WorldWideScience

Sample records for underlying causal factors

  1. The Causal Factors Underlying the Unwillingness of Farm Laborers’ Migration to Towns: a Case Study of Yunnan Province

    Directory of Open Access Journals (Sweden)

    Shuo Li

    2014-04-01

    Full Text Available Farmers’ settling down in small towns is not only a process of identity-changing, i.e., from rural population into urban population, but also a process of institutional change. At present, China’s urbanization rate is 52.57%. However, in reality, the farm laborers do not often hold a positive and active view about migrating to the towns permanently. Statistics show that in 6 counties in Yunnan Shangri-La, Xishuangbanna, Lijiang border areas and 5 central Yunnan counties, the non-agricultural household staff does not grow very rapidly. By analyzing a lot of underlying factors, this paper finds that influential factors for the transformation of rural population to towns may vary, mainly including factors such as fewer jobs, the issue of rural land use, the poor quality of education, higher level of living standard, and also puts forward some solutions accordingly.

  2. Violence in psychosis: conceptualizing its causal relationship with risk factors

    NARCIS (Netherlands)

    Lamsma, J.; Harte, J.M.

    2015-01-01

    Background: While statistically robust, the association between psychosis and violence remains causally unexplained. Objective: To provide an overview of possible causal pathways between risk factors and violence in psychosis. Methods: A structured narrative review of relevant studies published

  3. Causality

    Science.gov (United States)

    Pearl, Judea

    2000-03-01

    Written by one of the pre-eminent researchers in the field, this book provides a comprehensive exposition of modern analysis of causation. It shows how causality has grown from a nebulous concept into a mathematical theory with significant applications in the fields of statistics, artificial intelligence, philosophy, cognitive science, and the health and social sciences. Pearl presents a unified account of the probabilistic, manipulative, counterfactual and structural approaches to causation, and devises simple mathematical tools for analyzing the relationships between causal connections, statistical associations, actions and observations. The book will open the way for including causal analysis in the standard curriculum of statistics, artifical intelligence, business, epidemiology, social science and economics. Students in these areas will find natural models, simple identification procedures, and precise mathematical definitions of causal concepts that traditional texts have tended to evade or make unduly complicated. This book will be of interest to professionals and students in a wide variety of fields. Anyone who wishes to elucidate meaningful relationships from data, predict effects of actions and policies, assess explanations of reported events, or form theories of causal understanding and causal speech will find this book stimulating and invaluable.

  4. Enfermedades emergentes y reemergentes: factores causales y vigilancia

    OpenAIRE

    Carmen Luisa Suárez Larreinaga; Denis Berdasquera Corcho

    2000-01-01

    Este artículo tiene como objetivo exponer los conceptos y algunos de los factores causales más importantes en la aparición y diseminación de las enfermedades emergentes y reemergentes, así como presentar brevemente algunas de las actividades de vigilancia epidemiológica y su importancia en la detección y control de estas enfermedadesThe objective of this paper is to expound the concepts and some of the most important causal factors in the appearance and spreading of emergent and reemergent di...

  5. A possible realization of Einstein's causal theory underlying quantum mechanics

    International Nuclear Information System (INIS)

    Yussouff, M.

    1979-06-01

    It is shown that a new microscopic mechanics formulated earlier can be looked upon as a possible causal theory underlying quantum mechanics, which removes Einstein's famous objections against quantum theory. This approach is free from objections raised against Bohm's hidden variable theory and leads to a clear physical picture in terms of familiar concepts, if self interactions are held responsible for deviations from classical behaviour. The new level of physics unfolded by this approach may reveal novel frontiers in high-energy physics. (author)

  6. Enfermedades emergentes y reemergentes: factores causales y vigilancia

    Directory of Open Access Journals (Sweden)

    Carmen Luisa Suárez Larreinaga

    2000-12-01

    Full Text Available Este artículo tiene como objetivo exponer los conceptos y algunos de los factores causales más importantes en la aparición y diseminación de las enfermedades emergentes y reemergentes, así como presentar brevemente algunas de las actividades de vigilancia epidemiológica y su importancia en la detección y control de estas enfermedadesThe objective of this paper is to expound the concepts and some of the most important causal factors in the appearance and spreading of emergent and reemergent diseases, as well as to make a brief presentation of some of the epidemiological surveillance activities and their importance in the detection and control of these diseases

  7. Sleep Disturbance in Posttraumatic Stress Disorder: Epiphenomenon or Causal Factor?

    Science.gov (United States)

    Cox, Rebecca C; Tuck, Breanna M; Olatunji, Bunmi O

    2017-04-01

    The goal of this review is to integrate recent findings on sleep disturbance and PTSD, examine sleep disturbance as a causal factor in the development of PTSD, and identify future directions for research, treatment, and prevention. Recent research highlights a relationship between both objective and subjective sleep disturbance and PTSD across diverse samples. Sleep disturbance also predicts PTSD over time. Finally, treatments targeting sleep disturbance lead to decreased PTSD symptoms, while standard PTSD treatments conclude with residual sleep disturbance. Sleep disturbance may be more than a mere epiphenomenon of PTSD. Future research examining the causal role of sleep disturbance in the development of PTSD, as well as the utility of targeting sleep disturbance in prevention and treatment, is necessary to fully understand the likely bidirectional relationship between sleep disturbance and PTSD.

  8. Bayesian detection of causal rare variants under posterior consistency.

    Directory of Open Access Journals (Sweden)

    Faming Liang

    Full Text Available Identification of causal rare variants that are associated with complex traits poses a central challenge on genome-wide association studies. However, most current research focuses only on testing the global association whether the rare variants in a given genomic region are collectively associated with the trait. Although some recent work, e.g., the Bayesian risk index method, have tried to address this problem, it is unclear whether the causal rare variants can be consistently identified by them in the small-n-large-P situation. We develop a new Bayesian method, the so-called Bayesian Rare Variant Detector (BRVD, to tackle this problem. The new method simultaneously addresses two issues: (i (Global association test Are there any of the variants associated with the disease, and (ii (Causal variant detection Which variants, if any, are driving the association. The BRVD ensures the causal rare variants to be consistently identified in the small-n-large-P situation by imposing some appropriate prior distributions on the model and model specific parameters. The numerical results indicate that the BRVD is more powerful for testing the global association than the existing methods, such as the combined multivariate and collapsing test, weighted sum statistic test, RARECOVER, sequence kernel association test, and Bayesian risk index, and also more powerful for identification of causal rare variants than the Bayesian risk index method. The BRVD has also been successfully applied to the Early-Onset Myocardial Infarction (EOMI Exome Sequence Data. It identified a few causal rare variants that have been verified in the literature.

  9. Bayesian detection of causal rare variants under posterior consistency.

    KAUST Repository

    Liang, Faming

    2013-07-26

    Identification of causal rare variants that are associated with complex traits poses a central challenge on genome-wide association studies. However, most current research focuses only on testing the global association whether the rare variants in a given genomic region are collectively associated with the trait. Although some recent work, e.g., the Bayesian risk index method, have tried to address this problem, it is unclear whether the causal rare variants can be consistently identified by them in the small-n-large-P situation. We develop a new Bayesian method, the so-called Bayesian Rare Variant Detector (BRVD), to tackle this problem. The new method simultaneously addresses two issues: (i) (Global association test) Are there any of the variants associated with the disease, and (ii) (Causal variant detection) Which variants, if any, are driving the association. The BRVD ensures the causal rare variants to be consistently identified in the small-n-large-P situation by imposing some appropriate prior distributions on the model and model specific parameters. The numerical results indicate that the BRVD is more powerful for testing the global association than the existing methods, such as the combined multivariate and collapsing test, weighted sum statistic test, RARECOVER, sequence kernel association test, and Bayesian risk index, and also more powerful for identification of causal rare variants than the Bayesian risk index method. The BRVD has also been successfully applied to the Early-Onset Myocardial Infarction (EOMI) Exome Sequence Data. It identified a few causal rare variants that have been verified in the literature.

  10. Causal Factors of Corruption in Construction Project Management: An Overview.

    Science.gov (United States)

    Owusu, Emmanuel Kingsford; Chan, Albert P C; Shan, Ming

    2017-11-11

    The development of efficient and strategic anti-corruption measures can be better achieved if a deeper understanding and identification of the causes of corruption are established. Over the past years, many studies have been devoted to the research of corruption in construction management (CM). This has resulted in a significant increase in the body of knowledge on the subject matter, including the causative factors triggering these corrupt practices. However, an apropos systematic assessment of both past and current studies on the subject matter which is needful for the future endeavor is lacking. Moreover, there is an absence of unified view of the causative factors of corruption identified in construction project management (CPM). This paper, therefore, presents a comprehensive review of the causes of corruption from selected articles in recognized construction management journals to address the mentioned gaps. A total number of 44 causes of corruption were identified from 37 publications and analyzed in terms of existing causal factors of corruption, annual trend of publications and the thematic categorization of the identified variables. The most identifiable causes were over close relationships, poor professional ethical standards, negative industrial and working conditions, negative role models and inadequate sanctions. A conceptual framework of causes of corruption was established, after categorizing the 44 variables into five unique categories. In descending order, the five constructs are Psychosocial-Specific Causes, Organizational-Specific Causes, Regulatory-Specific Causes, Project-Specific Causes and Statutory-Specific Causes. This study extends the current literature of corruption research in construction management and contributes to a deepened understanding of the causal instigators of corruption identified in CPM. The findings from this study provide valuable information and extended knowledge to industry practitioners and policymakers as well as

  11. Misleading Children: Causal Attributions of Inconsistency under Repeated Questioning.

    Science.gov (United States)

    Siegal, Michael; And Others

    1988-01-01

    Four studies investigated whether inconsistency of children aged four to six on developmental tasks may reflect a misinterpretation of the experimenter's intent in communication under repeated questioning. (SKC)

  12. Accident Causal Factors on the Building Construction Sites: A Review

    Directory of Open Access Journals (Sweden)

    Opeyemi Samuel Williams

    2018-01-01

    Full Text Available The concerns for cost, quality and timely delivery of projects have been in existence from time immemorial, whereas the passion for these should be extended to safe execution of site works by the construction participants, as safety of life is very paramount. However, high level of commitment that is essential for the safe execution of site works has become a taboo. Hence, a plethora of accidents takes place on the site ranging from falls from height, contact with working tools, vehicle-related, slip and trip, collapse, exposure to harmful substances, to lifting and handling object accidents. It is pertinent to know that, responsibility for accidents on site cuts across all project participants (clients, consultants, contractors, workers, as well as the construction site environment. Recognition of the construction participants and site environmental factors as agents of accident is the focus of this research. Through extensive review of literature, a copious number of factors were identified and subsequently grouped under five factors as client-related, consultant-related, contractor-related, construction workers-related, and construction site-related. However, there has been a dearth of research in the grouping of accident contributing factors. The identification and understanding of these factors will go a long way in mitigating construction accidents, coupled with proven measures taken in positively addressing them. Efforts to prevent these causative factors include inter alia elimination of hazards from design, effective safety management, adequate planning of activities and employment of seasoned professionals by the client. The contractors are to embark on staff safety auditing, set up safety committees, conduct regular training for staff, use innovative technology, uphold housekeeping and report accident occurrence, while strict adherence to safety regulations must be adopted by all construction operatives.

  13. Obesity as a causal risk factor for deep venous thrombosis

    DEFF Research Database (Denmark)

    Klovaite, Jolanta; Benn, M; Nordestgaard, B G

    2015-01-01

    OBJECTIVE: To test the hypothesis that obesity is causally associated with deep venous thrombosis (DVT). DESIGN: A Mendelian randomization design. SETTING: The Copenhagen General Population Study and the Copenhagen City Heart Study combined. SUBJECTS: Body mass index (BMI) measurements were...... available for 87, 574 individuals of Danish descent from the adult general population. All subjects completed questionnaires and were genotyped for the FTO rs9939609 variant. MAIN OUTCOME MEASURE: First events of DVT with or without pulmonary embolism (PE). ANALYSIS: The results were assessed using Cox...... regression, instrumental variable analysis and Poisson regression. RESULTS: Observationally, the risk of DVT increased with increasing BMI (P-trend obese...

  14. Remnant cholesterol as a causal risk factor for ischemic heart disease

    DEFF Research Database (Denmark)

    Varbo, Anette; Benn, Marianne; Tybjærg-Hansen, Anne

    2013-01-01

    The aim of this study was to test the hypothesis that elevated nonfasting remnant cholesterol is a causal risk factor for ischemic heart disease independent of reduced high-density lipoprotein (HDL) cholesterol.......The aim of this study was to test the hypothesis that elevated nonfasting remnant cholesterol is a causal risk factor for ischemic heart disease independent of reduced high-density lipoprotein (HDL) cholesterol....

  15. Causal Factors for The Adoption Innovation Teacher’s Tv for Teachersand Educational Personnel

    Directory of Open Access Journals (Sweden)

    Thanadol Phuseerit

    2016-12-01

    Full Text Available The purposes of this research were: to 1 study factors for the adoption of the innovation teacher’s TV for Teachers and educational personnel 2 develop and examine consideration of the causal factors for the adoption of the innovation teacher’s TV for teachers and educational personnel model, 3 evaluate and approve causal factors for the adoption of the innovation teacher’s TV for Teachers and educational personnel by the specialists. The method: Step Were 1 Review the literature of the principles, theories and research on the causal factors for the adoption of innovation in education, also study teachers’ adoption of innovation teacher’s TV and causal factors for adoption of innovation teacher’s TV. Further were, analysis and content to collect data on the volume of queries. Collected which was from in-depth interviews. through focus groups, teachers and educational personnel. Identify factors that are associated with the adoption of innovation teacher’s TV. 2 to develop causal factors for the adoption of the innovation teacher’s TV for teachers and educational personnel model. 3 Check the consistency of the causal factors for the adoption of the innovation teacher’s TV for teachers and educational personnel model by experts 4 evaluate and approve causal factors to the adoption innovation teacher’s TV for teachers and educational personnel model from the specialists. The sample were 11 experts in innovation and educational technology. The sample were 450 people whith were Analyzed by Confirmatory Factor Analysis: CFA of Structural Equation Modeling: SEM of causal factor for the adoption of the innovation teacher’s TV for teachers and education personnel model. The instrument used in this study were: 1 a questionnaire causal factor for the adoption of the innovation teacher’s TV for teachers and education personnel, 2 semi-structured questionnaire for interviewing teachers and education personnel, 3 open ended question

  16. Review Youth violence: A review of risk factors, causal pathways ...

    African Journals Online (AJOL)

    This paper presents a review of theoretical and empirical research on risk factors for: 1) the development of violent and other antisocial behaviour; 2) international interventions targeting antisocial, including violent youths; and 3) outcome evaluations and meta-analyses of interventions targeting antisocial, including violent ...

  17. Meaningful Causal Model among Psycho-sociological Factors on ...

    African Journals Online (AJOL)

    Intervention programmes should be designed on the aforementioned factors so as to enhance the psychological well-being of the hearing impaired adolescents in southwest Nigeria. Keywords: Psychological well-being,, Age, Self-concept, Hearing impairment, Self-efficacy. Gender & Behaviour, 10(2), December 2012 ...

  18. Seeing Perfectly Fitting Factor Models That Are Causally Misspecified: Understanding That Close-Fitting Models Can Be Worse

    Science.gov (United States)

    Hayduk, Leslie

    2014-01-01

    Researchers using factor analysis tend to dismiss the significant ill fit of factor models by presuming that if their factor model is close-to-fitting, it is probably close to being properly causally specified. Close fit may indeed result from a model being close to properly causally specified, but close-fitting factor models can also be seriously…

  19. Poor sleep as a potential causal factor in aggression and violence

    NARCIS (Netherlands)

    Kamphuis, Jeanine; Meerlo, Peter; Koolhaas, Jacob; Lancel, Marike

    2012-01-01

    Clinical observations suggest that sleep problems may be a causal factor in the development of reactive aggression and violence. In this review we give an overview of existing literature on the relation between poor sleep and aggression, irritability, and hostility. Correlational studies are

  20. Age- and Sex-Specific Causal Effects of Adiposity on Cardiovascular Risk Factors

    Science.gov (United States)

    Fall, Tove; Hägg, Sara; Ploner, Alexander; Mägi, Reedik; Fischer, Krista; Draisma, Harmen H.M.; Sarin, Antti-Pekka; Benyamin, Beben; Ladenvall, Claes; Åkerlund, Mikael; Kals, Mart; Esko, Tõnu; Nelson, Christopher P.; Kaakinen, Marika; Huikari, Ville; Mangino, Massimo; Meirhaeghe, Aline; Kristiansson, Kati; Nuotio, Marja-Liisa; Kobl, Michael; Grallert, Harald; Dehghan, Abbas; Kuningas, Maris; de Vries, Paul S.; de Bruijn, Renée F.A.G.; Willems, Sara M.; Heikkilä, Kauko; Silventoinen, Karri; Pietiläinen, Kirsi H.; Legry, Vanessa; Giedraitis, Vilmantas; Goumidi, Louisa; Syvänen, Ann-Christine; Strauch, Konstantin; Koenig, Wolfgang; Lichtner, Peter; Herder, Christian; Palotie, Aarno; Menni, Cristina; Uitterlinden, André G.; Kuulasmaa, Kari; Havulinna, Aki S.; Moreno, Luis A.; Gonzalez-Gross, Marcela; Evans, Alun; Tregouet, David-Alexandre; Yarnell, John W.G.; Virtamo, Jarmo; Ferrières, Jean; Veronesi, Giovanni; Perola, Markus; Arveiler, Dominique; Brambilla, Paolo; Lind, Lars; Kaprio, Jaakko; Hofman, Albert; Stricker, Bruno H.; van Duijn, Cornelia M.; Ikram, M. Arfan; Franco, Oscar H.; Cottel, Dominique; Dallongeville, Jean; Hall, Alistair S.; Jula, Antti; Tobin, Martin D.; Penninx, Brenda W.; Peters, Annette; Gieger, Christian; Samani, Nilesh J.; Montgomery, Grant W.; Whitfield, John B.; Martin, Nicholas G.; Groop, Leif; Spector, Tim D.; Magnusson, Patrik K.; Amouyel, Philippe; Boomsma, Dorret I.; Nilsson, Peter M.; Järvelin, Marjo-Riitta; Lyssenko, Valeriya; Metspalu, Andres; Strachan, David P.; Salomaa, Veikko; Ripatti, Samuli; Pedersen, Nancy L.; Prokopenko, Inga; McCarthy, Mark I.

    2015-01-01

    Observational studies have reported different effects of adiposity on cardiovascular risk factors across age and sex. Since cardiovascular risk factors are enriched in obese individuals, it has not been easy to dissect the effects of adiposity from those of other risk factors. We used a Mendelian randomization approach, applying a set of 32 genetic markers to estimate the causal effect of adiposity on blood pressure, glycemic indices, circulating lipid levels, and markers of inflammation and liver disease in up to 67,553 individuals. All analyses were stratified by age (cutoff 55 years of age) and sex. The genetic score was associated with BMI in both nonstratified analysis (P = 2.8 × 10−107) and stratified analyses (all P < 3.3 × 10−30). We found evidence of a causal effect of adiposity on blood pressure, fasting levels of insulin, C-reactive protein, interleukin-6, HDL cholesterol, and triglycerides in a nonstratified analysis and in the <55-year stratum. Further, we found evidence of a smaller causal effect on total cholesterol (P for difference = 0.015) in the ≥55-year stratum than in the <55-year stratum, a finding that could be explained by biology, survival bias, or differential medication. In conclusion, this study extends previous knowledge of the effects of adiposity by providing sex- and age-specific causal estimates on cardiovascular risk factors. PMID:25712996

  1. Causal inference between bioavailability of heavy metals and environmental factors in a large-scale region.

    Science.gov (United States)

    Liu, Yuqiong; Du, Qingyun; Wang, Qi; Yu, Huanyun; Liu, Jianfeng; Tian, Yu; Chang, Chunying; Lei, Jing

    2017-07-01

    The causation between bioavailability of heavy metals and environmental factors are generally obtained from field experiments at local scales at present, and lack sufficient evidence from large scales. However, inferring causation between bioavailability of heavy metals and environmental factors across large-scale regions is challenging. Because the conventional correlation-based approaches used for causation assessments across large-scale regions, at the expense of actual causation, can result in spurious insights. In this study, a general approach framework, Intervention calculus when the directed acyclic graph (DAG) is absent (IDA) combined with the backdoor criterion (BC), was introduced to identify causation between the bioavailability of heavy metals and the potential environmental factors across large-scale regions. We take the Pearl River Delta (PRD) in China as a case study. The causal structures and effects were identified based on the concentrations of heavy metals (Zn, As, Cu, Hg, Pb, Cr, Ni and Cd) in soil (0-20 cm depth) and vegetable (lettuce) and 40 environmental factors (soil properties, extractable heavy metals and weathering indices) in 94 samples across the PRD. Results show that the bioavailability of heavy metals (Cd, Zn, Cr, Ni and As) was causally influenced by soil properties and soil weathering factors, whereas no causal factor impacted the bioavailability of Cu, Hg and Pb. No latent factor was found between the bioavailability of heavy metals and environmental factors. The causation between the bioavailability of heavy metals and environmental factors at field experiments is consistent with that on a large scale. The IDA combined with the BC provides a powerful tool to identify causation between the bioavailability of heavy metals and environmental factors across large-scale regions. Causal inference in a large system with the dynamic changes has great implications for system-based risk management. Copyright © 2017 Elsevier Ltd. All

  2. The influence of linguistic and cognitive factors on the time course of verb-based implicit causality.

    Science.gov (United States)

    Koornneef, Arnout; Dotlačil, Jakub; van den Broek, Paul; Sanders, Ted

    2016-01-01

    In three eye-tracking experiments the influence of the Dutch causal connective "want" (because) and the working memory capacity of readers on the usage of verb-based implicit causality was examined. Experiments 1 and 2 showed that although a causal connective is not required to activate implicit causality information during reading, effects of implicit causality surfaced more rapidly and were more pronounced when a connective was present in the discourse than when it was absent. In addition, Experiment 3 revealed that-in contrast to previous claims-the activation of implicit causality is not a resource-consuming mental operation. Moreover, readers with higher and lower working memory capacities behaved differently in a dual-task situation. Higher span readers were more likely to use implicit causality when they had all their working memory resources at their disposal. Lower span readers showed the opposite pattern as they were more likely to use the implicit causality cue in the case of an additional working memory load. The results emphasize that both linguistic and cognitive factors mediate the impact of implicit causality on text comprehension. The implications of these results are discussed in terms of the ongoing controversies in the literature-that is, the focusing-integration debate and the debates on the source of implicit causality.

  3. Donation to disaster relief campaigns: underlying social cognitive factors exposed

    NARCIS (Netherlands)

    Oosterhof, Liesbeth; Heuvelman, A.; Peters, O.

    2009-01-01

    number of very serious natural disasters have put an enormous pressure on relief organizations in the last few years. The present study exposes underlying social cognitive factors for donation to relief campaigns. A causal model was constructed, based on social cognitive theory, research on

  4. Study of Noise Canceling Performance of Feedforward Fuzzy-Based ANC System under Non-Causal Condition

    DEFF Research Database (Denmark)

    Mojallali, Hamed; Izadi-Zamanabadi, Roozbeh; Amini, Rouzbeh

    Feed-forward active noise control (ANC) systems act as adaptive systems to control and cancel undesired signals and noises. If the delay in the noise canceling subsystems increases more than the delays in the primary path, non-causal condition will occur in these systems. In this paper, study...... of noise canceling performance of feed-forward fuzzy-based ANC systems for ducts under non-causal condition is presented. For this purpose, we use fuzzy filtered-x algorithm as an adaptive filter and the results are compared with classical filteredx algorithm which is employed under the same conditions....... Analysis shows that ANC systems using fuzzy algorithm has better efficiency for noise cancellation in non-causal condition....

  5. Network interactions underlying mirror feedback in stroke: A dynamic causal modeling study

    Directory of Open Access Journals (Sweden)

    Soha Saleh

    2017-01-01

    Full Text Available Mirror visual feedback (MVF is potentially a powerful tool to facilitate recovery of disordered movement and stimulate activation of under-active brain areas due to stroke. The neural mechanisms underlying MVF have therefore been a focus of recent inquiry. Although it is known that sensorimotor areas can be activated via mirror feedback, the network interactions driving this effect remain unknown. The aim of the current study was to fill this gap by using dynamic causal modeling to test the interactions between regions in the frontal and parietal lobes that may be important for modulating the activation of the ipsilesional motor cortex during mirror visual feedback of unaffected hand movement in stroke patients. Our intent was to distinguish between two theoretical neural mechanisms that might mediate ipsilateral activation in response to mirror-feedback: transfer of information between bilateral motor cortices versus recruitment of regions comprising an action observation network which in turn modulate the motor cortex. In an event-related fMRI design, fourteen chronic stroke subjects performed goal-directed finger flexion movements with their unaffected hand while observing real-time visual feedback of the corresponding (veridical or opposite (mirror hand in virtual reality. Among 30 plausible network models that were tested, the winning model revealed significant mirror feedback-based modulation of the ipsilesional motor cortex arising from the contralesional parietal cortex, in a region along the rostral extent of the intraparietal sulcus. No winning model was identified for the veridical feedback condition. We discuss our findings in the context of supporting the latter hypothesis, that mirror feedback-based activation of motor cortex may be attributed to engagement of a contralateral (contralesional action observation network. These findings may have important implications for identifying putative cortical areas, which may be targeted with

  6. Exploring causal associations between alcohol and coronary heart disease risk factors

    DEFF Research Database (Denmark)

    Lawlor, Debbie A; Nordestgaard, Børge G; Benn, Marianne

    2013-01-01

    pressure (BP), lipids, fibrinogen, and glucose. Analyses were undertaken in 54 604 Danes (mean age 56 years). Both confounder-adjusted multivariable and IV analyses suggested that a greater alcohol consumption among those who drank any alcohol resulted in a higher BP [mean difference in SBP per doubling...... of alcohol consumption among drinkers: 0.76 mmHg (95% CI: 0.63, 0.90) from multivariable analyses and 0.94 mmHg (-3.03, 4.69) from IV analyses; P-value for difference in these results = 0.95]. The positive association of alcohol with HDLc in the multivariable analyses [4.9% (4.7, 5.1)] appeared stronger than......AimsTo explore the causal effect of long-term alcohol consumption on coronary heart disease risk factors.Methods and resultsWe used variants in ADH1B and ADH1C genes as instrumental variables (IV) to estimate the causal effect of long-term alcohol consumption on body mass index (BMI), blood...

  7. Tumor necrosis factor-alpha inhibition and VATER association: a causal relationship.

    Science.gov (United States)

    Carter, John D; Valeriano, Joanne; Vasey, Frank B

    2006-05-01

    Inflammatory conditions that may require the use of a tumor necrosis factor-a (TNF-a) antagonist often involve women of child-bearing age. TNF-a antagonists are presumed to be safe in pregnancy based on animal data. However, this has never been formally studied in prospective trials involving humans. We describe a patient with psoriasis and psoriatic arthritis who took etanercept 50 mg subcutaneously (SQ) twice weekly throughout her pregnancy. She gave birth to a child with VATER association. Animal and human data exist to suggest a possible causal relationship between the mother's use of etanercept and the child's development of VATER association. We propose that the TNF antagonists, specifically etanercept, be used with caution in pregnant women. Patient registries of women who take TNF-a antagonists during pregnancy also need to be followed to see if there is an increase in the birth defects that are part of VATER association.

  8. Fifteen-year population attributable fractions and causal pies of risk factors for newly developed hepatocellular carcinomas in 11,801 men in Taiwan.

    Directory of Open Access Journals (Sweden)

    Shu-Fen Liao

    Full Text Available Development of hepatocellular carcinoma (HCC is a multi-factorial process. Chronic infections with hepatitis B virus (HBV and hepatitis C virus (HCV are important risk factors of HCC. Host factors, such as alcohol drinking, may also play a role. This study aims to provide a synthesis view on the development of HCC by examining multiple risk factors jointly and collectively. Causal-pie modeling technique was applied to analyze a cohort of 11,801 male residents (followed up for 15 years in Taiwan, during which a total of 298 incident HCC cases were ascertained. The rate ratios adjusted by age were further modeled by an additive Poisson regression. Population attributable fractions (PAFs and causal-pie weights (CPWs were calculated. A PAF indicates the magnitude of case-load reduction under a particular intervention scenario, whereas a CPW for a particular class of causal pies represents the proportion of HCC cases attributable to that class. Using PAF we observed a chance to reduce around 60% HCC risk moving from no HBV-related intervention to the total elimination of the virus. An additional ∼15% (or ∼5% reduction can be expected, if the HBV-related intervention is coupled with an HCV-related intervention (or an anti-drinking campaign. Eight classes of causal pies were found to be significant, including four dose-response classes of HBV (total CPW=52.7%, one independent-effect class of HCV (CPW=14.4%, one HBV-alcohol interaction class (CPW=4.2%, one HBV-HCV interaction class (CPW=1.7%, and one all-unknown class (CPW=27.0%. Causal-pie modeling for HCC helps clarify the relative importance of each viral and host factor, as well as their interactions.

  9. Fifteen-year population attributable fractions and causal pies of risk factors for newly developed hepatocellular carcinomas in 11,801 men in Taiwan.

    Science.gov (United States)

    Liao, Shu-Fen; Yang, Hwai-I; Lee, Mei-Hsuan; Chen, Chien-Jen; Lee, Wen-Chung

    2012-01-01

    Development of hepatocellular carcinoma (HCC) is a multi-factorial process. Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are important risk factors of HCC. Host factors, such as alcohol drinking, may also play a role. This study aims to provide a synthesis view on the development of HCC by examining multiple risk factors jointly and collectively. Causal-pie modeling technique was applied to analyze a cohort of 11,801 male residents (followed up for 15 years) in Taiwan, during which a total of 298 incident HCC cases were ascertained. The rate ratios adjusted by age were further modeled by an additive Poisson regression. Population attributable fractions (PAFs) and causal-pie weights (CPWs) were calculated. A PAF indicates the magnitude of case-load reduction under a particular intervention scenario, whereas a CPW for a particular class of causal pies represents the proportion of HCC cases attributable to that class. Using PAF we observed a chance to reduce around 60% HCC risk moving from no HBV-related intervention to the total elimination of the virus. An additional ∼15% (or ∼5%) reduction can be expected, if the HBV-related intervention is coupled with an HCV-related intervention (or an anti-drinking campaign). Eight classes of causal pies were found to be significant, including four dose-response classes of HBV (total CPW=52.7%), one independent-effect class of HCV (CPW=14.4%), one HBV-alcohol interaction class (CPW=4.2%), one HBV-HCV interaction class (CPW=1.7%), and one all-unknown class (CPW=27.0%). Causal-pie modeling for HCC helps clarify the relative importance of each viral and host factor, as well as their interactions.

  10. Is the Association Between Education and Fertility Postponement Causal? The Role of Family Background Factors.

    Science.gov (United States)

    Tropf, Felix C; Mandemakers, Jornt J

    2017-02-01

    A large body of literature has demonstrated a positive relationship between education and age at first birth. However, this relationship may be partly spurious because of family background factors that cannot be controlled for in most research designs. We investigate the extent to which education is causally related to later age at first birth in a large sample of female twins from the United Kingdom (N = 2,752). We present novel estimates using within-identical twin and biometric models. Our findings show that one year of additional schooling is associated with about one-half year later age at first birth in ordinary least squares (OLS) models. This estimate reduced to only a 1.5-month later age at first birth for the within-identical twin model controlling for all shared family background factors (genetic and family environmental). Biometric analyses reveal that it is mainly influences of the family environment-not genetic factors-that cause spurious associations between education and age at first birth. Last, using data from the Office for National Statistics, we demonstrate that only 1.9 months of the 2.74 years of fertility postponement for birth cohorts 1944-1967 could be attributed to educational expansion based on these estimates. We conclude that the rise in educational attainment alone cannot explain differences in fertility timing between cohorts.

  11. A review of the use of human factors classification frameworks that identify causal factors for adverse events in the hospital setting.

    Science.gov (United States)

    Mitchell, R J; Williamson, A M; Molesworth, B; Chung, A Z Q

    2014-01-01

    Various human factors classification frameworks have been used to identified causal factors for clinical adverse events. A systematic review was conducted to identify human factors classification frameworks that identified the causal factors (including human error) of adverse events in a hospital setting. Six electronic databases were searched, identifying 1997 articles and 38 of these met inclusion criteria. Most studies included causal contributing factors as well as error and error type, but the nature of coding varied considerably between studies. The ability of human factors classification frameworks to provide information on specific causal factors for an adverse event enables the focus of preventive attention on areas where improvements are most needed. This review highlighted some areas needing considerable improvement in order to meet this need, including better definition of terms, more emphasis on assessing reliability of coding and greater sophistication in analysis of results of the classification. Practitioner Summary: Human factors classification frameworks can be used to identify causal factors of clinical adverse events. However, this review suggests that existing frameworks are diverse, limited in their identification of the context of human error and have poor reliability when used by different individuals.

  12. Expert explanations of honeybee losses in areas of extensive agriculture in France: Gaucho compared with other supposed causal factors

    Energy Technology Data Exchange (ETDEWEB)

    Maxim, L [Institut des Sciences de la Communication, CNRS UPS 3088, 27 Rue Damesme, 75013 Paris (France); Van der Sluijs, J P, E-mail: laura.maxim@iscc.cnrs.f, E-mail: J.P.vanderSluijs@uu.n [Copernicus Institute for Sustainable Development and Innovation, Department of Science, Technology and Society, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht (Netherlands)

    2010-01-15

    Debates on causality are at the core of controversies as regards environmental changes. The present paper presents a new method for analyzing controversies on causality in a context of social debate and the results of its empirical testing. The case study used is the controversy as regards the role played by the insecticide Gaucho, compared with other supposed causal factors, in the substantial honeybee (Apis mellifera L.) losses reported to have occurred in France between 1994 and 2004. The method makes use of expert elicitation of the perceived strength of evidence regarding each of Bradford Hill's causality criteria, as regards the link between each of eight possible causal factors identified in attempts to explain each of five signs observed in honeybee colonies. These judgments are elicited from stakeholders and experts involved in the debate, i.e., representatives of Bayer Cropscience, of the Ministry of Agriculture, of the French Food Safety Authority, of beekeepers and of public scientists. We show that the intense controversy observed in confused and passionate public discourses is much less salient when the various arguments are structured using causation criteria. The contradictions between the different expert views have a triple origin: (1) the lack of shared definition and quantification of the signs observed in colonies; (2) the lack of specialist knowledge on honeybees; and (3) the strategic discursive practices associated with the lack of trust between experts representing stakeholders having diverging stakes in the case.

  13. Expert explanations of honeybee losses in areas of extensive agriculture in France: Gaucho compared with other supposed causal factors

    International Nuclear Information System (INIS)

    Maxim, L; Van der Sluijs, J P

    2010-01-01

    Debates on causality are at the core of controversies as regards environmental changes. The present paper presents a new method for analyzing controversies on causality in a context of social debate and the results of its empirical testing. The case study used is the controversy as regards the role played by the insecticide Gaucho, compared with other supposed causal factors, in the substantial honeybee (Apis mellifera L.) losses reported to have occurred in France between 1994 and 2004. The method makes use of expert elicitation of the perceived strength of evidence regarding each of Bradford Hill's causality criteria, as regards the link between each of eight possible causal factors identified in attempts to explain each of five signs observed in honeybee colonies. These judgments are elicited from stakeholders and experts involved in the debate, i.e., representatives of Bayer Cropscience, of the Ministry of Agriculture, of the French Food Safety Authority, of beekeepers and of public scientists. We show that the intense controversy observed in confused and passionate public discourses is much less salient when the various arguments are structured using causation criteria. The contradictions between the different expert views have a triple origin: (1) the lack of shared definition and quantification of the signs observed in colonies; (2) the lack of specialist knowledge on honeybees; and (3) the strategic discursive practices associated with the lack of trust between experts representing stakeholders having diverging stakes in the case.

  14. The Causal Factors Associated with the Loving Care of the Mothers of Children with Multiple Disabilities.

    Science.gov (United States)

    Sadati, Ahmad Kalateh; Salehzade, Hamze; Hemmati, Soroor; Darvish, Manijeh; Heydari, Seyed Taghi; Tabrizi, Reza

    2015-10-01

    Families with disabled children need more psycho-social considerations. Motherhood care of the children with multiple disabilities is difficult. Due to its importance, the aim of this study was to investigate the causal factors affecting loving care of mothers of children with multiple disabilities. The study used a cross-sectional method in which 75 mothers of exceptional children with multiple disabilities (physical and mental) in elementary schools in Shiraz, Iran. The data were collected through questionnaires which, besides demographical factors, evaluated the relationship between mothers' loving care of children with multiple disabilities and four other variables including purpose in life, life satisfaction, religious attitude, and sense of coherence. Mann-Whitney U was used for comparison between mothers' loving care and other variables. Results revealed that demographic variables did not have a significant relationship with loving care. In the case of social variables, there was a significant relationship between mothers' loving care and purpose in life (Pdisabled children is a unique phenomenon which is due to attachment of mother-child situation. Nevertheless, these mothers are vulnerable and marginalized people who need more attention and social supports provided by related governmental institutions and also NGOs actors.

  15. Computed tomographic assessment of the causal factors of unsuccessful medialization thyroplasty.

    Science.gov (United States)

    Iwahashi, Toshihiko; Ogawa, Makoto; Hosokawa, Kiyohito; Mochizuki, Ryuichi; Inohara, Hidenori

    2015-03-01

    The present results demonstrate that a small implant size, undercorrection of the vocal fold, antero-posterior implant malposition, and the use of expanded polytetrafluoroethylene (ePTFE) are the primary factors that cause a poor outcome of medialization thyroplasty (MT). To assess the postoperative laryngeal condition using computed tomography (CT) in patients with unilateral vocal fold paralysis who underwent MT alone, and to identify the primary causal factors in terms of the surgical procedures that affect the outcomes of MT. Twenty-two patients who underwent MT alone were divided into two groups based on either the maximal phonation time or the perceived vocal breathiness. Two laryngologists assessed the postoperative laryngeal CT images during sustained vowel phonation and judged whether there were abnormalities of the arytenoid cartilage position, window position, implant size, and implant position, as well as the degree of correction of the vocal fold. As implant material, a silicone block, ePTFE, and hydroxyapatite had been inserted in 2, 9, and 11 patients, respectively. Comparisons of the prevalence of abnormalities in the abovementioned factors between the different outcomes and between the types of material used for the implant were performed. Twelve patients with a poor outcome and 10 with a good outcome showed 36 and 18 abnormal findings identified by either of the two laryngologists, respectively. In the poor outcome group, a smaller implant size and undercorrection of the vocal fold showed both high kappa values and a significantly higher prevalence than those in the good outcome group (p < 0.001 and p < 0.05), respectively. The comparison between material types demonstrated that the sheet-like material (ePTFE) group exhibited a significantly higher prevalence of undercorrection than the block-like material group (p < 0.05).

  16. Causal Factors and Adverse Events of Aviation Accidents and Incidents Related to Integrated Vehicle Health Management

    Science.gov (United States)

    Reveley, Mary S.; Briggs, Jeffrey L.; Evans, Joni K.; Jones, Sharon M.; Kurtoglu, Tolga; Leone, Karen M.; Sandifer, Carl E.

    2011-01-01

    Causal factors in aviation accidents and incidents related to system/component failure/malfunction (SCFM) were examined for Federal Aviation Regulation Parts 121 and 135 operations to establish future requirements for the NASA Aviation Safety Program s Integrated Vehicle Health Management (IVHM) Project. Data analyzed includes National Transportation Safety Board (NSTB) accident data (1988 to 2003), Federal Aviation Administration (FAA) incident data (1988 to 2003), and Aviation Safety Reporting System (ASRS) incident data (1993 to 2008). Failure modes and effects analyses were examined to identify possible modes of SCFM. A table of potential adverse conditions was developed to help evaluate IVHM research technologies. Tables present details of specific SCFM for the incidents and accidents. Of the 370 NTSB accidents affected by SCFM, 48 percent involved the engine or fuel system, and 31 percent involved landing gear or hydraulic failure and malfunctions. A total of 35 percent of all SCFM accidents were caused by improper maintenance. Of the 7732 FAA database incidents affected by SCFM, 33 percent involved landing gear or hydraulics, and 33 percent involved the engine and fuel system. The most frequent SCFM found in ASRS were turbine engine, pressurization system, hydraulic main system, flight management system/flight management computer, and engine. Because the IVHM Project does not address maintenance issues, and landing gear and hydraulic systems accidents are usually not fatal, the focus of research should be those SCFMs that occur in the engine/fuel and flight control/structures systems as well as power systems.

  17. Effective connectivity of brain regions underlying third-party punishment: Functional MRI and Granger causality evidence.

    Science.gov (United States)

    Bellucci, Gabriele; Chernyak, Sergey; Hoffman, Morris; Deshpande, Gopikrishna; Dal Monte, Olga; Knutson, Kristine M; Grafman, Jordan; Krueger, Frank

    2017-04-01

    Third-party punishment (TPP) for norm violations is an essential deterrent in large-scale human societies, and builds on two essential cognitive functions: evaluating legal responsibility and determining appropriate punishment. Despite converging evidence that TPP is mediated by a specific set of brain regions, little is known about their effective connectivity (direction and strength of connections). Applying parametric event-related functional MRI in conjunction with multivariate Granger causality analysis, we asked healthy participants to estimate how much punishment a hypothetical perpetrator deserves for intentionally committing criminal offenses varying in levels of harm. Our results confirmed that TPP legal decisions are based on two domain-general networks: the mentalizing network for evaluating legal responsibility and the central-executive network for determining appropriate punishment. Further, temporal pole (TP) and dorsomedial prefrontal cortex (PFC) emerged as hubs of the mentalizing network, uniquely generating converging output connections to ventromedial PFC, temporo-parietal junction, and posterior cingulate. In particular, dorsomedial PFC received inputs only from TP and both its activation and its connectivity to dorsolateral PFC correlated with degree of punishment. This supports the hypothesis that dorsomedial PFC acts as the driver of the TPP activation pattern, leading to the decision on the appropriate punishment. In conclusion, these results advance our understanding of the organizational elements of the TPP brain networks and provide better insights into the mental states of judges and jurors tasked with blaming and punishing legal wrongs.

  18. Evaluating WAIS-IV structure through a different psychometric lens: structural causal model discovery as an alternative to confirmatory factor analysis.

    Science.gov (United States)

    van Dijk, Marjolein J A M; Claassen, Tom; Suwartono, Christiany; van der Veld, William M; van der Heijden, Paul T; Hendriks, Marc P H

    Since the publication of the WAIS-IV in the U.S. in 2008, efforts have been made to explore the structural validity by applying factor analysis to various samples. This study aims to achieve a more fine-grained understanding of the structure of the Dutch language version of the WAIS-IV (WAIS-IV-NL) by applying an alternative analysis based on causal modeling in addition to confirmatory factor analysis (CFA). The Bayesian Constraint-based Causal Discovery (BCCD) algorithm learns underlying network structures directly from data and assesses more complex structures than is possible with factor analysis. WAIS-IV-NL profiles of two clinical samples of 202 patients (i.e. patients with temporal lobe epilepsy and a mixed psychiatric outpatient group) were analyzed and contrasted with a matched control group (N = 202) selected from the Dutch standardization sample of the WAIS-IV-NL to investigate internal structure by means of CFA and BCCD. With CFA, the four-factor structure as proposed by Wechsler demonstrates acceptable fit in all three subsamples. However, BCCD revealed three consistent clusters (verbal comprehension, visual processing, and processing speed) in all three subsamples. The combination of Arithmetic and Digit Span as a coherent working memory factor could not be verified, and Matrix Reasoning appeared to be isolated. With BCCD, some discrepancies from the proposed four-factor structure are exemplified. Furthermore, these results fit CHC theory of intelligence more clearly. Consistent clustering patterns indicate these results are robust. The structural causal discovery approach may be helpful in better interpreting existing tests, the development of new tests, and aid in diagnostic instruments.

  19. The impact of school leadership on school level factors: validation of a causal model

    NARCIS (Netherlands)

    Krüger, M.L.; Witziers, B.; Sleegers, P.

    2007-01-01

    This study aims to contribute to a better understanding of the antecedents and effects of educational leadership, and of the influence of the principal's leadership on intervening and outcome variables. A path analysis was conducted to test and validate a causal model. The results show no direct or

  20. Deconstructing Constructivism: Modeling Causal Relationships Among Constructivist Learning Environment Factors and Student Outcomes in Introductory Chemistry

    Science.gov (United States)

    Komperda, Regis

    The purpose of this dissertation is to test a model of relationships among factors characterizing aspects of a student-centered constructivist learning environment and student outcomes of satisfaction and academic achievement in introductory undergraduate chemistry courses. Constructivism was chosen as the theoretical foundation for this research because of its widespread use in chemical education research and practice. In a constructivist learning environment the role of the teacher shifts from delivering content towards facilitating active student engagement in activities that encourage individual knowledge construction through discussion and application of content. Constructivist approaches to teaching introductory chemistry courses have been adopted by some instructors as a way to improve student outcomes, but little research has been done on the causal relationships among particular aspects of the learning environment and student outcomes. This makes it difficult for classroom teachers to know which aspects of a constructivist teaching approach are critical to adopt and which may be modified to better suit a particular learning environment while still improving student outcomes. To investigate a model of these relationships, a survey designed to measure student perceptions of three factors characterizing a constructivist learning environment in online courses was adapted for use in face-to-face chemistry courses. These three factors, teaching presence, social presence, and cognitive presence, were measured using a slightly modified version of the Community of Inquiry (CoI) instrument. The student outcomes investigated in this research were satisfaction and academic achievement, as measured by standardized American Chemical Society (ACS) exam scores and course grades. Structural equation modeling (SEM) was used to statistically model relationships among the three presence factors and student outcome variables for 391 students enrolled in six sections of a

  1. Abdominal obesity: causal factor or simply a symptom of obesity-related health risk

    Directory of Open Access Journals (Sweden)

    Oh S

    2014-07-01

    Full Text Available Sechang Oh,1 Kiyoji Tanaka,2 Jin-won Noh,3 Rina So,2,4 Takehiko Tsujimoto,2 Hiroyuki Sasai,1,4 Mijung Kim,5 Junichi Shoda11Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan; 2Faculty of Health and Sports Science, University of Tsukuba, Tsukuba, Ibaraki, Japan; 3Department of Healthcare Management, Eulji University, Seongnam-si, Gyeonggi-do, Republic of Korea; 4Japan Society for the Promotion of Science, Tokyo, Japan; 5Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, JapanBackground: Abdominal fat (AF reduction is advocated in the treatment of obesity-related diseases. Nonetheless, recent studies have shown additional beneficial effects against obesity-related health risks, independent of AF reduction. Therefore it is important to determine whether AF plays a causal role in promoting metabolic disorders or is simply a symptom of increased obesity-related health risk factors. Clarification of the primary role of AF in the pathogenesis of obesity-related disease is also important.Objective: This retrospective study was conducted with the objectives of 1 comparison between groups exhibiting equivalent amounts of AF loss that resulted from distinct treatments (exercise and dietary restriction with respect to degrees of improvement in obesity-related health risk factors and 2 determination of definite differences in the outcomes of obesity-related health risk in subjects receiving identical treatment (exercise but exhibiting a remarkable difference in AF reduction.Design: In 66 subjects who completed a 12-week exercise or dietary restriction program, 17 parameters (systolic blood pressure [SBP] and diastolic blood pressure [DBP]; high-sensitivity C-reactive protein [hs-CRP]; leptin, adiponectin, tumor necrosis factor [TNF]-α, interleukin [IL]-6; alanine aminotransferase [ALT], gamma glutamyl transpeptidase [γGT]; lipid profile: high-density lipoprotein cholesterol [HDLC], triglyceride [TG

  2. Biomechanical and psychosocial exposures are independent risk factors for carpal tunnel syndrome: assessment of confounding using causal diagrams.

    Science.gov (United States)

    Harris-Adamson, Carisa; Eisen, Ellen A; Neophytou, Andreas; Kapellusch, Jay; Garg, Arun; Hegmann, Kurt T; Thiese, Matthew S; Dale, Ann Marie; Evanoff, Bradley; Bao, Stephen; Silverstein, Barbara; Gerr, Fred; Burt, Susan; Rempel, David

    2016-11-01

    Between 2001 and 2010, six research groups conducted coordinated prospective studies of carpal tunnel syndrome (CTS) incidence among US workers from various industries to estimate exposure-response relationships. This analysis examined the presence and magnitude of confounding between biomechanical and workplace psychosocial factors and incidence of dominant-hand CTS. 1605 participants, without CTS at enrolment, were followed for up to 3.5 years (2471 person-years). Demographic information, medical history and workplace psychosocial stress measures were collected at baseline. Individual workplace biomechanical exposures were collected for each task and combined across the workweek using time-weighted averaging (TWA). CTS case criteria were based on symptoms and results of electrophysiological testing. HRs were estimated with Cox proportional hazard models. Confounding was assessed using causal diagrams and an empirical criterion of 10% or greater change in effect estimate magnitude. There were 109 incident CTS cases (IR=4.41/100 person-years; 6.7% cumulative incidence). The relationships between CTS and forceful repetition rate, % time forceful hand exertion and the Threshold Limit Value for Hand Activity Level (TLV-HAL) were slightly confounded by decision latitude with effect estimates being attenuated towards the null (10-14% change) after adjustment. The risk of CTS among participants reporting high job strain was attenuated towards the null by 14% after adjusting for the HAL Scale or the % time forceful hand exertions. Although attenuation of the relationships between CTS and some biomechanical and work psychosocial exposures was observed after adjusting for confounding, the magnitudes were small and confirmed biomechanical and work psychosocial exposures as independent risk factors for incident CTS. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. A causal examination of the effects of confounding factors on multimetric indices

    Science.gov (United States)

    Schoolmaster, Donald R.; Grace, James B.; Schweiger, E. William; Mitchell, Brian R.; Guntenspergen, Glenn R.

    2013-01-01

    The development of multimetric indices (MMIs) as a means of providing integrative measures of ecosystem condition is becoming widespread. An increasingly recognized problem for the interpretability of MMIs is controlling for the potentially confounding influences of environmental covariates. Most common approaches to handling covariates are based on simple notions of statistical control, leaving the causal implications of covariates and their adjustment unstated. In this paper, we use graphical models to examine some of the potential impacts of environmental covariates on the observed signals between human disturbance and potential response metrics. Using simulations based on various causal networks, we show how environmental covariates can both obscure and exaggerate the effects of human disturbance on individual metrics. We then examine from a causal interpretation standpoint the common practice of adjusting ecological metrics for environmental influences using only the set of sites deemed to be in reference condition. We present and examine the performance of an alternative approach to metric adjustment that uses the whole set of sites and models both environmental and human disturbance effects simultaneously. The findings from our analyses indicate that failing to model and adjust metrics can result in a systematic bias towards those metrics in which environmental covariates function to artificially strengthen the metric–disturbance relationship resulting in MMIs that do not accurately measure impacts of human disturbance. We also find that a “whole-set modeling approach” requires fewer assumptions and is more efficient with the given information than the more commonly applied “reference-set” approach.

  4. A quantum causal discovery algorithm

    Science.gov (United States)

    Giarmatzi, Christina; Costa, Fabio

    2018-03-01

    Finding a causal model for a set of classical variables is now a well-established task—but what about the quantum equivalent? Even the notion of a quantum causal model is controversial. Here, we present a causal discovery algorithm for quantum systems. The input to the algorithm is a process matrix describing correlations between quantum events. Its output consists of different levels of information about the underlying causal model. Our algorithm determines whether the process is causally ordered by grouping the events into causally ordered non-signaling sets. It detects if all relevant common causes are included in the process, which we label Markovian, or alternatively if some causal relations are mediated through some external memory. For a Markovian process, it outputs a causal model, namely the causal relations and the corresponding mechanisms, represented as quantum states and channels. Our algorithm opens the route to more general quantum causal discovery methods.

  5. Elevated body mass index as a causal risk factor for symptomatic gallstone disease:

    DEFF Research Database (Denmark)

    Stender, Stefan; Nordestgaard, Børge G; Tybjaerg-Hansen, Anne

    2013-01-01

    disease during up to 34 years of follow-up. Subjects were genotyped for three common variants known to associate with BMI: FTO(rs9939609); MC4R(rs17782313); and TMEM18(rs6548238). The number of BMI-increasing alleles was calculated for each participant. In observational analyses, mean baseline BMI was 55......Elevated body mass index (BMI) is associated with an increased risk of gallstone disease. Whether this reflects a causal association is unknown. Using a Mendelian randomization approach, we studied 77,679 individuals from the general population. Of these, 4,106 developed symptomatic gallstone...

  6. Factores causales de la explotación sexual infantil en niños, niñas y adolescentes en Colombia (causal factors of child sexual exploitation in boys, girls, and adolescents in Colombia

    Directory of Open Access Journals (Sweden)

    Nora H. Londoño

    2015-01-01

    Full Text Available Resumen: El propósito de la presente investigación fue identificar factores causales de la explotación sexual comercial en la infancia y la adolescencia en Colombia. Para ello se analizaron tres casos de estudio: Medellín, Sincelejo y Magangué. Se realizaron talleres y se aplicaron encuestas en cada una de las ciudades en Instituciones gubernamentales encargadas de intervenir el fenómeno y en algunas instituciones educativas, con la participación de funcionarios, profesionales, docentes, directivos y estudiantes. Para el análisis de datos se realizó una matriz explicativa con la participación de 4 jurados. Las categorías de análisis fueron factores medioambientales, familiares e individuales. Abstract: The purpose of this piece of research aimed to identify causal factors of trade sexual exploitation on children and adolescents in Colombia. For this purpose, three case studies were analyzed: Medellín, Sincelejo, and Magangué. Workshops were conducted and surveys were implemented in each of the cities in both governmental institutions, in charge of intervening the phenomenon and in some educational institutions, with the participation of officials, professionals, teachers, directors, and students. As for the data analysis, an explanatory matrix was carried out, with the participation of 4 judges. The categories of analysis were those related to the environment, the family, and the individual.

  7. Molecular epidemiology of acute leukemia in children: causal model, interaction of three factors-susceptibility, environmental exposure and vulnerability period.

    Science.gov (United States)

    Mejía-Aranguré, Juan Manuel

    Acute leukemias have a huge morphological, cytogenetic and molecular heterogeneity and genetic polymorphisms associated with susceptibility. Every leukemia presents causal factors associated with the development of the disease. Particularly, when three factors are present, they result in the development of acute leukemia. These phenomena are susceptibility, environmental exposure and a period that, for this model, has been called the period of vulnerability. This framework shows how the concepts of molecular epidemiology have established a reference from which it is more feasible to identify the environmental factors associated with the development of leukemia in children. Subsequently, the arguments show that only susceptible children are likely to develop leukemia once exposed to an environmental factor. For additional exposure, if the child is not susceptible to leukemia, the disease does not develop. In addition, this exposure should occur during a time window when hematopoietic cells and their environment are more vulnerable to such interaction, causing the development of leukemia. This model seeks to predict the time when the leukemia develops and attempts to give a context in which the causality of childhood leukemia should be studied. This information can influence and reduce the risk of a child developing leukemia. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  8. Causal universe

    CERN Document Server

    Ellis, George FR; Pabjan, Tadeusz

    2013-01-01

    Written by philosophers, cosmologists, and physicists, this collection of essays deals with causality, which is a core issue for both science and philosophy. Readers will learn about different types of causality in complex systems and about new perspectives on this issue based on physical and cosmological considerations. In addition, the book includes essays pertaining to the problem of causality in ancient Greek philosophy, and to the problem of God's relation to the causal structures of nature viewed in the light of contemporary physics and cosmology.

  9. Implementation and test of proposals to integrate human factors in reporting and causal analysis in nuclear power plants

    International Nuclear Information System (INIS)

    Wilpert; Maimer, H.; Miller, R.; Fahlbruch, B.; Leiber, I.; Szameitat, S.; Baggen, R.; Gans, A.; Becker, G.

    1998-01-01

    The research project 'Implementation and Test of Proposals to integrate Human Factors in Reporting and Causal Analysis in Nuclear Power Plants' ('Implementation and Test', SR 2039/8) is based on two antecedent projects: 'Reporting System' (SR 2039/1) and 'Causal Analysis' (SR 2039/2). The project 'Implementation and Test' conducted various tests and introductory programs in cooperation with different target groups concerning the event analysis methodology 'SOL - Safety through Organizational Learning': Regulators, consultant organizations, union/works councillors and utilities. Thus, SOL was concurrently optimized and [apted for the practice in the German nuclear power industry. SOL was also validated in a German nuclear power plant using a concrete event. Results of the 'Implementation and Test' project demonstrate that SOL is fit to conduct event analyses practicably and economically with appropriate comprehensiveness and depth. SOL facilitates the identification of relevant contributing factors of events. This report concludes with various concrete proposals for the further development of the Program of the Federal Ministry of Environment, Nature Protection and Reactor Safety (BMU) and the Federal Agency of R[iation Protection (BfS) concerning 'The Contribution of Humans to Safety of Nuclear Power Plants'. (orig.) [de

  10. Causal mapping

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2006-01-01

    The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method......The lecture note explains how to use the causal mapping method as well as the theoretical framework aoosciated to the method...

  11. Neural Correlates of Causal Power Judgments

    Directory of Open Access Journals (Sweden)

    Denise Dellarosa Cummins

    2014-12-01

    Full Text Available Causal inference is a fundamental component of cognition and perception. Probabilistic theories of causal judgment (most notably causal Bayes networks derive causal judgments using metrics that integrate contingency information. But human estimates typically diverge from these normative predictions. This is because human causal power judgments are typically strongly influenced by beliefs concerning underlying causal mechanisms, and because of the way knowledge is retrieved from human memory during the judgment process. Neuroimaging studies indicate that the brain distinguishes causal events from mere covariation, and between perceived and inferred causality. Areas involved in error prediction are also activated, implying automatic activation of possible exception cases during causal decision-making.

  12. A holistic review on the autoimmune disease vitiligo with emphasis on the causal factors.

    Science.gov (United States)

    Patel, Seema; Rauf, Abdur; Khan, Haroon; Meher, Biswa Ranjan; Hassan, Syed Shams Ul

    2017-08-01

    Vitiligo is an idiopathic systemic autoimmune disease affecting skin, hair and oral mucosa. This genetic yet acquired disease characterized by melanin loss is a cause of morbidity across all races. Though thyroid disturbance has been recognized as a key trigger of this pathology, an array of other factors plays critical role in its manifestation. Multiple hormones (corticotropin-releasing hormone, adrenocorticotropic hormone, α-melanocyte-stimulating hormone, melatonin, calcitriol, testosterone, estrogen), genes (Human leukocyte antigen (HLA), Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), Forkhead box D3 (FOXD3), Cluster of differentiation 117 (CD117), Estrogen receptor (ESR) 1, Cyclooxygenase-2 (COX2), Vitiligo-associated protein 1 (VIT1)), and lifestyle choices (stress, diet, cosmetic products, and medications) have been suspected as drivers of this disorder. The pathological mechanisms have been understood in recent times, with the aid of genomic studies; however a universally-effective therapy is yet to be achieved. This review discusses these under-investigated facets of vitiligo onset and progression; hence, it is expected to enrich vitiligo research. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Oxidative stress as a potential causal factor for autoimmune hemolytic anemia and systemic lupus erythematosus

    Science.gov (United States)

    Fujii, Junichi; Kurahashi, Toshihiro; Konno, Tasuku; Homma, Takujiro; Iuchi, Yoshihito

    2015-01-01

    The kidneys and the blood system mutually exert influence in maintaining homeostasis in the body. Because the kidneys control erythropoiesis by producing erythropoietin and by supporting hematopoiesis, anemia is associated with kidney diseases. Anemia is the most prevalent genetic disorder, and it is caused by a deficiency of glucose 6-phosphate dehydrogenase (G6PD), for which sulfhydryl oxidation due to an insufficient supply of NADPH is a likely direct cause. Elevated reactive oxygen species (ROS) result in the sulfhydryl oxidation and hence are another potential cause for anemia. ROS are elevated in red blood cells (RBCs) under superoxide dismutase (SOD1) deficiency in C57BL/6 mice. SOD1 deficient mice exhibit characteristics similar to autoimmune hemolytic anemia (AIHA) and systemic lupus erythematosus (SLE) at the gerontic stage. An examination of AIHA-prone New Zealand Black (NZB) mice, which have normal SOD1 and G6PD genes, indicated that ROS levels in RBCs are originally high and further elevated during aging. Transgenic overexpression of human SOD1 in erythroid cells effectively suppresses ROS elevation and ameliorates AIHA symptoms such as elevated anti-RBC antibodies and premature death in NZB mice. These results support the hypothesis that names oxidative stress as a risk factor for AIHA and other autoimmune diseases such as SLE. Herein we discuss the association between oxidative stress and SLE pathogenesis based mainly on the genetic and phenotypic characteristics of NZB and New Zealand white mice and provide insight into the mechanism of SLE pathogenesis. PMID:25949934

  14. The influence of linguistic and cognitive factors on the time course of verb-based implicit causality

    NARCIS (Netherlands)

    Koornneef, A.W.; Dotlacil, J.; Sanders, T.J.M.

