scientists

ALLIGATORS ARE FEASTING ON SHARKS IN AMERICA’S RIVERS AND ESTUARIES, SCIENTISTS DISCOVER

There is always a bigger fish, the old adage goes and if there isn’t, at the very least there is a bigger alligator, new research confirms.

Even when it comes to sharks—an infamous predator of the sea—as they risk becoming prey to the American alligator when they venture into freshwater, a study published in Southeastern Naturalist confirms.

The study of the stomach contents of 500 living alligators captured and examined by Kansas State University researcher James Nifong and IMSS wildlife biologist Russell Lowers unveiled four different species of sharks, including nurse sharks and stingrays.

The American alligator, also known as Alligator mississippiensis, and the various types of sharks usually swim in waters that rarely overlap as alligators are freshwater dwellers, while sharks top food chains in salt waters.

On the rare occasion where either species feels some wanderlust for the other’s ecosystem, the alligator is liable to swap its meal of crustaceans, snails, and smaller fish for more vicious prey.

gator-shark-smAmerican alligator preying on a nurse shark.U.S. FISH AND WILDLIFE SERVICE J.N. “DING” DARLING NATIONAL WILDLIFE REFUGE.

Sharks have been spotted slipping into freshwater areas on occasion. Equally, while alligators lack salt glands—a requirement if their body is to filter the saltwater they plan on surviving in—the species can suss out whenever saltwater becomes temporarily diluted, after heavy rainfall for example.

“Alligators seek out fresh water in high-salinity environments,” said Nifong in a statement. “When it rains really hard, they can actually sip fresh water off the surface of the saltwater. That can prolong the time they can stay in a saltwater environment.”

Alligators are not inherently the victor in an altercation with any shark, however. In fact, as the relationship between the two species becomes closer, what the dynamic between them looks like is more of mutual hunting or “reciprocal predation.” In other words, it is likely that once hungry and pitted in the same environment, it is a question of size that determines if the alligator eats the shark or vice versa.

“The frequency of one predator eating the other is really about size dynamic,” Nifong said “If a small shark swims by an alligator and the alligator feels like it can take the shark down, it will, but we also reviewed some old stories about larger sharks eating smaller alligators.”

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Hitler’s Scientists May Have Tested the First Atomic Weapon

Most people are familiar with the famous mushroom-shaped cloud picture which shows the famous atomic bomb dropping on Nagasaki, Japan on August 9, 1945. But what if Germany also had produced its own smaller-scale mushroom cloud a year earlier in the fall of 1944?

The Germans may have lost the neck-and-neck race to build a successful nuclear bomb during WWII, but it’s clear that they were able to test a pretty impressive warhead in 1944.

“A cloud shaped like a mushroom with turbulent, billowing sections (at about 7000 meters) stood, without any seeming connections over the spot where the explosion took place. Strong electrical disturbances and the impossibility to continue radio communication as by lightning turned up.”

This was a statement made by German test pilot Hans Zinsser, in Allan Hall’s DailyMail.com article, who was doing test flights over Ludwigslust at the time. He was not the only witness to the spectacular sight that day.

The Dawn of Nuclear Weapons

In December 1938, German chemist Otto Hahn discovered nuclear fission, the building block of nuclear chain reactions and disastrously dangerous atomic weapons. Shortly after this discovery, Germany’s nuclear weapons project was born.

For over four years, groups of German scientists explored the possibilities of nuclear weapons production under Adolf Hitler’s watchful eye. The Third Reich achieved success in building “uranium machines” otherwise known as nuclear reactors. However, after repeated alterations to the design, they lacked enough of a heavily-ionized water source known as “heavy water.”

Once their supply of heavy water from Norway was cut off, Hitler’s team only had enough resources for a few more large-scale experiments. This resulted in the sensational production of the first nuclear warhead testing cloud ever seen.

The First Ever Nuclear Test

Mark Walker’s article “Nazis and the Bomb,” published by PBS’s Nova states: “During the last months of the war, a small group of scientists working in secret under Diebner and with the strong support of the physicist Walther Gerlach, who was by that time head of the uranium project, built and tested a nuclear device.”

The multi-colored cloud that was several miles wide was definitely not the imagination of those few eyewitnesses who came forward to describe it. Two German pilots, as well as an Italian observer sent by famed dictator Benito Mussolini, described the sight in similar detail to each other.

Germany was not able to produce the atomic weapons it had hoped for in order to gain the upper hand in WWII. In 1942, Hitler ordered the Reich Research Council to be reorganized as a separate division from the military. With Reich Minister for Armament and Ammunition, Albert Speer, heading the council, the project morphed into a study for alternative energy production, Mail Online reported.

This change did not prevent the germans from being able to demonstrate at least one impressive large-scale test of nuclear power. No one can be sure of the exact nature of the warhead that Germany tested, but what remains undisputed is that it was accomplished and reported by several different sources.

There’s enough wind energy over the oceans to power human civilization, scientists say

New research published on Monday finds there is so much wind energy potential over oceans that it could theoretically be used to generate “civilization scale power” — assuming, that is, that we are willing to cover enormous stretches of the sea with turbines, and can come up with ways to install and maintain them in often extreme ocean environments.

It’s very unlikely that we would ever build out open ocean turbines on anything like that scale — indeed, doing so could even alter the planet’s climate, the research finds. But the more modest message is that wind energy over the open oceans has large potential — reinforcing the idea that floating wind farms, over very deep waters, could be the next major step for wind energy technology.

“I would look at this as kind of a greenlight for that industry from a geophysical point of view,” said Ken Caldeira of the Carnegie Institution for Science in Stanford, Calif. The study, in the Proceedings of the National Academy of Sciences, was led by Carnegie researcher Anna Possner, who worked in collaboration with Caldeira.

