Showing papers by "University of Nebraska–Lincoln published in 1974"
TL;DR: The dimethoxyphenylpenicilloyl-tubular-basement-membrane "hapten protein conjugate" apparently led to an immune response with antitubular basement- Membrane antibodies being involved in the immunopathogenesis of the patient's interstitial nephritis.
Abstract: Antitubular basement-membrane antibodies were detected by indirect immunofluorescence in the serum of a patient in whom severe renal failure developed while he was receiving methicillin. A renal biopsy showed a severe mononuclear interstitial infiltrate with focal areas of tubular degeneration. IgG, C3 and a methicillin antigen assumed to be dimethoxyphenylpenicilloyl were present in a linear pattern along the tubular basement membrane but not along the glomerular basement membrane. The dimethoxyphenylpenicilloyl-tubular-basement-membrane "hapten protein conjugate" apparently led to an immune response with antitubular basement-membrane antibodies being involved in the immunopathogenesis of the patient's interstitial nephritis. (N Engl J Med 291:381–384, 1974)
218 citations
TL;DR: It is shown here that the carnivore bulla is formed by three and in some cases four ontogenetic elements: tympanic, rostral entotyMPanic, caudalEntotympanic(s), which appear to correspond to bulla elements discovered over 50 years ago by Van der Klaauw in representative species of several other orders of mammals.
Abstract: Basicranial anatomy of mammalian carnivores is significant in the determination of carnivore evolution. One of the least understood yet most often studied features of the basicranium is the auditory bulla, a bony capsule enclosing the middle ear. Although previously believed to be formed by a tympanic bone alone, or by tympanic and entotympanic, it is shown here that the carnivore bulla is formed by three and in some cases four ontogenetic elements: tympanic, rostral entotympanic, caudal entotympanic(s). These elements in Carnivora appear to correspond to bulla elements discovered over 50 years ago by Van der Klaauw in representative species of several other orders of mammals.
Increased auditory sensitivity appears to have been attained in various carnivore lineages by increase in the volume of the middle ear cavity, principally by hypertrophy of the caudal entotympanic, but also by different yet less common anatomical strategies such as invasion of the mastoid bone by the middle ear space. Five basic types of bulla among living Carnivora can be recognized, based largely on the relationship of the caudal entotympanic to the other bulla elements.
Closely associated with the bulla in the auditory region are the median and promontory branches of the internal carotid artery. These branches exhibit a precise relationship to the bulla elements, particularly the rostral entotympanic. The promontory branch is much reduced or completely lacking in all living carnivores. Reduction or loss of the median branch is explained as the result of the development of arterial retia on the anastomotic artery in the orbital region. Reduction of the median branch is particularly characteristic of the aeluroid Carnivora, in which a greater proportion of the cerebral blood supply passes to the brain in the external carotid artery via the anastomotic branch, and is cooled in the orbital region by a countercurrent heat exchange mechanism formed by arterial retia closely associated with venous blood in surrounding sinuses. The arctoid and cynoid Carnivora are characterized by only rudimentary development of retia along the anastomotic artery, and the median branch is much better developed than in the aeluroids. Among arctoids, ursids parallel the aeluroids in the development of a countercurrent mechanism but employ the median branch of the internal carotid rather than the anastomotic branch of the external carotid artery.
Bulla structure and nature of the carotid circulation in the auditory region can be determined from fossil Carnivora as well as for living forms. This study attempts to define basicranial anatomical patterns characteristic of living Carnivora which then can be used to trace the evolution of lineages in the fossil record.
200 citations
TL;DR: A general review of geometrical and statistical light models is presented in this article, where four different types of leaf dispersion are considered in this review: regular, clumped, random and variable.
132 citations
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94 citations
TL;DR: The absolute photoionization cross sections for the outer $\mathrm{ns}$ subshells of argon, krypton, and xenon have been measured from their respective ionization thresholds to 41 eV as well as at one point near the ionization threshold of neon.
Abstract: The absolute photoionization cross sections for the outer $\mathrm{ns}$ subshells of argon, krypton, and xenon have been measured from their respective ionization thresholds to 41 eV as well as at one point near the ionization threshold of neon. The technique of photoelectron spectroscopy was used to determine the ratio of the $s$ to $p$ photoelectrons. Measurements of the total cross sections and of the magnitudes of multiple-ionization processes allowed an accurate determination of the subshell cross sections to be made.
88 citations
TL;DR: In this article, the authors evaluate the performance of the Bowen Ratio Energy Balance (BREB) technique in the climatic conditions characteristic of the central Great Plains, a region where a significant proportion of the energy consumed by evapotranspiration is supplied from advected sensible heat.
