The UN refugee agency (难民署) is heaping pressure on Europe to help Italy defuse (平息) the “unfolding tragedy” of tens of thousands of migrants flooding its shores. Italy needs more international support to deal with a growing number of migrants who have braved a risky Mediterranean crossing to reach Europe this year, UN High Commissioner for Refugees Filippo Grandi said on Saturday.

     “What is happening in front of our eyes in Italy is an unfolding tragedy,” Grandi said in a statement. “In the course of last weekend, 12,600 migrants and refugees arrived on its shores, and an estimated 2,030 have lost their lives in the Mediterranean since the beginning of the year.” Italy, he said, was “playing its part” in taking in those rescued and offering protection to those in need. “These efforts must be continued and strengthened. But this cannot be an Italian problem alone.”

    Separately, a source in Paris said the interior ministers of France, Germany and Italy would meet in the French capital on Sunday to discuss an approach to help Rome.

    Violence in Calais

    Europe has been dealing with the worst migration crisis since the end of World War II with the arrival of large numbers of people fleeing the wars in Syria and Iraq while others from Africa are seeking an escape from poverty or political persecution (迫害).

    In the northern French port city of Calais, police stepped in over the past two days to break up fighting among African migrants armed with sticks and rocks. Calais has for years been a magnet (磁铁) for migrants and refugees hoping to cross the Channel to Britain.

    Last October, France broke up the disreputable tent camp known as “the Jungle” transferring thousands of migrants to centers around the country. But hundreds remain near the port, mostly Africans and Afghans, who fight sporadically with police as they make nightly attempts to stow away (偷乘) onto trucks heading across the Channel to Britain.

    Have you ever noticed tiny raised areas on the branches of a tree? These may have been insects. These small insects feed on tree sap (汁液). Insects on urban trees are notably more abundant than those on rural trees. As a result, urban trees suffer from heavy infestations (害虫横行), and are often unhealthy or die. To protect and restore urban trees' health, we need to determine the factors that make these tree pests more successful in urban habitats.

    Living organisms interact closely with their environment. The warmer, more drought-stressed trees harbor more successful pests than cooler, less drought-stressed trees. As cities and natural habitats become hotter and drier, damaging insects will become more abundant on urban trees.

    Trees within urban forests are valuable economically and for the environmental sustainability (可持续性) of the region. More than half of the world's population lives in cities. Across the globe, people are moving into cities at a faster rate than ever. Rapid growth may turn cities into places with harder conditions. Although cities are primarily made of buildings, roads, parking lots, and vehicles, there are still plants in them. The trees within a city are referred to as the urban forest. Urban forests offer very big benefits to human and environmental health. They improve air and water quality, provide habitat for wildlife, cool down temperatures and beautify our environment. They make cities livable.

    However, being a city tree is not easy. Heat released by human activities is trapped in cities. As a result, temperatures in urban areas are often warmer than their surrounding rural areas. We call this urban warming or the urban heat island effect. Urban habitats are mostly made of surfaces of asphalt (沥青) and concrete. These surfaces reduce the amount of rainwater that reaches tree roots. As a result, urban forests may suffer, which can negatively affect people and the environment.

    What can we do to restore urban forests? Regular irrigation when possible may help keep pest populations under control. Planting tree species that are suitable to handle heat and drought stress would also reduce the occurrence of insect pest outbreaks.

    China now has 52 sites included on the UNESCO World Heritage list, which was established to safeguard unique and irreplaceable cultural and natural sites around the world. Let's have a look at some of them, which may give you some clues on your next travel plan.

    Mausoleum of the First Qin Emperor

    The Mausoleum of the First Qin Emperor is located in Lintong county, near Xi'an city, capital of Shaanxi province. A total of 8,000 life-size terracotta warriors, chariots and horses, and hundreds of bronze weapons have been unearthed from it. Many state leaders and experts worldwide believe that the discovery of the mausoleum is a major archeological find and can be called the eighth wonder of the world, paralleling Egypt's pyramids.

    Kulangsu, a Historic International Settlement

    Gulangyu Island, known in the local dialect as Kulangsu, is located on the entry of the Jiulong River, facing the city of Xiamen. The island was occupied by at least a dozen countries, including Great Britain, France and Japan. As a result, Western culture grew rapidly there in the 19th century, especially music. With such a harmonious blend of Western music and Eastern culture, Gulangyu is naturally referred to as the “island of music”. It is famous for its outstanding musicians and musical instruments.

