Showing papers by "University of Washington published in 1985"
TL;DR: The recently‐developed statistical method known as the “bootstrap” can be used to place confidence intervals on phylogenies and shows significant evidence for a group if it is defined by three or more characters.
Abstract: The recently-developed statistical method known as the "bootstrap" can be used to place confidence intervals on phylogenies. It involves resampling points from one's own data, with replacement, to create a series of bootstrap samples of the same size as the original data. Each of these is analyzed, and the variation among the resulting estimates taken to indicate the size of the error involved in making estimates from the original data. In the case of phylogenies, it is argued that the proper method of resampling is to keep all of the original species while sampling characters with replacement, under the assumption that the characters have been independently drawn by the systematist and have evolved independently. Majority-rule consensus trees can be used to construct a phylogeny showing all of the inferred monophyletic groups that occurred in a majority of the bootstrap samples. If a group shows up 95% of the time or more, the evidence for it is taken to be statistically significant. Existing computer programs can be used to analyze different bootstrap samples by using weights on the characters, the weight of a character being how many times it was drawn in bootstrap sampling. When all characters are perfectly compatible, as envisioned by Hennig, bootstrap sampling becomes unnecessary; the bootstrap method would show significant evidence for a group if it is defined by three or more characters.
40,349 citations
TL;DR: A method of correcting for the phylogeny has been proposed, which specifies a set of contrasts among species, contrasts that are statistically independent and can be used in regression or correlation studies.
Abstract: Recent years have seen a growth in numerical studies using the comparative method. The method usually involves a comparison of two phenotypes across a range of species or higher taxa, or a comparison of one phenotype with an environmental variable. Objectives of such studies vary, and include assessing whether one variable is correlated with another and assessing whether the regression of one variable on another differs significantly from some expected value. Notable recent studies using statistical methods of this type include Pilbeam and Gould's (1974) regressions of tooth area on several size measurements in mammals; Sherman's (1979) test of the relation between insect chromosome numbers and social behavior; Damuth's (1981) investigation of population density and body size in mammals; Martin's (1981) regression of brain weight in mammals on body weight; Givnish's (1982) examination of traits associated with dioecy across the families of angiosperms; and Armstrong's (1983) regressions of brain weight on body weight and basal metabolism rate in mammals. My intention is to point out a serious statistical problem with this approach, a problem that affects all of these studies. It arises from the fact that species are part of a hierarchically structured phylogeny, and thus cannot be regarded for statistical purposes as if drawn independently from the same distribution. This problem has been noticed before, and previous suggestions of ways of coping with it are briefly discussed. The nonindependence can be circumvented in principle if adequate information on the phylogeny is available. The information needed to do so and the limitations on its use will be discussed. The problem will be discussed and illustrated with reference to continuous variables, but the same statistical issues arise when one or both of the variables are discrete, in which case the statistical methods involve contingency tables rather than regressions and correlations.
8,833 citations
TL;DR: Yields ranged from 0.3–200 nanograms of DNA per milligram of tissue, and in no case tested was inhibition observed for restriction enzymes BamHI or EcoRI.
Abstract: We have developed a DNA extraction procedure for milligram amounts of plant tissue. Yields ranged from 0.3-200 nanograms of DNA per milligram of tissue. The factors affecting yield are discussed. Fresh tissue, as well as herbarium specimens (22-118 years old) and mummified seeds and embryos (500 to greater than 44 600 years old) were used. All tissues attempted (57 types from 29 species) yielded measurable amounts of DNA. In no case tested was inhibition observed for restriction enzymes BamHI or EcoRI.
1,829 citations
TL;DR: Transgenic mice bearing the cellular myc oncogene coupled to the immunoglobulin μ or κ enhancer frequently develop a fatal lymphoma within a few months of birth and constitutive c-myc expression appears to be highly leukaemogenic at several stages of B-cell maturation.
Abstract: Transgenic mice bearing the cellular myc oncogene coupled to the immunoglobulin mu or kappa enhancer frequently develop a fatal lymphoma within a few months of birth. Since the tumours represent represent both immature and mature B lymphocytes, constitutive c-myc expression appears to be highly leukaemogenic at several stages of B-cell maturation. These myc mice should aid study of lymphoma development, B-cell ontogeny and immunoglobulin regulation.
1,781 citations
TL;DR: It is shown that the supersymmetric string theory model has both flat and anti-de Sitter space as solutions, but that the cosmological branch is unstable, because the graviton becomes a ghost there: the theory solves its owncosmological problem.
