Human immunity depends mainly on the environment, not on heredity.
Release date: 2015-01-16
The immune system is the main defense mechanism of the human body against diseases. A twin study at Stanford University School of Medicine shows that human immune status depends primarily on the environment rather than on heredity, especially for older people. The study was published in the January 15 issue of Cell.
The impact of genes on human health is not to be described. With the rapid advancement of sequencing technology and the consequent decline in sequencing costs, many scientists have attempted to predict human health through small changes in the genome. Such research shows us the contribution of genetics to human health, but it is worth noting that few genetic variations contribute significantly to specific health conditions.
“Many people think that sequencing a person's genome can tell him what disease he will get in 50 years,†said Professor Mark Davis, senior author of the article. Although genomic variation plays a key role in some diseases, the immune system is highly adaptable to respond to infection, trauma and even tumor formation.
Genetic VS environment
“Different people have very different immune systems. We want to know if this phenomenon reflects genetic differences. Our research shows that in most cases (including the immune response caused by flu vaccine) genetic factors are immune The state does not play a decisive role, the real thing is the environment and the bacteria you have been exposed to," Davis said.
To separate the environmental and genetic effects, Davis and colleagues compared identical twins and fraternal twins. Identical twins inherit the same genome, although genetic errors are inevitable in cell division, but the genetic similarity between identical twins is almost 100%. The fraternal twins are genetically similar to the common hand and foot, sharing an average of 50% of the genes.
Both twins have experienced the same uterus environment. In general, the childhood environment of twins is the same, so they are the ideal research object to distinguish between genetic influence and environmental impact.
The researchers recruited 78 pairs of identical twins and 27 pairs of fraternal twins, each taking their blood samples. Subsequently, the researchers tested more than two hundred immune components and immune activities in these blood samples.
The power of the environment
Scientists at Stanford University analyzed the differences between twins based on the level and activity of immune components. They found that in three-quarters of the tests, non-genetic effects (such as bacterial or toxin exposure history, vaccination, diet, and oral hygiene) completely overshadowed genetic factors. This advantage of environmental impact is more pronounced in older identical twins (over 60 years of age).
The researchers also found that the environment had a significant impact on antibody production when vaccinated. Previous studies have pointed out that genetic factors can have a strong impact on vaccine response. Davis believes that these studies are generally carried out in children, and the immune system has not undergone a long-term transformation of the environment.
This study shows that the immune system has amazing plasticity. For example, a chronic viral infection can have a large impact on the composition and responsiveness of the immune system. Nine out of ten people in the developing world and three-fifths of Americans are long-term carriers of cytomegalovirus. The virus is generally harmless, but it is a threat to people with immunodeficiency. In 60% of the tests, the presence or absence of cytomegalovirus caused a large difference between twins.
"Non-genetic factors (especially bacteria) play a big role in immune variability," Davis said. “At least in the first two decades of your life, when the immune system is still mature, this wonderful system will adapt to different environmental conditions. In the face of pathogens, intestinal symbionts, nutrients, healthy people The immune system continues to adapt, overshadowing the effects of most genetic factors."
Source: Biopass
The performance of the Baby Monitor Security Camera
The performance of the baby monitor is reflected by its built-in parameters and function combination. The following shows some properties that a high-quality and applicable baby monitor should have. The requirements for baby monitors in this part apply to all audio/video, digital/analog home baby monitors and wireless baby monitors, and are not changed due to the combination mode of the monitoring end and the control end.
The size shall be as small as possible: the small baby monitor (monitoring end and control end) is more convenient to install and carry in the family.Low power display: the baby monitor, especially the monitoring terminal, must work continuously for a long time. Once the product is low in power, it cannot remind parents to charge it in time. When the power continues to be consumed until it is exhausted, the control terminal will be unable to continue to receive any signal.
Voice trigger prompt: Voice trigger means that once the monitoring terminal detects the noise caused by the abnormal behavior of infants or children, it will be displayed at the control terminal through the noise prompt lamp.
The transmission signal frequency can be adjusted: the monitoring end of the baby monitor provides audio and video digital signals to the control end by transmitting wireless signals. If the transmission frequency of the monitoring end is not selected properly, it will produce electromagnetic interference with other household appliances, digital equipment, etc., which will affect the normal use of the product. Therefore, it is necessary to select a baby monitor that allows users to adjust the frequency of the transmitted signal at the monitoring end.
Adjustable volume: a friendly baby monitor will provide a volume selection knob or button at the control end. When parents are in an environment with loud background sound, they can hear the activity sound of babies and children by turning up the volume; When it is late at night or in a quiet environment, the low volume will not affect the normal rest of the people around you when you are answering normally.
VOX function: VOX is the abbreviation of sound activation start. The monitor with VOX function is in standby mode under normal conditions, and the screen and horn stop working, thus reducing the energy consumption of the product; Once it is detected that the monitored object has an abnormal sound exceeding the set standard, it will immediately flash its alarm lamp at the control terminal or directly light up the screen, and simultaneously play the audio and video information sent by the monitoring terminal.
Digital signals and analog signals: baby monitors using digital signals, such as Baohushen baby monitors, will have better transmission efficiency and provide users with clearer sound and picture quality; Moreover, digital signals can be encrypted to prevent being intercepted and interpreted by other receivers, effectively protecting users' family privacy; The electromagnetic signal interference of digital signal will be lower than that of analog signal, so as not to affect the normal work of other household appliances and equipment.
Monitoring end extension: The baby monitor with a friendly user experience should allow users to use one control end to manage the activities of several monitoring ends at the same time, especially in some families with multiple children. This good scalability not only reduces the trouble of carrying multiple control ends at the same time, but also reduces the objective additional expenses for these families.
Temperature display: some products will have the function of realizing the current indoor temperature, and even can set a critical value. Once the room temperature exceeds or falls below the critical value, an alarm signal will be sent. This is a very considerate function for temperature sensitive newborn children or sick children.
Intercom function: The high-end baby monitor allows parents to have a direct conversation with the baby (child) at one end of the monitoring end through the control end, so that children who are alone can provide psychological comfort. If children have any temporary needs or words, they can be known without bothering the guardian to run to the child.
Signal range: theoretically, the signal sent by the monitoring terminal can be received by the remote control terminal, which is more convenient for users to use the baby monitor flexibly. Now more and more families live in large family rooms, even multi-storey villas, and the baby monitor with strong signal receiving ability provides these families with a more convenient way of use. Parents no longer need to set the room beside the children in order to see and hear their children's every move. They can even take the control terminal to go out for a short walk!
Power supply mode: The baby monitor with built-in battery can automatically switch to the battery power supply mode when the external AC power supply is suddenly stopped, so that the user will not be affected to continue to monitor the child in the power failure environment.
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