    2016-01-01

    In three eye-tracking experiments the influence of the Dutch causal connective “want” (because) and the working memory capacity of readers on the usage of verb-based implicit causality was examined. Experiments 1 and 2 showed that although a causal connective is not required to activate implicit

  15. Age- and Sex-Specific Causal Effects of Adiposity on Cardiovascular Risk Factors

    NARCIS (Netherlands)

    Fall, T.; Hägg, S.; Ploner, A.; Mägi, R.; Fischer, K.; Draisma, H.H.M.; Sarin, A.-P.; Benyamin, B.; Ladenvall, C.; Akerlund, M.; Kals, M.; Esko, T.; Nelson, C.P.; Kaakinen, M.; Huikari, V.; Mangino, M.; Meirhaeghe, A.; Kristiansson, K.; Nuotio, M.L.; Kobl, M.; Grallert, H.; Dehghan, A.; Kuningas, M.; de Vries, P.S.; de Bruijn, R.F.A.G.; Willems, S.M.; Heikkilä, K.; Silventoinen, K.; Pietilainen, K.H.; Legry, V.; Giedraitis, V.; Goumidi, L.; Syvänen, A.C.; Strauch, K.; Koenig, W.; Lichtner, P.; Herder, C.; Palotie, A.; Menni, C.; Uitterlinden, A.G.; Kuulasmaa, K.; Havulinna, A.S.; Moreno, L.A.; Gonzalez-Gross, M.; Evans, A.; Tregouet, D.A.; Yarnell, J.W.; Virtamo, J.; Ferrières, J.; Veronesi, G.; Perola, M.; Arveiler, D.; Brambilla, P.; Lind, L.; Kaprio, J.; Hofman, A.; Stricker, B.H.; van Duijn, C.M.; Arfan Ikram, M.; Franco, O.H.; Cottel, D.; Dallongeville, J.; Hall, A.S.; Jula, A.; Tobin, M.D.; Penninx, B.W.J.H.; Peters, A.; Gieger, C.; Samani, N.J.; Montgomery, G.W.; Whitfield, J.B.; Martin, N.G.; Groop, L.; Spector, T.D.; Magnusson, P.K.; Amouyel, P.; Boomsma, D.I.; Nilsson, P.M.; Järvelin, M.R.; Lyssenko, V.; Metspalu, A.; Strachan, D.P.; Salomaa, V.; Ripatti, S.; Pedersen, N.L.; Prokopenko, I.; McCarthy, M.I.; Ingelsson, E.

    2015-01-01

    Observational studies have reported different effects of adiposity on cardiovascular risk factors across age and sex. Since cardiovascular risk factors are enriched in obese individuals, it has not been easy to dissect the effects of adiposity from those of other risk factors. We used a Mendelian

  16. Age- and sex-specific causal effects of adiposity on cardiovascular risk factors

    NARCIS (Netherlands)

    M. Fall (Magnus); S. Hägg (Sara); A. Ploner (Alexander); R. Mägi (Reedik); K. Fischer (Krista); G. Draisma (Gerrit); A.-P. Sarin; B. Benyamin (Beben); C. Ladenvall (Claes); M. Åkerlund (Mikael); M. Kals (Mart); T. Esko (Tõnu); C.P. Nelson (Christopher P.); M. Kaakinen (Marika); V. Huikari (Ville); M. Mangino (Massimo); A. Meirhaeghe (Aline); K. Kristiansson (Kati); M.-L. Nuotio (Marja-Liisa); M. Kobl (Michael); H. Grallert (Harald); A. Dehghan (Abbas); M. Kuningas (Maris); P.S. de Vries (Paul); R.F.A.G. de Bruijn (Renée); S.M. Willems (Sara); K. Heikkilä (Kauko); K. Silventoinen (Karri); K.H. Pietilainen (Kirsi Hannele); V. Legry (Vanessa); V. Giedraitis (Vilmantas); L. Goumidi (Louisa); A.C. Syvanen; K. Strauch (Konstantin); W. Koenig (Wolfgang); P. Lichtner (Peter); C. Herder (Christian); A. Palotie (Aarno); C. Menni (Cristina); A.G. Uitterlinden (André); K. Kuulasmaa (Kari); A.S. Havulinna (Aki); L. Moreno (Luis); M. Gonzalez-Gross (Marcela); A. Evans (Alun); D.-A. Tregouet (David-Alexandre); J.W.G. Yarnell (John W.); J. Virtamo (Jarmo); J. Ferrieres (Jean); G. Veronesi (Giovanni); M. Perola (Markus); D. Arveiler (Dominique); P. Brambilla (Paolo); L. Lind (Lars); J. Kaprio (Jaakko); A. Hofman (Albert); B.H.Ch. Stricker (Bruno); C.M. van Duijn (Cornelia); M.A. Ikram (Arfan); O.H. Franco (Oscar); D. Cottel (Dominique); J. Dallongeville; A.S. Hall (Alistair); A. Jula (Antti); M.D. Tobin (Martin); B.W.J.H. Penninx (Brenda); A. Peters (Annette); C. Gieger (Christian); N.J. Samani (Nilesh); G.W. Montgomery (Grant); J. Whitfield (John); N.G. Martin (Nicholas); L. Groop (Leif); T.D. Spector (Timothy); P.K. Magnusson (Patrik); P. Amouyel (Philippe); D.I. Boomsma (Dorret); P. Nilsson (Peter); M.-R. Jarvelin (Marjo-Riitta); V. Lyssenko (Valeriya); A. Metspalu (Andres); D.P. Strachan (David); V. Salomaa (Veikko); S. Ripatti (Samuli); N.L. Pedersen (Nancy); I. Prokopenko (Inga); M.I. McCarthy (Mark); E. Ingelsson (Erik)

    2015-01-01

    textabstractObservational studies have reported different effects of adiposity on cardiovascular risk factors across age and sex. Since cardiovascular risk factors are enriched in obese individuals, it has not been easy to dissect the effects of adiposity from those of other risk factors. We used a

  17. Donation to disaster relief campaigns: underlying social cognitive factors exposed.

    Science.gov (United States)

    Oosterhof, Liesbeth; Heuvelman, Ard; Peters, Oscar

    2009-05-01

    A number of very serious natural disasters have put an enormous pressure on relief organizations in the last few years. The present study exposes underlying social cognitive factors for donation to relief campaigns. A causal model was constructed, based on social cognitive theory, research on attitudes, and the impact of media exposure. The aim was to expand and improve an already existing model by Cheung and Chan [Cheung, C. K., & Chan, C. M. (2000). Social-cognitive factors of donating money to charity, with special attention to an international relief organisation. Evaluation and Program Planning, 23, 241-253]. The expanded model showed a better fit. Furthermore, the expanded model explained two-thirds of the variance of the intention to donate to a disaster relief campaign. The greatest predictor of the intention to donate proved to be "Past donation to disaster relief campaigns." The factor "News exposure" was indicated to be a valuable additional factor, as it had a significant direct effect on "Awareness of a disaster relief campaign" and was the only factor that had a total effect on all other factors, including "Intention to donate to a disaster relief campaign."

  18. A review of protective factors and causal mechanisms that enhance the mental health of Indigenous Circumpolar youth.

    Science.gov (United States)

    MacDonald, Joanna Petrasek; Ford, James D; Willox, Ashlee Cunsolo; Ross, Nancy A

    2013-12-09

    To review the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. A systematic literature review of peer-reviewed English-language research was conducted to systematically examine the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with elements of a realist review. From 160 records identified in the initial search of 3 databases, 15 met the inclusion criteria and were retained for full review. Data were extracted using a codebook to organize and synthesize relevant information from the articles. More than 40 protective factors at the individual, family, and community levels were identified as enhancing Indigenous youth mental health. These included practicing and holding traditional knowledge and skills, the desire to be useful and to contribute meaningfully to one's community, having positive role models, and believing in one's self. Broadly, protective factors at the family and community levels were identified as positively creating and impacting one's social environment, which interacts with factors at the individual level to enhance resilience. An emphasis on the roles of cultural and land-based activities, history, and language, as well as on the importance of social and family supports, also emerged throughout the literature. More than 40 protective factors at the individual, family, and community levels were identified as enhancing Indigenous youth mental health. These included practicing and holding traditional knowledge and skills, the desire to be useful and to contribute meaningfully to one's community, having positive role models, and believing in one's self. Broadly, protective factors at the family and community levels were identified as positively creating and impacting one's social

  19. Causal associations between risk factors and common diseases inferred from GWAS summary data

    DEFF Research Database (Denmark)

    Zhu, Zhihong; Zheng, Zhili; Zhang, Futao

    2018-01-01

    Health risk factors such as body mass index (BMI) and serum cholesterol are associated with many common diseases. It often remains unclear whether the risk factors are cause or consequence of disease, or whether the associations are the result of confounding. We develop and apply a method (called...

  20. Optimal causal inference: estimating stored information and approximating causal architecture.

    Science.gov (United States)

    Still, Susanne; Crutchfield, James P; Ellison, Christopher J

    2010-09-01

    We introduce an approach to inferring the causal architecture of stochastic dynamical systems that extends rate-distortion theory to use causal shielding--a natural principle of learning. We study two distinct cases of causal inference: optimal causal filtering and optimal causal estimation. Filtering corresponds to the ideal case in which the probability distribution of measurement sequences is known, giving a principled method to approximate a system's causal structure at a desired level of representation. We show that in the limit in which a model-complexity constraint is relaxed, filtering finds the exact causal architecture of a stochastic dynamical system, known as the causal-state partition. From this, one can estimate the amount of historical information the process stores. More generally, causal filtering finds a graded model-complexity hierarchy of approximations to the causal architecture. Abrupt changes in the hierarchy, as a function of approximation, capture distinct scales of structural organization. For nonideal cases with finite data, we show how the correct number of the underlying causal states can be found by optimal causal estimation. A previously derived model-complexity control term allows us to correct for the effect of statistical fluctuations in probability estimates and thereby avoid overfitting.

  1. A review of protective factors and causal mechanisms that enhance the mental health of Indigenous Circumpolar youth

    Directory of Open Access Journals (Sweden)

    Joanna Petrasek MacDonald

    2013-12-01

    Full Text Available Objectives . To review the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. Study design . A systematic literature review of peer-reviewed English-language research was conducted to systematically examine the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North. Methods . This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA guidelines, with elements of a realist review. From 160 records identified in the initial search of 3 databases, 15 met the inclusion criteria and were retained for full review. Data were extracted using a codebook to organize and synthesize relevant information from the articles. Results . More than 40 protective factors at the individual, family, and community levels were identified as enhancing Indigenous youth mental health. These included practicing and holding traditional knowledge and skills, the desire to be useful and to contribute meaningfully to one's community, having positive role models, and believing in one's self. Broadly, protective factors at the family and community levels were identified as positively creating and impacting one's social environment, which interacts with factors at the individual level to enhance resilience. An emphasis on the roles of cultural and land-based activities, history, and language, as well as on the importance of social and family supports, also emerged throughout the literature. Conclusions . Healthy communities and families foster and support youth who are resilient to mental health challenges and able to adapt and cope with multiple stressors, be they social, economic, or environmental. Creating opportunities and environments where youth can successfully navigate challenges and enhance their resilience can in turn contribute to fostering healthy Circumpolar communities. Looking at the

  2. Factors influencing immunisation coverage among children under ...

    African Journals Online (AJOL)

    Background This article explores the hypothesis that predisposing and enabling factors of households influence the vaccination status of the children under the age of five in Khartoum State, Sudan. Method The study was a cross-sectional survey among a representative sample of 410 male and female children under five ...

  3. Identification and Sensitivity Analysis for Average Causal Mediation Effects with Time-Varying Treatments and Mediators: Investigating the Underlying Mechanisms of Kindergarten Retention Policy.

    Science.gov (United States)

    Park, Soojin; Steiner, Peter M; Kaplan, David

    2018-03-01

    Considering that causal mechanisms unfold over time, it is important to investigate the mechanisms over time, taking into account the time-varying features of treatments and mediators. However, identification of the average causal mediation effect in the presence of time-varying treatments and mediators is often complicated by time-varying confounding. This article aims to provide a novel approach to uncovering causal mechanisms in time-varying treatments and mediators in the presence of time-varying confounding. We provide different strategies for identification and sensitivity analysis under homogeneous and heterogeneous effects. Homogeneous effects are those in which each individual experiences the same effect, and heterogeneous effects are those in which the effects vary over individuals. Most importantly, we provide an alternative definition of average causal mediation effects that evaluates a partial mediation effect; the effect that is mediated by paths other than through an intermediate confounding variable. We argue that this alternative definition allows us to better assess at least a part of the mediated effect and provides meaningful and unique interpretations. A case study using ECLS-K data that evaluates kindergarten retention policy is offered to illustrate our proposed approach.

  4. Epidemiological causality.

    Science.gov (United States)

    Morabia, Alfredo

    2005-01-01

    Epidemiological methods, which combine population thinking and group comparisons, can primarily identify causes of disease in populations. There is therefore a tension between our intuitive notion of a cause, which we want to be deterministic and invariant at the individual level, and the epidemiological notion of causes, which are invariant only at the population level. Epidemiologists have given heretofore a pragmatic solution to this tension. Causal inference in epidemiology consists in checking the logical coherence of a causality statement and determining whether what has been found grossly contradicts what we think we already know: how strong is the association? Is there a dose-response relationship? Does the cause precede the effect? Is the effect biologically plausible? Etc. This approach to causal inference can be traced back to the English philosophers David Hume and John Stuart Mill. On the other hand, the mode of establishing causality, devised by Jakob Henle and Robert Koch, which has been fruitful in bacteriology, requires that in every instance the effect invariably follows the cause (e.g., inoculation of Koch bacillus and tuberculosis). This is incompatible with epidemiological causality which has to deal with probabilistic effects (e.g., smoking and lung cancer), and is therefore invariant only for the population.

  5. Approaches for Strengthening Causal Inference Regarding Prenatal Risk Factors for Childhood Behavioural and Psychiatric Disorders

    Science.gov (United States)

    Lewis, Sarah J.; Relton, Caroline; Zammit, Stanley; Smith, George Davey

    2013-01-01

    Background: The risk of childhood behavioural and psychiatric diseases could be substantially reduced if modifiable risk factors for these disorders were identified. The critical period for many of these exposures is likely to be in utero as this is the time when brain development is most rapid. However, due to confounding and other limitations of…

  6. Is the Association Between Education and Fertility Postponement Causal? The Role of Family Background Factors

    NARCIS (Netherlands)

    Tropf, Felix C.; Mandemakers, Jornt J.

    A large body of literature has demonstrated a positive relationship between education and age at first birth. However, this relationship may be partly spurious because of family background factors that cannot be controlled for in most research designs. We investigate the extent to which education is

  7. Is the Association Between Education and Fertility Postponement Causal? The Role of Family Background Factors

    NARCIS (Netherlands)

    Tropf, Felix C.; Mandemakers, Jornt J.

    2017-01-01

    A large body of literature has demonstrated a positive relationship between education and age at first birth. However, this relationship may be partly spurious because of family background factors that cannot be controlled for in most research designs. We investigate the extent to which education

  8. LA INFLAMACIÓN COMO FACTOR CAUSAL EMERGENTE DE LA ENFERMEDAD CARDIOVASCULAR

    OpenAIRE

    Fernández Mora, Tania; Departamento de Microbiología Facultad de Ciencias Pontificia Universidad Javeriana, Bogotá; Patiño Cuervo, Diana Cristina; Departamento de Microbiología Facultad de Ciencias Pontificia Universidad Javeriana, Bogotá

    2007-01-01

    La ateroesclerosis está involucrada en el desarrollo de la enfermedad cardiovascular, una de las principales enfermedades de morbi-mortalidad en el mundo. Se han determinado una serie de factores de riesgo ,tanto clásicos como emergentes, implicados en el desarrollo de esta enfermedad. Recientes investigaciones han demostrado que la inflamación juega un papel clave en el desarrollo de la ateroesclerosis. Las células del sistema inmune se encuentran presentes en todos los estadios de las lesio...

  9. LA INFLAMACIÓN COMO FACTOR CAUSAL EMERGENTE DE LA ENFERMEDAD CARDIOVASCULAR

    Directory of Open Access Journals (Sweden)

    T. Fernández-Mora

    2007-06-01

    Full Text Available La ateroesclerosis está involucrada en el desarrollo de la enfermedad cardiovascular, una de las principales enfermedades de morbimortalidad en el mundo. Se han determinado una serie de factores de riesgo, tanto clásicos como emergentes, implicados en el desarrollo de esta enfermedad. Recientes investigaciones han demostrado que la inflamación juega un papel clave en el desarrollo de la ateroesclerosis. Las células del sistema inmune se encuentran presentes en todos los estadios de las lesiones arterioescleróticasy sus moléculas efectoras pueden acelerar la progresión de las lesiones y orquestar los mecanismos de inflamación inducidos en los síndromes coronarios agudos. La evidencia crítica implica a mediadores de la inmunidad tanto innata como adquirida en los diferentes estados de la ateroesclerosis. Dentro de loscomponentes inmunes involucrados en el proceso de la ateroesclerosis se encuentran componentes celulares como macrófagos, linfocitos, células dendríticas, mastocitos, células NK; componentes humoralescomo anticuerpos, citocinas proinflamatorias y moduladoras de la respuesta inmune, complemento, proteínas de fase aguda; y otros componentes como moléculas de adhesión y de choque térmico. A partirdel esclarecimiento del papel del sistema inmune en el desarrollo de la arterioesclerosis, han surgido una serie de perspectivas diagnósticas y terapéuticas para la enfermedad cardiovascular.

  10. Factor structure underlying components of allostatic load.

    Directory of Open Access Journals (Sweden)

    Jeanne M McCaffery

    Full Text Available Allostatic load is a commonly used metric of health risk based on the hypothesis that recurrent exposure to environmental demands (e.g., stress engenders a progressive dysregulation of multiple physiological systems. Prominent indicators of response to environmental challenges, such as stress-related hormones, sympatho-vagal balance, or inflammatory cytokines, comprise primary allostatic mediators. Secondary mediators reflect ensuing biological alterations that accumulate over time and confer risk for clinical disease but overlap substantially with a second metric of health risk, the metabolic syndrome. Whether allostatic load mediators covary and thus warrant treatment as a unitary construct remains to be established and, in particular, the relation of allostatic load parameters to the metabolic syndrome requires elucidation. Here, we employ confirmatory factor analysis to test: 1 whether a single common factor underlies variation in physiological systems associated with allostatic load; and 2 whether allostatic load parameters continue to load on a single common factor if a second factor representing the metabolic syndrome is also modeled. Participants were 645 adults from Allegheny County, PA (30-54 years old, 82% non-Hispanic white, 52% female who were free of confounding medications. Model fitting supported a single, second-order factor underlying variance in the allostatic load components available in this study (metabolic, inflammatory and vagal measures. Further, this common factor reflecting covariation among allostatic load components persisted when a latent factor representing metabolic syndrome facets was conjointly modeled. Overall, this study provides novel evidence that the modeled allostatic load components do share common variance as hypothesized. Moreover, the common variance suggests the existence of statistical coherence above and beyond that attributable to the metabolic syndrome.

  11. Characteristics and Causal Factors of Hysteresis in the Hydrodynamics of a Large Floodplain System: Poyang Lake (China)

    Science.gov (United States)

    Zhang, X.; Zhang, Q.; Werner, A. D.

    2017-12-01

    Previous research has revealed complex hysteretic relationships between stage, storage volume and surface area of a lake-floodplain system, Poyang Lake (China), indicating that both the floodplain and the permanently inundated region contributed to the lake's volume-stage hysteresis. However, the causal factors for Poyang Lake hysteresis have not been clearly elucidated, and the reasons why both clockwise and counterclockwise hysteresis occurred in the same system remains unknown. This study aims to address these knowledge gaps by exploring further Poyang Lake's hysteretic behavior, partly by considering for the first time the hysteretic nature of stage-flow relationships. Remotely sensed imagery is used to verify water surface areas simulated within a hydrodynamic model, which shows good agreement in the stage-area relationship between the two methods. The new results show a three-phase hydrological regime in stage-flow relationships, which further interprets the occurrence of hysteretic stage-area relationships of the lake-floodplain system. That is, the clockwise stage-area relationship is caused by classic floodplain hydrological process, where restricted water volumes are retained on the floodplain during recession. The counterclockwise stage-area relationship is caused by the `river effect', otherwise known as the backwater effect. The river effect is enhanced by the time lag between the peaks of lake's catchment inflow and Yangtze discharge. The time lag also leads to hysteretic functions between the Yangtze discharge and the lake stage. Thus, the hysteretic hydrology regime of Poyang Lake is the combination of hydrological processes normally associated with rivers, floodplains and lakes, whereby the significant spatiotemporal variations in hysteresis can be attributed to clear factors. These factors dominate at different times, in different parts of the lake and during different phases of lake stage fluctuations, resulting in a unique tri-modal hysteretic

  12. Entropy for theories with indefinite causal structure

    International Nuclear Information System (INIS)

    Markes, Sonia; Hardy, Lucien

    2011-01-01

    Any theory with definite causal structure has a defined past and future, be it defined by light cones or an absolute time scale. Entropy is a concept that has traditionally been reliant on a definite notion of causality. However, without a definite notion of causality, the concept of entropy is not all lost. Indefinite causal structure results from combining probabilistic predictions and dynamical space-time. The causaloid framework lays the mathematical groundwork to be able to treat indefinite causal structure. In this paper, we build on the causaloid mathematics and define a causally-unbiased entropy for an indefinite causal structure. In defining a causally-unbiased entropy, there comes about an emergent idea of causality in the form of a measure of causal connectedness, termed the Q factor.

  13. Long-term variations and causal factors in nitrogen and phosphorus transport in the Yellow River, China

    Science.gov (United States)

    Tao, Yu; Wei, Meng; Ongley, Edwin; Li, Zicheng; Jingsheng, Chen

    2010-02-01

    This paper is to examine the water quality of the Yellow River basin on the basis of collated data of nitrogen (40 years) and phosphorus (20 years), and also of the relevant chemical fertilizer application, population, and industrial wastewater, etc. Relationship among these elements was discussed in order to explore their causal links, in relation to the temporal variation of nitrogen and phosphorus transportation. Results indicate that the transported nitrogen load in the lower Yellow River has had an increasing trend during the past 40 years but declined considerably in the later 1990s due to the reduction in flow discharge that led to desiccation of the lower reaches of the Yellow River. Whereas, nitrogen contribution to the estuary from Huayuankou to Lijin reach was minus due to the large amount of water diversion from the Yellow River for irrigation purpose. Phosphorus content fluctuated within a certain range without any tendency, but also decreased in the later 1990s due to the desiccation in the lower reaches. Our analysis indicates that nitrogen load in the Yellow River has been mainly impacted by population growth and nitrogen fertilizer application, but showed no statistically significant relationship with wastewater loads. In contrast, total phosphorus content in the Yellow River showed no relationship with population, fertilizer use and wastewater discharge in the basin, but presented significant correlation with suspended solids concentration of the Yellow River. Calculations indicate that the phosphorus content in suspended solids of the Yellow River was 0.54 g/kg, which is quite close to the background value of phosphorus in the soil of the Loess Plateau - the intensive soil erosion area in China, through which the Yellow River flows. Therefore, we conclude that phosphorus transportation in the Yellow River is dominantly controlled by soil erosion from the Loess Plateau. The results are significant for estuarine management in that nitrogen, a key

  14. Covariation in Natural Causal Induction.

    Science.gov (United States)

    Cheng, Patricia W.; Novick, Laura R.

    1991-01-01

    Biases and models usually offered by cognitive and social psychology and by philosophy to explain causal induction are evaluated with respect to focal sets (contextually determined sets of events over which covariation is computed). A probabilistic contrast model is proposed as underlying covariation computation in natural causal induction. (SLD)

  15. Revisiting the Factors Underlying Maxillary Midline Diastema

    Directory of Open Access Journals (Sweden)

    Abdullah M. Zakria Jaija

    2016-01-01

    Full Text Available Aim. The aim of this study is to analyze the etiological factors underlying the presence of maxillary midline diastema in a sample of orthodontic patients. Materials and Methods. One hundred patients who fulfill the inclusion criteria were selected from 1355 patients seeking orthodontic treatment. The pretreatment orthodontic records were analyzed. The width of the maxillary midline diastema was measured clinically with a digital caliper at two levels: the mesioincisal angles of the central incisors and five millimeters from the incisal edge. The two measurements were averaged, and patients with diastema of more than 0.5 millimeter in width were enrolled. Results. Diastema is a multifactorial clinical finding with more than one underlying etiological cause. The interrelationship between the familial pattern of midline diastema and the microdontia, macroglossia, labial frenum, and alveolar cleft conforms was clear. The effect of a mesiodens and the upper lateral incisor whether bilaterally missing, unerupted, or peg shaped was minimal. Conclusion. Etiological factors underlying maxillary midline diastema are interconnected. Using a checklist as a guide during handling maxillary midline diastema is important in the different stages of treatment.

  16. The Genetic and Environmental Factors Underlying Hypospadias

    Science.gov (United States)

    Pask, Andrew; Heloury, Yves; Sinclair, Andrew H.

    2016-01-01

    Hypospadias results from a failure of urethral closure in the male phallus and affects 1 in 200–300 boys. It is thought to be due to a combination of genetic and environmental factors. The development of the penis progresses in 2 stages: an initial hormone-independent phase and a secondary hormone-dependent phase. Here, we review the molecular pathways that contribute to each of these stages, drawing on studies from both human and mouse models. Hypospadias can occur when normal development of the phallus is disrupted, and we provide evidence that mutations in genes underlying this developmental process are causative. Finally, we discuss the environmental factors that may contribute to hypospadias and their potential immediate and transgen erational epigenetic impacts. PMID:26613581

  17. Causal factors of low stakeholder engagement : A survey of expert opinions in the context of healthcare simulation projects

    NARCIS (Netherlands)

    Jahangirian, Mohsen; Borsci, Simone; Shah, Syed Ghulam Sarwar; Taylor, Simon J.E.

    2015-01-01

    While simulation methods have proved to be very effective in identifying efficiency gains, low stakeholder engagement creates a significant limitation on the achievement of simulation modeling projects in practice. This study reports causal factors—at two hierarchical levels (i.e., primary and

  18. Neural networks for action representation underlying automatic mimicry: A functional magnetic-resonance imaging and dynamic causal modeling study

    Directory of Open Access Journals (Sweden)

    Akihiro T Sasaki

    2012-08-01

    Full Text Available Automatic mimicry is based on the tight linkage between motor and perception action representations in which internal models play a key role. Based on the anatomical connection, we hypothesized that the direct effective connectivity from the posterior superior temporal sulcus (pSTS to the ventral premotor area (PMv formed an inverse internal model, converting visual representation into a motor plan, and that reverse connectivity formed a forward internal model, converting the motor plan into a sensory outcome of action. To test this hypothesis, we employed dynamic causal-modeling analysis with functional magnetic-resonance imaging. Twenty-four normal participants underwent a change-detection task involving two visually-presented balls that were either manually rotated by the investigator’s right hand (‘Hand’ or automatically rotated. The effective connectivity from the pSTS to the PMv was enhanced by hand observation and suppressed by execution, corresponding to the inverse model. Opposite effects were observed from the PMv to the pSTS, suggesting the forward model. Additionally, both execution and hand observation commonly enhanced the effective connectivity from the pSTS to the inferior parietal lobule (IPL, the IPL to the primary sensorimotor cortex (S/M1, the PMv to the IPL, and the PMv to the S/M1. Representation of the hand action therefore was implemented in the motor system including the S/M1. During hand observation, effective connectivity toward the pSTS was suppressed whereas that toward the PMv and S/M1 was enhanced. Thus the action-representation network acted as a dynamic feedback-control system during action observation.

  19. Success factors of an enterprise under crisis

    Directory of Open Access Journals (Sweden)

    Yaroslava V Danilina

    2017-06-01

    Full Text Available Objective to analyze the impact of economic crisis in Russia on the enterprisesrsquo access to productive resources as well as on the level of their competencies. Methods historical abstractlogical. Results the article states that despite the influence of external factors the main activities of the company are internal capabilities and resources of the firm. It is shown that under crisis a company must adapt to the limited resources i.e. change the competences of using them. Under modern conditions the competitive advantage can be based on two components ndash access to resources and internal ability of the company to use them. Therefore under the resource constraints such competencies should be generated as 1 ability to use a smaller amount of resources 2 more efficient use of available resources 3 search for the new resources development of own resources. The study determined that the acquisition of new competencies by the company will be associated with the use and improvement of its cognitive capabilities which are a function of organizational and individual knowledge possessed by the enterprise i.e. its intellectual capital. The article analyses the experience of development of new competencies under crisis by the example of reorganization of quotPrompriborquot plant and activities of quotGalogenquot JSC. Analysis of the experience of these companies which not only survived during the crisis but also acquired new competences and skills have led to the conclusion that the key role in this process was played by working with the main part of a company39s intellectual capital i.e. human capital. Thus a conclusion is made about the value of people and their common interests during the transformations within the enterprise. Scientific novelty for the first time the cognitive aspects of the enterprisesrsquo modernization system are considered from the viewpoint of the new resource and competence theory of the enterprise. Practical significance the

  20. Causal Modeling of Cancer-Stromal Communication Identifies PAPPA as a Novel Stroma-Secreted Factor Activating NFκB Signaling in Hepatocellular Carcinoma

    Science.gov (United States)

    Engelmann, Julia C.; Amann, Thomas; Ott-Rötzer, Birgitta; Nützel, Margit; Reinders, Yvonne; Reinders, Jörg; Thasler, Wolfgang E.; Kristl, Theresa; Teufel, Andreas; Huber, Christian G.; Oefner, Peter J.

    2015-01-01

    Inter-cellular communication with stromal cells is vital for cancer cells. Molecules involved in the communication are potential drug targets. To identify them systematically, we applied a systems level analysis that combined reverse network engineering with causal effect estimation. Using only observational transcriptome profiles we searched for paracrine factors sending messages from activated hepatic stellate cells (HSC) to hepatocellular carcinoma (HCC) cells. We condensed these messages to predict ten proteins that, acting in concert, cause the majority of the gene expression changes observed in HCC cells. Among the 10 paracrine factors were both known and unknown cancer promoting stromal factors, the former including Placental Growth Factor (PGF) and Periostin (POSTN), while Pregnancy-Associated Plasma Protein A (PAPPA) was among the latter. Further support for the predicted effect of PAPPA on HCC cells came from both in vitro studies that showed PAPPA to contribute to the activation of NFκB signaling, and clinical data, which linked higher expression levels of PAPPA to advanced stage HCC. In summary, this study demonstrates the potential of causal modeling in combination with a condensation step borrowed from gene set analysis [Model-based Gene Set Analysis (MGSA)] in the identification of stromal signaling molecules influencing the cancer phenotype. PMID:26020769

  1. Classical planning and causal implicatures

    DEFF Research Database (Denmark)

    Blackburn, Patrick Rowan; Benotti, Luciana

    In this paper we motivate and describe a dialogue manager (called Frolog) which uses classical planning to infer causal implicatures. A causal implicature is a type of Gricean relation implicature, a highly context dependent form of inference. As we shall see, causal implicatures are important...... to generate clarification requests"; as a result we can model task-oriented dialogue as an interactive process locally structured by negotiation of the underlying task. We give several examples of Frolog-human dialog, discuss the limitations imposed by the classical planning paradigm, and indicate...

  2. Causally nonseparable processes admitting a causal model

    International Nuclear Information System (INIS)

    Feix, Adrien; Araújo, Mateus; Brukner, Caslav

    2016-01-01

    A recent framework of quantum theory with no global causal order predicts the existence of ‘causally nonseparable’ processes. Some of these processes produce correlations incompatible with any causal order (they violate so-called ‘causal inequalities’ analogous to Bell inequalities ) while others do not (they admit a ‘causal model’ analogous to a local model ). Here we show for the first time that bipartite causally nonseparable processes with a causal model exist, and give evidence that they have no clear physical interpretation. We also provide an algorithm to generate processes of this kind and show that they have nonzero measure in the set of all processes. We demonstrate the existence of processes which stop violating causal inequalities but are still causally nonseparable when mixed with a certain amount of ‘white noise’. This is reminiscent of the behavior of Werner states in the context of entanglement and nonlocality. Finally, we provide numerical evidence for the existence of causally nonseparable processes which have a causal model even when extended with an entangled state shared among the parties. (paper)

  3. Principal stratification in causal inference.

    Science.gov (United States)

    Frangakis, Constantine E; Rubin, Donald B

    2002-03-01

    Many scientific problems require that treatment comparisons be adjusted for posttreatment variables, but the estimands underlying standard methods are not causal effects. To address this deficiency, we propose a general framework for comparing treatments adjusting for posttreatment variables that yields principal effects based on principal stratification. Principal stratification with respect to a posttreatment variable is a cross-classification of subjects defined by the joint potential values of that posttreatment variable tinder each of the treatments being compared. Principal effects are causal effects within a principal stratum. The key property of principal strata is that they are not affected by treatment assignment and therefore can be used just as any pretreatment covariate. such as age category. As a result, the central property of our principal effects is that they are always causal effects and do not suffer from the complications of standard posttreatment-adjusted estimands. We discuss briefly that such principal causal effects are the link between three recent applications with adjustment for posttreatment variables: (i) treatment noncompliance, (ii) missing outcomes (dropout) following treatment noncompliance. and (iii) censoring by death. We then attack the problem of surrogate or biomarker endpoints, where we show, using principal causal effects, that all current definitions of surrogacy, even when perfectly true, do not generally have the desired interpretation as causal effects of treatment on outcome. We go on to forrmulate estimands based on principal stratification and principal causal effects and show their superiority.

  4. Discrete causal theory emergent spacetime and the causal metric hypothesis

    CERN Document Server

    Dribus, Benjamin F

    2017-01-01

    This book evaluates and suggests potentially critical improvements to causal set theory, one of the best-motivated approaches to the outstanding problems of fundamental physics. Spacetime structure is of central importance to physics beyond general relativity and the standard model. The causal metric hypothesis treats causal relations as the basis of this structure. The book develops the consequences of this hypothesis under the assumption of a fundamental scale, with smooth spacetime geometry viewed as emergent. This approach resembles causal set theory, but differs in important ways; for example, the relative viewpoint, emphasizing relations between pairs of events, and relationships between pairs of histories, is central. The book culminates in a dynamical law for quantum spacetime, derived via generalized path summation.

  5. Negative Mood and Obsessive-Compulsive Related Clinical Constructs: An Examination of Underlying Factors

    Directory of Open Access Journals (Sweden)

    Gary I. Britton

    2017-09-01

    Full Text Available Emerging evidence suggests that many of the clinical constructs used to help understand and explain obsessive-compulsive (OC symptoms, and negative mood, may be causally interrelated. One approach to understanding this interrelatedness is a motivational systems approach. This approach suggests that rather than considering clinical constructs and negative affect as separable entities, they are all features of an integrated threat management system, and as such are highly coordinated and interdependent. The aim of the present study was to examine if clinical constructs related to OC symptoms and negative mood are best treated as separable or, alternatively, if these clinical constructs and negative mood are best seen as indicators of an underlying superordinate variable, as would be predicted by a motivational systems approach. A sample of 370 student participants completed measures of mood and the clinical constructs of inflated responsibility, intolerance of uncertainty, not just right experiences, and checking stop rules. An exploratory factor analysis suggested two plausible factor structures, one where all construct items and negative mood items loaded onto one underlying superordinate variable, and a second structure comprising of five factors, where each item loaded onto a factor representative of what the item was originally intended to measure. A confirmatory factor analysis showed that the five factor model was preferential to the one factor model, suggesting the four constructs and negative mood are best conceptualized as separate variables. Given the predictions of a motivational systems approach were not supported in the current study, other possible explanations for the causal interrelatedness between clinical constructs and negative mood are discussed.

  6. Classical planning and causal implicatures

    DEFF Research Database (Denmark)

    Blackburn, Patrick Rowan; Benotti, Luciana

    for understanding the structure of task-oriented dialogues. Such dialogues locate conversational acts in contexts containing both pending tasks and the acts which bring them about. The ability to infer causal implicatures lets us interleave decisions about "how to sequence actions" with decisions about "when......In this paper we motivate and describe a dialogue manager (called Frolog) which uses classical planning to infer causal implicatures. A causal implicature is a type of Gricean relation implicature, a highly context dependent form of inference. As we shall see, causal implicatures are important...... to generate clarification requests"; as a result we can model task-oriented dialogue as an interactive process locally structured by negotiation of the underlying task. We give several examples of Frolog-human dialog, discuss the limitations imposed by the classical planning paradigm, and indicate...

  7. Does causal action facilitate causal perception in infants younger than 6 months of age?

    Science.gov (United States)

    Rakison, David H; Krogh, Lauren

    2012-01-01

    Previous research has established that infants are unable to perceive causality until 6¼ months of age. The current experiments examined whether infants' ability to engage in causal action could facilitate causal perception prior to this age. In Experiment 1, 4½-month-olds were randomly assigned to engage in causal action experience via Velcro sticky mittens or not engage in causal action because they wore non-sticky mittens. Both groups were then tested in the visual habituation paradigm to assess their causal perception. Infants who engaged in causal action - but not those without this causal action experience - perceived the habituation events as causal. Experiment 2 used a similar design to establish that 4½-month-olds are unable to generalize their own causal action to causality observed in dissimilar objects. These data are the first to demonstrate that infants under 6 months of age can perceive causality, and have implications for the mechanisms underlying the development of causal perception. © 2011 Blackwell Publishing Ltd.

  8. Mono-Causal and Multi-Causal Theories of Disease: How to Think Virally and Socially about the Aetiology of AIDS.

    Science.gov (United States)

    Furman, Katherine

    2017-04-04

    In this paper, I utilise the tools of analytic philosophy to amalgamate mono-causal and multi-causal theories of disease. My aim is to better integrate viral and socio-economic explanations of AIDS in particular, and to consider how the perceived divide between mono-causal and multi-causal theories played a role in the tragedy of AIDS denialism in South Africa in the early 2000s. Currently, there is conceptual ambiguity surrounding the relationship between mono-causal and multi-causal theories in biomedicine and epidemiology. Mono-causal theories focus on single, typically microbial, sources of illness and are most concerned with infectious diseases. By contrast, multi-causal theories allow for multiple factors to underpin a disease's aetiology, including socio-economic and behavioural factors, and they usually focus on chronic non-communicable diseases. However, if these theories are taken to be strictly distinct, this prevents the inclusion of both microbial and socio-economic factors in a single explanation of any particular disease. This strict distinction became a problem when trying to explain the disproportionate prevalence of AIDS in southern Africa and ultimately contributed to the tragedy of AIDS denialism in South Africa. In tandem with viewing how the perceived divide between multi-causal and mono-causal theories underpinned AIDS denialism, I examine Thabo Mbeki's specific role, while acknowledging that AIDS is being deprioritised on a broader international level. Overall, I will demonstrate that any long-term plan to eliminate AIDS will require viral and socio-economic factors to be considered simultaneously and that such a theoretical approach requires a clearer understanding of the underlying concepts of disease aetiology.

  9. Causality in Science

    Directory of Open Access Journals (Sweden)

    Cristina Puente Águeda

    2011-10-01

    Full Text Available Causality is a fundamental notion in every field of science. Since the times of Aristotle, causal relationships have been a matter of study as a way to generate knowledge and provide for explanations. In this paper I review the notion of causality through different scientific areas such as physics, biology, engineering, etc. In the scientific area, causality is usually seen as a precise relation: the same cause provokes always the same effect. But in the everyday world, the links between cause and effect are frequently imprecise or imperfect in nature. Fuzzy logic offers an adequate framework for dealing with imperfect causality, so a few notions of fuzzy causality are introduced.

  10. Underlying Factors for Practicality of the Production Control Systems

    DEFF Research Database (Denmark)

    Arica, Emrah; Strandhagen, Jan Ola; Hvolby, Hans-Henrik

    2012-01-01

    This paper gives indications to important factors that must be considered for effectiveness of the production control systems under uncertainty. Five key factors have been identified by the literature study. Production schedule generation and execution approach under uncertainty, information...... and communication technology, coordination and feedback, human factors and decision making, and measurement are the identified factors to be taken into account. Industrial interviews with three case companies, that are participating to the research program called The Norwegian Manufacturing Future (SFI NORMAN...

  11. Causality in Europeanization Research

    DEFF Research Database (Denmark)

    Lynggaard, Kennet

    2012-01-01

    to develop discursive institutional analytical frameworks and something that comes close to the formulation of hypothesis on the effects of European Union (EU) policies and institutions on domestic change. Even if these efforts so far do not necessarily amount to substantive theories or claims of causality...... of discursive causalities towards more substantive claims of causality between EU policy and institutional initiatives and domestic change....

  12. Granger Causality and Unit Roots

    DEFF Research Database (Denmark)

    Rodríguez-Caballero, Carlos Vladimir; Ventosa-Santaulària, Daniel

    2014-01-01

    , eventually rejecting the null hypothesis, even when the series are independent of each other. Moreover, controlling for these deterministic elements (in the auxiliary regressions of the test) does not preclude the possibility of drawing erroneous inferences. Granger-causality tests should not be used under...... stochastic nonstationarity, a property typically found in many macroeconomic variables....

  13. The Functions of Danish Causal Conjunctions

    Directory of Open Access Journals (Sweden)

    Rita Therkelsen

    2004-01-01

    Full Text Available In the article I propose an analysis of the Danish causal conjunctions fordi, siden and for based on the framework of Danish Functional Grammar. As conjunctions they relate two clauses, and their semantics have in common that it indicates a causal relationship between the clauses. The causal conjunctions are different as far as their distribution is concerned; siden conjoins a subordinate clause and a main clause, for conjoins two main clauses, and fordi is able to do both. Methodologically I have based my analysis on these distributional properties comparing siden and fordi conjoining a subordinate and a main clause, and comparing for and fordi conjoining two main clauses, following the thesis that they would establish a causal relationship between different kinds of content. My main findings are that fordi establishes a causal relationship between the events referred to by the two clauses, and the whole utterance functions as a statement of this causal relationship. Siden presupposes such a general causal relationship between the two events and puts forward the causing event as a reason for assuming or wishing or ordering the caused event, siden thus establishes a causal relationship between an event and a speech act. For equally presupposes a general causal relationship between two events and it establishes a causal relationship between speech acts, and fordi conjoining two main clauses is able to do this too, but in this position it also maintains its event-relating ability, the interpretation depending on contextual factors.

  14. Distress screening using distress thermometer in head and neck cancer patients undergoing radiotherapy and evaluation of causal factors predicting occurrence of distress

    Directory of Open Access Journals (Sweden)

    Shirley Lewis

    2013-01-01

    Full Text Available Introduction: Distress is commonly seen in head and neck cancer patients undergoing radiotherapy. Causal factors of distress are multifactorial; which encompasses physical, psychological, spiritual, and existential factors with complex interrelationship among the factors. Materials and Methods: Thirty patients undergoing head and neck radiotherapy were included in the study. Patients were screened for pain scores, distress scores, physical and psychological symptoms, and spiritual and emotional distress. Results: Significant increasing trend seen for pain score, distress score, and total number of symptoms during 2 nd week, 4 th week, and on completion of radiotherapy treatment (all P′s < 0.001 compared to pretreatment. Those who had chemotherapy (CT along with radiation had significantly greater pain score (t = 5.54, P = 0.03 and distress score (t = 3.9, P = 0.05 at 2 weeks into radiotherapy compared to those who did not receive CT. There was significantly higher grade of skin toxicity in those with spiritual distress (Somers′ d = 0.36, P = 0.02 and higher grade of mucositis in those with existential distress (d = 0.34, P = 0.02 at 4 weeks into radiotherapy. Conclusion: Positive correlation between distress score and pain score and occurrence of physical symptoms. Increasing trend seen for pain score, distress score, and total number of symptoms during 2 nd week, 4 th week, and completion of radiotherapy treatment compared to pretreatment. Increase in distress score in those with existential and spiritual distress.

  15. Tools for Detecting Causality in Space Systems

    Science.gov (United States)

    Johnson, J.; Wing, S.

    2017-12-01

    Complex systems such as the solar and magnetospheric envivonment often exhibit patterns of behavior that suggest underlying organizing principles. Causality is a key organizing principle that is particularly difficult to establish in strongly coupled nonlinear systems, but essential for understanding and modeling the behavior of systems. While traditional methods of time-series analysis can identify linear correlations, they do not adequately quantify the distinction between causal and coincidental dependence. We discuss tools for detecting causality including: granger causality, transfer entropy, conditional redundancy, and convergent cross maps. The tools are illustrated by applications to magnetospheric and solar physics including radiation belt, Dst (a magnetospheric state variable), substorm, and solar cycle dynamics.

  16. A systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease.

    Science.gov (United States)

    Mente, Andrew; de Koning, Lawrence; Shannon, Harry S; Anand, Sonia S

    2009-04-13

    Although a wealth of literature links dietary factors and coronary heart disease (CHD), the strength of the evidence supporting valid associations has not been evaluated systematically in a single investigation. We conducted a systematic search of MEDLINE for prospective cohort studies or randomized trials investigating dietary exposures in relation to CHD. We used the Bradford Hill guidelines to derive a causation score based on 4 criteria (strength, consistency, temporality, and coherence) for each dietary exposure in cohort studies and examined for consistency with the findings of randomized trials. Strong evidence supports valid associations (4 criteria satisfied) of protective factors, including intake of vegetables, nuts, and "Mediterranean" and high-quality dietary patterns with CHD, and associations of harmful factors, including intake of trans-fatty acids and foods with a high glycemic index or load. Among studies of higher methodologic quality, there was also strong evidence for monounsaturated fatty acids and "prudent" and "western" dietary patterns. Moderate evidence (3 criteria) of associations exists for intake of fish, marine omega-3 fatty acids, folate, whole grains, dietary vitamins E and C, beta carotene, alcohol, fruit, and fiber. Insufficient evidence (< or =2 criteria) of association is present for intake of supplementary vitamin E and ascorbic acid (vitamin C); saturated and polyunsaturated fatty acids; total fat; alpha-linolenic acid; meat; eggs; and milk. Among the dietary exposures with strong evidence of causation from cohort studies, only a Mediterranean dietary pattern is related to CHD in randomized trials. The evidence supports a valid association of a limited number of dietary factors and dietary patterns with CHD. Future evaluation of dietary patterns, including their nutrient and food components, in cohort studies and randomized trials is recommended.

  17. Introductive remarks on causal inference

    Directory of Open Access Journals (Sweden)

    Silvana A. Romio

    2013-05-01

    Full Text Available One of the more challenging issues in epidemiological research is being able to provide an unbiased estimate of the causal exposure-disease effect, to assess the possible etiological mechanisms and the implication for public health. A major source of bias is confounding, which can spuriously create or mask the causal relationship. In the last ten years, methodological research has been developed to better de_ne the concept of causation in epidemiology and some important achievements have resulted in new statistical models. In this review, we aim to show how a technique the well known by statisticians, i.e. standardization, can be seen as a method to estimate causal e_ects, equivalent under certain conditions to the inverse probability treatment weight procedure.

  18. Weather Information Communications (WINCOMM) Project: Dissemination of Weather Information for the Reduction of Aviation Weather-Related Accident Causal Factors

    Science.gov (United States)

    Jarrell, Michael; Tanger, Thomas

    2004-01-01

    Weather Information Communications (WINCOMM) is part of the Weather Accident Prevention (WxAP) Project, which is part of the NASA's Aviation Safety and Security Program. The goals of WINCOMM are to facilitate the exchange of tactical and strategic weather information between air and ground. This viewgraph presentation provides information on data link decision factors, architectures, validation goals. WINCOMM is capable of providing en-route communication air-to-ground, ground-to-air, and air-to-air, even on international or intercontinental flights. The presentation also includes information on the capacity, cost, and development of data links.

  19. Causal Analysis for Performance Modeling of Computer Programs

    Directory of Open Access Journals (Sweden)

    Jan Lemeire

    2007-01-01

    Full Text Available Causal modeling and the accompanying learning algorithms provide useful extensions for in-depth statistical investigation and automation of performance modeling. We enlarged the scope of existing causal structure learning algorithms by using the form-free information-theoretic concept of mutual information and by introducing the complexity criterion for selecting direct relations among equivalent relations. The underlying probability distribution of experimental data is estimated by kernel density estimation. We then reported on the benefits of a dependency analysis and the decompositional capacities of causal models. Useful qualitative models, providing insight into the role of every performance factor, were inferred from experimental data. This paper reports on the results for a LU decomposition algorithm and on the study of the parameter sensitivity of the Kakadu implementation of the JPEG-2000 standard. Next, the analysis was used to search for generic performance characteristics of the applications.

  20. Causal Dynamic Relationships between Political–Economic Factors and Export Performance in the Renewable Energy Technologies Market

    Directory of Open Access Journals (Sweden)

    Bongsuk Sung

    2018-04-01

    Full Text Available This study explores how political–economic forces could affect export performance in the renewable energy technologies market. We conduct panel framework analyses to verify the characteristics of panel data for 19 countries before establishing the panel estimator meant to test the effects of political–economic forces on export specialization. We consider the results of the panel framework analyses and develop an empirical model to test casual dynamic relationships between political–economic forces and export performance. The results from the least squares dummy variable-corrected estimation indicate that the major factors promoting the export specialization of renewable energy technologies are, in order of decreasing importance, public pressure, market size, and government demand-pull policy. However, the traditional energy industry has no significant effect on export performance. Finally, this study finds that dynamic effects exist in all estimations.

  1. Nutritional status of children under five years and associated factors

    African Journals Online (AJOL)

    ACSS

    Information on nutritional status of children under five years is an indicator of the nutritional situation in society. Identification of core factors influencing nutrition of this population supports plans to alleviate child malnutrition and its consequences. This study sought to determine the nutritional status of children under five ...

  2. mediation: R Package for Causal Mediation Analysis

    Directory of Open Access Journals (Sweden)

    Dustin Tingley

    2014-09-01

    Full Text Available In this paper, we describe the R package mediation for conducting causal mediation analysis in applied empirical research. In many scientific disciplines, the goal of researchers is not only estimating causal effects of a treatment but also understanding the process in which the treatment causally affects the outcome. Causal mediation analysis is frequently used to assess potential causal mechanisms. The mediation package implements a comprehensive suite of statistical tools for conducting such an analysis. The package is organized into two distinct approaches. Using the model-based approach, researchers can estimate causal mediation effects and conduct sensitivity analysis under the standard research design. Furthermore, the design-based approach provides several analysis tools that are applicable under different experimental designs. This approach requires weaker assumptions than the model-based approach. We also implement a statistical method for dealing with multiple (causally dependent mediators, which are often encountered in practice. Finally, the package also offers a methodology for assessing causal mediation in the presence of treatment noncompliance, a common problem in randomized trials.

  3. A Simple Test for Causality in Volatility

    Directory of Open Access Journals (Sweden)

    Chia-Lin Chang

    2017-03-01

    Full Text Available An early development in testing for causality (technically, Granger non-causality in the conditional variance (or volatility associated with financial returns was the portmanteau statistic for non-causality in the variance of Cheng and Ng (1996. A subsequent development was the Lagrange Multiplier (LM test of non-causality in the conditional variance by Hafner and Herwartz (2006, who provided simulation results to show that their LM test was more powerful than the portmanteau statistic for sample sizes of 1000 and 4000 observations. While the LM test for causality proposed by Hafner and Herwartz (2006 is an interesting and useful development, it is nonetheless arbitrary. In particular, the specification on which the LM test is based does not rely on an underlying stochastic process, so the alternative hypothesis is also arbitrary, which can affect the power of the test. The purpose of the paper is to derive a simple test for causality in volatility that provides regularity conditions arising from the underlying stochastic process, namely a random coefficient autoregressive process, and a test for which the (quasi- maximum likelihood estimates have valid asymptotic properties under the null hypothesis of non-causality. The simple test is intuitively appealing as it is based on an underlying stochastic process, is sympathetic to Granger’s (1969, 1988 notion of time series predictability, is easy to implement, and has a regularity condition that is not available in the LM test.

  4. The Relative Predictive Contribution and Causal Role of Phoneme Awareness, Rhyme Awareness, and Verbal Short-Term Memory in Reading Skills: A Review

    Science.gov (United States)

    Melby-Lervag, Monica

    2012-01-01

    The acknowledgement that educational achievement is highly dependent on successful reading development has led to extensive research on its underlying factors. A strong argument has been made for a causal relationship between reading and phoneme awareness; similarly, causal relations have been suggested for reading with short-term memory and rhyme…

  5. Causality in Classical Physics

    Indian Academy of Sciences (India)

    IAS Admin

    Classical physics encompasses the study of phys- ical phenomena which range from local (a point) to nonlocal (a region) in space and/or time. We discuss the concept of spatial and temporal non- locality. However, one of the likely implications pertaining to nonlocality is non-causality. We study causality in the context of ...

  6. Causality in Classical Electrodynamics

    Science.gov (United States)

    Savage, Craig

    2012-01-01

    Causality in electrodynamics is a subject of some confusion, especially regarding the application of Faraday's law and the Ampere-Maxwell law. This has led to the suggestion that we should not teach students that electric and magnetic fields can cause each other, but rather focus on charges and currents as the causal agents. In this paper I argue…

  7. On the conceptual distinction of general causality orientations

    DEFF Research Database (Denmark)

    Olesen, Martin Hammershøj

    electronic questionnaires of dispositional personality traits (NEO-FFI) and general causality orientations (GCOS). Proposed separate latent models and alternative shared latent models of the underlying individual differences constructs had been developed in a previous exploratory study (Olesen, Thomsen......, Schnieber & Tønnesvang, under review). The models were tested using confirmatory factor analyses. Results showed that all three causality orientations were distinct from but closely related to personality traits. Hence, integrative efforts are suggested in relation to comprehensive personality frameworks......This study investigates the conceptual overlap and distinction between individual differences in the Five-Factor Model and Self-determination theory. Participants were 223 adults (age mean=43.74; 60.09% women), who originated in a Danish national probability sample. The participants completed...

  8. Causality in demand

    DEFF Research Database (Denmark)

    Nielsen, Max; Jensen, Frank; Setälä, Jari

    2011-01-01

    to fish demand. On the German market for farmed trout and substitutes, it is found that supply sources, i.e. aquaculture and fishery, are not the only determinant of causality. Storing, tightness of management and aggregation level of integrated markets might also be important. The methodological......This article focuses on causality in demand. A methodology where causality is imposed and tested within an empirical co-integrated demand model, not prespecified, is suggested. The methodology allows different causality of different products within the same demand system. The methodology is applied...... implication is that more explicit focus on causality in demand analyses provides improved information. The results suggest that frozen trout forms part of a large European whitefish market, where prices of fresh trout are formed on a relatively separate market. Redfish is a substitute on both markets...

  9. Non-Causal Computation

    Directory of Open Access Journals (Sweden)

    Ämin Baumeler

    2017-07-01

    Full Text Available Computation models such as circuits describe sequences of computation steps that are carried out one after the other. In other words, algorithm design is traditionally subject to the restriction imposed by a fixed causal order. We address a novel computing paradigm beyond quantum computing, replacing this assumption by mere logical consistency: We study non-causal circuits, where a fixed time structure within a gate is locally assumed whilst the global causal structure between the gates is dropped. We present examples of logically consistent non-causal circuits outperforming all causal ones; they imply that suppressing loops entirely is more restrictive than just avoiding the contradictions they can give rise to. That fact is already known for correlations as well as for communication, and we here extend it to computation.

  10. Determining Stochasticity and Causality of Vegetation Dynamics in the Southwestern Amazon: Non-linear Time Series Analysis and Dynamic Factor Analysis of EVI2 Data

    Science.gov (United States)

    Klarenberg, G.

    2015-12-01

    Infrastructure projects such as road paving have proven to bring a variety of (mainly) socio-economic advantages to countries and populations. However, many studies have also highlighted the negative socio-economic and biophysical effects that these developments have at local, regional and even larger scales. The "MAP" area (Madre de Dios in Peru, Acre in Brazil, and Pando in Bolivia) is a biodiversity hotspot in the southwestern Amazon where sections of South America's Inter-Oceanic Highway were paved between 2006 and 2010. We are interested in vegetation dynamics in the area since it plays an important role in ecosystem functions and ecosystem services in socio-ecological systems: it provides information on productivity and structure of the forest. In preparation of more complex and mechanistic simulation of vegetation, non-linear time series analysis and Dynamic Factor Analysis (DFA) was conducted on Enhanced Vegetation Index (EVI) time series - which is a remote sensing product and provides information on vegetation dynamics as it detects chlorophyll (productivity) and structural change. Time series of 30 years for EVI2 (from MODIS and AVHRR) were obtained for 100 communities in the area. Through specific time series cluster analysis of the vegetation data, communities were clustered to facilitate data analysis and pattern recognition. The clustering is spatially consistent, and appears to be driven by median road paving progress - which is different for each cluster. Non-linear time series analysis (multivariate singular spectrum analysis, MSSA) separates common signals (or low-dimensional attractors) across clusters. Despite the presence of this deterministic structure though, time series behavior is mostly stochastic. Granger causality analysis between EVI2 and possible response variables indicates which variables (and with what lags) are to be included in DFA, resulting in unique Dynamic Factor Models for each cluster.

  11. Heterogeneous Causal Effects and Sample Selection Bias

    DEFF Research Database (Denmark)

    Breen, Richard; Choi, Seongsoo; Holm, Anders

    2015-01-01

    The role of education in the process of socioeconomic attainment is a topic of long standing interest to sociologists and economists. Recently there has been growing interest not only in estimating the average causal effect of education on outcomes such as earnings, but also in estimating how...... causal effects might vary over individuals or groups. In this paper we point out one of the under-appreciated hazards of seeking to estimate heterogeneous causal effects: conventional selection bias (that is, selection on baseline differences) can easily be mistaken for heterogeneity of causal effects....... This might lead us to find heterogeneous effects when the true effect is homogenous, or to wrongly estimate not only the magnitude but also the sign of heterogeneous effects. We apply a test for the robustness of heterogeneous causal effects in the face of varying degrees and patterns of selection bias...

  12. Causality and headache triggers

    Science.gov (United States)

    Turner, Dana P.; Smitherman, Todd A.; Martin, Vincent T.; Penzien, Donald B.; Houle, Timothy T.

