Showing papers by "University of British Columbia published in 2005"

Trastuzumab after adjuvant chemotherapy in HER2-positive breast cancer

Abstract: background Trastuzumab, a recombinant monoclonal antibody against HER2, has clinical activity in advanced breast cancer that overexpresses HER2. We investigated its efficacy and safety after excision of early-stage breast cancer and completion of chemotherapy. methods This international, multicenter, randomized trial compared one or two years of trastuzumab given every three weeks with observation in patients with HER2-positive and either node-negative or node-positive breast cancer who had completed locoregional therapy and at least four cycles of neoadjuvant or adjuvant chemotherapy. results Data were available for 1694 women randomly assigned to two years of treatment with trastuzumab, 1694 women assigned to one year of trastuzumab, and 1693 women assigned to observation. We report here the results only of treatment with trastuzumab for one year or observation. At the first planned interim analysis (median follow-up of one year), 347 events (recurrence of breast cancer, contralateral breast cancer, second nonbreast malignant disease, or death) were observed: 127 events in the trastuzumab group and 220 in the observation group. The unadjusted hazard ratio for an event in the trastuzumab group, as compared with the observation group, was 0.54 (95 percent confidence interval, 0.43 to 0.67; P<0.0001 by the log-rank test, crossing the interim analysis boundary), representing an absolute benefit in terms of disease-free survival at two years of 8.4 percentage points. Overall survival in the two groups was not significantly different (29 deaths with trastuzumab vs. 37 with observation). Severe cardiotoxicity developed in 0.5 percent of the women who were treated with trastuzumab. conclusions One year of treatment with trastuzumab after adjuvant chemotherapy significantly improves disease-free survival among women with HER2-positive breast cancer. (clinicaltrials.gov number, NCT 00045032.)

Diagnosis and management of dementia with Lewy bodies: Third report of the DLB Consortium

Abstract: The dementia with Lewy bodies (DLB) Consortium has revised criteria for the clinical and pathologic diagnosis of DLB incorporating new information about the core clinical features and suggesting improved methods to assess them. REM sleep behavior disorder, severe neuroleptic sensitivity, and reduced striatal dopamine transporter activity on functional neuroimaging are given greater diagnostic weighting as features suggestive of a DLB diagnosis. The 1-year rule distinguishing between DLB and Parkinson disease with dementia may be difficult to apply in clinical settings and in such cases the term most appropriate to each individual patient should be used. Generic terms such as Lewy body (LB) disease are often helpful. The authors propose a new scheme for the pathologic assessment of LBs and Lewy neurites (LN) using alpha-synuclein immunohistochemistry and semiquantitative grading of lesion density, with the pattern of regional involvement being more important than total LB count. The new criteria take into account both Lewy-related and Alzheimer disease (AD)-type pathology to allocate a probability that these are associated with the clinical DLB syndrome. Finally, the authors suggest patient management guidelines including the need for accurate diagnosis, a target symptom approach, and use of appropriate outcome measures. There is limited evidence about specific interventions but available data suggest only a partial response of motor symptoms to levodopa: severe sensitivity to typical and atypical antipsychotics in ∼50%, and improvements in attention, visual hallucinations, and sleep disorders with cholinesterase inhibitors.

The new higher level classification of eukaryotes with emphasis on the taxonomy of protists

Abstract: This revision of the classification of unicellular eukaryotes updates that of Levine et al. (1980) for the protozoa and expands it to include other protists. Whereas the previous revision was primarily to incorporate the results of ultrastructural studies, this revision incorporates results from both ultrastructural research since 1980 and molecular phylogenetic studies. We propose a scheme that is based on nameless ranked systematics. The vocabulary of the taxonomy is updated, particularly to clarify the naming of groups that have been repositioned. We recognize six clusters of eukaryotes that may represent the basic groupings similar to traditional ''kingdoms.'' The multicellular lineages emerged from within monophyletic protist lineages: animals and fungi from Opisthokonta, plants from Archaeplastida, and brown algae from Stramenopiles.

