Month: December, 2017

Treating Genetic Disorders Before Birth

Physicians may one day be able to treat genetic blood diseases before a child is even born.

In a study of mice that was published this week in the Journal of Clinical Investigation, researchers at the University of California, San Francisco, have found that transplanting a mother’s own stem cells into her fetus populates its bone marrow with healthy cells while avoiding immune rejection.

If the findings hold true in humans, stem-cell transplants from mother to fetus could prime the fetus for a bone-marrow transplant from its mother—or a donor that is tissue-matched to the mother—after birth.




Diseases such as sickle cell anemia and beta thalassemia result from abnormal red blood cells and can be treated with bone-marrow transplants.

But it’s not always possible to find a match.

And standard bone-marrow transplants, even between tissue-matched donors, must be followed with a lengthy course of immunosuppressive drugs.

Scientists theorize that bone-marrow transplants performed when a fetus is still developing would override this problem.

They suspect that the fetus’s immature immune system could be tricked into adopting those foreign cells and recognizing them as its own.

The fetus is wired to tolerate cells—when it encounters cells from mom, it tolerates them,” says Tippi MacKenzie, the pediatric surgeon at UCSF who led the new research.

Research in animals has shown the promise of that approach.

But early tests in humans came up against a serious setback—the donor cells were being rejected and killed off before a fetus could assimilate them, and no one was quite sure why.

It’s a conundrum,” says MacKenzie.

The blame, it seems, may be mom’s. MacKenzie and her colleagues found that when they injected a fetus with hematopoietic stem cells that were not matched to the mother or fetus, the infusion prompted an influx of maternal immune cells into the fetus.

“What we saw was that it’s not the fetal immune system that’s rejecting the cells—it’s the mother’s,” MacKenzie says.

“And if it’s the mother’s immune system that’s rejecting them, we may be able to transplant maternal cells for some of these disorders and get them to engraft.”

Indeed, when researchers injected the fetus with stem cells from a donor that was tissue-matched to the mother, the cells happily took root in the fetus’s bone marrow.

But Flake, who pioneered the fetal-stem-cell transplant treatment for severe combined immunodeficiency disease (SCID), or “bubble boy syndrome,” says that although a single dose of maternal or maternally matched donor cells might not cure disease.

It could prime the fetus’s immune system into accepting a stem-cell transplant from the same person later in life.

The next step, MacKenzie says, will be to test the treatment in larger mammals and nonhuman primates.

But for now, her lab is more focused on understanding precisely what’s going on in the maternal-fetal immune system interactions.

We’re trying to figure out the mechanism by which the mother cells are exerting their effect. And we’re looking at the idea of immune-cell trafficking between mom and fetus—to what extent does it happen in human pregnancies?”

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Pass it on: New Scientist

According To Psychologist, Love At First Sight Doesn’t Actually Exist

We’ve all seen that movie moment when two strangers meet and feel an instant romantic connection.

In fact, “love at first sight” has been a mainstay of literature for thousands of years, and people in real life often claim to experience a similar spark.

But is that feeling actually love? Not quite, according to the authors of a new study.

In the study, researchers investigated whether people feel love at first sight — LAFS — or whether they believe retroactively that they felt that way, once they’ve already formed an attachment to a romantic partner.

The scientists also questioned whether what people call: “love” at a first encounter is truly representative of the complex emotions that make up love — or just a powerful physical attraction.




Prior studies have shown that being in love activates certain brain regions, and the location of the activity can vary depending on what type of love the person is feeling, such as emotional, maternal or passionate love.

Intense, passionate love activates the same networks in the brain as addiction does, and more long-term love sparked responses in brain regions associated with attachment and reward.

Researchers have also previously reported that as many as 1 in 3 people in Western countries claim to have experienced LAFS.

And that the feeling is associated with more passion and stronger bonds within the relationship, the scientists wrote in the new study.

But there was little evidence indicating if LAFS occurred when people thought it did — at the moment of their first meeting ― or if they merely remembered it happening that way through the lens of their current romantic feelings, the study authors explained.

