Showing papers by "Carleton University published in 1985"
TL;DR: In this article, the choice between licensing and direct investment as a vehicle for international technology transfer is hypothesized to be related to characteristics of the individual technology, parent corporation, and the host country involved in the transfer.
Abstract: The choice between licensing and direct investment as a vehicle for international technology transfer is hypothesized to be related to characteristics of the individual technology, parent corporation, and the host country involved in the transfer. A set of hypotheses regarding these relationships are developed and tested in a logit statistical model for a sample of 1,226 technology transfers. We find that hypotheses regarding the effects of technology and parents characteristics are strongly supported by this analysis; hypotheses regarding the effect of host country characteristics on transfer patterns receive mixed support.
407 citations
TL;DR: Efficient algorithms for the optimal attack problem, the problem of computing the strength, and the problems of finding a minimum cost “reinforcement” to achieve a desired strength are given.
Abstract: In a nonnegative edge-weighted network, the weight of an edge represents the effort required by an attacker to destroy the edge, and the attacker derives a benefit for each new component created by destroying edges. The attacker may want to minimize over subsets of edges the difference between (or the ratio of) the effort incurred and the benefit received. This idea leads to the definition of the “strength” of the network, a measure of the resistance of the network to such attacks. Efficient algorithms for the optimal attack problem, the problem of computing the strength, and the problem of finding a minimum cost “reinforcement” to achieve a desired strength are given. These problems are also solved for a different model, in which the attacker wants to separate vertices from a fixed central vertex.
264 citations
TL;DR: Bilateral kainic acid infusions into the nucleus Accumbens resulted in a drastic destruction of cell bodies yet did not damage catecholamine innervation in areas anterior to the accumbens, suggesting the possibility that these results are due to destruction of systems necessary for stimulant and opiate reward.
Abstract: In previous experiments we have demonstrated that bilateral infusions of 6-hydroxydopamine (6-OHDA) into the nucleus accumbens result in a drastic reduction in the rate of cocaine self-administration. If this effect is due to the destruction of a presynaptic dopaminergic element in this nucleus, then selective removal of the postsynaptic neuron should also disrupt cocaine self-administration. This hypothesis was tested using the neurotoxin kainic acid. Bilateral kainic acid infusions into the nucleus accumbens resulted in a drastic destruction of cell bodies yet did not damage catecholamine innervation in areas anterior to the accumbens. The effects of these kainic acid infusions were evaluated in rats that had previously acquired cocaine self-administration behavior. These lesions were found to severely disrupt cocaine intake and the degree of damage produced in the accumbens was found to correlate (r = 0.88) with postlesion cocaine intake. These lesions were additionally found to disrupt apomorphine and heroin self-administration. The possibility that these results are due to destruction of systems necessary for stimulant and opiate reward is discussed.
243 citations
TL;DR: In this paper, a minimum area for considering population survival includes several woods and interconnecting fencerows, and such landscape mosaics should be the elementary units in much conservation planning and management.
196 citations
TL;DR: The group decision support system “NEGO” assists DMs in finding a compromise in GDM and has been used for solving a GDM problem at the corporate level and is currently utilized in management courses.
146 citations
TL;DR: This work is extended to give a combinatorial algorithm for the problem of minimizing a submodular function, for which the amount of work is bounded by a polynomial in the size of the underlying set and the largest function value (not its length).
Abstract: Earlier work of Bixby, Cunningham, and Topkis is extended to give a combinatorial algorithm for the problem of minimizing a submodular function, for which the amount of work is bounded by a polynomial in the size of the underlying set and the largest function value (not its length).
123 citations
TL;DR: The results clearly demonstrate that freeze tolerant frogs have no anticipatory synthesis of cryoprotectant as a preparation for winter but rather can translate the initiation of extracellular ice formation into a signal which rapidly activates cryoprotsectant production by liver.
