Israeli science in XNUMX

It was an excellent year of interesting, theoretical and experimental scientific developments by Israeli scientists. Below is a representative selection of content. The studies appear in the order of their publication during the year

1. Why do baby dolphins cling to their mother

Prof. Danny Weiss from the Technion found how the dolphin pups stay close to their mother - for physical reasons. Similar to mothers on land who carry Walden in their arms or on their backs in his early years, the dolphin also facilitates the cub's progress to her side, but the way she does it is different.

Weiss found that the dolphin helps the cub to move forward through the Bernoulli effect, which causes a body in the water to be drawn to the area where the water flows; The phenomenon is caused by the drop in pressure in the area where the liquid flows (this is the pressure in the directions perpendicular to the direction of the flow), then the relatively high pressure from the environment where the liquid does not flow pushes the young dolphin into the low pressure area. That is why the body of the puppy is drawn to the proximity of its mother's body which is in motion.

In addition, when the dolphin moves through the water, part of the water mass surrounding it is pushed forward and part back; The young dolphin finds the area where the water moves forward and thus helps him to move forward. In this way the pup gets 50 to 65 percent of the strength it needs to stay close to the dolphin. The cub swims close to its mother for its first three years.

Weiss studied the relationship between mothers and pups for the National Oceanic and Atmospheric Administration, in San Diego, California, with the goal of preventing the capture of baby dolphins by tuna nets. Today it is customary to operate boats near the net in order to scare the dolphins and encourage them to jump over the nets, but the pups stay behind while the mothers jump.

2. Stopping premature aging of cells

Dr. Meir Lahav from the Rabin Medical Center (Bilinson) and Prof. Arnon Nagler from the Sheba Medical Center found a way to stop premature aging of cells. In cells there is a kind of "timer" called a telomere, which is a measure of the number of divisions the cell has undergone. It is found at the end of each chromosome in the cell, and gets shorter with each division.

Certain medical treatments cause accelerated division of the cells, and therefore telomere shortening and premature aging of the tissue: after transplantation, accelerated aging occurs in the transplanted tissue. Even in bone marrow transplantation, an increase in the rate of division of the cells in the transplanted bone marrow is evident.

A similar phenomenon occurs after chemotherapy: any chemotherapy damages the bone marrow, and then as compensation an accelerated division of the stem cells in the bone marrow occurs, which causes premature aging and may even cause the creation of additional malignant tumors. The researchers found the enzyme that causes the shortening of telomeres.

In doing so, they were able to slow down their shortening through the injection of biological growth factors. These substances, which inhibited the shortening of telomeres, prevented the accelerated aging of the treated tissues. Dr. Lahav presented the results of the study at a conference of the American Society of Hematology.

3. Self-organization of particles on a nanometer scale

A mathematical model describing the self-organization of particles on a nanometer scale was developed by Eran Rabani from Tel Aviv University, in collaboration with researchers from the USA. Self-assembly (self-assembly) is a phenomenon that characterizes many systems in nature - chemical, biological and physical - consisting of tiny objects that arrange themselves independently in macroscopic structures such as bubbles, stripes, etc.

Understanding the phenomenon - why a certain spatial order is formed and not another, and whether it can be controlled is important not only from a pure research point of view, but has applied potential in the fields of nanotechnology. The model of Eran Rabani and his research colleagues dealt with a collection of nano-crystals that are inside some liquid, then they are poured onto a substrate and they organize spontaneously into some macroscopic structure while the liquid around them evaporates (see: Eran Rabani - "Self-organization of nanoscale structures", Galileo 64, p. 18).

The model predicts the formation of a certain order based on parameters such as the evaporation rate of the liquid, the forces acting between the crystals and the speed of their movement within the liquid.

4. Translation of neural signals from the brain into movement

A team led by Elon Vadia from the Interdisciplinary Center for Neural Computing at the Hebrew University succeeded in translating neural signals from the brain into movement, and displaying it on a computer screen. This development has the potential to become a useful application for paralyzed people, allowing them to move robotic limbs or communicate through a computer.

