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Showing papers by "North Carolina State University published in 1985"


Journal ArticleDOI
TL;DR: In this article, the authors report some empirical results on the strength of the quality-price relation and find that for many products, the relation between quality and price appears to be very weak.
Abstract: The author reports some empirical results on the strength of the quality-price relation. For many products, the relation between quality and price appears to be very weak; hence, for many products,...

466 citations


Journal ArticleDOI
TL;DR: The main emphases are on the difference between socially optimal and individually optimal (equilibrium) controls and on the use of dynamic-programming inductive analysis to show that an optimal control is monotonic or characterized by one or more "critical numbers".
Abstract: Congestion in a queueing system can sometimes be controlled by restricting arrivals, either by "closing a gate" or by charging an entrance fee or toll. We review both static (open-loop) and dynamic (closed-loop) models for control of admission to a queueing system. The main emphases are on the difference between socially optimal and individually optimal (equilibrium) controls and on the use of dynamic-programming inductive analysis to show that an optimal control is monotonic or characterized by one or more "critical numbers." We discuss the potential for use of these models in the analysis of computer/ communication systems and compare the results to certain others in the literature.

411 citations


Journal ArticleDOI
TL;DR: Radiochemical measurements of 234Th (t1/2 = 24 days), 137Cs (bomb-produced), and 210Pb (t 1 2 = 22y) have been used to characterize rates of mixing, deposition, and accumulation on 100-day and 100-y time scales in East China Sea sediments as mentioned in this paper.

373 citations



Journal ArticleDOI
TL;DR: High soil-arthropod and earthworm densities under no-tillage systems suggest an expanded and beneficial involvement for these soil fauna in crop-residue-decomposition processes.
Abstract: Soil-arthropod and earthworm densities (number m−2) were higher (P < 0.05) under no-tillage than conventional tillage practices. Enchytraeid worms were higher in conventional tillage. Two predaceous groups, ground beetles (Carabidae: Coleoptera) and spiders (Araneae), comprised more than one-half of all soil macroarthropods collected. All major microarthropod suborders (Oribatids, Prostigmatids, Mesostigmatids, and the order Collembola) were higher (P < 0.01) under no-tillage than conventional tillage. High soil-arthropod and earthworm densities under no-tillage systems suggest an expanded and beneficial involvement for these soil fauna in crop-residue-decomposition processes.

293 citations


Journal ArticleDOI
TL;DR: In this article, the hydrodynamics of cocurrent gas-liquid flow in packed beds is analyzed by extending the concept of relative permeability to the inertial regime, where the relative permeabilities of the gas and liquid phases are functions of the saturation of the liquid phase.
Abstract: The hydrodynamics of cocurrent gas-liquid flow in packed beds is analyzed by extending the concept of relative permeability to the inertial regime. The relative permeabilities of the gas and liquid phases are functions of the saturation of the liquid phase. These functions are found from an analysis of experimental data. The relations obtained are used to develop empirical correlations for predicting liquid holdup and pressure drop in gas-liquid cocurrent downflow in packed beds over a wide range of operating conditions. The correlations proposed give very good results when compared to experimental data yielding, in general, mean relative deviations lower than existing correlations. In addition, a new equation is proposed for predicting static holdup in packed beds which is based on a more physically realistic characteristic length than that used in previous studies.

276 citations


Journal ArticleDOI
TL;DR: In this paper, longitudinal and lateral dispersion coefficients were measured at various axial positions in a packed bed in the Peclet number range from 102 to 104, and three different types of packings were used: uniform size particles, a narrow size distribution, and a wide size distribution.
Abstract: Longitudinal and lateral dispersion coefficients were measured at various axial positions in a packed bed in the Peclet number range from 102 to 104. Three different types of packings were used: uniform size particles, a narrow size distribution, and a wide size distribution. For the case of uniform particles the longitudinal dispersivities were found to be strong functions of position in the bed unless the dispersion length satisfies a constraint dependent on the value of the Peclet number. Generally, the larger the Peclet number, the larger the required length for constant axial dispersivities to be achieved. For the case of the wide size distribution, longitudinal dispersivities were larger than in the uniform particle case, and they required a longer dispersion length to achieve a constant value. This suggests a characteristic length for dispersion larger than the mean hydraulic radius. The lateral dispersivities were found to be insensitive to the distribution of particle sizes or location in the bed.

