Showing papers by "Ohio State University published in 2001"

Bad is Stronger than Good

Abstract: The greater power of bad events over good ones is found in everyday events, major life events (e.g., trauma), close relationship outcomes, social network patterns, interpersonal interactions, and learning processes. Bad emotions, bad parents, and bad feedback have more impact than good ones, and bad information is processed more thoroughly than good. The self is more motivated to avoid bad self-definitions than to pursue good ones. Bad impressions and bad stereotypes are quicker to form and more resistant to disconfirmation than good ones. Various explanations such as diagnosticity and salience help explain some findings, but the greater power of bad events is still found when such variables are controlled. Hardly any exceptions (indicating greater power of good) can be found. Taken together, these findings suggest that bad is stronger than good, as a general principle across a broad range of psychological phenomena.

The recognition of human movement using temporal templates

Abstract: A view-based approach to the representation and recognition of human movement is presented. The basis of the representation is a temporal template-a static vector-image where the vector value at each point is a function of the motion properties at the corresponding spatial location in an image sequence. Using aerobics exercises as a test domain, we explore the representational power of a simple, two component version of the templates: The first value is a binary value indicating the presence of motion and the second value is a function of the recency of motion in a sequence. We then develop a recognition method matching temporal templates against stored instances of views of known actions. The method automatically performs temporal segmentation, is invariant to linear changes in speed, and runs in real-time on standard platforms.

Is the Resource-Based “View” a Useful Perspective for Strategic Management Research? Yes

Abstract: Here I examine each of the major issues raised by Priem and Butler (this issue) about my 1991 article and subsequent resource-based research. While it turns out that Priem and Butler's direct criticisms of the 1991 article are unfounded, they do remind resource-based researchers of some important requirements of this kind of research. I also discuss some important issues not raised by Priem and Butler—the resolutions of which will be necessary if a more complete resource-based theory of strategic advantage is to be developed.

Profiles of dark haloes: evolution, scatter and environment

Abstract: We study dark-matter halo density profiles in a high-resolution N-body simulation of aCDM cosmology. Our statistical sample contains �5000 haloes in the range 10 11 10 14 h −1 M⊙ and the resolution allows a study of subhaloes inside host haloes. The profiles are parameterized by an NFW form with two parameters, an inner radius rs and a virial radius Rvir, and we define the halo concentration cvirRvir/rs. We find that, for a given halo mass, the redshift dependence of the median concentration is cvir / (1 + z) −1 . This corresponds to rs(z) � constant, and is contrary to earlier suspicions that cvir does not vary much with redshift. The implications are that high- redshift galaxies are predicted to be more extended and dimmer than expected before. Second, we find that the scatter in halo profiles is large, with a 1� �(logcvir) = 0.18 at a given mass, corresponding to a scatter in maximum rotation velocities of �Vmax/Vmax = 0.12. We discuss implications for modelling the Tully-Fisher relation, which has a smaller reported intrinsic scatter. Third, subhaloes and haloes in dense environments tend to be more concentrated than isolated haloes, and show a larger scatter. These results suggest that cvir is an essential parameter for the theory of galaxy modelling, and we briefly discuss implications for the universality of the Tully- Fisher relation, the formation of low surface brightness galaxies, and the origin of the Hubble sequence. We present an improved analytic treatment of halo formation that fits the measured relations between halo parameters and their redshift dependence, and can thus serve semi-analytic studies of galaxy formation.

Marriage and health: his and hers.

Abstract: This review focuses on the pathway leading from the marital relationship to physical health. Evidence from 64 articles published in the past decade, particularly marital interaction studies, suggests that marital functioning is consequential for health; negative dimensions of marital functioning have indirect influences on health outcomes through depression and health habits, and direct influences on cardiovascular, endocrine, immune, neurosensory, and other physiological mechanisms. Moreover, individual difference variables such as trait hostility augment the impact of marital processes on biological systems. Emerging themes in the past decade include the importance of differentiating positive and negative dimensions of marital functioning, the explanatory power of behavioral data, and gender differences in the pathways from the marital relationship to physiological functioning. Contemporary models of gender that emphasize self-processes, traits, and roles furnish alternative perspectives on the differential costs and benefits of marriage for men's and women's health.