The study takes, as its outset, prior research that has found that there’s probably an upper  limit to the amount of energy that can be generated by a wind farm that’s located on land. The limit arises both because natural and human structures on land create friction that slows down the wind speed, but also because each individual wind turbine extracts some of the energy of the wind and transforms it into power that we can use — leaving less wind energy for other turbines to collect.

“If each turbine removes something like half the energy flowing through it, by the time you get to the second row, you’ve only got a quarter of the energy, and so on,” explained Caldeira.

The ocean is different. First, wind speeds can be as much as 70 percent higher than on land. But a bigger deal is what you might call wind replenishment. The new research found that over the mid-latitude oceans, storms regularly transfer powerful wind energy down to the surface from higher altitudes, meaning that the upper limit here for how much energy you can capture with turbines is considerably higher.

“Over land, the turbines are just sort of scraping the kinetic energy out of the lowest part of the atmosphere, whereas over the ocean, it’s depleting the kinetic energy out of most of the troposphere, or the lower part of the atmosphere,” said Caldeira.

The study compares a theoretical wind farm of nearly 2 million square kilometers located either over the U.S. (centered on Kansas) or in the open Atlantic. And it finds that covering much of the central U.S. with wind farms would still be insufficient to power the U.S. and China, which would require a generating capacity of some 7 terawatts annually (a terawatt is equivalent to a trillion watts).

But the North Atlantic could theoretically power those two countries and then some. The potential energy that can be extracted over the ocean, given the same area, is “at least three times as high.”

It would take an even larger, 3 million square kilometer wind installation over the ocean to provide humanity’s current power needs, or 18 terawatts, the study found. That’s an area even larger than Greenland.

Hence, the study concludes that “on an annual mean basis, the wind power available in the North Atlantic could be sufficient to power the world.”

But it’s critical to emphasize that these are purely theoretical calculations. They are thwarted by many practical factors, including the fact that the winds aren’t equally strong in all seasons, and that the technologies to capture their energy at such a scale, much less transfer it to shore, do not currently exist.

Oh, and then there’s another large problem: Modeling simulations performed in the study suggest that extracting this much wind energy from nature would have planetary-scale effects, including cooling down parts of the Arctic by as much as 13 degrees Celsius.

“Trying to get civilization scale power out of wind is a bit asking for trouble,” Caldeira said. But he said the climate effect would be smaller if the amount of energy being tapped was reduced down from these extremely high numbers, and if the wind farms were more spaced out across the globe.

“I think it lends itself to the idea that we’re going to want to use a portfolio of technologies, and not rely on this only,” said Caldeira.

Energy gurus have long said that among renewable sources, solar energy has the greatest potential to scale up and generate terawatt-scale power, enough to satisfy large parts of human energy demand. Caldeira doesn’t dispute that. But his study suggests that at least if open ocean wind becomes accessible someday, it may have considerable potential too.

Alexander Slocum, an MIT mechanical engineering professor who has focused on offshore wind and its potential, and who was not involved in the research, said he considered the paper a “very good study” and that it didn’t seem biased.

“The conclusion implied by the paper that open ocean wind energy farms can provide most of our energy needs is also supported history: as a technology gets becomes constrained (e.g., horse drawn carriages) or monopolized (OPEC), a motivation arises to look around for alternatives,” Slocum continued by email. “The automobile did it to horses, the U.S. did it to OPEC with fracking, and now renewables are doing it to the hydrocarbon industry.”

“The authors do acknowledge that considerable technical challenges come into play in actually harvesting energy from these far off-shore sites, but I appreciate their focus on the magnitude of the resource,” added Julie Lundquist, a wind energy researcher at the University of Colorado, Boulder. “I hope this work will stimulate further interest in deep water wind energy.”

Underscoring the theoretical nature of the calculations, Lundquist added by email that “current and foreseeable wind turbine deployments both on- and off-shore are much smaller than would be required to reach the atmospheric energy limitations that this work and others are concerned with.”

The research points to a kind of third act for wind energy. On land, turbines are very well established and more are being installed every year. Offshore, meanwhile, coastal areas are now also seeing more and more turbine installations, but still in relatively shallow waters.

But to get out over the open ocean, where the sea is often well over a mile deep, is expected to require yet another technology — likely a floating turbine that extends above the water and sits atop some kind of very large submerged floating structure, accompanied by cables that anchor the entire turbine to the seafloor.

Experimentation with the technology is already happening: Statoil is moving to build a large floating wind farm off the coast of Scotland, which will be located in waters around 100 meters deep and have 15 megawatts (million watts) of electricity generating capacity. The turbines are 253 meters tall, but 78 meters of that length refers to the floating part below the sea surface.

“The things that we’re describing are likely not going to be economic today, but once you have an industry that’s starting in that direction, should provide incentive for that industry to develop,” said Caldeira.

Scientists just discovered the first brainless animal that sleeps

https://www.washingtonpost.com/news/speaking-of-science/wp/2017/09/21/scientists-just-discovered-the-first-animal-without-a-brain-that-sleeps/?utm_term=.776108d3b2d5

 

It was well past midnight when Michael Abrams, Claire Bedbrook and Ravi Nath crept into the Caltech lab where they were keeping their jellyfish. They didn’t bother switching on the lights, opting instead to navigate the maze of desks and equipment by the pale blue glow of their cellphones. The students hadn’t told anyone that they were doing this. It wasn’t forbidden, exactly, but they wanted a chance to conduct their research without their PhD advisers breathing down their necks.

“When you start working on something totally crazy, it’s good to get data before you tell anybody,” Abrams said.

