Thumb-Sucking and Nail-Biting May Lead to Lower Risk of Allergies

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 For years, parents have been hounding their children to get their fingers out of their mouths and stop that thumb-sucking or nail-biting (or in some cases, both) that’s so often seen in young children. Many parents harbor the concern that so much finger-to-mouth time may affect the teeth or the development of speech.
 

 But it turns out there may be a hidden advantage to all those years of wrinkly thumbs and super short nails.
 
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<img alt="Thumb Sucking" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/10756088_03d432ef9d_o-cropped.width-990_XUkTnq0.jpg"/>
<figcaption>Babies begin sucking their thumb at a young age, a behavior that sometimes persists after the child has stopped breastfeeding.
 
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 In a study published Monday in the journal
 
 Pediatrics
 
 , children who were described by their parents as thumb-suckers or nail-biters were less likely to test positive for certain allergens later in life.
 

 The study examined 1,037 children in New Zealand, who were tested periodically as they grew up.
 

 Here’s Perri Klass, reporting for
 
 The New York Times
 
 :
 
<blockquote>

 In the study, parents were asked about their children’s nail-biting and thumb-sucking habits when the children were 5, 7, 9 and 11 years old. Skin testing for allergic sensitization to a range of common allergens including dust mites, grass, cats, dogs, horses and common molds was done when the children were 13 years old, and then later when they were 32. Thirty-one percent of the children were described as “frequent” nail biters or thumb suckers (or both) at one or more of those ages.
 

 The study found that children who frequently sucked a thumb or bit their nails were significantly less likely to have positive allergic skin tests both at 13 and again at 32. Children with both habits were even less likely to have a positive skin test than those with only one of the habits.
 
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 Even when factors that are usually associated with allergy risk, such as pets, parents with allergies, breastfeeding, and socioeconomic status, were taken into account, the study’s results remained true.
 

 The study is one of many to look into the controversial hygiene hypothesis. Formulated in 1989, the hypothesis suggests that there may be a link between diseases that accelerate the immune system, like eczema, asthma, and allergy, and a lack of exposure to various microbes early in life. When children are frequently putting their hands in their mouth, as they do if they suck their thumb or bit their nails, they are exposing themselves to an ecosystem of microbes from the world around them.
 

 In turns out, according to the results of this study, that some exposure may actually help train a child’s immune system to fight off disease instead of eliciting an allergic response. However, the study found that there was no decrease in cases of asthma or hay fever amongst the children studied.
 

 Although thumb-sucking and nail-biting can be issues for children, often they will end up stopping on their own, developmental pediatrician Lynn Davidson told
 
 The New York Times
 
 . If a child is getting older and still holding on to the habit, Davidson suggests analyzing when and why they resort to sucking their thumb or biting their nails, and using behavioral techniques like squeezing a foam ball to slowly change the habit.
 

 But this study suggests that at a young age, having a certain affinity for your thumb and fingers is not necessarily a bad thing. In fact, it may just be good for you.
 
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 Photo credit:
 <a href="https://www.flickr.com/photos/annegirl/10756088">
 Lucian/ Flickr (CC BY-NC-ND 2.0)
 </a>

Iron Nanoparticle-Coated Graphite Flakes Could Vastly Improve Lithium Ion Batteries

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 Few objects define our lives today like the lithium ion battery. Without them, we probably wouldn’t have the smartphones, laptops, tablets, and other rechargeable electronics that have exploded in popularity in recent years.
 

 But as our devices continue to get more powerful, batteries have fallen short. Plus, as electric vehicles have become commonplace, scientists have been searching for ways to increase battery performance and lifetime without sacrificing safety. And the answer may lie in magnets.
 
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<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/battery-terminal.width-990_fdIvt4N.jpg"/>
<figcaption>Batteries function by allowing electrons to flow from the positively-charged cathode to the negatively-charged anode, producing an electric current.
 
