Look into hunters' eyes

    Have you ever been face to face with a cat or a sheep? If you have,you probably noticed that cats narrow their eyes to vertical (垂直的) slits (狭缝),while sheep have horizontal pupils (瞳孔).

     Why is the difference?

    Scientists from the Universities of California Berkeley and Durham in Britain may have the answer. Their research, published recently in the journal Science Advances, suggested that pupils' shapes could tell whether an animal is a hunter or gets hunted.

    The researchers took a close look at the eyes of 214 land animals.The challenge was to see if they could find a relationship between an animal's role in the food chain and the pupils' shapes.

    They found a pattern. Species with pupils that are vertical slits are more likely to be small ambush predators (捕猎者) – creatures that lie in wait for their lunch.In contrast,those with horizontal pupils are more likely to be plant-eating prey (猎物) species.

    Evolution chose the arrangement for a good reason.For hunters such as household cats,it appears that vertical pupils not only improve their ability to keep track of moving objects like mice,but also maximize (使最大化) their ability to judge the distances of the animals they hunt.

    However, an interesting discovery from the study is that the slit pupils are mostly linked to hunters that are close to the ground. Therefore, bigger cats who actively hunt down their prey, like tigers and lions, don't have slit pupils.

    On the other hand, for plant-eating prey animals, horizontal pupils give them a wider field of vision.When stretched (伸展) horizontally,the pupils allow for more light to enter from the front, back, and sides. Meanwhile, they also limit the amount of light from the sun above so the animal can see the ground better.“ Once they do find a predator,they need to see where they are running,” said leading researcher Martin Banks,a UC Berkeley professor of optometry (视光学).“They have to see well enough out of the corner of their eye to run quickly and jump over things.”

    But what happens when they bend down to eat? Researchers checked this by watching prey animals in the Oakland Zoo in California, US. They believe that when goats lower their heads to eat,their eyes rotate (旋转) to keep their pupils horizontal.

    So it seems that the eyes are indeed the window to the soul!

    Most dictionaries will tell you a number of things about a language. There are three important things. These three things are spelling, pronunciation(发音) and meaning.

    First, a dictionary will tell you the spelling of a word. If you are not sure about the spelling of a word, you can try to find the correct spelling in a dictionary. Words are listed in an alphabetical (字母表的) order —— a, b, c and so on. For example, on a dictionary page the "poor" comes before "poverty" and the word "poverty" comes before the "power".

    The words are always given in alphabetical order. The second thing, a dictionary will tell you the pronunciation. Most dictionaries give phonetic, or sound alphabet. The phonetic alphabet (音标) shows pronunciation. The third thing, a dictionary will tell you the meaning of words. You can look up a word and find out what it means. Many words have more than one meaning, and a good dictionary will tell you all of the word's meanings. For example, in English the common word "get" has over 20 different meanings.

    What is it?

    KindSpring has created a series of 21-Day Challenges designed to help individuals and groups grow in values that help create positive change. Regardless of profession, age, culture or geography, when we try to cultivate(培养) certain values we create a ripple effect(连锁反应) that has the power to transform our lives and the world for the better. When we practice these values together over and over again, our efforts encourage and strengthen each other in remarkable ways. Each of our 21-Day Challenges focuses on a specific value — from kindness to mindfulness. Click here for more information.

    How does it work?

    A small daily commitment + a daily prompt(提示)+ a process for communication. Each 21-Day Challenge invites participants to carry out one small daily action related to the main theme. Every day for three weeks a unique idea is emailed out that serves as a prompt. Participants are encouraged to carry out the act and share stories of their experiences in both online and offline spaces. You can sign up to participate as an individual or you can “host” a challenge for a group you belong to. The challenges were developed for workplace, school/college and family environments, but are broadly usable. Any group is more than welcome to take them on. At the end of 21 days, you may continue the practice with your group, take on a new challenge, or even design your own. There is no charge for any of our services. All the challenges are offered as a gift. Five steps to host a challenge.

    Why should we do it?

    The 21-Day Challenges are all designed to fit the pace of modern day life. They are not very time-consuming（耗时的）, and in most cases demand less than five minutes a day. Twenty-one days certainly can't change everything, but it can begin a new way of being. You are invited to bring these practices to your company, school, community center, or family. Get started with joining a challenge or hosting one here. Let us know if you have questions—we're delighted to help any way we can!