Abstract: Most reports show good agreement between evapotranspiration (ET) rates estimated by the Bowen Ratio-Energy Balance (BREB) method and rates measured with lysimeters, although underestimation by the BREB model has occasionally been reported. This study was conducted to evaluate the performance of the BREB technique in the climatic conditions characteristic of the central Great Plains, a region where a significant proportion of the energy consumed by evapotranspiration is supplied from advected sensible heat. Agreement between the BREB method and lysimetric measurements of ET is good during non-advective periods but during advective periods the BREB model underestimates ET by about 20%. Data collected in this study suggest that the difference is due primarily to an inequality of the exchange coefficients for beat (Kh) and water vapor (Kw). In the development of the BREB method these coefficients are assumed to be identical but our results indicate that the ratio Kh/Kw is greater than 1 for the stabl...
86 citations
78 citations
TL;DR: Lower Miocene crossstratified sands of the Gering and Monroe Creek Formations exposed on Scotts Bluff National Monument in western Nebraska, U.S.A., were deposited by migrating sand bars in a braided river system similar to the modern Platte River in eastern Nebraska and, like the Platte, contain local lenses of parallel stratified sediment that accumulated in ponded areas of abandoned channels as mentioned in this paper.
78 citations
TL;DR: In this paper, the cyclic conformer of ozone was found to lie 16 kcal/mole above the preferred (open-chain) form of this substance, and the possible experimental significance of such a relatively stable ring conformer was assessed.
72 citations
TL;DR: A Steiner system S(l, m, n) is a system of subsets of size m from an n-set S, such that each d-subset from S is contained in precisely one block.
TL;DR: The residual encoding system with a Kalman filter or a stochastic approximation algorithm for identifying the predictor coefficients has produced good quality speech at a data rate of 16 kbit/s.
Abstract: A new method of speech digitization called residual encoding is introduced, and its application to the speech digitization problem is studied. The residual encoding system is a form of differential pulse code modulation which utilizes both an adaptive quantizer and an adaptive predictor. The residual encoder differs from previous systems in two ways. First, a sequential estimation method is used to continuously update the predictor coefficients, and second, the predictor coefficients are not transmitted, but are extracted from the estimate of the speech signal at both the transmitter and receiver. No form of pitch extraction is employed. The residual encoding system with a Kalman filter or a stochastic approximation algorithm for identifying the predictor coefficients has produced good quality speech at a data rate of 16 kbit/s.
TL;DR: ULV malathion (9.7 oz AI/acre) was applied by air to a 16 square mile area during August of 1968, 1969, 1970; adult Diabrotica virgifera LeConte populations were reduced the following season by 39, 54, and 72%.
Abstract: ULV malathion (9.7 oz AI/acre) was applied by air to a 16 square mile area during August of 1968, 1969, 1970. Adult Diabrotica virgifera LeConte populations were reduced the following season by 39, 54, and 72%. No economic infestations occurred in the treated area the year following any application. Postspray migration of beetles was very limited but adult migration during the peak emergence period the following season contributed to repopulation of the treated area. Migration and fecundity appear to be density-dependent factors which favor increases under low populations. Area suppression does not appear economically feasible, but adult control in individual fields may be an acceptable alternative to soil insecticides applied for larval control. A model was developed for timing treatments against adults; treatments between Aug. 1–15 should result in adequate population suppression to prevent damage the following season. Mid-August population levels of 1.0 beetle/plant were an acceptable economic threshold for determining the need for control measures.
TL;DR: Neither enzymes that have been postulated to be involved in ammonium assimilation nor NADP(+)-specific isocitrate dehydrogenase exhibited any large changes in specific activities during the initial period when nitrogenase activity declined.
Abstract: Soybean Glycine max. L. Merr. nodule senescence was studied using the loss of acetylene reduction by intact tap root nodules as its indication. Tap root nodules from two varieties (Calland and Beeson) of field-grown soybeans were used. The specific activities of nitrogenase (micromoles/minute gram fresh weight of nodules) as measured by the acetylene reduction assay decreased abruptly between 58 to 65 and 68 to 75 days after planting the Beeson and Calland soybeans, respectively. Major changes were not detected in dry weight, total nitrogen, and leghemoglobin levels during the period when in vivo nitrogenase activity declined. Ammonium levels in the cytosol of nodules and poly-beta-hydroxybutyrate increased moderately just prior to or coincidental with the loss of nitrogenase activity. Neither enzymes that have been postulated to be involved in ammonium assimilation nor NADP(+)-specific isocitrate dehydrogenase exhibited any large changes in specific activities during the initial period when nitrogenase activity declined.
