Perhaps even more incredible is that it's smack bang in the middle of Kentucky.
Mammoth Cave National Park preserves this unique and historical natural wonder. As large as the limestone cave system is, park officials, estimate there be another 600 miles of cave passageways that have yet to be explored.
those unexplored, more than 200 caves exist in the park that are disconnected from the larger system.
The incredible rock formations have resulted in the park (recognize) as a World Heritage Site, thanks to its extraordinary size and scientific importance — making it one of only 13 natural US sites with that title.
The caves were created naturally by the process of limestone erosion, which is known as "karst topography". Rain and rivers slowly dissolve and shape soft limestone, which creates the vast underground network. The system is still being shaped and carved today. Not only are they a stunning destination to visit, but the system also provides drinking water for roughly 40% of the US population — and they're historical significance too.
The caves act as a time capsule that preserve over 5, 000 years of human history — and the caves' first explorers were Native Americans, who (mine) the upper levels of Mammoth Cave. Thanks to the cave system's atmosphere and natural protection from any kind of human disturbance, the archaeological sites have been left in great shape. Several sets of Native American remains have been recovered, (provide) fascinating evidence of pre-Columbian funerary practices.
Mammoth Cave was established as a national park thanks to strong local support. Back in the 1920s, Secretary of the Interior Hubert Work created the Southern Appalachian National Park Commission in 1925 to survey (propose) park sites, including the caves. After years of work acquiring the land for the park, as well as building roads, trails, and public facilities, Mammoth Cave National Park was established on July 1, 1941.
Pioneering African Americans were some of the first cave guides, and are responsible for some of the more recently discovered passageways. Stephen Bishop, who was a slave, worked in the cave from 1838 to 1856 and ventured beyond the tour routes that (establish). He crossed a terrifying drop called the "bottomless pit" to discover unmapped areas of the cave system. Although they were unrecognized at the time, pioneers like Bishop helped spark the golden age of cave exploration.
The park now receives around 2 million visitors a year, with roughly a quarter taking a tour of the caves – everything from a cultural tour to the more adventurous scrambling tours on offer. The cave supports more than 130 wildlife species, such as the eyeless cavefish, has adapted to the lightless environment by no longer growing eyes, and the cave crayfish.
Mammoth Cave National Park is also much more than just a cave; its surrounding forest contains one of (diverse) habitats in the country. There are miles of trails open for horseback riding, with kayak and canoe trails and great fishing spots. There are also more than 1, 300 flowering species in the forest, and animals like wood warblers, thrushes, and bald eagles can regularly be spotted.
A. attraction B. waiting C. mystery D. unique E. simply F. originally G. stable H. popularity I. donating J. searching K. interfere |
There's a rarely-visited, dusty corner of the world where something magical happens. The place, which looks like Mars with its red rock landscape, is the Tatacoa Desert, in Colombia.
Tatacoa is located in the region of Huila, south of the country's capital Bogotá. Although Tatacoa, with its protruding cacti and red rippled rocks, is called a desert, it is in fact a dry tropical forest. But the exciting, and very , feature of this desert, is what happens above it, at night.
Thanks to its remote location — it's almost 30 miles and an hour's drive over bumpy winding roads to the nearest town — Tatacoa has no light pollution to with the night sky.
Up to 88 constellations (星座) are visible on a clear night, as well as both hemispheres — something that happens nowhere else in the world.
The warm and dry climate helps with stargazing; a atmosphere, which happens in dry spots or places of high elevation, decreases something called scintillation, which is when a star's light rises and falls rapidly. It's why stars twinkle, which looks beautiful but isn't so great for astronomers.
Not only is Tatacoa a natural wonder, but the DIY observatory that's run by a Colombian man named Javier Fernanda Rua Restrepo has become a star too. In fact, this humble building attracts stargazers from all over the world, from China to Iceland to Australia. And Restrepo has also become well-known in astronomer circles, with a few scientists their own telescopes to support the grassroots observatory.
The Colombian, who is from Cali, fell in love with the stars thanks to his father's interest in astronomy and science, and first visited Tatacoa in 1997, to try to see the Comet Hale-Bopp. He stayed for a couple of days before heading back to his hometown. But within a month, he returned to Tatacoa — and never left, camping out for weeks on end for the night to come so that he could watch the stars.
At first Restrepo had worked at the Colombian government's observatory, which he helped staff for 15 years. But after budget cuts meant he lost his job, he figured he would build his own.
In 2015, Restrepo opened the doors to his observatory — Tatacoa Astronomia — with just one telescope. Now, as Colombia has grown in as a tourist destination, hundreds flock to Restrepo's star party, which he holds once a year in July.