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 A team of scientists, led by André Studart of ETH Zurich in Switzerland, built a lithium ion battery with a graphite anode, a fairly standard setup. (An anode is the part of the battery through which electrons flow into a device—the negative side.) But, in a twist, they used a magnetic field to align the graphite flakes inside the battery so that lithium ions can have a clear path as they move across the battery, leading in increased performance. The study was published in the journal
 
 Nature Energy
 
 .
 

 Lithium-ion battery anodes are often composed of graphite flakes due to their safety, non-toxicity, and low-cost. However, graphite flakes have a significant drawback that can hamper a battery’s effectiveness. Here’s Shalini Saxena, writing for
 
 Ars Technica
 
 :
 
<blockquote>

 [Graphite] limits the movement of lithium ions, which is a fundamental part of charging and discharging. The lithium ions are only able to move within the planes between stacked graphene sheets and often have to navigate a highly tortuous path as they move around during charge and discharge. This slow movement through the electrodes remains a critical challenge in the development of batteries with improved performance.
 
</blockquote>

 Aligning the graphite flakes, the team thought, should give the lithium ions a clearer path, boosting the battery’s performance.
 

 While the idea sounded good in theory, there was a slight problem: graphite isn’t magnetic, and therefore does not respond to magnetic fields. To work around this, scientists coated the graphite flakes with iron oxide nanoparticles and dunked the mixture in ethanol to make it easier for the graphite flakes to settle in a preferred orientation.
 

 The graphite particles were then hit with a rotating magnetic field. Scientists found that after the graphite flakes were influenced by the magnetic field, they tilted at an angle of 60˚ above the plane of the current collector, forming channels for the lithium ions to escape. Flakes that had not been exposed to the magnetic field orientation fell almost parallel to the current collector, creating a maze-like path for the ions.
 

 The magnetically oriented graphite offered the lithium ions a much straighter path through the electrode. In a trial scenario, the scientists found that the new, less twisted anode structures improved lithium storage capacity by 160–300%.
 

 If this new fabrication technique can be implemented cheaply and at at scale, it could give ubiquitous lithium ion batteries a significant performance boost, enabling smaller devices with longer battery lives along with vastly more usable electric cars.
 
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 Photo credit:
 <a href="https://www.flickr.com/photos/jamesalmond/4591869543/">
 James Almond/ Flickr (CC BY-NC-ND 2.0)
 </a>

Some of our genes don't peak in activity until after we die (though not in these people—they're taking part in a disaster response simulation).

Some Genes Don’t Turn On Until After You Die

Typically, when a person’s heart stops beating, they’re pronounced dead. But don’t tell that to their genes, some of which only come to life two days after they’ve kicked the bucket.


 In fact, hundreds of genes suddenly started churning out messenger RNA, which sends a signal to various cellular machines to start making the stuff of life, such as proteins. Peter Noble and Alex Pozhitkov, both at the University of Washington, discovered this life-after-death scenario in mice and zebrafish. They released their results recently on the BioRxiv, a prepublication server.


 Here’s Anna Williams, reporting for New Scientist:

<blockquote>

 Hundreds of genes with different functions “woke up” immediately after death. These included fetal development genes that usually turn off after birth, as well as genes that have previously been associated with cancer. Their activity peaked about 24 hours after death.

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 It takes time for the DNA to be unraveled by proteins called histones, according to Noble. As it unravels, genes that were previously silent, such as those involved in embryological development, may become active again as the genes that are used to suppress them break down.


 “You’d think that when something dies, that everything would be turned off and everything would be silent, but that’s not the case,” Noble told NOVA Next. “In complex organisms, when we suddenly die, it takes awhile for the [DNA] complexes to break down, and they reach many barriers.”


 Though the study focused on mice and zebrafish, the two organisms are commonly used in genetic studies as models for humans.


 These findings could change the way that organ transplants are handled.


 For example, liver transplant patients tend to have much higher rates of cancer, and up until now this was thought to be an immune response.


 “Our results suggest it may not be [an immune response],” Noble said. “It may be just the fact that cancer genes are turned on at death as a natural phenomenon.”


 With this knowledge, scientists could test an organ for active cancer genes before transplant occurs, drastically reducing the chances of cancer in the new recipient.

