Scientists weigh the pros and cons of smart screen time for toddlers
4:00pm, February 26, 2015
Scientists and parents wonder whether tablets are all fun and games for toddlers.
Give a toddler an iPhone and 10 minutes, and she’ll take at least 50 selfies and buy a car on eBay. Give her an iPad, and she’ll stumble upon decidedly non-kid-friendly episodes of Breaking Bad.
With smartphones and tablets, children are exposed to an unprecedented amount of screen time on a daily basis. As with other tech toys, kids can pose a hazard to smart devices, possibly cracking the screen or dropping it a cereal bowl in the process. But how will exposure to these screens affect their brains and behavior?
Most of the research on screen time has focused on television. Previous studies suggest that children under 30 months learn less from educational TV programs like Sesame Street than they do from real-life interactions. TV exposure can take the place of playing outside and chatting and playing with parents and other caregivers — with negative effects on the child’s development. Too much TV has been linked to issues with language development, attention issues and, perhaps less directly, obesity. And in older children, the amount of time a child spends watching TV also corresponds to the degree of change seen in their growing brains.
But there aren’t many published studies on toddlers and tablets, so for the most part it’s an open question what effect adding a smartphone and iPad to the 60-inch LED TV will have on a developing child. “As parents we will need to keep adapting to a changing culture and rapidly evolving technologies, and it’s our job to protect our child’s most important relationships and learning experiences while not driving ourselves crazy with guilt for every bit of screen time our child gets,” says Jenny Radesky, a pediatrician at Boston University Medical Center.
Radesky and her Boston University colleagues Jayna Schumacher and Barry Zuckerman published a review paper on the subject in the January 1 Pediatrics. They call for new recommendations for parents and more research on the effects of this particular flavor of screen time on toddlers. Based on what little work has been done, they also offer some preliminary guidance.
The TV studies can provide guidelines about how long kids should be watching and at what age. In 1999, the American Academy of Pediatrics came out with a statement discouraging media use in children under two years old. They reaffirmed that position in 2011, and again in October of 2013. However, the organization has yet to take a direct stance on smartphones and tablets.
While these devices can function as simple viewing screens, smartphones and tablets can be more than a portable television. For one thing, they’re interactive. That opens the door to potential education and development benefits. “No app can read a child’s cues and respond contingently the way a caregiver can, at least not yet,” Radesky says. “But apps can respond to child prompts, taps or vocalizations.” This interactive facet might mean children could learn from small screen media at an earlier age than current recommendations suggest.
Dimitri Christakis, a pediatrician at Seattle Children’s Research Institute, advocated as much in an opinion piece in JAMA Pediatrics last May. But, linking screen time to what’s going on in the brain and to behavior is hard. His lab recently found that 15- to 18-month-old toddlers playing with blocks had higher levels of cortisol, a hormone that regulates stress levels, compared with those watching DVDs. That would suggest that a little stress, measured by cortisol in this experiment, may be associated with activities that toddlers can learn from. Christakis thinks that, when it comes to cortisol levels, tinkering with apps on a tablet may be more like playing with blocks than watching a screen. But researchers don’t really know what healthy levels of cortisol are in infants. In general, it’s also hard to link cortisol levels to long-term brain or behavior effects.
Tablets and smartphones can also facilitate interactions with parents, family and friends. A 2013 study in Child Development found that video chatting through a smartphone app can be just as effective as chatting in person when it comes to helping 24- to 30-month-old children bond and learn new words.
Last year, Laura Sanders wrote about her involvement in project at Georgetown University that’s looking further into how children interact with video calls. Radesky is keen to investigate what kids can learn from apps versus the real world and whether apps might be more beneficial for some children versus others — like kids who develop language skills slower or those with neurobiological issues.
In the education realm, there’s a lot of potential, but also a lot of hype. E-books and apps designed to help kids learn to read could help with early literacy by exposing toddlers to letters, words and phonetics. The few studies that have been done focus on older children, though.
At the same time, e-books often come with extras like sound effects and videos that can be distracting, potentially messing with the child’s attention and understanding of the story or the task or the lesson they’re supposed to be learning. “The delight a child gets from touching a screen and making something happen is both edifying and potentially addictive,” Christakis writes. Just like with TV, setting limits reduces the potential for developing tablet-addicted toddlers. At this point, Radesky and her colleagues affirm that it’s up to parents to use their best judgment. Trying an app or game before turning a toddler loose on it is always a good idea, they write.
