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Wed, 18 Oct 2017
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Brain

Brain imaging studies skewed by non-representative sample groups lead to errors in understanding brain development

Any scientist who studies groups of people knows that the characteristics of the "sample"-the group of people selected for the study-can profoundly impact the study's findings. To produce the most accurate findings, a study group ought to be as similar as possible to the people in the larger population you want to say something about.

A new UC San Francisco-led study shows that failure to follow this basic principle of population science-a common complaint about research in the cognitive sciences-can profoundly skew the results of brain imaging studies, leading to errors that may be throwing off neuroscientists' understanding of normal brain development.

"Much of what we know about how the brain develops comes from samples that don't look like the broader U.S. at all," said Kaja LeWinn, ScD, an epidemiologist and assistant professor of psychiatry at UCSF, member of the UCSF Weill Institute for Neurosciences, and lead author of the new study. "We would never try to understand the burden of other health conditions, like cardiovascular disease, in a sample with much higher socioeconomic status than the U.S. population as a whole, for instance."

Microscope 2

Newly discovered genes critical for hearing will provide insight into causes of hearing loss in humans

© National Human Genome Research Institute
This image shows the coding region in a segment of eukaryotic DNA.
Fifty-two previously unidentified genes that are critical for hearing have been found by testing over 3,000 mouse genes. The newly discovered genes will provide insights into the causes of hearing loss in humans, say scientists from Medical Research Council (MRC) Harwell, who led the analysis by the International Mouse Phenotyping Consortium (IMPC).

The study, published in Nature Communications, tested 3,006 strains of 'knock-out' mice for signs of hearing loss. 'Knock-out' mice have one gene from their genome inactivated, which helps researchers to uncover the functions of that gene. The IMPC aims to generate a 'knock-out' mouse for every gene in the mouse genome.

The hearing thresholds of the knock-out mice were assessed with rising volumes of sound at five different frequencies - mice were considered hearing impaired if they could not hear the quieter sounds for two or more frequencies.

They identified 67 genes that were associated with hearing loss, of which 52 had not been previously linked with hearing loss. The genes identified varied in how they affected hearing - effects ranged from mild to severe hearing loss or resulted in difficulties at lower or higher frequencies.

Brain

Paradox of perception: Human brain remembers visual features in reverse order than it detects them

© Ning Qian/Columbia's Zuckerman Institute
Visual depiction of one- and two-line tasks that participants were asked to complete and that was key to the paper's findings.
Scientists at Columbia's Zuckerman Institute have contributed to solving a paradox of perception, literally upending models of how the brain constructs interpretations of the outside world. When observing a scene, the brain first processes details-spots, lines and simple shapes-and uses that information to build internal representations of more complex objects, like cars and people. But when recalling that information, the brain remembers those larger concepts first to then reconstruct the details-representing a reverse order of processing. The research, which involved people and employed mathematical modeling, could shed light on phenomena ranging from eyewitness testimony to stereotyping to autism.

This study was published today in Proceedings of the National Academy of Sciences.

"The order by which the brain reacts to, or encodes, information about the outside world is very well understood," said Ning Qian, PhD, a neuroscientist and a principal investigator at Columbia's Mortimer B. Zuckerman Mind Brain Behavior Institute. "Encoding always goes from simple things to the more complex. But recalling, or decoding, that information is trickier to understand, in large part because there was no method-aside from mathematical modeling-to relate the activity of brain cells to a person's perceptual judgment."

Microscope 2

Scientists find treatment that causes cancer cells to self-destruct - without affecting healthy cells

© Albert Einstein College of Medicine
This image depicts the structure of the BAX protein (purple). The activator compound BTSA1 (orange) has bound to the active site of BAX (green), changing the shape of the BAX molecule at several points (shown in yellow, magenta and cyan). BAX, once in its final activated form, can home in on mitochondria and puncture their outer membranes, triggering apoptosis (cell death).
Scientists at Albert Einstein College of Medicine have discovered the first compound that directly makes cancer cells commit suicide while sparing healthy cells. The new treatment approach, described in today's issue of Cancer Cell, was directed against acute myeloid leukemia (AML) cells but may also have potential for attacking other types of cancers.

"We're hopeful that the targeted compounds we're developing will prove more effective than current anti-cancer therapies by directly causing cancer cells to self-destruct," says Evripidis Gavathiotis, Ph.D., associate professor of biochemistry and of medicine and senior author of the study. "Ideally, our compounds would be combined with other treatments to kill cancer cells faster and more efficiently-and with fewer adverse effects, which are an all-too-common problem with standard chemotherapies."

Comment: But will the lucrative and death-dealing Cancer Industry ever permit this research to be practically implemented??


Mars

NASA shares detailed images of Martian pits believed to have been formed by glaciers

© NASA / JPL / University of Arizona
Haunting high resolution video showing the formation of lines of Martian pits in the fretted terrain of the Red Planet's 'Protonilus Mensae' region has been released by NASA.

The mesmerizing footage, captured in March of this year, was shared by NASA's Mars Reconnaissance Orbiter imaging project, HiRise.

Protonilus Mensae is an area of Mars in the Ismenius Lacus quadrangle. The terrain features cliffs, flat-topped hills, and wide valleys, believed to have been formed by debris-covered glaciers moving across the Red Planet's surface.


Cassiopaea

Most luminous white dwarf eruption spotted by astronomers

University of Leicester contributes to best-ever results on a 'new star' in a nearby galaxy.
© OGLE survey
Astronomers have today announced that they have discovered possibly the most luminous 'new star' ever - a nova discovered in the direction of one of our closest neighboring galaxies: The Small Magellanic Cloud.

