34 research outputs found
Lessons Learnt from Some Natural Energy Sources
The chapter presents in a systematic manner the lessons learnt from the natural energy systems (NES) and their specific features. The conclusions are based on the evaluation of the risk impact on environment and for the improvement of the risk evaluation methodologies of such systems. A specific feature of the NES is the interdependence between them and society/mankind and the environment. Risk analyses for such systems have specific features underlined while compared with the features of the artificial (man-made) energy systems (MMES). Previous works illustrated in detail the NES versus MMES differences. This chapter presents the main aspects of such a review, when applied to a specific NES, the natural nuclear fission reactor in Oklo, Gabon (NES_Oklo). NES_Oklo operated about two billion years ago for about two hundreds millions of years. The lessons drawn from studying how this reactor was built, operated and self-decommissioned are of high importance for nuclear energy and not only. There are conclusions drawn from the study of Oklo reactor, which seem to shake some taboo issues in Physics, like for instance the light speed limit and other fundamental aspects of Quantum Mechanics, which have also important philosophical implications
Some Issues on Possible Connections between Creativity in Science and Technology and Old Cultural Frameworks
The paper presents some results related to the approaches used to identify possible connections between aspects of creativity in science and technology and old cultural topics and paradigms. The analysis is performed for some specific cases for nuclear physics and nuclear energy issues considered of interest in the Romanian environment. Five cases were analyzed. The evaluation method is based on some previous results proposed by the author in order to illustrate the identified, in a systematic manner, connections between creativity in science and technology and old cultural framework. By using the proposed method, a set of connections was identified for the chosen cases. The approach was tested for some specific cases, but it is expected that it may be applied to other examples as well
Some Considerations on the Lessons Learnt from the Cavalcade of Changes in Physics’ Models
This paper presents an attempt to explain and to make predictions on the change process in the physics’ models. One important goal of the search for such an attempt is to develop an approach that is able to have a certain degree of predictability of at least the direction in which the models will change, assuming that in general it is possible to have an answer to the question, whether this change process has a certain rhythmicity and follows some patterns, or it is a totally chaotic one. The paradigmatic approach of Kuhn on changes in science was one of the starting points for this search, and the use of topological aspects to describe models in physics was a starting point of the search for the approach. By using notions of categories and of syzygies from mathematics, a new approach is proposed to evaluate the direction of changes in science and technology, with an example from the nuclear physics and technology
Risk Informed Support of Decision Making in Nuclear Power Plant Emergency Zoning - Generic Framework towards Harmonising NPP Emergency Planning Practices
The report provides a systematic overview of the essential aspects of risk informed support of decision making (RIDM) in nuclear power plant (NPP) emergency zoning (EZ) as a contribution to harmonising strategic practices in the area. Owing to the state-of-the-art understanding and increased characterisation of NPP severe accidents, overall management of them should be analysed as an integrated complex process. The interrelationship of NPP emergency operating procedures, safety and risk assessments, severe accident management guidelines, and emergency off-site actions should be planned and organised to minimize the consequences of such accidents. A deterministic approach, coupled with both probabilistic safety assessment (PSA) technology and PSA results can play significant role in the development of relevant nuclear utility, regulatory and all stakeholders policies. The report describes the background, objectives and current state of a corresponding activity within JRC-IE's Analysis and Management of Nuclear Accidents (AMA) Action on probabilistic safety / risk assessment methodologies and practices for RIDM approach applied to NPP EZ. The approach is interdisciplinary, based on integration of PSA technology, severe accident phenomenology, and radiological protection.JRC.F.4-Nuclear design safet
Replication Study and Meta-Analysis in European Samples Supports Association of the 3p21.1 Locus with Bipolar Disorder
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GWAS of Suicide Attempt in Psychiatric Disorders and Association With Major Depression Polygenic Risk Scores
Objective: More than 90% of people who attempt suicide have a psychiatric diagnosis;however, twin and family studies suggest that the genetic etiology of suicide attempt is partially distinct from that of the psychiatric disorders themselves. The authors present the largest genome-wide association study (GWAS) on suicide attempt, using cohorts of individuals with major depressive disorder, bipolar disorder, and schizophrenia from the Psychiatric Genomics Consortium. Methods: The samples comprised 1,622 suicide attempters and 8,786 nonattempters with major depressive disorder;3,264 attempters and 5,500 nonattempters with bipolar disorder;and 1,683 attempters and 2,946 nonattempters with schizophrenia. A GWAS on suicide attempt was performed by comparing attempters to nonattempters with each disorder, followed by a meta-analysis across disorders. Polygenic risk scoring was used to investigate the genetic relationship between suicide attempt and the psychiatric disorders. Results: Three genome-wide significant loci for suicide attempt were found: one associated with suicide attempt in major depressive disorder, one associated with suicide attempt in bipolar disorder, and one in the meta-analysis of suicide attempt in mood disorders. These associations were not replicated in independent mood disorder cohorts from the UK Biobank and iPSYCH. No significant associations were found in the meta-analysis of all three disorders. Polygenic risk scores for major depression were significantly associated with suicide attempt in major depressive disorder (R-2=0.25%), bipolar disorder (R-2=0.24%), and schizophrenia (R-2=0.40%). Conclusions: This study provides new information on genetic associations and demonstrates that genetic liability for major depression increases risk for suicide attempt across psychiatric disorders. Further collaborative efforts to increase sample size may help to robustly identify genetic associations and provide biological insights into the etiology of suicide attempt
GWAS of Suicide Attempt in Psychiatric Disorders Identifies Association With Major Depression Polygenic Risk Scores
Objective: Over 90% of suicide attempters have a psychiatric diagnosis, however twin and family studies suggest that the genetic etiology of suicide attempt (SA) is partially distinct from that of the psychiatric disorders themselves. Here, we present the largest genome-wide association study (GWAS) on suicide attempt using major depressive disorder (MDD), bipolar disorder (BIP) and schizophrenia (SCZ) cohorts from the Psychiatric Genomics Consortium.
