Israeli teens who won top prizes in the Intel Israel Young Scientists Competition last March have now won second and fourth prizes in two categories at the Intel International Science and Engineering Fair competition of 1,500 youths from 50 countries that was held in Reno, Nevada, this week. Shira Ahissar of Rehovot's Aharon Katzir School, who researched logical thinking in people with schizophrenia, won second prize in the behavioral science category. Shahar Gvirtz and Yadid Algawi of the Dan Region Amit School - who used a home microwave oven and dried Fistia and Salvinia aquatic plants to remove most of the lead contaminants from water - came in fourth place in the category of research teams. The inexpensive technique can be adapted to commercial use, including the cleaning of waste water for industry, urban gardening, agriculture and electric power production, they told The Jerusalem Post during the Jerusalem competition. The Intel International Science and Engineering Fair is the largest and most important of youth competitions in scientific and engineering research. More than a fifth of those who participate apply for or register patents for their ideas. Ahissar took second place in the Intel-Israel competition organized by the microprocessor development and production company and Jerusalem's Bloomfield Science Museum. Gvirtz and Algawi won first place in the Israeli competition; all three received their prizes at Beit Hanassi from President Shimon Peres on the anniversary of Albert Einstein's birth. "Big ideas start in giving an equal chance to everyone. The competition gave these pupils a change to go out on a wonderful mission of scientific discovery, and we are proud of their achievements," said Intel Israel general manager Maxine Fassberg, who also is an Intel Corporation vice president. The Israeli winners would inspire others to follow in their footsteps, she said. A workshop by outstanding science teachers from around the world on teaching through projects was held in parallel; the Israeli representatives were Dr. Eli Eisenberg of ORT, Dr. Anna Heller of the Herzliya Sciences Center and Dr. Amnon Yosef of the Lehman High School in Dimona.