Starting exercise

You want to start doing exercise? Congratulations! You have just taken your first step towards a new and improved you!

Most people assume that regular exercise does wonders for the body and mind—but what exactly are its health benefits? To start with, physical activity increases the efficiency of your heart and lungs. During exercise, your heart and lungs must work harder. This extra effort makes them grow stronger over the long term. Moreover, exercise is good for your mental health. Working out can help you reduce stress and get over negative feelings.

Exercise is any activity that gets your body moving. Exercise doesn’t have to mean breaking a sweat at the gym or running a marathon. Any physical activity counts towards improving your health — something is always better than nothing. If you are just starting exercise for the first time, remember to start at a level that is comfortable for you.

Scientists have long known that what you eat can make or break a workout and possibly affect your fitness results. Like cars that run on petrol, your body burns carbohydrates (碳水化合物) for energy. Foods like noodles, rice, fruit and vegetables give your body plenty of carbohydrates to keep up your energy during a long workout. To help your muscles recover and repair themselves after exercise, you need to eat foods rich in protein, such as fish, eggs and milk products.

Choose the right clothing and shoes for the exercise and physical activity you plan to do is also important. To prevent injury, make sure your clothes and footwear are both comfortable and safe. What’s more, remember to warm up before exercising and stretch at the end of your workout.

So, now you know the benefits of exercise and how to do it safely and effectively. What are you waiting for?

【推荐1】Chinese scientists have identified a new protein that restricts HIV infection, a discovery that could pave the way for the development of new drugs against the virus. The protein, P-selectin glycoprotein ligand 1 (PSGL-1), which exists in human cells, can inhibit (抑制) the process by which HIV reproduces, according to research published in the science journal Nature Microbiology this month.

However, the study also showed that PSGL-1 can be negatively affected by Vpu－an accessory (附属) protein of HIV－which can neutralize the ability of PSGL-1 to resist HIV. Further research is under way to develop a drug that can inhibit the HIV protein so that PASGL-1 can restrict HIV, according to Tan Xu, a researcher at Tsinghua University's School of Pharmaceutical Sciences, a leading author of the study.

Several other proteins in human cells that could resist HIV have been discovered over the past 10 years, but the virus can also evade (避开) them. PSGL-1 shows particular promise in that it can inhibit the HIV in multiple ways－especially by blocking the infectiousness of virus offspring, Tan said.

“We are starting to research into small molecule (分子) compounds in the hope of finding one that can restore PSGL-1’s anti-HIV function. In this way we can develop a very effective antiviral drug for people with HIV/AIDS,” he said. Tan said it will require at least three to five years for the research to reach the preclinical stage, and more time after that before a clinical trial is possible. The research was conducted by researchers at Tsinghua University in Beijing, Fudan University in Shanghai and George Mason University in the United States.

Existing treatment methods for people with HIV/AIDS, which mostly rely on a combination of different drugs, can prevent the disease from progressing but cannot cure it, and long-term use of drugs can result in drug resistance.

An estimated 37 million people in the world live with HIV, according to the Joint United Nations Programme on HIV/AIDS. The study provides new leads to developing antiviral drugs, Tsinghua University said in a statement.

【推荐3】Octopuses(章鱼) are some of the cleverest animals on the planet! So what makes them so smart? Let’s focus first on their defense mechanisms. Faced with multiple predators(捕食者)—including fish, birds and whales—octopuses are masters of disguise.They can imitate their environment by changing their skin colour.

Without a shell, octopuses are weak and easily hurt physically, and always try to remain hidden in a shelter such as a hole or the space beneath a rock. Some prefer to wrap themselves in shells and small stones, while others transport their shelters in their arms. This is the case for the coconut octopus, which,true to its name, has been observed carrying coconut shells around to hide within in case of danger.

Octopuses are also fearsome predators themselves, and their attack mechanisms are suited to the wide variety of prey(猎物) they consume, including seashells,fish and even other creatures like them. They can use their vision and camouflage skills to hunt, and their arms to explore,touch and taste their environment to seize every bit of food within reach.

Octopuses can also use conditional discrimination, that is, they can change their choice depending on the situation. For example, they can learn to attack an object only in the presence of bubbles. They can also use space learning, and find a hidden shelter by remembering its position. Last but not least, octopuses can learn by watching other octopuses carry out tasks, such as choosing one specific object over another. This is surprising,because they are mainly solitary(独居的)creatures.

Octopuses meet every criteria for the definition of intelligence: They show a great flexibility in obtaining information (using several senses and learning socially), in processing it (through discriminative and conditional learning), in storing it (through long- term memory) and in applying it toward both predators and prey.

【推荐2】Why does Haiti so tend to have fatal earthquakes? Earthquakes have been causing huge damage in Haiti since at least the 18th century. The capital city has been destroyed twice in 19 years. The 21st century has been no more kind.

The Earth’s outer shell is made tip of tectonic plates (构造板块) that move. Haiti sits near the crossing of two tectonic plaits that make up the Earth’s outer shell. Earthquakes can occur when those plates move against each other and create friction (摩擦力).

Haiti is also overpopulated. Plus, many of its buildings are designed to resist hurricanes but not earthquakes. Those buildings can survive strong winds bat are easy to fail down when the ground shrikes. Poor building practices can also play a role.

“I think it’s important to recognize that there’s no such thing as a natural disaster,” said Wendy Bohon, a geologist. “What you have is a natural disaster that comes with a weak architecture system. We do know that earthquakes like this can cause huge damage because of the fault,” said Wendy. “And it’s quite a significant risk in places that don’t have the construction practices to resist the shaking.”

Construction of more earthquake-resistant buildings remains a challenge in Haiti, which is the poorest nation in the Western Hemisphere. “While there have been some success stories of Haitians building more earthquake-resistant structures, the country has lacked a centralized effort to do so,” said Mark Schuller, a professor of anthropology and nonprofit and NGO studies at Northern Illinois University. Haiti’s government has become increasingly weak, while non-governmental organizations only focus on their own projects.

“There is technical knowledge in Haiti, There are trained architects. There are city planners. That’s not the problem,” Schuller said. “The problem is a lack of funding for coordination (协调), and lack of political will from donors to organizations providing aid.”