Showing papers by "University of Windsor published in 1990"
TL;DR: In this paper, selective chemical separation techniques for isotopic analysis of coexisting calcite, dolomite, siderite, and magnesite have been investigated.
Abstract: Selective chemical separation techniques for isotopic analysis of coexisting calcite, dolomite, siderite and magnesite have been investigated in this study. Comparison of reaction rates of all pure carbonate minerals with 100% phosphoric acid at 25° and 50°C demonstrated that a uniformly fine grain size (<200 mesh) is required. Tests with fine-grained (<200 mesh) pure calcite, dolomite, siderite and magnesite reacted at 25°C (calcite) and 50°C (others) show that δ18O of evolved CO2 increases during the course of reaction. This is probably due to a slight kinetic isotope effect associated with rapid dissolution of sub-micrometer carbonate crystallites adhered to the outer surfaces of the very fine-grained crystals. Isotopic analysis of carbonates based on CO2 from incomplete acid reactions is accurate only after minimum reaction times. Conversely, much longer reaction times than the minima are not required.
Experiments conducted on variable mixtures of calcite-dolomite, dolomite-siderite and calcite-dolomite-siderite demonstrated the magnitudes of cross-contamination on the inferred isotopic compositions of the individual minerals. The isotopic compositions and magnitudes of their uncertainty can be evaluated for individual carbonates selectively extracted from natural mixtures by variable time-temperature protocol.
345 citations
TL;DR: Evidence was found for supporting the idea that the coordination between these two components was achieved by a sensorimotor process, and given the goal of a prehension movement, it was argued that the two components are linked functionally rather than temporally or spatially.
322 citations
TL;DR: In this article, a normative sample of 619 boys and girls from 11 to 18 years of age who attended public school in Ontario, Canada was examined by examining subscale performance of the Eating Disorder Inventory (EDI).
Abstract: Although anorexia nervosa typically begins during adolescence with proneness to the disorder beginning even earlier, reliability and normative studies of the Eating Disorder Inventory (EDI) have relied primarily on college-aged students. This problem was addressed by examining subscale performance of a normative sample of 619 boys and girls from 11 to 18 years of age who attended public school in Ontario, Canada. Analyses of the internal consistency of the EDI subscales Bulimia and Maturity Fears failed to demonstrate adequate reliability for either boys or girls. Perfectionism and Interpersonal Distrust subscales were also unreliable for the boys. Analysis of variance procedures revealed that girls scored higher than boys on Drive for Thinness, Body Dissatisfaction, and Interoceptive awareness. Older (14–18 years) girls differed from younger (11–13 years) girls, scoring higher on Body Dissatisfaction and lower on Interpersonal Distrust. Older and younger boys did not differ from each other on any of the EDI subscales, nor did they differ from the 14–18-year-old norms presented by Rosen, Silberg, and Gross (1988). Older girls, on the other hand, scored higher than the Rosen et al. norms on Drive for Thinness and Interoceptive Awareness. EDI percentile scores are presented for girls 11–13 and 14–18 years of age.
177 citations
TL;DR: In this paper, a study on the loss and recovery of hydrophobicity of RTV (room-temperature vulcanizing) silicone-rubber insulator coatings in a salt-fog chamber is reported.
Abstract: The results of a study on the loss and recovery of hydrophobicity of RTV (room-temperature vulcanizing) silicone-rubber insulator coatings in a salt-fog chamber are reported. The results complement those previously reported on the ability of the coatings to suppress leakage current and insulator flashover. The temporary loss of hydrophobicity caused by dry-band arcing and the subsequent recovery are studied in depth. The gradual loss of hydrophobicity as determined from the leakage current and the contact-angle measurements is shown to be related to the physical changes to the coating brought about by dry-band arcing. >
150 citations
TL;DR: In this article, a generalized group technology problem of manufacturing a group of parts in which each part can have alternative process plans and each operation in these plans can be performed on alternative machines is considered.
