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Airborne concentrations of 8 polycyclic aromatic hydrocarbons (PAHs): fluoranthene, Flt, Pyrene, Pyr, benzo(a)anthracene, BaA, chrysene, Chr, benzo(b)fluoranthene + benzo(k)fluoranthene,B(b + k)F, benzo(a)pyrene, BaP and benzo(g,h,i)perylene, B(ghi)P,were measured in Jinámar, a small town on the island of Gran Canaria (Spain) during a 12 month period (January 1995–December 1995). Concentrations ranged between 0.613 ng m-3 for B(ghi)P and 0.040 and 0.046 ng m-3 for pyrene and chrysene. Except for BaA all PAHs occurred at lower concentrations at temperatures below 20 °C. Relative humidity seems to influence concentrations of pyrene, chrysene, benzo(b + k)fluoranthene and benzo(a)pyrene, also affecting the latter ina different way to the other three hydrocarbons cited.  相似文献   
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Water, Air, &; Soil Pollution - In the last 20&;nbsp;years, a new generation of materials was developed: the biodegradable plastics. They reduce the accumulation of plastic in the environment...  相似文献   
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Anoplocephala perfoliata (Cestoda, Cyclophyllidea), the commonest intestinal tapeworm of horses, can cause colic, intussusceptions, ileal impactions and intestinal perforations. Common diagnostic techniques for A. perfoliata infection, i.e. coprology and serology, show inherent limitations in terms of sensitivity and specificity and new approaches are thus required. Hence, the present study compared the reliability of coprological, serological (i.e. ELISA) and molecular (i.e. nested PCR) methods in detecting A. perfoliata infection in naturally infected horses and in horses treated with a combination of ivermectin and praziquantel. Of 42 horses subjected to coprological examination, 16 and 26 resulted negative and positive, respectively for the presence of A. perfoliata eggs at the coprological examination. The 26 coprologically positive animals were also positive by nested PCR. Fifteen out of the 16 horses coprologically negative were negative at the molecular assay, while one yielded a PCR product detectable on an agarose gel. Eighteen out of 26 positive horses were treated with a combination of ivermectin 18.7 mg/g and praziquantel 140.3mg/g and resulted subsequently negative by coprology and nested PCR performed 2 weeks after treatment. All infected and untreated animals had a high ELISA test optical density indicating high infection intensity and associated risk of colic. However, high optical density values were also obtained in four horses post-treatment and in three horses that were negative on molecular and coprological analysis. The results of the present work indicate that the nested PCR assay represents a valid method for the specific molecular detection of A. perfoliata in faecal samples collected from naturally infected horses and may have advantages over coprological and serological approaches for diagnosing A. perfoliata infection.  相似文献   
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This study is the first report of combining ability and heterosis for important vitamins and antioxidant plant pigments in cauliflower. Five CMS lines were crossed with 8 male fertile lines in line × tester design to develop 40 hybrids. These hybrids along with parental lines were evaluated for different vitamins and anti-oxidant pigments to reveal extent of heterosis and genetic combining ability. The CMS line Ogu12A was good general combiner (gca effect) and Ogu16A was poor general combiner for most of the important traits under study. Most of the heterotic hybrid combinations were associated high specific combing ability (sca effect). However, gca effect was also important in developing quality heterotic hybrids. The proportions of $\sigma_{\text{gca}}^{ 2} /\sigma_{\text{sca}}^{2}$ were less than unity in all the cases indicating the role of non-additive gene action for most of the traits. Highest number of heterotic hybrids in positive direction was recorded for ascorbic acid content followed by anthocyanin content. The accumulated average heterosis of the 40 hybrids was in positive direction for ascorbic acid, anthocyanin and lycopene concentration whereas it was in negative direction for carotenoids and chlorophyll pigments. Very high heterosis for ascorbic acid, anthocyanin and carotenoids in cauliflower indicated the scope for development of F1 hybrids with higher concentration of these vitamins and anti-oxidant pigments. It is possible to develop heterotic hybrids for different vitamins and anti-oxidant plant pigments through selection of parental lines based on desirable genetic combing ability.  相似文献   
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