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 For most genes, overall mRNA levels should decrease over time after death. However, in 548 zebrafish genes and 515 mouse genes, mRNA levels peaked after death. This meant that the decaying bodies had enough excess energy for these genes to switch on and continue functioning long after the animal died.


 The big question following these findings is why these specific genes turn on after the heart has stopped beating. One hypothesis, Noble and Pozhitkov said, is that the body using the last of its energy to heal itself, similar to what happens while someone is alive.


 The second hypothesis researchers have for why this may be happening has to do with how DNA unravels following death.


 Photo credit:
 <a href="https://www.flickr.com/photos/jotequila/4981170386/">
 Juan Eduardo Donoso / Flickr (CC BY-NC-ND 2.0)
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Many genes associated with cancer and embryological development peak in activity up to two days after death.

Orangutans are very genetically similar to humans, and share a common ancestor. Photo credit: Bjørn Christian Tørrissen/ Wikimedia Commons / (CC BY-NC-ND 2.0)

Human-Like Speech Seen In Orangutans For The First Time

In science, we study primates to learn about ourselves. Orangutans share 97% of their genetic code with humans and have common traits like increased brain size, sociability, and handy opposable thumbs.


 And now, there’s one more trait that we may share with our great ape cousins: speech.

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 Researchers at the University of Durham in Britain have successfully used a learning game to get an orangutan at the Indianapolis Zoo to mimic human sounds in a conversational context, something that has never been done before with primates.


 This discovery could shed light on how humans first developed the abilities that would lead to speech.


 Here’s lead researcher Adriano Lameria in
 
 New Scientist
 
 , explaining what science stands to gain from this discovery:

<blockquote>

 “This opens up the potential for us to learn more about the vocal capacities of early hominids that lived before the split between the orangutan and human lineages to see how the vocal system evolved towards full-blown speech in humans.”

</blockquote>

 Previously researchers believed that orangutans did not have control over their voices, instead only making involuntary sounds of arousal. But this research clearly shows that they have the potential to control their own voices.

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 To discover this, scientist played a “game” with eight-year-old Rocky where he gets rewarded for copying sounds made by the scientists that included a various range of different tones and pitches.


 The sounds Rocky created in these games were compared with the sounds from over 120 orangutans in captive and wild populations, and found to be markedly different when it comes to Rocky’s ability to control his voice in the same way that humans do during a conversation.


 Although it doesn’t look like we’ll soon be having intelligent discussions with our orangutan brothers, this level of voice control could clarify the picture of how humans adapted to exhibit the most dynamic language skills in the natural world.

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 Photo credit:
 <a href="https://commons.wikimedia.org/wiki/File:Portrait_of_an_Orangutan_2012.JPG">
 Bjørn Christian Tørrissen/ Wikimedia Commons / (CC BY-NC-ND 2.0)
 </a>


 Video credit:
 <a href="https://www.youtube.com/watch?v=lPRFx6SRUjk">
 New Scientist/ Youtube
 </a>

An orangutan at the Indianapolis Zoo has exhibited vocal control similar to how humans behave in a conversational setting.

Electricity in US, Canada, and Mexico Will Be 50% Carbon-Free in 9 Years

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 North American leaders made a commitment to bring climate action to their forefront of their agenda at the North American Leaders’ Summit in Ottawa, Ontario this week.
 

 On Wednesday, President Barack Obama, President Enrique Peña of Mexico, and Prime Minister Justin Trudeau of Canada pledged to reach a joint goal of to see half the continent’s energy come from clean sources by 2025.
 
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<img alt="Solar Cells" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/5782168458_8dec2f4c84_o-cropped.width-990_mj94qyo.jpg"/>
<figcaption>Advances in renewable energy have been popping up across North America, including this 32-megawatt photovoltaic array in Long Island, New York.
 
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 “We find ourselves now at a moment where the alignment in terms of policy goals and focus on clean energy between our three countries is stronger than it has been in decades,” White House climate advisor Brian Deese told reporters.
 

