56 research outputs found
Collective decisions with interdependent valuations
Many collective decision problems have the common feature that individuals' desired outcomes are correlated but not identical. This paper studies collective decisions with private information about these desired policies. Each agent holds private information which mainly concerns his own bliss point, but this private information also affects all other agents' bliss points. We concentrate on two specific mechanisms, the mean and the median mechanism. We establish existence of two symmetric Bayesian Nash equilibria of the corresponding game and compare the performance of the mechanisms for different degrees of interdependencies. Applications of our framework include the assignment of voting rights in the council of the European Central Bank, the design of decision processes in teams, firms, and international organizations.collective decisions, asymmetric information, interdependent valuations
Information acquisition and decision making in committees: a survey
JEL Classification: D71, E52Committees, costly information acquisition, monetary policy committees, strategic voting
Cancer History: A Predictor of IPMN Subtype and Dysplastic Status?
Introduction
The aim of this study was to determine the association of PMH and FH of pancreatic (PDAC) and non-pancreatic cancers with IPMN malignant risk.
Methods
A retrospective review of a prospective database of IPMN patients undergoing resection was performed to assess FH and PMH.
Results
FH of PDAC was present in 13% of 362 included patients. Of these, 8% had at least one first degree relative (FDR) with PDAC. The rate of PDAC positive FH in non-invasive versus invasive IPMN patients was 14% and 8%, respectively (p = 0.3). In main duct IPMN patients, FH (44%) and PMH of non-pancreatic cancer (16%) was higher than that seen in branch duct IPMN (FH 29%; PMH 6%; p = 0.004 and 0.008).
Conclusions
FH of PDAC is not associated with IPMN malignant progression. FH and PMH of non-pancreatic cancer is associated with main duct IPMN, the subtype with the highest rate of invasive transformation
In silico discovery of blood cell macromolecular associations
Background
Physical molecular interactions are the basis of intracellular signalling and gene regulatory networks, and comprehensive, accessible databases are needed for their discovery. Highly correlated transcripts may reflect important functional associations, but identification of such associations from primary data are cumbersome. We have constructed and adapted a user-friendly web application to discover and identify putative macromolecular associations in human peripheral blood based on significant correlations at the transcriptional level.
Methods
The blood transcriptome was characterized by quantification of 17,328 RNA species, including 341 mature microRNAs in 105 clinically well-characterized postmenopausal women. Intercorrelation of detected transcripts signal levels generated a matrix with > 150 million correlations recognizing the human blood RNA interactome. The correlations with calculated adjusted p-values were made easily accessible by a novel web application.
Results
We found that significant transcript correlations within the giant matrix reflect experimentally documented interactions involving select ubiquitous blood relevant transcription factors (CREB1, GATA1, and the glucocorticoid receptor (GR, NR3C1)). Their responsive genes recapitulated up to 91% of these as significant correlations, and were replicated in an independent cohort of 1204 individual blood samples from the Framingham Heart Study. Furthermore, experimentally documented mRNAs/miRNA associations were also reproduced in the matrix, and their predicted functional co-expression described. The blood transcript web application is available at http://app.uio.no/med/klinmed/correlation-browser/blood/index.php and works on all commonly used internet browsers.
Conclusions
Using in silico analyses and a novel web application, we found that correlated blood transcripts across 105 postmenopausal women reflected experimentally proven molecular associations. Furthermore, the associations were reproduced in a much larger and more heterogeneous cohort and should therefore be generally representative. The web application lends itself to be a useful hypothesis generating tool for identification of regulatory mechanisms in complex biological data sets.publishedVersio
Bone mineral density and the risk of incident dementia:A meta-analysis
Background: It is not known whether bone mineral density (BMD) measured at baseline or as the rate of decline prior to baseline (prior bone loss) is a stronger predictor of incident dementia or Alzheimer's disease (AD). Methods:We performed a meta-analysis of three longitudinal studies, the Framingham Heart Study (FHS), the Rotterdam Study (RS), and the Rush Memory and Aging Project (MAP), modeling the time to diagnosis of dementia as a function of BMD measures accounting for covariates. We included individuals with one or two BMD assessments, aged ≥60 years, and free of dementia at baseline with follow-up available. BMD was measured at the hip femoral neck using dual-energy X-ray absorptiometry (DXA), or at the heel calcaneus using quantitative ultrasound to calculate estimated BMD (eBMD). BMD at study baseline (“baseline BMD”) and annualized percentage change in BMD prior to baseline (“prior bone loss”) were included as continuous measures. The primary outcome was incident dementia diagnosis within 10 years of baseline, and incident AD was a secondary outcome. Baseline covariates included age, sex, body mass index, ApoE4 genotype, and education. Results: The combined sample size across all three studies was 4431 with 606 incident dementia diagnoses, 498 of which were AD. A meta-analysis of baseline BMD across three studies showed higher BMD to have a significant protective association with incident dementia with a hazard ratio of 0.47 (95% CI: 0.23–0.96; p = 0.038) per increase in g/cm2, or 0.91 (95% CI: 0.84–0.995) per standard deviation increase. We observed a significant association between prior bone loss and incident dementia with a hazard ratio of 1.30 (95% CI: 1.12–1.51; p < 0.001) per percent increase in prior bone loss only in the FHS cohort. Conclusions: Baseline BMD but not prior bone loss was associated with incident dementia in a meta-analysis across three studies.</p
