POWER GENERATOR RUNS ON SALTWATER

by Jeremy Deaton

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Gaze at the end of a river, where saltwater and freshwater meet. It may not look like anything, but new research suggests this could be a massive source of electricity.
Imagine a tub divided in half by a semi-permeable membrane. On one side of the membrane, the tub is filled with saltwater. On the other side, it is filled with freshwater. Molecules from the freshwater side will squeeze through the membrane to dilute the salty side (such is water’s love of equilibrium). This process is called osmosis.
Osmosis can be used to generate power. As molecules passes through the membrane, the water level on the salty side of the tank rises. Rising water can move a turbine to run a generator. Historically, however, osmotic power plants have generated too little power to have any practical application.

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Recently, a team of researchers from Switzerland and the United States built a new kind of osmotic power generator that vastly outperforms any that came before. In their version, one side of the tank contains a higher concentration of seawater ions than the other side of the tank. The membrane, which is just three atoms thick, features a single opening through which only positive ions can pass. An electrode connects the two sides. When positive ions squeeze through the membrane, their electrons transfer to the electrode, producing a current.

The ultra-thin membrane and its microscopic opening are key to the success of the generator. Larger membranes with myriad openings could generate huge sums of energy. The researchers say a membrane just one square meter in size could produce 1 megawatt of electricity, enough to power roughly 750 homes.
A version of this technology could be deployed to river estuaries where freshwater and saltwater meet. Unlike wind turbines and solar panels, they would reliably generate electricity at all hours of the day, potentially enough to power entire cities.

Source: PopScience

What’s ahead for science in 2017?

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As science journalists look back on the top stories of the year, scientists push on, asking the next questions and chasing fresh data. What big discoveries might they deliver in 2017? Science News writers reveal what they are watching for — and hoping for — in the year ahead.


Bruce Bower
Behavioral Sciences
“I look forward to seeing where the reproducibility debate goes,” says Bruce Bower, referring to recent reports that many findings in psychology (and other sciences) don’t hold up in repeat experiments (SN: 4/2/16, p. 8). Some psychology journals now publish multilab replication efforts that often challenge influential findings, such as the claim that willpower decreases the more you use it. Continue reading “What’s ahead for science in 2017?”

The Impact Of Pregnancy On Mother’s Brain

121916_ls_pregnancy-brain_mainPregnancy can have so many impacts on the mother’s life, including her brain. Pregnancy selectively shrinks gray matter to make a mom’s brain more responsive to her baby and based on the report in Nature Neuroscience, it can last for years.

Lissa Galea, the neuroscientist of the University of British Columbia in Vacounver stated that several studies, including this one suggested that a women’s reproductive history can have long-lasting, possibly permanent changes to her brain health.

For this study, the participants consist of 25 women who wanted to get pregnant with their first child. A detailed anatomy scans were performed on them, before they got pregnant and two months after they gave birth. Pregnancy has so much impact to the point where researchers could predict whether woman had been pregnant based on the changes of their brain.

The results had shown that a women who had carried and given birth had less gray matter in certain regions of their brains compared to 20 women who had not been pregnant, 19 first-time fathers and 17 childless men. These changes will still remain two years after pregnancy.

A shrinking brain might appear as something bad however, “reductions in gray matter are not necessarily a bad thing.” Elseline Hoekzema, the co-author of the study of the study, neuroscientist at Leiden University, Netherlands stated. This is because the same thing will occur during adolescence as it is essential for a normal cognitive and emotional development. “Following those important teenage years, pregnancy could be thought as a second stage of brain maturing.” She added.

More research has been conducted and they had suggested that pregnancy sculpts the mother’s brain in a very specific way to make women more responsive to their helpless infants. The region that shrunk the most were parts of the frontal and temporal corticles as well as the midline, these regions are thought to be a part of taking other people’s mental perspectives. Thus, the shrinkage could occur with the purpose to help the mother to be a better care for the baby. The brain regions that changed the most also showed large responses to the pictures of their infants and even on questionnaires on their attachment to their baby, the scores for the women whose brains changed the most are higher.

