Research

Scientists Grow Working Human Brain Circuits

Researchers at the Stanford University School of Medicine have successfully grown the first-ever working 3D brain circuits in a petri dish. Writing in the journal Nature, they say the network of living cells will allow us to study how the human brain develops.

Scientists have been culturing brain cells in the lab for some time now. But previous projects have produced only flat sheets of cells and tissue, which can’t really come close to recreating the three-dimensional conditions inside our heads. The Stanford researchers were especially interested in the way brain cells in a developing fetus can join up together to create networks.

“We’ve never been able to recapitulate these human-brain developmental events in a dish before,” senior author Sergiu Pasca, MD said in a statement.

Studying real-life pregnant women and their fetuses can also be ethically and technically tricky, which means there’s still a…

Shock-absorbing spear points kept early North Americans on the hunt

Clovis points
CLOVIS LINEUP Researchers studied how stone replicas of spear points (two at right) used by ancient Clovis people absorbed pressure. Results suggest Clovis points fluted at the base absorbed shock, preventing tip breakage while hunting. Three casts of actual fluted Clovis points are on the left.

Ancient North Americans hunted with spear points crafted to absorb shock.

Clovis people, who crossed a land bridge from Asia to North America around 13,500 years ago, fashioned stone weapons that slightly crumpled at the base rather than breaking at the tip when thrust into prey, say civil engineer Kaitlyn Thomas of Southern Methodist University in Dallas and colleagues. The Clovis crumple rested on a toolmaking technique called fluting, in which a thin groove was chipped off both sides of a stone point’s base, the researchers report in the May Journal of Archaeological Science.

Computer models and pressure testing of replicas of fluted and unfluted Clovis points support the idea that fluted bases worked like shock absorbers, preventing tip breakage, the scientists conclude. Slight compression and folding of stone at the base of fluted points after an impact did not cause enough damage to prevent the points from being reused, they say.

“Fluted Clovis points have a shock-absorbing property that increases their durability, which fit a population that needed reliable weapons on a new, unknown continent,” says archaeologist and study coauthor Metin Eren of Kent State University in Ohio. While Clovis people weren’t the first New World settlers (SN: 6/11/16, p. 8), they roamed throughout much of North America. Individuals traveled great distances to find food and move among seasonal camps, Eren says.

spear point
A Clovis stone point replica, chiseled by Kent State archaeologist Metin Eren, contains a fluted section at…

Study Finds Women in Academia Do More Unpaid “Service” Work

In today’s unsurprising news, a new study has found that women in academia perform more unpaid labor than men. Researchers writing in the journal Research in Higher Education say female professors are more likely—and more expected—to give their time to students, while their better-compensated male colleagues use those same hours to publish, conduct research, and advance their careers.

Education experts culled data from the 2014 Faculty Survey of Student Engagement (FSSE), which asked nearly 19,000 faculty members at 143 colleges about their interactions with their students. They also dug into detailed faculty activity reports at two institutions.

The results showed a significant difference in the way academic men and women spent their time. Female respondents to the FSSE spent an average of 30 minutes more per week on service tasks like advising students, serving on committees, and leading extracurricular activities. Even among full professors, women devoted significantly more time to service activities than their male counterparts. This was true even after the researchers controlled for variables like race, academic department, and university.

The paper’s authors couldn’t pinpoint the root cause (or…

Researchers Create Motorized Wheelchair Made for the Water Park

image credit: University of Pittsburgh

Despite advances in technology, there are many aspects of the world that remain inaccessible to people with disabilities. But researchers at the University of Pittsburgh are working to make one activity easier for people who use motorized wheelchairs: navigating water parks.

The average motorized wheelchair has a number of electrical and battery components that can’t get wet, limiting who can access the joys of splash parks and pools. But a new wheelchair that uses compressed air instead of a heavy battery could change that, Gizmodo recently reported.

Created through a joint research project between University of Pittsburgh engineers, the university’s medical center, and the U.S. Department of Veterans Affairs, the PneuChair is lighter and quicker to charge…

Language heard, but never spoken, by young babies bestows a hidden benefit

mother and baby laughing and playing
Babies who heard Korean spoken in their first six months of life were better able to pick up the language later as adults, a study finds. The results show how early language exposure patterns the brain in ways that may not be revealed for decades, if ever.

The way babies learn to speak is nothing short of breathtaking. Their brains are learning the differences between sounds, rehearsing mouth movements and mastering vocabulary by putting words into meaningful context. It’s a lot to fit in between naps and diaper changes.

A recent study shows just how durable this early language learning is. Dutch-speaking adults who were adopted from South Korea as preverbal babies held on to latent Korean language skills, researchers report online January 18 in Royal Society Open Science. In the first months of their lives, these people had already laid down the foundation for speaking Korean — a foundation that persisted for decades undetected, only revealing itself later in careful laboratory tests.

Researchers tested how well people could learn to identify and speak tricky Korean sounds. “For Korean listeners, these sounds are easy to distinguish, but for second-language…

Random mutations play large role in cancer, study finds

GROWING PAINS As cells divide and grow to replenish and repair organs, accidental mutations may crop up in cancer-associated genes. A new study suggests such random mistakes are the source of 66 percent of mutations in cancer cells (illustrated here) across the board.

Researchers have identified new enemies in the war on cancer: ones that are already inside cells and that no one can avoid.