Widespread Parallel Evolution in Sticklebacks by Repeated Fixation of Ectodysplasin Alleles

Abstract: Major phenotypic changes evolve in parallel in nature by molecular mechanisms that are largely unknown. Here, we use positional cloning methods to identify the major chromosome locus controlling armor plate patterning in wild threespine sticklebacks. Mapping, sequencing, and transgenic studies show that the Ectodysplasin (EDA) signaling pathway plays a key role in evolutionary change in natural populations and that parallel evolution of stickleback low-plated phenotypes at most freshwater locations around the world has occurred by repeated selection of Eda alleles derived from an ancestral low-plated haplotype that first appeared more than two million years ago. Members of this clade of low-plated alleles are present at low frequencies in marine fish, which suggests that standing genetic variation can provide a molecular basis for rapid, parallel evolution of dramatic phenotypic change in nature.

Sequential Monte Carlo methods for multitarget filtering with random finite sets

Abstract: Random finite sets (RFSs) are natural representations of multitarget states and observations that allow multisensor multitarget filtering to fit in the unifying random set framework for data fusion. Although the foundation has been established in the form of finite set statistics (FISST), its relationship to conventional probability is not clear. Furthermore, optimal Bayesian multitarget filtering is not yet practical due to the inherent computational hurdle. Even the probability hypothesis density (PHD) filter, which propagates only the first moment (or PHD) instead of the full multitarget posterior, still involves multiple integrals with no closed forms in general. This article establishes the relationship between FISST and conventional probability that leads to the development of a sequential Monte Carlo (SMC) multitarget filter. In addition, an SMC implementation of the PHD filter is proposed and demonstrated on a number of simulated scenarios. Both of the proposed filters are suitable for problems involving nonlinear nonGaussian dynamics. Convergence results for these filters are also established.

Evolutionary dynamics on graphs

Abstract: Evolutionary dynamics have been traditionally studied in the context of homogeneous or spatially extended populations1,2,3,4. Here we generalize population structure by arranging individuals on a graph. Each vertex represents an individual. The weighted edges denote reproductive rates which govern how often individuals place offspring into adjacent vertices. The homogeneous population, described by the Moran process3, is the special case of a fully connected graph with evenly weighted edges. Spatial structures are described by graphs where vertices are connected with their nearest neighbours. We also explore evolution on random and scale-free networks5,6,7. We determine the fixation probability of mutants, and characterize those graphs for which fixation behaviour is identical to that of a homogeneous population7. Furthermore, some graphs act as suppressors and others as amplifiers of selection. It is even possible to find graphs that guarantee the fixation of any advantageous mutant. We also study frequency-dependent selection and show that the outcome of evolutionary games can depend entirely on the structure of the underlying graph. Evolutionary graph theory has many fascinating applications ranging from ecology to multi-cellular organization and economics.

The Social Processes of Organizational Sensemaking.

Abstract: A longitudinal study of the social processes of organizational sensemaking suggests that they unfold in four distinct forms: guided, fragmented, restricted, and minimal. These forms result from the degree to which leaders and stakeholders engage in “sensegiving”—attempts to influence others' understandings of an issue. Each of the four forms of organizational sensemaking is associated with a distinct set of process characteristics that capture the dominant pattern of interaction. They also each result in particular outcomes, specifically, the nature of the accounts and actions generated.

Validating the organizational climate measure: links to managerial practices, productivity and innovation

Abstract: This paper describes the development and validation of a multidimensional measure of organizational climate, the Organizational Climate Measure (OCM), based upon Quinn and Rohrbaugh's Competing Values model. A sample of 6869 employees across 55 manufacturing organizations completed the questionnaire. The 17 scales contained within the measure had acceptable levels of reliability and were factorially distinct. Concurrent validity was measured by correlating employees' ratings with managers' and interviewers' descriptions of managerial practices and organizational characteristics. Predictive validity was established using measures of productivity and innovation. The OCM also discriminated effectively between organizations, demonstrating good discriminant validity. The measure offers researchers a relatively comprehensive and flexible approach to the assessment of organizational members' experience and promises applied and theoretical benefits. Copyright © 2005 John Wiley & Sons, Ltd.

