Showing papers by "Purdue University published in 1982"
TL;DR: Screening results with seed extracts of 41 species of Euphorbiaceae were compared with 9KB and 9PS cytotoxicities and the method is rapid, reliable, inexpensive, and convenient as an in-house general bioassay tool.
Abstract: A method, utilizing brine shrimp (Artemia salina Leach), is proposed as a simple bioassay for natural product research. The procedure determines LC (50) values in microg/ml of active compounds and extracts in the brine medium. Activities of a broad range of known active compounds are manifested as toxicity to the shrimp. Screening results with seed extracts of 41 species of Euphorbiaceae were compared with 9KB and 9PS cytotoxicities. The method is rapid, reliable, inexpensive, and convenient as an in-house general bioassay tool.
3,617 citations
Book•
01 Jan 1982TL;DR: The goal of this book is to introduce the mathematical principles of data security and to show how these principles apply to operating systems, database systems, and computer networks.
Abstract: From the Preface (See Front Matter for full Preface)
Electronic computers have evolved from exiguous experimental enterprises in the 1940s to prolific practical data processing systems in the 1980s. As we have come to rely on these systems to process and store data, we have also come to wonder about their ability to protect valuable data.
Data security is the science and study of methods of protecting data in computer and communication systems from unauthorized disclosure and modification. The goal of this book is to introduce the mathematical principles of data security and to show how these principles apply to operating systems, database systems, and computer networks. The book is for students and professionals seeking an introduction to these principles. There are many references for those who would like to study specific topics further.
Data security has evolved rapidly since 1975. We have seen exciting developments in cryptography: public-key encryption, digital signatures, the Data Encryption Standard (DES), key safeguarding schemes, and key distribution protocols. We have developed techniques for verifying that programs do not leak confidential data, or transmit classified data to users with lower security clearances. We have found new controls for protecting data in statistical databases--and new methods of attacking these databases. We have come to a better understanding of the theoretical and practical limitations to security.
1,937 citations
TL;DR: These results demonstrate a numerical increase in a neuronal population during adulthood in the mammalian brain in rats 30, 120, 200, and 365 days old.
Abstract: Volumetric estimates of the total number of granule cells in rats 30, 120, 200, and 365 days old increase linearly by approximately 35 to 43 percent between 1 month and 1 year. Total volume of the granular layer also grows linearly during that time. These results demonstrate a numerical increase in a neuronal population during adulthood in the mammalian brain.
605 citations
TL;DR: The presence and metabolic activity of psychrotrophic microorganisms in milk and dairy products are reviewed and methods to control these microorganisms are presented, ranging from simple plate counting techniques to detection of metabolites produced by the psychrotrophs.
531 citations
TL;DR: It is proved that the output of a recursive median filter is invariant to subsequent passes by the same filter and that for nonmedian nth ranked-order operations, repeated application of the operation will reduce any signal to a constant.
Abstract: Some modifications of the median filter are given and their properties are derived. In addition, some results for standard median filters are given. It is shown that for nonmedian nth ranked-order operations, repeated application of the operation will reduce any signal to a constant. Also, it is proved that the output of a recursive median filter is invariant to subsequent passes by the same filter.
505 citations
TL;DR: Five new techniques for tree pattern matching are presented, analyzed for time and space complexity, and compared with previously known methods.
Abstract: ABSTgACT. Tree pattern matching is an interesting special problem which occurs as a crucial step m a number of programmmg tasks, for instance, design of interpreters for nonprocedural programming languages, automatic implementations of abstract data types, code optimization m compilers, symbohc computation, context searching in structure editors, and automatic theorem provmg. As with the sorting problem, the variations in requirements and resources for each application seem to preclude a uniform, umversal solution to the tree-pattern-matching problem. Instead, a collection of well-analyzed techmques, from which specific applications may be selected and adapted, should be sought. Five new techniques for tree pattern matching are presented, analyzed for time and space complexity, and compared with previously known methods. Particularly important are applications where the same patterns are matched against many subjects and where a subject may be modified incrementally Therefore, methods which spend some tune preprocessmg patterns in order to improve the actual matching time are included
483 citations
434 citations
TL;DR: To answer the role of polymorphism in parallel computation, the characteristics of parallel processing and the benefits and limitations of VLSI technology are reviewed.
