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Showing papers by "Carleton University published in 1979"


Journal ArticleDOI
03 Aug 1979-Science
TL;DR: Growth of syngeneic P815 mastocytoma in DBA/2J male mice was evaluated and a single session of inescapable shock resulted in earlier tumor appearance, exaggeration of tumor size, and decreased survival time in recipient animals.
Abstract: Growth of syngeneic P815 mastocytoma in DBA/2J male mice was evaluated as a result of various stress regimens. A single session of inescapable shock resulted in earlier tumor appearance, exaggeration of tumor size, and decreased survival time in recipient animals. Escapable shock had no such effects. The effects of the inescapable shock were mitigated if mice received long-term shock treatment.

296 citations


Journal ArticleDOI
TL;DR: It was hypothesized that both DA and NE, as well as ACh, are involved in the escape deficit observed after inescapable shock, and that these transmitters mediate the interference by their influence on response initiation and maintenance, rather than on associative or cognitive processes.
Abstract: Following exposure to inescapable shock, subsequent escape performance is disrupted if the task is one in which animals receive forced exposure to shock for several seconds before escape is possible. The extent of the deficit is directly related to the severity of the initial stress and the duration of escape delay used during test. Treatment with a tyrosine hydroxylase inhibitor, α-methyl-p-tyrosine (α-MpT), a dopamine-β-hydroxylase inhibitor, FLA-63, or dopamine antagonists, haloperidol, and pimozide, mimicked the effects of inescapable shock in the different escape paradigms. The effects of haloperidol were antagonized by treatment with scopolamine. As observed in the case of inescapable shock, prior escape training abated the disruptive effects of the drug treatments. Finally, decreasing or blocking catecholamine activity or increasing cholinergic activity exacerbated the effect of a moderate amount of inescapable shock on subsequent escape performance. These treatments also induced reductions in shock-elicited activity. Conversely, treatment with a catecholamine stimulant, l-dopa, or a cholinergic blocker, scopolamine, anatagonized the reduction in shock-elicited activity and the escape deficits engendered by prior inescapable shock. It was hypothesized that both DA and NE, as well as ACh, are involved in the escape deficit observed after inescapable shock, and that these transmitters mediate the interference by their influence on response initiation and maintenance, rather than on associative or cognitive processes.

277 citations


Journal ArticleDOI
TL;DR: The vocal repertoire of the little brown bat, Myotis lucifugus, is studied in this article, where the authors identify and associate ten vocalizations with specific behavioral contexts and find that despite the gregarious nature of the species, a simple social system exists and the small repertoire is therefore not surprising.
Abstract: 1. As part of an overall study of the social behavior of the little brown bat, Myotis lucifugus, we compiled the vocal repertoire of this gregarious species in its natural habitat. Ten vocalizations were identified and associated with certain behavioral contexts. 2. Echolocation pulses, although primarily used for or entation, are also available as interindividual communication signals and modified forms are used in several situations such as during near-collisions in flight and the first flights of newly volant young. 3. Nonecholocation calls are used in three main contexts. Agonistic vocalizations appear to take the place of physical aggression and may be used to protect an individual's position within a roost. Two vocalizations emitted in maternal-infant situations appear to contain vocal signatures which are important for individual recognition. During mating, a distinct copulation call given by males likely conveys a male's sexual motivation to a female in the absence of precopulatory displays. 4. The size of the vocal repertoire is comparable to those of some solitary mammals. Behavioral observations indicate that despite the gregarious nature of the species, a simple social system exists and the small repertoire is therefore not surprising.

234 citations



Journal ArticleDOI
TL;DR: The results suggest that DA and NE act in a serial fashion to produce the escape deficits in mice, and although both newly synthesized and previously stored amines contribute to the interference, the short latency responses seen during initial test trials could not be ascribed to previously storedAmines.
Abstract: Following exposure to inescapable shock, mice exhibit deficits of escape performance, which are progressively more pronounced as training continues. Comparable effects were produced by DA and NE depletion by α-MpT and reserpine, NE depletion by FLA-63, and DA receptor blockade through haloperidol. Treatment with PCPA or 5-HTP did not influence performance. The disruptive effects of reserpine and α-MpT, as well as haloperidol and FLA-63, were additive. Unexpectedly, mice that received both reserpine and FLA-63 exhibited escape latencies that were significantly lower than those of mice that received either treatment alone. Consistent with the view that increased DA synthesis in the reserpine plus FLA-63 condition prevented the escape interference, L-DOPA antagonized the effects of both α-MpT and FLA-63. The results suggest that DA and NE act in a serial fashion to produce the escape deficits. Moreover, although both newly synthesized and previously stored amines contribute to the interference, the short latency responses seen during initial test trials could not be ascribed to previously stored amines.