Tatacoa Astronomia is only open on starry nights, and Restrepo remains the sole employee. But that doesn't distract from the intimacy and the specialness of the place. The structure sits on a small patch of land that Restrepo bought himself, and is cordoned (隔离) off by tarpaulin (油布) to add an extra sense of and intrigue (阴谋) for visitors.
"The stars… they put my life into its tiny perspective, " he says, "and they constantly remind me there are greater things out there. "
Acupuncture(针灸), an ancient Chinese medical practice, has been the remedy for countless patients for thousands of years. Before modern medicine came to life, ancient Chinese used stone tools to1 pain. Over time, this primitive practice2 evolved into a comprehensive and profound medical system and3 the root of acupuncture.
Acupuncture is a treatment that aims to4 the body's self-regulating functions. Its therapeutic principles are in line with the5 concepts of traditional Chinese medicine, which emphasizes all-inclusive treatment, meridian(经络) adjustment, balance of bodily functions and overall physiological well-being.
Practices can6 in forms, including needle insertion, cupping and scraping. Needle insertion, the most common method, is7 by inserting hair-thin needles into meridians, 8 specific points on the body that9 vital energy (the qi). Practitioners lift, twirl and rotate needles to unblock the flow of energy;10 yin and yang balance; and stimulate the body's innate11 to heal itself.
Looking beyond China, acupuncture has become a global12 . Over the years, acupuncture has seen many advancements in scientific research and modern medicine. It is now a mainstream13 and complementary treatment for a variety of weaknesses. According to a 2019 WHO report, acupuncture is used in 113 of its 120 member countries, 14 its widespread recognition and application.
As an ancient Chinese medical15 with a rich history and deep cultural significance, acupuncture is an embodiment of profound cultural heritage and a holistic path to healing.
Han Guorui, a folk artist specializing in making Dongming grain pictures, is generally busy in autumn as he needs to collect materials for his work. This year, he has been even busier, as he has attended fairs to demonstrate his skills and promote grain art.
The grain pictures, which take their name from Dongming county in Heze, Shandong province, are a traditional folk craft with a history of more than 200 years. The practice was listed as a provincial intangible cultural heritage(非物质文化遗产) in 2016 by the Shandong Provincial Department of Culture and Tourism.
After being treated to prevent decay and insect infestation, grains, grass and vegetable seeds are glued together to form a picture.
"We use the different shapes and colors of grains and seeds, which are all collected from the field, " says Han.
Born in Dongming, a county along the banks of the Yellow River, he attended a regional fair in mid-October. His pictures attracted many children who asked questions, such as, "will these seeds sprout", and "can these grains be eaten?"
Han answered the children's questions while showing them how to use grains and seeds to make a picture.
"Only now, when food is sufficient, can people make a picture with surplus grain, " he says.
To make pictures that more people like, Han works in the style of Chinese ink and Western oil paintings. Now his grain pictures are not only sold in cities across China, but also to overseas markets, including some European countries, South Korea and Japan, he says.
"Grain pictures have become a cultural product that is helping to enrich farmers living on the Yellow River plain, " says Han.
The Yellow River, the country's second longest, is considered the cradle of Chinese civilization. For thousands of years, the people living along its banks have nurtured rich and vibrant cultures that have endured to this day.
To give people the opportunity to familiarize themselves with its rich culture and plentiful products, Shandong province has organized fairs named after the river throughout the year, with some events held in communities to involve more people.
At the fairs, intangible cultural heritage items, handicrafts, local delicacies, performances, and agricultural products are available.
At one fair in a community in Jinan, the capital city of Shandong, in late October, more than 10 types of handicrafts were on show, including gourd-carving, paper-cutting, textiles and hemp rope weaving.
"The fair builds a bridge between intangible cultural heritage producers and consumers. Using items that are embodied with traditional culture is a good way to pass on culture, " says Sun Xicai, deputy director of Jinan Folk Literature and Art Association.
At the fair, 60-something Yu Shaoqing, who was selling animal-shaped textile products, attracted a lot of buyers.
"Many young people show an interest in my products. They buy them to decorate their rooms and cars, " says Yu.
Yu, who worked in embroidery design before retiring, designs her products, which take the shape of animals like tigers, rabbits and ducks. Currently, she is working on a dragon design for next year to welcome the Year of the Dragon.
Persistently engaging in negative thinking patterns may raise the risk of Alzheimer's disease, finds a new UCL-led study.
In the study of people aged over 55, published in Alzheimer's & Dementia, researchers found 'repetitive negative thinking' (RNT) is linked to subsequent cognitive decline as well as the deposition (沉积) of harmful brain proteins linked to Alzheimer's.
Lead author Dr Natalie Marchant (UCL Psychiatry) said: "Depression and anxiety in mid-life and old age are already known to be risk factors for dementia(痴呆). Here, we found that certain thinking patterns implicated in depression and anxiety could be an underlying reason why people with those disorders are more likely to develop dementia.
