Showing papers by "Purdue University published in 1970"
TL;DR: Plasminogen was prepared from human plasma by affinity chromatography on L-lysine-substituted Sepharose with a specific activity of 100 caseinolytic units per milligram of nitrogen.
Abstract: Plasminogen was prepared from human plasma by affinity chromatography on L-lysine-substituted Sepharose. Thirty milligrams of plasminogen, with a specific activity of 100 caseinolytic units (Committee on Thrombolytic Agents) per milligram of nitrogen, were obtained from 340 milliliters of plasma. This corresponds to over 200-fold purification from plasma. Disc-gel electrophoresis at pH 8.3 indicated seven distinct bands, all of which contained activity.
2,051 citations
TL;DR: In this paper, the first and second-order Raman spectra of diamond were studied using the 4880 and 5145 lines of an Ar ion laser and the 6328 \AA{} line of a He-Ne laser.
Abstract: The first- and second-order Raman spectra of diamond were studied using the 4880 \AA{} and 5145 \AA{} lines of an Ar ion laser and the 6328 \AA{} line of a He-Ne laser. The spectra were recorded at room, liquid-nitrogen, and liquid-helium temperatures. In addition to the second-order spectrum previously reported by Krishnan, a new weaker second-order spectrum was observed in the range 1600-2100 ${\mathrm{cm}}^{\ensuremath{-}1}$. Polarization studies were carried out on both the first- and second-order spectra. From such studies it was established that the 1332-${\mathrm{cm}}^{\ensuremath{-}1}$ Raman line is the zone-center optical phonon with ${\ensuremath{\Gamma}}^{(25+)}$ (${F}_{2g}$) symmetry. The prominent features in both the second-order Raman spectra reported here and the second-order infrared spectra are interpreted in terms of the critical points of the phonon dispersion curves established from neutron spectroscopy and on the basis of space-group selection rules.
623 citations
TL;DR: A method is developed herein to use the Karhunen-Loeve expansion to extract features relevant to classification of a sample taken from one of two pattern classes.
Abstract: The Karhunen-Lo6ve expansion has been used previously to extract important features for representing samples taken from a given distribution. A method is developed herein to use the Karhunen-Loeve expansion to extract features relevant to classification of a sample taken from one of two pattern classes. Numerical examples are presented to illustrate the technique.
562 citations
TL;DR: The findings are consistent with the hypothesis that vesicles produced by the endomembrane system in the subapical region become concentrated in the apex where they are incorporated at the expanding surface.
Abstract: Hyphal tips of fungi representing Oomycetes, Zygomycetes, Ascomycetes, Basidiomycetes, and Deuteromycetes were examined by light and electron microscopy and compared with respect to their protoplasmic organization. In all fungi studied, there is a zone at the hyphal apex which is rich in cytoplasmic vesicles but nearly devoid of other cell components. Some vesicle profiles are continuous with the plasma membrane at the apices of these tip-growing cells. The subapical zones of hyphae contain an endomembrane system which includes smooth-surfaced cisternae associated with small clusters of vesicles. The findings are consistent with the hypothesis that vesicles produced by the endomembrane system in the subapical region become concentrated in the apex where they are incorporated at the expanding surface. Septate fungi (Ascomycetes, Basidiomycetes, and Deuteromycetes) have an apical body (Spitzenkorper) which is associated with growing hyphal tips. In electron micrographs of these fungi, an additional specialized region within the accumulation of apical vesicles is shown for the first time. This region corresponds on the bases of distribution among fungi, location in hyphae, size, shape and boundary characteristics to the Spitzenkorper seen by light microscopy. This structure is not universally associated with tip growth, whereas apical vesicles are widespread among tip-growing systems.
429 citations
TL;DR: Adsorption, therefore, appears to be one of the major factors affecting the interactions occurring between pesticides and soil colloids.
Abstract: Seven factors are known to influence the fate and behavior of pesticides in soil systems: (1) chemical decomposition, (2) photochemical decomposition, (3) microbial decomposition, (4) volatilization, (5) movement, (6) plant or organism uptake, and (7) adsorption. The phenomenon of adsorption-desorption directly or indirectly influences the magnitude of the effect of the other six factors. Adsorption, therefore, appears to be one of the major factors affecting the interactions occurring between pesticides and soil colloids.
404 citations
TL;DR: In this article, the structural importance of linguistic units was shown to be related to their recall, and the linguistic units were then objectively ordered according to their importance to the structure of the larger prose passage.