Abstract: Expansion of supersymmetric string theory suggests that the leading quadratic curvature correction to the Einstein action is the Gauss-Bonnet invariant. We show that this model has both flat and anti-de Sitter space as solutions, but that the cosmological branch is unstable, because the graviton becomes a ghost there: The theory solves its own cosmological problem. The general static spherically symmetric solution is exhibited; it is asymptotically Schwarzschild. The sign of the Gauss-Bonnet coefficient determines whether there is a normal event horizon (for the string-generated sign) or a naked singularity. We discuss the effects of higher-curvature corrections and of an explicit cosmological term on stability.
1,447 citations
Book•
01 Jan 1985TL;DR: In this article, a vector radiative transfer equation for nonspherical particles is developed for both active and passive remote sensing of earth terrains, and the effective propagation constants and backscattering coefficients are calculated and illustrated for dense media.
Abstract: Active and passive microwave remote sensing of earth terrains is studied. Electromagnetic wave scattering and emission from stratified media and rough surfaces are considered with particular application to the remote sensing of soil moisture. Radiative transfer theory for both the random and discrete scatterer models is examined. Vector radiative transfer equations for nonspherical particles are developed for both active and passive remote sensing. Single and multiple scattering solutions are illustrated with applications to remote sensing problems. Analytical wave theory using the Dyson and Bethe-Salpeter equations is employed to treat scattering by random media. The backscattering enhancement effects, strong permittivity fluctuation theory, and modified radiative transfer equations are addressed. The electromagnetic wave scattering from a dense distribution of discrete scatterers is studied. The effective propagation constants and backscattering coefficients are calculated and illustrated for dense media.
1,398 citations
TL;DR: A method for estimating the average level of gene flow in a subdivided population, as measured by the average number of migrants exchanged between local populations, Nm, is presented and it is shown that this result is relatively insensitive to changes in parameters of the model other than Nm and the number of individuals sampled per population.
Abstract: A. method for estimating the average level of gene flow in a subdivided population, as measured by the average number of migrants exchanged between local populations, Nm, is presented. The results from a computer simulation model show that the logarithm of Nm is approximately linearly related to the logarithm of the average frequency of private alleles, p(1), in a sample of alleles from the population. It is shown that this result is relatively insensitive to changes in parameters of the model other than Nm and the number of individuals sampled per population. The dependence of the value of p(1) on the numbers of individuals sampled provides a rough way to correct for differences in sample size. This method was applied to data from 16 species, showing that estimated values of Nm range from much greater than 1 to less than 0.1. These results confirm the qualitative analysis of Slatkin (1981). This method was also applied to subsamples from a population to show how to measure the extent of isolation of local populations.
1,351 citations
TL;DR: This study examined the psychometric properties of the " original" seven factored scales derived by Aldwin et al. from Folkman and Lazarus' Ways of Coping Checklist versus a revised set of scales.
Abstract: This study examined the psychometric properties of the "original" seven factored scales derived by Aldwin et al. from Folkman and Lazarus' Ways of Coping Checklist (WCCL) versus a revised set of scales. Four psychometric properties were examined including the reproducibility of the factor structure of the original scales, the internal consistency reliabilities and intercorrelations of the original and the revised scales, the construct and concurrent validity of the scales, and their relationships to demographic factors. These properties were studied on three distressed samples: 83 psychiatric outpatients, 62 spouses of patients with Alzheimer's disease, and 425 medical students. The revised scales were consistently shown to be more reliable and to share substantially less variance than the original scales across all samples. In terms of construct validity, depression was positively related to the revised Wishful Thinking Scale and negatively related to the revised Problem-Focused Scale consistently across samples. Anxiety was also related to these scales, and in addition, it was positively related to the Seeks Social Support Scale across samples. The Mixed Scale was the only original scale that was consistently related to depression and anxiety across the three samples. Evidence for concurrent validity was provided by the fact that medical students in group therapy had significantly higher original and revised scale scores than students not participating in such groups. Both sets of scales were shown to be generally free of demographic biases.
1,083 citations
TL;DR: Integration of the fusion gene in all three species and expression of the gene in transgenic rabbits and pigs are reported here.
Abstract: Direct microinjection has been used to introduce foreign DNA into a number of terminally differentiated cell types as well as embryos of several species including sea urchin, Candida elegans, Xenopus, Drosophila and mice. Various genes have been successfully introduced into mice including constructs consisting of the mouse metallothionein-I (MT) promoter/regulator region fused to either the rat or human growth hormone (hGH) structural genes. Transgenic mice harbouring such genes commonly exhibit high, metal-inducible levels of the fusion messenger RNA in several organs, substantial quantities of the foreign growth hormone in serum and enhanced growth. In addition, the gene is stably incorporated into the germ line, making the phenotype heritable. Because of the scientific importance and potential economic value of transgenic livestock containing foreign genes, we initiated studies on large animals by microinjecting the fusion gene, MT-hGH, into the pronuclei or nuclei of eggs from superovulated rabbits, sheep and pigs. We report here integration of the gene in all three species and expression of the gene in transgenic rabbits and pigs.
