Showing papers by "University of Houston published in 1969"
427 citations
TL;DR: Reactions of compounds which interfere with other cholesterol color reagents have been studied and found to be unreactive in this procedure, finding two Δ5 compounds, cholesterol and dehydroepiandrosterone, underwent reaction to yield sensitive purple colors whereas the naturally occurring compounds were unreactive.
399 citations
TL;DR: A large number of chlorinated hydrocarbon insecticides commonly used in agriculture for pest control persist for extended periods in soils, and therefore generate problems of environmental pollution.
Abstract: MANY chlorinated hydrocarbon insecticides commonly used in agriculture for pest control persist for extended periods in soils, and therefore generate problems of environmental pollution. For example, in certain circumstances, lindane (γ-isomer of hexachlorocyclohexane or γ-BHC) is known to persist in soil for periods of up to 11 yr1. Such lengthy persistence has been attributed in part to the inability of the soil microflora to attack the insecticide molecule2.
119 citations
TL;DR: In this article, the influence of two kinds of market information (price and store image) on consumers' judgments of product quality was measured, and it was shown that price was not the dominant market information.
Abstract: In this laboratory experiment, the influence of two kinds of market information—price and store image—on consumers’ judgments of product quality was measured. Although price was the dominant indivi...
115 citations
104 citations
TL;DR: The nonpolar (acetone-soluble) lipids of the extremely halophilic bacterium, Halobacterium cutirubrum, were found to consist of red carotenoid pigments and squalenes with a small amount of a vitamin K-type quinone, identified as menaquinone-8 (MK-8).
96 citations
TL;DR: In this article, three groups of male albino mice were given six daily 2-h exposures to escapable, inescapable, or no electric shock on a 30sec-on/30sec-off alternating schedule.
Abstract: Three groups (N = 9) of male albino mice were given six daily 2-h exposures to escapable, inescapable, orno electric shock. Shock was programmed on a 30-sec-on/30-sec-off alternating schedule. The pole-climbing behavior of an escapable shock S could terminate or prevent shock both for itself and for its yoked inescapable shock pair-member. AUSs then were given, after a 24-h rest, five water-escape trials in which swimming time was measured. The escapable shock S s learned the water-escape task faster than the no shock controlSs. The inescapable shock Ss swam increasingly slower over trials.
75 citations
TL;DR: In this paper, the thermal properties of the cobalt, nickel, copper, zinc, and cadmium-II complexes of diethyldithiocarbamic acid were determined by TG, DTA, and high temperature reflectance spectroscopy.
Abstract: The cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), silver(I) and mercury(II) complexes of diethyldithiocarbamic acid were prepared and their thermal properties determined by TG, DTA, and high temperature reflectance spectroscopy. It was found that the copper(II), nickel(II), and zinc(II) chelates were completely volatile and thus represent a new class of volatile metal chelates. Vapor pressure measurements were made on four of the metal complexes; heats of vaporization ranged from 9.3±0.2 kcal/mole for Na[Co(DDC)3] to 24.2±0.6 kcal/mole for Zn(DDC)2.
73 citations
TL;DR: The Quarterly is reserved for brief reports of research in progress, discussions of unsolved problems, methodological studies, and public opinion data not extensively analyzed or interpreted as discussed by the authors, as well as hypotheses and insights that may be useful to other students of public opinion.
Abstract: This section of the Quarterly is reserved for brief reports of research in progress, discussions of unsolved problems, methodological studies, and public opinion data not extensively analyzed or interpreted. Succinct case histories are welcomed, as well as hypotheses and insights that may be useful to other students of public opinion. Usually, material in this section will be shorter, more informal, and more tentative than in the preceding pages of the Quarterly.
73 citations
TL;DR: Ethylene activity in lettuce seed (Lactuca satina) germination and tomato (Lycopersicon esculentum) petiole epinasty has been characterized by using heat to inhibit ethylene synthesis by enabling a separation of the production of ethylene from the effect of Ethylene.
Abstract: Ethylene activity in lettuce seed (Lactuca satina) germination and tomato (Lycopersicon esculentum) petiole epinasty has been characterized by using heat to inhibit ethylene synthesis. This procedure enabled a separation of the production of ethylene from the effect of ethylene. Ethylene was required in tomato petioles to produce the epinastic response and auxin was found to be active in producing epinasty through a stimulation of ethylene synthesis with the resulting ethylene being responsible for the epinasty. In the same manner, it was shown that gibberellic acid stimulated ethylene synthesis in lettuce seeds. The ethylene produced then in turn stimulated the seeds to germinate. It was hypothesized that ethylene was the intermediate which caused epinasty or seed germination. Auxin and gibberellin primarily induced their response by stimulating ethylene production.