It’s hard to sift through the millions of apps out there that market themselves as education products to figure out what actually works and what doesn’t. For now, parents looking for advice on the subject can turn to organizations that focus on early childhood development, like Zero to Three or Resources for Early Learning. The New America Foundation has reviewed some literacy apps, but their effectiveness may depend on the level of stimulation and the child’s age. “For kids 2 and younger, there’s no evidence that apps can teach anything,” Radesky says.
Despite the call for more research on the subject, results from ongoing and future studies may not even end up vindicating or condemning toddlers’ exposure to tablets and smartphones. “It’s not a pro or con, black or white type of argument,” says Radesky. “It’s more about balance, content and how we use the device.”
And while the long-term effects of small-screen screen time on toddlers remain unclear, anecdotal field studies and tech repair shops confirm that toddlers can be lethal to smartphones and tablets.
quinta-feira, 26 de fevereiro de 2015
Researchers working on the Brainflight project have successfully demonstrated mind-controlled drone flight
In what may be a just a taste of what's possible when you merge robotics and neuroscience, researchers from Portugal's Brainflight project have successfully demonstrated a drone flight piloted by human thought.
The Brainflight project is led by Portuguese technology firm Tekever with the backing of several science organizations across Europe and follows in the footsteps of similar research efforts carried out around the globe. Back in 2012, researchers at Zhejiang University in China were able to demonstrate a mind-controlled drone by slapping a electroencephalogram (EEG) headset on subjects to measure their brainwaves. More recently, a project at the University of Minnesota saw pilots able to control quadcopters by imagining opening or closing their fists.
The Brainflight also uses an EEG cap, which is fitted with electrodes to monitor brainwaves. Purpose-built algorithms then translate these brain waves into control commands for the drone, determining a flight path based on the activity of the brain and a mission defined by the researchers prior to takeoff. The team tested out the system using flight simulators for both manned aircraft and unmanned aerial vehicles (UAVs). It then proceeded to carry out live flight testing with the UAV.
After a period of training their brains, the pilots were instructed to focus on moving a small circle on a screen up and down, which commanded the drone to move left and right. So enthused was the team by the success of the technique, it hopes that it could one day even be used to control commercial aircraft.
"This is an amazing high-risk and high-payoff project, with long-term impact that has already provided excellent results and will require further technology maturation," says Tekever Chief Operating Officer, Ricardo Mendes. "We truly believe that Brainflight represents the beginning of a tremendous step change in the aviation field, empowering pilots and de-risking missions, and we’re looking forward to deliver these benefits to the market with highly innovative products."
The thought of a packed 747 cruising across the Pacific Ocean controlled by somebody's thoughts is a little unsettling, but the rationale behind wanting to expand the technique to manned flight may not be as pie in the sky as it seems. The team believes that the system has the potential to make piloting an aircraft as intuitive as a regular activities like walking and running, in turn freeing up brainpower for higher thinking while also making the profession accessible to those with physical disabilities.
Other possible applications for the technology, as noted by Tekever, include offering new ways for disabled people to interact with their environments and controlling other vehicles such as cars, boats and trains.
The Archiblox Archi+ Carbon Positive House produces more energy than it uses
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Prefab houses can be quick and affordable to build. Now, a prefab house from Australian architects Archiblox promises the additional benefit of generating more energy than it uses. The Archi+ Carbon Positive House has a variety of sustainability features, including a green roof and a solar array.
Archiblox says the house is the "world's first carbon positive prefabricated house," by which it means the first prefab house to be energy positive. It has to be said that Gizmag has covered other houses whose designers might dispute that claim, such as the Odooproject and more recently, the P.A.T.H. range. Nonetheless, the sustainability credentials of the Archi+ appear to have been considered down to the last detail.
To begin with, the Archi+ makes use of passive design – features that work with the surrounding environment to the benefit of the house. Shades on the outside of the house, for example, are used to help keep it cool during the summer, but can be retracted in winter to help with heating. Floor-to-ceiling sliding glass doors, meanwhile, maximize sun penetration during winter and can be opened during the summer.
The house uses a "buffer zone" to help moderate its temperature. The northernmost section of the structure is separated via an interior wall and has a depth that is enough to keep the hot temperatures from the high angle of the summer sun contained from the rest of the house. The lower angle of the winter sun, meanwhile, allows it to reach through to the main body of the house.