Eight common genetic variants associated with serum dheas levels suggest a key role in ageing mechanisms
Dehydroepiandrosterone sulphate (DHEAS) is the most abundant circulating steroid secreted by adrenal glands-yet its function is unknown. Its serum concentration declines significantly with increasing age, which has led to speculation that a relative DHEAS deficiency may contribute to the development of common age-related diseases or diminished longevity. We conducted a meta-analysis of genome-wide association data with 14,846 individuals and identified eight independent common SNPs associated with serum DHEAS concentrations. Genes at or near the identified loci include ZKSCAN5 (rs11761528; p = 3.15×10-36), SULT2A1 (rs2637125; p = 2.61×10-19), ARPC1A (rs740160; p = 1.56×10-16), TRIM4 (rs17277546; p = 4.50×10-11), BMF (rs7181230; p = 5.44×10-11), HHEX (rs2497306; p = 4.64×10-9), BCL2L11 (rs6738028; p = 1.72×10-8), and CYP2C9 (rs2185570; p = 2.29×10-8). These genes are associated with type 2 diabetes, lymphoma, actin filament assembly, drug and xenobiotic metabolism, and zinc finger proteins. Several SNPs were associated with changes in gene expression levels, and the related genes are connected to biological pathways linking DHEAS with ageing. This study provides much needed insight into the function of DHEAS
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
Decision making in the European Union: Externalities and incomplete information
This dissertation consists of three essays on collective decisions, whereby the focus is on the influence of external effects and incomplete information on the results of different decision processes. In the first essay, I analyze collective decisions where individually desired outcomes are correlated but not identical. Each individual holds private information that mainly concerns his own desired policy but also affects all other individuals. Two direct mechanisms, the median and the mean, are analyzed. I establish the existence of symmetric Bayesian Nash equilibria of the corresponding games. In equilibrium, under the median mechanism individuals understate their private information, whereas under the mean mechanism they overstate it. As a consequence, the performance of the mechanisms depends upon the extent to which individual interests influence each other. The second essay focuses on fiscal stabilization decisions under the European Stability and Growth Pact when member states experience negative spillovers of debt issuance due to a common monetary policy. Private information on behalf of interest groups about costs or benefits of delayed stabilization leads to a war of attrition that may be mitigated by a fine for deficits. In the presence of private benefits of delay however, the effect of a fine is not unambiguously welfare increasing. Moreover, the pact does not implement the ex post efficient decision. Therefore, I adapt an expected externality mechanism. This mechanism yields the best achievable outcome in the presence of private information, but is unfortunately not able to ensure voluntary participation ex post. In the third essay, the influence of different decision procedures on the entry decision into a monetary union in the presence of asymmetric shocks and externalities in decision making is analyzed. The result is that - concentrating on the perspective of a potential member - unification performs relatively poor compared to separation. This holds irrespective of the decision procedure. The only possibility to make entry profitable for a potential member is to grant it a merely exclusive decision right in common policies. However and despite the fact that transaction costs are not explicitly modeled, there exist combinations of interdependencies and preferences that make entry desirable
Emotions and behavioural ethics : the case of asset management and investment banking
This PhD Dissertation, structured by essays, aims to contribute to the field of emotions and behavioural ethics by spanning across disciplinary boundaries and methodological approaches. The ‘General Introduction’ provides a background as well as an overview of the contributions of this PhD Dissertation. The first essay provides the first systematic review on emotions and ethical decision-making, based on 38 empirical studies published between 2008 and 2017. At a methodological level, it reflects on the research methods that have been deployed so far to validate the study of the role of emotions on ethical decision-making. At a content level, it outlines the impact, in terms of outcomes, of different categories of emotions on ethical decision-making, through developing a 2x2 matrix of categories and outcomes. It concludes by recommending future thematic research avenues at both a methodological and content-level. The second essay provides the first exploratory study of implicit ethical behaviour and integral emotion responses in the asset management industry, through critical incident interviews with 38 elite fund managers in top-tier and boutique asset management companies in the UK. The latent thematic analysis of the interviews, guided by an essentialist paradigm, contributes to a contextualised elaboration of theory by developing a framework linking dimensions of ethical behaviour (i.e., authenticity and responsibility) with emotion responses (i.e., control and motivation). It contributes to the literature on ethical theories/value orientation, emotion regulation and appraisal theories by highlighting congruencies and incongruencies with existing research. The third essay provides a group-level psychosocial analysis of ethical risk on both a conscious and unconscious tier. Furthermore, it identifies how emotional contagion and RegTech (i.e., regulatory technology) efficiency affect ethical risk. It develops a mid-range model of ethical risk, alongside a typology of ethical behaviour and risk, and discusses theoretical and managerial implications
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