6,341 research outputs found
Nuclear magnetic resonance spectroscopy: Abnormal splitting of ethyl groups due to molecular asymmetry
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
Relying on the Information of Interested Parties
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 makerās 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
Price and Advertising Signals of Product Quality
We present a signalling model, based on ideas of Phillip Nelson, in which both the introductory price and the level of directly āuninformativeā 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
Molecular basis for resistance of acanthamoeba tubulins to all major classes of antitubulin compounds
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:
Species at Risk Act, Sakinaw sockeye, Cultus sockeye, fisheries management, extinction.
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Mediating punitiveness: understanding public attitudes towards work-related fatality cases
This paper concerns an empirical investigation into public attitudes towards work-related fatality cases, where organizational offenders cause the death of workers or members of the public. This issue is particularly relevant following the introduction of the Corporate Manslaughter and Corporate Homicide Act 2007 into UK law. Here, as elsewhere, the use of criminal law against companies reflects governmental concerns over public confidence in the lawās ability to regulate risk. The empirical findings demonstrate that high levels of public concern over these cases do not translate into punitive attitudes. Such cases are viewed rationally and constructively, and lead to instrumental rather than purely expressive enforcement preferences
Improving Phrap-Based Assembly of the Rat Using āReliableā Overlaps
The assembly methods used for whole-genome shotgun (WGS) data have a major impact on the quality of resulting draft genomes. We present a novel algorithm to generate a set of āreliableā overlaps based on identifying repeat k-mers. To demonstrate the benefits of using reliable overlaps, we have created a version of the Phrap assembly program that uses only overlaps from a specific list. We call this version PhrapUMD. Integrating PhrapUMD and our āreliable-overlapā algorithm with the Baylor College of Medicine assembler, Atlas, we assemble the BACs from the Rattus norvegicus genome project. Starting with the same data as the Nov. 2002 Atlas assembly, we compare our results and the Atlas assembly to the 4.3 Mb of rat sequence in the 21 BACs that have been finished. Our version of the draft assembly of the 21 BACs increases the coverage of finished sequence from 93.4% to 96.3%, while simultaneously reducing the base error rate from 4.5 to 1.1 errors per 10,000 bases. There are a number of ways of assessing the relative merits of assemblies when the finished sequence is available. If one views the overall quality of an assembly as proportional to the inverse of the product of the error rate and sequence missed, then the assembly presented here is seven times better. The UMD Overlapper with options for reliable overlaps is available from the authors at http://www.genome.umd.edu. We also provide the changes to the Phrap source code enabling it to use only the reliable overlaps
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