【推荐1】A dog can be a person’s best friend, or so the theory goes. But that relationship can be tested when a dog begins barking at an empty comer of a room, at a door, or anywhere where there doesn’t appear to be any activity at all taking place. Is the dog hallucinating? Is it communicating with ET? Or does it simply want to drive its owner crazy?

According to the American Kennel Club, the most common explanation for dogs’ barking without reasons is that it’s not really unprompted at all. Dogs are, obviously, equipped with superior hearing, including the ability to detect sounds that are higher in pitch. It is said a dog could be reacting to a noise that a person wouldn’t be able to hear. If a dog barks seemingly for no apparent reason at night, it might be because the noise nearby is lessened and some barking of other dogs become more clearly. Because dogs are territorial, one dog barking can turn into many others to guard themselves.

Dogs are also able to see better in the dark than humans thanks to their ability to get more light into their retinas (视网膜). If a dog is reacting to what looks to you like an empty backyard at night, it’s possible that something has caught their attention, be it a wild animal, a leaf, or a stranger.

That’s not to say that dogs only bark because of their cute senses. Some dogs might bark out of boredom in which case more exercise or play time is probably needed. They might also be trying to get their owner’s attention.

The AKC recommends that owners avoid scolding their dogs for barking, since they’re simply trying to remain alert, instead, you can try calming the dog to let them know you’re aware of their concern. If they tend to bark while gazing out a window, you can also try to pull the curtains. If you suspect the source is an audio cue, some white noise, like a television or radio can help.

Less often, chronic barking might be a sign of cognitive issues. If barking is persistent and no fugitive is hiding out in your bushes, then you might consider a trip to the vet.

【推荐3】A bear that wandered what is now China about six million years ago is the oldest bamboo-eating panda ancestor yet found-and it had the same short and fat false thumbs that stick from the wrists of today’s pandas alongside their five fingers. Fossils(化石) of the new species suggest such “thumbs,” which helped the animals eat bamboo, maintained their peculiar shape to facilitate the beast’s four-legged movement.

The fossils, found in the province of Yunnan and described in Scientific Reports, also push back the date that pandas’ ancestors likely changed from eating meat to chewing bamboo-from two million to six million years ago. “Giving up on a meat-eating diet means trading the unstable life of a meat-eater for quiet consumption of the plentiful bamboo,” says paleontologist and study lead author Xiaoming Wang of the Natural History Museum of Los Angeles, adding that it was “not a bad deal.”

Although the fossils dug from the province’s Zhaotong Basin included only teeth and some limb(肢) bones from the bear, these were typical enough for Wang and his colleagues to identify the fossils as belonging to an early member of the panda lineage called Ailurarctos. A wrist bone in the collection, with its proto-thumb, stands out among the remains. “Its structure is really close to that of the living panda,” says Juan Abella Pérez of Miquel Crusafont Catalan Institute of Paleontology in Barcelona, who was not involved in the new study.

Why didn’t this short and fat thumb evolve into a longer, larger false thumb to better grasp a meal? The researchers propose that walking on all fours was the key reason. If the panda’s thumb were larger, Wang and his colleagues suggest, the appendage(附属物) could have affected its walking or faced a high risk of breaking. In a sense, this makes the evolution of the panda’s thumb all the more impressive. The structure was limited by the need to move as well as to eat.

【推荐1】Scientists are investigating whether rising global temperatures may lead to more stillbirths (死胎), saying further study is needed on the subject as climates change.

Researchers from The University of Queensland’s (UQ) School of Earth and Environmental Science and the Mater Research Institute reviewed 12 studies, finding extreme temperature exposures throughout pregnancy appeared to increase risk of stillbirth, particularly late in pregnancy.

UQ PhD candidate Jessica Sexton said while this was very early research, it did show a possible link between stillbirth and high and low temperature exposures during pregnancy.

“Overall, risk of stillbirth appears to increase when the temperature is below 15 degrees Celcius and above 23.4 degrees Celsius, with the highest risk being above 29.4 degrees Celsius,” Ms Sexton said.

“An estimated 17 to 19 percent of stillbirths are potentially due to frequent exposure to extreme hot and cold temperatures during pregnancy.”

“And, as the world’s temperatures rise due to climate change, this link will potentially increase stillbirth likelihood globally.”