Astronomers from the University of Leicester contributed to the discovery by using the Swift satellite observatory to help understand what was likely the most luminous white dwarf eruption ever seen.

A nova happens when an old star erupts dramatically back to life. In a close binary star system consisting of a white dwarf and a Sun-like companion star, material is transferred from the companion to the white dwarf, gradually building up until it reaches a critical pressure. Then uncontrolled nuclear burning occurs, leading to a sudden and huge increase in brightness. It is called a nova because it appeared to be a new star to the ancients.

Microscope 1

Mitochondrial DNA could be used to predict risk of heart attacks and sudden cardiac deaths a decade before they happen

© Wire_man/Shutterstock
The mitochondria are the energy-generating organelles in the cell.
Johns Hopkins researchers report that the level, or "copy number," of mitochondrial DNA-genetic information stored not in a cell's nucleus but in the body's energy-creating mitochondria-is a novel and distinct biomarker that is able to predict the risk of heart attacks and sudden cardiac deaths a decade or more before they happen. In the future, testing blood for this genetic information could not only help physicians more accurately predict a risk for life-threatening cardiac events, but also inform decisions to begin-or avoid-treatment with statins and other drugs.

The two studies, one on cardiovascular disease published in JAMA Cardiology on Oct. 11 and the other focused on sudden cardiac death and published in the European Heart Journal on June 30, revealed that including the mitochondrial DNA copy number improved the accuracy of currently used clinical measures for a patient's risk of a deadly cardiac event. In short, the lower the copy number, the higher the risk.

"We believe the mitochondrial DNA copy number is a novel risk factor for cardiovascular disease, in addition to known predictors like LDL, total cholesterol and blood pressure, and it adds sensitivity and specificity to whether or not you should be taking a statin," says Dan Arking, Ph.D., associate professor of medicine at the McKusick-Nathans Institute of Genetic Medicine and co-director of the Biological Mechanisms Core of the Older Americans Independence Center at the Johns Hopkins University School of Medicine.

Pumpkin 2

Like the mythical monster Hydra: Some plants grow bigger while boosting chemical defenses when clipped

© Julie McMahon
Like a Hydra, some plants grow bigger and boost their chemical defenses after being clipped.
Some plants behave like the mythical monster Hydra: Cut off their heads and they grow back, bigger and better than before. A new study finds that these "overcompensators," as they are called, also augment their defensive chemistry - think plant venom - when they are clipped.

Clipping removes the primary stem and simulates what browsing mammals do when they eat plants in the wild.

The study, reported in the journal Ecology, is the first to find this link and to trace it to three interconnected molecular pathways. The discovery could lead to the development of new methods for boosting plant growth while reducing the need for insecticides, the researchers said.

"You would think that a plant would either produce a lot of defensive chemicals to prevent it from being eaten or that it would put its energy into regrowing after being eaten - but not both, given its limited energy," said graduate student Miles Mesa, who led the research with University of Illinois animal biology professor Ken Paige/. "But we found that the plants that overcompensated - with higher reproductive success after having been damaged - also produced more defensive chemicals in their tissues."

Arrow Up

Puzzling spike in radioactive particles across Europe, baffles scientists

© Daily Star
Increase of ruthenium-106
Radiation monitors have detected radioactive particles in the air across Europe, although the source remains a mystery.

Germany's Office for Radiation Protection reported increased radioactivity in parts of Central and Western Europe over the last week. The heightened levels were detected at several trace measuring stations in Europe, and at six locations in Germany.

The particles are ruthenium-106, an isotope used in cancer radiation therapy for eye tumors and at times in radioisotope thermoelectric generators (RTGs) which provide power to satellites. An increase of ruthenium-106 has been detected in the air in Austria, France, Germany, Italy and Switzerland.

While officials say there's no need to panic, they don't know where the material has come from. The elevated radiation levels don't present a threat to human health.

"New analyzes of the source of the radioactive material are likely to indicate a release in the southern Ural," the Office for Radiation Protection said, "but other regions in Southern Russia can not be excluded."

It said that because it's only ruthenium-106 that has been detected, this rules out a nuclear power plant accident.

Similar spikes in radioactive particles have occurred across Europe in the past, but they are rare. In February, trace amounts of radioactive Iodine-131 were detected across parts of Europe. The iodine faded, and the source of the radioactivity wasn't identified, Motherboard reports. France's IRSN institute announced the trace amounts were detected over Norway, Finland, Poland, Germany, Czech Republic, France and Spain.

Beaker

Dr. Henry Bauer interview discussing the corruption of science

Kyrie Irving, is an amazing basketball player, who made quite a stir earlier this year regarding the flat earth theory.

Ben Nichols, this is a shout out to you. He came to us with this super conspiracy theory, he said, "The earth is flat."

No, the earth is flat.

Oh here we go.

No the earth is flat.

Now, don't get me wrong, there's no way a bright, Duke University educated guy like Kyrie Irving should fall for something anyone can debunk with the United Airlines timetable and some common sense. But take a minute to understand how he formed his opinion.

Hopefully they'll either back my belief or they'll throw it in the water. I think it's interesting for people to find out on their own.

You've seen pictures of the planet thought right? Like it's a circle?

I've seen a lot of things that have been... and my educational system has said that was real and it turned out to be completely fake. I don't mind, I don't mind going against the grain in terms of my thoughts and what I believe.

And with that, you might begin to understand why today's guest, Dr. Henry Bauer, might cut Kyrie some slack.

The popular view of science has not caught up with the present situation where people should be as skeptical about what official science says as they are about what the experts say about any other aspect of society.

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