The “totally crazy” undertaking in question: an experiment to determine whether jellyfish sleep.

It had all started when Bedbrook, a graduate student in neurobiology, overheard Nath and Abrams mulling the question over coffee. The topic was weird enough to make her stop at their table and argue.

“Of course not,” she said. Scientists still don’t fully know why animals need to snooze, but research has found that sleep is a complex behavior associated with memory consolidation and REM cycles in the brain. Jellyfish are so primitive they don’t even have a brain — how could they possibly share this mysterious trait?

Her friends weren’t so sure. “I guess we’re going to have to test it,” Nath said, half-joking.

Bedbrook was dead serious: “Yeah. Yeah, we are.”

After months of late-night research, Bedbrook has changed her mind. In a paper published Thursday in the journal Current Biology, she, Nath and Abrams report that the upside-down jellyfish Cassiopea exhibit sleeplike behavior — the first animals without a brain known to do so. The results suggest that sleep is deeply rooted in our biology, a behavior that evolved early in the history of animal life and has stuck with us ever since.

Further study of jellyfish slumber might bring scientists closer to resolving what Nath called “the paradox of sleep.”

Think about it, he urged. If you’re asleep in the wild when a predator comes along, you’re dead. If a food source strolls past, you go hungry. If a potential mate walks by, you miss the chance to pass on your genetic material.

“Sleep is this period where animals are not doing the things that benefit from a natural selection perspective,” Nath said.

Abrams chimed in: “Except for sleep.” Nath laughed.

“We know it must be very important. Otherwise, we would just lose it,” Bedbrook said. If animals could evolve a way to live without sleep, surely they would have. But many experiments suggest that when creatures such as mice are deprived of sleep for too long, they die. Scientists have shown that animals as simple as the roundworm C. elegans, with a brain of just 302 neurons, need sleep to survive.

Cassiopea has no brain to speak of — just a diffuse “net” of nerve cells distributed across their small, squishy bodies. These jellyfish barely even behave like animals. Instead of mouths, they suck in food through pores in their tentacles. They also get energy via a symbiotic relationship with tiny photosynthetic organisms that live inside their cells.

“They’re like weird plant animals,” Bedbrook said.

They’re also ancient: Cnidarians, the phylogenetic group that includes jellies, first arose some 700 million years ago, making them some of Earth’s first animals. These traits make Cassiopea an ideal organism to test for the evolutionary origins of sleep. Fortuitously, Abrams already had some on hand.

So the trio designed an experiment. At night, when the jellies were resting and their professors were safely out of the picture, the students would test for three behavioral criteria associated with sleep.

First: Reversible quiescence. In other words, the jellyfish become inactive but are not paralyzed or in a coma. The researchers counted the jellyfish’s movements and found they were 30 percent less active at night. But when food was dropped into the tank, the creatures perked right up. Clearly not paralyzed.

Second: An increased arousal threshold. This means it’s more difficult to get the animals’ attention; they have to be “woken up.” For this, the researchers placed sleeping jellies in containers with removable bottoms, lifted the containers to the top of their tank, then pulled out the bottom. If the jellyfish were awake, they’d immediately swim to the floor of the tank. But if they were asleep, “they’d kind of strangely float around in the water,” Abrams said.

“You know how you wake up with vertigo? I pretend that maybe there’s possible chance that the jellyfish feel this,” Nath added. “They’re sleeping and then they wake up and they’re like, ‘Ahhhh!’ ”

And third: The quiescent state must be homeostatically regulated. That is, the jellyfish must feel a biological drive to sleep. When they don’t, they suffer.

“This is really equivalent to how we feel when we pull an all-nighter,” Bedbrook said. She’s all too familiar with the feeling — getting your PhD requires more late nights than she’s willing to count.

The jellyfish have no research papers to keep them awake past their bedtimes, so the scientists prevented them from sleeping by “poking” them with pulses of water every 20 minutes for an entire night. The following day, the poor creatures swam around in a daze, and the next night they slept especially deeply to make up for lost slumber.

Realizing they really had something here, the students clued their professors in on what they were doing. The head of the lab where Nath worked, Caltech and Howard Hughes Medical Institute biologist Paul Sternberg, offered the trio a closet in which they could to continue their experiments.

“It’s important,” Sternberg said, “because it’s [an organism] with what we think of as a more primitive nervous system. … It raises the possibility of an early evolved fundamental process.”

Sternberg, along with Abram and Bedbrook’s advisers, is a co-author on the Current Biology paper.

Allan Pack, the director of the Center for Sleep and Respiratory Neurobiology at the University of Pennsylvania, was not involved in the jellyfish research, but he’s not surprised by the finding, given how prevalent sleep is in other species.

“Every model that has been looked at … shows a sleep-like state,” he said.

But the revelations about jellyfish sleep are important, he said, because they show how basic sleep is. It appears to be a “conserved” behavior, one that arose relatively early in life’s history and has persisted for millions of years. If the behavior is conserved, then perhaps the biological mechanism is too. Understanding why jellyfish, with their simple nerve nets, need sleep could lead scientists to the function of sleep in humans.

“I think it’s one of the major biological questions of our time,” Pack said. “We spend a third of a life sleeping. Why are we doing it? What’s the point?”

9/11 CHILDREN: SCIENTISTS FIND TOXINS IN THEIR BABY TEETH

http://www.newsweek.com/911-children-babies-toxins-health-risks-september-11-attacks-tin-lead-662922?spMailingID=2260306&spUserID=MzQ4OTUyNDAxNTAS1&spJobID=870483799&spReportId=ODcwNDgzNzk5S0

 

On September 11, 2001, Lucie Lagodich was just 11 months old but already able to sit up. A private family photo snapped on that day and shared with Newsweek by her mother, Tracy Gill, shows her perched on an exposed, cement rooftop in downtown Manhattan. Just above her, two plumes of smoke drift from the giant holes ripped in the World Trade Center towers.

