| 1. |
- Anderbrant, Olle, et al.
(författare)
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Field response of the pine sawfly Neodiprion sertifer to controlled release of diprionyl acetate, diprionyl propionate and trans-perillenal
- 1992
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Ingår i: Journal of Chemical Ecology. - 0098-0331. ; 18:10, s. 1707-1725
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Tidskriftsartikel (refereegranskat)abstract
- Two dispenser types for pine sawfly (Hymenoptera: Diprionidae) pheromones-glass capillaries and dental cotton rolls-are described, and release rates reported. Glass capillaries of different diameters were used in field tests to determine dose-response relationships of (2 S,3 S,7 S)-3,7-dimethylpentadecan-2-yl acetate (diprionyl acetate), diprionyl propionate, and trans-perillenal on the trap catch of male Neodiprion sertifer. A linear relationship between the logarithm of the capillary cross-sectional area and the logarithm of the release rate was found. However, capillaries of the same diameter could vary in the amount released by as much as a factor of 10. Both the acetate and propionate were attractive alone, but no synergistic effect was found. trans-Perillenal did not show any behavioral activity. Dental cotton rolls have been used extensively in diprionid pheromone research without knowledge about release rates. The release rate from rolls loaded with different amounts of diprionyl acetate was determined by extracting rolls after different times under constant temperature and wind conditions or after use in field tests. Quantification of diprionyl acetate was done on GC. The release rate was found to be proportional to the amount applied over several orders of magnitude, and persisted for several weeks. Capillaries and rolls with similar release rates caught similar numbers of sawflies.
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| 2. |
- Anderbrant, Olle, et al.
(författare)
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Field response of the pine sawfly Neodiprion sertifer to the pheromone (2S, 3S, 7S)‐diprionyl acetate and its stereoisomers
- 1992
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Ingår i: Entomologia Experimentalis et Applicata. - : Wiley. - 0013-8703. ; 62:2, s. 169-181
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Tidskriftsartikel (refereegranskat)abstract
- All eight optical isomers of 3,7‐dimethyl‐2‐pentadecanyl acetate (diprionyl acetate), of high optical purity (>97.4%), were tested for a behavioural activity on male pine sawflies, Neodiprion sertifer (Geoffr.) (Hymenoptera: Diprionidae), in northern Europe. Males were strongly attracted to (2S, 3S, 7S)‐diprionyl acetate. Addition of more than 0.1% of the (2S, 3R, 7R)‐isomer reduced the catch and above 2% the attraction was completely inhibited. Contrary to what has been reported for North American and Japanese populations, so significant synergistic effect of small amounts of the (2S, 3R, 7R)‐isomer could be demonstrated. The effects of addition of the other six optical isomers alone or in combinations, were also studied, but none was found to be a synergist. The (2S, 3R, 7S)‐isomer had a weak inhibitory effect, and completely inhibited the attraction to the (2S, 3S, 7S)‐isomer when applied in about equal amounts as the attractant. In some cases a reduction in catch was noted when other isomers were tested, but this could be attributed to the very small amounts of the inhibitory (2S, 3R, 7R)‐isomer present in these isomers. 1992 The Netherlands Entomological Society
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| 3. |
- Bengtsson, Marie, et al.
(författare)
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Structure-activity relationships for chain-shortened analogs of (Z)-5-decenyl acetate, a pheromone component of the turnip moth, Agrotis segetum
- 1990
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Ingår i: Journal of Chemical Ecology. - 0098-0331. ; 16:3, s. 667-684
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Tidskriftsartikel (refereegranskat)abstract
- Structure-activity relationships for chain-shortened analogs of (Z)-5-decenyl acetate, a pheromone component of the turnip moth, Agrotis segetum, have been studied by electrophysiological single-sensillum technique and interpreted in terms of a previously reported receptor-interaction model. The results indicate that the terminal methyl group, as well as the acetate group, interacts with highly complementary receptor sites. The terminal alkyl chain is suggested to interact with a hydrophobic "pocket" extending over the two methylene groups closest to the terminal methyl group. The amounts of stimulus actually released from the odor source have been studied. The results demonstrate the necessity to take differences of volatility into account in comparisons of electrophysiological data for compounds of different chain lengths. It is shown that relative vapor pressures may to a good approximation be employed to estimate correction factors.
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| 4. |
- Löfstedt, Christer, et al.