    Qinghai Hoh Xil

    Hoh Xil, which means “beautiful girl” in Mongolian, is located in the north-eastern end of the Qinghai-Tibetan Plateau. Hoh Xil National Nature Reserve is China's largest and the world's third largest uninhabited area. Because of the high altitude and fierce weather, it is impossible for people to live there, and therefore, it is a paradise for wildlife and home to more than 230 species of wild animals including endangered species such as the Tibetan antelope, which is recognized as the National Class I Protected animal.

    Huangshan Mountain

    Huangshan, known as “the loveliest mountain of China”, lies in the south of Anhui province in eastern China. The scenic area covers 154 sq km, and is famous for its peaks, rocks, pines, clouds and springs. It also has a rich cultural heritage. Xu Xiake, a famous traveler of the Ming Dynasty (1368-1644), visited Huangshan twice, and described it in a poem, calling it the best of all mountains in China. Today it holds the same fascination for visitors, poets, painters and photographers.

    In the depths of the French Guianese rainforest, there still remain unusual groups of indigenous(土著的)people. Surprisingly, these people live largely by their own laws and their own social customs. And yet, people in this area are in fact French citizens because it has been a colony of the French Republic since 1946. In theory, they should live by the French law. However, their remote locations mean that the French law is often ignored or unknown, thus making them into an interesting area of “lawlessness” in the world.

    The lives of these people have finally been recorded thanks to the effects of a Frenchman form Paris called Gin. Gin spent five months in early 2015 exploring the most remote corners of this area, which sits on the edge of the Amazon rainforest, with half its population of only 250,000 living in its capital, Cayenne.

    “I have a special love for the French Guianese people. I have worked there on and off for almost ten years,” says Gin. “I've been able to keep firm friendships with them. Thus I have been allowed to gain access to their living environment. I don't see it as a lawless land. But rather I see it as an area of freedom.”

    “I wanted to show the audience a photographic record touching upon the uncivilized life,” continues Gin. “I prefer to work in black and white, which allows me to show different specific worlds more clearly.”

    His black-and-white pictures present a world almost lost in time. These pictures show people seemingly pushed into a world that they were unprepared for. These local citizens now have to balance their traditional self-supporting hunting lifestyle with the lifestyle offered by the modern French Republic, which brings with it not only necessary state welfare, but also alcoholism, betrayal and even suicide.

    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.

    Chinese retail giant Alibaba has developed a new automated(自动化的) vehicle which is easy to mass-produce and could serve a number of functions. These could include delivery messenger or automated coffee selling machine, it said.

    The Cainiao G Plus can travel at up to nine miles per hour, reports The Verge news site. It was showed at a conference where Alibaba founder Jack Ma announced a 100bn yuan ($15.5bn) would be put into smart logistics(物流).This includes devices such as warehouse robots as well as delivery aids.

    AI expert and author Calum Chace described the G Plus as being like the "ugly big brother" of a delivery project developed by UK firm Starship Technologies. Starship has been working on this project for several years, so the Alibaba project looks to be behind as well as ugly, he said. "But that won't matter. Anything to do with artificial intelligence is put in the first place for China, which has set itself the target of overtaking the US as world leader in AI by 2030".

    China benefits from having free access to large amounts of data, essential for training algorithms(算法), he added, probably a disadvantage in Europe since the introduction of GDPR law, designed to protect privacy.

    "Don't bet against the Chinese pulling ahead in any AI-related competition, be it self-driving cars, facial recognition, or delivery projects," Mr Chace said.

    The G Plus vehicle is fitted with solid state Lidar – the laser sensors which form an important part of the system autonomous vehicles use to be aware of their surroundings.

    Solid state Lidar is cheaper and easier to produce than the traditional system, which involves spinning multiple lasers in circles to help build up a 360-degree image of what surrounds the vehicle. There are various developers creating their own versions but essentially it uses fewer lasers and a tiny swinging mirror.

    Last month BMW said that its autonomous vehicles will be fitted with solid state Lidar when they will be launched in 2021.