Showing papers by "University of New Brunswick published in 1980"
TL;DR: A method called the row generation scheme is developed to solve the problem of obtaining a minimal weighted tree which spans the set S of nodes, termed in literature as the Steiner problem in graphs.
Abstract: Consider a connected undirected graph G[N; E] with N = S ∪ P, the set of nodes, where P is designated as the set of Steiner points. A weight is associated with each edge ei of the set E. The problem of obtaining a minimal weighted tree which spans the set S of nodes has been termed in literature as the Steiner problem in graphs. A specialized integer programming (set covering) formulation is presented for the problem. The number of constraints in this formulation grows exponentially with the size of the problem. A method called the row generation scheme is developed to solve the above problem. The method requires knowing the constraints only implicitly. Several other problems which can be put in a similar framework can also be handled by the above scheme. The generality of the scheme and its efficiency is discussed. Finally the computational result is demonstrated.
151 citations
133 citations
TL;DR: Progress in the development of a system to provide sensory feedback of the pinch force of an artificial hand is described and details of a practical system, presently in use by two amputees prior to full-scale clinical evaluation, are presented.
Abstract: Progress in the development of a system to provide sensory feedback of the pinch force of an artificial hand is described. Design criteria relating to electrocutaneous stimulation and compatibility with myoelectric control are discussed. Details of a practical system, presently in use by two amputees prior to full-scale clinical evaluation, are presented.
99 citations
TL;DR: Preliminary field data indicate that attractancy of lures containing all four components present in a similar source ratio to a calling female is not significantly different from lure containing E11/Z11 unsaturated aldehydes alone.
Abstract: Chemical analyses of glands from virgin female eastern spruce bud worm by capillary GC show three major classes of compounds: 14-carbon aldehydes, acetates and alcohols Each class consists of an E11/Z11 unsaturated pair with an E/Z ratio of 95/5 The corresponding saturated compounds in each class are also present at 2–3% of the E11-components E11-14:Ac is the major component of the gland, 30–40 ng/insect with E11-14:Ald and E11-14:OH at 1–3 ng/insect
Analysis of female effluvia collected on Porapak Q® and pumping chamber washes show the presence of four compounds, E11-14:Ald, Z11-14:Ald, 14:Ald and E11-14:Ac (95:5:2:02) Rate of emission of E11-14:Ald from 2–3 day old virgin females maximized at 20–40 ng/insect/night Preliminary field data indicate that attractancy of lures containing all four components present in a similar source ratio to a calling female is not significantly different from lures containing E11/Z11 unsaturated aldehydes alone
79 citations
TL;DR: In this article, diffusivity data derived from sorption rate measurements are presented for CO2 in 4A and 5A zeolite crystals. But, the data are interpreted according to the usual isothermal model, and the apparent diffusion falls with decreasing crystal size.
72 citations
TL;DR: S1 cleavage in the Hawick Rocks of the Galloway area is non-axial planar, cutting obliquely across the F1 folds in a predominantly clockwise sense.
70 citations
TL;DR: In this article, three experiments were conducted examining the superior retention of related word pairs when the second word in the pair required some active construction on the part of the subject (filling in a missing letter).
62 citations
TL;DR: This study provides an alternative method to using external annual rings for age determination by identifying the internal growth lines formed by late spring of each year prior to spawning and are probably in response to decreased winter growth.
Abstract: Shells of known-age Mya arenaria have revealed an internal annual growth pattern in this bivalve. The number of external growth rings on the shell exterior does not correspond to the age of the clams. This study provides an alternative method to using external annual rings for age determination. The internal growth lines are visible in thin sections when the shells are cut from the umbo to the ventral margin. The lines are formed by late spring of each year prior to spawning and are probably in response to decreased winter growth. When the 7 year olds were examined it was difficult to distinguish the most recent growth line and the inner shell layer. This could result in ages being underestimated. This annual pattern of internal growth lines could be useful to biologists and paleoecologists engaged in population studies.
59 citations
TL;DR: The CR elicited by an exposure to a lithium-conditioned flavor CS+ was measured in a paradigm which closely approximated traditional conditioned suppression of licking in rats.
53 citations
TL;DR: A new 1:3 mixture of TPSC1 and tetrazole afforded excellent yield and extremely fast rate of reaction with the lowest rate of sulfonation, and mechanisms for the coupling reactions with these condensing reagents to account for the difference in their rates and yields are discussed.