Cultural distance revisited: Towards a more rigorous conceptualization and measurement of cultural differences

Abstract: Cultural distance is a widely used construct in international business, where it has been applied to foreign investment expansion, entry mode choice, and the performance of foreign invested affiliates, among others. The present paper presents a critical review of the cultural distance construct, outlining its hidden assumptions and challenging its theoretical and methodological properties. A comprehensive framework for the treatment of the construct is developed and concrete steps aimed at enhancing rigor are delineated.

Transected neurites, apoptotic neurons, and reduced inflammation in cortical multiple sclerosis lesions.

Abstract: Multiple Sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system that causes motor, sensory, and cognitive deficits. The present study characterized demyelinated lesions in the cerebral cortex of MS patients. One hundred twelve cortical lesions were identified in 110 tissue blocks from 50 MS patients. Three patterns of cortical demyelination were identified: Type I lesions were contiguous with subcortical white matter lesions; Type II lesions were small, confined to the cortex, and often perivascular; Type III lesions extended from the pial surface to cortical layer 3 or 4. Inflammation and neuronal pathology were studied in tissue from 8 and 7 patients, respectively. Compared to white matter lesions, cortical lesions contained 13 times fewer CD3-positive lymphocytes (195 vs 2,596/mm3 of tissue) and 6 times fewer CD68-positive microglia/macrophages (11,948 vs 67,956/mm3 of tissue). Transected neurites (both axons and dendrites) occurred at a density of 4,119/mm3 in active cortical lesions, 1,107/mm3 in chronic active cortical lesions, 25/mm3 in chronic inactive cortical lesions, 8/mm3 in myelinated MS cortex, and 1/mm3 in control cortex. In active and chronic active cortical lesions, activated microglia closely apposed and ensheathed apical dendrites, neurites, and neuronal perikarya. In addition, apoptotic neurons were increased significantly in demyelinated cortex compared to myelinated cortex. These data support the hypothesis that demyelination, axonal transection, dendritic transection, and apoptotic loss of neurons in the cerebral cortex contribute to neurological dysfunction in MS patients.

C-Reactive Protein Elevation in Patients With Atrial Arrhythmias Inflammatory Mechanisms and Persistence of Atrial Fibrillation

Abstract: Background Atrial fibrillation (AF) may persist due to structural changes in the atria that are promoted by inflammation. C-reactive protein (CRP), a marker of systemic inflammation, predicts cardiovascular events and stroke, a common sequela of AF. We hypothesized that CRP is elevated in patients with atrial arrhythmias. Methods and Results Using a case-control study design, CRP in 131 patients with atrial arrhythmias was compared with CRP in 71 control patients. Among arrhythmia patients, 6 had frequent atrial ectopy or tachycardia, 86 had paroxysmal AF, 39 had persistent AF lasting >30 days, and 70 had lone arrhythmias. CRP was higher in arrhythmia than in control patients (median, 0.21 versus 0.096 mg/dL; P<0.001). Arrhythmia patients in AF within 24 hours before sampling had higher CRP than those in sinus rhythm (0.30 versus 0.15 mg/dL; P<0.001). CRP in controls was not different than in patients with atrial ectopy or tachycardia. Lone arrhythmia patients had a CRP of 0.21 mg/dL, which was not signif...

Current Approaches to Primary Therapy for Papillary and Follicular Thyroid Cancer

Abstract: Papillary and follicular thyroid cancer, together referred to as differentiated thyroid cancer (DTC), is usually curable when discovered at an early stage. Its management, however, is often a challenge because there have been no prospective randomized trials of treatment and none are likely to be done, given its typically prolonged course and relative infrequency. Instead, clinicians rely on large patient cohort studies in which therapy has not been randomized, leading to some disagreement about management. Nonetheless, thyroid cancer mortality rates have fallen significantly (20%, P , 0.05) in the United States between 1973 and 1996 (1), almost certainly due to early diagnosis and effective treatment of DTC, which comprises 90% of thyroid cancers and 70% of the thyroid cancer deaths (2). The decline in mortality, however, occurred only in women (1), perhaps because they undergo routine medical examinations more than men, in whom thyroid cancer is typically discovered at an older age (1). DTC is more likely to be completely resected and ablated with iodine-131 (I), an approach that has become more popular in the past several decades, when discovered at an early stage (3, 4). Much of the following discussion refers to treatment of DTC because the approach to treatment of papillary and follicular cancer is usually very similar.

Sex differences in autoimmune disease

Abstract: Autoimmune diseases are more prevalent in women than men. A new interest in understanding the biology of this difference as well as funding opportunities have focused attention on research priorities in sex differences.

