 Welcome to Learning English, a daily 30-minute program from the Voice of America. I'm Ashley Thompson. And I'm Dan Novak. This program is designed for English learners, so we speak a little slower, and we use words and phrases, especially written for people learning English. Coming up on the program, I have a story on an AI wellness platform developed by a school shooting survivor. John Russell reports on indoor food growing operations facing an uncertain future. Brian Lin has a story on how scientists have recovered genetic RNA from an extinct Tasmanian tiger. Later, Faith Perlow brings us the everyday grammar lesson about discussing alien life. Faith and I then discuss our own opinions about whether there is life on other planets. But first, Kai Korber was a student at Marjory Stoneman Douglas High School in Florida when a gunman murdered 14 students and three school workers there in February 2018. Seeing other students and himself struggle to return to normal, Korber wanted to do something to help people deal with their emotions. Some of his classmates from the school have advocated for gun control policies or entered politics. Some took time to heal and work on their studies. Korber's background in technology led him in a different direction, to build a smartphone app. The result was Joy, AI wellness platform. It uses artificial intelligence to suggest small mindfulness activities for people based on how they are feeling. The algorithm is designed to recognize how a person feels from the sound of their voice. It does not matter the words or language they speak. Like many of his fellow students from Marjory Stoneman Douglas, Korber said he suffered from post-traumatic stress disorder for a very long time. He recently has it eased a little. Korber started a research team at the University of California at Berkeley to build an AI tool to see if his idea was possible. The idea was a platform that provides those struggling with a wellness practice on the go that meets our emotional needs on the go. He said it was important to offer quick activities. Sometimes the activities last just a few seconds and can be done anywhere the user might be. Mohamed Zarif Mustafa is a former classmate of Korber's. He has been using the app for a few months. I used the app about three times a week because the practices are short and easy to get into, Zarif Mustafa said. It really helps me quickly de-stress before I have to do things like job interviews. To use joy, the user simply speaks into the app over a phone or computer. The AI is supposed to recognize how you are feeling from your voice, then suggest short activities. If the user is feeling neutral, the app suggests several activities, like a 15 second exercise called mindful consumption. It gets you to think about all the lives and beings involved in producing what you eat or use that day. Another activity calls for practicing how to make an effective apology. The user asks users to write a letter to their future self. One suggestion asks sad users to track how many times they have laughed over a 7 day period. The user is supposed to count the laughs up at the end of the week to see what moments made them happy. The iPhone app costs $8 a month. It is a work in progress. And like other AI tools, the more people use it, the better it becomes. Many wellness apps on the market claim to help people with mental health issues, but it is not always clear whether they work, said Colin Walsh. He is a professor of biomedical informatics at Vanderbilt University and has studied the use of AI in suicide prevention. The stakes also matter. Facebook, for instance, has faced some criticism in the past for its suicide prevention tool. It used AI as well as humans to identify users who may be considering suicide. If the technology is simply directing someone to spend some time outside and the stakes are lower, it is unlikely to cause harm, Walsh said. Korber said people often forget, after mass shootings, that survivors do not bounce back right away from the experience. It takes years to recover, he said. His work has also been slower and more thoughtful than tech business leaders of the past, he added. I guess young Mark Zuckerberg was very move fast and break things, Korber said. And for me, I'm all about building quality products that serve social good in the end. Indoor food growing operations are seeing both successes and failures in the United States. Some companies in the food industry are investing even as competitors fail. California-based Plenty Unlimited this summer begin work on a $300 million indoor plant, while Kroger announced that it will be increasing its availability of vertically farmed produce. Meanwhile, two indoor farming companies that got strong backing, New Jersey's Arrow Farms and Kentucky's App Harvest, filed for bankruptcy reorganization. And a five-year-old company in Detroit, Planted Detroit, shut its doors this summer. The industry changes do not worry Jacob Portillo, a grower with Eaton Green Technology, an indoor farming company. The fact that other people are failing and other people are succeeding, that's going to happen in any industry you go to. But specifically for us, I think that the sustainable competitors are going to start winning, he said. Indoor farming brings growing inside in what experts sometimes call controlled environment agriculture. There are different methods. One method called vertical farming involves stacking produce from floor to ceiling, often under artificial lights, and with the plants growing in nutrient-enriched water. Other growers are trying very large greenhouses, indoor