Abstract: When von Neumann computers were still new and exciting, scientists noted in popular accounts that unlike mechanical devices, computers are polymorphic-their function can be radically changed simply by changing programs. Polymorphism is fundamental, but this familiar and obvious fact receives little mention any more, even though it underlies important advances such as time-sharing and programmable microcode. Now, however, as we are confronted with the potential for highly parallel computers made possible by very-largescale integrated circuit technology, we may ask: What is the role of polymorphism in parallel computation? To answer this question, we must review the characteristics of parallel processing and the benefits and limitations of VLSI technology.
402 citations
TL;DR: In this article, low temperature heat capacities for water and deuterium oxide have been remeasured using different sample preparation and data analysis procedures from those used in the original studies of this anomalous region.
Abstract: : Low temperature heat capacities for water and deuterium oxide have been remeasured using different sample preparation and data analysis procedures from those used in the original studies of this anomalous region. Self-consistent results have been obtained with reproducibilities of 1%. Comparisons are made with the behavior in the superheated region at 1 atm pressure calculated from a refined equation of state by Haar et al. It appears that the kinetic metastability limit of the liquid (nucleation terminated) at both hot and cold extremes may be reached at the same value of the liquid heat capacity.
397 citations
TL;DR: The ability of the sudden increase in cuff pressure oscillations during cuff deflation to indicate systolic pressure was examined and found to overestimate syStolic pressure slightly in man, but more in animals.
Abstract: In this study, human subjects and dogs were used to determine the ability of the oscillometric method to indicate systolic and diastolic pressure. In the human studies, the auscultatory method was used as the reference. In the animal studies, directly recorded blood pressure was used as the reference. The ability of the sudden increase in cuff pressure oscillations during cuff deflation to indicate systolic pressure was examined and found to overestimate systolic pressure slightly in man, but more in animals. Systolic pressure was encountered when the cuff pressure oscillations were about one half of their maximum amplitude. However, in both man and animals the ratio was not constant; although the range was less in man than in animals. Diastolic pressure was encountered when cuff-pressure oscillation amplitude was about 0.8 of the maximal amplutide. This ratio for diastolic pressure was not constant over a range of diastolic pressure. The range of variability was less for man than for the dog.
347 citations
TL;DR: Using the phenomenon of deviance by employees against the rules of the formal work organization as the behavior of interest, the differential saliences of both formal (i.e., management) and informa...
Abstract: Using the phenomenon of deviance by employees against the rules of the formal work organization as the behavior of interest, the differential saliences of both formal (i.e., management) and informa...
TL;DR: It is shown that the ESC provides fault tolerance for any single failure, and the network can be controlled even when it has a failure, using a simple modification of a routing tag scheme proposed for the Generalized Cube.
Abstract: The Extra Stage Cube (ESC) interconnection network, a fault-tolerant structure, is proposed for use in large-scale parallel and distributed supercomputer systems. It has all of the interconnecting capabilities of the multistage cube-type networks that have been proposed for many supersystems. The ESC is derived from the Generalized Cube network by the addition of one stage of interchange boxes and a bypass capability for two stages. It is shown that the ESC provides fault tolerance for any single failure. Further, the network can be controlled even when it has a failure, using a simple modification of a routing tag scheme proposed for the Generalized Cube. Both one-to-one and broadcast connections under routing tag control are performable by the faulted ESC. The ability of the ESC to operate with multiple faults is examined. The ways in which the ESC can be partitioned and permute data are described.
TL;DR: The Coase Theorem as mentioned in this paper states that a change in a liability rule will leave the agents' production and consumption decisions both unchanged and economically efficient within the following implicit (implicit) framework: (a) two agents to each externality (and bargain), (b) perfect knowledge of one another's (convex) production and profit or utility functions, competitive markets, zero transactions costs; (e) costless court system,2 (f) profit-maximizing producers and expected utility maximizing consumers, (g) no wealth effects, agents will strike
Abstract: IN The Problem of Social Cost,1 Ronald Coase investigated the economic effects of liability rules for externalities when the affected parties can bargain with each other. More specifically, Coase posited that a change in a liability rule will leave the agents' production and consumption decisions both unchanged and economically efficient within the following (implicit) framework: (a) two agents to each externality (and bargain), (b) perfect knowledge of one another's (convex) production and profit or utility functions, (c) competitive markets, (d) zero transactions costs; (e) costless court system,2 (f) profit-maximizing producers and expected utility-maximizing consumers, (g) no wealth effects, (h) agents will strike mutually advantageous bargains in the absence of transactions costs. This result-commonly called the "Coase Theorem"-has generated a great deal of economic and legal discussion, much of it aimed at exploring the effects of weakening one or another of the model's assumptions.3 Some of the most common theoretical discussions focus on the
13 Sep 1982
TL;DR: The Revision Control System (RCS) as mentioned in this paper is a software tool that helps in managing multiple revisions of text, which is useful for text that is revised frequently, for example programs and documentation.
