【推荐1】Summer is by far my favorite season of the year. I love the warm temperature, the longer, sunnier days and the opportunity to spend more time by the lake. But my love for the season quickly ends when I think of mosquitoes (蚊子). While their bites alone can be annoying, it’s just infuriating when I come inside with several new bright-red welts (红肿) while my friends so kindly report how they don’t have a single one.

Why is that? It’s not that we’re particularly unlucky. There are actually scientific reasons why mosquitoes single out certain people.

Contrary to what you might think, mosquitoes don’t bite people for food—they feed on plant nectar (花蜜). Only female mosquitoes bite, and they do so to receive proteins from your blood needed to develop their eggs.

A common belief is that mosquitoes are attracted to certain blood types. While there are no firm conclusions as to which blood type is more attractive to mosquitoes, several studies have suggested that mosquitoes are not so attracted to people with blood group A. However, they find people with blood group O a little tastier.

Mosquitoes are highly visual hunters when it comes to finding a human to bite. Research has shown that mosquitoes are more attracted to the color black, but there has been little additional research into why this is the case.

Mosquitoes can smell out a person through the carbon dioxide given off when we breathe. Therefore, people who give off more of it—larger individuals and people who are breathing heavily when working out—are more attractive to a mosquito.

In a study, mosquitoes were observed to land on participants more frequently after they had drank a small amount of beer. Probably, mosquitoes are more attracted to people who have been drinking beer.

Mosquito bites are annoying. The best way to handle mosquito bites is not to get bitten in the first place.

When served cauliflower or broccoli, some kids turn away in annoyance. Don’t blame them—a new study suggests specific enzymes (酶) in saliva (唾液) might make these vegetables taste terrible to some children.

These enzymes, called cysteine lyases, are produced by bacteria in the mouth.

The same enzymes are also locked away in the cells of Brassica vegetables like broccoli and cauliflower. When we chew broccoli, these enzymes spill out of their storage containers while those in our mouth start to work.

These enzymes break down a compound (化合物) called S-methyl-L-cysteine sulfoxide (SMCSO) in these vegetables, and this breakdown process transforms the compound into sharp smell molecules (分子). Previous studies of adults suggest the level of cysteine lyase activity in a person’s saliva determines how much the SMCSO breaks down. This, in turn, influences how these vegetables taste to adults.

According to these past studies, when different adults consume broccoli, there can be a huge difference in how many unpleasant smells the food lets off as their saliva-borne enzymes break it to bits. But the authors wondered whether the same difference can be seen in kids, who are usually more sensitive to bitter and sour tastes. They suspected that kids whose saliva produced the most smelly, SMCSO-sourced compounds would show the strongest dislike for broccoli.        

And the team’s new study proved their assumption. While both adults’ and kids’ saliva produced smelly compounds when exposed to cauliflower, these smells did not influence whether adults liked the vegetable. On the other hand, kids whose saliva produced high concentrations of these smells reported hating cauliflower the most.

The new study included 98 pairs of parents and children aged 6 to 8. After taking samples of each participant’s saliva, the scientists mixed it into raw cauliflower powder. They measured the SMCSO-sourced smell compounds let off and found each participant’s saliva generated a different quantity of smells.   

Interestingly, the degree of sickly smell production was similar between parents’ saliva and their children’s. This indicates that parents and kids likely carry similar bacteria in their mouths, which would cause them to produce similar levels of cysteine lyases.

Our senses of taste and smell are strongest in youth, which may make kids even more sensitive to these differences in flavor. The same preference pattern is not seen in adults, who also produce plenty of bad smells. This suggests that the adults came to tolerate the taste of Brassica vegetables. The findings agree with past studies of how our tastes change over time: we can learn to overcome our distaste for certain food by eating it more.

【推荐1】From rolling hills to mountain ranges, views make any road trip memorable, but for blind passenger this is part of the experience they miss. Motor company Ford tries to change that. It teamed up with GTB Roma and Ae do Project—to develop a technology that will give those unfortunate passengers away to feel nature’s beauty through their car windows.

The prototype (原型) of the smart car window has a device with an outside-facing camera. With just a press of a button, the system takes a picture of the current view. The colorful picture is then turned into an image with different shades of grey through LED lights, which vibrates (震动) differently. As the finger passes over different regions of the image, its shaking movements provide feedback through the sense of touch to the person using it. The smart window also comes with a voice assistant that uses AI to identify the scene and help the passengers get information on what they’re seeing.

