Tag Archives: future

Boys who play video games seem to have lower depression risk — but not girls

Boys who regularly play video games at age 11 are less likely to display depression symptoms when they’re 14. But this doesn’t seem to be the case for girls. Taken together, the findings suggest that video games can have both a positive and a negative effect on mental health, and it’s not always a straightforward relationship.

Image in public domain.

Screens

If there’s one thing that has changed drastically in the past two decades, it’s computers. Computers used to be incredibly big, bulky, and not that capable. That couldn’t be further from the truth nowadays. The smartphone in your pocket is millions of times more powerful than the equipment that sent people to the moon, and year on year, they just get more and more powerful.

As a result, screens have become almost ubiquitous in our society. You have your small screen that you carry in your pocket, the big screen you work on, the even bigger screen you watch movies on, sometimes even screens on utilities. Screens are everywhere, and we’re not really sure if that’s a good thing — especially when it comes to kids.

Ever since computers became mainstream, researchers have voiced concerns about screens, concerns ranging from vision to mental health problems. But screens allow us to do different things and can have varying effects, and we should consider this instead of drawing any blanket conclusions, researchers say.

“Screens allow us to engage in a wide range of activities. Guidelines and recommendations about screen time should be based on our understanding of how these different activities might influence mental health and whether that influence is meaningful,” says Aaron Kandola the author of the new study.

At first, the general idea seemed to be that video games can have a negative effect on mental health, making children more aggressive and worsening their mental health. But a flurry of recent studies paints a very different picture, showing not only that much of this damage was overstated, but that in many instances, casual video gaming can actually improve the mental health of children.

In the new study, the results are a mixed bag. A research team involving from UCL, Karolinska Institutet (Sweden) and the Baker Heart and Diabetes Institute (Australia) reviewed data from 11,341 adolescents who are part of the Millennium Cohort Study, a nationally representative sample of young people who have been involved in research since they were born in the UK in 2000-2002. They asked the teens at age 11 about how much they spend on social media, video games, and other internet activities. Then, at age 14, they asked them again about any depression symptoms.

After accounting for other factors that may affect the results (such as socioeconomic status, physical activity, or reports of bullying), the researchers look at how depression symptoms were linked with screen habits. At age 14, boys who played video games most days had 24% fewer depressive symptoms than boys who played video games less than once a month. This effect, however, was not observed on girls. Although it’s not clear why this happens, researchers link it with different screen use patterns between boys and girls.

“While we cannot confirm whether playing video games actually improves mental health, it didn’t appear harmful in our study and may have some benefits. Particularly during the pandemic, video games have been an important social platform for young people,” adds Kandola, who is a PhD student at UCL Psychiatry.

Sitting down and social media cause problems

The researchers note that the positive effect on boys was only significant among those with low physical activity. We all know (or should know) that sitting down for prolonged periods is really bad for your health, but it’s important to know that sitting down can affect your mind as well as your body. Kandola’s previous research has shown that sedentary behavior seems to increase the risk of depression and anxiety in adolescents. So it could very well be that sitting down (and not screen time itself) is causing harmful effects.

“We need to reduce how much time children – and adults – spend sitting down, for their physical and mental health, but that doesn’t mean that screen use is inherently harmful.”

Social media also plays a role. For girls, this role seems to be particularly important. Researchers found that girls (but not boys) who used social media at age 11 had 13% more depressive symptoms when they were 14. The same association was not found for more moderate use of social media. This fits with previous studies indicating that intense social media usage can increase feelings of loneliness and alienation.

The study only shows an association, not a cause-effect relationship. But it seems to suggest that not all screen time is equal, and video games can have a positive component. Researchers say that video games could support mental health, especially those that feature problem-solving, social, cooperative, and engaging elements. At any rate, reducing the amount of sedentary time seems to be a much healthier intervention than reducing screen time.

Senior author Dr. Mats Hallgren from the Karolinska Institutet has conducted other studies in adults, finding that active screen time (when you’re doing something like playing a game) seems to have a different effect on depression than passive screen time (watching something).

“The relationship between screen time and mental health is complex, and we still need more research to help understand it. Any initiatives to reduce young people’s screen time should be targeted and nuanced. Our research points to possible benefits of screen time; however, we should still encourage young people to be physically active and to break up extended periods of sitting with light physical activity,” says Hallgren.