Abstract: SUMMARY In this paper we consider a generalized group technology problem of manufacturing a group of parts in which each part can have alternative process plans and each operation in these plans can be performed on alternative machines. The objective is to model and analyse how alternative process plans influence the resource utilization when the part families and machine groups are formed simultaneously. Accordingly, we develop three integer programming models to successively study the effect of alternative process plans and simultaneous formation of part families and machine groups. An illustrative example is included.
142 citations
TL;DR: In this paper, five types of strategy research are reviewed, including instructional need research, strategy development, and experimental evaluation, and two other types of research should be conducted to determine whether there is a need for strategy instruction and develop a treatment with preliminary evaluations, as can formal evaluation of the resultant intervention in true experiments.
Abstract: Five types of strategy research are reviewed. (1) We argue it makes sense first to determine whether there is a need for strategy instruction. If there is, (2) development of a treatment with preliminary evaluations can follow, as can (3) formal evaluation of the resultant intervention in true experiments. As instructional need research, strategy development, and experimental evaluation proceed, two other types of research should be conducted. (4) It is important to study the acceptability of strategy interventions to educators and students. (5) Research on material modifications can provide information about how strategy benefits can be made available to students when strategy instruction is not effective or unlikely to occur. Very little strategy instruction has been evaluated in all five types of research covered here, making obvious the need for more systematic research on strategies. Observational, ethnographic, and experimental methods are required in order to address the many issues comprising comprehensive empirical analysis of any type of strategy instruction, with many recommendations made here about how to conduct informative studies.
141 citations
TL;DR: The authors examined the assoication between Canadian unions and their member's attitudes and found that unionized workers in Canada are less satisfied with the quality of their jobs than non-union workers.
Abstract: This paper examines the assoication between Canadian unions and their member' attitudes. Data on job satisfaction indicate that unionized workers in Canada are less happy with the quality of their jobs than non-union workers. The former, however, are more satisfied with their financial compensation and job security than non-members.
137 citations
126 citations
TL;DR: A simple, rapid method for isolating human DNA has been developed, which can be routinely used in clinical chemistry laboratories, and was found quite suitable for digestion by a variety of restriction endonucleases and for restriction fragment length polymorphism analysis.
Abstract: A simple, rapid method for isolating human DNA has been developed, which can be routinely used in clinical chemistry laboratories. The entire procedure takes less than 90 min, and as many as 12 blood samples can be handled in one cycle. One milliliter of EDTA-treated blood is lysed and centrifuged to yield a nuclear fraction. The nuclear pellet is treated with sodium dodecyl sulfate/urea and phenol/chloroform to remove contaminating proteins, then the crude DNA extract is purified by use of a Sephadex G-25 spin-column. Typical 260 nm/280 nm absorbance ratio (used to assess purity) and yield for DNA so purified were 1.84 and 24.5 micrograms/mL, respectively. Within- and between-day CVs for recovery of DNA from pooled blood were 8% and 11% respectively. Such DNA preparations were found quite suitable for digestion by a variety of restriction endonucleases and for restriction fragment length polymorphism analysis. We are using this method to isolate DNA from whole blood of myocardial infarction patients for studies on the apolipoprotein B gene.
83 citations
TL;DR: Two methods of estimating the uncertainty in the set of objects retrieved in response to every query, based on information theory, are proposed: the measure of uncertainty is used to rank objects for presentation to a user.
Abstract: Information systems exist to model, store, and retrieve all types of data. Problems arise when some of the data are missing or imprecisely known or when an attribute is not applicable to a particular object. A consistent and useful treatment of such exceptions is necessary. The approach taken here is to allow any attribute value to be a regular precise value, a string denoting that the value is missing, a string denoting that the attribute is not applicable, or an imprecise value. The imprecise values introduce uncertainty into query evaluation, since it is no longer obvious which objects should be retrieved. To handle the uncertainty, two set of objects are retrieved in response to every query: the set of objects that are known to satisfy with complete certainty and the set that possibly satisfies the query with various degrees of uncertainty. Two methods of estimating this uncertainty, based on information theory, are proposed. The measure of uncertainty is used to rank objects for presentation to a user.