202 citations



Journal ArticleDOI
TL;DR: The ears of moths tested in Canada and Côte d'Ivoire are most sensitive to sounds between 20 and 40 kHz, and much less sensitive to sound over 65 kHz, which suggests the use of low intensity, high frequency echolocation calls may constitute a bat counter-maneuver against insects tuned to bat calls.
Abstract: The ears of moths we tested in Canada and Cote d'Ivoire are most sensitive to sounds between 20 and 40 kHz, and much less sensitive to sound over 65 kHz. The insectivorous bats most commonly encountered in these (and other) locations use high intensity, frequency modulated echolocation calls with frequency components in the 20–40 kHz range, making them detectable by the most sensitive tympanate moths up to 40 m away. In Africa bats such as species in the Nycteridae, Megadermatidae, and some in the Hipposideridae, use low intensity calls with high frequency components, and these species are not detectable by moths at over 2 m. The hearing ability of moths may significantly influence the feeding efficiency of bats, and changes in the intensity and frequency components of bat echolocation calls can drastically reduce the range at which bats are detected, and thus the time available to the moths for evasive behaviour (Fig. 4). The use of low intensity, high frequency echolocation calls may constitute a bat counter-maneuver against insects tuned to bat calls.

143 citations


Journal ArticleDOI
TL;DR: In this article, a quark model based on quantum chromodynamics and tested against noncharmed baryons was employed to predict masses and decay rates of ground-state and excited quarks containing one charmed quark.
Abstract: We employ a quark model based on quantum chromodynamics and tested against noncharmed baryons to predict masses and decay rates of ground-state and excited baryons containing one charmed quark. Among other conclusions, the calculations indicate that the orbitally excited ${\ensuremath{\Lambda}}_{c}$ $\frac{1}{{2}^{\ensuremath{-}}}$ analogous to the $\ensuremath{\Lambda}(1405)$ is stable against strong decays.

139 citations


Journal ArticleDOI

131 citations


Journal ArticleDOI
TL;DR: These data confirm previous reports that the central catecholamines are capable of inhibiting a variety of forms of seizure and are replicated in two experiments using adult- and infant-injected rats.

126 citations


Journal ArticleDOI
TL;DR: Among rats trained to bar press to asymptote using a nonretractable bar, pimozide reduced the within and between days bar-press rate such that performance was indistinguishable from that of animals placed on extinction in the absence of the drug treatment.
Abstract: Administration of the dopamine receptor blocker pimozide (1.0 mg/kg) disrupted the initiation, but not the maintenance, of home cage food consumption. Likewise, the number of pellets consumed during magazine training was decreased among pimozide-treated rats during the first, but not the second day of training. The acquisition of a bar-press response for food reinforcement (using a retractable bar) was severely retarded by pimozide. However, such an impairment was not evident if animals initially received 2 training days in the absence of the drug. Further, among rats trained to bar press to asymptote using a nonretractable bar, pimozide reduced the within and between days bar-press rate such that performance was indistinguishable from that of animals placed on extinction in the absence of the drug treatment. When transferred from the pimozide treatment to extinction in the absence of drug, the response rate increased to the level observed during the first session of either extinction or pimozide in the continuous reinforcement condition. The results are discussed in terms of sensory-motor and reinforcement consequences of dopamine receptor blockade.

Journal ArticleDOI
TL;DR: The effects of inescapable shock on subsequent escape performance and shock-elicited activity were examined in six lines of mice selectively bred for differences in general locomotor activity and the lines that displayed the least interference after tyrosine hydroxylase inhibition exhibited the smallest reduction in levels of catecholamines.
Abstract: The effects of inescapable shock on subsequent escape performance and shock-elicited activity were examined in six lines of mice selectively bred for differences in general locomotor activity The line differences in locomotor activity were found to be unrelated to the differences observed on shock-elicited activity However, escape performance following exposure to inescapable shock was predictable from the levels of shock-elicited activity Those lines that displayed the greatest decline in motor activity during shock likewise displayed the most pronounced escape deficits The line differences in escape performance induced by inescapable shock could be mimicked by treatment with a tyrosine hydroxylase inhibitor, alpha-methyl-p-tyrosine As predicted, the lines that displayed the least interference after tyrosine hydroxylase inhibition exhibited the smallest reduction in levels of catecholamines The effects on escape performance following inescapable shock are interpreted in terms of the role of response maintenance deficits produced by catecholamine depletion

Journal ArticleDOI
TL;DR: The use of the heat of adsorption of moisture on zeolite molecular sieves is discussed in this article, where the advantages of zeolites are high heat and high capacity, and easy control of the store following from control of heat output by regulations of flows of moist air.


