【推荐1】Imagine a town with crosswalks but no pedestrians, cars and trucks but no drivers. Welcome to Mcity, a fake “city” built by researchers who are testing out the driverless cars of the future.

The controlled test environment, which opened today (July 20, 2015) at the University of Michigan in Ann Arbor, covers 32 acres (the size of about 24 football fields) and contains all the trappings of a real suburb or small city. There is an entire network of roads lined with sidewalks, streetlights, stop signs and traffic signals. There’s even a “downtown” area complete with fake buildings and outdoor dining areas.

The idea behind Mcity is simple: test out new driverless car innovations in a human-free environment before these technologies are unleashed in the real world.

"Mcity is a safe, controlled, and realistic environment where we are going to figure out how the incredible potential of connected and automated vehicles can be realized quickly, efficiently and safely," Peter Sweatman, director of the Mobility Transformation Center at U-M, said in a statement.

The roads of Mcity are built to stand up to “rigorous, repeatable” testing, according to MTC officials. While Mcity drivers don't have to compete with real pedestrians, there will be one mechanical foot-traveler (a robot-like machine named Sebastian) that steps out into traffic to see whether the automated cars can hit the brakes in time. The fake city also features a traffic circle, a bridge, a tunnel, some unpaved roads, and even a four-lane highway with entrance and exit ramps, according to a report by Bloomberg Business.

In addition to evaluating fully automated, or driverless cars, the researchers also hope to test out so-called connected vehicles within Mcity’s limits. Connected cars can either communicate with one another (vehicle-to-vehicle control, or V2V) or with pieces of equipment, such as traffic lights, that are located near roadways (vehicle-to-infrastructure control, or V2I).

Even the smallest details of Mcity have been planned out in advance to copy the conditions that connected and automated vehicles could face in the real world. For example, there are street signs covered up with graffiti, and faded yellow and white lane markings line the streets.

Mcity is just one part of a much larger project that MTC and its partner organizations are establishing in an effort to get a whole fleet of connected and driverless cars on the road in Ann Arbor by 2021. In addition to the fake city, MTC is also continuing to launch connected and semi-autonomous(半自动) cars on real roadways. Eventually, the University of Michigan and the Michigan Department of Transportation said they hope to put 20,000 connected cars on the roads of southern Michigan.

【推荐2】Getting stuck in a traffic jam is one of the most boring problems for people living in big cities.The fact that you’re moving so slowly leads too stress,anger and the wish that your car could just fly over the traffic like an airplane.

Soon,however, that wish could come true .On May 8, US car-renting company Uber showed off what it described as “the transportation mode of the future: on-demand air   transport,”reported ABC News .

According to Nikhill Goel, head of products for Uber Air, the company's air taxi service may launch test flights in the US cities of Dallas and Los Angeles , as well as Dubai in the United Arab Emirates, as early as 2020. If everything goes according to plan, passengers will be able to fly to work by 2023 .

When the Olympics comes to Los Angeles in 2028 . Uber “expects to have hundreds , if not thousands , of its aircraft in the skies.” Goel told Newsweek .

So what would Uber's flying vehicles be like ?

They are small , electric aircraft that take off and land vertically (垂直地) , and they give off zero emissions (排放) and are quiet enough to operate in cities .

Just like an airplane , the vehicles will have fixed wings to help them glide . But while a helicopter has just one big fixed rotor (定量) . Uber's vehicles will have multiple rotors , which will help increase fuel efficiency (效率) while reducing emissions and noise.

Because of these fixed wines and multiple rotors . Uber’s flying taxis“should be quieter and safer than a helicopter.” reported ABC News .

However , the service still has a long way to go before it's ready to accept passengers.For example , to avoid any potential accidents . Uber is working with NASA to study air traffic control problems associated with low-flying aircraft. But just as Dubai's Mayor Betty Price said in a news release . “This program is revolutionary and future -oriented (面向未来的). ”

【推荐3】It is often difficult for farmers to identify diseases quickly enough to protect their crops and those on neighboring farms. Now, some farmers are using a simple device directly in the field to find viruses before they spread.