1,080 citations
TL;DR: A comprehensive developmental approach to preventing youth crime based on the social development model, an integration of social control theory and social learning theory, and prevention approaches consistent with the model are described.
Abstract: This paper describes a comprehensive developmental approach to preventing youth crime based on the social development model, an integration of social control theory and social learning theory. The model asserts that the most important units of socialization, family, schools, peers, and community, influence behavior sequentially. Positive socialization is achieved when youths have the opportunity within each unit to be involved in conforming activities, when they develop skills necessary to be successfully involved, and when those with whom they interact consistently reward desired behaviors. These conditions should increase attachment to others, commitment to conforming behavior, and belief in the conventional order. These social bonds to conventional society inhibit association with delinquent pers and, in turn, prevent delinquent behavior. The paper describes prevention approaches consistent with the model. Rigorous evaluation of the delinquency prevention effects of these interventions is needed.
938 citations
TL;DR: Although the perception that nitrogen plays a major role in the ecology of the sea goes back at least to the turn of the century, it is only in the past 2 decades, after significant advances in analytical methodologies, that the importance of nitrogen to marine primary production and importance of the oceans in the global nitrogen cycle have begun to be quantified as mentioned in this paper.
Abstract: Although the perception that nitrogen plays a major role in the ecology of the sea goes back at least to the turn of the century, it is only in the past 2 decades, after significant advances in analytical methodologies, that the importance of nitrogen to marine primary production and the importance of the oceans in the global nitrogen cycle have begun to be quantified. Articles on marine nitrogen cycling studies have appeared, and continue to appear, in every major journal dealing with the environment. The book Nitrogen in the Marine Environment is a compilation of the major results and insights of these studies.
TL;DR: It is reported here that coupling of the mAChR in embryonic chick atrial cells to this inward rectifying K channel requires intracellular GTP, the first demonstration that a GTP-binding protein can regulate the function of an ionic channel without acting through cyclic nucleotide second messengers.
Abstract: Binding of acetylcholine (ACh) to cardiac muscarinic ACh receptors (mAChR) activates a potassium channel that slows pacemaker activity1–3. Although the time course of this activation suggests a multi-step process with intrinsic delays of 30–100 ms4–6 no second-messenger system has been demonstrated to link the mAChR to the channel. Changes in cyclic nucleotide levels (cyclic AMP and cyclic GMP) do not affect this K channel or its response to muscarinic agonists7,8. Indeed, electrophysiological experiments argue against the involvement of any second messenger that diffuses through the cytoplasm9. We report here that coupling of the mAChR in embryonic chick atrial cells to this inward rectifying K channel requires intracellular GTP. Furthermore, pretreatment of cells with IAP (islet-activating protein from the bacterium Bordetella pertussis) eliminates the ACh-induced inward rectification. As IAP specifically ADP-ribosylates two GTP-binding proteins, Ni and No, that can interact with mAChRs10, we conclude that a guanyl nucleotide-binding protein couples ACh binding to channel activation. This represents the first demonstration that a GTP-binding protein can regulate the function of an ionic channel without acting through cyclic nucleotide second messengers.
TL;DR: The new formulation generalizes the earlier result and draws the conclusion that there must be a symmetry breaking in the many-body ground state when applying to the fractional quantized Hall effect.
Abstract: Whenever the Fermi level lies in a gap (or mobility gap) the bulk Hall conductance can be expressed in a topologically invariant form showing the quantization explicitly. The new formulation generalizes the earlier result by Thouless, Kohmoto, Nightingale, and den Nijs to the situation where many-body interaction and substrate disorder are also present. When applying to the fractional quantized Hall effect, we draw the conclusion that there must be a symmetry breaking in the many-body ground state. The possibility of writing the fractionally quantized Hall conductance as a topological invariant is also discussed.
TL;DR: In this article, a new methodological approach for examining the impact of country of origin on product evaluations is proposed, which takes the form of a multiattribute attitudinal model analyzed by means of a system.
Abstract: A new methodological approach for examining the impact of country of origin on product evaluations is proposed. It takes the form of a multiattribute attitudinal model analyzed by means of a system...
