Showing papers by "University of Washington published in 1981"
TL;DR: A computationally feasible method for finding such maximum likelihood estimates is developed, and a computer program is available that allows the testing of hypotheses about the constancy of evolutionary rates by likelihood ratio tests.
Abstract: The application of maximum likelihood techniques to the estimation of evolutionary trees from nucleic acid sequence data is discussed. A computationally feasible method for finding such maximum likelihood estimates is developed, and a computer program is available. This method has advantages over the traditional parsimony algorithms, which can give misleading results if rates of evolution differ in different lineages. It also allows the testing of hypotheses about the constancy of evolutionary rates by likelihood ratio tests, and gives rough indication of the error of the estimate of the tree.
13,111 citations
TL;DR: In this paper, a review of existing literature on the subject reveals the existence of at least four such patterns: the North Atlantic and North Pacific Oscillations identified by Walker and Bliss (1932), a zonally symmetric seesaw between sea level pressures in polar and temperature latitudes, first noted by Lorenz (1951), and what we will refer to as the Pacific/North American pattern, which has been known to operational long-range forecasters in this country since the 1950's.
Abstract: Contemporaneous correlations between geopotential heights on a given pressure surface at widely separated points on earth, referred to as teleconnections in this paper, are studied in an attempt to identify and document recurrent spatial patterns which might be indicative of standing oscillations in the planetary waves during the Northern Hemisphere winter, with time scales on the order of a month or longer. A review of existing literature on the subject reveals the existence of at least four such patterns: the North Atlantic and North Pacific Oscillations identified by Walker and Bliss (1932). a zonally symmetric seesaw between sea level pressures in polar and temperature latitudes, first noted by Lorenz (1951), and what we will refer to as the Pacific/North American pattern, which has been known to operational long-range forecasters in this country since the 1950's. A data set consisting of NMC monthly mean sea level pressure and 500 mb height analyses for a 15-year period is used as a basis fo...
3,781 citations
TL;DR: A prospective general population study of 22 707 Chinese men in Taiwan has shown that the incidence of primary hepatocellular carcinoma (PHC) among carriers of hepatitis B surface antigen (HBsAg) is much higher than among non-carriers as discussed by the authors.
2,652 citations
TL;DR: A review of both laboratory and field studies on the effect of setting goals when learning or performing a task found that specific, challenging goals led more often to higher performance than easy goals, 'do your best' goals or no goals as discussed by the authors.
Abstract: : A review of both laboratory and field studies on the effect of setting goals when learning or performing a task found that specific, challenging goals led more often to higher performance than easy goals, 'do your best' goals or no goals. This is one of the most robust and replicable findings in the psychological literature, with 90% of the studies showing positive or partially positive results. The main mechanisms by which goals affect performance are by directing attention, mobilizing effort, increasing persistence, and motivating strategy development. Goal setting is most likely to improve task performance when the goals are specific and sufficiently challenging, when the subjects have sufficient ability (and ability differences are controlled), when feedback is provided to show progress in relation to the goal, when rewards such as money are given for goal attainment, when the exerimenter manager is supportive, and when the assigned goals are actually accepted by the individual. No reliable individual differences have emerged in goal setting studies, probably because goals were typically assigned rather than self-set. Need for achievement and self esteem may be the most promising individual difference variables. (Author)
2,592 citations
TL;DR: In this article, a general procedure for decomposition of non-stationary time series into a permanent and transitory component allowing both components to be stochastic is introduced. But the decomposition methodology depends only on past data and therefore is computable in real-time.
2,311 citations
TL;DR: In this paper, the interannual variability of seasonal means for the Northern Hemisphere winter during the period 1951-78 was examined, with emphasis on vertical structure and teleconnections to middle latitudes.
