【推荐1】Dogs greet other dogs nose-first, as it were—sniffing each other from fore to (especially) aft. People are not quite so open about the process of sniffing each other out. But the size of the perfume industry suggests scent is important in human relations, too. There is also evidence that human beings can infer kinship (亲戚关系), deduce emotional states and even detect disease via the sense of smell.

Now, researchers of the Weizmann Institute of Science in Israel, have gone a step further. They think they have shown, admittedly in a fairly small sample of individuals, that friends actually smell alike. They have also shown that this is probably the case from the beginning, with people picking friends at least partly on the basis of body odour (气味), rather than the body odours of people who become friends subsequently converging (趋同).

They stated their research by testing the odours of 20 pairs of established non-romantic, same-sex friends. They did this using an electronic nose and also two groups of specially employed human “smellers.” The e-nose employed a set of gas sensors to assess T-shirts worn by participants. One group of human smellers were given pairs of these shirts and asked to rate how similar they smelt. Those in the other group were asked to rate the odours of individual T-shirts on five subjective dimensions: pleasantness, intensity, attractiveness, competence and warmth. All three approaches yielded the same result. The T-shirts of friends smelt more similar to each other than the T-shirts of strangers. Friends, in other words, do indeed smell alike.

Why scent might play a role in forming friendships remains obscure. Other qualities related with being friends, including age, appearance, education, religion and race, are either immediately obvious or rapidly become so. But while some individuals have strong and noticeable body odour, many—at least since the use of soap has become widespread—do not. It is present. But it is subconscious.

【推荐3】How many species can be found in a glass of ocean water? If you’ve ever been involved in a school experiment looking at ocean or river water under a microscope, you’ll know that even a single drop is filled with life, from small insects and fish you can see with your eyes down to bacteria, fish eggs and even tiny creatures that can only be revealed under microscope.

Scientists are now looking even more closely, using the relatively recent technique of environmental DNA (eDNA) sequencing (测序). This allows researchers to get some DNA from a sample of water, and then to match it against known reference sequences.

Not only can eDNA identify thousands of species in a single sample of water, but the technique can be used in the field to assess biodiversity in water and other environments faster, more comprehensively, yet also much less harmfully than traditional physical surveys.

The approach is growing so quickly that the first Australian and New Zealand Environmental DNA Conference was held in Hobart in February 2023, bringing together some of the world’s leading researchers and technology providers in the space.

There is still much to be learned. Because of the DNA copy technique, the slightest pollution can deliver false results. Scientists are also still learning about how eDNA is distributed in the environment, how far it travels from its “point of release”, and how different water qualities affect how well mixed it is in the water column. There are also many things that can affect results when sampling. eDNA degrades (分解) faster in warmer water because of increased microbial (微生物的) activity, a strong driver of eDNA degradation. Yet this effect can be reduced by an increased production of eDNA under these conditions.

So there is no specific answer to the question. But with the new techniques and others in development, the answer is far higher than you would have counted through your school microscope. California-based Illumina is a leader in eDNA sequencing and it was also a gold sponsor of the Hobart event. Its “next-generation sequencing” workflow involves a three-stage process after sample collection.

【推荐3】Working without going to work? Yeye, a project manager and online English teacher, has been traveling around the world without giving up her job, reported Global Times. Traveling from Yunnan to Zhejiang and Hainan while working remotely via a laptop since 2020, she is one of the many so-called “digital nomads”(数字游民).

Digital nomads are people who are location-independent and use technology to perform their jobs while living a nomadic lifestyle, according to Investopedia, an information source platform for financial content. Digital nomads work remotely as they travel around, telecommuting rather than being physically present at a company office.

The number of digital nomads has increased strongly in the past few years. A 2021 report stated that in the US the number of digital nomads increased by 112 percent from 7.3 million in 2019 to 15.5 million in 2021. Hu Jiayin, an assistant professor at the National School of Development at Peking University, said in a speech that “nearly 80 percent of job hunters of Zhaopin, a job seeking platform, long to become digital nomads”.