 Here’s Jean Chemnick and Emily Holden, detailing the plan for Scientific American:
 
<blockquote>

 [The new clean energy target] calls for the continent’s power grid to draw 50 percent of its generation by 2025 from renewable energy, efficiency, nuclear power and fossil fuels with carbon capture and storage technology. The goal is continent-wide, and it would require a steep increase in clean power and efficiency over the next nine years. Thirty-seven percent of North America’s overall power last year came from clean sources.
 
</blockquote>

 Although it’s an ambitious goal, domestic policies in the three countries are already moving toward cleaner environmental practices. There’s an effort already underway by the United States and Canada to reduce methane emissions by 40-45% by 2025 in the gas and oil sector. In addition to the new pledge, Mexico agreed to sign on to this additional agreement.
 

 Canada is busy formulating a new climate initiative based on many of the carbon and clean energy initiatives already implemented by provinces. In Mexico, the government enacted a law last December aimed at transitioning the country’s energy sources to be more efficient and bring more green power to the grid.
 

 Meanwhile, the United States’ Clean Power Plan, unveiled by President Obama last August, will be the central component when it comes to meeting the continent-wide goals. At the moment the plan is facing litigation and a Supreme Court stay, but in the meantime President Obama assured that federal tax incentives for renewables would get the country started on the path towards more green energy.
 

 Whatever happens in the U.S. will dictate whether the pact succeeds or fails. The U.S. generates about 4,000 terawatt-hours of electricity every year, while Canada only generates about 600 terawatt-hours and Mexico even less. Plus,, the generation of non-emitting energy is not split evenly between the U.S., Mexico, and Canada.
 

 The United States drew approximately 32% of its energy from non-fossil-fuel sources last year, a figure that’s expected to rise to 41 percent by 2025, according to the U.S. Energy Information Administration.
 

 Non-fossil fuels sources supplied 22% of Mexico’s power last year, less than half what’s required to hit the target.
 

 Canada currently leads the continent when it comes to green energy. Last year, nearly 80% of Canada’s energy came from carbon-free sources. But the volume of energy it produces pales in comparison to the energy output of the United States and Mexico, which makes it difficult for Canada to pick up slack from the other two if they fall short of their goals.
 

 In the U.S., experts warn that declines in nuclear energy due to competition from natural gas and delays in the rollout of the Clean Power Plan, may make meeting the 2025 deadline difficult.
 

 But the fact that there is an agreement at all is a promising sign that across the continent, the landscape is changing in regards to energy, and that North America must adapt to stay economically and environmentally stable.
 
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 Photo credit:
 <a href="https://www.flickr.com/photos/brookhavenlab/5782168458/">
 Brookhaven National Laboratory / Flickr (CC BY-NC-ND 2.0)
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A Human-Like Menstrual Cycle Has Been Discovered in the Spiny Mouse

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 When it comes to studying menstruation, mice have been all but useless—they don’t have periods.
 


 Rather, mice have what’s called an estrous cycle. They reabsorb the uterine lining if conception fails to occur, instead of shedding it through menstruation.
 

 However, researchers at Monash University in Clayton, Australia have evidence to suggest that the spiny mouse does indeed have a menstruation cycle.
 
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<figcaption>The spiny mouse is the first rodent known to have a menstrual cycle.
 
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 The belief that rodents don’t menstruate has led scientists to consider them poor models when studying women’s reproductive issues. But this new finding could change how we study reproductive health.
 

 The African spiny mouse is native to the deserts of Africa, though it has since spread to southwest Asia and southern Europe. They have been used previously in tissue regeneration research due to their ability to regrow lost skin.
 

 The study, involving 14 female spiny mice, showed that the mice possessed a menstrual cycle similar to that of women. While the menstrual cycle in the mice lasted only 9 days, the ratio of time spent bleeding was 20-40%, compared to 15-35% time bleeding for women.
 