Abstract: Atmospheric phenomena associated with the Southern Oscillation are examined, with emphasis on vertical structure and teleconnections to middle latitudes. This paper is specifically concerned with the interannual variability of seasonal means for the Northern Hemisphere winter during the period 1951–78. Among the variables considered are sea surface temperature in the equatorial Pacific, precipitation at selected equatorial Pacific stations, a “Southern Oscillation Index” of sea level pressure, 200 mb height and tropospheric mean temperature at stations throughout the tropics, and Northern Hemisphere geopotential height fields. Selected statistics derived from surface data also are examined for the period 1910–45. Results are presented in the form of time series and correlation statistics for the variables listed above. Results concerning the relationships between sea surface temperature, sea level pressure and rainfall are consistent with the major conclusions of previous studies by J. Bjerknes a...
1,837 citations
1,392 citations
TL;DR: The identification of three proteins which interact with the pheromone of the wild silk moth Antheraea polyphemus are reported: a phersomone-binding protein and a pherOMone-degrading esterase, both uniquely located in the pothole-sensitive sensilla; and a second ester enzyme common to all cuticular tissues except the sensilla.
Abstract: The antennae of male silk moths are extremely sensitive to the female sex pheromone such that a male moth can find a female up to 4.5 km away1. This remarkable sensitivity is due to both the morphological and biochemical design of these antennae. Along the branches of the plumose antennae are the sensilla trichodea, each consisting of a hollow cuticular hair containing two unbranched dendrites bathed in a fluid, the receptor lymph2,3. The dendrites and receptor lymph are isolated from the haemolymph by a barrier of epidermal cells which secreted the cuticular hair4–6. Pheromone molecules are thought to diffuse down 100 A-wide pore tubules through the cuticular wall and across the receptor lymph space to receptors located in the dendritic membrane6,7. To prevent the accumulation of residual stimulant and hence sensory adaptation, the pheromone molecules are subsequently inactivated in an apparent two-step process of rapid ‘early inactivation’ followed by much slower enzymatic degradation8,9. The biochemistry involved in this sequence of events is largely unknown. We report here the identification of three proteins which interact with the pheromone of the wild silk moth Antheraea polyphemus: a pheromone-binding protein and a pheromone-degrading esterase, both uniquely located in the pheromone-sensitive sensilla; and a second esterase common to all cuticular tissues except the sensilla.
1,072 citations
TL;DR: Foraging mode within one species varies with changes in food availability, and any general model of foraging velocity must be complex because foraging mode constrains numerous important aspects of ecology.
Abstract: Desert lizards are typically either widely foraging or sit-and-wait predators, and these foraging modes are correlated with major differences in ecology. Foraging mode is related to the type of prey eaten by lizards. Widely foraging lizards in the Kalahari desert, the Western Australian desert, and the North American desert generally eat more prey that are sedentary, unpredictably distributed, and clumped (e.g., termites) or that are large and inaccessible (inactive scorpions) than do sit-and- wait lizards. In contrast, sit-and-wait lizards eat more prey that are active. Foraging mode also appears to influence the types of predators that in turn eat the lizards. For example, a sit-and-wait snake eats predominately widely foraging lizards. Crossovers in foraging mode thus exist between trophic levels. Widely foraging lizards may also encounter predators more frequently, as suggested by analyses of relative tail lengths; but tail break frequencies are ambiguous. Daily maintenance energetic expen- ditures of widely foraging lizards appear to be about 1.3-1.5 times greater than those of sit-and-wait lizards in the same habitats, but gross food gains are about 1.3-2.1 times greater. Widely foraging species also have lower relative clutch volumes, apparently in response to enhanced risks of predation. Foraging mode within one species varies with changes in food availability. Physiology, morphology, and risk of predation might generally restrict the flexibility of foraging mode. Because foraging mode constrains numerous important aspects of ecology, any general model of foraging velocity must be complex.
986 citations
TL;DR: In this paper, the strength of binding between a given metal and the surface may vary by an order of magnitude or more from one site to another, suggesting that the surface is composed of many groups of binding sites.
