Showing papers by "University of New Brunswick published in 1983"

Shortest chain subject to side constraints

Abstract: Certain properties of a shortest chain subject to several side constraints are established. Based on these an implicit enumeration algorithm, that is, a generalization of the one given by Dijkstra for the case without any side constraint, is presented. Validation of the algorithm and an illustrative example are included.

Numerical simulation of a fixed-bed adsorption column by the method of orthogonal collocation

Abstract: Prediction de la reponse transitoire d'une colonne d'adsorption en resolvant par cette methode un probleme lineaire complique dont on a donne recemment une solution analytique exacte

Deformation and metamorphism in the Bard area of the Sesia Lanzo Zone, Western Alps, during subduction and uplift

Abstract: The structure, microstructure and petrology of a small area close to the village of Bard in Val d'Aosta (Italy) has been studied in detail. The area lies across the contact between the Gneiss Minuti (GM) and the Eclogitic Micaschist (EMS) Complexes of the Lower element of the Sesia portion of the Sesia-Lanzo Zone (Western Alps). Both complexes have undergone high-pressure metamorphism, but the metamorphic assemblages indicate a sudden increase in pressure in going across the contact from the GM to the EMS. Therefore, we interpret the contact as a thrust dividing the lower element of the Sesia into two sub-elements. This interpretation is supported by structural evidence. The early Alpine (90-70 Ma) metamorphic history is best preserved in the EMS and is one of increasing pressure associated with thrusting. The maximum P/T recorded in the EMS is >1500 MPa (>15kbar) and 550°C and in the GM is < 1500-1300 MPa (< 15-13 kbar) and 500-550°C. We suggest that the rocks were probably in an active Benioff zone during this time. From then on the histories of the GM and EMS are the same. Deformation continued and the thrust and thrust slices were folded during decreasing pressure. We interpret the first postthrusting deformation in terms of uplift associated with continued shortening of the crust and underplating after the Benioff zone had become inactive and a new Benioff zone had developed further to the north-west. A still later deformation and the Lepontine metamorphism (38 Ma) are related to continued uplift. Much of this deformation is characterized by structures indicative of vertical shortening and lateral spreading as the mountains rose above the general level of the surface.

Gene expression: chemical synthesis and molecular cloning of a bacteriophage T5 (T5P25) early promoter

Abstract: A sixty base pair DNA duplex containing the nucleotide sequence of the bacteriophage T5 early (T5P25) promoter has been constructed using a combination of chemical synthesis and enzymatic methods. Subsequent to cloning into pBR322, the promoter has been demonstrated to be biologically active being capable of directing the efficient expression of genes under its control. This serves as a prototype for an approach to the study of the in vivo structure-function relationships and efficiency of promoters.

Heritability of dorsal spines in the fourspine stickleback ( Apeltes quadracus )

Abstract: Heritabilities of dorsal spine number in Apeltes quadracus are estimated for four widely separated sites in New Brunswick, Canada. The additive genetic variance is high with values ranging from 0·47±0·049 to 0·80±0·128; average heritability for the four sites is 0·61 ± 0·068. The sexes do not differ for estimates. Directional selection over three generations shows a rapid response suggesting that few loci are involved and that stabilizing selection acts on natural populations.

Spruce Budworm Moth Flight and Storms: Case Study of a Cold Front System

Abstract: Field studies in New Brunswick on the dispersal and redistribution of night-flying spruce budworm moths have made particular use of detailed synoptic analysis, weather radar (ground and airborne), and airborne Doppler wind-finding; moth-sampling by light-traps, pheromone-traps and aircraft-trapping; insect-detecting radar; and experimental forest spraying. By these means moths have been recorded arriving in very large numbers, with mesoscale wind systems associated with rainstorms. A case study is presented of such an influx in western New Brunswick in association with wind shifts and weather at an active cold front in July 1975.

Identification of a Best Algorihthm for Digital Distance Protection of Transmission Lines

Abstract: The paper describes amethod for seeking out the best or optimal combination of digital distance relay and digital filter algorithm for transmission line protection. It is found that this best combination consists of a 3rd order recursive low pass filter algorithm and distance relay algorithm based on the solution of the differential equation representing the transmission line model. Typical relay transient operating characteristics on R-X co-ordinates are presented.