Abstract: The triggering of cryoprotectant synthesis was examined in the freeze tolerant wood frog,Rana sylvatica. A slow decrease in ambient temperature (1°C every 2 days) from 3° to −2.1 °C was used to search for a specific trigger temperature. None was found. Instead it was found that, despite subzero temperature, animals which remained in a supercooled unfrozen state had low blood glucose (1.66±0.44 μmol/ml) while those which had frozen had high blood glucose (181±16 μmol/ml). These results indicate that it is the initiation of ice nucleation, rather than a specific subzero temperature, which triggers cryoprotectant glucose synthesis. This was confirmed by monitoring the freezing curves for individual frogs with sampling of blood and tissues at various times relative to the initiation of nucleation (detected as an instantaneous temperature jump from −3 to −1°C). Animals sampled before nucleation had low blood and liver glucose contents and a low percentage of liver phosphorylase in thea form. Within 4 min of the initiation of freezing, however, blood glucose had jumped to 16 μmol/ml and liver glucose to 39.5 μmol/g wet weight. Glucose in both compartments continued to increase as the time of freezing increased correlated with an increase in liver phosphorylasea content from 47% before nucleation to 100% after 50 min of freezing. The results clearly demonstrate that freeze tolerant frogs have no anticipatory synthesis of cryoprotectant as a preparation for winter but rather can translate the initiation of extracellular ice formation into a signal which rapidly activates cryoprotectant production by liver.
109 citations
TL;DR: It is suggested that ideal habitat for black rat snakes is a small scale mosaic of field and forest and that their disappearance from other parts of their range in Canada may be related to the disappearance of such mosaics due to land clearing for agriculture.
Abstract: ABSTRACr.-From late May to mid-September 1982 we investigated habitat selection by black rat snakes (Elaphe o. obsoleta) at the Queen's University Biological Station in eastern Ontario. We implanted radio transmitters in 4 male and 3 female snakes and used their daily positions as habitat sampling points. We also sampled the available habitat using randomly selected points. We located the snakes 472 times (>90% success) which produced 107 habitat sample points. All snake sample points were separated into active or inactive based on the length of time the snake remained in that position (less than or greater than 7 days, respectively). During the bird breeding season black rat snakes showed a preference for field habitat although in both the field and deciduous forest the snake points were significantly clustered along the habitat interface. Following the bird breeding season, field and deciduous forest habitats were used in proportion to their availability and the preference for the ecotone was no longer found in field samples. We found only limited evidence of non-random habitat use within habitats with regard to both plant species composition and vegetation structure. Inactive sites were diverse but all were located on the forest-field interface, had open exposure to direct sun and provided shelter for the snakes. We suggest from these results that ideal habitat for black rat snakes is a small scale mosaic of field and forest and that their disappearance from other parts of their range in Canada may be related to the disappearance of such mosaics due to land clearing for agriculture.
109 citations
TL;DR: Qualitative analysis by gas chromatography-mass spectrometry of the auxins present in the root, cotyledons and epicotyl of 3-dold etiolated pea seedlings has shown that all three organs contain phenylacetic acid, IAA and IPA.
Abstract: Qualitative analysis by gas chromatography-mass spectrometry (GC-MS) of the auxins present in the root, cotyledons and epicotyl of 3-dold etiolated pea (Pisum sativum L., cv. Alaska) seedlings has shown that all three organs contain phenylacetic acid (PAA), 3-indoleacetic acid (IAA) and 4-chloro-3-indoleacetic acid (4Cl-IAA). In addition, 3-indolepropionic acid (IPA) was present in the root and 3-indolebutyric acid (IBA) was detected in both root and epicotyl. Phenylacetic acid, IAA and IPA were measured quantitatively in the three organs by GC-MS-single ion monitoring, using deuterated internal standards. Levels of IAA were found to range from 13 to 115 pmol g-1 FW, while amounts of PAA were considerably higher (347–451 pmol g-1 FW) and the level of IPA was quite low (5 pmol g-1 FW). On a molar basis the PAA:IAA ratio in the whole seedling was approx. 15:1.