“There is the innocence of the child, and then there is this horrible event taking place, with no connection between the two,” says Lagodich, now 16. “When I look at that photo, it is so surreal to me. It was such an insane moment in our history. I don’t remember it, but, in some way or another, it has always been a part of me.”

The baby teeth of 9/11-era children like Lagodich have become the focus of a pilot study in recent months by scientists at New York’s Mount Sinai Hospital. They are examining how pollutants released into the air when the World Trade Center towers collapsed may have long-term health consequences for children who grew up near Ground Zero, many of them now teenagers and young adults. In preliminary results shared exclusively with Newsweek, the doctors said approximately half of the baby teeth tested from four small batches last week showed traces of tin and lead, neurotoxins found in the dust cloud left by the fallen towers.

“We didn’t know what we’d find, but the lead and tin, these two elements, turned up as a strong signal in the data,” says the study’s lead scientist, Dr. Roberto Lucchini, professor of preventive medicine at Mount Sinai’s Icahn School of Medicine. “It shows the need to broaden the research to include more baby teeth that would allow us to form firm scientific conclusions.”

Neurotoxins are destructive compounds that can affect the entire nervous system, which include the brain and the spinal cord, regulating everything from anxiety to obesity. “Of course, we know that the inhalation of dust and particles can trigger cancer and respiratory and cardiovascular problems. But it can also create systemic reactions throughout the body, regulating things like hormones, behavior and the brain,” Lucchini notes.

Related: Cancer and other diseases link to the 9/11 attacks are surging

9/11 childrenTracy Gill and daughter, Lucie Valentine Lagodich, in September 2001, near Ground Zero.SIMEON LAGODICH

Doctors at Mount Sinai estimate that as many as 400,000 people have been affected by cancers, diseases and mental illnesses linked to the September 11 attacks. This figure includes those who lived and worked within a mile and a half of Ground Zero in Manhattan and Brooklyn, the majority of whom still don’t know they’re at risk.

Two of the batches of teeth tested in Lucchini’s study showed “very unusual patterns” in their chemical compositions, says Dr. Manish Arora, an associate professor of dentistry and environmental medicine at the Icahn school. “We’ve seen tin in the teeth of adults who are much older, 50 or 60, yes, but I’ve never seen it in kids,” says Arora, citing studies around the world. “We also saw repeated lead exposure in the teeth of a second child in this study, which means we have to sit down with the family and find out if there were any other reasons the child may have been exposed.”

Arora, who studies the impact of chemical exposures from early childhood on lifelong health, has examined hundreds of samples of baby teeth in industrial cities in Italy and in high-traffic areas of Mexico City, but he has never seen results like those he’s finding in the baby teeth of the 9/11-era children. “It is completely different from what we’ve seen before,” he says. “This was really something so intensive for these children to be exposed to at the time. It is very important for us to understand the risks so we can provide them with information and recommendations.”

The batches of baby teeth used in the study, donated by the parents of children both born and unborn at the time of 9/11, were blind-tested by Arora using a laser that can detect chemical exposures from microscopic pieces of dental tissue. Analyzing bands of the teeth is much like mapping the growth rings of a tree, with each slice revealing a universe of information, Lucchini says.

“With a tree, a wide ring means there was plenty of rain and the tree was in good health that year,” he tells Newsweek. A thin ring means the conditions were not as ideal. It’s very similar with teeth.” Baby teeth are purer than any other kind because they are made of prenatal material, so chemical exposures are easier to measure and the outcomes clearer.

One of the pilot study’s biggest challenges: finding children in lower Manhattan who still have their baby teeth some 16 years after the attacks. The pilot study took batches from four individuals, including one child who wasn’t born until the spring of 2012, Lucchini says.

“Another one was being held in the mother’s arms as the towers came down,” he says. “If there was an absorption of chemicals through the mother to the infant during the pregnancy, that means these chemical elements did not reach just the teeth but the rest of the child.” For purposes of privacy, the study did not reveal which results came from which children.

9/11 - World Trade CenterAn American flag flies near the base of the destroyed World Trade Center on September 11, 2001.PETER MORGAN/REUTERS

Lucchini, who collected most of the baby teeth during the past year from people throughout lower Manhattan, says he is hoping to recruit more participants for the study, as it is ongoing and he wants to expand its scale to reach more conclusive results. He says people can mail their teeth or drop them off. “We will take teeth any way we can,” he says. “But they have to be out of the mouth.”

Kimberly Flynn, co-founder and director of the downtown outreach group 9/11 Environmental Action, helped Lucchini contact the community for his study. She estimates that about 40,000 children were attending school or day care near Ground Zero during the attacks. “Children exposed to the 9/11 environmental disaster remain the least studied of any of the exposed population,” she says. “The community continues to demand answers that will help families and children better understand what their future risks may be from 9/11 exposures.”

Other studies focusing on the children of 9/11 are beginning to trickle out. One released September 7 by New York University Langone Health researchers showed early signs of heart disease risk among children exposed to the toxic chemicals from September 11.

Lagodich, who watched the Freedom Tower rise in the footprint of Ground Zero from the window of her downtown middle school, was one of the subjects of Lucchini’s baby teeth study, she says. A competitive swimmer and the captain of her champion table tennis team, she says she’s never noticed any health problems, but with all the headlines, “I do worry about it.”

