Showing papers by "Ohio State University published in 1987"

Nonlinear pulse propagation in a monomode dielectric guide

Abstract: We derive the nonlinear wave equation for an envelope of an electromagnetic wave in a monomode dielectric waveguide. Concrete examples are given for a single-mode optical fiber where the coefficients of resultant nonlinear Schrodinger equation with higher-order dispersion and dissipation (both linear and nonlinear) are given in terms of properties of the eigenfunction of the guided wave as well as of the material nonlinearity and dispersion. Using a newly-developed perturbation method, we show that the higher-order dispersions (linear and nonlinear) perserve the profile of a single soliton but to split up a bound N soliton ( N \geq 2 ) into individual solitons with different heights which propagate at different velocities. We also show that the higher-order nonlinear dissipation due to the induced Raman effect downshifts the carrier frequency of a single soliton in proportion to the distance of propagation and to the fourth power of the soliton amplitude.

Polaron lattice in highly conducting polyaniline: Theoretical and optical studies.

Abstract: We present optical-absorption data together with band-structure calculations for the polaron lattice and bipolaron lattice for the highly conducting form of polyaniline, proton-doped polyemeraldine. We show that the polaron-lattice band structure fully accounts for the observed optical transitions. These results are in marked contrast with the electronic structure of other doped conducting polymers, in that only one single broad polaron band appears deep in the gap together with a very narrow band nearly degenerate with the conduction-band edge.

The Career psychology of women

Abstract: Summarizing literature from the twenty-year-old field of women's career development, this book brings scholars and professionals up-to-date in their understanding of the factors influencing women's career choices and career adjustment across the life span. It serves as a vital base for theoretical and empirical work in the study of women's career development. It includes topics such as: success and satisfaction; the interface of home and work; dual-career couples; sexual harassment; the influence of education; and self-concept and sex role-related characteristics.

Marital quality, marital disruption, and immune function

Abstract: Marital disruption is associated with significant increases in a variety of psychologic and physical disorders. In order to examine psychologic and physiologic mediators, self-report data and blood samples were obtained from 38 married women and 38 separated/divorced women. Among married subjects, poorer marital quality was associated with greater depression and a poorer response on three qualitative measures of immune function. Women who had been separated 1 year or less had significantly poorer qualitative and quantitative immune function than their sociodemographically matched married counterparts. Among the separated/divorced cohort, shorter separation periods and greater attachment to the (ex)husband were associated with poorer immune function and greater depression. These data are consistent with epidemiologic evidence linking marital disruption with increased morbidity and mortality.

Methodology review: Clustering methods

Abstract: A review of clustering methodology is presented, with emphasis on algorithm performance and the re sulting implications for applied research. After an over view of the clustering literature, the clustering process is discussed within a seven-step framework. The four major types of clustering methods can be characterized as hierarchical, partitioning, overlapping, and ordina tion algorithms. The validation of such algorithms re fers to the problem of determining the ability of the methods to recover cluster configurations which are known to exist in the data. Validation approaches in clude mathematical derivations, analyses of empirical datasets, and monte carlo simulation methods. Next, interpretation and inference procedures in cluster anal ysis are discussed. inference procedures involve test ing for significant cluster structure and the problem of determining the number of clusters in the data. The paper concludes with two sets of recommendations. One set deals with topics in clustering that would ben ...

Market Segmentation, Product Differentiation, and Marketing Strategy:

Abstract: Despite the pervasive use of the terms “market segmentation” and “product differentiation,” there has been and continues to be considerable misunderstanding about their meaning and use. The authors...

Dexterity measures for the design and control of kinematically redundant manipulators

Abstract: In this paper, we have proposed a number of measures for the quantification of dexterity of manipulators. The use of such measures is especially important for kinematically redundant manipulators since they can satisfy secondary cri teria in addition to satisfying a specification of end-effector motion. We will compare several measures for the problems offinding an optimal configuration for a given end-effector position, finding an optimal workpoint, and designing the op timal link lengths of an arm.

