587 resultados para Causality


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According to Bell's theorem a large class of hidden-variable models obeying Bell's notion of local causality (LC) conflict with the predictions of quantum mechanics. Recently, a Bell-type theorem has been proven using a weaker notion of LC, yet assuming the existence of perfectly correlated event types. Here we present a similar Bell-type theorem without this latter assumption. The derived inequality differs from the Clauser-Horne inequality by some small correction terms, which render it less constraining.

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BACKGROUND/AIMS: Nutritional supplements are widely used. Recently, liver injury after consumption of Herbalife preparations was reported but the underlying pathogenesis remained cryptic. METHODS: Two patients presented with cholestatic hepatitis and pruritus, and cirrhosis, respectively. Viral, alcoholic, metabolic, autoimmune, neoplastic, vascular liver diseases and synthetic drugs as the precipitating causes of liver injury were excluded. However, both patients reported long-term consumption of Herbalife products. All Herbalife products were tested for contamination with drugs, pesticides, heavy metals, and softeners, and examined for microbial contamination according to standard laboratory procedures. Bacteria isolated from the samples were identified as Bacillus subtilis by sequencing the 16S rRNA and gyrB genes. RESULTS: Causality between consumption of Herbalife products and disease according to CIOMS was scored "probable" in both cases. Histology showed cholestatic and lobular/portal hepatitis with cirrhosis in one patient, and biliary fibrosis with ductopenia in the other. No contamination with chemicals or heavy metals was detected, and immunological testing showed no drug hypersensitivity. However, samples of Herbalife products ingested by both patients showed growth of Bacillus subtilis of which culture supernatants showed dose- and time-dependent hepatotoxicity. CONCLUSIONS: Two novel incidents of severe hepatic injury following intake of Herbalife products contaminated with Bacillus subtilis emphasize its potential hepatotoxicity.

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Clinical studies indicate that exaggerated postprandial lipemia is linked to the progression of atherosclerosis, leading cause of Cardiovascular Diseases (CVD). CVD is a multi-factorial disease with complex etiology and according to the literature postprandial Triglycerides (TG) can be used as an independent CVD risk factor. Aim of the current study is to construct an Artificial Neural Network (ANN) based system for the identification of the most important gene-gene and/or gene-environmental interactions that contribute to a fast or slow postprandial metabolism of TG in blood and consequently to investigate the causality of postprandial TG response. The design and development of the system is based on a dataset of 213 subjects who underwent a two meals fatty prandial protocol. For each of the subjects a total of 30 input variables corresponding to genetic variations, sex, age and fasting levels of clinical measurements were known. Those variables provide input to the system, which is based on the combined use of Parameter Decreasing Method (PDM) and an ANN. The system was able to identify the ten (10) most informative variables and achieve a mean accuracy equal to 85.21%.

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In this paper I first discuss some non-causal change constructions which have largely gone unnoticed in the literature, such as The butler bowed the guests in (which is said to code mild causation) and The supporters booed Newcastle off at the interval (which only codes temporal coextension between its two constitutive subevents). Since the same structure (i.e. the transitive object-oriented change construction) can be used to code a wide spectrum of causal and temporal relations, the question arises of what cognitive mechanisms may be involved in such meaning shifts. I argue that variation can be motivated on the basis of the figure/ground segregation which the conceptualiser can impose upon the integrated scene coded by the change construction. The integrated scene depicts a force-dynamic scenario but also evokes a unique temporal setting (i.e. temporal overlap or coextension between the constitutive subevents). Such a “bias” towards temporal overlap can be used by the conceptualiser to background causation and highlight temporal overlap interpretations. It is also shown that figure/ground segregation can be appealed to to account for the causal interpretation of intransitive change constructions, e.g. The kettle boiled dry. If the conceptual distance between the verbal event and the non-verbal event is (relatively) great, causality can be highlighted even in intransitive patterns.