246 citations


Journal ArticleDOI
TL;DR: In this paper, it is shown that the Si can be grown at 1600 K and 760 torr on (100) Si substrates using and and if the Si is initially reacted with the alone.
Abstract: Crack‐free monocrystalline films having very smooth final surfaces may be reproducibly grown at 1600 K and 760 torr on (100) Si substrates using and and if the Si is initially reacted with the alone. This initial step produces a buffer layer which reduces the mismatches in expansion coefficients and lattice parameters and thus allows the subsequent growth of the film to a thickness exceeding 5 μm. It is necessary to heat the Si wafers from room temperature to the reaction temperature in a and environment rather than preheating the substrates to the reaction temperature. An off‐axis orientation of the Si in excess of approximately 3° results in a very rough final growth surface on the film.

240 citations


Journal ArticleDOI
TL;DR: In this article, the problem of volt/var control on general radial distribution systems is formulated, simplified and solved, where the objective is to minimize the peak power and energy losses while keeping the voltage within specified limits under varying load conditions.
Abstract: In this paper (Part I) and two companion papers (Part II and Part III) the problem of volt/var control on general radial distribution systems is formulated, simplified and solved. The objective is to minimize the peak power and energy losses while keeping the voltage within specified limits under varying load conditions. The decision variables to be optimally determined are (i) the locations, sizes and the real-time control of the specified number of ON/OFF switched and fixed capacitors and (ii) the locations and real-time control of the minimum number of voltage regulators. It is shown in this paper (Part I) that the regulator (volt) and the capacitor (var) problem may be treated as two decoupled problems. Part II of this set of three papers, conjoined with Part 1. provides the analytical tools by which optimal solutions for both problems may be determined. Application of the theory to representative radial systems is shown in Part III whhich also illustrates the economic benefits and numerical results achievable through both regulation and compensation schemes.

220 citations


Journal ArticleDOI
TL;DR: Plasmid curing experiments suggested that both bacteriocin immunity and production determinants were encoded by pMD136, which had identical activity spectra against species of Pediococcus, Clostridium, Staphylococcus and Streptococcus.
Abstract: Pediococcus pentosaceus FBB61 and L7230, isolated from cucumber fermentations, produced a bacteriocin, designated pediocin A, which had identical activity spectra against species of Pediococcus, Clostridium, Staphylococcus, and Streptococcus. Both strains possessed a 13.6-megadalton plasmid (pMD136). Plasmid curing experiments suggested that both bacteriocin immunity and production determinants were encoded by pMD136. Use of pediocin-producing strains in food fermentations is discussed.

213 citations


Journal ArticleDOI
TL;DR: In this article, the numerical results obtained through the application of the optimal design and control schemes of the capacitor and voltage regulator problems (which are formulated and solved on an analytical basis in the previous paper, Parts I and II) are demonstrated on a thirty-bus test system with six lateral branches.
Abstract: In this paper, the numerical results obtained through the application of the optimal design and control schemes of the capacitor and voltage regulator problems (which are formulated and solved on an analytical basis in the previous paper, Parts I and II) are demonstrated on a thirty-bus test system with six lateral branches. The results are discussed in order to demonstrate the applicability of the theory and the bases underlying the modeling of the overall problem.