TL;DR: In this paper, the true value of the ion current, and hence the absolute photon flux, is obtained by extrapolating the current to zero gas pressure, and the short-wavelength limit is determined only by the sensitivity of the current-measuring apparatus and by present knowledge of the photoionization processes that occur in the rate gases.
Abstract: Absolute photon-flux measurements in the vacuum ultraviolet have extended to short wavelengths by use of rare-gas ionization chambers. The technique involves the measurement of the ion current as a function of the gas pressure in the ion chamber. The true value of the ion current, and hence the absolute photon flux, is obtained by extrapolating the ion current to zero gas pressure. Examples are given at 162 and 266 A. The short-wavelength limit is determined only by the sensitivity of the current-measuring apparatus and by present knowledge of the photoionization processes that occur in the rate gases.
TL;DR: Evidence is presented that genotypic differences exist in plant responses to water stress and a practical technique for measuring desiccation and heat tolerance demonstrates that genetically controlled tolerance factors can be selected for and used in plant breeding programs.
TL;DR: A breeding and genetic program to develop Phaseolus vulgaris bean varieties tolerant to the bacterial pathogens Pseudomonasphaseolicola, Xanthomonas phaseoli and Corynebacterium flaccumfaciens was conducted from 1962 to the present and the research progress is reported.
Abstract: A breeding and genetic program to develop Phaseolus vulgaris bean varieties tolerant to the bacterial pathogens Pseudomonas phaseolicola, Xanthomonas phaseoli and Corynebacterium flaccumfaciens was conducted from 1962 to the present tme. The research progress is reported. Great Northern (GN) Nebraska #1, sel. 27 and PI 150414 dry bean lines were highly tolerant to races 1 and 2 of the halo blight bacterium (P. phaseolicola). The tolerant inoculated leaf, pod, and non-systemic chlorosis reactions to this bacterium were each controlled by different major genes. Coupling linkage was detected between genes controlling the leaf and systemic chlorosis reactions. GN Nebraska #1, sel. 27 and PI 207262 were tolerant to isolates (USA) of X. phaseoli, causal pathogen of common blight disease. Reaction to this bacterium was inherited quantitatively. Narrow sense heritability estimates of the disease reaction were low. Genes controlling late maturity and tolerant reaction were found to be linked in crosses with GN Nebraska #1, sel. 27 but linkage was not apparent in one cross with PI 207262. A different reaction of pod and foliage was observed in some bean lines. Susceptibility increased with the onset of plant maturity. PI 165078 was tolerant to C. flaccumfaciens and the disease reaction was simply inherited. The dry bean varieties ‘GN Tara’ and ‘GN Jules’, tolerant X. phaseoli, and ‘GN Emerson’ tolerant to C. flaccumfaciens and X. phaseoli were released in recent years. Breeding approaches to develop bean varieties tolerant to these bacterial pathogens is discussed.
TL;DR: In this paper, an improved criterion for computing the normalized 2 × 2 complex reflection matrix of an anisotropic surface from multiple-null ellipsometer measurements (in excess of three) is given.
Abstract: The technique of generalized ellipsometry is briefly reviewed. An improved criterion for computing the normalized 2 × 2 complex reflection matrix of an anisotropic surface from multiple-null ellipsometer measurements (in excess of three) is given. Generalized ellipsometry, together with the recently developed 4 × 4-matrix methods for the study of the reflection and transmission of polarized light by stratified anisotropic media, provide the basic tools to carry out and to interpret ellipsometric measurements on anisotropic structures. As an example, the case of uniaxial (absorbing) crystals, with the optic axis parallel to the surface, is considered. From three or more null measurements at a single unknown orientation of the optic axis, the five parameters (the ordinary and extraordinary complex indices of refraction and the angle of inclination of the optic axis from the plane of incidence) that characterize a uniaxial crystal of calcite are all determined.
TL;DR: In this paper, the polymeric copper(II) chelates of 2,5-dihydroxy-p -benzoquinone, 5,8-Dihydrox-1,4-naphthoquinone and 6,11dihdroxynaphthacenequinone have been prepared under similar conditions and relative thermal stabilities were determined by differential thermal analysis.
TL;DR: Virions of the isolates of barley yellow dwarf virus transmitted by Macrosiphum avenae (MAV) and by Rhopalosiphum padi (RPV) contain a single component of single-stranded RNA of molecular weight 2.0 × 10 6, estimated by sedimentation and gel electrophoretic mobility of formalinized RNA.