The study was published in Psychological Medicine.

Bacterial cement.

What is the house of the future going to look like?

How will our homes morph in the future to meet the demands of today?

House.

Image via Pixabay.

Computers are rapidly becoming ubiquitous in many areas of our lives. We’re also becoming more environmentally-conscious, and more technologically-savvy. At the same time, we’re more and more pressed for time in today’s hectic world. Throughout history, our homes have changed to keep pace with our wants, needs, and possibilities, so it’s a pretty safe bet that the home will transform to both meet the requirements of modern life, as well as to take advantage of its advances. But what, exactly, will this transformation involve?

We don’t really know — but we do have some pretty good guesses. Today, let’s take a look at what future homes could be built from, how they’ll handle utilities, how we’ll get around inside them, and how to keep them at a comfortable temperature.

A brick-by-brick analysis

Fans of English architecture, sorry to break it to you, but the tried-and-tested brick’s prospects don’t look so good. Many traditional building materials, from bricks and mortar to steel and cement, release a lot of CO2 during their manufacturing processes. This doesn’t jive very well with our efforts at fighting climate change, however, so they will probably be increasingly phased out of use.

MycoTecture.

This structure was grown from the fungus Ganoderma lucidum.
Image credits Philip Ross.

Instead, why not lay down fungus bricks? Made from dried mycelia, the tangled root-like fibers that grow beneath mushrooms, these are definitely more eco-friendly than traditional bricks. And, they’re good for you too, not just for the environment. They are stronger than concrete, pound for pound, fire-proof, resistant to water and mold, and can be grown into virtually any shape. Philip Ross, an artist and lecturer at Stanford University who spearheaded the development of these mushroom bricks has co-founded MycoWorks, a company that aims to bring the product to markets.

Right now, MycoWorks’s flagship product is a type of fake leather “grown rapidly from mycelium and agricultural byproducts in a carbon-negative process” — so your couch will definitely match the walls. But what is the material like?

“It’s sort of like a plastic that can potentially be used for God knows what,” Ross told Glasstire in an interview.

Cementing eco-friendliness

Bacterial cement.

Image via Eco-Cement.

If bricks just don’t represent you that well, bacteria have got your back (and walls). As part of a European Union-backed project, a company in Madrid has developed a cheaper, sustainable, bacteria-based ‘eco-cement‘. The material starts out as a bacterial mix, which you have to supply with soil and nutrients, then simmer at around 30°C for around three hours. After this initial fermentation process, the bacteria have basically produced limestone (which is a central ingredient of cement). Throw in an armful of sand, industrial cement residue, and rice husk ash and voila — cement!

“Our raw materials are basically all waste. So we don’t have added costs,” said Laura Sánchez Alonso, a mining Engineer and Eco-Cement project coordinator. “For instance, we don’t need to extract and transport the limestone commonly used to produce cement. And we also save the energy costs”

This bacterial approach can shave some 11% off of greenhouse emissions, and 27% off of the production costs of cement. Researchers have yet to determine how many wall-related discussions this cement will spark at your housewarming party, but unofficial estimates say it is ‘a lot’.

Wooden’t you like to live here?

Brock wooden skyscraper.

The wooden Brock skyscraper was constructed ahead of target.
Image credits Acton Ostry Architects, the developeres of the project.

Wood is making a comeback as a building material. It has several very appealing properties: it’s a strong, sustainable material which stores carbon dioxide to boot. It’s also very versatile, and we’re learning to do more and more awesome things with it. If you need steel but want wood, it can do that — just make it superdense. Need windows but all you have are planks? Fret not; transparent wood is stronger than glass and easy to make. From timber skyscrapers to wind turbines, to taller skyscrapers, wood is definitely the most modern ancient building material.

“(As) a building like this becomes a reality, it really paves the way for additional projects across the country, probably throughout North America and throughout the world,” said Lynn Embury-Williams, executive director of the Canadian Wood Council’s Wood Works BC program, who worked on the Brock Commons, a wooden skyscraper student dorm for the University of British Columbia campus.

Insulation

Insulation has a big role to play in making your home energy-efficient. If you’re a sci-fi type of guy, aerogels are right down your alley (and, ideally, up your walls). For the fantasy fans among you, staw might be more palatable — but just as effective.

Heating is cool

Radiator.