Her mother, Gill, says she and her husband, Simeon, both artists who co-own a period frame gallery in New York, debated leaving their home in Tribeca after the attacks, but chafed at the thought of allowing violent extremists to drive them from their neighborhood. “I’d never felt so patriotic before,” says Gill, now 57. “We put signs up in our windows in big letters saying, ‘HERE TO STAY.’ Also, you just don’t leave a rent-stabilized place in Tribeca.”

Enrolling in Lucchini’s study—the first 9/11 study Lagodich has participated in—certainly wasn’t an easy decision for her and her family, but, she says, as a student fellow at the Museum of Natural History, she cannot help but be intellectually fascinated by the ongoing effects of September 11.

“I’m into the sciences and history,” Lagodich says. “And this is a case where the two have collided in a way where history is affecting both the past and the future.”

Scientists are closing in on warm caves under Antarctica which could support secret life

Australian scientists investigating ice caves under Antarctica’s glaciers say they are so warm they could support animals and plants.

Around Mount Erebus, an active volcano on Ross Island in Antarctica, steam has hollowed out extensive cave systems.

Dr Ceridwen Fraser from the ANU Fenner School of Environment and Society says forensic analyses of soil samples from these caves have revealed intriguing traces of DNA from algae, mosses and small animals.

“It can be really warm inside the caves, up to 25 degrees Celsius in some caves,” Fraser says.

“You could wear a T-shirt in there and be pretty comfortable. There’s light near the cave mouths, and light filters deeper into some caves where the overlying ice is thin.”

Most of the DNA found in the caves is similar to DNA from plants and animals found elsewhere in Antarctica but not all could be fully identified.

“The results from this study give us a tantalising glimpse of what might live beneath the ice in Antarctica – there might even be new species of animals and plants,” she says.

The next step will be to take a closer look at the caves and search for living organisms.

 

Co-researcher Professor Craig Cary, from the University of Waikato in New Zealand, says previous research found that diverse bacterial and fungal communities lived in Antartica’s volcanic caves.

“The findings from this new study suggest there might be higher plants and animals as well,” Professor Cary said.

Dr Charles Lee, another co-researcher from the University of Waikato, says there are many other volcanoes in Antarctica, so subglacial cave systems could be common across the icy continent.

“We don’t yet know just how many cave systems exist around Antarctica’s volcanoes, or how interconnected these subglacial environments might be. They’re really difficult to identify, get to and explore,” Dr Lee says.

The research, published in the international journal Polar Biology, was funded by the Australian Research Council, with sample collection supported by Antarctica New Zealand and the Marsden Fund.

In Breakthrough, Scientists Edit a Dangerous Mutation From Genes in Human Embryos

Scientists for the first time have successfully edited genes in human embryos to repair a common and serious disease-causing mutation, producing apparently healthy embryos, according to a study published on Wednesday.

The research marks a major milestone and, while a long way from clinical use, it raises the prospect that gene editing may one day protect babies from a variety of hereditary conditions.

But the achievement is also an example of human genetic engineering, once feared and unthinkable, and is sure to renew ethical concerns that some might try to design babies with certain traits, like greater intelligence or athleticism.

Scientists have long feared the unforeseen medical consequences of making inherited changes to human DNA. The cultural implications may be just as disturbing: Some experts have warned that unregulated genetic engineering may lead to a new form of eugenics, in which people with means pay to have children with enhanced traits even as those with disabilities are devalued.

The study, published in the journal Nature, comes just months after a national scientific committee recommended new guidelines for modifying embryos, easing blanket proscriptions but urging the technique be used only for dire medical problems.

 

“We’ve always said in the past gene editing shouldn’t be done, mostly because it couldn’t be done safely,” said Richard Hynes, a cancer researcher at the Massachusetts Institute of Technology who co-led the committee. “That’s still true, but now it looks like it’s going to be done safely soon,” he said, adding that the research is “a big breakthrough.”

“What our report said was, once the technical hurdles are cleared, then there will be societal issues that have to be considered and discussions that are going to have to happen. Now’s the time.”

Scientists at Oregon Health and Science University, with colleagues in California, China and South Korea, reported that they repaired dozens of embryos, fixing a mutation that causes a common heart condition that can lead to sudden death later in life.

If embryos with the repaired mutation were allowed to develop into babies, they would not only be disease-free but also would not transmit the disease to descendants.

The researchers averted two important safety problems: They produced embryos in which all cells — not just some — were mutation-free, and they avoided creating unwanted extra mutations.

“It feels a bit like a ‘one small step for (hu)mans, one giant leap for (hu)mankind’ moment,” Jennifer Doudna, a biochemist who helped discover the gene-editing method used, called CRISPR-Cas9, said in an email.

Gene Editing in Embryos
Scientists tried two techniques to remove a dangerous mutation. In the first, genetic “scissors” were inserted into fertilized eggs. The mutation was repaired in some of the resulting embryos but not always in every cell. The second method worked better: By injecting the “scissors” along with the sperm into the egg, more embryos emerged with repaired genes in every cell.

FIRST TECHNIQUE
When gene-editing components were introduced into a fertilized egg, some embryos contained a patchwork of repaired and unrepaired cells.

“I expect these results will be encouraging to those who hope to use human embryo editing for either research or eventual clinical purposes,” said Dr. Doudna, who was not involved in the study.

Much more research is needed before the method could be tested in clinical trials, currently impermissible under federal law. But if the technique is found to work safely with this and other mutations, it might help some couples who could not otherwise have healthy children.

Potentially, it could apply to any of more than 10,000 conditions caused by specific inherited mutations. Researchers and experts said those might include breast and ovarian cancer linked to BRCA mutations, as well as diseases like Huntington’s, Tay-Sachs, beta thalassemia, and even sickle cell anemia, cystic fibrosis or some cases of early-onset Alzheimer’s.

