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  • 1990-1994  (16)
  • 1965-1969  (2)
  • Polymer and Materials Science  (14)
  • plant-insect interaction  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Possible roles of cotton bud sugars and terpenoids in oviposition by the boll weevil (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 757-772 
    Details
    ISSN: 1573-1561
    Keywords: Cotton ; Gossypium spp ; boll weevil ; Anthonomus grandis ; Coleoptera ; Curculionidae ; oviposition ; plant-insect interaction ; terpenoids ; sugars
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Several cottonGossypium spp. race stocks have been identified that possess resistance to the boll weevilAnthonomus grandis Boh. because oviposition is decreased. In this work, a number of known cotton constituents that influence stimulation of feeding and attractancy for this insect were found to have little or no influence on oviposition. These include gossypol, β-bis-abolol, caryophyllene, some fatty acids and their methyl esters, some wax esters, flavonoids, condensed tannins, and chrysanthemin. Analysis of cotton bud surfaces showed that the content of volatile terpenoids was generally higher in resistant lines, but bioassays did not show decreased oviposition in the presence of the terpenoids. The sugars (glucose, fructose, and sucrose) found in anthers, uniformly stimulated oviposition in the bioassay, and their content was higher in susceptible lines. These results suggest that a major basis of resistance to boll weevils as related to oviposition may be the decreased content of sugars in resistant lines. The analysis of free sugars in the anthers, and perhaps also the analysis of bud surface terpenoids, may provide a basis for selection or genetic production of cotton lines resistant to the boll weevil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01016487
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  • 2
    Electronic Resource
    Electronic Resource
    Roles of amino acids, protein, and fiber in leaf-feeding resistance of corn to the fall armyworm (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 1977-1995 
    Details
    ISSN: 1573-1561
    Keywords: Fall armyworm ; Spodoptera frugiperda ; Lepidoptera ; Noctuidae ; corn ; Zea mays ; plant-insect interaction ; amino acids ; herbivory ; feeding resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The free amino acids have been shown by isolational work and choice bioassays to be more important than all other factors evaluated in defining leaf-feeding resistance of corn (Zea mays L.) to fall armyworm (FAW) [(Spodoptera frugiperda J.E. Smith)] larvae. 6-MBOA (6-methoxybenzoxazolinone) and maysin, toxins present in corn, were shown not to be significant factors for leaf-feeding resistance to first-instar FAW larvae because of their low concentrations in the whorl. Amino acid analysis showed that while the ratios of the essential amino acids in susceptible (S) and resistant (R) lines were similar, there were differences in the nonessential amino acids, particularly aspartic acid, which was higher in R lines. Also, the ratio of essential amino acids to nonessential amino acids was important, being too low in expressed whorl leaf juice (obtained from V8–V10 growth stage plants) to support larval growth, although juice was stimulatory in choice tests. The total protein content of whorls in S lines was about 15% higher than in R lines, but the significance of this difference is uncertain, because nutritional tests showed that larval growth increased with total protein only up to 12% protein. Sugars were only slightly stimulatory. Thus, the amino acids along with higher hemicellulose content of R lines, established by us earlier, appear to explain much of the basis of resistance in corn to larval leaf-feeding of the FAW.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01020510
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  • 3
    Electronic Resource
    Electronic Resource
    Effects of cotton plant allelochemicals and nutrients on behavior and development of tobacco budworm (1991)
    Springer
    Journal of chemical ecology 17 (1991), S. 1107-1121 
    Details
    ISSN: 1573-1561
    Keywords: Tobacco budworm ; Heliothis virescens ; Lepidoptera ; Noctuidae ; cotton ; Gossypium hirsutum ; plant resistance ; plant-insect interaction ; terpenoids ; gossypol ; allelochemicals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Female moths of the tobacco budworm,Heliothis virescens (F.), oviposit in the terminals of the cotton plant,Gossypium hirsutum (L.). The hatched larvae migrate to the terminal area and then to small squares (buds), on which they feed, finally burrowing into the anthers where they grow and develop. They attempt to avoid gossypol glands as they feed. Chemically related evidence explains, in part, these observations. The calyx crown of resistant lines (which is avoided) is high in the terpenoid aldehydes (TAs) including gossypol. HPLC data showed that the gossypol content of both susceptible and resistant glanded lines is equal, while the hemigossypolone and heliocides H1 and H2 are greatly increased in resistant lines and presumably are more closely associated with resistance. Analysis for total amino acids in cotton square tissues showed that there was a gradation from the calyx and calyx crown, which were lowest, to the anthers, the site of final insect development, which were highest. Synthetic diets mimicking amino acid distribution in anthers were found to be successful for larval growth and development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01402937
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  • 4
    Electronic Resource
    Electronic Resource
    Arrestant responses of southwestern corn borer larvae to free amino acids: Structure-activity relationships (1993)