The researchers inserted into the motor cortex in the brains of monkeys fine electrodes that do not damage the brain tissue, which picked up the nerve signals that were sent in the cortex of the animal when it made movements with its hand. The researchers were able to identify the electrical signals that characterize certain movements. In this study, only gross movements were detected; In order to enable fine motor skills, additional research work will be required.

5. Tracing the recovery of the peripheral nervous system

And another preliminary study, the results of which may, in the future, help to heal nerve damage: Michael Feinzylver and colleagues from the Weizmann Institute of Science traced the recovery process of the peripheral nervous system. Nerve fibers (axons) of the central nervous system (cranial brains and spinal cord) do not regenerate after an injury.

Peripheral nerve cysts, on the other hand, are able to heal, but sometimes their recovery is partial and slow. The researchers tried to locate the process related to the healing of damaged nerve fibers, and partially identified the proteins involved in the process and where they are secreted in response to injury. The complete identification of the proteins, as well as the genes active in the recovery process, is the next step. The goal is to improve the regeneration of peripheral nerves, and possibly apply their recovery process to nerve damage in the central nervous system as well.

6. How the predatory bacteria works

Alon Mozes from the Hadassah Medical Center, and Emanuel Hansky and Carlos Hidalgo-Grass from the Hebrew University deciphered the mechanism of action of the "predatory bacterium" Streptococcus A. This is a bacterium that causes "shushna" (a skin disease) and strep throat in mild cases. When it penetrates the lungs, bloodstream, muscle or fat tissue - it can be fatal.

The "Toxic Shock Syndrome", which manifests itself in the drop in blood pressure and multisystem damage, and the "Predatory Bacteria Syndrome", which manifests itself in the rapid destruction of tissues, are both caused by Streptococcus A. The researchers sought to find what makes the bacterium so virulent. They found that the cells of the immune system, whose high concentration is often found near a foreign body, are not in the environment of the bacteria; The immune system avoids attacking the predatory bacteria in the same way it attacks other invaders.

The reason for this, the researchers found, is a mutation identified in the bacterium, which causes it to produce a protein that breaks down one of the substances secreted by the infected tissue and whose purpose is to recruit the cells of the immune system. Therefore, the cells that aim to destroy the bacteria do not reach the tissue. In this study it was not found what causes the mutation and why only some of the Streptococcus A bacteria become predators.

7. The mechanism of flower growth

Alon Samach from the Faculty of Zoology of the Hebrew University, in collaboration with a group from Germany, identified the mechanism that causes plants to bloom depending on the number of hours of daylight per day and the intensity of the sunlight. The scientists used the Arabidopsis plant, which is used in many studies and is the first plant whose genome has been fully deciphered.

The researchers focused on the effect of the duration of light, its wavelengths and its intensity - which are absorbed through light receptors in the plant - on the stability of the protein responsible for flowering. The constance protein, which triggers the flowering, is produced by a gene whose activity is different during the day and night. Its activity is especially high about 12 hours after dawn. It follows that on short days it is only active in the dark, while on longer days it is active even before dark.

In the dark, a mechanism is activated that breaks down the protein, and therefore its accumulation - which triggers the flowering - is possible only in long enough days when the gene is active even before nightfall. Also, the researchers found that the wavelength of the light affects the breakdown of the Constance protein; Red light, for example, prevents the breakdown of the protein and therefore encourages flowering. This discovery makes it possible to influence the flowering times of plants by controlling the amount of light and the wavelengths.

8. Characterize the gambler

A study aimed at characterizing compulsive casino gamblers in Israel was conducted at Ben Gurion University of the Negev. The researchers focused on the individual and his subjective experience, with the intention of understanding the process that causes him to become a compulsive gambler. The researchers found that the compulsive gamblers start from a feeling of nothingness that comes from difficult experiences they had in their childhood or adulthood.

Gambling gives them the "king experience" - the feeling of power and aggrandizement that accompanies gambling, which leads them to addiction. Addicts continue to gamble despite the heavy financial and family cost, until the "king's illusion" is shattered. A better understanding of the psychological factors and reasons leading to gambling addiction is important in view of the expansion of the scope of activities of casinos in Israel, and the need to build a rehab program for addicts.