Image via Pixabay.

Insulation is just half of the equation — we also want to heat the place up during winter and cool it down in the summer. In other words, we want temperature control. One of the sleekest upcoming systems in this area is a thermal battery developed by the EMPA (the Swiss Federal Laboratories for Materials Testing and Research). It mixes NaOH (sodium hydroxide, lye) with water to generate heat during cold months. When summer swings by, recharging the battery is as simple as leaving it out in the sun to dry.

Alternatively, if your goal is to stay cool on a budget, this air conditioning unit might spark your fancy. In broad lines, it pushes air through a paper-like membrane to dry it down. Then, this dry air is pumped over metallic plates inside the AC to force water to evaporate at room temperature. Since water needs to absorb energy to turn from a liquid to a gas, this cools down the plates, which in turn cool down the surrounding air. The system also generates about 12 to 15 liters (12.68 to 15.85 quarts) of potable water per day.

Getting around

Elevators.

Image credits Suppadeth Wongyee.

One of the best parts of technology is that it makes life easier and more enjoyable. Getting around the house might not seem like that much of a hassle, but for the elderly or those living with disabilities, it can become quite hard. Stairs are a time-proven feature but are hard to navigate for someone in a wheelchair, for example. Elevators seem like the ideal fix, but let’s be honest — how many of us can afford to install new-age residential elevators? We’re not all French kings, after all.

One British company is touting new-age residential elevators as the ideal solution. Their product is basically a home elevator that can “fit into the corner of a room and ascends through a hole in the ceiling with no lift shaft required,” according to the South China Morning Post.

“You could describe it as a high-end chair lift. People don’t want, in many cases, a chair-lift on their beautiful staircase and they don’t necessarily want a lift; it’s about looking at the lift for the long-term future proofing the property,” said John McSweeney, the company’s founder.

“And unlike a stairlift which is a permanent feature on your staircase, the lift can be sent away when you don’t need it — so it’s never the elephant in the room.”

Water, power, gas

Solar roof.

Image credits Ulrike Leone.

Perhaps the single best way your house can generate its own clean power is with a solar panel roof. When working in tandem with a battery bank, such a roof could, with a bit of luck and help from geography, even make your home energy-independent — or even a net energy contributor to the larger grid. Since it’s clean, relatively cheap and easy to maintain, and quite efficient, I think solar roofs will catch on in the houses of the future. And, if you need to make sure you’re generating as much energy as possible, you can turn your windows into a source of power as well.

Water has always been a little trickier to reliably generate at home. Wells aren’t a realistic option for those of us living in big cities. Even if you own a plot of land big enough to dig said well, groundwater tends to be very polluted underneath cities — so you shouldn’t drink it. But, we have ways to get a drink out of Mother Nature.

This simple, manganese-oxide-coated-sand approach can be used to purify stormwater. The sand particles physically block impurities, while the coating breaks down organic pollutants. The team intended for it to be used on a large scale, to supply displaced communities with clean water aquifers; it can thus easily be turned to the task of supplying ‘placed’ communities with clean water they can then pump out or tap with a well, for example. However, it can probably be adapted to provide clean rainwater for single homes at a time.

Trees are more sustainable than sand, capture CO2, and can also clean your water. By tapping into sapwood’s natural filtration properties, this team of researchers created a simple and elegant water filter. The only thing it can’t filter, the team explains, are viruses.

“Today’s filtration membranes have nanoscale pores that are not something you can manufacture in a garage very easily,” says Rohit Karnik, one of the researchers that developed the filter. “The idea here is that we don’t need to fabricate a membrane, because it’s easily available. You can just take a piece of wood and make a filter out of it.”

So far, so good for all of those who favor a more natural approach — but what if you want to call upon the full brunt of science and precision technology when turning the tap? Graphite may be the filter of choice for you, then. The team behind that filter reports it removes “99% of natural organic matter from water at low pressure,” which is nothing to scoff at.

For potable water, however, I’d recommend going the safe route and doing away with filters completely. Something like a scaled-up Solarball could provide a family with all the drinking water it requires, germ- and contaminants- free.

As far as gas usage goes — just don’t. Use electricity instead.

Researchers fit Italian woman with futuristic, bionic hand

Almerina Mascarello lost her hand in a work accident — in July 1993, her hand was crushed by an industrial press. After almost 25 years, her luck completely changed.