beds of soil in big buildings, and using special robots for parts of the farming process. Supporters say growing indoors uses less water and land and permits food to be grown closer to consumers, saving on transport. Your growing is also a way to protect crops from increasingly extreme weather caused by climate change. The companies often say their products are free of pesticides, although the foods are usually not marketed as organic. But critics question the sustainability of operations that can require a lot of energy for artificial light, and they say paying for that light can make profitability impossible. Tom Kimmerer is a plant expert who taught at the University of Kentucky. Kimmerer has followed indoor farming alongside his research into the growth of plants both outdoors and inside. He said his first thought on vertical farm companies, especially those that used a lot of artificial light, was, boy, this is a dumb idea, mainly due to high energy costs. The industry has admitted those high costs. Some companies are seeking to push costs down by using solar power. But even the companies that use a lot of artificial light that does not come from renewables say they can be profitable by eventually producing a high volume of produce year round. But Kimmerer thinks there are better ways to provide food locally and extend the growing season outdoors. He pointed to Elmwood Stock Farm outside Lexington, Kentucky. The farm can grow tomatoes and greens the whole year using tools like high tunnels, also known as hoop houses. These are greenhouse-like structures that protect crops while still being partially open to the outdoors. He thinks investment flowing toward new versions of indoor farming would be better spent on solutions for outdoor farmers like special robots or money support for regenerative practices. Kurt Covington of Ag America Lending, a private investment company centered on agriculture, is not convinced that indoor farming operations can work, except in special cases. Given the high cost of indoor operations, Covington said, it's just hard to be very profitable. I'm John Russell. VOA Learning English has launched a new program for children. It is called Let's Learn English with Anna. The new course aims to teach children American English through asking and answering questions and experiencing fun situations. For more information, visit our website, learningenglish.voanews.com. Researchers say they have recovered genetic material from the Tasmanian tiger, an Australian animal that has long been extinct. The discovery could help scientists learn more about these creatures before they disappeared from Earth. The recovered material is called ribonucleic acid, or RNA. RNA is a group of molecules present in all living cells that is important for genetic activity. It is similar to DNA, the molecules that contain an organism's genetic instructions. RNA carries genetic information it receives from DNA. RNA combines groups of proteins that organisms require to live and works to control cell metabolism. The researchers said the recovered RNA came from skin and muscle from the remains of a Tasmanian tiger stored since 1891 in a museum in Stockholm, Sweden. Scientists have in recent years taken DNA from different ancient animals and plants. But the team said it was the first time RNA has been recovered from an extinct animal. Scientists believe the Tasmanian tiger once lived on the Australian continent and surrounding islands. It was a top predator at the time hunting kangaroos and other animals. The last known Tasmanian tiger is believed to have died in a Tasmanian zoo in 1936. Emilio Marmel Sanchez is with the Center for Paleogenetics in Stockholm. He was the lead writer of a study describing the research results. The study recently appeared in the publication Genome Research. Sanchez told Reuters News Service RNA material gives scientists a taste of the real biology involving the cells and tissues of the Tasmanian tigers before they went extinct. Mark Friedländer of Stockholm University was a co-writer of the study. He said, if we want to understand extinct species, we need to understand what gene complements they have and also what the genes were doing and which were active. Researchers have questioned how long RNA could survive at room temperature. The remains stored at the Swedish Natural History Museum were in a state of semi-mummification. This means skin, muscles, and bones remained, but inside organs were lost. Most researchers thought that RNA would only survive for a very short time, like days or weeks at room temperature, said evolutionary geneticist Luve Dahlian. He is with the Center for Paleogenetics. Dahlian added that while this might be the case when remains are wet, it does not appear to be so when they are dried. The Tasmanian tiger looked similar to a wolf, except for the tiger-like lines appearing on its back. When people arrived in Australia about 50,000 years ago, large animal population losses followed. The arrival of European colonizers in the 18th century destroyed the remaining populations around the island of Tasmania. Private de-extinction programs have been launched with the aim of bringing back some extinct animals. These include the Tasmanian tiger, flightless Dodo bird, and woolly mammoth. However, many researchers have warned about the difficulties of using genetic processes to actually recreate an extinct species. While Sanchez of the Center for Paleogenetics said he too has concerns about such processes, he noted that he does advocate for more research on the biology of these extinct animals. I'm Brian Lin. For the last