Abstract: The Revision Control System (RCS) is a software tool that helps in managing multiple revisions of text. RCS automates the storing, retrieval, logging, identification, and merging of revisions, and provides access control. It is useful for text that is revised frequently, for example programs and documentation.This paper presents the design and implementation of RCS. Both design and implementation are evaluated by contrasting RCS with SCCS, a similar system. SCCS is implemented with forward, merged deltas, while RCS uses reverse, separate deltas. (Deltas are the differences between successive revisions.) It is shown that the latter technique improves run-time efficiency, while requiring almost no extra space.
TL;DR: The Bayesian method of choosing the best model for a given one-dimensional series among a finite number of candidates belonging to autoregressive, moving average, AR, ARMA, and other families is dealt with.
Abstract: This paper deals with the Bayesian method of choosing the best model for a given one-dimensional series among a finite number of candidates belonging to autoregressive (AR), moving average (MA), ARMA, and other families. The series could be either a sequence of observations in time as in speech applications, or a sequence of pixel intensities of a two-dimensional image. The observation set is not restricted to be Gaussian. We first derive an optimum decision rule for assigning the given observation set to one of the candidate models so as to minimize the average probability of error in the decision. We also derive an optimal decision rule so as to minimize the average value of the loss function. Then we simplify the decision rule when the candidate models are different Gaussian ARMA models of different orders. We discuss the consistency of the optimal decision rule and compare it with the other decision rules in the literature for comparing dynamical models.
TL;DR: In this paper, the authors present Communicative Strategies in Organizational Conflicts: Reliability and Validity of a Measurement Scale (CSMS), a survey of communication strategies in conflict resolution.
Abstract: (1982). Communicative Strategies in Organizational Conflicts: Reliability and Validity of a Measurement Scale. Annals of the International Communication Association: Vol. 6, Communication Yearbook 6, pp. 629-652.
TL;DR: This study is the first demonstration of a net numerical gain in a neuronal population during adulthood in the mammalian brain, and it is suggested that their influence grows with age.
Abstract: The total number of granule cells in the dentate gyrus was estimated in 17 male rats, four each aged 30, 120, and 200 days, and five aged 365 days. There is a substantial 35–43% linear increase between 1 month and 1 year. Two parameters of the granular layer are involved in the numerical change. First, total granular layer volume grows linearly with age. Second, average volume of a single granule cell nucleus in the ventral dentate gyrus decreases with age. Older rats tend to have a larger granular layer filled with more and smaller cells. In another group of 21 male rats, 3H-thymidine injections were given on four consecutive days during juvenile (30–33, n = 6) and adult life (60–63, n = 5; 120–123, n = 6; 180–183, n = 4). All animals survived to 200 days of age. The proportion of labeled mature granule cells and labeled presumptive granule cell precursors were determined in anatomically-matched slices. With older ages at injection, there is a decline in labeled mature granule cells and a concurrent increase in labeled precursors. These data are compatible with the constant level of granule cell increase determined volumetrically. Most of the late granule cells originate nearly simultaneously along the base of the main bulk of the granular layer; very few are found in the dorsal tip (septal extreme) and ventral tip (temporal extreme). This study is the first demonstration of a net numerical gain in a neuronal population during adulthood in the mammalian brain. Since the granule cells play a pivotal role in hippocampal function, these data suggest that their influence grows with age.
TL;DR: HUBERT et al. as discussed by the authors reviewed 26 temperament instruments, developed to assess temperament at the infant, preschool, and school-age levels, and gave particular attention to instrument content, standardization samples, reliability, and validity.