“You could certainly help families who have been blighted by a horrible genetic disease,” said Robin Lovell-Badge, a professor of genetics and embryology at the Francis Crick Institute in London, who was not involved in the study.

“You could quite imagine that in the future the demand would increase. Maybe it will still be small, but for those individuals it will be very important.”

The researchers also discovered something unexpected: a previously unknown way that embryos repair themselves.

In other cells in the body, the editing process is carried out by genes that copy a DNA template introduced by scientists. In these embryos, the sperm cell’s mutant gene ignored that template and instead copied the healthy DNA sequence from the egg cell.

“We were so surprised that we just couldn’t get this template that we made to be used,” said Shoukhrat Mitalipov, director of the Center for Embryonic Cell and Gene Therapy at Oregon Health and Science University and senior author of the study. “It was very new and unusual.”

The research significantly improves upon previous efforts. In three sets of experiments in China since 2015, researchers seldom managed to get the intended change into embryonic genes.

And some embryos had cells that did not get repaired — a phenomenon called mosaicism that could result in the mutation being passed on — as well as unplanned mutations that could cause other health problems.

In February, a National Academy of Sciences, Engineering and Medicine committee endorsed modifying embryos, but only to correct mutations that cause “a serious disease or condition” and when no “reasonable alternatives” exist.
Sheldon Krimsky, a bioethicist at Tufts University, said the main uncertainty about the new technique was whether “reasonable alternatives” to gene editing already exist.

As the authors themselves noted, many couples use pre-implantation genetic diagnosis to screen embryos at fertility clinics, allowing only healthy ones to be implanted. For these parents, gene editing could help by repairing mutant embryos so that more disease-free embryos would be available for implantation.

Hank Greely, director of the Center for Law and the Biosciences at Stanford, said creating fewer defective embryos also would reduce the number discarded by fertility clinics, which some people oppose.
The larger issue is so-called germline engineering, which refers to changes made to embryo that are inheritable.

“If you’re in one camp, it’s a horror to be avoided, and if you’re in the other camp, it’s desirable,” Dr. Greely said. “That’s going to continue to be the fight, whether it’s a feature or a bug.”

For now, the fight is theoretical. Congress has barred the Food and Drug Administration from considering clinical trials involving germline engineering. And the National Institutes of Health is prohibited from funding gene-editing research in human embryos. (The new study was funded by Oregon Health and Science University, the Institute for Basic Science in South Korea, and several foundations.)

The authors say they hope that once the method is optimized and studied with other mutations, officials in the United States or another country will allow regulated clinical trials.

“I think it could be widely used, if it’s proven safe,” said Dr. Paula Amato, a co-author of the study and reproductive endocrinologist at O.H.S.U. Besides creating more healthy embryos for in vitro fertilization, she said, it could be used when screening embryos is not an option or to reduce arduous IVF cycles for women.

Dr. Mitalipov has pushed the scientific envelope before, generating ethical controversy with a so-called three-parent baby procedure that would place the nucleus of the egg of a woman with defective cellular mitochondria into the egg from a healthy woman. The F.D.A. has not approved trials of the method, but Britain may begin one soon.

The new study involves hypertrophic cardiomyopathy, a disease affecting about one in 500 people, which can cause sudden heart failure, often in young athletes.

It is caused by a mutation in a gene called MYBPC3. If one parent has a mutated copy, there is a 50 percent chance of passing the disease to children.
Using sperm from a man with hypertrophic cardiomyopathy and eggs from 12 healthy women, the researchers created fertilized eggs. Injecting CRISPR-Cas9, which works as a genetic scissors, they snipped out the mutated DNA sequence on the male MYBPC3 gene.

They injected a synthetic healthy DNA sequence into the fertilized egg, expecting that the male genome would copy that sequence into the cut portion. That is how this gene-editing process works in other cells in the body, and in mouse embryos, Dr. Mitalipov said.

Instead, the male gene copied the healthy sequence from the female gene. The authors don’t know why it happened.

Maybe human sex cells or gametes evolved to repair themselves because they are the only cells that transmit genes to offspring and “need special protection,” said Juan Carlos Izpisua Belmonte, a co-author and geneticist at the Salk Institute.

Out of 54 embryos, 36 emerged mutation-free, a significant improvement over natural circumstances in which about half would not have the mutation. Another 13 embryos also emerged without the mutation, but not in every cell.

The researchers tried to eliminate the problem by acting at an earlier stage, injecting the egg with the sperm and CRISPR-Cas9 simultaneously, instead of waiting to inject CRISPR-Cas9 into the already fertilized egg.

That resulted in 42 of 58 embryos, 72 percent, with two mutation-free copies of the gene in every cell. They also found no unwanted mutations in the embryos, which were destroyed after about three days.

The method was not perfect. The remaining 16 embryos had unwanted additions or deletions of DNA. Dr. Mitalipov said he believed fine-tuning the process would make at least 90 percent of embryos mutation-free.

And for disease-causing mutations on maternal genes, the same process should occur, with the father’s healthy genetic sequence being copied, he said.

But the technique will not work if both parents have two defective copies. Then, scientists would have to determine how to coax one gene to copy a synthetic DNA sequence, Dr. Mitalipov said.

Otherwise, he said, it should work with many diseases, “a variety of different heritable mutations.”
R. Alta Charo, a bioethicist at University of Wisconsin at Madison, who led the committee with Dr. Hynes, said the new discovery could also yield more information about causes of infertility and miscarriages.

She doubts a flood of couples will have “edited children.”

“Nobody’s going to do this for trivial reasons,” Dr. Charo said. “Sex is cheaper and it’s more fun than IVF, so unless you’ve got a real need, you’re not going to use it.”

