Nonfiction-Science Writing

During my visit to Tucson, Arizona during the winter break, I had many close encounters with cacti on the hiking trail, including getting pricked by a jumping cholla cactus. However, I decided to research possibly the most iconic cactus in the world: the massive saguaro cactus. The saguaro cactus is not very common; it is only found in Arizona and parts of northern Mexico. The Sonoran Desert in Arizona is one of the few places with naturally growing saguaro cacti. Saguaro cacti are amazing plants. For one thing, large saguaro cacti are incredibly valuable. This is because it takes a saguaro cactus several hundred years to grow to that size. In fact, the signature “arms” of the saguaro actually don’t grow until the cactus is at least 60-years-old. The saguaro cactus has a unique, accordion-like skin texture that can expand to gather more water in wet weather. Amazingly, some can expand up to 16 inches during a rainy season. Yet another adaptation that the saguaro and some other desert plants have developed is a thin web of roots just below the surface. This allows them to capture rainwater even if deeper soil is not very saturated. Weather significantly affects the growth of a cactus’s arms. If a winter is unusually cold, the cold could weaken an arm and make it sag. If the damage is not too severe, the arm will continue growing in its new direction. The saguaro flower, the state flower of Arizona, is typically only open for one day. When it is open in the day, it is pollinated by various birds and insects, including bees and white-winged doves. At night, it is pollinated by lesser long-nosed or Mexican long-tongued bats. The spines of a saguaro are very unique adaptations. While they resemble, say, a hedgehog’s spines, they are actually modified leaves. Their first purpose of the spines of a saguaro is fairly obvious—to protect them from predators. But this does not deter all predators. For example, javelinas (a type of wild pig), tortoises, and pack rats are unfazed by the painful spines. The main reason that the leaves of a saguaro have evolved into spines is that spines lower the transpiration rate, or the rate at which water is lost via water vapor. Stomata are minute pores on leaves, which allow water vapor to escape. Since saguaro spines have no stomata, the transpiration rate is reduced. The third purpose of a saguaro’s spines, surprisingly, is to provide shade for the cactus. While a single spine does not seem to provide much shade, multiply that spine by one hundred or one thousand, and you will realize how much help these spines provide. The shade these spines provide helps lower the surface temperature of a cactus, which lowers the amount of water lost to the atmosphere. The way a cactus has evolved to life in the desert is quite amazing. I can never forget the sight of hundreds of towering saguaros standing in the Sabino Canyon near Tucson. Despite their daunting appearances, they provide shelters to little birds and reach their arms out as if to welcome people to the Sonoran Desert. Marco Lu, 11Champaign, IL

I walked out onto the balcony. I was barefoot and the balcony was hot, so I was jumping around. We were in South Carolina to see the eclipse. My dad put a blanket on the floor so I didn’t burn my feet. I swiftly jumped onto it to save my poor feet from being burned by the intense heat. I then put on my special eclipse glasses. Now I could carelessly look at the sun without blinding myself. I saw the moon hovering over the bright sun, one quarter of the way to totality. I ducked down, and my mom handed me some cold, refreshing iced tea we had gotten just for this occasion. I learned about the stages of a total solar eclipse on a NASA website. P1 is called first contact. The moon looks like it is touching the sun but it’s actually not covering it at all. When it was halfway to totality, I ducked down again, took off my glasses and gazed at the ground, wondering what totality would be like. Maybe an explosion of blinding light? A dark light? I imagined in my head what would happen. Now, at three-fourths the way to totality, it was much colder and much darker, like sitting under an umbrella. I slurped my iced tea and put on my special glasses, then I stared at the eclipse in amazement. For some reason, my mouth was wide open. I ducked down, removed my glasses, and pretended to be a tour guide. “Shade break. A beautiful experience,” I said to my sister. She laughed. P2 is second contact. It looks like the moon is covering the sun and there are more sun rays than the sun, but the sun still shows. It is the last instant before totality. It usually looks like a diamond ring! I drank some iced tea and gurgled it in my mouth. Racing the clock, I put my glasses back on and looked up right in time to see… TOTALITY! In an explosion of light, the sun and moon seemed to pop out, then arranged themselves into a beautiful, shimmering, ghostly ring. Everyone around me cheered. My dad took pictures by putting his glasses onto his camera lens. I could not believe it. Totality is the point when the moon covers the sun completey so you can only see the sun rays. Totality can only be seen in a path of totality, which is less than ten miles wide but sometimes more than 10,000 miles long. Totality only occurs because the sun’s radius is approximately 400 times the radius of the moon, and the moon is approximately 400 times closer to the earth than the sun. This makes the sun seem smaller than the moon, so the moon can “cover the sun.” Afterwards, when the moon started to show the sun again, sunglasses were not needed anymore. Totality was really fun. P3 is third contact. It looks like a mirror image of the diamond ring. It is the moment right after totality ends. P4 is fourth contact. It looks like a mirror image of First Contact. It is the first moment after totality where the sun is not being covered by the moon, but some of the sun rays are. Later on, I thought more about eclipses. I was amazed at the sun’s brightness in the beginning and the darkness during totality. I would like to see an eclipse again and share my experience with others. I wondered what others thought of the eclipse and if they liked it as much as I did. Kyle Wu, 9New York, NY

There is a need for organ donors all over the world. Many people lie in hospital beds hoping for a replacement organ. There just aren’t enough available, and no wonder. To get just a few, someone young and healthy would have to die in a way that doesn’t affect their organs. In the U.S. alone, an average of 10 people die every day because there weren’t organs for them. Scientists have worked with this problem for a while. First, they turned to animals like the monkey as donors. But most of these experiments failed. In 1984, scientists transplanted a baboon heart into a newborn. The heart seemed to work at first, but baby Fae lived for only 20 days. Two more men with livers transplanted from monkeys only lived a little longer, one living for 70 days and the other for 26. These experiments failed because our immune systems recognize the transplanted organs as foreign and attack them. Recently, however, scientists have had a breakthrough, not with apes, but with…pigs! Pigs have organs of similar size to ours, and they have the same functions. But, as with the ape organs, there are problems. The two main issues are that pig cells are coated with a distinctive sugar that alerts our immune system that there’s an intruder, and that the pig genome carries dormant viruses that could hurt humans. These viruses are called Porcine Endogenous Retroviruses, or PERVs. For this problem, scientists use a gene-editing technique called CRISPR. They are now able to knock out the gene for the sugars on the cells, and some groups are identifying and trying to cut out some of the PERVs. It’s a huge task. But progress has been made. One team of scientists identified 45 genes that need to be removed. On August 10th, 2017, 37 piglets lacking some PERVs were born in China. 15 survived. Another big step forward was the creation of a pig lacking 3 PERV genes. 30% of patients should be able to host those organs. Even though the technology has leapt forward, I wouldn’t count on a porcine organ anytime soon. Scientists have only gotten to testing the pig organs on apes, and those experiments have had mixed results. And even if they could identify all the PERVS and remove them and successfully create a litter of pigs missing the PERVS, there’s no guarantee hospitals and doctors would accept replacement organs from pigs. The scientists definitely have a long battle ahead of them. Taryn Morlock, 11Chicago, IL