"We hope that our findings could be used to develop strategies to lower people's risk of dementia by helping them to reduce their negative thinking patterns. "
For the Alzheimer's Society-supported study, the research team from UCL, INSERM and McGill University studied 292 people over the age of 55 who were part of the PREVENT-AD cohort study, and a further 68 people from the IMAP+ cohort.
Over a period of two years, the study participants responded to questions about how they typically think about negative experiences, focusing on RNT patterns like rumination (沉思) about the past and worry about the future. The participants also completed measures of depression and anxiety symptoms.
Their cognitive function was assessed measuring memory, attention, spatial cognition, and language. Some (113) of the participants also underwent PET brain scans, measuring deposits of tau and amyloid, two proteins which cause the most common type of dementia, Alzheimer's disease, when they build up in the brain.
The researchers found that people who exhibited higher RNT patterns experienced more cognitive decline over a four-year period, and declines in memory (which is among the earlier signs of Alzheimer's disease), and they were more likely to have amyloid and tau deposits in their brain.
"We propose that repetitive negative thinking may be a new risk factor for dementia as it could contribute to dementia in a unique way, " said Dr Marchant.
The researchers suggest that RNT may contribute to Alzheimer's risk via its impact on indicators of stress such as high blood pressure, as other studies have found that physiological stress can contribute to amyloid and tau deposition.
Co-author Dr Gael Chételat commented: "Our thoughts can have a biological impact on our physical health, which might be positive or negative. Mental training practices such as meditation might help promoting positive- while down-regulating negative-associated mental schemes.
"Looking after your mental health is important, and it should be a major public health priority, as it's not only important for people's health and well-being in the short term, but it could also impact your eventual risk of dementia. "
Zion National Park in Utah has plenty of trails, but Angels Landing may be the most breathtaking. Picture this. You begin the hike on the wide and well-maintained West Rim Trail. It follows the river and then crosses the bottom of the canyon, surrounded by 270-million-year-old layers of rock. Relaxing, right? Just wait for it. The trail then starts to climb via a series of switchbacks (急转弯) leading up the side of the mountain. Then more switchbacks: 21 tighter turns, called "Walter's Wiggles, " where elevation levels rapidly increase. Your heartbeat is probably rapidly increasing at this point, too.
On top of Walter's Wiggles, you can stop for a stunning view (perhaps with a marriage proposal) and a restroom stop while you contemplate (仔细考虑) the final stretch of the hike. If you're afraid of heights, it's best to turn back now. The last stretch is the real test of bravery.
The last half mile of the hike is what really ranks it as one of the nation's most dangerous. Angels Landing itself is a fin-like formation jutting (突出) 1, 500 feet out of the canyon, and this is where you make the final 500-foot climb. Guardrails and chains bolted (拴住) into the cliff help you keep from tumbling over the extremely steep ledge. You're literally living on the edge, and you don't want to trust the "angels" down there to catch you. Once you reach the top, however, it'll all be worth it: 360-degree views of the canyon make a great backdrop for kicking back and having a meal before you come back down the way you came.
Angels Landing might be dangerous, but thankfully, not too many people have had fatal falls. According to the park website, seven people have died in the 100 years the park has existed. Still, this is a very vigorous hike. If you're out of shape, bringing young children along, feel ill or prone to fainting, or are just plain afraid of heights, opt for an easier trail.
Angel's Landing is a great hike for most of the year, besides the cold winter months when the trails could become dangerously slippery. Summer is the most popular time of year — and therefore the most crowded — but it can also get extremely hot, so opt for an early morning hike while the temperatures are still mild.
Sure, it's dangerous, but there's a reason this is one of Zion 's most popular hikes. If you're up for the challenge, Angels Landing will definitely deliver rewards.
This article first appeared on Curiosity. com.
The rate of childhood obesity in the U. S. has tripled over the past 50 years. But what this trend means for children's long-term health, and what to do about it (if anything), is not so clear.
The American Academy of Pediatrics (AAP) made waves this year by recommending that doctors put obese kids as young as two years old on intensive, family-oriented lifestyle and behavior plans. This advice marks a shift from the organization's previous stance of "watch and wait, " and it reflects the AAP's belief that obesity is a disease and the group's adoption of a more proactive position on childhood obesity.
Yet the lifestyle programs the AAP recommends are expensive, inaccessible to most children and hard to maintain — and the guidelines acknowledge these barriers. Few weight-loss drugs have been approved for older children, although many are used off-label. And surgery, while becoming more common, has inherent risks and few long-term safety data — it could, for instance, cause nutritional deficits in growing children. Furthermore, it's not clear whether interventions in youngsters help to improve health or merely add to the stigma overweight kids face from a fat-phobic society. This stigma can lead to mental health problems and eating disorders.