several months, there have been many news reports about possible alien life and strange objects in the skies, sometimes called UFOs. The stories have led to public discussion in the United States. Today, we have some English terms and structures to share that can help learners take part in the discussion too. Let's start with the basic yes-no question of, do you believe in aliens? The verb believe is common to hear when talking about non-earth life in the universe. To believe something means to accept something as true. Simple answers to this question are, Yes, I believe in aliens. No, I do not believe in them. If you want to emphasize that you believe in aliens, you can use do before the main verb of believe in the positive form. This gives extra emphasis to the main verb. The stress would be on the verb do when you speak. I do believe in aliens. I do believe that we are not alone in the universe. Another way we can express our opinion about aliens is through adverbs of possibility. Possibility is the likelihood of something happening. There are adverbs to show a stronger chance of something happening, like the adverbs definitely or certainly. And there are adverbs to show a weaker chance or probability of something occurring, like maybe, probably, or perhaps. Let's look at a short dialogue using these adverbs of possibility. Do you believe in aliens, Joy? I certainly believe in aliens. I think they are definitely among us. So, you believe the sightings of UFOs are true? Clearly, the UFOs are probably held in Area 51. Maybe they are not enemies. Perhaps they want to be friendly. Joy uses three strong adverbs to express her opinion and show the chance of something happening. The adverbs certainly and clearly are used to add emphasis and confidence to Joy's opinions about aliens. She uses the strong adverb definitely to show that she thinks there is a strong possibility that aliens might already live among humans. Joy also uses a weaker adverb of probably to express that she thinks that UFOs might be held in Area 51. Notice the placement of the adverbs. Typically, we place adverbs before the main verb in the sentence. I certainly believe in aliens. But some adverbs like maybe and perhaps can be used in the beginning of sentences. Carlos said, Maybe they are not enemies. Perhaps they want to be friendly. Next, we have the placement of adverbs with auxiliary verbs like be or have. Adverbs always come after the auxiliary verb but before the base verb like in these examples. I think they are definitely among us. The UFOs are probably held in Area 51. And lastly, adverbs can be used as interjections or at the beginning of sentences. Interjections are short statements that show more of a feeling and are grammatically independent from other sentences. They usually have an exclamation mark as punctuation. Joy uses the adverb clearly as an interjection to answer Carlos' question about UFO sightings. Carlos then answers joy using the adverbs maybe and perhaps to express his opinion about the chance that aliens are friendly. He uses the weaker adverbs here maybe and perhaps often come in the beginning of the sentence. Today, we looked at how we can express our opinion of alien life. The verb believe is often used to express if we accept aliens as true. We can use the verb do in front of the main verb in the positive to give extra emphasis to our belief. And we looked at the use of adverbs of possibility. We can use stronger adverbs such as definitely or clearly to say that there is a greater chance of something and to add emphasis to our opinions. Weaker adverbs such as maybe and perhaps can express that the likelihood of something happening is less. And finally, we looked at the placement of those adverbs within sentences. Now it is your turn. Share your opinions of aliens using the expressions and grammar above. Do you believe in life outside of Earth? Are there aliens among us? Let us know in an email to LearningEnglish at voanews.com. I'm Faith Perlow. You just heard Faith Perlow present this week's everyday grammar. Welcome back to the show, Faith. Thanks, Dan. So obviously my first question for you after listening to this week's story is do you believe in aliens, Faith? I do believe in aliens, Dan. Definitely. The universe is so big and there are so many things we don't know. We learn new information about our planet and universe all the time. So it is fun to think about the possibilities out there. Do you believe in aliens, Dan? I do believe there is life on other planets. I certainly think that with all the billions of stars and billions of other solar systems, that the universe must contain life besides what is here on Earth. But I probably don't think humans will ever come into contact with aliens. The universe is just too big and the distance is too far. I recently watched the 2016 film Arrival. The movie is about aliens coming to Earth and trying to communicate with humans. In it, the main character, Louise, played by actress Amy Adams, tries to learn their language. If humans learn the alien language, they can perceive or think about time differently. I'm not going to give away the ending, but the movie got me thinking about how we talk about aliens and things that are possible or not possible. I saw that film. It was really interesting. It was a lot different from other movies that have aliens. Anyway, this week's story showed some really fun ways to use English. Thanks for sharing it with us, Faith. And that's our program for today. Join us again tomorrow to keep learning English through stories from around the world. I'm Ashley Thompson. And I'm Dan Novak.