Showing papers by "Iowa State University published in 1979"
TL;DR: In this article, the limit distributions of the estimator of p and of the regression t test are derived under the assumption that p = ± 1, where p is a fixed constant and t is a sequence of independent normal random variables.
Abstract: Let n observations Y 1, Y 2, ···, Y n be generated by the model Y t = pY t−1 + e t , where Y 0 is a fixed constant and {e t } t-1 n is a sequence of independent normal random variables with mean 0 and variance σ2. Properties of the regression estimator of p are obtained under the assumption that p = ±1. Representations for the limit distributions of the estimator of p and of the regression t test are derived. The estimator of p and the regression t test furnish methods of testing the hypothesis that p = 1.
23,509 citations
TL;DR: In this article, the prominent lines of 70 elements as emitted in an inductively coupled plasma excitation source have been identified and the lines are listed alphabetically by element and numerically by wavelength.
Abstract: The prominent lines of 70 elements as emitted in an inductively coupled plasma excitation source have been identified. The lines are listed alphabetically by element and numerically by wavelength. Detection limit capabilities are estimated for each spectral line.
391 citations
345 citations
TL;DR: In this article, a review of previous studies on the prediction of employee turnover conducted in the past 50 years is critically reviewed, which resulted in five general categories: attitudinal (job satisfaction), biodata, work-related, personal, and test score predictors.
324 citations
TL;DR: In this paper, the MCSCF wave function is determined through a sequence of eigenvalue problems in the multiconfiguration space and the single-excitation space, which are used iteratively to improve the natural orbitals.
Abstract: A novel approach is developed for optimizing molecular orbitals within the context of a multiconfiguration self-consistent-field problem. The MCSCF wave function is determined through a sequence of eigenvalue problems in the multiconfiguration space and the single-excitation space. They are used iteratively to improve the natural orbitals, which in turn are related, by successively improved transformations, to the MCSCF orbitals. The mathematical problems arising out of this general concept are solved and the computational implementation is discussed. In many applications the method has proven itself as a powerful approach in forcing rapid convergence. Adaptation to spin and spatial symmetry is maintained throughout, and the procedure is applicable to excited states as well as to ground states. 3 figures, 2 tables.
256 citations
TL;DR: The effective population size is the same as that for a population with discrete generations having the same variance of lifetime family size and the same number of individuals entering the population per generation.
Abstract: A simple derivation is given far a formula obtained previously for the effective size of random-mating populations with overlapping generations. The effective papulation size is the same as that for a population with discrete generations having the same variance of lifetime family size and the same number of individuals entering the population per generation.
251 citations
TL;DR: In this paper, the effects of asking students questions at different levels of cognitive complexity during learning were discussed, and it was shown that higher level questions can have facilitative effects on both reproductive and productive knowledge.
Abstract: The paper is concerned with the effects of asking students questions at different levels of cognitive complexity during learning. The first section reviewed research on levels of questions. It was shown that higher level questions can have facilitative effects on both reproductive and productive knowledge, but that the conditions under which such facilitation occurs are not well understood. The second section outlines an information processing model of human cognition that can account for question level effects and that serves to integrate previous research on question level and to provide direction for future research in this area.
248 citations
TL;DR: In this paper, a simple system for the separation and determination of mixtures of inorganic and organic anions is described, where the anions are separated on a column containing a macroporous anion-exchange resin which has a very low exchange capacity of 0.007-0.07 mequiv/g.
246 citations
TL;DR: The literature of ridge regression and James-Stein estimation is broadly reviewed in this paper, and critical comments are interpolated on a number of papers, expressing their viewpoints on ridge regression, and their antipathy to its mechanical use.
Abstract: The literature of ridge regression and James-Stein estimation is broadly reviewed, and critical comments are interpolated on a number of papers. The authors also express their viewpoints on ridge regression and their antipathy to its mechanical use.
216 citations
TL;DR: In this article, a modification of the colorimetric procedure was described that permits use of phosphoric acid containing these impurities and allows accurate and precise determination of urea in soil extracts.
