In the next selection of the most interesting scientific news:
- Alzheimer's disease may be associated with gum disease.
- Groundwater – A time bomb for future generations
- The smell of pizza discourages appetite
- Life on Earth may be the result of a collision with another planet.
New data on the infectious nature of Alzheimer's disease
More and more scientific publications confirm the worrying hypothesis that Alzheimer's syndrome is an infectious disease.
Recently, scientists have received other and very powerful proof of the existence of a link between the bacterium and the symptom of Alzheimer's disease, and the source of this danger is unexpected.
An article by a group of authors, led by microbiologist Jan Pottemp of the University of Louisville, provides data on bacterial discovery. Porphyromonas gingivalis in the brain of patients suffering from Alzheimer's syndrome. This microorganism occurs as a result of chronic periodontitis or inflammation of the gums, which affects hundreds of millions of people.
Experiments conducted on laboratory animals have shown that this pathogenic bacteria that causes inflammation of the gums penetrates the brain and stimulates the production of amyloid plaque proteins that are the major symptom of Alzheimer's disease.
A research team, coordinated by the Cortexyme pharmacology firm, has not claimed to have found the real cause of Alzheimer's disease. At least for now.
"Infectious pathogens have been suspected of causing or contributing to the development of Alzheimer's symptoms but for the first time we have obtained a convincing evidence of a bacterial infection with this terrible disease," says company chief Stephen Dominini.
In addition, scientists have been able to identify a group of toxic enzymes that are secreted by bacteria that have entered the brain affected by Alzheimer's syndrome. These toxins correlate with two different markers of the disease: a group of tau proteins and protein, ubiquitin.
"Our discovery of antigens of such toxins in the brain of people suffering from Alzheimer's disease as well as people with Alzheimer's pathology but not diagnosed with dementia shows that colonization of the brain by bacteria P. gingivalis is not the result of gum disease caused by poor dental care as a result of dementia, and an earlier event that precedes the appearance of dementia symptoms in elderly patients, the authors of the article noted.
Created by the company under the COR388 door, which is already undergoing clinical trials in patients with Alzheimer's disease, it has been shown in experiments on mice to reduce the number of bacteria. P. gingivalis, living in the brain as a result of infection while reducing the production of beta-amyloid and neuronal inflammation.
Scientists are cautiously optimistic about this study. Over the past 15 years, major world pharmaceutical companies have not provided any treatment for Alzheimer's, and many have stopped research in this area by finding them unprofitable.
These results are published in Science Advances.
Underground water supplies are not endless, waterworks warn
More than two billion people worldwide are completely dependent on the water reserves contained in the water horizons.
In the face of rising global climate change, this dependence becomes more and more obvious. Recent studies by geologists and environmentalists have revealed that groundwater stocks differ differently from climate change in different climatic zones.
- The metropolitan areas, which face drinking water shortages
- Too hot? The Londoners who survived the Great Stink of 1858 would not understand
For example, in the Sahara Desert there are stocks of underground relic water that were formed 10 million years ago.
Around half a century ago, many countries in this region began an active exploitation of underground water sources. However, the recovery of water horizons is slowing down due to the reduction in total rainfall in North Africa.
In many parts of the Sahara, half a century ago, extensive palm forests exist, which can only grow under shallow groundwater – no more than 6 meters. Over the years, many such groves and plantations just die because the groundwater level has dropped to hundreds of meters.
In other cases, for example, as in Tunisia or Egypt, groundwater is now pumped from pumping stations at a depth of 2-3 km. They must first be chilled for use in irrigated plants.
So this problem turns into a time bomb that we leave to future generations. Our grandchildren will have to solve it in the face of an even more serious environmental crisis.
"Our research shows that groundwater tanks are extremely inert in their responses to climate change and only half of all groundwater in the world fit into the 100-year scale that people usually work on," said Mark Cuthbert of the University of Cardiff, who has been involved in a recent study of groundwater problems.
"This means that in many areas of the world, for example in the Amazon Valley or in Central Africa, where there are many rainfalls, these changes occur every 10 years, that is, very fast, but in Sahara the groundwater still reacts of climate change, which happened 10 thousand years ago, "- says the scientist.
The data for this study is published in the journal Nature Climate Change.
The smell of fatty foods leads to a decrease in appetite.
There is new evidence of the effect of appetite smell. A group of American biologists have found that inhaling the smell of fatty foods for more than two minutes suppresses the receptors that control hunger.
The time factor here is decisive – the first reaction to the smell is a starvation, but the long-lasting effect of the odor suppresses it.
- Painful food that some people think is a real delicacy
- The smell of fresh bread and hot chocolate. How we are forced to buy
"The smell of the room can be a powerful appetite suppressant," says one researcher, Dr Dispan Bisvas, of the University of South Florida.
Scientists now propose to use this technique in school chairs or in big grocery stores. They tried in practical experiments, spraying the aromas of apples, strawberries, pizzas and sweets in such rooms.
In a typical school canteen in the United States, where about 900 students go to lunch, the number of complaints about unhealthy foods decreases to 21.43% as a result of the evaporation of a smell of pizza. The smell of apples led to a decrease in these purchases to 36.96%, and the lack of smell gave 36.54%.
Scientists attribute these results to the fact that the human brain is unable to accurately tell the sources of pleasant sensations.
"We suppose that the odors of food that are particularly attractive activate the centers of pleasure in the brain, causing satisfaction, which in turn reduces the actual use of such food," the publication says.
So, do not be surprised if during the next flight you feel the strong smell of pizza in the cabin – maybe the airline is trying to influence your appetite in the direction of reduction.
The article is published in the latest issue of the Journal of Marketing Research.
A collision with an unknown planet can lead to life on Earth
Earth's biological life could not have come about as a result of natural processes, but after a collision with a large planet with the size of the current Mars about 4.5 billion years ago.
This is described in an article in Science Advances.
A new hypothesis is based on the fact that this hypothetical planet called Thea, a collision with which also led to the formation of the moon, brought with it elements such as carbon, nitrogen, hydrogen, and sulfur that were previously lacking on Earth required components of organic synthesis.
- Scientists: The moon came from striking a similar body in the Earth
- The disaster that makes us live
Based on our well-known facts, it is difficult to explain how on Earth in the early stages of its formation there may be so many volatile substances and gases that have been involved in the formation of the atmosphere, the hydrosphere and the biosphere.
Earlier, it was believed that during the initial stages of the formation of the Solar System, the Earth was subjected to an intense bombardment of meteorites and asteroids, which had light elements, mostly carbon, for hundreds of millions of years.
However, the isotopic composition of the most common meteorites-chondrites shows that these elements are too small to initiate the process of the origin of life on Earth.
In a number of practical experiments, scientists replicate the conditions that existed at the surface of the Earth in the presence of high pressure and temperature. By distracting the magma with various compounds, scientists determine when the sulfur level contained in the magma leads to the release of carbon and nitrogen present in the silicate rocks of the outer shell of the Earth.
Armed with this data, scientists have received computer models of about one billion scenarios that describe the formation of volatile components in the Earth's biosphere.
"We have found that all the indicators – the isotope composition, the nitrogen and carbon ratio, and the total amount of carbon, nitrogen and sulfur in the Earth's silicates – do not contradict the magnitude of the collision of our planet with another Mars- there were a lot of sulfur and light elements, "the researchers write.