Race, School Integration, and Friendship Segregation in America1

Abstract: Integrated schools may still be substantively segregated if friendships fall within race. Drawing on contact theory, this study tests whether school organization affects friendship segregation in a national sample of adolescent friendship networks. The results show that friendship segregation peaks in moderately heterogeneous schools but declines at the highest heterogeneity levels. As suggested by contact theory, in schools where extracurricular activities are integrated, grades tightly bound friendship, and races mix within tracks, friendship segregation is less pronounced. The generally positive relation between heterogeneity and friendship segregation suggests that integration strategies built on concentrating minorities in large schools may accentuate friendship segregation.

Relation of gene expression phenotype to immunoglobulin mutation genotype in B cell chronic lymphocytic leukemia.

Abstract: The most common human leukemia is B cell chronic lymphocytic leukemia (CLL), a malignancy of mature B cells with a characteristic clinical presentation but a variable clinical course. The rearranged immunoglobulin (Ig) genes of CLL cells may be either germ-line in sequence or somatically mutated. Lack of Ig mutations defined a distinctly worse prognostic group of CLL patients raising the possibility that CLL comprises two distinct diseases. Using genomic-scale gene expression profiling, we show that CLL is characterized by a common gene expression “signature,” irrespective of Ig mutational status, suggesting that CLL cases share a common mechanism of transformation and/or cell of origin. Nonetheless, the expression of hundreds of other genes correlated with the Ig mutational status, including many genes that are modulated in expression during mitogenic B cell receptor signaling. These genes were used to build a CLL subtype predictor that may help in the clinical classification of patients with this disease.

Neighborhood disadvantage, disorder, and health.

Abstract: We examine the question of whether living in a disadvantaged neighborhood damages health, over and above the impact of personal socioeconomic characteristics. We hypothesize that (1) health correlates negatively with neighborhood disadvantage adjusting for personal disadvantage, and that (2) neighborhood disorder mediates the association, (3) partly because disorder and the fear associated with it discourage walking and (4) partly because they directly impair health. Data are from the 1995 Community, Crime, and Health survey, a probability sample of 2,482 adults in Illinois, with linked information about the respondent's census tract. We find that residents of disadvantaged neighborhoods have worse health (worse self-reported health and physical functioning and more chronic conditions) than residents of more advantaged neighborhoods. The association is mediated entirely by perceived neighborhood disorder and the resulting fear. It is not mediated by limitation of outdoor physical activity. The daily stress associated with living in a neighborhood where danger, trouble, crime and incivility are common apparently damages health. We call for a bio-demography of stress that links chronic exposure to threatening conditions faced by disadvantaged individuals in disadvantaged neighborhoods with physiological responses that may impair health.

Peak bone mass

Abstract: R. P. Heaney, S. Abrams, B. Dawson-Hughes, A. Looker, R. Marcus, V. Matkovic and C. Weaver Creighton University, Omaha, NE; Children’s Nutrition Research Center, Houston, TX; Tufts University, Boston, MA; National Osteoporosis Foundation, Washington, DC; National Center for Health Statistics, Hyattsville, MD; Stanford University, Palo Alto, CA; Ohio State University, Columbus, OH; and Purdue University, West Lafayette, IN, USA

Soil degradation by erosion

Abstract: Soil degradation by accelerated erosion is a serious problem and will remain so during the 21st century, especially in developing countries of the tropics and subtropics. Yet, its extent, severity, and economic and environmental impacts are debatable. Estimates of global and regional land area affected are tentative and subjective. Results of field measurements are often technique-dependent. Considerable progress has been made in modeling soil erosion, yet field validation of these models remains to be done for principal soils and ecoregions. Similar to the land area affected, estimates of erosional impacts on crop yield, productivity and soil quality are tentative and subjective. Further, erosion-induced losses on crop yield are scale-dependent because of the compensatory beneficial effects on yields from depositional sites, and technology-dependent because of the masking effects of input such as fertilizers and irrigation. Erosion caused changes in soil carbon dynamics and non-point source water pollution are important environmental impacts. While erosion (e.g., detachment and transport) can lead to emission of trace gases into the atmosphere, deposition can bury and sequester some of the carbon. In addition to improving the database on the land area affected, there is also a need to assess erosional impacts on productivity and soil C balance at the watershed, regional, and global scale. Copyright © 2001 John Wiley & Sons, Ltd.