First-time fathers appears to not have any changes on their brain, thus the effects on the mother’s brain is suggested not to be the cause by the seismic social upheaval of becoming a parent. Instead, these changes were caused by pregnancy hormones such as estrogen and progesterone. “Pregnancy is a time of exposure to massive amounts of hormones that get into their brain.” said John Russell, neuroendocrinologist of University of Edinburgh. However, he also points out that when the changes occur is still unsure as they only studied the brains before and after pregnancy but not during pregnancy. The extreme hormonal drop that comes during birth may also reshape the brain.

The planet is heating up faster than species can migrate

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Visitors to the Santa Catalina Mountains just outside Tucson, Arizona encounter a very disturbing sight: patches of dead alligator junipers scattered across hillsides at the base of the range. Wildfires did not destroy these trees — climate change did.

The trees can’t survive where it’s hot, so many have moved to higher elevations, where it is cooler. But if the heat keeps rising, they will die there too, and eventually cease to exist entirely.

“They can’t cope with the conditions,” says John J. Wiens, professor of ecology and evolutionary biology at the University of Arizona. “They simply can’t change fast enough.”

What is far worse, however, is that this is no isolated example.

The plight of the alligator juniper is but one obvious piece of a frightening pattern of local extinction currently underway “everywhere, all over the planet,” Wiens says, “It is happening among birds, plants, animals, in the ocean and in the freshwater environment.”

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Alligator juniper

Climate change could doom numerous species irreversibly, including those that people depend on for resources and food. “If it’s happening a little now, it will happen a lot in the future,” Wiens says. “We have a moral imperative to be sure that the future does not play out.”

The trend is especially troubling in tropical and subtropical environments––lowland places like the rainforest, where climate-threatened species have nowhere else to go. “For plants and animals that can’t move, they’re dead,” Wiens says.

Wiens recently examined the fate of hundreds of plant and animal species around the world, concluding that local extinctions already have occurred in nearly half of the 976 species he studied. His research, published today in PLOS Biology, found that 450 plant and animal species have disappeared locally, a result he finds especially striking, since mean temperatures have increased less than 1 degree Celsius since the pre-industrial era.

“Local extinctions are already widespread,” he says. “The results suggest that even modest changes in climate are enough to drive local populations in many species to extinction. They also suggest that local populations in many species cannot shift their climatic niches rapidly enough to prevent extinction. We know the climate is going to change even more, which bodes really badly for overall survival.”

Camilo Mora, assistant professor of geography at the University of Hawaii at Mānoa, who has studied the impact of climate change on plant growth, describes Wiens’ work as an important new piece of evidence of “the massive destruction of nature” caused by human-induced warming.

“The fingerprint of climate change on nature is demonstrated yet again,” says Mora, who was not involved in Wiens’ study. “This is not rocket science. Whenever you heat up a place, species are forced to deal with it. Climate change, compounded by other stressors, appears to be too much for species to take. Clearly, we are making it hard for species to endure us.”

Jeremy Kerr, a professor of biology at the University of Ottawa who hasstudied the effects of climate change on bumblebees, called these growing extinctions “dangerous [because] we rely on a lot of these species for ecosystem services we can’t really do without, like pollination.”

“Some of the species that are disappearing serve critical functions,” he adds. “We all know about monarch butterflies, one of the most beautiful animals in the world. Climate change… is contributing to their decline. Other animals that are even more important for practical reasons are bumblebees, and we now know that climate change is part of the reason for their decline also. These losses chip away at the planet’s life support systems, which we need.”

Monarch Butterfly

Pixabay

Monarch butterfly

David Inouye, a professor emeritus of biology at the University of Maryland who studies the impact of climjate change on the environment, agrees.

“Scientists have predicted for a while now that we are entering the sixth major mass extinction event in the history of life on the planet,” he says. “Evidence for this is now accumulating…this study provides insights into the range shifts that can already be documented in both plants and animals in response to the changing climate, and how the dynamics of range shifts can lead to local, and eventually, global extinctions.”

In fact, Inouye says, he has seen similar trends in his own research. “In my work in the Rocky Mountains, we have observed several species of animals, from moose to mosquitoes, moving up in altitude, and plants disappearing from the lower part of their former ranges,” he says. “Bumblebees are also moving up in altitude. If plants and pollinators don’t move at the same rates, historic interactions will be disrupted, potentially leading to more examples of local extinctions.”

Bumble bee

Pixabay

Bumble bee

Even those species that try to move upward may not be able to do so, according to the new study. Human factors, such as agriculture, roads, and increasing urbanization may impede their ability to relocate by leaving them no other live-able habitats, the study says.

