6,344 research outputs found

    Nuclear magnetic resonance spectroscopy: Abnormal splitting of ethyl groups due to molecular asymmetry

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    Nuclear magnetic resonance (n.m.r.) spectroscopy provides an excellent means for qualitative identification of ethyl groups by use of the familiar three-four pattern of spin-spin splitting (1). It has been observed previously (2) that the methylene protons of systems of the type R-CH2-CR1R2R3 (where R1 can be the same as R or different) may be magnetically nonequivalent and display AB rather than A2-type spectra (3). We now wish to report several examples of this type of behavior with ethyl groups, particularly ethoxy groups, knowledge of which could be important to anyone using n.m.r. for organic qualitative analysis

    Price and Advertising Signals of Product Quality

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    We present a signalling model, based on ideas of Phillip Nelson, in which both the introductory price and the level of directly ā€œuninformativeā€ advertising or other dissipative marketing expenditures are choice variables and may be used as signals for the initially unobservable quality of a newly introduced experience good. Repeat purchases play a crucial role in our model

    Relying on the Information of Interested Parties

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    We investigate the conventional wisdom that competition among interested parties attempting to influence a decision maker by providing veriļ¬able information brings out all the relevant information. We ļ¬nd that, if the decision maker is strategically sophisticated and well informed about the relevant variables and about the preferences of the interested party or parties, competition may be unnecessary; while if the decision maker is unsophisticated or not well informed, competition is not generally suļ¬€icient. However, if the interested partiesā€™ interests are suļ¬€iciently opposed, or if the decision maker is seeking to advance the partiesā€™ decision makerā€™s need for prior knowledge about the relevant variables and for strategic sophistication. In other settings, only the combination of competition among information providers and a sophisticated skepticism is suļ¬€icient to allow defective decision making

    Molecular basis for resistance of acanthamoeba tubulins to all major classes of antitubulin compounds

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    Tubulin is essential to eukaryotic cells and is targeted by several antineoplastics, herbicides, and antimicrobials. We demonstrate that Acanthamoeba spp. are resistant to five antimicrotubule compounds, unlike any other eukaryote studied so far. Resistance correlates with critical amino acid differences within the inhibitor binding sites of the tubulin heterodimers

    Extinction by Miscalculation:

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    Species at Risk Act, Sakinaw sockeye, Cultus sockeye, fisheries management, extinction.

    Unlimited Medical Liability?

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    Body odor quality predicts behavioral attractiveness in humans

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    Growing effort is being made to understand how different attractive physical traits co-vary within individuals, partly because this might indicate an underlying index of genetic quality. In humans, attention has focused on potential markers of quality such as facial attractiveness, axillary odor quality, the second-to-fourth digit (2D:4D) ratio and body mass index (BMI). Here we extend this approach to include visually-assessed kinesic cues (nonverbal behavior linked to movement) which are statistically independent of structural physical traits. The utility of such kinesic cues in mate assessment is controversial, particularly during everyday conversational contexts, as they could be unreliable and susceptible to deception. However, we show here that the attractiveness of nonverbal behavior, in 20 male participants, is predicted by perceived quality of their axillary body odor. This finding indicates covariation between two desirable traits in different sensory modalities. Depending on two different rating contexts (either a simple attractiveness rating or a rating for long-term partners by 10 female raters not using hormonal contraception), we also found significant relationships between perceived attractiveness of nonverbal behavior and BMI, and between axillary odor ratings and 2D:4D ratio. Axillary odor pleasantness was the single attribute that consistently predicted attractiveness of nonverbal behavior. Our results demonstrate that nonverbal kinesic cues could reliably reveal mate quality, at least in males, and could corroborate and contribute to mate assessment based on other physical traits
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