Check out the latest Science For Thought Volume 3 No.3 (2017) .
Check out the latest Science For Thought Volume 3 No.3 (2017) .
When we brought our first baby home from the hospital, our pediatrician advised us to have her sleep in our room. We put our tiny new roommate in a crib near our bed (though other containers that were flat, firm and free of blankets, pillows or stuffed animals would have worked, too).
The advice aims to reduce the risk of sleep-related deaths, including sudden infant death syndrome, or SIDS. Studies suggest that in their first year of life, babies who bunk with their parents (but not in the same bed) are less likely to die from SIDS than babies who sleep in their own room. The reasons aren’t clear, but scientists suspect it has to do with lighter sleep: Babies who sleep near parents might more readily wake themselves up and avoid the deep sleep that’s a risk factor for SIDS.
Acting like miniature trees that soak up sunlight and release oxygen, photosynthetic bacteria injected into the heart may lighten the damage from heart attacks, a new study in rats suggests.
When researchers injected the bacteria into rats’ hearts, the microbes restored oxygen to heart tissue after blood supply was cut off as in a heart attack, researchers at Stanford University report June 14 in Science Advances.
“It’s really out of the box,” says Himadri Pakrasi, a systems biologist at Washington University in St. Louis who was not involved in the research. “It reads like science fiction to me, but it’s fantastic if it works.”
The organism, called Synechococcus elongatus, has been used recently to produce biofuels, but this may be the first time the cyanobacteria have ever been used in a medical setting, he says.
Other researchers also reacted enthusiastically to the study. “It’s outrageous, but outrageous in a good way,” says Susan Golden, who studies cyanobacteria at the University of California, San Diego. Cardiovascular scientist Matthias Nahrendorf of Massachusetts General Hospital in Boston says, “I enjoy the idea. It’s really fresh.”
Bringing oxygen to starved tissues is what Stanford cardiovascular surgeon Joseph Woo had in mind when he and colleagues dreamed up the plan to put light-harvesting bacteria into the heart. In a heart attack, clogged arteries or blood clots cut off blood flow to the organ. Without oxygen supplied by the blood, heart cells die.
Woo wanted a way for the heart to make its own oxygen or access another supply until doctors could open blocked vessels and restore blood flow. Plants make oxygen from carbon dioxide and sunlight, so Woo wondered, “Why not bring the tree to your heart?”
He and colleagues started by grinding up kale and spinach to harvest chloroplasts, the organelles within plant cells that carry out photosynthesis. But the chloroplasts didn’t survive outside the cells. That’s when the researchers learned about S. elongatus, a photosynthetic organism that Golden and other researchers have long used to study circadian rhythms.
After finding that cyanobacteria could provide oxygen to heart cells in a lab dish, the next step was to see how the cyanobacteria would fare in an animal. The researchers stopped blood flow to part of rats’ hearts and after 15 minutes injected either cyanobacteria or a saline solution. The bacteria increased oxygen in heart tissue to about three times the levels measured right after the heart attack, while saline-treated rats had almost no increase in oxygen.
And that was in the dark: When researchers exposed the heart to light, rats that got the bacteria had 25 times higher oxygen levels than they did after the heart attack. Four weeks after the treatment, these rats had less heart damage than untreated rodents, indicating long-term benefits. In fact, the hearts of photosynthesis-treated rats were beating strongly: Blood flow out of the heart was 30 percent higher in rats treated with cyanobacteria and light than those treated with the bacteria in the dark. That extra blood flow could make the difference between life and death for some patients, Woo says. The results indicate that the bacteria need light to supply heart cells with enough oxygen to stave off damage. That presents a difficulty if the cyanobacteria are ever to be used in people: Getting light into the heart is a major hurdle.
“It will be next to impossible to open the chest to light,” says Nahrendorf. “A day on the beach won’t do the trick.” Woo says the researchers are working with engineers at Stanford to make devices that can shine light through bones and skin to reach the heart and other deep tissues.
Injecting bacteria into the heart is also a risky proposition. “What you’re doing is infecting a tissue, and that’s rarely a good thing,” says Nahrendorf. But the cyanobacteria were cleared from the rats’ bodies within 24 hours and didn’t provoke the immune system to attack the heart, the researchers found. Some other cyanobacteria produce toxins, says Golden. “But this organism is benign,” she says.
Cyanobacteria might also supply oxygen to tissues in other diseases, such as brain injuries, strokes or nonhealing wounds in people with diabetes, says Arnar Geirsson, a cardiovascular scientist at Yale University. Photosynthetic bacteria might also help preserve organs for transplant.
“I’m quite impressed,” Geirsson says. “It’s a really unique way to deliver oxygen.”
Running is a sport that both men and women enjoy, whether they’re racing in a 5K or a marathon, or competing for a team or their country while speeding around a track. But no matter the venue, it’s pretty common to see men clock faster times than women do.