 Scientists stumbled upon the menstruation discovery unexpectedly. Here’s Anna Nowogrodzki reporting for
 


 Nature
 


 :
 

<blockquote>

 Study co-author Hayley Dickinson, a reproductive physiologist at Monash University, says that the mouse discovery was hiding in plain sight. Monash established a breeding colony of spiny mice in 2003, and later transferred the animals to the nearby Hudson Institute for Medical Research. When Dickinson’s lab announced the menstruation discovery, several past students asked her how they could have missed it.
 


 “The answer, as with many discoveries in science, is that no one really looked,” Dickinson says. “Everyone knew that rodents didn’t menstruate.”
 

</blockquote>


 Up to this point, reproductive health research has had to focus on primates, which is time-consuming and expensive.
 



 With this discovery, the Monash team is beginning further research examining the processes surrounding the breaking down and regrowing of the mice’s uterine lining.
 



 When it comes to human menstruation, there are many parts that remain a mystery. Scientists still don’t know the source of the cells used to repopulate the uterine lining after each menstrual cycle, according Francesco DeMayo, a reproductive biologist at the U.S. National Institute of Environmental Health Sciences quoted in
 


 Nature.
 



 Although this finding is the first of its kind, it will take much more research to prove that the spiny mouse is a good model for human menstruation. But doctors and scientists like DeMayo are hopeful that these findings will kickstart a new wave of research into the female reproductive system.
 




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 Photo credit:
 <a href="https://commons.wikimedia.org/wiki/File:Sinaistachelmaus.jpg">
 Marcel Burkhard / Wikimedia Commons
 </a>

'Amnesic Shadow' Suggests That People Could Actively Repress Memories

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 What if forgetting something wasn’t always an inconvenience? What if it was just your brain helping you out? It turns out that may be the case, according to new research delving into the depths of human memory.
 

 The interconnectedness of the brain is usually seen as an advantage, a feature that sets humans apart when it comes to cognitive potential. But in some instances, the brain’s quick responses and interconnected pathways can be detrimental to overall mental health, particularly when it comes to painful memories that we’d rather not think about.
 
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<figcaption>A drawing of the hippocampus in the brain made by Camillo Golgi, an Italian physician and early neuroscientist.
 
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 Memories in the brain are linked, meaning that one memory can trigger the retrieval of another without any conscious effort. Sometimes this leads to the resurgence of particularly distressing memories.
 

 But researchers at the University of Cambridge have discovered that humans may be able to train themselves to halt the spontaneous retrieval of potentially unpleasant memories.
 

 Previous imaging studies have shown that the brain’s frontal areas have the ability to dampen the activity of the hippocampus, a key part of the brain in memory formation, suppressing memory retrieval. Scientists wanted to look at what happens in the brain after these memories are suppressed.
 

 Here’s Bahar Gholipour reporting with
 
 Scientific American
 
 :
 
<blockquote>

 [The researchers] asked 381 college students to learn pairs of loosely related words. Later, the students were shown one word and asked to recall the other—or to do the opposite and to actively not think about the other word. Sometimes between these tasks they were shown unusual images, such as a peacock standing in a parking lot.
 

 As described in
 
 Nature Communications
 
 , the researchers found that the participants’ ability to subsequently recall the peacocks and other strange pictures was about 40 percent lower if they had been instructed to suppress memories of words before or after seeing the images, compared with trials in which they had been asked to recall the words.
 
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 This finding suggests that controlling memory is possible, and that actively forgetting a particular memory dampens your brain’s capabilities to remember another. The brain, in an effort to forget one certain event, will block recollection of other unrelated events that occurred during the drop is hippocampal activity, a phenomenon known as “amnesic shadow”.
 

 This finding could shed light on why some people’s general memory function decreases after experiencing a trauma event that their brains try to suppress.
 

 But temporary amnesia aside, the ability to suppress memory may be beneficial if we can do it on demand. The researchers are now looking into that possibility by monitoring participants’ brain activity and giving them real-time feedback on decreased hippocampal activity. They hope that by doing this, people can learn to selectively forget the past. This could have real-world benefits when it comes to treating conditions such as post-traumatic stress disorder.
 
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 Photo credit: Golgi/Public Domain

Julia Davis

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