TL;DR: It was not until the appearance of the paper by Oppenheimer and Kugel in 1934 and of the comprehensive study by Thannhauser in 1945 that the two syndromes were clearly delineated and the character of the skin changes defined.
TL;DR: Cette revue critique de la recherche montre l'existence d'une association entre la depression and the douleur chronique.
Abstract: Cette revue critique de la recherche montre l'existence d'une association entre la depression et la douleur chronique. Les modeles biologiques et psychologiques expliquant les mecanismes de cette interaction sont resumes
TL;DR: It is demonstrated that a significant portion of the mitogenic activity for 3T3 cells secreted by cultured human alveolar and peritoneal macrophages is due to a molecule (or molecules) similar to platelet-derived growth factor (PDGF).
TL;DR: Ghiorso et al. as discussed by the authors used a mathematical programming approach to determine the stable heterogeneous (solids+liquid) equilibrium phase assemblage at a particular temperature and pressure in magmatic systems both closed and open to oxygen.
Abstract: Thermodynamic and mathematical relations are presented to facilitate the description of an algorithm for the calculation of chemical mass transfer in magmatic systems. This algorithm extends the silicate liquid solution model of Ghiorso et al. (1983) to allow for the quantitative modelling of natural magmatic processes such as crystal fractionation, equilibrium crystallization, magma mixing and solid-phase assimilation. The algorithm incorporates a new method for determining the saturation surface of a non-ideal multicomponent solid-solution crystallizing from a melt. It utilizes a mathematical programming (optimization) approach to determine the stable heterogeneous (solids+liquid) equilibrium phase assemblage at a particular temperature and pressure in magmatic systems both closed and open to oxygen. Closed system equilibria are computed by direct minimization of the Gibbs free energy of the system. Open system equilibria are determined by minimization of the Korzhinskii potential (Thompson 1970), where oxygen is treated as a perfectly mobile component. Magmatic systems undergoing chemical mass transfer processes are modelled in a series of discrete steps in temperature, pressure or bulk composition, with each step characterized by heterogeneous solid-liquid equilibrium. A numerical implementation of the algorithm has been developed (in the form of a FORTRAN 77 computer program) and calculations demonstrating its utility are provided in an accompanying paper (Ghiorso and Carmichael 1985).
TL;DR: The behavior of the glacier in surge has many remarkable features, which can provide clues to a detailed theory of the surging process and is akin to a proposed mechanism of overthrust faulting.
Abstract: The hundredfold speedup in glacier motion in a surge of the kind the kind that took place in Variegated Glacier in 1982-1983 is caused by the buildup of high water pressure in the basal passageway system, which is made possible by a fundamental and pervasive change in the geometry and water-transport characteristics of this system. The behavior of the glacier in surge has many remarkable features, which can provide clues to a detailed theory of the surging process. The surge mechanism is akin to a proposed mechanism of overthrust faulting.
TL;DR: In this article, an approximate dispersion relation for near-inertial internal waves propagating in geostrophic shear is formulated that includes straining by the mean flow shear.
Abstract: An approximate dispersion relation for near-inertial internal waves propagating in geostrophic shear is formulated that includes straining by the mean flow shear. Near-inertial and geostrophic motions have similar horizontal scales in the ocean. This implies that interaction terms involving mean flow shear of the form (v·Δ)V as well as the mean flow itself [(V·Δ)v] must be retained in the equations of motion. The vorticity ζ shifts the lower bound of the internal waveband from the planetary value of the Coriolis frequency f to an effective Coriolis frequency feπ = f + ζ/2. A ray tracing approach is adopted to examine the propagation behavior of near-inertial waves in a model geostrophic jet. Trapping and amplification occur in regions of negative vorticity where near-inertial waves' intrinsic frequency &omega0 can be less than the effective Coriolis frequency of the surrounding ocean. Intense downward-propagating near-inertial waves have been observed at the base of upper ocean negative vorticity...
TL;DR: An 81-electrode system is described which is designed for topographic studies of spontaneous and evoked EEG activities and the utilization of this “10% system” is suggested to promote standardization.
Abstract: .An 81-electrode system is described which is designed for topographic studies of spontaneous and evoked EEG activities. This method combines the standard leads of the International 10–20 System with supplementary electrodes applied midway between leads of the 10–20 system or electrodes in turn situated between 10–20 leads. Auxiliary electrode designations refer to the underlying brain areas and to adjacent leads of the 10–20 method. The utilization of this “10% system” is suggested to promote standardization.
TL;DR: In this paper, a mathematical model of wood pyrolysis is presented that is in satisfactory agreement with experimental reaction product distributions over a range of conditions of practical importance for gasification and combustion.
