Showing papers by "University of Wisconsin-Madison published in 1988"

Condor-a hunter of idle workstations

Abstract: The design, implementation, and performance of the Condor scheduling system, which operates in a workstation environment, are presented. The system aims to maximize the utilization of workstations with as little interference as possible between the jobs it schedules and the activities of the people who own workstations. It identifies idle workstations and schedules background jobs on them. When the owner of a workstation resumes activity at a station, Condor checkpoints the remote job running on the station and transfers it to another workstation. The system guarantees that the job will eventually complete, and that very little, if any, work will be performed more than once. A performance profile of the system is presented that is based on data accumulated from 23 stations during one month. >

A three-phase soft-switched high power density DC/DC converter for high power applications

Abstract: Three DC/DC converter topologies suitable for high-power-density high-power applications are presented. All three circuits operate in a soft-switched manner, making possible a reduction in device switching losses and an increase in switching frequency. The three-phase dual-bridge converter proposed is shown to have the most favorable characteristics. This converter consists of two three-phase inverter stages operating in a high-frequency six-step mode. In contrast to existing single-phase AC-link DC/DC converters, lower turn-off peak currents in the power devices and lower RMS current ratings for both the input and output filter capacitors are obtained. This is in addition to smaller filter element values due to the higher-frequency content of the input and output waveforms. Furthermore, the use of a three-phase symmetrical transformer instead of single-phase transformers and a better utilization of the available apparent power of the transformer (as a consequence of the controlled output inverter) significantly increase the power density attainable. >

Analysis of the geometry of the hydroxymethyl radical by the “different hybrids for different spins” natural bond orbital procedure

Abstract: We have carried out ab initio UHF/6-31G* calculations on the hydroxymethyl radical, CH 2 OH, and have found the equilibrium structure to be nearly planar with barriers to internal rotation occurring at staggered and eclipsed geometries, in good agreement with experiment. The electronic structure of the radical was analyzed via the “different hybrids for different spins” natural bond orbital (DHDS NBO) procedure, which finds separate Lewis structures for each of the spin systems. The α spin Lewis structure resembles that of the anion; the β spin Lewis structure resembles the corresponding cation. This simple picture, in conjunction with Bent's rule, allows one to understand the principal electronic factors which dictate the structure of the radical CH 2 group and its torsional and inversion potentials. Charge transfer between oxygen non-bonding orbitals and the empty radical orbital in the β spin system is the dominant interaction determining the torsional potential. Smaller hyperconjugative interactions in the α spin system resemble interactions in closed-shell molecules and directly oppose the effect of radical hyperconjugation, thus illustrating the central idea that open-shell potential energy features result from competition between the two different spin systems.

Capacitation of bovine sperm by heparin.

Abstract: Capacitation of bovine sperm was evaluated by determining the ability of sperm to fertilize bovine oocytes in vitro and to undergo an acrosome reaction upon exposure to lysophosphatidylcholine (LC). Incubation of sperm with heparin (10 micrograms/ml) increased the percentage of oocytes fertilized, but this required exposing sperm to heparin for at least 4 h before adding them to oocytes. There was no effect on the percentage of motile or acrosome-reacted sperm after exposure of noncapacitated sperm to 100 micrograms/ml LC for 15 min. When sperm were incubated for 4 h with heparin, exposure to 100 micrograms/ml LC for 15 min had no effect on the percentage of sperm that were motile, but the percentage of acrosome-reacted sperm increased from less than 10% to over 70%. The acrosome reactions (ARs) induced by LC were synchronous, reached maximal levels within 15 min, and differed (p less than 0.001) between sperm incubated under capacitating (with heparin) and noncapacitating conditions (without heparin). The time course required for heparin to capacitate sperm as judged by in vitro fertilization and to render sperm sensitive to LC induction of the AR were found to be similar. The percentage of ARs induced by LC and percentage of oocytes fertilized by sperm were found to be heparin-dose-dependent, with the maximum responses occurring at 5-10 micrograms/ml heparin. The correlation between the mean fertilization and LC-induced AR percentages was 0.997 (p less than 0.01). These studies demonstrate capacitation of bovine sperm by heparin requires at least a 4-h exposure of sperm to heparin and suggest that plasma membrane changes prior to an AR can be detected by exposure of bovine sperm to LC.