    2013-01-01

    Objective The objective of this study was to explore the conditions necessary to assign causal status to headache triggers. Background The term “headache trigger” is commonly used to label any stimulus that is assumed to cause headaches. However, the assumptions required for determining if a given stimulus in fact has a causal-type relationship in eliciting headaches have not been explicated. Methods A synthesis and application of Rubin’s Causal Model is applied to the context of headache causes. From this application the conditions necessary to infer that one event (trigger) causes another (headache) are outlined using basic assumptions and examples from relevant literature. Results Although many conditions must be satisfied for a causal attribution, three basic assumptions are identified for determining causality in headache triggers: 1) constancy of the sufferer; 2) constancy of the trigger effect; and 3) constancy of the trigger presentation. A valid evaluation of a potential trigger’s effect can only be undertaken once these three basic assumptions are satisfied during formal or informal studies of headache triggers. Conclusions Evaluating these assumptions is extremely difficult or infeasible in clinical practice, and satisfying them during natural experimentation is unlikely. Researchers, practitioners, and headache sufferers are encouraged to avoid natural experimentation to determine the causal effects of headache triggers. Instead, formal experimental designs or retrospective diary studies using advanced statistical modeling techniques provide the best approaches to satisfy the required assumptions and inform causal statements about headache triggers. PMID:23534872

  13. Developing Causal Understanding with Causal Maps: The Impact of Total Links, Temporal Flow, and Lateral Position of Outcome Nodes

    Science.gov (United States)

    Jeong, Allan; Lee, Woon Jee

    2012-01-01

    This study examined some of the methodological approaches used by students to construct causal maps in order to determine which approaches help students understand the underlying causes and causal mechanisms in a complex system. This study tested the relationship between causal understanding (ratio of root causes correctly/incorrectly identified,…

  14. Self-Esteem and Locus of Causality as Vulnerability Factors for the Development of Actual/Ideal Self-Discrepancies in Late Childhood

    Directory of Open Access Journals (Sweden)

    Lisa Di Blas

    2017-05-01

    Full Text Available Self-discrepancies influence psychological well-being and self-acceptance across several domains. Middle to late childhood is a critical age for the development of self-discrepancies (SD. The present study was aimed at investigating antecedents of actual/ideal self-discrepancies in 9- to 11-year-old children by adopting a repeated measure design, with two measurement occasions. At the baseline (T1, children (N=261 completed a self-esteem questionnaire, a measure of actual/ideal SDs we developed around the Five Factor Model domains, and the Strengths and Difficulties Questionnaire; 4 months later (T2 a subsample (N=96 provided self-ratings again. Children's parents (N=195 referred on their own feelings towards their children along the Profile of Mood States as well as on their perceived locus of control of their children's undesirable behaviors; a subsample of parents (N=80 provided ratings again 4 months later. Principal component analyses from children's self-discrepancies at T1 yielded four domains: Intellect, Emotional Stability, Impulse Control, and Sociability. Self-rated discrepancies across time were moderately stable. Concurrently, higher SDs in Intellect were associated with lower children's self-esteem. Cross-lagged pattern analyses showed that lower self-esteem predicted increases in children's SDs, but not vice versa; in addition, change levels in SDs were correlated with change levels in self-esteem. Parents' perceived internal locus of causality of their children's undesirable behaviors also accounted for changes in children's SDs. Parents' feelings of depression accounted for increases in girls' SDs. The present findings further support the association between self-esteem and SDs, indicate the direction of association across time, and suggest possible mechanisms by which parents affect the development of the children's self-views.

  15. Assessment of causal link between psychological factors and symptom exacerbation in inflammatory bowel disease: a protocol for systematic review of prospective cohort studies

    Directory of Open Access Journals (Sweden)

    Schoultz Mariyana

    2013-01-01

    Full Text Available Abstract Background Inflammatory bowel disease is an idiopathic chronic disease that affects around 28 million people worldwide. Symptoms are distressing and have a detrimental effect on patients’ quality of life. A possible link between exacerbation of symptoms and psychological factors has been suspected but not established. Previous reviews concerned with this link had conceptual and methodological limitations. In this paper we set out a protocol that lays the foundations for a systematic review that will address these shortcomings. The aim of this review is to provide researchers and clinicians with clarity on the role of psychological factors in inflammatory bowel disease symptom exacerbation. Method/design We will identify all original, published, peer reviewed studies relevant to the topic and published in English from inception to November 2012. The databases MEDLINE, EMBASE, CINAHL and PsychINFO will be systematically searched. The search terms will include: inflammatory bowel disease, Crohn’s disease, ulcerative colitis, psychological stress, mental stress, life stress, family stress, hassles, social stress, coping, mood disorders, anxiety and depression in sequential combinations. Studies will be screened according to predetermined inclusion and exclusion criteria by two reviewers. We will include clinical prospective cohort studies of all human participants aged 18 years or over with a diagnosis of inflammatory bowel disease. All eligible papers will be independently and critically appraised using the Critical Appraisal Skills Programme (CASP tool by two reviewers. Two reviewers will independently extract and synthesise data from the studies using a predefined data extraction sheet. Disagreements will be resolved by discussion between reviewers and a third party will be consulted if agreement is not reached. Synthesised data will be analysed using Bradford Hill criterion for causality. If data permits, meta-analysis will be

  16. Dynamics and causality constraints

    International Nuclear Information System (INIS)

    Sousa, Manoelito M. de

    2001-04-01

    The physical meaning and the geometrical interpretation of causality implementation in classical field theories are discussed. Causality in field theory are kinematical constraints dynamically implemented via solutions of the field equation, but in a limit of zero-distance from the field sources part of these constraints carries a dynamical content that explains old problems of classical electrodynamics away with deep implications to the nature of physicals interactions. (author)

  17. Causality and Time in Historical Institutionalism

    DEFF Research Database (Denmark)

    Mahoney, James; Mohamedali, Khairunnisa; Nguyen, Christoph

    2016-01-01

    This chapter explores the dual concern with causality and time in historical institutionalism using a graphical approach. The analysis focuses on three concepts that are central to this field: critical junctures, gradual change, and path dependence. The analysis makes explicit and formal the logic...... underlying studies that use these “causal-temporal” concepts. The chapter shows visually how causality and temporality are linked to one another in varying ways depending on the particular pattern of change. The chapter provides new tools for describing and understanding change in historical- institutional...

  18. Biological factors underlying regularity and chaos in aquatic ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 26; Issue 1. Biological factors underlying regularity and chaos in aquatic ecosystems: Simple models of complex dynamics. A B Medvinsky S V Petrovskii D A Tikhonov I A Tikhonova G R Ivanitsky E Venturino H Malchow. Articles Volume 26 Issue 1 March 2001 pp 77-108 ...

  19. Production Of Some Virulence Factors Under Different Growth ...

    African Journals Online (AJOL)

    The production of some virulence factors under different growth conditions and antibiotic susceptbility pattern of Aeromonas hydrophila were investigated in this sudy. The virulence actors tested on the isolates included haemolytic activity, exopolysaccharide (capsule) and toxin production. Other cell property evaluated was ...

  20. Factors underlying male and female use of violent video games

    NARCIS (Netherlands)

    Hartmann, T.; Möller, I.; Krause, C.

    2015-01-01

    Research has consistently shown that males play violent video games more frequently than females, but factors underlying this gender gap have not been examined to date. This approach examines the assumption that males play violent video games more because they anticipate more enjoyment and less

  1. Socio-Demographic Factors in Under Five Children with Acute ...

    African Journals Online (AJOL)

    Objective: To determine the socio-demographic factors in under five children with acute diarrhoea. Design: A prospective cross-sectional study. Setting: Children's Emergency Room and Children's Outpatient Clinic of the University of Nigeria Teaching Hospital, Enugu, Nigeria. Subjects: One hundred and seventy-four ...

  2. Obesity and infection: reciprocal causality.

    Science.gov (United States)

    Hainer, V; Zamrazilová, H; Kunešová, M; Bendlová, B; Aldhoon-Hainerová, I

    2015-01-01

    Associations between different infectious agents and obesity have been reported in humans for over thirty years. In many cases, as in nosocomial infections, this relationship reflects the greater susceptibility of obese individuals to infection due to impaired immunity. In such cases, the infection is not related to obesity as a causal factor but represents a complication of obesity. In contrast, several infections have been suggested as potential causal factors in human obesity. However, evidence of a causal linkage to human obesity has only been provided for adenovirus 36 (Adv36). This virus activates lipogenic and proinflammatory pathways in adipose tissue, improves insulin sensitivity, lipid profile and hepatic steatosis. The E4orf1 gene of Adv36 exerts insulin senzitizing effects, but is devoid of its pro-inflammatory modalities. The development of a vaccine to prevent Adv36-induced obesity or the use of E4orf1 as a ligand for novel antidiabetic drugs could open new horizons in the prophylaxis and treatment of obesity and diabetes. More experimental and clinical studies are needed to elucidate the mutual relations between infection and obesity, identify additional infectious agents causing human obesity, as well as define the conditions that predispose obese individuals to specific infections.

  3. Evidence and causality assessment in environmental epidemiology: methodological aspects

    International Nuclear Information System (INIS)

    Valleron, A.J.

    2000-01-01

    There are usually three major steps in the study of the possible impact of environmental factors on health: 1) to demonstrate that there is an association between exposure to the factor and the disease under study; 2) to demonstrate that this association is causal; 3) to evaluate the health benefit that could be obtained by removing the source of exposure. Statistical methods are commonly assumed to provide an objective way of achieving these three steps. This paper reviews some of the conditions that have to be met to allow proper interpretations and to avoid some of the controversies that are often found in health-environment studies. First, it should be remembered that the so-called P value which is used to qualify 'statistically significant' associations between risk factors and diseases does not give any indication of the probability that this association is actual, while far too often it is believed that it does. The probability that an association between an environmental factor and a disease is real could, however, be estimated by using Bayesian methods. These methods require that the a priori probabilities be stated, which is difficult to do in practice. Some directions to overcome this difficulty are presented. Second, the analysis of causality cannot be carried out on statistical grounds alone and the so-called 'causality criteria' are of limited practical interest. Definition of what is a cause, and upon which conditions a candidate factor of a disease can be considered as a cause, deserves much research effort, and careful consideration of the huge literature (mostly outside of the epidemiological field, for example in logic) which is devoted to this subject. Finally, the measurement of the role of a factor in a disease is very often assessed through the use of 'attributable fraction' or 'attributable mortality'. This should be done only when it is demonstrated that the considered factor is causal. Moreover, the interpretation of attributable fractions

  4. Factors limiting the operation of structures under high gradient

    International Nuclear Information System (INIS)

    Schriber, S.O.

    1986-01-01

    Factors limiting the operation of rf structures under high-gradient conditions are described. Included are recent rf measurements at laboratories in Europe, Asia, and North America and how these measurements relate to earlier data as exemplified by the use of the Kilpatrick criterion (Kp). Operation limitations will cover mechanical, geometry, thermal, and surface constraints and the associated impact on structure design, fabrication, and material selection. Generally, structures operating continuous wave (100% duty factor) appear to be limited to peak surface fields at about twice the Kilpatrick limit, whereas pulsed structures operating with pulse lengths less than a millisecond can attain peak surface fields five times the Kilpatrick limit

  5. Dynamics Of Causal Sets

    CERN Document Server

    Rideout, D P

    2001-01-01

    The Causal Set approach to quantum gravity asserts that spacetime, at its smallest length scale, has a discrete structure. This discrete structure takes the form of a locally finite order relation, where the order, corresponding with the macroscopic notion of spacetime causality, is taken to be a fundamental aspect of nature. After an introduction to the Causal Set approach, this thesis considers a simple toy dynamics for causal sets. Numerical simulations of the model provide evidence for the existence of a continuum limit. While studying this toy dynamics, a picture arises of how the dynamics can be generalized in such a way that the theory could hope to produce more physically realistic causal sets. By thinking in terms of a stochastic growth process, and positing some fundamental principles, we are led almost uniquely to a family of dynamical laws (stochastic processes) parameterized by a countable sequence of coupling constants. This result is quite promising in that we now know how to speak of dynamics ...

  6. A common genetic factor underlies hypertension and other cardiovascular disorders

    Directory of Open Access Journals (Sweden)

    Spector Tim D

    2004-11-01

    Full Text Available Abstract Background Certain conditions characterised by blood vessel occlusion or vascular spasm have been found to cluster together in epidemiological studies. However the biological causes for these associations remain controversial. This study used a classical twin design to examine whether these conditions are linked through shared environmental exposures or by a common underlying genetic propensity to vasospasm. Methods We investigated the association between hypertension, migraine, Raynaud's phenomenon and coronary artery disease in twins from a national register. Phenotype status was determined using a questionnaire and the genetic and environmental association between phenotypes was estimated through variance components analysis. Results Responses were obtained from 2,204 individuals comprising 525 monozygotic and 577 dizygotic pairs. There was a significant genetic contribution to all four traits with heritabilities ranging from 0.34 to 0.64. Multivariate model-fitting demonstrated that a single common genetic factor underlies the four conditions. Conclusions We have confirmed an association between hypertension, migraine, Raynaud's phenomenon and coronary artery disease, and shown that a single genetic factor underlies them. The demonstration of a shared genetic factor explains the association between them and adds weight to the theory of an inherited predisposition to vasospasm.

  7. Causal inference in econometrics

    CERN Document Server

    Kreinovich, Vladik; Sriboonchitta, Songsak

    2016-01-01

    This book is devoted to the analysis of causal inference which is one of the most difficult tasks in data analysis: when two phenomena are observed to be related, it is often difficult to decide whether one of them causally influences the other one, or whether these two phenomena have a common cause. This analysis is the main focus of this volume. To get a good understanding of the causal inference, it is important to have models of economic phenomena which are as accurate as possible. Because of this need, this volume also contains papers that use non-traditional economic models, such as fuzzy models and models obtained by using neural networks and data mining techniques. It also contains papers that apply different econometric models to analyze real-life economic dependencies.

  8. Rate-Agnostic (Causal) Structure Learning.

    Science.gov (United States)

    Plis, Sergey; Danks, David; Freeman, Cynthia; Calhoun, Vince

    2015-12-01

    Causal structure learning from time series data is a major scientific challenge. Extant algorithms assume that measurements occur sufficiently quickly; more precisely, they assume approximately equal system and measurement timescales. In many domains, however, measurements occur at a significantly slower rate than the underlying system changes, but the size of the timescale mismatch is often unknown. This paper develops three causal structure learning algorithms, each of which discovers all dynamic causal graphs that explain the observed measurement data, perhaps given undersampling. That is, these algorithms all learn causal structure in a "rate-agnostic" manner: they do not assume any particular relation between the measurement and system timescales. We apply these algorithms to data from simulations to gain insight into the challenge of undersampling.

  9. Perceptual causality in children.

    Science.gov (United States)

    Schlottmann, Anne; Allen, Deborah; Linderoth, Carina; Hesketh, Sarah

    2002-01-01

    Three experiments considered the development of perceptual causality in children from 3 to 9 years of age (N = 176 in total). Adults tend to see cause and effect even in schematic, two-dimensional motion events: Thus, if square A moves toward B, which moves upon contact, they report that A launches B--physical causality. If B moves before contact, adults report that B tries to escape from A--social or psychological causality. A brief pause between movements eliminates such impressions. Even infants in the first year of life are sensitive to causal structure in both contact and no-contact events, but previous research with talking-age children found poor verbal reports. The present experiments used a picture-based forced-choice task to reduce linguistic demands. Observers saw eight different animations involving squares A and B. Events varied in whether or not these agents made contact; whether or not there was a delay at the closest point; and whether they moved rigidly or with a rhythmic, nonrigid "caterpillar" motion. Participants of all ages assigned events with contact to the physical domain and events without contact to the psychological domain. In addition, participants of all ages chose causality more often for events without delay than with delay, but these events became more distinct over the preschool range. The manipulation of agent motion had only minor and inconsistent effects across studies, even though children of all ages considered only the nonrigid motion to be animal-like. These results agree with the view that perceptual causality is available early in development.

  10. Regression to Causality

    DEFF Research Database (Denmark)

    Bordacconi, Mats Joe; Larsen, Martin Vinæs

    2014-01-01

    Humans are fundamentally primed for making causal attributions based on correlations. This implies that researchers must be careful to present their results in a manner that inhibits unwarranted causal attribution. In this paper, we present the results of an experiment that suggests regression...... more likely. Our experiment drew on a sample of 235 university students from three different social science degree programs (political science, sociology and economics), all of whom had received substantial training in statistics. The subjects were asked to compare and evaluate the validity...

  11. Illness causal beliefs in Turkish immigrants.

    Science.gov (United States)

    Minas, Harry; Klimidis, Steven; Tuncer, Can

    2007-07-24

    People hold a wide variety of beliefs concerning the causes of illness. Such beliefs vary across cultures and, among immigrants, may be influenced by many factors, including level of acculturation, gender, level of education, and experience of illness and treatment. This study examines illness causal beliefs in Turkish-immigrants in Australia. Causal beliefs about somatic and mental illness were examined in a sample of 444 members of the Turkish population of Melbourne. The socio-demographic characteristics of the sample were broadly similar to those of the Melbourne Turkish community. Five issues were examined: the structure of causal beliefs; the relative frequency of natural, supernatural and metaphysical beliefs; ascription of somatic, mental, or both somatic and mental conditions to the various causes; the correlations of belief types with socio-demographic, modernizing and acculturation variables; and the relationship between causal beliefs and current illness. Principal components analysis revealed two broad factors, accounting for 58 percent of the variation in scores on illness belief scales, distinctly interpretable as natural and supernatural beliefs. Second, beliefs in natural causes were more frequent than beliefs in supernatural causes. Third, some causal beliefs were commonly linked to both somatic and mental conditions while others were regarded as more specific to either somatic or mental disorders. Last, there was a range of correlations between endorsement of belief types and factors defining heterogeneity within the community, including with demographic factors, indicators of modernizing and acculturative processes, and the current presence of illness. Results supported the classification of causal beliefs proposed by Murdock, Wilson & Frederick, with a division into natural and supernatural causes. While belief in natural causes is more common, belief in supernatural causes persists despite modernizing and acculturative influences. Different

  12. Causality and Free Will

    Czech Academy of Sciences Publication Activity Database

    Hvorecký, Juraj

    2012-01-01

    Roč. 19, Supp.2 (2012), s. 64-69 ISSN 1335-0668 R&D Projects: GA ČR(CZ) GAP401/12/0833 Institutional support: RVO:67985955 Keywords : conciousness * free will * determinism * causality Subject RIV: AA - Philosophy ; Religion

  13. Explaining through causal mechanisms

    NARCIS (Netherlands)

    Biesbroek, Robbert; Dupuis, Johann; Wellstead, Adam

    2017-01-01

    This paper synthesizes and builds on recent critiques of the resilience literature; namely that the field has largely been unsuccessful in capturing the complexity of governance processes, in particular cause–effects relationships. We demonstrate that absence of a causal model is reflected in the

  14. Personality factors underlying suicidal behavior among military youth.

    Science.gov (United States)

    Soltaninejad, Abdollah; Fathi-Ashtiani, Ali; Ahmadi, Khodabakhsh; Mirsharafoddini, Hediye Sadat; Nikmorad, Alireza; Pilevarzadeh, Motahare

    2014-04-01

    Suicidal behavior is one the most significant mental health problems in the military. Militaries are closed systems that operate in particular situations. Military service is associated with certain stressful conditions. On this basis, there is likely of trauma in the military environment. Measures of suicidal behavior are pathologically complex. A range of biological, psychological, social, and institutional factors are involved in the incidence and prevalence of these behaviors. One of the underlying factors in suicidal behavior is individuals' personality. The study population comprised of the Iranian Armed Forces. To recruit the sample of the research, 1659 soldiers were selected by multistage sampling. Data were collected using the Beck Scale for Suicide Ideation (BSSI) and NEO-Five Factor Inventory. There was a significant positive correlation (r = 0.323) between neuroticism and suicide ideation; however, significant negative correlations existed between three other personality traits --extraversion [r = -0.306], agreeableness [r = -0.227], and conscientiousness [r = -0.271] and suicidal ideation. Unlike neuroticism, extraversion and conscientiousness personality factors could reduce significantly (as much 14% as are predicted) levels of suicidal ideation. Based on these results, neuroticism might increase suicide, but extraversion and conscientiousness personality traits are associated with a reduced risk of suicide.

  15. Kant on causal laws and powers.

    Science.gov (United States)

    Henschen, Tobias

    2014-12-01

    The aim of the paper is threefold. Its first aim is to defend Eric Watkins's claim that for Kant, a cause is not an event but a causal power: a power that is borne by a substance, and that, when active, brings about its effect, i.e. a change of the states of another substance, by generating a continuous flow of intermediate states of that substance. The second aim of the paper is to argue against Watkins that the Kantian concept of causal power is not the pre-critical concept of real ground but the category of causality, and that Kant holds with Hume that causal laws cannot be inferred non-inductively (that he accordingly has no intention to show in the Second analogy or elsewhere that events fall under causal laws). The third aim of the paper is to compare the Kantian position on causality with central tenets of contemporary powers ontology: it argues that unlike the variants endorsed by contemporary powers theorists, the Kantian variants of these tenets are resistant to objections that neo-Humeans raise to these tenets.

  16. Testing for causality in covarying traits: genes and latitude in a molecular world.

    Science.gov (United States)

    O'Brien, Conor; Bradshaw, William E; Holzapfel, Christina M

    2011-06-01

    Many traits are assumed to have a causal (necessary) relationship with one another because of their common covariation with a physiological, ecological or geographical factor. Herein, we demonstrate a straightforward test for inferring causality using residuals from regression of the traits with the common factor. We illustrate this test using the covariation with latitude of a proxy for the circadian clock and a proxy for the photoperiodic timer in Drosophila and salmon. A negative result of this test means that further discussion of the adaptive significance of a causal connection between the covarying traits is unwarranted. A positive result of this test provides a point of departure that can then be used as a platform from which to determine experimentally the underlying functional connections and only then to discuss their adaptive significance.

  17. Space, time and causality

    International Nuclear Information System (INIS)

    Lucas, J.R.

    1984-01-01

    Originating from lectures given to first year undergraduates reading physics and philosophy or mathematics and philosophy, formal logic is applied to issues and the elucidation of problems in space, time and causality. No special knowledge of relativity theory or quantum mechanics is needed. The text is interspersed with exercises and each chapter is preceded by a suggested 'preliminary reading' and followed by 'further reading' references. (U.K.)

  18. Operator ordering and causality

    OpenAIRE

    Plimak, L. I.; Stenholm, S. T.

    2011-01-01

    It is shown that causality violations [M. de Haan, Physica 132A, 375, 397 (1985)], emerging when the conventional definition of the time-normal operator ordering [P.L.Kelley and W.H.Kleiner, Phys.Rev. 136, A316 (1964)] is taken outside the rotating wave approximation, disappear when the amended definition [L.P. and S.S., Annals of Physics, 323, 1989 (2008)] of this ordering is used.

  19. Palliative medicine specialists' causal explanations for depression in the palliative care setting: a qualitative in-depth interview study.

    Science.gov (United States)

    Ng, Felicity; Crawford, Gregory B; Chur-Hansen, Anna

    2016-06-01

    Medical practitioners have different causal explanations for depression, and may have greater difficulty in explaining causality of depression in the palliative care setting. The objective of this study was to investigate and describe the causal explanations of depression in the palliative care setting, from the perspective of palliative medicine specialists. Palliative medicine specialists practising in Australia were recruited and purposively sampled. Individual semistructured, in-depth interviews were conducted to explore their explanatory models of depression, including a focus on causal explanations. Nine participants were interviewed to reach data saturation. Interview transcripts were analysed for themes. Six themes for causal explanations of depression were identified: (1) Depression is inexplicable; (2) Biological explanations-primarily neurotransmitter depletion; (3) Psychological explanations-including reaction to circumstances, inability to accept illness and dying, diminished self, and coping mechanisms; (4) Social explanations-including inadequate social support, and contribution from modern medicine and societal norms; (5) Interrelationships between causal factors-mainly multifactoriality; (6) Different explanation for de novo and pre-existing depressions. Participants also articulated a link between causal explanations and clinical interventions. Palliative medicine specialists hold causal explanations of depression that align with the biopsychosocial and vulnerability-stress models. They use multiple individual explanations with diverse theoretical underpinnings, and largely view depression as multifactorial in causality. Given that causal explanations are linked to clinical interventions, these findings have implications for clinical practice and medical education. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  20. Psychiatric comorbidity and causal disease models.

    Science.gov (United States)

    van Loo, Hanna M; Romeijn, Jan-Willem; de Jonge, Peter; Schoevers, Robert A

    2013-12-01

    In psychiatry, comorbidity is the rule rather than the exception. Up to 45% of all patients are classified as having more than one psychiatric disorder. These high rates of comorbidity have led to a debate concerning the interpretation of this phenomenon. Some authors emphasize the problematic character of the high rates of comorbidity because they indicate absent zones of rarities. Others consider comorbid conditions to be a validator for a particular reclassification of diseases. In this paper we will show that those at first sight contrasting interpretations of comorbidity are based on similar assumptions about disease models. The underlying ideas are that firstly high rates of comorbidity are the result of the absence of causally defined diseases in psychiatry, and second that causal disease models are preferable to non-causal disease models. We will argue that there are good reasons to seek after causal understanding of psychiatric disorders, but that causal disease models will not rule out high rates of comorbidity--neither in psychiatry, nor in medicine in general. By bringing to the fore these underlying assumptions, we hope to clear the ground for a different understanding of comorbidity, and of models for psychiatric diseases. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Mapping Mendelian Factors Underlying Quantitative Traits Using RFLP Linkage Maps

    Science.gov (United States)

    Lander, E. S.; Botstein, D.

    1989-01-01

    The advent of complete genetic linkage maps consisting of codominant DNA markers [typically restriction fragment length polymorphisms (RFLPs)] has stimulated interest in the systematic genetic dissection of discrete Mendelian factors underlying quantitative traits in experimental organisms. We describe here a set of analytical methods that modify and extend the classical theory for mapping such quantitative trait loci (QTLs). These include: (i) a method of identifying promising crosses for QTL mapping by exploiting a classical formula of SEWALL WRIGHT; (ii) a method (interval mapping) for exploiting the full power of RFLP linkage maps by adapting the approach of LOD score analysis used in human genetics, to obtain accurate estimates of the genetic location and phenotypic effect of QTLs; and (iii) a method (selective genotyping) that allows a substantial reduction in the number of progeny that need to be scored with the DNA markers. In addition to the exposition of the methods, explicit graphs are provided that allow experimental geneticists to estimate, in any particular case, the number of progeny required to map QTLs underlying a quantitative trait. PMID:2563713

  2. Public opinion about large offshore wind power: Underlying factors

    International Nuclear Information System (INIS)

    Firestone, Jeremy; Kempton, Willett

    2007-01-01

    This paper address factors underlying public opinion regarding offshore wind power based on a survey of residents near a proposed development off Cape Cod, MA, USA. Supporters are found to be younger, better educated, and more likely to own their own home. Opponents are more likely to earn over $200,000/year, and more likely to expect to see the project from their daily routine. The overwhelming majority of the population expects negative impacts from the project; much smaller numbers expect positive effects. When asked which factors most affected their position, the most frequently mentioned was damage to marine life/environmental impacts, followed by electricity rates, aesthetics, and impacts on fishing or boating. When the expectations expressed by our respondents are compared with the findings of the project's draft Environmental Impact Statement, many of the beliefs upon which opinion are based appear to be factually incorrect. Finally, we tested whether change in the project would affect support. The biggest change was an increase in the level of support, by 47% of the sample, if the project was the first of 300 such projects, in sum having proportionately larger impacts as well as greater benefits. Implications of this research are discussed

  3. Probabilistic causality and radiogenic cancers

    International Nuclear Information System (INIS)

    Groeer, P.G.

    1986-01-01

    A review and scrutiny of the literature on probability and probabilistic causality shows that it is possible under certain assumptions to estimate the probability that a certain type of cancer diagnosed in an individual exposed to radiation prior to diagnosis was caused by this exposure. Diagnosis of this causal relationship like diagnosis of any disease - malignant or not - requires always some subjective judgments by the diagnostician. It is, therefore, illusory to believe that tables based on actuarial data can provide objective estimates of the chance that a cancer diagnosed in an individual is radiogenic. It is argued that such tables can only provide a base from which the diagnostician(s) deviate in one direction or the other according to his (their) individual (consensual) judgment. Acceptance of a physician's diagnostic judgment by patients is commonplace. Similar widespread acceptance of expert judgment by claimants in radiation compensation cases does presently not exist. Judicious use of the present radioepidemiological tables prepared by the Working Group of the National Institutes of Health or of updated future versions of similar tables may improve the situation. 20 references

  4. Morse theory on timelike and causal curves

    International Nuclear Information System (INIS)

    Everson, J.; Talbot, C.J.

    1976-01-01

    It is shown that the set of timelike curves in a globally hyperbolic space-time manifold can be given the structure of a Hilbert manifold under a suitable definition of 'timelike.' The causal curves are the topological closure of this manifold. The Lorentzian energy (corresponding to Milnor's energy, except that the Lorentzian inner product is used) is shown to be a Morse function for the space of causal curves. A fixed end point index theorem is obtained in which a lower bound for the index of the Hessian of the Lorentzian energy is given in terms of the sum of the orders of the conjugate points between the end points. (author)

  5. Causal interpretation of stochastic differential equations

    DEFF Research Database (Denmark)

    Sokol, Alexander; Hansen, Niels Richard

    2014-01-01

    We give a causal interpretation of stochastic differential equations (SDEs) by defining the postintervention SDE resulting from an intervention in an SDE. We show that under Lipschitz conditions, the solution to the postintervention SDE is equal to a uniform limit in probability of postintervention...... structural equation models based on the Euler scheme of the original SDE, thus relating our definition to mainstream causal concepts. We prove that when the driving noise in the SDE is a Lévy process, the postintervention distribution is identifiable from the generator of the SDE....

  6. A Causal Model of Faculty Turnover Intentions.

    Science.gov (United States)

    Smart, John C.

    1990-01-01

    A causal model assesses the relative influence of individual attributes, institutional characteristics, contextual-work environment variables, and multiple measures of job satisfaction on faculty intentions to leave their current institutions. Factors considered include tenure status, age, institutional status, governance style, organizational…

  7. Probable autoimmune causal relationship between periodontitis and ...

    African Journals Online (AJOL)

    Periodontitis is a multifactorial disease with microbial dental plaque as the initiator of periodontal disease. However, the manifestation and progression of the disease is influenced by a wide variety of determinants and factors. The strongest type of causal relationship is the association of systemic and periodontal disease.

  8. Designing and testing a classroom curriculum to teach preschoolers about the biology of physical activity: The respiration system as an underlying biological causal mechanism

    Science.gov (United States)

    Ewing, Tracy S.

    The present study examined young children's understanding of respiration and oxygen as a source of vital energy underlying physical activity. Specifically, the purpose of the study was to explore whether a coherent biological theory, characterized by an understanding that bodily parts (heart and lungs) and processes (oxygen in respiration) as part of a biological system, can be taught as a foundational concept to reason about physical activity. The effects of a biology-based intervention curriculum designed to teach preschool children about bodily functions as a part of the respiratory system, the role of oxygen as a vital substance and how physical activity acts an energy source were examined. Participants were recruited from three private preschool classrooms (two treatment; 1 control) in Southern California and included a total of 48 four-year-old children (30 treatment; 18 control). Findings from this study suggested that young children could be taught relevant biological concepts about the role of oxygen in respiratory processes. Children who received biology-based intervention curriculum made significant gains in their understanding of the biology of respiration, identification of physical and sedentary activities. In addition these children demonstrated that coherence of conceptual knowledge was correlated with improved accuracy at activity identification and reasoning about the inner workings of the body contributing to endurance. Findings from this study provided evidence to support the benefits of providing age appropriate but complex coherent biological instruction to children in early childhood settings.

  9. Causal Entropic Forces

    Science.gov (United States)

    Wissner-Gross, A. D.; Freer, C. E.

    2013-04-01

    Recent advances in fields ranging from cosmology to computer science have hinted at a possible deep connection between intelligence and entropy maximization, but no formal physical relationship between them has yet been established. Here, we explicitly propose a first step toward such a relationship in the form of a causal generalization of entropic forces that we find can cause two defining behaviors of the human “cognitive niche”—tool use and social cooperation—to spontaneously emerge in simple physical systems. Our results suggest a potentially general thermodynamic model of adaptive behavior as a nonequilibrium process in open systems.

  10. Investigating Driver Fatigue versus Alertness Using the Granger Causality Network

    Directory of Open Access Journals (Sweden)

    Wanzeng Kong

    2015-08-01

    Full Text Available Driving fatigue has been identified as one of the main factors affecting drivers’ safety. The aim of this study was to analyze drivers’ different mental states, such as alertness and drowsiness, and find out a neurometric indicator able to detect drivers’ fatigue level in terms of brain networks. Twelve young, healthy subjects were recruited to take part in a driver fatigue experiment under different simulated driving conditions. The Electroencephalogram (EEG signals of the subjects were recorded during the whole experiment and analyzed by using Granger-Causality-based brain effective networks. It was that the topology of the brain networks and the brain’s ability to integrate information changed when subjects shifted from the alert to the drowsy stage. In particular, there was a significant difference in terms of strength of Granger causality (GC in the frequency domain and the properties of the brain effective network i.e., causal flow, global efficiency and characteristic path length between such conditions. Also, some changes were more significant over the frontal brain lobes for the alpha frequency band. These findings might be used to detect drivers’ fatigue levels, and as reference work for future studies.

  11. Intelligent diagnosis of jaundice with dynamic uncertain causality graph model.

    Science.gov (United States)

    Hao, Shao-Rui; Geng, Shi-Chao; Fan, Lin-Xiao; Chen, Jia-Jia; Zhang, Qin; Li, Lan-Juan

    2017-05-01

    Jaundice is a common and complex clinical symptom potentially occurring in hepatology, general surgery, pediatrics, infectious diseases, gynecology, and obstetrics, and it is fairly difficult to distinguish the cause of jaundice in clinical practice, especially for general practitioners in less developed regions. With collaboration between physicians and artificial intelligence engineers, a comprehensive knowledge base relevant to jaundice was created based on demographic information, symptoms, physical signs, laboratory tests, imaging diagnosis, medical histories, and risk factors. Then a diagnostic modeling and reasoning system using the dynamic uncertain causality graph was proposed. A modularized modeling scheme was presented to reduce the complexity of model construction, providing multiple perspectives and arbitrary granularity for disease causality representations. A "chaining" inference algorithm and weighted logic operation mechanism were employed to guarantee the exactness and efficiency of diagnostic reasoning under situations of incomplete and uncertain information. Moreover, the causal interactions among diseases and symptoms intuitively demonstrated the reasoning process in a graphical manner. Verification was performed using 203 randomly pooled clinical cases, and the accuracy was 99.01% and 84.73%, respectively, with or without laboratory tests in the model. The solutions were more explicable and convincing than common methods such as Bayesian Networks, further increasing the objectivity of clinical decision-making. The promising results indicated that our model could be potentially used in intelligent diagnosis and help decrease public health expenditure.

  12. Intelligent diagnosis of jaundice with dynamic uncertain causality graph model*

    Science.gov (United States)

    Hao, Shao-rui; Geng, Shi-chao; Fan, Lin-xiao; Chen, Jia-jia; Zhang, Qin; Li, Lan-juan

    2017-01-01

    Jaundice is a common and complex clinical symptom potentially occurring in hepatology, general surgery, pediatrics, infectious diseases, gynecology, and obstetrics, and it is fairly difficult to distinguish the cause of jaundice in clinical practice, especially for general practitioners in less developed regions. With collaboration between physicians and artificial intelligence engineers, a comprehensive knowledge base relevant to jaundice was created based on demographic information, symptoms, physical signs, laboratory tests, imaging diagnosis, medical histories, and risk factors. Then a diagnostic modeling and reasoning system using the dynamic uncertain causality graph was proposed. A modularized modeling scheme was presented to reduce the complexity of model construction, providing multiple perspectives and arbitrary granularity for disease causality representations. A “chaining” inference algorithm and weighted logic operation mechanism were employed to guarantee the exactness and efficiency of diagnostic reasoning under situations of incomplete and uncertain information. Moreover, the causal interactions among diseases and symptoms intuitively demonstrated the reasoning process in a graphical manner. Verification was performed using 203 randomly pooled clinical cases, and the accuracy was 99.01% and 84.73%, respectively, with or without laboratory tests in the model. The solutions were more explicable and convincing than common methods such as Bayesian Networks, further increasing the objectivity of clinical decision-making. The promising results indicated that our model could be potentially used in intelligent diagnosis and help decrease public health expenditure. PMID:28471111

  13. Preschoolers prefer to learn causal information

    Directory of Open Access Journals (Sweden)

    Aubry eAlvarez

    2015-02-01

    Full Text Available Young children, in general, appear to have a strong drive to explore the environment in ways that reveal its underlying causal structure. But are they really attuned specifically to casual information in this quest for understanding, or do they show equal interest in other types of non-obvious information about the world? To answer this question, we introduced 20 three-year-old children to two puppets who were anxious to tell the child about a set of novel artifacts and animals. One puppet consistently described causal properties of the items while the other puppet consistently described carefully matched non-causal properties of the same items. After a familiarization period in which children learned which type of information to expect from each informant, children were given the opportunity to choose which they wanted to hear describe each of eight pictured test items. On average, children chose to hear from the informant that provided causal descriptions on 72% of the trials. This preference for causal information has important implications for explaining the role of conceptual information in supporting early learning and may suggest means for maximizing interest and motivation in young children.

  14. Causal inheritance in plane wave quotients

    International Nuclear Information System (INIS)

    Hubeny, Veronika E.; Rangamani, Mukund; Ross, Simon F.

    2003-01-01

    We investigate the appearance of closed timelike curves in quotients of plane waves along spacelike isometries. First we formulate a necessary and sufficient condition for a quotient of a general spacetime to preserve stable causality. We explicitly show that the plane waves are stably causal; in passing, we observe that some pp-waves are not even distinguishing. We then consider the classification of all quotients of the maximally supersymmetric ten-dimensional plane wave under a spacelike isometry, and show that the quotient will lead to closed timelike curves iff the isometry involves a translation along the u direction. The appearance of these closed timelike curves is thus connected to the special properties of the light cones in plane wave spacetimes. We show that all other quotients preserve stable causality

  15. Child Care Subsidy Use and Child Development: Potential Causal Mechanisms

    Science.gov (United States)

    Hawkinson, Laura E.

    2011-01-01

    Research using an experimental design is needed to provide firm causal evidence on the impacts of child care subsidy use on child development, and on underlying causal mechanisms since subsidies can affect child development only indirectly via changes they cause in children's early experiences. However, before costly experimental research is…

  16. Modeling the Underlying Predicting Factors of Tobacco Smoking among Adolescents.

    Science.gov (United States)

    Jafarabadi, M Asghari; Allahverdipour, H; Bashirian, S; Jannati, A

    2012-01-01

    With regard to the willing and starting tobacco smoking among young people in Iran. The aim of the study was to model the underlying factors in predicting the behavior of tobacco smoking among employed youth and students in Iran. In this analytical cross-sectional study, based on a random cluster sampling were recruited 850 high school students, employed and unemployed youth age ranged between 14 and 19 yr from Iran. The data of demographic and tobacco smoking related variables were acquired via a self-administered questionnaire. A series of univariate and multivariate logistic regressions were performed respectively for computing un-adjusted and adjusted Odds Ratios utilizing SPSS 17 software. A number of 189 persons (25.6%) were smoker in the study and the mean smoking initiation age was 13.93 (SD= 2.21). In addition, smoker friend, peer persistence, leaving home, and smoking in one and six month ago were obtained as independent predictors of tobacco smoking. The education programs on resistance skills against the persistence of the peers, improvement in health programs by governmental interference and policy should be implemented.

  17. The causal relationships between neurocognition, social cognition and functional outcome over time in schizophrenia: a latent difference score approach.

    Science.gov (United States)

    Hoe, M; Nakagami, E; Green, M F; Brekke, J S

    2012-11-01

    Social cognition has been identified as a significant construct for schizophrenia research with relevance to diagnosis, assessment, treatment and functional outcome. However, social cognition has not been clearly understood in terms of its relationships with neurocognition and functional outcomes. The present study sought to examine the empirical independence of social cognition and neurocognition; to investigate the possible causal structure among social cognition, neurocognition and psychosocial functioning. The sample consists of 130 individuals diagnosed with schizophrenia. All participants were recruited as they were admitted to four community-based psychosocial rehabilitation programs. Social cognition, neurocognition and psychosocial functioning were measured at baseline and 12 months. The empirical independence of social cognition and neurocognition was tested using confirmatory factor analysis (CFA) and the possible causal structure among social cognition, neurocognition and psychosocial functioning was investigated using latent difference score (LDS) analysis. A two-factor model of social cognition and neurocognition fit the data very well, indicating the empirical independence of social cognition, whereas the longitudinal CFA results show that the empirical independence of neurocognition and social cognition is maintained over time. The results of the LDS analysis support a causal model that indicates that neurocognition underlies and is causally primary to social cognition, and that neurocognition and social cognition are causally primary to functional outcome. Social cognition and neurocognition could have independent and distinct upward causal effects on functional outcome. It is also suggested that the approaches for remediation of neurocognition and social cognition might need to be distinct.

  18. Mendelian randomization: use of genetics to enable causal inference in observational studies

    NARCIS (Netherlands)

    Verduijn, Marion; Siegerink, Bob; Jager, Kitty J.; Zoccali, Carmine; Dekker, Friedo W.

    2010-01-01

    The aim of aetiologic studies in epidemiology is to investigate whether factors are causally related to diseases and therefore become a potential target for therapeutic interventions. Mendelian randomization enables estimation of causal relationships in observational studies using genetic variants

  19. The causal link between energy and output growth: Evidence from Markov switching Granger causality

    International Nuclear Information System (INIS)

    Kandemir Kocaaslan, Ozge

    2013-01-01

    In this paper we empirically investigate the causal link between energy consumption and economic growth employing a Markov switching Granger causality analysis. We carry out our investigation using annual U.S. real GDP, total final energy consumption and total primary energy consumption data which cover the period between 1968 and 2010. We find that there are significant changes in the causal relation between energy consumption and economic growth over the sample period under investigation. Our results show that total final energy consumption and total primary energy consumption have significant predictive content for real economic activity in the U.S. economy. Furthermore, the causality running from energy consumption to output growth seems to be strongly apparent particularly during the periods of economic downturn and energy crisis. We also document that output growth has predictive power in explaining total energy consumption. Furthermore, the power of output growth in predicting total energy consumption is found to diminish after the mid of 1980s. - Highlights: • Total energy consumption has predictive content for real economic activity. • The causality from energy to output growth is apparent in the periods of recession. • The causality from energy to output growth is strong in the periods of energy crisis. • Output growth has predictive power in explaining total energy consumption. • The power of output growth in explaining energy diminishes after the mid of 1980s

  20. Causal inference based on counterfactuals

    Directory of Open Access Journals (Sweden)

    Höfler M

    2005-09-01

    Full Text Available Abstract Background The counterfactual or potential outcome model has become increasingly standard for causal inference in epidemiological and medical studies. Discussion This paper provides an overview on the counterfactual and related approaches. A variety of conceptual as well as practical issues when estimating causal effects are reviewed. These include causal interactions, imperfect experiments, adjustment for confounding, time-varying exposures, competing risks and the probability of causation. It is argued that the counterfactual model of causal effects captures the main aspects of causality in health sciences and relates to many statistical procedures. Summary Counterfactuals are the basis of causal inference in medicine and epidemiology. Nevertheless, the estimation of counterfactual differences pose several difficulties, primarily in observational studies. These problems, however, reflect fundamental barriers only when learning from observations, and this does not invalidate the counterfactual concept.

  1. Causal Reasoning with Mental Models

    Science.gov (United States)

    2014-08-08

    mreasoner/. 445 In broad terms, three strands of evidence corroborate the model theory of causal deductions. The 446 first strand of evidence bears ...models and causal reasoning Sangeet Khemlani et al. 13 She will not gain weight. 459 Will she not eat protein? 460 The results therefore bear out the... Adele Goldberg, Catrinel Haught, Max Lotstein, Marco Ragni, and Greg 821 Trafton for helpful criticisms. 822 Khemlani et al. Causal reasoning with

  2. Resultados de un programa de seguridad alimentaria en la reducción de la desnutrición crónica y sus factores causales en niños peruanos

    Directory of Open Access Journals (Sweden)

    Carlos Rojas D

    2007-04-01

    Full Text Available Objetivos: Determinar el efecto de un programa de seguridad alimentaria (Redes Sostenibles para la Seguridad Alimentaria: REDESA sobre la desnutrición crónica y sus factores causales en niños menores de tres años. Materiales y métodos: El resultado sobre la desnutrición se evaluó a través de la comparación de los porcentajes obtenidos en la evaluación inicial (2001 y en la evaluación final del Programa (2006. La desnutrición crónica fue definida como un índice de talla para la edad menor a -2DS, la referencia empleada fueron los patrones de la NCHS. El muestreo fue aleatorio multietápico; el tamaño muestral de la línea de base fueron 2643 niños y sus familias, para la evaluación final fueron 1597. Los factores causales se agruparon en: a salud y alimentación, que comprendían las enfermedades diarreicas agudas (EDA, lactancia materna exclusiva (LME, alimentación durante y después de las enfermedades diarreicas; b los económicos, que comprendía los ingresos familiares anuales y los gastos en alimentación. Resultados: La desnutrición crónica se redujo de 34,2% a 24,3%. Las EDA se redujeron de 35,0% a 16,4%, la LME se incrementó de 25,0% a 72,2%, la alimentación durante y después de las EDA se incrementó desde 3,3% a 45,0% y de 15,0% a 77,0% respectivamente, en todos los casos las diferencias fueron estadísticamente significativas (p<0,01. Los ingresos familiares anuales se incrementaron en 61%, mientras que el dinero destinado a la compra de alimentos se incrementó en 34,5%, los incrementos fueron estadísticamente significativas (p<0,01. Conclusión: La desnutrición crónica y sus factores causales tuvieron una mejora sustantiva entre la población beneficiaria del Programa REDESA.

  3. Path integrals on causal sets

    International Nuclear Information System (INIS)

    Johnston, Steven

    2009-01-01

    We describe a quantum mechanical model for particle propagation on a causal set. The model involves calculating a particle propagator by summing amplitudes assigned to trajectories within the causal set. This 'discrete path integral' is calculated using a matrix geometric series. Amplitudes are given which, when the causal set is generated by sprinkling points into 1+1 or 3+1 Minkowski spacetime, ensure the particle propagator agrees in a suitable sense, with the retarded causal propagator for the Klein-Gordon equation.

  4. Causality Statistical Perspectives and Applications

    CERN Document Server

    Berzuini, Carlo; Bernardinell, Luisa

    2012-01-01

    A state of the art volume on statistical causality Causality: Statistical Perspectives and Applications presents a wide-ranging collection of seminal contributions by renowned experts in the field, providing a thorough treatment of all aspects of statistical causality. It covers the various formalisms in current use, methods for applying them to specific problems, and the special requirements of a range of examples from medicine, biology and economics to political science. This book:Provides a clear account and comparison of formal languages, concepts and models for statistical causality. Addr

  5. Structural Equations and Causal Explanations: Some Challenges for Causal SEM

    Science.gov (United States)

    Markus, Keith A.

    2010-01-01

    One common application of structural equation modeling (SEM) involves expressing and empirically investigating causal explanations. Nonetheless, several aspects of causal explanation that have an impact on behavioral science methodology remain poorly understood. It remains unclear whether applications of SEM should attempt to provide complete…

  6. Resultados de un programa de seguridad alimentaria en la reducción de la desnutrición crónica y sus factores causales en niños peruanos

    OpenAIRE

    Carlos Rojas D; Rosa Flores M; Rosario Céspedes K

    2007-01-01

    Objetivos: Determinar el efecto de un programa de seguridad alimentaria (Redes Sostenibles para la Seguridad Alimentaria: REDESA) sobre la desnutrición crónica y sus factores causales en niños menores de tres años. Materiales y métodos: El resultado sobre la desnutrición se evaluó a través de la comparación de los porcentajes obtenidos en la evaluación inicial (2001) y en la evaluación final del Programa (2006). La desnutrición crónica fue definida como un índice de talla para la edad menor a...

  7. Prevalence and risk factors of asymptomatic malaria among under ...

    African Journals Online (AJOL)

    user

    Children who were not sleeping under insecticide treated nets were 15 times more likely to be infected with malaria parasites compared to those who were sleeping under nets [AOR=15.27; 95%CI=4.42-. 52.82; p<0.001]. ... environmental modification, human behaviour and insecticide resistance (MOH, 2014). Although.

  8. Activity of recombinant factor VIIa under different conditions in vitro

    DEFF Research Database (Denmark)

    Bladbjerg, Else-Marie; Jespersen, Jørgen

    2008-01-01

    Recombinant activated factor VII (NovoSeven; Novo Nordisk A/S, Måløv, Denmark) is an effective drug for treatment of bleeding in patients with haemophilia A or B and inhibitors. Little is known about physiological conditions influencing the efficacy of recombinant activated factor VII. We...

  9. Risk factors of poor anthropometric status in children under five ...

    African Journals Online (AJOL)

    Methods: Data generated by questionnaire and anthropometric indices were used to construct a logistic regression model, taking into account hierarchical relationships of risk factors to determine the odds of a child being stunted, underweight or overweight. Statistical significance was set at p < 0.05. Results: Factors ...

  10. Re-thinking local causality

    NARCIS (Netherlands)

    Friederich, Simon

    There is widespread belief in a tension between quantum theory and special relativity, motivated by the idea that quantum theory violates J. S. Bell's criterion of local causality, which is meant to implement the causal structure of relativistic space-time. This paper argues that if one takes the

  11. Expert Causal Reasoning and Explanation.

    Science.gov (United States)

    Kuipers, Benjamin

    The relationship between cognitive psychologists and researchers in artificial intelligence carries substantial benefits for both. An ongoing investigation in causal reasoning in medical problem solving systems illustrates this interaction. This paper traces a dialectic of sorts in which three different types of causal resaoning for medical…

  12. Introduction to causal dynamical triangulations

    DEFF Research Database (Denmark)

    Görlich, Andrzej

    2013-01-01

    The method of causal dynamical triangulations is a non-perturbative and background-independent approach to quantum theory of gravity. In this review we present recent results obtained within the four dimensional model of causal dynamical triangulations. We describe the phase structure of the mode...

  13. Paradoxical Behavior of Granger Causality

    Science.gov (United States)

    Witt, Annette; Battaglia, Demian; Gail, Alexander

    2013-03-01

    Granger causality is a standard tool for the description of directed interaction of network components and is popular in many scientific fields including econometrics, neuroscience and climate science. For time series that can be modeled as bivariate auto-regressive processes we analytically derive an expression for spectrally decomposed Granger Causality (SDGC) and show that this quantity depends only on two out of four groups of model parameters. Then we present examples of such processes whose SDGC expose paradoxical behavior in the sense that causality is high for frequency ranges with low spectral power. For avoiding misinterpretations of Granger causality analysis we propose to complement it by partial spectral analysis. Our findings are illustrated by an example from brain electrophysiology. Finally, we draw implications for the conventional definition of Granger causality. Bernstein Center for Computational Neuroscience Goettingen

  14. Cervical cancer precursors and hormonal contraceptive use in HIV-positive women: application of a causal model and semi-parametric estimation methods.

    Directory of Open Access Journals (Sweden)

    Hannah H Leslie

    Full Text Available OBJECTIVE: To demonstrate the application of causal inference methods to observational data in the obstetrics and gynecology field, particularly causal modeling and semi-parametric estimation. BACKGROUND: Human immunodeficiency virus (HIV-positive women are at increased risk for cervical cancer and its treatable precursors. Determining whether potential risk factors such as hormonal contraception are true causes is critical for informing public health strategies as longevity increases among HIV-positive women in developing countries. METHODS: We developed a causal model of the factors related to combined oral contraceptive (COC use and cervical intraepithelial neoplasia 2 or greater (CIN2+ and modified the model to fit the observed data, drawn from women in a cervical cancer screening program at HIV clinics in Kenya. Assumptions required for substantiation of a causal relationship were assessed. We estimated the population-level association using semi-parametric methods: g-computation, inverse probability of treatment weighting, and targeted maximum likelihood estimation. RESULTS: We identified 2 plausible causal paths from COC use to CIN2+: via HPV infection and via increased disease progression. Study data enabled estimation of the latter only with strong assumptions of no unmeasured confounding. Of 2,519 women under 50 screened per protocol, 219 (8.7% were diagnosed with CIN2+. Marginal modeling suggested a 2.9% (95% confidence interval 0.1%, 6.9% increase in prevalence of CIN2+ if all women under 50 were exposed to COC; the significance of this association was sensitive to method of estimation and exposure misclassification. CONCLUSION: Use of causal modeling enabled clear representation of the causal relationship of interest and the assumptions required to estimate that relationship from the observed data. Semi-parametric estimation methods provided flexibility and reduced reliance on correct model form. Although selected results suggest an

  15. Spatial Causality. An application to the Deforestation Process in Bolivia

    Directory of Open Access Journals (Sweden)

    Javier Aliaga

    2011-01-01

    Full Text Available This paper analyses the causes of deforestation for a representative set of Bolivian municipalities. The literature on environmental economics insists on the importance of physical and social factors. We focus on the last group of variables. Our objective is to identify causal mechanisms between these factors of risk and the problem of deforestation. To this end, we present a testing strategy for spatial causality, based on a sequence of Lagrange Multipliers. The results that we obtain for the Bolivian case confirm only partially the traditional view of the problem of deforestation. Indeed, we only find unequivocal signs of causality in relation to the structure of property rights.

  16. Causal aspects of diffraction

    International Nuclear Information System (INIS)

    Crawford, G.N.

    1981-01-01

    The analysis is directed at a causal description of photon diffraction, which is explained in terms of a wave exerting real forces and providing actual guidance to each quantum of energy. An undulatory PSI wave is associated with each photon, and this wave is assumed to imply more than an informative probability function, so that it actually carries real energy, in much the same way as does an electro-magnetic wave. Whether or not it may be in some way related to the electromagnetic wave is left as a matter of on-going concern. A novel application of the concept of a minimum energy configuration is utilized; that is, a system of energy quanta seeks out relative positions and orientations of least mutual energy, much as an electron seeks its Bohr radius as a position of least mutual energy. Thus the concept implies more a guiding interaction of the PSI waves than an interfering cancellation of these waves. Similar concepts have been suggested by L. de Broglie and D. Bohm

  17. Clear message for causality

    Energy Technology Data Exchange (ETDEWEB)

    Steinberg, Aephraim M. [Institute for Experimental Physics, University of Vienna, Vienna (Austria)

    2003-12-01

    Experiment confirms that information cannot be transmitted faster than the speed of light. Ever since Einstein stated that nothing can travel faster than light, physicists have delighted in finding exceptions. One after another, observations of such 'superluminal' propagation have been made. However, while some image or pattern- such as the motion of a spotlight projected on a distant wall - might have appeared to travel faster than light, it seemed that there was no way to use the superluminal effect to transmit energy or information. In recent years, the superluminal propagation of light pulses through certain media has led to renewed controversy. In 1995, for example, Guenther Nimtz of the University of Cologne encoded Mozart's 40th Symphony on a microwave beam, which he claimed to have transmitted at a speed faster than light. Others maintain that such a violation of Einstein's speed limit would wreak havoc on our most fundamental ideas about causality, allowing an effect to precede its cause. Relativity teaches us that sending a signal faster than light would be equivalent to sending it backwards in time. (U.K.)

  18. Increasing the Power to Detect Causal Associations by Combining Genotypic and Expression Data in Segregating Populations

    OpenAIRE

    Zhu, Jun; Wiener, Matthew C; Zhang, Chunsheng; Fridman, Arthur; Minch, Eric; Lum, Pek Y; Sachs, Jeffrey R; Schadt, Eric E

    2007-01-01

    To dissect common human diseases such as obesity and diabetes, a systematic approach is needed to study how genes interact with one another, and with genetic and environmental factors, to determine clinical end points or disease phenotypes. Bayesian networks provide a convenient framework for extracting relationships from noisy data and are frequently applied to large-scale data to derive causal relationships among variables of interest. Given the complexity of molecular networks underlying c...

  19. Factors underlying residential radon concentration: Results from Galicia, Spain

    International Nuclear Information System (INIS)

    Barros-Dios, J.M.; Ruano-Ravina, A.; Gastelu-Iturri, J.; Figueiras, A.

    2007-01-01

    Radon causes lung cancer when inhaled for prolonged periods of time. A range of factors influence residential radon concentration and this study therefore sought to ascertain which dwelling-related factors exert an influence on radon levels. A cross-sectional study was conducted from 2001 to 2003 which analyzed 983 homes of as many subjects randomly selected from the 1991 census. Sampling was carried out by district and stratified by population density to ensure that more detectors were placed in the most heavily populated areas. Radon concentration and different dwelling characteristics were measured in each of the homes selected. Bivariate and multivariate analyses were performed to ascertain which factors influenced radon concentration. The geometric mean of radon concentration was 69.5 Bq/m 3 , and 21.3% of homes had concentrations above 148 Bq/m 3 . Factors shown to influence radon concentration in the bivariate analysis were: age of dwelling; interior building material; exterior building material; and storey on which the detector was placed. Explanatory variables in the multivariate analysis were: age of dwelling; number of storeys; distance off floor; and interior building material. The model was significant, but the variability explained was around 10%. These results highlight the fact that the study area is an area of high radon emission and that factors other than those directly related with the characteristics of the dwelling also influence radon concentration

  20. PCR-based identification of cacao black pod causal agents and identification of biological factors possibly contributing to Phytophthora megakarya's field dominance in West Africa

    Science.gov (United States)

    Among the Phytophthora species that cause black pod of cacao, P. megakarya is the most virulent, posing a serious threat to cacao production in Africa. Correct identification of the species causing the black pod and understanding the virulence factors involved are important for developing sustainabl...

  1. Thinking in a Foreign language reduces the causality bias.

    Science.gov (United States)

    Díaz-Lago, Marcos; Matute, Helena

    2018-02-01

    The purpose of this research is to investigate the impact of a foreign language on the causality bias (i.e., the illusion that two events are causally related when they are not). We predict that using a foreign language could reduce the illusions of causality. A total of 36 native English speakers participated in Experiment 1, 80 native Spanish speakers in Experiment 2. They performed a standard contingency learning task, which can be used to detect causal illusions. Participants who performed the task in their native tongue replicated the illusion of causality effect, whereas those performing the task in their foreign language were more accurate in detecting that the two events were causally unrelated. Our results suggest that presenting the information in a foreign language could be used as a strategy to debias individuals against causal illusions, thereby facilitating more accurate judgements and decisions in non-contingent situations. They also contribute to the debate on the nature and underlying mechanisms of the foreign language effect, given that the illusion of causality is rooted in basic associative processes.

  2. Granger-Causality Maps of Diffusion Processes

    Czech Academy of Sciences Publication Activity Database

    Wahl, B.; Feudel, U.; Hlinka, Jaroslav; Wächter, M.; Peinke, J.; Freund, J.A.

    2016-01-01

    Roč. 93, č. 2 16 February (2016), č. článku 022213. ISSN 2470-0045 R&D Projects: GA ČR GA13-23940S; GA MZd(CZ) NV15-29835A Institutional support: RVO:67985807 Keywords : Granger causality * stochastic process * diffusion process * nonlinear dynamical systems Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.366, year: 2016

  3. Prevalence and risk factors of asymptomatic malaria among under ...

    African Journals Online (AJOL)

    user

    have resulted in significant decline of malaria incidence between 2006 and 2008 in Rwanda. (Bizimana et al., 2015). The mortality rate in children under-five years old also decreased by 61% between 2000 and 2010. The prevalence of malaria in this age group declined from 2.6% in 2007 to. 1.4% in 2010 (PMI, 2014) .

  4. Causal boundary for stably causal space-times

    International Nuclear Information System (INIS)

    Racz, I.

    1987-12-01

    The usual boundary constructions for space-times often yield an unsatisfactory boundary set. This problem is reviewed and a new solution is proposed. An explicit identification rule is given on the set of the ideal points of the space-time. This construction leads to a satisfactory boundary point set structure for stably causal space-times. The topological properties of the resulting causal boundary construction are examined. For the stably causal space-times each causal curve has a unique endpoint on the boundary set according to the extended Alexandrov topology. The extension of the space-time through the boundary is discussed. To describe the singularities the defined boundary sets have to be separated into two disjoint sets. (D.Gy.) 8 refs

  5. Factors Underlying Technology Adoption in Academic Libraries in Kuwait

    Science.gov (United States)

    Al-Fadhli, Meshal; Corrall, Sheila; Cox, Andrew

    2016-01-01

    The study analyzed factors shaping adoption of technology in academic libraries in Kuwait. The research was based on interviews conducted with library directors, staff, and users, combined with observation and document analysis. A major aspect of the Kuwaiti context was a relative lack of financial restraints and an enthusiasm for technology…

  6. Biological effects under combined action of radiation and chemical factors

    International Nuclear Information System (INIS)

    Malenchenko, A.F.

