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  • 1
    Electronic Resource
    Electronic Resource
    Temporal snychrony and patterns in an exotic host-parasitoid community (1994)
    Springer
    Oecologia 100 (1994), S. 196-199 
    Details
    ISSN: 1432-1939
    Keywords: Braconidae ; Tephritidae ; Temporal ; Synchrony
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We studied an imported host-parasitoid community in Hawaii, asking to what extent the species covaried in a systematic fashion even though all species were exotic to Hawaii, and occurred in an artificial agroecosystem (a commercial guava, Psidium guajava L., orchard). Using knock-down pyrethrin sprays we were able to accurately quantify numbers of the host, [oriental fruit fly, Bactrocera dorsalis (Hendel)] and its four major parasitoid species [Biosteres arisanus (Sonan), Diachasmimorpha longicaudata (Ashmead), Psyttalia incisi (Silvestri), and Bi. vandenboschi (Fullaway)] at hourly intervals. We found that the parasitoids' activity and abundance was well correlated with the activity and abundance of their host, and that all four parasitoid species covaried in concert with one another. In fact, the magnitude of correlation between the different species in this system was greater than the correlation with temperature. This show clearly that an entirely exotic community, reassembled piecemeal as a result of biocontrol efforts, can end up with patterns of temporal covariation that are highly coincident. One other interesting result concerns the speed with which sprayed trees were recolonized by the fruit fly and its parasitoids. The time that it took each species to reach its mean density prior to removal by the first pyrethrin spray at 0600 hours varied. It took 2 h for female B. dorsalis to recolonize guava trees to pre-spray levels. It took 3 h for Bi. arisanus, 4 h for D. longicaudata, 7 h for Bi. vandenboschi and 14 h for P. incisi to reach pre-spray levels. The fact that Bi. arisanus recolonized vacant trees almost as rapidly as did the fruit fly pest suggest that there is little opportunity for the fruit fly to escape in space and time by “staying one step ahead of its enemies”.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317147
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  • 2
    Electronic Resource
    Electronic Resource
    Kinetics of ion transport in lipid membranes induced by lysine-valinomycin and derivatives (1979)
    Springer
    European biophysics journal 6 (1979), S. 39-56 
    Details
    ISSN: 1432-1017
    Keywords: Lipid membranes ; Valinomycin ; Ion transport ; Fast kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Summary Lysine-valinomycin and two N∈-acyl derivatives are compared with respect to their potency to transport Rb+ ions across thin lipid membranes. Lysine-valinomycin acts as a neutral ion carrier only above a pH of about 7 of the aqueous solutions, while at lower pH the molecules seem to be positively charged due to a protonation of the ε-NH2 group of the lysine residue. A kinetic analysis based on voltage jump relaxation experiments and on the nonlinearity of the current-voltage characteristics showed that the conductance increment λ per carrier molecule for uncharged lysine-valinomycin is similar to that of natural valinomycin. The attachment of a rather bulky side group such as the dansyl or para-nitrobenzyloxycarbonyl group reduced λ by approximately one order of magnitude. Some of the relaxation data of the valinomycin analogues were influenced by an unspedfic relaxation of the pure lipid membrane. This structural relaxation represents a limitation to the possibility of analyzing specific transport systems in thin lipid membranes by the voltage jump or charge pulse techniques. It is shown that the time dependence of this structural relaxation — which was first published by Sargent (1975) — is at variance with a three capacitor equivalent circuit of the membrane, which was suggested by Coster and Smith (1974) on the basis of a.c. measurements. A modified equivalent circuit has been found to represent a satisfactory analogue for the current relaxation in the presence of valinomycin. It turned out, however, that such an equivalent circuit provides little insight into the molecular mechanism of transport.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00537594
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  • 3
    Electronic Resource
    Electronic Resource
    Optical and electrical studies on dansyllysine-valinomycin in thin lipid membranes (1976)
    Springer
    European biophysics journal 2 (1976), S. 119-137 
    Details
    ISSN: 1432-1017
    Keywords: Valinomycin ; Lipid membranes ; Fluorescence ; Relaxation methods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Summary Dansyllysine-valinomycin, a fluorescent analogue of the ionophore valinomycin was synthesized and incorporated into black lipid membranes. Its concentration inside the membrane was measured fluorometrically and was also determined from electrical relaxation experiments, which were analyzed on the basis of a previously proposed carrier model. The results of both methods agreed within less than one order of magnitude. This appears satisfactory in view of the sources of error inherent in both procedures. A conductance increment per carrier molecule of about 3 · 10−17 Ω−1 was obtained for dansyllysine-valinomycin in diphytanoyllecithin membranes at 25
