIT Alliance for Research and Technology (SMART)}.

To adapt the mice for the study of malaria, the researchers injected them with human red blood cells every day for a week, at which point 25 percent of their red blood cells were human — enough for the malaria parasite to cause an infection.

The researchers investigated the role of NK cells and macrophages during the first two days of malaria infection. They found that eliminating macrophages had very little impact on the immune response during those early stages. However, in mice lacking NK cells, parasite levels went up sevenfold, suggesting that NK cells are critical to controlling infection early on.

To further investigate the role of NK cells, the researchers placed human NK cells in a sample of infected and uninfected red blood cells. The NK cells randomly interacted with both types of cells, but they latched onto infected cells much longer, eventually killing them.

"This indicates that NK cells may provide an important immune defense against malaria", says Lewis Lanier.

The researchers also identified a cell adhesion protein called LFA-1 that helps NK cells bind to red blood cells. They are now studying this process in more detail and trying to figure out what other molecules, including those produced by the malaria parasite, might be involved.

Chen and Colleagues also hope to use these mice to study experimental malaria vaccines or drugs. And in another future study, they plan to inject the mice with human red blood cells from people with sickle cell anemia to investigate how the sickle-shaped red blood cells help people survive malaria infection.
 
The humanized mouse project described in the new PNAS (Proceedings of the National Academy of Sciences) study
The research was funded by the National Research Foundation Singapore through SMART’s Interdisciplinary Research Group in Infectious Disease.


 Reference:
 Adapted from a news release issued by MIT

Scientists discover new pathway for artificial photosynthesis

Humans have for ages taken cues from nature to build their own devices, but duplicating the steps in the complicated electronic dance of photosynthesis remains one of the biggest challenges and opportunities for chemists.

UEA scientists reveal that chocolate, tea and wine could guard against diabetes

Jan 20 2014.  Eating high levels of flavonoids including anthocyanins and other compounds (found in berries, tea, and chocolate) could offer protection from type 2 diabetes – according to research from the University of East Anglia (UEA) and King’s College London.

As reported in a news release by the University of East Anglia, findings published today in the Journal of Nutrition reveal that high intakes of these dietary compounds are associated with lower insulin resistance and better blood glucose regulation.

US Scientists genetically engineering Tulsi.

Jan 18 2014.  Led by an Indian-American, a team of scientists at a US university aregenetically engineering tulsi (Ocimum tenuiflorum) or basil to enhance its pharmaceutical value, the institute said.

Study: Caffeine Can Improve Memory

New research from Johns Hopkins shows caffeine's enhancement of long-term memory.

January-13-2014.  For some, it’s the tradition of steeping tealeaves to brew the perfect cup of tea. For others, it’s the morning shuffle to a coffee maker for a hot jolt of java. Then there are those who like their wake up with the kind of snap and a fizz usually found in a carbonated beverage..

Mystery of Alexander the Great's death solved? Ruler was 'killed by toxic wine' claim scientists

 Alexander the Great may have been killed by toxic wine made from a poisonous but harmless-looking plant, scientists have claimed.

The mystery of why the Greek King of Macedon, ruler of the largest empire in the ancient world, died at just 32 has baffled historians and scientists for over 2000 years.

'Hand of God' Spotted by NASA Space Telescope NuSTAR........

January 1o,2014. Religion and astronomy may not overlap often, but a new NASA X-ray image captures a celestial object that resembles the "Hand of God."

The cosmic "hand of God" was produced when a star exploded and ejected an enormous cloud of material, which NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, glimpsed in high-energy X-rays, shown in blue in the photo. NASA's Chandra X-ray Observatory had imaged the green and red parts previously, using lower-energy X-rays.

High Good, Low Bad Cholesterol Levels Are Healthy for Brain, Too

High levels of "good" cholesterol and low levels of "bad" cholesterol are correlated with lower levels of the amyloid plaque deposition in the brain that is a hallmark of Alzheimer's disease, in a pattern that mirrors the relationship between good and bad cholesterol in cardiovascular disease, UC Davis researches have found.

Hot, gassy Earth-like planet found circling red giant

An international team of astronomers found that although the planet weighs same as Earth.The oddball exoplanet candidate KOI-314c is located about 200 light-years away and is roughly the same mass as Earth, but its extremely thick atmosphere makes the world about 60 percent larger than our home planet, scientists say.

GSLV-D5 marks India's mastery over indigenous cryogenic technology

One of India’s most ambitious dreams became a reality on Sunday when its Geosynchronous Satellite Launch Vehicle (GSLV-D5), powered by an indigenous cryogenic engine, effortlessly put the 1,982-kg GSAT-14 communication satellite into a perfect orbit after 17 minutes of flight.from the spaceport at Sriharikota, Andhra Pradesh at 4.18 pm on Sunday.

Researchers ID gene that influences the ability to remember faces

New findings suggest the oxytocin receptor, a gene known to influence mother-infant bonding and pair bonding in monogamous species, also plays a special role in the ability to remember faces.

This research has important implications