The equivalence of perfect fluid space-times and viscous magnetohydrodynamic space-times in general relativity

Abstract: The work of a previous article [1] is extended to show that space-times which are the exact solutions of the field equations for a perfect fluid also may be exact solutions of the field equations for a viscous magnetohydrodynamic fluid. Conditions are found for this equivalence to exist and viscous magnetohydrodynamic solutions are found for a number of known perfect fluid space-times.

Asymmetrical folding in the Hawick Rocks of the Galloway area, Southern Uplands

Abstract: Synopsis The asymmetry, scale and regionally uniform distribution of F 1 folds in the Hawick Rocks do not support previous interpretations of the major structure. The F 1– F 4 phases of folding previously proposed are re-interpreted as two phases. The F 2 folds are developed mainly along a 2–3 km wide strike belt. Variation in the scale and asymmetry of F 1 folding across the Southern Uplands is outlined. The style of F 1 folding in the Hawick Rocks is consistent with deformation accompanying sequential accretion of sediments at a subduction zone.

The axial dispersed plug flow model for continuous counter‐current adsorbers

Abstract: On a etabli l'expression theorique de la hauteur equivalente a un plateau theorique, et on l'a compare a l'expression analogue pour un systeme de chromatographie. Le rapport de ces grandeurs est generalement 0,5 dans les conditions pratiques de fonctionnement, mais la relation precise depend des nombres de Peclet et de Stanton ainsi que du rapport des debits a contre-courant

A new look at FRW cosmologies

Abstract: The question of whether the material distribution in any cosmological model can be interpreted unambiguously is considered. We suggest that the answer is negative, and discuss problems in theoretical cosmology which may arise from this ambiguity of interpretation.

Grazing by the gastropod, Lacuna vincta , in the lower intertidal area at Musquash Head, New Brunswick, Canada

Abstract: Lacuna vincta appeared at Musquash Head, New Brunswick, in large numbers from June to August 1981 principally on lower midlittoral and infralittoral fringe Fucus edentatus. The population reached a mean maximum of 280/m2 in June; by mid September the animals had disappeared. The L. vincta grazed heavily and deposited egg masses on Fucus edentatus but little on other species. All fine and filamentous and encrusting algal species and rock were avoided for egg deposition. Egg mass abundance peaked with the population in June with a mean of 180/m2. Mean egg production in June was 83000/m2.Both snail and egg mass distributions were correlated with the percentage cover of F. edentatus, reaching a maximum at 40–75 cm above mean low tide level.The snails ranged in length from 2–7 mm, consisting of three cohorts from different larval settlements. Growth was rapid in July averaging 0·6 mm/month slowing later.The food plant Fucus edentatus showed a heavy impact of the herbivore. Weight reductions attributable to grazing rose from 56 % in June to 79 % in August and grazed plants tended to thicken rather than elongate with growth. Grazing removed about 79 % of the net production of F. edentatus which averaged 61 g dry wt/m2/day. The impact of the L. vincta population on F. edentatus seems extraordinarily severe.

On cardioactive steroids. XII. The synthesis of (natural) bufalin and α′‐isobufalin

Abstract: An efficient and simple synthesis of bufalin (1)via furan-containing intermediates is described. The same method was also used for the synthesis of α-isobufalin (2) which was prepared with equal simplicity, but in lower yield.

Neural differentiation in fly CNS transplants cultured in vivo

Abstract: To study the influence of afferent retinal innervation on neuronal organization in the CNS during differentiation in the fly Sarcophaga bullata, we transplanted larval CNS with or without eye imaginal discs into freshly pupariated animals. After metamorphosis and eclosion of the adult flies, the transplants were recovered and analyzed histologically. Optic lobes transplanted with eye disc differentiated fully like normal in situ optic lobes. In transplants without discs the outermost optic neuropil, the lamina, did not differentiate at all, and the more central ones, medulla, lobula, and lobula plate, were reduced in volume. Although certain neuron types present in normal optic lobes could be identified, the strict columnar and layered organization of these neuropils was no longer apparent in the eyeless transplants. The experiments confirm the earlier notion that afferent innervation strongly influences normal differentiation in the peripheral optic lobes of insects, whereas more central neuropil regions are less dependent on the retinal innervation. In addition, we show that the formation of the normal pattern of dendritic arborizations as well as strict columns and layers in these lobes seems to require retinal and/or laminar input.