Determining the geographic origin of potatoes with trace metal analysis using statistical and neural network classifiers.

The objective of this research was to develop a method to confirm the geographical authenticity of Idaho-labeled potatoes as Idaho-grown potatoes. Elemental analysis (K, Mg, Ca, Sr, Ba, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, S, Cd, Pb, and P) of potato samples was performed using ICPAES. Six hundred eight potato samples were collected from known geographic growing sites in the U.S. and Canada. An exhaustive computational evaluation of the 608 x 18 data sets was carried out using statistical (PCA, CDA, discriminant function analysis, and k-nearest neighbors) and neural network techniques. The neural network classification of the samples into two geographic regions (defined as Idaho and non-Idaho) using a bagging technique had the highest percentage of correct classifications, with a nearly 100% degree of accuracy. We report the development of a method combining elemental analysis and neural network classification that may be widely applied to the determination of the geographical origin of unprocessed, fresh commodities.

Components of a calmodulin-dependent protein kinase cascade. Molecular cloning, functional characterization and cellular localization of Ca2+/calmodulin-dependent protein kinase kinase beta.

Ca2+/calmodulin-dependent protein kinases I and IV (CaMKI and CaMKIV, respectively) require phosphorylation on an equivalent single Thr in the activation loop of subdomain VIII for maximal activity. Two distinct CaMKI/IV kinases, CaMKKalpha and CaMKKbeta, were purified from rat brain and partially sequenced (Edelman, A. M., Mitchelhill, K., Selbert, M. A., Anderson, K. A., Hook, S. S., Stapleton, D., Goldstein, E. G., Means, A. R., and Kemp, B. E. (1996) J. Biol. Chem. 271, 10806-10810). We report here the cloning and sequencing of cDNAs for human and rat CaMKKbeta, tissue and regional brain localization of CaMKKbeta protein, and mRNA and functional characterization of recombinant CaMKKbeta in vitro and in Jurkat T cells. The sequences of human and rat CaMKKbeta demonstrate 65% identity and 80% similarity with CaMKKalpha and 30-40% identity with CaMKI and CaMKIV themselves. CaMKKbeta is broadly distributed among rat tissues with highest levels in CaMKIV-expressing tissues such as brain, thymus, spleen, and testis. In brain, CaMKKbeta tracks more closely with CaMKIV than does CaMKKalpha. Bacterially expressed CaMKKbeta undergoes intramolecular autophosphorylation, is regulated by Ca2+/CaM, and phosphorylates CaMKI and CaMKIV on Thr177 and Thr200, respectively. CaMKKbeta activates both CaMKI and CaMKIV when coexpressed in Jurkat T cells as judged by phosphorylated cAMP response element-binding protein-dependent reporter gene expression. CaMKKbeta activity is enhanced by elevation of intracellular Ca2+, although substantial activity is observed at the resting Ca2+ concentration. The strict Ca2+ requirement of CaMKIV-dependent phosphorylation of cAMP response element-binding protein, is therefore controlled at the level of CaMKIV rather than CaMKK.

Auditory stimulation effect on a comatose survivor of traumatic brain injury.

The purposes of this case study were (1) to determine whether a comatose patient responded differentially to four types of auditory stimuli--voices of family members and friends, classical music, popular music, and nature sounds--and (2) to determine what physiological measures and behavioral observations best captured changes in responsiveness. The patient participated in 28 sessions that were videotaped for later behavioral analysis. During all sessions, measures were taken of pulse rate, respiration rate, and skin resistance. Visual inspection of the data and Auto Regressive Integrated Moving Average (ARIMA) analyses revealed greater increases in responsiveness with the presentation of taped voices of family and friends than with other types of taped stimuli. Behavioral observations of body movements and measures of pulse rate were superior to observations of facial expressions and measures of respiration rate and galvanic skin response in revealing changes in responsiveness. Despite extreme diversity among comatose persons, the research findings support the contention that responses to various auditory stimuli differ and are measurable with relatively simple behavioral and physiological observations.

Interactions between calcium entry blockers and vecuronium bromide in anaesthetized cats.

Possible interactions between three calcium entry blocking agents (nifedipine, verapamil and bepridil) and the non-depolarizing neuromuscular blocking agent, vecuronium bromide, were investigated in chloralose-anaesthetized cats. In i.v. doses which caused decreases in arterial pressure, the calcium entry blockers did not affect indirectly-elicited twitches of tibialis muscle, but did potentiate the effects of vecuronium. No such potentiation of vecuronium was observed with the vasodilator drug, sodium nitroprusside. Experiments using close-arterial injections of acetylcholine suggested that the probable site of interaction is on the postsynaptic muscle membrane and probably involves blockade of calcium channels in skeletal muscle.