395 citations
362 citations
TL;DR: The fast Fourier transform (FFT) technique for cross correlation of misregistered imagery to determine spatial distances is discussed in detail and a method of achieving translational, rotational, and scaling corrections between images is described.
Abstract: A system for spatial registration of digitized multispectral and multitemporal imagery is described. Multispectral imagery can be obtained from sources such as multilens cameras, multichannel optical-mechanical line scanners, or multiple vidicon systems which employ filters or other spectral separation techniques to sense selected portions of the spectrum. Spatial registration is required so that multidimensional analysis can be performed on contextually similar image elements from different wavelength bands and at different times. The general registration problem is discussed first; then the fast Fourier transform (FFT) technique for cross correlation of misregistered imagery to determine spatial distances is discussed in detail. A method of achieving translational, rotational, and scaling corrections between images is described. Results of correlation analysis of multispectral scanner imagery and digitized satellite photography is presented. Use of the system for registration of multispectral airborne line-scanner imagery and space photography is described. Application of the techniques to preprocessing of earth resources satellite imagery from systems such as the earth-resources technology satellite (ERTS) scanner and vidicon system is discussed in conclusion.
351 citations
TL;DR: In this article, the composition regions of a large number of binary salt-water systems in which macroscopic samples can be obtained in the vitreous state have been determined, and the glass transition temperatures Tg within these regions have also been measured.
Abstract: As a first stage in a study of the low‐temperature‐region behavior of aqueous solutions, the composition regions of a large number of binary salt‐water systems in which macroscopic samples can be obtained in the vitreous state have been determined. The glass transition temperatures Tg within these regions have also been measured. Correlations of the magnitude of Tg at a given composition with the formal charge on the cation (for salts with a common anion) and with the viscosity “B” coefficient of the anion (for salts with a common cation) are presented. In addition, an important correlation is found with the basicity of the anion which is interpreted in terms of the bonding of anions to the protons of the water molecules in the cationic hydration sheath. Thermodynamic relations for the composition dependence of Tg are presented. From the breaks in the otherwise monotonic composition dependence of Tg in the chloride systems, the existence of low temperature liquid–liquid immiscibility regions is proposed and is utilized in discussion of “total” hydration numbers. The Tg for pure water, obtained by extrapolation of the data, is found to be in agreement with the value obtained for vapor‐deposited vitreous ice but to be incompatible with the value predicted from thermodynamic data; an interpretation in terms of different short‐range order possibilities for water molecules is offered.
315 citations
TL;DR: The authors analyzes the overlap of opinion leadership across six broad product categories and finds substantial overlap, particularly across those product categories of similar interest, and suggests substantial overlap among opinion leaders across different product categories.
Abstract: This article analyzes the overlap of opinion leadership across six broad product categories; its data suggest substantial overlap—particularly across those product categories of similar interest.
296 citations
TL;DR: In this article, the pore size distributions and total porosity of a number of reference clays, naturally-occurring subsoils, and commercial clay samples prepared in various ways were determined by mercury porosimetry.
Abstract: Abstraet-A knowledge of the distribution of pore sizes in clay and soil bodies is a useful element in the microstructural characterization of such materials. Pore-size distributions and total porosity of a number of reference clays, naturally-occurring subsoils, and commercial clay samples prepared in various ways were determined by mercury porosimetry. The range of equivalent pore diameter explored covered almost five orders of magnitude, from several hundred microns down to approximately 150A. The method and its assumptions are critically evaluated, and measurements of the contact angle of mercury on clays yield values of 139 ~ for montmorillonite and 147 ~ for kaolinite and illite clays. The extent of shrinkage on oven-drying prior to mercury intrusion is assessed in each case and found to vary from insignificant to as much as 30 per cent of the pore space, depending on microstructural state and degree of initial saturation. The development of techniques for water removal which do not involve change in pore structure is explored. Some preliminary results for structurally weak saturated clays suggest that critical-region drying and perhaps freeze-drying procedures may be practical.
TL;DR: In this paper, the Boltzmann equation in the local approximation of the electromagnetic wave equation in a tensor medium yields two normal modes, whose complex propagation constants and polarizations are determined by the microscopic medium parameters as well as the angle θ between wave vector q and applied magnetic field B0.