101 citations
TL;DR: The main findings are that populations in completely isolated patches have lower survival probabilities than those in patches that are connected to other patches, and that the survival probabilities of populations in connected patches increases with the size of the largest geometric figure of which the patch is a part.
97 citations
TL;DR: It is proved that the 2-amalgam of perfect graphs is perfect, a new graph composition that generalizes many of the operations known to preserve perfection, such as the clique identification, substitution, join and amalgam operations.
TL;DR: The wall patterns produced in culture closely resemble those described for intact tissues (annular, spiral, reticulate, scalariform, pitted) using fluorescence microscopy and immuno-cytochemical techniques.
Abstract: Xylogenesis has been studied in primary suspension cultures ofZinnia elegans L.: The wall patterns produced in culture closely resemble those described for intact tissues (annular, spiral, reticulate, scalariform, pitted). Using fluorescence microscopy and immuno-cytochemical techniques we have followed both the changes in wall deposition and microtubule organization during xylogenesis. Calcofluor white has been used to detect secondary wall deposition before it can be observed using either phase contrast or polarization optics. The development of tracheary elements can be divided into three stages: 1. microtubules grouped into bands without secondary wall deposition evident; 2. groups of microtubules subtending wall material only visible using Calcofluor white; 3. a complex microtubule pattern reflected by well developed wall thickenings detected using Calcofluor, phase contrast and polarization optics.
TL;DR: Macrotus californicus, an insectivorous bat, captures prey on the ground, and shows great sensory flexibility in hunting for prey: it uses high frequency, low intensity, frequency modulated echolocation to locate prey in total darkness.
Abstract: Macrotus californicus, an insectivorous bat, captures prey on the ground, and shows great sensory flexibility in hunting for prey: it uses high frequency, low intensity, frequency modulated echolocation to locate prey in total darkness, however data from this study suggest that it uses vision preferentially, and switches off its echolocation when adequate illumination is available. When souncs of prey are available it exploits these also. It uses echolocation only 50% of the time at 4.2x10-2 mL, comparable to ground luminance on a brightly moonlit night, and employs vision even at 10-3 mL.
TL;DR: It is proposed that, in untreated Zinnia cultures, microtubules are reoriented by a gradual shift from longitudinal to transverse and this reorientation normally occurs before differentiation becomes visible.
Abstract: InZinnia elegans tissue cultures, cortical microtubules reorient from longitudinal to transverse arrays as the culture age increases and before differentiation of tracheary elements is visible. The orientation of microtubules, in the period just before visible differentiation, determines the direction of the secondary wall bands in forming tracheary elements. Taxol, applied early in culture, stabilizes the microtubules of most cells in the longitudinal direction. Tracheary elements differentiating in these taxol treated cultures show secondary wall bands parallel to the long axis of the cell while those differentiating in control cultures always have wall bands transverse to the long axis of the cell. It is proposed that, in untreatedZinnia cultures, microtubules are reoriented by a gradual shift from longitudinal to transverse and this reorientation normally occurs before differentiation becomes visible. Once initiated, tracheary element differentiation involves lateral association of microtubules to form the discrete bands typical of secondary wall patterns.
TL;DR: A survey of office workers is carried out to examine their use both of paper calendars and of electronic calendars that are commercially available as part of integrated office systems, assessing the degree to which electronic calendars meet the needs of users.
Abstract: Manufacturers of integrated electronic office systems have included electronic versions of the calendar in almost every system they offer. This paper describes a survey of office workers, carried out to examine their use both of paper calendars and of electronic calendars that are commercially available as part of integrated office systems. It assesses the degree to which electronic calendars meet the needs of users. Our survey shows that the simple paper calendar is a tool whose power and flexibility is matched by few, if any, of the current commercially available electronic calendars. Recommendations for features that should be included in electronic calendars and automatic schedulers are included.