Journal ArticleDOI
TL;DR: Interestingly, 122 base pairs of nucleotide sequence interior to atp 6 have extensive homology with the 5' end of the cytochrome oxidase subunit II gene of maize mitochondria, suggesting recombination between the two genes.
Abstract: The ATPase subunit 6, located in the inner mitochondrial membrane, is encoded by mitochondrial genomes in animals and fungi. We have isolated and characterized a mitochondrial gene, designated atp 6, that encodes the subunit 6 polypeptide of Zea mays. Nucleotide and predicted amino acid sequence comparisons have revealed a homology of 44.6 and 33.2% with the yeast ATPase subunit 6 gene and polypeptide, respectively. The predicted protein in maize contains 291 amino acids with a molecular weight of 31,721. Hydropathy profiles generated for the maize and yeast polypeptides are very similar and contain large hydrophobic domains, characteristic of membrane bound proteins. RNA transfer blot analysis indicates that atp 6 is actively transcribed. Interestingly, 122 base pairs of nucleotide sequence interior to atp 6 have extensive homology with the 5′ end of the cytochrome oxidase subunit II gene of maize mitochondria, suggesting recombination between the two genes.

Journal ArticleDOI
TL;DR: The results suggest that selection for increased testicular size would lead to improvement in female reproduction, particularly an increase in calving rate and a decrease in age at first breeding.
Abstract: Data from 528 male and 645 female progeny of 63 sires were used to estimate genetic correlations between female and male reproductive traits. Data were from two Hereford herds involved in a long-term selection program of the North Carolina Agricultural Experiment Service. Testicular measurements of circumference, diameter, length and volume were obtained on bulls at 205 and 365 d. Testicular growth measures were defined as differences between 205-and 365-d measurements. Heifers were placed in the breeding herd as yearlings and given two breeding seasons to produce a calf. Traits utilized from females were three age-at-first-breeding traits, two age-at-first-calving traits, two pregnancy rate traits, rebreeding interval and calving interval. Genetic correlations were estimated from half-sib and from sire-daughter analyses. Seventy-five percent or more of the correlations of testicular measurements with pregnancy rats, age at first breeding and age at first calving were in the favorable direction. Average correlations were .62, -.55 and -.66, respectively. For each of the remaining female traits, approximately 50% of the correlations were favorable and the average correlations were small. Correlations were summarized by testicular measurement with favorable correlations given a negative sign. Testicular diameter had more favorable correlations (80%) than length, volume or circumference (70%). However, average correlations were similar (-.31, -.30, -.34 and -.26, respectively). Testicular measurements taken at either 205 or 365 d had the same percentage of favorable correlations (72%), while testicular growth measurements had a slightly higher percentage of favorable correlations (78%). Average correlations of 365-d measures were higher (-.38) than either 205-d or growth measures (-.25 and -.28, respectively). Heritabilities for testicular measurements tended to be moderate to high, while those for female reproduction tended to be low to moderate. These results suggest that selection for increased testicular size would lead to improvement in female reproduction, particularly an increase in calving rate and a decrease in age at first breeding.

Journal ArticleDOI
TL;DR: The OPA assay was relatively as successful as a 2,4,6-trinitrobenzenesulfonic acid (TNBS) procedure in predicting the extent of hydrolysis of a protein substrate and was demonstrated by measuring the degree of proteolytic degradation caused by trypsin, subtilisin, Pronase, and chymotrypsin of various soluble protein substrates.


Journal ArticleDOI
TL;DR: In this article, the authors present a useful overview of the properties of high strength concrete that are of concern to structural engineers and the design profession, and conclude that at the material level, high-strength concrete is less ductile than normal strength concrete, but at the sectional level for reinforced concrete elements, if the ratio p/pb is kept constant, the deflection ductility is essentially independent of the strength of concrete.
Abstract: The authors have presented a useful overview of the properties of high strength concrete that are of concern to structural engineers and the design profession. They state in their conclusions that "at the material level, high strength concrete is less ductile than normal strength concrete, but at the sectional level for reinforced concrete elements, if the ratio p/ pb is kept constant, the deflection ductility is essentially independent of the strength of concrete. • This conclusion is perhaps a little optimistic and needs some further clarification and caution. An extensive parametric evaluation was conducted by the discussor 3tl using a computerized nonlinear analysis and the same stress-strain curves for concrete (of compressive strength between 5 to 13 ksi) as those used by the authors. Sectional duc-

Journal ArticleDOI
TL;DR: The authors showed that the sensitivity of consumption to transitory income is not due to liquidity constraints, but rather due to the inadequate estimation procedure of the consumption function, which supports tax discounting.