In Tanzania, several viruses are a threat to cassava crops. Farmers struggle to identify the diseases in an urgent effort to avoid severe crop damage. The disease identification process is often difficult when farmers are acting on their own. If they do not know what is attacking their crops, they cannot decide the best way to fight the disease. A device from British technology company Oxford Nanopore is changing that. The device extracts deoxyribonucleic acid, better known as DNA, from plants. DNA is the carrier of genetic information in nearly all living things. The device helps farmers identify what is harming their crops so they can change to more resistant crops.

Laura Boykin is with the University of Western Australia and also works with the Cassava Virus Action Project. She brought the device to a Tanzanian farm owned by Asha Mohamed. She said, “We are here collecting leaf punches from infected material to test, to do a DNA extraction and then start sequencing (排序) in the field.” The testing identified a number of viruses in the cassava fields near Mohamed’s farm. The process also discovered that plants considered resistant to disease had a very low viral level. Once the viruses were identified, Asha Mohamed was given two kinds of seeds that are resistant to the diseases.

In another case, DNA was collected from a pawpaw tree farm in Kenya. With that test, the technology was able to identify diseases affecting Naomi Mumo’s crops. Naomi Mumo said, “All my pawpaw were affected by a disease, and I didn’t know what kind of disease it was. But now, I have people who have identified the disease using new technology, and within a very short time. So I’m very happy.”

The speed at which farmers identify diseases can mean the difference between the success or failure on large areas of crop land. Now, the use of such simple and easily transportable DNA sequencing devices is making that possible.

【推荐1】The Paris climate agreement finalised in December last year heralded a new era for climate action. For the first time, the world’s nations agreed to keep global warming well below 2°C.

This is vital for climate-vulnerable nations. Fewer than 4% of countries are responsible for more than half of the world’s greenhouse gas emissions. In a study published in Nature Scientific Reports, we reveal just how deep this injustice runs.

Developed nations such as Australia, the United States, Canada, and European countries are essentially climate “free-riders”: causing the majority of the problems through high greenhouse gas emissions, while incurring few of the costs such as climate change’s impact on food and water. In other words, a few countries are benefiting enormously from the consumption of fossil fuels, while at the same time contributing disproportionately to the global burden of climate change.

On the flip side, there are many “forced riders”, who are suffering from the climate change impacts despite having scarcely contributed to the problem. Many of the world’s most climate vulnerable countries, the majority of which are African or small island states, produce a very small quantity of emissions. This is much like a non-smoker getting cancer from second-hand smoke, while the heavy smoker is fortunate enough to smoke in good health.

The Paris agreement has been widely welcomed as a positive step forward in addressing climate change for all, although the details on addressing “climate justice” can be best described as sketchy.

The goal of keeping global temperature rise “well below” 2℃ is praiseworthy but the emissions-reduction pledges submitted by countries leading up to the Paris talks are very unlikely to deliver on this.

More than $100 billion in funding has been put on the table for supporting developing nations to reduce emissions. However, the agreement specifies that there is no formal distinction between developed and developing nations in their responsibility to cut emissions, effectively ignoring historical emissions. There is also very little detail on who will provide the funds or, importantly, who is responsible for their provision. Securing these funds, and establishing who is responsible for raising them will also be vital for the future of climate-vulnerable countries.

The most climate-vulnerable countries in the world have contributed very little to creating the global disease from which they now suffer the most. There must urgently be a meaningful mobilisation of the policies outlined in the agreement if we are to achieve national emissions reductions while helping the most vulnerable countries adapt to climate change.

And it is clearly up to the current generation of leaders from high-emitting nations to decide whether they want to be remembered as climate change tyrants or pioneers.