The COVID-19 pandemic is another new reason for the rising popularity of becoming a digital nomad worldwide, noted Investopedia. During the pandemic, remote work is largely admitted by companies as being useful, making them increasingly aware that the necessary work can still be done smoothly without having workers at the office. Besides, working remotely is indeed a good way to reduce the risk of being infected whenever there are confirmed cases nearby. As long as conditions allow for it, digital nomads may also travel as they work.

The digital nomad lifestyle also suits the young generation’s pursuit of freedom, according to Hu. “Young people born in the 2000s long for freedom as well as stability,” she said. A job with no on-site requirement is therefore attractive to them. With a laptop, digital nomads can work anywhere they want. Traveling, bathing, or lying in bed can happen at the same time as working, Hu said.

【推荐1】You don’t have to brave the crowds at the Tidal Basin to enjoy the glories of cherry blossom (樱花), which always runs for one month. The delicate pink and white blooms decorate the district. Washington-based nonprofit Casey Trees has a detailed map of where to find them.

Using the map’s explanation, you can check out a neighborhood’s list of trees. The map is color-coded by a variety of cherry blossom, and there are several: Yoshino, Okame, Oshi-ma, and Sour Cherry, just to name a few.

Michaila Musman, the Geographic Information Systems manager at Casey Trees，suggests tracking down the Sargent Cherry, which develops pinkish white blossoms and is called the “cream” of flowering cherries by the Arbor Day Foundation. “They can also support bird species around the city, which is a wonderful bonus.” says Musman.

The map is an annual tradition at Casey Trees. The organization plans to use it to help protect Washington’s trees. To build the map, staff and volunteers walked into the city’s parks to identify and measure every tree they came across. “We can do better advocacy and tree protection if we know what our trees across the city look like.” said Musman.

Other data points for the map come from DDOT’s Urban Forestry Division and from cherry trees that Casey Trees has planted. Most of the trees on the map are located on public land. So if your yard or your neighbor’s yard is the proud home of a cherry tree, it may not appear (considering it as your own secret garden).

And if you miss the cherries this time around, the organization also maintains a separate map of all the flowering trees in the city. Musman recommends checking out the Eastern Red bud. “They are native to this area and they have very beautiful blossoms.” she says, “It seems as though they came right out of a Dr. Seuss’ book.”

【推荐2】Plants are our useful companions on Earth. They consume carbon dioxide and release oxygen, provide us with dietary and medicinal products and brighten up our environment. However, they are the victims of circumstances. Planted in an adequately sunny spot and provided with water they thrive (茁壮成长). However, put in unfortunate conditions, they have no choice but to wither (枯萎) and die. Bu what if plants could relocate to better places?

It was this question that Sun Tianqi, founder of a Chinese robotics firm Vincross, asked himself while watching a dead sunflower. "I thought if it could have taken a 30-foot walk out of the shadow to where the other sunflowers were, it would have lived healthily," he said.

He decided then to build a robot that would let plants do just that. The innovative roboticist took one of his company's traditional HEXA robot models and built a "flowerpot," which replaced HEXA's shell.

According to its site, HEXA is a "six-legged robot that comes complete with all the necessary sensors." The result is an impressive plant robot that can chase (追逐) the sun, hide for shelter, interact with humans when tapped and perform a funny dance to indicate it is thirsty.

Although the plant robot may have many useful future applications, Tiangi's reasons for creating it seem to have been philosophical. "Plants are passive. No matter if they are being cut, bitten, burned or pulled from the earth, or when they lack sunshine, water, or are too hot or cold, they will hold still and take whatever is happening to them," he said. "They have the fewest degrees of freedom among all the creatures in nature. This is simply the setting that nature gives to plants. I do hope that this project can bring some inspiration to the relationship between technology and unfavorable natural settings," concluded Tianqi.