An extraordinary fortunate event

 “I was flicking through a magazine on invalidity when I noticed a page asking people to undergo a test for a prosthesis. The Gemelli doctor phoned me a year later and asked me if I would like to be a guinea pig for a bionic hand“, she told ANSA.

“I said I would think about it and I said yes in May of last year. I went to Rome for the operation in June”Mascarello added.

Via Pixabay/Tumisu

The prosthetic — named LifeHand2 — was engineered by a team led by Silvestro Micera, from Scuola Superiore Sant’Anna in Pisa and the École polytechnique fédérale de Lausanne. Neurologist Paolo Maria Rossini’s team from Rome’s Policlinico Gemelli Hospital did the medical work.

How the hand works

The medical team inserted hair-thin electrodes into Almerina’s upper arm nerves. These electrodes conduct sensorial information from the hand to a computer in a backpack. The computer translates the gathered info into a language the brain can understand. Basically, the computer transmits to the upper arm nerves electrical signals, telling the brain the consistency and shape of the object.

bionic-hand

Almerina Mascarello opening a water bottle with the help of her new bionic hand. Credit: Youtube / Euronews.

A similar version of the bionic hand was priorly used by Danish patient Dennis Aabo Sorensen, who lost his hand in 2004 due to a firework explosion. His bionic hand was so sensitive that he was able to determine the consistency of different objects in 78 percent of cases. In 88 percent of cases, he could distinguish between a baseball, a glass, and a tangerine.

Credit: Youtube / Euronews.

The bionic hand is sophisticated enough to relay texture. Credit: Youtube / Euronews.

However, Mascarello’s implant and annexes were adjusted to fit into a backpack, unlike Sorensen’s. The bioengineering team’s goal is to create a hand prosthesis that has all the necessary components built in, miniaturizing the electronics as much as possible.

“We are going more and more in the direction of science fiction movies, like Luke Skywalker’s bionic hand in Star Wars – a fully controlled, fully natural, sensorized prosthesis, identical to the human hand.” lead researcher Micera told the BBC.

Sadly, Mascarello had to give up her prosthesis for further research. She felt like she was complete after 24 years, gathering joy from all the small things, like being able to tie her own shoes or dress alone. Unfortunately, only the research project is completed will she receive her own prosthetic hand.

“Now I’m eagerly awaiting them to call me and tell me it’s ready”, she stated.

Great Scott! Today is future day!

Do you know what day today is? It’s Back to the Future day! That’s right, Marty McFly and Doc Brown traveled to October 21, 2015, and that’s exactly today – we’re living in the future, ladies and gentlemen.

Marty McFly, portrayed by Michael J Fox, immortalised the concept of the hoverboard in Back to the Future II. Image via Universal Pictures.

Image via Universal Pictures.

If you’re extremely confused by now and have absolutely no idea what I’m talking about, this is a reference to a memorable movie, Back to the Future (to be more precise, Back to the Future 2), a science fiction film directed by Robert Zemeckis starring Michael J. Fox and Christopher Lloyd, who travel in past an in the future using a modified DeLorean. The movie came out 30 years ago, and they got quite a lot of things right about the “current future”. Several companies are working on a real hoverboard, just like the one Marty uses, but we don’t really dress like they did in the movie future. They also didn’t anticipate the development of the internet and mobile phones, but they nailed thumb scanners and hi-tech wearable technology. All in all, they did pretty OK.

Chris Averill, CEO of We Are Experience, which works on digital transformation projects, said that the writers of Back to the Future 2 actually set the standard for future sci-fi Hollywood predictions:

“So much of the video communication stuff in the film is really spot on,” he said. “And of course they foresaw wearable technology and things like Google Glass way before anyone thought that would be possible.”

Marty McFly looks into what appears to be a tablet in his bid to restore Hill Valley’s clock tower in 2015. Image via Universal Pictures.

He also said legal issues are preventing some of the inventions predicted by the movie.