    Chinese scientists recently have produced two monkeys with the same gene, Zhong Zhong and Hua Hua, using the same technique that gave us Dolly the sheep. These monkeys are not actually the first primates（灵长类）to be cloned. Another one named Tetra was produced in the late 1990s by embryo（胚胎）splitting, the division of an early-stage embryo into two or four separate cells to make clones. By contrast, they were each made by replacing an egg cell nucleus（原子核）with DNA from a differentiated body cell. This Dolly method, known as somatic cell nuclear transfer（SCNT）, can create more clones and allows researchers greater control over the edits they make to the DNA.

    Success came from adopting several new techniques. These included a new type of microscopy to better view the cells during handling or using several materials that encourage cell reprogramming, which hadn't been tried before on primates. Still, the research process proved difficult, and many attempts by the team failed. Just two healthy baby monkeys born from more than 60 tested mothers. This leads to many researchers' pouring water on the idea that the team's results bring scientists closer to cloning humans. They thought this work is not a stepping stone to establishing methods for obtaining live born human clones. Instead, this clearly remains a very foolish thing to attempt, it would be far too inefficient, far too unsafe, and it is also pointless.

    But the scientists involved emphasize that this is not their goal. There is now no barrier for cloning primate species, thus cloning humans is closer to reality. However, their research purpose is entirely for producing non-human primate models for human diseases; they absolutely have no intention, and society will not permit this work to be extended to humans. Despite limitations, they treat this breakthrough a novel model system for scientists studying human biology and disease.

    Scientists have found an unexpected use for virtual reality headsets (耳机). The devices (装置), widely used by computer gamers, show pictures that can be used to test the navigational (导航的) skills of people, who were thought to be at risk of dementia (痴呆). Those who do worse in the tests will be the ones more likely to develop Alzheimer's disease later in life, scientists now believe.

    The discovery that the loss of navigational skills was associated with Alzheimer's was made several years ago by Dennis Chan and his colleagues based at several centers in the UK. These studies used computers to test navigational tasks. But now scientists plan to take their tests to a new level with the use of the virtual reality headsets in which wearers are placed in man-made environments through which they must navigate.

    Around 300 people, aged between 40 and 60, will be arranged to participate in the study. Some will have a gene that puts them at risk of the condition or will come from a family with a history of Alzheimer's. Not all will certainly be affected by the disease, however. Chan's project aims to find out who will. Wearing the headsets, participants will be asked to navigate their way through a series of different environments and then remember the details.

    Researchers recently pointed out the significance of a tiny area of the brain known as the entorhinal cortex (an important memory center in the brain). It acts as a center in a widespread brain network that controls navigation. This now appears to be the first part of the brain that seems to be easily harmed by Alzheimer's.

    The goal of the work is to help people as they develop the disease. "So far, drug trials for Alzheimer's have been applied when people have already got dementia, by which time considerable damage to the brain has already occurred," Chan told the Obsenver. "If we can develop drugs and use them earlier, for example, before the disease has spread beyong the entorhinal cortex, then this would have the potential to prevent the dementia."

    I waited half an hour, set the board, and sat in the studio, reviewing my questions until the telephone lines flashed.

    "Hello?"

    "This is Connie Chung. I'm so sorry I'm late."

    Connie Chung was one of the only four women anchors（主播）to make it into the club of major evening network television news. For almost an hour we talked about the industry. When I asked if she ever had an instructor throughout her trials, she turned around and offered to instruct me. When I asked why she decided to do it, she simply replied, "Because you're good."

    That afternoon I rushed home and told my mother what had happened. Without looking up, she just said "Good for you." Hearing this, I felt a sense of loss.  Her consistent response always made me feel under-appreciated.

    Until then I had been searching for something that I would never get—that sense of love and acceptance in a house full of negativity（消极）.

    I knew I needed to get rid of all the negativity in my life first, so I packed my bags and walked out of the house, thinking a risk would allow me to open myself to the world again and receive all the positive energy that I needed.

    Then radio became my way of connecting with others. My ability to book high-level guests and celebrities（名人）was gradually recognized and eventually all the words of encouragement from past guests and colleagues helped me to re-build my confidence levels. "I can do this," I kept telling myself, and pushed even harder to find my next aim.

    People had faith in me, so I developed faith in myself. Their positive attitudes towards themselves and towards me helped me develop my own positive attitude, leading to productive interactions with celebrities and adding to my list of instructors.

    I may not have started life surrounded by positivity but I surely feel that I am surrounded by it now. It's amazing how positivity builds on itself.