TL;DR: In this article, intact beef was packaged in a PVC film, stored at 5°C and illuminated with 250 ft-c light, and a significant alteration in color stability was observed when compared to storage in the dark.
Abstract: When intact beef was packaged in a PVC film, stored at 5°C and illuminated with 250 ft-c light, a significant alteration in color stability was observed when compared to storage in the dark. Fluorescent lights, emitting light of lower wavelengths, were most detrimental to color, in comparison to incandescent lights. Upon prolonged storage large bacterial numbers on the surface created a reducing environment and caused the conversion of surface MetMb to reduced Mb, which was responsible for the purple color that developed. Gel electrophoresis indicated that no significant alterations occurred in the structure of myoglobin or hemoglobin (color pigments) upon storage at 5°C for as long as 18 days. Color instability of meat stored under soft white fluorescent light is almost entirely due to the effect of the light, whereas color instability when stored under incandescent light is due to a combination of light energy and bacterial growth.
TL;DR: Evidence is presented which suggests that the dsRNAs may contain a short single-stranded RNA tail, and the two smaller RNA segments reanneal rapidly even at low temperatures; in contrast, the large dsRNA reannealed only at higher temperatures.
Abstract: The three double-stranded ribonucleic acid (dsRNA) segments of the bacteriophage φ6 were isolated and shown to have similar melting temperatures and base compositions. RNA:RNA hybridization experiments with the isolated segments eliminate the possibility that the two smaller dsRNA segments arise from a cleavage of the large dsRNA segment. The two smaller RNA segments reanneal rapidly even at low temperatures; in contrast, the large dsRNA reannealed only at higher temperatures. Evidence is also presented which suggests that the dsRNAs may contain a short single-stranded RNA tail.
TL;DR: In this paper, the effects of generalized component imperfections, azimuth-angle errors, and errors of the normalized Fourier coefficients of the detected photoelectric current on the measured ratio of reflection coefficients ρ in rotating-analyzer ellipsometers (RAE) are determined.
Abstract: The effects of generalized component imperfections, azimuth-angle errors, and errors of the normalized Fourier coefficients of the detected photoelectric current on the measured ratio of reflection coefficients ρ in rotating-analyzer ellipsometers (RAE) are determined. The problem is formulated in such a way that much of the earlier work done on error analysis for null ellipsometers (NE) can be adapted to RAE. The results are conveniently expressed in terms of coupling coefficients that determine the extent to which a given source of error couples to an error of the measured value of ρ. The optical properties of the compensator (if used) and of the surface can be simultaneously obtained from a set of two measurements using RAE, in a manner similar to two-zone measurements in NE. In addition, novel methods of obtaining and combining the results from two measurements are examined, with the objective of cancelling the effect of many of the systematic sources of errors. One such method employs two incident polarizations of the same ellipticity but with orthogonal azimuths, in which case the measured value of ρ is almost independent of the input optics. If the two incident polarizations are chosen, instead, to have equal but opposite ellipticity and azimuth, the effects of the polarizer imperfection, off-diagonal elements in the compensator, entrance-window, surface, and exit-window imperfection matrices, as well as polarizer and compensator azimuth-angle errors, all disappear upon such two-measurement averaging; the effects of analyzer imperfection or azimuth-angle error and errors of the normalized Fourier coefficients are only partially cancelled. Finally, use of RAE in generalized ellipsometry and its attendant problems are examined.
TL;DR: In this article, the authors describe the structure of Herpetomonas megaseliae and show that the Golgi body changes from a stack of flattened sacs to an aggregation of vesicles, and the posterior extension of flagellar pocket precedes migration of the kinetoplast.
Abstract: SYNOPSIS
Ultrastructure of both undifferentiated (promastigote and paramastigote) and differentiated (opisthomastigote) forms of Herpetomonas megaseliae is described. There is a posterior migration of the kinetoplast at the end of the exponential growth phase. The posterior extension of the flagellar pocket precedes migration of the kinetoplast. Opisthomastigotes have an electron-translucent mitochondrial matrix in comparison with undifferentiated forms. The Golgi body changes from a stack of flattened sacs to an aggregation of vesicles. Several structures previously reported from Trypanosomatidae, e.g. subpellicular organelles, pellicular microtubules, membrane whorls, stored metabolic products, surface blebs, and an intraflagellar body are also present in H. megaseliae.
TL;DR: Transgressive segregation for early flowering and common blight susceptibility occurred in progeny derived from the cross of the two late-flowering blight tolerant lines, PI 207262 and GN Nebraska 1, sel.