978 citations
TL;DR: In a classic paper, Hutchinson (1959) set the tone for much of the ecological work done during the past 20 years by suggesting that ecologists try to explain the numbers of species of animals by explaining how the species could coexist.
Abstract: In a classic paper, Hutchinson (1959) set the tone for much of the ecological work done during the past 20 years by suggesting that ecologists try to explain the numbers of species of animals. Hutchinson's approach was ecological, explaining diversity by explaining how the species could coexist. There can be little question that competitive exclusion sets an upper limit on species diversity, but it is not obvious that this upper limit will be achieved. There may be additional constraints on the process of speciation, constraints set by genetics rather than ecology. It has been usual for evolutionists to reject the possibility of sympatric speciation, and this amounts to asserting the existence of such genetic constraints. Even if the ecological opportunity for coexistence is present, under the conventional view lack of geographic isolation can prevent speciation. The attempt by Rosenzweig (1975) to give a comprehensive explanation of continental species diversity takes as its starting point the assumption that geographic isolation is a necessary prerequisite to species formation. A number of workers have made and analyzed detailed population genetic models of sympatric or parapatric speciation, in particular Maynard Smith (1966), Dickinson and Antonovics (1973), and Caisse and Antonovics (1978). Balkau and Feldman (1973) made a model of migration modification which can also be regarded as a model of parapatric speciation. The upshot of these models is that it is not difficult for sympatric speciation to occur. While these authors have largely been concerned with showing that sym-
TL;DR: Combination immmunosuppression appears to favorably affect and, in some cases, premanently arrest the adverse natural course of extensive chronic GVHD.
01 Jun 1981
TL;DR: The cold upper halcoline of the Arctic Ocean is maintained by large-scale lateral advection from the adjoining continental shelves, where dense and saline shelf water is produced during freezing; the salinization of the water column is especially pronounced in certain areas of persistent ice divergence as mentioned in this paper.
Abstract: The cold upper halcoline of the Arctic Ocean is maintained by large-scale lateral advection from the adjoining continental shelves, where dense and saline shelf water is produced during freezing; the salinization of the water column is especially pronounced in certain areas of persistent ice divergence. Estimates show the annual rate at which the dense shelf water feeds into the Polar Basin is probably in the neighborhood of 2.5 x 106 m3 s−1; this is of the same order as the inflow of warm and saline water from the Atlantic. A consequence of this process is that the halocline must be a heat sink for the underlying Atlantic water, thereby shielding the ice cover from an upward heat flux. The Atlantic water is thus linked rather directly to the enormous shelf seas that border the Polar Basin. Proposed massive river diversions in the Arctic could, by increasing the shelf salinities and driving a deeper flow into the interior, cause a thinning of the halocline and place the Atlantic water in more direct contact with the surface mixed layer.
TL;DR: This paper proves that even severely restricted instances of packing and covering problems remain NP-hard in two or more dimensions, and helps to fill the gap by showing that some very constrained intersection graph problems in two dimensions are not very constrained.
TL;DR: A plasmid containing the structural gene for thymidine kinase from herpes simplex virus fused to the promoter/regulatory region of the mouse metallothionein-I gene was injected into the pronucleus of fertilized one-cell mouse eggs; the eggs were subsequently reimplanted into the oviducts of pseudopregnant mice.
TL;DR: The programming language aspects of a graphic simulation laboratory named ThingLab, which is an object-oriented system that employs inheritance and part-whole hierarchies to describe the structure of a simulation, are presented.
Abstract: The programming language aspects of a graphic simulation laboratory named ThingLab are presented. The design and implementation of ThingLab are extensions to Smalltalk. In ThingLab, constraints are used to specify the relations that must hold among the parts of the simulation. The system is object-oriented and employs inheritance and part-whole hierarchies to describe the structure of a simulation. An interactive, graphic user interface is provided that allows the user to view and edit a simulation.