    1990-01-01

    The paper considers the manifoild factors of environmental pollution effect upon living organisms and their possible response manifested in additivity, synergism and anthogonism. Consideration is also given to the possible practical measures for improving ecological situation and decreasing the risk of anthropogenesis negative after-effects

  7. Factors underlying taking a child to HIV care: implications for ...

    African Journals Online (AJOL)

    Objective: With the aim of reducing pediatric loss to follow-up (LTFU) from HIV clinical care programs in sub-Saharan Africa, we sought to understand the personal and socio-cultural factors associated with the behavior of caregivers taking HIV-infected and -exposed children for care in western Kenya. Methods: Between ...

  8. Factors influencing the Nigerian shipping market under a depressed ...

    African Journals Online (AJOL)

    The Nigerian economy is currently characterized by intolerable inflation, continuous devaluation of the local currency, the Naira, capital flight, falling the standard of living of the populace, slow rate of industrial development and very poor shipping business. All these factors coupled with worldwide economic recession ...

  9. Functional equations with causal operators

    CERN Document Server

    Corduneanu, C

    2003-01-01

    Functional equations encompass most of the equations used in applied science and engineering: ordinary differential equations, integral equations of the Volterra type, equations with delayed argument, and integro-differential equations of the Volterra type. The basic theory of functional equations includes functional differential equations with causal operators. Functional Equations with Causal Operators explains the connection between equations with causal operators and the classical types of functional equations encountered by mathematicians and engineers. It details the fundamentals of linear equations and stability theory and provides several applications and examples.

  10. Factors Involved in Sludge Granulation under Anaerobic Conditions

    Directory of Open Access Journals (Sweden)

    Jalal Shayegan

    2011-03-01

    Full Text Available This paper investigates the effects of factors involved in sludge anaerobic granulation. Granulated sludge formation is the main parameter contributing to the success of UASB reactors. Anaerobic granulation leads to reduced reactor size, space requirement, and investment costs. Operation costs are also greatly reduced due to lack of aeration. An important parameter affecting process performance is the size of sludge granules; the factors involved in granule size will be investigated. Some of the important parameters of anaerobic sludge granulation are: existence of growth cores as inert particles or granulated sludge, process operational conditions (Sludge Loading Rate and Organic Loading Rate, Loading rate increase and …, and environment conditions (nutrients, temperature, pH, combination and ….

  11. Correction factors for assessing immersion suits under harsh conditions.

    Science.gov (United States)

    Power, Jonathan; Tikuisis, Peter; Ré, António Simões; Barwood, Martin; Tipton, Michael

    2016-03-01

    Many immersion suit standards require testing of thermal protective properties in calm, circulating water while these suits are typically used in harsher environments where they often underperform. Yet it can be expensive and logistically challenging to test immersion suits in realistic conditions. The goal of this work was to develop a set of correction factors that would allow suits to be tested in calm water yet ensure they will offer sufficient protection in harsher conditions. Two immersion studies, one dry and the other with 500 mL of water within the suit, were conducted in wind and waves to measure the change in suit insulation. In both studies, wind and waves resulted in a significantly lower immersed insulation value compared to calm water. The minimum required thermal insulation for maintaining heat balance can be calculated for a given mean skin temperature, metabolic heat production, and water temperature. Combining the physiological limits of sustainable cold water immersion and actual suit insulation, correction factors can be deduced for harsh conditions compared to calm. The minimum in-situ suit insulation to maintain thermal balance is 1.553-0.0624·TW + 0.00018·TW(2) for a dry calm condition. Multiplicative correction factors to the above equation are 1.37, 1.25, and 1.72 for wind + waves, 500 mL suit wetness, and both combined, respectively. Calm water certification tests of suit insulation should meet or exceed the minimum in-situ requirements to maintain thermal balance, and correction factors should be applied for a more realistic determination of minimum insulation for harsh conditions. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  12. Factors underlying variable DNA methylation in a human community cohort.

    Science.gov (United States)

    Lam, Lucia L; Emberly, Eldon; Fraser, Hunter B; Neumann, Sarah M; Chen, Edith; Miller, Gregory E; Kobor, Michael S

    2012-10-16

    Epigenetics is emerging as an attractive mechanism to explain the persistent genomic embedding of early-life experiences. Tightly linked to chromatin, which packages DNA into chromosomes, epigenetic marks primarily serve to regulate the activity of genes. DNA methylation is the most accessible and characterized component of the many chromatin marks that constitute the epigenome, making it an ideal target for epigenetic studies in human populations. Here, using peripheral blood mononuclear cells collected from a community-based cohort stratified for early-life socioeconomic status, we measured DNA methylation in the promoter regions of more than 14,000 human genes. Using this approach, we broadly assessed and characterized epigenetic variation, identified some of the factors that sculpt the epigenome, and determined its functional relation to gene expression. We found that the leukocyte composition of peripheral blood covaried with patterns of DNA methylation at many sites, as did demographic factors, such as sex, age, and ethnicity. Furthermore, psychosocial factors, such as perceived stress, and cortisol output were associated with DNA methylation, as was early-life socioeconomic status. Interestingly, we determined that DNA methylation was strongly correlated to the ex vivo inflammatory response of peripheral blood mononuclear cells to stimulation with microbial products that engage Toll-like receptors. In contrast, our work found limited effects of DNA methylation marks on the expression of associated genes across individuals, suggesting a more complex relationship than anticipated.

  13. Assessing statistical significance in causal graphs.

    Science.gov (United States)

    Chindelevitch, Leonid; Loh, Po-Ru; Enayetallah, Ahmed; Berger, Bonnie; Ziemek, Daniel

    2012-02-20

    Causal graphs are an increasingly popular tool for the analysis of biological datasets. In particular, signed causal graphs--directed graphs whose edges additionally have a sign denoting upregulation or downregulation--can be used to model regulatory networks within a cell. Such models allow prediction of downstream effects of regulation of biological entities; conversely, they also enable inference of causative agents behind observed expression changes. However, due to their complex nature, signed causal graph models present special challenges with respect to assessing statistical significance. In this paper we frame and solve two fundamental computational problems that arise in practice when computing appropriate null distributions for hypothesis testing. First, we show how to compute a p-value for agreement between observed and model-predicted classifications of gene transcripts as upregulated, downregulated, or neither. Specifically, how likely are the classifications to agree to the same extent under the null distribution of the observed classification being randomized? This problem, which we call "Ternary Dot Product Distribution" owing to its mathematical form, can be viewed as a generalization of Fisher's exact test to ternary variables. We present two computationally efficient algorithms for computing the Ternary Dot Product Distribution and investigate its combinatorial structure analytically and numerically to establish computational complexity bounds.Second, we develop an algorithm for efficiently performing random sampling of causal graphs. This enables p-value computation under a different, equally important null distribution obtained by randomizing the graph topology but keeping fixed its basic structure: connectedness and the positive and negative in- and out-degrees of each vertex. We provide an algorithm for sampling a graph from this distribution uniformly at random. We also highlight theoretical challenges unique to signed causal graphs

  14. Consciousness and the "Causal Paradox"

    OpenAIRE

    Velmans, Max

    1996-01-01

    Viewed from a first-person perspective consciousness appears to be necessary for complex, novel human activity - but viewed from a third-person perspective consciousness appears to play no role in the activity of brains, producing a "causal paradox". To resolve this paradox one needs to distinguish consciousness of processing from consciousness accompanying processing or causing processing. Accounts of consciousness/brain causal interactions switch between first- and third-person perspectives...

  15. Biology, Genetics, and Environment: Underlying Factors Influencing Alcohol Metabolism.

    Science.gov (United States)

    Wall, Tamara L; Luczak, Susan E; Hiller-Sturmhöfel, Susanne

    2016-01-01

    Gene variants encoding several of the alcohol-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), are among the largest genetic associations with risk for alcohol dependence. Certain genetic variants (i.e., alleles)--particularly the ADH1B*2, ADH1B*3, ADH1C*1, and ALDH2*2 alleles--have been associated with lower rates of alcohol dependence. These alleles may lead to an accumulation of acetaldehyde during alcohol metabolism, which can result in heightened subjective and objective effects. The prevalence of these alleles differs among ethnic groups; ADH1B*2 is found frequently in northeast Asians and occasionally Caucasians, ADH1B*3 is found predominantly in people of African ancestry, ADH1C*1 varies substantially across populations, and ALDH2*2 is found almost exclusively in northeast Asians. Differences in the prevalence of these alleles may account at least in part for ethnic differences in alcohol consumption and alcohol use disorder (AUD). However, these alleles do not act in isolation to influence the risk of AUD. For example, the gene effects of ALDH2*2 and ADH1B*2 seem to interact. Moreover, other factors have been found to influence the extent to which these alleles affect a person's alcohol involvement, including developmental stage, individual characteristics (e.g., ethnicity, antisocial behavior, and behavioral undercontrol), and environmental factors (e.g., culture, religion, family environment, and childhood adversity).

  16. Spatiotemporal causal modeling for the management of Dengue Fever

    Science.gov (United States)

    Yu, Hwa-Lung; Huang, Tailin; Lee, Chieh-Han

    2015-04-01

    Increasing climatic extremes have caused growing concerns about the health effects and disease outbreaks. The association between climate variation and the occurrence of epidemic diseases play an important role on a country's public health systems. Part of the impacts are direct casualties associated with the increasing frequency and intensity of typhoons, the proliferation of disease vectors and the short-term increase of clinic visits on gastro-intestinal discomforts, diarrhea, dermatosis, or psychological trauma. Other impacts come indirectly from the influence of disasters on the ecological and socio-economic systems, including the changes of air/water quality, living environment and employment condition. Previous risk assessment studies on dengue fever focus mostly on climatic and non-climatic factors and their association with vectors' reproducing pattern. The public-health implication may appear simple. Considering the seasonal changes and regional differences, however, the causality of the impacts is full of uncertainties. Without further investigation, the underlying dengue fever risk dynamics may not be assessed accurately. The objective of this study is to develop an epistemic framework for assessing dynamic dengue fever risk across space and time. The proposed framework integrates cross-departmental data, including public-health databases, precipitation data over time and various socio-economic data. We explore public-health issues induced by typhoon through literature review and spatiotemporal analytic techniques on public health databases. From those data, we identify relevant variables and possible causal relationships, and their spatiotemporal patterns derived from our proposed spatiotemporal techniques. Eventually, we create a spatiotemporal causal network and a framework for modeling dynamic dengue fever risk.

  17. [Therapy of polyneuropathies. Causal and symptomatic].

    Science.gov (United States)

    Müller-Felber, W

    2001-05-28

    In the first instance, polyneuropathies are treated causally. The most common underlying cause is diabetes mellitus or alcohol abuse. In a large number of patients with polyneuropathy, however, the underlying cause cannot be definitively identified. For these--but equally for patients with etiologically clear polyneuropathy--a stock-taking of clinical symptoms should be carried out and, where indicated, symptomatic treatment initiated. In addition to medication aimed at combating pain, muscular spasm, autonomic functional disorders, and for the prevention of thrombosis, physical measures (physiotherapy, foot care, orthopedic shoes) are of primary importance.

  18. Factors Underlying Farmers’ Decisions to Participate in Networks

    Directory of Open Access Journals (Sweden)

    Bianka Kühne

    2013-11-01

    Full Text Available 800x600 The objective of this elicitation study is to provide insights into farmers’ beliefs which influence their participation in knowledge exchange and innovation networks to enable the enhancement of network participation. A set of facilitating and impeding factors was obtained. Participants identified (a 13 categories of behavioural beliefs (e.g. ‘You learn something’ and ‘Low perceived return on investment’, (b 4 groups of normative beliefs (influence of colleagues, spouses, network coordinators and chain partners and (c 11 control beliefs (facilitators or barriers related to, for example, ‘Network skills’, ‘No time’ and ‘Perceived restraint by farmers in communicating openly and honestly’. Normal 0 21 false false false DE X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0pt 5.4pt 0pt 5.4pt; mso-para-margin:0pt; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";}

  19. Cognitive and Ocular Factors Jointly Determine Pupil Responses under Equiluminance.

    Directory of Open Access Journals (Sweden)

    Tomas Knapen

    Full Text Available Changes in pupil diameter can reflect high-level cognitive signals that depend on central neuromodulatory mechanisms. However, brain mechanisms that adjust pupil size are also exquisitely sensitive to changes in luminance and other events that would be considered a nuisance in cognitive experiments recording pupil size. We implemented a simple auditory experiment involving no changes in visual stimulation. Using finite impulse-response fitting we found pupil responses triggered by different types of events. Among these are pupil responses to auditory events and associated surprise: cognitive effects. However, these cognitive responses were overshadowed by pupil responses associated with blinks and eye movements, both inevitable nuisance factors that lead to changes in effective luminance. Of note, these latter pupil responses were not recording artifacts caused by blinks and eye movements, but endogenous pupil responses that occurred in the wake of these events. Furthermore, we identified slow (tonic changes in pupil size that differentially influenced faster (phasic pupil responses. Fitting all pupil responses using gamma functions, we provide accurate characterisations of cognitive and non-cognitive response shapes, and quantify each response's dependence on tonic pupil size. These results allow us to create a set of recommendations for pupil size analysis in cognitive neuroscience, which we have implemented in freely available software.

  20. Violation of causality in f( T) gravity

    Science.gov (United States)

    Otalora, G.; Rebouças, M. J.

    2017-11-01

    In the standard formulation, the f( T) field equations are not invariant under local Lorentz transformations, and thus the theory does not inherit the causal structure of special relativity. Actually, even locally violation of causality can occur in this formulation of f( T) gravity. A locally Lorentz covariant f( T) gravity theory has been devised recently, and this local causality problem seems to have been overcome. The non-locality question, however, is left open. If gravitation is to be described by this covariant f( T) gravity theory there are a number of issues that ought to be examined in its context, including the question as to whether its field equations allow homogeneous Gödel-type solutions, which necessarily leads to violation of causality on non-local scale. Here, to look into the potentialities and difficulties of the covariant f( T) theories, we examine whether they admit Gödel-type solutions. We take a combination of a perfect fluid with electromagnetic plus a scalar field as source, and determine a general Gödel-type solution, which contains special solutions in which the essential parameter of Gödel-type geometries, m^2, defines any class of homogeneous Gödel-type geometries. We show that solutions of the trigonometric and linear classes (m^2 electromagnetic field matter component. We extended to the context of covariant f( T) gravity a theorem which ensures that any perfect-fluid homogeneous Gödel-type solution defines the same set of Gödel tetrads h_A^{ μ } up to a Lorentz transformation. We also showed that the single massless scalar field generates Gödel-type solution with no closed time-like curves. Even though the covariant f( T) gravity restores Lorentz covariance of the field equations and the local validity of the causality principle, the bare existence of the Gödel-type solutions makes apparent that the covariant formulation of f( T) gravity does not preclude non-local violation of causality in the form of closed time

  1. Reflexivity, Complexity and Causality

    DEFF Research Database (Denmark)

    Søgaard, Villy

    2008-01-01

    Artiklen (der er under revision) tager sit udgangspunkt i, at samfundsvidenskabernes forskningsgenstand (til forskel fra f.eks. klassisk, newtonsk, fysik) er kendetegnet ved en høj grad af kompleksitet, ved refleksivitet (vores forståelse af samfundet er en del af det), og ved en kausalitet, der ...

  2. Puzzles in modern biology. III.Two kinds of causality in age-related disease.

    Science.gov (United States)

    Frank, Steven A

    2016-01-01

    The two primary causal dimensions of age-related disease are rate and function. Change in rate of disease development shifts the age of onset. Change in physiological function provides necessary steps in disease progression. A causal factor may alter the rate of physiological change, but that causal factor itself may have no direct physiological role. Alternatively, a causal factor may provide a necessary physiological function, but that causal factor itself may not alter the rate of disease onset. The rate-function duality provides the basis for solving puzzles of age-related disease. Causal factors of cancer illustrate the duality between rate processes of discovery, such as somatic mutation, and necessary physiological functions, such as invasive penetration across tissue barriers. Examples from cancer suggest general principles of age-related disease.

  3. Causality in cancer research: a journey through models in molecular epidemiology and their philosophical interpretation

    Directory of Open Access Journals (Sweden)

    Paolo Vineis

    2017-06-01

    Full Text Available Abstract In the last decades, Systems Biology (including cancer research has been driven by technology, statistical modelling and bioinformatics. In this paper we try to bring biological and philosophical thinking back. We thus aim at making different traditions of thought compatible: (a causality in epidemiology and in philosophical theorizing—notably, the “sufficient-component-cause framework” and the “mark transmission” approach; (b new acquisitions about disease pathogenesis, e.g. the “branched model” in cancer, and the role of biomarkers in this process; (c the burgeoning of omics research, with a large number of “signals” and of associations that need to be interpreted. In the paper we summarize first the current views on carcinogenesis, and then explore the relevance of current philosophical interpretations of “cancer causes”. We try to offer a unifying framework to incorporate biomarkers and omic data into causal models, referring to a position called “evidential pluralism”. According to this view, causal reasoning is based on both “evidence of difference-making” (e.g. associations and on “evidence of underlying biological mechanisms”. We conceptualize the way scientists detect and trace signals in terms of information transmission, which is a generalization of the mark transmission theory developed by philosopher Wesley Salmon. Our approach is capable of helping us conceptualize how heterogeneous factors such as micro and macro-biological and psycho-social—are causally linked. This is important not only to understand cancer etiology, but also to design public health policies that target the right causal factors at the macro-level.

  4. Causality and analyticity in optics

    International Nuclear Information System (INIS)

    Nussenzveig, H.M.

    In order to provide an overall picture of the broad range of optical phenomena that are directly linked with the concepts of causality and analyticity, the following topics are briefly reviewed, emphasizing recent developments: 1) Derivation of dispersion relations for the optical constants of general linear media from causality. Application to the theory of natural optical activity. 2) Derivation of sum rules for the optical constants from causality and from the short-time response function (asymptotic high-frequency behavior). Average spectral behavior of optical media. Applications. 3) Role of spectral conditions. Analytic properties of coherence functions in quantum optics. Reconstruction theorem.4) Phase retrieval problems. 5) Inverse scattering problems. 6) Solution of nonlinear evolution equations in optics by inverse scattering methods. Application to self-induced transparency. Causality in nonlinear wave propagation. 7) Analytic continuation in frequency and angular momentum. Complex singularities. Resonances and natural-mode expansions. Regge poles. 8) Wigner's causal inequality. Time delay. Spatial displacements in total reflection. 9) Analyticity in diffraction theory. Complex angular momentum theory of Mie scattering. Diffraction as a barrier tunnelling effect. Complex trajectories in optics. (Author) [pt

  5. Hierarchical organisation of causal graphs

    International Nuclear Information System (INIS)

    Dziopa, P.

    1993-01-01

    This paper deals with the design of a supervision system using a hierarchy of models formed by graphs, in which the variables are the nodes and the causal relations between the variables of the arcs. To obtain a representation of the variables evolutions which contains only the relevant features of their real evolutions, the causal relations are completed with qualitative transfer functions (QTFs) which produce roughly the behaviour of the classical transfer functions. Major improvements have been made in the building of the hierarchical organization. First, the basic variables of the uppermost level and the causal relations between them are chosen. The next graph is built by adding intermediary variables to the upper graph. When the undermost graph has been built, the transfer functions parameters corresponding to its causal relations are identified. The second task consists in the upwelling of the information from the undermost graph to the uppermost one. A fusion procedure of the causal relations has been designed to compute the QFTs relevant for each level. This procedure aims to reduce the number of parameters needed to represent an evolution at a high level of abstraction. These techniques have been applied to the hierarchical modelling of nuclear process. (authors). 8 refs., 12 figs

  6. The impact of vascular endothelial growth factor and basic fibroblast growth factor on cardiac fibroblasts grown under altered gravity conditions

    DEFF Research Database (Denmark)

    Ulbrich, Claudia; Leder, Annekatrin; Pietsch, Jessica

    2010-01-01

    Myocardium is very sensitive to gravitational changes. During a spaceflight cardiovascular atrophy paired with rhythm problems and orthostatic intolerance can occur. The aim of this study was to investigate the impact of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor...... (VEGF) on cardiac fibroblasts (CF) grown under altered gravity conditions....

  7. A Complex Systems Approach to Causal Discovery in Psychiatry.

    Directory of Open Access Journals (Sweden)

    Glenn N Saxe

    Full Text Available Conventional research methodologies and data analytic approaches in psychiatric research are unable to reliably infer causal relations without experimental designs, or to make inferences about the functional properties of the complex systems in which psychiatric disorders are embedded. This article describes a series of studies to validate a novel hybrid computational approach--the Complex Systems-Causal Network (CS-CN method-designed to integrate causal discovery within a complex systems framework for psychiatric research. The CS-CN method was first applied to an existing dataset on psychopathology in 163 children hospitalized with injuries (validation study. Next, it was applied to a much larger dataset of traumatized children (replication study. Finally, the CS-CN method was applied in a controlled experiment using a 'gold standard' dataset for causal discovery and compared with other methods for accurately detecting causal variables (resimulation controlled experiment. The CS-CN method successfully detected a causal network of 111 variables and 167 bivariate relations in the initial validation study. This causal network had well-defined adaptive properties and a set of variables was found that disproportionally contributed to these properties. Modeling the removal of these variables resulted in significant loss of adaptive properties. The CS-CN method was successfully applied in the replication study and performed better than traditional statistical methods, and similarly to state-of-the-art causal discovery algorithms in the causal detection experiment. The CS-CN method was validated, replicated, and yielded both novel and previously validated findings related to risk factors and potential treatments of psychiatric disorders. The novel approach yields both fine-grain (micro and high-level (macro insights and thus represents a promising approach for complex systems-oriented research in psychiatry.

  8. A Causal Theory of Modality

    Directory of Open Access Journals (Sweden)

    José Tomás Alvarado

    2009-08-01

    Full Text Available This work presents a causal conception of metaphysical modality in which a state of affairs is metaphysically possible if and only if it can be caused (in the past, the present or the future by current entities. The conception is contrasted with what is called the “combinatorial” conception of modality, in which everything can co-exist with anything else. This work explains how the notion of ‘causality’ should be construed in the causal theory, what difference exists between modalities thus defined from nomological modality, how accessibility relations between possible worlds should be interpreted, and what is the relation between the causal conception and the necessity of origin.

  9. Causal structure in categorical quantum mechanics

    Science.gov (United States)

    Lal, Raymond Ashwin

    Categorical quantum mechanics is a way of formalising the structural features of quantum theory using category theory. It uses compound systems as the primitive notion, which is formalised by using symmetric monoidal categories. This leads to an elegant formalism for describing quantum protocols such as quantum teleportation. In particular, categorical quantum mechanics provides a graphical calculus that exposes the information flow of such protocols in an intuitive way. However, the graphical calculus also reveals surprising features of these protocols; for example, in the quantum teleportation protocol, information appears to flow `backwards-in-time'. This leads to question of how causal structure can be described within categorical quantum mechanics, and how this might lead to insight regarding the structural compatibility between quantum theory and relativity. This thesis is concerned with the project of formalising causal structure in categorical quantum mechanics. We begin by studying an abstract view of Bell-type experiments, as described by `no-signalling boxes', and we show that under time-reversal no-signalling boxes generically become signalling. This conflicts with the underlying symmetry of relativistic causal structure. This leads us to consider the framework of categorical quantum mechanics from the perspective of relativistic causal structure. We derive the properties that a symmetric monoidal category must satisfy in order to describe systems in such a background causal structure. We use these properties to define a new type of category, and this provides a formal framework for describing protocols in spacetime. We explore this new structure, showing how it leads to an understanding of the counter-intuitive information flow of protocols in categorical quantum mechanics. We then find that the formal properties of our new structure are naturally related to axioms for reconstructing quantum theory, and we show how a reconstruction scheme based on

  10. On Storks and Babies: Correlation, Causality and Field Experiments

    Directory of Open Access Journals (Sweden)

    Lambrecht Anja

    2016-11-01

    Full Text Available The explosion of available data has created much excitement among marketing practitioners about their ability to better understand the impact of marketing investments. Big data allows for detecting patterns and often it seems plausible to interpret them as causal. While it is quite obvious that storks do not bring babies, marketing relationships are usually less clear. Apparent “causalities” often fail to hold up under examination. If marketers want to be sure not to walk into a causality trap, they need to conduct field experiments to detect true causal relationships. In the present digital environment, experiments are easier than ever to execute. However, they need to be prepared and interpreted with great care in order to deliver meaningful and genuinely causal results that help improve marketing decisions.

  11. Quantum theory and local causality

    CERN Document Server

    Hofer-Szabó, Gábor

    2018-01-01

    This book summarizes the results of research the authors have pursued in the past years on the problem of implementing Bell's notion of local causality in local physical theories and relating it to other important concepts and principles in the foundations of physics such as the Common Cause Principle, Bell's inequalities, the EPR (Einstein-Podolsky-Rosen) scenario, and various other locality and causality concepts. The book is intended for philosophers of science with an interest in the formal background of sciences, philosophers of physics and physicists working in foundation of physics.

  12. De Broglie's causal interpretations of quantum mechanics

    International Nuclear Information System (INIS)

    YOAV Ben-Dov

    1989-01-01

    In this article we trace the history of de Broglie's two causal interpretations of quantum mechanics, namely the double solution and the pilot wave theories, at the two periods in which he developed them: 1924-27 and 1952 onwards. Examining the reasons for which he always preferred the first theory to the second, reasons that are mainly concerned with the question of the physical nature of the quantum wave function, we try to show the continuity and the coherence of his underlying vision

  13. Conditional Granger Causality of Diffusion Processes

    Czech Academy of Sciences Publication Activity Database

    Wahl, B.; Feudel, U.; Hlinka, Jaroslav; Wächter, M.; Peinke, J.; Freund, J.A.

    2017-01-01

    Roč. 90, č. 10 (2017), č. článku 197. ISSN 1434-6028 R&D Projects: GA ČR GA13-23940S; GA MZd(CZ) NV15-29835A Institutional support: RVO:67985807 Keywords : Granger causality * stochastic process * diffusion process * nonlinear dynamical systems Subject RIV: BB - Applied Statistics, Operational Research OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 1.461, year: 2016

  14. Causal feedbacks in climate change

    NARCIS (Netherlands)

    Nes, van E.H.; Scheffer, M.; Brovkin, V.; Lenton, T.M.; Ye, H.; Deyle, E.; Sugihara, G.

    2015-01-01

    The statistical association between temperature and greenhouse gases over glacial cycles is well documented1, but causality behind this correlation remains difficult to extract directly from the data. A time lag of CO2 behind Antarctic temperature—originally thought to hint at a driving role for

  15. Study of capillary experiments and hydrologic factors under subsurface drip irrigation with fractal theory

    International Nuclear Information System (INIS)

    Zhou, W; Cao, L

    2012-01-01

    Soil spatial variability is one of the primary environmental factors that influences the hydraulic factors and technical indicators of subsurface drip irrigation (SDI), whose emitters are buried in the soil. This paper aimed at evaluating these effects of soil spatial variability on hydrologic factors under SDI. And some SDI emitter and capillary experiments were designed to obtain test data and distribution of pressure and emitter discharge. First, The results of labyrinth non-turbulent mosaic drip emitter test and fractal theory were used to research the fractal and quantitative relationship between single emitter hydrologic factors and soil physical parameters; and then, the capillary experiments and the relationship among hydrologic factors of capillary were used to analyze the fractal and quantitative relationship between hydrologic factors of capillary and soil physical parameters, which explained the inner relationship between spatial variability of soil and hydrologic factors of filed pipeline network under SDI, and provide theory support for the plan, design, management and production of SDI.

  16. Formalizing Neurath's ship: Approximate algorithms for online causal learning.

    Science.gov (United States)

    Bramley, Neil R; Dayan, Peter; Griffiths, Thomas L; Lagnado, David A

    2017-04-01

    Higher-level cognition depends on the ability to learn models of the world. We can characterize this at the computational level as a structure-learning problem with the goal of best identifying the prevailing causal relationships among a set of relata. However, the computational cost of performing exact Bayesian inference over causal models grows rapidly as the number of relata increases. This implies that the cognitive processes underlying causal learning must be substantially approximate. A powerful class of approximations that focuses on the sequential absorption of successive inputs is captured by the Neurath's ship metaphor in philosophy of science, where theory change is cast as a stochastic and gradual process shaped as much by people's limited willingness to abandon their current theory when considering alternatives as by the ground truth they hope to approach. Inspired by this metaphor and by algorithms for approximating Bayesian inference in machine learning, we propose an algorithmic-level model of causal structure learning under which learners represent only a single global hypothesis that they update locally as they gather evidence. We propose a related scheme for understanding how, under these limitations, learners choose informative interventions that manipulate the causal system to help elucidate its workings. We find support for our approach in the analysis of 3 experiments. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. Are bruxism and the bite causally related?

    Science.gov (United States)

    Lobbezoo, F; Ahlberg, J; Manfredini, D; Winocur, E

    2012-07-01

    In the dental profession, the belief that bruxism and dental (mal-)occlusion ('the bite') are causally related is widespread. The aim of this review was to critically assess the available literature on this topic. A PubMed search of the English-language literature, using the query 'Bruxism [Majr] AND (Dental Occlusion [Majr] OR Malocclusion [Majr])', yielded 93 articles, of which 46 papers were finally included in the present review*. Part of the included publications dealt with the possible associations between bruxism and aspects of occlusion, from which it was concluded that neither for occlusal interferences nor for factors related to the anatomy of the oro-facial skeleton, there is any evidence available that they are involved in the aetiology of bruxism. Instead, there is a growing awareness of other factors (viz. psychosocial and behavioural ones) being important in the aetiology of bruxism. Another part of the included papers assessed the possible mediating role of occlusion between bruxism and its purported consequences (e.g. tooth wear, loss of periodontal tissues, and temporomandibular pain and dysfunction). Even though most dentists agree that bruxism may have several adverse effects on the masticatory system, for none of these purported adverse effects, evidence for a mediating role of occlusion and articulation has been found to date. Hence, based on this review, it should be concluded that to date, there is no evidence whatsoever for a causal relationship between bruxism and the bite. © 2012 Blackwell Publishing Ltd.

  18. Causal Discovery from Nonstationary/Heterogeneous Data: Skeleton Estimation and Orientation Determination.

    Science.gov (United States)

    Zhang, Kun; Huang, Biwei; Zhang, Jiji; Glymour, Clark; Schölkopf, Bernhard

    2017-08-01

    It is commonplace to encounter nonstationary or heterogeneous data, of which the underlying generating process changes over time or across data sets (the data sets may have different experimental conditions or data collection conditions). Such a distribution shift feature presents both challenges and opportunities for causal discovery. In this paper we develop a principled framework for causal discovery from such data, called Constraint-based causal Discovery from Nonstationary/heterogeneous Data (CD-NOD), which addresses two important questions. First, we propose an enhanced constraint-based procedure to detect variables whose local mechanisms change and recover the skeleton of the causal structure over observed variables. Second, we present a way to determine causal orientations by making use of independence changes in the data distribution implied by the underlying causal model, benefiting from information carried by changing distributions. Experimental results on various synthetic and real-world data sets are presented to demonstrate the efficacy of our methods.

  19. Factors associated with asthma among under-fives in Mulago hospital, Kampala Uganda

    DEFF Research Database (Denmark)

    Nantanda, Rebecca; Ostergaard, Marianne S; Ndeezi, Grace

    2013-01-01

    Asthma is the most common chronic childhood illness, with rapidly increasing prevalence in low-income countries. Among young children, asthma is often under-diagnosed.We investigated the factors associated with asthma among under-fives presenting with acute respiratory symptoms at Mulago hospital...

  20. Adaptive under relaxation factor of MATRA code for the efficient whole core analysis

    International Nuclear Information System (INIS)

    Kwon, Hyuk; Kim, S. J.; Seo, K. W.; Hwang, D. H.

    2013-01-01

    Such nonlinearities are handled in MATRA code using outer iteration with Picard scheme. The Picard scheme involves successive updating of the coefficient matrix based on the previously calculated values. The scheme is a simple and effective method for the nonlinear problem but the effectiveness greatly depends on the under-relaxing capability. Accuracy and speed of calculation are very sensitively dependent on the under-relaxation factor in outer-iteration updating the axial mass flow using the continuity equation. The under-relaxation factor in MATRA is generally utilized with a fixed value that is empirically determined. Adapting the under-relaxation factor to the outer iteration is expected to improve the calculation effectiveness of MATRA code rather than calculation with the fixed under-relaxation factor. The present study describes the implementation of adaptive under-relaxation within the subchannel code MATRA. Picard iterations with adaptive under-relaxation can accelerate the convergence for mass conservation in subchannel code MATRA. The most efficient approach for adaptive under relaxation appears to be very problem dependent

  1. P3-10: Crossmodal Perceptual Grouping Modulates Subjective Causality between Action and Outcome

    Directory of Open Access Journals (Sweden)

    Takahiro Kawabe

    2012-10-01

    Full Text Available Agents have to determine which external events their action has causally produced. A sensation of causal relation between action and outcome is called subjective causality. Subjective causality has been linked to the comparator model. This model assumes that the brain compares an internal prediction for action outcome with an actual sensory outcome, distinguishing between self and externally produced outcomes depending on spatiotemporal congruency. However, recent studies have expressed some doubt about the idea that subjective causality arises depending solely on the spatiotemporal congruency, suggesting instead that other perceptual/cognitive factors play a critical role in determining subjective causality. We hypothesized that crossmodal grouping between action and outcome contributed to subjective causality. Crossmodal temporal grouping is an essential factor for crossmodal simultaneity judgments with ungrouped crossmodal signals likely to be judged as non-simultaneous. We predicted that subjective causality would decrease when an agent's action was not temporally grouped with action outcome. In the experiment, observers were asked to press a key in order to trigger a display change with some temporal delay. To disrupt temporal grouping between action and outcome, a task-irrelevant visual flash or tone was sometimes presented synchronously with the button press and/or the display change. Subjective causality was decreased when the flash or the tone was coincided with the button press. This demonstrates that perceptual grouping has a key role in determination of subjective causality, a result that is not accounted for by the standard comparator model.

  2. Are familial factors underlying the association between socioeconomic position and prescription medicine?

    DEFF Research Database (Denmark)

    Madsen, Mia; Andersen, Per Kragh; Gerster, Mette

    2013-01-01

    Although well established, the association between socioeconomic position and health and health behaviour is not clearly understood, and it has been speculated that familial factors, for example, dispositional factors or exposures in the rearing environment, may be underlying the association....... The objective was to compare prescription fillings within twin pairs who are partly or fully genetically identical and share childhood exposures....

  3. Two roads to noncommutative causality

    International Nuclear Information System (INIS)

    Besnard, Fabien

    2015-01-01

    We review the physical motivations and the mathematical results obtained so far in the isocone-based approach to noncommutative causality. We also give a briefer account of the alternative framework of Franco and Eckstein which is based on Lorentzian spectral triples. We compare the two theories on the simple example of the product geometry of the Minkowski plane by the finite noncommutative space with algebra M 2 (C). (paper)

  4. What determines health: a causal analysis using county level data.

    Science.gov (United States)

    Rettenmaier, Andrew J; Wang, Zijun

    2013-10-01

    This article revisits the long-standing issue of the determinants of health outcomes. We make two contributions to the literature. First, we use a large and comprehensive US county level health data set that has only recently become available. This data set includes five measures of health outcomes and 24 health risk factors in the categories of health behaviors, clinical care, social and economic factors, and physical environment. Second, to distinguish causality from correlation, we implement an emerging data-driven method to study the causal factors of health outcomes. Among all included potential health risk factors, we identify adult smoking, obesity, motor vehicle crash death rate, the percent of children in poverty, and violent crime rate to be major causal factors of premature mortality. Adult smoking, preventable hospital stays, college or higher education, employment, children in poverty, and adequacy of social support determine health-related quality of life. Finally, the Chlamydia rate, community safety, and liquor store density are three important factors causally related to low birth weight. Policy implications of these findings are discussed.

  5. Concept of statistical causality and local martingales

    Directory of Open Access Journals (Sweden)

    Valjarević Dragana

    2016-01-01

    Full Text Available In this paper we consider a statistical concept of causality in continuous time in filtered probability spaces which is based on Granger's definitions of causality. The given causality concept is closely connected to the preservation of the property being a local martingale if the filtration is getting larger. Namely, the local martingale remains unpredictable if the amount of information is increased. We proved that the preservation of this property is equivalent with the concept of causality.

  6. ["We must relate to ourselves". Substance, causality, and narrative text].

    Science.gov (United States)

    Schmucker, P

    2006-11-01

    Since Aristotle the concept of "substance" has described those features of an object which remain constant over time despite varying additional stochastic factors (coincidences). "Causality" places several or more chronological events into a direct relationship. The change of stochastic factors on a substance always has a causal justification. Based on these metaphysical considerations the present contemplations will apply the concept of substance to people. The causal explanation for changes during the lifetime is achieved by narrative sentences. These are, therefore, decisive for the maintenance of the identity of individuals and collectives despite all time-linked changes. The conclusion is reached that speech and thought processes based on speech patterns are essential for humans.

  7. Linear and nonlinear causality between renewable energy consumption and economic growth in the USA

    OpenAIRE

    Xu, Haiyun

    2016-01-01

    This study aims to investigate Granger causality between renewable energy consumption (REC) and economic growth (EG) for USA. To accomplish this objective and to add the stronger evidence to the controversial issue, the tests were done under a new framework that embeds wavelet analysis, a novel tool, in nonlinear causality test approaches developed recently. The classical linear causality test procedure was also involved for comparison. The empirical data sources from the US...

  8. Behavioural Pattern of Causality Parameter of Autoregressive ...

    African Journals Online (AJOL)

    In this paper, a causal form of Autoregressive Moving Average process, ARMA (p, q) of various orders and behaviour of the causality parameter of ARMA model is investigated. It is deduced that the behaviour of causality parameter ψi depends on positive and negative values of autoregressive parameter φ and moving ...

  9. Causal knowledge and reasoning in decision making

    NARCIS (Netherlands)

    Hagmayer, Y.; Witteman, C.L.M.

    2017-01-01

    Normative causal decision theories argue that people should use their causal knowledge in decision making. Based on these ideas, we argue that causal knowledge and reasoning may support and thereby potentially improve decision making based on expected outcomes, narratives, and even cues. We will

  10. The argumentative impact of causal relations

    DEFF Research Database (Denmark)

    Nielsen, Anne Ellerup

    1996-01-01

    such as causality, explanation and justification. In certain types of discourse, causal relations also imply an intentional element. This paper describes the way in which the semantic and pragmatic functions of causal markers can be accounted for in terms of linguistic and rhetorical theories of argumentation....

  11. Exploring Torus Universes in Causal Dynamical Triangulations

    DEFF Research Database (Denmark)

    Budd, Timothy George; Loll, R.

    2013-01-01

    Motivated by the search for new observables in nonperturbative quantum gravity, we consider Causal Dynamical Triangulations (CDT) in 2+1 dimensions with the spatial topology of a torus. This system is of particular interest, because one can study not only the global scale factor, but also global ....... Apart from setting the stage for the analysis of shape dynamics on the torus, the new set-up highlights the role of nontrivial boundaries and topology....... shape variables in the presence of arbitrary quantum fluctuations of the geometry. Our initial investigation focusses on the dynamics of the scale factor and uncovers a qualitatively new behaviour, which leads us to investigate a novel type of boundary conditions for the path integral. Comparing large...

  12. Development of effective connectivity during own- and other-race face processing: A Granger causality analysis

    Directory of Open Access Journals (Sweden)

    Guifei Zhou

    2016-09-01

    Full Text Available Numerous developmental studies have suggested that other-race effect (ORE in face recognition emerges as early as in infancy and develops steadily throughout childhood. However, there is very limited research on the neural mechanisms underlying this developmental ORE. The present study used Granger causality analysis (GCA to examine the development of children’s cortical networks in processing own- and other-race faces. Children were between 3 to 13 years. An old-new paradigm was used to assess their own- and other-race face recognition with ETG-4000 (Hitachi Medical Co., Japan acquiring functional near infrared spectroscopy (fNIRS data. After preprocessing, for each participant and under each face condition, we obtained the causal map by calculating the weights of causal relations between the time courses of oxy-Hb of each pair of channels using GCA. To investigate further the differential causal connectivity for own-race faces and other-race faces at the group level, a repeated measure analysis of variance (ANOVA was performed on the GCA weights for each pair of channels with the face race task (own-race face vs. other-race face as the within-subject variable and the age as a between-subject factor (continuous variable. We found an age-related increase in functional connectivity, paralleling a similar age-related improvement in behavioral face processing ability. More importantly, we found that the significant differences in neural functional connectivity between the recognition of own-race faces and that of other-race faces were moderated by age. Thus, like the behavioral ORE, the neural ORE emerges early and undergoes a protracted developmental course.

  13. Norms and customs: causally important or causally impotent?

    Science.gov (United States)

    Jones, Todd

    2010-01-01

    In this article, I argue that norms and customs, despite frequently being described as being causes of behavior in the social sciences and ordinary conversation, cannot really cause behavior. Terms like "norms" and the like seem to refer to philosophically disreputable disjunctive properties. More problematically, even if they do not, or even if there can be disjunctive properties after all, I argue that norms and customs still cannot cause behavior. The social sciences would be better off without referring to properties like norms and customs as if they could be causal.

  14. Diagnostic reasoning using qualitative causal models

    International Nuclear Information System (INIS)

    Sudduth, A.L.

    1992-01-01

    The application of expert systems to reasoning problems involving real-time data from plant measurements has been a topic of much research, but few practical systems have been deployed. One obstacle to wider use of expert systems in applications involving real-time data is the lack of adequate knowledge representation methodologies for dynamic processes. Knowledge bases composed mainly of rules have disadvantages when applied to dynamic processes and real-time data. This paper describes a methodology for the development of qualitative causal models that can be used as knowledge bases for reasoning about process dynamic behavior. These models provide a systematic method for knowledge base construction, considerably reducing the engineering effort required. They also offer much better opportunities for verification and validation of the knowledge base, thus increasing the possibility of the application of expert systems to reasoning about mission critical systems. Starting with the Signed Directed Graph (SDG) method that has been successfully applied to describe the behavior of diverse dynamic processes, the paper shows how certain non-physical behaviors that result from abstraction may be eliminated by applying causal constraint to the models. The resulting Extended Signed Directed Graph (ESDG) may then be compiled to produce a model for use in process fault diagnosis. This model based reasoning methodology is used in the MOBIAS system being developed by Duke Power Company under EPRI sponsorship. 15 refs., 4 figs

  15. A theory of causal learning in children: causal maps and Bayes nets.

    Science.gov (United States)

    Gopnik, Alison; Glymour, Clark; Sobel, David M; Schulz, Laura E; Kushnir, Tamar; Danks, David

    2004-01-01

    The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously understood in terms of the formalism of directed graphical causal models, or Bayes nets. Children's causal learning and inference may involve computations similar to those for learning causal Bayes nets and for predicting with them. Experimental results suggest that 2- to 4-year-old children construct new causal maps and that their learning is consistent with the Bayes net formalism.

  16. A hierarchical causal taxonomy of psychopathology across the life span.

    Science.gov (United States)

    Lahey, Benjamin B; Krueger, Robert F; Rathouz, Paul J; Waldman, Irwin D; Zald, David H

    2017-02-01

    We propose a taxonomy of psychopathology based on patterns of shared causal influences identified in a review of multivariate behavior genetic studies that distinguish genetic and environmental influences that are either common to multiple dimensions of psychopathology or unique to each dimension. At the phenotypic level, first-order dimensions are defined by correlations among symptoms; correlations among first-order dimensions similarly define higher-order domains (e.g., internalizing or externalizing psychopathology). We hypothesize that the robust phenotypic correlations among first-order dimensions reflect a hierarchy of increasingly specific etiologic influences . Some nonspecific etiologic factors increase risk for all first-order dimensions of psychopathology to varying degrees through a general factor of psychopathology. Other nonspecific etiologic factors increase risk only for all first-order dimensions within a more specific higher-order domain. Furthermore, each first-order dimension has its own unique causal influences. Genetic and environmental influences common to family members tend to be nonspecific, whereas environmental influences unique to each individual are more dimension-specific. We posit that these causal influences on psychopathology are moderated by sex and developmental processes. This causal taxonomy also provides a novel framework for understanding the heterogeneity of each first-order dimension: Different persons exhibiting similar symptoms may be influenced by different combinations of etiologic influences from each of the 3 levels of the etiologic hierarchy. Furthermore, we relate the proposed causal taxonomy to transdimensional psychobiological processes, which also impact the heterogeneity of each psychopathology dimension. This causal taxonomy implies the need for changes in strategies for studying the etiology, psychobiology, prevention, and treatment of psychopathology. (PsycINFO Database Record (c) 2017 APA, all rights

  17. A Hierarchical Causal Taxonomy of Psychopathology across the Life Span

    Science.gov (United States)

    Lahey, Benjamin B.; Krueger, Robert F.; Rathouz, Paul J.; Waldman, Irwin D.; Zald, David H.

    2016-01-01

    We propose a taxonomy of psychopathology based on patterns of shared causal influences identified in a review of multivariate behavior genetic studies that distinguish genetic and environmental influences that are either common to multiple dimensions of psychopathology or unique to each dimension. At the phenotypic level, first-order dimensions are defined by correlations among symptoms; correlations among first-order dimensions similarly define higher-order domains (e.g., internalizing or externalizing psychopathology). We hypothesize that the robust phenotypic correlations among first-order dimensions reflect a hierarchy of increasingly specific etiologic influences. Some nonspecific etiologic factors increase risk for all first-order dimensions of psychopathology to varying degrees through a general factor of psychopathology. Other nonspecific etiologic factors increase risk only for all first-order dimensions within a more specific higher-order domain. Furthermore, each first-order dimension has its own unique causal influences. Genetic and environmental influences common to family members tend to be nonspecific, whereas environmental influences unique to each individual are more dimension-specific. We posit that these causal influences on psychopathology are moderated by sex and developmental processes. This causal taxonomy also provides a novel framework for understanding the heterogeneity of each first-order dimension: Different persons exhibiting similar symptoms may be influenced by different combinations of etiologic influences from each of the three levels of the etiologic hierarchy. Furthermore, we relate the proposed causal taxonomy to transdimensional psychobiological processes, which also impact the heterogeneity of each psychopathology dimension. This causal taxonomy implies the need for changes in strategies for studying the etiology, psychobiology, prevention, and treatment of psychopathology. PMID:28004947

  18. A theory of causal learning in children: Causal maps and Bayes nets

    OpenAIRE

    Gopnik, A; Glymour, C; Sobel, D M; Schulz, L E; Kushnir, T; Danks, D

    2004-01-01

    The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously understood in terms of the formalism of directed graphical causal models, or Bayes nets. Children's causal learning and inference may involve computatio...

  19. Acute appendicitis following blunt abdominal trauma. Coincidence or causality?

    Directory of Open Access Journals (Sweden)

    Sergio Iván Latorre

    2017-01-01

    Full Text Available Acute appendicitis is a common disease in clinical practice; some well-defined causes include luminal obstruction by fecoliths, lymphoid hyperplasia, foreign bodies and intestinal parasites. Closed abdominal trauma has been associated as an etiological factor, although, their causal relationship is still unclear. This paper presents the case of a patient with appendicitis after a closed abdominal trauma.

  20. Identifying Causality from Alarm Observations

    DEFF Research Database (Denmark)

    Kirchhübel, Denis; Zhang, Xinxin; Lind, Morten

    on an abstracted model of the mass and energy flows in the system. The application of MFM for root cause analysis based alarm grouping has been demonstrated and can be extended to reason about the direction of causality considering the entirety of the alarms present in the system for more comprehensive decision...... support. This contribution presents the foundation for combining the cause and consequence propagation of multiple observations from the system based on an MFM model. The proposed logical reasoning matches actually observed alarms to the propagation analysis in MFM to distinguish plausible causes...

  1. Random number generators and causality

    International Nuclear Information System (INIS)

    Larrondo, H.A.; Martin, M.T.; Gonzalez, C.M.; Plastino, A.; Rosso, O.A.

    2006-01-01

    We advance a prescription to randomize physical or algorithmic Random Number Generators (RNG's) that do not pass Marsaglia's DIEHARD test suite and discuss a special physical quantifier, based on an intensive statistical complexity measure, that is able to adequately assess the improvements produced thereby. Eight RNG's are evaluated and the associated results are compared to those obtained by recourse to Marsaglia's DIEHARD test suite. Our quantifier, which is evaluated using causality arguments, can forecast whether a given RNG will pass the above mentioned test

  2. The connexion of duality and causal properties for generalized free fields

    International Nuclear Information System (INIS)

    Garber, W.D.

    1975-01-01

    It is shown that the time-slice axiom and the diamond property are equivalent for the generalized free field. If, in addition, there is a mass gap, duality is equivalent to either causality requirement. It is further shown that the local rings associated with certain space-time regions are factors in the case of causal generalized free fields with mass gap. Necessary and sufficient conditions for causality and duality and some examples for causal and acausal generalized free fields are also given. (orig.) [de

  3. A Causal Model for Fluctuating Sugar Levels in Diabetes Patients

    Directory of Open Access Journals (Sweden)

    Kinzang Chhogyal

    2012-09-01

    Full Text Available Background Causal models of physiological systems can be immensely useful in medicine as they may be used for both diagnostic and therapeutic reasoning. Aims In this paper we investigate how an agent may use the theory of belief change to rectify simple causal models of changing blood sugar levels in diabetes patients. Method We employ the semantic approach to belief change together with a popular measure of distance called Dalal distance between different state descriptions in order to implement a simple application that simulates the effectiveness of the proposed method in helping an agent rectify a simple causal model. Results Our simulation results show that distance-based belief change can help in improving the agent’s causal knowledge. However, under the current implementation there is no guarantee that the agent will learn the complete model and the agent may at times get stuck in local optima. Conclusion Distance-based belief change can help in refining simple causal models such as the example in this paper. Future work will include larger state-action spaces, better distance measures and strategies for choosing actions.

  4. A causal model for fluctuating sugar levels in diabetes patients.

    Science.gov (United States)

    Chhogyal, Kinzang; Nayak, Abhaya; Schwitter, Rolf; Sattar, Abdul

    2012-01-01

    Causal models of physiological systems can be immensely useful in medicine as they may be used for both diagnostic and therapeutic reasoning. In this paper we investigate how an agent may use the theory of belief change to rectify simple causal models of changing blood sugar levels in diabetes patients. We employ the semantic approach to belief change together with a popular measure of distance called Dalal distance between different state descriptions in order to implement a simple application that simulates the effectiveness of the proposed method in helping an agent rectify a simple causal model. Our simulation results show that distance-based belief change can help in improving the agent's causal knowledge. However, under the current implementation there is no guarantee that the agent will learn the complete model and the agent may at times get stuck in local optima. Distance-based belief change can help in refining simple causal models such as the example in this paper. Future work will include larger state-action spaces, better distance measures and strategies for choosing actions.

  5. Information flow and causality as rigorous notions ab initio

    Science.gov (United States)

    Liang, X. San

    2016-11-01

    Information flow or information transfer the widely applicable general physics notion can be rigorously derived from first principles, rather than axiomatically proposed as an ansatz. Its logical association with causality is firmly rooted in the dynamical system that lies beneath. The principle of nil causality that reads, an event is not causal to another if the evolution of the latter is independent of the former, which transfer entropy analysis and Granger causality test fail to verify in many situations, turns out to be a proven theorem here. Established in this study are the information flows among the components of time-discrete mappings and time-continuous dynamical systems, both deterministic and stochastic. They have been obtained explicitly in closed form, and put to applications with the benchmark systems such as the Kaplan-Yorke map, Rössler system, baker transformation, Hénon map, and stochastic potential flow. Besides unraveling the causal relations as expected from the respective systems, some of the applications show that the information flow structure underlying a complex trajectory pattern could be tractable. For linear systems, the resulting remarkably concise formula asserts analytically that causation implies correlation, while correlation does not imply causation, providing a mathematical basis for the long-standing philosophical debate over causation versus correlation.

  6. CADDIS Volume 1. Stressor Identification: About Causal Assessment

    Science.gov (United States)

    An introduction to the history of our approach to causal assessment, A chronology of causal history and philosophy, An introduction to causal history and philosophy, References for the Causal Assessment Background section of Stressor Identification

  7. Energy consumption, carbon emissions and economic growth nexus in Bangladesh: Cointegration and dynamic causality analysis

    International Nuclear Information System (INIS)

    Jahangir Alam, Mohammad; Ara Begum, Ismat; Buysse, Jeroen; Van Huylenbroeck, Guido

    2012-01-01

    The paper investigates the possible existence of dynamic causality between energy consumption, electricity consumption, carbon emissions and economic growth in Bangladesh. First, we have tested cointegration relationships using the Johansen bi-variate cointegration model. This is complemented with an analysis of an auto-regressive distributed lag model to examine the results' robustness. Then, the Granger short-run, the long-run and strong causality are tested with a vector error correction modelling framework. The results indicate that uni-directional causality exists from energy consumption to economic growth both in the short and the long-run while a bi-directional long-run causality exists between electricity consumption and economic growth but no causal relationship exists in short-run. The strong causality results indicate bi-directional causality for both the cases. A uni-directional causality runs from energy consumption to CO 2 emission for the short-run but feedback causality exists in the long-run. CO 2 Granger causes economic growth both in the short and in the long-run. An important policy implication is that energy (electricity as well) can be considered as an important factor for the economic growth in Bangladesh. Moreover, as higher energy consumption also means higher pollution in the long-run, policy makers should stimulate alternative energy sources for meeting up the increasing energy demand. - Highlights: ► Dynamic causality among energy and electricity consumption, CO 2 and economic growth. ► Uni-directional causality exists from energy consumption to economic growth. ► Bi-directional causality exists between electricity consumption and economic growth. ► Feedback causality exists between CO 2 emission to energy consumption. ► CO 2 Granger causes economic growth both in the short and in the long-run.

  8. Weighing the causal pies in case-control studies.

    Science.gov (United States)

    Liao, Shu-Fen; Lee, Wen-Chung

    2010-07-01

    Epidemiologists are familiar with the concepts of Rothman's causal pies. Using real data the Hoffman study showed recently how to calculate the "proportion of diseased subjects who develop the disease due to classes of sufficient causes" (PDCs). The PDC is actually an attributable-fraction index. It may be specific to a particular risk factor profile but it does not correspond to any given class of causal pies. In this study, we show how to estimate the "causal-pie weights" (CPWs), so that each and every class of causal pies has one and only one CPW attached to it. To conform to Rothman's model, we apply a non-negative linear odds model to constrain all the odds ratios (ORs) to be equal to or greater than one, and the interactions between them to be additive or superadditive. Based on these constrained ORs, we calculate the population attributable fractions, and then the CPWs. We used a published case-control data to show the methodology. The CPWs succinctly quantify the relative importance of different classes of causal pies. The proposed method helps to clarify the multi-factorial and complex interactive effects in disease causation. It also provides important information for designing an efficient public health intervention strategy. 2010 Elsevier Inc. All rights reserved.

  9. The causality between energy consumption and economic growth in Turkey

    International Nuclear Information System (INIS)

    Erdal, Guelistan; Erdal, Hilmi; Esenguen, Kemal

    2008-01-01

    This paper applies the causality test to examine the causal relationship between primary energy consumption (EC) and real Gross National Product (GNP) for Turkey during 1970-2006. We employ unit root tests, the augmented Dickey-Fuller (ADF) and the Philips-Perron (PP), Johansen cointegration test, and Pair-wise Granger causality test to examine relation between EC and GNP. Our empirical results indicate that the two series are found to be non-stationary. However, first differences of these series lead to stationarity. Further, the results indicate that EC and GNP are cointegrated and there is bidirectional causality running from EC to GNP and vice versa. This means that an increase in EC directly affects economic growth and that economic growth also stimulates further EC. This bidirectional causality relationship between EC and GNP determined for Turkey at 1970-2006 period is in accordance with the ones in literature reported for similar countries. Consequently, we conclude that energy is a limiting factor to economic growth in Turkey and, hence, shocks to energy supply will have a negative impact on economic growth

  10. Causal attributions in Brazilian children's reasoning about health and illness

    Directory of Open Access Journals (Sweden)

    Boruchovitch Evely

    2000-01-01

    Full Text Available INTRODUCTION: At a time when a great number of diseases can be prevented by changing one's habits and life style, investigations have focused on understanding what adults and children believe to be desirable health practices and uncovering the factors associated with successful adherence to such practices. For these, causal attributions for health and illness were investigated among 96 Brazilian elementary school students. METHODS: Ninety six subjects, aged 6 to 14, were interviewed individually and their causal attributions were assessed through 14 true-false items (e.g. people stay well [healthy] because they are lucky. The relationship between the children's causal attributions and demographic characteristics were also examined. RESULTS: Overall, the results were consistent with previous researches. "Taking care of oneself" was considered the most important cause of good health. "Viruses and germs" and "lack of self-care" were the most selected causes of illness. Analyses revealed significant relationship between subjects' causal attribution and their age, school grade level, socioeconomic status and gender. CONCLUSIONS: The study findings suggest that there may be more cross-cultural similarities than differences in children's causal attributions for health and illness. Finding ways to help individuals engage in appropriate preventive-maintenance health practices without developing an exaggerated notion that the individuals can control their own health and illness is a challenge which remains to be addressed by further research.

  11. Case Studies Nested in Fuzzy-Set QCA on Sufficiency: Formalizing Case Selection and Causal Inference

    Science.gov (United States)

    Schneider, Carsten Q.; Rohlfing, Ingo

    2016-01-01

    Qualitative Comparative Analysis (QCA) is a method for cross-case analyses that works best when complemented with follow-up case studies focusing on the causal quality of the solution and its constitutive terms, the underlying causal mechanisms, and potentially omitted conditions. The anchorage of QCA in set theory demands criteria for follow-up…

  12. The structural variation of phytoplankton in the Gulf of Riga under the influence of environmental factors

    OpenAIRE

    Jurgensone, Iveta

    2011-01-01

    „The structural variation of phytoplankton in the Gulf of Riga under the influence of environmental factors.” Trends of phytoplankton (1976-2008) from the Gulf of Riga and the related environmental factors are investigated. Phytoplankton response to riverine DOM and nutrient increase was tested and the effect on the pelagic food web assessed. Changes in the winter-spring DIN/DIP ratio cause shift from diatoms to cyanobacteria. Dinoflagellate biomass remains constant after temperature excee...

