The chemical diversity and distribution of glucosinolates and isothiocyanates among plants

Parasitoids and predators of herbivores have evolved and function within a multitrophic context. Consequently, their physiology and behavior are in­ fluenced by elements from other trophic levels such as their herbivore victim (second trophic level) and its plant food (first trophic level) (126) . Natural enemies base their foraging decisions on information from these different trophic levels, and chemical information plays an important role. This review is restricted to the ecology of chemical information from the first and second trophic levels. The importance of so-called infochemicals, a subcategory of semiochemicals, in foraging by parasitoids and predators has been well documented (e.g. reviewed in 31, 78, Il l , 183, 185) , and we do not intend to repeat the details. But because of a lack of testable hypotheses, all this research is conducted rather haphazardly: the total puzzle of infochemical use has not been solved for any natural enemy species. Here we approach the use of infochemicals by natural enemies from an evolutionary and ecological standpoint. Our basic concept is that information from the first and second trophic levels differs in availability and in reliability, a difference that shapes the way infochemicals are used by a species. We generate hypotheses on (a)

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Ecology of infochemical use by natural enemies in a tritrophic context.

Bitter taste, phytonutrients, and the consumer: a review

The epidemiologic literature on the relationship between vegetable and fruit consumption and human cancer at a variety of sites is reviewed systematically. A total of 13 ecologic studies, nine cohort studies, and 115 case-control studies are included. Cancer of all sites, cancers of lung, breast, colon, rectum, esophagus, larynx, oral cavity and pharynx, stomach, pancreas, prostate, bladder, ovary, endometrium, cervix, and thyroid, as well as mesothelioma and gestational trophoblastic disease, are considered. Relevant data from clinical trials, animal, and in vitro studies are included. It is concluded that consumption of higher levels of vegetables and fruit is associated consistently, although not universally, with a reduced risk of cancer at most sites. The association is most marked for epithelial cancers--particularly those of the alimentary and respiratory tracts--and, currently, is weak to nonexistent for hormone-related cancers. The association exists for a wide variety of vegetables and fruit with some suggestion that raw forms are associated most consistently with lower risk. Possible mechanisms by which vegetable and fruit intake might alter risk of cancer and possible adverse effects of vegetable and fruit consumption will be considered in Part II of this review.

Vegetables, fruit, and cancer. I. Epidemiology.

Variation of glucosinolate accumulation among different organs and developmental stages of Arabidopsis thaliana.

This review surveys the occurrence, analysis, and properties of glucosinolates and derived compounds in plants and products intended for humans and animal consumption. The paper, which includes references published in 1981, is also intended to compliment existing reviews on the chemistry of these sulfur‐containing natural products. Particular emphasis is placed upon members of the Brassica family because of their importance as vegetables, condiments, oilseeds, and animal feedingstuffs. Since much of the work considered here relates to glucosinolate decomposition products, biochemical information concerning the nature, occurrence, and properties of the glucosinolate‐degrading enzyme, myrosinase, is considered in Section III. The methods available for the chemical analysis of glucosinolates and their various breakdown products are discussed critically. Factors affecting the glucosinolate content of plants and plant products arc outlined in Section VII. Particular emphasis is placed upon the effect of proces...

Glucosinolates and their breakdown products in food and food plants

Electron-rich heteroarenes stack with perfluoroarene side chains and twist arylene-ethynylene conjugated oligomers, while electron deficient heterocycles do not. These trends correlate with X-ray structures, optical spectra, and computations.

Crystal engineering of heterocyclic arylene(ethynylene) oligomers through programmed aromatic stacking

Instantaneous collapse of the wave function upon measurement of a single particle is one of the postulates of the Copenhagen interpretation of quantum mechanics. However, what happens when a many-body system in a macroscopic coherent state is measured one particle at a time? Here, we consider successive measurements of individual spins from a spin Bose condensate that starts in a Schrödinger cat state. When the spin measurements are done one particle at a time, the collapse of the spin condensate is not instantaneous but leads to probabilities for spin measurement that strongly depend on the previous measurements. What is surprising is that an almost complete collapse occurs in very few measurements. Even in a large system, a single cat component is emphasized quite quickly in the sequence of measurements. We examine the process by analysis of a simple two-Fock-state cat, as well as a cat state that has many components. Justification is given for our theoretical measurement process. 

Progressive quantum collapse

In previous important examinations by Aleiner et al. [Nat. Phys. 6, 900 (2010)] and Michal et al. [Proc. Natl. Acad. Sci. (U.S.A.) 113, E4455 (2016)], the fluid insulator transition has been explored in one-dimensional (1D) disordered bosons by analytical methods. However, the nature of this ``fluid'' is still not quite understood. Here we shed more light on this ``fluid'' by studying its properties under changes in the average particle number $\ensuremath{\langle}N\ensuremath{\rangle}$ and temperature $T$ in the absence of superfluidity. For this purpose, the worm algorithm path-integral Monte Carlo method is utilized in the grand-canonical ensemble. A measure for the width of path fluctuations is introduced that we call ${\ensuremath{\sigma}}_{J}$. It is found that by increasing $\ensuremath{\langle}N\ensuremath{\rangle}$, ${\ensuremath{\sigma}}_{J}$ rises as the bosons become less repulsive and gain more mobility. The compressibility $\ensuremath{\chi}(\ensuremath{\mu})$, $\ensuremath{\mu}$ being the chemical potential, reveals fluid behavior at the lower $\ensuremath{\gamma}$ and a proposed Bose-glass phase at the larger $\ensuremath{\gamma}$ (the Lieb-Liniger interaction parameter). The kinetic energy ${E}_{K}$ versus $\ensuremath{\gamma}$ at various $T$ signals a transition by its convergence towards a common value. ${E}_{K}$ versus $\ensuremath{\mu}$ reveals a peculiar inversion as one goes from small to larger values of the speckle strength $\ensuremath{\langle}V\ensuremath{\rangle}$ demonstrating a complex influence of the disorder. A tipover of ${E}_{K}$ versus $\ensuremath{\gamma}$ from an increasing to a decreasing trend at the lower $\ensuremath{\gamma}$ also signals a transition. Further, Luttinger's liquid theory cannot be applied to describe 1D bosons in strong disorder at finite $T$ because of the absence of superfluidity. Moreover, $\ensuremath{\langle}V\ensuremath{\rangle}$ largely controls the behavior of $\ensuremath{\chi}(\ensuremath{\mu})$, the pair-correlation function at the origin ${g}_{2}(0)$, and ${E}_{K}$. Surprisingly, the diffusion constant ${D}_{0}$ does not obey the classical isomorphism as it rises with $T$. We also emphasize the importance of this work via its applicability to quantum wires. 

W J Mullin

Papers

Glucosinolates and their breakdown products in food and food plants

Crystal engineering of heterocyclic arylene(ethynylene) oligomers through programmed aromatic stacking

Progressive quantum collapse

Unusual fluid of one-dimensional disordered bosons at finite temperature