Random mistakes made as stem cells divide are responsible for about two-thirds of the mutations in cancer cells, researchers from Johns Hopkins University report in the March 24 Science. Across all cancer types, environment and lifestyle factors, such as smoking and obesity, contribute 29 percent of cancer mutations, and 5 percent are inherited.

That finding challenges the common wisdom that cancer is the product of heredity and the environment. “There’s a third cause and this cause of mutations is a major cause,” says cancer geneticist Bert Vogelstein.

Such random mutations build up over time and help explain why cancer strikes older people more often. Knowing that the enemy will strike from within even when people protect themselves against external threats indicates that early cancer detection and treatment deserve greater attention than they have previously gotten, Vogelstein says.

Vogelstein and biomathematician Cristian Tomasetti proposed in 2015 that random mutations are the reason some organs are more prone to cancer than others. For instance, stem cells are constantly renewing the intestinal lining of the colon, which develops tumors more often than the brain, where cell division is uncommon. That report was controversial because it was interpreted as saying that most cancers are the result of “bad luck.” The analysis didn’t include breast and prostate cancers. Factoring in those common cancers might change the results, some scientists said. And because the researchers looked at only cancer within the United States, critics charged that the finding might not hold up when considering places around the world where different environmental factors, such as infections, affect cancer development.

In the new study, Vogelstein, Tomasetti and Hopkins colleague Lu Li examined data from 69 countries about 17 types of cancer, this time including breast and prostate. Again, the researchers found a strong link between cancer and tissues with lots of dividing stem cells. The team also used DNA data and epidemiological studies to calculate the proportions of mutations in cancer cells caused by heredity or environmental and lifestyle factors. Remaining mutations were attributed to random errors — including typos, insertions or deletions of genes, epigenetic changes (alterations of chemical tags on DNA or proteins that affect gene activity) and gene rearrangements. Such errors unavoidably happen when cells divide.

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Chance cancer

For many organs, more of the mutations that lead to cancer come from random mistakes in DNA…

Watch Hilariously Awkward Robots Rap About Their Machine-Learning Skills

How do robots learn to act more like humans? Not by rapping. Researchers from Telecommunications Research Institute in Kyoto, Japan recently summarized their latest work [PDF] by having two robots show off their lyrical skills, and boy, is it cringe-worthy (Gizmodo called it “agonizingly awkward”) and amazing.

Two robots, Robovie and the super creepy android ERICA, rap their way through a parody of the Sugarhill Gang’s “

Yale Researchers Find That Autism Genes Helped Us to Become Smarter

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Those with autism face distinct challenges. These usually have to do with certain social deficits. That might be why the results of a new study appear a bit puzzling. Genes linked to autism spectrum disorders (ASD) were actually preserved through the process of evolution, Yale researchers concluded. These genes actually made us smarter.

If you find these results strange, consider the large numbers of scientists and engineers known to have Asperger’s syndrome. There are autistic savants as well, as the movie Rain Man can attest, which was based on a true story. Or perhaps you’ve seen the work of mind-blowing artist Stephen Wiltshire, who can draw panoramic scenes of whole cities with perfect detail, from his memory alone.

This was a genome-wide study, zeroing in on gene variants associated with ASD. Researchers examined 5,000 cases of autism and analyzed the genome of each participant. They focused on evolutionary gene selection, particularly on which genes were positively selected. One clue which led researchers to these findings was that, more genes associated with autism were preserved by evolution than would have been through sheer randomness.

Autistic…

Scientists move closer to building synthetic yeast from scratch

Saccharomyces cerevisiae yeast
BUDDING STAR With five more synthetic chromosomes built, scientists are closer to creating a synthetic genome for Saccharomyces cerevisiae yeast (shown).

Synthetic yeast is on the rise.

Scientists have constructed five more yeast chromosomes from scratch. The new work, reported online March 9 in Science, brings researchers closer to completely lab-built yeast.

“We’re doing it primarily to learn a little more about how cells are wired,” says geneticist Jef Boeke of the New York University Langone Medical Center. But scientists might also be able to tinker with a synthetic yeast cell more efficiently than a natural one, allowing more precise engineering of everything from antiviral drugs to biofuels.

Boeke was…

9 Up-Close Scientific Images from the Wellcome Image Awards

Each year, the Wellcome Image Awards highlight some of the most fascinating scientific images from around the world, as chosen by a panel of experts from the fields of science communications and medicine. The awards go to photographers and researchers who create “informative, striking and technically excellent images that communicate significant aspects of healthcare and biomedical science,” according to the Wellcome Trust, a biomedical research charity based in the UK. Here are nine of this year’s winning images:

ZEBRAFISH EYE AND NEUROMASTS

Ingrid Lekk and Steve Wilson, University College London

In this 4-day-old zebrafish embryo, a certain gene expressed in the lens of the eye and other parts of the visual system glows red when it’s activated. You can see the lens of the eye, the head, and neuromasts (those red dots around the rim of the image) glowing red, while the nervous system glows blue.

BLOOD VESSELS OF THE AFRICAN GREY PARROT

This image was created using a 3D reconstruction of a euthanized parrot. It models the system of blood vessels in the parrot’s head and neck down to the capillary level.

INTRAOCULAR LENS IRIS CLIP

Mark Bartley, Cambridge University Hospitals NHS Foundation Trust

Iris clips can treat nearsightedness, cataracts, and other eye issues. This photo shows an iris clip fitting on the eye of a 70-year-old patient. He regained nearly all his vision after the surgery.

BRAIN-ON-A-CHIP

Collin…