Abstract: Some batches of phosphoric acid contain impurities that affect colorimetric determination of urea in soil extracts by the method of Douglas and Bremner, which involves measurement of the red color formed when an aliquot of extract is heated with diacetyl monoxime and thiosemicarbazide in the presence of phosphoric and sulfuric acid. A modification of this colorimetric procedure is described that permits use of phosphoric acid containing these impurities and allows accurate and precise determination of urea in soil extracts.
179 citations
TL;DR: The chapter discusses idealized patterns for cotton, a taprooted dicotyledonous plant, and maize, a fibrous-rooted monocotylesis plant, with both axial and radial resistances to water flow from midway between roots located deep within soil to the xylem at the land surface.
Abstract: Publisher Summary The chapter discusses both axial and radial resistances to water flow from midway between roots located deep within soil to the xylem at the land surface. The chapter discusses idealized patterns for cotton, a taprooted dicotyledonous plant, and maize, a fibrous-rooted monocotyledonous plant. Water uptake by cotton plants grown in a rhizotron compartment was modeled. In the analysis it was assumed (1) that the radial resistance to water flow from the midpoint between roots to lumen of the xylem was a function only of volumetric water content of the soil layer—that is, the radial resistance-water content relations did not vary with root age or with soil depth and (2) that axial resistance was negligible. The total quantity of water available at any one time for withdrawal by a plant increases with available soil water content and with volume of soil occupied by its roots. Plant species differ greatly in the shape and size of their root systems and in their water extraction patterns. The characteristic rooting pattern of each species is genetically controlled but environmentally modified.
TL;DR: Waxy maize starch has been examined by electron microscopy to learn details of the structure of the molecules and their organization in starch granules, envisioning the molecular chains as being packed in double helices as is appropriate for the A-type Xray diffraction pattern, both before and after the acid treatment.
TL;DR: In this article, the duplication theorem is applied to logarithms, arctangents, and elliptic integrals of all three kinds (including complete integrals) by successive applications of duplication theorem, and the convergence is improved by including a fixed number of terms of Taylor's series.
Abstract: Logarithms, arctangents, and elliptic integrals of all three kinds (including complete integrals) are evaluated numerically by successive applications of the duplication theorem. When the convergence is improved by including a fixed number of terms of Taylor's series, the error ultimately decreases by a factor of 4096 in each cycle of iteration. Except for Cauchy principal values there is no separation of cases according to the values of the variables, and no serious cancellations occur if the variables are real and nonnegative. Only rational operations and square roots are required. An appendix contains a recurrence relation and two new representations (in terms of elementary symmetric functions and power sums) forR-polynomials, as well as an upper bound for the error made in truncating the Taylor series of anR-function.
TL;DR: In this article, the Hartree-Fock limit of SCF wavefunctions is derived from the detailed quantitative information available from these calculations and a simple general procedure is formulated for generating optimal even-tempered basis sets for molecular calculations.
Abstract: Explicit formulas are established for simply generating arbitrarily large basis sets of optimal even-tempered Gaussian primitives which systematically approach complete bases for the entire function space. These bases, moreover, reproduce the corresponding optimal atomic SCF wavefunctions extremely closely and permit an extrapolation of the SCF energies to the Hartree-Fock limit. On the basis of the detailed quantitative information available from these calculations a simple general procedure is formulated for generating optimal even-tempered basis sets for molecular calculations.
TL;DR: It is suggested that the quality, rather than quantity, of social interaction is crucial to understanding adaptations to old age.
Abstract: Problems of social and psychological adjustment in later life have been examined by numerous investigators. Some have found positive relationships between social interaction and personal adjustment, while others have found interaction and adjustment to be unrelated. The purpose of the research reported here was to examine how different ways of measuring interaction may affect its relationship with personal adjustment. Data were obtained in interviews with 218 noninstitutionalized persons aged 70 and older. Findings indicate that both the number of persons interacted with, and the frequency of this interaction, are of little importance for the adjustment of older people. We suggest that the quality, rather than quantity, of social interaction is crucial to understanding adaptations to old age.
TL;DR: In this article, the number of viable seeds in a sample was estimated by placing samples in environments appropriate for seed germination and counting the number number of seedlings in the sample.
TL;DR: This chapter discusses the subfornical organ (SFO), a small, almost hemispherical or ovoid tubercle that protrudes into the lumen of the third ventricle at the level of the interventricular foramina in vertebrates.