The scientists collected data from about 500 encounters between nearly 400 participants, mostly heterosexual Dutch and German students in their mid-20s.

Using three stages of data collection — an online survey, a laboratory study and three dating events lasting up to 90 minutes each.

The researchers gathered information from their subjects about meeting prospective romantic partners.

They noted whether participants said that they felt something akin to LAFS upon a first meeting, and how physically attractive they ranked the person who inspired those feelings.

To define what qualified as “love,” subjects submitted self-analysis of several key components: “eros”,”intimacy,” “passion” and “commitment.”

During the tests, 32 different individuals reported experiencing LAFS a total of 49 times — and that observation wasn’t typically accompanied with high ratings for love components such as intimacy and commitment.

However, reports of LAFS did correspond with a potential partner scoring higher as physically attractive, the researchers discovered.

About 60 percent of the study participants were women, but men were more likely to report feeling LAFS “on the spot,” the study authors reported.

And in every case, their experience of LAFS was unreciprocated, suggesting that mutual, instantaneous LAFS “might generally be rare,” according to the study.

The authors determined that LAFS was, in fact, merely “a strong initial attraction” that people identified as love, either at the moment they felt it, or in retrospect.

And though some study subjects who were already involved with someone reported that they fell in love at first glance, it’s hard to say for sure if that happened the way they remembered.

Answering this question would require further investigation into romantic relationships, to see how those initial, powerful feelings of instantaneous love play out over time, the scientists wrote.

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Anthropocene: We Might Be About To Move From The Holocene To A New Epoch

After 11,700 years, the Holocene epoch may be coming to an end, with a group of geologists, climate scientists and ecologists meeting in Berlin this week to decide whether humanity’s impact on the planet has been big enough to deserve a new time period: the Anthropocene.

The term, coined in the 1980s by ecologist Eugene F. Stoermer, takes its prefix from the Ancient Greek word for human because its proponents believe the influence of humanity on the Earth’s atmosphere and crust in the last few centuries is so significant as to constitute a new geological epoch.




The Anthropocene Working Group assembles in Berlin on Friday, an interdisciplinary body of scientists and humanists working under the umbrella of the International Commission on Stratigraphy and “tasked with developing a proposal for the formal ratification of the Anthropocene as an official unit amending the Geological Time Scale“.

The 30-strong group, which includes a lawyer, has outlined two key questions which it will address during deliberations at the Haus der Kulturen der Welt:

How does the recent cognition of the immense quantitative shift in the biophysical conditions of the Earth affect both scientific research and a political response to these changes?”

And “Does the Anthropocene also pose a profound qualitative shift, a paradigm shift for the ways in which science, politics, and law advance accordingly?”

Following the Pleistocene, we have for the last 11,700 years lived in the Holocene epoch, which is characterized by the warmer and wetter conditions that came after the end of the last ice age and has seen humans establish new territories and the Earth’s population soar.

Many scientists are happy with the Holocene as a term, but after Nobel Prize-winning atmospheric chemist popularized the “Anthropocene” at the turn of the millennium it refuses to go away and the ICS has deemed it in need of serious debate.

Based around a series of presentations by members of the AWG and statements from invited speakers from the humanities, the social sciences, and political fields, the forum will “discuss both the extraordinary changes to the Earth system as well as its consequences in setting new agendas for governing, researching, and disseminating crucial knowledge.”

The group has given itself until 2016 to come up with a proposal to submit to the ISC, which ultimately determines what time period we live in.

This might seem like a long way away, but when you consider the earliest epoch, the Paleozoic, began approximately 541 to 252 million years ago, it’s just a speck in the Earth’s history.

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What Is A Horsepower?

The horsepower (hp) is a unit in the foot-pound-second ( fps ) or English system, sometimes used to express the rate at which mechanical energy is expended.

It was originally defined as 550 foot-pounds per second (ft-lb/s).




A power level of 1 hp is approximately equivalent to 746 watt s (W) or 0.746 kilowatt s (kW). To convert from horsepower to watts, multiply by 746.

