منابع مشابه
DDT resistance in flies carries no cost
Mutations that confer pesticide resistance are predicted to carry a cost in the absence of pesticide and consequently not to spread to fixation [1,2]. However, DDT resistance in Drosophila melanogaster (DDT-R) is approaching fixation globally, long after withdrawl of DDT [3]. There are two possible explanations for this. First, other insecticides, to which DDT-R confers cross-resistance [4], ma...
متن کاملresistance of anopheles sacharovi favre to ddt
a.sacharovi, which is one of the main malaria vectors of the palearchic region, is resistant to ddt in greece (1949), lebanon (1954), turkey (1959), syria and the u.s.s.r. (1972).the first record of a. sacharovi resistance to ddt in iran was given in 1959 from the kazeroon area, followed by izeh (1969) and meshkin-shahr (1970).this study (1973) urgently advises speedy measures to eliminate the ...
متن کاملResistance of microbial populations in DDT-contaminated and uncontaminated soils
One DDT-contaminated soil and two uncontaminated soils were used to enumerate DDT-resistant microbes (bacteria, actinomycetes and fungi) by using soil dilution agar plates in media either with 150 mg DDT ml−1 or without DDT at different temperatures (25, 37 and 55◦C). Microbial populations in this study were significantly (p<0.001) affected by DDT in the growth medium. However, the numbers of m...
متن کاملPleiotropic Effects of DDT Resistance on Male Size and Behaviour
Understanding the evolution and spread of insecticide resistance requires knowing the relative fitness of resistant organisms. In the absence of insecticides, resistance is predicted to be costly. The Drosophila melanogaster DDT resistance allele (DDT-R) is associated with a male mating cost. This could be because resistant males are generally smaller, but DDT-R may also alter courtship behavio...
متن کاملAxiom Pinpointing is Hard
We investigate the complexity of several decision, enumeration and counting problems in axiom pinpointing in Description Logics. We prove hardness results that already hold for the propositional Horn fragment. We show that for this fragment, unless p = np, all minimal subsets of a given TBox that have a given consequence, i.e. MinAs, cannot be enumerated in a specified lexicographic order with ...
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ژورنال
عنوان ژورنال: Environmental Health Perspectives
سال: 2003
ISSN: 0091-6765
DOI: 10.1289/ehp.111-a272b