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Showing papers by "University of Windsor published in 1988"


Journal ArticleDOI
TL;DR: The unified method described previously for combining high-precision nonrelativistic variational calculations with relativistic and quantum electrodynamic corrections is applied to the 1s2 1S0, 1s 2 S 0, 1 s 2 S 1S 0 as discussed by the authors.
Abstract: The unified method described previously for combining high-precision nonrelativistic variational calculations with relativistic and quantum electrodynamic corrections is applied to the 1s2 1S0, 1s2...

357 citations


Journal ArticleDOI
TL;DR: In this paper, a theoretical model to determine the effect of dry band discharges on material performance was presented, and good agreement between the predicted behavior and the experimental findings was shown.
Abstract: The materials evaluated in fog produced from low (250 mu s/cm) and high (1000 mu s/cm) conductivity water include cylindrical rod samples of high-temperature-vulcanized silicone rubber and ethylene-propylene-diene monomer rubber (EPDM) containing various amounts of either alumina trihydrate or silica fillers, or both. Comparison is made with material performance results obtained with AC, which was reported in an earlier study. In both low- and high-conductivity fog, the time to failure with AC and +DC was very similar, but a reduction by a factor of about four was observed in the time to failure with -DC. For both AC and DC, silicone rubber performed better than EPDM samples in low-conductivity fog, while the order of performance was reversed in high-conductivity fog. A theoretical model to determine the effect of dry band discharges on material is presented. Good agreement between the predicted behavior and the experimental findings is shown. >

222 citations


Journal ArticleDOI
TL;DR: Investigating the genotypic characteristics of 10 D. pulex populations from each of 22 sites in the Great Lakes watershed revealed that populations reproducing by cyclic parthenogenesis were uncommon and restricted to southern sites.
Abstract: Some individuals of the cladoceran crustacean, Daphnia pulex, reproduce by cyclic parthenogenesis, while others are obligate parthenogens. Cyclic parthenogenesis is the primitive breeding system; the transition to obligate parthenogenesis has been linked to sex-limited meiosis- suppression. Detailed study of patterns of breeding-system distribution and clonal diversity is justified because D. pulex is the first species in which the loss of sex has been related to this mechanism. The present study investigated the genotypic characteristics of 10 D. pulex populations from each of 22 sites in the Great Lakes watershed. This analysis revealed that populations reproducing by cyclic parthenogenesis were uncommon and restricted to southern sites. Most populations reproduced by obligate parthenogenesis, with the electrophoretic survey revealing an average of three clones per pond and 145 unique clones over the watershed. A combinatorial analysis was used to examine the relationships between clone discovery in the asexual populations and both sample size and genetic-sampling intensity. This analysis showed that the few clones found in individual ponds were readily discriminated, while diversity on a regional scale was underestimated. These methods provide a quantitative basis for assessing the level of clonal di- versity in asexual populations and in asexually transmitted segments of the genome.

180 citations


Journal ArticleDOI
TL;DR: The inability of most hybrids to produce normal resting eggs is further evidence of a general genomic incompatibility between the parents, and there is no specific genetic incompatibility associated with the marker loci used.
Abstract: Sex in Daphnia is environmentally determined, and some obligately parthenogenetic clones of D. pulex have retained the ability to produce males. In the present study, males from 13 such clones were crossed to sexual females from closely related cyclical parthenogens both to determine whether the males were capable of producing viable hybrids and to determine the mode of reproduction of the hybrids. A total of 178 genetically confirmed hybrids were produced, with each of the 19 attempted crosses resulting in some viable hybrids. On average, only 34% of the hybrid eggs that initiated development survived to the reproductive stage, suggesting some incompatibility between the parents. The absence of any association between survivorship and parental or hybrid genotype indicated, however, that there is no specific genetic incompatibility associated with the marker loci used. The inability of most hybrids to produce normal resting eggs is further evidence of a general genomic incompatibility between the parents. Ten of the hybrids produced viable resting eggs, permitting tests to determine their mode of reproduction. Six of the 10 hybrids reproduced by cyclical parthenogenesis, like their maternal parent. The remaining four hybrids reproduced by obligate parthenogenesis, like their paternal parent, demonstrating that the genes suppressing meiosis can be transmitted by the male parent. These results support a model for the generation of new clones that involves the spread of genes suppressing meiosis and provide evidence that the high genotypic diversity observed in obligately parthenogenetic populations of D. pulex is a result of the multiple origin of new clones from the cyclical parthenogens. Evidence was also obtained suggesting that the obligately parthenogenetic clones carry a load of recessive deleterious genes.