To convert from watts to horsepower, multiply by 0.00134. To convert from horsepower to kilowatts, multiply by 0.746. To convert from kilowatts to horsepower, multiply by 1.34.

While the horsepower, the watt, and the kilowatt are all reducible to the same dimensional units, the horsepower is rarely used to express power in any form other than mechanical.

You will likely get raised eyebrows if you talk about a 1-hp microwave oven, just as you would feel uncomfortable talking about a 37-kW outboard motor.

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How Molten Salt Reactors Might Spell A Nuclear Energy Rebellion

Since former NASA engineer Kirk Sorensen revived forgotten molten salt reactor (MSR) technology in the 2000s, interest in MSR technology has been growing quickly.

Why this sudden interest in a nuclear technology that dates back to the 1950s?

The answer lies in both the phenomenal safety of MSRs and their potential to help solve so many of today’s energy related problems, from climate change to energy poverty to the intermittency of wind and solar power.

In fact, MSRs can operate so safely, they may alleviate public fears about nuclear energy.

Before looking at the potential of MSRs, though, it is useful to first take a high-level look at what they are and how they work.




What is a Molten Salt Reactor?

A molten salt reactor (MSR) is a type of nuclear reactor that uses liquid fuel instead of the solid fuel rods used in conventional nuclear reactors.

Using liquid fuel provides many advantages in safety and simplicity of design.

Unlike conventional reactors, the rate of fission in an MSR is inherently stable.

Nonetheless, should the fuel salt become too hot to operate safely, a freeze plug below the reactor will melt and the liquid content of the reactor will flow down into emergency dump tanks where it cannot continue to fission and can cool safely.

Why Molten Salt Reactors?

MSRs are a huge departure from the conventional reactors most people are familiar with. Key features include:

  • Unparalleled safety – MSRs are walk-away safe. They cannot melt down as can conventional reactors because they are molten by design. An operator cannot even force an MSR to overheat.
  • A solution to nuclear waste and stockpiles of plutonium – Conventional reactors use solid ceramic fuel rods containing enriched uranium. The fission of uranium in the fuel releases gases, such as xenon, which causes the fuel rods to crack.This cracking, in turn, makes it necessary to remove and replace the fuel rods well before most of the actinides such as uranium have fissioned.
  • Abundant energy cheaper than energy from coal – MSRs can be made cheaply because they are simple compared to conventional reactors that have large pressurized containment domes and many engineered and redundant safety systems.

  • Load following solar and wind power – Gas plants must ramp up quickly when power from wind and sun is scarce, and ramp down quickly when the sun is shining or the wind is blowing.
  • Abundant energy for millions of years – Although it is sometimes claimed that nuclear power is not sustainable, the truth is that there is enough nuclear fuel on earth to provide humanity with abundant energy for millions of years.
  • Replaces fossil fuels where wind and solar are problematic – MSR technology has potential far beyond generating electricity cheaply and without emitting CO2.

MSRs could also be used to power large container ships, which currently run on diesel.

The 15 largest of these ships produce as much air pollution every day as do all of the cars on the planet.

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3D-Printed Chains of Ice And The Robot-Assisted Igloos Of The Future

A small but dedicated team led by Pieter Sijpkes and Jorge Angeles has been spear-heading the experimental use of ice at the university.

Creating everything from 3D-printed chains to what they describe as “commercial and industrial part modeling” used in fabrication, including full-scale construction tests for “the ice-tourism industry.”

For instance,” they explain, “small-scale ice models represent economical alternatives to intricate 3D models of architectural objects, be they scale models of buildings, site models, or building details.




Why prototype in plastic, in other words, when you can simply use the renewable, re-meltable, and re-freezable resource of freshwater?

Awesomely, like something out of the X-Men, Sijpkes and Angeles add that “casting techniques are being investigated in order to produce high-quality metal copies from ice originals.”

Here’s how the printing is done:

The idea is that you deposit a very thin bead of water onto your build surface is the same way that would extrude plastic.”