“They’ve now made new transport technology such as Segways and motorised balance boards illegal on the roads,” he said. “So I would say the risk-averse culture we have now has stopped future transport happening. The new ways of travelling that were predicted in Back to the Future Part II are actually being capped because people are too worried. So, even though we now have the technology to do even more of this stuff, we are too scared, or too aware of health and safety, to let them on the roads. ”

Several companies and even science organizations are doing celebrations for the movie. The National Space Centre in Leicester is hosting a Back to the Future night, while Nintendo has released Nintendo has released Wild Gunman, the arcade game that Mcfly plays in Cafe 80s. Pepsi has also revealed 6,500 limited-edition, tiny bottles of Pepsi Perfect, the vitamin-enriched variety of cola the pair drinks in the future.

How The Jetsons predicted the future

I remember watching The Jetsons out of sheer admiration for the future. The plot was kind of meh, some episodes were good, some episodes were so-so, but to the child I was at the time, The Jetsons was the future. So here we are now, in 2014… it’s the future – where’s my flying car or my transporter tube? Where’s my futuristic cities, where’s my regular space travel? Well, those things are quite a mile away from becoming a common reality, some have become part of our lives.

Flatscreens… flatscreens everywhere

The first season of The Jetsons aired in 1962, with a run of 24 episodes. They depict a world in the 2060s, where flatscreens are the norm – everywhere. Sure, nowadays that seems common, but if you just take a look at other series, which were developed much later, even in the 1990s, you don’t see this rise of flatscreens. I always giggle a bit when I see the guys from Star Trek or Stargate doing interstellar travel with ease, but still not having flat screens.

Source: techvert.com

Another interesting fact – George is still often reading the news on his paper newspaper, but sometimes, he is reading it on a smart TV – just like you would read it on a tablet. Interestingly enough, the first production flat panel display was the Aiken tube, developed in the early 1950s and produced in limited numbers in 1958. The plasma tube was invented in 1964, but few people imagined they would develop so quickly. In 2012, flat screens surpassed 50% of the market.

Household robots

They got it right… sort of. Rosie is a robot maid able to think for herself and learn new things. She also appears to have a personality… and in this regard, we still don’t have robots like this. But we do have cleaning robots – in 2012, Honda‘s Asimo was the most advanced robot to date. It can walk, talk and have simple interactions with humans. You also have robots which can keep the house clean, most notably the iRobots – so we do have robots which can interact with us and clean the house – we just don’t have robots which can do both at the same time. But, we still have almost half a century to work that out.

Out of control environmental degradation

This is my favorite one; it is never said out loud, but it is heavily implied several times throughout the series. In the Jetsons, everybody in the upper classes lives in very high buildings – you could basically say they “live in the sky”. But why?

They do it because pollution has run out of control. The most clear reference is when mister Spacely, George Jetson’s boss, says his company was founded in 1937, where it continued to prosper until massive surface pollution necessitated a move to the elevated platforms seen in the series. George Jetson also mentions that grass is “ancient history” (in a Flinstones crossover), and that if you want to go to the surface of the planet, you have to pass through the “smog layer”.

So while it is never directly mentioned that the surface of the planet is heavily polluted, it is severely implied – something, which, if we don’t change something soon, will likely happen until 2062.

Video chat

Video chat was predicted by many, but The Jetsons were among the first. While you don’t see mister George or mister Spacely use Plantronics Cisco Headsets  or Skype to talk to their families, the technology is similar. Videophones and videoconferences (with more than 2 people) were developed all the way back in the 970s as part of AT&T’s development of Picturephone technology. However, it wasn’t until the early 2000s that everything really took off, and now everyone can use a Plantronics office headset or your smartphone or even your TV. Just like with LCDs, many people were predicting them, but it was the Jetsons who guessed how ubiquitous it would all become.

The PillCam

After 9 years of development and bureaucratic processes, the PillCam was finally approved! What’s the PillCam? Rembember when George goes to the doctor? The doctor just gives him a pill to swallow and sees what’s inside his stomach – and that’s exactly what the PillCam does!

Well, of course it doesn’t work in color yet (like The Jetsons), but it’s basically the same principle. This episode is one of the more darker ones produced in the series, with George feeling like he has nothing left to live for and going on a pseudo-suicidal spree. This is the future, but people can still do stupid things.