The Archi+ has a small footprint of 53 sq m (570 sq ft) into which it squeezes a bedroom, bathroom, living area, kitchen, dining area, laundry nook, modular cabinetry and a sun-room. Its small size minimizes the amount of electricity and heating energy required.
Cross-flow ventilation uses the prevailing breezes from the south to bring fresh air into the house through underground piping before expelling old air from high north-facing windows. The windows themselves are double-glazed, thermally broken and have draft-proof seals, all of which helps to minimize heat loss.
Archiblox can't provide Gizmag with air tightness figures, but does say that the house is designed to be be as airtight as possible. Likewise, there is no information available as to exactly how much energy the houses uses, other than to say that it's a fraction of the 15-21 kWh that the 5 KW roof-mounted solar panels produce each day. Any surplus energy generated is fed back into the grid.
Amongst the other green features of the house are the sustainably-sourced materials from which it is built and the finishes (such as glue and paint) that are free of formaldehyde and volatile organic compounds. The green roof helps to insulate the house, and an internal vegetable garden is watered with recycled grey water.
The Archi+ was recently installed for display in Melbourne's City Square and costs from AU$260,000 (US$205,000).
Researchers explore individuals' confidence or reluctance to vaccinate their families and the associated effects on global health, in a collection published on February 25, 2015 by the open-access journal, PLOS Currents: Outbreaks. The collection is accompanied by the editorial "Hesitancy, trust and individualism in vaccination decision-making" by Jonathan E. Suk et al. from the European Centre for Disease Prevention and Control (ECDC).
Vaccines are thought to be one of the most successful public health measures, but some individuals are hesitant to vaccinate their families for a variety of reasons. Due to the current spread of vaccine-preventable diseases, including the most recent measles outbreaks in California and Berlin, Suk notes that the issue of vaccine hesitancy "appears to be increasingly pressing and politicized in many parts of the world." Peretti-Watel et al. and Larson et al. analyze the ambiguity of the language surrounding the terms vaccine hesitancy and confidence, and stress the importance of clarifying these terms when communicating about vaccinations. Other researchers examined how public trust in larger social structures and health systems correlates with the decision to vaccinate in both the United States and Europe. The collection also hones in on issues surrounding specific vaccines, including a paper that investigates US women's intentions to request the Tdap and influenza vaccines while pregnant, as well as an article about the H1N1 vaccination and how public communication affects individuals' perceptions of vaccines. Likewise, contemporary vaccination coverage is explored in Schuster et al., which relates to the ongoing measles outbreak in Berlin and its disproportionate effects in young adults.
While some articles address specific vaccination concerns, all wrestle with the issues that arise when even a small subset of vaccine-hesitant or resistant individuals potentially undermine immunization efforts. This leads to the question posed by Larson et al., "How much confidence [in vaccines] is enough?" Suk believes this is a significant question to explore as vaccine hesitancy remains an issue of both policy and personal decision.
The freely available collection is available at: http://currents.plos.org/outbreaks/perspectives-on-vaccine-hesitancy-and-vaccination-coverage/
PNNL's new zinc-polyiodide flow battery has a high energy density, which reduces its size and cost and makes it well suited to store energy in densely populated cities. Shown here are electrolytes from another PNNL flow battery, a vanadium-redox flow battery.
Ensuring the power grid keeps the lights on in large cities could be easier with a new battery design that packs far more energy than any other battery of its kind and size.
The new zinc-polyiodide redox flow battery, described in Nature Communications, uses an electrolyte that has more than two times the energy density of the next-best flow battery used to store renewable energy and support the power grid. And its energy density is approaching that of a type of lithium-ion battery used to power portable electronic devices and some small electric vehicles.
"With improved energy density and inherent fire safety, flow batteries could provide long-duration energy storage for the tight confines of urban settings, where space is at a premium," said Imre Gyuk, energy storage program manager at the Department of Energy's Office of Electricity Delivery and Energy Reliability, which funded this research. "This would enhance the resiliency and flexibility of the local electrical grid."
"Another, unexpected bonus of this electrolyte's high energy density is it could potentially expand the use of flow batteries into mobile applications such as powering trains and cars," said the study's corresponding author, Wei Wang, a materials scientist at DOE's Pacific Northwest National Laboratory.