168 citations


Journal ArticleDOI
TL;DR: These and other developmental manisfestations of the NLD syndrome are examined within the context of several types of neurological disease/developmental disabilities, including cranio-cerebral trauma, hydrocephalus and autism, and are related to a developmental model.
Abstract: The syndrome of Nonverbal Learning Disabilities (NLD) is characterized by deficient performances in visual-spatial-organizational abilities, complex psychomotor and tactile-perceptual skills (both usually more marked on the left side of the body), and conceptual/problem-solving abilities. Over the course of development, above-average facility in single-word reading and spelling and below-average skills in mechanical arithmetic are evident. Extreme difficulties in dealing with novel and otherwise complex material are especially apparent. Automatic, rote language skills become increasingly well developed and socio-emotional disturbances of the internalized variety become increasingly more apparent with advancing years. These and other developmental manisfestations of the NLD syndrome are examined within the context of several types of neurological disease/developmental disabilities, including cranio-cerebral trauma, hydrocephalus, and autism, and are related to a developmental model (Rourke, 1987) ...

145 citations


Journal ArticleDOI
D. Watt1, L. Coon1, M. Bibby2, J. Goldak2, C. Henwood2 
TL;DR: A computer algorithm originally developed for predicting the hardenability of low alloy steels has been adapted to forecast the microstructural development in weld heat-affected zones (HAZ) as mentioned in this paper.

129 citations


Journal ArticleDOI
TL;DR: In this paper, high precision variational eigenvalues are presented for the 1s21S state of H−, and the 1 s 2 s 3 S 1 −1 s n d 3 D 1 transition frequency measurements of Hlousek et al. are compared with the known quantum electrodynamic (Lamb shift) contribution of − 0.13488 cm−1 to the ionization energy.
Abstract: High precision variational eigenvalues are presented for the 1s21S state of H−, and the 1s2 1S, 1s2s1S and 1s2s3S helium, together with relativistic, mass polarization and relativistic recoil corrections. In addition to the nonrelativistic energy, all corrections of order α 2 , μ M ( μ M ) 2 and α 2 M are calculated to an accuracy of better than 10−6 cm−1. Previous results of similar accuracy are available for the 1 s n d 1 D and 3 D states up to n = 8. A comparison with the high precision 1 s 2 s 3 S 1 −1 s n d 3 D 1 transition frequency measurements of Hlousek et al. indicates that the known quantum electrodynamic (Lamb shift) contribution of − 0.13488 cm−1 to the ionization energy of the 1s2s 3S1 state is too small in magnitude by 0.00048(6) cm−1. A discrepancy of this size can reasonably be accounted for by as yet uncalculated contributions to the two-electron Lamb shift.

117 citations


Journal ArticleDOI
TL;DR: In this paper, the probability-weighted moment and the maximum-likelihood estimators of two parameters in the log-logistic distribution were studied in a wide variety of meteorological data.
Abstract: We consider the probability-weighted moment and the maximum-likelihood estimators of two parameters in the log-logistic distribution. Quantile estimators are obtained using both methods. The distributional properties of these estimators are studied in large samples, via asymptotic theory, and in small and moderate samples, via Monte Carlo simulation. The distribution is shown to be appropriate for a wide variety of meteorological data.

104 citations



Journal ArticleDOI
TL;DR: Experimental observations of, and theoretical models for, hysteresis in metal-hydrogen systems are reviewed in this article, where the authors show that the magnitude of the hystresis is affected by many different factors including temperature, alloy composition, hydrogen aliquot size, annealing of metal sample, number of absorption/desorption cycles and particle size.

