Showing papers by "University of Arizona published in 1985"
01 Jan 1985
TL;DR: In this paper, the authors compare sandstone compositions by grouping diverse grain types into a few operational categories having broad genetic significance and displaying compositional fields associated with different provenances on standard triangular diagrams.
Abstract: Detrital modes of sandstone suites primarily reflect the different tectonic settings of provenance terranes, although various other sedimentological factors also influence sandstone compositions. Comparisons of sandstone compositions are aided by grouping diverse grain types into a few operational categories having broad genetic significance. Compositional fields associated with different provenances can then be displayed on standard triangular diagrams.
1,431 citations
TL;DR: It is suggested that the use of some or all of these homologous phenoxazone ethers will provide both a simple routine test for the characterization of several types of inducing agents and a powerful tool for investigating the biochemical basis for cyt.
1,280 citations
TL;DR: Southern blot analysis of hamster, mouse and human DNA using this cDNA as a probe showed that P-glycoprotein is conserved and is probably encoded by a gene family, and that members of this putative family are amplified in multidrug-resistant cells.
Abstract: The multidrug-resistance phenotype expressed in mammalian cell lines is complex. Cells selected with a single agent can acquire cross-resistance to a remarkably wide range of compounds which have no obvious structural or functional similarities. The basis for cross-resistance seems to be a decreased net cellular accumulation of the drug involved, and has been attributed to alterations in the plasma membrane. An over-expressed plasma membrane glycoprotein of relative molecular mass (Mr) 170,000 (P-glycoprotein) is consistently found in different multidrug-resistant human and animal cell lines, and in transplantable tumours. Consequently, it has been postulated that P-glycoprotein directly or indirectly mediates multidrug resistance. Here we report the cloning of a complementary DNA encoding P-glycoprotein. Southern blot analysis of hamster, mouse and human DNA using this cDNA as a probe showed that P-glycoprotein is conserved and is probably encoded by a gene family, and that members of this putative family are amplified in multidrug-resistant cells.
822 citations
TL;DR: In this paper, the spectral behavior of a cotton canopy with four soil types alternately inserted underneath was examined at various levels of vegetation density, showing that soil and plant spectra interactively mix in a nonadditive, partly correlated manner to produce composite canopy spectra.
811 citations
TL;DR: One application of phase-shifting techniques to speckle interferometry is finding the phase of deformations, where up to ten waves of wavefront deformation can easily be measured.
Abstract: Speckle patterns have high frequency phase data, which make it difficult to find the absolute phase of a single speckle pattern; however, the phase of the difference between two correlated speckle patterns can be determined. This is done by applying phase-shifting techniques to speckle interferometry, which will quantitatively determine the phase of double-exposure speckle measurements. The technique uses computer control to take data and calculate phase without an intermediate recording step. The randomness of the speckle causes noisy data points which are removed by data processing routines. One application of this technique is finding the phase of deformations, where up to ten waves of wavefront deformation can easily be measured. Results of deformations caused by tilt of a metal plate and a disbond in a honeycomb structure brazed to an aluminum plate are shown.
740 citations
TL;DR: The problem of public goods provision has been central to many areas of economics, and public goods serve as a classic model of market failure and exist as the foundation for many modern theories of government as mentioned in this paper.
609 citations
TL;DR: Frequency of common infections was approximately 20-50% less in MS patients than controls; it was progressively less in those with greater disability, suggesting that MS patients could have superior immune defences against common viruses.
573 citations
TL;DR: In this article, two systematic biases (the framing of conflict and negotiator overconfidence) are suggested as possible influences on negotiator behaviors, and 100 subjects were asked to negotiate with a negotiator.
Abstract: Two systematic biases—the framing of conflict and negotiator overconfidence—are suggested as possible influences on negotiator behaviors. To investigate these biases, 100 subjects were asked to neg...
440 citations
TL;DR: In this paper, reflection spectrophotometry of 589 minor planets in a photometric system using eight filter passbands ranging from 0.34- to 1.04-micron wavelength is presented.
393 citations
TL;DR: Temperature was the only variable significantly correlated with the decay rates of all three viruses, an indication that MS-2 coliphage might be used as a model of animal virus survival in groundwater.
