【推荐1】Wouldn’t you want to travel more often without breaking the bank? If you are interested, read on to find out how you can do simple things to save money next time you go on vacation.

Airfares

Plan in advance and visit discount websites to see if there are better deals. If you are planning to stay in two countries and an airline makes you change planes on those countries anyway, you might be in luck. Check pricing on the flights to see if you can stay a few days at the country of the flight change instead of changing planes right away since airlines often let you do that for the same price.

Accommodations

Sometimes the smaller towns close to where you are going have hotels that are much less expensive. If you don’t mind the 15-minute ride, you might just save a large amount of money. Home exchanges are pretty cool and popular especially in Europe. If you are of the adventure type, this could be exciting and refreshing. Sometimes smaller hotel chains are willing to give you free upgrades or even free nights. If you are staying at a destination for at least a few days, consider a vacation home instead of hotels. They are often more comfortable and your cost will probably be cheaper.

Eating

Figure out where you will be and eat before you actually go out. Avoid breakfast from the hotels because chances are good that the breakfast from the hotel is expensive and isn’t great. It probably pays to walk out the front door in the morning and find a local cafe. You might just discover the local favorite unexpectedly. Want a breakfast that costs nothing? Ask for some bread to-go at the restaurant the night before. In addition, fancy lunches are often much less expensive than dinners. If you eat a big lunch and a light dinner, it’s also healthier.

【推荐2】“Don’t be a helicopter parent.” This message has been repeated frequently and others try to encourage parents to back off their kids and give them greater space and freedom to explore. But it doesn't actually tell parents how they should act. What kind of parenting style should be adopted in place of the overprotectiveness of helicoptering?

One possible answer is, “Be a lifeguard parent.” That means sitting apart from the action and keeping an eye on everything that’s going on, ready to jump in if needed. This was brought up by Dr. Mariana Brussoni, a developmental psychologist at the University of British Columbia and Richard Monette, editor-in-chief of Active for Life. They think life guarding should include three parts.

Open attention is the stage parents should be in most of the time, showing a caring interest in what kids are doing, but keeping their physical distance and remaining non — intrusive (不介入的). Focused attention is when a parent perceives (察觉) warning signs and becomes more alert. Maybe it’s time to check in with the child to see how they’re doing. It might be a good opportunity to help the child think through their actions, rather than directing them. Most of the time, play goes back to being safe and the parent can return to open attention. Active intervention is when a parent needs to step in to reduce immediate risk. A child might not realize they’re close to the edge of a busy road or deep water, so the parent has to ensure their safety.

Brussoni says most of a parent's time should be spent in open attention. Days could pass，without ever entering focused attention. Active intervention should be extremely rare. It’s crucial to avoid telling kids to be careful all the time. This sends a message that the child can’t do things without parental assistance.

No one said parenting was easy, but it can be less unbearable if you let go of some control, teach your kids to do things independently, and trust them to self — regulate. Everyone comes out happier in the end.

【推荐3】When Carson Palmer, a professional American football player, hurt his arm a few years ago, he took a week off from throwing the football. But in his head, Palme practiced every day. The following weekend, Palmer had the best game of his life.

For more than a century, scientists have been trying to understand how this mental training works. In the 1930s, researchers proved by experiment that when you’re imagining an action, your brain sends signals to your muscles which are too weak to tighten the muscles but might help train the body to perform. In other words, mental practice might create a pattern in your head, like an inner how-to guide for a particular skill.

Sports psychologists have conducted hundreds of studies comparing imagined and physical practice for actions. On the whole, the research shows that mental training works. A 2012 study, for example, compared 32 amateur golfers who practiced hitting the balls to another 32 who merely held a golf club in their hands and visualized (想象) their swings.

Under the same training rules, both groups improved their skills by getting the ball about 4 inches closer to the hole.

Visualization has advantages over the real thing: You can do it anywhere, even when injured. It is safe — a major plus for high-risk performers such as gymnasts and surgeons. And you can practice for longer periods of time because you’re not restricted by physical tiredness. That’s not to say it’s easy. “We’ve had Olympic-level athletes sitting in our lab, visualizing the movements for two hours,” says Tadhg Macintyre, a sports psychologist at the University of Limerick in Ireland. “When we’re done, they’re absolutely tired.”

It doesn’t work for everyone, though. “If you’re a novice, the effect can be harmful,” warns Macintyre. “If you’re trying to visualize a free throw, and you don’t even know the proper movement, then you’re probably going to mentally practice the wrong skill.”