Abstract: The inheritance of the reaction to Xanthomonas phaseoli (E. F. Smith) Dowson Nebraska isolate Xp-816, cause of common blight disease of beans Phaseolus vulgaris L. was studied in crosses between the late flowering, indeterminate, blight tolerant dry bean PI 207262 (Colombia) and susceptible cvs. GN 1140, an early flowering and indeterminate dry bean; Dark Red Kidney, a late flowering and determinate dry bean; and Gallatin 50, an early and determinate green bean. The tolerant disease reaction was dominant in the F1. A continuous distribution of disease reaction ratings, skewed in the direction of dominance, occurred in the F2 derived from the first 2 crosses while a slight bimodal distribution was observed in the F2 of the last cross. A low narrow sense heritability estimate of 14% was calculated by the regression of F3 progeny means on individual F2 plants, in the cross GN 1140×PI 207262. The occurrence of a small number of nonsegregating families in a low number of F3 families indicates that a small number of major genes were involved in controlling the disease reaction. Linkage did not appear to be involved between genes controlling early flowering (early maturity) and common blight tolerance. Coupling linkage occurred between genes controlling determinate plant habit and early flowering. A crossover value of 8.4% was estimated. Recombinants for early maturity, determinate habit, and blight tolerance were obtained. Transgressive segregation for early flowering and common blight susceptibility occurred in progeny derived from the cross of the two late-flowering blight tolerant lines, PI 207262 and GN Nebraska 1, sel. 27, indicating that the parents possessed different genes controlling these traits.
TL;DR: A generalized mechanism is proposed for the action of pyridoxal phosphate dependent transaminase which extends Braunstein and Snell mechanism to include the structures which contribute to the labilization of β hydrogens of amino acids by the transaminases that have been studied.
TL;DR: Three subpopulations of “ Mezcla Varietales Amarillos” population (MVA) were selected for prolificacy and grain yield in three different seasonal conditions: (i) MVA-A selected in rainy seasons (A); (ii) M VA-B selected in dry seasons (B); (iii) Mva-AB selected under both seasonal conditions each year.
Abstract: The present study was designed to find what seasonal effect mass selection would render when practiced within a maize (Zea mays L.) population. Three subpopulations of “ Mezcla Varietales Amarillos” population (MVA) were selected for prolificacy and grain yield in three different seasonal conditions: (i) MVA-A selected in rainy seasons (A); (ii) MVA-B selected in dry seasons (B); (iii) MVA-AB selected under both seasonal conditions each year. Three cycles in MVA-A and-MVA-B, and six in MVA-AB were tested during three A and three B growing seasons for evaluation of progress. Mass selection in MVA-A resulted in an increase in grain yield of 10.5% per cycle when tested in the A seasons (direct response) and only 0.8% when tested in the B seasons (indirect response). For ears per plant the corresponding responses were 8.8 and 1.0%. The direct response in grain yield in MVA-B was only 2.5% per cycle whereas it was 7.6% when tested in the A seasons. The gain in ears per plant was 11.4% in the tests in the A seasons, but the direct response was 4.4% per cycle. In MVA-AB, there was a gain in grain yield of 5.3 and 1.1% per cycle in the tests in A and B seasons. For prolificacy, the respective gains were 7.0 and 3.3% per cycle. The authors acknowledge the cooperation of J. Antonio Rivera and L. Miguel Estrada, Agronomists, of the Corn Program of the Instituto Colombiano Agropecuario at Turipana Experimental Center for their invaluable help in collecting some of the data. This work was supported in part by grants from the Rockefeller Foundation to the corn program of ICA in Colombia and to the corn program at the University of Nebraska.
TL;DR: In this article, large-angle inelastic scattering is considered using the Glauber approximation for the scattered wave function, but without the additional approximation of purely transverse linear momentum transfer.
Abstract: Large-angle inelastic scattering is considered using the Glauber approximation for the scattered wave function, but without the additional approximation of purely transverse linear momentum transfer. At large angles, the electron-proton interaction dominates and has Rutherford ${q}^{\ensuremath{-}4}$ behavior. Furthermore, with the direction of $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}$ unrestricted the $\mathrm{L}\mathrm{y}\ensuremath{-}\ensuremath{\alpha}$ radiation is found to be, in general, elliptically polarized.
TL;DR: In this paper, the authors study the structure of rings whose modules satisfy the conclusion of a classical theorem well known to every beginning student of algebra, namely: every finitely generated module over a principal ideal domain is a direct sum of cyclic submodules.