Given that both men and women train equally hard, why is it that men, on average, are faster runners than women? Even the world’s fastest man is about a second speedier on the 100-meter dash than the world’s fastest woman: Usain Bolt did it in 9.58 seconds, versus the late Florence Griffith Joyner’s time of 10.49 seconds. Continue reading “Why Do Men Run Faster Than Women?”
Never underestimate the value of a disposable mucus house.
Filmy, see-through envelopes of mucus, called “houses,” get discarded daily by the largest of the sea creatures that exude them. The old houses, often more than a meter across, sink toward the ocean bottom carrying with them plankton and other biological tidbits snagged in their goo.
Now, scientists have finally caught the biggest of these soft and fragile houses in action, filtering particles out of seawater for the animal to eat. The observations, courtesy of a new deepwater laser-and-camera system, could start to clarify a missing piece of biological roles in sequestering carbon in the deep ocean, researchers say May 3 in Science Advances. Continue reading “Sea creatures’ sticky ‘mucus houses’ catch ocean carbon really fast”
Mars may have had a far-out birthplace.
Simulating the assembly of the solar system around 4.56 billion years ago, researchers propose that the Red Planet didn’t form in the inner solar system alongside the other terrestrial planets as previously thought. Mars instead may have formed around where the asteroid belt is now and migrated inward to its present-day orbit, the scientists report in the June 15 Earth and Planetary Science Letters. The proposal better explains why Mars has such a different chemical composition than Earth, says Stephen Mojzsis, a study coauthor and geologist at the University of Colorado Boulder.
The Earth is home to a range of climates, from the scorching dunes of the Sahara to the freezing ridges of Antarctica. Given this diversity, why are climate scientists so alarmed about a worldwide temperature increase of just 2.7 degrees Fahrenheit (1.5 degrees Celsius)?
Changing the average temperature of an entire planet, even if it’s just by a few degrees, is a big deal, said Peter deMenocal, a paleoclimate scientist at Lamont-Doherty Earth Observatory at Columbia University in New York.
“A person living in any one location can experience huge changes in weather and even in climate, but those are often compensated by changes on opposite sides of the world,” deMenocal told Live Science. [Is Global Warming Melting Antarctica’s Ice?] Continue reading “How Would Just 2 Degrees of Warming Change the Planet?”
Girls and boys with attention-deficit/hyperactivity disorder don’t just behave differently. Parts of their brains look different, too. Now, researchers can add the cerebellum to that mismatch.
For boys, symptoms of the disorder tend to include poor impulse control and disruptive behavior. Girls are more likely to have difficulty staying focused on one task. Studies show that those behavioral differences are reflected in brain structure. Boys with ADHD, for example, are more likely than girls to display abnormalities in premotor and primary motor circuits, pediatric neurologist Stewart Mostofsky of Kennedy Krieger Institute in Baltimore has reported previously.
Now, Mostofsky and colleagues have looked at the cerebellum, which plays a role in coordinating movement. He reported the new findings March 25 at the Cognitive Neuroscience Society’s annual meeting in San Francisco.
Girls ages 8 to 12 with ADHD showed differences in the volume of various regions of their cerebellum compared with girls without the condition, MRI scans revealed. A similar comparison of boys showed abnormalities, too. But those differences didn’t match what’s seen between girls, preliminary analyses suggest. So far, researchers have looked at 18 subjects in each of the four groups, but plan to quintuple that number in the coming months.
Differences seem most prominent in areas of the cerebellum that control higher-order motor functions, Mostofsky said. Those circuits help regulate attention and plan out behavior, versus directing basics like hand-eye coordination. That could help explain why ADHD affects girls’ behavior differently than boys’.
Source : Sciencenews
Video podcasts from the last symposium held on 14.3.2017 are now available on our official YouTube channel.
YSF 2017 Lecture #6
After an influenza infection, the nose recruits immune cells with long memories to keep watch for the virus, research with mice suggests.
For the first time, this type of immune cell — known as tissue resident memory T cells — has been found in the nose, researchers report June 2 in Science Immunology. Such nasal resident memory T cells may prevent flu from recurring. Future nasal spray vaccines that boost the number of these T cells in the nose might be an improvement over current flu shots, researchers say.
It’s known that some T cell sentinels take up residence in specific tissues, including the brain, liver, intestines, skin and lungs. In most of these tissues, the resident memory T cells start patrolling after a localized infection. “They’re basically sitting there waiting in case you get infected with that pathogen again,” says Linda Wakim, an immunologist at the University of Melbourne in Australia. If a previous virus invades again, the T cells can quickly kill infected cells and make chemical signals, called cytokines, to call in other immune cells for reinforcement. These T cells can persist for years in most tissues.
Face-to-face, a human and a chimpanzee are easy to tell apart. The two species share a common primate ancestor, but over millions of years, their characteristics have morphed into easily distinguishable features. Chimps developed prominent brow ridges, flat noses, low-crowned heads and protruding muzzles. Human noses jut from relatively flat faces under high-domed crowns.
YSF 2017 Lecture #5 – Williams Syndrome