(författare)
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Pheromone differences between sibling taxa Diachrysia chrysitis (linnaeus, 1758) and D. tutti (Kostrowicki, 1961) (Lepidoptera Noctuidae)
- 1994
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Ingår i: Journal of Chemical Ecology. - 0098-0331. ; 20:1, s. 91-109
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Tidskriftsartikel (refereegranskat)abstract
- The noctuid sibling taxa Diachrysia chrysitis s. str. and D. tutti, of yet uncertain taxonomic status, have previously been shown to possess differences in morphology and to be attracted to different mixtures of the two presumed pheromone components (Z)-5-decenyl acetate and (Z)-7-decenyl acetate. Typical D. tutti males (clearly broken forewing marking) are known to respond to a 2: 100 mixture of the two isomers, whereas D. chrysitis males (unbroken marking) are attracted to a 100: 10 mixture. We investigated female pheromone production and male electroantennographic (EAG) response in Diachrysia families raised in the laboratory from field-collected gravid females. Extracts of individual females from typical D. tutti and D. chrysitis families were subjected to gas chromatography with simultaneous flame ionization and electroantennographic detection. All females produced mixtures of Z5- and Z7-10:OAc, but female D. chrysitis produced predominantly Z5-10:OAc and the antennae of their brothers responded more strongly to the Z5 peak than to the Z7-10:OAc peak, whereas the opposite was true for D. tutti families. The pheromone components were shown to be biosynthesized from hexadecanoic and tetradecanoic acid, respectively by Z11-desaturation followed by chain shortening, reduction, and acetylation. The EAG responses of males trapped with the typical D. tutti and D. chrysitis blends, as well as with an intermediate blend, were investigated. Males trapped with the D. tutti mixture almost exclusively had a clearly broken wing marking and showed strongest EAG response to Z7-10:OAc. The intermediate blend and the D. chrysitis mixture gave more mixed catches, but with a prevalence of males with an unbroken (or almost unbroken) wing marking and with a higher mean response to Z5-10:OAc. Some males with typical D. tutti EAG responses were attracted in the field to the D. chrysitis pheromone. In the flight tunnel some D. chrysitis males were attracted also to the D. tutti mixture. This indicates that cross attraction may take place between the two taxa under natural conditions.
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| 5. |
- Svahn, Gudmund, et al.
(författare)
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PACS for radiology conferences--improvement of application software
- 1994
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Ingår i: Computer Methods and Programs in Biomedicine. - 0169-2607. ; 43:1-2, s. 81-84
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Tidskriftsartikel (refereegranskat)abstract
- The introduction of PACS in a radiology department means that most functions that are available in the film-based system must be included. One important function is the radiology conference. The handling and application programs of digital workstations are normally not developed for demonstrations of many images in a limited time. This paper describes a workstation with specially designed software for radiology conferences. The application is separated in preparation and presentation of the cases to be demonstrated. Very fast image handling is achieved during the conference because the function is based on the principle of prefetching of the selected images. The images are presented on a large screen with high resolution. The experiences of digital radiology conferences are good. However, reference films from previous examinations create extra work because they have to be shown on the conventional lightbox.
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| 6. |
- Wu, Wen-Qi, et al.
(författare)
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Electrophysiological and behavioral responses of turnip moth males, Agrotis segetum to fluorinated pheromone analogs
- 1993
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Ingår i: Journal of Chemical Ecology. - 0098-0331. ; 19:1, s. 143-157
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Tidskriftsartikel (refereegranskat)abstract
- The electrophysiological and behavioral responses of male Agrotis segetum to fluorinated analogs of (Z)-5-decenyl acetate (Z5-10:OAc) were investigated. The single sensillum recordings showed that 4,4-difluoro-(Z)-5-decenyl acetate (4,4-F2), 7,7-difluoro-(Z)-5-decenyl acetate (7,7-F2), 10,10,10-trifluoro-(Z)-5-decenyl acetate (10,10,10-F3) and 7,7,8,8-tetrafluoro-(Z)-5-decenyl acetate (7,7,8,8-F4) were each 100-fold less active than the natural Z5-10 : OAc, whereas the 7,7,8,8,9,9,10,10,10-nonafluoro-(Z)-5-decenyl acetate (F9) analog was essentially inactive. A mixture of Z5-10 : OAc, Z7-12 : OAc, and Z9-14 : OAc on a filter paper dispenser was as attractive as female gland extracts when tested in a flight tunnel. With Z5-10:OAc omitted, the two-component mixture elicited a significantly lower male response. Four analogs, 7,7-F2, 10,10,10-F3, 7,7,8,8-F4, and F9, were added separately to the two-component mixture to replace Z5-10:OAc. The responses elicited by the mixtures containing the 7,7-F2, 10,10,10-F3, and 7,7,8,8-F4 analogs did not differ significantly from that of the natural three-component mixture and the two-component mixture, whereas the mixture containing F9 elicited a significantly lower male response, as low as the response to the two-component mixture. In a field test the mixtures containing 10,10,10-F3 and 7,7,8,8-F4 were significantly more active than the two-component mixture, but still less active than the natural three-component mixture. It appears that field tests provided greater discrimination among pheromone analogs in assessing their behavioral activity than the flight-tunnel test did. Structure-activity analyses demonstrate the importance of the lipophilic interaction between the terminal alkyl chain and the receptor site for the activity of the stimulus. The lipophobicity of the fluorinated analogs impedes a productive receptor interaction.
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