Going with the flow
Both flow and lithium-ion batteries were invented in the 1970s, but only the lithium-ion variety took off at that time. Lithium-ion batteries could carry much more energy in a smaller space than flow batteries, making them more versatile. As a result, lithium-ion batteries have been used to power portable electronics for many years. And utilities have begun using them to store the increasing amounts of renewable energy generated at wind farms and solar power facilities.
But the high-energy lithium-ion batteries' packaging can make them prone to overheating and catching fire. Flow batteries, on the other hand, store their active chemicals separately until power is needed, greatly reducing safety concerns. This feature has prompted researchers and developers to take a serious second look at flow batteries.
Stacking up against the competition
Like other flow batteries, the zinc-polyiodide battery produces power by pumping liquid from external tanks into the battery's stack, a central area where the liquids are mixed. The external tanks in PNNL's new battery hold aqueous electrolytes, watery solutions with dissolved chemicals that store energy.
When the battery is fully discharged, both tanks hold the same electrolyte solution: a mixture of the positively charged zinc ions, Zn2+, and negatively charged iodide ion, I-. But when the battery is charged, one of the tanks also holds another negative ion, polyiodide, I3-. When power is needed, the two liquids are pumped into the central stack. Inside the stack, zinc ions pass through a selective membrane and change into metallic zinc on the stack's negative side. This process converts energy that's chemically stored in the electrolyte into electricity that can power buildings and support the power grid's operations.
To test the feasibility of their new battery concept, Wei and his PNNL colleagues created a small battery on a lab countertop. They mixed the electrolyte solution, separating a black zinc-polyiodide liquid and a clear zinc-iodide liquid in two glass vials as miniature tanks. Hoses were connected between the vials, a pump and a small stack.
They put the 12-watt-hour capacity battery -- comparable to about two iPhone batteries -- through a series of tests, including determining how different concentrations of zinc and iodide in the electrolyte affected energy storage. Electrical capacity is measured in watt-hours; electric cars use about 350 watt-hours to drive one mile in the city.
More power to it
The demonstration battery put out far more energy for its size than today's most commonly used flow batteries: the zinc-bromide battery and the vanadium battery. PNNL's zinc-polyiodide battery also had an energy output that was about 70 percent that of a common lithium-ion battery called a lithium iron phosphate battery, which is used in portable electronics and in some small electric vehicles.
Lab tests revealed the demonstration battery discharged 167 watt-hours per liter of electrolyte. In comparison, zinc-bromide flow batteries generate about 70 watt-hours per liter, vanadium flow batteries can create between 15 and 25 watt-hours per liter, and standard lithium iron phosphate batteries could put out about 233 watt-hours per liter.. Theoretically, the team calculated their new battery could discharge even more -- up to 322 watt-hours per liter -- if more chemicals were dissolved in the electrolyte.
Safe and versatile, but not perfect yet
PNNL's zinc-polyiodide battery is also safer because its electrolyte isn't acidic like most other flow batteries. It's nearly impossible for the water-based electrolyte to catch fire and it doesn't require expensive materials that are needed to withstand the corrosive nature of other flow batteries.
Another advantage of PNNL's new flow battery is that it can operate in extreme climates. The electrolyte allows it to work well in temperatures as cold as -4 degrees Fahrenheit and as warm as +122 degrees. Many batteries have much smaller operating windows and can require heating and cooling systems, which cut into a battery's net power production.
One problem the team encountered was a build-up of metallic zinc that grew from the central stack's negative electrode and went through the membrane, making the battery less efficient. Researchers reduced the buildup, called zinc dendrite, by adding alcohol to the electrolyte solution.
Managing zinc dendrite formation will be a key in enabling PNNL's zinc-polyiodide battery to be used in the real world. Wei and his colleagues will continue to experiment with different alcohols and other additives and use advanced instruments to characterize how the battery's materials respond to those additives. The team will also build a larger, 100-watt-hour model of the battery for additional testing.
The Democratic Republic of Congo contains half of Africa's tropical forest and the second largest continuous tropical forest in the world. This animation of Landsat images from 1999 and 2008 shows how much deforestation has occurred between those years -- impinging even on Virunga National Park. These images are from the same Landsat datasets used by researchers at the University of Maryland to study the 34 countries -- including the Democratic Republic of the Congo -- that contain 80 percent of the forested tropical lands.