TL;DR: Optimal application of in vitro manipulation of donor marrow as a method for preventing graft-versus-host disease will require more effective immunosuppression of the recipient in order to assure sustained engraftment and function of donor stem cells.
TL;DR: In this paper, the authors expand upon the geophysical, chemical, and possible microbiological analogies between contemporary and Archean hydrothermal systems and suggest several hypotheses, related to their model for the origin and evolution of life at Archean vents, which can be tested in present-day hydrothermic systems.
Abstract: Submarine hydrothermal vents are the only comtemporary geological environment which may be called truly primeval; they continue to be a major source of gases and dissolved elements to the modern ocean as they were to the Archean ocean. Then, as now, they encompassed a multiplicity of physical and chemical gradients as a direct result of interactions between extensive hydrothermal activity in the Earth's crust and the overlying oceanic and atmospheric environments. We have proposed that these gradients provided the necessary multiple pathways for the abiotic synthesis of chemical compounds, origin and evolution of ‘precells’ and ‘precell’ communities and, ultimately, the evolution of free-living organisms. This hypothesis is consistent with the tectonic, paleontological, and degassing history of the earth and with the use of thermal energy sources in the laboratory to synthesize amino acids and complex organic compounds. In this paper, we expand upon the geophysical, chemical, and possible microbiological analogies between contemporary and Archean hydrothermal systems and suggest several hypotheses, related to our model for the origin and evolution of life at Archean vents, which can be tested in present-day hydrothermal systems.
TL;DR: It is inferred that the lskT-encoded protein-tyrosine kinase may aid in transducing proliferative or differentiative signals unique to lymphocytes in order to mediate neoplastic transformation in lymphocytes.
TL;DR: In the lower Amazon River, suspended sediment is stored during rising stages of the river and resuspended during falling river stages; the pattern of storage and res Suspension damps out the extreme values of high and low sediment discharge and tends to keep them near the mean value.
Abstract: In the lower Amazon River, suspended sediment is stored during rising stages of the river and resuspended during falling river stages. The storage and resuspension in the reach are related to the mean slope of the flood wave on the river surface; this slope is smaller during rising river stages than during falling stages. The pattern of storage and resuspension damps out the extreme values of high and low sediment discharge and tends to keep them near the mean value between 3.0 x 106 and 3.5 x 106 metric tons per day. Mean annual discharge of suspended sediment in the lower Amazon is between 1.1 x 109 and 1.3 x 109 metric tons per year.
TL;DR: In this article, the authors operateally defined three top-level management priorities and made some suggestions about these priorities' relative levels of importance across three stages of organizational life (organizational life cycle).
Abstract: This research operationally defined three top-level management priorities and made some suggestions about these priorities' relative levels of importance across three stages of organizational life ...
TL;DR: It is concluded that intracoronary streptokinase reduces one-year mortality among patients with acute myocardial infarction, but this improvement occurs only among those in whom thrombolysis results in coronary artery reperfusion.
Abstract: After cardiac catheterization and coronary arteriography, 134 patients who had had an acute myocardial infarction were randomly assigned to treatment with intracoronary streptokinase (4000 U per minute, begun approximately 4 1/2 hours after the onset of symptoms, for a total of 286,000 +/- 77,800 U over 72 +/- 24 minutes); 116 control patients received standard care after they returned to the coronary care unit, immediately after angiography. Preliminary results of this trial have been published in the Journal (1983; 309:1477-81). During the first 30 days, 5 deaths occurred in the streptokinase group and 13 occurred in the control group (3.7 vs 11.2 per cent, P = 0.02); during the first year, the corresponding figures were 11 and 17 deaths (8.2 vs. 14.7 per cent, P = 0.10). However, when a minor imbalance in the ejection fraction and infarct location between the two groups was adjusted by logistic regression, the difference in one-year mortality became significant (P = 0.03). In the streptokinase group, 2 of the 80 patients in whom perfusion was reestablished (2.5 per cent) had died by one year, whereas 3 of the 13 with partial reperfusion (23.1 per cent) and 6 of the 41 with no reperfusion (14.6 per cent) had died (P = 0.008). Mortality among patients with partial reperfusion was not significantly different from that among those without reperfusion (P greater than 0.90). No base-line clinical, angiographic, or hemodynamic variable was predictive of successful reperfusion, according to univariate and multivariate analyses. We conclude that intracoronary streptokinase reduces one-year mortality among patients with acute myocardial infarction, but this improvement occurs only among those in whom thrombolysis results in coronary artery reperfusion.