TL;DR: A method is presented by which a microcomputer is used to reconstruct the structure of a three-dimensional object from images obtained with a pair of non-metric cameras when the images contain the vertices of a cube as test pattern and the camera-object configuration satisfies straightforward geometrical conditions.
Abstract: A method is presented by which a microcomputer is used to reconstruct the structure of a three-dimensional object from images obtained with a pair of non-metric cameras when the images contain the vertices of a cube as test patternand the camera-object configuration satisfies straightforward geometrical conditions. With a still camera and stroboscopic or repeating flash illumination, or with a cine camera, this method provides a simple and economic means of recording the flight path and wing movements of a flying animal accurately and reliably. Numerical methods for the further analysis of three-dimensional position data to determine velocity, acceleration, energy and curvature, and to interpolate and to correct for distortion due to inaccurate data records are described. The method is illustrated by analysis of a slow, powered turn of the bat Plecotus auritus (L.). Accurate reconstruction of the flight path permits mechanical forces and accelerations acting on the bat during the turn to be estimated: turning speed and radius in a narrow space are restricted by the bat9s ability to generate sufficient lift to support the weight in nonlinear level flight.
TL;DR: Subjects appeared not to treat the two sources of information as independent; rather, the probability of a correct response in the combined vision-touch condition could be best described as the arithmetic mean of the vision and touch conditions.
Abstract: In two completely randomized experiments, subjects were required to judge either which was the rougher of two abrasive papers or whether two abrasive papers were the same or different. Judgments were made visually, tactually, or with both vision and touch available. The subjects used either the right hand or the left hand in the touch conditions. Differences between the hands in terms of either proportion correct or mean latency were negligible in both experiments. Accuracy was statistically equivalent across conditions, although the latency of visual judgments was shorter. In the same-different experiment, comparable accuracy for vision and touch appeared to result from different strategies. Subjects in the touch condition were much less likely to be correct without guessing on “different” trials. In a third, within-subject experiment, a comparison was made of four probability models of dual-mode efficiency. Subjects appeared not to treat the two sources of information as independent; rather, the probability of a correct response in the combined vision-touch condition could be best described as the arithmetic mean of the vision and touch conditions. Latencies for the combined condition also appeared to reflect a similar compromise. Implications for further research are discussed.
TL;DR: In this paper, the authors discuss techniques for decompositions of objects into the minimum number of some component type in many applications, the objects encountered are rectilinear polygons in image processing.
Abstract: Publisher Summary This chapter discusses techniques for decompositions of objects into the minimum number of some component type In many applications, the objects encountered are rectilinear polygons In image processing, the boundaries of objects are often stored on a grid that usually implies that digitized images are rectilinear polygons Very large-scale integration (VLSI) designs are also often stored on a grid and typically contain many rectilinear polygons The chapter discusses the decompositions of rectilinear polygons when Steiner points are allowed and when Steiner points are disallowed It also discusses the decomposition of arbitrary simple polygons when Steiner points are allowed and when Steiner points are disallowed The result in this study concerns the partitioning of a polygonal region into a minimum number of trapezoids with two horizontal sides Triangles with a horizontal side are considered to be trapezoids with two horizontal sides, one of which is degenerate This problem is closely related to VLSI artwork data processing systems of electron-beam lithography for VLSI microfabrication The chapter also discusses the decomposition of object which contains holes
Journal Article•
TL;DR: Maternal caffeine intake of more than 300 mg daily during pregnancy was associated with lowered birth weight and smaller head circumference of the infant after accounting for maternal nicotine use, and no relationship was apparent between maternal caffeine use and the incidence of caesarian sections, breech births, miscarriages or premature births.