Rather than fixating on numbers on a scale, the U. S. and countries with similar trends should focus on an underlying truth: we need to invest in more and safer places for children to play where they can move and run around, climb and jump, ride and skate.
In 2020 the Centers for Disease Control and Prevention found, unsurprisingly, that kids' sports participation increases with their parents' incomes: about 70 percent of kids whose families earn more than $105, 000 a year participate in sports, but only 51 percent of middle-class kids and 31 percent of children at or below the poverty line do. This disparity hurts people of color the most. More than 60 percent of white children, for instance, participate in athletics, but only 42 percent of Black children and 47 percent of Hispanic children do. Experts blame these problems on the privatization of sports — as public investment in school-based athletics dwindles, expensive private leagues have grown, leaving many kids out.
According to the U. S. Department of Health and Human Services' Physical Activity Guidelines for Americans, children between ages six and 17 should get at least an hour of moderate to intense physical activity every day. Yet only 21 to 28 percent of U. S. kids meet this target, two government-sponsored surveys found. The nonprofit Active Healthy Kids Global Alliance evaluates physical activity in American children, and in 2022 the group gave the U. S. a grade of D–.
Why is it so hard to get kids moving? In addition to fewer opportunities at school, researchers cite increased screen time, changing norms around letting kids play outdoors unsupervised, and a lack of safe places for them to play outside the home.
New York City, for example, had 2, 067 public playgrounds as of 2019 — a "meager" amount for its large population, according to a report from the city comptroller — and inspectors found hazardous equipment at one quarter of them. In Los Angeles in 2015, only 33 percent of youths lived within walking distance of a park, according to the L. A. Neighborhood Land Trust. Lower-income neighborhoods tend to have the fewest public play spaces, despite often having a high population density.
Kids everywhere need more places to play: trails, skate parks and climbing walls, gardens and ball fields, bike paths and basketball courts. Vigorous public funding to build and keep up these areas is crucial, but other options such as shared-use agreements can make unused spaces available to the public.
A. Moving more may not prevent a child from becoming overweight, but studies show clearly that it helps both physical and mental health. B. And although rural areas have more undeveloped outdoor space, they often lack playgrounds, tracks and exercise facilities C. A lack of safe places for them to play outside the home also contributes to kids obesity. D. It also suggested prescribing weight-loss drugs to children 12 and older and surgery to teens 13 and older. E. Increased screen time and changing norms around letting kids play outdoors are unsupervised. F. They have significant side effects for both kids and adults. |
There are many reasons why some cats are bad-tempered; their temperament can be influenced by their upbringing or they are simply born that way. However, even the sweetest, most affectionate cats can suddenly become bad-tempered and behave out of character. According to veterinarian Dr Katrina Warren, the problem can generally be solved, but you'll need to look for underlying issues.
Changes in a cat's behaviour can often be explained by a health problem. Pain can cause cats to behave very differently and it's easy to mistake a problem as behavioural, when in fact it is medical. Should you observe a significant change in your cat's behaviour, then a visit to the vet is the best place to start? Watch out for changes in eating, drinking or litter-box habits. Also hiding and avoiding being touched. Be sure to report all changes to your vet. There are many cat health problems that can be readily treated to ease symptoms and pain for your cat.
It pays to remember that cats don't like to share or queue. Sharing of ‘resources' such as litter trays and foodbowls can cause stress and anxiety for many cats. It's always a good idea to provide each cat with their own litter box, food, water bowls and bed as a minimum. One litter box for each cat plus a spare is even better, as are multiple sleeping spots and extra scratching posts. A lack of space to hide from or avoid other cats, competition for territory and lack of individual attention can also add to household friction. If your cat is feeling anxious, offering it an elevated place to sit, such as a climbing tree, can be helpful.
Moving to a new house, the arrival of a new baby, new pets and other types of change can seriously impact cat behaviour. Cats are creatures of habit and tend to be territorial, so a change in routine may cause them to react in a number of ways, including withdrawal or aggression. Try to keep your cat's environment as calm as possible and make sure there are places where they feel safe. Sometimes confining them to a single room with a litter box, bedding and home comforts can help them to settle.
Some cats simply do not like being touched and handled These are often cats that received limited socialisation with humans when they were kittens. These cats do best in a quiet household without children and need understanding and patience to help build their confidence.
随着中国传统文化越来越受到国人的重视,例如中国的各种传统节日,它们充满了中国的历史、理念、哲学思考和善良的中国人对人性的深刻认知和理解。假如你是中华中学的学生李敏,关于这个话题在知乎上写一篇文章,谈谈你的看法,题目自拟。你的文章必须包括:1. 选择一项中国传统节日和一项西方节日进行对比;2. 谈谈你对中国传统文化的理解。