A time-dependent Hamilton-Jacobi formulation of reachable sets for continuous dynamic games

Abstract: We describe and implement an algorithm for computing the set of reachable states of a continuous dynamic game. The algorithm is based on a proof that the reachable set is the zero sublevel set of the viscosity solution of a particular time-dependent Hamilton-Jacobi-Isaacs partial differential equation. While alternative techniques for computing the reachable set have been proposed, the differential game formulation allows treatment of nonlinear systems with inputs and uncertain parameters. Because the time-dependent equation's solution is continuous and defined throughout the state space, methods from the level set literature can be used to generate more accurate approximations than are possible for formulations with potentially discontinuous solutions. A numerical implementation of our formulation is described and has been released on the web. Its correctness is verified through a two vehicle, three dimensional collision avoidance example for which an analytic solution is available.

Healthy nutrition environments: concepts and measures.

Abstract: The authors provide a conceptual model of a healthy nutrition environment, then review the types of measures required to assess various aspects of this environment. Measures fall into priority categories of consumer and community environments.

Are invasive species the drivers or passengers of change in degraded ecosystems

Abstract: Few invaded ecosystems are free from habitat loss and disturbance, leading to uncertainty whether dominant invasive species are driving community change or are passengers along for the environmental ride. The ''driver'' model predicts that invaded communities are highly interactive, with subordinate native species being limited or ex- cluded by competition from the exotic dominants. The ''passenger'' model predicts that invaded communities are primarily structured by noninteractive factors (environmental change, dispersal limitation) that are less constraining on the exotics, which thus dominate. We tested these alternative hypotheses in an invaded, fragmented, and fire-suppressed oak savanna. We examined the impact of two invasive dominant perennial grasses on community structure using a reduction (mowing of aboveground biomass) and removal (weeding of above- and belowground biomass) experiment conducted at different seasons and soil depths. We examined the relative importance of competition vs. dispersal limitation with experimental seed additions. Competition by the dominants limits the abundance and re- production of many native and exotic species based on their increased performance with removals and mowing. The treatments resulted in increased light availability and bare soil; soil moisture and N were unaffected. Although competition was limiting for some, 36 of 79 species did not respond to the treatments or declined in the absence of grass cover. Seed additions revealed that some subordinates are dispersal limited; competition alone was insufficient to explain their rarity even though it does exacerbate dispersal inefficiencies by lowering reproduction. While the net effects of the dominants were negative, their presence restricted woody plants, facilitated seedling survival with moderate disturbance (i.e., treatments applied in the fall), or was not the primary limiting factor for the occurrence of some species. Finally, the species most functionally distinct from the dominants (forbs, woody plants) responded most significantly to the treatments. This suggests that relative abundance is determined more by trade-offs relating to environmental conditions (long- term fire suppression) than to traits relating to resource capture (which should most impact functionally similar species). This points toward the passenger model as the underlying cause of exotic dominance, although their combined effects (suppressive and facilitative) on community structure are substantial.

