Showing papers by "Université du Québec à Montréal published in 1985"

The internal structure of phonological elements: a theory of charm and government *

Abstract: In this article we have two primary objectives: (1) to elaborate in some detail a theory of phonological representations embedded within a parametric framework, and (2) to apply this theory to a particular vowel system which displays some rather interesting properties. This work is a continuation of a collaboration on a programme of research on phonological theory begun in 1982 (cf. Vergnaud 1982; Kaye & Vergnaud 1984; Kaye et al. 1984, 1985, in preparation).This programme incorporates the view that phonology is to be regarded as a system of universal principles defining the class of human phonological systems. These principles underdetermine given phonologies in certain specific areas. A complete phonological system consists, then, of these principles along with sets of parameter values. Taken together, the principles and language-specific parameter settings give a complete characterisation of the phonological system under study. In this model, a phonological system contains no rule component. The observed phonological phenomena result from a combination of the general principles governing phonological representations and structures and the parameter values in operation in the particular language. We view this line of research as a continuation of the development of a theory of markedness (cf. Chomsky & Halle 1968 (SPE); Kean 1975, 1979). At the moment of writing, this view of phonology remains a long-term objective of our research programme. However, an increasing number of phonological processes which were formerly considered to be manifestations of rules are now successfully derivable from the principles of Universal Phonology (UP) (cf. Kaye & Lowenstamm 1984, to appear).

Giftedness and Talent: Reexamining a Reexamination of the Definitions

Abstract: In the scientific literature, there is ambiguity in the distinction between the concepts of giftedness and talent. This paper examines several common definitions of these two terms, with particular emphasis on the models proposed by Renzulli (1979) and Cohn (1981). Our critique of these two models leads to a clear differentiation between giftedness and talent: the former is associated with domains of abilities which foster and explain exceptional performance in varied fields of activities, that is, talents. Thus, one can be gifted without necessarily being talented (as with the case of underachievers), but not vice versa. Several factors which can act as catalysts for the actualization of giftedness in specific talents are discussed, particularly motivation and environmental quality.

In vivo mutant frequency rises among breast cancer patients after exposure to high doses of γ-radiation

Abstract: Human in vivo mutant frequencies can be measured by cloning freshly isolated lymphocytes in selective media containing 6-thioguanine (TG). This method was applied to monitoring environmental mutagenesis, by studying lymphocytes separated from peripheral blood of 12 cancer patients undergoing radiotherapy. Before therapy, cancer patients had an average 8.6 × 10−6 mutants/cell, compared to 2.4 × 10−6 mutants/cell for heart patients and 1.1 × 10−6 mutants/cell for healthy controls. After exposure of cancer patients to 50 Gy of γ-radiation delivered to the treated area, or an estimated 4 Gy received by each lymphocyte, patients averaged 36.8 × 10−6 mutants/viable cell.

Monopoles and rational maps: A note on a theorem of Donaldson

Abstract: In a recent paper, Donaldson gave a description of the moduli space of SU(2) monopoles in terms of rational maps; this was done indirectly, via the associated solution of Nahm's equations. We give here an interpretation of these rational maps in terms of the monopole's spectral curve, and then as “scattering data” for the monopole itself.

Inability of chrysotile asbestos fibers to modulate the 2-acetylaminofluorene-induced UDS in primary cultures of rat hepatocytes.

Abstract: There is now growing evidence that asbestos fibers could act in association with genotoxic compounds, either as cocarcinogens or promoters, in the process of carcinogensis. The hepatocyte/UDS assay system has been taken to advantage to investigate the capacity of fibers to modulate the effects of genotoxic compounds on the cell, as we previously demonstrated the hepatocytes can engage in phagocytosis of chrysotile fibers. Measurement of UDS was performed by a biochemical procedure involving liquid scintillation counting (LSC) of a purified DNA fraction as well as by radioautography. Both LSC and radioautography revealed that chrysotile asbestos fibers UICC B at concentrations up to 100 μg/ml do not elicit UDS, whereas 2-acetylaminofluorene (2-AAF) at low concentrations (0.05–0.625 μg/ml) significantly induces it in parallel positive controls. In an attempt to test the cocarcinogen hypothesis, cultures of hepatocytes were simultaneously exposed for 20 h to 2-AAF (0.05 and 0.25 μg/ml) and asbestos fibers (1 and 10 μg/ml) given as simple mixtures. It was found that the 2-AAF-induced UDS activity was the same whether fibers were present or not. This was observed with both UDS evaluation procedures at all concentration combinations selected. An analysis of variance applied to the data collected from several experiments confirmed that there was no significant 2-AAF-fiber interaction. Our data suggest the absence of intrinsic genotoxic properties for chrysotile fibers. They also indicate that the modulation of the cellular response to genotoxic agents by asbestos fibers is not detected under our test conditions and may require longer-term exposures to be expressed.