Journal ArticleDOI
TL;DR: In this article, the textural attributes of 8 different heat-induced protein gel preparations evaluated by torsion failure testing and Instron texture profile analysis (TPA) were compared to sensory ratings by a trained texture profile panel.
Abstract: The textural attributes of 8 different heat-induced protein gel preparations evaluated by torsion failure testing and Instron texture profile analysis (TPA) were compared to sensory ratings by a trained texture profile panel. The gels presented a wide range of textural properties as determined by the instrumental and sensory parameters. Among the instrumental parameters, true shear strain at failure was the most frequent and significant predictor of sensory notes. Initial shear modulus and 50% compression force had the poorest correlations with sensory notes. Comparison of the two instrumental tests produced high correlations between shear stress at failure and TPA hardness; true shear strain at failure and TPA cohesiveness; and, initial shear modulus and 50% compression force. High correlations were also observed among various panel notes. Canonical correlation analyses showed that sets of linear combinations of parameters from each one of the 3 tests (torsion, TPA or sensory) were highly correlated to sets from either of the other two. Regression equations relating each of the instrumental tests to sensory notes were developed. Of the torsion failure parameters, the logarithm of true shear strain most commonly appeared in the equations. Of the TPA parameters, cohesiveness and its logarithm were the terms that were most frequent. High R2 values were obtained for regression equations developed for predicting torsion failure parameters based on TPA parameters.

Journal ArticleDOI
TL;DR: RNA transfer blot analysis indicated that the F(0)-ATPase proteolipid gene sequence is actively transcribed, producing an initial transcript that is large and extensively processed.
Abstract: The F0-ATPase proteolipid, also referred to as subunit 9 or the dicyclohexylcarbodiimide-binding protein, is encoded by a mitochondrial gene in maize that we have designated atp 9. The clone containing atp 9 was selected for investigation from a mitochondrial DNA library because of its abundant transcript in total maize mitochondrial RNA preparations. Sequence analysis of the clone revealed an open reading frame that was readily identified by its nucleotide homology with the ATPase subunit 9 gene of yeast. As deduced from the nucleotide sequence, the maize ATPase subunit 9 protein contains 74 amino acids with a molecular weight of 7368. Substantial amino acid sequence homology is conserved among maize, yeast, bovine, and Neurospora mitochondrial ATPase subunit 9 proteins, regardless of whether the gene is nuclearly encoded (bovine and Neurospora) or mitochondrially encoded (yeast and maize). RNA transfer blot analysis indicated that the gene sequence is actively transcribed, producing an initial transcript that is large and extensively processed.

Journal ArticleDOI
01 Aug 1985-Nature
TL;DR: In this paper, the authors compared the FAO/UNEP survey with other sources of data on rates of deforestation and stocks of carbon in the tropics, then they presented the calculated net flux of carbon between tropical forests and the atmosphere based on these different data; and, finally, they considered the accuracy of current estimates of the net biotic flux.
Abstract: Deforestation in the tropics is responsible for an annual net release of carbon to the atmosphere, estimated for 1980 at between 0.5 and 4.2 × 1015 g (refs 1–6). By comparison, the release of carbon from combustion of fossil fuels was 5.2 × 1015 g in 1980. The wide range of estimates for the tropical biota and soils has been due primarily to different estimates of the rate of deforestation2,7. A recent assessment of the world's tropical forests by the Food and Agriculture Organization/UN Environment Program8,9 provides a comprehensive, country-by-country survey of deforestation in the late 1970s as well as estimates of the volumes of wood in tropical forests. The assessment thus provides an independent data base, perhaps the most reliable to date, from which terrestrial releases of carbon to the atmosphere can be calculated. Here we compare the FAO/UNEP survey with other sources of data on rates of deforestation and stocks of carbon in the tropics; then we present the calculated net flux of carbon between tropical forests and the atmosphere based on these different data; and, finally, we consider the accuracy of current estimates of the net biotic flux.

