A calmodulin-target peptide hybrid molecule with unique calcium-binding properties

This paper describes the production and properties of a hybridprotein comprising the full length of the Xenopus laevis cabnodulin(CaM) sequence, followed, through a gh/cylgh/dne linker, bythe 26-residue CaM-binding region of myosin light-chain kinase(M13). This hybrid molecule appears to have high thermal stability(T_m > 75°C in the presence of Ca²⁺) as well as unusualCa²⁺-binding properties: (i) a wide-range biphasic Ca²⁺-bindingresponse (extending over pCa 4.8-7.4) and (ii) a high apparentbinding constant (pCa_50% = 6.3, a 10-fold increase from thatof wild-type CaM). NMR and CD data indicate that the CaM-M13hybrid molecule exists in equilibrium in an approximate 1:1ratio between two major conformations, one of which is similarto the compact globular structure of the CaM-M13 complex [M.Daira,G.M.Clore, A.M.Gronenborn, G.Zhu, C.B.Klee and A.Bax (1992)Science, 256, 632-638] and the other to the dumbbell-like structureof the wild type CaM [Y.S.Babu, C.E.Bugg and W.J.Cook (1988)J. Mol. Biol., 204, 191-204]. The biphasic Ca²⁺-binding curvecan be interpreted using a linear combination of two Hill bindingcurves with significantly different dissociation constants (2x 10^-6 M and 8 x 10^-6 M), which can be attributed to the twoconformations in equilibrium. The present study has opened anavenue to engineer proteins with higher Ca²⁺-binding affinitiesusing the known CaM structures as a template Received April 23, 1993; revised August 5, 1993; accepted August 25, 1993.     

Comparison in Use of the 9-Point Hedonic Scale between Americans, Chinese, Koreans, and Thai

Understanding cross-cultural sensory acceptance differences are essential for developing successful products for international markets. The most common scale for acceptance testing is the 9-point hedonic scale that was developed in the United States (US) by Peryam and Pilgrim (1957)Food Technology, 11, 9–14. The objectives of this research were to compare the usage of the 9-point hedonic scale between American, Korean, Chinese and Thai consumers, as well as to examine if there were significant differences in preference between consumers of the same culture residing in the US and their country of origin. A total of 575 respondents were recruited from eight respondent cells including two from the US and six from three Asian ethnic groups (Korean, Chinese, and Thai) with two locations (residing in United States and their country of origin). All respondents evaluated sample pairs using 9-point hedonic scales translated directly from English into their respective languages. Each respondent evaluated various foods on the 9-point hedonic scale and chose the most preferred among sample pairs. Food samples were selected to cover the full range of hedonic ratings for each culture. Results indicate that Chinese, Korean, and Thai respondents use the 9-point hedonic scale differently from American respondents, irrespective of residency in the US or length of stay. These ethnic groups use a smaller range of the 9-point hedonic scale than Americans. Moreover, there were no significant differences in food preferences for Thai and Korea consumers residing in the US or their native countries. Observed differences in food preferences among Chinese residing in the US vs. Taiwan were possibly attributed to the diverse sampling of Chinese selected in the US that were not all representative of Chinese consumers from Taiwan. Additionally, length of stay in the US did not significantly affect food preference among these ethnic groups.     

Interface cracks in adhesively bounded lap-shear joints

A study on the elastic behavior of interface cracks in adhesively bonded lap-shear joints is presented. The problem is investigated by using a recently developed method of analysis based on conservation laws in elasticity for nonhomogeneous solids and fundamental relationships in fracture mechanics of dissimilar materials. The formulation leads to a pair of linear algebraic equations in mixed-mode stress intensity factors. Singular crack-tip stress intensity solutions are determined directly by information extracted from the far field. Stress intensity factors and associated energy release rates are obtained for various cases of interest. Fundamental nature of the interfacial flaw behavior in lap-shear adhesive joints is examined in detail.     

Ductile fracture of cracked steel plates

A simple relationship between loading for crack initiation, or onset of ductile tear, and crack length is presented for center-cracked plates of mild steel. Formulation of the nonlinear boundary-value problem is based on incremental theory of plasticity for Prandtl-Reuss materials. Quasi-static solutions corresponding to a series of incremental loading conditions are obtained by the mothod of finite elements. Tests conducted on plates of two types of mild steel agree with numerical results.     

Comparisons of a neural network and a nearest-neighbor classifiervia the numeric handprint recognition problem

A comparison is made of two techniques for recognizing numeric handprint characters using a variety of features including 2D fast Fourier transform coefficients, geometrical moments, and topological features. A backpropagation network and a nearest neighbor classifier are evaluated in terms of recognition performance and computational requirements. The results indicate that for complex problems, the neural network performs comparably to the nearest-neighbor classifier while being significantly more cost effective.     

Verification of concurrent control flow in distributed computer systems

An approach to verifying control flow in distributed computer systems (DCS) is presented. The approach is based on control flow checking among software components distributed over processors and cooperating among them. In this approach, control-flow behavior of DCS software is modeled and contained in special software components called verifiers. The verifiers are distributed over the processors and consulted to check the correctness of the control flow in DCS software during its execution. Algorithms for deriving the verifiers are presented. This technique can detect global errors including synchronization errors as well as local errors. It can be used for sequential or concurrent software at various levels of details. Experiments show that using this technique requires no significant overhead.<>