Nanotechnology

Everything in The Jetsons revolves around nanotechnologies – even George’s car shrinking to a suit-case size, and we’re beginning to see that. As of August 21, 2008, the Project on Emerging Nanotechnologies estimates that over 800 manufacturer-identified nanotech products are publicly available, with new ones hitting the market at a pace of 3–4 per week and the number continuously growing. So while we don’t have shrinking cars, we have itanium dioxide in sunscreen, cosmetics, surface coatings,and some food products; Carbon allotropes used to produce gecko tape; silver in food packaging, clothing, disinfectants and household appliances; zinc oxide in sunscreens and cosmetics, surface coatings, paints and outdoor furniture varnishes; and cerium oxide as a fuel catalyst. We’re still in the incipient phases of nanotechnology, but we’re getting there.

BONUS: one thing The Jetsons didn’t get right: stereotypes

If you look at The Jetsons, the future looks pretty great – if you’re upper class and white. There are no black, Asian or Hispanic people (I may be wrong and I may have slipped something, but either way, they’re clearly underrepresented). Hopefully, the future will belong to people of all ethnic groups, races and colours. Now, I don’t think they meant to make it like this in a racist spur or anything like that – remember, the show was filmed in the 60s, and it is a victim of the stereotypes of that time. Let’s not make the same mistake, OK? Let’s build an even better future – for everybody!

Scientists claim they have identified a 'crystal ball' mathematical equation which can be used to predict if a system is about to move over to a disorderly state. In theory, it could be used to predict complex real life systems like financial stock market crashes.

Mathematical equation helps predict calamities, financial crashes or epilepsy seizures

Scientists claim they have identified a 'crystal ball' mathematical equation which can be used to predict if a system is about to move over to a disorderly state. In theory, it could be used to predict complex real life systems like financial stock market crashes.

Scientists claim they have identified a ‘crystal ball’ mathematical equation which can be used to predict if a system is about to move over to a disorderly state. In theory, it could be used to predict complex real life systems like financial stock market crashes.

In science we have what are called “laws”, be them Newton’s Laws of Motion or Archimedes’ Principle, because these mathematical expressions describe systems in a rigid set of boundaries, essentially helping predict how these systems will behave in the future. What about overly complex, highly dynamic systems; could we use a single mathematical equation to predict outcomes for such systems? An  University of Sussex-led study found a mathematical equation that may help predict calamities such as financial crashes in economic systems and epileptic seizures in the brain.

The team of neuroscientists led by Dr Lionel Barnett sought to mathematically describe how various parts of a systems simultaneously behave differently, while still being integrated (the parts depend on each other). Collaborating with scientists at the University’s Sackler Centre for Consciousness Science and the Centre for Research in Complex Systems at Charles Sturt University in Australia, the team used mathematics and detailed computer simulations to show that a measure of ‘information flow’ reaches a peak just before a system moves from a healthy state to an unhealthy state.

This is known as a ‘phase transition’ and in real world systems these can have huge implications, like epileptic seizures or financial market crashes. Predicting such events in the past had been extremely difficult to undertake. Barnett and colleagues, however, showed for the first time that their method can reliably predict phase transitions in a physics standard system – so-called Ising models.

” This conjecture is verified for a ferromagnetic 2D lattice Ising model with Glauber dynamics and a transfer entropy-based measure of systemwide information flow. Implications of the conjecture are considered, in particular, that for a complex dynamical system in the process of transitioning from disordered to ordered dynamics (a mechanism implicated, for example, in financial market crashes and the onset of some types of epileptic seizures); information dynamics may be able to predict an imminent transition,” reads the paper’s abstract.

“The key insight in the paper is that the dynamics of complex systems – like the brain and the economy – depend on how their elements causally influence each other; in other words, how information flows between them. And that this information flow needs to be measured for the system as a whole, and not just locally between its various parts,” Dr. Barnett said.

It will be interesting to see how University of Susses researchers’ method fairs with complex real world system, and to which degree their equation can reliably predict when a phase transition will occur.

Professor Anil Seth, Co-Director of the Sackler Centre, says: “The implications of the work are far-reaching. If the results generalise to other real-world systems, we might have ways of predicting calamitous events before they happen, which would open the possibility for intervention to prevent the transition from occurring.”
“For example, the ability to predict the imminent onset of an epileptic seizure could allow a rapid medical intervention (perhaps via brain stimulation) which would change the course of the dynamics and prevent the seizure. And if similar principles apply to financial markets, climate systems, and even immune systems, similar interventions might be possible. Further research is needed to explore these exciting possibilities.”

The findings were published in the journal Physical Review Letters.