Showing papers by "Indiana University published in 1999"

Critical Values for Cointegration Tests in Heterogeneous Panels with Multiple Regressors

Abstract: I. INTRODUCTION In this paper we describe a method for testing the null of no cointegration in dynamic panels with multiple regressors and compute approximate critical values for these tests. Methods for non-stationary panels, including panel unit root and panel cointegration tests, have been gaining increased acceptance in recent empirical research. To date, however, tests for the null of no cointegration in heterogeneous panels based on Pedroni (1995, 1997a) have been limited to simple bivariate examples, in large part due to the lack of critical values available for more complex multivariate regressions. The purpose of this paper is to fill this gap by describing a method to implement tests for the null of no cointegration for the case with multiple regressors and to provide appropriate critical values for these cases. The tests allow for considerable heterogeneity among individual members of the panel, including heterogeneity in both the long-run cointegrating vectors as well as heterogeneity in the dynamics associated with short-run deviations from these cointegrating vectors.

Revisiting the Commons: Local Lessons, Global Challenges

Abstract: In a seminal paper, Garrett Hardin argued in 1968 that users of a commons are caught in an inevitable process that leads to the destruction of the resources on which they depend. This article discusses new insights about such problems and the conditions most likely to favor sustainable uses of common-pool resources. Some of the most difficult challenges concern the management of large-scale resources that depend on international cooperation, such as fresh water in international basins or large marine ecosystems. Institutional diversity may be as important as biological diversity for our long-term survival.

NF-κB activation by tumour necrosis factor requires the Akt serine–threonine kinase

Abstract: Activation of the nuclear transcription factor NF-kappaB by inflammatory cytokines requires the successive action of NF-kappaB-inducing kinase (NIK) and an IKB-kinase (IKK) complex composed of IKKalpha and IKKbeta. Here we show that the Akt serine-threonine kinase is involved in the activation of NF-kappaB by tumour necrosis factor (TNF). TNF activates phosphatidylinositol-3-OH kinase (PI(3)K) and its downstream target Akt (protein kinase B). Wortmannin (a PI(3)K inhibitor), dominant-negative PI(3)K or kinase-dead Akt inhibits TNF-mediated NF-kappaB activation. Constitutively active Akt induces NF-kappaB activity and this effect is blocked by dominant-negative NIK. Conversely, NIK activates NF-kappaB and this is blocked by kinase-dead Akt. Thus, both Akt and NIK are necessary for TNF activation of NF-kappaB. Akt mediates IKKalpha phosphorylation at threonine 23. Mutation of this amino acid blocks phosphorylation by Akt or TNF and activation of NF-kappaB. These findings indicate that Akt is part of a signalling pathway that is necessary for inducing key immune and inflammatory responses.

Cisplatin, radiation, and adjuvant hysterectomy compared with radiation and adjuvant hysterectomy for bulky stage IB cervical carcinoma

Abstract: Background Bulky stage IB cervical cancers have a poorer prognosis than smaller stage I cervical cancers. For the Gynecologic Oncology Group, we conducted a trial to determine whether weekly infusions of cisplatin during radiotherapy improve progression-free and overall survival among patients with bulky stage IB cervical cancer. Methods Women with bulky stage IB cervical cancers (tumor, ≥4 cm in diameter) were randomly assigned to receive radiotherapy alone or in combination with cisplatin (40 mg per square meter of body-surface area once a week for up to six doses; maximal weekly dose, 70 mg), followed in all patients by adjuvant hysterectomy. Women with evidence of lymphadenopathy on computed tomographic scanning or lymphangiography were ineligible unless histologic analysis showed that there was no lymph-node involvement. The cumulative dose of external pelvic and intracavitary radiation was 75 Gy to point A (cervical parametrium) and 55 Gy to point B (pelvic wall). Cisplatin was given during external...

