Assessment of relevant factors and relationships concerning human dermal exposure to pesticides in greenhouse applications     

Martínez Vidal JL  Egea González FJ  Garrido Frenich A  Martínez Galera M  Aguilera PA  López Carrique E 《Pest management science》2002,58(8):784-790

Principal component analysis (PCA) was applied to the gas chromatographic data obtained from 23 different greenhouse trials. This was used to establish which factors, including application technique (very small, small, medium and large drop-size), crop characteristics (short/tall, thin/dense) and pattern application of the operator (walking towards or away from the treated area) are relevant to the dermal exposure levels of greenhouse applicators. The results showed that the highest exposure by pesticides during field applications in greenhouses, in the climatic conditions and in the crop conditions typical of a southern European country, occurs on the lower legs and front thighs of the applicators. Similar results were obtained by hierarchical cluster analysis (HCA). Drop-size seems to be very important in determining total exposure, while height and density of crops have little influence on total exposure under the conditions of the present study. No pesticide type is a major factor in total exposure. The application of multiple regression analysis (MRA) allowed assessment of the relationships between the pesticide exposure of the less affected parts of the body with the most affected parts.  相似文献   

The snarls and sneers that keep violence at bay     

Pennisi E 《Science (New York, N.Y.)》2000,289(5479):576-577

The ability to mete out violence appears to be linked to survival in the animal kingdom. But a handful of researchers is now making a persuasive case that scores are settled far more often by subtle, nonviolent signals such as a curled lip or a snarl. Their provocative idea is that inflicting violence on a member of one's own species is a pathological condition that arises when these signals are missed or misinterpreted.  相似文献   

Developmental biology. Embryonic lens prompts eye development     

Pennisi E 《Science (New York, N.Y.)》2000,289(5479):522-523

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Biotechnology. Perseverance leads to cloned pig in Japan     

Pennisi E  Normile D 《Science (New York, N.Y.)》2000,289(5482):1118-1119

Low success rates and unpredictable results have plagued cloning researchers, particularly those trying to clone pigs. Now, on page 1188, Japanese researchers offer the first scientific report of a cloned pig, named Xena, raising hopes that pigs could one day provide an unlimited supply of organs for transplantation thanks to their close physiological relationship to humans. But this week those hopes were dealt a blow by more evidence suggesting that pig retroviruses can infect human cells.  相似文献   

Gene therapy on trial     

Marshall E 《Science (New York, N.Y.)》2000,288(5468):951-957

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FDA halts all gene therapy trials at Penn     

Marshall E 《Science (New York, N.Y.)》2000,287(5453):565, 567

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Intellectual property. NIH cuts deal on use of OncoMouse     

Marshall E 《Science (New York, N.Y.)》2000,287(5453):567

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Evolutionary biology. Twinned genes live life in the fast lane     

Pennisi E 《Science (New York, N.Y.)》2000,290(5494):1065-1066

On page 1151, researchers describe new insights into how genes arise and fuel evolution. By trolling through sequence data for nine very distinct organisms, they have uncovered evidence that genes are copied far more frequently--and the duplicates are lost from the genome far faster--than researchers had thought. What's more, the work suggests that some duplicate genes play a key role in the evolution of new traits and in speciation.  相似文献   

Human genome. Finally, the book of life and instructions for navigating it     

Pennisi E 《Science (New York, N.Y.)》2000,288(5475):2304-2307

The race is over. On 26 June, to much fanfare, two rival teams announced that they had each completed a version of the "book of life"--a rough draft of the complete human genetic code. So what, exactly, is in these two different volumes, and how will they fine-tune it so that everyone from workaday biologists to pharmaceutical giants can mine its gold?  相似文献   

Animal cloning. Clones: a hard act to follow     

Pennisi E  Vogel G 《Science (New York, N.Y.)》2000,288(5472):1722-1727

Often left out of news reports of cloned animals is the fact that for every 100 attempts, just two or three live offspring typically result. Now many researchers are going back to the lab to attempt to find out why. They are probing fundamental questions of cell biology, as well as trying to figure out whether there is something inherently flawed in "asexual" reproduction in mammals, or whether some problem lies in the in vitro component of the process. For now, the serious obstacles suggest that human cloning may be a long way off.  相似文献