Journal ArticleDOI
TL;DR: In this article, the authors show that if ρ = 1, the limiting distribution of nonlinear least squares regression estimators of the parameters appearing in the preceding model are obtained.
Abstract: Let the time series {Yt : t ∈ (1, 2, …)} satisfy Yt = ρY t-1 + Z t and Zt + Σ p i=1 a i Zt−1 = et + Σ q j=1 β j et-j, where {e t } is a sequence of normal, independently distributed (NID(0, σ2)) random variables, and y 0 = 0. Associated with the Zt process are the characteristic equations mp + Σ p i=1 aimp-i = 0 and mq + Σ q j=1 βjmq-j = 0, the roots of which are assumed to be less than one in absolute value. Thus, using the notation of Box and Jenkins (1976), we would say Yt is an ARIMA(p, 1, q) process if ρ = 1. Under the assumption that ρ = 1, the limiting distributions of nonlinear least squares regression estimators of the parameters appearing in the preceding model are obtained. Regression t-type statistics for testing the hypothesis that ρ = 1 are discussed. Similar results are obtained for models that allow a nonzero mean. An illustrative example is given.

Journal ArticleDOI
TL;DR: The results suggest that induction of the hypersensitive reaction in tobacco proceeds through the activation of a passive plasmalemma K(+)/H(+) exchange mechanism, and it is hypothesized that activation of this exchange is a major contributing factor in hypersensitive plant cell death.
Abstract: Net electrolyte efflux from suspension-cultured tobacco cells undergoing the hypersensitive reaction to Pseudomonas syringae pv. pisi resulted from a specific efflux of K+ which was accompanied by an equimolar net influx of H+. These fluxes began 60 to 90 minutes after inoculation of tobacco cells with bacteria, reached maximum rates of 6 to 9 micromoles per gram fresh weight tobacco cells per hour within 2.5 to 3 hours, and dropped below 4 micromoles per gram per hour within 5 hours. Tobacco cells lost approximately 35% of total K+ during this period, and average cellular pH declined by approximately 0.75 pH unit. These events were accompanied by a 30% decrease in cellular ATP. K+ and H+ fluxes were inhibited by the protonophore (p-trifluoromethoxy)carbonyl cyanide phenylhydrazone and by increasing the K+ concentration of the external solution. Tobacco leaf discs inoculated with the bacterium also exhibited a specific net K+ efflux and H+ influx. These results suggest that induction of the hypersensitive reaction in tobacco proceeds through the activation of a passive plasmalemma K+/H+ exchange mechanism. It is hypothesized that activation of this exchange is a major contributing factor in hypersensitive plant cell death.

Journal ArticleDOI
01 Dec 1985-Virology
TL;DR: The sequence of the 1491 nucleotides found at the 3' end of the genome of the highly aphid-transmissible (HAT) isolate of tobacco etch virus (TEV) has been determined and the deduced amino acid sequences of the two TEV capsid proteins displayed 98% homology and a 66% Homology with PeMV capside protein.