56 citations
TL;DR: In this article, the use of state-space techniques and Routh's algorithm was used for performing the continued fraction inversion. But this method is not suitable for the case of polynomials.
Abstract: The operation of converting a continued fraction into a rational transfer function of two polynomials is tedious. By the use of state-space techniques and Routh's algorithm, a new method is established for performing the continued fraction inversion.
TL;DR: In this paper, the stability aspects of a chemical reaction occurring on a catalytic wire were investigated and conditions for the existence of non-unique steady states and for asymptotic stability were derived.
TL;DR: In this paper, the spectral and thermal properties of rhodium(II) acetate adducts were investigated using thermogravimetric analysis and differential scanning calorimetry.
TL;DR: A comparison of the fine structure of the absorption spectrum of fluoranthene and seven simple derivatives recorded at 77°K reveals the presence of seven separate electronic transitions below 43 000 cm −1 as mentioned in this paper.
TL;DR: In this article, an experimental measurement of the flux of neutrinos from the Sun has been reported, and the authors concluded that less than 9% of the Sun's energy is produced by the carbon-nitrogen cycle.
Abstract: AN experimental measurement of the flux of neutrinos from the Sun has recently been reported1. The method uses 3.9×105 l. of C2Cl4 to absorb neutrinos in the 37Cl(ν,e−)37Ar reaction, which has a threshold at 0.81 MeV and is energy-sensitive. Because of the enhanced cross-section for energetic neutrinos, the chief contribution to the counting rate was expected from 8B decay in the solar core2. But the number of neutrinos detected did not exceed the measured background for the instrument, and so served only to provide an upper limit on the flux of energetic solar neutrinos. The authors concluded that less than 9 per cent of the Sun's energy is produced by the carbon–nitrogen cycle.
TL;DR: In this paper, the temperature dependence of the electron capture detector has been studied for a number of derivatives of n-hexanol, cyclohexanol and aniline, and the mode of the capture process was determined.
Abstract: The temperature dependency phenomena of the electron capture detector has been studied for a number of derivatives of n-hexanol, cyclohexanol, phenol, n-hexylamine, cyclohexylamine, and aniline. The electron capturing moiety of the derivatives was formed using pentafluorobenzoyl chloride, pentafluorophenacetyl chloride, and pentafluorophenoxyacetyl chloride. By plotting LnKT3/2 vs 1/T where K is the capture coefficient, the mode of the capture process, i.e., dissociative or non-dissociative was determined. The possibility of improving both response and resolution by making use of this temperature dependence effect is pointed out.
TL;DR: Growth rates of all three organisms were increased in the presence of seven amino acids (original four plus leucine, lysine, and isoleucine), and important differences in pH tolerance were noted among the species.
Abstract: Physarum flavicomum, P. polycephalum, and P. rigidum grew at pH 4.2 in a medium composed of mineral salts, glucose, biotin, thiamine, hematin, and four amino acids. Important differences in pH tolerance were noted among the species. The minimal medium of P. flavicomum and P. polycephalum contained the amino acids methionine, glycine, and arginine, but valine was also required by P. rigidum. Starting with an inoculum of about 0.3 mg of protein per 25 ml of minimal medium, P. flavicomum and P. polycephalum grew to 23 mg and P. rigidum to 12 mg of protein per 25 ml in 3, 2, and 4 weeks, respectively. P. flavicomum and P. polycephalum grew with valine or leucine replacing arginine in the minimal medium but the growth yields and growth rates were decreased. All three species utilized homocysteine thiolactone in the minimal media in place of methionine. Serine adequately replaced glycine for P. rigidum but was inhibitory in the minimal medium of P. flavicomum or P. polycephalum unless homocysteine thiolactone also replaced methionine. Growth rates of all three organisms were increased in the presence of seven amino acids (original four plus leucine, lysine, and isoleucine).
TL;DR: Spectrophotometric evidence is presented to demonstrate the presence of metal ion complexes of Schiff bases of Histidine as intermediates in the transamination reactions, which may contribute to understanding the role of histidine in enzyme catalysis.