The Health and Well-Being of Caregivers of Children With Cerebral Palsy

Abstract: Objective. Most children enjoy healthy childhoods with little need for specialized health care services. However, some children experience difficulties in early childhood and require access to and utilization of considerable health care resources over time. Although impaired motor function is the hallmark of the cerebral palsy (CP) syndromes, many children with this development disorder also experience sensory, communicative, and intellectual impairments and may have complex limitations in self-care functions. Although caregiving is a normal part of being the parent of a young child, this role takes on an entirely different significance when a child experiences functional limitations and possible long-term dependence. One of the main challenges for parents is to manage their child9s chronic health problems effectively and juggle this role with the requirements of everyday living. Consequently, the task of caring for a child with complex disabilities at home might be somewhat daunting for caregivers. The provision of such care may prove detrimental to both the physical health and the psychological well-being of parents of children with chronic disabilities. It is not fully understood why some caregivers cope well and others do not. The approach of estimating the “independent” or “direct” effects of the care recipient9s disability on the caregiver9s health is of limited value because (1) single-factor changes are rare outside the context of constrained experimental situations; (2) assumptions of additive relationships and perfect measurements rarely hold; and (3) such approaches do not provide a complete perspective, because they fail to examine indirect pathways that occur between predictor variables and health outcomes. A more detailed analytical approach is needed to understand both direct and indirect effects simultaneously. The primary objective of the current study was to examine, within a single theory-based multidimensional model, the determinants of physical and psychological health of adult caregivers of children with CP. Methods. We developed a stress process model and applied structural equation modeling with data from a large cohort of caregivers of children with CP. This design allowed the examination of the direct and indirect relationships between a child9s health, behavior and functional status, caregiver characteristics, social supports, and family functioning and the outcomes of caregivers9 physical and psychological health. Families ( n = 468) of children with CP were recruited from 19 regional children9s rehabilitation centers that provide outpatient disability management and supports in Ontario, Canada. The current study drew on a population available to the investigators from a previous study, the Ontario Motor Growth study, which explored patterns of gross motor development in children with CP. Data on demographic variables and caregivers9 physical and psychological health were assessed using standardized, self-completed parent questionnaires as well as a face-to-face home interview. Structural equation modeling was used to test specific hypotheses outlined in our conceptual model. This analytic approach involved a 2-step process. In the first step, observed variables that were hypothesized to measure the underlying constructs were tested using confirmatory factor analysis; this step led to the so-called measurement model. The second step tested hypotheses about relationships among the variables in the structural model. All of the hypothesized paths in the conceptual model were tested and included in the structural model. However, only paths that were significant were shown in the final results. The direct, indirect, and total effects of theoretical constructs on physical and psychological health were calculated using the structural model. Results. The most important predictors of caregivers9 well-being were child behavior, caregiving demands, and family function. A higher level of behavior problems was associated with lower levels of both psychological (β = −.22) and physical health (β = −.18) of the caregivers, whereas fewer child behavior problems were associated with higher self-perception (β = −.37) and a greater ability to manage stress (β = −.18). Less caregiving demands were associated with better physical (β = .23) and psychological (β = .12) well-being of caregivers, respectively. Similarly, higher reported family functioning was associated with better psychological health (β = .33) and physical health (β = .33). Self-perception and stress management were significant direct predictors of caregivers9 psychological health but did not directly influence their physical well-being. Caregivers9 higher self-esteem and sense of mastery over the caregiving situation predicted better psychological health (β = .23). The use of more stress management strategies was also associated with better psychological health of caregivers (β = .11). Gross income (β = .08) and social support (β = .06) had indirect overall effects only on psychological health outcome, whereas self-perception (β = .22), stress management (β = .09), gross income (β = .07), and social support (β = .06) had indirect total effects only on physical health outcomes. Conclusions. The psychological and physical health of caregivers, who in this study were primarily mothers, was strongly influenced by child behavior and caregiving demands. Child behavior problems were an important predictor of caregiver psychological well-being, both directly and indirectly, through their effect on self-perception and family function. Caregiving demands contributed directly to both the psychological and the physical health of the caregivers. The practical day-to-day needs of the child created challenges for parents. The influence of social support provided by extended family, friends, and neighbors on health outcomes was secondary to that of the immediate family working closely together. Family function affected health directly and also mediated the effects of self-perception, social support, and stress management. In families of children with CP, strategies for optimizing caregiver physical and psychological health include supports for behavioral management and daily functional activities as well as stress management and self-efficacy techniques. These data support clinical pathways that require biopsychosocial frameworks that are family centered, not simply technical and short-term rehabilitation interventions that are focused primarily on the child. In terms of prevention, providing parents with cognitive and behavioral strategies to manage their child9s behaviors may have the potential to change caregiver health outcomes. This model also needs to be examined with caregivers of children with other disabilities.