76 citations


Journal ArticleDOI
TL;DR: In this article, the Watt/Coon algorithm is coupled with a transient finite element heat transfer analysis for computing the microstructure as a function of space and time ( x, y, z, t ) in the heat-affected zone (HAZ) of low alloy steel welds.

Patent
10 May 1988
TL;DR: In this article, a relatively low cost processor based optical system is used to carry out the method, where an area of the surface whose roughness is to be assessed is illuminated by a light source, and a reflected light is directed to the lens of the video camera.
Abstract: A relatively low cost processor based optical system is used to carry out the method. An area of the surface whose roughness is to be assessed is illuminated by a light source, and a reflected light is directed to the lens of the video camera. The analog output of the video camera is digitized, and the digital signal is provided to a processor which performs an analysis to provide a parameter indicative of the roughness of the surface.

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the opinions of 408 students from the University of Windsor, Ontario as to whether certain traits and abilities are trainable (a) to themselves and (b) to others).
Abstract: The debate continues as to whether or not entrepreneurial traits and abilities can be taught or not. This study reviews the opinions of 408 students from the University of Windsor, Ontario as to whether certain traits and abilities are trainable (a) to themselves and (b) to others. Overall, it was found that both traits and abilities can be taught with independent thought and the ability to set goals and develop plans found to be the most trainable. The least trainable traits and abilities were creative thinking and the use of analytical and diagnostic skills. Respondents were subdivided by sex and by seniority at university.

Journal ArticleDOI
TL;DR: In this paper, the authors combine the output of several models that deal with future climatic, hydrologic and economic conditions in the Great Lakes and make some predictions about the possible impact of one scenario of 2 × CO2 climate on Great Lakes shipping.
Abstract: This paper represents an attempt to combine the output of several models that deal with future climatic, hydrologic and economic conditions in the Great Lakes and makes some predictions about the possible impact of one scenario of 2 × CO2 climate on Great Lakes shipping. It is realized that there is a great deal of uncertainty in all the models and that improvements are continually being made. Data from a General Circulation Model of future temperature and precipitation in the Great Lakes basin, a Great Lakes levels and flows model from the Canada Centre for Inland Waters and an International Joint Commision's Great Lakes economic model modified by the University of Wisconsin were used. The 1900–1976 period of lake levels and flows was used. The hydrologic model indicated that future mean lake levels may be reduced by one-half meter, and that the extreme low levels of the mid 1960's could occur 77% of the time in the future. No ice cover is predicted for any lake except Erie, permitting an eleven month shipping season. Five scenarios of future impact on shipping were evaluated. It was found that mean annual shipping costs may increase by 30% and the frequency of years when costs exceed those of the period of low lake levels (1963–65) could rise to 97%. Possible policy options in a future with climatically induced lower lake levels could include regulation to keep levels artificially high by diversions into the system, or increased dredging of the connecting channels.

Journal ArticleDOI
TL;DR: A modular architecture for very fast digital signal processing (DSP) elements are presented and the technique evolves from the decomposition of each closed calculation using the ring/field associativity property.
Abstract: A modular architecture for very fast digital signal processing (DSP) elements are presented. The computation is performed over finite rings (or fields) and is able to emulate processing over the integer ring using residue number systems. The computations are restricted to closed operations (ring or field binary operators) with the ability to perform limited scaling operations. Computations naturally defined over finite mathematical systems are also easily implemented using this approach. The technique evolves from the decomposition of each closed calculation using the ring/field associativity property. Linear systolic arrays, formed with multiple elements, each of a single generic form, are used for all calculations. The pipeline cycle is determined from the generic cell and is predicted to be very fast by a critical path analysis. The cells are matched to the VLSI medium, and the resulting array structures are very dense. Examples of DSP applications are given to illustrate the technique, and example cell and array VLSI layouts are presented for a 3- mu m CMOS process. >

Journal ArticleDOI
TL;DR: In this paper, a method of solving the Brinkman equation using Cartesian tensors is developed, where general expressions for the velocity vector and the pressure, which can directly be used in situations where boundary conditions are expressible in Cartesian-tensor form, are obtained.
Abstract: A method of solving the Brinkman equation, using Cartesian tensors, is developed. General expressions for the velocity vector and the pressure, which can directly be used in situations where boundary conditions are expressible in Cartesian-tensor form, are obtained. It is shown how the drag on a porous sphere can be directly and easily calculated using this method.