Chemical synthesis inside the collision cell of a MS/MS system: 1—Formation of adduct ions between protonated esters and ammonia

Abstract: An evaluation of the TAGA 6000 tandem quadrupole MS/MS capabilities for the study of the formation of adduct ions is presented. It is shown that under chemical ionization conditions the protonated molecular ions of esters react with neutral ammonia inside the collision cell of the instrument to yield adduct ions. Under the same reaction conditions the molecular ions obtained under electron impact conditions do not yield any adduct. Although it is not yet clear whether the adduct structure is of the cluster or covalently bonded type, the experimental results argue mainly in favor of the latter. The center-of-mass energy range usable for the formation of adduct ions is narrow and an order of magnitude lower than the energy required for collision-induced dissociation. However, despite the weak parent ion center-of-mass energies used, the spectra exhibit fragments characteristic of the adduct ion structures. Finally, by controlling the parent ion center-of-mass axial kinetic energy, the number of parent ions and the target thickness, it is possible to measure and control all the usual physicochemical parameters for adduct ion formation.

Absence of genotoxic effects of nonasbestos mineral fibers.

Abstract: The biological activity of natural and synthetic mineral fibers has been examined. Natural attapulgite [(Mg, Al)2Si4O10(OH).4H20], synthetic xonotlite [Ca3Si3O8(OH)2] and natural sepiolite [Mg2Si3O8.2H2O] were selected. Genotoxic effects were investigated by means of a well established cellular model based upon the measurement of unscheduled DNA synthesis (UDS) in rat hepatocytes in primary culture. The intrinsic capacity of the fibers (1 and 10 µ/ml) to induce UDS was first tested. None of the fiber types showed detectable UDS-eliciting activity. Also, the possible modulation of the cellular response to genotoxic agents by the materials was examined by exposing the cells to mixtures of 2-acetylaminofluorene (AAF) (0.05 and 0.25 µg/ml) and fibers (1 and 10 µg/ml). In these experiments, the UDS response was significantly diminished in the presence of xonotlite. This phenomenon may reflect changes in the uptake and/or metabolism of AAF or may result from an inhibition of DNA repair processes, the latter suggesting a possible cocarcinogenic potential for this synthetic silicate. These results point to the immediate necessity of studying more extensively the biological effects of fibrous materials that can be used as substitutes for asbestos.

Regulation of RNA Synthesis by DNA-Dependent RNA Polymerases and RNases during Cold Acclimation in Winter and Spring Wheat

Abstract: Chromatin DNA-dependent RNA polymerases and RNases activities were measured in winter and spring varieties to understand the overall regulation of RNA synthesis during cold acclimation. We found that total RNA polymerase activities were significantly higher in chromatin isolated from winter wheat compared to the spring wheat during the acclimation period. This increase was parallel to the increase in protein and RNA contents during hardening. The ratio of RNA polymerase I to RNA polymerase II activity was higher than 2 in winter wheat after 30 days of hardening compared, to a ratio of 0.90 under the nonhardening conditions. The increase in activity and the ratio of polymerase I to polymerase II was maintained after the separation of the enzymes from the template, suggesting that RNA synthesis is regulated in part at the enzyme level. On the other hand, the chromatin associated RNase activity decreased in both varieties during acclimation, indicating a nonspecific inhibition caused by low temperature rather than a selective genetic response associated with cold acclimation.

V-functions in the control of motion

Abstract: The geometry and application of K-functions is studied which provide a generalization of the Liapunov direct method in stability theory to allow the control of motion. A sufficiency theorem is proved that provides a means for quantitative design and investigation of dynamical systems.

Bombardier's Mass Production of the Snowmobile: The Canadian Exception?

Abstract: In the preceding article, Chris DeBresson and Joseph Lampel propose a new, nonlinear view of technological evolution. In this article, they use their new model to take us through the changes in one firm over a period of more than 50 years. Their model emerges as less constraining in strategic options than in the traditional view, and richer in its representation of technological change.

Geology of Montreal, Province of Quebec, Canada

Abstract: Situated on an island at the confluence of the St. Lawrence and Ottawa rivers in the Province of Quebec, Montreal has been a gateway to western exploration and commercial development ever since its discovery in 1535 and its founding as Ville-Marie in 1642. Nowadays, it is still a major Canadian transportation centre. The area lies within the St. Lawrence Lowlands, between the Precambrian Shield to the northwest and the Appalachians to the east, and is underlain by slightly deformed and faulted sandstone, carbonate rocks and shales of Cambro-Ordovician age. Mount Royal, the large hill from which the city takes its name, is one of a series of Mesozoic plutons that intruded the sedimentary rocks. Surficial deposits are of Wisconsin age or younger, and include tills, interstadial silts and sands, marine clay, marine and estuarine beach materials and recent peat deposits. There are no significant geological constraints to development in the area. Overburden materials present designers with a range of foundation conditions in terms of bearing capacity, settlement and the control of excavation stability but most major constructions are founded on rock. Investigation and design techniques combine the latest in both European and American practice but remain conventional. Environmental concerns related to the geology proper are not very significant. The seismicity of the area is relatively high. Montreal is near the centre of a broad zone, classified as No. 2 on the 0 (most stable) to 3 Canadian system, that covers most of southern Quebec. The bedrock formations have historically furnished the city with a cheap and abundant source of building materials and the presence of rock close to surface has led to the extensive use of rock tunnels for water supply, trunk sewers and for the “Metro” subway and stations into Montreal9s “under-ground city” that provides a haven in winter for downtown workers and shoppers. Montreal hosts a large and active geotechnical community, becoming increasingly more involved in all local development projects. The paper is presented in SI units, now used exclusively in Canada.