On image analysis by the methods of moments

Abstract: Various types of moments have been used to recognize image patterns in a number of applications. A number of moments are evaluated and some fundamental questions are addressed, such as image-representation ability, noise sensitivity, and information redundancy. Moments considered include regular moments, Legendre moments, Zernike moments, pseudo-Zernike moments, rotational moments, and complex moments. Properties of these moments are examined in detail and the interrelationships among them are discussed. Both theoretical and experimental results are presented. >

A subfamily of stress proteins facilitates translocation of secretory and mitochondrial precursor polypeptides

Abstract: Depletion of a subset of 7OK stress proteins in yeast mutants shows that they are involved in the post-translational import of precursor polypeptides into both mitochondria and the lumen of the endoplasmic reticulum. The identification of such a basic function may explain the remarkable evolutionary conservation of the gene family encoding these proteins.

Gender differences in verbal ability: A meta-analysis.

Abstract: Many regard gender differences in verbal ability to be one of the well-established findings in psychology. To reassess this belief. Y.'C located 165 studies that reported data on gender differences in verbal ability. The Y.'Cightcd mean effect size (d) was +0.11, indicating a slight female superiority in performance. The difference is so small that we argue that gender differences in verbal ability no longer exist. Analyses of effect sizes for different measures of verbal ability showed almost all to be small in magni tude: for vocabulary. d = 0.02; for analogies, d = 0.16 (slight male superiority in performance): for reading comprehension. d = 0.03: for speech production, d = 0.33 (the largest effect size): for essay writing, d = 0.09; for anagrams, d = 0.22; and for tests of general verbal abil ity, d = 0.20. For the 1985 administration of the Scholastic Aptitude TestVerbal. d = 0.11. indicating superior male performance. Analysis of tests requiring different cognitive processes involved inverbal ability yielded no evidence of substantial gender differences in any aspect of processing. Similarly, an analj,is by age indicated no striking changes in the magnitude of gender differences :ot different ages. countering Maccoby and Jacklin's ( 1974) conclusion that gender differences in verbal ability emerge around age II. For studies published in 1973 or earlier. d = 0.23 and for studies published after !973, a = 0.10, indicating a slight decline in the magnitude of the gender difference in recent years. The implications of these fi ndings are discussed, including their implications for theories of sex differences in brain latcralization and their relation to changing gender roles.

A stable genomic source of P element transposase in Drosophila melanogaster.

Abstract: A single P element insert in Drosophila melanogaster, called P[ry+ delta 2-3](99B), is described that caused mobilization of other elements at unusually high frequencies, yet is itself remarkably stable. Its transposase activity is higher than that of an entire P strain, but it rarely undergoes internal deletion, excision or transposition. This element was constructed by F. Laski, D. Rio and G. Rubin for other purposes, but we have found it to be useful for experiments involving P elements. We demonstrate that together with a chromosome bearing numerous nonautonomous elements it can be used for P element mutagenesis. It can also substitute efficiently for "helper" plasmids in P element mediated transformation, and can be used to move transformed elements around the genome.

Principles of solid-organ preservation by cold storage.

Abstract: Presentation d'une nouvelle solution de conservation convenant aussi bien pour le refroidissement de l'organe in situ dans l'organisme du donneur que pour la conservation in vitro sous hypothermie. Integration des principes de base de l'ischemie hypothermique anaerobie et du metabolisme specifique de l'organe. La methode est appliquable non seulement au rein mais aussi au foie, au pancreas et probablement a d'autres organes

Applied Production Analysis: A Dual Approach

Abstract: This book contains a modern treatment of production economics from a dual perspective, with a special emphasis on recent developments in the field. The book prepares the reader to apply the tools and concepts of the dual approach production economics to real world problems and data sets. Among other topics covered are flexible function forms, aggregation across inputs and outputs using the theory of separable structures, aggregation over economic optimizing firms, the representation of multioutput technologies, and the analysis and measurement of technical change from both a primal and dual perspective.