Abstract: The efficiencies and problems of sulfonation of several condensing reagents for deoxyoligoribonucleotide synthesis have been studied. While 2,4,6-triisopropylbenzenesulfonyl chloride (TPSC1) gave very low yield and slow rate of coupling, the new 1:3 mixture of TPSC1 and tetrazole afforded excellent yield and extremely fast rate of reaction with the lowest rate of sulfonation. The difference and advantages of this mixture over triisopropylbenzenesulfonyl tetrazole (TPSTe) and mesitylenesulfonyl tetrazole (MSTe) are discussed. Mechanisms for the coupling reactions with these condensing reagents to account for the difference in their rates and yields of coupling are discussed.
48 citations
TL;DR: In this article, the laser-Stark spectrum of methanol has been studied up to Stark fields of about 55 kV/cm with the 890.761-GHz HCN laser, in both parallel and perpendicular polarizations.
TL;DR: A new economic dispatching method, based on two transportation techniques, is presented that uses a stepwise approximation of the generator and transmission line incremental costs to find the optimum based on the nonlinear model.
Abstract: A new economic dispatching method, based on two transportation techniques, is presented. The minimum cost flow method is used to find an initial optimum based on a linear model. The resultant consistent set of power flows is used as the starting point for the Minty algorithm. The Minty algorithm uses a stepwise approximation of the generator and transmission line incremental costs to find the optimum based on the nonlinear model.
TL;DR: Evidence is given supporting the hypothesis of convergence in threat displays among territorial species competing for resources that are at unusually low levels if the available resources do not allow the evolution of character displacement to avoid competition, convergence inthreat displays may evolve.
Abstract: Threespine sticklebacks (Gasterosteus aculeatus) breed in the shallows of lakes and streams during the spring when the males usually develop a greenish dorsum and a bright red color on the anterior undersides. The red is subject to sexual selection, and functions as a territorial threat display in the breeding colonies (Pelkwijk and Tinbergen, 1937; McPhail, 1969; Semler, 1971; herein). As we would expect, populations are frequently monomorphic for red males. McPhail (1969) discovered populations of sticklebacks on the Olympic Peninsula, Washington, where breeding males are entirely jet black (Fig. 1). He noted that their distribution coincides with that of Novumbra hubbsi, a small fish about the size of a stickleback which is endemic to a few drainages. We (Hagen and Moodie, 1979) have shown that there is a remarkably detailed correlation between the distributions of the two. Novumbra is now known to occur in four independent drainages, and in each, breeding male sticklebacks are black. Within the Chehalis River, western Washington, populations of sticklebacks are monomorphic red where Novumbra is absent and monomorphic black where it is present. In between there are steep clines in morph frequency with blacks increasing to 100% where they coexist with Novumbra. The red and black morphs are apparently controlled by two autosomal alleles without dominance, but their expression is affected by polygenic modifiers (Hagen and Moodie, 1979). McPhail (1969) showed with laboratory experiments that Novumbra: 1) is more successful at preying on the fry of red males than on blacks, and 2) shows a significantly greater orientation to red males that are tending their nests than to blacks. Thus, McPhail argued that as red males are more conspicuous while tending their nests, their offspring will suffer greater predation, so blacks will evolve where they coexist with Novumbra. The purpose of this paper is to give evidence supporting an alternative hypothesis. Cody (1974, and earlier) developed the hypothesis of convergence in threat displays among territorial species competing for resources that are at unusually low levels. If the available resources (or genetic variance in the species) do not allow the evolution of character displacement to avoid competition, convergence in threat displays may evolve. If the increase in fitness that results from excluding other territorial species using the resources exceeds the fitness of genotypes that do not (because they do not share a threat display), convergence for threat displays will evolve. Consequently, several species will use the resources as would a single species and the fitness of each is increased. Cody gives many examples of territorial species that converge in threat displays (visual or vocal) only where they are sympatric. Even more compelling are his examples of several territorial species that vary geographically in threat displays, and the coexisting species vary in parallel. We now know that, like sticklebacks, male Novumbra hold breeding territories where they are highly aggressive, and during reproduction they are predominantly black (Fig. 1). They breed in the same habitats with sticklebacks at about the
TL;DR: In this paper, the first higher-mode cutoff parameter of an elliptical optical fiber waveguide was computed from the exact characteristic equations, and the results were attributed to limitations of the approximation used in that work.