Moreover, “many species are already confined to islands, peninsulas and mountaintops where dispersal to higher latitudes or elevations may not be possible,” the study says, adding: “Even if dispersal is unimpeded by human or natural barriers, it may simply occur too slowly to allow species to remain within their climatic niche.”

If the heat doesn’t kill directly, it can encourage potentially dangerous interactions, Wiens says. Certain plants may become vulnerable to beetle attacks, for example, and amphibians are prone to the deadly chytrid fungus, whose growth is stimulated by heat.

“In Arizona, we no longer have any natural Tarahumara frog populations because of the fungus,” Wiens says. “Climate is the basic cause, but the proximate cause may be something else.’’

For his study, Wiens conducted a meta-analysis of dozens of existing studies demonstrating how species have shifted their geographic ranges over time in response to global warming. Using these “range-shift” studies, he found that local extinctions have occurred in the warmest parts of the ranges for nearly half of the plant and animal species studied.

His research also found that local extinctions varied by region, and were more than twice as likely to occur among tropical species compared to those in more temperate locations. This latter is important because most plant and animal species live in the tropics.

“If species live in a preserve in the topics, or in a place that has been deforested, it’s not really possible for them to move,” Wiens says. “They may be able to move up a mountain in Arizona, but that’s not going to work in a rainforest.”

“We are locked into a climate pattern, and things don’t seem to be able to adapt,” added Wiens. “This is only going to get worse if the climate warms further.”

Mora, of the University of Hawaii, agrees. “When places start failing to meet basic human needs for water… We will also very likely start seeing people moving as well,” he says. “Our planet is increasingly becoming unsuitable for many species, potentially even us.”

Marlene Cimons writes for Nexus Media, a syndicated newswire covering climate, energy, policy, art and culture.

Original article on http://www.popsci.com/planet-is-heating-up-faster-than-species-can-migrate

This Mysterious Gliding Mammal Is a ‘Sister’ to Primates

By Mindy Weisberger, Senior Writer of Live Science.

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A colugo with its young hangs upside down, with the pink skin of its gliding membrane visible between its limbs.
Credit: Norman Lim

Gliding mammals called colugos sail through the air using membranes that stretch between their limbs and resemble the wings of bats. But these furry gliders are actually a sister group to primates, a new study finds.

Colugos are tree dwellers, with limbs connected by flaps of skin known as a patagium, or gliding membrane. These critters live in southeast Asia, and adults measure about 14 to 16 inches (35 to 40 centimeters) long and weigh around 2 to 4 lbs. (1 to 2 kilograms).

Scientists have debated colugos’ lineage for the past century. Some experts had linked them to tree shrews, with which colugos share certain physical traits. But recent genetic sequencing revealed that colugos are more closely related to primates — the group that includes great apes and humans. This finding could help scientists develop a clearer picture of evolution in the earliest primates, the researchers suggested. [Image Gallery: Evolution’s Most Extreme Mammals]

There are only two known colugo species — sometimes referred to as “flying lemurs,” though they are not lemurs and do not fly — and they are poorly understood for a number of reasons, according to study co-author William Murphy, a professor in the Department of Veterinary Integrative Biosciences at Texas A&M University.

Colugos’ unusual gliding adaptations have hampered efforts to keep them in captivity, Murphy told Live Science in an email. And their nocturnal lifestyle high in the tree canopies makes it difficult for scientists to observe and track them in the wild.

“Only a few publications have documented their [colugos’] ecology and habits,” Murphy said.

Obtaining fresh tissue samples from colugos for DNA sequencing was understandably challenging, Murphy noted. The first attempts to analyze colugos’ DNA — which represented only part of the colugo genome — didn’t provide any easy answers. The colugo lineage diverged from other mammals more than 80 million years ago, Murphy told Live Science. And early DNA analysis couldn’t pinpoint colugos’ location on the mammalian family tree, leaving scientists uncertain as to whether they were more closely related to primates, tree shrews, or the group that includes rabbits and rodents, he explained.

For the new study, researchers sequenced the complete genome of a west Javan colugo for the first time, comparing it to sets of protein-coding genes from 21 other mammal species. They also looked for certain rare genetic markers that, when found, are “very reliable indicators” of relationships between animal groups, Murphy said.