Abstract: More than 50% of the outbreaks of waterborne disease in the United States are due to the consumption of contaminated groundwater. An estimated 65% of the cases in these outbreaks are caused by enteric viruses. Little, however, is known about the persistence of viruses in groundwater. The purpose of this study was to determine whether measurable chemical and physical factors correlate with virus survival in groundwater. Groundwater samples were obtained from 11 sites throughout the United States. Water temperature was measured at the time of collection. Several physical and chemical characteristics, including pH, nitrates, turbidity, and hardness, were determined for each sample. Separate water samples were inoculated with each of three viruses (poliovirus 1, echovirus 1, and MS-2 coliphage) and incubated at the in situ groundwater temperature; selected samples were also incubated at other temperatures. Assays were performed at predetermined intervals over a 30-day period to determine the number of infective viruses remaining. Multiple regression analysis revealed that temperature was the only variable significantly correlated with the decay rates of all three viruses. No significant differences were found among the decay rates of the three viruses, an indication that MS-2 coliphage might be used as a model of animal virus survival in groundwater.
385 citations
TL;DR: A geometrical arrangement is shown whereby the effect can be made the basis of a new method for concentrating and separating motile cells, and the role of gyrotaxis is discussed in the maintenance of naturally occurring descending streams of cells and in bioconvection patterns.
Abstract: The swimming direction of algal cells can be guided so that the cells are focused into a concentrated beam. This directed locomotion, or taxis, results from the orientation of the cells' axes by compensating gravitational and viscous torques. It is named gyrotaxis because of this origin. Gyrotaxis includes rheotaxis1, which is concerned with orientation and locomotion of elongated microorganisms, especially spermatozoa, in fluids with a velocity gradient. I present here a simplified theory of gyrotaxis, together with experimental evidence. A geometrical arrangement is shown whereby the effect can be made the basis of a new method for concentrating and separating motile cells. Unlike standard concentration/separation techniques, the gyrotactic method requires active participation of the cells and can, in principle, distinguish among them on the basis of morphology and swimming behaviour. I also discuss the role of gyrotaxis in the maintenance of naturally occurring descending streams of cells and in bioconvection patterns.
TL;DR: This chapter presents a comprehensive review of the published information on the cytology, genetics, and evolution of Gossypium and presents recent data and information on genome organization with which a hypothesis is proposed for the origin of the allotetraploid species that is different from that generally assumed.
Abstract: Publisher Summary This chapter presents a comprehensive review of the published information on the cytology, genetics, and evolution of Gossypium . In addition, it presents recent data and information on genome organization with which a hypothesis is proposed for the origin of the allotetraploid species that is different from that generally assumed. The genus Gossypium consists of 35 diploid species that are divided into seven genome groups and six allotetraploid species, each with the same two subgenomes. The genome relationships are also discussed in the chapter. Moreover, with the advent of the new technology of genetic engineering and its potential for improving the commercial cottons by inter- and intra- genomic transfer of desirable genetic segments, the basic genetic analyses should have even greater application in the future. The successful application of genetic engineering is greatly enhanced by the availability of fundamental knowledge of the genetic organization of the chromosomes gained through the classical genetic and cytogenetic approaches. Thus, to utilize the full potential of the new technology, it is of utmost importance that the classical approaches to the genetic analysis of the chromosomes of cotton be augmented.
TL;DR: A cytochrome c-551 and a pair of 'high redox-potential' ferredoxins (iso-high-potentially iron-sulfur proteins) were found to be the major soluble electron-transport proteins in Ectothiorhodospira halophila.
Journal Article•
TL;DR: The presence ofPRL receptors on T and B lymphocytes suggests that PRL may be involved in the regulation of humoral and cell-mediated immunity, and that one effect of CsA on immune function may be its ability to inhibit the effects of PRL action on these lymphocytes.
Abstract: Prolactin (PRL) receptors have been identified recently on human peripheral blood mononuclear cells (MNC) and may be involved in the regulation of cell-mediated immunity. Cyclosporine (CsA), an immunosuppressive cyclic endecapeptide utilized to prolong graft survival in human organ transplant patients, affects PRL binding to MNC. At concentrations of CsA from 10(-10) through 10(-8) M, the amount of PRL bound to MNC markedly increased to ca. 400% of controls, whereas CsA concentrations of 10(-6) and 10(-5) M totally inhibited PRL binding to lymphocytes. The ability of low concentrations of CsA to enhance PRL binding was temperature-dependent and did not occur when binding assays were conducted at 4 degrees C. PRL displaced [3H]CsA from lymphocytes with ca. 50% displacement at 10(-9) M PRL and total displacement at concentrations of 10(-7), 10(-6), and 10(-5) M. Growth hormone did not displace [3H]CsA in similar experiments. CsA also did not alter the binding of a beta-receptor antagonist to MNC, again suggesting that CsA was specific in its antagonism of PRL binding. A CsA analog with no immunosuppressive action, cyclosporin H, did not alter PRL binding to MNC. Furthermore, PRL receptors were demonstrated on four cell lines of human and mouse origin. Finally, PRL receptors were identified on purified populations of T and B lymphocytes isolated from human spleens, and CsA again inhibited PRL binding at concentrations of 10(-7) and 10(-6) M. The presence of PRL receptors on T and B lymphocytes suggests that PRL may be involved in the regulation of humoral and cell-mediated immunity, and that one effect of CsA on immune function may be its ability to inhibit the effects of PRL action on these lymphocytes.