Equity incentives and earnings management

Abstract: This paper examines the link between managers' equity incentives—arising from stock‐based compensation and stock ownership—and earnings management. We hypothesize that managers with high equity incentives are more likely to sell shares in the future and this motivates these managers to engage in earnings management to increase the value of the shares to be sold. Using stock‐based compensation and stock ownership data over the 1993–2000 time period, we document that managers with high equity incentives sell more shares in subsequent periods. As expected, we find that managers with high equity incentives are more likely to report earnings that meet or just beat analysts' forecasts. We also find that managers with consistently high equity incentives are less likely to report large positive earnings surprises. This finding is consistent with the wealth of these managers being more sensitive to future stock performance, which leads to increased reserving of current earnings to avoid future earnings disappointm...

Fifty years of the critical incident technique: 1954-2004 and beyond:

Abstract: It has now been 50 years since Flanagan (1954) published his classic article on the critical incident technique (CIT) - a qualitative research method that is still widely used today This article reviews the origin and evolution of the CIT during the past 50 years, discusses CIT’s place within the qualitative research tradition, examines the robustness of the method, and offers some recommendations for using the CIT as we look forward to its next 50 years of use The focus of this article is primarily on the use of the CIT in counselling psychology, although other disciplines are touched upon

Performance evaluation and design trade-offs for network-on-chip interconnect architectures

Abstract: Multiprocessor system-on-chip (MP-SoC) platforms are emerging as an important trend for SoC design. Power and wire design constraints are forcing the adoption of new design methodologies for system-on-chip (SoC), namely, those that incorporate modularity and explicit parallelism. To enable these MP-SoC platforms, researchers have recently pursued scaleable communication-centric interconnect fabrics, such as networks-on-chip (NoC), which possess many features that are particularly attractive for these. These communication-centric interconnect fabrics are characterized by different trade-offs with regard to latency, throughput, energy dissipation, and silicon area requirements. In this paper, we develop a consistent and meaningful evaluation methodology to compare the performance and characteristics of a variety of NoC architectures. We also explore design trade-offs that characterize the NoC approach and obtain comparative results for a number of common NoC topologies. To the best of our knowledge, this is the first effort in characterizing different NoC architectures with respect to their performance and design trade-offs. To further illustrate our evaluation methodology, we map a typical multiprocessing platform to different NoC interconnect architectures and show how the system performance is affected by these design trade-offs.

Synthesis of iron fertilization experiments: From the iron age in the age of enlightenment

Abstract: Comparison of eight iron experiments shows that maximum Chl a, the maximum DIC removal, and the overall DIC/Fe efficiency all scale inversely with depth of the wind mixed layer (WML) defining the light environment. Moreover, lateral patch dilution, sea surface irradiance, temperature, and grazing play additional roles. The Southern Ocean experiments were most influenced by very deep WMLs. In contrast, light conditions were most favorable during SEEDS and SERIES as well as during IronEx-2. The two extreme experiments, EisenEx and SEEDS, can be linked via EisenEx bottle incubations with shallower simulated WML depth. Large diatoms always benefit the most from Fe addition, where a remarkably small group of thriving diatom species is dominated by universal response of Pseudo-nitzschia spp. Significant response of these moderate (10–30 μm), medium (30–60 μm), and large (>60 μm) diatoms is consistent with growth physiology determined for single species in natural seawater. The minimum level of “dissolved” Fe (filtrate < 0.2 μm) maintained during an experiment determines the dominant diatom size class. However, this is further complicated by continuous transfer of original truly dissolved reduced Fe(II) into the colloidal pool, which may constitute some 75% of the “dissolved” pool. Depth integration of carbon inventory changes partly compensates the adverse effects of a deep WML due to its greater integration depths, decreasing the differences in responses between the eight experiments. About half of depth-integrated overall primary productivity is reflected in a decrease of DIC. The overall C/Fe efficiency of DIC uptake is DIC/Fe ∼ 5600 for all eight experiments. The increase of particulate organic carbon is about a quarter of the primary production, suggesting food web losses for the other three quarters. Replenishment of DIC by air/sea exchange tends to be a minor few percent of primary CO2 fixation but will continue well after observations have stopped. Export of carbon into deeper waters is difficult to assess and is until now firmly proven and quite modest in only two experiments.