  13. On the causal set–continuum correspondence

    International Nuclear Information System (INIS)

    Saravani, Mehdi; Aslanbeigi, Siavash

    2014-01-01

    We present two results that concern certain aspects of the question: when is a causal set well approximated by a Lorentzian manifold? The first result is a theorem that shows that the number–volume correspondence, if required to hold even for arbitrarily small regions, is best realized via Poisson sprinkling. The second result concerns a family of lattices in 1+1 dimensional Minkowski space, known as Lorentzian lattices, which we show provide a much better number–volume correspondence than Poisson sprinkling for large volumes. We argue, however, that this feature should not persist in higher dimensions. We conclude by conjecturing a form of the aforementioned theorem that holds under weaker assumptions, namely that Poisson sprinkling provides the best number–volume correspondence in 3+1 dimensions for spacetime regions with macroscopically large volumes. (paper)

  14. Temporal Causality Analysis of Sentiment Change in a Cancer Survivor Network.

    Science.gov (United States)

    Bui, Ngot; Yen, John; Honavar, Vasant

    2016-06-01

    Online health communities constitute a useful source of information and social support for patients. American Cancer Society's Cancer Survivor Network (CSN), a 173,000-member community, is the largest online network for cancer patients, survivors, and caregivers. A discussion thread in CSN is often initiated by a cancer survivor seeking support from other members of CSN. Discussion threads are multi-party conversations that often provide a source of social support e.g., by bringing about a change of sentiment from negative to positive on the part of the thread originator. While previous studies regarding cancer survivors have shown that members of an online health community derive benefits from their participation in such communities, causal accounts of the factors that contribute to the observed benefits have been lacking. We introduce a novel framework to examine the temporal causality of sentiment dynamics in the CSN. We construct a Probabilistic Computation Tree Logic representation and a corresponding probabilistic Kripke structure to represent and reason about the changes in sentiments of posts in a thread over time. We use a sentiment classifier trained using machine learning on a set of posts manually tagged with sentiment labels to classify posts as expressing either positive or negative sentiment. We analyze the probabilistic Kripke structure to identify the prima facie causes of sentiment change on the part of the thread originators in the CSN forum and their significance. We find that the sentiment of replies appears to causally influence the sentiment of the thread originator. Our experiments also show that the conclusions are robust with respect to the choice of the (i) classification threshold of the sentiment classifier; (ii) and the choice of the specific sentiment classifier used. We also extend the basic framework for temporal causality analysis to incorporate the uncertainty in the states of the probabilistic Kripke structure resulting from the

  15. Space and time in perceptual causality

    Directory of Open Access Journals (Sweden)

    Benjamin Straube

    2010-04-01

    Full Text Available Inferring causality is a fundamental feature of human cognition that allows us to theorize about and predict future states of the world. Michotte suggested that humans automatically perceive causality based on certain perceptual features of events. However, individual differences in judgments of perceptual causality cast doubt on Michotte’s view. To gain insights in the neural basis of individual difference in the perception of causality, our participants judged causal relationships in animations of a blue ball colliding with a red ball (a launching event while fMRI-data were acquired. Spatial continuity and temporal contiguity were varied parametrically in these stimuli. We did not find consistent brain activation differences between trials judged as caused and those judged as non-caused, making it unlikely that humans have universal instantiation of perceptual causality in the brain. However, participants were slower to respond to and showed greater neural activity for violations of causality, suggesting that humans are biased to expect causal relationships when moving objects appear to interact. Our participants demonstrated considerable individual differences in their sensitivity to spatial and temporal characteristics in perceiving causality. These qualitative differences in sensitivity to time or space in perceiving causality were instantiated in individual differences in activation of the left basal ganglia or right parietal lobe, respectively. Thus, the perception that the movement of one object causes the movement of another is triggered by elemental spatial and temporal sensitivities, which themselves are instantiated in specific distinct neural networks.

  16. Causal attribution among women with breast cancer

    Directory of Open Access Journals (Sweden)

    Ana Carolina W. B. Peuker

    2016-01-01

    Full Text Available Abstract Causal attribution among women with breast cancer was studied. The study included 157 women outpatients with breast cancer. A form for sociodemographic and clinical data and the Revised Illness Perception Questionnaire (IPQ-R were used. The results showed that women attributed breast cancer primarily to psychological causes, which does not correspond to known multifactorial causes validated by the scientific community. Providing high quality, patient-centered care requires sensitivity to breast cancer women’s beliefs about the causes of their cancer and awareness of how it can influence patient’s health behaviors after diagnosis. If women with breast cancer attribute the illness to modifiable factors then they can keep a healthy lifestyle, improving their recovery and decrease the probability of cancer recurrence after diagnosis.

  17. Risk Factors for Malnutrition Among Under-Five-Year olds in an ...

    African Journals Online (AJOL)

    Objectives: To identify risk factors associated with the development of malnutrition in the under-five-year olds in a homogeneous inner city community. Design: A community-based, case-control study. Materials and Methods: One hundred and thirty eight children (subjects and controls) aged less than five years living in the ...

  18. Overland flow under rainfall : some aspects related to modelling and conditioning factors

    NARCIS (Netherlands)

    Lima, de J.L.M.P.

    1989-01-01

    This study concerns the theory and some practical aspects of overland flow under rainfall. Of the conditioning factors and processes which govern the generation of overland flow, the following were studied: depression storage, infiltration, morphology and wind. Special attention was paid to

  19. Water risk factors pre-disposing the under five children to diarrhoeal ...

    African Journals Online (AJOL)

    Conclusions: The significant water risk factors as identified were the mode of water transportation, and the poor handling of water at the household level, including lack of or inappropriate water treatment methods. These, combined with the low education level further pre dispose the under five children to diarrhoea, thus ...

  20. Review of International Research on Factors Underlying Teacher Absenteeism. REL 2015-087

    Science.gov (United States)

    Lee, Mary; Goodman, Crystal; Dandapani, Nitara; Kekahio, Wendy

    2015-01-01

    Throughout the U.S.-affiliated Pacific Region, teacher absenteeism has posed a long-standing challenge. This report draws on research literature from international contexts and case studies to identify the underlying factors that may relate to teacher absenteeism. Resources included in this report were selected with a focus on non-U.S. Pacific…

  1. Correction factor to dye-measured flow velocity under varying water and sediment discharges

    Science.gov (United States)

    Dye-tracing technique was a widely used method to measure velocity of overland flow in soil erosion studies under both laboratory and field conditions. Few studies were performed to quantify the effects of sediment load on correction factor on steep slopes. The objective was to investigate the poten...

  2. The implication of using a fixed form factor in areas under different ...

    African Journals Online (AJOL)

    The implication of using a fixed form factor in areas under different rainfall and soil conditions for Pinus kesiya in Zambia. ... Trees were sampled from the three plantation groups and 10 sample plots were established in which 10 trees were randomly sampled for cutting. Height and diameter at breast height (dbh) were the ...

  3. A Cyclodissipativity Condition for Power Factor Improvement under Nonsinusoidal Source with Significant Impedance

    NARCIS (Netherlands)

    Puerto-Flores, Dunstano del; Ortega, Romeo; Scherpen, Jacquelien M.A.

    2010-01-01

    The main contribution of this paper is an extension of a recent result that reformulates and solves the power factor compensation for nonlinear loads under nonsinusoidal regime in terms of cyclodissipativity. In the aforementioned result the generator was assumed to be ideal, that is, with

  4. Brain-derived neurotrophic factor in VMH as the causal factor for and therapeutic tool to treat visceral adiposity and hyperleptinemia in type 2 diabetic Goto-Kakizaki rats

    Directory of Open Access Journals (Sweden)

    Fumihiko eMaekawa

    2013-10-01

    Full Text Available We previously reported that the type 2 diabetic Goto-Kakizaki (GK rats at young adult ages (6-12 weeks exhibited increased visceral fat mass and hyperleptinemia, due to hyperphagia caused primarily by neuropeptide Y (NPY overexpression in the hypothalamic arcuate nucleus. Later, we found that GK rats continued to exhibit mesenteric fat accumulation and hyperleptinemia at least until 26 weeks of age, while hyperphagia and NPY overexpression ceased at 15 weeks of age. Therefore, we hypothesized that the long-lasting fat accumulation and hyperleptinemia are due to unidentified brain dysfunction other than NPY overexpression. In GK rats aged 26 weeks, glucose transporter-2 (GLUT2 mRNA expression in ventromedial hypothalamus (VMH was markedly reduced in parallel with significant decreases in brain-derived neurotrophic factor (BDNF mRNA level and BDNF-expressing cell numbers in the VMH. Pharmacologic inhibition of glucose utilization reduced BDNF mRNA expression in VMH in vivo and in vitro. The results suggested that impaired glucose utilization caused the reduction of BDNF. On the other hand, intracerebroventricular injection of BDNF for 6 days ameliorated hyperleptinemia in a long-lasting manner concurrently with feeding suppression in GK rats. Restricted feeding paired to BDNF-treated rats reduced plasma leptin level only transiently. BDNF treatment also reduced mesenteric fat mass in GK rats. These results reveal a novel action mode of BDNF to long-lastingly counteract visceral adiposity and hyperleptinemia in addition to and independently of its anorexigenic action. These results suggest that visceral fat accumulation and hyperleptinemia are at least partly due to the reduction of BDNF in VMH primarily caused by impaired glucose utilization in GK rats. The BDNF supplementation could provide an effective treatment of visceral obesity, hyperleptinemia and leptin resistance in type 2 diabetes.

  5. Study of mortality risk factors for children under age 5 in Abu Dhabi.

    Science.gov (United States)

    Al-Hosani, H A; Brebner, J; Bener, A B; Norman, J N

    2003-05-01

    We investigated the association of biological, sociocultural and economic risk factors with child mortality in Abu Dhabi from 1 January-31 December 1997. With McNemar chi-squared test, most selected biological risk factors were statistically associated with child mortality, although maternal age older than 40 years and history of fetal death were not positively correlated with neonate, infant or age under 5 mortality. Among sociocultural and economic risk factors, maternal lack of formal education and low monthly income were significantly associated with child death. Consanguinity was significantly associated with under 5 and infant but not neonatal mortality. Gestation <37 weeks was highly associated with mortality among all ages. Strengthening health care programmes and emphasizing the need to identify high risk groups should be priorities.

  6. Linear causal modeling with structural equations

    CERN Document Server

    Mulaik, Stanley A

    2009-01-01

    Emphasizing causation as a functional relationship between variables that describe objects, Linear Causal Modeling with Structural Equations integrates a general philosophical theory of causation with structural equation modeling (SEM) that concerns the special case of linear causal relations. In addition to describing how the functional relation concept may be generalized to treat probabilistic causation, the book reviews historical treatments of causation and explores recent developments in experimental psychology on studies of the perception of causation. It looks at how to perceive causal

  7. Temporal Causality and the Dynamics of Crime in Turkey

    OpenAIRE

    Halicioglu, Ferda

    2012-01-01

    This study is concerned with understanding of the factors of aggregate, nonviolent and violent crime categories in Turkey for the period 1965-2009. The determinants of all crime categories are related to selected socio-economic factors. Bounds testing approach to cointegration is employed to test the existence of long-run relationship amongst the variables. Cointegration analysis yields the major contributors of crime are income and unemployment. The direction of causalities between the vari...

  8. Electromagnetic pulses, localized and causal

    Science.gov (United States)

    Lekner, John

    2018-01-01

    We show that pulse solutions of the wave equation can be expressed as time Fourier superpositions of scalar monochromatic beam wave functions (solutions of the Helmholtz equation). This formulation is shown to be equivalent to Bateman's integral expression for solutions of the wave equation, for axially symmetric solutions. A closed-form one-parameter solution of the wave equation, containing no backward-propagating parts, is constructed from a beam which is the tight-focus limit of two families of beams. Application is made to transverse electric and transverse magnetic pulses, with evaluation of the energy, momentum and angular momentum for a pulse based on the general localized and causal form. Such pulses can be represented as superpositions of photons. Explicit total energy and total momentum values are given for the one-parameter closed-form pulse.

  9. Test-retest reliability of the underlying latent factor structure of alcohol subjective response.

    Science.gov (United States)

    Lutz, Joseph A; Childs, Emma

    2017-04-01

    Alcohol subjective experiences are multi-dimensional and demonstrate wide inter-individual variability. Recent efforts have sought to establish a clearer understanding of subjective alcohol responses by identifying core constructs derived from multiple measurement instruments. The aim of this study was to evaluate the temporal stability of this approach to conceptualizing alcohol subjective experiences across successive alcohol administrations in the same individuals. Healthy moderate alcohol drinkers (n = 104) completed six experimental sessions each, three with alcohol (0.8 g/kg), and three with a non-alcoholic control beverage. Participants reported subjective mood and drug effects using standardized questionnaires before and at repeated times after beverage consumption. We explored the underlying latent structure of subjective responses for all alcohol administrations using exploratory factor analysis and then tested measurement invariance over the three successive administrations using multi-group confirmatory factor analyses. Exploratory factor analyses on responses to alcohol across all administrations yielded four factors representing "Positive mood," "Sedation," "Stimulation/Euphoria," and "Drug effects and Urges." A confirmatory factor analysis on the separate administrations indicated acceptable configural and metric invariance and moderate scalar invariance. In this study, we demonstrate temporal stability of the underlying constructs of subjective alcohol responses derived from factor analysis. These findings strengthen the utility of this approach to conceptualizing subjective alcohol responses especially for use in prospective and longitudinal alcohol challenge studies relating subjective response to alcohol use disorder risk.

  10. Space-time as a causal set

    International Nuclear Information System (INIS)

    Bombelli, L.; Lee, J.; Meyer, D.; Sorkin, R.D.

    1987-01-01

    We propose that space-time at the smallest scales is in reality a causal set: a locally finite set of elements endowed with a partial order corresponding to the macroscopic relation that defines past and future. We explore how a Lorentzian manifold can approximate a causal set, noting in particular that the thereby defined effective dimensionality of a given causal set can vary with length scale. Finally, we speculate briefly on the quantum dynamics of causal sets, indicating why an appropriate choice of action can reproduce general relativity in the classical limit

  11. Targeted Maximum Likelihood Estimation for Causal Inference in Observational Studies.

    Science.gov (United States)

    Schuler, Megan S; Rose, Sherri

    2017-01-01

    Estimation of causal effects using observational data continues to grow in popularity in the epidemiologic literature. While many applications of causal effect estimation use propensity score methods or G-computation, targeted maximum likelihood estimation (TMLE) is a well-established alternative method with desirable statistical properties. TMLE is a doubly robust maximum-likelihood-based approach that includes a secondary "targeting" step that optimizes the bias-variance tradeoff for the target parameter. Under standard causal assumptions, estimates can be interpreted as causal effects. Because TMLE has not been as widely implemented in epidemiologic research, we aim to provide an accessible presentation of TMLE for applied researchers. We give step-by-step instructions for using TMLE to estimate the average treatment effect in the context of an observational study. We discuss conceptual similarities and differences between TMLE and 2 common estimation approaches (G-computation and inverse probability weighting) and present findings on their relative performance using simulated data. Our simulation study compares methods under parametric regression misspecification; our results highlight TMLE's property of double robustness. Additionally, we discuss best practices for TMLE implementation, particularly the use of ensembled machine learning algorithms. Our simulation study demonstrates all methods using super learning, highlighting that incorporation of machine learning may outperform parametric regression in observational data settings. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Inferring connectivity in networked dynamical systems: Challenges using Granger causality

    Science.gov (United States)

    Lusch, Bethany; Maia, Pedro D.; Kutz, J. Nathan

    2016-09-01

    Determining the interactions and causal relationships between nodes in an unknown networked dynamical system from measurement data alone is a challenging, contemporary task across the physical, biological, and engineering sciences. Statistical methods, such as the increasingly popular Granger causality, are being broadly applied for data-driven discovery of connectivity in fields from economics to neuroscience. A common version of the algorithm is called pairwise-conditional Granger causality, which we systematically test on data generated from a nonlinear model with known causal network structure. Specifically, we simulate networked systems of Kuramoto oscillators and use the Multivariate Granger Causality Toolbox to discover the underlying coupling structure of the system. We compare the inferred results to the original connectivity for a wide range of parameters such as initial conditions, connection strengths, community structures, and natural frequencies. Our results show a significant systematic disparity between the original and inferred network, unless the true structure is extremely sparse or dense. Specifically, the inferred networks have significant discrepancies in the number of edges and the eigenvalues of the connectivity matrix, demonstrating that they typically generate dynamics which are inconsistent with the ground truth. We provide a detailed account of the dynamics for the Erdős-Rényi network model due to its importance in random graph theory and network science. We conclude that Granger causal methods for inferring network structure are highly suspect and should always be checked against a ground truth model. The results also advocate the need to perform such comparisons with any network inference method since the inferred connectivity results appear to have very little to do with the ground truth system.

  13. Dynamics and causalities of atmospheric and oceanic data identified by complex networks and Granger causality analysis

    Science.gov (United States)

    Charakopoulos, A. K.; Katsouli, G. A.; Karakasidis, T. E.

    2018-04-01

    Understanding the underlying processes and extracting detailed characteristics of spatiotemporal dynamics of ocean and atmosphere as well as their interaction is of significant interest and has not been well thoroughly established. The purpose of this study was to examine the performance of two main additional methodologies for the identification of spatiotemporal underlying dynamic characteristics and patterns among atmospheric and oceanic variables from Seawatch buoys from Aegean and Ionian Sea, provided by the Hellenic Center for Marine Research (HCMR). The first approach involves the estimation of cross correlation analysis in an attempt to investigate time-lagged relationships, and further in order to identify the direction of interactions between the variables we performed the Granger causality method. According to the second approach the time series are converted into complex networks and then the main topological network properties such as degree distribution, average path length, diameter, modularity and clustering coefficient are evaluated. Our results show that the proposed analysis of complex network analysis of time series can lead to the extraction of hidden spatiotemporal characteristics. Also our findings indicate high level of positive and negative correlations and causalities among variables, both from the same buoy and also between buoys from different stations, which cannot be determined from the use of simple statistical measures.

  14. Identification of the underlying factor structure of the Derriford Appearance Scale 24

    Directory of Open Access Journals (Sweden)

    Timothy P. Moss

    2015-07-01

    Full Text Available Background. The Derriford Appearance Scale24 (DAS24 is a widely used measure of distress and dysfunction in relation to self-consciousness of appearance. It has been used in clinical and research settings, and translated into numerous European and Asian languages. Hitherto, no study has conducted an analysis to determine the underlying factor structure of the scale.Methods. A large (n = 1,265 sample of community and hospital patients with a visible difference were recruited face to face or by post, and completed the DAS24.Results. A two factor solution was generated. An evaluation of the congruence of the factor solutions on each of the the hospital and the community samples using Tucker’s Coefficient of Congruence (rc = .979 and confirmatory factor analysis, which demonstrated a consistent factor structure. A main factor, general self consciousness (GSC, was represented by 18 items. Six items comprised a second factor, sexual and body self-consciousness (SBSC. The SBSC scale demonstrated greater sensitivity and specificity in identifying distress for sexually significant areas of the body.Discussion. The factor structure of the DAS24 facilitates a more nuanced interpretation of scores using this scale. Two conceptually and statistically coherent sub-scales were identified. The SBSC sub-scale offers a means of identifying distress and dysfunction around sexually significant areas of the body not previously possible with this scale.

  15. Degradation of the mitochondrial complex I assembly factor TMEM126B under chronic hypoxia.

    Science.gov (United States)

    Fuhrmann, Dominik C; Wittig, Ilka; Dröse, Stefan; Schmid, Tobias; Dehne, Nathalie; Brüne, Bernhard

    2018-02-20

    Cell stress such as hypoxia elicits adaptive responses, also on the level of mitochondria, and in part is mediated by the hypoxia-inducible factor (HIF) 1α. Adaptation of mitochondria towards acute hypoxic conditions is reasonably well understood, while regulatory mechanisms, especially of respiratory chain assembly factors, under chronic hypoxia remains elusive. One of these assembly factors is transmembrane protein 126B (TMEM126B). This protein is part of the mitochondrial complex I assembly machinery. We identified changes in complex I abundance under chronic hypoxia, in association with impaired substrate-specific mitochondrial respiration. Complexome profiling of isolated mitochondria of the human leukemia monocytic cell line THP-1 revealed HIF-1α-dependent deficits in complex I assembly and mitochondrial complex I assembly complex (MCIA) abundance. Of all mitochondrial MCIA members, we proved a selective HIF-1-dependent decrease of TMEM126B under chronic hypoxia. Mechanistically, HIF-1α induces the E3-ubiquitin ligase F-box/WD repeat-containing protein 1A (β-TrCP1), which in turn facilitates the proteolytic degradation of TMEM126B. Attenuating a functional complex I assembly appears critical for cellular adaptation towards chronic hypoxia and is linked to destruction of the mitochondrial assembly factor TMEM126B.

  16. Influencing Factors of Stunting in Children Under 5 Years Old in Jilin Province,2013.

    Science.gov (United States)

    Wang, Ying; He, Yonghuan; Zhang, Qijun; Wang, Qiuyan; Feng, Xinglin

    2017-04-20

    Objective To analyze the influencing factors of stunting in children under 5 years old in Jilin province in 2013,with an attempt to further improve the nutrition status among children. Methods Data on stunting in children under 5 years old in Jilin province were extracted from the National Health Services Survey 2013 in Jilin province. The influencing factors of stunting were analyzed by using univariate analysis and Logistic regression analysis.. Results The stunting prevalence in children under 5 years old was 23.8% in 2013. Univariate analysis showed that urban residence (OR=0.38,95% CI=0.25-0.57),high income (OR=0.40,95% CI=0.24-0.66),mother's education level (higher than primary school) (OR=0.50,95% CI=0.32-0.81),safe water coverage (OR=0.41,95% CI=0.22-0.75),and clean toilet coverage (OR=0.36,95% CI=0.24-0.53) are protective factors of stunting. After adjusting other factors,urban residence (OR=0.54,95% CI=0.31-0.94),safe water coverage (OR=0.28,95% CI=0.13-0.60),and clean toilet coverage (OR=0.40,95% CI=0.24-0.67) still showed protective effects. Conclusion The urban-rural disparity and the availability of safe water and clean toilet are the major factors of stunting among children under 5 years old in Jilin province. The major public health service program should be fully implemented to improve the nutrition status among children.

  17. Causal ubiquity in quantum physics. A superluminal and local-causal physical ontology

    International Nuclear Information System (INIS)

    Neelamkavil, Raphael

    2014-01-01

    A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly [non-causal] processes, something exists processually in extension-motion, between the causal and the [non-causal]. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That is, the QM world is sub-luminally, luminally and superluminally local-causal throughout, and the Law of Causality is ubiquitous in the micro-world. Thus, ''probabilistic causality'' is a merely epistemic term.

  18. Causal ubiquity in quantum physics. A superluminal and local-causal physical ontology

    Energy Technology Data Exchange (ETDEWEB)

    Neelamkavil, Raphael

    2014-07-01

    A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly [non-causal] processes, something exists processually in extension-motion, between the causal and the [non-causal]. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That is, the QM world is sub-luminally, luminally and superluminally local-causal throughout, and the Law of Causality is ubiquitous in the micro-world. Thus, ''probabilistic causality'' is a merely epistemic term.

  19. Immune Organs and Haemopoietic System Under Modelling of the Mission Factors

    Science.gov (United States)

    Sapin, M. R.; Grigoriev, A. I.; Erofeeva, L. M.; Grigorenko, D. E.; Fedorenko, B. S.

    1997-07-01

    Literary and experimental data on the character of changes in immune organs and lymphoid tissue of respiratory system and digestive system in laboratory animals during the mission factors model are given. Inhibition of reproductive function in bone marrow, thymus and spleen under irradiation of gamma-rays and accelerated carbon ions, tensity of immune response in the lymphoid structures of larynx, trachea and bronchi under the influence of acetaldehyde vapors and decrease of lymphoid tissue square on histological series in spleen and small intestine with an increase of concentration of microbial bodies in the drinking water were estimated.

  20. There aren't plenty more fish in the sea: a causal network approach.

    Science.gov (United States)

    Nikolic, Milena; Lagnado, David A

    2015-11-01

    The current research investigated how lay representations of the causes of an environmental problem may underlie individuals' reasoning about the issue. Naïve participants completed an experiment that involved two main tasks. The causal diagram task required participants to depict the causal relations between a set of factors related to overfishing and to estimate the strength of these relations. The counterfactual task required participants to judge the effect of counterfactual suppositions based on the diagrammed factors. We explored two major questions: (1) what is the relation between individual causal models and counterfactual judgments? Consistent with previous findings (e.g., Green et al., 1998, Br. J. Soc. Psychology, 37, 415), these judgments were best explained by a combination of the strength of both direct and indirect causal paths. (2) To what extent do people use two-way causal thinking when reasoning about an environmental problem? In contrast to previous research (e.g., White, 2008, Appl. Cogn. Psychology, 22, 559), analyses based on individual causal networks revealed the presence of numerous feedback loops. The studies support the value of analysing individual causal models in contrast to consensual representations. Theoretical and practical implications are discussed in relation to causal reasoning as well as environmental psychology. © 2015 The British Psychological Society.

  1. Quasi-Experimental Designs for Causal Inference

    Science.gov (United States)

    Kim, Yongnam; Steiner, Peter

    2016-01-01

    When randomized experiments are infeasible, quasi-experimental designs can be exploited to evaluate causal treatment effects. The strongest quasi-experimental designs for causal inference are regression discontinuity designs, instrumental variable designs, matching and propensity score designs, and comparative interrupted time series designs. This…

  2. Causal random geometry from stochastic quantization

    DEFF Research Database (Denmark)

    Ambjørn, Jan; Loll, R.; Westra, W.

    2010-01-01

     in this short note we review a recently found formulation of two-dimensional causal quantum gravity defined through Causal Dynamical Triangulations and stochastic quantization. This procedure enables one to extract the nonperturbative quantum Hamiltonian of the random surface model including the...... the sum over topologies. Interestingly, the generally fictitious stochastic time corresponds to proper time on the geometries...

  3. Special Relativity, Causality and Quantum Mechanics-2

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. Special Relativity, Causality and Quantum Mechanics - 2. Guruprasad Kar Samir Kunkri Sujit K Choudhary. General Article Volume 11 Issue 9 ... Keywords. Causality; quantum entanglement; cloning; local realism; completely positive maps.

  4. Causal Mediation Analysis: Warning! Assumptions Ahead

    Science.gov (United States)

    Keele, Luke

    2015-01-01

    In policy evaluations, interest may focus on why a particular treatment works. One tool for understanding why treatments work is causal mediation analysis. In this essay, I focus on the assumptions needed to estimate mediation effects. I show that there is no "gold standard" method for the identification of causal mediation effects. In…

  5. Research on Safety Factor of Dam Slope of High Embankment Dam under Seismic Condition

    Directory of Open Access Journals (Sweden)

    Li Bin

    2015-01-01

    Full Text Available With the constant development of construction technology of embankment dam, the constructed embankment dam becomes higher and higher, and the embankment dam with its height over 200m will always adopt the current design criteria of embankment dam only suitable for the construction of embankment dam lower than 200m in height. So the design criteria of high embankment dam shall be improved. We shall calculate the stability and safety factors of dam slope of high embankment dam under different dam height, slope ratio and different seismic intensity based on ratio of safety margin, and clarify the change rules of stability and safety factors of dam slope of high embankment dam with its height over 200m. We calculate the ratio of safety margin of traditional and reliable method by taking the stable, allowable and reliability index 4.2 of dam slope of high embankment dam with its height over 200m as the standard value, and conduct linear regression for both. As a result, the conditions, where 1.3 is considered as the stability and safety factors of dam slope of high embankment dam with its height over 200m under seismic condition and 4.2 as the allowable and reliability index, are under the same risk control level.

  6. Investigating the Underlying Factors of Corruption in the Public Construction Sector: Evidence from China.

    Science.gov (United States)

    Shan, Ming; Le, Yun; Yiu, Kenneth T W; Chan, Albert P C; Hu, Yi

    2017-12-01

    Over recent years, the issue of corruption in the public construction sector has attracted increasing attention from both practitioners and researchers worldwide. However, limited efforts are available for investigating the underlying factors of corruption in this sector. Thus, this study attempted to bridge this knowledge gap by exploring the underlying factors of corruption in the public construction sector of China. To achieve this goal, a total of 14 structured interviews were first carried out, and a questionnaire survey was then administered to 188 professionals in China. Two iterations of multivariate analysis approaches, namely, stepwise multiple regression analysis and partial least squares structural equation modeling were successively utilized to analyze the collected data. In addition, a case study was also conducted to triangulate the findings obtained from the statistical analysis. The results generated from these three research methods achieve the same conclusion: the most influential underlying factor leading to corruption was immorality, followed by opacity, unfairness, procedural violation, and contractual violation. This study has contributed to the body of knowledge by exploring the properties of corruption in the public construction sector. The findings from this study are also valuable to the construction authorities as they can assist in developing more effective anti-corruption strategies.

  7. Repair of Partly Misspecified Causal Diagrams.

    Science.gov (United States)

    Oates, Chris J; Kasza, Jessica; Simpson, Julie A; Forbes, Andrew B

    2017-07-01

    Errors in causal diagrams elicited from experts can lead to the omission of important confounding variables from adjustment sets and render causal inferences invalid. In this report, a novel method is presented that repairs a misspecified causal diagram through the addition of edges. These edges are determined using a data-driven approach designed to provide improved statistical efficiency relative to de novo structure learning methods. Our main assumption is that the expert is "directionally informed," meaning that "false" edges provided by the expert would not create cycles if added to the "true" causal diagram. The overall procedure is cast as a preprocessing technique that is agnostic to subsequent causal inferences. Results based on simulated data and data derived from an observational cohort illustrate the potential for data-assisted elicitation in epidemiologic applications. See video abstract at, http://links.lww.com/EDE/B208.

  8. Analysis of the Survival of Children Under Five in Indonesia and Associated Factors

    Science.gov (United States)

    Nur Islami Warrohmah, Annisa; Maniar Berliana, Sarni; Nursalam, Nursalam; Efendi, Ferry; Haryanto, Joni; Has, Eka Misbahatul M.; Ulfiana, Elida; Dwi Wahyuni, Sylvia

    2018-02-01

    The under-five mortality rate (U5MR) remains a challenge for developing nations, including Indonesia. This study aims to assess the key factors associated with mortality of Indonesian infants using survival analysis. Data taken from 14,727 live-born infants (2007-2012) was examined from the nationally representative Indonesian Demographic Health Survey. The Weibull hazard model was performed to analyse the socioeconomic status and related determinants of infant mortality. The findings indicated that mother factors (education, working status, autonomy, economic status, maternal age at birth, birth interval, type of births, complications, history of previous mortality, breastfeeding, antenatal care and place of delivery); infant factors (birth size); residence; and environmental conditions were associated with the childhood mortality. Rural or urban residence was an important determining factor of infant mortality. For example, considering the factor of a mother’s education, rural educated mothers had a significant association with the survival of their infants. In contrast, there was no significant association between urban educated mothers and their infants’ mortality. The results showed obvious contextual differences which determine the childhood mortality. Socio-demographic and economic factors remain critical in determining the death of infants. This study provides evidence for designing targeted interventions, as well as suggesting specific needs based on the population’s place of residence, in the issue of U5MR. Further interventions should also consider other identified variables while developing programmes to address infant’s needs.

  9. Causality and skies: is non-refocussing necessary?

    Science.gov (United States)

    Bautista, A.; Ibort, A.; Lafuente, J.

    2015-05-01

    The causal structure of a strongly causal, null pseudo-convex, space-time M is completely characterized in terms of a partial order on its space of skies defined by means of a class of non-negative Legendrian isotopies called sky isotopies. It is also shown that such partial order is determined by the class of future causal celestial curves, that is, curves in the space of light rays which are tangent to skies and such that they determine non-negative sky isotopies. It will also be proved that the space of skies Σ equipped with Low’s (or reconstructive) topology is homeomorphic and diffeomorphic to M under the only additional assumption that M separates skies, that is, that different events determine different skies. The sky-separating property of M is sharp and the previous result provides an answer to the question about the class of space-times whose causal structure, topological and differentiable structure can be reconstructed from their spaces of light rays and skies. These results can be understood as a Malament-Hawking-like theorem stated in terms of the partial order defined on the space of skies.

  10. Hypothalamic corticotropin-releasing factor is centrally involved in learning under moderate stress.

    Science.gov (United States)

    Lucas, Morgan; Chen, Alon; Richter-Levin, Gal

    2013-08-01

    The corticotropin-releasing factor (CRF) neuropeptide is found to have a pivotal role in the regulation of the behavioral and neuroendocrine responses to stressful challenges. Here, we studied the involvement of the hypothalamic CRF in learning under stressful conditions. We have used a site-specific viral approach to knockdown (KD) CRF expression in the paraventricular nucleus of the hypothalamus (PVN). The two-way shuttle avoidance (TWSA) task was chosen to assess learning and memory under stressful conditions. Control animals learned to shuttle from one side to the other to avoid electrical foot shock by responding to a tone. Novel object and social recognition tasks were used to assess memory under less stressful conditions. KD of PVN-CRF expression decreased the number of avoidance responses in a TWSA session under moderate (0.8 mA), but not strong (1.5 mA), stimulus intensity compared to control rats. On the other hand, KD of PVN-CRF had no effect on memory performance in the less stressful novel object or social recognition tasks. Interestingly, basal or stress-induced corticosterone levels in CRF KD rats were not significantly different from controls. Taken together, the data suggest that the observed impairment was not a result of alteration in HPA axis activity, but rather due to reduced PVN-CRF activity on other brain areas. We propose that hypothalamic CRF is centrally involved in learning under moderate stressful challenge. Under 'basal' (less stressful) conditions or when the intensity of the stress is more demanding, central CRF ceases to be the determinant factor, as was indicated by performances in the TWSA with higher stimulus intensity or in the less stressful tasks of object and social recognition.

  11. Are the educational differences in incidence of cardiovascular disease explained by underlying familial factors?

    DEFF Research Database (Denmark)

    Madsen, Mia; Andersen, Per K; Gerster, Mette

    2014-01-01

    To isolate the effect of education from the influence of potential underlying factors, we investigated the association of education with the risk of cardiovascular disease (CVD) and ischemic heart disease (IHD) using twin data to adjust for familial factors shared within twins, including genetic...... make-up and childhood environment. The study was based on data from the Danish Twin Registry linked to administrative and heath registers in Statistics Denmark. A total of 11,968 monozygotic and 20,464 dizygotic same sexed twins were followed from 1980 to 2009, including more than 8000 events of CVD....... Unpaired and intra-pair analyses were compared. In the unpaired analyses, an inverse educational gradient in CVD- and IHD risk was observed. This association was not replicated in the intra-pair analyses that control for shared familial factors exploiting that twins share their intrauterine- and childhood...

  12. Reconstructing Causal Biological Networks through Active Learning.

    Directory of Open Access Journals (Sweden)

    Hyunghoon Cho

    Full Text Available Reverse-engineering of biological networks is a central problem in systems biology. The use of intervention data, such as gene knockouts or knockdowns, is typically used for teasing apart causal relationships among genes. Under time or resource constraints, one needs to carefully choose which intervention experiments to carry out. Previous approaches for selecting most informative interventions have largely been focused on discrete Bayesian networks. However, continuous Bayesian networks are of great practical interest, especially in the study of complex biological systems and their quantitative properties. In this work, we present an efficient, information-theoretic active learning algorithm for Gaussian Bayesian networks (GBNs, which serve as important models for gene regulatory networks. In addition to providing linear-algebraic insights unique to GBNs, leading to significant runtime improvements, we demonstrate the effectiveness of our method on data simulated with GBNs and the DREAM4 network inference challenge data sets. Our method generally leads to faster recovery of underlying network structure and faster convergence to final distribution of confidence scores over candidate graph structures using the full data, in comparison to random selection of intervention experiments.

  13. Causal ubiquity in quantum physics a superluminal and local-causal physical ontology

    CERN Document Server

    Neelamkavil, Raphael

    2014-01-01

    A fixed highest criterial velocity (of light) in STR (special theory of relativity) is a convention for a layer of physical inquiry. QM (Quantum Mechanics) avoids action-at-a-distance using this concept, but accepts non-causality and action-at-a-distance in EPR (Einstein-Podolsky-Rosen-Paradox) entanglement experiments. Even in such allegedly non-causal processes, something exists processually in extension-motion, between the causal and the non-causal. If STR theoretically allows real-valued superluminal communication between EPR entangled particles, quantum processes become fully causal. That

  14. Illusions of causality: How they bias our everyday thinking and how they could be reduced

    Directory of Open Access Journals (Sweden)

    Helena eMatute

    2015-07-01

    Full Text Available Illusions of causality occur when people develop the belief that there is a causal connection between two events that are actually unrelated. Such illusions have been proposed to underlie pseudoscience and superstitious thinking, sometimes leading to disastrous consequences in relation to critical life areas, such as health, finances, and wellbeing. Like optical illusions, they can occur for anyone under well-known conditions. Scientific thinking is the best possible safeguard against them, but it does not come intuitively and needs to be taught. Teaching how to think scientifically should benefit from better understanding of the illusion of causality. In this article, we review experiments that our group has conducted on the illusion of causality during the last 20 years. We discuss how research on the illusion of causality can contribute to the teaching of scientific thinking and how scientific thinking can reduce illusion.

  15. Illusions of causality: how they bias our everyday thinking and how they could be reduced.

    Science.gov (United States)

    Matute, Helena; Blanco, Fernando; Yarritu, Ion; Díaz-Lago, Marcos; Vadillo, Miguel A; Barberia, Itxaso

    2015-01-01

    Illusions of causality occur when people develop the belief that there is a causal connection between two events that are actually unrelated. Such illusions have been proposed to underlie pseudoscience and superstitious thinking, sometimes leading to disastrous consequences in relation to critical life areas, such as health, finances, and wellbeing. Like optical illusions, they can occur for anyone under well-known conditions. Scientific thinking is the best possible safeguard against them, but it does not come intuitively and needs to be taught. Teaching how to think scientifically should benefit from better understanding of the illusion of causality. In this article, we review experiments that our group has conducted on the illusion of causality during the last 20 years. We discuss how research on the illusion of causality can contribute to the teaching of scientific thinking and how scientific thinking can reduce illusion.

  16. Untangling the causal relationship between tax burden distribution and economic growth in 23 OECD countries: Fresh evidence from linear and non-linear Granger causality

    Directory of Open Access Journals (Sweden)

    Sami Saafi

    2017-12-01

    Full Text Available The aim of the paper is to investigate the linear and nonlinear causality between a set of alternative tax burden ratios and economic growth in 23 OECD countries. To that end, the linear causality approach of Toda– Yamamoto (1995 and the nonparametric causality method of Kyrtsou and Labys (2006 are applied to annual data spanning from 1970 to 2014. Results obtained from the nonlinear causality test tend to reject the neutrality hypothesis for the tax structure–growth relationship in 19 of the 23 OECD countries. In the majority of the countries under investigation, the evidence is in line with the growth hypothesis where causality running from economic growth to tax burden ratios was detected in Australia, Denmark, Finland, Japan, New Zealand, and Norway. The opposite causality running from tax structure to economic growth was found in Germany, Netherlands, Portugal, and Sweden. In contrast, the neutrality hypothesis was supported in Austria, Italy, Luxembourg, and the USA, whereas the feedback hypothesis was supported in Turkey and the UK. Additional robustness checks show that when the signs of variations are taken into account, there is an asymmetric causality running from positive tax burden shocks to positive per capita GDP shocks for Belgium, France, and Turkey. Overall, our findings suggest that policy implications of the tax structure-economic growth relationships should be interpreted with caution, taking into account the test-dependent and country-specific results.

  17. Risk Factors of Diarrhea in Children Under Five Years in Urban Slums

    Directory of Open Access Journals (Sweden)

    Balakrishna Kalakheti

    2016-12-01

    Full Text Available Introduction: Diarrhea is a leading cause of mortality in children in developing countries and the condition is worse in slums. In order to provide effective preventive and management strategies, it is important to identify factors associated with the disease. This study was carried out to investigate the risk factors of diarrhea in  children under five years of age in urban slums. Methods: Parents of all children under five years from the urban slums of Tansen municipality, Palpa, Nepal were interviewed using a standardized pretested questionnaire and proforma. Parental variables, environmental factors, and presence of diarrhea in those children in past three months were collected by trained enumerators and the data were analyzed with statistical software SPSS-10. Results: A total of 450 under five years children were enrolled in the study. There were 216 (48% male and 234 (52% female children with F:M ratio of 1.08:1. Occurrence of diarrhea was lower if the children were breast-fed for more than six months, well-nourished, used fountain water for drinking, or used boiled or treated water. Similarly, diarrhea prevalence was lower if father had a regular job, daily income in the family was more than one US dollar, there was a toilet in the house, practice of hand washing was followed before feeding or preparing food, or there was no child suffering from diarrhea in the neighborhood. Conclusion: There are a few variables that are significantly related to diarrhea in children under five years of age. In order to decrease the diarrheal episodes in children in the slums of the developing countries, priority could be given in the improvement of those variables.

  18. Causal systems categories: differences in novice and expert categorization of causal phenomena.

    Science.gov (United States)

    Rottman, Benjamin M; Gentner, Dedre; Goldwater, Micah B

    2012-07-01

    We investigated the understanding of causal systems categories--categories defined by common causal structure rather than by common domain content--among college students. We asked students who were either novices or experts in the physical sciences to sort descriptions of real-world phenomena that varied in their causal structure (e.g., negative feedback vs. causal chain) and in their content domain (e.g., economics vs. biology). Our hypothesis was that there would be a shift from domain-based sorting to causal sorting with increasing expertise in the relevant domains. This prediction was borne out: the novice groups sorted primarily by domain and the expert group sorted by causal category. These results suggest that science training facilitates insight about causal structures. Copyright © 2012 Cognitive Science Society, Inc.

  19. Cytoplasmic FMR1-Interacting Protein 2 Is a Major Genetic Factor Underlying Binge Eating.

    Science.gov (United States)

    Kirkpatrick, Stacey L; Goldberg, Lisa R; Yazdani, Neema; Babbs, R Keith; Wu, Jiayi; Reed, Eric R; Jenkins, David F; Bolgioni, Amanda F; Landaverde, Kelsey I; Luttik, Kimberly P; Mitchell, Karen S; Kumar, Vivek; Johnson, W Evan; Mulligan, Megan K; Cottone, Pietro; Bryant, Camron D

    2017-05-01

    Eating disorders are lethal and heritable; however, the underlying genetic factors are unknown. Binge eating is a highly heritable trait associated with eating disorders that is comorbid with mood and substance use disorders. Therefore, understanding its genetic basis will inform therapeutic development that could improve several comorbid neuropsychiatric conditions. We assessed binge eating in closely related C57BL/6 mouse substrains and in an F 2 cross to identify quantitative trait loci associated with binge eating. We used gene targeting to validate candidate genetic factors. Finally, we used transcriptome analysis of the striatum via messenger RNA sequencing to identify the premorbid transcriptome and the binge-induced transcriptome to inform molecular mechanisms mediating binge eating susceptibility and establishment. C57BL/6NJ but not C57BL/6J mice showed rapid and robust escalation in palatable food consumption. We mapped a single genome-wide significant quantitative trait locus on chromosome 11 (logarithm of the odds = 7.4) to a missense mutation in cytoplasmic FMR1-interacting protein 2 (Cyfip2). We validated Cyfip2 as a major genetic factor underlying binge eating in heterozygous knockout mice on a C57BL/6N background that showed reduced binge eating toward a wild-type C57BL/6J-like level. Transcriptome analysis of premorbid genetic risk identified the enrichment terms morphine addiction and retrograde endocannabinoid signaling, whereas binge eating resulted in the downregulation of a gene set enriched for decreased myelination, oligodendrocyte differentiation, and expression. We identified Cyfip2 as a major significant genetic factor underlying binge eating and provide a behavioral paradigm for future genome-wide association studies in populations with increased genetic complexity. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  20. Nonparametric causal effects based on incremental propensity score interventions

    OpenAIRE

    Kennedy, Edward H.

    2017-01-01

    Most work in causal inference considers deterministic interventions that set each unit's treatment to some fixed value. However, under positivity violations these interventions can lead to non-identification, inefficiency, and effects with little practical relevance. Further, corresponding effects in longitudinal studies are highly sensitive to the curse of dimensionality, resulting in widespread use of unrealistic parametric models. We propose a novel solution to these problems: incremental ...

  1. Causal inference, probability theory, and graphical insights.

    Science.gov (United States)

    Baker, Stuart G

    2013-11-10

    Causal inference from observational studies is a fundamental topic in biostatistics. The causal graph literature typically views probability theory as insufficient to express causal concepts in observational studies. In contrast, the view here is that probability theory is a desirable and sufficient basis for many topics in causal inference for the following two reasons. First, probability theory is generally more flexible than causal graphs: Besides explaining such causal graph topics as M-bias (adjusting for a collider) and bias amplification and attenuation (when adjusting for instrumental variable), probability theory is also the foundation of the paired availability design for historical controls, which does not fit into a causal graph framework. Second, probability theory is the basis for insightful graphical displays including the BK-Plot for understanding Simpson's paradox with a binary confounder, the BK2-Plot for understanding bias amplification and attenuation in the presence of an unobserved binary confounder, and the PAD-Plot for understanding the principal stratification component of the paired availability design. Published 2013. This article is a US Government work and is in the public domain in the USA.

  2. Oil prices and the world business cycle: A causal investigation

    OpenAIRE

    Tapia, Jose

    2016-01-01

    Oil shocks have been often considered as exogenous factors responsible of economic downturns. In this paper the hypothesized exogeneity of oil prices is investigated by using running cross-correlations, distributed lag-regressions, Granger causality tests and VAR models applied to annual data 1960-2014 of oil prices and global economic activity—as measured by world GDP. Strong evidence is found that (a) the relation between oil prices and the global economy has significantly changed since th...

  3. Moving towards causality in attention-deficit hyperactivity disorder: overview of neural and genetic mechanisms

    Science.gov (United States)

    Gallo, Eduardo F; Posner, Jonathan

    2016-01-01

    Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by developmentally inappropriate levels of inattention and hyperactivity or impulsivity. The heterogeneity of its clinical manifestations and the differential responses to treatment and varied prognoses have long suggested myriad underlying causes. Over the past decade, clinical and basic research efforts have uncovered many behavioural and neurobiological alterations associated with ADHD, from genes to higher order neural networks. Here, we review the neurobiology of ADHD by focusing on neural circuits implicated in the disorder and discuss how abnormalities in circuitry relate to symptom presentation and treatment. We summarise the literature on genetic variants that are potentially related to the development of ADHD, and how these, in turn, might affect circuit function and relevant behaviours. Whether these underlying neurobiological factors are causally related to symptom presentation remains unresolved. Therefore, we assess efforts aimed at disentangling issues of causality, and showcase the shifting research landscape towards endophenotype refinement in clinical and preclinical settings. Furthermore, we review approaches being developed to understand the neurobiological underpinnings of this complex disorder including the use of animal models, neuromodulation, and pharmaco-imaging studies. PMID:27183902

  4. Consanguinity among the risk factors for underweight in children under five: a study from rural Sindh

    International Nuclear Information System (INIS)

    Hasnain, S.F.; Hashmi, S.K.

    2009-01-01

    Malnutrition is a common problem, especially in developing countries. Of the 11 million children under 5 who die each year in the developing countries mainly from preventable causes, the death of about 54% are either directly or indirectly attributable to malnutrition. The objectives of this study were to assess the prevalence and associated factors for underweight in rural Sindh. Methods: A cross-sectional survey was conducted in Jhangara Town, located in District Dadu, Sindh. Eight hundred children under 5 years of age were enrolled. A questionnaire was used to elicit required information and anthropometric measurements were made. Results: The overall prevalence for underweight was 54.3% in the study population, which was higher than the prevalence reported by PDHS 1990 - 91. In multivariate analysis, various factors for underweight were consanguinity (OR=1.5, 95% CI=1.0 - 2.07), low birth weight (parents perspective) (OR=1.6, 95% CI=1.08 - 2.16) and lack of breast-feeding (OR=2.7, 95% CI=1.19 - 6.17). Conclusion: Effective strategies to discourage consanguineous marriages between first cousins are required. Promoting breast feeding is another factor that should be incorporated while designing control strategies to reduce morbidity and mortality due to malnutrition in children (<5 years). (author)

  5. On the origin of Hill's causal criteria.

    Science.gov (United States)

    Morabia, A

    1991-09-01

    The rules to assess causation formulated by the eighteenth century Scottish philosopher David Hume are compared to Sir Austin Bradford Hill's causal criteria. The strength of the analogy between Hume's rules and Hill's causal criteria suggests that, irrespective of whether Hume's work was known to Hill or Hill's predecessors, Hume's thinking expresses a point of view still widely shared by contemporary epidemiologists. The lack of systematic experimental proof to causal inferences in epidemiology may explain the analogy of Hume's and Hill's, as opposed to Popper's, logic.

  6. Dual Causality and the Autonomy of Biology.

    Science.gov (United States)

    Bock, Walter J

    2017-03-01

    Ernst Mayr's concept of dual causality in biology with the two forms of causes (proximate and ultimate) continues to provide an essential foundation for the philosophy of biology. They are equivalent to functional (=proximate) and evolutionary (=ultimate) causes with both required for full biological explanations. The natural sciences can be classified into nomological, historical nomological and historical dual causality, the last including only biology. Because evolutionary causality is unique to biology and must be included for all complete biological explanations, biology is autonomous from the physical sciences.

  7. Identifying causal linkages between environmental variables and African conflicts

    Science.gov (United States)

    Nguy-Robertson, A. L.; Dartevelle, S.

    2017-12-01

    Environmental variables that contribute to droughts, flooding, and other natural hazards are often identified as factors contributing to conflict; however, few studies attempt to quantify these causal linkages. Recent research has demonstrated that the environment operates within a dynamical system framework and the influence of variables can be identified from convergent cross mapping (CCM) between shadow manifolds. We propose to use CCM to identify causal linkages between environmental variables and incidences of conflict. This study utilizes time series data from Climate Forecast System ver. 2 and MODIS satellite sensors processed using Google Earth Engine to aggregate country and regional trends. These variables are then compared to Armed Conflict Location & Event Data Project observations at similar scales. Results provide relative rankings of variables and their linkage to conflict. Being able to identify which factors contributed more strongly to a conflict can allow policy makers to prepare solutions to mitigate future crises. Knowledge of the primary environmental factors can lead to the identification of other variables to examine in the causal network influencing conflict.

  8. Influence factor analysis of atmospheric electric field monitoring near ground under different weather conditions

    International Nuclear Information System (INIS)

    Wan, Haojiang; Wei, Guanghui; Cui, Yaozhong; Chen, Yazhou

    2013-01-01

    Monitoring of atmospheric electric field near ground plays a critical role in atmospheric environment detecting and lightning warning. Different environmental conditions (e.g. buildings, plants, weather, etc.) have different influences on the data's coherence in an atmospheric electric field detection network. In order to study the main influence factors of atmospheric electric field monitoring under different weather conditions, with the combination of theoretical analysis and experiments, the electric field monitoring data on the ground and on the top of a building are compared in fair weather and thunderstorm weather respectively in this paper. The results show that: In fair weather, the field distortion due to the buildings is the main influence factor on the electric field monitoring. In thunderstorm weather, the corona ions produced from the ground, besides the field distortion due to the buildings, can also influence the electric field monitoring results.

  9. Experimental Adiabatic Quantum Factorization under Ambient Conditions Based on a Solid-State Single Spin System.

    Science.gov (United States)

    Xu, Kebiao; Xie, Tianyu; Li, Zhaokai; Xu, Xiangkun; Wang, Mengqi; Ye, Xiangyu; Kong, Fei; Geng, Jianpei; Duan, Changkui; Shi, Fazhan; Du, Jiangfeng

    2017-03-31

    The adiabatic quantum computation is a universal and robust method of quantum computing. In this architecture, the problem can be solved by adiabatically evolving the quantum processor from the ground state of a simple initial Hamiltonian to that of a final one, which encodes the solution of the problem. Adiabatic quantum computation has been proved to be a compatible candidate for scalable quantum computation. In this Letter, we report on the experimental realization of an adiabatic quantum algorithm on a single solid spin system under ambient conditions. All elements of adiabatic quantum computation, including initial state preparation, adiabatic evolution (simulated by optimal control), and final state read-out, are realized experimentally. As an example, we found the ground state of the problem Hamiltonian S_{z}I_{z} on our adiabatic quantum processor, which can be mapped to the factorization of 35 into its prime factors 5 and 7.

  10. Factors impacting same-day cancellation of outpatient pediatric magnetic resonance imaging under anesthesia

    International Nuclear Information System (INIS)

    Hoffman, Andrea S.; Matlow, Anne; Shroff, Manohar; Cohen, Eyal

    2015-01-01

    Studies of elective surgical procedures indicate that cancellation is common and preventable. Little is known about cancellation of anesthesia-supported elective diagnostic imaging. To describe the reasons for same-day cancellation of MRI studies performed under sedation or anesthesia and identify patient characteristics associated with cancellations. This case-control study was carried out in a university-affiliated tertiary care children's hospital. Cases were defined as elective outpatient MRI studies booked under anesthesia that were cancelled after the patient had arrived in the radiology department in 2009. Matched controls were identified by selecting the same day and time 1 week before or after the cancelled case. Main outcome measures included demographics, MRI study characteristics, and social and medical factors. There were 111 outpatient anesthesia-supported MRI studies cancelled on the same day as the assessment (cancellation rate: 4.5%), of which 74.6% were related to family and patient factors, while 22% were related to system factors. Cancelled cases involved patients who lived in lower median income quintile neighborhoods compared to controls (2 vs. 3; P = 0.0007; odds ratio [OR] 3.81; 95% confidence interval [CI] 1.18-12.34). Those who traveled a greater median distance (in kilometers) were less likely to be cancelled (18.8 vs. 27.1, P = 0.0035). Although cancelled patients had a lower mean number of total medical services (2.5 vs. 3.0; P = 0.03; OR = 0.78; 95% CI 0.62-0.98), current medical factors (past 12 months) did not impact cancellations. Same-day cancellations of anesthesia-supported MRI studies are not uncommon, and the main predictor of cancellation seems to be socioeconomic rather than medical. (orig.)

  11. Factors impacting same-day cancellation of outpatient pediatric magnetic resonance imaging under anesthesia

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, Andrea S. [University of Toronto, Department of Paediatrics, Division of Developmental Paediatrics, Holland Bloorview Kids Rehabilitation Hospital, Toronto (Canada); Matlow, Anne [University of Toronto, Strategic Initiatives, Postgraduate Medical Education, Toronto (Canada); Shroff, Manohar [University of Toronto, Department of Diagnostic Imaging, Division of Neuroradiology, Hospital for Sick Children, Toronto (Canada); Cohen, Eyal [University of Toronto, Division of Paediatric Medicine and Child Health Evaluative Sciences, Hospital for Sick Children, Department of Paediatrics and Institute of Health Policy, Management and Evaluation, Toronto (Canada)

    2014-07-24

    Studies of elective surgical procedures indicate that cancellation is common and preventable. Little is known about cancellation of anesthesia-supported elective diagnostic imaging. To describe the reasons for same-day cancellation of MRI studies performed under sedation or anesthesia and identify patient characteristics associated with cancellations. This case-control study was carried out in a university-affiliated tertiary care children's hospital. Cases were defined as elective outpatient MRI studies booked under anesthesia that were cancelled after the patient had arrived in the radiology department in 2009. Matched controls were identified by selecting the same day and time 1 week before or after the cancelled case. Main outcome measures included demographics, MRI study characteristics, and social and medical factors. There were 111 outpatient anesthesia-supported MRI studies cancelled on the same day as the assessment (cancellation rate: 4.5%), of which 74.6% were related to family and patient factors, while 22% were related to system factors. Cancelled cases involved patients who lived in lower median income quintile neighborhoods compared to controls (2 vs. 3; P = 0.0007; odds ratio [OR] 3.81; 95% confidence interval [CI] 1.18-12.34). Those who traveled a greater median distance (in kilometers) were less likely to be cancelled (18.8 vs. 27.1, P = 0.0035). Although cancelled patients had a lower mean number of total medical services (2.5 vs. 3.0; P = 0.03; OR = 0.78; 95% CI 0.62-0.98), current medical factors (past 12 months) did not impact cancellations. Same-day cancellations of anesthesia-supported MRI studies are not uncommon, and the main predictor of cancellation seems to be socioeconomic rather than medical. (orig.)

  12. Risk Factors for Pneumonia in Children under 5 Years in a Teaching Hospital in Nepal.

    Science.gov (United States)

    Karki, S; Fitzpatrick, A L; Shrestha, S

    2014-01-01

    Pneumonia is a leading cause of mortality among children under-five years of age globally. The WHO (2014) has reported that indoor air pollution caused by cooking and heating with biomass fuel, living in crowed homes and parenting smoking are risk factors of pneumonia. The objective of the study was to identify the risk factors for pneumonia among children under-5 years of age. A case control study was carried out among the mothers having under-5 years children who were admitted in the paediatric ward of Dhulikhel Hospital in 2012/13. A convenience sampling technique was used to select 50 children with pneumonia and 150 children with non-pneumonia diseases matched on age, sex and setting. A semi-structured interview consisting of questions related to risk factors for pneumonia was used to collect data from mothers of both cases and controls. Sex of the child did not differ by case/control group whereas the children with pneumonia were slightly older with 26% cases and 15% controls older than 3 years of age. Mother's education was similar in both groups as was family income. Living in a household with a chulo with smoke increased the odds of having pneumonia significantly, with the risk almost 4 times greater if the chulo was located within the same building (OR: 3.76, 95% CI: 1.20-11.82, p=0.02). Children who had diarrhea in the past 3 months were protected from pneumonia (OR: 0.38, 95% CI: 0.18- 0.82, p=0.01). An increasing trend of pneumonia was observed among children of tobacco smoking parents with greater risk if both parents smoked; it was, however, not statically significant (OR: 2.21, 95% CI: 0.56-8.82, p=0.26). The present study suggests that two factors related to smoke, presence of a smoky chulo in a household and both parents smoking, are modifiable risk factors related to pneumonia in young children. Reliable longitudinal studies, interventions, and programs to educate parents in prevention are important for reducing mortality and morbidities related

  13. Selecting appropriate cases when tracing causal mechanisms

    DEFF Research Database (Denmark)

    Beach, Derek; Pedersen, Rasmus Brun

    2016-01-01

    The last decade has witnessed resurgence in the interest in studying the causal mechanisms linking causes and outcomes in the social sciences. This article explores the overlooked implications for case selection when tracing mechanisms using in-depth case studies. Our argument is that existing case...... selection guidelines are appropriate for research aimed at making cross-case claims about causal relationships, where case selection is primarily used to control for other causes. However, existing guidelines are not in alignment with case-based research that aims to trace mechanisms, where the goal...... is to unpack the causal mechanism between X and Y, enabling causal inferences to be made because empirical evidence is provided for how the mechanism actually operated in a particular case. The in-depth, within-case tracing of how mechanisms operate in particular cases produces what can be termed mechanistic...

  14. Causality Between Urban Concentration and Environmental Quality

    Directory of Open Access Journals (Sweden)

    Amin Pujiati

    2015-08-01

    Full Text Available Population is concentrated in urban areas can cause the external diseconomies on environment if it exceeds the carrying capacity of the space and the urban economy. Otherwise the quality of the environment is getting better, led to the concentration of population in urban areas are increasingly high. This study aims to analyze the relationship of causality between the urban concentration and environmental quality in urban agglomeration areas. The data used in the study of secondary data obtained from the Central Bureau of statistics and the City Government from 2000 to 2013. The analytical method used is the Granger causality and descriptive. Granger causality study results showed no pattern of reciprocal causality, between urban concentration and the quality of the environment, but there unidirectional relationship between the urban concentration and environmental quality. This means that increasing urban concentration led to decreased environmental quality.

  15. Risk and causality in newspaper reporting.

    Science.gov (United States)

    Boholm, Max

    2009-11-01

    The study addresses the textual representation of risk and causality in news media reporting. The analytical framework combines two theoretical perspectives: media frame analysis and the philosophy of causality. Empirical data derive from selected newspaper articles on risks in the Göta älv river valley in southwest Sweden from 1994 to 2007. News media content was coded and analyzed with respect to causal explanations of risk issues. At the level of individual articles, this study finds that the media provide simple causal explanations of risks such as water pollution, landslides, and flooding. Furthermore, these explanations are constructed, or framed, in various ways, the same risk being attributed to different causes in different articles. However, the study demonstrates that a fairly complex picture of risks in the media emerges when extensive material is analyzed systematically.

  16. When Work is Related to Disease, What Establishes Evidence for a Causal Relation?

    Science.gov (United States)

    Verbeek, Jos

    2012-06-01

    Establishing a causal relationship between factors at work and disease is difficult for occupational physicians and researchers. This paper seeks to provide arguments for the judgement of evidence of causality in observational studies that relate work factors to disease. I derived criteria for the judgement of evidence of causality from the following sources: the criteria list of Hill, the approach by Rothman, the methods used by International Agency for Research on Cancer (IARC), and methods used by epidemiologists. The criteria are applied to two cases of putative occupational diseases; breast cancer caused by shift work and aerotoxic syndrome. Only three of the Hill criteria can be applied to an actual study. Rothman stresses the importance of confounding and alternative explanations than the putative cause. IARC closely follows Hill, but they also incorporate other than epidemiological evidence. Applied to shift work and breast cancer, these results have found moderate evidence for a causal relationship, but applied to the aerotoxic syndrome, there is an absence of evidence of causality. There are no ready to use algorithms for judgement of evidence of causality. Criteria from different sources lead to similar results and can make a conclusion of causality more or less likely.

