Are squat toilets really more hygienic than toilets? | Expo Daily

Are squat toilets really more hygienic than toilets?

Many studies at home and abroad have compared sit-down and squat-down toilets. The results may be surprising: sit-down toilets in public restrooms may actually be cleaner than squat-down toilets!

In 2011, a foreign research team conducted a year-long study on 40 local toilets (20 toilets and 20 squat toilets). Although there was no difference in the types of microorganisms present on the two toilets, the results showed that there were more pathogenic bacteria on the surface of the utensils in the squat toilets.

Regardless of the defecation method, splashes and aerosols will be generated when flushing. These tiny particles will carry bacteria. However, toilets on the market now have a siphon structure with an S-shaped pipe inside, and most aerosol particles will be effectively confined to a certain range. And because the human body is far away from the water surface, the spread of aerosols is further limited. If the toilet lid is closed when flushing, the spread of germs can be further limited.

Squat toilets are different. When people are squatting, their noses and mouths are lower and closer to drains and sewers, so the probability of inhaling splashes and aerosols is greater. In addition, squat toilets have no covers, so when flushing, splashing water droplets and aerosols will be fully diffused into the air, which will increase the chance of contact with pathogens.

Image source: pixabay

Why are earthquakes so frequent on Taiwan Island?

Taiwan's meteorological department said that Hualien has experienced frequent and continuous earthquakes since last night, all of which are aftershocks of the Hualien earthquake on April 3 earlier this month. So far, there have been more than 1,000 aftershocks. With so many earthquakes in Taiwan recently, are you also wondering - why does our treasure island Taiwan have frequent earthquakes? From a geological perspective, Taiwan Island is located at the oblique convergence of the southeastern edge of the Eurasian Plate and the Philippine Sea Plate , and is part of the West Pacific Plate Convergence Belt - Volcanic Island Arc Belt - Seismic Belt. With the Taitung Longitudinal Valley crust docking zone as the boundary, the west belongs to the Eurasian Continental Plate, and the east belongs to the Philippine Sea Plate. In southern Taiwan, the Eurasian Continental Plate subducts eastward under the Philippine Sea Plate with the South China Sea oceanic crust as the lead; in northeastern Taiwan, the Philippine Sea Plate subducts northwestward under the Eurasian Continental Plate, forming a unique double subduction zone - the Manila Trench and the Ryukyu Trench.

These two subduction zones are important components of the western Pacific trench-arc-basin system formed in the Neogene. They are typical arc-continent collision orogenic belts on the western margin of the Pacific Ocean. The double subduction zones significantly control the geological characteristics and tectonic structures of Taiwan Island and the surrounding waters, and the geological structure is complex.

Image source: Geographic Commune

Those balloons and lanterns flying in the sky,

What happened in the end?

They will all fall back to the ground in the end , but there are many uncertain factors in the sky, so there is no way to determine the time and place of falling.

Generally, a balloon filled with hydrogen can float into the sky. As the balloon flies higher and higher, the air becomes thinner and the air pressure slowly drops. At this time, the balloon will continue to expand and finally return to the ground because of a rupture.

The Kongming lantern heats the surrounding air by burning, reducing its density. Its semi-enclosed lampshade gathers the low-density hot air, thus gaining a buoyancy greater than its own gravity. When the fuel of the Kongming lantern is burned out, or a strong wind blows out its flame, it will float down with the wind, falling to the ground or hanging on a tree branch.

It should be noted that these falling balloons and fragments of Kongming lanterns will pollute the environment, and unburned Kongming lanterns may even cause fires and huge losses, so we must pay more attention to safety while praying and making wishes.

3 fossils, teeth and ears become one

Recently, Researcher Mao Fangyuan and his team from the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, published two groundbreaking research results in the journal Nature, bringing new insights into our understanding of the evolutionary history of mammals .

Through in-depth research on the Jurassic Shuma fossils unearthed in Daohugou, Inner Mongolia, scientists have established a new genus and species, Zhou's Near-stalked Tooth. This discovery not only enriches the classification of Shuma, but also provides a new perspective for the study of the early evolution of mammals.

Even more exciting, these fossils also reveal that the formation of the mammalian middle ear is a systemic change involving multiple structures, from teeth to jaws, to skulls and inner ears, which together contributed to the unique hearing and chewing abilities of mammals.

For a long time, there has been controversy in the academic community about the relationship between the Shutherians and the southern sphenodonts. The research results of Mao Fangyuan's team show that the Shutherians are more closely related to the columnar toothed animals than to the southern sphenodonts. This conclusion was recognized by Thomas Rich, the original hypothesis proposer, and put an end to the 40-year academic controversy.

This study not only reinterpreted many features and corrected the unclear homology problem, but also reconstructed a new phylogenetic framework for mammals. This provides three main clues for us to understand the evolutionary direction of early mammals, which is of great significance to the early evolution and phylogeny of mammals.

Ecological reconstruction of Zhou's Peristyle Tooth by Zhao Chuang

Image source: China Science Daily

Severe social isolation linked to 19% increased risk of Parkinson's disease

Parkinson's disease (PD) is one of the fastest growing causes of disability in the elderly population, and social isolation is a highly concerned factor in PD.

Researchers from Fudan University analyzed 192,340 participants aged 60 and above who did not have dementia or Parkinson's disease. The researchers measured the social isolation of the participants through a composite score of three questions, including the number of family members, the frequency of friends/family visits, and leisure/social activities. Among them, 89,075 subjects (46.3%) belonged to the least isolated group, and 26,161 subjects (13.6%) belonged to the most isolated group.

During the 12.5-year follow-up, the researchers recorded a total of 2,048 PD cases. The final results showed that compared with the low social isolation group, the risk of future Parkinson's disease in the severe social isolation group increased by 19%. Analysis of genetic susceptibility showed that in the high genetic risk group, the risk of future Parkinson's disease in severe social isolation increased by 28%.

The research team speculates that the biological mechanism by which social isolation increases the risk of Parkinson's disease may be due to dysregulation of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, which increases neuroinflammation and oxidative stress. In addition, social isolation may limit people's access to social support and medical resources. This study highlights the importance of social isolation screening and intervention strategies in the elderly to reduce the risk of PD.

The content is compiled from China Science Expo Weibo, Bring Science Home, China Science Daily, Institute of Physics, Chinese Academy of Sciences, and Global Science

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