Showing papers by "University of Notre Dame published in 1984"

The Theory of Power and Conflict in Channels of Distribution

Abstract: This review article develops an integrated overview of the present status of the theory of power and conflict in marketing channels. It includes a presentation of the conceptual foundation provided...

Isotypes and specificities of immunoglobulins produced by germ-free mice fed chemically defined ultrafiltered "antigen-free" diet.

Abstract: The regulation of the “spontaneously” occurring (“background”) Ig synthesis of mice has been studied by determining the numbers of IgM-, IgG- and IgA-secreting cells and a part of the IgM antibody-specificity repertoire in spleen, bone marrow (BM) and mesenteric lymph nodes (MLN) of conventional and “antigen-free” mice. These antigen-free mice were germ-free raised and fed an ultrafiltered solution of chemically defined low molecular weight nutrients, and thus devoid of exogenous antigenic stimulation. The secretion of IgM, IgG and IgA by spleen, BM and MLN cells was assessed in the protein A plaque assay, while specific IgM antibody-secreting cells were detected by plaque assays specific for differently haptenated sheep red blood cells. In general, antigen-free and conventional mice were found to have roughly equal numbers of IgM-secreting cells in spleen and BM. The number of IgG-secreting cells in the spleen of antigen-free mice was the same as in the spleen of conventional mice, but in the BM their number was 3–5-fold decreased. About one half of the antigen-free mice did not have MLN, and in the half which did, 5 times less IgM- and more than 100-fold less IgG-secreting cells were found as compared with conventional mice. The number of IgA-secreting cells in antigen-free mice was drastically decreased in all three organs tested. The antibody-specificity repertoire of the “background” IgM-secreting cells in the spleen and BM of the antigen-free and conventional mice was much alike. This indicates that in antigen-free mice the available antibody repertoires are established independently of exogenous and/or mitogenic stimulation.

The boundary layer induced by a convected two-dimensional vortex

Abstract: The response of a wall boundary layer to the motion of a convected vortex is investigated. The principal cases considered are for a rectilinear filament of strength –κ located a distance a above a plane wall and convected to the right in a uniform flow of speed U∞*. The inviscid solution predicts that such a vortex will remain at constant height a above the wall and be convected with constant speed αU∞*. Here α is termed the fractional convection rate of the vortex, and cases in the parameter range 0 [les ] α < 1 are considered. The motion is initiated at time t* = 0 and numerical calculations of the developing boundary-layer flow are carried out for α = 0, 0.2, 0.4, 0.55, 0.7, 0.75 and 0.8. For α < 0.75, a rapid lift-up of the boundary-layer streamlines and strong boundary-layer growth occurs in the region behind the vortex; in addition an unusual separation phenomenon is observed for α [les ] 0.55. For α [ges ] 0.75, the boundary-layer development is more gradual, but ultimately substantial localized boundary-layer growth also occurs. In all cases, it is argued that a strong inviscid–viscous interaction will take place in the form of an eruption of the boundary-layer flow. The generalization of these results to two-dimensional vortices with cores of finite dimension is discussed.

Computerization as a Predominate Technology: Its Influence on the Structure of Newspaper Organizations

Abstract: Newspaper organizations were examined for the influence of computerization, when viewed as the predominate organizational technology, on the locus of decision making and division of labor. The rela...

Object Relations, Role Models, and Cultivation of the Self

Abstract: Psychoanalytic object relations theory and symbolic interactionism both emphasize the mediating role of representations in the socialization process, yet the relationship between the external envir...

Memory strategy instruction is made of this: Metamemory and durable strategy use.

Abstract: Although the use of task‐appropriate strategies facilitate memory, newly acquired strategies often have two negative characteristics: They are neither durable nor generalizable. The present article considers an alternative approach to strategy instructions that leads to skills that are more general and better maintained after instruction has ceased. This approach focuses on the role of knowledge about strategies (metamemory) as a precursor of effective strategy deployment. Three perspectives on the role of metamemory in improving strategy use are considered: (a) occasions when metamemory develops simply as a function of using a strategy (the Laissez‐Faire approach); (b) situations in which Explicit Provision of metamemorial information increases strategy use; and (c) the production of higher‐level strategies that operate on other strategies, thus enhancing metamemorial knowledge about them (Metamemory Acquisition Procedures). Future research directions and educational implications associated with each app...

