Learn More
In this article, we provide guidance for substantive researchers on the use of structural equation modeling in practice for theory testing and development. We present a comprehensive, two-step modeling approach that employs a series of nested models and sequential chi-square difference tests. We discuss the comparative advantages of this approach over a(More)
In this paper we examine the use of the key informant methodology by researchers investigating interorganizational relationships. To increase the reliability of informant reports, the use of multiple informants has often been advocated. However, interorganizational research still tends to rely on single informants. Here, we investigate issues having to do(More)
This study investigates the adoption of total cost of ownership (TCO) analysis to improve sourcing decisions. TCO can be seen as an application of activity based costing (ABC) that quantifies the costs that are involved in acquiring and using purchased goods or services. TCO supports purchasing decision-makers in focusing on total value received and not(More)
With few exceptions the genetic codes of all known organisms encode the same 20 amino acids, yet all that is required to add a new building block are a unique tRNA/aminoacyl-tRNA synthetase pair, a source of the amino acid, and a unique codon that specifies the amino acid. For example, the amber nonsense codon, TAG, together with orthogonal Methanococcus(More)
We describe a general and rapid route for the addition of unnatural amino acids to the genetic code of Saccharomyces cerevisiae. Five amino acids have been incorporated into proteins efficiently and with high fidelity in response to the nonsense codon TAG. The side chains of these amino acids contain a keto group, which can be uniquely modified in vitro and(More)
Experimental and analytical studies are conducted on four repair/upgrade details for welded moment connections. The first of these seeks to improve the weld material without doing anything to the beam and column sections at the joint (weld enhancement). The simplest of these removes the cracked weld material and replaces it with a more ductile, notch-tough(More)