The rate at which tropical forests were cut, burned or otherwise lost from the 1990s through the 2000s accelerated by 62 percent, according to a new study which dramatically reverses a previous estimate of a 25 percent slowdown over the same period. That previous estimate, from the U.N.'s Food and Agriculture Organization's (FAO) Forest Resource Assessment, was based on a collection of reports from dozens of countries. The new estimate, in contrast, is based on vast amounts of Landsat image data which directly record the changes to forests over 20 years.
"Several satellite-based local and regional studies have been made for changing rates of deforestation [during] the 1990s and 2000s, but our study is the first pan-tropical scale analysis," explains University of Maryland, College Park, geographer Do-Hyung Kim, lead author of the new study accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
Kim and his University of Maryland colleagues Joseph Sexton and John Townshend looked at 34 forested countries which comprise 80 percent of forested tropical lands. They analyzed 5,444 Landsat scenes from 1990, 2000, 2005 and 2010 with a hectare-scale (100 by 100 meter) resolution to determine how much forest was lost and gained. Their procedure was fully automated and computerized both to make the huge datasets manageable and to minimize human error.
They found that during the 1990-2000 period the annual net forest loss across all the countries was 4 million hectares (15,000 square miles) per year. During the 2000-2010 period, the net forest loss rose to 6.5 million hectares (25,000 square miles) per year -- a 62 percent increase is the rate of deforestation. That last rate is the equivalent to clear cutting an area the size of West Virginia or Sri Lanka each year, or deforesting an area the size of Norway every five years.
In terms of where the deforestation was happening, they found that tropical Latin America showed the largest increase of annual net loss of 1.4 million hectares (5,400 square miles) per year from the 1990s to the 2000s, with Brazil topping the list at 0.6 million hectares (2,300 square miles) per year. Tropical Asia showed the second largest increase at 0.8 million hectares (3,100 square miles) per year, with similar trends across the countries of Indonesia, Malaysia, Cambodia, Thailand and the Philippines. Tropical Africa showed the least amount of annual net forest area loss. Still, there was a steady increase of net forest loss in tropical Africa due to cutting primarily in Democratic Republic of Congo and Madagascar.
The new, satellite-based study "really provides a benchmark of tropical forest clearing not provided by other means," said geographer Douglas Morton, who studies forest cover by satellite sensing at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and was not a coauthor on the GRL paper.
However, the U.N. agency's report is not as flawed as it may seem, argues Rodney Keenan, a University of Melbourne, Australia, forest science researcher who participated in the agency's last forest assessment. Unlike the satellite evaluation, he explained, other deforestation estimates, such as the FAO's 2010 assessment, are based on ground based surveys of trees, often supplemented by imagery. "Both approaches are useful and people need to understand the distinctions and implications of different approaches," he said.
While the new study is "an important contribution to the overall picture," Keenan added, it "should not be seen as contradicting the FAO figures." Not so, say Kim and his colleagues. "We made it very clear in our paper where the FAO missed deforestation that is obvious in satellite images," Kim said, noting that, for example, the FAO reported no change of deforestation rate for 16 of 34 countries from 1990 through 2010, whereas Landsat images show otherwise.
Morton notes that the new, satellite-based estimates are particularly important for those trying to understand the global amounts of carbon being released into the air (primarily in the forms of the climate-warming gases carbon dioxide and methane) or being taken up by plants, soils and waters.
"Tropical deforestation plays a big role in global climate cycles," he explained, pointing out that the cutting and burning of forests accounted for 20 percent of greenhouse gas emissions in 1990s.
It's not really a surprise that the new research shows dramatically higher deforestation rates although "without the transparency of Landsat satellite data is difficult to put your finger on changing trends," Morton added.
"Tropical deforestation has become increasingly more mechanized," he observed. "In the 60s, it was axes; in the 70s, chainsaws; and in the 2000s, it was tractors." For him, he explained, an increase in deforestation rates makes technological sense.
We’ve partnered with National Geographic Learning and Cengage Learning to roll out three English-language curriculums, each digging into TED Talks. Photo: Sacha Vega/TED
“The world has a new mania — a mania for learning English,” said Jay Walker on the TED stage in 2009.
English is accepted as a shared language of science, a language of global business and the language of the Internet, with at least 1.5 billion students learning it worldwide. So the TED Distribution team wondered: What if students could learn English through TED Talks?