Abstract: The interaction of electromagnetic waves with free-carrier plasmas in semiconductors and semimetals is analysed, with particular emphasis on microwave and infrared effects arising in the presence of external magnetic fields. The general frequency- and field-dependent dielectric tensor is initially developed for a single isotropic band via the Boltzmann equation in the local approximation. Solution of the electromagnetic wave equation in the tensor medium yields two normal modes, whose complex propagation constants and polarizations are determined by the microscopic medium parameters as well as the angle θ between wave vector q and applied magnetic field B0. We first consider wave propagation in the lossless (collisionless) limit, and concentrate on the properties of normal modes in the Faraday (q parallel B0) and Voigt (q perpendicular B0) geometries. Essential features of the wave interaction with the medium are conveniently set forth in `contour maps' which display zeroes and infinities of the lossless dielectric constants, indicating resonances, dielectric anomalies and black-out regions for each mode of propagation over a wide range of frequencies and fields. Losses are then explicitly incorporated into the dielectric tensor, and their effect discussed in some detail. A number of experimental examples associated with the single band model are presented, including free-carrier absorption, cyclotron resonance, Faraday and Voigt effects, helicon waves, magnetoplasma reflection and small-particle effects. The presentation is subsequently generalized to more complicated systems. The dielectric tensor is developed for a multiple-carrier plasma and for anisotropic bands. A variety of new effects is seen to arise, including hybrid resonances, tilted-orbit resonances and Alfven wave propagation. `Contour maps' of appropriate lossless dielectric constants are again found convenient in discussing these new features. Effects of spatial dispersion (nonlocal phenomena) and of orbital quantization on the high-frequency response of a free-carrier system are then considered. The contribution of the polar lattice, which gives rise to a vast array of coupled magnetoplasma-phonon modes, is finally examined. A further elaboration of certain topics arising in this review is presented in an appendix, including a detailed discussion of electron dynamics, the `polariton' formalism, fundamentals of Kramers-Kronig analysis and magneto-optics of birefringent media.
TL;DR: In this article, the Laplace continued fraction was used to compute the Gauss-Hermite quadrature of the first quadrant of the real line in the first order.
Abstract: The paper is concerned with the computation of $w(z) = \exp ( - z^2 ){\operatorname{erfc}}( - iz)$ for complex $z = x + iy$ in the first quadrant $Q_1 :x \geqq 0,y \geqq 0$. Using Stieltjes– theory of continued fractions it is first observed that the Laplace continued fraction for $w(z)$, although divergent on the real line, represents $w(z)$ asymptotically for $z \to \infty $ in the sector $ S:{{ - \pi} / 4} < \arg z < {{5\pi } / 4}$. Specifically, the nth convergent approximates $w(z)$ to within an error of $O(z^{ - 2n - 1} 1)$ as $z \to \infty $ in S. A recursive procedure is then developed which permits evaluating $w(z)$ to a prescribed accuracy for any $z \in Q_1 $. The procedure has the property that as $| z |$ becomes sufficiently large, it automatically reduces to the evaluation of the Laplace continued fraction, or, equivalently, to Gauss–Hermite quadrature of $({i / \pi })\int_{ - \infty }^\infty {\exp ( - t^2 ){{dt} / {(z - t)}}} $.
TL;DR: The chapter describes that spherical viruses self-assemble, as a variety of other biologically significant structures, and the detailed conditions required, do not unexpectedly differ among the viruses.
Abstract: Publisher Summary This chapter discusses the self-assembly of spherical plant viruses. The realization that the treatment of certain spherical viruses with 1 M NaCl or other salts at suitable pH levels provided a method for preparing protein subunits appropriate for reconstitution studies. Some of the viruses respond to the method and others do not. Those that respond probably lack a true nucleic acid-free top component, but may have more than one component, such as pea enation mosaic virus or Tulare apple mosaic virus. It is shown that self-assembly could actually occur, at least, with tobacco mosaic virus (TMV) protein. The directions for self-assembly in all simple viruses resides in their protein structure units, which are equated with single equivalent protein molecules, which aggregate to form minimum-energy structures. Icosahedral as well as tubular viruses are predicted to self-assemble on this basis. The chapter describes that spherical viruses self-assemble, as a variety of other biologically significant structures, and the detailed conditions required, do not unexpectedly differ among the viruses.
TL;DR: Thyroxine treatment greatly enhances the development of the median eminence in the tadpole, and androgens organize the “male” quality of hypothalamic control of gonadotropin secretion in the mouse and rat.
Abstract: SOME endocrine glands seem to influence the development and organization of neural regions which in turn control them. Thus thyroxine treatment greatly enhances the development of the median eminence in the tadpole1, and androgens organize the “male” quality of hypothalamic control of gonadotropin secretion in the mouse and rat2–4.
TL;DR: The pattern of invertase activity in comparison with that of Sucrose-uridine diphosphate glucosyltransferase supports previous suggestions, that the latter plays a key role in the conversion of sucrose to starch.