Cardiac rehabilitation after myocardial infarction. Combined experience of randomized clinical trials.

Abstract: Randomized clinical trials of cardiac rehabilitation following myocardial infarction have typically demonstrated a lower mortality in treated patients, but with a statistically significant reduction in only one trial. To overcome the problem of not being able to detect small but clinically important benefits in mortality in randomized clinical trials of exercise and risk factor rehabilitation after myocardial infarction with small numbers of patients, we carried out a meta-analysis on the combined results of ten randomized clinical trials that included 4347 patients (control, 2145 patients; rehabilitation, 2202 patients). The pooled odds ratios of 0.76 (95% confidence intervals, 0.63 to 0.92) for all-cause death and of 0.75 (95% confidence intervals, 0.62 to 0.93) for cardiovascular death were significantly lower in the rehabilitation group than in the control group, with no significant difference for nonfatal recurrent myocardial infarction. These results suggest that, for appropriately selected patients, comprehensive cardiac rehabilitation has a beneficial effect on mortality but not on nonfatal recurrent myocardial infarction. ( JAMA 1988;260:945-950)

Newton-Raphson and EM Algorithms for Linear Mixed-Effects Models for Repeated-Measures Data

Abstract: We develop an efficient and effective implementation of the Newton—Raphson (NR) algorithm for estimating the parameters in mixed-effects models for repeated-measures data. We formulate the derivatives for both maximum likelihood and restricted maximum likelihood estimation and propose improvements to the algorithm discussed by Jennrich and Schluchter (1986) to speed convergence and ensure a positive-definite covariance matrix for the random effects at each iteration. We use matrix decompositions to develop efficient and computationally stable implementations of both the NR algorithm and an EM algorithm (Laird and Ware 1982) for this model. We compare the two methods (EM vs. NR) in terms of computational order and performance on two sample data sets and conclude that in most situations a well-implemented NR algorithm is preferable to the EM algorithm or EM algorithm with Aitken's acceleration. The term repeated measures refers to experimental designs where there are several individuals and several...

Synaptic reorganization in the hippocampus induced by abnormal functional activity.

Abstract: Abnormal functional activity induces long-lasting physiological alterations in neural pathways that may play a role in the development of epilepsy. The cellular mechanisms of these alterations are not well understood. One hypothesis is that abnormal activity causes structural reorganization of neural pathways and promotes epileptogenesis. This report provides morphological evidence that synchronous perforant path activation and kindling of limbic pathways induce axonal growth and synaptic reorganization in the hippocampus, in the absence of overt morphological damage. The results show a previously unrecognized anatomic plasticity associated with synchronous activity and development of epileptic seizures in neural pathways.

On the Functioning of the Southern Oscillation in the South American Sector. Part I: Surface Climate

Abstract: The functioning of the Southern Oscillation (SO) over South America and the surrounding tropical Atlantic and eastern Pacific Oceans is studied through analyses of bimonthly patterns of correlation between an SO index and the fields of pressure, wind, temperature and rainfall; hydrometeorological anomalies being further ascertained from river discharge and lake level records and measurements of outgoing longwave radiation. Most pronounced is the anomalously low pressure over the eastern Pacific during the negative SO phase (defined by anomalously low/high pressure at Tahiti/Darwin). Consistently positive SO-pressure correlations over the eastern tropical Pacific extend eastward into the North Atlantic region and southern South America during the respective winter semester. During the austral winter the tendency for anomalously abundant rainfall in central Chile during the negative SO phase appears related to an anomalously weak and northward displaced South Pacific subtropical high, while relativ...