Abstract: Publisher Summary This chapter discusses the subfornical organ (SFO). SFO is a small, almost hemispherical or ovoid tubercle that protrudes into the lumen of the third ventricle at the level of the interventricular foramina. This topographic relationship is consistent in all vertebrates, regardless of whether the fornix is present or absent, as in lower vertebrates, and it is thus more appropriate to refer to the organ as the “interventricular organ.” The SFO derives from the ependymal wall of the telencephalon, from the dorsal portion of the commissural plate at the point of origin of the telencephalic-choroid plexus. The structure of the fetal SFO approaches that of the adult SFO. The morphological components of the SFO are neuronal perikarya and their dendrites and axons, dendrites and axons of unknown origin and destination, macroglial cells and microglial cells, ependymal cells and tanycytes, supraependymal neurons, glial cells, macrophages, and a rich vascular supply.
TL;DR: There are fears that increased nitrogen fertilisation of soils may increase release of N2O from soils through denitrification of nitrate and thereby pose a threat to the stratospheric ozone layer protecting the Earth from biologically harmful UV radiation from the Sun.
Abstract: THERE are fears that increased nitrogen fertilisation of soils may increase release of N2O from soils through denitrification of nitrate and thereby pose a threat to the stratospheric ozone layer protecting the Earth from biologically harmful UV radiation from the Sun1–6.
TL;DR: It is proved that for every tally language set in NP there exists a polynomial time equivalent set inNP that isp-selective, and it follows that if NEXT ≠ DEXT, then polynometric time Turing and many-one reducibilities differ onNP.
Abstract: The notion ofp-selective sets, and tally languages, are used to study polynomial time reducibilities onNP. P-selectivity has the property that a setA belongs to the classP if and only if bothĀ ≤
A andA isp-selective. We prove that for every tally language set inNP there exists a polynomial time equivalent set inNP that isp-selective. From this result it follows that if NEXT ≠ DEXT, then polynomial time Turing and many-one reducibilities differ onNP.
TL;DR: In this article, a factor analysis of responses to Rosenberg's 10-item self-esteem scale by 1,332 older men living in small communities suggested this was not a unidimensional scale.
Abstract: Further factor analysis of responses to Rosenberg's 10-item self-esteem scale by 1,332 older men living in small communities suggested this was not a unidimensional scale.
TL;DR: Ilimaquinone (1) is a new sponge metabolite of composition C22H30O4 whose structure, which was determined by spectral correlations and X-ray crystallography, comprises a rearranged drimane sesquiterpene moiety linked to a 2-hydroxy-5methoxybenzoquinone at C-3.
TL;DR: The production of dextransucrase from Leuconostoc mesenteroides NRRL B-512F was stimulated 2-fold by the addition of 0.005% of calcium chloride to the medium; levansucrase levels were unaffected; and the mannoglycoprotein character of the enzyme was confirmed.
16 Jul 1979
TL;DR: The notion of p-selective sets, and tally languages, are used to study polynomial time reducibilities on NP as mentioned in this paper, and it has been shown that for every tally language set in NP there exists a polynomially time equivalent set that is pselective.
Abstract: The notion of p-selective sets, and tally languages, are used to study polynomial time reducibilities on NP. P-selectivity has the property that a set A belongs to the class P if and only if both Ā ≤ m P A and A is p-selective. We prove that for every tally language set in NP there exists a polynomial time equivalent set in NP that is p-selective. From this result it follows that if NEXT ≠ DEXT, then polynomial time Turing and many-one reducibilities differ on NP.
TL;DR: In this paper, a multiconfiguration self-consistent field (MCSCF) calculation is carried out for the lowest two states of /sup 1/A/sub g/sigma/sup 2/..pi../sup 2/) and it is established that both these dissociations proceed without any barrier in the energy curve.