Journal ArticleDOI
TL;DR: This work and the more recent description of five additional Mexican maize races by Hernandez and Alanis (1970) provide an understanding of the racial diversity in Mexican maize and the correlations between isozyme variation and ecological-geographical parameters are discussed.
Abstract: Twelve plants each of 94 collections of maize (Zea mays L. subsp. mays) representing 34 races from Mexico were analyzed for 13 enzyme systems encoded by 23 loci. This analysis revealed an exceptionally high level of variation within and among the races. We recorded an average of 7.09 alleles/locus and an expected heterozygosity of 0.182. Seventy-two percent of the isozyme variation resided within collections, and 27% among collections. Races from northern and northwestern Mexico tend to possess higher levels of variation than those from the south. Variation for some isozyme alleles is strongly correlated with altitude. Maize is among the most variable species that have been studied isoenzymatically. Maize has levels of variation comparable to those found in its wild relatives, the teosintes. Principal component and cluster analyses showed continuous variation among the races with no well-defined racial complexes; however, three weakly differentiated groups were apparent: 1) the high-elevation Mexican pyramidal races, 2) the northern and northwestern races, and 3) most remaining races including the southern and western low-elevation dent and flour corns. of Mexico from the desert northwest to the tropical lowlands of Chiapas. Over this ecogeographic landscape, maize has diversified into a multitude of forms, each adapted to the demands of its environment and the desires of its cultivators. Because the morphological-ecological variation among these forms is continuous in nature, the classification of Mexican maize into discrete categories is difficult. Despite these difficulties, Wellhausen, Roberts and Hernandez (1952) produced a useful morphological classification of Mexican maize including the description of 29 races and subraces. This work and the more recent description of five additional Mexican maize races by Hernandez and Alanis (1970) provide an understanding of the racial diversity in Mexican maize. In this paper, we examine the pattern of isozyme variation among and within the races of maize of Mexico. The isozyme data are used to examine relationships among the races and to assess the amount of genetic variation within each race. Further, the correlations between isozyme variation and ecological-geographical parameters are discussed and the amount of genetic variation in Mexican maize, teosinte, and other plants compared. MATERIA1S AND METHODSWe examined 12 plants each from 93 collections of maize from Mexico and 1 collection from Guatemala (TaMAIZE (Zea mays L. subsp. mays) is the third most important cereal worldwide and the single most important food plant in Latin America. In Mexico and other Latin American countnes, maize has a central role in the native cultures, being displayed with prominence and reverence in both religious ceremonies and secular festivals (Anderson, 1952; Mangelsdorf 1974). The cultural importance of maize in Mexican society testifies to its long history of cultivation in this country. The oldest known archaeological maize ears were discovered near Puebla, Mexico, and were dated to the fifth millenium B.C. (MacNeish, 1967). This and other evidence have established Mexico as the cradle of maize domestication (Mangelsdorf, 1974). Not surprisingly, Mexico is also the homeland of the only close relative and probable wild ancestor of maize, teosinte (Wilkes, 1967; Doebley, 1983). Maize is cultivated in nearly every district ' Received for publication 1 1 June 1984; revision accepted 2 October 1984. Paper No. 9615 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC. This investigation was supported, in part, by a grant from Pioneer Hi-Bred International of Johnston, Iowa, and by NIH Research Grant No. GM11546 from the National Institute of General Medical Sciences of the U.S.A. We wish to thank Drs. Peter Bretting, Ted Emigh, Paul Sisco, David Timothy, and Jon Wendel for providing helpful criticisms on this paper.

Journal ArticleDOI
TL;DR: It is proposed that S‐1 and S‐2 code for functions involved with their maintenance and replication, based on their structural organization and their viral‐like characteristics.
Abstract: Mitochondria from the S male-sterile cytoplasm of maize contain unique DNA-protein complexes, designated S-1 and S-2 These complexes consist of double-stranded linear DNAs with proteins covalently attached to the 5' termini To learn more about these unusual DNAs we have determined the complete nucleotide sequence of the S-1 DNA molecule (6397 bp) The sequence of S-2 has been previously determined S-1 and S-2 are structurally similar and contain 17kb of sequence homology S-1 is terminated by exact 208-bp inverted repeats that are identical with the terminal inverted repeats of S-2 S-1 and S-2 also contain a 1462-bp region of nearly perfect homology, which includes one of the terminal inverted repeats The homology between the two molecules may be maintained, in part, by homologous recombination S-1 has three long unidentified open reading frames, URF2 (1017 bp), URF3 (2787 bp) and URF4 (768 bp) URF2 occurs in the 1462-bp region of homology and is identical in length and location in both S-1 and S-2 Based on their structural organization and their viral-like characteristics, we propose that S-1 and S-2 code for functions involved with their maintenance and replication