Scientists find key ‘friendliness’ genes that distinguish dogs from wolves

Mira Abed

Your dog is basically a super social wolf, and scientists may have found the gene that makes him want to cuddle with you.

A new study shows that friendliness in dogs is associated with the same genes that make some people hyper-social.

The study found that structural variations in three genes on chromosome 6 are correlated with how much canines socialize with humans. An analysis of DNA from two dozen animals revealed that these genes look very different in dogs than they do in wolves.

Mutations in the same genes are also linked with a rare developmental disorder in humans called Williams-Beuren Syndrome, or WBS. People with WBS are typically hyper-social, meaning they form bonds quickly and show great interest in other people, including strangers. Other symptoms include developmental and learning disabilities as well as cardiovascular problems.

To Bridgett vonHoldt, who studies canine genetics at Princeton University, some of these traits sounded a lot like the behaviors of domesticated dogs, especially compared with wolves.

For example, dogs like to stay close to humans and gaze at them for longer periods of time than wolves do. Dogs also tend to be less independent in problem-solving when they’re around people, and they retain their affinity for humans throughout their lives.

“Many dogs maintain their puppy-like enthusiasm for social interactions throughout their life, whereas wolves grow out of this behavior and engage in more mature, abbreviated greetings as they age,” said Monique Udell, who studies animal behavior at Oregon State University and co-authored the new study. “One might think of how a young child greets you versus a teenager or adult relative.”

These behaviors are typical of what scientists call domestication syndrome, and researchers have noticed them in other kinds of domesticated animals as well. But they don’t fully understand how the underlying genetic changes develop.

“Everyone wants to find the genes that make dogs different from wolves, and try to understand how domestication changed the genome,” vonHoldt said.

She already had a head start. In 2010, as part of her doctoral research, vonHoldt had mapped the entire genome of 225 gray wolves and 912 dogs from 85 breeds. There were a few genes that stood out as consistently different between dogs and wolves, especially the WBS gene WBSCR17. But vonHoldt still didn’t have a handle on how those genetic differences were related to behavior.

VonHoldt met Udell three years ago, and they started chatting about canines. Together they realized that if they combined vonHoldt’s genetic expertise with Udell’s canine behavior data, they might be able to find the missing link.

They decided to examine the social behavior of a group of dogs and a group of wolves and then analyze their DNA in the region that included the WBSCR17 gene.

This idea was pretty new. While scientists have analyzed the genes responsible for specific clinical disorders in dogs, something as complex and varied as social behavior is a lot trickier to study.

After selecting 18 dogs and 10 gray wolves who had been socialized with humans, they began their work with a series of behavioral tests.

When the dogs were given a puzzle box with a sausage hidden inside, only two of the 18 were able to open the box whether or not a human was present. Wolves performed much better: eight of the 10 opened the box when a human was present, and nine of them opened the box when they were left alone.

When dogs were in the presence of a human, they spent a median of 20% of their time looking at the person and only 10% of the time looking at the box. The wolves, on the other hand, spent nearly 100% of the time looking at the box whether or not a human was present.

Udell said that these results agreed with previous studies that have shown that dogs are not as good at independent problem-solving as wolves, and that they get more distracted by social stimulation.

Next came the sociability test, which took place in four phases. In each, a human sat in a chair near a dog or a wolf for two minutes, and researchers recorded how much time the canine in question spent within 1 meter of the person.

In the first round, the person was a stranger who sat passively in the chair, not making eye contact or speaking to the animal. In the second round, the stranger actively engaged with the canine. Then the two phases were repeated with an owner or caretaker instead of a stranger.

The researchers determined that when familiar humans were present, dogs spent a median of 93% of their time near people while wolves spent only 36% of theirs. When the humans were strangers, the dogs stuck around 53% of the time and wolves 28%. This difference was not statistically significant and could have been due to chance.

While there was some variation between individual dogs and individual wolves, what was really important to the researchers was to determine whether there was a link between the sociability of each canine and what his or her DNA looked like.

So they took blood samples from 16 of the dogs and eight of the wolves and analyzed a large chunk of DNA on chromosome 6, including the region associated with WBS. (Two of the dogs and two of the wolves were not included in this part of the study.)

They found mutations in three genes that were much more common in the hyper-social canines, most of which were dogs. These three genes are called GTF2I, GTF2IRD1 and WBSCR17, and have also been shown to cause an increase in social behavior in mice and are believed to do the same in humans.

Interestingly, two of the wolves were very social and dog-like in their behavior, while one of the dogs acted quite wolf-like. The team found that the two social wolves had more mutations in these three genes, while the wolf-like dog had fewer mutations.

Adam Miklósi, an ethologist at Eötvös Loránd University in Hungary, said that the results would have been more convincing with a larger sample size.

The study authors acknowledged that their sample size was small, but they pointed out that the link between DNA and behavior was quite distinct. “I think it’s astounding that we have significance,” vonHoldt said.

Despite the difficulty in finding human-socialized wolves to use as subjects, the authors said they would like to study larger samples in the future. They also want to understand how this trend varies by dog breed.

VonHoldt is especially curious about exactly how the genetic mutations result in increased social behavior, and plans to research that question in more detail.

Eventually, she may figure out how wolves evolved into man’s best friend.

Ravens Surprise Scientists By Showing They Can Plan

A raven flies in the Seedskadee National Wildlife Refuge in Wyoming.

Tom Koerner/U.S. Fish and Wildlife Service

As recently as 10 years ago, humans were thought to be the only species with the ability to plan.

Recent studies on great apes showed the ability is not uniquely human. Now, scientists in Sweden have come to the surprising conclusion that ravens can also deliberately prepare for future events.