“As the prototype started taking shape, we realized we were giving birth to a completely new language that would give blind people a new chance to visualize and experience traveling,” Federico Russo, one director of GTB Roma, said. “When the idea was at its first stage, we looked for suppliers all around the world to make it come to life.” He believes the technology can be employed not just in cars. “It could be introduced into schools and institutions for blind people as a tool that could be used in multiple ways.”

The technology may show up in a Ford autonomous vehicle. It’s known that the company is testing their technology and future business model and struggling to figure out how an autonomous vehicle gives different passengers the details needed to get from one destination to another. It’s unclear when this technology will be made available. However, the idea of building something for the less advantaged is indeed a kind and influential action.

【推荐2】Most of us want to be in peak physical condition, get in shape and be healthy. While some gym bunnies are more obsessed with looking ripped, for many of us nutrition and watching what you eat is a vital way to stay healthy. But when it comes to food, what is calorie counting, and what are the positives and negatives of it?

A law in the UK came into force in April 2022 that requires large businesses such as restaurants, takeaways, and cafes to display the calorie information of non-pre-packed food and soft drinks on their menus. It’s a strategy aimed to tackle obesity and give people a more informed choice of what goes down their gullets(食道). According to the NHS (National Health Service), generally, the recommended daily intake of calories for male adults is 2,500 per day, while female adults should consume 2,000 to maintain their weight levels. For those of us who wish to drop a few pounds, experts advise us to consume fewer calories than the recommended daily number, eat a balanced diet, and increase our levels of physical activity.

However, there are some skeptics when it comes to calorie counting. 200 calories of fresh fruit and 200 calories of junk food, for example cookies, have the same caloric value. However, there is a question of the health benefits of what you’re consuming, regardless of calories. While fresh fruit like apples contains things like vitamin C, junk food could contain an unhealthy level of sugar and fats. Likewise, fruit may fill you up and leave you not desiring more food for longer than a biscuit with equal calories - meaning, overall, you eat less. Simply counting calories, while useful for weight loss, doesn’t take into account your intake of good fats, carbohydrates, and proteins - things that your body needs. So, if you’re trying to stick to a low-carb diet, just looking at numbers of calories on a menu won’t be that useful. So, always be mindful that what you’re eating is part of a healthy balanced diet.

【推荐3】Sohabati Devi grows rice and vegetables in the village of Dodhghat in Uttar Pradesh, India. One night, floods drowned her fields. Thankfully, she’d planted a special type of rice. Scientists had improved its DNA to contain a specific bit of genetic (基因的) material called SUB1A, which helps rice plants survive being completely drowned for two weeks. Indeed, after the flood went away, roughly half of Devi’s rice crop was still alive. Now some scientists don’t just want to help crops survive climate change. They’re looking to develop crops that actively fight climate change.

During photosynthesis (光合作用), plants turn CO₂ from the air into the carbon-rich sugar and oxygen they need. Plants also send carbon into the soil through their roots. However, plants “can’t use all the sunlight when full sun is shining on the leaves,”   notes Krishna Niyogi, a biologist at UC Berkeley. Actually, too much sunlight can damage plant cells. To guard against this, plants have something like a safety valve (阀). If it could react to changing light faster, plants could get more sun energy, Niyogi says.

Three proteins control the opening and closing of those safety valves. To increase the levels of these proteins, Niyogi’s team added three genes into tobacco plants. The result was that plants grew 14-20% larger than usual. This is important as larger plants store more carbon.

Encouraging photosynthesis to pull more CO₂ from the air is a great start to ward helping farms fight climate change, but this removal is short-term. When a plant dies, microbes in the soil eat it. Those microbes then put off CO₂ and other greenhouse gases, which return to the air. The deeper plant roots grow into the soil, though, the longer it takes that carbon to make its way back out again. “The roots are the vehicle to actually store the carbon and take it out of the atmosphere,”   says Wolfgang Busch, a biologist at the Salk Institute in San Diego, California.

From root surveys and other studies, Busch has identified around 50 genes that help plants grow deeper, bigger roots.