The TED speaker series features “ideas worth spreading”. With over 1,400 to choose from, we've selected a few that are perfect for students.

    Larry Smith: Why you will fail to have a great career

    We humans may have an unfavorable habit of making excuses for ourselves of or being too confident about ourselves. Accordingly, Larry Smith, a professor of economics at the University of Waterloo in Canada, tells us why most of us will fail to have a great career. Luckily, as he puts it, there is a way out-follow your heart, as long as it is good for your career.

    Andy Puddicombe: All it takes is 10 mindful minutes

Between dance team, volunteering and –oh, right—lectures, your life's crazy factor（因素）is about to go way up. In this entertaining and informative talk, Mindfulness, expert Andy Puddicombe teaches us how to be “more healthy, more mindful and less distracted” by taking just 10 minutes out of the day to be “more present”.

    Shane Koyczan: To this day…for the bullied（欺凌）and beautiful

    This talk is sure to stay with you. Shane Koyczan's “To This Day” is an affecting spoken-word poem about bullying and being different that gained over 10 million views on YouTube. In this talk, Koyczan gives a live reading of the poem, along with some stories about his background.

    Susan Cain: The power of introverts（性格内向者）

    Does a cup of tea and a good book sound like a perfect Friday night? In this personal talk, Susan Cain argues that introverts have talents and abilities. Our culture may value being outgoing, but the world needs all kinds.

    Fitbit Charge

    A special cut-off, just $39.99!

    Come and get one!

    Energize your day with Charge—an advanced activity wristband that tracks your steps taken, distance traveled, calories burned, floors climbed and active minutes. Stay connected throughout the day with real-time fitness statistics and Caller ID on the OLED display. And when the day is done, it automatically monitors your sleep and sets a silent, shaking alarm. Whether you're at the office or on the go, Charge wirelessly syncs (同步) your statistics to your smartphone and computer to help you find the motivation you need to achieve your goals.

    DETAILED INFORMATION

    Size: Small fits 5.5"--6.5", Large fits 6.5"--7.7". Refer to this sizing guide to be sure you get the right fit.

    Activity Tracking -- Accurately track all-day statistics like steps taken, distance traveled, calories burned, stairs climbed, and active minutes.

    See daily statistics, time of day, and exercise mode with a bright OLED display.

    Auto Sleep + Silent Alarm — Monitor your sleep automatically and wake with a silent alarm.

    Caller ID — Get call notice right on your wrist when your smartphone is nearby.

    Access real-time run statistics like time, distance, and pace to stay on track.

    Sync statistics wirelessly and automatically to your computer and over 150 leading smartphones.

    See compatible (兼容的) iOS, Android, and Windows phones.

    FREQUENTLY ASKED QUESTIONS

    How do I reset my tracker?

    If your tracker is not responding, it may be fixed by restarting.

    1 Plug your charging cable into the USB port and insert your tracker into the charging cable.

    2 Insert a paperclip into the small pinhole on the back of the charger.

    3 Press on the pinhole for 3—4 seconds.

    Your tracker will now be reset. Take your tracker out of the charger and insert it back into the wristband.

    How do I charge my tracker?

    Your tracker battery lasts for about 5 days. To charge it, remove the tracker from the band and place it in the charger until all 5 lights are solid.

    If you have more questions, you may log in and post your questions here. We will solve your problems as soon as possible.

    One of the questions surrounding climate change is how it might affect the food supply for a growing global population. A new study suggests that researchers have been overlooking how two key human responses to climate—how much land people choose to farm, and the number of crops they plant—will affect food production in the future. The new study focused on the Brazilian state of Mato Grosso, an emerging（新兴的）global breadbasket（产粮地区）that as of 2013 supplied 10 percent of the world's soybeans. The researchers used variations in temperature and precipitation（降水）across the state over an eight-year period to estimate the sensitivity of the region's agricultural production to climate change. Those historical comparisons can help in making predictions about the sensitivity of agriculture to future climate change.

    The study found that, if the patterns from 2002 to 2008 hold in the future, an increase in average temperature in Mato Grosso of just 1 degree will lead to a 9 to 13 percent reduction in overall production of soy and corn. “This is worrisome given that the temperature in the study region is predicted to rise by 2 degrees by 2050,” said Avery Cohn, who led the study.

    Most studies of this kind look only at the extent to which climate shocks affect crop output. But researchers can miss critical dynamics（动力）that can affect overall output, says Leah VanWey, one of the study's senior authors. “If you look at output alone, you're not looking at all of the information because there are economic and social changes going on as well,” said VanWey.

    If output decreases, farmers may put less land area into production because it's not profitable. Farmers may also vary the number of crops they plant in a growing season. Double cropping is common in Mato Grosso. But if the weather is bad, farmers may change their decision to plant a second crop.