  17. When Work is Related to Disease, What Establishes Evidence for a Causal Relation?

    Directory of Open Access Journals (Sweden)

    Jos Verbeek

    2012-06-01

    Full Text Available Establishing a causal relationship between factors at work and disease is difficult for occupational physicians and researchers. This paper seeks to provide arguments for the judgement of evidence of causality in observational studies that relate work factors to disease. I derived criteria for the judgement of evidence of causality from the following sources: the criteria list of Hill, the approach by Rothman, the methods used by International Agency for Research on Cancer (IARC, and methods used by epidemiologists. The criteria are applied to two cases of putative occupational diseases; breast cancer caused by shift work and aerotoxic syndrome. Only three of the Hill criteria can be applied to an actual study. Rothman stresses the importance of confounding and alternative explanations than the putative cause. IARC closely follows Hill, but they also incorporate other than epidemiological evidence. Applied to shift work and breast cancer, these results have found moderate evidence for a causal relationship, but applied to the aerotoxic syndrome, there is an absence of evidence of causality. There are no ready to use algorithms for judgement of evidence of causality. Criteria from different sources lead to similar results and can make a conclusion of causality more or less likely.

  18. Causales de ausencia de responsabilidad penal

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    Jaime Sandoval Fernández

    2003-01-01

    Full Text Available Este trabajo se ocupa de las causales de ausencia de responsabilidad penal, especialmente de aquellas que tienen efecto en el injusto. Como subtemas se delimita el concepto de responsabilidad penal y su ausencia. Se estudian las principales teorias a cerca de la relación tipicidad-antijuridicidad y su incidencia en el derecho penal colombiano. Por último contiene una propuesta acerca de cómo deberian agruparse las causales del arto 32 C. PlOO.

  19. Dimensions Underlying Measures of Disability, Personal Factors, and Health Status in Cervical Radiculopathy

    Science.gov (United States)

    Halvorsen, Marie; Kierkegaard, Marie; Harms-Ringdahl, Karin; Peolsson, Anneli; Dedering, Åsa

    2015-01-01

    Abstract This cross-sectional study sought to identify dimensions underlying measures of impairment, disability, personal factors, and health status in patients with cervical radiculopathy. One hundred twenty-four patients with magnetic resonance imaging-verified cervical radiculopathy, attending a neurosurgery clinic in Sweden, participated. Data from clinical tests and questionnaires on disability, personal factors, and health status were used in a principal-component analysis (PCA) with oblique rotation. The PCA supported a 3-component model including 14 variables from clinical tests and questionnaires, accounting for 73% of the cumulative percentage. The first component, pain and disability, explained 56%. The second component, health, fear-avoidance beliefs, kinesiophobia, and self-efficacy, explained 9.2%. The third component including anxiety, depression, and catastrophizing explained 7.6%. The strongest-loading variables of each dimension were “present neck pain intensity,” “fear avoidance,” and “anxiety.” The three underlying dimensions identified and labeled Pain and functioning, Health, beliefs, and kinesiophobia, and Mood state and catastrophizing captured aspects of importance for cervical radiculopathy. Since the variables “present neck pain intensity,” “fear avoidance,” and “anxiety” had the strongest loading in each of the three dimensions; it may be important to include them in a reduced multidimensional measurement set in cervical radiculopathy. PMID:26091482

  20. Investigating Causality Between Agricultural and Economic Growth in Iran

    Directory of Open Access Journals (Sweden)

    A. Falsafian

    2010-10-01

    Full Text Available Although rate of economic growth is not the only way to measure economic development, it is relatively more important than the other indices. Agriculture sector plays the main role on economic growth and sustainable development. In addition, it has significant impact on most social, political and economic issues by producing strategic food products for ever-increasing population. Therefore, the present study investigated causal relationship between agricultural and economic growth in Iran. To this end, the Granjer’s causality test was used after employing the Augmented Dicky-Fuller test to see if the variables under consideration are stationary. The result showed that there is a long learn feedback relationship between these variables and agricultural developments.

  1. Stability and causality of multi-local theories

    Science.gov (United States)

    Polonyi, Janos

    2017-11-01

    The regularized theories are non-local at the scale of the cutoff, leading so to the usual difficulties of non-local theories. In this work the conservation laws and causality are investigated for classical field theories with multi-cluster action. The conservation laws are found to play a less significant role than in local theories because due to the non-locality the conserved quantities are not integrals of the motion, and they can exist even without underlying symmetries. Moreover, the conservation of the energy cannot prevent the instability brought about by the unbounded nature of the energy from below. Hence a sufficient condition of stability is lost. Theories, obtained by appropriate point splitting of local interactions are shown to be causal thereby a necessary condition of stability can be retained.

  2. Causal attribution of mental illness in South-Eastern Nigeria.

    Science.gov (United States)

    Ikwuka, Ugo; Galbraith, Niall; Nyatanga, Lovemore

    2014-05-01

    Understanding of mental illness in sub-Saharan Africa has remained under-researched in spite of the high and increasing neuropsychiatric burden of disease in the region. This study investigated the causal beliefs that the Igbo people of south-eastern Nigeria hold about schizophrenia, with a view to establishing the extent to which the population makes psychosocial, biological and supernatural attributions. Multi-stage sampling was used to select participants (N = 200) to which questionnaires were administered. Mean comparison of the three causal models revealed a significant endorsement of supernatural causation. Logistic regressions revealed significant contributions of old age and female gender to supernatural attribution; old age, high education and Catholic religious denomination to psychosocial attributions; and high education to biological attributions. It is hoped that the findings would enlighten, augment literature and enhance mental health care service delivery.

  3. Analysis of automotive rolling lobe air spring under alternative factors with finite element model

    International Nuclear Information System (INIS)

    Wong, Pak Kin; Xie, Zhengchao; Zhao, Jing; Xu, Tao; He, Feng

    2014-01-01

    Air springs are widely used in automotive suspensions for their superior performance in terms of low friction motion, adjustable load carrying capacity and user-friendly ride height control. However, it has posed great difficulties in constructing an accurate model as well as the analysis of the influence of alternative factors, such as cord angle, cord diameter and initial pressure. In this paper, a numerical model of the rolling lobe air spring (RLAS) is built by using finite element method and compared with an existing analytical model. An experiment with respect to the vertical stiffness of the RLAS is carried out to validate the accuracy of the proposed model. Evaluation result reveals that the existing analytical model cannot represent the performance of the RLAS very well, whereas the accuracy of the numerical model is very good. With the verified numerical model, the impacts of many alternative factors on the characteristics of the RLAS are analyzed. Numerical results show that the newly proposed model is reliable to determine the vertical characteristic and physical dimensions of the RLAS under the alternative factors.

  4. Nutritional status and associated factors in under five children of rawalpindi

    International Nuclear Information System (INIS)

    Mahmood, S.; Nadeem, S.; Saif, T.; Mannan, M.; Arshad, U.

    2016-01-01

    Background: Malnutrition is a serious child health issue throughout the developing world. Pakistan has the second highest infant and child mortality rate in South Asia. This study was carried out to assess the nutritional status of children under 5 years of age and to determine the frequency and association of malnutrition with various demographic variables in the study group. Methods: A multi-centre, cross sectional study was conducted at the immunization centres of the 3 allied hospitals of Rawalpindi Medical College during March-May 2014. Healthy children of under 5 years of age without confirmed diagnosis of any disease/ailment were included. Guardians of 100 children were interviewed using a structured questionnaire. Demographic variables include age, gender, family size, family income, breast feeding, maternal education, presence of a family member with special needs and presence of siblings under 5 years in family. Weight (kg) was measured and malnutrition was assessed by weight for age. Results: Malnutrition was found to be present in 32 percentage of children. Adequately nourished children were 68 percentage, while moderately and severely malnourished children were 14 percentage and 18 percentage respectively. Our study indicated malnutrition to be significantly associated with maternal illiteracy (p=0.01) and presence of a family member with special needs (p=0.05). No significant association was found between malnutrition and gender, family size, family income, breast feeding and presence of siblings under 5 years of age. Conclusion: There is a need to plan composite interventions to elucidate the factors that place children at greater risk for malnutrition. (author)

  5. Furthering the representation of causal chains between water and land use in Life Cycle Assessment

    OpenAIRE

    Moxnes, Martin Flaktveit

    2015-01-01

    In this thesis the causal chains between deforestation and increased flood impacts are assessed for expanding the life cycle impact assessment (LCIA) methodology. Until recently the impact categories water use and land use have been treated separately, even though they are closely interrelated in reality. Heuvelmans et al. (2005) established a framework for the causal chains between land use and the water balance, but the work stayed theoretical and operational characterization factors did no...

  6. Entanglement entropy in causal set theory

    Science.gov (United States)

    Sorkin, Rafael D.; Yazdi, Yasaman K.

    2018-04-01

    Entanglement entropy is now widely accepted as having deep connections with quantum gravity. It is therefore desirable to understand it in the context of causal sets, especially since they provide in a natural manner the UV cutoff needed to render entanglement entropy finite. Formulating a notion of entanglement entropy in a causal set is not straightforward because the type of canonical hypersurface-data on which its definition typically relies is not available. Instead, we appeal to the more global expression given in Sorkin (2012 (arXiv:1205.2953)) which, for a Gaussian scalar field, expresses the entropy of a spacetime region in terms of the field’s correlation function within that region (its ‘Wightman function’ W(x, x') ). Carrying this formula over to the causal set, one obtains an entropy which is both finite and of a Lorentz invariant nature. We evaluate this global entropy-expression numerically for certain regions (primarily order-intervals or ‘causal diamonds’) within causal sets of 1  +  1 dimensions. For the causal-set counterpart of the entanglement entropy, we obtain, in the first instance, a result that follows a (spacetime) volume law instead of the expected (spatial) area law. We find, however, that one obtains an area law if one truncates the commutator function (‘Pauli–Jordan operator’) and the Wightman function by projecting out the eigenmodes of the Pauli–Jordan operator whose eigenvalues are too close to zero according to a geometrical criterion which we describe more fully below. In connection with these results and the questions they raise, we also study the ‘entropy of coarse-graining’ generated by thinning out the causal set, and we compare it with what one obtains by similarly thinning out a chain of harmonic oscillators, finding the same, ‘universal’ behaviour in both cases.

  7. Violation of causality in f(T) gravity

    Energy Technology Data Exchange (ETDEWEB)

    Otalora, G. [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile); Reboucas, M.J. [Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, RJ (Brazil)

    2017-11-15

    In the standard formulation, the f(T) field equations are not invariant under local Lorentz transformations, and thus the theory does not inherit the causal structure of special relativity. Actually, even locally violation of causality can occur in this formulation of f(T) gravity. A locally Lorentz covariant f(T) gravity theory has been devised recently, and this local causality problem seems to have been overcome. The non-locality question, however, is left open. If gravitation is to be described by this covariant f(T) gravity theory there are a number of issues that ought to be examined in its context, including the question as to whether its field equations allow homogeneous Goedel-type solutions, which necessarily leads to violation of causality on non-local scale. Here, to look into the potentialities and difficulties of the covariant f(T) theories, we examine whether they admit Goedel-type solutions. We take a combination of a perfect fluid with electromagnetic plus a scalar field as source, and determine a general Goedel-type solution, which contains special solutions in which the essential parameter of Goedel-type geometries, m{sup 2}, defines any class of homogeneous Goedel-type geometries. We show that solutions of the trigonometric and linear classes (m{sup 2} < 0 and m = 0) are permitted only for the combined matter sources with an electromagnetic field matter component. We extended to the context of covariant f(T) gravity a theorem which ensures that any perfect-fluid homogeneous Goedel-type solution defines the same set of Goedel tetrads h{sub A}{sup μ} up to a Lorentz transformation. We also showed that the single massless scalar field generates Goedel-type solution with no closed time-like curves. Even though the covariant f(T) gravity restores Lorentz covariance of the field equations and the local validity of the causality principle, the bare existence of the Goedel-type solutions makes apparent that the covariant formulation of f(T) gravity

  8. Factors underlying anxiety in HIV testing: risk perceptions, stigma, and the patient-provider power dynamic.

    Science.gov (United States)

    Worthington, Catherine; Myers, Ted

    2003-05-01

    Client anxiety is often associated with diagnostic testing. In this study, the authors used a grounded theory approach to examine the situational and social factors underlying anxiety associated with HIV testing, analyzing transcripts from semistructured interviews with 39 HIV test recipients in Ontario, Canada (selected based on HIV serostatus, risk experience, geographic region, gender, and number of HIV tests), then integrating emergent themes with existing research literature. Analysis revealed four themes: perceptions of risk and responsibility for health, stigma associated with HIV, the patient-provider power dynamic, and techniques used by test recipients to enhance control in their interactions with providers. Service implications include modifications to information provision during the test session, attention to privacy and anonymity, and sensitivity to patient-provider interactions.

  9. [Epidemiology and risk factors in injuries due to fall in infants under one year-old].

    Science.gov (United States)

    Jiménez de Domingo, Ana; Rubio García, Elena; Marañon Pardillo, Rafael; Arias Constanti, Vanessa; Frontado Haiek, Luis Alberto; Soriano Arola, Marta; Ripoll Oliveras, Francesc; Remón García, Cristina; Estopiña Ferrer, Gloria; Lorente Romero, Jorge

    2017-06-01

    To describe the epidemiological characteristics of unintentional injuries due to falls in children under one year and to analyse the risk factors associated with severe injuries. This multicentre, observational and cross-sectional study included all children less than one year treated for unintentional fall in the Emergency Departments of 8 Spanish Hospitals, belonging to the «Unintentional Paediatric Injury Workshop» of the Spanish Paediatric Emergency Society, between March 1st, 2014 and February 28th, 2015. Out of 289,887 emergency department cases, 1,022 were due to unintentional falls. The median age was 8 months and 52.5% were males. Fall injuries were more frequent among children aged 9-12 months (37.6%), and 83.5% occurred at home. The most common mechanism was fall from nursery equipment (69.4%), and 47.8% occurred from a height under 50cm. More than two-thirds (68%) of falls were witnessed, but in half of the cases (329) the caregiver was not in area. Serious injuries were seen in 12% of cases. In this study, a fall height greater than 50cm, falls in the street, from the arms of the carer, and from the stairs were identified as independent risk factors for worse outcomes. The most serious injuries occur in children 50cm, though not related to unwitnessed falls. Because the most common serious injury mechanism is the fall from the arms of the carer, from stairs, and falls in the street, these facts should be highlighted in order to avoid morbidity. Copyright © 2015 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. The Arabidopsis Transcription Factor MYB112 Promotes Anthocyanin Formation during Salinity and under High Light Stress.

    Science.gov (United States)

    Lotkowska, Magda E; Tohge, Takayuki; Fernie, Alisdair R; Xue, Gang-Ping; Balazadeh, Salma; Mueller-Roeber, Bernd

    2015-11-01

    MYB transcription factors (TFs) are important regulators of flavonoid biosynthesis in plants. Here, we report MYB112 as a formerly unknown regulator of anthocyanin accumulation in Arabidopsis (Arabidopsis thaliana). Expression profiling after chemically induced overexpression of MYB112 identified 28 up- and 28 down-regulated genes 5 h after inducer treatment, including MYB7 and MYB32, which are both induced. In addition, upon extended induction, MYB112 also positively affects the expression of PRODUCTION OF ANTHOCYANIN PIGMENT1, a key TF of anthocyanin biosynthesis, but acts negatively toward MYB12 and MYB111, which both control flavonol biosynthesis. MYB112 binds to an 8-bp DNA fragment containing the core sequence (A/T/G)(A/C)CC(A/T)(A/G/T)(A/C)(T/C). By electrophoretic mobility shift assay and chromatin immunoprecipitation coupled to quantitative polymerase chain reaction, we show that MYB112 binds in vitro and in vivo to MYB7 and MYB32 promoters, revealing them as direct downstream target genes. We further show that MYB112 expression is up-regulated by salinity and high light stress, environmental parameters that both require the MYB112 TF for anthocyanin accumulation under these stresses. In contrast to several other MYB TFs affecting anthocyanin biosynthesis, MYB112 expression is not controlled by nitrogen limitation or an excess of carbon. Thus, MYB112 constitutes a regulator that promotes anthocyanin accumulation under abiotic stress conditions. © 2015 American Society of Plant Biologists. All Rights Reserved.

  11. Epidemiological characteristics and underlying risk factors for mortality during the autumn 2009 pandemic wave in Mexico.

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    Gerardo Chowell

    Full Text Available BACKGROUND: Elucidating the role of the underlying risk factors for severe outcomes of the 2009 A/H1N1 influenza pandemic could be crucial to define priority risk groups in resource-limited settings in future pandemics. METHODS: We use individual-level clinical data on a large series of ARI (acute respiratory infection hospitalizations from a prospective surveillance system of the Mexican Social Security medical system to analyze clinical features at presentation, admission delays, selected comorbidities and receipt of seasonal vaccine on the risk of A/H1N1-related death. We considered ARI hospitalizations and inpatient-deaths, and recorded demographic, geographic, and medical information on individual patients during August-December, 2009. RESULTS: Seasonal influenza vaccination was associated with a reduced risk of death among A/H1N1 inpatients (OR = 0.43 (95% CI: 0.25, 0.74 after adjustment for age, gender, geography, antiviral treatment, admission delays, comorbidities and medical conditions. However, this result should be interpreted with caution as it could have been affected by factors not directly measured in our study. Moreover, the effect of antiviral treatment against A/H1N1 inpatient death did not reach statistical significance (OR = 0.56 (95% CI: 0.29, 1.10 probably because only 8.9% of A/H1N1 inpatients received antiviral treatment. Moreover, diabetes (OR = 1.6 and immune suppression (OR = 2.3 were statistically significant risk factors for death whereas asthmatic persons (OR = 0.3 or pregnant women (OR = 0.4 experienced a reduced fatality rate among A/H1N1 inpatients. We also observed an increased risk of death among A/H1N1 inpatients with admission delays >2 days after symptom onset (OR = 2.7. Similar associations were also observed for A/H1N1-negative inpatients. CONCLUSIONS: Geographical variation in identified medical risk factors including prevalence of diabetes and immune suppression may in part

  12. Factors influencing the recycling rate under the volume-based waste fee system in South Korea.

    Science.gov (United States)

    Park, Seejeen

    2018-04-01

    Since the early 2000s, the Republic of Korea (South Korea) has maintained its top-rank status for its municipal solid waste (MSW) recycling rate among OECD (Organization for Economic Cooperation and Development) member countries. The volume-based waste fee system (VWF) has been considered to be the major factor contributing to the high recycling performance, and extant research has verified the positive relationship between VWF adoption and the MSW recycling rate. Nevertheless, there exists a gap in the literature, as past research has focused more on testing the positive effects of VWF rather than on investigating the determinants of recycling rates after the adoption of VWF. The current study seeks to address this gap by investigating the various factors that affect recycling rates under the VWF system. More specifically, using data from 16 regions in South Korea over a period of 11 years, this study empirically tests the effects of VWF pricing, the citizen cost burden ratio for the VWF system, and pro-environmental behavior related to VWF on the recycling rate. The findings indicate that economic incentives such as cost savings on VWF plastic bag purchases and reduced burden from paying VWF expenses result in higher recycling rates. The findings also demonstrate that pro-environmental behavior in the VWF context positively affects the recycling rate. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Horse impoundments under Control of Horses legislation in the Munster region of Ireland: factors affecting euthanasia.

    Science.gov (United States)

    Cullinane, M; O'Sullivan, E; Collins, D M; Byrne, A W; More, S J

    2015-01-24

    Recently, considerable international attention has been paid to the problem of unwanted horses. In Ireland, stray horses, particularly in urban areas, are a further problem. The Control of Horses Act 1996 was enacted in response to an ongoing problem of uncontrolled horses in public places. As yet, no research work has been conducted focusing on stray horses in Ireland. This paper describes horses impounded under the Act in the Munster region of Ireland during 2005-2012 and the factors influencing decisions regarding their disposal. A logistic regression model was developed to investigate factors influencing the probability that a horse was euthanised during impoundment. In total, 3625 seizure events were recorded, most towards the end of the study period. Predictors for euthanasia during 2010-2012 included seizure location, sex, age, colour, body condition score and year. This study highlights the problem of stray horses in Ireland, particularly in urban areas. There is a need for rigorous enforcement of newly enacted horse identification legislation, allowing a fully integrated traceability system. More is required to manage the long-established societal problems of stray horses in urban settings, with a uniform approach by all Local Authorities being long overdue. British Veterinary Association.

  14. Hygiene and sanitation risk factors of diarrhoeal disease among under-five children in Ibadan, Nigeria.

    Science.gov (United States)

    Oloruntoba, Elizabeth Omoladun; Folarin, Taiwo Bukola; Ayede, Adejumoke Idowu

    2014-12-01

    Diarrhoea diseases are among the leading causes of morbidity and mortality in under-five-children (U-5C) in Nigeria. Inadequate safe water, sanitation, and hygiene account for the disease burden. Cases of diarrhoea still occur in high proportion in the study area despite government-oriented interventions. To determine the hygiene and sanitation risk factors predisposing U-5C to diarrhoea in Ibadan, Nigeria. Two hundred and twenty pairs of children, matched on age, were recruited as cases and controls over a period of 5 months in Ibadan. Questionnaire and observation checklist were used to obtain information on hygiene practices from caregivers/mothers and sanitation conditions in the households of 30% of the consenting mothers/caregivers. Data were analysed using descriptive and inferential statistics. Caregivers/mothers' mean ages were 31.3 ±7.5 (cases) and 30.6 ±6.0(controls) years. The risk of diarrhoea was significantly higher among children whose mothers did not wash hands with soap before food preparation (OR=3.0, psanitation conditions within households were risk factors for diarrhoea. This study revealed the feasibility of developing and implementing an adequate model to establish intervention priorities in sanitation in Ibadan, Nigeria.

  15. Association between maternal socioeconomic factors and nutritional outcomes in children under 5 years of age,

    Directory of Open Access Journals (Sweden)

    Tatiane Géa-Horta

    Full Text Available Abstract Objective: To estimate the association between maternal socioeconomic factors and the occurrence of nutritional outcomes in children under five years of age in a representative sample of the Brazilian population. Methods: This was a cross-sectional study that evaluated data from the latest National Survey of Children and Women's Demographics and Health, carried out in Brazil in 2006-2007. Maternal employment and maternal level of schooling were the main exposures. The following nutritional outcomes in children were considered: height/age 2SD for overweight. Generalized estimating equations (GEE were utilized as the regression method. Results: After adjustments, it was observed that children whose mothers had low level of schooling had a higher chance of having short stature (OR = 3.97, 95% CI, 1.23-12.80 and children whose mothers worked outside the home were more likely to have excess weight (OR = 1.57, 95% CI, 1.02-2.42. Maternal employment was not associated with short stature in children (OR = 1.09, 95% CI, 0.67-1.77. Conclusion: Maternal level of schooling was associated with short stature in children and maternal employment with overweight, indicating the need to take into account the socioeconomic factors when proposing programs and strategies aimed at health and nutrition improvement of children, considering inter-sectoral interventions.

  16. Associated factors of malnutrition among African children under five years old, Bom Jesus, Angola

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    Ema Cândida Branco FERNANDES

    Full Text Available ABSTRACT Objective: To identify the determinants of wasting and stunting in children under five years old in the commune of Bom Jesus, Angola Methods: A population-based cross-sectional study was conducted with 742 children in 2010, and nutritional deficits were defined by World Health Organization criteria. Prevalence ratios and associated factors of wasting and stunting were estimated using Poisson regression with robust variance, using a conceptual hierarchical model Results: For both deficits, there were significant differences in the prevalence ratios according to the children's neighborhood and age. Boys and those children living in households whose water supply came from the river or lake, as well those with recent expulsion of parasites and infections were more likely to present stunting. Children of fathers with higher number of children or that which the fathers were not living at home and whose mothers were 25-34 years old were less likely to have wasting Conclusion: It was identified independent variables from different levels of determination of malnutrition, standing out the basic sanitation conditions and family structure as important predictors of the nutritional deficits. The knowledge of the associated factors of malnutrition may contribute for subside public policies in planning interventions to improve the childhood nutrition status in Bom Jesus and communes with similar characteristics in Angola.

  17. Hypoxia-inducible factor 1-mediated human GATA1 induction promotes erythroid differentiation under hypoxic conditions.

    Science.gov (United States)

    Zhang, Feng-Lin; Shen, Guo-Min; Liu, Xiao-Ling; Wang, Fang; Zhao, Ying-Ze; Zhang, Jun-Wu

    2012-08-01

    Hypoxia-inducible factor promotes erythropoiesis through coordinated cell type-specific hypoxia responses. GATA1 is essential to normal erythropoiesis and plays a crucial role in erythroid differentiation. In this study, we show that hypoxia-induced GATA1 expression is mediated by HIF1 in erythroid cells. Under hypoxic conditions, significantly increased GATA1 mRNA and protein levels were detected in K562 cells and erythroid induction cultures of CD34(+) haematopoietic stem/progenitor cells. Enforced HIF1α expression increased GATA1 expression, while HIF1α knockdown by RNA interference decreased GATA1 expression. In silico analysis revealed one potential hypoxia response element (HRE). The results from reporter gene and mutation analysis suggested that this element is necessary for hypoxic response. Chromatin immunoprecipitation (ChIP)-PCR showed that the putative HRE was recognized and bound by HIF1 in vivo. These results demonstrate that the up-regulation of GATA1 during hypoxia is directly mediated by HIF1.The mRNA expression of some erythroid differentiation markers was increased under hypoxic conditions, but decreased with RNA interference of HIF1α or GATA1. Flow cytometry analysis also indicated that hypoxia, desferrioxamine or CoCl(2) induced expression of erythroid surface markers CD71 and CD235a, while expression repression of HIF1α or GATA1 by RNA interference led to a decreased expression of CD235a. These results suggested that HIF1-mediated GATA1 up-regulation promotes erythropoiesis in order to satisfy the needs of an organism under hypoxic conditions. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  18. Tachyon kinematics and causality: A systematic, thorough analysis

    International Nuclear Information System (INIS)

    Recami, E.

    1985-01-01

    The chronological order of the events along a space-like path is not invariant under Lorentz transformations, as wellknown. This led to an early conviction that tachyons would give rise to causal anomalies. A relativistic version of the Stuckelberg-Feynman 'switching procedure' (SWP) has been invoked as the suitable tool to eliminate those anomalies. The application of the 'SWP' does eliminate the motions backwards in time, but interchanges the roles of source and detector. This fact triggered the proposal of a host of causal 'paradoxes'. Till now, however, it has not been recognized that such paradoxes can be sensibly discussed (and completely solved, at least 'in microphysics') only after having properly developed the tachyon relativistic mechanics. It is shown how to apply the 'SWP', both in the case of ordinary Special Relativity, and in the case with tachyons. Then, the kinematics of the tachyon-exchange between two (ordinary) bodies is carrefully exploited. Being finally able to tackle the tachyon-causality problem, the paradoxes are sucessively solved: (i) by Tolman-Regge; (ii) by Pirani; (iii) by Edmonds; (iv) by Bell. At last, a further new paradox associated with the transmission of signals by modulated tachyon beams is discussed. (Author) [pt

  19. The Relevance of Causal Social Construction

    Directory of Open Access Journals (Sweden)

    Marques Teresa

    2017-02-01

    Full Text Available Social constructionist claims are surprising and interesting when they entail that presumably natural kinds are in fact socially constructed. The claims are interesting because of their theoretical and political importance. Authors like Díaz-León argue that constitutive social construction is more relevant for achieving social justice than causal social construction. This paper challenges this claim. Assuming there are socially salient groups that are discriminated against, the paper presents a dilemma: if there were no constitutively constructed social kinds, the causes of the discrimination of existing social groups would have to be addressed, and understanding causal social construction would be relevant to achieve social justice. On the other hand, not all possible constitutively socially constructed kinds are actual social kinds. If an existing social group is constitutively constructed as a social kind K, the fact that it actually exists as a K has social causes. Again, causal social construction is relevant. The paper argues that (i for any actual social kind X, if X is constitutively socially constructed as K, then it is also causally socially constructed; and (ii causal social construction is at least as relevant as constitutive social construction for concerns of social justice. For illustration, I draw upon two phenomena that are presumed to contribute towards the discrimination of women: (i the poor performance effects of stereotype threat, and (ii the silencing effects of gendered language use.

  20. Socio-demographic factors related to under-diagnosis of childhood asthma in Upper Silesia, Poland.

    Science.gov (United States)

    Zejda, Jan E; Farnik, Małgorzata; Smółka, Irena; Lawson, Joshua; Brożek, Grzegorz M

    2017-06-07

    Introduction. The presented study of 4,535 children aged 7-17 years in the Upper Silesian region of Poland yielded 186 cases of previously known asthma, and 44 children with newly diagnosed asthma. The aim of the presented study was to identify non-medical factors that could explain why children with a newly established diagnosis ('undiagnosed asthma') had not been diagnosed in the past. Materials and method. The study was performed according to a case-control design. Parents of the children answered questionnaires on socio-economic status and family-related factors. Statistical determinants of undiagnosed asthma were explored using raw (OR) and logistic odds ratios with their 95% confidence intervals (logOR, 95%CI). Results. Children with undiagnosed asthma were younger compared to the group with previously known asthma (11.3±2.1 vs. 12.6±2.5 years; p=0.0008). Newly diagnosed cases were more frequent in children who had less parental attention (less than 1 hour/day spent by parent with child - OR=4.36; 95%CI: 1.76-10.81) and who were not registered with specialized health care (OR=2.20; 95%CI: 0.95-5.06). Results of logistic regression analysis suggest that under-diagnosis of asthma is related to age below 12 years - logOR = 3.59 (95%CI: 1.28-10.36), distance to a health centre > 5 km - logOR = 3.45 (95%CI: 1.05-11.36), time spent with child Conclusion. Among non-medical determinants of undiagnosed asthma the age of a child plays a major role. Another factors of importance is the large distance between residence and health centre, and low parental attention at home.

  1. Biophysical and sociocultural factors underlying spatial trade-offs of ecosystem services in semiarid watersheds

    Directory of Open Access Journals (Sweden)

    Marina García-Llorente

    2015-09-01

    Full Text Available Biophysical and social systems are linked to form social-ecological systems whose sustainability depends on their capacity to absorb uncertainty and cope with disturbances. In this study, we explored the key biophysical and socio-cultural factors underlying ecosystem service supply in two semiarid watersheds of southern Spain. These included variables associated with the role that freshwater flows and biodiversity play in securing the system's capacity to sustain essential ecosystem services and their relationship with social demand for services, local water governance, and land-use intensification. Our results reveal the importance of considering the invisible dimensions of water and biodiversity, i.e. green freshwater flows and trait-based indicators, because of their relevance to the supply of ecosystem services. Furthermore, they uncover the importance of traditional irrigation canals, a local water governance system, in maintaining the ecosystems' capacity to supply services. The study also highlights the complex trade-offs that occur because of the spatial mismatch between ecosystem service supply (upstream and ecosystem service demand (downstream in watersheds. Finally, we found that land-use intensification generally resulted in losses of the biophysical factors that underpin the supply of some ecosystem services, increases in social demand for less diversified services, and the abandonment of local governance practices. Attempts to manage social-ecological systems toward sustainability at the local scale should identify the key biophysical and socio-cultural factors that are essential for maintaining ecosystem services and should recognize existing interrelationships between them. Land-use management should also take into account ecosystem service trade-offs and the consequences resulting from land-use intensification.

  2. Variability of photosynthetic parameters of Pinus sibirica Du Tour needles under changing climatic factors

    Directory of Open Access Journals (Sweden)

    A.P. Zotikova

    2013-12-01

    Full Text Available The air temperature and relative humidity and the intensity of photosynthetically active radiation are the basic ecological factors determining geographical distribution of a species. Wood plant adaptation depends on the intensity of physiological and biochemicalprocesses of plants as a response to changing environmental factors. Investigations to reveal (detect the variability of modification andgenetic components of the photosynthetic parameters in needles of the Siberian cedar (Pinus sibirica Du Tour mountain ecotypes, distributed in central part of the Altai Mountains, were carried out. Also, the survey was extended to some experiments with these ecotypes introduced to mild climate and flat regions from south-western of Siberia. The length and thickness of needles, the size of chloroplasts, content of the photosynthetic pigments, and the functional activity of chloroplastsat the level of photo system II were the evaluated traits. Growing under mountainous conditions (at about 2000m elevation, the two-year-old needles were shorter and thicker and contained very large in size chloroplasts while the content of chlorophylls and carotinoids was twice lower than that in the local ecotype growing in the lowlands. On the other hand, more green and yellow pigments were found in needles of mountain ecotypes planted in the lowlands compared to the local lowland ectype trees. A decrease in pool of the photosynthetic pigments in the highlands ecotypes is probably due to decreased biosynthesis andincreased photo-destruction caused by severe light and temperature conditions. These parameters are likely to be associated withmodifications due to intense insolation, low temperature, ozone concentration, UV radiation, and other negative factors that are morepronounced at high elevation. Despite the large pool of accumulated photosynthetic pigments, the functional activity of chloroplasts in themountain ecotype at the level

  3. Causal binding of actions to their effects.

    Science.gov (United States)

    Buehner, Marc J; Humphreys, Gruffydd R

    2009-10-01

    According to widely held views in cognitive science harking back to David Hume, causality cannot be perceived directly, but instead is inferred from patterns of sensory experience, and the quality of these inferences is determined by perceivable quantities such as contingency and contiguity. We report results that suggest a reversal of Hume's conjecture: People's sense of time is warped by the experience of causality. In a stimulus-anticipation task, participants' response behavior reflected a shortened experience of time in the case of target stimuli participants themselves had generated, relative to equidistant, equally predictable stimuli they had not caused. These findings suggest that causality in the mind leads to temporal binding of cause and effect, and extend and generalize beyond earlier claims of intentional binding between action and outcome.

  4. Normalizing the causality between time series

    Science.gov (United States)

    Liang, X. San

    2015-08-01

    Recently, a rigorous yet concise formula was derived to evaluate information flow, and hence the causality in a quantitative sense, between time series. To assess the importance of a resulting causality, it needs to be normalized. The normalization is achieved through distinguishing a Lyapunov exponent-like, one-dimensional phase-space stretching rate and a noise-to-signal ratio from the rate of information flow in the balance of the marginal entropy evolution of the flow recipient. It is verified with autoregressive models and applied to a real financial analysis problem. An unusually strong one-way causality is identified from IBM (International Business Machines Corporation) to GE (General Electric Company) in their early era, revealing to us an old story, which has almost faded into oblivion, about "Seven Dwarfs" competing with a giant for the mainframe computer market.

  5. Spatial hypersurfaces in causal set cosmology

    International Nuclear Information System (INIS)

    Major, Seth A; Rideout, David; Surya, Sumati

    2006-01-01

    Within the causal set approach to quantum gravity, a discrete analogue of a spacelike region is a set of unrelated elements, or an antichain. In the continuum approximation of the theory, a moment-of-time hypersurface is well represented by an inextendible antichain. We construct a richer structure corresponding to a thickening of this antichain containing non-trivial geometric and topological information. We find that covariant observables can be associated with such thickened antichains and transitions between them, in classical sequential growth models of causal sets. This construction highlights the difference between the covariant measure on causal set cosmology and the standard sum-over-histories approach: the measure is assigned to completed histories rather than to histories on a restricted spacetime region. The resulting re-phrasing of the sum-over-histories may be fruitful in other approaches to quantum gravity

  6. Factors responsible for under-utilization of postnatal care services in Maiduguri, north-eastern Nigeria

    Directory of Open Access Journals (Sweden)

    Idris Usman Takai

    2015-01-01

    Full Text Available Background: In Maiduguri, the utilization of available postnatal care services is still very low. This may be influenced by demographic, socioeconomic, cultural, and obstetric factors among others. Objective: The aim of this study is to understand the current status of utilization of maternal postnatal health care services and identify factors responsible for under.utilization of available postnatal care services in Maiduguri. Materials and Methods: A. cross.sectional, questionnaire.based study was conducted involving 350 women in their reproductive age group. (15.49. years, who had delivered previously, residing in Maiduguri and who came to access any of the available maternal health care services at the State Specialist Hospital, Maiduguri over a 3.month period. The Chi.squared statistics and multivariate logistic regression analysis were used. Results: Out of the grand total of 350 questionnaires that were distributed during the study period, 18 questionnaires were excluded from analysis due to incomplete responses, 332 with complete responses were therefore analyzed, giving a response rate of 94.9%. The results showed that only 16.9% of the respondents attended postnatal care services within 42. days after delivery. Most of the mothers. (60.9% were not knowledgeable about postnatal care services. A. very high proportion of participants. (69.4% did not attend antenatal clinics, and over. 70% of the study population had delivered at home. The study has identified some factors that have an important influence on utilization of postnatal care services in Maiduguri. These included awareness of postnatal care services. (odds ratio. [OR] 12.04, 95% confidence interval. [CI]: 10.26, P =. 0.000, higher educational status of the woman. (OR 7.15, 95% CI: 5.19, P =0.000, lower parity. (OR 5.22, 95% CI: 3.21, P = 0.001 and marital status. (married woman.OR 3.44, 95% CI: 2.17, P =0.002. Educational attainment of the husband also significantly affected the

  7. Accounting for occurrences: an explanation for some novel tendencies in causal judgment from contingency information.

    Science.gov (United States)

    White, Peter A

    2009-06-01

    Contingency information is information about empirical associations between possible causes and outcomes. In the present research, it is shown that, under some circumstances, there is a tendency for negative contingencies to lead to positive causal judgments and for positive contingencies to lead to negative causal judgments. If there is a high proportion of instances in which a candidate cause (CC) being judged is present, these tendencies are predicted by weighted averaging models of causal judgment. If the proportion of such instances is low, the predictions of weighted averaging models break down. It is argued that one of the main aims of causal judgment is to account for occurrences of the outcome. Thus, a CC is not given a high causal judgment if there are few or no occurrences of it, regardless of the objective contingency. This argument predicts that, if there is a low proportion of instances in which a CC is present, causal judgments are determined mainly by the number of Cell A instances (i.e., CC present, outcome occurs), and that this explains why weighted averaging models fail to predict judgmental tendencies under these circumstances. Experimental results support this argument.

  8. Inferring causality from noisy time series data

    DEFF Research Database (Denmark)

    Mønster, Dan; Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    Convergent Cross-Mapping (CCM) has shown high potential to perform causal inference in the absence of models. We assess the strengths and weaknesses of the method by varying coupling strength and noise levels in coupled logistic maps. We find that CCM fails to infer accurate coupling strength...... and even causality direction in synchronized time-series and in the presence of intermediate coupling. We find that the presence of noise deterministically reduces the level of cross-mapping fidelity, while the convergence rate exhibits higher levels of robustness. Finally, we propose that controlled noise...

  9. The role of causal maps in intellectual capital measurement and management

    DEFF Research Database (Denmark)

    Montemari, Marco; Nielsen, Christian

    2013-01-01

    model Findings – This paper illustrates how causal mapping can be used to understand how intellectual capital really works in the specific business context in which it is deployed. Moreover, exploiting the causal map as a platform for detracting a set of indicators can provide information on the length......Purpose – The purpose of this paper is to investigate the measurement and the management of the dynamic aspects of intellectual capital through the use of causal mapping. Design/methodology/approach – The study details the methods utilized in a single in-depth case study of a network-based business...... of the lag and the persistence of the effects of managerial actions. In addition, it can signal when and how to refine and update the causal map. The combination of these factors supports the dynamic measurement and management of intellectual capital. Research limitations/implications – The paper presented...

  10. Causality Illusion and Overconfidence in Predicting (QuasiStochastic Financial Events

    Directory of Open Access Journals (Sweden)

    Petr Houdek

    2017-03-01

    Full Text Available We argue that individuals systematically interpret sequences of events in a  causal manner. The aim of this article is to show that people do so even if they are aware of the stochastic nature of the respective sequence. The bias can explain some anomalous behaviour of investors in financial markets. Small as well as professional investors may illusorily perceive causality of former random success and future yield. Laboratory experiments testing the interpretation of stochastically occurring events in financial designs as well as analyses of real trading data from financial markets confirm that investors indeed interpret (quasirandom events casually; they make incorrect predictions and they egocentrically allocate responsibility for their success. The causality illusion induces overconfidence, inefficient investment and risk seeking. In the conclusion, we discuss factors that may limit effects of the causality illusion and suggest future areas for research.

  11. Assessing the validity of road safety evaluation studies by analysing causal chains.

    Science.gov (United States)

    Elvik, Rune

    2003-09-01

    This paper discusses how the validity of road safety evaluation studies can be assessed by analysing causal chains. A causal chain denotes the path through which a road safety measure influences the number of accidents. Two cases are examined. One involves chemical de-icing of roads (salting). The intended causal chain of this measure is: spread of salt --> removal of snow and ice from the road surface --> improved friction --> shorter stopping distance --> fewer accidents. A Norwegian study that evaluated the effects of salting on accident rate provides information that describes this causal chain. This information indicates that the study overestimated the effect of salting on accident rate, and suggests that this estimate is influenced by confounding variables the study did not control for. The other case involves a traffic club for children. The intended causal chain in this study was: join the club --> improve knowledge --> improve behaviour --> reduce accident rate. In this case, results are rather messy, which suggests that the observed difference in accident rate between members and non-members of the traffic club is not primarily attributable to membership in the club. The two cases show that by analysing causal chains, one may uncover confounding factors that were not adequately controlled in a study. Lack of control for confounding factors remains the most serious threat to the validity of road safety evaluation studies.

  12. Parents' and pupils' causal attributions for difficult classroom behaviour.

    Science.gov (United States)

    Miller, Andy; Ferguson, Eamonn; Moore, Eleanor

    2002-03-01

    Studies of causal attributions for difficult pupil behaviour in schools have tended to focus on the perspectives of teachers. The present study examines the causal attributions made by parents for difficult behaviour in classrooms. It reveals the structure of these attributions and serves as a direct comparison to a previous study of pupils' attributions (Miller, Ferguson, & Byrne, 2000) and, more indirectly, with the teacher studies. The participants were 144 parents (106 mothers and 38 fathers) whose children all attended the same inner city school. A questionnaire was constructed following three initial small group interviews with parents to identify the wide range of factors they viewed as potential causes of difficult classroom behaviour. This was then administered to all the parents of children attending the same inner-city primary school. Factor analysis indicated that parents' attributions for misbehaviour were best represented by three factors: (1) 'fairness of teachers' actions', (2) 'pupil vulnerability to peer influences and adverse family circumstances', and (3) 'differentiation of classroom demands and expectations'. While there were no differences between parents in terms of gender or ethnicity, they did see the first two factors as more significant contributors to pupil misbehaviour than the third. There is both agreement and conflict between parents' attributions and those made by pupils and by teachers. The implementation of policy initiatives, such as home-school agreements and Pastoral Support Programmes, risk exacerbating tensions and difficulties if these differences in attributions are not acknowledged and acted upon.

  13. Thyroid functional disease: an under-recognized cardiovascular risk factor in kidney disease patients

    Science.gov (United States)

    Rhee, Connie M.; Brent, Gregory A.; Kovesdy, Csaba P.; Soldin, Offie P.; Nguyen, Danh; Budoff, Matthew J.; Brunelli, Steven M.; Kalantar-Zadeh, Kamyar

    2015-01-01

    Thyroid functional disease, and in particular hypothyroidism, is highly prevalent among chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients. In the general population, hypothyroidism is associated with impaired cardiac contractility, endothelial dysfunction, atherosclerosis and possibly higher cardiovascular mortality. It has been hypothesized that hypothyroidism is an under-recognized, modifiable risk factor for the enormous burden of cardiovascular disease and death in CKD and ESRD, but this has been difficult to test due to the challenge of accurate thyroid functional assessment in uremia. Low thyroid hormone levels (i.e. triiodothyronine) have been associated with adverse cardiovascular sequelae in CKD and ESRD patients, but these metrics are confounded by malnutrition, inflammation and comorbid states, and hence may signify nonthyroidal illness (i.e. thyroid functional test derangements associated with underlying ill health in the absence of thyroid pathology). Thyrotropin is considered a sensitive and specific thyroid function measure that may more accurately classify hypothyroidism, but few studies have examined the clinical significance of thyrotropin-defined hypothyroidism in CKD and ESRD. Of even greater uncertainty are the risks and benefits of thyroid hormone replacement, which bear a narrow therapeutic-to-toxic window and are frequently prescribed to CKD and ESRD patients. In this review, we discuss mechanisms by which hypothyroidism adversely affects cardiovascular health; examine the prognostic implications of hypothyroidism, thyroid hormone alterations and exogenous thyroid hormone replacement in CKD and ESRD; and identify areas of uncertainty related to the interplay between hypothyroidism, cardiovascular disease and kidney disease requiring further investigation. PMID:24574542

  14. Following The Trail: Factors Underlying the Sudden Expansion of the Egyptian Mongoose (Herpestes ichneumon) in Portugal

    Science.gov (United States)

    Barros, Tânia; Carvalho, João; Pereira, Maria João Ramos; Ferreira, Joaquim P.; Fonseca, Carlos

    2015-01-01

    Species range-limits are influenced by a combination of several factors. In our study we aimed to unveil the drivers underlying the expansion of the Egyptian mongoose in Portugal, a carnivore that was confined to southern Portugal and largely increased its range during the last three decades. We evaluated the expansion of the species in three periods (1980-1990, 1990-2000 and 2000-2010), by projecting the presence/absence data of the species in each temporal range and proposed four hypotheses to explain this sudden expansion associated to changes in the barrier effects of human infrastructure and topographic features, and in the availability of suitable areas due to climate change or land use. An exploratory analysis was made using Spearman rank correlation, followed by a hierarchical partitioning analysis to select uncorrelated potential explanatory variables associated with the different hypotheses. We then ran Generalized Linear Models (GLM) for every period for each hypothesis and for every combination of hypotheses. Our main findings suggest that dynamic transitions of land-use coupled with temperature and rainfall variations over the decades are the main drivers promoting the mongoose expansion. The geographic barriers and the human infrastructures functioned as barriers for mongoose expansion and have shaped its distribution. The expansion of the Egyptian mongoose across the Portuguese territory was due to a variety of factors. Our results suggest a rapid shift in species range in response to land-use and climate changes, underlining the close link between species ranges and a changing environment. PMID:26266939

  15. Incidence of academic failure and its underlying factors in Lorestan university of medical sciences

    Directory of Open Access Journals (Sweden)

    Farzad Ebrahimzadeh

    2016-02-01

    Full Text Available Background: Academic failure, conceived of as lack of success in one’s education, is of paramount importance for students of medical sciences and it might lead to more acute problems. The present study set out to investigate the prevalence and underlying reasons of academic failure in Lorestan University of medical sciences.  Materials and Methods: In this cohort study, academic records of all students of Lorestan University of Medical Sciences during the academic years of 2006-2011 were collected from education and student affair center and also, demographic and educational records were entered into a checklist. Inappropriate grade point average, being a provisional student, prolonged graduation, expulsion and dropout were taken into account as academic failure. To model the related effective factors, logistic regression was adopted and significance level was set at 0.05. Results: The cumulative incidence of academic failure was about 25.1%. Factors such as department, being self-funded or government-funded student, academic grade students are pursuing, the elapsed time between academic grades, gender and location of residence were related to academic failure (P<0.05. It is worth mentioning that no relationship was observed between the academic failure and being accepted based on quota system. Conclusion: The most important at risk groups were students of department of medicine and health, associate or medical doctoral students, self-funded students, students with a considerable time elapsed between their academic grades, male students and students living in dormitory. It is suggested that these students refer to consulting centers of university or educational supervisors and receive particular attention.

  16. 75 FR 7212 - Definition of “Reasonable Factors Other Than Age” Under the Age Discrimination in Employment Act

    Science.gov (United States)

    2010-02-18

    ... ``remarkable similarity between the congressional goals'' of Title VII and ``those present in the Wirtz Report... factors other than age.'' \\8\\ The RFOA provision ``plays its principal role'' in disparate impact cases... Factors Other Than Age'' Under the Age Discrimination in Employment Act AGENCY: Equal Employment...

  17. A Lagrange multiplier-type test for idiosyncratic unit roots in the exact factor model under misspecification

    NARCIS (Netherlands)

    Zhou, X.; Solberger, M.

    2013-01-01

    We consider an exact factor model and derive a Lagrange multiplier-type test for unit roots in the idiosyncratic components. The asymptotic distribution of the statistic is derived under the misspecification that the differenced factors are white noise. We prove that the asymptotic distribution is

  18. Causality in criminal forensic and in civil disability cases: Legal and psychological comparison.

    Science.gov (United States)

    Young, Gerald

    2015-01-01

    Causality (or causation) is central to every legal case, yet its underlying philosophical, legal, and psychological definitions and conceptions vary. In the criminal context, it refers to establishing the responsibility of the perpetrator of the criminal act at issue in terms of the person's mental state (mens rea), and whether the insanity defense applies. In the forensic disability and related context, it refers to whether the index event is a material or contributing cause in the multifactorial array that led to the psychological condition at issue. In both the criminal and tort contexts, the legal test is a counterfactual one. For the former, it refers to whether the outcome involved would have resulted absent the act (e.g., in cases of simultaneous criminal lethal action, which one is the but-for responsible one). For the latter, it concerns whether the claimed psychological condition would be present only because of the incident at issue. The latter event at issue is distinguished from the criminal one by its negligence compared to the voluntary intent in the criminal case. The psychological state of the perpetrator of criminal conduct can be analyzed from a biopsychosocial perspective as much as the civil one. In this regard, in the civil case, such as in forensic disability and related assessments, pre-existing, precipitating, and perpetuating factors need to be considered causally, with personal and social resilience and protective factors added, as well. In the criminal context, the same biopsychosocial model applies, but with mental competence and voluntariness added as a critical factor. The advent of neurolaw has led to use of neuroscience in court, but it risks reducing the complexity of criminal cases to unifactorial, biological models. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. CausalTrail: Testing hypothesis using causal Bayesian networks [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Daniel Stöckel

    2015-12-01

    Full Text Available Summary Causal Bayesian Networks are a special class of Bayesian networks in which the hierarchy directly encodes the causal relationships between the variables. This allows to compute the effect of interventions, which are external changes to the system, caused by e.g. gene knockouts or an administered drug. Whereas numerous packages for constructing causal Bayesian networks are available, hardly any program targeted at downstream analysis exists. In this paper we present CausalTrail, a tool for performing reasoning on causal Bayesian networks using the do-calculus. CausalTrail's features include multiple data import methods, a flexible query language for formulating hypotheses, as well as an intuitive graphical user interface. The program is able to account for missing data and thus can be readily applied in multi-omics settings where it is common that not all measurements are performed for all samples. Availability and Implementation CausalTrail is implemented in C++ using the Boost and Qt5 libraries. It can be obtained from https://github.com/dstoeckel/causaltrail

  20. Somatoform disorders and causal attributions in patients with suspected allergies: Do somatic causal attributions matter?

    Science.gov (United States)

    Groben, Sylvie; Hausteiner, Constanze

    2011-03-01

    Somatic causal illness attributions are being considered as potential positive criteria for somatoform disorders (SFDs) in DSM-V. The aim of this study was to investigate whether patients diagnosed with SFDs tend towards a predominantly somatic attribution style. We compared the causal illness attributions of 48 SFD and 149 non-somatoform disorder patients, in a sample of patients presenting for an allergy diagnostic work-up, and those of 47 controls hospitalised for allergen-specific venom immunotherapy. The SFD diagnosis was established by means of the Structured Clinical Interview for DSM-IV. Both spontaneous and prompted causal illness attributions were recorded through interview and by means of the causal dimension of the Revised Illness Perception Questionnaire (IPQ-R), respectively. Patients' spontaneous and prompted responses were assigned to a psychosocial, somatic, or mixed attribution style. Both in the free-response task and in their responses to the IPQ-R, SFD patients were no more likely than their nonsomatoform counterparts to focus on somatic explanations for their symptoms. They were just as likely to make psychosocial or mixed causal attributions. However, patients with SFDs were significantly more likely to find fault with medical care in the past. Our data do not support the use of somatic causal illness attributions as positive criteria for SFDs. They confirm the dynamic and multidimensional nature of causal illness attributions. Clinical implications of these findings are discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Diarrhea Prevalence, Care, and Risk Factors Among Poor Children Under 5 Years of Age in Mesoamerica.

    Science.gov (United States)

    Colombara, Danny V; Hernández, Bernardo; McNellan, Claire R; Desai, Sima S; Gagnier, Marielle C; Haakenstad, Annie; Johanns, Casey; Palmisano, Erin B; Ríos-Zertuche, Diego; Schaefer, Alexandra; Zúñiga-Brenes, Paola; Zyznieuski, Nicholas; Iriarte, Emma; Mokdad, Ali H

    2016-03-01

    Care practices and risk factors for diarrhea among impoverished communities across Mesoamerica are unknown. Using Salud Mesoamérica Initiative baseline data, collected 2011-2013, we assessed the prevalence of diarrhea, adherence to evidence-based treatment guidelines, and potential diarrhea correlates in poor and indigenous communities across Mesoamerica. This study surveyed 14,500 children under 5 years of age in poor areas of El Salvador, Guatemala, Mexico (Chiapas State), Nicaragua, and Panama. We compared diarrhea prevalence and treatment modalities using χ(2) tests and used multivariable Poisson regression models to calculate adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) for potential correlates of diarrhea. The 2-week point prevalence of diarrhea was 13% overall, with significant differences between countries (P < 0.05). Approximately one-third of diarrheal children were given oral rehydration solution and less than 3% were given zinc. Approximately 18% were given much less to drink than usual or nothing to drink at all. Antimotility medication was given to 17% of diarrheal children, while antibiotics were inappropriately given to 36%. In a multivariable regression model, compared with children 0-5 months, those 6-23 months had a 49% increased risk for diarrhea (aRR = 1.49, 95% CI = 1.15, 1.95). Our results call for programs to examine and remedy low adherence to evidence-based treatment guidelines. © The American Society of Tropical Medicine and Hygiene.

  2. Marital incompatibility among couples living in rural Gonabad and underlying factors

    Directory of Open Access Journals (Sweden)

    Fateme Pirnahad

    2017-06-01

    Full Text Available Iranian families face many challenges these days. This study aimed to examine marital incompatibility and underlying factors among couples in rural Gonabad based on sociological views and socio-cultural characteristics of the villagers. The study collected data by using questionnaires. The statistical population included 380 married men and women living in the villages of Gonabad county. The samples were selected through cluster sampling method proportional to size. Preliminary interviews and a researcher-made questionnaire were used in order to collect the data. The validity and reliability of the questionnaire were confirmed through face validity and Cronbach's alpha coefficient, respectively. The mean age of the participants and their mean age at marriage were 39 and 21 years, respectively. An equal percentage of males and females participated in the present study. The results of multivariate regression analysis showed that three out of five hypotheses on the relationship between independent and dependent variables could not be rejected. These three hypotheses suggested a significant direct relationship between conflict of values and marital incompatibility, and a significant inverse relationship of fulfillment of needs and family social capital with marital incompatibility. The two variables of Role Strain and Homogamy were not significantly correlated with the independent variable. In view of the influence of changes in the modern era over the needs and expectations of people, it is necessary to provide rural couples with education appropriate to cultural context of their society.

  3. Factors Associated with Klebsiella Bacteremia and Its Outcome in Under-Five Children Admitted with Diarrhea

    Directory of Open Access Journals (Sweden)

    Shamima Akhter

    2016-01-01

    Full Text Available Although Klebsiella bacteremia in children is perceived to be associated with fatal consequences, data are scarce on those children presenting with diarrhea. We evaluated the factors associated with Klebsiella bacteremia in such children. In this retrospective chart analysis, data of all diarrheal children was retrieved from electronic medical record system (named as SHEBA of Dhaka Hospital of International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b, from January 1, 2010, to December 31, 2012, who had their blood culture done. This was a study having a case-control design where comparison of clinical and laboratory characteristics was done among children with Klebsiella bacteremia (cases = 30 and those without any bacteraemia (controls = 90. Controls were selected randomly. The cases more often had fatal outcome (p<0.001. In logistic regression analysis, after adjusting for potential confounders such as young age, severe dehydration, severe wasting, abnormal mentation, hypotension, and fast breathing, the cases were independently associated with hospital-acquired infection and positive stool growth (for all, p<0.05. The study highlights the importance of obtaining blood cultures in hospitalized children under five years old with diarrheal illness in the presence of either hospital-acquired infection or positive stool culture to have better outcome.

  4. Rapid release of active tissue factor from human arterial smooth muscle cells under flow conditions.

    Science.gov (United States)

    Stampfuss, Jan-Julius; Censarek, Petra; Fischer, Jens W; Schrör, Karsten; Weber, Artur-Aron

    2006-05-01

    Circulating tissue factor (TF) is an important determinant of coronary thrombosis. Among other cell types, such as monocytes, vascular smooth muscle cells (SMCs) are capable of releasing TF. When studied under static conditions, SMCs do release TF, but this process is slow and, thus, cannot explain the elevated levels of circulating TF, as observed in patients with acute coronary syndromes. The present study demonstrates that cultured human mammary artery SMCs very rapidly (minutes) release active, microparticle-bound TF when exposed to flow conditions. There was a clear log-linear correlation between the shear rate (range 10 s(-1) to 1500 s(-1)) and the procoagulant activity of SMC perfusates. Flow-dependent release of TF was transient (10 minutes) and did not measurably reduce cell surface TF content. Interestingly, a time-dependent (t(1/2) 30 minutes) re-exposure of releasable TF was detected after a no-flow period. These data demonstrate that SMCs may become a pathophysiologically relevant source of TF that can be rapidly released into the circulation in situations in which endothelial damage occurs and SMCs come into a close contact with the flowing blood.

  5. Underlying factors related to errors in financial mathematics due to incorrect or rigidity of thinking

    Directory of Open Access Journals (Sweden)

    Xolani Khalo

    2014-12-01

    Full Text Available The main aim of the study was (1 to identify the underlying factors related to errors due to incorrect association, and (2 to understand why learners continue to make such errors so that mechanisms to avoid such errors could be devised. The study was conducted by means of a case study guided by the positivists’paradigm where the research sample comprised of 105 Grade 10 Mathematics Literacy learners as respondents. Having used Polya’s problem-solving techniques, Threshold Concept and Newman’s Error Analysis as the theoretical frameworks for the study, a four-point Likert scale and a content-based structure-interview questionnaire were developed to address the research question. Four sets of structured-interview questionnaires were used for collecting data, aimed at addressing the main objective of the study. In order to test the reliability and consistency of the questionnaires for this study, Cronbach’s Alpha was tested for standardised items (α = 0.705. Once the data was collected, it was analysed through content and correlation analysis. Based on the frequency table which summarises learner responses, it could be ascertained that the majority (n =63, 60% of learners admitted to sometimes confusing addition with multiplication. The relationship between learners forgetting to write units and learners writing down an incorrect number/figure revealed a significance where p = .04 (r = +.17 illustrated a weak correlation between the afore-stated variables.

  6. Urinary incontinence in bitches under primary veterinary care in England: prevalence and risk factors.

    Science.gov (United States)

    O'Neill, D G; Riddell, A; Church, D B; Owen, L; Brodbelt, D C; Hall, J L

    2017-12-01

    To estimate prevalence and demographic risk factors for urinary incontinence in bitches under primary veterinary care in England. The study population included all bitches within the VetCompass database from September 1, 2009 to July 7, 2013. Electronic patient records were searched for urinary incontinence cases and additional demographic and clinical information was extracted. Of 100,397 bitches attending 119 clinics in England, an estimated 3108 were diagnosed with urinary incontinence. The prevalence of urinary incontinence was 3·14% (95% confidence intervals: 2·97 to 3·33). Medical therapy was prescribed to 45·6% cases. Predisposed breeds included the Irish setter (odds ratio: 8·09; 95% confidence intervals: 3·15 to 20·80; Prisk breeds including the Irish setter, Dobermann, bearded collie, rough collie and Dalmatian. These results provide an evidence base for clinicians to enhance clinical recommendations on neutering and weight control, especially in high-risk breeds. © 2017 British Small Animal Veterinary Association.