80 citations
TL;DR: A hierarchical analysis of population structure in the cyclic parthenogens by using a fixation-index approach indicates that this is one of the most extremely subdivided species yet studied.
Abstract: The geographic structure of Daphnia pulex populations from the central United States is analyzed with respect to isozyme and mitochondrial DNA variation. The species complex consists of cyclic and obligate parthenogens. A hierarchical analysis of population structure in the cyclic parthenogens by using a fixation-index approach indicates that this is one of the most extremely subdivided species yet studied. This genetic structure, much of which accrues within 100 km, is certainly due in part to the limited dispersal ability of Daphnia. However, previous work has shown that fluctuating selection can account for the spatial heterogeneity in isozyme frequencies in these populations. This may explain why the population subdivision for the mitochondrial genome increases approximately three times as rapidly with distance as does that for nuclear genes, which is slower than the neutral expectation. The obligate parthenogens are shown to be polyphyletic in origin, evolutionarily young, and, in some cases, geographically widespread.
TL;DR: The crystal structure of carp parvalbumin has been refined by restrained least-squares analysis employing X-ray diffractometer data to 1.5-A resolution and there are significant differences in the amino-terminal region, which was extensively refit, and in the number of oxygen atoms liganding calcium in the CD and EF sites.
Abstract: The crystal structure of carp parvalbumin (pI = 4.25) has been refined by restrained least-squares analysis employing X-ray diffractometer data to 1.5-A resolution. The final residual for 12,653 reflections between 10 and 1.5 A with I(hkl) greater than 2 sigma(I) is 0.215. A total of 74 solvent molecules were included in the least-squares analysis. The root mean square deviation from ideality of bond lengths is 0.024 A. The model has a root mean square difference of 0.59 A from the positions of the main-chain atoms in a previously reported structure [Moews, P. C., & Kretsinger, R. H. (1975) J. Mol. Biol. 91, 201-228], which was refined by difference Fourier syntheses using data collected by film to 1.9 A. Although the overall features of the two models are very similar, there are significant differences in the amino-terminal region, which was extensively refit, and in the number of oxygen atoms liganding calcium in the CD and EF sites, which increased from six to seven in the CD site and decreased from eight to seven in the EF site.
TL;DR: Bethe logarithms accurate to 14 or 15 places to the right of the decimal are tabulated for all states of hydrogen up to {ital n}=20 for Rydberg states of two-electron atoms.
Abstract: Bethe logarithms accurate to 14 or 15 places to the right of the decimal are tabulated for all states of hydrogen up to n=20. Approximation methods for Rydberg states of two-electron atoms are discussed.
TL;DR: The development of algorithms for the machine recognition of optically captured Arabic characters and their isolation from the printed text and an algorithm for separation of individual characters are discussed.
TL;DR: The authors examined antecedent and outcome models for all four factors of union commitment (loyalty to the union, responsibility to union, willingness to work for the union and belief in unionism).
Abstract: This research examined antecedent and outcome models for all four factors of union commitment (loyalty to the union, responsibility to the union, willingness to work for the union and belief in unionism). A hypothesis that union commitment would act as an intervening variable between the antecedents and outcomes was also tested. Unionized employees (n = 481) from a large mid-western communications company completed a survey. Antecedents of loyalty to the union included national and local union mission fulfilment, and chief steward and officer accessibility. Chief steward accessibility and sex were identified as antecedents of responsibility to the union. Belief in unionism was predicted by local union mission fulfilment. Both national and local union mission fulfilment were significant antecedents of willingness to work for the union. All of the outcomes in the study, both behavioural (attendance at union meetings, union activity and member voting behaviour) and attitudinal (cognitive consideration in voting, member support for political action), were related to at least one of the four factors. Support was also found for establishing union commitment as an intervening variable between the hypothesized antecedents and outcomes.
TL;DR: No significant differences in body burdens were detected for any of the compounds between mussels placed in corrals containing uncontaminated sand and those with natural sediment, suggesting the water phase represents the xenobiotic source.