TL;DR: This paper reported the discovery of buried lake muds in north-west Sudan, in the hyperarid core of the Eastern Sahara, which yield sedimentological and palynological data clearly interpretable as recording an early to mid-Holocene humid episode that supported a relatively-deep stratified lake surrounded by tropical savanna woodland vegetation.
Abstract: A major problem in the study of Holocene palaeoenvironments of the arid and wind-deflated Sahara is the low preservation potential of sediments from which a record of past climatic change can be established. Several indirect and imprecisely dated pieces of evidence have suggested humid episodes in the Holocene that may have supported more productive ecosystems and denser human populations than today. Searches for reliable proxy data on past climates, however, have failed to yield satisfactory results. We report here the discovery of buried lake muds in north-west Sudan, in the hyperarid core of the Eastern Sahara, which yield sedimentological and palynological data clearly interpretable as recording an early to mid-Holocene humid episode that supported a relatively-deep stratified lake surrounded by tropical savanna woodland vegetation.
TL;DR: By introducing the phase data of a third wavelength, one can measure the phase of a very steep wave front and the repeatability of the measurement is better than 25-A rms (λ = 6328 A).
Abstract: This paper describes a method to enhance the capability of two-wavelength phase-shifting interferometry. By introducing the phase data of a third wavelength, one can measure the phase of a very steep wave front. Experiments have been performed using a linear detector array to measure surface height of an off-axis parabola. For the wave front being measured the optical path difference between adjacent detector pixels was as large as 3.3 waves. After temporal averaging of five sets of data, the repeatability of the measurement is better than 25-A rms (λ = 6328 A).
TL;DR: The results indicate that females discriminate among males on the basis of color and that females of different strains prefer the same male colors rather than those characteristics of males of their own strain.
Abstract: Experiments were designed to determine the effects of male pigmentation patterns on female choice in guppies. When presented with a series of variably-colored males, females of different genetic strain consistently exhibited similar preferences (Tables 1 and 2), preferring those males with the greatest development of both carotenoid and iridescent pigments (Table 3). A partial rank correlation analysis of pigments of males indicates positive correlations between the iridescent and carotenoid pigments and also between melanins and showiness (Table 4). Only when either the carotenoid or iridescent pigments were held constant was there any effect of the other pigments on the ranking order of males by the females. Other pigments appear to be relatively unimportant in influencing female choice of males. These results indicate that females discriminate among males on the basis of color and that females of different strains prefer the same male colors rather than those characteristics of males of their own strain. The results support those models of sexual selection that hold that sexually selected traits honestly advertise the phenotypic and genetic qualities of males; they do not support models of runaway selection for particular male traits, such as first proposed by Fisher (1930).
TL;DR: The transcription of the chimaeric gene as well as the NPTII activity of the resulting fusion protein were shown to be light inducible and resistant to kanamycin.
Abstract: The light-inducible nuclear gene coding for the small subunit of ribulose-1,5-bisphosphate carboxylase (Rubisco), produces a precursor protein with an amino-terminal transit peptide which is transported into the plastids and cleaved by a specific proteinase To test whether the promoter and transit peptide-coding sequences of the small subunit gene can be used to direct the light-inducible synthesis and transport of a foreign protein into chloroplasts, a chimaeric gene was constructed consisting of the promoter, first exon and intron as well as part of the second exon of the small subunit Rubisco gene fused to the amino-terminal end of the neomycin phosphotransferase II gene, (nptII) of Tn5 Tobacco tissue, as well as whole plants, into which this chimaeric gene was introduced, were resistant to kanamycin The transcription of the chimaeric gene as well as the NPTII activity of the resulting fusion protein were shown to be light inducible The fusion protein is processed and located within the chloroplasts of the transformed plants
TL;DR: This paper describes some practical methods to calibrate the phase shifter in phase-shifting interferometry (PSI) using a piezoelectric transducer that has a nonlinearity of <1%.