Spectroscopic Target Selection for the Sloan Digital Sky Survey: The Luminous Red Galaxy Sample

Abstract: We describe the target selection and resulting properties of a spectroscopic sample of luminous red galaxies (LRGs) from the imaging data of the Sloan Digital Sky Survey (SDSS). These galaxies are selected on the basis of color and magnitude to yield a sample of luminous intrinsically red galaxies that extends fainter and farther than the main flux-limited portion of the SDSS galaxy spectroscopic sample. The sample is designed to impose a passively evolving luminosity and rest-frame color cut to a redshift of 0.38. Additional, yet more luminous red galaxies are included to a redshift of ~0.5. Approximately 12 of these galaxies per square degree are targeted for spectroscopy, so the sample will number over 100,000 with the full survey. SDSS commissioning data indicate that the algorithm efficiently selects luminous (M^+_g ≈ -21.4) red galaxies, that the spectroscopic success rate is very high, and that the resulting set of galaxies is approximately volume limited out to z = 0.38. When the SDSS is complete, the LRG spectroscopic sample will fill over 1 h^(-3) Gpc^3 with an approximately homogeneous population of galaxies and will therefore be well suited to studies of large-scale structure and clusters out to z = 0.5.

Gene Mutations in the Succinate Dehydrogenase Subunit SDHB Cause Susceptibility to Familial Pheochromocytoma and to Familial Paraganglioma

Abstract: The pheochromocytomas are an important cause of secondary hypertension. Although pheochromocytoma susceptibility may be associated with germline mutations in the tumor-suppressor genes VHL and NF1 and in the proto-oncogene RET, the genetic basis for most cases of nonsyndromic familial pheochromocytoma is unknown. Recently, pheochromocytoma susceptibility has been associated with germline SDHD mutations. Germline SDHD mutations were originally described in hereditary paraganglioma, a dominantly inherited disorder characterized by vascular tumors in the head and the neck, most frequently at the carotid bifurcation. The gene products of two components of succinate dehydrogenase, SDHC and SDHD, anchor the gene products of two other components, SDHA and SDHB, which form the catalytic core, to the inner-mitochondrial membrane. Although mutations in SDHC and in SDHD may cause hereditary paraganglioma, germline SDHA mutations are associated with juvenile encephalopathy, and the phenotypic consequences of SDHB mutations have not been defined. To investigate the genetic causes of pheochromocytoma, we analyzed SDHB and SDHC, in familial and in sporadic cases. Inactivating SDHB mutations were detected in two of the five kindreds with familial pheochromocytoma, two of the three kindreds with pheochromocytoma and paraganglioma susceptibility, and 1 of the 24 cases of sporadic pheochromocytoma. These findings extend the link between mitochondrial dysfunction and tumorigenesis and suggest that germline SDHB mutations are an important cause of pheochromocytoma susceptibility.

An Overview of Analytic Rotation in Exploratory Factor Analysis.

Abstract: The use of analytic rotation in exploratory factor analysis will be examined. Particular attention will be given to situations where there is a complex factor pattern and standard methods yield poor solutions. Some little known but interesting rotation criteria will be discussed and methods for weighting variables will be examined. Illustrations will be provided using Thurstone's 26 variable box data and other examples.

The Halo Occupation Distribution: Towards an Empirical Determination of the Relation Between Galaxies and Mass

Abstract: We investigate galaxy bias in the framework of the ``Halo Occupation Distribution'' (HOD), which defines the bias of a population of galaxies by the conditional probability P(N|M) that a dark matter halo of virial mass M contains N galaxies, together with prescriptions that specify the relative spatial and velocity distributions of galaxies and dark matter within halos. By populating the halos of a cosmological N-body simulation using a variety of HOD models, we examine the sensitivity of different galaxy clustering statistics to properties of the HOD. The galaxy correlation function responds to different aspects of P(N|M) on different scales. Obtaining the observed power-law form of xi(r) requires rather specific combinations of HOD parameters, implying a strong constraint on the physics of galaxy formation; the success of numerical and semi-analytic models in reproducing this form is entirely non-trivial. Other clustering statistics such as the galaxy-mass correlation function, the bispectrum, the void probability function, the pairwise velocity dispersion, and the group multiplicity function are sensitive to different combinations of HOD parameters and thus provide complementary information about galaxy bias. We outline a strategy for determining the HOD empirically from redshift survey data. This method starts from an assumed cosmological model, but we argue that cosmological and HOD parameters will have non-degenerate effects on galaxy clustering, so that a substantially incorrect cosmological model will not reproduce the observations for any choice of HOD. Empirical determinations of the HOD as a function of galaxy type from the 2dF and SDSS redshift surveys will provide a detailed target for theories of galaxy formation, insight into the origin of galaxy properties, and sharper tests of cosmological models.