To test this theory, we’ve partnered with National Geographic Learning and Cengage Learning to roll out three English-language curriculums, each grounded in the ideas of TED speakers. The first in the series: World English, a four-level survey course that teaches basic reading, listening, speaking and writing skills. For those a little more advanced: 21st-Century Reading, which is designed to improve reading comprehension of all kinds of texts, including infographics and charts, and to inspire community action. And coming up next: Business English, created to help develop English skills for the workplace. All are served up as a mix of paperback workbooks and online materials. World English and 21st-Century Reading have volumes out, and Business English will be available soon. Each workbook costs around $50US, and schools can also license the curriculum.
Typically, language learning courses lean on hypothetical situations for conversation prompts — you might have to ask about the location of the bathroom, talk about meeting someone at the library or compliment someone on their hat. So Cengage loved the idea of adapting content from TED and National Geographic to give English language learning a real-world foundation. By creating lessons around ideas, they hope that participants pick up the language as a side effect of getting curious and inspired.
“You learn how to put together a sentence in the context of real issues and ideas going on in our world,” says our Content Distribution Editor, Janet Lee. “It’s a different way of learning.”
In World English, each lesson pairs activities on a general interest topic — like family, work and housing — with a talk from TED’s archives. For example, after reading a transcript of Diana Reiss’s talk on the interspecies internet, students match animals with their primary sense: sight, smell or hearing. For a lesson around Eric Whitacre’s virtual choir, students are prompted to discuss how to start an online community.
Education consultant Mary Kadera helped identify the TED Talks that would be a fit for each unit’s topic. For her, the challenge in programming World English was having to boil down an 18-minute idea to its most basic essence without sacrificing the speaker’s intent. “A basic learner typically comes in knowing around 200 words,” she says. “We spend a lot of time editing those transcripts so that they’re accessible to people with limited English vocabularies, yet capture what the speaker had in mind.”
21st-Century Reading was created for a younger audience, and has a TED idea built into every unit. Once learners have mastered the vocabulary, grammar and comprehension exercises for a talk, they are encouraged to go out and do more research on how to implement the idea in their school or community. Activities have ranged from exploring a public art project, like Candy Chang’s “Before I die” wall, to planting a community garden inspired by Ron Finley. “It feels very TED-like — you can turn your curiosity and inspiration into something actionable,” says Kadera.
The third series, Business English, is for the call center representative working on campaigns for English-speaking companies, or for the marketer looking to expand into new countries. The exercises here also tackle grammar, speaking, writing and reading, but through a business lens. TED’s wealth of business-related talks on management, branding and work-life balance are embedded in the activities.
When Cengage surveyed ESL teachers all over the world before creating these new series, they heard from many who were already using TED Talks in their classrooms. Part of the motivation for this partnership was to support teachers with a more formalized and engaging course structure around TED’s content.
“I love the idea that maybe one day someone who’s learned English from these TED/Cengage projects will be on TED stage somewhere,” says Kadera, “giving a talk in English.”
By Krystian Aparta
They say that children learn languages the best. But that doesn’t mean that adults should give up. We asked some of the polyglots in TED’s Open Translation Project to share their secrets to mastering a foreign language. Their best strategies distill into seven basic principles:
What does it mean to “have tomatoes on your eyes?” Find out below…
By Helene Batt and Kate Torgovnick May
It’s a piece of cake. You can’t put lipstick on a pig. Why add fuel to the fire? Idioms are those phrases that mean more than the sum of their words. As our Open Translation Project volunteers translate TED Talks into 105 languages, they’re often challenged to translate English idioms into their language. Which made us wonder: what are their favorite idioms in their own tongue?
Below, we asked translators to share their favorite idioms and how they would translate literally. The results are laugh-out-loud funny.
From German translator Johanna Pichler:
The idiom: Tomaten auf den Augen haben.
Widely used food additives promotes colitis, obesity and metabolic syndrome, shows study of emulsifiers
This photo shows bacteria that are present deeper in the mucus layer that lines the intestine and closer to the epithelium than they should be.
Emulsifiers, which are added to most processed foods to aid texture and extend shelf life, can alter the gut microbiota composition and localization to induce intestinal inflammation that promotes the development of inflammatory bowel disease and metabolic syndrome, new research shows.
The research, published Feb. 25 in Nature, was led by Georgia State University Institute for Biomedical Sciences' researchers Drs. Benoit Chassaing and Andrew T. Gewirtz, and included contributions from Emory University, Cornell University and Bar-Ilan University in Israel.
Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, afflicts millions of people and is often severe and debilitating. Metabolic syndrome is a group of very common obesity-related disorders that can lead to type-2 diabetes, cardiovascular and/or liver diseases. Incidence of IBD and metabolic syndrome has been markedly increasing since the mid-20th century.
The term "gut microbiota" refers to the diverse population of 100 trillion bacteria that inhabit the intestinal tract. Gut microbiota are disturbed in IBD and metabolic syndrome. Chassaing and Gewirtz's findings suggest emulsifiers might be partially responsible for this disturbance and the increased incidence of these diseases.
"A key feature of these modern plagues is alteration of the gut microbiota in a manner that promotes inflammation," says Gewirtz.
"The dramatic increase in these diseases has occurred despite consistent human genetics, suggesting a pivotal role for an environmental factor," says Chassaing. "Food interacts intimately with the microbiota so we considered what modern additions to the food supply might possibly make gut bacteria more pro-inflammatory."
Addition of emulsifiers to food seemed to fit the time frame and had been shown to promote bacterial translocation across epithelial cells. Chassaing and Gewirtz hypothesized that emulsifiers might affect the gut microbiota to promote these inflammatory diseases and designed experiments in mice to test this possibility.
The team fed mice two very commonly used emulsifiers, polysorbate 80 and carboxymethylcellulsose, at doses seeking to model the broad consumption of the numerous emulsifiers that are incorporated into almost all processed foods. They observed that emulsifier consumption changed the species composition of the gut microbiota and did so in a manner that made it more pro-inflammatory. The altered microbiota had enhanced capacity to digest and infiltrate the dense mucus layer that lines the intestine, which is normally, largely devoid of bacteria. Alterations in bacterial species resulted in bacteria expressing more flagellin and lipopolysaccharide, which can activate pro-inflammatory gene expression by the immune system.
Such changes in bacteria triggered chronic colitis in mice genetically prone to this disorder, due to abnormal immune systems. In contrast, in mice with normal immune systems, emulsifiers induced low-grade or mild intestinal inflammation and metabolic syndrome, characterized by increased levels of food consumption, obesity, hyperglycemia and insulin resistance.
The effects of emulsifier consumption were eliminated in germ-free mice, which lack a microbiota. Transplant of microbiota from emulsifiers-treated mice to germ-free mice was sufficient to transfer some parameters of low-grade inflammation and metabolic syndrome, indicating a central role for the microbiota in mediating the adverse effect of emulsifiers.
The team is now testing additional emulsifiers and designing experiments to investigate how emulsifiers affect humans. If similar results are obtained, it would indicate a role for this class of food additive in driving the epidemic of obesity, its inter-related consequences and a range of diseases associated with chronic gut inflammation.
While detailed mechanisms underlying the effect of emulsifiers on metabolism remain under study, the team points out that avoiding excess food consumption is of paramount importance.
"We do not disagree with the commonly held assumption that over-eating is a central cause of obesity and metabolic syndrome," Gewirtz says. "Rather, our findings reinforce the concept suggested by earlier work that low-grade inflammation resulting from an altered microbiota can be an underlying cause of excess eating."
The team notes that the results of their study suggest that current means of testing and approving food additives may not be adequate to prevent use of chemicals that promote diseases driven by low-grade inflammation and/or which will cause disease primarily in susceptible hosts.
This study was funded by the National Institutes of Health and Crohn's & Colitis Foundation of America.
February 25, 2015
University of Georgia
Women going through menopause often struggle with weight gain that results when their estrogen levels drop, and many turn to weight-loss supplements. But those supplements may cause an accumulation of fat in the liver and a potentially life-threatening condition called non-alcoholic fatty liver disease. Now researchers have shown in studies of post-menopausal animals that a mix of phytochemicals, along with vitamin D, may help protect the liver against inflammation caused by fat accumulation.
Women going through menopause often struggle with weight gain that results when their estrogen levels drop, and many turn to weight-loss supplements to help them shed those extra pounds. But those supplements may cause an accumulation of fat in the liver and a potentially life-threatening condition called non-alcoholic fatty liver disease.
Now researchers at the University of Georgia have shown in studies of post-menopausal animals that a mix of phytochemicals, along with vitamin D, may help protect the liver against inflammation caused by the accumulation of fat. The study was published recently in the journal Obesity.