Journal ArticleDOI
Bill Jones1
01 Dec 1979-Pain
TL;DR: Rollman misleadingly gives the impression that he is questioning the general validity of the application of TSD to answering questions in pain research, but that is not the case and there is no one TSD model as Rollman often seems to imply.
Abstract: Rollman [13,14] has clearly raised important questions about the application of signal detection (TSD) procedures to the study of the perceived painfulness of stimuli. Researchers have often failed to realize that the discriminability of two usually painful stimuli need not be related to their reported painfulness. Thus indices of discrimination accuracy derived form TSD are logically (throughout necessarily empirically) independent of the analgesic properties of any treatment. However, Rollman misleadingly gives the impression that he is questioning the general validity of the application of TSD to answering questions in pain research. This is not the case. Procedures derived from TSD may play an important part in answering questions of interest to pain researchers especially as Rollman has exaggerated the practical difficulties associated with TSD experiments. It must be emphasized that there is no one TSD model as Rollman often seems to imply but a variety of models[5,9]. The usefulness of any model in any situation is a matter for experiment. Rollman has certainly criticized effectively one dubious analogy to TSD procedures which pain researchers have used. That is not the same as questioning the general usefulness of TSD models.

Journal ArticleDOI
TL;DR: This work proves several results concerning the existence of solutions to NOP and settles the cases when the tables accomodate the same ''small'' number of people or when there are only two tables one of them Accomodating a ''small''.

Journal ArticleDOI
TL;DR: Following repeated d-amphetamine injections the circling ordinarily induced by a single injection was abolished, whereas the locomotor effects of amphetamine remained unaltered, consistent with earlier work suggesting that tolerance may occur in those behaviors that involve a noradrenergic component.
Abstract: Systemic treatment with d-amphetamine produced a dose-dependent increase in the circling behavior of normal mice. Treatment with both α-methyl-p-tyrosine (α-MpT) and FLA-63 antagonized the amphetamine-induced circling behavior. Similarly, blockade of B-adrenergic receptors by propranolol and dopamine receptors by haloperidol reversed the circling response elicited by amphetamine. In contrast to α-MpT and haloperidol, however, neither FLA-63 nor propranolol attenuated the locomotor excitation engendered by amphetamine. Following repeated d-amphetamine injections the circling ordinarily induced by a single injection was abolished, whereas the locomotor effects of amphetamine remained unaltered. These findings are consistent with earlier work suggesting that tolerance may occur in those behaviors that involve a noradrenergic component.

Book ChapterDOI
TL;DR: In this paper, strong approximation results and methodology are used to obtain inprobability representations of the empirical process when the parameters of the underlying distribution function are estimated under a null hypothesis and a sequence of alternatives converging to the null hypothesis.
Abstract: Strong approximation results and methodology are used to obtain in-probability representations of the empirical process when the parameters of the underlying distribution function are estimated. These representations are obtained under a null hypothesis and a sequence of alternatives converging to the null hypothesis. The fairly general conditions on the estimators are often satisfied by maximum likelihood estimators. The asymptotic distribution of the estimated empirical process depends, in general, on the true value of the unknown parameters. Some useful methods of overcoming this difficulty are discussed.

Journal ArticleDOI
TL;DR: In this article, contrast time for pairs of vertical-line stimuli, sufficiently different that they can be errorlessly discriminated with respect to visual extent, was examined as a function of arithmetic relations (physical ratio and difference) on members of the pair.

Journal ArticleDOI
TL;DR: In this article, a graphite-furnace atomic absorption spectrometry (HGA-2100) method is described for the direct determination of traces of molybdenum (O.1 −4 ng) in synthetic sea water.

Journal ArticleDOI
TL;DR: In this paper, the pore-water chemistry is reported for four sites in the Ottawa area and the roles of leaching and intense and mild weathering in influencing the geotechnical properties of these Postglacial marine clays are discussed.

Journal ArticleDOI
TL;DR: The dominance hierarchy was determined in six groups of rainbow trout fingerlings and the dominant fish exhibited significantly lower levels of norepinephrine and higher levels of dopamine than the submissive members.

Journal ArticleDOI
TL;DR: During their development the epidermal cells undergo marked shape change from periclinally flattened, polygonal at the root pole, through columnar on the meristem flank to tabular in the root hair zone, and initiation of a root hair is characterized by deposition of polysaccharide on the inside of the periclinal wall where the hair will develop.
Abstract: In the apical meristems of main and young lateral roots of corn the uniseriate epidermis is clearly continuous with the most distal cell tier of the quiescent centre. These cells are characterized by the presence on their outer periclinal walls of material which forms the thin root cap junction layer over the apical pole and which thickens appreciably over the flanks of the meristem to form a distinctive extracellular deposit on the young epidermal cells. This material is polysaccharide in nature as indicated by strong periodic acid Schiff's positivity but its autofluorescence also suggests the presence of phenolic compounds. During their development the epidermal cells undergo marked shape change from periclinally flattened, polygonal at the root pole, through columnar on the meristem flank to tabular in the root hair zone. The mucigel thins markedly as cells become tabular but initiation of a root hair is characterized by deposition of polysaccharide on the inside of the periclinal wall where the hair will develop.