Sample size in factor analysis: The role of model error

Abstract: This article examines effects of sample size and other design features on correspondence between factors obtained from analysis of sample data and those present in the population from which the samples were drawn. We extend earlier work on this question by examining these phenomena in the situation in which the common factor model does not hold exactly in the population. We present a theoretical framework for representing such lack of fit and examine its implications in the population and sample. Based on this approach we hypothesize that lack of fit of the model in the population will not, on the average, influence recovery of population factors in analysis of sample data, regardless of degree of model error and regardless of sample size. Rather, such recovery will be affected only by phenomena related to sampling error which have been studied previously. These hypotheses are investigated and verified in two sampling studies, one using artificial data and one using empirical data.

A Universal Angular Momentum Profile for Galactic Halos

Abstract: We study the angular momentum profiles of a statistical sample of halos drawn from a high-resolution N-body simulation of the ΛCDM cosmology. We find that the cumulative mass distribution of specific angular momentum j in a halo of mass Mv is well fitted by a universal function, M(< j) = Mvμj/(j0 + j). This profile is defined by one shape parameter (μ or j0) in addition to the global spin parameter λ. It follows a power law M(< j) ∝ j over most of the mass and flattens at large j, with the flattening more pronounced for small values of μ (or large j0 at a fixed λ). Compared to a uniform sphere in solid-body rotation, most halos have a higher fraction of their mass in the low- and high-j tails of the distribution. High-λ halos tend to have high μ values, corresponding to a narrower, more uniform j distribution. The spatial distribution of angular momentum in halos tends to be cylindrical and is well-aligned within each halo for ~80% of the halos. The more misaligned halos tend to have low μ values. When averaged over spherical shells encompassing mass M, the halo j profiles are fitted by j(M) ∝ Ms with s = 1.3 ± 0.3. We investigate two ideas for the origin of this profile. The first is based on a revised version of linear tidal-torque theory combined with extended Press-Schechter mass accretion, and the second focuses on j transport in minor mergers. Finally, we briefly explore implications of the M(< j) profile on the formation of galactic disks assuming that j is conserved during an adiabatic baryonic infall. The implied gas density profile deviates from an exponential disk, with a higher density at small radii and a tail extending to large radii. The steep central density profiles may imply disk scale lengths that are smaller than observed. This is reminiscent of the "angular momentum problem" seen in hydrodynamic simulations, even though we have assumed perfect j conservation. A possible solution is to associate the central excesses with bulge components and the outer regions with extended gaseous disks.

Implicit Attitude Measures: Consistency, Stability, and Convergent Validity

Abstract: In recent years, several techniques have been developed to measure implicit social cognition. Despite their increased use, little attention has been devoted to their reliability and validity. This article undertakes a direct assessment of the interitem consistency, stability, and convergent validity of some implicit attitude measures. Attitudes toward blacks and whites were measured on four separate occasions, each 2 weeks apart, using three relatively implicit measures (response-window evaluative priming, the Implicit Association Test, and the response-window Implicit Association Test) and one explicit measure (Modern Racism Scale). After correcting for interitem inconsistency with latent variable analyses, we found that (a) stability indices improved and (b) implicit measures were substantially correlated with each other, forming a single latent factor. The psychometric properties of response-latency implicit measures have greater integrity than recently suggested.

Baryons in the warm-hot intergalactic medium

Abstract: Approximately 30%-40% of all baryons in the present-day universe reside in a warm-hot intergalactic medium (WHIM), with temperatures in the range 105 < T < 107 K. This is a generic prediction from six hydrodynamic simulations of currently favored structure formation models having a wide variety of numerical methods, input physics, volumes, and spatial resolutions. Most of these warm-hot baryons reside in diffuse large-scale structures with a median overdensity around 10-30, not in virialized objects such as galaxy groups or galactic halos. The evolution of the WHIM is primarily driven by shock heating from gravitational perturbations breaking on mildly nonlinear, nonequilibrium structures such as filaments. Supernova feedback energy and radiative cooling play lesser roles in its evolution. WHIM gas may be consistent with observations of the 0.25 keV X-ray background without being significantly heated by nongravitational processes because the emitting gas is very diffuse. Our results confirm and extend previous work by Cen & Ostriker and Dave et al.