All of their research pointed to the same conclusion: that colugos were a sister group to primates. According to Murphy, understanding the nature of this relationship could affect how scientists interpret the fossils of extinct mammals that share characteristics with both colugos and primates.

At the same time, the researchers made another unexpected discovery. As part of their exploration of the colugo genome, they extracted DNA from tissue samples in museums, most of which were collected 50 to 100 years ago from colugos across all their known ranges. The scientists found that there were likely far more species of colugos than previously suspected, Murphy told Live Science.

“Our genetic results suggest that there are at least seven to eight colugo species, and possibly as many as 14,” he said, adding that further analysis of the specimens and documentation of their genetic data would be required before the final number of species can be confirmed.

The findings were published online today (Aug. 10) in the journal Science.

Original article on Live Science.

The Neuroscience of Lucid Dreams

Lucid dreams are perhaps the most bizarre perceptual experience one can have. You are asleep and dreaming, but suddenly you realize that it’s all just a dream. At that point, you can choose to wake up (I usually do… I don’t think I’ve ever had a lucid dream that wasn’t a nightmare) or you can continue to dream on, with one important advantage. You’re now aware that the world around you is completely made up by your brain. As with the post-awakening of Neo in the movie “The Matrix”, you can bend the physical laws to your liking. You can fly, stop bullets with your bare hands, or even deliver magical punches to the bad guys to make them shrink in size (yeah, I have weird dreams). There is no spoon.

The very first dream that I remember having, at the age of 4 or 5, was a lucid dream. I was waiting for my mother to finish her purchases at the neighborhood newsstand, when the boogeyman showed up. He must have been a philosophical boogeyman interested in moral dilemmas, because he asked me to decide the menu for his next meal: me or my mother. If I didn’t decide, he would eat us both. My mother, just a couple of meters away, was blissfully unaware of this exchange. I felt paralyzed. I didn’t want to be eaten, but feeding my mamá to the monster for dinner was unthinkable. I’d never been in such a horrible situation in my short life. Then it occurred to me: this is just too awful to be real, so it follows that I must be dreaming. I woke up with a start.

There have been other lucid dreams since. Sometimes I have two in a month, other times I go for the better part of a year without them. It turns out, the ability to experience lucid dreams differs wildly from one person to another.

A recent study, published earlier this month in the Journal of Neuroscience, set out to determine if people with high and low dream lucidity were also dissimilar in their metacognitive ability, that is, the ability to reflect on, and report, one’s mental states.
The study participants completed questionnaires that assessed their lucid dreaming frequency, intensity, and degree of control, and also their metacognitive skills, including their self-reflection and self-consciousness. The experimental subjects moreover underwent brain imaging while conducting a thought monitoring task. This consisted of two 11-minute runs during which the subjects had to evaluate the each and every thought that entered their heads on an externally-internally oriented scale. Externally oriented thoughts meant thoughts related to the external environment, such as the visual surroundings, or the noise from the scanner. Internally oriented thoughts were not related to the immediate environment, such as remembering past events or planning for the day ahead.

The research showed that the brains of people with high and low dream lucidity were different. Subjects with high lucidity had greater gray matter volume in the frontopolar cortex, compared to those with low lucidity. This brain region also showed higher activity during thought monitoring in both high- and low-lucidity subjects, with stronger increases in the high-lucidity group. The scientists concluded that lucid dreaming and metacognition share some underlying mechanisms, particularly with regards to thought monitoring. This relationship had been previously suspected, but never before explored at the neural level.

Future research may tell us if it’s possible to control the frequency and contents of our lucid dreaming by training ourselves to monitor our thoughts while we’re awake. I, for one, would love some lucid dreams that don’t involve Freddy Krueger every now and then.

Source: Scientific American

Related: Outer Places – Are dreams interactions between quantum parallel worlds?

Schrödinger’s cat: A thought experiment in quantum mechanics

Austrian physicist Erwin Schrödinger, one of the founders of quantum mechanics, posed this famous question: If you put a cat in a sealed box with a device that has a 50% chance of killing the cat in the next hour, what will be the state of the cat when that time is up?