“But these findings are from the very limited research currently available, so expectant mothers shouldn’t be anxious – there’s still plenty of follow-up research that needs to happen.”

Professor Vicki Flenady, Director of the Centre of Research Excellence in Stillbirth (Stillbirth CRE)at Mater Research, said the research highlighted the importance of research to reduce global stillbirth rates.

“Even in 2021, a stillbirth occurs somewhere in the world every 16 seconds,” Professor Flenady said.

“Stillbirth has a long-lasting impact on women and their families, who often experience profound psychological suffering, even in high-income countries.”

“Here in Australia, stillbirth is still a major public health problem.”

“To fully understand the effects of mothers’ exposure to extreme temperatures and stillbirth, future studies should focus on the biological mechanisms (机制)involved and contributing factors, in addition to improving measurement of temperature exposure.”

【推荐2】Household chores might seem a drag, but researchers have suggested tasks like dusting, scrubbing floors and washing the windows might help adults to stay healthy into old age.

Writing in the journal BMJ Open, a Singapore-based team of researchers said regular physical activity “improves physical and mental health, mitigates the risks and effects of chronic diseases, and reduces falls, immobility, dependency and mortality (死亡率) among older adults”. The team randomly recruited (征召) adults from the town of Yishun in Singapore, and asked them to complete cognitive function tests as well as activities to assess their physical capabilities, such as standing up from a chair as quickly as they could. Participants were also quizzed on their levels of physical activity, including the amount of light housework (such as dusting) and heavy housework (such as floor-scrubbing) they did, and were assessed for their risk of having a fall based on measures such as knee extension strength.

The study involved 249 participants aged 21-64 and 240 participants aged 65-90. Most of those who reported doing high levels of heavy or light housework were women. After taking into account factors including age and sex, the team found cognitive scores and attention scores were 8% and 14% higher respectively for older adults doing high amounts of heavy housework—on average 131 minutes a week compared with low levels, which appeared to amount to none at all.

Sit-to-stand times were lower for older adults reporting high amounts of heavy housework compared with low amounts, while they were also assessed asbeing at lower risk of having a fall. The team also found cognitive scores were 5% higher for older adults who reported high levels of light housework — on average doing 902 minutes a week — and memory scores were also higher, comparedwiththoseundertakinglowlevelsofsuchtasks,averaging89minutesaweek.

Gill Livingston, professor of psychiatry of older people at University College London, who was not involved in the work, said the study was interesting but had little meaning as people who are not so well may be expected to do less housework. “I think the advice would be that housework can be good exercise, which is good for your heart and brain. We cannot draw any conclusions from this study that it is specifically protective,” she said.

Charlie Foster, professor of physical activity and public health at the University of Bristol, also urged caution, noting the study relied on self-reported levels of household chores, which may be inaccurate, and did not fully take into account other factors which may influence the results.

【推荐3】A deep learning algorithm (算法;计算程序) can remove city noise from earthquake monitoring tools, making it easier to show exactly when and where a small earthquake occurs.

“Earthquake monitoring in urban settings is important because it helps us understand the fault (断层) systems that underlie easily harmed cities,” says Gregory Baroza at Stanford University in California. “By seeing where the faults go, we can better anticipate earthquake events ahead of time.”

However, the city noise, from cars, aircraft, helicopters and buses makes it difficult to notice the underground changes that show an, earthquake is happening.

To try to improve our ability to.name and locate earthquakes correctly, Baroza and his friends trained a deep neural (神经的) network to tell between earthguake changes and other noise sources.

Around 80, 000 samples of urban noise and 33,751 samples of earthquake changes were put together in different forms to train, test and prove the neural network. The noise samples came from audio recorded in Long Beach, California, while the earthquake charges were taken from the rural area around San Jacinto, also in California.

The research is very useful for the field, says Maarten de Hoop at Rice University in Houston, Texas. But he does stress lone disadvantage: the neural network was trained on data marked by humans, and the readings we really from one area. The fact that the model was carefully checked only to remove noise from sounds inn California, means it is less likely to be, successful when presented with noise from elsewhere.

Baroza is also unsure about how well they model would work in places other than California “Depending on the environment, noise-features are probably going to-be different from the ones it’s trained on,” he says.