9. Drive through the vacuum

Physicist Alexander Feigel from the Weizmann Institute of Science proposed a way to move small objects using vacuum energy. It is accepted today that empty space also contains energy, known as "empty energy", and it is made possible by quantum mechanics. The idea is based on the momentum of virtual photons - the carriers of the electromagnetic force. An electromagnetic field can be seen as a "sea" of virtual photons.

Feigel claimed that the object immersed in this "sea" would receive momentum from the virtual photons, and the direction of the momentum would depend on the direction of the field. The claim is actually equivalent to the statement that the void can have momentum, which will be transferred to the bodies that are in it. It is worth noting that this does not contradict the laws of conservation of momentum and energy. This is an idea that may be useful in applications involving very small amounts of material.

If the experiment goes ahead, it won't be the first time that vacuum energy has been converted into a measurable force. This has already been done based on a phenomenon known as the Casimir effect. The Casimir effect is based on the fact that empty space is full of energy: two parallel plates are placed next to each other, which causes destructive interference of some of the wavelengths of the electromagnetic spectrum in the space between the plates. Therefore the "radiation pressure of the vacuum" outside the plates, where all the wavelengths exist, is less than the pressure between them, and a measurable gravitational force acts between the plates.

10. Degenerative brain diseases

Initial experiments - so far only in mice - were conducted with a new substance that prevents free radical damage to cells. Dafna Atlas from the Hebrew University, Daniel Ofen from Tel Aviv University and Eldad Melamed from the Rabin Medical Center developed a substance known as 4AD for the treatment of degenerative brain diseases. At the beginning of the research, a number of substances were developed, which were intended to be chemically close to the natural substances that protect the cells from oxidative damage.

Among this group of substances, AD4 has been tested for toxicity and found to be completely non-toxic. The substance penetrates the brain through the septum that separates it from the rest of the body, then into the cells, where it neutralizes free radicals, which probably play a role in causing degenerative brain diseases such as Alzheimer's, multiple sclerosis and Parkinson's. In experiments conducted on mice, which show symptoms similar to those of humans, it was found that the new substance causes a reduction in the symptoms of the disease and a decrease in the amount of enzymes that destroy the damaged cell walls.

11. An improvement to the electron microscope

The Israeli company Quantumix (QuantomiX), founded by members of the Weizmann Institute of Science, presented at a biotech conference held in May 2004 an improvement to the electron microscope: now it is possible to observe with the help of an electron microscope even a wet sample, which is a substantial improvement for researchers in the life sciences.

An electron microscope "observes" using an electron beam and not a light beam, thus achieving a higher resolution (resolution). In order not to interfere with the passage of electrons, the sample needs to be found in a vacuum, so the microscope is only suitable for solid samples. Until now, researchers had to dry their samples and watch them in order to keep their shape during the viewing process, thus changing their properties.
The company presented a box (capsule) made of a thin and strong membrane, transparent to the electron beam of the microscope. The wet sample is housed in its natural state in a box, which is strong enough to withstand the pressure difference between its contents and the vacuum environment of the microscope.

The material from which the box is made was developed precisely within the framework of research in the field of semiconductors. This application has many uses, and one of them, which resulted in a collaboration with the Obesity Research Institute in Boston, is related to measuring the size of a fat particle in blood vessels.

12. Improved underwater photography

Yoav Shechner and Nir Karpel from the Technion developed a method for underwater photography, which allows greater sharpness than before and estimation of distances under water. The method overcomes the optical disturbance created by the water by combining a physical means - a special filter connected to the camera - and correction using a mathematical algorithm. This method has the potential to help those involved in underwater research, mapping and maintaining underwater structures.

12. What to do with the decrease in solar radiation

Researchers from the Volcanic Institute in Beit Dagan, led by Jerry Stanhill, were among the first to identify a global trend: the intensity of solar radiation reaching the Earth (in a wide range of wavelengths) has decreased in recent years. In Israel, there was a decrease of about 20% in the intensity of radiation during the last fifty years.

The Israeli researchers presented the results of their research at a conference held by the geophysical societies of the United States and Canada in May 2004, in Montreal, Canada. The findings from around the world indicate that this is a global trend, although it is not clear what the dimensions of the phenomenon are.