Abstract: Prospective information gathered through the course of pregnancy, perinatal measurements, and retrospective data collected postnatally were used to investigate the changing patterns and effects of caffeine use of 286 women participating in the Ottawa Prenatal Prospective Study. Data were collected on maternal use of tea, coffee, caffeinated soft-drinks, chocolate bars and drinks and caffeinated medication. The volume and analysed caffeine concentration of 53 samples of coffee and tea, prepared by subjects as they usually consumed it, were used to examine the predictive potential of the women's subjective description of the beverages. Self-reports of volume and beverage strength were found to be valid predictors; the method of coffee preparation held little predictive power. An algorithm for estimating caffeine intake retrospectively over time was developed. During pregnancy most women continued to consume caffeine but usually at lower intake levels. After pregnancy, caffeine consumption tended to persist at reduced levels for several months and then returned to prepregnancy patterns. Maternal caffeine intake of more than 300 mg daily during pregnancy was associated with lowered birth weight and smaller head circumference of the infant after accounting for maternal nicotine use. No relationship was apparent between maternal caffeine use and the incidence of caesarian sections, breech births, miscarriages or premature births.
TL;DR: In this paper, the authors found that the proportion of 14C exuded from a given length of mature root into its soil sheath, or into the adjacent unattached soil in the case of bare roots, was the same (5%) in both root types when compared with the ethanol-soluble 14C in the tissues of this length.
Abstract: The roots of a mature, field-grown maize plant are dimorphic: the primary root and those from the oldest nodes are bare with a heavily lignified cortex arid sloughed epidermis; those from younger nodes, except for a bare elongation zone, have an intact epidermis surrounded by a persistent soil sheath. Sheathed roots consistently have more layers of cortical cells, but the ratio of volumes of cortex to stele (ca 4) and the cross-sectional area of phloem (ca3× 10−2 mm2) are similar in each type. Assimilated carbon (from 14C applied to a small area of one leaf) was translocated to all roots and actively metabolized in cortex and stele of both types. After 1 to 2 days the proportion of 14C exuded from a given length of mature root into its soil sheath, or into the adjacent unattached soil in the case of bare roots, was the same (5%) in both root types when compared with the ethanol-soluble 14C in the tissues of this length. Up to 75% of the ethanol-soluble label in the roots was in a cationic fraction (amino acids and unidentified compounds), ca 1% was in an anionic fraction and the remainder was in a neutral fraction (sugars). Approximately equal amounts of soluble 14C were found in the stele, cortex and laterals.
TL;DR: In this article, the authors consider the welfare effects of a transfer payment in a two-commodity world with two agents (countries), by taking the presence of exogenous and endogenous distortions into account.
Abstract: This paper reconsiders the welfare effects of a transfer payment in a two-commodity world with two agents (countries), by taking the presence of exogenous and endogenous distortions into account. When there is an exogenous tax-cumsubsidy on production, consumption, or trade, the analysis demonstrates that a transfer may paradoxically enrich the donor and immiserize the recipient under certain specific conditions. These welfare paradoxes are also shown to be possible if the transfer endogenously induces "directly unproductive profit-seeking" activity of lobbyists. Concluding remarks emphasize the paper's relevance for policymakers.
TL;DR: In this article, the optimal submodular flow problem can be solved in polynomial time using only combinatorial steps like building auxiliary digraphs, finding augmenting paths, and modulo an efficient oracle.
Abstract: Previously the only polynomial-time solution algorithm to solve the optimal submodular flow problem introduced by Edmonds and Giles was based on the ellipsoid method. Here, modulo an efficient oracle for minimizing certain submodular functions, a polynomial time procedure is presented which uses only combinatorial steps like building auxiliary digraphs, finding augmenting paths. The minimizing oracle is currently available only via the ellipsoid method, in general; however in important special cases, such as network flows, matroid intersections, orientations, and directed cut coverings, the necessary oracle can be provided combinatorially.