Number of Directors and Financial Performance: A Meta-Analysis

Abstract: Although a host of theory-driven rationales suggest a relationship between board of directors size and firm performance, the literature provides no consensus about the direction of that relationship. A meta-analysis of 131 samples (N = 20,620) provided systematic evidence of nonzero, positive, true population estimates of board size-performance relationships.

Classification of sporadic Creutzfeldt‐Jakob disease based on molecular and phenotypic analysis of 300 subjects

Abstract: Phenotypic heterogeneity in sporadic Creutzfeldt-Jakob disease (sCJD) is well documented, but there is not yet a systematic classification of the disease variants. In a previous study, we showed that the polymorphic codon 129 of the prion protein gene (PRNP), and two types of protease-resistant prion protein (PrP(Sc)) with distinct physicochemical properties, are major determinants of these variants. To define the full spectrum of variants, we have examined a series of 300 sCJD patients. Clinical features, PRNP genotype, and PrP(Sc) properties were determined in all subjects. In 187, we also studied neuropathological features and immunohistochemical pattern of PrP(Sc) deposition. Seventy percent of subjects showed the classic CJD phenotype, PrP(Sc) type 1, and at least one methionine allele at codon 129; 25% of cases displayed the ataxic and kuru-plaque variants, associated to PrP(Sc) type 2, and valine homozygosity or heterozygosity at codon 129, respectively. Two additional variants, which included a thalamic form of CJD and a phenotype characterized by prominent dementia and cortical pathology, were linked to PrP(Sc) type 2 and methionine homozygosity. Finally, a rare phenotype characterized by progressive dementia was linked to PrP(Sc) type 1 and valine homozygosity. The present data demonstrate the existence of six phenotypic variants of sCJD. The physicochemical properties of PrP(Sc) in conjunction with the PRNP codon 129 genotype largely determine this phenotypic variability, and allow a molecular classification of the disease variants.

Investigating Deep Phylogenetic Relationships among Cyanobacteria and Plastids by Small Subunit rRNA Sequence Analysis

Abstract: Small subunit rRNA sequence data were generated for 27 strains of cyanobacteria and incorporated into a phylogenetic analysis of 1,377 aligned sequence positions from a diverse sampling of 53 cyanobacteria and 10 photosynthetic plastids. Tree inference was carried out using a maximum likelihood method with correction for site-to-site variation in evolutionary rate. Confidence in the inferred phylogenetic relationships was determined by construction of a majority-rule consensus tree based on alternative topologies not considered to be statistically significantly different from the optimal tree. The results are in agreement with earlier studies in the assignment of individual taxa to specific sequence groups. Several relationships not previously noted among sequence groups are indicated, whereas other relationships previously supported are contradicted. All plastids cluster as a strongly supported monophyletic group arising near the root of the cyanobacterial line of descent.

Culture specific and cross-culturally generalizable implicit leadership theories: Are attributes of charismatic/transformational leadership universally endorsed?

Abstract: This study focuses on culturally endorsed implicit theories of leadership (CLTs). Although cross-cultural research emphasizes that different cultural groups likely have different conceptions of what leadership should entail, a controversial position is argued here: namely that attributes associated with charismatic/transformational leadership will be universally endorsed as contributing to outstanding leadership. This hypothesis was tested in 62 cultures as part of the Global Leadership and Organizational Behavior Effectiveness (GLOBE) Research Program. Universally endorsed leader attributes, as well as attributes that are universally seen as impediments to outstanding leadership and culturally contingent attributes are presented here. The results support the hypothesis that specific aspects of charismatic/transformational leadership are strongly and universally endorsed across cultures.