Dynamics of Constrained Multibody Systems

Abstract: Etude des equations de mouvement de systemes a n corps soumis a des contraintes soit geometriques (boucles fermees), soit cinematiques (mouvement specifique)

Dynamics of constrained multibody systems

Abstract: Etude des equations de mouvement de systemes a n corps soumis a des contraintes soit geometriques (boucles fermees), soit cinematiques (mouvement specifique)

A Model for Orientation Effects in Electron‐Transfer Reactions

Abstract: A method for solving the single‐particle Schrodinger equation with an oblate spheroidal potential of finite depth is presented. The wave functions are then used to calculate the matrix element T_BA which appears in theories of nonadiabatic electron transfer. The results illustrate the effects of mutual orientation and separation of the two centers on TBA. Trends in these results are discussed in terms of geometrical and nodal structure effects. Analytical expressions related to T_BA for states of spherical wells are presented and used to analyze the nodal structure effects for T_BA for the spheroidal wells.

Homotopy theory and simplicial groupoids

Abstract: The homotopy theory of simplical groups is well known [2, Ch. VI] to be equivalent to the pointed homotopy theory of reduced (i.e. only one vertex) simplicial sets (by means of a pair of adjoint functors G and W. The aim of this note is to show that similarly, the homotopy theory of simplical groupoids is equivalent to the (unpointed) homotopy theory of (all) simplical sets. This we do by 1. (i) showing that the category of simplicial groupoids admits a closed model catagory structure in the sense of Quillen [3], and 2. (ii) extending the functors G and W to pair of adjoint functors G: (simplicial sets)↔(simplicial groupoids): W which induce the desired equivalence of homotopy theories. We also show that the category of simplical groupoids admits a simplical structure which produces “function complexes” and “simplical monoids of self homotopy equivalences” of the correct homotopy types.

Friction, Restitution, and Energy Loss in Planar Collisions

Abstract: Both particle and rigid body planar collisions are covered in this paper. For particles, the classical equations for oblique impacts are derived using Newton’s laws along with definitions of the coefficient of restitution and equivalent coefficient of friction. A general expression is obtained for the kinetic energy loss explicity containing the two coefficients. This expression for energy loss as a function of the friction coefficient possesses a maximum. The value of the friction coefficient at the maximum is a limiting value which can be used to determine whether or not sliding exists at separation. The maximum energy loss is independent of the physical mechanism of generation of tangential forces (friction) and serves as an upper bound for two-particle collisions. It is shown that to properly formulate and solve the rigid body problem, a moment must be considered at the common “point” of impact. A moment coefficient of restitution must be defined. This leads to six linear algebraic equations from which the six final velocity components can be calculated. An analytical solution is obtained for the general rigid body problem. In a reduced form, it is used to solve the problem of a single rigid body impacting a rigid barrier. This solution is then applied to a classical textbook problem. As shown for particle impacts, the concepts of limiting friction coefficient and maximum energy loss apply to rigid body impacts.

Critical exponents by the scaling-field method: The isotropic N -vector model in three dimensions