Abstract: The first higher-mode cutoff parameter of an elliptical optical fibre waveguide is computed from the exact characteristic equations. Discrepancies with previously published results are attributed to limitations of the approximation used in that work.
TL;DR: The indigenous heterotrophic bacteria in the water of two contrasting rivers have been examined over a period of 1 year and were found to be predominantly fluorescent Pseudomonas spp.
TL;DR: A preliminary study of the error probability for 5-state control of a myoelectric control system based on the utilisation of a single muscle site for the 3- state control of an myoeLECTric prosthesis.
Abstract: A myoelectric control system is one in which the operation of a device is controlled by the electric potential produced by voluntary contraction of a muscle. The utilisation of a single muscle site for the 3-state control of a myoelectric prosthesis has proven beneficial for certain amputees. It has been proposed that a single muscle site could be used for 5-state control, perhaps for an elbow and hand. This paper presents a preliminary study of the error probability for 5-state control.
TL;DR: In this paper, different electrically neutral lipophilic di- and triamides were prepared and their ion selectivity in membranes studied, and the ionophore N, N-diheptyl-N, N′-dimethyl-succinamide preferred Ca2+ over Mg2+ by a factor of 20 but rejected Na+ and K+ in respect to Mg 2+ by an order of 100 and 10, respectively.
Abstract: Different electrically neutral lipophilic di- and triamides were prepared and their ion selectivity in membranes studied. In membranes the ionophore N, N′-diheptyl-N, N′-dimethyl-succinamide prefers Ca2+ over Mg2+ by a factor of 20 but rejects Na+ and K+ in respect to Mg2+ by a factor of 100 and 10, respectively. This selectivity suffices to perform useful intracellular Mg2+ activity studies.
TL;DR: A comprehensive review of work in the field of non-linear oscillations can be found in this paper, where a brief discussion of second-order systems is followed by a presentation of exact criteria, approximate analytical methods and computational techniques for limit cycles in single variable systems.
Abstract: This survey paper presents a comprehensive review of work in the field of non-linear oscillations. A brief discussion of second-order systems is followed by a presentation of exact criteria, approximate analytical methods and computational techniques for limit cycles in single variable systems. Multivariate systems are then covered from an analogous viewpoint which allows the reader to clearly identify both how single variable methods have been extended and the possibilities for further research. Particular emphasis is placed on describing function methods since it is believed that, where exact solutions are not possible, the approach may not only give approximate solutions but provides good insight for further computational or simulation studies. The coverage is essentially restricted to continuous lumped parameter systems and includes both free and forced oscillations. Several applications of the theories in various fields of engineering and science are discussed and indicate the broad interest in non-l...
TL;DR: In this article, the stereochemistry of the photoaddition between α, β-unsaturated ketones and olefins is discussed and it is shown that the product is determined by the relative stability of the excited state.
TL;DR: Saccular sensitivity appears related to the normal environment occupied by the salamander, with that of an aquatic animal being more sensitive at low frequencies than that of a terrestrial animal.
TL;DR: In this paper, the relative intensity measurements of Linton and Nicholls1 on the AlO blue-green system have been placed on an absolute scale using the radiative lifetimes of Johnson et al.2 and Dagdigian et al., and absolute values of Einstein A coefficients, band strenghts and band oscillator strengths are presented for 75 bands of the system.
Abstract: The relative intensity measurements of Linton and Nicholls1 on the AlO blue-green system have been placed on an absolute scale using the radiative lifetimes of Johnson et al.2 and Dagdigian et al.3 for levels of the B2Σ state of AlO. Absolute values of Einstein A coefficients, band strenghts and band oscillator strengths are presented for 75 bands of the system.
TL;DR: In this paper, a review of literature indicates that there does not appear to be any generally accepted criteria for using the terms armored bed or paved bed for describing the surface layer of gravel-bed river.
Abstract: The terms armored and paved have both been used to describe the surface layer of gravel-bed river. A review of literature indicates that there does not appear to be any generally accepted criteria for using the terms armored bed or paved bed.