Intergenerational consequences of family disruption.

Abstract: This paper examines the effects of childhood family disruption on adult family experience by applying proportional hazard models to data from the National Survey of Family Growth (NSFG). The results provide strong evidence that women who spend part of their childhoods in one-parent families are more likely to marry and bear children early, give birth before marriage, and have their own marriages break up. The major exception is that, among blacks, early marriage is unrelated to family background. Several explanations for intergenerational consequences are tested, including the economic-deprivation hypothesis, the socialization hypothesis, and the stress hypothesis. The results are most consistent with the socialization explanation, which argues that parental role models and parental supervision are the major factors in determining offspring's future family-formation behavior.

Interprocedural slicing using dependence graphs

Abstract: A slice of a program with respect to a program point p and variable x consists of all statements of the program that might affect the value of x at point p. This paper concerns the problem of interprocedural slicing — generating a slice of an entire program, where the slice crosses the boundaries of procedure calls. To solve this problem, we introduce a new kind of graph to represent programs, called a system dependence graph, which extends previous dependence representations to incorporate collections of procedures (with procedure calls) rather than just monolithic programs. Our main result is an algorithm for interprocedural slicing that uses the new representation.The chief difficulty in interprocedural slicing is correctly accounting for the calling context of a called procedure. To handle this problem, system dependence graphs include some data-dependence edges that represent transitive dependencies due to the effects of procedure calls, in addition to the conventional direct-dependence edges. These edges are constructed with the aid of an auxiliary structure that represents calling and parameter-linkage relationships. This structure takes the form of an attribute grammar. The step of computing the required transitive-dependence edges is reduced to the construction of the subordinate characteristic graphs for the grammar's nonterminals.

Role identity and reasoned action in the prediction of repeated behavior

Abstract: In this study we compare predictions derivedfrom the theory of reasoned action and identity theory regarding intentions to give blood and blood donation behavior over a seven-month period. Using a sample of 658 blood donors stratified by number of donations, we found that the addition of measures of the importance of the blood donor role identity, of social relations connected to blood donation, and of habit significantly improved the prediction of intentions and donation over the levels provided by the Fishbein-Ajzen model. A developmental analysis suggested that the theory of reasoned action was most effective in predicting intentions and donation for first-time donors. Whereas the full augmented model was most applicable to long-term donors. The results were interpreted to mean that although the Fishbein-Ajzen model may be the most parsimonious model for the prediction of many non-role behaviors, it should be augmented with identity-theory variables for the prediction of established role behaviors.

Glycosylated hemoglobin predicts the incidence and progression of diabetic retinopathy.

Abstract: The relationship between hyperglycemia, measured by glycosylated hemoglobin at the initial examination, and the four-year incidence and progression of diabetic retinopathy was examined in a population-based study in Wisconsin Younger- (n = 891) and older-onset (n = 987) persons participating in baseline and follow-up examinations were included Glycosylated hemoglobin was measured by microcolumn Retinopathy was determined from stereoscopic fundus photographs In the younger-onset group, comparing the highest with the lowest quartile of glycosylated hemoglobin, the relative risk for developing any diabetic retinopathy was 19; for proliferative retinopathy, 218; and for progression, 40 Among older-onset persons taking insulin, the corresponding relative risks were 19, 40, and 21 Among older-onset persons not taking insulin, relative risks were 40 for any retinopathy and 62 for progression A positive relationship between incidence and progression of retinopathy and glycosylated hemoglobin remained after controlling for duration of diabetes, age, sex, and baseline retinopathy These data suggest a strong and consistent relationship between hyperglycemia and incidence and progression of retinopathy ( JAMA 1988;260:2864-2871)