TL;DR: In this article, the serrated grain boundary formation potential of a large number of conventionally forged, powder processed, and investment cast Ni-based superalloys is reviewed and the prerequisite conditions for its occurrence are highlighted.
Abstract: The serrated grain boundary formation potential of a large number of conventionally forged, powder processed, and investment cast Ni-based superalloys is reviewed. A mechanism of serrated grain boundary formation by which grain boundaryγ′ particles move and displace the local grain boundary segment is discussed and the prerequisite conditions for its occurrence are highlighted. The practical implications of the serrated grain boundary formation are also discussed. It is suggested that modifying the existing heat-treatment cycles in some investment cast and powder processed Ni-based superalloys would improve their properties. The possibility of minimizing weld cracking in superalloys by creating serrated grain boundaries in the base metal and the heat affected zone is also discussed.
TL;DR: In this paper, the stiffness matrix for the DKT plate-bending element is formulated explicitly in a global co-ordinate system, which avoids transformations of stiffness, and elasticity properties for anisotropic materials, from local to global coordinates.
Abstract: The stiffness matrix for the DKT plate-bending element is formulated explicitly in a global co-ordinate system. This approach avoids transformations of stiffness, and elasticity properties for anisotropic materials, from local to global co-ordinates, which were required in previous formulations. A FORTRAN listing of the algorithm is appended for potential users.
TL;DR: In this article, a study was conducted to replicate some of the findings of Andrews and McKennell (1980), who examined affective, cognitive, and other components of global subjective well-being measures among respondents from the United States and Britain.
Abstract: A study was conducted to replicate some of the findings of Andrews and McKennell (1980), who examined affective, cognitive, and other components of global subjective well-being measures among respondents from the United States and Britain. Using data collected from 1068 Canadians, linear structural relations (LISREL) estimates of affective, cognitive, and error components of three global well-being measures provided general support for Andrews and McKennell's findings. Implications of the results, such as impact on the design of future studies and measures of subjective well-being, are discussed.
TL;DR: The minimum cut problem is a well-solved special case of submodular function minimization and it is shown that it is in fact equivalent to minimizing a modular function over a ring family.
Abstract: The minimum cut problem is a well-solved special case of submodular function minimization. We show that it is in fact equivalent to minimizing a modular function over a ring family. One-half of this equivalence follows from classical work of Rhys and Picard. We give a number of applications to testing membership in special kinds of matroid polyhedra.
TL;DR: In this paper, a rigid cylindrical inclusion is modeled as a field of distributed forces which represent the normal and shear tractions that act on the inclusion-elastic medium interface.
TL;DR: In this paper, the authors examined the transfer of 15N from the amino group of asparagine, supplied via the transpiration stream, in fully expanded pea leaves, and showed that photorespiratory nitrogen metabolism is not a closed cyclic process.
Abstract: In pea leaves, much of the metabolism of imported asparagine is by transamination. This activity was previously shown to be localized in the peroxisomes, suggesting a possible connection between asparagine and photorespiratory nitrogen metabolism. This was investigated by examination of the transfer of 15N from the amino group of asparagine, supplied via the transpiration stream, in fully expanded pea leaves. Label was transferred to aspartate, glutamate, alanine, glycine, serine, ammonia, and glutamine (amide group). Under low oxygen (1.8%), or in the presence of α-hydroxy-2-pyridine methanesulfonic acid (an inhibitor of glycolate oxidase, a step in the photorespiratory formation of glyoxylate), there was a substantial (60-80%) decrease in transfer of label to glycine, serine, ammonia, and glutamine. Addition of isonicotinyl hydrazide (an inhibitor of formation of serine from glycine) caused a 70% decrease in transfer of asparagine amino nitrogen to serine, ammonia, and glutamine, while a 4-fold increase in labeling of glycine was observed. The results demonstrate the involvement of asparagine in photorespiration, and show that photorespiratory nitrogen metabolism is not a closed cyclic process.