Everyone’s heard of Schrödinger’s cat, and if you’re not a physicist or a liar, you can probably admit that you don’t really get it. Well, hold onto your hats: A new study pushes the thought experiment into even stranger territory. Scientists have given Schrödinger’s kitty a second box to play in. If the infamous imaginary cat can be both alive and dead at the same time, they argue, it can also be both dead and alive simultaneously in two locations at once.

 

It goes a little something like this: A cat sits in a box, along with some kind of poison. The poison’s release is set to be triggered by the radioactive decay of a subatomic particle. But scientists know that these tiny particles are capable of being in multiple states at once – meaning that a particle could be decaying or not decaying at the same time. It follows that the poison could simultaneously be released and not released, and by extension, the cat could be dead and not dead.

“It’s understandable that people don’t understand it,” Wang said. “You can’t understand it using common sense. We can’t either.”

But the math shows that such a thing must be possible – at the microscopic level, anyway. “And we just follow the math,” Wang said.

When Austrian physicist Erwin Schrödinger spun this paradoxical tale in 1935, he wasn’t saying that cats can be simultaneously dead and alive. He was actually criticizing the prevailing school of thought in quantum mechanics, the Copenhagen interpretation, by showing how preposterous it would be when scaled up to affect objects in the visible world. The Copenhagen interpretation suggested that particles existed in all possible states (different positions, energies or speeds) until they were observed, at which point they collapsed into one set state. If that were true, he was arguing, you’d be able to have a cat that was simultaneously dead and alive until you opened your creepy cat-killing box to check on it.

Unfortunately for our buddy Erwin, the ridiculousness of his analogy hasn’t kept the whole dead-and-alive-until-proven-otherwise-and-then-suddenly-you’re-either-dead-or-alive thing from being true, at least at the microscopic scale.

Wang and his colleagues paired the famous cat paradox with another tenet of quantum mechanics: quantum entanglement, the phenomenon Einstein referred to as “spooky action at a distance.” When two interacting subatomic particles become entangled, any change induced in one will be inflicted upon the other, no matter how distantly they’re separated.

The Yale team built a tiny chamber with two aluminum cavities for subatomic particles to bounce around inside, then connected them with a superconducting chip made of sapphire. They were able to use electricity to induce a particular state on the particles in each chamber — two states at once, in fact, because quantum mechanics is weird. And because the chambers were linked by spooky action, both states could be inflicted at once in two places at once.

To get back to the cat, you can think of it this way: The fact that a cat in one box is simultaneously dead and alive causes another cat in another box to also be simultaneously dead and alive.

Your brain probably hurts too much to wonder why Wang and his fellow researchers care about these wacky particles, but here it is: They hope their findings can help advance the field of quantum computing.

A typical computer is made up of “bits” that can be coded as either zeroes or ones. But in theory, a quantum computer — one built using the crazy dead-and-alive particles we’ve been talking about — could have bits that were zeroes and ones at the same time. These computers would likely be much faster and more powerful than the computers we have today, at least for certain processes, because the machines would be able to simultaneously run many different calculations.

But since these particles lock into a single state when they’re observed, you need a way to correct errors without, you know, checking for errors.

“It’s well understood that 99 percent of computation or more will be done to correct for errors, rather than computation itself,” Wang told Live Science. But his team hopes that inducing these simultaneous “cat” states in redundant particles could help keep things in check.

“It turns out ‘cat’ states are a very effective approach to storing quantum information redundantly, for implementation of quantum error correction. Generating a cat in two boxes is the first step towards logical operation between two quantum bits in an error-correctible manner,” study co-author Robert Schoelkopf said in a statement.

Source: Schrödinger’s cat just got even weirder (and even more confusing)

More : Schrödinger’s cat: A thought experiment in quantum mechanics – Chad Orzel

Related: ‘Quantum Cheshire Cat’ becomes reality

 

 

 

What is epigenetics?

ep·i·ge·net·ics
epəjəˈnediks/
noun BIOLOGY
definition the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself.

Here’s a conundrum: Identical twins originate from the same DNA … so how can they turn out so different — even in traits that have a significant genetic component? Carlos Guerrero-Bosagna explains that while nature versus nurture has a lot to do with it, a deeper, related answer can be found within something called epigenetics. Find out what it is all about here: What is epigenetics?

Source: TedEd

Educator Carlos Guerrero-Bosagna
Script Editor Eleanor Nelsen
Director Chris Bishop
Animator Chris Bishop