Abstract: HUBERT, NANCY C.; WACHS, THEODORE D.; PETERS-MARTIN, PATRICIA; and GANDOUR, MARY JANE. The Study of Early Temperament: Measurement and Conceptual Issues. CHILD DEVELOPMENT, 1982, 53, 571-600. 26 temperament instruments, developed to assess temperament at the infant, preschool, and school-age levels, were reviewed. Particular attention is given to instrument content, standardization samples, reliability, and validity. Psychometrically, most current temperament instruments approached high interjudge reliability, moderate internal consistency, and test-retest reliability; however, stability data are inconsistent and interparent agreement coefficients were low. Validity data which were available showed little convergence between instruments and inconsistent findings regarding concurrent and predictive validity. At present, no single psychometrically adequate instrument is available. Specific instruments may be useful for certain situations. Suggestions are made for future approaches to instrument development in this area.
TL;DR: In this paper, a power-law dependence, isobaric yield was found to describe the data over a broad range of yields, which is a signature for the fragment formation mechanism.
Abstract: Isotopically resolved nuclear fragments (${A}_{f}, {Z}_{f}$), $3l~{Z}_{f}l~14$, produced by protons in the energy range $80l~{E}_{\mathrm{inc}}l~350$ GeV incident on krypton and xenon targets have been studied at the Internal Target Laboratory of the Fermi National Accelerator. A power-law dependence, isobaric yield $\ensuremath{\propto}{{A}_{f}}^{\ensuremath{-}\ensuremath{\tau}}$, was found to describe the data over a broad range of yields. The particular value of $\ensuremath{\tau}$ is a signature for the fragment formation mechanism.
TL;DR: In this paper, the authors examined the effects of bargaining role and sex role composition on the frequencies and sequences of bargaining talk and found that management representatives relied on defensive tactics while labor negotiators specialized in offensive maneuvers.
Abstract: This investigation examined the effects of bargainer role and sex‐role composition on the frequencies and sequences of bargaining talk. Thirty‐two male and thirty‐two female bargainers were assigned to labor‐management roles in same‐sex or mixed‐sex dyads to bargain a simulated grievance case. A modified version of the Bargaining Process Analysis (BPA) was employed to test for reciprocity of bargaining strategies. The findings demonstrated that management representatives relied on defensive tactics while labor negotiators specialized in offensive maneuvers; these strategies emerged in the interaction structure of negotiators, especially in their use of attack‐defend and offensive‐information giving patterns. Impasse dyads, as compared with agreement pairs, exhibited a tightly‐structured, reciprocal pattern of attack‐attack or defend‐defend, with management initiating this cycle.
TL;DR: In this paper, the conventional Newton-Raphson power flow study has been reformulated to permit the inclusion of nonlinear loads, which give rise to harmonic signals which propagate throughout the power system.
Abstract: The conventional Newton-Raphson power flow study has been reformulated to permit the inclusion of nonlinear loads. These loads give rise to harmonic signals which propagate throughout the power system. The reformulation is based on the reduction to zero of the mismatch active power and reactive voltamperes, the imbalance current at harmonic frequencies, and the mismatch apparent Voltamperes. Conclusions on the existence of positive, negative, and zero sequence signals are made for harmonic frequencies. The harmonic power flow study formulation is illustrated for a three phase full wave bridge rectifier. A companion paper presents a discussion of the actual computer implementation and several practical examples.
TL;DR: In words were produced imitatively and non-imitatively in greater numbers and in earlier sessions than OUT words, providing evidence for the influence of selection and avoidance, and the degree of phonetic accuracy of these two types of productions did not differ.
Abstract: The influence of phonological selection and avoidance upon early lexical acquisition was examined within an experimental paradigm. During 10 bi-weekly experimental sessions, 12 children (1;0.21 to 1;3.15 at the outset) were presented with 16 contrived lexical concepts, each consisting of a nonsense word and four unfamiliar referents. For each child, eight words involved phonological characteristics which had been evidenced in production (in) and eight had characteristics which had not been evidenced in production or selection (out), in words were produced imitatively and non-imitatively in greater numbers and in earlier sessions than OUT words, providing evidence for the influence of selection and avoidance. The degree of phonetic accuracy of these two types of productions did not differ. These findings are discussed in terms of a proposal concerning early phonological representation and acquisition.
TL;DR: In this article, the equilibrium moisture content (EMC) was determined for thirty pharmaceutical excipients for the purposes of the Handbook of Pharmaceutical Excipients (HOPE) under the sponsorship of the Academy of Pharmaceutical Sciences.