【推荐1】Swot satellite is scheduled to be launched Thursday morning to conduct a comprehensive survey of Earth’s vital resource. By using advanced microwave radar technology it will collect height-surface measurements of oceans, lakes and rivers in high-definition de tail over 90% of the globe. It’s really the first time to observe nearly all water on the planet’s surface.

The major mission is to explore how oceans help to minimize climate change by absorbing atmospheric heat and carbon dioxide in a natural process. Oceans are estimated to have absorbed more than 90% of the extra heat trapped in the Earth’s atmosphere by human-caused greenhouse gases. Swot will scan the seas from the orbit and precisely measure fine differences in surface elevations (高度) around smaller currents and eddies (漩涡), where much of the oceans’ decrease of heat and carbon is believed to occur. “Studying the mechanism will help climate scientists answer a key question: What is the turning point at which oceans start releasing, rather than absorbing, huge amounts of heat back into the atmosphere and speed up global warming, rather than limiting it,” said Nadya Shiffer, Swot’s program scientist.

By comparison, earlier studies of water bodies relied on data of rivers or oceans taken at specific points, or from satellites that can only track measurements along a one-dimensional line, requiring scientists to fill in data gaps through extrapolation (外推法). Thanks to the radar instrument, Swot can scan through cloud cover and darkness over wide ranges of the Earth. This enables scientists to accurately map their observations in two dimensions regardless of weather or time of day and to cover large geographic areas far more quickly than was previously possible.

“Rather than giving us a line of elevations, it’s giving us a map of elevations, and that’s just a total gamechanger,” said Tamlin Pavelsky, Swot freshwater science leader.

【推荐2】According to a new study, many birds in the Amazon rainforest have become smaller as temperatures have increased. The difference hasn’t been obvious, but it has been significant enough that some scientists have suggested it’s a universal response to climate change.

But new research finds that the body size reductions aren’t happening across the board with some large-brained birds having much less significant changes.

For the study, researchers studied some data on about 70,000 birds that had died when they crashed into buildings in Chicago from 1978 to 2016. They added data on the brain volume and lifespan for 49 of the 52 species of migratory birds (候鸟) in the original study.

They found that birds with very large brains had reductions in overall body size that were about one-third of the reductions noted in birds with smaller brains. They thought that in birds, the species with big brains are the ones that build tools, manage to survive in tough environments, live longer, invest more time and energy into raising babies, and end up surviving better in the wild.

Researchers aren’t certain exactly how warmer temperatures might lead to decreasing body size in birds, but they are considering two possible explanations, which could even be happening at the same time. First, natural selection might be favoring birds that can dissipate heat better. This is because smaller birds have higher surface area to volume ratios (比例), so being small can help birds stay cool. Second, warmer summers might have less food available for birds at the time when they are feeding their babies. In that case, birds might be getting smaller because of decreased food over the years.

The findings don’t suggest that climate change is having zero impact on bigger-brained birds, but researchers believe these findings can inform us of climate change and help set conservation priorities.

【推荐3】As a popular subject of study among evolutionary ecologists, the three-spined stickleback (三刺鱼) is known for their different shapes, sizes, and behaviors—they can even live in both sea water and fresh water, and under a wide range of temperatures. But what makes that?

The researchers tracked six populations of the fish before and after seasonal changes to their environment, using genome sequencing (基因组测序) . Seasonal changes result in great changes in habitat structure and balance of salt and freshwater, and only those fish able to tolerate these rapid changes survive into the next season.

“These changes probably resemble the habitat shifts experienced by stickleback populations during the past 10,000 years, says Professor Barrett “We hope to gain insight into the genetic changes that may have resulted from natural selection long in the past.”

Remarkably, the researchers discovered the evidence of genetic changes driven by the seasonal shifts in habitats, which mirrored the differences found between long-established freshwater and saltwater populations. “These genetic changes occurred in independent populations over a single season, highlighting just how quickly the effects of natural selection can be detected,” says Professor Barrett, “the findings suggest that we may be able to use the genetic differences to predict how populations may adapt to the environment.”

The research emphasizes the importance of studying species in dynamic environments to gain a better understanding of how natural selection operates. In the further research, they plan to investigate how repeatable the observed genetic changes are, by testing whether they show up year after year. Doing so would demonstrate their ability to reliably forecast the evolutionary future of these populations.