Pathogenesis of Gout

Abstract: Researchers have recently made advances in defining the pathogenesis of gout, including elucidating its risk factors and tracing the molecular mechanisms of renal urate transport and crystal-induce

Natalizumab induction and maintenance therapy for Crohn's disease.

Abstract: BackgroundNatalizumab, a humanized monoclonal antibody against α4 integrin, inhibits leukocyte adhesion and migration into inflamed tissue. MethodsWe conducted two controlled trials to evaluate natalizumab as induction and maintenance therapy in patients with active Crohn's disease. In the first trial, 905 patients were randomly assigned to receive 300 mg of natalizumab or placebo at weeks 0, 4, and 8. The primary outcome was response, defined by a decrease in the Crohn's Disease Activity Index (CDAI) score of at least 70 points, at week 10. In the second trial, 339 patients who had a response to natalizumab in the first trial were randomly reassigned to receive 300 mg of natalizumab or placebo every four weeks through week 56. The primary outcome was a sustained response through week 36. A secondary outcome in both trials was disease remission (a CDAI score of less than 150). ResultsIn the first trial, the natalizumab and placebo groups had similar rates of response (56 percent and 49 percent, respective...

Introduction of Combined CHOP Plus Rituximab Therapy Dramatically Improved Outcome of Diffuse Large B-Cell Lymphoma in British Columbia

Abstract: Purpose For more than two decades, cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) has been the standard therapy for diffuse large B-cell lymphoma (DLBCL). The addition of rituximab to CHOP has been shown to improve outcome in elderly patients with DLBCL. We conducted a population-based analysis to assess the impact of this combination therapy on adult patients with DLBCL in the province of British Columbia (BC). Methods We compared outcomes during a 3-year period; 18 months before (prerituximab) and 18 months after (postrituximab) institution of a policy recommending the combination of CHOP and rituximab for all patients with newly diagnosed advanced-stage (stage III or IV or stage I or II with “B” symptoms or bulky [> 10 cm] disease) DLBCL. Results A total of 292 patients were evaluated; 140 in the prerituximab group (median follow-up, 42 months) and 152 in the postrituximab group (median follow-up, 24 months). Both progression-free survival (risk ratio, 0.56; 95% CI, 0.39 to 0.81; P =...

Introduction of combined CHOP plus rituximab therapy dramatically improved outcome of diffuse large B-cell lymphoma in British Columbia

Abstract: Purpose For more than two decades, cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) has been the standard therapy for diffuse large B-cell lymphoma (DLBCL). The addition of rituximab to CHOP has been shown to improve outcome in elderly patients with DLBCL. We conducted a population-based analysis to assess the impact of this combination therapy on adult patients with DLBCL in the province of British Columbia (BC). Methods We compared outcomes during a 3-year period; 18 months before (prerituximab) and 18 months after (postrituximab) institution of a policy recommending the combination of CHOP and rituximab for all patients with newly diagnosed advanced-stage (stage III or IV or stage I or II with B symptoms or bulky [> 10 cm] disease) DLBCL. Results A total of 292 patients were evaluated; 140 in the prerituximab group (median follow-up, 42 months) and 152 in the postrituximab group (median follow-up, 24 months). Both progression-free survival (risk ratio, 0.56; 95% Cl, 0.39 to 0.81; P =.002) and overall survival (risk ratio, 0.40; 95% Cl, 0.27 to 0.61, P <.0001) were significantly improved in the postrituximab group. After controlling for age and International Prognostic Index score, era of treatment remained a strong independent predictor of progression-free survival (risk ratio, 0.59; 95% Cl, 0.41 to 0.85; P =.005) and overall survival (risk ratio, 0.43; 95% Cl, 0.29 to 0.66; P <.001). The benefit of treatment in the postrituximab era was present regardless of age. Conclusion The addition of rituximab to CHOP chemotherapy has resulted in a dramatic improvement in outcome for DLBCL patients of all ages in the province of BC.