Abstract: Biological and physical factors affecting the body burdens of hexachlorobenzene, octachlorostyrene, and four polychlorobiphenyl (PCB) congeners in freshwater mussels from Lake St. Clair, Ontario, Canada were investigated. Specimens ofLampsilis radiata (Barnes) and the non-nativeElliptio complanata (Lightfoot) were deployed for forty days at four Lake St. Clair sites, to investigate whether the water or the sediment phase represented the primary source of contaminants and to examine the effect of enclosure of the mussels on contaminant uptake. No significant differences in body burdens were detected for any of the compounds between mussels placed in corrals containing uncontaminated sand and those with natural sediment, suggesting the water phase represents the xenobiotic source. Among three enclosure types of varying restriction there were no significant differences in the body burden of each compound indicating the effect of confinement on uptake is minimal. Weak negative correlations between body burden and body length existed for all compounds, although there were no significant differences between the sexes or, with the exception of PCB congener 118, among five indigenous species.
TL;DR: In this paper, an expert system approach was developed to define appropriate layouts of machining facilities under specific combinations of manufacturing and materials handling systems, incorporating six factors relating product variety and quantity, degrees of flexibility, level of automation, materials handling system, work-in-process and environmental considerations.
Abstract: SUMMARY The paper develops an expert systems approach to define appropriate layouts of machining facilities under specific combinations of manufacturing and materials handling systems. The knowledge base incorporates six factors relating product variety and quantity, degrees of flexibility, level of automation, materials handling system, work-in-process and environmental considerations. The EXSYS system program has been used to manipulate the knowledge base. The program operates in tandem mode and interfaces with algorithms to optimize the selection of materials handling equipment, and generate appropriate layouts. Application of the program is illustrated for an existing facility.
TL;DR: Results support the construct validity of the BES female subscales and their utility for research in populations at increased risk for body-image or eating-disorder disturbances.
Abstract: The female subscales of the Body Esteem Scale (BES) have demonstrated convergent and discriminant validity in two previous studies. However, relationships between BES dimensions, weight, and other body-image measures have not been adequately examined. In this study, 200 women with a mean age of 27.6 years completed the BES, the Eating Disorder Inventory, the Self-Consciousness Scale, the Tennessee Self-Concept Scale, a figure rating task, a phototechnical body-size estimation procedure, and items concerning weight satisfaction and attractiveness. BES Weight Concern was most closely related to weight variables and other body image measures where BES Sexual Attractiveness and Physical Condition were more strongly associated with less specific self-perceptions and attitudes. Results support the construct validity of the BES female subscales and their utility for research in populations at increased risk for body-image or eating-disorder disturbances.
TL;DR: In this paper, a dual-camera calibration algorithm and procedure is presented, which is based on the method of direct linear transformation and results in an overdetermined set of linear algebraic equations that can be utilized in determining the coordinate position of some identifiable feature in a scene relative to any set of orthogonal axes.
Abstract: A dual-camera calibration algorithm and procedure are presented. The algorithm is based on the method of direct linear transformation and results in an overdetermined set of linear algebraic equations that can be utilized in determining the coordinate position of some identifiable feature in a scene relative to any set of orthogonal axes. Both radial and tangential lens distortions are considered in a second step of the calibration algorithm to improve the accuracy of the position sensor. Since the algorithm incorporates both types of lens distortions, it can be applied to a camera with any combinations of lenses, e.g. a lens system with a supplementary lens for close-up observations. >
TL;DR: The results indicate that the hemispheric processes involved in disengaging and shifting response strategies between dichotic channels may share common neuronal mechanisms with cognitive processes that are important to school achievement.
TL;DR: In this paper, the vibrational assignment of totally symmetric modes in a series of D 4 h and C 4 v phthalocyanine (Pc) molecules was attempted using infrared, Raman, SERS, and vibrational calculations.
TL;DR: The results support the notion that patterns of cognitive performance are related to patterns of psychosocial functioning in children with LD, and group average linkage cluster analysis using 10 PIC scales revealed 6 psychossocial subtypes.