Journal ArticleDOI
TL;DR: In this article, an interpretive polemic is presented to clarify the concept of "system" as it is employed in family therapy, and, by doing so, to undermine and call into question the practice that follows from, or is contained within, a systemic perspective.
Abstract: This paper is an interpretive polemic. It has two aims: (a) to clarify the concept of “system” as it is employed in family therapy, and, by doing so, to undermine and call into question the practice that follows from, or is contained within, a systemic perspective,1 (b) it will offer several suggestions towards the development of an alternative perspective which preserves the idea of system in a social network/diachronic framework. With respect to the first aim, an argument will be made that there are severe and insurmountable problems in attempting to maintain a systemic perspective, that the methodology of analysis is fatally flawed, and that the results of analysis imprisons the therapist in a framework, which though extremely powerful interpersonally, must be rejected as overly authoritarian and overly restrictive in the range of perceptions of social situations allowed. A position will be adopted advocating a move of decentering family therapy to a more peripheral space within a social network perspective. What immediately follows is a redefinition and repunctuation of what can only be considered as a highly problematic paradigm.

Journal ArticleDOI
TL;DR: In this paper, night-flying trichoptera and ephemeroptera were attracted using long-wave ultraviolet light and collected from 8 Canadian sites adjacent to the St. Clair and Detroit rivers.

Journal ArticleDOI
TL;DR: In this article, a methode based on un algorithme permettant de calculer les coefficients du developpement asymptotique de la solution a la singularite is proposed.


Journal ArticleDOI
TL;DR: In this paper, the authors applied the time-phase mode of the long-range distribution planning model to an actual distribution system and incorporated an accurate formulation of the continuous nonlinear cost function.
Abstract: The time-phase mode of the long-range distribution planning model introduced in a recent publication by the authors (1985) is applied to an actual distribution system. The model incorporates an accurate formulation of the continuous nonlinear cost function. Once the load-time variation in the area under consideration is known, the model takes into account the different types of costs (fixed costs, variable costs, and the cost of energy losses) for all planned facilities (substations and feeders), and then either the optimum construction or expansion of the system is obtained to satisfy the network operational and security constraints. A realistic utility example is used to compare the dynamic and the static solutions. >

Journal ArticleDOI
TL;DR: The paper deals with the computer simulation of the cathodic protection systems used for corrosion prevention, and the boundary element method is employed to discretize the governing mathematical model.

Journal ArticleDOI
TL;DR: Significant main effects for psychologists' sex were found for both the perceived usefulness of drug treatment and prognostic outlook ratings.
Abstract: The hypothesis that clinicians' perceptions of psychological maladjustment are related to the deviation of symptoms from prevailing gender role stereotypes was explored. Case history descriptions were sent to a random sample of practicing psychologists. These clinicians viewed female patients with "masculine" symptoms (e.g., alcoholism or antisocial behavior) as more psychologically disturbed than males with the same symptoms; they also perceived male patients with "feminine" symptoms (e.g., depression and anxiety) as more psychologically disturbed than their female counterparts. Significant main effects for psychologists' sex were found for both the perceived usefulness of drug treatment and prognostic outlook ratings.

Journal ArticleDOI
TL;DR: Far from being poor models for linguistic behavior, mothers of autistic children appear, therefore, to be quite responsive to their children's relative capabilities.
Abstract: The relationship between autistic children's level of functioning and maternal speech to children was examined. Ten higher functioning verbal and 10 lower functioning nonverbal children were videotaped in a 15-minute interaction with their mothers. Results revealed that mothers of the higher functioning verbal children asked more questions, used more language modeling, gave more reinforcement for language, and answered more children-initiated questions than did mothers of the lower functioning nonverbal children. Mothers of the nonverbal children employed more directives, used shorter mean lengths of utterance, and reinforced their children's motoric rather than spoken behavior. Far from being poor models for linguistic behavior, mothers of autistic children appear, therefore, to be quite responsive to their children's relative capabilities.