TL;DR: It was concluded that sound in this species is a threat display which provides an expression for agonism alternative to the performance of actions which could injure the female or drive her away, and lessens the risk of injury to male or female during territory or brood defense.
Abstract: Pairs of Cichlasoma centrarchus were observed daily in the laboratory. Both males and females made sounds during a breeding cycle but all sounds were aggressive in context; no sounds were heard to accompany courtship. Males made more sounds before spawning than afterwards and these were associated with territorial defense and with establishment of dominance over the female. Females produced more sounds after spawning than before, most in the context of brood defense but some toward the male during pre-spawning nest preparation. Prior to spawning, the number of sounds made by the males toward their mates increased but the aggressive actions accompanying them became less intense. No such inverse correlation of agonistic intensity with number of sounds made was found for the females. From this study and earlier ones by the author it was concluded that sound in this species is a threat display which 1) provides an expression for agonism alternative to the performance of actions which could injure the female or drive her away, and 2) lessens the risk of injury to male or female during territory or brood defense.
TL;DR: Investigation revealed that band patterns of different parts of the taeniid strobila were basically identical; hence, individual worms were useful for analysis regardless of their state of development when collected, and small quantities of tapeworm material used in analysis allows specific differentiation of single proglottids of Taenia spontaneously expelled from live hosts.
TL;DR: A series of electrically neutral lipophilic di-, tri-, and tetra-amides containing tertiary-amine N-atoms were prepared in order to investigate their selectivity for alkali and alkaline earth metal cations in solvent polymeric membranes as mentioned in this paper.
Abstract: A series of electrically neutral lipophilic di-, tri-, and tetra-amides containing tertiary-amine N-atoms were prepared in order to investigate their selectivity for alkali and alkaline earth metal cations in solvent polymeric membranes Considerable selectivity changes were observed for membranes incorporating certain of these ligands as compared with ligand-free membranes A 1:1 cation/ligand complex was isolated from N, N′, N″-triheptyl-N, N′, N″-trimethyl-nitrilotriacetamid and Mg (SCN)2 whereas with Ca (SCN)2 the corresponding 2:3 cation/ligand complex was formed N, N′, N″, N‴, N‴-tetramethyl-ethylenediaminetetraacetamide yields a 1:1 cation/ligand complex with Mg (SCN)2
TL;DR: In this article, the random vibration of a beam impacting a spring-like stop is discussed and the mean square response and the frequency of impacts are obtained by an equivalent linearization, and reasonable agreement is obtained between these results and the results for an equivalent non-linear single-degree-of-freedom system.
01 Jan 1980
TL;DR: In this paper, a double-zeta basis set was used for fluorine-bond function optimization for BF, CF, NF, and OF bonds, and it was shown that bond functions can effectively replace d orbitals when added to the basis set.
01 Jan 1980
TL;DR: In this paper, a regional palaeogeography for the Soudleyan of the Welsh Basin is proposed and four lithofacies (regular layered, irregular layered, mottled and homogeneous) are differentiated on the basis of their geometry, lithology, sedimentary and biogenic structures and associated faunas, and described in detail.
Abstract: Soudleyan rocks in the Berwyn Hills, North Wales, consist essentially of marine mudstones and thin siltstones and fine sandstones, but also include interbedded pyroclastic formations which are at least partly subaerial in origin. In the marine sediments the association of current and wave ripples, small steep sided channels, rare desiccation cracks plus a Planolites , Skolithos, Teichichnus and Cruziana -dominated ichnofauna associated with shallow marine benthic brachiopod-dominated shelly assemblages suggests a shallow subtidal origin with water depths of less than 25 m. Four lithofacies (regular layered, irregular layered, mottled and homogeneous) are differentiated on the basis of their geometry, lithology, sedimentary and biogenic structures and associated faunas, and are described in detail. Comparable subtidal facies extend northwestwards across North Wales into the Arenig-Bala and Snowdon-Tremadoc districts and southeastwards into South Salop, with slightly deeper water argillaceous facies in the intervening Shelve and Breidden Hills areas. Southwest of the Berwyn Hills offshore mudstones are present in the Corris-Cader Idris and Builth-Abbey Cwmhir areas and clastic turbidites in the Cardigan area. A regional palaeogeography for the Soudleyan of the Welsh Basin is proposed.