Journal ArticleDOI
TL;DR: Primary benefits of controlled breeding are convenience and efficient use of labor for detection of estrus and insemination and biotechnical procedures such as embryo transfer and insertion of specific genes may enhance rates of genetic improvement for important economic traits.

Journal ArticleDOI
TL;DR: In this paper, the mechanisms of the crystalline to amorphous transformation in ion implanted III-V compound semiconductors and silicon are reviewed and validity of these models has been tested in view of the recent high resolution transmission electron microscopy results from damage or ammorphous/crystalline interfaces.
Abstract: This review attempts to cover the mechanisms of the crystalline to amorphous transformation in ion implanted III–V compound semiconductors and silicon. Existing models for such a transformation are reviewed and validity of these models has been tested in view of the recent high resolution transmission electron microscopy results from damage or amorphous/crystalline interfaces. Drastic reduction in amorphization due to in situ annealing during ion implantation has been demonstrated. In the latter part of this review the mechanisms of atom migrations across the amorphous/crystalline interface, origin or the nucleation of dislocations, stacking faults, microtwins, precipitates, etc. on annealing of amorphous or damage regions in III–Vs and Si have been covered. Finally, correlations among the reported structural and electrical results have been discussed.

Journal ArticleDOI
TL;DR: Based on nucleotide and amino acid homology, a mitochondrial gene is identified that appears to code for the F1-ATPase α subunit of Zea mays, and is present as a single copy in the maize.
Abstract: The alpha subunit of the F(1)-ATPase complex of maize is a mitochondrial translational product, presumably encoded by the mitochondrial genome. Based on nucleotide and amino acid homology, we have identified a mitochondrial gene, designated atpalpha, that appears to code for the F(1)-ATPase alpha subunit of Zea mays. The atpalpha gene is present as a single copy in the maize. Texas cytoplasm and is actively transcribed. The maize alpha polypeptide has a predicted length of 508 amino acids and a molecular mass of 55,187 daltons. Amino acid homologies between the maize mitochondrial alpha subunit and the tobacco chloroplast CF(1) and Escherichia coli alpha subunits are 54 and 51%, respectively. The origin of the atpalpha gene is discussed.

Journal ArticleDOI
TL;DR: It is shown that the method of Takahashi corresponds to a modified block Gauss-Seidel step and aggregation, whereas that of Vantilborgh corresponds to an modified block Jacobistep and aggregation.
Abstract: Iterative aggregation/disaggregation methods provide an efficient approach for computing the stationary probability vector of nearly uncoupled (also known as nearly completely decomposable) Markov chains. Three such methods that have appeared in the literature recently are considered and their similarities and differences are outlined. Specifically, it is shown that the method of Takahashi corresponds to a modified block Gauss-Seidel step and aggregation, whereas that of Vantilborgh corresponds to a modified block Jacobi step and aggregation. The third method, that of Koury et al., is equivalent to a standard block Gauss-Seidel step and iteration. For each of these methods, a lemma is established, which shows that the unique fixed point of the iterative scheme is the left eigenvector corresponding to the dominant unit eigenvalue of the stochastic transition probability matrix. In addition, conditions are established for the convergence of the first two of these methods; convergence conditions for the third having already been established by Stewart et al. All three methods are shown to have the same asymptotic rate of convergence.

Journal ArticleDOI
TL;DR: In this paper, the effects of a low level of dietary sodium, and a high dietary level of zinc as induced molting agents for commercial strains of laying hens were compared in three trials.