Bayesian Logical Data Analysis for the Physical Sciences: A Comparative Approach with Mathematica® Support

Abstract: Preface Acknowledgements 1. Role of probability theory in science 2. Probability theory as extended logic 3. The how-to of Bayesian inference 4. Assigning probabilities 5. Frequentist statistical inference 6. What is a statistic? 7. Frequentist hypothesis testing 8. Maximum entropy probabilities 9. Bayesian inference (Gaussian errors) 10. Linear model fitting (Gaussian errors) 11. Nonlinear model fitting 12. Markov Chain Monte Carlo 13. Bayesian spectral analysis 14. Bayesian inference (Poisson sampling) Appendix A. Singular value decomposition Appendix B. Discrete Fourier transforms Appendix C. Difference in two samples Appendix D. Poisson ON/OFF details Appendix E. Multivariate Gaussian from maximum entropy References Index.

Self-regulation and self-presentation: regulatory resource depletion impairs impression management and effortful self-presentation depletes regulatory resources.

Abstract: Self-presentation may require self-regulation, especially when familiar or dispositional tendencies must be overridden in service of the desired impression. Studies 1-4 showed that self-presentation under challenging conditions or according to counter-normative patterns (presenting oneself modestly to strangers, boastfully to friends, contrary to gender norms, to a skeptical audience, or while being a racial token) led to impaired self-regulation later, suggesting that those self-presentations depleted self-regulatory resources. When self-presentation conformed to familiar, normative, or dispositional patterns, self-regulation was less implicated. Studies 5-8 showed that when resources for self-regulation had been depleted by prior acts of self-control, self-presentation drifted toward less-effective patterns (talking too much, overly or insufficiently intimate disclosures, or egotistical arrogance). Thus, inner processes may serve interpersonal functions, although optimal interpersonal activity exacts a short-term cost.

Combining probability from independent tests: the weighted Z-method is superior to Fisher's approach

Abstract: The most commonly used method in evolutionary biology for combining information across multiple tests of the same null hypothesis is Fisher's combined probability test. This note shows that an alternative method called the weighted Z-test has more power and more precision than does Fisher's test. Furthermore, in contrast to some statements in the literature, the weighted Z-method is superior to the unweighted Z-transform approach. The results in this note show that, when combining P-values from multiple tests of the same hypothesis, the weighted Z-method should be preferred.

On the Industry Concentration of Actively Managed Equity Mutual Funds

Abstract: Mutual fund managers may decide to deviate from a well-diversified portfolio and concentrate their holdings in industries where they have informational advantages. In this paper, we study the relation between the industry concentration and the performance of actively managed U.S. mutual funds from 1984 to 1999. Our results indicate that, on average, more concentrated funds perform better after controlling for risk and style differences using various performance measures. This finding suggests that investment ability is more evident among managers who hold portfolios concentrated in a few industries. ACTIVELY MANAGED MUTUAL FUNDS are an important constituent of the financial sector. Despite the well-documented evidence that, on average, actively managed funds underperform passive benchmarks, mutual fund managers might still differ substantially in their investment abilities.1 In this paper, we examine whether some fund managers create value by concentrating their portfolios in industries where they have informational advantages. Conventional wisdom suggests that investors should widely diversify their holdings across industries to reduce their portfolios' idiosyncratic risk. Fund

Gender Role Attitudes and the Labour-market Outcomes of Women across OECD Countries

Abstract: This paper uses data from the World Value Surveys (1990, 1995,1999) to investigate the impact of gender role attitudes and work values on women's labour-market outcomes across 25 OECD countries. Anti-egalitarian views are found to display the strongest negative association with female employment rates and the gender pay gap. These views are, however, softening among recent cohorts. On the other hand, perceptions of women's role as homemakers, which are likely formed in youth and linked to religious ideology, are more persistent over time. They could be implicated in the recent slowdown of the gender convergence in pay. Finally, the unavoidable clash between family values and egalitarian views, that takes the form of an inner conflict for many women--the so-called 'mother's guilt'--is another obstacle in the path towards greater gender equality in the labour market. Copyright 2005, Oxford University Press.