TL;DR: In this article, the Raman spectra of crystalline graphite, graphite damaged by ion-etching, and structurally disordered pyrolytic and glassy carbons were examined as a function of excitation wavelength λ over the range 488.0 to 647.1 nm.
TL;DR: In this paper, a statistical procedure for the choice of functional form for a hedonic price equation is proposed, and a highly general functional form is specified that yields all other functional forms of interest as special cases.
TL;DR: The map location of tumor-derived RNA transcribed from the T-DNA, the role of phytohormones in crown gall tumorigenesis and the eventual use of the Ti plasmid as a vehicle for introducing genes of choice into the genomes of higher plants are discussed.
Book•
01 Mar 1981TL;DR: In this paper, the authors review the book "Research in Corporate Social Performance and Policy," vol. 3, by Lee E. Preston, and present a review of the book's content.
Abstract: The article reviews the book "Research in Corporate Social Performance and Policy," vol. 3, by Lee E. Preston.
TL;DR: Assessment at least 10 years postretention of sixty-five cases previously treated in the permanent-dentition stage with first-premolar extractions, traditional edgewise mechanics, and retention revealed considerable variation among patients.
TL;DR: Although these results indicate a higher complication rate than earlier retrospective ASGE surveys on endoscopy, they are comparable to other available data about the risks of endoscopies in the specific group of patients with upper gastrointestinal bleeding.
TL;DR: It is argued that uniform circuit complexity introduced by Borodin is a reasonable model of parallel complexity and that context-free language recognition is in NC, the class of polynomial size andPolynomial-in-log depth circuits.
TL;DR: Physicians overestimated the patients' probability of pneumonia but were sensitive to relative differences in the predictive value of symptoms when present and absent, and appeared to use base-rate information correctly when making clinical judgments.
Abstract: This study reports on physicians' processing of probabilistic information while they were treating possible pneumonia patients at an outpatient clinic. Physicians overestimated the patients' probability of pneumonia but were sensitive to relative differences in the predictive value of symptoms when present and absent, and appeared to use base-rate information correctly when making clinical judgments.
TL;DR: It is concluded that neutrophil-derived neutral proteases mediate endothelial cell detachment in vitro through digestion of endothelium cell surface proteins including fibronectin including sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
Abstract: Neutrophil-mediated endothelial injury was assessed in vitro using assays of cell lysis and cell detachment. Activation of human peripheral blood neutrophils adherent to human umbilical vein endothelial cell monolayers by serum-treated zymosan produced dose-dependent endothelial cell detachment without concomitant cell lysis. This injury was inhibited by neutral protease inhibitors, but not by catalase or superoxide dismutase. Neutrophils from a patient with chronic granulomatous disease also produced endothelial cell detachment when activated by serum-treated zymosan similar to normal neutrophils. Endothelial detachment was also produced by cell-free postsecretory media from activated neutrophils or by partially purified human neutrophil granule fraction and was inhibitable by tryptic, elastase, and serine protease inhibitors, but not by an acid protease inhibitor. Analysis of iodinated endothelial cell surface proteins that had been exposed to partially purified neutrophil granule fraction showed complete loss of proteins migrating in the region of fibronectin by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This result was prevented in the presence of neutral protease inhibitors. We conclude that neutrophil-derived neutral proteases mediate endothelial cell detachment in vitro through digestion of endothelial cell surface proteins including fibronectin.
TL;DR: The transcriptionally active Ev-3 and inactive ev-1 endogenous retrovirus loci in chick cells differ in that ev-3 is undermethylated, preferentially sensitive to DNase I digestion, and contains nuclease hypersensitive sites in each of its two long terminal repeats.
