【推荐3】You may have heard of the “fight or flight” response—an evolutionary system that allows us to enter a survival state in the presence of physical or psychological threats.

Your fight-or-flight mode is activated by the sympathetic nervous system. It’s meant to force you into action in order to temporarily protect or prepare yourself for something bad.     1     . Exposure to stressful situations may be perceived by your brain and body as intense and repetitive, locking you into a fight-or-flight state that may continue to exist for days, months or even years. We asked experts about signs that your mind and body have not returned to their normal, resting state.

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When stress is long-lasting, the body’s response system becomes overwhelmed, causing a collapse that may leave you unfeeling to everything. This emotional situation can make you feel like you’re on autopilot or disconnected from yourself and others. You might not be able to respond to emotions, which can lead to forgetfulness, difficulty of focusing, tiredness, hopelessness and self-destructive behaviors.

You’re always tired, but can’t rest

    3    . It keeps the mind and body alert and in survival mode to protect themselves. Sleep disturbances and muscle tension can be caused by biological changes. Other sleep problems can include nightmares, early waking, restless sleep and difficulty of falling asleep. Long-lasting exposure to cortisol, the stress hormone in the body, can put us in a constant state of awareness to our surroundings.

How to calm your fight-or-flight response

Eliminating long-lasting stress can be difficult.    4     . Physical ways to ensure you’re taking care of yourself include exercising, eating regularly and getting enough sleep.    5    . Most of all, it’s important to recognize when you need help, which can mean getting support from available resources.

【推荐1】Sharon Roseman was five years old when her world changed forever.She was playing Blind Man’s Bluff with friends outside her house.When she removed her blindfold (眼罩), she couldn’t recognize where she was.From that moment on, Roseman has been lost every day of her life.

Roseman is not alone in her experience.As an adult living in Denver, Colorado, in 2008, Roseman was diagnosed with a rare and newly discovered condition called Developmental Topographical Disorientation(DTD), which is a disorder that dramatically affects people’s abilities to navigate their familiar environment.

Dr. Giuseppe Iaria of the University of Calgary in Canada is credited with first identifying DTD.He confirms that odd as it sounds, people with DTD have no brain damage. He thinks genetic factors are likely to be responsible for it.

Paul Dudchenko, from the University of Stirling in the United Kingdom, has what he calls a place-cell theory. He says we get lost because all our hippocampal cells appear to be connected to landmarks. “They use things in the environment to orientate (确定方向) themselves and create a cognitive map,” he says. “If we don’t have things in the outside world to update the cognitive map, then it is likely to error.” That’s why people who are lost in a snowstorm, for instance, tend to go in circles. They think they’re heading in the right direction, but without external reference points their brain is unable to form a cognitive map, so they naturally tend to get lost.

“There seems to be a systematic error in the way people with DTD place landmarks in their mind,” Dudchenko says. How exactly this happens is still under investigation, but Dudchenko thinks the answer lies in the relationship between the various regions of the brain responsible for spatial cognition (空间认知).

For his part, Giuseppe Iaria is continuing with his research.Some of his recent work has focused on the role genes play in DTD.As well as helping sufferers of DTD, Iaria believes his research will offer an explanation for why some people are better at finding their way than others.While top researchers have more to learn, they are confident the answers won’t stay lost in the complexity of the brain forever.

【推荐1】A group of researchers have developed a new material which is soft but very strong. It can be worn and washed like ordinary clothing and could finally turn sports clothes into smart “wearables”.

The so-called “carbon nanotube threads” (碳纳米管线) can be used to measure heart rate to test heart conditions. But instead of having to be stuck on the skin, they can be fixed on a T-shirt and worn like usual athletic wear. The researchers say the threads can comfortably move with the wearer, and be washed and worn repeatedly without breaking down.

Though going into production for customers is still a long way off, the material could finally help replace some medical facilities, such as the heart-rate monitoring machines and watches, in addition to other possible uses. For the latest study, researchers worked with a rope-maker to make the threads together into a material similar to ordinary thread that could be sewn (缝纫) into athletic clothes. The resulting “smart” shirt provides “soft, wearable, dry sensors for continuous” heart-rate monitoring, the study states. With some improvement, the clothes with these carbon nanotube threads could be able to track other human body life signs, according to the researchers.

The “smart” shirts aren’t entirely without wires (电线), however. One example shows the nanotube in the shirt feeding testing results to wires on the bottom that transmit the information through Bluetooth technology to a computer.

“The threadlike material — thin enough to run through a sewing machine — is not only soft and comfortable to the touch, but also so strong that you can build a powerline out of it,” said Dewy, a member of the research team. “Nothing else behaves like this promising material.”

【推荐2】According to University World News, there are around 200 million students who are affected due to the COVID-19 pandemic. However, great minds did not let the hours go for nothing. As online education was already familiar, chances of establishing the mainstream policy of conducting classes through online increased greatly.

A huge response from all over the world is seen. Many universities and schools started conducting their classes through Ding Talk TV, CCTalk or other conferencing portals (入口). It is known that this procedure will not last if situation becomes stable again as what is now going on is only a “Better than nothing” option, but the appeal and impact of “E-Learning” will definitely remain.

Undoubtedly the online education will make a huge impact on the lifestyle and time consumption of the people as life will become even faster and more comfortable than now. Also the transportation problem of the country will be solved as students will be able to conduct the classes from home. More precisely, wastage of time will be removed completely, which would help the students to become more concentrated and hardworking. Another major problem is the accommodation problem which will be settled completely as anybody can access the classes sitting in their own home.

However this E-Learning method may result in some possible problems in future. Even for the time being, though the credit (学分) hours are counted and the students are graded on the basis of online exams, some courses and subjects should be left out for later to be conducted physically. For example, subjects which do not require practical experiments or are computer related, such as literature, history, law, computer science, mathematics, etc. are completely okay to be conducted in both the classroom and E-Learning. Whereas, chemistry, biology, agricultural science, all the medical departments, etc. or in short, whatever the course is, if that requires practical application, practice and fieldwork, shouldn’t be conducted in the virtual class.

Therefore, all the courses which require lab work or practical application, should be separated and designed as a “Lab Year” and conducted those classes physically when situation becomes normal. Even some of the theoretical courses, such as law, journalism, should have a few courses conducted later for the students’ own benefit in future. In other words, there should be a balanced way of handling the situation.