【推荐2】Green tree ants are important builders in the rainforest. They’re like the worker bees of the ant world. The native forest of Thala Beach Nature Reserve is the natural home of these insects.

They climb all over the tree that contains their nest and protect it from enemies with great fierceness. The ants are often in the fruiting trees of Tropical North Queensland. When an animal tries to help themselves to some tasty fruit, they find themselves attacked by a powerful, frightening army of green tree ants! Their bite is not very painful but many ants attacking at the same time can be extremely uncomfortable.

The nests are large and constructed by sticking the leaves at the end of branches together to create a home looking roughly like a globe. Most of the nest construction and weaving is conducted at night. A mature colony of green tree ants can hold as many as 100,000 to 500,000 workers and may include as many as 12 trees and contain as any as 150 nests. Green tree ant colonies have one queen and a colony can live up to eight years.

However, the ants are so busy that they fail to spot a dishonest figure. There is a spider called the Salticid spider, or the jumping spider, as they are sometimes referred to, which has excellent eyesight and is only active during daylight, weaving a protective covering of silk to spend the night in. Interestingly, the Salticid spider does not look like a green tree ant. Instead, it chemically copies green tree ants’ smell. Effectively pretending to be an ant, it goes into the green tree ants’ nest, enters the nursery and feasts on their babies. Green tree ants don’t have good eyesight and smell everything with their antennae (two long thin parts on an ant’s head). Therefore, the ants think the spider is another ant and ignore its presence within the nest.

Next time, as you wander around Thala’s native forest, keep an eye out for these busy little creatures. Look up into the trees and you’ll likely spot their nests.

【推荐3】Some colors that people see late at night could cause signs of the condition mental health experts call clinical depression. That was the finding of a study that builds on earlier study findings. They show that individuals who live or work in low levels of light overnight can develop clinical depression.

Doctors use the words “clinical depression” to describe severe form of depression. Signs may include loss of interest or pleasure in most activities, low energy levels and thoughts of death or suicide.

In the new study, American investigators designed an experiment that exposed hamsters to different colors. The animals were separated into 4 groups. One group of hamsters was kept in the dark during their nighttime period. Another group was placed in blue light, a third group slept in white light. While a fourth was put in red light. After four weeks, the researchers noted how much sugary water the hamsters drank. They found that the more depressed animals drank the less amount of water.

Randy Nelson, who heads the Department of Neuroscience at Ohio State University, says animals that slept in blue and white light appeared to be the most depressed. “What we saw is these animals didn’t show any sleep disruptions at all but they did have messed up circadian clock genes and they did show sign of depression whereas if they were in the pale red light, they did not.” He says there’s a lot of blue in white light, which explains why the blue light and white light hamsters appear to be more depressed than the hamsters that see red light or darkness.

Mr. Nelson has suggestions for people who work late at night, or those who like to stay up late. “My recommendation is if you are just living a typical mostly active life during the day, mostly inactive at night, you need to limit exposure to TVs which are quite bluish in the light they give off and computer screens and things like that. You can get filtered glass, you can get filters on your computer screen and filters on your e-Readers to put it more in the reddish light.”

【推荐2】Smart cities are coming. And you can be sure that hackers(黑客) won’t be very far behind.

We’ve already gotten a glimpse of that future, as cities across the globe start to use technology to connect their services and residents in ways that was science fiction just a few years ago. They are using sensors to collect data — such as traffic, garbage collecting, and road conditions —and then using that data to deliver services to more people and more efficiently.

But this rush to become a smart city has a major drawback: The more connected a city is, the easier it is to cyber-attacks. Hackers have, in recent years, effectively held cities hostage through ransom ware(赎金器), sometimes damaging critical systems for months at a time. The damage can cost millions to repair, as Baltimore and Atlanta have discovered.

And this is just the beginning. As cities add connectivity to their streetlights, power grids, dams, transit lines and other services, they are adding more targets that have the potential to be hacked. What’s more, as additional information on residents is collected, officials worry the result —lots of data could attract nation-states or terrorists who could incorporate the data into physical and cyber war.

What cyber security lesson can’t be taught in this hack? For example: Don’t open email attachments from unfamiliar sources; don’t click on unrecognized links; don’t leave sensitive information visible on the walls or surfaces of your office. But let’s just stick to the most important lesson: The information you share on social media can be used to profile and target you, whether that’s by engineering click bait(点击诱饵) aimed at your particular interests, guessing your password based on your birthday or figuring out your schedule and travels so that an intruder can access your home or office.

Wednesday, September 18, 2019 THE WALL STREET JOURNAL.

【推荐3】The UK will ban all new petrol and diesel-powered vehicles from its roads beginning in 19 years for environmental reasons, a government report says.

The plan aims to start removing petrol and diesel engines in 2040. It follows a similar official statement in France and comes after the British government was ordered by the High Court to develop new plans to reduce NO2 in the air. Judges ruled that previous clean-air plans were not enough to meet European Union pollution limits in the coming years.

The British government has said the poor air quality has an unnecessary and avoidable negative effect on citizens’ health, and costs up to $3.5 billion in annual lost productivity.

Part of the new plan involves an offer of $260 million to local governments to change rules where vehicle emissions (排放量) are over EU standards. Ideas so far include changing road layouts, reprogramming traffic lights and charging a fee for the oldest and most polluting cars on the road.

The plan also includes $1.3 billion for government purchase of extreme-low-emission vehicles, nearly $130 million to improve infrastructure for electric vehicle charging stations and $378 million for remodeling existing vehicles.

Climate change is also a reason for the plan to get these vehicles off the road. “We can’t carry on with petrol and diesel cars,” Environment Secretary Michael Gove said. “It’s important that we all prepare for a significant change which deals not just with the problems of health caused by emissions, but the broader problems caused in terms of accelerating climate change.”

Gove added that local communities are partly responsible for coming up with ways to limit emissions, including possible limitations on commuters (上下班往返的人) and the addition of cleaner mass transportation options. Local leaders are called on to draw up “appropriate plans” to deal with climate challenges related to emissions, he said.