Journal ArticleDOI
TL;DR: In this paper, 2.4-Lithio-2.2 equivalents of n-butyllithium (DME/0°C/15 min) were trapped by a variety of electrophiles to produce 3,4-disubstituted furans in good yield.

Journal ArticleDOI
01 Sep 1988-Wear
TL;DR: In this paper, the wear rate of the pantograph contact strip and the overhead contact copper wire was investigated using a wear machine simulating a railway current collection system, and wear performance at speeds from 60 to 250 km h−1 was examined with and without current collection.

Journal ArticleDOI
TL;DR: The vibrational spectra of thin solid films of three perylene tetracarboxylic di-imide derivatives (phenyl, methyl, and unsubstituted) were reported in this paper.

Book ChapterDOI
TL;DR: Dispersal efficiency, calculated using population size estimates, revealed differences among the three species, but these differences were not consistent with that expected from their distributional patterns, suggesting that factors other than dispersal alone determine the distributions of copepod species.
Abstract: Freshwater pond copepod species at a low-arctic site show distributional and life history differences which may reflect different dispersal efficiencies. In order to ascertain levels of gene flow among populations, cellulose acetate gel electrophoresis was used to examine allozyme variation in Heterocope septentrionalis, Hesperodiaptomus victoriaensis and Leptodiaptomus tyrrelli near Churchill, Canada. Differentiation of gene frequencies among populations of these species, plus Hesperodiaptomus eiseni and Hesperodiaptomus arcticus at other sites along Hudson Bay was moderate. The variation in gene frequencies was less than that of other passively dispersing organisms from the same habitats, and only slightly greater than that reported for an intertidal copepod with pelagic larvae. The mean number of dispersers exchanged among populations per generation, estimated from Wright’s island model, averages 4.1 for the three species. Dispersal efficiency, calculated using population size estimates, revealed differences among the three species. However, these differences were not consistent with that expected from their distributional patterns. This suggests that factors other than dispersal alone determine the distributions of copepod species.

Journal ArticleDOI
TL;DR: Oncomodulin dimer was shown to activate two calmodulin-dependent enzymes, cyclic nucleotide phosphodiesterase and calcineurin phosphatase, with the activity constants of 63 and 1 nM, respectively, indicating that these enzymes have different domain contact requirements for activation.
Abstract: Oncomodulin, an oncofetal Ca2+-binding protein, contains a single Cys residue in position 18 of its primary structure. The reactivity of the Cys-18 thiol has been probed with 5,5'-dithiobis(2-nitrobenzoate) (NbS2). The kinetics of the reaction indicate that the thiol group is approximately 10-fold more reactive in the presence of Ca2+ than in its absence. Evidence presented here shows that oncomodulin can dimerize by intermolecular disulfide formation via the Cys-18 thiol. The kinetics of dimer formation indicate that the second-order rate constant for this reaction is approximately 6-fold higher than that observed for the reaction of the Cys-18 thiol with NbS2, possibly indicating that intermolecular electrostatic interactions precede disulfide formation. The disulfide-linked dimer of oncomodulin appears to be more similar to calmodulin than oncomodulin since the dimer displayed "calmodulin-like" affinity for the amphiphilic peptide melittin. In addition, oncomodulin dimer was shown to activate two calmodulin-dependent enzymes, cyclic nucleotide phosphodiesterase and calcineurin phosphatase, with the activity constants of 63 and 1 nM, respectively, indicating that these enzymes have different domain contact requirements for activation.

Journal ArticleDOI
TL;DR: In this article, surface enhanced Raman scattering (SERS) was used to identify the phthalimide anion adsorbed on the surface of colloidal silver in terms of the relative intensities of vibrational modes assigned to irreducible representations of the C2ν point group.