Relationships between parts A and B of the Trail Making Test.

Abstract: Two measures of relationship between Parts A and B of the Trail Making Test (TMT) were examined in a large, acute rehabilitation population (N = 497). A difference (B-A) and a ratio (B/A) score were calculated and compared to other neuropsychological measures. The difference score was found to be correlated highly with intelligence and severity of impairment and, to a lesser degree, with age, education, and memory functioning. The ratio measure was correlated moderately or showed no significant relationship with other variables. This finding supported the curvilinear nature of the relationship between the ratio measure and cerebral impairment, as suggested by Golden, Osmon, Moses, and Berg (1981). Both measures were examined for their ability to distinguish between right and left cerebral damage. Only a trend toward differentiating lateralized damage was found; the ratio measure and a geometric transformation of the ratio showed greater sensitivity than did the difference measure. Results are discussed in terms of the potential usefulness of TMT relationship measures in neuropsychological inference.

Characterization of a cis-Diamminedichloroplatinum(II)-resistant Human Ovarian Cancer Cell Line and Its Use in Evaluation of Platinum Analogues

Abstract: Human ovarian cancer cell lines with stable cisplatin resistance have been developed by chronic exposure of the parent cisplatin-sensitive A2780 line to increasing concentrations of cisplatin. 2780CP8 (CP8 refers to this cell line's growth in medium containing 8 microM cisplatin) has several clonal cytogenetic abnormalities but lacks homogeneously staining regions or double-minute chromosomes. It has a significantly greater monolayer growth rate, cloning efficiency in agarose, and total glutathione content compared to the A2780 line, but similar activities of several glutathione-dependent enzymes. The 2780CP8 subline is 7.3-fold resistant to cisplatin compared to the A2780 line, as well as cross-resistant to irradiation and melphalan. It is not cross-resistant to Adriamycin, but this develops with increased cisplatin resistance (14-fold) obtained by further cisplatin exposure of 2780CP8. Of the cisplatin analogues tested which are of current clinical interest, carboplatin, iproplatin, and tetraplatin, only the latter is more cytotoxic than cisplatin in the A2780 and 2780CP8 lines. The 2780CP8 subline is also cross-resistant to these analogues in the relative order carboplatin greater than iproplatin greater than tetraplatin (most to least cross-resistant). Treatment of a highly cisplatin resistant cell line (2780CP70) with either melphalan or cisplatin was associated with a significant increase in [3H]thymidine incorporation into DNA in the presence of 10 mM hydroxyurea compared with the parent sensitive cell line which showed essentially no capacity to repair DNA damage by these drugs. A2780 and its cisplatin-resistant cell lines may thus be useful in studying drug resistance mechanisms, in screening new drugs for activity (especially against drug resistant tumors), and in formulating induction and salvage therapies for ovarian cancer.

Ferromagnetic behavior of [Fe(C5Me5)2]+.bul. [TCNE]-.bul.. Structural and magnetic characterization of decamethylferrocenium tetracyanoethenide, [Fe(C5Me5)2]+.bul. [TCNE]-.bul..cntdot.MeCN and decamethylferrocenium pentacyanopropenide, [Fe(C5Me5)2]+.bul. [C3(CN)5]-

Abstract: Les deux composes cristallisent dans le systeme monoclinique, groupe C2/C. Comportement magnetique

Chronic stress and immunity in family caregivers of Alzheimer's disease victims.

Abstract: Although acute stress has been associated with transient immunosuppression, little is known about the immunologic consequences of chronic stress in humans. In order to investigate possible health-related consequences of a long-term stressor, we obtained blood samples for immunologic and nutritional analyses and psychologic data from 34 family caregivers of Alzheimer's disease (AD) victims and 34 sociodemographically matched comparison subjects. Family caregivers for AD victims were more distressed than comparison subjects without similar responsibilities. Greater impairment in the AD victim was associated with greater distress and loneliness in caregivers. Caregivers had significantly lower percentages of total T lymphocytes and helper T lymphocytes than did comparison subjects, as well as significantly lower helper-suppressor cell ratios; caregivers also had significantly higher antibody titers to Epstein-Barr virus than did comparison subjects, presumably reflecting poorer cellular immune system control of the latent virus in caregivers. The percentages of natural killer cells and suppressor T lymphocytes did not differ significantly. These data suggest that chronically stressed AD family caregivers do not show immunologic or psychologic adaptation to the level of their well-matched age peers.