  7. Analytical Solution for Stress Field and Intensity Factor in CSTBD under Mixed Mode Conditions

    Directory of Open Access Journals (Sweden)

    Najaf Ali Ghavidel

    2014-06-01

    Full Text Available Considering the fact that rocks fail faster under tensile stress, rock tensile strength is of greatimportance in applications such as blasting, rock fragmentation, slope stability, hydraulic fracturing,caprock integrity, and geothermal energy extraction. There are two direct and indirect methods tomeasure tensile strength. Since direct methods always encompass difficulties in test setup, indirectmethods, specifically the Brazilian test, have often been employed for tensile strength measurement.Tensile failure is technically attributed to crack propagation in rock. Fracture mechanics hassignificant potential for the determination of crack behaviour as well as propagation pattern. To applyBrazilian tests, cracked disc geometry has been suggested by the International Society for RockMechanics ISRM. Accordingly, a comprehensive study is necessary to evaluate stress field and stressintensity factor (SIF around the crack in the centre of the specimen. In this paper, superpositionprinciple is employed to solve the problem of cracked straight-through Brazilian disc (CSTBD, usingtwo methods of dislocation and complex stress function. Stress field and SIF in the vicinity of thecrack tip are then calculated. With the proposed method, the magnitude of critical load for crackinitiation in structures can be predicted. This method is valid for any crack of any arbitrary length andangle. In addition, numerical modelling has been carried out for the Brazilian disc. Finally, theanalytical solution has been compared with numerical modelling results showing the same outcomefor both methods.

  8. Localization and causality in relativistic quantum mechanics

    International Nuclear Information System (INIS)

    Perez, J.F.; Wilde, I.F.

    It is shown that in relativistic quantum mechanics there is no criterion for the strict localization of a state in a bounded space-time region compatible with causality, translation covariance and the spectral condition (or positivity of energy together with Lorentz covariance) [pt

  9. Catastrophizing and Causal Beliefs in Whiplash

    NARCIS (Netherlands)

    Buitenhuis, J.; de Jong, P. J.; Jaspers, J. P. C.; Groothoff, J. W.

    2008-01-01

    Study Design. Prospective cohort study. Objective. This study investigates the role of pain catastrophizing and causal beliefs with regard to severity and persistence of neck complaints after motor vehicle accidents. Summary of Background Data. In previous research on low back pain, somatoform

  10. Special Relativity, Causality and Quantum Mechanics - 1

    Indian Academy of Sciences (India)

    information theory in general and quantum non-locality and entanglement in particular. Right. S Kunkri - current research interest is the role of entanglement in quantum information processing and the connection between quantum operations and causality. Centre. S K Choudhary - current research interest is the study of ...

  11. Marriage and Anomie: A Causal Argument

    Science.gov (United States)

    Lee, Gary R.

    1974-01-01

    A sample of 394 married couples is employed to test the possibility of an association between marital satisfaction and personal (attitudinal) anomie. The hypothesis is supported. Conclusions are offered relevant to anomie theory, and to utilization of marital and family phenomena as independent variables in causal explanations of nonfamily events.…

  12. Causal Measurement Models: Can Criticism Stimulate Clarification?

    Science.gov (United States)

    Markus, Keith A.

    2016-01-01

    In their 2016 work, Aguirre-Urreta et al. provided a contribution to the literature on causal measurement models that enhances clarity and stimulates further thinking. Aguirre-Urreta et al. presented a form of statistical identity involving mapping onto the portion of the parameter space involving the nomological net, relationships between the…

  13. Causal Meta-Analysis : Methodology and Applications

    NARCIS (Netherlands)

    Bax, L.J.

    2009-01-01

    Meta-analysis is a statistical method to summarize research data from multiple studies in a quantitative manner. This dissertation addresses a number of methodological topics in causal meta-analysis and reports the development and validation of meta-analysis software. In the first (methodological)

  14. Black Hole Complementarity and Violation of Causality

    OpenAIRE

    Rozenblit, Moshe

    2017-01-01

    Analysis of a massive shell collapsing on a solid sphere shows that black hole complementarity (BHC) violates causality in its effort to save information conservation. In particular, this note describes a hypothetical contraption based on BHC that would allow the transfer of information from the future to the present.

  15. THE CAUSAL TEXTURE OF TRADE UNION ENVIRONMENTS

    African Journals Online (AJOL)

    Admin

    This paper is an attempt to fill an important gap in the existing literature on trade unions by providing a more adequate theoretical formulation of trade union environments. The discussion suggests that unlike the environment of business and related organisations whose causal texture is understood in terms of uncertainty, ...

  16. Are bruxism and the bite causally related?

    NARCIS (Netherlands)

    Lobbezoo, F.; Ahlberg, J.; Manfredini, D.; Winocur, E.

    2012-01-01

    In the dental profession, the belief that bruxism and dental (mal-)occlusion (‘the bite’) are causally related is widespread. The aim of this review was to critically assess the available literature on this topic. A PubMed search of the English-language literature, using the query ‘Bruxism [Majr

  17. Sequential causal learning in humans and rats

    NARCIS (Netherlands)

    Lu, H.; Rojas, R.R.; Beckers, T.; Yuille, A.; Love, B.C.; McRae, K.; Sloutsky, V.M.

    2008-01-01

    Recent experiments (Beckers, De Houwer, Pineño, & Miller, 2005;Beckers, Miller, De Houwer, & Urushihara, 2006) have shown that pretraining with unrelated cues can dramatically influence the performance of humans in a causal learning paradigm and rats in a standard Pavlovian conditioning paradigm.

  18. Dimensional reduction in causal set gravity

    Science.gov (United States)

    Carlip, S.

    2015-12-01

    Results from a number of different approaches to quantum gravity suggest that the effective dimension of spacetime may drop to d = 2 at small scales. I show that two different dimensional estimators in causal set theory display the same behavior, and argue that a third, the spectral dimension, may exhibit a related phenomenon of ‘asymptotic silence.’

  19. The Causal Relationship between Financial Development and ...

    African Journals Online (AJOL)

    The study employs cointegration, vector error correction model and Granger causality test to ascertain causation between financial development and economic performance in Tanzania. Economic performance is measured by the real GDP, whereas proxies for financial development are: the ratio of money supply to nominal ...

  20. Causal and Teleological Explanations in Biology

    Science.gov (United States)

    Yip, Cheng-Wai

    2009-01-01

    A causal explanation in biology focuses on the mechanism by which a biological process is brought about, whereas a teleological explanation considers the end result, in the context of the survival of the organism, as a reason for certain biological processes or structures. There is a tendency among students to offer a teleological explanation…

  1. Special Relativity, Causality and Quantum Mechanics - 2

    Indian Academy of Sciences (India)

    Peaceful Coexistence of Special Relativity and. Quantum Mechanics. As discussed in Part 1, in the framework of the special theory of relativity, causality holds. This can be stated as follows: there is a finite speed for any signal, i.e. , for anything that carries information, and the highest speed for any signal is identical to the ...

  2. Causal Relationship between Teachers' Job Performance and ...

    African Journals Online (AJOL)

    The study investigated teachers' job performance and students' academic achievement in secondary schools for the existence of bi-causal relationship in Nigeria. The ex-post facto research design was adopted in the study. The population of the study covered all the Economic teachers and senior school students in class ...

  3. Introducing mechanics by tapping core causal knowledge

    NARCIS (Netherlands)

    Klaassen, C.W.J.M.; Westra, A.S.; Emmett, K.M.; Eijkelhof, H.M.C.; Lijnse, P.L.

    2008-01-01

    This article concerns an outline of an introductory mechanics course. It is based on the argument that various uses of the concept of force (e.g. from Kepler, Newton and everyday life) share an explanatory strategy based on core causal knowledge. The strategy consists of (a) the idea that a force

  4. Causality and analyticity in quantum fields theory

    International Nuclear Information System (INIS)

    Iagolnitzer, D.

    1992-01-01

    This is a presentation of results on the causal and analytical structure of Green functions and on the collision amplitudes in fields theories, for massive particles of one type, with a positive mass and a zero spin value. (A.B.)

  5. Causality relationship between energy demand and economic ...

    African Journals Online (AJOL)

    This paper attempts to examine the causal relationship between electricity demand and economic growth in Nigeria using data for 1970 – 2003. The study uses the Johansen cointegration VAR approach. The ADF and Phillips – Perron test statistics were used to test for stationarity of the data. It was found that the data were ...

  6. The Causal Priority of Form in Aristotle

    Directory of Open Access Journals (Sweden)

    Kathrin Koslicki

    2014-12-01

    Full Text Available In various texts (e.g., Met. Z.17, Aristotle assigns priority to form, in its role as a principle and cause, over matter and the matter-form compound. Given the central role played by this claim in Aristotle's search for primary substance in the Metaphysics, it is important to understand what motivates him in locating the primary causal responsibility for a thing's being what it is with the form, rather than the matter. According to Met. Theta.8, actuality [energeia/entelecheia] in general is prior to potentiality [dunamis] in three ways, viz., in definition, time and substance. I propose an explicitly causal reading of this general priority claim, as it pertains to the matter-form relationship. The priority of form over matter in definition, time and substance, in my view, is best explained by appeal to the role of form as the formal, efficient and final cause of the matter-form compound, respectively, while the posteriority of matter to form according to all three notions of priority is most plausibly accounted for by the fact that the causal contribution of matter is limited to its role as material cause. When approached from this angle, the work of Met. Theta.8 can be seen to lend direct support to the more specific and explicitly causal priority claim we encounter in Met. Z.17, viz., that form is prior to matter in its role as the principle and primary cause of a matter-form compound's being what it is.

  7. A quantum probability model of causal reasoning

    Directory of Open Access Journals (Sweden)

    Jennifer S Trueblood

    2012-05-01

    Full Text Available People can often outperform statistical methods and machine learning algorithms in situations that involve making inferences about the relationship between causes and effects. While people are remarkably good at causal reasoning in many situations, there are several instances where they deviate from expected responses. This paper examines three situations where judgments related to causal inference problems produce unexpected results and describes a quantum inference model based on the axiomatic principles of quantum probability theory that can explain these effects. Two of the three phenomena arise from the comparison of predictive judgments (i.e., the conditional probability of an effect given a cause with diagnostic judgments (i.e., the conditional probability of a cause given an effect. The third phenomenon is a new finding examining order effects in predictive causal judgments. The quantum inference model uses the notion of incompatibility among different causes to account for all three phenomena. Psychologically, the model assumes that individuals adopt different points of view when thinking about different causes. The model provides good fits to the data and offers a coherent account for all three causal reasoning effects thus proving to be a viable new candidate for modeling human judgment.

  8. Special Relativity, Causality and Quantum Mechanics - 1

    Indian Academy of Sciences (India)

    We discuss the significance of Einstein's second postulate of the special theory of relativity (STR) stipulating the constancy of the speed of light in vacuum. The causality that follows from the. STR may be a more general principle to orga- nize our knowledge of all phenomena. In partic- ular, quantum dynamics can be derived ...

  9. Special Relativity, Causality and Quantum Mechanics - 2

    Indian Academy of Sciences (India)

    tum world. An example of a game which can be won exploiting quantum entanglement, but which can never be won classically, is described. Peaceful Coexistence of Special Relativity and. Quantum Mechanics. As discussed in Part 1, in the framework of the special theory of relativity, causality holds. This can be stated.

  10. Effects of hydrostatic pressure on the electron g|| factor and g-factor anisotropy in GaAs-(Ga, Al)As quantum wells under magnetic fields

    International Nuclear Information System (INIS)

    Porras-Montenegro, N; Duque, C A; Oliveira, L E; Reyes-Gomez, E

    2008-01-01

    The hydrostatic-pressure effects on the electron-effective Lande g || factor and g-factor anisotropy in semiconductor GaAs-Ga 1-x Al x As quantum wells under magnetic fields are studied. The g || factor is computed by considering the non-parabolicity and anisotropy of the conduction band through the Ogg-McCombe effective Hamiltonian, and numerical results are displayed as functions of the applied hydrostatic pressure, magnetic fields, and quantum-well widths. Good agreement between theoretical results and experimental measurements in GaAs-(Ga, Al)As quantum wells for the electron g factor and g-factor anisotropy at low values of the applied magnetic field and in the absence of hydrostatic pressure is obtained. Present results open up new possibilities for manipulating the electron-effective g factor in semiconductor heterostructures.

  11. A Cross-Cultural Validation of Perceived Locus of Causality Scale in Physical Education Context

    Science.gov (United States)

    Wang, C. K. John; Hagger, Martin; Liu, Woon Chia

    2009-01-01

    We examined the validity of the factor structure and invariance of the Perceived Locus of Causality (PLOC) scale instrument scores across two nations endorsing collectivist (Singapore) and individualist (Great Britain) cultural values. Results indicated that confirmatory factor analytic models of the PLOC exhibited adequate ft according to…

  12. [Risk factors and frequency of postoperative nausea and vomiting in patients operated under general anesthesia].

    Science.gov (United States)

    Grabowska-Gaweł, Anna; Porzych, Katarzyna; Piskunowicz, Grazyna

    2006-01-01

    Postoperative nausea and vomiting belong to fairly frequent postoperative complications, but they occupy a distant position on the list of complications, which most probably result from a general conviction that they do not pose a direct threat to patients. The objective of this work is specification of factors facilitating occurrence of postoperative nausea and vomiting, and determination of frequency of their occurrence in patients operated under general anesthesia. Questionnaire about the occurrence of postoperative nausea and vomiting (PONV), was carried out and included 253 adult sick persons (102 female and 151 male patients), in the age between 23-76 (average 42.3 +/- 6.1 years), who had undergone operative procedure in the field of abdominal and urology surgery, orthopedic, thyroid surgery and laryngological, ophthalmology and plastic surgery, under general anesthesia. The questionnaire form included preoperative characteristics of a patient (age, sex, smoking, motion sickness and migraine headaches in history, and PONV occurring earlier), type of operative procedure, used anesthetic agents, and analgesic agents applied in postoperative analgesia. The anesthesiologist administering anesthetic was not informed about the investigation carried out and did not receive any additional pieces of advice regarding the type of applied anesthetic agents or the method of conducting postoperative analgesia. Visual Analogue Scale (VAS) was used in the evaluation of nausea. Nausea and vomiting were assessed every two hours within the first postoperative 12 hours and every 4 hours for the next 24 hours. Nausea and vomiting were treated as two separate complications. Nausea itself occurred in 22.7% of patients; whereas vomiting in 13.2%. Both symptoms occurred in 14.2% of patients. Nausea occurred 4.1 +/- 0.8 hours after operation; whereas vomiting after 5.3 +/- 1.1 hours. Women suffered more often than men from (R = 0.678 p patients suffering from PONV earlier (R = 0

  13. Experimental occlusal disharmony - A promoting factor for anxiety in rats under chronic psychological stress.

    Science.gov (United States)

    Tang, Xuan; Li, Jian; Jiang, Ting; Han, Shu-Hui; Yao, Dong-Yuan

    2017-04-03

    Clinically, patients under chronic psychological stress (PS) appear to be more susceptible to occlusal disharmony (OD) compared with those without PS. OD was proved to introduce anxiety-like stress. Therefore, the purpose of the study was to investigate whether OD would affect psychological stress-induced anxiety and its underlying mechanisms. Chronic PS was induced by a communication box, and OD was produced by bonding a 0.3mm-thick crown on the right maxillary first molar of male Sprague-Dawley rats. Sixty-seven rats were randomly divided into 8 groups: (A) chronic PS plus OD group (n=6); (B) chronic PS plus sham OD group (n=6); (C) chronic PS only group (n=6); (D) OD group (n=6); (E) sham OD group (n=6); (F) control group (n=6); (G) naive group (n=6); (H) foot-shock group (n=25). Open-field test (OFT) and elevated plus maze test (EPM) were conducted on the 7th, 21th, 35th day to measure the anxiety level of each group except naive and foot-shock group. In addition, corticosterone (CORT) level in serum, 5-hydroxytryptamine (5-HT) and 5-HT 2A receptor (5-HT 2A R) expressions in prefrontal cortex (PFC), hippocampal CA1 and dentate gyrus (DG) areas were measured on the 35th day to elucidate the mechanism(s) by which the exacerbation occurred. The significant differences in OFT and EPM tests on day 21 or day 35 between groups (p0.05), together with a gradual decrease in values of all the parameters mentioned above from group A to group G. The significant changes in exploratory behaviors, serum CORT concentration, 5-HT and 5-HT 2A R expressions induced by OD in rats with or without chronic PS, and more obvious alterations in rats with chronic PS, may indicate that OD may be a promoting factor for anxiety through both peripheral and central pathways via the hypothalamus-pituitary-adrenal (HPA) axis and 5-HT system. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Factors Underlying the Temporal Increase in Maternal Mortality in the United States.

    Science.gov (United States)

    Joseph, K S; Lisonkova, Sarka; Muraca, Giulia M; Razaz, Neda; Sabr, Yasser; Mehrabadi, Azar; Schisterman, Enrique F

    2017-01-01

    To identify the factors underlying the recent increase in maternal mortality ratios (maternal deaths per 100,000 live births) in the United States. We carried out a retrospective study with data on maternal deaths and live births in the United States from 1993 to 2014 obtained from the birth and death files of the Centers for Disease Control and Prevention. Underlying causes of death were examined between 1999 and 2014 using International Classification of Diseases, 10th Revision (ICD-10) codes. Poisson regression was used to estimate maternal mortality rate ratios (RRs) and 95% confidence intervals (CIs) after adjusting for the introduction of a separate pregnancy question and the standard pregnancy checkbox on death certificates and adoption of ICD-10. Maternal mortality ratios increased from 7.55 in 1993, to 9.88 in 1999, and to 21.5 per 100,000 live births in 2014 (RR 2014 compared with 1993 2.84, 95% CI 2.49-3.24; RR 2014 compared with 1999 2.17, 95% CI 1.93-2.45). The increase in maternal deaths from 1999 to 2014 was mainly the result of increases in maternal deaths associated with two new ICD-10 codes (O26.8, ie, primarily renal disease; and O99, ie, other maternal diseases classifiable elsewhere); exclusion of such deaths abolished the increase in mortality (RR 1.09, 95% CI 0.94-1.27). Regression adjustment for improvements in surveillance also abolished the temporal increase in maternal mortality ratios (adjusted maternal mortality ratios 7.55 in 1993, 8.00 per 100,000 live births in 2013; adjusted RR 2013 compared with 1993 1.06, 95% CI 0.90-1.25). Recent increases in maternal mortality ratios in the United States are likely an artifact of improvements in surveillance and highlight past underestimation of maternal death. Complete ascertainment of maternal death in populations remains a challenge even in countries with good systems for civil registration and vital statistics.

  15. MiRNA-directed regulation of VEGF and other angiogenic factors under hypoxia.

    Directory of Open Access Journals (Sweden)

    Zhong Hua

    Full Text Available MicroRNAs (miRNAs are a class of 20-24 nt non-coding RNAs that regulate gene expression primarily through post-transcriptional repression or mRNA degradation in a sequence-specific manner. The roles of miRNAs are just beginning to be understood, but the study of miRNA function has been limited by poor understanding of the general principles of gene regulation by miRNAs. Here we used CNE cells from a human nasopharyngeal carcinoma cell line as a cellular system to investigate miRNA-directed regulation of VEGF and other angiogenic factors under hypoxia, and to explore the principles of gene regulation by miRNAs. Through computational analysis, 96 miRNAs were predicted as putative regulators of VEGF. But when we analyzed the miRNA expression profile of CNE and four other VEGF-expressing cell lines, we found that only some of these miRNAs could be involved in VEGF regulation, and that VEGF may be regulated by different miRNAs that were differentially chosen from 96 putative regulatory miRNAs of VEGF in different cells. Some of these miRNAs also co-regulate other angiogenic factors (differential regulation and co-regulation principle. We also found that VEGF was regulated by multiple miRNAs using different combinations, including both coordinate and competitive interactions. The coordinate principle states that miRNAs with independent binding sites in a gene can produce coordinate action to increase the repressive effect of miRNAs on this gene. By contrast, the competitive principle states when multiple miRNAs compete with each other for a common binding site, or when a functional miRNA competes with a false positive miRNA for the same binding site, the repressive effects of miRNAs may be decreased. Through the competitive principle, false positive miRNAs, which cannot directly repress gene expression, can sometimes play a role in miRNA-mediated gene regulation. The competitive principle, differential regulation, multi-miRNA binding sites, and false

  16. Linear and nonlinear causality between renewable energy consumption and economic growth in the USA

    Directory of Open Access Journals (Sweden)

    Haiyun Xu

    2016-12-01

    Full Text Available This study aims to investigate Granger causality between renewable energy consumption (REC and economic growth (EG for USA. To accomplish this objective and to add the stronger evidence to the controversial issue, the tests were done under a new framework that embeds wavelet analysis, a novel tool, in nonlinear causality test approaches developed recently. The classical linear causality test procedure was also involved for comparison. The empirical data sources from the USA Energy Information Administration and Economist Intelligence Unit (EIU CountryData database. Sample period is from January 1993 to October 2014. The results indicate significantly the existence of unidirectional causality from EG to REC and support the conservation hypothesis. In additional, further evidences show that the causal relationship among them is not constant and depends on the time scale or frequency ranges, and that wavelet analysis is an important aid to capture the nonlinear causality. This suggests that renewable energy limitations do not seem to damage economic growth. These results have implications of importance for research analysts as well as policy makers of energy economy.

  17. How causal analysis can reveal autonomy in models of biological systems

    Science.gov (United States)

    Marshall, William; Kim, Hyunju; Walker, Sara I.; Tononi, Giulio; Albantakis, Larissa

    2017-11-01

    Standard techniques for studying biological systems largely focus on their dynamical or, more recently, their informational properties, usually taking either a reductionist or holistic perspective. Yet, studying only individual system elements or the dynamics of the system as a whole disregards the organizational structure of the system-whether there are subsets of elements with joint causes or effects, and whether the system is strongly integrated or composed of several loosely interacting components. Integrated information theory offers a theoretical framework to (1) investigate the compositional cause-effect structure of a system and to (2) identify causal borders of highly integrated elements comprising local maxima of intrinsic cause-effect power. Here we apply this comprehensive causal analysis to a Boolean network model of the fission yeast (Schizosaccharomyces pombe) cell cycle. We demonstrate that this biological model features a non-trivial causal architecture, whose discovery may provide insights about the real cell cycle that could not be gained from holistic or reductionist approaches. We also show how some specific properties of this underlying causal architecture relate to the biological notion of autonomy. Ultimately, we suggest that analysing the causal organization of a system, including key features like intrinsic control and stable causal borders, should prove relevant for distinguishing life from non-life, and thus could also illuminate the origin of life problem. This article is part of the themed issue 'Reconceptualizing the origins of life'.

  18. A framework for assessing frequency domain causality in physiological time series with instantaneous effects.

    Science.gov (United States)

    Faes, Luca; Erla, Silvia; Porta, Alberto; Nollo, Giandomenico

    2013-08-28

    We present an approach for the quantification of directional relations in multiple time series exhibiting significant zero-lag interactions. To overcome the limitations of the traditional multivariate autoregressive (MVAR) modelling of multiple series, we introduce an extended MVAR (eMVAR) framework allowing either exclusive consideration of time-lagged effects according to the classic notion of Granger causality, or consideration of combined instantaneous and lagged effects according to an extended causality definition. The spectral representation of the eMVAR model is exploited to derive novel frequency domain causality measures that generalize to the case of instantaneous effects the known directed coherence (DC) and partial DC measures. The new measures are illustrated in theoretical examples showing that they reduce to the known measures in the absence of instantaneous causality, and describe peculiar aspects of directional interaction among multiple series when instantaneous causality is non-negligible. Then, the issue of estimating eMVAR models from time-series data is faced, proposing two approaches for model identification and discussing problems related to the underlying model assumptions. Finally, applications of the framework on cardiovascular variability series and multichannel EEG recordings are presented, showing how it allows one to highlight patterns of frequency domain causality consistent with well-interpretable physiological interaction mechanisms.

  19. Mechanisms underlying the nociceptive responses induced by platelet-activating factor (PAF) in the rat paw.

    Science.gov (United States)

    Marotta, Denise M; Costa, Robson; Motta, Emerson M; Fernandes, Elizabeth S; Medeiros, Rodrigo; Quintão, Nara L M; Campos, Maria M; Calixto, João B

    2009-04-01

    Platelet-activating factor (PAF) is an inflammatory mediator widely known to exert relevant pathophysiological functions. However, the relevance of PAF in nociception has received much less attention. Herein, we have investigated the mechanisms underlying PAF-induced spontaneous nociception and mechanical hypersensitivity in the rat paw. PAF injection (1- 30 nmol/paw) resulted in a dose-related overt nociception, whilst only the dose of 10 nmol/ paw produced a significant and time-related mechanical hypersensitivity. Local coinjection of PAF antagonist WEB2086 significantly inhibited both spontaneous nociception and mechanical hypersensitivity. Moreover, the coinjection of the natural IL-1beta receptor antagonist (IRA) notably prevented both PAF-induced nociceptive responses, whilst these responses were not altered by anti-TNFalpha coinjection. Interestingly, pretreatment with the ultrapotent vaniloid agonist resiniferotoxin, coinjection of the TRPV1 receptor antagonist SB366791, or mast cell depletion with compound 48/80 markedly prevented PAF-induced spontaneous nociception. Conversely, PAF-elicited mechanical hypersensitivity was strikingly susceptible to distinct antineutrophil-related strategies, namely the antineutrophil antibody, the selectin blocker fucoidin, the chemokine CXCR2 receptor antagonist SB225002, and the C5a receptor antibody anti-CD88. Notably, the same antineutrophil migration strategies significantly prevented the increase of myeloperoxidase activity induced by PAF. The mechanical hypersensitivity caused by PAF was also prevented by the cyclooxygenase inhibitors indomethacin or celecoxib, and by the selective beta(1) adrenergic receptor antagonist atenolol. Collectively, the present results provide consistent evidence indicating that distinct mechanisms are involved in the spontaneous nociception and mechanical hypersensitivity caused by PAF. They also support the concept that selective PAF receptor antagonists might constitute interesting

  20. Marijuana Use and Driving Under the Influence among Young Adults: A Socioecological Perspective on Risk Factors.

    Science.gov (United States)

    Berg, Carla J; Daniel, Carmen N; Vu, Milkie; Li, Jingjing; Martin, Kathleen; Le, Lana

    2018-02-23

    Given increases in marijuana use and driving under the influence (DUI), it is critical to identify those at risk in order to inform intervention efforts. We used a socioecological framework to examine correlates of level of marijuana use and DUI in the past month among young adult marijuana users. We recruited 1567 participants aged 18-34 years via Facebook ads targeting tobacco and marijuana users in August 2014 to complete an online survey assessing marijuana use and DUI, as well as related multilevel factors. Analyses focused on 649 participants reporting past 30-day marijuana use. The sample was an average age of 24.48 (SD = 5.10), 43.9% female, and 76.4% White and used marijuana an average of 17.86 (SD = 11.29) days in the past month. Notably, 48.4% reported driving after marijuana use at least once in the past month, and 74.0% were passengers. Multivariable regression indicated that greater use was associated with: being older; being male; greater symptoms of dependence; residing in a state with recreational marijuana legalized; having a medical marijuana card; having parents and more friends who use; higher coping motives; lower perceived harm to health; and less concern about driving after marijuana use (adjusted R-squared = 0.294). Correlates of driving after using marijuana in the past month included: being younger; more frequent use; having more friends who use; higher enhancement motives; and less concern about driving after using (Nagelkerke R-squared = 0.442). Conclusions/Importance: Interventions and campaigns should address social norms and risk perceptions regarding marijuana use, particularly as it relates to DUI.

  1. Tissue factor-expressing tumor cells can bind to immobilized recombinant tissue factor pathway inhibitor under static and shear conditions in vitro.

    Directory of Open Access Journals (Sweden)

    Sara P Y Che

    Full Text Available Mammary tumors and malignant breast cancer cell lines over-express the coagulation factor, tissue factor (TF. High expression of TF is associated with a poor prognosis in breast cancer. Tissue factor pathway inhibitor (TFPI, the endogenous inhibitor of TF, is constitutively expressed on the endothelium. We hypothesized that TF-expressing tumor cells can bind to immobilized recombinant TFPI, leading to arrest of the tumor cells under shear in vitro. We evaluated the adhesion of breast cancer cells to immobilized TFPI under static and shear conditions (0.35 - 1.3 dyn/cm2. We found that high-TF-expressing breast cancer cells, MDA-MB-231 (with a TF density of 460,000/cell, but not low TF-expressing MCF-7 (with a TF density of 1,400/cell, adhered to recombinant TFPI, under static and shear conditions. Adhesion of MDA-MB-231 cells to TFPI required activated factor VII (FVIIa, but not FX, and was inhibited by a factor VIIa-blocking anti-TF antibody. Under shear, adhesion to TFPI was dependent on the TFPI-coating concentration, FVIIa concentration and shear stress, with no observed adhesion at shear stresses greater than 1.0 dyn/cm2. This is the first study showing that TF-expressing tumor cells can be captured by immobilized TFPI, a ligand constitutively expressed on the endothelium, under low shear in vitro. Based on our results, we hypothesize that TFPI could be a novel ligand mediating the arrest of TF-expressing tumor cells in high TFPI-expressing vessels under conditions of low shear during metastasis.

  2. Investigating cognitive transfer within the framework of music practice: genetic pleiotropy rather than causality.

    Science.gov (United States)

    Mosing, Miriam A; Madison, Guy; Pedersen, Nancy L; Ullén, Fredrik

    2016-05-01

    The idea of far transfer effects in the cognitive sciences has received much attention in recent years. One domain where far transfer effects have frequently been reported is music education, with the prevailing idea that music practice entails an increase in cognitive ability (IQ). While cross-sectional studies consistently find significant associations between music practice and IQ, randomized controlled trials, however, report mixed results. An alternative to the hypothesis of cognitive transfer effects is that some underlying factors, such as shared genes, influence practice behaviour and IQ causing associations on the phenotypic level. Here we explored the hypothesis of far transfer within the framework of music practice. A co-twin control design combined with classical twin-modelling based on a sample of more than 10,500 twins was used to explore causal associations between music practice and IQ as well as underlying genetic and environmental influences. As expected, phenotypic associations were moderate (r = 0.11 and r = 0.10 for males and females, respectively). However, the relationship disappeared when controlling for genetic and shared environmental influences using the co-twin control method, indicating that a highly practiced twin did not have higher IQ than the untrained co-twin. In line with that finding, the relationship between practice and IQ was mostly due to shared genetic influences. Findings strongly suggest that associations between music practice and IQ in the general population are non-causal in nature. The implications of the present findings for research on plasticity, modularity, and transfer are discussed. © 2015 John Wiley & Sons Ltd.

  3. Mendelian Randomization for the Identification of Causal Pathways in Atherosclerotic Vascular Disease.

    Science.gov (United States)

    Jansen, Henning; Lieb, Wolfgang; Schunkert, Heribert

    2016-02-01

    Epidemiological and clinical studies have identified many physiological traits and biomarkers that are statistically associated with coronary artery disease (CAD). For some of these traits and biomarkers it is well established that they represent true causal risk factors for CAD. For other biomarkers, however, the distinct character of association is still a matter of debate. Randomized controlled trials (RCT) had a pivotal role in establishing causal associations between risk factors and biomarkers and CAD in some settings by demonstrating that therapeutic intervention targeting risk factors/biomarkers also affect the risk for clinical outcomes, such as CAD. In other scenarios, however, RCTs did not demonstrate clear benefits associated with lowering biomarker levels and therefore suggest that the association between these biomarkers (like C reactive protein) and CAD was driven by confounding or reverse causation. Even accurately conducted RCTs are not immune against incorrect causal inference. Moreover, the extensive costs and efforts required to conduct RCTs asked for alternative study designs to elucidate potential causal associations. Mendelian Randomization studies represent one such alternative by using genetic variants as proxies for specific biomarkers to investigate potential causal relations between biomarkers and clinical outcomes. In this review, we briefly describe the principles of MR studies and summarize recent MR studies in the context of CAD.

  4. Causal knowledge and the development of inductive reasoning.

    Science.gov (United States)

    Bright, Aimée K; Feeney, Aidan

    2014-06-01

    We explored the development of sensitivity to causal relations in children's inductive reasoning. Children (5-, 8-, and 12-year-olds) and adults were given trials in which they decided whether a property known to be possessed by members of one category was also possessed by members of (a) a taxonomically related category or (b) a causally related category. The direction of the causal link was either predictive (prey→predator) or diagnostic (predator→prey), and the property that participants reasoned about established either a taxonomic or causal context. There was a causal asymmetry effect across all age groups, with more causal choices when the causal link was predictive than when it was diagnostic. Furthermore, context-sensitive causal reasoning showed a curvilinear development, with causal choices being most frequent for 8-year-olds regardless of context. Causal inductions decreased thereafter because 12-year-olds and adults made more taxonomic choices when reasoning in the taxonomic context. These findings suggest that simple causal relations may often be the default knowledge structure in young children's inductive reasoning, that sensitivity to causal direction is present early on, and that children over-generalize their causal knowledge when reasoning. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Framework for assessing causality in disease management programs: principles.

    Science.gov (United States)

    Wilson, Thomas; MacDowell, Martin

    2003-01-01

    To credibly state that a disease management (DM) program "caused" a specific outcome it is required that metrics observed in the DM population be compared with metrics that would have been expected in the absence of a DM intervention. That requirement can be very difficult to achieve, and epidemiologists and others have developed guiding principles of causality by which credible estimates of DM impact can be made. This paper introduces those key principles. First, DM program metrics must be compared with metrics from a "reference population." This population should be "equivalent" to the DM intervention population on all factors that could independently impact the outcome. In addition, the metrics used in both groups should use the same defining criteria (ie, they must be "comparable" to each other). The degree to which these populations fulfill the "equivalent" assumption and metrics fulfill the "comparability" assumption should be stated. Second, when "equivalence" or "comparability" is not achieved, the DM managers should acknowledge this fact and, where possible, "control" for those factors that may impact the outcome(s). Finally, it is highly unlikely that one study will provide definitive proof of any specific DM program value for all time; thus, we strongly recommend that studies be ongoing, at multiple points in time, and at multiple sites, and, when observational study designs are employed, that more than one type of study design be utilized. Methodologically sophisticated studies that follow these "principles of causality" will greatly enhance the reputation of the important and growing efforts in DM.

  6. Some factors underlying individual differences in speech recognition on PRESTO: a first report.

    Science.gov (United States)

    Tamati, Terrin N; Gilbert, Jaimie L; Pisoni, David B

    2013-01-01

    Previous studies investigating speech recognition in adverse listening conditions have found extensive variability among individual listeners. However, little is currently known about the core underlying factors that influence speech recognition abilities. To investigate sensory, perceptual, and neurocognitive differences between good and poor listeners on the Perceptually Robust English Sentence Test Open-set (PRESTO), a new high-variability sentence recognition test under adverse listening conditions. Participants who fell in the upper quartile (HiPRESTO listeners) or lower quartile (LoPRESTO listeners) on key word recognition on sentences from PRESTO in multitalker babble completed a battery of behavioral tasks and self-report questionnaires designed to investigate real-world hearing difficulties, indexical processing skills, and neurocognitive abilities. Young, normal-hearing adults (N = 40) from the Indiana University community participated in the current study. Participants' assessment of their own real-world hearing difficulties was measured with a self-report questionnaire on situational hearing and hearing health history. Indexical processing skills were assessed using a talker discrimination task, a gender discrimination task, and a forced-choice regional dialect categorization task. Neurocognitive abilities were measured with the Auditory Digit Span Forward (verbal short-term memory) and Digit Span Backward (verbal working memory) tests, the Stroop Color and Word Test (attention/inhibition), the WordFam word familiarity test (vocabulary size), the Behavioral Rating Inventory of Executive Function-Adult Version (BRIEF-A) self-report questionnaire on executive function, and two performance subtests of the Wechsler Abbreviated Scale of Intelligence (WASI) Performance Intelligence Quotient (IQ; nonverbal intelligence). Scores on self-report questionnaires and behavioral tasks were tallied and analyzed by listener group (HiPRESTO and LoPRESTO). The extreme

  7. Elements of Causal Inference: Foundations and Learning Algorithms

    DEFF Research Database (Denmark)

    Peters, Jonas Martin; Janzing, Dominik; Schölkopf, Bernhard

    A concise and self-contained introduction to causal inference, increasingly important in data science and machine learning......A concise and self-contained introduction to causal inference, increasingly important in data science and machine learning...

  8. The Hankel transform of causal distributions

    Directory of Open Access Journals (Sweden)

    Manuel A. Aguirre T.

    2012-03-01

    Full Text Available In this note we evaluate the unidimensional distributional Hankel transform of \\dfrac{x^{\\alpha-1}_{+}}{\\Gamma^{\\alpha}},\\dfrac{x^{\\alpha-1}_{-}}{\\Gamma^{\\alpha}},dfrac{|x|^{\\alpha-1}}{\\Gamma^{\\frac{\\alpha}{2}}},dfrac{|x|^{\\alpha-1}sgn(x}{\\Gamma^{\\frac{\\alpha +1}{2}}} and (x± i0^{\\alpha-1} and then we extend the formulae to certain kinds of n-dimensional distributions calles "causal" and "anti-causal" distributions. We evaluate the distributional Handel transform of \\dfrac{(m^2+P^{\\alpha -1}_{-}}{\\Gamma^{(\\alpha} }, \\dfrac{|m^2+P|^{\\alpha -1}_{-}}{\\Gamma^{(\\frac{\\alpha}{2}}}, \\dfrac{|m^2+P|^{\\alpha -1}sgn(m^2+P}{\\Gamma (\\frac{\\alpha +1}{2 }} and (m^2+P±i0^{\\alpha-1}

  9. Kernel Method for Nonlinear Granger Causality

    Science.gov (United States)

    Marinazzo, Daniele; Pellicoro, Mario; Stramaglia, Sebastiano

    2008-04-01

    Important information on the structure of complex systems can be obtained by measuring to what extent the individual components exchange information among each other. The linear Granger approach, to detect cause-effect relationships between time series, has emerged in recent years as a leading statistical technique to accomplish this task. Here we generalize Granger causality to the nonlinear case using the theory of reproducing kernel Hilbert spaces. Our method performs linear Granger causality in the feature space of suitable kernel functions, assuming arbitrary degree of nonlinearity. We develop a new strategy to cope with the problem of overfitting, based on the geometry of reproducing kernel Hilbert spaces. Applications to coupled chaotic maps and physiological data sets are presented.

  10. Finite quantum electrodynamics the causal approach

    CERN Document Server

    Scharf, Günter

    2014-01-01

    In this classic text for advanced undergraduates and graduate students of physics, author Günter Scharf carefully analyzes the role of causality in quantum electrodynamics. His approach offers full proofs and detailed calculations of scattering processes in a mathematically rigorous manner. This third edition contains Scharf's revisions and corrections plus a brief new Epilogue on gauge invariance of quantum electrodynamics to all orders. The book begins with Dirac's theory, followed by the quantum theory of free fields and causal perturbation theory, a powerful method that avoids ultraviolet divergences and solves the infrared problem by means of the adiabatic limit. Successive chapters explore properties of the S-matrix — such as renormalizability, gauge invariance, and unitarity — the renormalization group, and interactive fields. Additional topics include electromagnetic couplings and the extension of the methods to non-abelian gauge theories. Each chapter is supplemented with problems, and four appe...

  11. Factors affecting 137Cs bio- availability under the application of different fertilizing systems

    Science.gov (United States)

    Fedorkova, M. V.; Belova, N. I.

    2012-04-01

    Although it has been 25 years since the Chernobyl accident, it was generally found that radiocaesium remained bio-availability in some regions. Plant uptake of 137Cs is depended from quantity of exchangeable radionuclide and strongly influenced by soil properties. The addition of fertilizers to soil induces chemical and biological changes that influence the distribution of free ions the different phases (soil and soil solution). In this study we try to estimate influence of different soil conditions affecting the 137Cs bio-availability under the application of manure and inorganic fertilizers. Our research carried out in 2001-2008 years on contaminated after Chernobyl accident sod-podzolic soil during of prolonged field experiment. The experimental site was located in south-west of Bryansk region, Russia. Contamination density by 137Cs in the sampling point was equal to 475±30 kBq/m2. The sequence of crops in rotation was: 1) potato; 2) oats 3) lupine 4) winter rye. Three fertilizing systems were compared: organic - 80 tons per hectare of cow manure; inorganic fertilizing system - different rates of NPK (low, temperate and high) and mixed - 40 tons per hectare of cow manure + NPK. Main soil properties and chemical form of 137Cs and K (potassium) were detected. Radiocaesium activity was determined in soil and plant samples by gamma spectrometry, using a high purity Ge detectors. Overall efficiency was known to an accuracy of about 10-12%. Obtained results shows, that various fertilizing systems influence soil properties, chemical forms of 137Cs and K in soil and radionuclide soil-to-plant transfer in different ways. The highest reduction of exchangeable 137Cs in soil was found in case with application of organic fertilizers and also - temperate NPK rates. Part of exchangeable 137Cs is equal 6.8% (from total activity) in case of manure, 7.8% in case of inorganic fertilizers with control value - 10.2%. Caesium mobility in soil is affected by such soil properties as

  12. Regulation of glucose transporter protein-1 and vascular endothelial growth factor by hypoxia inducible factorunder hypoxic conditions in Hep-2 human cells.

    Science.gov (United States)

    Xu, Ou; Li, Xiaoming; Qu, Yongtao; Liu, Shuang; An, Jie; Wang, Maoxin; Sun, Qingjia; Zhang, Wen; Lu, Xiuying; Pi, Lihong; Zhang, Min; Shen, Yupeng

    2012-12-01

    The present study evaluated the regulation of glucose transporter protein-1 (Glut-1) and vascular endothelial growth factor (VEGF) by hypoxia inducible factor 1α (HIF-1α) under hypoxic conditions in Hep-2 human cells to explore the feasibility of these three genes as tumor markers. Hep-2 cells were cultured under hypoxic and normoxic conditions for 6, 12, 24, 36 and 48 h. The proliferation of Hep-2 cells was evaluated using an MTT assay. The protein and mRNA expression levels of HIF-1α, Glut-1 and VEGF were detected using the S-P immunocytochemical method, western blotting and reverse transcription polymerase chain reaction (RT-PCR). The results revealed that the expression levels of HIF-1α, Glut-1 and VEGF protein in Hep-2 cells were significantly elevated under hypoxic conditions compared with those under normoxic conditions over 36 h. Under hypoxic conditions, mRNA levels of HIF-1α were stable, while mRNA levels of Glut-1 and VEGF changed over time. In conclusion, Glut-1 and VEGF were upregulated by HIF-1α under hypoxic conditions in a time-dependent manner in Hep-2 cells and their co-expression serves as a tumor marker.

  13. Perspectives on Underlying Factors for Unhealthy Diet and Sedentary Lifestyle of Adolescents at a Kenyan Coastal Setting

    OpenAIRE

    Derrick Ssewanyana; Derrick Ssewanyana; Amina Abubakar; Amina Abubakar; Amina Abubakar; Amina Abubakar; Anneloes van Baar; Patrick N. Mwangala; Patrick N. Mwangala; Charles R. Newton; Charles R. Newton; Charles R. Newton

    2018-01-01

    Unhealthy diet and physical inactivity are among the key modifiable risk factors for non-communicable diseases, such as diabetes and cardiovascular disease. Although such diseases often only appear in adulthood, these behaviors are typically initiated or reinforced already during adolescence. However, knowledge on underlying factors for adolescents’ unhealthy dieting and physical inactivity in sub-Saharan Africa (SSA) is poor. We conducted in-depth interviews and focus group discussions to ex...

  14. Time and Causality in the Economic Process – a Critical Approach Based on Consistency Criteria

    Directory of Open Access Journals (Sweden)

    Cristina TĂNĂSESCU

    2011-01-01

    Full Text Available Our paper proposes a critical analysis based on criteria of consistency of the fundamental concepts underlying the comprehensive description of economic process, namely: time, context and causality. Issues of such action taken by us arise from the existence of the fact that the emergence of new paradigms, amid an economic complexity, should include elements of theoretical, instrumental and methodological nature. Moreover, dominant economic science, at this time (positivist, is subject to an epistemological imperialism exercised by Newtonian mechanics, without one's own epistemology. Regarding the underlying causality explaining the economic process, we find that, yet at this time, it is a singular and efficient one (in the Aristotelian sense, but not a teleological one, so we wonder whether the final causality (purpose form may better explain the economic process and his completeness, and in this sense, the shaping of new paradigms based on premises other than those already existed, in understanding the economic process.

  15. On the causality relations in thermoelectricity

    Science.gov (United States)

    Vázquez, Federico; López de Haro, Mariano; Figueroa, Aldo

    2018-01-01

    The relationship between the causality principle and the existence of couplings between different thermodynamic driving forces in a given phenomenon is discussed. The case of thermoelectricity is explicitly analyzed. A transport equation for the propagation of thermal disturbances in a sample after an electric potential difference is applied is derived. The consequences of the non-hyperbolic character of this equation and the need for investigating its possible connection with nonequilibrium thermodynamics formulations are pointed out.

  16. Multivariable Mendelian randomization: the use of pleiotropic genetic variants to estimate causal effects.

    Science.gov (United States)

    Burgess, Stephen; Thompson, Simon G

    2015-02-15

    A conventional Mendelian randomization analysis assesses the causal effect of a risk factor on an outcome by using genetic variants that are solely associated with the risk factor of interest as instrumental variables. However, in some cases, such as the case of triglyceride level as a risk factor for cardiovascular disease, it may be difficult to find a relevant genetic variant that is not also associated with related risk factors, such as other lipid fractions. Such a variant is known as pleiotropic. In this paper, we propose an extension of Mendelian randomization that uses multiple genetic variants associated with several measured risk factors to simultaneously estimate the causal effect of each of the risk factors on the outcome. This "multivariable Mendelian randomization" approach is similar to the simultaneous assessment of several treatments in a factorial randomized trial. In this paper, methods for estimating the causal effects are presented and compared using real and simulated data, and the assumptions necessary for a valid multivariable Mendelian randomization analysis are discussed. Subject to these assumptions, we demonstrate that triglyceride-related pathways have a causal effect on the risk of coronary heart disease independent of the effects of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.

  17. Papular urticaria: A review of causal agents in Colombia.

    Science.gov (United States)

    Lozano, Ana Milena; López, Juan Felipe; Zakzuk, Josefina; García, Elizabeth

    2016-12-01

    Papular urticaria is a chronic allergic reaction induced by insect bites, which is common in the tropics. The objective of this review was to deepen on epidemiological and immunological aspects of this disease, focused on data published in Latin American countries.We conducted a non-systematic review of the literature through electronic search on the epidemiology of papular urticaria, the entomological characteristics of the causative agents and associated immunological mechanisms.Several reports from medical centers suggest that papular urticaria is common in Latin America. Only one epidemiological survey designed to estimate prevalence of papular urticaria has been published, reporting that about a quarter of children under six years of age is affected by this condition in Bogotá. There is evidence on the causal relationship among exposure to indoor fleas, poverty and papular urticaria in Bogotá, a representative city of the Andean altitudes. Information about causal insects in tropical warmer areas is scarce, although from clinical reports Aedes aegypti and Culex quienquefasciatus appear to be the most common. Th2 cellular-mediated mechanisms are involved in its pathogenesis, which explains its delayed hypersensitivity. The role of immunoglobulin E is not clear in this disease. Insect-derived antigens directly involved in papular urticaria etiology are unknown. However, it is possible that common molecules among causal insects mediate cross-reactive reactions, such as Cte f 2 allergen, found in cat fleas, and its counterparts in mosquitoes.Papular urticaria is a frequent disease in Latin America that should be further investigated. Immunological characterization of the molecular components that cause this condition may solve questions about its pathogenesis.

  18. Causal Relationship between Construction Production and GDP in Turkey

    OpenAIRE

    Hakkı Kutay Bolkol

    2015-01-01

    This study empirically investigates the causal relationship between construction production and GDP for Turkey during 2005Q1-2013Q4 period. Because it is found that, there is no cointegration which means there is no long run relationship between variables, VAR Granger Causality Method is used to test the causality in short run. The findings reveal that, the causality runs from GDP to Building Production and Building Production to Non-Building Production (i.e. bidirectional relationship). Find...

  19. The fuzzy cube and causal efficacy: representation of concomitant mechanisms in stroke.

    Science.gov (United States)

    Jobe, Thomas H.; Helgason, Cathy M.

    1998-04-01

    Twentieth century medical science has embraced nineteenth century Boolean probability theory based upon two-valued Aristotelian logic. With the later addition of bit-based, von Neumann structured computational architectures, an epistemology based on randomness has led to a bivalent epidemiological methodology that dominates medical decision making. In contrast, fuzzy logic, based on twentieth century multi-valued logic, and computational structures that are content addressed and adaptively modified, has advanced a new scientific paradigm for the twenty-first century. Diseases such as stroke involve multiple concomitant causal factors that are difficult to represent using conventional statistical methods. We tested which paradigm best represented this complex multi-causal clinical phenomenon-stroke. We show that the fuzzy logic paradigm better represented clinical complexity in cerebrovascular disease than current probability theory based methodology. We believe this finding is generalizable to all of clinical science since multiple concomitant causal factors are involved in nearly all known pathological processes.

  20. 75 FR 80114 - Agency Information Collection (Obligation To Report Factors Affecting Entitlement) Activity Under...

    Science.gov (United States)

    2010-12-21

    ... collection. Abstract: Claimants who applied for or receives compensation, pension or dependency and indemnity compensation benefits must report changes in their entitlement factors. Individual factors such as income... direction of the Secretary. Denise McLamb, Program Analyst, Enterprise Records Service. BILLING CODE 8320-01...

  1. Detecting Causality by Combined Use of Multiple Methods: Climate and Brain Examples.

    Directory of Open Access Journals (Sweden)

    Yoshito Hirata

    Full Text Available Identifying causal relations from time series is the first step to understanding the behavior of complex systems. Although many methods have been proposed, few papers have applied multiple methods together to detect causal relations based on time series generated from coupled nonlinear systems with some unobserved parts. Here we propose the combined use of three methods and a majority vote to infer causality under such circumstances. Two of these methods are proposed here for the first time, and all of the three methods can be applied even if the underlying dynamics is nonlinear and there are hidden common causes. We test our methods with coupled logistic maps, coupled Rössler models, and coupled Lorenz models. In addition, we show from ice core data how the causal relations among the temperature, the CH4 level, and the CO2 level in the atmosphere changed in the last 800,000 years, a conclusion also supported by irregularly sampled data analysis. Moreover, these methods show how three regions of the brain interact with each other during the visually cued, two-choice arm reaching task. Especially, we demonstrate that this is due to bottom up influences at the beginning of the task, while there exist mutual influences between the posterior medial prefrontal cortex and the presupplementary motor area. Based on our results, we conclude that identifying causality with an appropriate ensemble of multiple methods ensures the validity of the obtained results more firmly.

  2. A new approach to causality in the frequency domain

    OpenAIRE

    Mehmet Dalkir

    2004-01-01

    This study refers to the earlier work of analysis in the frequency domain. A different definition of causality is made, and its implications to the general idea of causality are discussed. The causality relationship between two monetary aggregates, simple sum and Divisia indices, and their relation with the personal income is analyzed using wavelet time-scale decomposition.

  3. A Quantitative Causal Model Theory of Conditional Reasoning

    Science.gov (United States)

    Fernbach, Philip M.; Erb, Christopher D.

    2013-01-01

    The authors propose and test a causal model theory of reasoning about conditional arguments with causal content. According to the theory, the acceptability of modus ponens (MP) and affirming the consequent (AC) reflect the conditional likelihood of causes and effects based on a probabilistic causal model of the scenario being judged. Acceptability…

  4. How to Be Causal: Time, Spacetime and Spectra

    Science.gov (United States)

    Kinsler, Paul

    2011-01-01

    I explain a simple definition of causality in widespread use, and indicate how it links to the Kramers-Kronig relations. The specification of causality in terms of temporal differential equations then shows us the way to write down dynamical models so that their causal nature "in the sense used here" should be obvious to all. To extend existing…

  5. Pathway Analysis and the Search for Causal Mechanisms

    Science.gov (United States)

    Weller, Nicholas; Barnes, Jeb

    2016-01-01

    The study of causal mechanisms interests scholars across the social sciences. Case studies can be a valuable tool in developing knowledge and hypotheses about how causal mechanisms function. The usefulness of case studies in the search for causal mechanisms depends on effective case selection, and there are few existing guidelines for selecting…

  6. [The laboratory evaluation of pathogenic factors under retarded consolidation of fractures of bones of lower extremities].

    Science.gov (United States)

    Stogov, V M; Kireeva, E A; Karasev, A G

    2014-12-01

    The study was carried out to comparatively analyze metabolic profile and content of growth factors in blood serum of patients with retarded consolidation of fractures of bones of lower extremities. The evaluation was applied to concentration of metabolites, growth factors and enzyme activity of blood serum in 13 patients with retarded consolidation of fractures of thigh and shank bones (main group). The comparative group included 14 patients with solid fractures of thigh and shank bones. The analysis established that as compared to patients with solid fractures of bones, in patients with retarded consolidation of fractures blood serum contained reliably higher concentration of triglycerides, products of glycolysis, epidermal growth factor and transforming growth factors TGF-α and TGF-β2. The content of vitamin E and insullin-like growth factor (IGF-1) was decreased The given markers can be labeled as potential markers of diagnostic and prognosis of development of retarded consolidation of fractures.

  7. Spatial Causality. An application to the Deforestation Process in Bolivia

    Directory of Open Access Journals (Sweden)

    Javier Aliaga

    2011-01-01

    Full Text Available Este trabajo analiza las causas de la deforestación para un conjunto representativo de municipios bolivianos. La literatura sobre economía ambiental insiste en la importancia de los factores físicos y sociales. Nos centramos en el último grupo de variables. Nuestro objetivo es identificar los mecanismos causales entre estos factores de riesgo y el problema de la deforestación. Con este fin, se presenta una estrategia de análisis para identificar mecanismos de causalidad espacial, basada en una secuencia de los multiplicadores de Lagrange. Los resultados que obtenemos para el caso de Bolivia confirman sólo parcialmente la visión tradicional del problema de la deforestación. De hecho, sólo encontramos signos inequívocos de causalidad en relación con la estructura de los derechos de propiedad.

  8. A Causal Relationship of Occupational Stress among University Employees.

    Science.gov (United States)

    Kaewanuchit, Chonticha; Muntaner, Carles; Isha, Nizam

    2015-07-01

    Occupational stress is a psychosocial dimension of occupational health concept on social determinants of health, especially, job & environmental condition. Recently, staff network of different government universities of Thailand have called higher education commission, and Ministry of Education, Thailand to resolve the issue of government education policy (e.g. wage inequity, poor welfare, law, and job & environment condition) that leads to their job insecurity, physical and mental health problems from occupational stress. The aim of this study was to investigate a causal relationship of occupational stress among the academic university employees. This cross sectional research was conducted in 2014 among 2,000 academic university employees at Thai government universities using stratified random sampling. Independent variables were wage, family support, periods of duty, and job & environmental condition. Dependent variable was stress. Job & environmental condition, as social and environmental factor, and periods of duty as individual factor had direct effect to stress (Pstress (P stress among academic university employees at moderate level.

  9. The Causality of Evolution on Different Fitness Landscapes

    Science.gov (United States)

    Vyawahare, Saurabh; Austin, Robert; Zhang, Qiucen; Kim, Hyunsung; Bestoso, John

    2013-03-01

    Evolution of antibiotic resistance is a growing problem. One major reason why most antibiotics fail is because of mutations on drug targets (e.g. essential enzymes). Sequencing of clinically resistant isolates have shown that multiple mutational-hotspots exist in coding regions, which could potentially prohibit the binding of drugs. However, it is not clear whether the appearance of each mutation is random or influenced by other factors. In this paper, we compare evolution of resistance to ciprofloxacin from two distinct but well characterized genetic backgrounds. By combining our recently developed evolution reactor and deep whole-genome sequencing, we show different alleles of σs factor lead to fixation of different mutations in gyrA gene that confer ciprofloxacin resistance to bacteria Escherichia coli. Such causality of evolution in different genes provides an opportunity to control the evolution of antibiotic resistance. Sponsored by the NCI/NIH Physical Sciences Oncology Centers

  10. Causal beliefs about depression in different cultural groups – What do cognitive psychological theories of causal learning and reasoning predict?

    OpenAIRE

    York eHagmayer; Neele eEngelmann

    2014-01-01

    Cognitive psychological research focuses on causal learning and reasoning while cognitive anthropological and social science research tend to focus on systems of beliefs. Our aim was to explore how these two types of research can inform each other. Cognitive psychological theories (causal model theory and causal Bayes nets) were used to derive predictions for systems of causal beliefs. These predictions were then applied to lay theories of depression as a specific test case. A systematic lite...

  11. Data analysis of the inactivation of foodborne microorganisms under high hydrostatic pressure to establish global kinetic parameters and influencing factors

    NARCIS (Netherlands)

    Santillana Farakos, S.M.; Zwietering, M.H.

    2011-01-01

    The inactivation rate of foodborne microorganisms under high hydrostatic pressure (HHP) is influenced by factors such as substrate, species, strain, temperature, pH, and stage of growth of the cell. In this study, 445 DP-values from previously published data were analyzed, including those from

  12. Identifying key factors for mobilising under-utilised low carbon land resources : A case study on Kalimantan

    NARCIS (Netherlands)

    Goh, Chun Sheng; Junginger, Martin; Potter, Lesley; Faaij, André; Wicke, Birka

    2018-01-01

    Mobilising under-utilised low carbon (ULC) land for future agricultural expansion helps minimising further carbon stock loss. This study examined the regency cases in Kalimantan, a carbon loss hotspot, to understand the key factors for mobilising ULC land via narrative interviews with a range of

  13. [Analysis of characteristics of alpha electroencephalogram during the interaction between emotion and cognition based on Granger causality].

    Science.gov (United States)

    Wang, Ning; Wei, Ling; Li, Yingjie

    2012-12-01

    Studying the functional network during the interaction between emotion and cognition is an important way to reveal the underlying neural connections in the brain and nowadays, it has become a hot topic in cognitive neuroscience. Granger causality (GC), based on multivariate autoregressive (MVAR) model, and being able to be used to analyse causal characteristic of brain regions has been widely used in electroencephalography (EEG) in event-related paradigms research. In this study, we recorded the EEGs from 13 normal subjects (6 males and 7 females) during emotional face search task. We utilized Granger causality to establish a causal model of different brain areas under different rhythms at specific stages of cognition, and then convinced the brain dynamic network topological properties in the process of emotion and cognition. Therefore, we concluded that in the alpha band, (1) negative emotion face induced larger causal effects than positive ones; (2) 100-200ms emotional signal was the most prominent ones while 300-400ms and 700-800ms would take the second place; (3) The rear brain region modulated the front in the process of causal modulation; (4) The frontal and pillow area involved in the brain causal modulation as a key brain area; and (5) Negative partiality existed in the information processing, especially during 0-100ms after the negative expression stimulation.