“Once a layer has been laid down there would be a delay of a few minutes while it freezes in the cold build chamber.”

“Once frozen, the next layer is deposited and the process repeats. By keeping the beads of water only a few millimeters in size surface tension alone should be enough to keep them in place.”

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At Last, Make Perfect Popcorn With Science

Popcorn has been around for hundreds, if not thousands of years.

But though scientists have long known that expanding moisture within a kernel of corn causes it to burst into all its edible glory, they’ve had to contend with lingering popcorn mysteries.

What’s really going on when popcorn puffs? What makes that popping sound, anyway?

And what’s the perfect temperature for popping corn?

Now, French scientists have answers on both fronts. The BBC reports that a team of physicists used high-speed cameras to observe popcorn as it was heated in an oven.




As they cranked up the oven temp in 10°C increments, they could see every wobble, burst and jump as unpinned kernels turned into popcorn.

At 2,900 frames per second, the physicists were able to see the physical mechanisms that give popcorn its pop. First, it forms a “flake” as internal pressure begins to fracture the kernel.

Then, a compressed “leg” erupts from the kernel, causing it to take off and jump.

They concluded that “popcorn is midway between two categories of moving systems: explosive plants using fracture mechanisms and jumping animals using muscles.”

And when the scientists synced up audio recordings to unravel the mystery of the sound that gives popcorn its name, they learned that it’s not caused by the fracturing kernel or its rebound as it pops, but by a release of pressurized water vapor.

So what’s the ideal temperature for popping corn? When heated to 338 degrees Fahrenheit, only 34 percent of kernels popped.

But by bumping up the temperature another increment to 356F, the scientists found that 96 percent of the kernels popped. At last—better popcorn through physics.

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SpaceX Launch Leaves Ghostly Glowing Trail In The Sky

People along the West Coast looked toward the heavens Friday to find a strange, morphing orb glowing in the night sky.

It looked like the stuff of science fiction, but it was actually the mark of a SpaceX rocket hauling a group of telecom satellites into Earth’s orbit.

The rocket took off from the Vandenberg Air Force Base in central California, and kicked up a flurry of wonder from social media users from across the state.

SpaceX CEO Elon Musk fueled the fun by teasing onlookers who were confused by the eerie contrail.

Nuclear alien UFO from North Korea,” he tweeted.




But the show was, in fact, put on by the rocket’s exhaust meeting the crisp air.

Water vapor from the aircraft engine exhaust is immediately exposed to very cold temperatures at very high altitudes.”

“The impurities in the exhausts and the very cold temperatures are the perfect recipe for a condensation trail,” writes meteorologist and Forbes contributor Marshall Shepherd.

It’s just like what airplanes leave behind when they streak across the sky.

Friday’s launch marked SpaceX’s 18th and final launch for the 2017 calendar year, making it the busiest private-sector rocket company in the world.

The mission was to deliver a group of 10 telecommunications satellites to low-Earth orbit for a company called Iridium, which is in the process of replacing its vast satellite network.

It’ll be used to deliver communications services and, among other things, track airplane traffic.

Musk took advantage of the buzz created by Friday’s spectacle to tout SpaceX’s next big feat: conducting a test launch of its massive new rocket, called Falcon Heavy.

That’s due in January.

To translate, “rocket cores” refer to the boosters at the base of the rocket.

They provide the initial thrust at lift-off. SpaceX’s defining move is to guide those boosters back to Earth for a safe landing so they can be reused in future missions.

The Falcon Heavy has three boosters, two more than SpaceX’s operational Falcon 9 rocket, and SpaceX will attempt to recover all of them.

Droneship refers to a landing pad that SpaceX sends into the ocean to capture boosters that fly out with a horizontal trajectory.

Reusing hardware is all part of SpaceX’s plan to drastically drive down the cost of spaceflight, and the company has all but mastered the move. It’s landed rockets on 20 separate occasions.

No rocket landing was attempted on Friday, however.

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Has The Mystery Of How The Moon Was Formed Finally Been Solved?

The object that smashed into earth to create the moon was far smaller than thought, a new simulation has shown.