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00863705
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  • 4
    Electronic Resource
    Electronic Resource
    Indium-based liquid clathrates. II. Inclusion compounds derived from salts of the tetrachloroindate anion, InCl 4 − , and the crystal structure of [Li·15-c-5] [In(CH3)3Cl] (15-c-5=15-crown-5) (1987)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 5 (1987), S. 683-688 
    Details
    ISSN: 1573-1111
    Keywords: Liquid clathrate ; indium ; crystal structure ; crown ether
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Indium(III) chloride reacts with 12-c-4 to give the 1:1 adduct [InCl3·12-c-4]. This complex is a convenient In precursor to liquid clathrates. [InCl3·12-c-4] reacts with LiCl to form [Li·12-c-4] [InCl4]. When the reaction is carried out in the presence of an aromatic solvent such as toluene, a liquid inclusion complex forms readily. It has been determined that the C6H5CH3:[Li·12-c-4] [InCl4] ratio is 2. Alkylation of the 15-c-5 adduct of InCl3 with methyllithium yields [Li·15-c-5] [In(CH3)3Cl]. The salt fails to form inclusion complexes with aromatic molecules. This compound has been characterized using single crystal X-ray diffraction. The molecule belongs to the monoclinic space groupP21/n, witha=7.515(2),b=18.952(6), andc=13.938(7) Å, β=95.12(3)° andD calc=1.43 g cm−3 for Z=4. Least squares refinement based upon 2348 observed reflections led to a finalR=0.039.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00656587
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  • 5
    Electronic Resource
    Electronic Resource
    Indium-based liquid clathrates. III. Inclusion compounds derived from [Bu4N][InCl3X] salts and their suitability as a catalysis medium (1988)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 6 (1988), S. 233-236 
    Details
    ISSN: 1573-1111
    Keywords: Liquid clathrate ; indium ; catalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Tetrabutylammonium salts of the mixed haloindates, [Bu4N][InCl3X], X=Cl, Br, I, interact with aromatic solvents forming liquid inclusion compounds. The aromatic/cation ratio (A/C), a measure of the amount of guest aromatic, has been determined for a variety of simple aromatics. The values range from 2.6 to 0.4, substantially lower than the A/A of similar [Bu4N][Al2R6X] liquid clathrates. The ability of these liquid clathrates to function as catalysis media has been explored. The solubility of (Ph3P)2Rh(CO)Cl and (Ph3P)3RhCl in the various clathrates was determined. It was found that significant leaching of the catalyst into the bulk aromatic solvent occurred, ranging from 13 to 94%. A related liquid clathrate, [Li·12-crown-4][InCl4]·(C6H5CH3)2, had 〈1% of the dissolved catalyst leached.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00682135
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  • 6
    Electronic Resource
    Electronic Resource
    Attraction of Female Oriental Fruit Fly, Bactrocera dorsalis, to Volatile Semiochemicals from Leaves and Extracts of a Nonhost Plant, Panax (Polyscias guilfoylei) in Laboratory and Olfactometer Assays (1997)
    Springer
    Journal of chemical ecology 23 (1997), S. 1389-1401 
    Details
    ISSN: 1573-1561
    Keywords: Oriental fruit fly ; Bactrocera dorsalis ; female attractant ; panax ; fruit fly control ; semiochemicals ; kairomones ; Tephritidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Fresh whole leaves and solvent–water leaf extracts of the hedgerow plant panax, Polyscias guilfoylei (Bull), were tested for their attractiveness to male and female Oriental fruit flies, Bactrocera dorsalis, in laboratory flight tunnel and cage olfactometer bioassays. Fresh mature whole panax leaves were found to be attractive to mated female oriental fruit flies in the flight tunnel. Response of males and virgin females was low and in most instances not significantly different from controls. Attraction of mated female flies to the layers resulting from a methylene chloride–water partition or a hexane–water partition of freshly ground leaves using small McPhail traps was greatest in the methylene chloride fraction. When methylene chloride and water layers were tested competitively in a multiple-choice rotating olfactometer, the methylene chloride fraction was more attractive. Tests involving the methylene chloride–water interface (an emulsion of the two partitioned layers) with and without a standard attractant NuLure, showed the emulsion layer to be significantly more attractive than the other fractions or NuLure. In outdoor cage olfactometer assays of methylene chloride and water fractions, activity was greatest in the methylene chloride fraction. The results suggests that volatile semiochemicals from this nonhost plant are attractive to mated female Oriental fruit flies. The results are discussed in relation to the chemical ecology of B. dorsalis and the potential use of this nonhost plant for detection and control of female Oriental fruit flies in the field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/B:JOEC.0000006471.46161.8d
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