  14. Cellular Senescence as the Causal Nexus of Aging.

    Science.gov (United States)

    Bhatia-Dey, Naina; Kanherkar, Riya R; Stair, Susan E; Makarev, Evgeny O; Csoka, Antonei B

    2016-01-01

    In this paper we present cellular senescence as the ultimate driver of the aging process, as a "causal nexus" that bridges microscopic subcellular damage with the phenotypic, macroscopic effect of aging. It is important to understand how the various types of subcellular damage correlated with the aging process lead to the larger, visible effects of anatomical aging. While it has always been assumed that subcellular damage (cause) results in macroscopic aging (effect), the bridging link between the two has been hard to define. Here, we propose that this bridge, which we term the "causal nexus", is in fact cellular senescence. The subcellular damage itself does not directly cause the visible signs of aging, but rather, as the damage accumulates and reaches a critical mass, cells cease to proliferate and acquire the deleterious "senescence-associated secretory phenotype" (SASP) which then leads to the macroscopic consequences of tissue breakdown to create the physiologically aged phenotype. Thus senescence is a precondition for anatomical aging, and this explains why aging is a gradual process that remains largely invisible during most of its progression. The subcellular damage includes shortening of telomeres, damage to mitochondria, aneuploidy, and DNA double-strand breaks triggered by various genetic, epigenetic, and environmental factors. Damage pathways acting in isolation or in concert converge at the causal nexus of cellular senescence. In each species some types of damage can be more causative than in others and operate at a variable pace; for example, telomere erosion appears to be a primary cause in human cells, whereas activation of tumor suppressor genes is more causative in rodents. Such species-specific mechanisms indicate that despite different initial causes, most of aging is traced to a single convergent causal nexus: senescence. The exception is in some invertebrate species that escape senescence, and in non-dividing cells such as neurons, where

  15. A Bayesian Theory of Sequential Causal Learning and Abstract Transfer.

    Science.gov (United States)

    Lu, Hongjing; Rojas, Randall R; Beckers, Tom; Yuille, Alan L

    2016-03-01

    Two key research issues in the field of causal learning are how people acquire causal knowledge when observing data that are presented sequentially, and the level of abstraction at which learning takes place. Does sequential causal learning solely involve the acquisition of specific cause-effect links, or do learners also acquire knowledge about abstract causal constraints? Recent empirical studies have revealed that experience with one set of causal cues can dramatically alter subsequent learning and performance with entirely different cues, suggesting that learning involves abstract transfer, and such transfer effects involve sequential presentation of distinct sets of causal cues. It has been demonstrated that pre-training (or even post-training) can modulate classic causal learning phenomena such as forward and backward blocking. To account for these effects, we propose a Bayesian theory of sequential causal learning. The theory assumes that humans are able to consider and use several alternative causal generative models, each instantiating a different causal integration rule. Model selection is used to decide which integration rule to use in a given learning environment in order to infer causal knowledge from sequential data. Detailed computer simulations demonstrate that humans rely on the abstract characteristics of outcome variables (e.g., binary vs. continuous) to select a causal integration rule, which in turn alters causal learning in a variety of blocking and overshadowing paradigms. When the nature of the outcome variable is ambiguous, humans select the model that yields the best fit with the recent environment, and then apply it to subsequent learning tasks. Based on sequential patterns of cue-outcome co-occurrence, the theory can account for a range of phenomena in sequential causal learning, including various blocking effects, primacy effects in some experimental conditions, and apparently abstract transfer of causal knowledge. Copyright © 2015

  16. Socio-demographic factors related to under-diagnosis of childhood asthma in Upper Silesia, Poland

    Directory of Open Access Journals (Sweden)

    Jan E. Zejda

    2017-06-01

    Among non-medical determinants of undiagnosed asthma the age of a child plays a major role. Another factors of importance is the large distance between residence and health centre, and low parental attention at home.

  17. Bleeding and asymptomatic overdose in patients under Vitamin K antagonist therapy: Frequency and risk factors

    Directory of Open Access Journals (Sweden)

    F. Ben Mbarka

    2018-03-01

    Full Text Available Background: Vitamin K antagonists are widely used in the treatment and prevention of thromboembolic disease. However, these drugs can cause serious side effects, especially bleeding. This study aims to evaluate frequency and risk factors of both bleeding and asymptomatic overdose in North African patients undergoing Vitamin K antagonist therapy. Methods: We performed a cross-sectional study in patients undergoing Vitamin K antagonist therapy. A statistical analysis has been conducted to identify overdose and bleeding risk factors by using chi-square test (p < .05. Results: One hundred and eleven patients were included. We recorded 14 cases of bleeding and 26 cases of asymptomatic overdose. Advanced age, poor adherence, concomitant use of paracetamol and history of previous bleeding are significant risk factors of over-anticoagulation. An INR value over 6 at admission, a high therapeutic target range for INR, concomitant use of acetylsalicylic acid, lack of information on overdose signs and measures to be taken in case of bleeding were identified as risk factors for bleeding. Conclusion: Most of the risk factors identified in our study seem to be related to patients lack of information and education. These results highlight the importance of creating a therapeutic patient education program. Keywords: Vitamin K antagonist, Bleeding, Risk factor, Overdose

  18. Cultural influences on causal beliefs about depression among Latino immigrants.

    Science.gov (United States)

    Caplan, Susan; Escobar, Javier; Paris, Manuel; Alvidrez, Jennifer; Dixon, Jane K; Desai, Mayur M; Scahill, Lawrence D; Whittemore, Robin

    2013-01-01

    This study describes causal beliefs about depression among Dominican, Colombian, and Ecuadorian immigrants. The authors describe participants' narratives about how particular supernatural or religious beliefs may contribute to or alleviate depression. Latino primary care patients (n = 177) were interviewed with the Beliefs About Causes of Depression Scale, a list of 35 items rated from not at all important to extremely important. Participants had the option of expanding on responses using an informal conversational approach. Underlying themes of these explanatory comments were derived from narrative and content analysis. Major themes that emerged were Psychosocial and Religious and Supernatural causal beliefs. A third theme emerged that represented the integration of these categories in the context of the immigrant experience. This article adds to the understanding of cross-cultural beliefs about depression. Psychosocial stressors related to the immigrant experience and adverse life events were highly endorsed, but the meaning of these stressors was construed in terms of religious and cultural values. To provide culturally appropriate services, nurses should be aware of and discuss the patient's belief systems, illness interpretations, and expectations of treatment.

  19. Information causality from an entropic and a probabilistic perspective

    International Nuclear Information System (INIS)

    Al-Safi, Sabri W.; Short, Anthony J.

    2011-01-01

    The information causality principle is a generalization of the no-signaling principle which implies some of the known restrictions on quantum correlations. But despite its clear physical motivation, information causality is formulated in terms of a rather specialized game and figure of merit. We explore different perspectives on information causality, discussing the probability of success as the figure of merit, a relation between information causality and the nonlocal ''inner-product game,'' and the derivation of a quadratic bound for these games. We then examine an entropic formulation of information causality with which one can obtain the same results, arguably in a simpler fashion.

  20. Maternal and child under-nutrition in rural and urban communities of Lagos state, Nigeria: the relationship and risk factors

    Science.gov (United States)

    2013-01-01

    Background Poor nutritional status of mothers has a direct and indirect consequence on their own health and that of their children. The objective of this study was to determine the relationship between nutritional status of mothers and their children and the risk factors for under-nutrition among mothers and children in rural and urban communities of Lagos State, Nigeria. Methods This was a cross sectional survey conducted using the multistage random sampling technique. A total of 300 mother-child pairs were studied, consisting of 150 each from rural and urban communities. Under-nutrition in mothers and children was determined using standard criteria. Results The prevalence of under-nutrition among mothers was significantly higher in rural than urban communities (10.7% vs. 2.7%, p = 0.014). The prevalences of underweight and stunted children were also significantly higher in rural than urban communities (19.4% vs. 9.3%, p maternal and child under nutrition differs across rural and urban communities. Conclusions The prevalence of maternal and child under-nutrition is high in both communities although higher in rural communities. Efforts at reducing the vicious cycle of under-nutrition among mothers and children should concentrate on addressing risk factors specific for each community. PMID:23880121

  1. Biological causal links on physiological and evolutionary time scales.

    Science.gov (United States)

    Karmon, Amit; Pilpel, Yitzhak

    2016-04-26

    Correlation does not imply causation. If two variables, say A and B, are correlated, it could be because A causes B, or that B causes A, or because a third factor affects them both. We suggest that in many cases in biology, the causal link might be bi-directional: A causes B through a fast-acting physiological process, while B causes A through a slowly accumulating evolutionary process. Furthermore, many trained biologists tend to consistently focus at first on the fast-acting direction, and overlook the slower process in the opposite direction. We analyse several examples from modern biology that demonstrate this bias (codon usage optimality and gene expression, gene duplication and genetic dispensability, stem cell division and cancer risk, and the microbiome and host metabolism) and also discuss an example from linguistics. These examples demonstrate mutual effects between the fast physiological processes and the slow evolutionary ones. We believe that building awareness of inference biases among biologists who tend to prefer one causal direction over another could improve scientific reasoning.

  2. Form and function: Optional complementizers reduce causal inferences

    Directory of Open Access Journals (Sweden)

    Hannah Rohde

    2017-05-01

    Full Text Available Many factors are known to influence the inference of the discourse coherence relationship between two sentences. Here, we examine the relationship between two conjoined embedded clauses in sentences like 'The professor noted that the student teacher did not look confident and (that the students were poorly behaved'. In two studies, we find that the presence of 'that 'before the second embedded clause in such sentences reduces the possibility of a forward causal relationship between the clauses, i.e., the inference that the student teacher’s confidence was what affected student behavior. Three further studies tested the possibility of a backward causal relationship between clauses in the same structure, and found that the complementizer’s presence aids that relationship, especially in a forced-choice paradigm. The empirical finding that a complementizer, a linguistic element associated primarily with structure rather than event-level semantics, can affect discourse coherence is novel and illustrates an interdependence between syntactic parsing and discourse parsing.

  3. Magnitude and valence of outcomes as determinants of causal judgments

    Directory of Open Access Journals (Sweden)

    Diana Delgado

    2013-01-01

    Full Text Available El propósito de este proyecto es examinar si el modelo de bloqueo predice la atribución de juicios causales al variar la valencia y la magnitud de las consecuencias. El arreglo experimental consiste en la presentación de reportes sobre los efectos positivos y negativos que producen diferentes sustancias al ser consumidas solas o en conjunto con otras. Los participantes del primer grupo estuvieron expuestos a consecuencias de alta magnitud y los del segundo grupo, a consecuencias de baja magnitud. Se evaluó si la atribución de causalidad es consistente con las predicciones del efecto bloqueo mediante dos tipos de pregunta: una pregunta acerca si la sustancia X produce o no el efecto, y una pregunta sobre la probabilidad de que X produzca el efecto. Se examinaron las diferencias en los juicios causales cuando las atribuciones son producto del razonamiento lógico o intuitivo. Si bien no se observó evidencia del efecto bloqueo, se obtuvieron efectos de interacción entre los factores valencia y condición experimental (sustancias bloqueo y control. Se discuten los hallazgos en términos de las diferencias entre el aprendizaje asociativo en humanos y animales no humanos, y en términos de las implicaciones sobre las diferencias teóricas entre el condicionamiento evaluativo y el condicionamiento predictivo.

  4. Phenotypic and Causal Structure of Conduct Disorder in the Broader Context of Prevalent Forms of Psychopathology

    Science.gov (United States)

    Lahey, Benjamin B.; Waldman, Irwin D.

    2011-01-01

    Background A better understanding of the nature and etiology of conduct disorder (CD) can inform nosology and vice-versa. We posit that any prevalent form of psychopathology, including CD, can be best understood if it is studied in the context of other correlated forms of child and adolescent psychopathology using formal models to guide inquiry. Methods Review of both cross-sectional and longitudinal studies of the place of CD in the phenotypic and causal structure of prevalent psychopathology, with an emphasis on similarities and differences between CD and oppositional defiant disorder (ODD). Papers were located using Web of Science by topic searches with no restriction on year of publication. Results Although some important nosologic questions remain unanswered, the dimensional phenotype of CD is well defined. CD differs from other disorders in its correlates, associated impairment, and course. Nonetheless, it is robustly correlated with many other prevalent dimensions of psychopathology both concurrently and predictively, including both other “externalizing” disorders and some “internalizing” disorders. Based on emerging evidence, we hypothesize that these concurrent and predictive correlations result primarily from widespread genetic pleiotropy, with some genetic factors nonspecifically influencing risk for multiple correlated dimensions of psychopathology. In contrast, environmental influences mostly act to differentiate dimensions of psychopathology from one another both concurrently and over time. CD and ODD share half of their genetic influences, but their genetic etiologies are distinct in other ways. Unlike most other dimensions of psychopathology, half of the genetic influences on CD appear to be unique to CD. In contrast, ODD broadly shares nearly all of its genetic influences with other disorders and has little unique genetic variance. Conclusions CD is a relatively distinct syndrome at both phenotypic and etiologic levels, but much is revealed

  5. Factor VIIa-mediated tenase function on activated platelets under flow.

    Science.gov (United States)

    Goel, M S; Diamond, S L

    2004-08-01

    Tissue factor (TF) and/or active factor (F)VIIa may be stored inside resting platelets. The objective of this study was to examine if platelets, following activation of GPVI, could support tenase and prothrombinase activity without any exogenously added tissue factor. Thrombin (IIa) formation on gel-filtered platelets with added factors or the clotting of platelet-free plasma (PFP) or platelet-rich plasma (PRP) supplemented with corn trypsin inhibitor (CTI) (to inhibit factor XIIa) was studied in well plate assays with a fluorogenic thrombin substrate or in flow assays by fibrin visualization. Pretreatment of convulxin (CVX)-stimulated, fibrinogen-adherent, gel-filtered platelets with anti-TF, anti-FVII/VIIa, or 1 nm PPACK [inhibitor of FVIIa, factor XIa and factor (F)IIa] delayed fibrin deposition on platelets perfused with PFP/CTI at 62.5 s(-1). Anti-TF or anti-FVII/VIIa also attenuated thrombin generation in plate assays using recalcified PRP/CTI treated with CVX. Anti-TF or anti-FVII/VIIa (but not inhibited factor IXa) delayed the burst in thrombin production by gel-filtered platelets suspended in prothrombin and CVX by 14 min and 40 min, respectively. Anti-FVII/VIIa completely eliminated thrombin generation on fibrinogen-adherent, gel-filtered platelets pretreated with 10 micro m PPACK and 10 micro m EGR-CK [inhibitor of factor (F)Xa], rinsed, and then supplemented with CVX, prothrombin, and FX. Addition of anionic phospholipid to PFP/CTI or to a mixture of prothrombin, FX, and recVIIa was not sufficient to generate detectable tenase activity. Lastly, isolated, unactivated neutrophils suspended in FX, FII and recVIIa supported a very low level of thrombin generation sensitive to antagonism of P-selectin, CD18, and TF. Activated platelets supported tenase and prothrombinase activity by elevating the function or level of FVIIa and exposing active FVIIa or FVIIa-cofactor(s), distinct from anionic lipid, that may be, in part, TF.

  6. X - FACTOR EVALUATION UNDER RPI-X REGULATION FOR INDIAN ELECTRICITY DISTRIBUTION UTILITIES

    Directory of Open Access Journals (Sweden)

    PAVAN KHETRAPAL

    2017-07-01

    Full Text Available With regulators’ growing interest in improving operational efficiency and quality supply, the time is nearing when performance based regulation will become norm for regulating the distribution tariff in Indian electricity distribution sector. In this context, the State Electricity Regulatory Commissions proposed replacing rate-of-return regulation with most commonly used performance based regulatory regime, i.e., Price Cap regulation also known as RPI-X (Retail Price Index - Productivity Offset regulatory framework. However, the potential problem associated with applying price cap regulation scheme in practice is the determination of productivity offset or X factor used in price caps setting. This paper proposed an approach to calculate the X-factor for 58 government-owned and privately-owned electricity distribution utilities in India during a five year period from 2007/08 to 2011/12. A Stochastic Frontier model through an input distance function is first applied to compute the Malmquist Total Factor Productivity (TFP and the estimated TFP is then used to calculate the utility-specific X-factor. With rely on calculated X-factor, the distribution utilities would be able to cap either on prices or revenues thus accounting the inflation in the tariff determination. This will be more realistic approach as compared to cost plus approach.

  7. Blocking in children's causal learning depends on working memory and reasoning abilities

    NARCIS (Netherlands)

    McCormack, T.; Simms, V.; McGourty, J.; Beckers, T.

    2013-01-01

    A sample of 99 children completed a causal learning task that was an analogue of the food allergy paradigm used with adults. The cue competition effects of blocking and unovershadowing were assessed under forward and backward presentation conditions. Children also answered questions probing their

  8. Causal Modeling of Secondary Science Students' Intentions to Enroll in Physics.

    Science.gov (United States)

    Crawley, Frank E.; Black, Carolyn B.

    1992-01-01

    Reports a study using the causal modeling method to verify underlying causes of student interest in enrolling in physics as predicted by the theory of planned behavior. Families were identified as major referents in the social support system for physics enrollment. Course and extracurricular conflicts and fear of failure were primary beliefs…

  9. Industry efficiency and total factor productivity growth under resources and environmental constraint in China.

    Science.gov (United States)

    Tao, Feng; Li, Ling; Xia, X H

    2012-01-01

    The growth of China's industry has been seriously depending on energy and environment. This paper attempts to apply the directional distance function and the Luenberger productivity index to measure the environmental efficiency, environmental total factor productivity, and its components at the level of subindustry in China over the period from 1999 to 2009 while considering energy consumption and emission of pollutants. This paper also empirically examines the determinants of efficiency and productivity change. The major findings are as follows. Firstly, the main sources of environmental inefficiency of China's industry are the inefficiency of gross industrial output value, the excessive energy consumption, and pollutant emissions. Secondly, the highest growth rate of environmental total factor productivity among the three industrial categories is manufacturing, followed by mining, and production and supply of electricity, gas, and water. Thirdly, foreign direct investment, capital-labor ratio, ownership structure, energy consumption structure, and environmental regulation have varying degrees of effects on the environmental efficiency and environmental total factor productivity.

  10. Conservation agriculture and the efficient use of the production factors under mediterranean agriculture

    OpenAIRE

    Carvalho, Mário

    2014-01-01

    Nesta comunicação são abordados os vários contributos que a agricultura de conservação pode dar, para aumentar a eficiência do uso de factores em ambiente Mediterrânico. Começa por se fazer uma apreciação dos constrangimentos climáticos e edáficos e a evolução da eficiência no uso dos factores, pela agricultura portuguesa, entre 1987 e 2011. De seguida abordam-se as estratégias possíveis para aumentar a eficiência no uso dos factores no contexto de sistemas de agricultura de conservação. ...

  11. DEGRADATION WORKS OF MONUMENTAL ART CAST BRONZE UNDER THE INFLUENCE OF ENVIRONMENTAL FACTORS

    Directory of Open Access Journals (Sweden)

    Delia NICA-BADEA

    2012-11-01

    Full Text Available Intensive pollution, combined with the lack of conservation of monuments exposed to these environments make the main cause of deterioration of cultural objects to atmospheric corrosion metal. This paper proposes a study of the main factors leading to degradation Bronze alloy, cast bronze monuments exposed to open atmosphere: corrosive environmental factors, stability and products of corrosion of bronze. In general, all corrosion products present on a metal surface are indicated as 'skate', can be composed of single-layer or multilayer products. The paper also includes a case study on the influence of environmental factors on degradation Matthias monument statue in Cluj-Napoca, Romania. Visual inspection of the monument informs us that have white spots, gray, reddish not consistent with the base color green patina, surfaces showing depigmentation, the rain washed areas, crystallization, deposition of air-borne particles.

  12. Emergent Geometry from Entropy and Causality

    Science.gov (United States)

    Engelhardt, Netta

    In this thesis, we investigate the connections between the geometry of spacetime and aspects of quantum field theory such as entanglement entropy and causality. This work is motivated by the idea that spacetime geometry is an emergent phenomenon in quantum gravity, and that the physics responsible for this emergence is fundamental to quantum field theory. Part I of this thesis is focused on the interplay between spacetime and entropy, with a special emphasis on entropy due to entanglement. In general spacetimes, there exist locally-defined surfaces sensitive to the geometry that may act as local black hole boundaries or cosmological horizons; these surfaces, known as holographic screens, are argued to have a connection with the second law of thermodynamics. Holographic screens obey an area law, suggestive of an association with entropy; they are also distinguished surfaces from the perspective of the covariant entropy bound, a bound on the total entropy of a slice of the spacetime. This construction is shown to be quite general, and is formulated in both classical and perturbatively quantum theories of gravity. The remainder of Part I uses the Anti-de Sitter/ Conformal Field Theory (AdS/CFT) correspondence to both expand and constrain the connection between entanglement entropy and geometry. The AdS/CFT correspondence posits an equivalence between string theory in the "bulk" with AdS boundary conditions and certain quantum field theories. In the limit where the string theory is simply classical General Relativity, the Ryu-Takayanagi and more generally, the Hubeny-Rangamani-Takayanagi (HRT) formulae provide a way of relating the geometry of surfaces to entanglement entropy. A first-order bulk quantum correction to HRT was derived by Faulkner, Lewkowycz and Maldacena. This formula is generalized to include perturbative quantum corrections in the bulk at any (finite) order. Hurdles to spacetime emergence from entanglement entropy as described by HRT and its quantum

  13. Investigating the change of causality in emerging property markets during the financial tsunami

    Science.gov (United States)

    Hui, Eddie C. M.; Chen, Jia

    2012-08-01

    In this paper, we employ the multivariate CUSUM (cumulative sum) test for covariance structure as well as the renormalized partial directed coherence (PDC) method to capture the structural causality change of real estate stock indices of five emerging Asian countries and regions (i.e., Thailand, Malaysia, South Korea, PR China, and Taiwan). Meanwhile, we develop a method to make the comparison of renormalized PDC more intuitive and a set of criteria to measure the result. One of our findings indicates that the regional influence of the Chinese real estate stock market on the causality structure of the five markets has arisen under the effect of the financial tsunami.

  14. Changes in dynamics processes of the muscles’ traction under influence of stress-factors

    Directory of Open Access Journals (Sweden)

    D. M. Nozdrenko

    2006-01-01

    Full Text Available Change of fibers’ dynamic parameters of the frog Rana temporaria skeletal muscle m. tibialis traction under influence of modulated stimulation and aluminium chloride solutions was studied. At 10-4,5·10-4 and 10‑3 M·l-1 concentrations of aluminium chloride the nonlinear decrease of the muscle fibers’ traction parameters was observed.

  15. Midline fascial plication under continuous digital transrectal control: which factors determine anatomic outcome?

    NARCIS (Netherlands)

    Milani, A.L.; Withagen, M.I.J.; Schweitzer, K.J.; Janszen, E.W.; Vierhout, M.E.

    2010-01-01

    INTRODUCTION AND HYPOTHESIS: The aim of the study was to report anatomic and functional outcome of midline fascial plication under continuous digital transrectal control and to identify predictors of anatomic failure. METHODS: Prospective observational cohort. Anatomic success defined as POP-Q stage

  16. Factors associated with the risk of caries development after comprehensive dental rehabilitation under general anesthesia

    Directory of Open Access Journals (Sweden)

    Yai-Tin Lin

    2016-06-01

    Conclusion: This study has shown that SM count and CRA score were associated with new caries development in ECC children who needed to be treated under general anesthesia. The modified Cariogram used in this study is another significant tool for predicting new carries development in this particular population.

  17. Factors Associated with Sex under the Influence of Alcohol among Adolescents with Divorced Parents

    Science.gov (United States)

    Orgiles, Mireia; Carratala, Elena; Carballo, Jose L.; Piqueras, Jose A.; Espada, Jose P.

    2013-01-01

    This study addresses the association of diverse individual variables, traditionally associated with sexual risk practices in the general population, with sex under the influence of alcohol in adolescents with divorced parents. A sample of 132 adolescents provided information about their knowledge and attitudes toward HIV/AIDS and sexual risk…

  18. L2 Speaking Development during Study Abroad: Fluency, Accuracy, Complexity, and Underlying Cognitive Factors

    Science.gov (United States)

    Leonard, Karen Ruth; Shea, Christine E.

    2017-01-01

    We take a multidimensional perspective on the development of second language (L2) speaking ability and examine how changes in the underlying cognitive variables of linguistic knowledge and processing speed interact with complexity, fluency, and accuracy over the course of a 3-month Spanish study abroad session. Study abroad provides a unique…

  19. Dynamic panel data models and causality : Applications to labor supply, health and insurance

    NARCIS (Netherlands)

    Michaud, P.C.

    2005-01-01

    One of the main findings concerns the importance of common persistent factors, or unobserved traits of respondents, in order to study dynamic relationships between two variables of interest using panel data. The ¿hand of the past¿ can reinforce existent causal relationships, or blur their effect,

  20. Feedback Both Helps and Hinders Learning: The Causal Role of Prior Knowledge

    Science.gov (United States)

    Fyfe, Emily R.; Rittle-Johnson, Bethany

    2016-01-01

    Feedback can be a powerful learning tool, but its effects vary widely. Research has suggested that learners' prior knowledge may moderate the effects of feedback; however, no causal link has been established. In Experiment 1, we randomly assigned elementary school children (N = 108) to a condition based on a crossing of 2 factors: induced strategy…

  1. A Causal Model of Career Development and Quality of Life of College Students with Disabilities

    Science.gov (United States)

    Chun, Jina

    2017-01-01

    Researchers have assumed that social cognitive factors play significant roles in the career development of transition youth and young adults with disabilities and those without disabilities. However, research on the influence of the career decision-making process as a primary causal agent in one's psychosocial outcomes such as perceived level of…

  2. Alterations of markers of oxidative stress caused by environmental factors and their dynamics under impact of native biomodulators

    International Nuclear Information System (INIS)

    Stasytyte-Buneviciene, D.; Juozulynas, A.; Bunevicius, J.

    2004-01-01

    Intensified formation of free radicals is one of the most important harmful factors of ionizing radiation acting upon human organism. Under physiological conditions, anti oxidative system preserves from harmful influence of free radicals. To avoid a disturbing influence of oxidative stress upon the processes of human homeostasis, additional quantities of antioxidants are indispensable. Among native biomodulators, pollen are well known for their anti oxidative, antitoxic and radioprotective properties. Dynamics of alterations of markers of oxidative stress as well as possibilities of restitution of their qualitative and quantitative indices were studied using native pollen. Correction programme was performed on 50 persons, 9 males and 41 female, residing and working under impact of harmful factors of oxidative stress, who used pollen 10 g per day during a period of 30 days. Control group consisted of 57 persons, 10 males and 47 females living and working under the same conditions. Blood tests (diene conjugates, malonic dialdehyde and katalase) using standard spectrophotometric methodic were studied before and after the course of treatment. After the treatment, contents of metabolites of lipid peroxidation, diene conjugates and malonic dialdehyde in blood serum essentially reduced. Activity of catalase decreased significantly in blood serum of the males and regularly smoking females. In conclusion, data presented demonstrate anti oxidative efficiency of native pollen and suggest more often it's applying in cases with alterated processes of homeostasis under impact of harmful factors of oxidative stress including influence of ionizing radiation. (author)

  3. A Causal Theory of Mnemonic Confabulation.

    Science.gov (United States)

    Bernecker, Sven

    2017-01-01

    This paper attempts to answer the question of what defines mnemonic confabulation vis-à-vis genuine memory. The two extant accounts of mnemonic confabulation as "false memory" and as ill-grounded memory are shown to be problematic, for they cannot account for the possibility of veridical confabulation, ill-grounded memory, and well-grounded confabulation. This paper argues that the defining characteristic of mnemonic confabulation is that it lacks the appropriate causal history. In the confabulation case, there is no proper counterfactual dependence of the state of seeming to remember on the corresponding past representation.

  4. A Causal Theory of Mnemonic Confabulation

    Directory of Open Access Journals (Sweden)

    Sven Bernecker

    2017-07-01

    Full Text Available This paper attempts to answer the question of what defines mnemonic confabulation vis-à-vis genuine memory. The two extant accounts of mnemonic confabulation as “false memory” and as ill-grounded memory are shown to be problematic, for they cannot account for the possibility of veridical confabulation, ill-grounded memory, and well-grounded confabulation. This paper argues that the defining characteristic of mnemonic confabulation is that it lacks the appropriate causal history. In the confabulation case, there is no proper counterfactual dependence of the state of seeming to remember on the corresponding past representation.

  5. Causal Factors in Alcohol Rehabilitation Success or Failure.

    Science.gov (United States)

    1980-03-01

    items was administered routinely to all rehabilitation partici- pants and provided a wide range of information on family and social background...information pertaining to family background, social and occupational his- tory, military service, and drinking history and alcohol-related problems. At the...84 30 73.7 113 21 84.3 Total 939 143 585 82 707 73 A X 2 = 12.16; df = 2; p < .01 26.51; 2; p < .001 14.65; 2; p < .001ik Age Alcohol Problema 17, 28

  6. Serum Concentration of Growth Factors in Dogs under Different Conditions of Distraction Osteogenesis.

    Science.gov (United States)

    Stogov, M V; Tushina, N V; Emanov, A A

    2015-12-01

    Concentrations of insulin-like growth factors 1 and 2 (IGF-1 and IGF-2), stem cell factor (SCF), vascular endothelial growth factor (VEGF), and transforming growth factor β1 (TGF-β1) were measured in the blood serum of dogs subjected to experimental lengthening of shin bones. In animals subjected to shin bone lengthening at a rate of 1 mm/day in 4 steps, the concentrations of SCF and TGF-β1 significantly increased in the middle of distraction and IGF-1 concentration increased by the end of distraction. In animals subjected to lengthening at a rate of 1.5 mm/day in 6 steps, the levels of IGF-1 and TGF-β1 significantly increased in the middle of distraction and the concentration of IGF-2 at the end of distraction. In animals subjected to lengthening at a rate of 3 mm/day in 120 steps, the concentrations of IGF-1 and TGF-β1 significantly decreased in the middle of distraction and concentrations of IGF-1, VEGF, and TGF-β1 increased by the end of distraction.

  7. A bHLH transcription factor regulates iron intake under Fe deficiency in chrysanthemum.

    Science.gov (United States)

    Zhao, Min; Song, Aiping; Li, Peiling; Chen, Sumei; Jiang, Jiafu; Chen, Fadi

    2014-10-24

    Iron (Fe) deficiency can represent a serious constraint on crop growth and productivity. A number of members of the bHLH transcription factor family are known to be involved in the plant Fe deficiency response. Plants have evolved two distinct uptake strategies when challenged by Fe deficiency: dicotyledonous and non-graminaceous species rely mostly on a reduction strategy regulated by bHLH transcription factors, whereas rice relies on a chelation strategy, also regulated by bHLH transcription factors. CmbHLH1, a bHLH transcription factor which is localized within the nucleus, was isolated from chrysanthemum. Its transcription was up-regulated both by Fe deficiency and by the exogenous application of abscisic acid. The roots of transgenic chrysanthemum plants in which CmbHLH1 was up-regulated were better able than those of the wild type chrysanthemum cultivar to acidify their immediate external environment by enhancing the transcription of the H(+)-ATPase encoding gene CmHA. However, there was no effect of the transgene on the efficiency of uptake of either manganese or zinc. Here, Chrysanthemum CmbHLH1 contributed to Fe uptake via H(+)-ATPase mediated acidification of the rhizosphere. ABA may be positively involved in the process.

  8. Association between maternal socioeconomic factors and nutritional outcomes in children under 5 years of age

    Directory of Open Access Journals (Sweden)

    Tatiane Géa‐Horta

    2016-11-01

    Conclusion: Maternal level of schooling was associated with short stature in children and maternal employment with overweight, indicating the need to take into account the socioeconomic factors when proposing programs and strategies aimed at health and nutrition improvement of children, considering inter‐sectoral interventions.

  9. Software Piracy among College Students: A Comprehensive Review of Contributing Factors, Underlying Processes, and Tackling Strategies

    Science.gov (United States)

    Liang, Zhili; Yan, Zheng

    2005-01-01

    This article reviewed empirical studies published in the past 30 years that examined software piracy among college students. It focused on three areas of study: (a) major factors that affect college students' intentions, attitudes, and moral intensity regarding software piracy, (b) various decision-making processes that underlie software piracy…

  10. Socio-economic factors predisposing under five-year-old children to ...

    African Journals Online (AJOL)

    Background: Malnutrition is one of the leading causes of morbidity and mortality in children aged five years and below. Risk factors for severe protein energy malnutrition (PEM) have been identified as ignorance, family size, mothers and fathers education, poverty, residence, chronic infections, and congenital defects or ...

  11. ’I want my HDTV’? Underlying factors of perceived usefulness for high definition television

    NARCIS (Netherlands)

    Baaren, Eva; van de Wijngaert, Lidwien; Huizer, E.; Tscheligi, Manfred; Obrist, Marianna; Lugmayr, Artur

    2008-01-01

    While traditional technology acceptance models concentrate on relationships between usefulness and acceptance, they leave unresolved the questions about why a certain technology is found useful, in which contexts, and by whom. This paper presents an empirical study of some of the factors behind

  12. Finite Difference Methods for Option Pricing under Lévy Processes: Wiener-Hopf Factorization Approach

    Directory of Open Access Journals (Sweden)

    Oleg Kudryavtsev

    2013-01-01

    factorization identity. Notice that our algorithm has the same complexity as the ones which use the explicit-implicit scheme, with a tridiagonal matrix. However, our method is more accurate. We support the advantage of the new method in terms of accuracy and convergence by using numerical experiments.

  13. Influential Factors and Strategy of Sustainable Product Development under Corporate Social Responsibility in Taiwan

    Directory of Open Access Journals (Sweden)

    Jui-Che Tu

    2013-01-01

    Full Text Available This study aimed to adopt the perspective of corporate social responsibility (CSR to explore the intention of sustainable product development in Taiwan, as well as leading to the creation of influential factors that affect corporate sustainable product development intention. In this research, the induction analysis was conducted to understand the implementation of sustainable product development, and this was supplemented with questionnaire surveys and in-depth interviews to evaluate developmental intention. In addition, principal component analysis was used for factor analysis and content analysis in the 6 W expression method, leading to the creation of the influential factors. The research results have demonstrated that the factors affecting the intention of corporate sustainable product development include having a sustainable design and a development purpose, a corporate development purpose, sustainable development concepts, a sustainable design value, a sustainability concept, and a manufacturing process quality. For sustainable product development, corporate social responsibility needs to be most concerned with the added value of products, regulation requirements, and accommodation of the industrial chain, costs, and quality.

  14. On Power Factor Improvement by Lossless Linear Filters under Nonlinear Nonsinusoidal Conditions

    NARCIS (Netherlands)

    Puerto-Flores, D. del; Ortega, R.; Scherpen, J.M.A.

    2011-01-01

    Recently, it has been established that the problem of power factor compensation for nonlinear loads with nonsinusoidal source voltage can be recast in terms of the property of cyclodissipativity. The purpose of this brief note is to review and to illustrate the application of this framework to the

  15. Divergent composition of algal-bacterial biofilms developing under various external factors

    NARCIS (Netherlands)

    Barranguet, C.; Veuger, B.; van Beusekom, S.A.M.; Marvan, P.; Sinke, J.J.; Admiraal, W.

    2005-01-01

    The influence of external factors other than nutrients on biofilm development and composition was studied with a combination of optical (Confocal Laser Scanning Microscopy, PAM fluorometry) and chemical methods (EPS extraction, HPLC, TOC determination). The development of algal-bacterial biofilms

  16. Dynamic Granger-Geweke causality modeling with application to interictal spike propagation.

    Science.gov (United States)

    Lin, Fa-Hsuan; Hara, Keiko; Solo, Victor; Vangel, Mark; Belliveau, John W; Stufflebeam, Steven M; Hämäläinen, Matti S

    2009-06-01

    A persistent problem in developing plausible neurophysiological models of perception, cognition, and action is the difficulty of characterizing the interactions between different neural systems. Previous studies have approached this problem by estimating causal influences across brain areas activated during cognitive processing using structural equation modeling (SEM) and, more recently, with Granger-Geweke causality. While SEM is complicated by the need for a priori directional connectivity information, the temporal resolution of dynamic Granger-Geweke estimates is limited because the underlying autoregressive (AR) models assume stationarity over the period of analysis. We have developed a novel optimal method for obtaining data-driven directional causality estimates with high temporal resolution in both time and frequency domains. This is achieved by simultaneously optimizing the length of the analysis window and the chosen AR model order using the SURE criterion. Dynamic Granger-Geweke causality in time and frequency domains is subsequently calculated within a moving analysis window. We tested our algorithm by calculating the Granger-Geweke causality of epileptic spike propagation from the right frontal lobe to the left frontal lobe. The results quantitatively suggested that the epileptic activity at the left frontal lobe was propagated from the right frontal lobe, in agreement with the clinical diagnosis. Our novel computational tool can be used to help elucidate complex directional interactions in the human brain. (c) 2009 Wiley-Liss, Inc.

  17. Capturing cognitive causal paths in human reliability analysis with Bayesian network models

    International Nuclear Information System (INIS)

    Zwirglmaier, Kilian; Straub, Daniel; Groth, Katrina M.

    2017-01-01

    reIn the last decade, Bayesian networks (BNs) have been identified as a powerful tool for human reliability analysis (HRA), with multiple advantages over traditional HRA methods. In this paper we illustrate how BNs can be used to include additional, qualitative causal paths to provide traceability. The proposed framework provides the foundation to resolve several needs frequently expressed by the HRA community. First, the developed extended BN structure reflects the causal paths found in cognitive psychology literature, thereby addressing the need for causal traceability and strong scientific basis in HRA. Secondly, the use of node reduction algorithms allows the BN to be condensed to a level of detail at which quantification is as straightforward as the techniques used in existing HRA. We illustrate the framework by developing a BN version of the critical data misperceived crew failure mode in the IDHEAS HRA method, which is currently under development at the US NRC . We illustrate how the model could be quantified with a combination of expert-probabilities and information from operator performance databases such as SACADA. This paper lays the foundations necessary to expand the cognitive and quantitative foundations of HRA. - Highlights: • A framework for building traceable BNs for HRA, based on cognitive causal paths. • A qualitative BN structure, directly showing these causal paths is developed. • Node reduction algorithms are used for making the BN structure quantifiable. • BN quantified through expert estimates and observed data (Bayesian updating). • The framework is illustrated for a crew failure mode of IDHEAS.

  18. Searching for recursive causal structures in multivariate quantitative genetics mixed models.

    Science.gov (United States)

    Valente, Bruno D; Rosa, Guilherme J M; de Los Campos, Gustavo; Gianola, Daniel; Silva, Martinho A

    2010-06-01

    Biology is characterized by complex interactions between phenotypes, such as recursive and simultaneous relationships between substrates and enzymes in biochemical systems. Structural equation models (SEMs) can be used to study such relationships in multivariate analyses, e.g., with multiple traits in a quantitative genetics context. Nonetheless, the number of different recursive causal structures that can be used for fitting a SEM to multivariate data can be huge, even when only a few traits are considered. In recent applications of SEMs in mixed-model quantitative genetics settings, causal structures were preselected on the basis of prior biological knowledge alone. Therefore, the wide range of possible causal structures has not been properly explored. Alternatively, causal structure spaces can be explored using algorithms that, using data-driven evidence, can search for structures that are compatible with the joint distribution of the variables under study. However, the search cannot be performed directly on the joint distribution of the phenotypes as it is possibly confounded by genetic covariance among traits. In this article we propose to search for recursive causal structures among phenotypes using the inductive causation (IC) algorithm after adjusting the data for genetic effects. A standard multiple-trait model is fitted using Bayesian methods to obtain a posterior covariance matrix of phenotypes conditional to unobservable additive genetic effects, which is then used as input for the IC algorithm. As an illustrative example, the proposed methodology was applied to simulated data related to multiple traits measured on a set of inbred lines.

  19. Learning to learn from stories: children's developing sensitivity to the causal structure of fictional worlds.

    Science.gov (United States)

    Walker, Caren M; Gopnik, Alison; Ganea, Patricia A

    2015-01-01

    Fiction presents a unique challenge to the developing child, in that children must learn when to generalize information from stories to the real world. This study examines how children acquire causal knowledge from storybooks, and whether children are sensitive to how closely the fictional world resembles reality. Preschoolers (N = 108) listened to stories in which a novel causal relation was embedded within realistic or fantastical contexts. Results indicate that by at least 3 years of age, children are sensitive to the underlying causal structure of the story: Children are more likely to generalize content if the fictional world is similar to reality. Additionally, children become better able at discriminating between realistic and fantastical story contexts between 3 and 5 years of age. © 2014 The Authors. Child Development © 2014 Society for Research in Child Development, Inc.

  20. Risk factors of Acute Respiratory Infection (ARI in under-fives in a rural hospital of Central India

    Directory of Open Access Journals (Sweden)

    Amar M. Taksande

    2015-11-01

    Full Text Available Introduction: Acute Respiratory Infection (ARI is a major cause of morbidity and mortality in developing countries in children especially in under-fives. Every year in the world, about 13 million under-5 children dies, 95% from developing countries; one third of total deaths are due to ARI. The aim of this study was to identify the significant risk factors for ARI in children less than five years of age living in rural areas of Central India.Methods: A hospital based case control study was undertaken to determine risk factors associated with respiratory tract infections in children. Children less than 5 years admitted in a pediatric ward with diagnosis of ARI were enrolled in the study as cases (n = 300 while the same number of controls (n = 300 were selected from neighborhood and were matched for age, sex and religion. Details of risk factors in cases and controls were recorded in pre-designed proforma. Results: A significant association was found between ARI and lack of breastfeeding, nutritional status, immunization status, delayed weaning, prelactal feeding, living in overcrowded conditions, mothers’ literacy status, low birth weight and prematurity. Among the environmental variables, inadequate ventilation, improper housing condition, exposure to indoor air pollution in form of combustion from fuel used for cooking were found as significant risk factors for ARI in under-fives.Conclusions: ARIs are affected by socio-demographic and socio-cultural risk factors, which can be modified with simple interventions. The various risk factors identified in this study were lack of breastfeeding, undernutrition, delayed weaning, overcrowding and prelactal feeding.

  1. Energy Consumption and Economic Growth in Algeria: Cointegration and Causality Analysis

    Directory of Open Access Journals (Sweden)

    Cherfi Souhila

    2012-01-01

    Full Text Available This study investigates the energy consumption-growth nexus in Algeria. The causal relationship between the logarithm of per capita energy consumption (LPCEC and the logarithm of per capita GDP (LPCGDP during the 1965-2008 period is examined using the threshold cointegration and Granger causality tests. The estimation results indicate that the LPCEC and LPCGDP for Algeria are non cointegrated and that there is a uni-directional causality running from LPCGDP to LPCEC, but not vice versa. The research results strongly support the neoclassical perspective that energy consumption is not a limiting factor to economic growth in Algeria. Accordingly, an important policy implication resulting from this analysis is that government can pursue the conservation energy policies that aim at curtailing energy use for environmental friendly development purposes without creating severe effects on economic growth. The energy should be efficiently allocated into more productive sectors of the economy.

  2. Prenatal nutrition, epigenetics and schizophrenia risk: can we test causal effects?

    Science.gov (United States)

    Kirkbride, James B; Susser, Ezra; Kundakovic, Marija; Kresovich, Jacob K; Davey Smith, George; Relton, Caroline L

    2012-06-01

    We posit that maternal prenatal nutrition can influence offspring schizophrenia risk via epigenetic effects. In this article, we consider evidence that prenatal nutrition is linked to epigenetic outcomes in offspring and schizophrenia in offspring, and that schizophrenia is associated with epigenetic changes. We focus upon one-carbon metabolism as a mediator of the pathway between perturbed prenatal nutrition and the subsequent risk of schizophrenia. Although post-mortem human studies demonstrate DNA methylation changes in brains of people with schizophrenia, such studies cannot establish causality. We suggest a testable hypothesis that utilizes a novel two-step Mendelian randomization approach, to test the component parts of the proposed causal pathway leading from prenatal nutritional exposure to schizophrenia. Applied here to a specific example, such an approach is applicable for wider use to strengthen causal inference of the mediating role of epigenetic factors linking exposures to health outcomes in population-based studies.

  3. In Vitro Modeling of Brain Progenitor Cell Development under the Effect of Environmental Factors.

    Science.gov (United States)

    Kuvacheva, N V; Morgun, A V; Komleva, Yu K; Khilazheva, E D; Gorina, Ya V; Lopatina, O L; Arutyunyan, S A; Salmina, A B

    2015-08-01

    We studied in vitro development of brain progenitor cells isolated from healthy 7-9-month-old Wistar rats and rats with experimental Alzheimer's disease kept under standard conditions and in enriched (multistimulus) environment in vivo. Progenitor cells from healthy animals more rapidly formed neurospheres. Considerable changes at the early stages of in vitro development of brain progenitor cells were observed in both groups kept in enriched environment.

  4. G-computation demonstration in causal mediation analysis.

    Science.gov (United States)

    Wang, Aolin; Arah, Onyebuchi A

    2015-10-01

    Recent work has considerably advanced the definition, identification and estimation of controlled direct, and natural direct and indirect effects in causal mediation analysis. Despite the various estimation methods and statistical routines being developed, a unified approach for effect estimation under different effect decomposition scenarios is still needed for epidemiologic research. G-computation offers such unification and has been used for total effect and joint controlled direct effect estimation settings, involving different types of exposure and outcome variables. In this study, we demonstrate the utility of parametric g-computation in estimating various components of the total effect, including (1) natural direct and indirect effects, (2) standard and stochastic controlled direct effects, and (3) reference and mediated interaction effects, using Monte Carlo simulations in standard statistical software. For each study subject, we estimated their nested potential outcomes corresponding to the (mediated) effects of an intervention on the exposure wherein the mediator was allowed to attain the value it would have under a possible counterfactual exposure intervention, under a pre-specified distribution of the mediator independent of any causes, or under a fixed controlled value. A final regression of the potential outcome on the exposure intervention variable was used to compute point estimates and bootstrap was used to obtain confidence intervals. Through contrasting different potential outcomes, this analytical framework provides an intuitive way of estimating effects under the recently introduced 3- and 4-way effect decomposition. This framework can be extended to complex multivariable and longitudinal mediation settings.

  5. G-computation demonstration in causal mediation analysis

    International Nuclear Information System (INIS)

    Wang, Aolin; Arah, Onyebuchi A.

    2015-01-01

    Recent work has considerably advanced the definition, identification and estimation of controlled direct, and natural direct and indirect effects in causal mediation analysis. Despite the various estimation methods and statistical routines being developed, a unified approach for effect estimation under different effect decomposition scenarios is still needed for epidemiologic research. G-computation offers such unification and has been used for total effect and joint controlled direct effect estimation settings, involving different types of exposure and outcome variables. In this study, we demonstrate the utility of parametric g-computation in estimating various components of the total effect, including (1) natural direct and indirect effects, (2) standard and stochastic controlled direct effects, and (3) reference and mediated interaction effects, using Monte Carlo simulations in standard statistical software. For each study subject, we estimated their nested potential outcomes corresponding to the (mediated) effects of an intervention on the exposure wherein the mediator was allowed to attain the value it would have under a possible counterfactual exposure intervention, under a pre-specified distribution of the mediator independent of any causes, or under a fixed controlled value. A final regression of the potential outcome on the exposure intervention variable was used to compute point estimates and bootstrap was used to obtain confidence intervals. Through contrasting different potential outcomes, this analytical framework provides an intuitive way of estimating effects under the recently introduced 3- and 4-way effect decomposition. This framework can be extended to complex multivariable and longitudinal mediation settings

  6. The Importance of Specifying and Studying Causal Mechanisms in School-Based Randomised Controlled Trials: Lessons from Two Studies of Cross-Age Peer Tutoring

    Science.gov (United States)

    Morris, Stephen P.; Edovald, Triin; Lloyd, Cheryl; Kiss, Zsolt

    2016-01-01

    Based on the experience of evaluating 2 cross-age peer-tutoring interventions, we argue that researchers need to pay greater attention to causal mechanisms within the context of school-based randomised controlled trials. Without studying mechanisms, researchers are less able to explain the underlying causal processes that give rise to results from…

  7. A mathematical model of the immune and neuroendocrine systems mutual regulation under the technogenic chemical factors impact.

    Science.gov (United States)

    Zaitseva, N V; Kiryanov, D A; Lanin, D V; Chigvintsev, V M

    2014-01-01

    The concept of the triad regulatory metasystem, which includes the neuroendocrine and immune regulation systems, is currently generally accepted. Changes occurring in each of the regulatory systems in response to the impact of technogenic chemical factors are also well known. This paper presents mathematical models of the immune and neuroendocrine system functioning, using the interaction between these systems in response to bacterial invasion as an example, and changes in their performance under exposure to chemical factors, taking into account the stage of functional disorders in a producing organ, using the performance of the bone marrow as an example.

  8. The realization of protective and educational functions in numerous families and the underlying factors

    Directory of Open Access Journals (Sweden)

    PAULINA FORMA

    2017-10-01

    Full Text Available Every man has a specific personality determined by various factors, including genetic predispositions, environment, education and individual activity. It is because of these elements that one has certain goals to achieve in life and that one performs social roles in a specific way. The importance of the family that one is born to, the creators of the processes of education and socialisation, i.e. parents, teachers, pedagogues, guardians, the environment one spends time in, the schools one attends, the peer groups on identifies with, one's role models is not to be underestimated. Taking into account the multitude of factors determining the education of a child in a numerous family the environmental determinants (including age, education, professional activity of parents or the lack thereof, residence of the numerous family, financial situation, number of children in this system of multiple categories constituting the elements characterising the form of contemporary family of three or more children should be emphasized.

  9. Risk factors of diarrhea in children under 5 years in Al-Mukalla, Yemen.

    Science.gov (United States)

    Bahartha, Ali S; AlEzzi, Jalil I

    2015-06-01

    To assess the risk factors associated with diarrhea among children below 5-years-old in Mukalla, Yemen, and compare with other studies.   We conducted a case-control study on 200 children (100 cases and 100 controls) who attended the Maternity and Child Hospital, outpatient-clinics, and the Primary Health Care Centers in Al-Mukalla, Hadhramout, Yemen between February and April 2013.   We found that the significant risk factors associated with diarrhea were crowded housing (odds ratio [OR] 2.02; p=0.02; confidence interval [CI] 1.03-4.01), incomplete vaccination of the child (OR=2.02; p=0.027; CI: 1.08-3.8), and recurrent diarrheal illness during the last 3 months (OR=6.61; p=0.001; CI: 3.41-12.90).   Diarrheal diseases are strongly associated with incomplete vaccination, recurrent diarrheal disease, and crowded housing.

  10. Health care expenditure disparities in the European Union and underlying factors: a distribution dynamics approach.

    Science.gov (United States)

    Villaverde, José; Maza, Adolfo; Hierro, María

    2014-09-01

    This paper examines health care expenditure (HCE) disparities between the European Union countries over the period 1995-2010. By means of using a continuous version of the distribution dynamics approach, the key conclusions are that the reduction in disparities is very weak and, therefore, persistence is the main characteristic of the HCE distribution. In view of these findings, a preliminary attempt is made to add some insights into potentially main factors behind the HCE distribution. The results indicate that whereas per capita income is by far the main determinant, the dependency ratio and female labour participation do not play any role in explaining the HCE distribution; as for the rest of the factors studied (life expectancy, infant mortality, R&D expenditure and public HCE expenditure share), we find that their role falls somewhat in between.

  11. Structural and energetic factors controlling the enantioselectivity of dinucleotide formation under prebiotic conditions

    Czech Academy of Sciences Publication Activity Database

    Šponer, Judit E.; Mládek, Arnošt; Šponer, Jiří

    2013-01-01

    Roč. 15, č. 17 (2013), s. 6235-6242 ISSN 1463-9076 R&D Projects: GA ČR GAP208/10/2302 Grant - others:GA MŠk(CZ) ED1.1.00/02.0068 Program:ED Institutional research plan: CEZ:AV0Z50040702 Institutional support: RVO:68081707 Keywords : APPROXIMATE COULOMB POTENTIALS * PEPTIDE-BOND FORMATION * ZETA VALENCE QUALITY Subject RIV: BO - Biophysics Impact factor: 4.198, year: 2013

  12. Totem-Pole Power-Factor-Correction Converter under Critical-Conduction-Mode Interleaved Operation

    Science.gov (United States)

    Firmansyah, Eka; Tomioka, Satoshi; Abe, Seiya; Shoyama, Masahito; Ninomiya, Tamotsu

    This paper proposes a new power-factor-correction (PFC) topology, and explains its operation principle, its control mechanism, related application problems followed by experimental results. In this proposed topology, critical-conduction-mode (CRM) interleaved technique is applied to a bridgeless PFC in order to achieve high efficiency by combining benefits of each topology. This application is targeted toward low to middle power applications that normally employs continuous-conduction-mode boost converter.

  13. Key factors and underlying mechanisms for the enterprise systems lifecycle in public service organisations

    OpenAIRE

    SAXENA, DEEPAK KUMAR

    2017-01-01

    APPROVED This is a longitudinal Critical Realist case study in the Enterprise Systems (ES) area within the Information Systems (IS) domain. Based on the literature review, it is identified that the majority of the ES research is conducted around the implementation phase. It usually reports a myriad of critical success factors (CSFs) that are generally conceived to be static throughout the ES lifecycle. The literature review also notes that the literature on ES-mediated organisation change ...

  14. Auditory and Cognitive Factors Underlying Individual Differences in Aided Speech-Understanding among Older Adults

    Directory of Open Access Journals (Sweden)

    Larry E. Humes

    2013-10-01

    Full Text Available This study was designed to address individual differences in aided speech understanding among a relatively large group of older adults. The group of older adults consisted of 98 adults (50 female and 48 male ranging in age from 60 to 86 (mean = 69.2. Hearing loss was typical for this age group and about 90% had not worn hearing aids. All subjects completed a battery of tests, including cognitive (6 measures, psychophysical (17 measures, and speech-understanding (9 measures, as well as the Speech, Spatial and Qualities of Hearing (SSQ self-report scale. Most of the speech-understanding measures made use of competing speech and the non-speech psychophysical measures were designed to tap phenomena thought to be relevant for the perception of speech in competing speech (e.g., stream segregation, modulation-detection interference. All measures of speech understanding were administered with spectral shaping applied to the speech stimuli to fully restore audibility through at least 4000 Hz. The measures used were demonstrated to be reliable in older adults and, when compared to a reference group of 28 young normal-hearing adults, age-group differences were observed on many of the measures. Principal-components factor analysis was applied successfully to reduce the number of independent and dependent (speech understanding measures for a multiple-regression analysis. Doing so yielded one global cognitive-processing factor and five non-speech psychoacoustic factors (hearing loss, dichotic signal detection, multi-burst masking, stream segregation, and modulation detection as potential predictors. To this set of six potential predictor variables were added subject age, Environmental Sound Identification (ESI, and performance on the text-recognition-threshold (TRT task (a visual analog of interrupted speech recognition. These variables were used to successfully predict one global aided speech-understanding factor, accounting for about 60% of the variance.

  15. Transport Sector CO(2) Emissions Growth in Asia : Underlying Factors and Policy Options

    OpenAIRE

    Timilsina, G. R.; Shrestha, A.

    2009-01-01

    This study analyze the potential factors influencing the growth of transport sector carbon dioxide (CO(2)) emissions in selected Asian countries during the 1980-2005 period by decomposing annual emissions growth into components representing changes in fuel mix, modal shift, per capita gross domestic product (GDP) and population, as well as changes in emission coefficients and transportation energy intensity. We find that changes in per capita GDP, population growth and transportation energy i...

  16. Industry Efficiency and Total Factor Productivity Growth under Resources and Environmental Constraint in China

    Directory of Open Access Journals (Sweden)

    Feng Tao

    2012-01-01

    Full Text Available The growth of China's industry has been seriously depending on energy and environment. This paper attempts to apply the directional distance function and the Luenberger productivity index to measure the environmental efficiency, environmental total factor productivity, and its components at the level of subindustry in China over the period from 1999 to 2009 while considering energy consumption and emission of pollutants. This paper also empirically examines the determinants of efficiency and productivity change. The major findings are as follows. Firstly, the main sources of environmental inefficiency of China's industry are the inefficiency of gross industrial output value, the excessive energy consumption, and pollutant emissions. Secondly, the highest growth rate of environmental total factor productivity among the three industrial categories is manufacturing, followed by mining, and production and supply of electricity, gas, and water. Thirdly, foreign direct investment, capital-labor ratio, ownership structure, energy consumption structure, and environmental regulation have varying degrees of effects on the environmental efficiency and environmental total factor productivity.

  17. Industry Efficiency and Total Factor Productivity Growth under Resources and Environmental Constraint in China

    Science.gov (United States)

    Tao, Feng; Li, Ling; Xia, X. H.

    2012-01-01

    The growth of China's industry has been seriously depending on energy and environment. This paper attempts to apply the directional distance function and the Luenberger productivity index to measure the environmental efficiency, environmental total factor productivity, and its components at the level of subindustry in China over the period from 1999 to 2009 while considering energy consumption and emission of pollutants. This paper also empirically examines the determinants of efficiency and productivity change. The major findings are as follows. Firstly, the main sources of environmental inefficiency of China's industry are the inefficiency of gross industrial output value, the excessive energy consumption, and pollutant emissions. Secondly, the highest growth rate of environmental total factor productivity among the three industrial categories is manufacturing, followed by mining, and production and supply of electricity, gas, and water. Thirdly, foreign direct investment, capital-labor ratio, ownership structure, energy consumption structure, and environmental regulation have varying degrees of effects on the environmental efficiency and environmental total factor productivity. PMID:23365517

  18. Finite difference methods for option pricing under Lévy processes: Wiener-Hopf factorization approach.

    Science.gov (United States)

    Kudryavtsev, Oleg

    2013-01-01

    In the paper, we consider the problem of pricing options in wide classes of Lévy processes. We propose a general approach to the numerical methods based on a finite difference approximation for the generalized Black-Scholes equation. The goal of the paper is to incorporate the Wiener-Hopf factorization into finite difference methods for pricing options in Lévy models with jumps. The method is applicable for pricing barrier and American options. The pricing problem is reduced to the sequence of linear algebraic systems with a dense Toeplitz matrix; then the Wiener-Hopf factorization method is applied. We give an important probabilistic interpretation based on the infinitely divisible distributions theory to the Laurent operators in the correspondent factorization identity. Notice that our algorithm has the same complexity as the ones which use the explicit-implicit scheme, with a tridiagonal matrix. However, our method is more accurate. We support the advantage of the new method in terms of accuracy and convergence by using numerical experiments.

  19. Reliability and construct validity of factors underlying the emotional intelligence of Iranian EFL teachers

    Directory of Open Access Journals (Sweden)

    Ebrahim Khodadady

    2013-06-01

    The 133-item Emotional Quotient Inventory (EQ-i designed by Bar-On (1997 and translated by Dehshiry (2003 was revised and modified by removing the response validity items, changing reverse indicators into positively worded statements and revising the remaining 117 Persian indicators on the basis of schema theory. It was administered to 669 instructors most of whom were teaching English as a foreign language (EFL in national branches of Iran Language Institute in 15 cities. The application of the Principal Axis Factoring to the data and rotating the extracted factors via Varimax with Kaiser Normalization yielded 15 latent variables (LVs called Humanistic, Self-Satisfying, Self-Confident, Self-Aware, Self-Controlled, Research-Oriented, Content, Sociable, Empathetic, Tolerant, Flexible, Realistic, Independent, Emotional and Happy in this study. Not only did the modified Persian EQ-I proved to be more reliable than its original version, but also its thirteen LVs reached very high and acceptable levels of reliability. With the exception of the last, all the LVs also correlated significantly with each other and thus established the EI as a multifactorial construct whose constituting LVs are closely related to each other. The findings question correlating the so-called competences of EI and offer employing the factorially valid LVs as the best factors to explore the relationship between EI and variables involved in teaching and learning EFL.

  20. Human reliability under sleep deprivation: Derivation of performance shaping factor multipliers from empirical data

    International Nuclear Information System (INIS)

    Griffith, Candice D.; Mahadevan, Sankaran

    2015-01-01

    This paper develops a probabilistic approach that could use empirical data to derive values of performance shaping factor (PSF) multipliers for use in quantitative human reliability analysis (HRA). The proposed approach is illustrated with data on sleep deprivation effects on performance. A review of existing HRA methods reveals that sleep deprivation is not explicitly included at present, and expert opinion is frequently used to inform HRA model multipliers. In this paper, quantitative data from empirical studies regarding the effect of continuous hours of wakefulness on performance measures (reaction time, accuracy, and number of lapses) are used to develop a method to derive PSF multiplier values for sleep deprivation, in the context of the SPAR-H model. Data is extracted from the identified studies according to the meta-analysis research synthesis method and used to investigate performance trends and error probabilities. The error probabilities in test and control conditions are compared, and the resulting probability ratios are suggested for use in informing the selection of PSF multipliers in HRA methods. Although illustrated for sleep deprivation, the proposed methodology is general, and can be applied to other performance shaping factors. - Highlights: • Method proposed to derive performance shaping factor multipliers from empirical data. • Studies reporting the effect of sleep deprivation on performance are analyzed. • Test data using psychomotor vigilance tasks are analyzed. • Error probability multipliers computed for reaction time, lapses, and accuracy measures.