Quadrupolar Kondo effect in uranium heavy-electron materials?

Abstract: The possibility of an electric quadrupole Kondo effect for a non-Kramers doublet on a uranium (U) ion is a cubic metallic host is demonstrated by model calculations showing a Kondo upturn in the resistivity, universal quenching of the quadrupolar moment, and a heavy-electron anomaly in the electronic specific heat. With inclusion of excited crystal-field levels, some of the unusual magnetic-response data in the heavy-electron superconductor UBe13 may be understood. Structural phase transitions at unprecedented low temperatures may occur in U-based heavy-electron materials.

On spreading a rumor

Abstract: Suppose that one of n people knows a rumor. At the first stage, he passes the rumor to someone chosen at random; at each stage, each person already informed (“knower”) communicates the rumor to a person chosen at random and independently of all other past and present choices. Denote by $S_n $ the random number of stages before everybody is informed. How large is $S_n $ typically? Frieze and Grimmet, who introduced this problem, proved that, in probability, $S_n /( \log _2 n + \log n ) \to 1$. In this paper we show that, in fact, $S_n = \log _2 n + \log n + O( 1 )$ in probability. Our proof demonstrates that the number $I( t )$ of persons informed after t stages obeys very closely, with high probability, a deterministic equation $I( {t + 1} ) = n - ( {n - I( t )} )\exp ( - I( t )/n )$, $t\geqq 0$. A case when each knower passes the rumor to several members at every stage is also discussed.

A rapid cold-hardening process in insects

Abstract: Traditionally studies of cold tolerance in insects have focused on seasonal adaptations related to overwintering that are observed after weeks or months of exposure to low temperature. In contrast, an extremely rapid cold-hardening response was observed in nonoverwintering stages that confers protection against injury due to cold shock at temperatures above the supercooling point. This response was observed in nondiapausing larvae and pharate adults of the flesh fly, Sarcophaga crassipalpis, nondiapausing adults of the elm leaf beetle, Xanthogaleruca luteola, and the milkweed bug, Oncopeltus fasciatus. The rapid hardening response is correlated with the accumulation of glycerol.

Kanban, MRP, and Shaping the Manufacturing Environment

Abstract: There has been a great deal of interest recently in the Japanese approach to manufacturing, growing out of a concern for finding ways to reduce inventories and increase productivity. At this project's inception, its objective was to assess whether the kanban system could perform well in the manufacturing environments found in this country. Based on observations from managers visiting Japan, the project was enlarged to also assess which factors in a production environment have the biggest impact on performance-regardless of the system in use. Guided by a panel of production and inventory managers from diverse plant environments, a comprehensive list of factors thought most important to manufacturing effectiveness was constructed. The panel established low and high values for each one. These settings were considered representative of the range experienced in U.S. plant environments. The factor settings allowed a variety of representative plants to be tested with a large scale simulator. Results show that kanban, when implemented in certain environmental settings, does indeed perform exceptionally well. However, so do the more traditional systems used in the United States. Conversely, there are other plant environments in which all systems perform much worse. This suggests that the factors themselves are the keys to major improvement. Simultaneously reducing setup times and lot sizes is found to be the single most effective way to cut inventory levels and improve customer service. Shop factors of particular importance are yield rates and worker flexibility. Degree of product standardization and the product structure are also high impact factors. Less crucial than earlier believed, at least over the factor settings simulated, are inventory record inaccuracy, equipment failures, and vendor reliability. Such results suggest that the selection of a production/inventory system can be of less importance than the improvement of the manufacturing environment itself.