Forests Too Deer: Edge Effects in Northern Wisconsin

Abstract: Browsing by white-tailed deer (Odocoileus virginianus) can profoundly affect the abundance and population structure of several woody and herbaceous plant species. Enclosure studies and population surveys reveal that past and current deer densities as low as 4 deer/km2 may prevent regeneration of the once common woody species, Canada yew (Taxus canadensis), eastern hemlock (Tsuja canadensis), and white cedar Puja occidentalis), as well as several herbaceous species. Prior to European settlement, forests in northern Wisconsin contained relatively sparse deer populations (<4/km2), but extensive timber cutting in the late nineteenth century boosted deer populations. Continued habitat fragmentation resulting from scattered timber harvests and the creation of “wildlife openings” to improve deer forage maintain these high densities throughout much of the Northeast. Because deer wander widely, the effects of high deer densities penetrate deeply into remaining stands of old and mature forest, greatly modifying their composition Thus, abundant early successional and “edge” habitat, and the high deer densities they engender, represent significant external threats to these plant communities. We hypothesize that establishing large (200–400 km2) continuous areas of maturing forest, especially in conjunction with increased hunting, could reduce local deer densities and so provide a simple and inexpensive method for retaining species sensitive to the deleterious effects of browsing.

The vitamin D story: a collaborative effort of basic science and clinical medicine.

Abstract: The discovery in 1919-1924 of vitamin D and its production in skin and foods by UV irradiation led to the elimination of rickets as a major medical problem. The identification and chemical preparation of vitamin D in the next decade provided large quantities of vitamin D to the physician for the treatment of a variety of metabolic bone diseases. Early in the 1960s, little was known about the function of vitamin D in causing mineralization of the skeleton, and hence in preventing the disease rickets in children and osteomalacia in adults. With the application of modern tools of biochemistry came the discovery that vitamin D must first be modified by 25-hydroxylation in the liver followed by 1 alpha-hydroxylation in the kidney to produce the vitamin D hormone 1 alpha,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. This process is strongly feedback-regulated and is one of the major endocrine systems regulating plasma calcium and phosphorus concentrations. Furthermore, it is a major endocrine system regulating bone mass and state. With the chemical synthesis of 1,25-(OH)2D3 and many of its analogs has come the possibility of treating a number of metabolic bone diseases not previously managed adequately, such as vitamin D-resistant rickets, hypoparathyroidism, renal osteodystrophy, and osteoporosis. By using 1,25-(OH)2D3, considerable work has been carried out to understand how this hormone facilitates calcium transport across the intestinal membrane. Modern work is described on the molecular mechanism of action of the vitamin D hormone in eliciting the cellular responses that result in mineral homeostasis. The possible use of the vitamin D analogs to bring about differentiation of myelocytic-type leukemias and in the treatment of psoriasis has been an important new development. This paper will thus be a blend of basic science of the vitamin D system and the application of that information to the treatment of disease.

Group Conflict, Prejudice, and the Paradox of Contemporary Racial Attitudes

Abstract: The status of black Americans is the longest standing and most glaring exception to the American promise of freedom and equality. For this, as well as other reasons, social psychologists have long sought to shed light on the ways in which racial attitudes, beliefs, and values affect and are affected by patterns of black-white relations. Blackwhite relations now seem more complex and contradictory than ever before. From basic economic and demographic indicators to indicators of racial attitudes and beliefs, simultaneous patterns of progress, deterioration, and lack of change can be discerned.

On image analysis by the methods of moments

Abstract: Various types of moments have been used to recognize image patterns in a number of applications. The authors evaluate a number of moments and addresses some fundamental questions, such as image representation ability, noise sensitivity, and information redundancy. Moments considered include regular moments, Legendre moments, Zernike moments, pseudo-Zernike moments, rotational moments and complex moments. Properties of these moments are examined in detail, and the interrelationships among them are discussed. Both theoretical and experimental results are presented. >

Signal-to-noise ratios, performance criteria, and transformations

Abstract: For the analysis of designed experiments, Taguchi uses performance criteria that he calls signal-to-noise (SN) ratios. Three such criteria are here denoted by SN T , SN L , and SN S . The criterion SN T was to be used in preference to the standard deviation for the problem of achieving, for some quality characteristic y, the smallest mean squared error about an operating target value. Leon, Shoemaker, and Kacker (1987) showed how SN T was appropriate to solve this problem only when σ y was proportional to μ y . On that assumption, the same result could be obtained more simply by conducting the analysis in terms of log y rather than y. A more general transformation approach is here introduced for other, commonly met kinds of dependence between σ y and μ y (including no dependence), and a lambda plot is presented that uses the data to suggest an appropriate transformation. The criteria SN L and SN S were for problems in which the objective was to make the response as large or as small as possible. It is arg...