Abstract: This paper describes some practical methods to calibrate the phase shifter in phase-shifting interferometry (PSI). The phase shifter used in the experiment is a piezoelectric transducer (PZT) that has a nonlinearity of <1%. Using the quantitative method described in this paper, the repeatability in the measurement of the phase-shifting angle is ~0.046° rms, and the 3σ value is 0.139°. A calibration-insensitive phase calculation algorithm is discussed and compared with other synchronous detection equations (e.g., the three-bucket or the four-bucket method). Experimental results verify the calibration-insensitive mechanism of the self-calibrating algorithm.
TL;DR: In this paper, the authors presented a model, the only successful one among several attempts, in which the first two empirical generalizations can be derived as a consequence of the third, and the model assumes that species are ordered in a cascade or hierarchy such that a given species can prey on only those species below it and can be preyed on by those species above it in the hierarchy.
Abstract: Three recently discovered quantitative empirical generalizations describe major features of the structure of community food webs. These generalizations are: (i) a species scaling law: the mean proportions of basal, intermediate and top species remain invariant at approximately 0.19, 0.53, and 0.29, respectively, over the range of variation in the number of species in a web; (ii) a link scaling law: the mean proportions of trophic links in the categories basal-intermediate, basal-top, intermediate-intermediate, and intermediate-top remain invariant at approximately 0.27, 0.08, 0.30 and 0.35, respectively, over the range of variation in the number of species in a web; and (iii) a link-species scaling law: the ratio of mean trophic links to species remains invariant at approximately 1.86, over the range of variation in the number of species in a web. This paper presents a model, the only successful one among several attempts, in which the first two of these empirical generalizations can be derived as a consequence of the third. The model assumes that species are ordered in a cascade or hierarchy such that a given species can prey on only those species below it and can be preyed on by only those species above it in the hierarchy.
TL;DR: Experimental data presented in the paper show that optimization of surface roughness is necessary to obtain optimum magnetic amplitude, friction, and wear properties.
Abstract: Stylus-profiling techniques cannot be used for surface characterization of polymeric surfaces, such as magnetic tapes, because of their relatively low hardness. An interferometric-optical-profiling microscope system was used to obtain high-accuracy surface profiles of magnetic media, rapidly and without physical contact with the sample. The profilometer consists of a conventional, reflection-type optical microscope with a Mirau two-beam interferometer attachment. The interference patterns of the surface can be observed through the eyepieces and can be detected with a solid-state linear array of 1024 detector elements. By translating the reference surface of the interferometer with a piezoelectric transducer while taking consecutive measurements, accurate surface-height measurements can be obtained from each detector element. The microscope system is controlled by a microcomputer, which communicates with a desk-top computer for further analysis of the surface-profile data. A computer-controlled specimen stage is added to increase the sample size. The reasons for selecting the Mirau two-beam interferometry are also discussed. Sample data of magnetic tapes are presented. Experimental data presented in the paper show that optimization of surface roughness is necessary to obtain optimum magnetic amplitude, friction, and wear properties.
TL;DR: Both in vitro and in vivo studies indicate that bean tannins decrease protein digestibility, either by inactivating digestive enzymes or by reducing the susceptibility of the substrate proteins after forming complexes with tannin-protein complexes and absorbed ionizable iron.
Abstract: Tannins are one of several antinutritional factors present in dry beans and are located mainly in the seed coat or testa. The tannin content of dry beans ranges from 0.0 to 2.0% depending on the bean species and color of the seed coat. Many high tannin bean varieties are of lower nutritional quality than low tannin varieties of beans. Naturally occurring food legume tannins are reported to interact with proteins (both enzyme and nonenzyme proteins) to form tannin-protein complexes resulting in inactivation of digestive enzymes and protein insolubility. Both in vitro and in vivo studies indicate that bean tannins decrease protein digestibility, either by inactivating digestive enzymes or by reducing the susceptibility of the substrate proteins after forming complexes with tannins and absorbed ionizable iron. Other deleterious effects of tannins include a lowered feed efficiency and growth depression in experimental animals. The antinutritional activity of bean tannins can be reduced by processing (1 or a combination of 2 or more methods), for example dehulling, soaking, cooking and germination. Genetic selection also may help in breeding varieties low in tannins. Potential chemical treatments such as use of tannin complexing agents are discussed.