Stress-related immune suppression: Health implications

Abstract: This study used a year-long prospective design to assess linkages among distress, immunity, and illness. Serial blood samples were collected from 40 first-year medical students at the first, third, and fifth examination periods, as well as 1 month before each. There were significant decrements in the production of gamma-interferon by concanavalin A-stimulated lymphocytes obtained at the time of examinations. Antibody titers to Epstein-Barr virus (EBV) increased during examination periods, suggesting reactivation of latent EBV and therefore poorer cellular immune control of latent virus. We obtained data that suggest that T-cell killing by memory T lymphocytes of EBV transformed autologous B lymphocytes also declined during examination periods. The activity of a lymphokine, leukocyte migration inhibition factor, normally suppressed during recrudescence of herpes simplex virus type 2 infections, was altered during examination periods and an increase in both plasma and intracellular levels of cyclic AMP associated with examination stress was observed. An increase in the incidence of self-reported symptoms of infectious illness was also associated with examination periods. The data support the linkage between stress-related immunosuppression and health.

Comprehensive analysis of data pertaining to the weak neutral current and the intermediate-vector-boson masses.

Abstract: The results of a comprehensive analysis of existing data on the weak neutral current and the W and Z masses are presented. The principal results are the following. (a) There is no evidence for any deviation from the standard model. (b) A global fit to all data yields ${\mathrm{sin}}^{2}$${\mathrm{\ensuremath{\theta}}}_{\mathrm{W}}$\ensuremath{\equiv}1-${\mathrm{M}}_{\mathrm{W}}$${\mathrm{}}^{2}$/${\mathrm{M}}_{\mathrm{Z}}$${\mathrm{}}^{2}$=0.230\ifmmode\pm\else\textpm\fi{}0.0048, where this error and all others given here include full statistical, systematic, and theoretical uncertainties (computed assuming three fermion families, ${m}_{t}$\ensuremath{\le}100 GeV, and ${M}_{H}$\ensuremath{\le}1 TeV). (c) Allowing \ensuremath{\rho}\ensuremath{\equiv}${M}_{W}$${\mathrm{}}^{2}$/(${M}_{Z}$${}^{2}$${\mathrm{cos}}^{2}$${\mathrm{\ensuremath{\theta}}}_{\mathrm{W}}$) as well as ${\mathrm{sin}}^{2}$${\mathrm{\ensuremath{\theta}}}_{\mathrm{W}}$ to vary one obtains ${\mathrm{sin}}^{2}$${\mathrm{\ensuremath{\theta}}}_{\mathrm{W}}$=0.229\ifmmode\pm\else\textpm\fi{}0.0064 and \ensuremath{\rho}=0.998\ifmmode\pm\else\textpm\fi{}0.0086. This implies 90%-confidence-level (C.L.) upper limits of 0.047 and 0.081 for the vacuum expectation values (relative to those of Higgs doublets) for Higgs triplets with weak hypercharge of 0 and \ifmmode\pm\else\textpm\fi{}1, respectively. (d) The parameter ${\ensuremath{\delta}}_{W}$\ensuremath{\equiv}\ensuremath{\Delta}r-\ensuremath{\Delta}${s}^{2}$(1-\ensuremath{\Delta}r)/${\mathrm{sin}}^{2}$${\mathrm{\ensuremath{\theta}}}^{0}$, which is a measure of the radiative corrections relating deep-inelastic neutrino scattering, the W and Z masses, and muon decay, is determined to be 0.112\ifmmode\pm\else\textpm\fi{}0.037. This is consistent with the value ${\ensuremath{\delta}}_{W}$=0.106 expected for ${m}_{t}$=45 GeV and ${M}_{H}$=100 GeV and establishes the existence of radiative corrections at the 3\ensuremath{\sigma} level. (e) The radiative corrections are sensitive to isospin breaking associated with a large ${m}_{t}$.Assuming no deviation from the standard model, consistency of the various reactions requires ${m}_{t}$180 GeV at 90% C.L. for ${M}_{H}$\ensuremath{\le}100 GeV, with a slightly weaker limit for larger ${M}_{H}$. Similar results hold for the mass splittings between fourth-generation quarks or leptons. (f) Most of the parameters in model-independent fits to \ensuremath{ u}q, \ensuremath{ u}e, eq, and ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ processes are now determined uniquely and precisely. (g) Limits are given on the masses and mixing angles of additional Z bosons expected in popular models. For theoretically expected coupling constants one finds that the neutral-current constraints are usually more stringent than the direct-production limits from the CERN Sp\ifmmode\bar\else\textasciimacron\fi{}pS collider, but nevertheless masses as low as 120--300 GeV are typically allowed. (h) The implications of these results for grand unification are discussed. ${\mathrm{sin}}^{2}$${\mathrm{\ensuremath{\theta}}}_{\mathrm{W}}$ is \ensuremath{\ge}2.5 standard deviations above the prediction of minimal SU(5) and similar models for all ${m}_{t}$. It is closer to the prediction of simple supersymmetric grand unified theories but is still somewhat low. (i) The dominant theoretical uncertainty (the charm-quark threshold in deep-inelastic charged-current scattering) is considered in some detail.