    HOLLAND & BARRETT

    Valerian capsules(缬草胶囊)

    A traditional herbal medicinal product used for the temporary relief of symptoms of mild anxiety and to aid sleep. This is based on traditional use only.

    Active Ingredients:

    Each capsule contains 337mg of extract (as dry extract) from Valerian root (Valerian officinalis L) (equivalent to 1683mg-2020mg of Valerian root).

    Dosage（剂量）:

    For oral use only.

    For adults and elderly:

    Mild anxiety — Take 1 capsule 3 times daily.

    To aid sleep — Take 1 capsule 30 minutes to 1 hour before bedtime with an earlier dose during the evening if necessary.

    Swallow the capsule with water. As the effects of this product may not occur immediately, the capsule should be taken continuously for 2-4 weeks.

    The maximum dose is 4 capsules per day.

    Duration of use: If symptoms worsen or do not improve after 4 weeks, a doctor or a qualified healthcare practitioner should be consulted.

    Warnings:

    Do not exceed (超过) the stated dose.

    Do not take this product if you are:

    Under 18 years of age

    Pregnant or breastfeeding

    Allergic to Valerian or any of the excipients (辅药)in this product

    Already taking a medicine for sleep or anxiety

    Storage: Store the capsules below 25℃.

    Keep the bottle tightly closed.

    Keep out of sight and reach of children.

    Registration Holder:  NBTY Europe Limited, Samuel Ryder House, Barling Way, Nuneaton, Warwickshire, CV10 7RH, United Kingdom

    Students perform less well in final exams if smartphones are allowed in class, for non-academic (非学业的) purposes in lectures, a new study in Educational Psychology finds. Students who don't use smartphones themselves but attend lectures where their use is acceptable also do worse, suggesting that smartphone use damages the group learning environment.

    Researchers from Rutgers University in the US performed an in-class experiment to lest whether dividing attention between smartphones and the lecturer during the class affected students' performance in within-lecture tests and a final exam. 118 students at Rutgers University took part in the experiment during one term of their course. Smartphones were not allowed in half of the lectures and allowed in the other half. When smartphones were allowed, students were asked to record whether they had used them for non-academic purposes during the lecture.

    The study found that having a smartphone didn't lower students' scores in comprehension tests within lectures, but it did lower scores in the final exam by at least 5%, or half a grade. This finding shows for the first time that the main effect of divided attention in the classroom is on the length of time in keeping memory, with fewer things of a study task later remembered. In addition, when the use of smartphones was allowed in class, performance was also poorer for students who did not use them as well as for those who did.

    The study's lead author, Professor Arnold Glass, added: "These findings should alarm students and teachers that dividing attention is having a not obvious but harmful effect that is damaging their exam performance and final grade. To help manage the use of smartphones in the classroom, teachers should explain to students the alarming effect—not only for themselves, but for the whole class."

    This is the first-ever study in an actual classroom showing a relationship between losing attention from smartphones and exam performance. However, more researches are required to see how students are affected by using smartphones after school.

    Dutch officials toasted on Tuesday the opening of what is being called the world's first 3D-printed concrete bridge, which is meant to be used by cyclists. There was applause as officials wearing hard hats and workmen's jackets rode over the bridge on their bikes at the opening ceremony in the southeastern town of Gemert.

    "The bridge is not very big, but it was rolled out by a printer which makes it unique," Theo Salet, from the Eindhoven University of Technology, told Dutch broadcaster NOS. Work on printing the bridge, which has some 800 layers, took about three months after starting in June and it is made of pre-stressed concrete, according to the university. "One of the advantages of printing a bridge is that much less concrete is needed than in the conventional technique in which a mould (泥浆) is filled," it said on its website, adding "a printer deposits the concrete only where it is needed."

    The eight-metre (26-foot) bridge crosses a water-filled channel to connect two roads, and it was tested for safety to bear loads of up to two metric tons in cooperation with the BAM Infra Construction company. Although designed for bikes, it could take up to 40 trucks, the designers said "We are looking to the future," said the head of BAM, Marinus Schimmel. "3D printing meant fewer rare resources were needed and there was significantly less waste," he added.

    The Netherlands is among countries, with the United States and China, taking a lead in the cutting-edge technology of 3D printing, using computers and robotics to construct objects and structures from scratch without using much traditional manpower. Last year a Dutch architect unveiled (提示) a unique 3D printer with which he hopes to construct an "endless loop" building. And a Dutch start-up called MX3D has begun printing a stainless-steel bridge, of which a third is already completed. The aim is to finish printing by March and lay the bridge over an Amsterdam canal in the future.