"Women going through menopause have an increased tendency to store fat in their livers," said the study's lead author Colette Miller, a post-doctoral research associate in the College of Family and Consumer Sciences' department of foods and human nutrition. "They also have increases in visceral fat--the fat around their organs--where inflammation also occurs.
Many popular weight-loss supplements cause fat to mobilize in the body, increasing the accumulation of fat in the liver, explained Miller. Over time, the extra fat can lead to inflammation and scarring.
The plant compounds used by the UGA researchers--resveratrol, found in grapes; genistein, found in soybeans; and quercetin, found in apple peels and onions--have all been shown in previous studies to be fat-busters, causing fat cells to burst and release their contents.
Miller said it's nearly impossible to get enough of any of these compounds through food or supplements to gain any benefit. However, she said, together they have a synergistic effect that "cuts the doses you need."
While the treatment did not cause the animals ingesting the compounds to lose weight overall, the researchers saw that visceral fat layers were decreased.
"We were able to demonstrate that our phytochemical treatment is shuttling the fat away from the fat tissue to be burned or stored elsewhere," Miller said. "Ultimately what we saw was that there was no damage in the liver being caused by this increased fat associated with menopause."
Miller said fatty liver disease is a public health issue that will affect many people. Although it is usually associated with alcoholism, it is increasingly diagnosed in individuals who consume little to no alcohol, especially those who are overweight or obese, including adolescents and children.
Currently, the disease has no real treatment.
"There might be nothing you can do about the fat being shuttled to the liver, but if you can prevent the fat from being toxic or from causing disease, then that might be the best way of treating this," Miller said.
- Colette N. Miller, Jeong-Yeh Yang, Tucker Avra, Suresh Ambati, Mary Anne Della-Fera, Srujana Rayalam, Clifton A. Baile. A dietary phytochemical blend prevents liver damage associated with adipose tissue mobilization in ovariectomized rats. Obesity, 2015; 23 (1): 112 DOI: 10.1002/oby.20907
UCLA physicists offer a possible solution to the mystery of the origin of matter in the universe.
Most of the laws of nature treat particles and antiparticles equally, but stars and planets are made of particles, or matter, and not antiparticles, or antimatter. That asymmetry, which favors matter to a very small degree, has puzzled scientists for many years.
New research by UCLA physicists, published in the journal Physical Review Letters, offers a possible solution to the mystery of the origin of matter in the universe.
Alexander Kusenko, a professor of physics and astronomy in the UCLA College, and colleagues propose that the matter-antimatter asymmetry could be related to the Higgs boson particle, which was the subject of prominent news coverage when it was discovered at Switzerland's Large Hadron Collider in 2012.
Specifically, the UCLA researchers write, the asymmetry may have been produced as a result of the motion of the Higgs field, which is associated with the Higgs boson, and which could have made the masses of particles and antiparticles in the universe temporarily unequal, allowing for a small excess of matter particles over antiparticles.
If a particle and an antiparticle meet, they disappear by emitting two photons or a pair of some other particles. In the "primordial soup" that existed after the Big Bang, there were almost equal amounts of particles of antiparticles, except for a tiny asymmetry: one particle per 10 billion. As the universe cooled, the particles and antiparticles annihilated each other in equal numbers, and only a tiny number of particles remained; this tiny amount is all the stars and planets, and gas in today's universe, said Kusenko, who is also a senior scientist with the Kavli Institute for the Physics and Mathematics of the Universe.
The research also is highlighted by Physical Review Letters in a commentary in the current issue.
The 2012 discovery of the Higgs boson particle was hailed as one of the great scientific accomplishments of recent decades. The Higgs boson was first postulated some 50 years ago as a crucial element of the modern theory of the forces of nature, and is, physicists say, what gives everything in the universe mass. Physicists at the LHC measured the particle's mass and found its value to be peculiar; it is consistent with the possibility that the Higgs field in the first moments of the Big Bang was much larger than its "equilibrium value" observed today.
The Higgs field "had to descend to the equilibrium, in a process of 'Higgs relaxation,'" said Kusenko, the lead author of the UCLA research.
Two of Kusenko's graduate students, Louis Yang of UCLA and Lauren Pearce of the University of Minnesota, Minneapolis, were co-authors of the study. The research was supported by the U.S. Department of Energy (DE-SC0009937), the World Premier International Research Center Initiative in Japan and the National Science Foundation (PHYS-1066293).