Abstract: A total of 132 children with learning disabilities (LD) between the ages of 6 and 12 years were divided equally into 3 groups on the basis of the difference between WISC VIQ-PIQ scores (viz., VIQ greater than PIQ, VIQ = PIQ, and VIQ less than PIQ). The mean Personality Inventory for Children (PIC) profiles for the VIQ = PIQ and VIQ less than PIQ groups were normal; however, the VIQ greater than PIQ group showed pathological elevations on some PIC scales. Group average linkage cluster analysis using 10 PIC scales revealed 6 psychosocial subtypes. Within these subtypes, children with VIQ greater than PIQ were found at lower than expected frequencies in normal and mildly disturbed subtypes, but at higher than expected frequencies in seriously disturbed subtypes. These results support the notion that patterns of cognitive performance are related to patterns of psychosocial functioning in children with LD.
TL;DR: Expressions pour les valeurs moyennes de r P d'un etat hydrogenique arbitraire l a l'aide de coefficients independants de l'etat, determines par une methode recursive simple.
Abstract: Expressions pour les valeurs moyennes de r P d'un etat hydrogenique arbitraire l a l'aide de coefficients independants de l'etat, determines par une methode recursive simple. Resultats obtenus pour P negatif, jusqu'a −16, par une transformation algebrique pour P positif jusqu'a 13. Expression asymptotique pour chaque P pour de grandes valeurs de l
TL;DR: In this article, Petrographic, chemical and stable isotope investigations have been made on calcite, dolomite, and Fe-dolomites/ankerite from Permian-Triassic clastic sequences from the Iberian Range (Spain).
Journal Article•
TL;DR: The validity of self-reports of 48 adults with mental retardation of daily living competency using the recently revised Vineland Adaptive Behavior Scales was investigated and response validity and implications for use ofSelf-report for program planning and placement decisions were discussed.
Abstract: The validity of self-reports of 48 adults with mental retardation of daily living competency using the recently revised Vineland Adaptive Behavior Scales (Sparrow, Balla, & Cicchetti, 1984) was investigated. Self-report was compared to standard Vineland interviews of subjects' program counselors and to demonstrated competency in a real-life setting. On domains measuring adaptive skills, the subject and counselor interviews yielded highly consistent results. On the optional Maladaptive Behavior domain, however, the subjects with mental retardation underreported problematic behavior. Response validity and implications for use of self-report for program planning and placement decisions were discussed.
TL;DR: It is shown that ‘U:U and U:C wobble’ mechanisms can operate to allow the reading of these codons by cp tRNALeu (UAm7G) and cp tRNAArg(ICG) are able to decode the corresponding four-codon family.
Abstract: In chloroplasts, all 61 sense codons are found in chloroplast (cp) DNA sequences coding for proteins. However among the sequenced cp tRNAs or tRNA genes, tRNAs with anticodons complementary to codons CUU/C (Leu), CCU/C (Pro), GCU/C (Ala) and CGC/A/G (Arg) [or CGC/A (Arg) in Marchantia] have not been found. In this paper we show that cp tRNAAla(U*GC), cp tRNAPro(U*GG) and cp tRNAArg(ICG) are able to decode the corresponding four-codon family. In the case of leucine codons CUU/C, we show that ‘U:U and U:C wobble’ mechanisms can operate to allow the reading of these codons by cp tRNALeu (UAm7G).
TL;DR: In this article, the effects of the model's skill level and model's knowledge of results on performance of an aiming task were examined, and preliminary support for the contention that a correct model may not be the best for creating an accurate conceptual representation.
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TL;DR: Following a suggestion by Simon (1982), Baumol's model of unbalanced growth (1967) is opened to interregional trade as discussed by the authors, and consumers are forced to buy the two goods in fixed proportions.
TL;DR: The data suggest that some important questions on regulation of apolipoprotein B expression can be addressed by the long‐term culture of HepG2 cells in defined medium.