TL;DR: In this article, the authors found that images with equal pixel signal-to-noise ratio (SNRp) but different correlation properties give quite different observer-performance measures for a simple detection experiment.
Abstract: Pixel signal-to-noise ratio is one accepted measure of image quality for predicting observer performance in medical imaging. We have found, however, that images with equal pixel signal-to-noise ratio (SNRp) but different correlation properties give quite different observer-performance measures for a simple detection experiment. The SNR at the output of an ideal detector with the ability to prewhiten the noise is also a poor predictor of human performance for disk signals in high-pass noise. We have found constant observer efficiencies for humans relative to the performance of a nonprewhitening detector for this task.
TL;DR: In this paper, the empirical relation between the transient crater diameter and the final crater diameter of complex craters and basins is estimated using cumulative terrace widths, central uplift diameters, continuous ejecta radii, and transient crater reconstructions determined from lunar and terrestrial impact structures.
Abstract: The empirical relation between the transient crater diameter (Dg) and final crater diameter (Dr) of complex craters and basins is estimated using cumulative terrace widths, central uplift diameters, continuous ejecta radii, and transient crater reconstructions determined from lunar and terrestrial impact structures. The ratio Dg/Dr is a power law function of Dr, decreasing uniformly from unity at the diameter of the simple-complex crater morphology transition to about 0.5 for large multiring basins like Imbrium on the moon. The empirical constants in the Dg/Dr relation are interpreted physically to mean that the position of the final rim relative to the transient crater, and hence the extent of collapse, is controlled or greatly influenced by the properties of the zone of dissociated material produced by the impact shock. The continuity of the Dg/Dr relation over the entire spectrum of morphologic types from complex craters to multiring basins implies that the rims of all these structures form in the same tectonic environment despite morphologic differences.
TL;DR: In this paper, the authors used tandem accelerator mass spectrometers to measure as few as 107 atoms of 129I in 10 mg I with 10% precision and verified the usefulness of this tracer as an indicator of brine source and age.
TL;DR: In this paper, the authors explored the effect of layoffs on the subsequent productivity of "survivors" and found that the layoff caused participants to experience increased feelings of remorse and develop more negative attitudes toward their co-worker.
TL;DR: The incidence of measles in New York City and Baltimore was studied using recently developed techniques in nonlinear dynamics to suggest almost two dimensional, chaotic flows whose essential attributes are captured by one dimensional, unimodal maps.
Book•
01 Jan 1985TL;DR: Early studies of Missoula flooding centered on the anomalous physiography of the Channeled Scabland, which J. Harlen Bretz hypothesized in 1923 to have developed during a debacle that he named ‘The Spokane Flood'.
Abstract: Late Wisconsin floods from glacial Lake Missoula occurred between approximately 16 and 12 ka BP. Many floods occurred; some were demonstrably cataclysmic. Early studies of Missoula flooding centered on the anomalous physiography of the Channeled Scabland, which J. Harlen Bretz hypothesized in 1923 to have developed during a debacle that he named ‘The Spokane Flood’. Among the ironies in the controversy over this hypothesis was a mistaken view of uniformitarianism held by Bretz's adversaries. After resolution of the scabland's origin by cataclysmic outburst flooding from glacial Lake Missoula, research since 1960 emphasized details of flood magnitudes, frequency, routing and number. Studies of flood hydraulics and other physical parameters need to utilize modern computerized procedures for flow modeling, lake-burst simulation, and sediment-transport analysis. Preliminary simulation models indicate the probability of multiple Late Wisconsin jokulhlaups from Lake Missoula, although these models predict a wide range of flood magnitudes. Major advances have been made in the study of low-energy, rhythmically bedded sediments that accumulated in flood slack-water areas. The ‘forty floods’ hypothesis postulates that each rhythmite represents the deposition in such slack-water areas of separate, distinct cataclysmic floods that can be traced from Lake Missoula to the vicinity of Portland, Oregon. However, the hypothesis has numerous unsubstantiated implications concerning flood magnitudes, sources, routing and sedimentation dynamics. There were multiple great Late Wisconsin floods in the Columbia River system of the northwestern United States. Studies of high-energy, high altitude flood deposits are necessary to evaluate the magnitudes of these floods. Improved geochronologic studies throughout the immense region impacted by the flooding will be required to properly evaluate flood frequency. The cataclysmic flood concept championed by J. Harlen Bretz continues to stimulate exciting and controversial research.