Abstract: A numerical technique, termed the scaling-field method, is developed for solving by successive approximation Wilson's exact renormalization-group equation for critical phenomena in three-dimensional spin systems. The approach uses the scaling-field representation of the Wilson equation derived by Riedel, Golner, and Newman. A procedure is proposed for generating in a nonperturbative and unbiased fashion sequences of successively larger truncations to the infinite hierarchy of scaling-field equations. A "principle of balance" is introduced and used to provide a self-consistency criterion. The approach is then applied to the isotropic $N$-vector model. Truncations to order 13 (10, when $N=1$) scaling-field equations yield the leading critical exponents, $\ensuremath{ u}$ and $\ensuremath{\eta}$, and several of the correction-to-scaling exponents, ${\ensuremath{\Delta}}_{m}$, to high precision. Results for $N=0, 1, 2, \mathrm{and} 3$ are tabulated. For the Ising case ($N=1$), the estimates $\ensuremath{ u}=0.626\ifmmode\pm\else\textpm\fi{}0.009$, $\ensuremath{\eta}=0.040\ifmmode\pm\else\textpm\fi{}0.007$, and ${\ensuremath{\Delta}}_{1}\ensuremath{\equiv}{\ensuremath{\Delta}}_{400}=0.54\ifmmode\pm\else\textpm\fi{}0.05$ are in good agreement with recent high-temperature-series results, though exhibiting larger confidence limits at the present level of approximation. For the first time, estimates are obtained for the second and third correction-to-scaling exponents. For example, for the Ising model the second "even" and first "odd" correction-to-scaling exponents are ${\ensuremath{\Delta}}_{422}=1.67\ifmmode\pm\else\textpm\fi{}0.11$ and ${\ensuremath{\Delta}}_{500}=1.5\ifmmode\pm\else\textpm\fi{}0.3$, respectively. Extensions necessary to improve the accuracy of the calculation are discussed, while applications of the approach to anisotropic $N$-vector models are described elsewhere. Finally, the scaling-field method is compared with other techniques for the high-precision calculation of critical phenomena in three dimensions, i.e., high-temperature-series, Monte Carlo renormalization-group, and field-theoretic perturbation expansions.

Aedes triseriatus (Diptera: Culicidae) and La Crosse virus. III. Enhanced oral transmission by nutrition-deprived mosquitoes.

Abstract: Adult Aedes triseriatus , reared as larvae under a dietary regimen that produced 3 distinct body size classes [small (S), normal (N), and large (L)], were orally infected with La Crosse (LAC) virus. In all trials female mosquitoes that had endured the severest nutritional deprivation as larvae (S class) transmitted LAC virus at rates considerably higher than the mosquitoes from the moderately deprived N and nondeprived L classes (mean transmission rates of 82, 54, and 52%, respectively). While the S class mosquitoes ingested a proportionally larger infectious blood meal in relation to dry weight than the other 2 classes, the actual amount of virus ingested varied only about 0.4 log10 plaque-forming units/0.1 mg dry body weight among the 3 size classes. Thus, while enhanced oral transmission may be dose related to some extent, it is also apparent that adult mosquitoes nutritionally deprived as larvae may be physiologically less resistant to infection by LAC virus than less deprived individuals. These results indicate that virus transmission experiments conducted with adult mosquitoes reared on optimal larval diets in the laboratory may not reflect the vector capacity found in field populations. Consequently, epidemiologically important variables such as oral transmission rates may have been seriously underestimated in many previous studies.

How to bridge the gap between meaning and reference

Abstract: There is a temptation, during a revolution, to minimize the significant differences among the revolutionary parties. The activists themselves, due to their deep and unanimous opposition to the old regime and their exhilaration at recent successes, often find it difficult to overcome the illusion of general agreement on fundamentals. The past two decades has been a period of revolutionary activity in the philosophy of language. The members of the old regime are, as it were, the pro ponents of the Fregean picture of how words hook up with the world, the idea that singular terms express descriptive concepts and refer to those items that satisfy the concepts. Frege's perspective has been vigorously attacked by those recently called by one anthologist "the new theorists of reference", originally Donnellan, Kaplan, Kripke, and Putnam. Singular terms refer, according to the latter theorists, not by expressing concepts but in some much more immediate and direct way. The definite description, Frege's paradigm, has been replaced by a new paradigm or two, the demonstrative expression and/or the Millian proper name that merely tags but does describe its bearer. I plead guilty, as one of the advocates of the newer approach, to the charge of laboring under the illusion of agreement on fundamentals. I became suspicious, however, when I was accused of advocating the causal theory of reference, a view that seemed foreign to my thinking but was supposedly central to or even definitive of the new approach.1 The question I shall address, the question mentioned in the title, will highlight profound disagreements among the new theorists and will provide an opportunity to further develop the direct reference ap proach. I shall restrict my discussion to indexical reference, specifically to reference by means of pronouns and demonstratives. That there is a gap between meaning and reference in the case of indexical expressions has been a cornerstone of the new approach. Consider the first person pronoun. Each of us can use it to refer to ourselves, yet it is not ambiguous. Its lexical meaning remains constant

Methods of Analysis with Response-Shift Bias.