Since the measurements are carried out over periods of years, it is possible that differences in the quality of the measurement are distorting the data. Even if there are any flaws in the measurement, it is evident that this is a global phenomenon: in Russia, a decrease of about 20% in the radiation intensity was also observed; In Hong Kong there was a decrease of 37%, while in other regions of the world the decrease reaches only 10 percent.

The reasons for the decrease in radiation intensity are not fully understood, but it is assumed that the reason is air pollution, which interferes with the passage of the sun's rays through the atmosphere and changes the properties of the clouds. There is a suspicion that global warming, which creates increased evaporation and therefore thicker clouds, is also among the causes of the phenomenon. The reason is not related to the sun itself, whose strength, as measured by satellites, has not undergone any change.

13. Laser for detecting bombs and drugs

The Israeli company ITL, which specializes in the production of optical systems for security agencies around the world, has developed a prototype of a device that uses a laser beam for the identification of explosives and drugs from a distance. The device is based on spectrometry, which is also used to identify the materials found in distant stars. The laser beam, which is not harmful to a person, damages the object or the person being tested, which can be found at a distance of several meters or tens of meters from the system.

The impact of the radiation on the chemical substances causes them to emit back radiation at unique frequencies that are absorbed by the system and enable the identification of dangerous substances that have adhered to the subject's body. This technology could be an automatic and fast replacement for the manual security check currently accepted. In addition to the security uses, it will be possible to use the facility to test the composition of materials for various civilian uses, such as medicines.

14. Insect repellent packaging

Collaboration between researchers from the Volcanic Institute, Hamma Mashgav and the "Bio-Pak" company resulted in a useful development in the food industry: insect report packaging. The repellent is produced from a plant extract that is not harmful to humans, but repels the insects that may penetrate the contents of the package during storage.

The beginning of the idea is the custom of rural farmers to scatter leaves and fruits of azadrach near the grain, in order to protect it from pests. Fadel Mansour and Shlomo Navarro from the Volcanic Institute found that extracts of many other plants, besides azadrachta, can be used to repel various insects.

The plants used for the industrial production of the packaging are extracted from edible plants and are not toxic to humans. The plant extracts are inserted into the plastic material from which the packaging is made, without damaging the desired properties of the extract. The size of the potential market was estimated by the company at tens of billions (!) of dollars.

15. The relationship between noise and matter

Adi Shamir and Eran Trumer from the Weizmann Institute of Science found a connection between the noises made by the computer while it is working and the content of the processed material: the processors of computers performing encryption make sounds through which information about the encrypted material can be obtained. Theoretically, this could make it significantly easier for those who would try to break into a computer in order to obtain sensitive information.

These are loud sounds made by the processor, which can be easily separated from other noises, such as the noise of the fan in the computer body. Different encryption keys are characterized by different sound frequencies, and character strings of different lengths are reflected in sounds of different durations, due to the different time required for encryption.

This is not the only unconventional way of extracting sensitive information from computers: it is already known that it is possible to restore, at least partially, what is displayed on the computer screen by reflecting the light from the wall behind the screen, or by monitoring the electromagnetic radiation emitted by the screen.

16. A fateful memory

Collaboration between researchers from Tel Aviv, Bar Ilan and Columbia universities led to the identification of a mechanism related to the formation of long-term memory. It is now accepted that learning involves the creation of new nerve junctions (synapses) between nerve cells. Malka Cohen-Aramon discovered several years ago that electrical stimulation of nerve cell membranes in the cerebral cortex immediately triggers a reaction (polyADP-ribosylation) in the cell nucleus, as an alarm mechanism in the event of damage to the cell, which allows the DNA to be exposed to proteins that repair the damage caused to it.

In later work with James Schwartz of Columbia University, Cohen-Aramon discovered that this process is also related to the construction of long-term memory - where the DNA is apparently exposed and becomes accessible for transcription, which is necessary for the construction of the new nerve junctions. The research continues in Israel with researchers from Tel Aviv University and Bar Ilan who performed experiments on the "sea rabbit", a marine snail used in research on learning and memory.