“It is conservative to conclude that ravens perform similarly to great apes and young children,” the researchers write. However, monkeys have failed similar experiments.

We’ve known that ravens, and other members of the corvid family, are smart. Previously, they were shown to think ahead by caching food to eat later.

But some scientists argued that food caching was not proof of an ability to plan because the birds could simply be biologically wired to do so, cognitive zoologist Can Kabadayi from Lund University tells The Two-Way.

So, Kabadayi and co-author Mathias Osvath set up a series of experiments to see if five ravens could flexibly plan during tasks that they don’t do in the wild: using tools and bartering. These are similar to studies done on great apes. Their findings were published today in the journal Science.

The researchers trained the birds how to use a simple tool, a rock, which could be used to open a box containing a treat (a piece of dog food) if the birds dropped it through a small tube.

They then tested whether the birds could pick the right tool from a series of “distracter” objects – such as a wheel, a ball, a metal pipe and a toy car – then save it and use it later to open the box.

One version of the experiment had a delay of 15 minutes between selecting an object and being presented with the reward box, and the ravens succeeded 86 percent of the time. The second extended that period to 17 hours, and the success rate was even higher, at 88 percent.

The birds were also trained to use a specific token to barter with a human for a food reward. Then, a different experimenter offered them a tray with the token on it along with other distracter objects. “When the ravens knew that trading would only happen on the next day, they chose and stored these tokens as soon as they were offered to them,” scientists Markus Boeckle and Nicola S. Clayton wrote in a separate Science paper on the Lund University research.

The researchers found that the birds would tend to opt out of immediate food rewards because of the promise of a larger, tastier treats later.

They were more likely to be willing to endure delayed gratification when they only had to wait a few seconds, rather than minutes for the larger treat – which is also a key component of human decision making. “We basically found that the further ahead in the future a reward for ravens, the less value it gets,” says Kabadayi.

It’s safe to say that ravens and mammals have not inherited planning skills through a common ancestor, says Kabadayi – they last shared an ancestor about 320 million years ago.

To plan, “you need a lot of different skill sets to work together and that’s interesting, because how can that be similar between corvids and great apes given they are so different to each other evolutionarily?” says Kabadayi. The skills likely evolved independently, through convergent evolution, he says.

Why would ravens develop the ability to plan? Kabadayi says there are many different theories.

He says this kind of complex cognition may have developed in reaction to ravens’ complex social hierarchy – for example, they would need to remember previous interactions with other birds, which could contribute to memory and planning skills. However, he says there are many other hierarchical species that don’t have planning abilities.

Factors like environmental pressures or the fact that they are scavengers competing with each other could also contribute, he says. The sheer density of neurons in a bird’s brain, even though it is small compared to apes, might also play a role.

Kabadayi says that scientists would need to test a large number of species for their abilities to plan, and see how this correlates with the possible explanations.

Parrots would be interesting to test next, he says, because they have a “huge number of neurons in their brains” and have been shown to have good memories.

Strange ‘sea pickles’ keep washing ashore in the Pacific Northwest — and scientists are baffled

There are strange sea creatures known as “sea pickles” invading the Pacific Northwest.

These gelatinous and somewhat translucent organisms, called pyrosomes, have been seen congregating, sometimes by the thousands, close to shore from Northern California up to southeast Alaska — clogging fishing nets and washing up on beaches, according to the National Oceanic and Atmospheric Administration. Experts say that this year, the critters are appearing in very high numbers outside the normal range of the species.

Most recently, NBC Bay Area reported that the sea dwellers have been causing a stir in Monterey Bay, frustrating fishermen trying to catch salmon and shrimp.

So what are pyrosomes, where did they come from, and why are they swarming shores?

NOAA Fisheries described them this way:

Pyrosomes are pelagic Tunicates, which are part of Chordata, a phylum that includes humans. It is tough and slimy to the touch with small, pronounced bumps. Inside the wall of this gelatinous tube, which can get up to 60 cm, individual zooids are tightly packed together. These zooids have an incurrent and excurrent siphon and use cilia to pump water for feeding, respiration and movement. Using a mucus net, they filter water for small planktonic microorganisms.

Pyrosomes are known to aggregate in large clusters at the surface and the zooids bioluminesce to create beautiful light displays.

Experts say pyrosomes are found all over the world, typically in warmer tropical waters far offshore.

Ric Brodeur, a research biologist at the NOAA’s Northwest Fisheries Science Center in Newport, Ore., said that beachcombers in Oregon have been walking the beaches there for decades, but he has started getting reports of pyrosomes washing up on the beaches only in the past few months. He has also been going to sea on research cruises since the 1980s and saw his first pyrosome only in 2014. He believes the high abundance is related to unusually warm ocean conditions along the coast that resembles pyrosomes’ normal habitat.

Brodeur said it is too soon to say whether pyrosomes will become permanent residents of the Pacific Northwest, as the ocean could revert to colder conditions.

“We’ll have to wait to see how it goes, but certainly, it’s not a good sign for the ecosystem to have these critters out there instead of the normal fish and crustacean prey most fish, birds and mammals off our coast are accustomed to,” he said.

During research cruises in February and May, pyrosomes — some more than two feet long — were seen in the highest number 40 to 200 miles off the Oregon Coast.

“A five-minute midwater tow of a research net off the Columbia River in late May brought up approximately 60,000 pyrosomes,” NOAA’s Northwest Fisheries Science Center said in a blog post. “Scientists spent hours sorting through the massive catch to find the rare fish they were targeting.”

Researchers from NOAA Fisheries, along with researchers from Oregon State University and the University of Oregon, have been studying these sea creatures to learn more about them.

Read more:

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