Science in this week's hot topics | How much privacy can a photo reveal?

Recently, girls are practicing with Liu Genghong, boys are dancing with Wang Xinling, and children are singing "The Lone Brave Man". Which side are you on? Here are the most popular scientific topics selected from Weibo's hot search list this week:

1. How much privacy can a photo reveal?

Currently, on online social platforms, posting photos is a way for many people to share their lives, such as travel photos, food photos, home photos, etc., but it should be noted that many people choose to upload "original photos" in order to upload clearer photos (otherwise the facial features will be so blurred due to compression that they cannot be recognized), and this may leak some personal privacy information, because a photo (taken) is far more than what meets the eye.

When we use mobile phones or digital cameras to take pictures in our daily lives, in addition to freezing the beautiful scenery at that moment, we also attach a recognizable "label" to the photo. This "label" is the EXIF ​​(Exchangeable Image File) meta-information. Simply put, Exif information is a series of information collected by digital devices during the shooting process, and the information is placed in the header of the JPEG/TIFF file we are familiar with. The information includes the time of shooting, the equipment used (such as mobile phones, lenses, body, flash), shooting parameters (shutter speed, aperture F value, ISO speed, focal length, metering mode, etc.), image processing parameters (sharpening, contrast, saturation, white balance, etc.), image description and copyright statement, as well as GPS positioning data, which is basically equivalent to the "identity card" of a photo. For people who can read pictures, it is like reading his identity information from a stranger's face. If it is used by criminals, it may pose a risk to personal and property safety.

Therefore, when you are in a strange group or sending pictures to strangers, be careful not to send real photos, and do not check the original picture when sending. After all, current platforms such as WeChat and Weibo will compress pictures by default, thus erasing the exif information. If you really cannot avoid sending the original picture, you can turn off "record geographic location information" in the camera settings.

Hotspot sources:

https://s.weibo.com/

The editor has something to say: In fact, photo editing is also an excellent choice.

2. Monkeypox and smallpox are close relatives

Recently, according to the People's Daily, many countries including the United Kingdom, the United States, Portugal, Spain, Italy, Sweden, and Australia have reported cases of human infection with monkeypox virus.

Monkeypox is a viral zoonosis first discovered in 1958. The pathogen was isolated and identified by scientists from a group of monkeys used for research. The monkeys were named because of the "pox-like" infectious disease at the time. The pathogen of monkeypox virus is a DNA virus belonging to the genus Orthopoxvirus (which also includes vaccinia virus, cowpox virus and several other animal-related poxviruses) of the Poxviridae family. It is a "close relative" of the smallpox virus that only exists in history.

Since the eradication of smallpox in 1980, monkeypox virus has become the orthopoxvirus with the greatest impact on public health. The clinical symptoms of human infection with monkeypox virus are very similar to those of smallpox, but to a lesser degree. Patients will experience fever, headache, swollen lymph nodes, muscle aches and other symptoms in the early stage of the disease, and then develop a large rash on the face and body, and may cause secondary infection, bronchopneumonia, sepsis, etc. Generally speaking, the occurrence of infection cases in many regions around the world means that the virus is contagious to a certain extent, and the transmission mode of monkeypox virus is mainly through animals to humans, such as direct contact with the blood, body fluids, skin or mucosal damage of infected animals, etc., and eating improperly cooked infected animals are also risk factors. Therefore, the World Health Organization reminds that when traveling in areas where monkeypox virus is prevalent, you should avoid direct contact with wild animals (the natural hosts of monkeypox virus may be squirrels, Gambian rats and different types of monkeys), especially avoid contact with the meat, blood or other parts of sick or dead animals without protection, and the meat must be thoroughly cooked.

In addition, although human-to-human transmission is generally not easy to occur, based on the many infected people discovered recently, most of them are homosexuals, bisexuals or other men who have sex with men. Although it cannot be confirmed that monkeypox virus is a sexually transmitted virus like HIV, close contact during sexual intercourse or intimate activities may also be a key factor in transmission.

Hotspot sources:

https://s.weibo.com/

The editor has something to say: Smallpox vaccine can kill monkeypox virus by 85%, arrange!

3. How harmful are second-hand smoke and third-hand smoke?

When most people are "puffing out smoke", the smoke released from the burning end of the tobacco (sidestream smoke) and the tobacco smoke exhaled by the smoker (mainstream smoke) begin to "flow" in the air. These smoke seem to be just a group of illusory gases, but in fact, the smoke after the burning cigarette contains more than 4,000 kinds of chemical substances. After entering the air, it will form some very small but harmful particles, just like the PM2.5 (fine particulate matter) we are familiar with in daily life. Its concentration is very high. When the human body is exposed to this environment, it will "unconsciously" inhale the air containing harmful particles, which is what we often call secondhand smoke.

