El Niňo Is Good News For Israel

English

El Niňo, the periodic abnormal warming of surface water in the eastern equatorial Pacific, has long been notorious for the devastation it often inflicts on South America. But now it appears that its effects reach as far as the Middle East -- and surprisingly, they may actually be positive.

By studying tree rings, satellite cloud images and rain water, an Israeli research team led by the Weizmann Institute's Dr. Dan Yakir has discovered a striking correlation between El Niňo and rainfall in central Israel over the past 20 years: between 1975 and 1995, winters with above-average rainfall coincided with El Niňo events, while relatively dry winters coincided with below-average ocean surface temperature in the eastern equatorial Pacific. The researchers also found that El Niňo-associated variations in Israel's rainfall were significant for local plant growth.

Going back in history, the scientists noted that no El Niňo events were recorded during the decade-long drought that affected Israel in the 1930s. "And even further back in time, could it be that Pharaoh's seven bad years reflected an ancient period devoid of El Niňo events?" asks Dr. Yakir, referring to the major famine recounted in the Bible's book of Genesis.

If these findings are confirmed, it may be possible to take advantage of El Niňo forecasts to predict rain patterns in Israel more than a year in advance, which would be a great boon to Israel's water management and agriculture.
Environment
English
  • Climate record
  • Dan Yakir
  • Environmental Sciences and Energy Research

Nothing To Sneeze At

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A gene responsible for producing a protein that blocks allergic reactions has been discovered and studied by a team led by Prof. Israel Pecht of the Institute's Immunology Department.

In an allergic reaction, an allergen such as pollen triggers the immune system to respond abnormally, setting off a series of molecular processes that cause mast cells on the surface of the lungs, nose and other tissues to release chemicals. The result: the familiar bouts of wheezing, sneezing, or other reactions.

Pecht's team discovered that when molecules of a certain protein found on the membranes of these mat cells group together, they can interfere with the biochemical processes that lead to an allergic reaction. The scientists studied the structure of this protein, known as mast-cell-function-associated antigen (MAFA), and the gene responsible for its production, and found that it probably plays a role in intercellular communications.

In the future, it may be possible to prevent allergic reactions by designing medications that mimic the action of MAFA.
Life Sciences
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  • Allergy
  • Antigen
  • Immunology
  • Israel Pecht

Research on a Potential Cancer Vaccine

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A synthetic vaccine produced at the Weizmann Institute stopped lung cancer from spreading in mice and offers hope as a potential treatment form human cancers.

One of the major problems in cancer is that the immune system does not react to tumors with sufficient vigor, eventually enabling the cancer to overrun the body. With this research, the scientists appear to have found a way to prompt a stronger response from the immune system.

Prof. Lea Eisenbach and her colleagues in the Institute's Immunology Department discovered that connexin-37, a protein normally present in lung cells, contains a mutation in cancerous cells. When they injected mice with the mutant protein, the animals' immune systems produced white blood cells known as cytotoxic T lymphocytes that attacked and killed the cancerous cells.

The scientists developed a synthetic vaccine from this compound and found that it not only protected mice with cancer from the further spread of tumors but reduced the number of existing tumors. In experiments, some of the vaccinated mice were still alive more than a year later, while untreated mice died after a month.

If developed for human cancer therapy in the future, such vaccines could be particularly useful for mopping up the tiny tumors that often remain after surgeons have removed the main growth.
Life Sciences
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  • Cancer
  • Immunology
  • Lea Eisenbach
  • Vaccine

3-D Glasses for Robots

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The trouble with many robots and other automated systems equipped with artificial vision is that their eyes "see" the world as two-dimensional. As a result, they have great difficulty in assessing the relative positions of objects. Existing ways for robots to reconstruct 3-D images tend to be slow and cumbersome, but two Weizmann Institute physicists have developed a 3-D imaging technique that greatly speeds up and simplifies this process.

The system -- developed by Drs. Daniel Zajfman and Oded Heber of the Particle Physics Department -- uses two regular video cameras, a light source and a transparent fluorescent screen placed between the cameras and the object to be filmed. When light is reflected off the object, it strikes the screen and creates a flash that the cameras record along with the image of the object.

One camera films continuously, while the other has a shutter that opens for only a billionth of a second at a time, registering just a tiny fraction of the light particles emitted by the flashes. Because both the speed of light and the time it takes for the flashes to fade on the screen are known, it is possible to determine the exact distance between the screen and each point on the object's surface. This information, in turn, is combined with data from the 2-D picture to form a 3-D image.

The new 3-D imaging system can be applied in such diverse fields as aerial photography, cartography and surveying.
English
  • Daniel Zajfman
  • Particle Physics
  • Robot
  • Vision