Abstract: Howard and his colleagues have discovered an instrumentation related contamination which confounds the results of studies which employ self-report measures in a pre/post or posttest only design. This confounding influence is referred to as response-shift bias. Research has demonstrated that the traditional methods of analysis (i.e., analysis of posttests only, analysis of pre/post difference scores, and analysis of covariance using prescores (ANCOVA)) do not consider response-shift bias and produce biased estimates of the treatment effect. A retrospective pre/post design is recommended by Howard and his colleagues to control for response-shift bias. The only method of analysis which yields an unbiased estimate of the treatment effect is posttest minus retrospective pretest difference scores. The purpose of the present study is to determine the relative loss in statistical power of the traditional methods of analysis when response-shift bias is present. Analytic and Monte Carlo techniques were employed to ...

Singular functors and realization functors

Abstract: In [6] Quillen showed that the singular functor and the realization functor have certain properties which imply the equivalence of the weak homotopy theory of topological spaces with the homotopy theory of simplicial sets. The aim of this note is to generalize this result and to show that one can, in essentially the same manner, establish the equivalence of other homotopy theories (e.g., the equivariant homotopy theories) with homotopy theories of simplicial diagrams of simplicial sets. Applications to equivariant homotopy will be given in [3] and [4].

Theory of deep impurities in silicon-germanium alloys

Abstract: Calculations of the deep-energy levels of substitutional ${\mathrm{sp}}^{3}$-bonded defects in ${\mathrm{Si}}_{x} {\mathrm{Ge}}_{1\ensuremath{-}x}$ alloys suggest that the standard shallow dopants As and P and isoelectronic C defect may become deep traps for $x\ensuremath{\simeq}0.2$.

Terminal and interstitial deletions of the long arm of chromosome 7: A review with five new cases

Abstract: Sixteen cases of terminal deletions and 17 cases of interstitial deletions of the long arm of chromosome 7 have been reported to date. We present two new cases of the former and three of the latter. The somatic changes in these patients are tabulated and an update on the anomalies associated with the various cytogenetic entities is presented. Changes found in over one-third of patients with 7q terminal deletion syndrome include: developmental delay, pre- and postnatal growth retardation, generalized hypotonia, abnormal electroencephalograms with or without seizures, feeding problems in infancy, microcephaly, prominent forehead, ocular hypertelorism, eye defects, broad nasal bridge, bulbous nasal tip, auricular malformations, micrognathia, chest abnormalities, genital malformations in males, and abnormal palmar and plantar creases. Evidence for the localization of the Kidd blood group gene on chromosome 7 distal to band q32, as suggested by previous reports, is reviewed; we conclude that the evidence does not warrant placement of the gene in this region of the genome.

Optimal learning strategies and their spontaneous use: The importance of task-appropriate processing

Abstract: College students were given three verbal learning tasks to perform, with some subjects instructed to use a particular verbal or imaginal encoding strategy for all three tasks and other subjects not instructed to use any particular strategy. It was found that the relative effectiveness of the assigned encoding strategies varied as a function of the learning task. In addition, “uninstructed” subjects, for the most part, spontaneously employed strategies that produced recall comparable to that observed for subjects assigned the most effective strategy for a particular learning task. In Experiment 2, subjects were instructed to perform a different encoding strategy for each learning task. Subjects who were assigned the strategies in a “task-appropriate” fashion recalled more, in general, than subjects who were assigned the same strategies paired with the learning tasks in a haphazard fashion. Subjects not instructed to use a particular strategy again demonstrated relatively high recall and were found to vary processing across learning tasks. It was concluded that optimal learning for a range of tasks can require deployment of several semantic/elaborative strategies in a task-appropriate fashion. Furthermore, mature learners seem to spontaneously utilize semantic and imaginal strategies and do so task appropriately.

An obstruction theory for diagrams of simplicial sets

Abstract: We describe a version of obstruction theory for simplicial sets, which involves canonical obstruction cocycles and then use this to obtain a similar theory for diagrams of simplicial sets. An application of the latter (to the problem of realizing diagrams in the homotopy category by means of diagrams of simplicial sets) will be given in [4].