Coping with tragedies of the commons

Abstract: ▪ Abstract Contemporary policy analysis of the governance of common-pool resources is based on three core assumptions: (a) resource users are norm-free maximizers of immediate gains, who will not cooperate to overcome the commons dilemmas they face; (b) designing rules to change incentives of participants is a relatively simple analytical task; and (c) organization itself requires central direction. The chapter shows that these assumptions are a poor foundation for policy analysis. Findings from carefully controlled laboratory experiments that challenge the first assumption are summarized. A different assumption that humans are fallible, boundedly rational, and norm-using is adopted. The complexity of using rules as tools to change the structure of commons dilemmas is then discussed, drawing on extensive research on rules in field settings. Viewing all policies as experiments with a probability of failure, recent research on a different form of general organization—that of complex adaptive systems—is appl...

Aerodynamic Properties of Urban Areas Derived from Analysis of Surface Form

Abstract: Several methods to determine the aerodynamic characteristics of a site through analysis of its surface form (morphometry) are considered in relation to cities. The measures discussed include zero-plane displacement length (zd), roughness length (z0), depth of the roughness sublayer, and aerodynamic conductance. A sensitivity analysis is conducted on seven formulas to estimate zd and nine to estimate z0, covering a wide range of probable urban roughness densities. Geographic information systems developed for 11 sites in 7 North American cities are used to characterize their morphometry—the height, shape, three-dimensional area, and spatial distribution of their roughness elements (buildings and trees). Most of the sites are in residential suburbs, but one is industrial and two are near city centers. This descriptive survey of urban geometric form is used, together with the morphometric formulas, to derive the apparent aerodynamic characteristics of the sites. The resulting estimates of zd and z0 a...

Transgressive segregation, adaptation and speciation

Abstract: The production of extreme or 'transgressive' phenotypes in segregating hybrid populations has been speculated to contribute to niche divergence of hybrid lineages. Here, we assess the frequency of transgressive segregation in hybrid populations, describe its genetic basis and discuss the factors that best predict its occurrence. From a survey of 171 studies that report phenotypic variation in segregating hybrid populations, we show that transgression is the rule rather than the exception. In fact, 155 of the 171 studies (91%) report at least one transgressive trait, and 44% of 1229 traits examined were transgressive. Transgression occurred most frequently in intraspecific crosses involving inbred, domesticated plant populations, and least frequently in interspecific crosses between outbred, wild animal species. Quantitative genetic studies of plant hybrids consistently point to the action of complementary genes as the primary cause of transgression, although overdominance and epistasis also contribute. Complementary genes appear to be common for most traits, with the possible exception of those with a history of disruptive selection. These results lend credence to the view that hybridization may provide the raw material for rapid adaptation and provide a simple explanation for niche divergence and phenotypic novelty often associated with hybrid lineages.

Familial aggregation of VO(2max) response to exercise training: results from the HERITAGE Family Study.

Abstract: The aim of this study was to test the hypothesis that individual differences in the response of maximal O2 uptake (V˙o 2 max) to a standardized training program are characterized by familial aggreg...

Interim Report and Recommendations of the World Health Organization Task-Force for Osteoporosis

Abstract: Harry K. Genant (Chairman) , Cyrus Cooper (Rapporteur) , Gyula Poor (Rapporteur) , Ian Reid (Rapporteur) , George Ehrlich (Editor), J. Kanis (Editor), B. E. Christopher Nordin (Editor), Elizabet h Barrett-Connor , Dennis Black, J.-P. Bonjour, Bess Dawson-Hughes , Pierre D. Delmas, J. Dequeker , Sergio Ragi Eis, Carlo Gennari , Olaf Johnell , C. Conrad Johnston, Jr, Edith M. C. Lau, Uri A. Liberman, Robert Lindsay, Thomas John Martin, Basel Masri, Carlos A. Mautalen, Pierre J. Meunier, Paul D. Miller , Ambrish Mithal, Hirotoshi Morii , Socrates Papapoul os, Anthony Woolf, Wei Yu and Nikolai Khaltaev (WHO Secretariat) 30