Researchers at the Paris Institute of Earth Physics tested over two billion combinations of parameters to try and solve the mystery of how the moon formed.

The key, they concluded, was an impact with a body roughly one-tenth the mass of Earth.

Astronomers have long suspected that the moon was created when a giant protoplanet called Theia struck the newly formed Earth – a theory first put forward in the 1970s.




It says the huge collision created a vast cloud of debris, which coalesced into the moon.

However, until now, astronomers have not been able to explain how this left the moon and Earth chemically identical.

This led to two other ideas, which predicted dramatically different masses for the impact object.

In one, two half-Earths merged to form the Earth-moon system, and in the second, Theia was a small, high-velocity projectile that smacked into a larger and fast-spinning young Earth.

The researchers ran more than 2 billion simulations of the crash, and found an impactor larger than 15 per cent of the mass of Earth, couldn’t produce the chemistry we see in Earth’s mantle, instead leading to a mantle far too rich in nickel and cobalt.

This was known as the giant-impact hypothesis, or the Big Splash.

Now, a simulation created by researchers from Southwest Research Institute in Colorado has found that after this massive impact, there was a long period when leftover mini planets called planetesimals pounded the Earth.

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Why Sloths Live Life In the Slow Lane

Forests cover more than one-third of the land on Earth, yet few vertebrates make the canopy their home, and even fewer subsist solely on a diet of tree leaves.

In a new study in American Naturalist, researchers from the University of Wisconsin – Madison explain why this lifestyle is so rare and why animals that live in trees and eat leaves tend to live life at a slower pace.

Those species that do take advantage of this niche do not often radiate afterwards; that is, they don’t diversify and take on a variety of specialized forms.

The energetic constraints of a leafy diet are thought to prevent such adaptive radiation.

Leaves are an energetically and nutritionally poor food source. Most animals that live off plant leaves tend to be large, such as moose, elk, and deer.




Leaves are everywhere, but you need pretty complex gut machinery to be able to extract energy and nutrients from them,” says Jonathan Pauli, one of the study’s authors.

Most herbivores are big-bodied and they carry around big guts to break down and detoxify plant leaves.”

But animals that live in the treetops cannot be too big, or else the branches won’t support their body weight. So how do they make it on a nutritionally challenging diet?

Pauli and Zachariah Peery, along with co-authors Emily Fountain and William Karasov, set out to answer this question by measuring the daily energy expenditure of both two-toed and three-toed sloths in Costa Rica.

Both species of sloth are at the extreme end of specialization for a tree-dwelling, leaf-eating, lifestyle.

Pauli, Peery, and colleagues found that both sloth species expended very little energy, but three-toed sloths were especially slothful.

Three-toed sloths expended as little as 460 kilojoules of energy a day, the equivalent of burning only 110 calories. It is the lowest measured energetic output for any mammal.

Three-toed sloths use both behavioral and thermal strategies to limit their energy output. “They really are a slothful bunch,” says Pauli.

While two-toed sloths have bigger home ranges and move around quite a bit, three-toed sloths have very small home ranges and spend most of their time in just one or a few individual trees. “

“To limit energy costs, three-toed sloths find a good tree and camp out for a while and eat from it.”

The researchers then compared their sloth data to similar studies of other tree-dwelling, leaf-eating species from around the world.

Overall, the more specialized for the niche an animal was, the lower its daily energy expenditure.

While these species had lower metabolic rates than most mammals in general, they also relied heavily on thermoregulation and behavioral strategies to reduce their energetic expenditure.

The findings support the idea that tree-dwelling, leaf-eating mammals are tightly constrained by the poor nutritional quality of their diet, and thus, exhibit extremely low energetic output.

The researchers believe this impedes the opportunity for organisms to rapidly radiate into this niche.

For tree-dwelling, leaf-eating animals, there is a whole series of key innovations that are needed before they can crack into that open niche.

Sloths are the poster children for making a living in the treetops by saving energy. For them, slothfulness is a necessary virtue, not a deadly sin.

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