Method: Samples comprise 1622 suicide attempters and 8786 non-attempters with MDD, 3264 attempters and 5500 non-attempters with BIP and 1683 attempters and 2946 non-attempters with SCZ. SA GWAS were performed by comparing attempters to non-attempters in each disorder followed by meta-analyses across disorders. Polygenic risk scoring was used to investigate the genetic relationship between SA and the psychiatric disorders.
Results: Three genome-wide significant loci for SA were found: one associated with SA in MDD, one in BIP, and one in the meta-analysis of SA in mood disorders. These associations were not replicated in independent mood disorder cohorts from the UK Biobank and iPSYCH. No significant associations were found in the meta-analysis of all three disorders. Polygenic risk scores for major depression were significantly associated with SA in MDD (R2=0.25%, P=0.0006), BIP (R2=0.24%, P=0.0002) and SCZ (R2=0.40%, P=0.0006).
Conclusions: This study provides new information on genetic associations and demonstrates that genetic liability for major depression increases risk for suicide attempt across psychiatric disorders. Further collaborative efforts to increase sample size hold potential to robustly identify genetic associations and gain biological insights into the etiology of suicide attempt
Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders
Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe
Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors
Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe
Analysis of shared heritability in common disorders of the brain
ience, this issue p. eaap8757 Structured Abstract INTRODUCTION Brain disorders may exhibit shared symptoms and substantial epidemiological comorbidity, inciting debate about their etiologic overlap. However, detailed study of phenotypes with different ages of onset, severity, and presentation poses a considerable challenge. Recently developed heritability methods allow us to accurately measure correlation of genome-wide common variant risk between two phenotypes from pools of different individuals and assess how connected they, or at least their genetic risks, are on the genomic level. We used genome-wide association data for 265,218 patients and 784,643 control participants, as well as 17 phenotypes from a total of 1,191,588 individuals, to quantify the degree of overlap for genetic risk factors of 25 common brain disorders. RATIONALE Over the past century, the classification of brain disorders has evolved to reflect the medical and scientific communities' assessments of the presumed root causes of clinical phenomena such as behavioral change, loss of motor function, or alterations of consciousness. Directly observable phenomena (such as the presence of emboli, protein tangles, or unusual electrical activity patterns) generally define and separate neurological disorders from psychiatric disorders. Understanding the genetic underpinnings and categorical distinctions for brain disorders and related phenotypes may inform the search for their biological mechanisms. RESULTS Common variant risk for psychiatric disorders was shown to correlate significantly, especially among attention deficit hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder (MDD), and schizophrenia. By contrast, neurological disorders appear more distinct from one another and from the psychiatric disorders, except for migraine, which was significantly correlated to ADHD, MDD, and Tourette syndrome. We demonstrate that, in the general population, the personality trait neuroticism is significantly correlated with almost every psychiatric disorder and migraine. We also identify significant genetic sharing between disorders and early life cognitive measures (e.g., years of education and college attainment) in the general population, demonstrating positive correlation with several psychiatric disorders (e.g., anorexia nervosa and bipolar disorder) and negative correlation with several neurological phenotypes (e.g., Alzheimer's disease and ischemic stroke), even though the latter are considered to result from specific processes that occur later in life. Extensive simulations were also performed to inform how statistical power, diagnostic misclassification, and phenotypic heterogeneity influence genetic correlations. CONCLUSION The high degree of genetic correlation among many of the psychiatric disorders adds further evidence that their current clinical boundaries do not reflect distinct underlying pathogenic processes, at least on the genetic level. This suggests a deeply interconnected nature for psychiatric disorders, in contrast to neurological disorders, and underscores the need to refine psychiatric diagnostics. Genetically informed analyses may provide important "scaffolding" to support such restructuring of psychiatric nosology, which likely requires incorporating many levels of information. By contrast, we find limited evidence for widespread common genetic risk sharing among neurological disorders or across neurological and psychiatric disorders. We show that both psychiatric and neurological disorders have robust correlations with cognitive and personality measures. Further study is needed to evaluate whether overlapping genetic contributions to psychiatric pathology may influence treatment choices. Ultimately, such developments may pave the way toward reduced heterogeneity and improved diagnosis and treatment of psychiatric disorders