What Lies Beneath

“Earth” has always been an odd choice of name for the third planet from the Sun. After all, an alien (外星人) examining it through a telescope would note that two-thirds of its surface is     1     not of land but of oceans of water. Marine biologists think the oceans might host more than 2,000,000 species of marine animals, of which they have so far     2     perhaps a tenth.

A new     3     hopes to change this. Smoothly launched in London on April 27th, Ocean Census (海洋普查) aims to discover 100,000 new species of marine animal over the coming decade.

The attempt is happening now for two reasons. One is that, the longer scientists     4    , the fewer there will be to document. Climate change is heating the oceans, as well as making them more acidic as carbon dioxide is absorbed into the water.

The second one is technological. Marine biologists discover about 2,000 new species a year, a rate hardly changed since Darwin’s day. Ocean Census is     5     it can go faster. “Cyber taxonomy (网络分类学)”, for instance, involves feeding animal DNA information into computers, which can quickly decide whether it meets the     6     for a new species.

Exactly what the new effort might turn up, of course, is impossible to forecast. But history suggests it will be fruitful. Half a century ago scientists detected hot openings on the sea bed that were home to organisms living happily in conditions that, until then, had been thought     7     to life. These days, such openings are one credible     8     for the origin of all life on Earth.

More practical benefits can’t be ignored. Many drugs, for example, come originally from biological     9    . An ocean full of unrecorded life will almost certainly prove a rich seam (矿层) from which to     10     more.

To help make use of its data, Ocean Census plans to make it attainable to scientists and the public without charge, who will be able to search it for anything valuable or unexpected.

Human beings and cats are believed to be friends. They     1     together for about 9,500 years. As cat owners know well, cats do not follow humans’ order in the same way dogs do. Lots of cats love having cat companions, but if yours doesn’t, it might act out by showing fear or     2    .

“This doesn’t     3     mean you have to give your pet up! ―Cats are good learners,” says Kristyn Vitale, a     4     at the Human-Animal Interaction Lab at Oregon State University, US. She suggests     5     the cats into different areas of the house and people should slowly introduce them to one another using a method     6    —Smell, See, Touch: Take a toy from each cat and exchange them.

Give each cat the other cat’s toy along with lots of praise and rewards so they connect the smell with good things. After doing this a few times, set up a space     7     the cats will be able to see one another through a physical barrier,     8     a glass door or gate. Then feed them, so they start to connect positive feelings (food) with the sight of the other cat. After a few     9     feeding times, you can try to introduce the cats without a barrier—keep each cat with toys during their first meeting in the same room, so they have less time     10    .

—If owners go slow and give lots of rewards, many cats can learn to accept a companion cat, Vitale says.

If you have ever had a cat, or have watched one of the many funny cat videos online, you'll know that cats have a mind of their own. A lot of the things they do are hard to understand—they like to climb up tall furniture,    1    themselves in small spaces and attack small objects for no reason at all.

Now scientists have managed to    2    out what exactly is going on in the brains of our little friends.

According to Tony Bufflington, a veterinarian and professor at Ohio State University in the US, cats' strange behavior    3    comes from their way of life back in the wild.

"Cats today still have many of the same instincts that    4     them to live in the wild for millions of years," he said in a TED Talk. "To them, our homes are their jungles."

In the wild, cats are hunters. Their bodies and great    5    abilities allow them to climb to high spots to better look at the environment. Even though they don't have to hunt anymore in human houses, they still keep the old habit of     6    the living room from, for example, the top of the refrigerator.

cats' hunting instinct is also what makes them    7    small things like keys and USB drives. In the wild, they hunt whatever they can get, and most of the animals they kill are small.

However, cats can also be prey. This explains why they like to stay in small spaces like drawers or washing machines—they are    8    , or they think they are doing so, from more dangerous animals. This is also why cats    9    a clean litter box; a smelly one could easily show enemies where they are.

But knowing how cats' minds work is not only useful for better understanding them. It may also help cats' owners to better meet cats' needs.

For example, owners could try to make climbing easier for cats by moving their furniture around. They could also use "food puzzles" to make eating feel more like hunting instead of just feeling    10    .

If you can’t seem to catch enough Z’s during the week, you’re not alone. But bad things happen to your body when you’re sleep-deprived, not least of which is weight gain. Well, here’s some good news: Sleeping in on the weekend to make up for sleep lost during the week is     1     with lower body mass index (BMI), according to a study published in the Oxford University Press journal Sleep.

The researchers, a collaboration of scientists based in Boston, Massachusetts, and the Republic of Korean, sought to determine if what they refer to as “catch-up sleep”    2     body mass index (BMI) in the general population. To do so, they conducted face-to-face interviews of a random sampling of 2,156 adults, comparing their sleep habits with their BMI scores. The 932 participants who slept in – “catch-up sleepers” (people who sleep longer on the weekend than on weekdays by approximately two hours) had a(n)    3     lower BMI than the other subjects. What’s more, every additional hour of catch-up sleep was linked with a decrease in BMI.

As to why sleeping in on weekends can lead to weight loss, one of the study co-authors, Robert Thomas, MD, MMSc, of the Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine at the Beth Israel Deaconess Medical Center in Boston,    4     Reader’s Digest of the “substantial(大量的) experimental and epidemiological(流行病学的) data that short sleep contributes to weight gain.” He notes, “our best     5     as researchers are that there are balances to be kept, and the body can adjust and     6     within reason. Catch-up sleep allows the basic balance to be maintained.”

Although the study showed significant differences in BMI with the     7     of two or more hours of catch-up sleep, Dr. Thomas points out that there are “substantial individual differences,” such that the benefit we get from those extra hours will vary     8     on how much sleep each of us generally needs. “To determine your optional sleep, you can track the time spent sleeping on nights when there is no need to wake up to an alarm,” suggests Liza Baker, a health coach at Simply Health Coaching. That tells you about how many hours of sleep your body likes to get, since it     9     greatly across the population, from just 4 to 5 hours to 9 to 10 hours.

So can you actually lost weight by sleeping in on the weekend? Only if you’re paying off a sleep     10     from the week, according to the result of this study. It helps if you’re also eating less, Dr. Thomas adds.