Abstract: A number of enzymes presumably implicated in starch synthesis were assayed at various stages of endosperm development ranging from 8 days to 28 days after pollination. Activity for invertase, hexokinase, the glucose phosphate isomerases, the phosphoglucomutases, phosphorylase I, uridine diphosphate glucose pyrophosphorylase, and the starch granule-bound nucleoside diphosphate glucose-starch glucosyltransferase was present at the earliest stage of development (8 days) studied. Activity was detectable for phosphorylase III, the soluble adenosine diphosphate glucose-starch glucosyltransferase, adenosine diphosphate glucose pyrophosphorylase, and sucrose-uridine diphosphate glucosyltransferase at 12 days. For phosphorylase II and cytidine diphosphate glucose pyrophosphorylase, activity was first detectable at the 14- and 16-day stages, respectively. Rapid increases in starch content are observed prior to detectable activity for adenosine diphosphate glucose pyrophosphorylase, the soluble adenosine diphosphate glucose-starch glucosyltransferase and phosphorylases II and III. For all enzymes, except invertase, activity per endosperm rises to a peak at 22 or 28 days. Greatest activity for invertase is found at 12 days with a steady decline thereafter. The pattern of invertase activity in comparison with that of sucrose-uridine diphosphate glucosyltransferase supports previous suggestions, that the latter plays a key role in the conversion of sucrose to starch. In addition to phosphorylases I, II, and III, multiple forms of glucosephosphate isomerase and phosphoglucomutase were detected.
TL;DR: The story of a presidential election year is in many ways the story of the actions and interactions of those considered as possible candidates for their nation's highest office as discussed by the authors, and this was true in the election of 1968.
Abstract: The story of a presidential election year is in many ways the story of the actions and interactions of those considered as possible candidates for their nation's highest office. If this is true in the abstract, it certainly was true in the election of 1968. The political headlines of 1968 were captured by those who ran for the nominations of their parties, those who pondered over whether or not to run, those who chose to pull out of the race or were struck down during the campaign, those who raised a third party banner, and those who resisted suggestions to run outside the two-party structure. While 1968 may have been unusual in the extent to which many prospective candidates dominated the political scene, every presidential election is, in its own way, highlighted by those considered for the office of President. The political scientist has shown scholarly interest in the candidates. His interest, however, has been selective in its focus—mainly concentrating on the two actual party nominees and not the larger set of possible presidential candidates. Research in electoral behavior has detailed the popular image of the nominees in terms of the public's reactions to their record and experience, personal qualities, and party affiliation. Furthermore, attitudes toward the nominees have been shown to constitute a major short-term influence on the vote. Yet attitudes toward other candidates have been surveyed only to ascertain the behavior of those people who favored someone other than the ultimate nominees.
TL;DR: The genetics of the ability of the Great Plains race and Races A and E of the Hessian fly, Mayetiola destructor (Say), to survive on wheat cultivars ‘Seneca’ and ‘Monon,’ which have different genes for resistance (antibiosis), was studied.
Abstract: The genetics of the ability of the Great Plains race and Races A and E of the Hessian fly, Mayetiola destructor (Say), to survive on wheat cultivars ‘Seneca’ and ‘Monon,’ which have different genes for resistance (antibiosis), was studied in 3 crossing experiments. Results of reciprocal crosses between Great Plains race (larvae cannot survive on either cultivar) and Race A (larvae survive on Seneca but not on Monon) and between Great Plains race and Race E (larvae survive on Monon but not on Seneca) showed that the ability of Race A to survive on Seneca and of Race E to survive on Monon are controlled by single recessive gene pairs. The F2 and backcross generations demonstrated that males transmit only maternally derived chromosomes and that paternally derived chromosomes are eliminated during spermatogenesis. Since the F1 males of reciprocal crosses bred as if they were homozygous for the genotype of their female parent, the phenotype of F2 and backcross progenies differed according to the direction of the cross between the F1 parents.
In a test for allelism, the reciprocal crosses between Race A and Race E produced F1 progenies that were the phenotype of the Great Plains race. Therefore, the ability to survive on Seneca and the ability to survive on Monon are controlled by genes at different loci and not by alleles of the same gene. Then the genie systems of the insect and host are complementary since there is a gene-for-gene relationship, and each resistant gene in wheat has a complementary gene for survival in the insect.
TL;DR: Electron density distributions for the M4 isoenzyme of LDH reveal details of the conformation of the subunit, boundaries between the subunits, and features relevant to the binding of coenzyme and substrate.
Abstract: Electron density distributions for the M4 isoenzyme of LDH reveal details of the conformation of the subunit, boundaries between the subunits, and features relevant to the binding of coenzyme and substrate.