Abstract: The direct dissociation of ethylene into two methylenes is studied along the least motion reaction path by means of an ab initio multiconfiguration self-consistent-field (MCSCF) calculation. All eight configurations arising from those valence orbitals that form the CC bonds, seven of them singlet coupled and one triplet coupled, are taken into account. The HCH bond angle is optimized along the entire reaction path. Separate MCSCF optimizations are carried through for the lowest two states of /sup 1/A/sub g/ symmetry. The (/sup 1/A/sub g/sigma/sup 2/..pi../sup 2/) ethylene ground state dissociates into two (/sup 3/B/sub 1/sigma..pi..) ground-state methylenes. The (/sup 1/A/sub g/sigma/sup 2/..pi..*/sup 2/) excited state of ethylene dissociates into two (/sup 1/A/sub 1/sigma/sup 2/) excited methylenes. It is established that both these dissociations proceed without any barrier in the energy curve. In the ground state, where orbital symmetry is conserved, the ..pi..-bond breaks before the sigma-bond, and the calculated heat of reaction agrees within 6 kcal/mol with the experimental value. In the excited state, where orbital symmetry is not conserved, the nonbonded repulsion between methylene sigma/sup 2/ lone pairs is found to blend into the antibonding character of the excited ethylene, yielding an energy curve that is everywhere repulsive. However, themore » variation of the HCH angle during the dissociation process is not simple, initially it expands and subsequently it contracts. Quantitative analytical approaches are developed which furnish conceptual interpretations of the orbital changes and configurational changes along the reaction path.« less
TL;DR: Behavioral analgesia and tolerance reported here may involve habituation to novel distractive stimuli associated with the hot plate test environment.
Abstract: Rats not exposed to a hot plate with or without morphine and later tested on the functional hot plate with or without morphine, displayed increased paw lick latency relative to same-injected rats given pretest hot plate exposure. This analgesic effect, was termed behavioral analgesia since it, unlike morphine-induced analgesia, was not reversed by naloxone (Experiment 2). Behavioral tolerance was evident in animals exposed to the nonfunctional hot plate regardless of drug treatment and was dissociated from pharmacological tolerance. Behavioral analgesia and tolerance reported here may involve habituation to novel distractive stimuli associated with the hot plate test environment.
TL;DR: Rape attributions are discussed within the contexts of identification with victim's situation and perceptions of victim's control, and fault, blame, and responsibility were found not to be interchangeable.
Abstract: Perceptions of sexual assault were investigated as a function of sex of observer, nature of victim resistance, and assault outcome. Two hundred twenty-nine subjects were randomly assigned by sex to six resistance × outcome conditions. Hypotheses that women and men apply sex-role stereotypes in evaluating the rape situation were supported: (a) subjects were more certain that rape had occurred as the victim resisted more; (b) subjects attributed greater responsibility to the victim for completed than for attempted rape, while the reverse pattern was found for the assailant; (c) women attributed more responsibility to the assailant than did men; and (d) men attributed less fault and more intelligence, and women attributed more fault and less intelligence to the rape victim as she resisted more forcefully. Attributional terms; fault, blame, and responsibility were found not to be interchangeable. Rape attributions are discussed within the contexts of identification with victim's situation and perceptions of victim's control. Implications for choice of self-defense strategy and treatment of rape victims are also considered.
TL;DR: In this article, it was shown that the Kolmogorov-Sinai entropy of the adjoint of an automorphism on the dual group of a discrete group can be expressed as the inverse transposition of the matrix of an adjoint.
TL;DR: The production of pointing, the understanding of pointing and the comprehension of another's line of regard was investigated in 36 male and female infants 9-, 12-, and 14-months-old.
Abstract: Summary The production of pointing, the understanding of pointing and the comprehension of another's line of regard was investigated in 36 male and female infants 9-, 12-, and 14-months-old. Production of pointing was present in eight out of twelve 12-month-olds and in eleven out of twelve 14-month-olds; only a few of the youngest Ss pointed. For the youngest infants comprehension of pointing was a function of the distance between the person pointing and the object pointed to. All 12- and 14-month-old children comprehended the pointing to a nearby object and most of them also understood the pointing to a distant object. Ten out of twelve 12-month-olds and eleven out of twelve 14-month-olds were able to tell where another person was looking if both the cues of movement and orientation of the head and the eyes were present; their performance was less perfect with only the cue of orientation present or with only the eyes moving. Never more than three out of the twelve youngest Ss succeeded on any of these pe...
TL;DR: The predictive validity of WISC-R factor scores was examined with samples from the four sociocultural groups of Anglo, Black, Chicano, and native American Papago as discussed by the authors.