    Springer
    Journal of chemical ecology 19 (1993), S. 301-311 
    Details
    ISSN: 1573-1561
    Keywords: Southwestern corn borer ; Diatraea grandiosella Dyar ; Lepidoptera ; Pyralidae ; corn ; Zea mays L. ; plant-insect interaction ; amino acids ; sugars ; herbivory ; feeding resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The leaf-feeding resistance of corn or maizeZea mays L. to the southwestern corn borer, SWCB,Diatraea grandiosella Dyar has been attributed at least in part to decreased protein, increased crude fiber, and increased hemicellulose in the whorls of resistant genotypes. In this study, individual amino acids and sugars were evaluated as arrestants, with the objective of identifying those that gave weak or negative responses. Several structure-activity relationships were identified. Larvae responded to three-carbonn alkyl alpha amino acids more than to two-, four-, five-, and six-carbon compounds. Amino acids with terminal isopropyl functions gave decreased responses relative to theirn-alkyl counterparts. Dicarboxylic acids and their amides gave the lowest responses of all classes of amino acids. The normally occurring basic amino acids were all good arrestants. The guanido [HN:C(NH2)NH-] function was somewhat important to an arrestant response, as was the number of methylenes between the alpha and omega amino functions of diaminon-alkyl amino acids. Hydroxy amino acids were generally good arrestants unless the hydroxyl was located on a ring system. The two sugars present in expressed corn whorl juice, glucose and fructose, gave poor responses. However, two other sugars, mannose and arabinose, whose C-2 hydroxyls are conformationally in the axial position, were strongly arrestant. Formulated amino acid mixtures based on their content in whorl juice were as strong arrestants as whorl juice. However, the relative contributions of amino acids and sugars that are weak arrestants to the resistance of corn to SWCB larvae is uncertain because amino acid analyses did not reveal significantly higher contents of these amino acids in the whorl juices of resistant lines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00993697
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  • 5
    Electronic Resource
    Electronic Resource
    Probing the surface chemical structure of some novel poly(ortho esters) prepared with N-methyl and N-phenyl ethanolamine by time-of-flight secondary ion mass spectrometry (ToF-SIMS) (1992)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 3 (1992), S. 293-301 
    Details
    ISSN: 1042-7147
    Keywords: Poly(ortho esters) ; Biodegradable polymer ; Surface chemical analysis ; Time-of-flight secondary ion mass spectrometry (ToF-SIMS) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The surface chemical structures of a series of novel poly(ortho ester) homopolymer and copolymer films prepared using N-methyl- and N-phenyl-ethanolamine (MDE and PDE) have been investigated using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Systematic fragmentation patterns were observed within the ToF-SIMS spectra up to m/z = 1600, which were readily interpreted in terms of the polymer structures. Cations were detected which could be assigned to structures arising from the diols, the ortho ester species and diads, triads etc. of the monomer, from both the homopolymer and the random portion of the copolymer chains. The analysis of the proposed ion structures suggested two major mechanisms of fragmentation based on the cleavage of the ortho ester bonds involving either the exocyclic or the endocyclic alkoxy group. The Tof-SIMS peak area ratios for ions diagnostic of the diols and the ortho ester species reflected the bulk copolymer composition in a semi-quantitative fashion. The observation of such relationships for high mass cations (up to m/z = 500) is particularly noteworthy and has not been reported previously. These studies allow a dramatic insight into the surface chemical structure of these poly(ortho esters), information which has formed the foundation of current investigations on the mechanisms of the acid-catalysed surface degradation of these polymers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1992.220030603
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  • 6
    Electronic Resource
    Electronic Resource
    The analysis of the surface chemical structure of biomedical aliphatic polyanhydrides using XPS and ToF-SIMS (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 1597-1605 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The surface chemical structure of a range of aliphatic polyanhydride films has been examined using XPS and ToF-SIMS. The XPS data confirms the purity of the surface, and the experimental surface elemental ratios are in good general agreement with the known stoichiometry of the polyanhydrides. The ToF-SIMS spectra of the polyanhydrides are shown to be significantly different. The SIMS data conforms to a systematic fragmentation, in both negative- and positive-ion SSIMS spectra, occurring throughout the entire series of polyanhydrides examined. Radical cations are observed in the positive-ion spectra. These results are discussed in terms of the general fragmentation patterns observed in the SIMS analysis of polymers. The combined use of ToF-SIMS and XPS is shown, to provide a detailed insight into the interfacial chemical structure of these polyanhydrides.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070420613
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  • 7
    Electronic Resource
    Electronic Resource