Proceedings ArticleDOI
12 Mar 1979
TL;DR: In this paper, the authors conducted experiments to determine the characteristics of oscillating flows in a centrifugal compression system with vaneless diffusers and found that the critical flow coefficient at which onset of oscillations was observed increased as the diffuser width ratio was decreased and as the diameter ratio was increased.
Abstract: Experiments were conducted to determine the characteristics of oscillating flows in a centrifugal compression system with vaneless diffusers. The system was operated without a diffuser and with eight different diffuser configurations to determine the effects of diffuser diameter and width ratios on the unsteady behavior of the system. Mean and fluctuating velocity and static pressure measurements were carried out in the time and frequency domains. The system without a diffuser was found to be stable at all operating conditions. The installation of any of the eight diffusers resulted in the generation of self-excited oscillations at some operating conditions. It was found that the critical flow coefficient at which onset of oscillations was observed increased as the diffuser width ratio was decreased and as the diameter ratio was increased. Comparison between the characteristics of the oscillations observed in the present study and those observed by other investigators indicate that rotating stall in two geometrically similar diffusers can be an order of magnitude different in the non-dimensional rotational speed and level of unsteady pressure fluctuations. These differences point towards the possibility of existence of more than one set of flow conditions which could lead to the occurrence of the unsteady phenomena.Copyright © 1979 by ASME


Journal ArticleDOI
01 Jan 1979
TL;DR: In this article, the axially symmetric flexural interaction of a uniformly loaded circular plate resting in smooth contact with an isotropic elastic halfspace is examined by using an energy method.
Abstract: The axially symmetric flexural interaction of a uniformly loaded circular plate resting in smooth contact with an isotropic elastic halfspace is examined by using an energy method. In this development the deflected shape of the plate is represented in the form of a power series expansion which satisfies the kinematic constraints of the plate deformation. The flexural behavior of the plate is described by the classical Poisson-Kirchhoff thin plate theory. Using the energy formulation, analytical solutions are obtained for the maximum deflection, the relative deflection, and the maximum flexural moment in the circular plate. The results derived from the energy method are compared with equivalent results derived from numerical techniques. The solution based on the energy method yields accurate results for a wide range of relative rigidities of practical interest.

Journal ArticleDOI
TL;DR: In this paper, strong invariance principles for the latter and also for appropriate functionals of it are established for distribution-free tests of independence based on a multivariate empirical process.

Journal ArticleDOI
01 Jan 1979-Planta
TL;DR: Vascular regeneration is not affected by removal of the epicotyl or the root tip; it is greatly reduced but not prevented by Removal of the cotyledons.
Abstract: Severance of the stele of young main roots of pea (Pisum sativum L.) results in formation of a bridge of vascular tissue in the remaining cortex. Cell divisions occur close to the severed vascular tissues on both the proximal and distal sides of the cut within 24 h. Differentiation of new vascular strands subsequently begins in the same locations and progresses from both sides of the wound into the remaining cortex and also back along the original vascular strands. Most of the vascular tissue which forms the bridge through the cortex differentiates in the acropetal direction. Continuous strands composed of single sieve elements bypass the wound somewhat sooner than the first complete xylem strands; the latter in 60–70% of the cases, are present by 3 d. Cambial activity subsequently adds more xylem and phloem. Vascular regeneration is not affected by removal of the epicotyl or the root tip; it is greatly reduced but not prevented by removal of the cotyledons.

Journal ArticleDOI
TL;DR: A novel approach to modeling the slotted-ALOHA random access channel is presented to identify the channel's stability boundaries analytically as a function of the system's independent input parameters and facilitate the structuring of individual users' buffer-control as the focus of a dynamic control scheme.
Abstract: A novel approach to modeling the slotted-ALOHA random access channel is presented. The objectives of the model are threefold: (1) to identify the channel's stability boundaries analytically as a function of the system's independent input parameters; (2) to investigate the impact of buffer-control on the channel's behavior; and (3) to facilitate the structuring of individual users' buffer-control as the focus of a dynamic control scheme. The significance of maintaining channel stability via buffer-control lies in its conceptual simplicity and implementability. Simulation runs of a finite-population model have clearly revealed the variation in individual users' buffer sizes and their sensitivity to the retransmission procedure.

Journal ArticleDOI
TL;DR: In this paper, task-motivated and hypnotic subjects were given both auditory and visual hallucination suggestions that were either Brief, Long, or provided an imaginary Context, and the Long and Context suggestions were equated for length.