No description available.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 195-224) Also available in print.

Thesis (Ph. D.)--Columbia University, 1946. / Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 42.

Thesis (Ph. D.)--Columbia University, 1946. / Vita. Bibliography: p. 42.

Bibliography: pages 47-55. / The statement that similar sorts of plants often have similar medicinal properties (Le. contain similar chemicals) is at least 300 years old, while the concept probably dates back several thousand years (Stace, 1980). Indeed, a knowledge of the secondary chemicals produced by different plant species has played an important role since the early stages of man's cultural, and probably evolutionary, development (e.g. Leopold and Ardrey, 1972). Until recently, however, the biological role of this large group of compounds has remained largely obscure, with many plant physiologists regarding them as waste products and of no possible survival value to plants (Harborne, 1982). In recent years a tremendous increase in attention paid to these compounds has led to the suggestion that plant secondary substances evolved as herbivore deterrents, and diversified with the plants producing them as herbivores evolved various means of coping with their toxicity. In what follows I present an overview of events leading to the establishment of this theory, and a history of the discovery that some insect herbivores have turned the toxicity of plant secondary compounds to their own advantage, thereby becoming exclusively associated with toxic food plants. It will be seen that although this theory of plant-herbivore coevolution has become generally accepted, it has yet to be tested for a wide range of herbivores and chemical types. From this view I have taken a detailed look at a specific group of herbivores and plant toxins: Lepidoptera feeding on cyanide-producing plants.

published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

Theoretical and experimental aspects of high resolution spectroscopy are discussed. The theoretical work concentrates on the matrix elements of the rigid rotor and molecular hyperfine terms of the Hamiltonian of a rotating molecule. The experimental work consists of Stark cell and beam maser microwave spectroscopy on C1CN and HDO respectively. The theory of rotational spectroscopy is developed in a uniform manner based on the irreducible tensor method. It is shown how the effect of molecular symmetry may be incorporated into this method. The instrumentation required to observe the hyperfine splittings is discussed. This includes descriptions of the Stark cell and molecular beam maser microwave spectrometers. A new tunable C-band resonant cavity is described. The following molecular constants are reported for both common species of C1CN: rotational constant Bₒ, centrifugal distortion constant D(J), quadrupole coupling constant eqQ(k), and spin-rotation constant C(x). Values in MHz for C1CN are as follows: ³⁵C1CN; Bₒ = 5 907.820 ± 0.010, eqQ(C1) = -83.26 ± 0.06, eqQ(N) = -3.59 ± 0.08, C(C1) = -0.006 ± 0.006, C(N) = 0.013 ± 0.010; ³⁷C1CN; Bₒ = 5 847.246 ± 0.008, eqQ(C1) = -65.61 ± 0.06, eqQ(N) = -3.61 ± 0.08, C(C1) = -0.004 ± 0.006, C(N) = 0.010 ± 0.010. The following molecular constants for HDO are reported: quadrupole coupling tensor elements eqQ(D)(gg) and spin-rotation tensor elements C(x)(gg). The values in KHz are as follows: eqQ(D)(aa) = 276.45 ± .88, eqQ(D)(bb) = -110.97 ± 1.46, eqQ(D)(cc) = -165.77 ± 1.10, C(D)(aa) = 1.33 ± .20, C(D)(bb) = -4.38 ± .36, C(D)(cc) = -2.99 ± .24, C(H)(aa) = -58.42 ± .47, C(H)(bb) = -5.46 ± .83, C(H)(cc) = -23.28 ± .10. The values for the constants for C1CN agree with previous values but are more precise. Those for HDO do not agree with previous values but are thought to be more accurate since they are obtained for a larger data base.

Thesis (Ph. D.)--University of Chicago, 1932. / "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." Bibliography: p. 6.

No description available.

The synthesis and insecticidal activity of a series of 2,2-dicyano cyclopropane carboxylic acids, (3-phenoxyphenyl)- methyl esters were investigated. Synthesis of the compounds was accomplished by reaction of a dimethyl sulfonium carbethoxy ylide with propanedinitrile alkylidene compounds. Final products were formed in one step by use of the (3-phenoxyphenyl)-methyl ester of the ylide. Insecticidal activity was determined at 500 ppm application with Permethrin as the standard against houseflies, mexican bean beetles, and southern army worms.