Abstract: The transcriptionally active ev-3 and inactive ev-1 endogenous retrovirus loci in chick cells differ in that ev-3 is undermethylated, preferentially sensitive to DNase I digestion, and contains nuclease hypersensitive sites in each of its two long terminal repeats. Transient exposure of cells to 5-azacytidine, a cytosine analogue which cannot be methylated at the 5 position, results in the hypomethylation and transcriptional activation of ev-1, as well as the acquisition of at least one nuclease-hypersensitive site within the chromosomal domain of ev-1.
TL;DR: The W7 mouse thymoma cell line does not express the metallothionein-I (MT-I) gene in the presence of either cadmium or glucocorticoids, and the extent of DNA methylation within the MT-I gene and its flanks was determined by comparing the cleavage patterns generated by the isoschizomeric restriction enzymes Hpa II and Msp I.
TL;DR: An iterative REML method is introduced which makes rapid computation of the REML estimate of the evolutionary tree feasible and may also serve as a review of the basic logic of these estimates and tests for those readers unfamiliar with the existing human genetics literature.
Abstract: A small but complex literature on the estimation of evolutionary trees from quantitative characters (including gene frequencies) has existed for over 15 years (Edwards and Cavalli-Sforza, 1964; Cavalli-Sforza and Edwards, 1967, 1970; Edwards, 1970; Kidd and Sgaramella-Zonta, 1971; Thompson, 1973; Felsenstein, 1973a; Thompson, 1975; Cavalli-Sforza and Piazza, 1975; Astolfi et al., 1978). In general its methods are little-known and even less used by those in possession of relevant gene frequencies or quantitative character data. Though this results in part from the complexity of the mathematics in these papers and in part from their concentration in human genetics journals, a major block to the use of these statistical methods has been the difficulty of the computations. Thompson (1975) has produced an iterative computer program which is probably the most efficient method of finding maximum likelihood evolutionary trees. Thompson's method is the strict application of maximum likelihood estimation in a situation in which each character added to the data brings with it one new parameter to be estimated. It is easily demonstrated that in this case, these "nuisance parameters" cause the estimation procedure to fail to be consistent: that is, the estimate will not converge to the true tree as more and more characters are added. My own procedure (Felsenstein, 1973a) makes a restricted maximum likelihood (REML) estimate, but eliminates the presence of the nuisance parameters and thereby makes a consistent estimate of the evolutionary tree. Some of the differences between these approaches will be briefly dealt with later in this paper. This paper introduces an iterative REML method which makes rapid computation of the REML estimate of the evolutionary tree feasible. It may also serve as a review of the basic logic of these estimates and tests for those readers unfamiliar with the existing human geneticsoriented literature.
TL;DR: The possible evolutionary mechanisms by which the mitochondrial genome has grown within the cucurbit family is considered and the possible reasons for the existance of a seven to eight-fold range in mitochondrial genome size among such closely related species are considered.
TL;DR: The Personal Resource Questionnaire was administered as the measure of one of the independent variables in a study of 149 male or female spouses of individuals with multiple sclerosis and low intercorrelations for the dimensional subscales suggest that nurturance is an independent scale.
Abstract: The Personal Resource Questionnaire (PRQ) is a two-part measure of the multidimensional characteristics of social support. Part one provides descriptive information about the person's resources, the satisfaction with these resources, and whether or not there is a confidant. Part two contains a 25-item Likert scale developed according to Weiss's relational dimensions and a five-item Self-Help Ideology scale. The PRQ was administered as the measure of one of the independent variables in a study of 149 male or female spouses of individuals with multiple sclerosis. Content and face validity procedures were completed previous to the study. An internal consistency reliability coefficient of alpha = .89 was obtained for the PRQ Part 2. Moderate intercorrelations for the dimensional subscales--intimacy, social integration, worth, and assistance--indicate that there is some overlap of these dimensions. Low intercorrelations between nurturance and the other four subscales suggest that nurturance is an independent scale. Modest predictive validity coefficients were obtained. At the present time the intended use of the PRQ is for research. Plans for tool development include obtaining further construct validity information and test-retest reliability.