Abstract: The equilibrium moisture content (EMC) was determined for thirty pharmaceutical excipients. These data are to be included in the forth-coming publication of the Handbook of Pharmaceutical Excipients. This work was undertaken as a collaborative effort under the sponsorship of the Academy of Pharmaceutical Sciences. The results of this study are being reported herein prior to publication of the Handbook.The experimental procedure for determining equilibrium moisture content is included along with a method for classifying the hygroscopic property of solids.
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TL;DR: The first concrete rheology symposium as discussed by the authors was held at the University of Tokyo in 2000 and was attended by about 50 people, with heavy representation from abroad (Japan, People's Republic of China, United Kingdom, France, Belgium, Denmark).
Abstract: The symposium was attended by about 50 people, with heavy representation from abroad (Japan, People's Republic of China, United Kingdom, France, Belgium, Denmark). Four invited papers were presented, by Professors Sing (Brunei University), Tattersall (Univesity of Sheffield), Roy (Pennsylvania State University) and Young (University of Illinois). They were supplemented by papers on such aspects of concrete rheology as instrumentation, testing and applications, effect of chemical admixtures, effect of mineral admixtures and basic scientific aspects. The science of rheology as applied to fresh concrete technology is not completely developed. This is caused by the complexity of the materials used in concrete (cement, sand, aggregate, water and chemical and mineral admixtures) and by the dynamic character of the system. With time, chemical processes of hydration lead to physico-chemical (including rheological) changes which, in turn, affect the concrete behavior both in the fresh and the hardened stage. It is because of this complexity that the symposium has been attended by a very healthy mixture of scientists as well as technologists.
TL;DR: A drug transport model is proposed to account for the “non-ideal” bioconcentration of a variety of organics in fish, where uptake is a nonlinear function of partition coefficient, water solubility and membrane permeability.
Abstract: The accumulation of organic residues in fish is the result of competing rates of uptake and elimination, which can be modeled by pharmacokinetic techniques. Although first-order kinetics are usually assumed, they are rarely verified. Models with biphasic, second-order or Michaelis-Menten kinetics may prove to be better choices, depending on exposure level and mode of elimination. The well-known correlation between bioconcentration factor and partition coefficient (P) derives from separate correlations for the uptake and elimination rate constants with P. While such correlations appear to be linear in the range of log P = 2–5 for organics that are not metabolized, they sometimes fail at higher values of log P. A drug transport model is proposed to account for the “non-ideal” bioconcentration of a variety of organics in fish. According to this model, uptake is a nonlinear function of partition coefficient, water solubility and membrane permeability.
TL;DR: The regrowth reported here in mice is probably similar to the scattered clinical reports of fingertips regeneration in children, and presents a model system with which to explore the controls of wound healing and tissue reconstruction in mammals.
Abstract: Mice will replace the tip of a foretoe when it is amputated distal to the last interphalangeal joint. Amputation of the digit more proximal to the joint does not result in regrowth of the foretoe. Though this growth shares certain similarities with the epimorphic regeneration of amphibian limbs, the two processes are not the same. The regrowth reported here in mice is probably similar to the scattered clinical reports of fingertips regeneration in children, and presents a model system with which to explore the controls of wound healing and tissue reconstruction in mammals.
TL;DR: A gene encoding one of the 19,000 dalton zein proteins from a maize genomic library constructed in Charon 4A is isolated, and a basis for microheterogeneity within the gene family is identified.
TL;DR: In this article, a split-spectrum processing technique for an ultrasonic flaw detection system was developed which improves the flaw-to-grain echo ratio in large-grained materials.
TL;DR: There is an interesting degree of analogy between the fundamental binary solutions of geochemistry and the aqueous solutions of common experience; however, due to the stronger bonding in silicate systems, the anomalies are much more persistent.
Abstract: Ion dynamics computer simulation methods show that for many liquid silicates, like silica itself, the component diffusion coefficients show anomalous pressure dependences. This implies that their viscosities have negative pressure dependences. Overall, there is an interesting degree of analogy between the fundamental binary solutions of geochemistry and the aqueous solutions of common experience; however, due to the stronger bonding in silicate systems, the anomalies are much more persistent. Diffusivity maxima occur at pressures of 200 to 300 kilobars and are correlated with a prevalence of fivefold coordination of silicon ions. The relevance of these findings to planetary dynamics and thermophysical modeling problems is briefly considered.