Increasing voting behavior by asking people if they expect to vote.

Abstract: In two studies, students contacted by telephone were asked to predict whether they would perform a particular behavior (registering to vote or voting, respectively) in the next Tew days. The proportion who predicted that they would do these socially desirable behaviors exceeded the proportion of control subjects wh o performed the behavior without first being aske d to predict whether the y would . Further, in the voting study these errors of overprediction were self-erasing in the sense describe d by S. J. Sherman (Journal o f Personality and Social Psychology, 1980,39). That is, subjects who were asked to predict whether they would vote—all of whom predicted that they would—actually did vote with substantially greater probability than did the no-prediction control subjects. (Actual voting was verified by consulting official voter rolls.) Asking people to predict whether the y will perform a socially desirable action appears to increase their probability of performing the action. When making predictions about their own behavior, people tend to present themselves favorably; they predict that they will do what appears to be proper or good behavior. However, when given the opportunit y to act , a person' s likelihood of performing a socially desirable action may b e reduced by factors such as the action's time and energy costs, the availability of compelling alternatives, and missed opportunity through not responding promptly. Sherman (1980) showed that asking people to predict their actions does more than jus t reveal a tendency toward favorable self-presentations; the probability of the predicted action is affected. Once subjects have made a prediction, their behavior is likely to confirm that prediction. In one of Sherman's experiments, subjects who were asked to predict whether they would agree t o work 3 hour s t o collect money for the American Cancer Society (49% said they would) were much more likely (31%) to agree with a later request to do so than were those who were never asked to predict their behavior (4%). Thus, apparent errors in prediction are "self-erasing" (Sherman, 1980). Once a person predicts an action, that action is likely to occur, even when the initial prediction is an apparent gross overestimate of the likelihood of performance. In interpreting this finding, Sherman suggested that making a prediction produces a performance-facilitating cognitive representation in which the person

The surface windfield over the Antarctic ice sheets

Abstract: The intense radiative cooling of air over the ice slopes of Antarctica generates a surface wind regime that is strongly controlled by topography, and plays a key role in determining the behaviour of the atmosphere and ocean in high southern latitudes1–7. Resultant surface winds are intimately linked to the orientation of the ice terrain (Fig. 1) and display the highest degree of persistence found on Earth. The close coupling between wind and topography allows estimation of the former if the latter is known with some precision. Here we report on time-averaged, near-surface airflow over the Antarctic continent during winter diagnosed from a recent, accurate synthesis of terrain slopes and from estimates of the lower atmospheric temperature structure. The simulated drainage pat-tern exhibits strong spatial variability with the airflow concentrated into several zones near the coastal margin. These confluence regions are responsible for strong persistent katabatic winds over downstream coastal stretches and are indicative of zones of greatest katabatic potential.