Science News

Study explains why during ice ages there was less carbon dioxide in the air

Scientists have long since discovered that during the ice ages on Earth the carbon dioxide contained in the atmosphere was regularly lower, by about a third, compared to the warmer phases. There is no complete explanation about this effect and various theories have been created over time to explain their causes.

One of the most popular theories goes back to the oceans: during the cold ages and the ice ages, the seas cooled, more or less at the same rate (their temperature decreased by approximately 2.5 °C) and this caused a greater release of carbon dioxide in the air since the water, when it is colder, shows a greater degree of solubility of the CO2.

However, the models that refer to this theory show that the cooling of the seas was responsible for only a few percentage points with respect to the reduction of carbon dioxide in the atmosphere.
The mystery seems to have been solved by a new study published in Science Advances.

According to Andreas Schmittner, climatologist of the State University of Oregon, in reality the oceans, during the ice ages, would have cooled to a level much higher than previously theorized. The cooling of the water was such that it represented at least 50% of the causes that led to the decrease of CO 2 in the air.

Another third is represented by the increase in iron-laden dust in the seas, which led to an increase in the presence of phytoplankton which absorbed more carbon making it deposit on the seabed.
The seas increased the presence of iron as this, in the form of very fine dust, came from the continents and from the increase in ice in various regions of the world which in turn caused the release of iron from rocks and soil.

Adding together the two factors relating to the seas (cooling and increase in iron dust), we therefore explained, according to this study, at least three-quarters of the causes that led to the increase of CO2 in the atmosphere.

Science News

Mysterious Majoran quasiparticle identified with new system

The mysterious Majoran quasiparticle, also called Majorana fermion, is one of the strangest hypothetical particles ever conceived. It was hypothesized by the Italian physicist Ettore Majorana in 1937 and boasts strange properties including the fact that it is at the same time a particle and its antiparticle so that in certain contexts matter and antimatter can not annihilate themselves and appear as relatively stable couples that can interact even with your environment.

For this reason, in recent years the hypothetical Majorana particle has risen to prominence because it could be used in the context of quantum computing. In a quantum computer based on the Majorana quasiparticles, information would be stored in pairs of particles and the calculations would be determined by the annihilation of the quasi particles with each other depending on how they intertwine. Already in recent years some physicists have declared that they have identified it in some materials. This is the case, for example, of the so-called neutralino, another hypothetical particle of the supersymmetry model that could be a Majorana fermion.

The problem is that it is not possible to manipulate them and create an environment in which to carry out experiments to show their existence with a scientific method.

Now a new study, published this week in Science, proposes a new method for identifying Majorana quasiparticles in materials, as reported by Ali Yazdani, professor of physics at Princeton University and senior author of the study. With this method, according to the physicists who carried out this study, one can “verify their existence by imagining them and we can characterize their expected properties.”

Specifically, physicists have recreated another context in which the Majorana quasiparticle could be identified, that is, in the channel that can be created on the margins of a topological insulator when the latter is put in contact with a superconductor. Since the Majorana particles are formed at the two ends of the wires, it may be possible to visualize them by cutting the wire.

Performing the experiments, the researchers realized that the Majorana quasiparticles appear only when small magnets are magnetized parallel to the direction of electron flow along the channel. The quasi Majorana particle formed with this system is also quite robust according to the researchers, so much so that it resists even the interruption and can be activated and deactivated. The discovery can therefore be an important step forward for the possible use of this particle in the field of quantum computers.

Science News

Scientists delay aging of older mice with molecules taken from young mice

A group of scientists, through research published on Cell Metabolism, announces that they have extended the life span of a group of elderly mice by about 16% by inserting into their bodies a special protein contained in the blood of the youngest mice.

This protein, called eNAMPT (extracellular nicotinamide phosphoribosyltransferase), decreases in blood with age (both in rodents and in people and many other animals) which in parallel increases the health problems typical of old age, such as the weight gain, vision problems and all problems related to cognitive declines.

The eNAMPT protein plays an important role in those cells that produce energy in the body but become less and less efficient. Specifically, these proteins produce a sort of “fuel,” called NAD, which the body uses to remain active at all times. As Shin-ichiro Imai, professor of developmental biology at the University of Washington and senior author of the study, explains, this is a remarkable discovery as it could lead to completely new therapeutic pathways to make bodies healthier during the aging.

The same research group, however, has also experimented with another method to keep NAD levels constant with advancing age which sees the use of a molecule called NMN. Also, in this case, the researchers carried out experiments on mice by giving them this molecule by mouth and obtaining more or less the same effects.

This means, according to the researchers themselves, that the methods for ensuring that NAD levels do not decline ruinously with age are different.