Development of a Stroke-Specific Quality of Life Scale

Abstract: Background and Purpose—Clinical stroke trials are increasingly measuring patient-centered outcomes such as functional status and health-related quality of life (HRQOL). No stroke-specific HRQOL measure is currently available. This study presents the initial development of a valid, reliable, and responsive stroke-specific quality of life (SS-QOL) measure, for use in stroke trials. Methods—Domains and items for the SS-QOL were developed from patient interviews. The SS-QOL, Short Form 36, Beck Depression Inventory, National Institutes of Health Stroke Scale, and Barthel Index were administered to patients 1 and 3 months after ischemic stroke. Items were eliminated with the use of standard psychometric criteria. Construct validity was assessed by comparing domain scores with similar domains of established measures. Domain responsiveness was assessed with standardized effect sizes . Results—All 12 domains of the SS-QOL were unidimensional. In the final 49-item scale, all domains demonstrated excellent internal...

Economic Preferences or Attitude Expressions?: An Analysis of Dollar Responses to Public Issues

Abstract: Participants in contingent valuation surveys and jurors setting punitive damages in civil trials provide answers denominated in dollars. These answers are better understood as expressions of attitudes than as indications of economic preferences. Well-established characteristics of attitudes and of the core process of affective valuation explain several robust features of dollar responses: high correlations with other measures of attractiveness or aversiveness, insensitivity to scope, preference reversals, and the high variability of dollar responses relative to other measures of the same attitude.

Effects of Comprehensive-Income Characteristics on Nonprofessional Investors' Judgments: The Role of Financial-Statement Format

Abstract: Statement of Financial Accounting Standards No. 130 requires companies to report comprehensive income in a primary financial statement, but allows its presentation in either a statement of comprehensive income or a statement of stockholders' equity. In an experiment, we examine whether and how alternative presentation formats affect nonprofessional investors' processing of comprehensive-income information, specifically, information disclosing the volatility of unrealized gains on available-for-sale securities. The results show that investors' judgments of corporate and management performance reflect the volatility of comprehensive income only when it is presented in a statement of comprehensive income. We provide evidence consistent with our psychology-based framework that these findings occur because format affects how nonprofessional investors weight comprehensive-income information and not whether they acquire this information or how they evaluate it. Key Words: Comprehensive income; Nonprofessional investors; Presentation format; Volatility

The Influence of Task Interruption on Individual Decision Making: An Information Overload Perspective

Abstract: Interruptions are a common aspect of the work environment of most organizations. Yet little is known about how interruptions and their characteristics, such as frequency of occurrence, influence decision-making performance of individuals. Consequently, this paper reports the results of two experiments investigating the influence of interruptions on individual decision making. Interruptions were found to improve decision-making performance on simple tasks and to lower performance on complex tasks. For complex tasks, the frequency of interruptions and the dissimilarity of content between the primary and interruption tasks was found to exacerbate this effect. The implications of these results for future research and practice are discussed.

The logic of public announcements, common knowledge, and private suspicions

Abstract: This paper presents a logical system in which various group-level epistemic actions are incorporated into the object language That is, we consider the standard modeling of knowledge among a set of agents by multi-modal Kripke structures One might want to consider actions that take place, such as announcements to groups privately, announcements with suspicious outsiders, etc In our system, such actions correspond to additional modalities in the object language That is, we do not add machinery on top of models (as in Fagin et alia), but we reify aspects of the machinery in the logical language Special cases of our logic have been considered in Plaza, Gerbrandy, and Gerbrandy and Groeneveld The latter group of papers introduce a language in which one can faithfully represent all of the reasoning in examples such as the Muddy Children scenario In that paper we find operators for updating worlds via announcements to groups of agents who are isolated from all others We advance this by considering many more actions, and by using a more general semantics Our logic contains the infinitary operators used in the standard modeling of common knowledge We present a sound and complete logical system for the logic, and we study its expressive power