TL;DR: In this paper, the maximum likelihood estimation of the coefficients of multiple output linear dynamical systems and the noise correlations from the noisy measurements of input and output are discussed and conditions under which the estimates converge to their true values as the number of measurements tend to infinity.
Abstract: The maximum likelihood estimation of the coefficients of multiple output linear dynamical systems and the noise correlations from the noisy measurements of input and output are discussed. Conditions are derived under which the estimates converge to their true values as the number of measurements tend to infinity. The computational methods are illustrated by several numerical examples.
TL;DR: The basic concept of learning control is introduced, and the following five learning schemes are briefly reviewed: 1) trainable controllers using pattern classifiers, 2) reinforcement learning control systems, 3) Bayesian estimation, 4) stochastic approximation, and 5) Stochastic automata models.
Abstract: The basic concept of learning control is introduced. The following five learning schemes are briefly reviewed: 1) trainable controllers using pattern classifiers, 2) reinforcement learning control systems, 3) Bayesian estimation, 4) stochastic approximation, and 5) stochastic automata models. Potential applications and problems for further research in learning control are outlined.
TL;DR: Its substrate specificity over a range of pH values indicates that the newly purified enzyme may be responsible for the “triglyceride” lipoxidase activity reported by Koch.
01 Jan 1970
TL;DR: Two phase mixtures thermally induced flow oscillations, discussing scaling criteria, phase change numbers and stability boundaries were discussed in this paper, where the phase change number and scaling criteria were discussed.
Abstract: Two phase mixtures thermally induced flow oscillations, discussing scaling criteria, phase change numbers and stability boundaries
TL;DR: New mutants of Drosophila melanogaster with single-step lesions on the genes controlling the visual pathway are generated, and ERG characteristics suggest genetic blocks in theVisual pathway of several of them.
Abstract: WITH the objective of analysing visual processes, we have attempted to generate mutants of Drosophila melanogaster with single-step lesions on the genes controlling the visual pathway1. One of these (x-7) had an abnormal electroretinogram (ERG) consisting apparently of responses from the photoreceptor layer alone. Similar ERGs could be obtained from the mutants tan1,2 and ebony2. Indeed, the mutants x-7 and tan seemed to be allelic1. We now have new mutants, and ERG characteristics suggest genetic blocks in the visual pathway of several of them.
TL;DR: In this paper, the authors analyzed the effects of the Australian Ballot reform on the changing split ticket voting patterns of the American electorate in the 1876-1908 time period.
Abstract: In the last two decades of political science, there has been considerable interest in the determinants of electoral behavior. Theories have been developed and tested on the sociological, psychological, and political antecedents of the vote. Virtually neglected in this search for determinants have been the institutional or structural properties of the electoral system itself. With a few notable exceptions, such factors as electoral qualification requirements, registration laws, and ballot and voting systems have not generated much research enthusiasm. These institutional properties, however, provide the framework within which the effects of other independent variables must be judged. This applies to all basic electoral research—whether time specific or longitudinal—but especially to the latter. Too often longitudinal research tries to trace the causes of changing voting patterns without taking into account the institutional framework. A pointed example of this is Walter Dean Burnham's recent description of this country's “changing political universe” around the turn of the century—a change which he ascribed to a breakdown in party competition and consequent voter alienation, but which undoubtedly could be partially, if not largely, explained by reference to the many institutional changes in voting rules which occurred during this period. The effects of institutional properties must be sorted out if the researcher is to establish reliable baselines against which to measure the effects of other variables. The purpose of this study is to analyze the effects of one such institutional property of the electoral system—the Australian Ballot reform—on the changing split ticket voting patterns of the American electorate in the 1876–1908 time period.
TL;DR: A family of supervised, nonparametric decision rules, based on tolerance regions, is described which includes the k -Nearest Neighbor decision rules when there are two classes.
Abstract: A family of supervised, nonparametric decision rules, based on tolerance regions, is described which includes the k -Nearest Neighbor decision rules when there are two classes. There are two practical reasons for doing so: first, a family of decision rules similar to the k -Nearest Neighbor rules can be specified which applies to a broader collection of pattern recognition problems. This is because in the general class of rules constraints are weakened between the number of training samples required in each training sample set and the respective a priori class probabilities; and, a discrete loss function weighting the importance of the finite number of ways to make a decision error can be introduced. Second, within the family of decision rules based on tolerance regions, there are decision rules which have a property allowing for preprocessing of the training set data resulting in significant data reduction. Theoretical performance for a special case is presented.