Abstract: Non-enzymic transamination reactions at 85° between various amino acids and α-oxoglutaric acid are catalysed by metal ions, e.g. Al3+, Fe2+, Cu2+ and Fe3+. The reaction is optimum at pH4·0. Of the 14 amino acids studied histidine is the most active. In the presence of Al3+ histidine transaminates with α-oxoglutaric acid, forming glutamic acid and Al3+–imidazolylpyruvic acid complex as the end products. However, in the presence of Fe2+ or Cu2+ the products are glutamic acid and a 1:2 metal ion–imidazolylpyruvic acid chelate. The greater effectiveness of histidine in these reactions is attributed to the presence of the tertiary imidazole nitrogen atom, which is involved in the formation of stable sparingly soluble metal ion–imidazolylpyruvic acid complexes or chelates as end products of these reactions. Of the metal ions studied only Al3+, Fe2+, Fe3+ and Cu2+ are effective catalysts for the transamination reactions, and EDTA addition completely inhibits the catalytic effect of the Al3+. Spectrophotometric evidence is presented to demonstrate the presence of metal ion complexes of Schiff bases of histidine as intermediates in the transamination reactions. These results may contribute to understanding the role of histidine in enzyme catalysis.
TL;DR: In this paper, an analytic solution to the Reynolds equation for dynamic loading is obtained to describe the pressure distribution in a journal bearing of finite length, which is used to determine the equations of motion for the shaft relative to the bearing.
Abstract: : An analytic solution to the Reynolds equation for dynamic loading is obtained to describe the pressure distribution in a journal bearing of finite length. Integration of the pressure distribution results in expressions for the hydrodynamic forces in the bearing which are used to determine the equations of motion for the shaft relative to the bearing. Plots of the eccentricity ratio versus the attitude angle and the approaches to the limit cycle are given as examples of the numerical technique. (Author)
TL;DR: When distinctive neutral stimuli were repeatedly associated with drug-potentiated aggression and drug-depressed aggression, the stimuli came to exert specific stimulus control over aggressive display even after the drugs were discontinued.
Abstract: Male Siamese fighting fish exhibit stereotyped aggression reactions to their mirror reflections. When distinctive neutral stimuli (flickering colored lights) were repeatedly associated with drug-potentiated aggression (morphine sulfate) and drug-depressed aggression (phenergan), the stimuli came to exert specific stimulus control over aggressive display even after the drugs were discontinued.
TL;DR: In this article, the distribution of fatty acids and hydrocarbons in the seeds of Plantago ovata has been studied using gas chromatography and combined gas chromatology and mass spectrometry.
TL;DR: In this paper, the preparation of capillary columns coated with liquid phases containing silver nitrate was described, and the best results were obtained with ethyleneglycol bis (cyanoethyl) ether.
Abstract: The preparation of capillary columns coated with liquid phases containing silver nitrate is described. Several liquids were investigated, but the best results were obtained with ethyleneglycol bis (cyanoethyl) ether. Columns with plate efficiencies as high as 18,500 have been prepared. Analyses of C5–8 saturated and unsaturated hydrocarbon mixtures are presented.
TL;DR: Polycationic proteins cause an energy-dependent, low amplitude swelling of isolated mitochondria, supported either by substrate oxidation or by adenosine triphosphate, similar to those observed with parathyroid hormone.
TL;DR: In this article, the authors discuss contamination of exposed optical surfaces and light scattering by ice particles from cabin water vapor leakage from spacecraft debris atmosphere effects on observations, and discuss the effects of spacecraft deformation on observations.
TL;DR: In this paper, wood-concrete composite T-beams were fabricated and tested to destroy, and it was shown that Wood-Concrete bonded T-beam may carry substantial loads and function as true composite beams.
Abstract: Timber-concrete composite T-beams were fabricated and tested to destruction. Unreinforced precast concrete slabs were glued to timber beams using an epoxy compound resulting in a T-section with the concrete serving as the flange and the timber serving as the web. Using an equivalent all wood transformed section gave good experimental agreement for the neutral axis position and curvature in the test beams but poor agreement for deflection. Four beams failed in sliding shear at the high shear region while one beam reached the full flexural strength of the composite section. It was shown that wood-concrete bonded T-beams may carry substantial loads and function as true composite beams.
TL;DR: In this article, a theoretical analysis of the Doppler return from a random rough surface ace shows that the spectrum is composed of three distinct components: the coherent component, the incoherent component, and the amplitudes of these components depend on the variance of the surface and the antenna beamwidth averaging.
Abstract: A theoretical analysis of the Doppler return from a random rough surface ace shows that the Doppler spectrum is composed of three distinct components. The methods of analysis for determining the average power return for the static case and an application of the ergodic hypothesis for a stationary surface show that the assumption of a single Doppler component is based on a smooth surface. In addition to this coherent component, the incoherent components of the random rough surface produce two additional frequency components. The amplitudes of these latter components depend on the variance of the surfaceand the antenna beamwidth averaging. Radar measurements were made, utilizing a scatterometer, in order to measure the surface characteristics. s. Simultaneous measurements from a Doppler radar system were analysed to identify the additional frequency components.