The HiPAC project: combining active databases and timing constraints

Abstract: The HiPAC (High Performance ACtive database system) project addresses two critical problems in time-constrained data management: the handling of timing constraints in databases, and the avoidance of wasteful polling through the use of situation-action rules that are an integral part of the database and are monitored by DBMS's condition monitor. A rich knowledge model provides the necessary primitives for definition of timing constraints, situation-action rules, and precipitating events. The execution model allows various coupling modes between transactions, situation evaluations and actions, and provides the framework for correct concurrent execution of transactions and triggered actions. Different approaches to scheduling of time-constrained tasks and transactions are explored and an architecture is being designed with special emphasis on the interaction of the time-constrained, active DBMS and the operating system. Performance models are developed to evaluate the various design alternatives.

Statistical analysis of word-initial voiceless obstruents: preliminary data.

Abstract: A statistical procedure for classifying word‐initial voiceless obstruents is described. The data set to which the analysis was applied consisted of monosyllabic words starting with a voiceless obstruent. Each word was repeated six times in the carrier phrase ‘‘I can say —— , again’’ by each of ten speakers. Fast Fourier transforms (FFTs), using a 20‐ms Hamming window, were calculated every 10 ms from the onset of the obstruent through the third cycle of the following vowel. Each FFT was treated as a random probability distribution from which the first four moments (mean, variance, skewness, and kurtosis) were computed. Moments were calculated from linear and Bark transformed spectra. Data were pooled across vowel contexts for speakers of a given gender and input to a discriminant analysis. Using the moments calculated from the linear spectra, 92% of the voiceless stops were classified correctly when dynamic aspects of the stop were included. Even more important, the model constructed from the males’ data correctly classified about 94% of the voiceless stops produced by the female speakers. Classification of the voiceless fricatives when all places of articulation were included in the analysis did not exceed 80% correct when the moments from either the linear or Bark transformed scales were used. However, classification of only the voiceless sibilants was 98% correct when the moments from the Bark transformed spectra were used. As with the stops, the classification model held across gender.

Estimating the rate of photorespiration in leaves

Abstract: Photorespiration is the light-dependent evolution of CO2, which accompanies photosynthesis in C3plants. The four best known methods of measuring the rate of photorespiration have theoretical or technical problems, which make the results unreliable. However, the rate of photorespiration can be calculated from the rate of net CO2assimilation and the partial pressures of CO2and O2. Estimates of rates of photorespiration in the past and future can be made. The rate of photorespiration as a proportion of the rate of photosynthesis will fall to one half the current rate when the CO2level in the atmosphere doubles.

Resampling Inference with Complex Survey Data

Abstract: Methods for standard errors and confidence intervals for nonlinear statistics —such as ratios, regression, and correlation coefficients—have been extensively studied for stratified multistage designs in which the clusters are sampled with replacement, in particular, the important special case of two sampled clusters per stratum. These methods include the customary linearization (or Taylor) method and resampling methods based on the jackknife and balanced repeated replication (BRR). Unlike the jackknife or the BRR, the linearization method is applicable to general sampling designs, but it involves a separate variance formula for each nonlinear statistic, thereby requiring additional programming efforts. Both the jackknife and the BRR use a single variance formula for all nonlinear statistics, but they are more computing-intensive. The resampling methods developed here retain these features of the jackknife and the BRR, yet permit extension to more complex designs involving sampling without replace...