Studies have shown that exposure to secondhand smoke can cause lung lesions. Secondhand smoke inhaled by the human body can damage the epithelium and cilia of the airways, which is actually a defense system of our lungs. For people who are exposed to secondhand smoke for a long time, the lungs will gradually lose their protective umbrella, causing a long-term and lasting inflammatory response, thus forming two well-known lesions, one called chronic bronchitis (damage to the bronchi) and the other called emphysema (damage to the alveoli). In addition, tobacco smoke after burning will remain on the surfaces of some objects (such as walls, clothes, skin or hair surfaces, etc.). These residues contain some toxic carcinogens, such as various heavy metals and nicotine. After they are released back into the air, some of these compounds can react with oxidants and other compounds in the environment to generate secondary pollutants, that is, thirdhand smoke. This type of smoke has the greatest impact on children, because their respiratory system is more sensitive and their immune system is not perfect. In addition, the bad habit of sucking their hands often makes them easy to inhale and be contaminated with harmful substances, increasing the risk of children suffering from blood system diseases and respiratory system diseases.

Hotspot sources:

https://s.weibo.com/

The editor has something to say: "Please do not smoke in public places"

4. The Psyduck prototype may face extinction in the future

Recently, the magical Psyduck music box that moves in slow motion with its left hand and right hand has become popular on the Internet and has become another "new favorite" among young consumers after Lingna Belle and Bing Dwen Dwen.

Psyduck is a character in the anime "Pokémon". In the eyes of many people, Psyduck's flat beak and webbed feet make it look like a duck, but Psyduck has no feathers on its body and does not have wings like a duck. Instead, it has a pair of hand-like forelimbs. Therefore, Psyduck's prototype may be closer to a mammal that lays eggs - the platypus.

The platypus is one of the most primitive mammals in modern times. It belongs to the class Mammalia, the subclass Prototheria, and the order Monotremes. It is the only animal in the genus Ornithorhynchus of the family Platypus. It is distributed in eastern and southern Australia and Tasmania. Thanks to Australia's isolated geographical environment, the platypus has the dual characteristics of mammals and reptiles in its evolutionary position. On the one hand, there is hair on the body surface, the body temperature is relatively constant (between 24℃-34℃, which is the transition from variable temperature to constant temperature), and there is a diaphragm (a membrane-like muscle that separates the abdominal cavity and the thoracic cavity of mammals) and mammary glands, which are all characteristics of mammals. On the other hand, the platypus reproduces through oviparity. The eggs they lay are similar to those of reptiles, all of which are soft-shelled and leathery, and have a cloaca and cervical vertebrae, which are all characteristics of reptiles. Such animals with both mammalian and reptilian characteristics are precious "living fossil" species for studying biological evolution.

But at present, the platypus population is not large, and it only lives in some parts of Australia. In recent years, due to Australia's continued high temperature and drought, river pollution and other reasons, the platypus habitat has been shrinking. 40% of the areas on the east coast of Australia where platypuses once lived have no traces of platypuses now. Scientists predict that by 2070, the number of platypuses will drop sharply by 73%, and protection measures need to be formulated in advance to minimize the risk of extinction.

Hotspot sources:

https://s.weibo.com/

Editor's words: Padawan frowned and found that things were not simple

In conclusion:

① Everyone should carefully check whether the public photos reveal their living area and living environment. If key names, profile pictures and other sensitive information are involved, it is best to censor them;

② There have been no confirmed cases of monkeypox reported in my country so far, so there is no need to panic, but it is crucial to prevent imported cases;

③ Data show that the proportion of people under the age of 15 exposed to secondhand smoke is 72.4% nationwide, and a large number of studies have confirmed that children are more likely to be exposed to secondhand smoke when their parents smoke. Therefore, establishing a smoke-free family policy can effectively reduce the exposure of teenagers to secondhand smoke;

④ Due to its long-term isolation from other continents, although the platypus is an ancient mammal, it has no evolutionary relationship with other existing mammals. Instead, it is a specialized branch that separated from the mammals very early.

References:

[1] Cheng Senping, Xia Yankai, Hang Bo. Thirdhand smoke: a newly discovered health threat[J]. Science and Technology Review, 2014, 32(12):10.

[2] Xiao Lin, Wang Congxiao, Jiang Yuan, et al. Current situation of secondhand smoke exposure among Chinese adolescents[J]. Chinese Journal of Chronic Disease Prevention and Control, 2015, 23(3):4.

[3] Xu Weishu. The evolutionary position and ecological issues of platyrhynchos[J]. Bulletin of Biology, 1962(03):16-18.