    Poly(ethylene terephthalate) melt spinning via controlled threadline dynamics (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 46 (1992), S. 531-552 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Fiber melt spinning of poly(ethylene terephthalate) (PET) was studied via modification of threadline dynamics. Several techniques were implemented in the high-speed spinning process for the judicious control of threadline dynamics. This included a thermal conditioning zone (TCZ) for controlling the threadline temperature profile and a dydraulic drag bath (HDB) for controlling the threadline spinning stress. Through controlled threadline dynamics, key factors affecting the structure development - namely, temperature, tensile stress, and crystallization time - were manipulated to favor formation of a highly oriented and transversely uniform structure in the spun fibers. This carries the implication that optimum or near-optimum processing conditions are being applied during the structure development period. More specifically, tensile stress in the threadline, independent of temperature, is substantially increased to many orders higher than that ordinarily attained in the normal high-speed spinning process. Concurrently, the temperature crucial to the structure development is being independently optimized and its duration extended to attain a highly oriented structural order. Properties of the spun fibers were found to be correlated with the threadline parameters including cooling profile, tension profile, and strain rate. PET fibers spun via the one-step process with the introduction of the TCZ and HDB possess superior mechanical performance. Structural characterization suggests that the spun fibers have a high amorphous orientation factor and a uniform radial structure distribution. Further on-line studies indicate that structure development in the threadline is completely different from that of the traditional high-speed spinning process. The attenuation profile of the threadline is observed to be dependent of TCZ temperature, residence time in the HDB, temperature of the HDB, and take-up speed. It is believed that for the melt spinning process with the TCZ and the HDB, the threadline dynamics is changed from one controlled by inertia and air drag forces to one controlled by the imposed hydraulic drag.
    Additional Material: 26 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1992.070460320
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  • 8
    Electronic Resource
    Electronic Resource
    Effects of water content on the properties of starch/poly(ethylene-vinyl alcohol) blends (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 52 (1994), S. 353-363 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The physical properties of unmodified starch, poly(ethylene vinyl alcohol), glycerol, and water mixtures are reported. Thermal and melt-flow properties of the preprocessed, physically mixed materials were determined along with the tensile properties and morphology of injection-molded microtensile samples. Melt-flow properties were measured by a capillary rheometer, and the water content was varied from 4 to 18%. The morphology, rheology, and tensile properties are all highly related to the percentage of water present. A transition in the tensile properties and morphology of the blends was observed at approximately 11% moisture content. © 1994 John Wiley & Sons, Inc.This article is a US Government work and, as such, is in the public domain in the United States of America.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1994.070520301
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  • 9
    Electronic Resource
    Electronic Resource
    Effects of spinning conditions on morphology and properties of polyethylene terephthalate fibers spun at high speeds (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 44 (1992), S. 447-458 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Fiber spinning of polyethylene terephthalate (PET) was studied at take-up speeds ranging from 2000 m/min to 7000 m/min under various spinning conditions. Effects of changes in process variables on the molecular orientation, crystallinity, and properties of as-spun PET fibers are reported. Conventional cross-flow quench in high-speed spinning yields fibers with undesirable crimp and asymmetric structure with respect to the fiber axis. Radial-flow quench eliminates these problems. Changes in other spinning conditions, such as extrusion temperature, throughput or take-up denier, and molecular weight, may also affect the development of PET fiber structure in the high-speed threadline.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1992.070440310
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  • 10
    Electronic Resource
    Electronic Resource
    Ectopic induction of cartilage and bone by water-soluble proteins from bovine bone using a polyanhydride delivery vehicle (1990)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 24 (1990), S. 901-911 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Controlled release delivery vehicles for water-soluble osteogenic proteins from demineralized bovine bone matrix were constructed using polyanhydride polymers. The water-soluble proteins were isolated from a 4 M guanidine hydrochloride extract of bone matrix. The water-soluble proteins possessed Chondrogenic Stimulating Activity (CSA) when tested in stage 24 chick limb bud cell cultures, but were incapable of inducing cartilage or bone in vivo when implanted intramuscularly into mice by themselves. The polyanhydride polymers alone were also incapable of inducting ectopic cartilage or bone. However, when the water-soluble proteins were incorporated into the polymeric delivery vehicle, the combination was capable of inducing cartilage and bone up to 50% of the time. These results demonstrate that it is possible to use polyanhydride polymers as controlled-release delivery vehicles for soluble bioactive factors that interact with a local cell population.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820240708
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