Incentives and Penalties Related to Earnings Overstatements that Violate GAAP

Abstract: This paper investigates the incentives and the penalties related to earnings overstatements primarily in firms that are subject to accounting enforcement actions by the Securities and Exchange Commission (SEC). I find (1) that managers in treatment firms are more likely to sell their holdings and exercise stock appreciation rights in the period when earnings are overstated than are managers in control firms, and (2) that the sales occur at inflated prices. I do not find evidence that earnings overstatement in these firms is motivated by concerns about debt covenant violations or the cost of external financing. The evidence suggests that the monitoring of managers' trading behavior can be informative about the likelihood of earnings overstatement. Many economists believe that insider trading is an efficient method of compensating managers for their efforts. These economists argue that reputation losses would preclude managers from making profitable trades before periods of poor corporate performance. Conse...

The Unfolding Model of Voluntary Turnover: A Replication and Extension

Abstract: This work reports further theoretical development of Lee and Mitchell's (1994) unfolding model of voluntary turnover, which describes different psychological paths that people take when quitting or...

The Detection of Earnings Manipulation

Abstract: Presented are a profile of a sample of earnings manipulators, their distinguishing characteristics, and a suggested model for detecting manipulation. The model's variables are designed to capture either the financial statement distortions that can result from manipulation or preconditions that might prompt companies to engage in such activity. The results suggest a systematic relationship between the probability of manipulation and some financial statement variables. This evidence is consistent with the usefulness of accounting data in detecting manipulation and assessing the reliability of reported earnings. The model identifies approximately half of the companies involved in earnings manipulation prior to public discovery. Because companies that are discovered manipulating earnings see their stocks plummet in value, the model can be a useful screening device for investment professionals. The screening results, however, require determination of whether the distortions in the financial statement numbers r...

A reciprocal space based method for treating long range interactions in ab initio and force-field-based calculations in clusters

Abstract: A new reciprocal space based formalism for treating long range forces in clusters is presented. It will be shown how the new formalism can be incorporated into plane-wave based density function theory calculations, standard Ewald summation calculations, and smooth particle-mesh Ewald calculations to yield accurate and numerically efficient descriptions of long range interactions in cluster systems.

Hybrid Zones and the Genetic Architecture of a Barrier to Gene Flow Between Two Sunflower Species

Abstract: Genetic analyses of reproductive barriers represent one of the few methods by which theories of speciation can be tested. However, genetic study is often restricted to model organisms that have short generation times and are easily propagated in the laboratory. Replicate hybrid zones with a diversity of recombinant genotypes of varying age offer increased resolution for genetic mapping experiments and expand the pool of organisms amenable to genetic study. Using 88 markers distributed across 17 chromosomes, we analyze the introgression of chromosomal segments of Helianthus petiolaris into H. annuus in three natural hybrid zones. Introgression was significantly reduced relative to neutral expectations for 26 chromosomal segments, suggesting that each segment contains one or more factors that contribute to isolation. Pollen sterility is significantly associated with 16 of these 26 segments, providing a straightforward explanation of why this subset of blocks is disadvantageous in hybrids. In addition, comparison of rates of introgression across colinear vs. rearranged chromosomes indicates that close to 50% of the barrier to introgression is due to chromosomal rearrangements. These results demonstrate the utility of hybrid zones for identifying factors contributing to isolation and verify the prediction of increased resolution relative to controlled crosses.

Fungal endophyte symbiosis and plant diversity in successional fields.

Abstract: Increasing evidence suggests that microbial interactions are important determinants of plant biodiversity. The hypothesis that fungal endophyte symbiosis reduces diversity in successional fields was tested by manipulating infection of tall fescue, the most abundant perennial grass in the eastern United States. Over a 4-year period, species richness declined and tall fescue dominance increased in infected plots relative to uninfected plots without differences in total productivity. A host-specific endophyte, with negligible biomass, altered plant community structure in this long-term field experiment and may be reducing plant diversity throughout its expanding range.