Transformations for within-subject designs: A Monte Carlo investigation.

Explored the use of transformations to improve power in within-S designs in which multiple observations are collected for each S in each condition, such as reaction time (RT) and psychophysiological experiments. Often, the multiple measures within a treatment are simply averaged to yield a single number, but other transformations have been proposed. Monte Carlo simulations were used to investigate the influence of those transformations on the probabilities of Type I and Type II errors. With normally distributed data, Z and range correction transformations led to substantial increases in power over simple averages. With highly skewed distributions, the optimal transformation depended on several variables, but Z and range correction performed well across conditions. Correction for outliers was useful in increasing power, and trimming was more effective than eliminating all points beyond a criterion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dielectrophoretically controlled fabrication of single-crystal nickel silicide nanowire interconnects

We report here on applying electric fields and dielectric media to achieve controlled alignment of single-crystal nickel silicide nanowires between two electrodes. Depending on the concentration of nanowire suspension and the distribution of electrical field, various configurations of nanowire interconnects, such as single, chained, and branched nanowires were aligned between the electrodes. Several alignment mechanisms, including the induced charge layer on the electrode surface, nanowire dipole-dipole interactions, and an enhanced local electrical field surrounding the aligned nanowires are proposed to explain these novel dielectrophoretic phenomena of one-dimensional nanostructures. This study demonstrates the promising potential of dielectrophoresis for constructing nanoscale interconnects using metallic nanowires as building blocks.     

Biosynthetic precursors of fungal pyrrolizidines, the loline alkaloids

Loline alkaloids are saturated pyrrolizidines with a substituted 1-amino group and an oxygen bridge between C2 and C7, and are insecticidal metabolites of plant-symbiotic fungi (endophytes). Cultures of the endophyte, Neotyphodium uncinatum, incorporated labeled L-proline and L-homoserine into the 1-aminopyrrolizidine, N-formylloline. The A-ring carbons C1-C3 and the N1 were derived from L-homoserine; the B-ring carbons C5-C8 and the ring nitrogen were derived from L-proline. Incorporation of both deuterium atoms from L-[4,4-(2H2)]homoserine and feeding tests with labeled L-methionine indicated that L-homoserine incorporation was not achieved via aspartyl semialdehyde or S-adenosylmethionine, but probably involved a highly novel N--C bond-forming gamma-substitution reaction.     

Ion beam tritium labeling of proteins and peptides

A general method for tritiating proteins, peptides, and other nonvolatile organic compounds has been developed. A carefully controlled particle beam composed of T3+ and T2+ ions and fast T2 molecules is accelerated into a sample target within a vacuum chamber. This beam method has been used to tritiate ribonuclease A, porcine pancreatic elastase, thermolysin, soybean trypsin inhibitor, alpha 1-protease inhibitor, and the peptide aldehydes leupeptin and antipain. After removal of all readily exchangeable tritium, the products were obtained in 32-83% yields with specific radioactivities of 18-856 Ci/mol. The products were carefully characterized, shown to be chemically pure, and to have complete biological activity. Simple tritium hydrogen exchange accounts for at least 82% of the reaction pathway with proteins and for 100% of the reaction with the peptide aldehydes. The ion beam method is a mild procedure for general tritium labeling of fragile protein macromolecules and other sensitive biological molecules.     

The transmission of digital signals through random, time-variant, dispersive channels with application to chaff scatter

This paper is a report on the characterization and modeling of a specific dispersive communication channel, a chaff scatter channel. Theoretical and experimental results are given. The basic modeling of the chaff scatter channel as a linear, time-variant, random-parameter filter is given and its salient properties developed. Based on this model, a theoretical analysis of a continuous-phase binary FSK communications system operating over the chaff scatter channel is given. Experimental results obtained in the use of this system on an actual chaff scatter channel are then presented and compared with the theoretical results.     

Optimal synthesis of waste treatment plants

It is possible to simulate waste treatment plants with increasing accuracy and reliability. This study examines the application of the SEPSIM steady-state simulation program as the modelling basis of an optimal synthesis program. A modified form of Box's Complex method coupled with Fan's structural parameter method is presented and employed in the solution of the multidimensional optimization problem. The computational difficulties associated with the optimal synthesis of processing systems are discussed in some detail. It is found that an operating arrangement consisting of a trickling filter and an activated sludge system working in parallel is clearly indicated by the models as being the optimal system.     

Evaluation of decoquinate or lasalocid against coccidiosis from natural exposure in neonatal dairy calves.

Forty-one Holstein and Brown Swiss calves were raised as herd replacements under conditions in which they were allowed natural exposure to sporulated coccidial oocysts at a very early age. Two compounds previously shown to have anticoccidial efficacies, decoquinate and lasalocid, were used for this study. Calves were assigned randomly at birth to one of the treatments: decoquinate (approximately .5 mg/kg of BW) or lasalocid (approximately 1.0 mg/kg of BW) or to remain as unmedicated controls through 16 or 24 wk of age. Counts of fecal oocysts were reduced in the calves fed decoquinate for wk 4 to 8 and for both treated groups for wk 9 to 24. Calves fed decoquinate had increased BW, heart girth, and height at withers during wk 5 to 8. Both treated groups had higher gains than untreated calves during wk 12 to 16 with the decoquinate group larger than the lasalocid group. Feeding an anticoccidial compound to newborn calves reduced severity of coccidiosis when early natural exposure occurred.     

Grain Growth Phenomena in the Interface Region of α-Alumina Bilayer Composites

Microstructural development in the interface region of α-Al₂O₃ bilayer composites has been systematically investigated in terms of the sintering additive CaO–SiO₂, residual impurity level in the starting powders (particularly MgO), and sintering conditions. The interfacial microstructure is strongly related to relative CaO–SiO₂ doping levels in the two constituting layers and to residual impurities in the starting powders. The presence of high levels of impurities in the starting powder can substantially modify the features of CaO–SiO₂-Al₂O₃ liquid at the interface region, thereby strongly influencing α-Al₂O₃ grain growth across the interface. Three grain growth modes in the interface region thus have been identified for different combinations of impurity level and CaO–SiO₂ dopant in the α-Al₂O₃ bilayer. This provides an important mechanism for controlling two-dimensional structures in coatings, films, and layered ceramic materials for various engineering applications.     

Computer Modeling of the Local Telephone Network

In this paper, we describe the structure and operation of an innovative computer-based model of the local exchange telephone network known as the HCPM. This model can be used in a variety of regulatory arenas, since it provides a regulatory agency with an independent source of information about the forward-looking costs of providing local telephone service. The model can also be used more broadly by governmental agencies in planning for infrastructure development, expanding telephone service to currently unserved areas, or, as in the case of the U.S., designing an efficient universal service program. The HCPM represents an advance over previous models in its ability to build plant to precise customer locations if data are available, while retaining the flexibility of being able to produce good results even with more highly aggregate location data such as those available from the U.S. Census.