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BACKGROUND Infectious diseases and social contacts in early life have been proposed to modulate brain tumour risk during late childhood and adolescence. METHODS CEFALO is an interview-based case-control study in Denmark, Norway, Sweden and Switzerland, including children and adolescents aged 7-19 years with primary intracranial brain tumours diagnosed between 2004 and 2008 and matched population controls. RESULTS The study included 352 cases (participation rate: 83%) and 646 controls (71%). There was no association with various measures of social contacts: daycare attendance, number of childhours at daycare, attending baby groups, birth order or living with other children. Cases of glioma and embryonal tumours had more frequent sick days with infections in the first 6 years of life compared with controls. In 7-19 year olds with 4+ monthly sick day, the respective odds ratios were 2.93 (95% confidence interval: 1.57-5.50) and 4.21 (95% confidence interval: 1.24-14.30). INTERPRETATION There was little support for the hypothesis that social contacts influence childhood and adolescent brain tumour risk. The association between reported sick days due to infections and risk of glioma and embryonal tumour may reflect involvement of immune functions, recall bias or inverse causality and deserve further attention.

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'Sensing the self' relies on the ability to distinguish self-generated from external stimuli. It requires functioning mechanisms to establish feelings of agency and ownership. Agency is defined causally, where the subjects action is followed by an effect. Ownership is defined by the features of the effect, independent from the action. In our study, we manipulated these qualities separately. 13 right-handed healthy individuals performed the experiment while 76-channel EEG was recorded. Stimuli consisted of visually presented words, read aloud by the subject. The experiment consisted of six conditions: (a) subjects saw a word, read it aloud, heard it in their own voice; (b) like a, but the word was heard in an unfamiliar voice; (c) subject heard a word in his/her own voice without speaking; (d) like c, but the word was heard in an unfamiliar voice; (e) like a, but subjects heard the word with a delay; (f) subjects read without hearing. ERPs and difference maps were computed for all conditions. Effects were analysed topographically. The N100 (86-172 ms) displayed significant main effects of agency and ownership. The topographies of the two effects shared little common variance, suggesting independent effects. Later effects (174-400 ms) of agency and ownership were topographically similar, suggesting common mechanisms. Replicating earlier studies, significant N100 suppression was observed, with a topography resembling the agency effect. 'Sensing the self' appears to recruit from at least two very distinct processes: an agency assessment that represents causality and an ownership assessment that compares stimulus features with memory content.

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OBJECTIVE To report a case of severe myopathy associated with concomitant simvastatin and amiodarone therapy. CASE SUMMARY A 63-year-old white man with underlying insulin-dependent diabetes, recent coronary artery bypass surgery, and postoperative hemiplegia was treated with aspirin, metoprolol, furosemide, nitroglycerin, and simvastatin. Due to recurrent atrial fibrillation, oral anticoagulation with phenprocoumon and antiarrhythmic treatment with amiodarone were initiated. Four weeks after starting simvastatin 40 mg/day and 2 weeks after initiating amiodarone 1 g/day for 10 days, then 200 mg/day, he developed diffuse muscle pain with generalized muscular weakness. Laboratory investigations revealed a significant increase of creatine kinase (CK) peaking at 40 392 U/L. Due to a suspected drug interaction of simvastatin with amiodarone, both drugs were stopped. CK normalized over the following 8 days, and the patient made an uneventful recovery. An objective causality assessment revealed that the myopathy was probably related to simvastatin. DISCUSSION Myopathy is a rare but potentially severe adverse reaction associated with statins. Besides high statin doses, concomitant use of fibrates, defined comorbidities, and concurrent use of inhibitors of cytochrome P450 are important additional risk factors. This is especially relevant if statins predominantly metabolized by CYP3A4 are combined with inhibitors of this isoenzyme. Amiodarone is a potent inhibitor of several different CYP isoenzymes, including CYP3A4. CONCLUSIONS Avoiding the concomitant use of drugs with the potential to inhibit CYP-dependent metabolism (eg, amiodarone) or elimination of statins may decrease the risk of statin-associated myopathy. Alternatively, if drug therapy with a potent CYP inhibitor is inevitable, choosing a statin without relevant CYP metabolism (eg, pravastatin) should be considered.

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OBJECTIVE To expand the limited information on the prognostic impact of quantitatively obtained collateral function in patients with coronary artery disease (CAD) and to estimate causality of such a relation. DESIGN Prospective cohort study with long-term observation of clinical outcome. SETTING University Hospital. PATIENTS One thousand one hundred and eighty-one patients with chronic stable CAD undergoing 1771 quantitative, coronary pressure-derived collateral flow index measurements, as obtained during a 1-min coronary balloon occlusion (CFI is the ratio between mean distal coronary occlusive pressure and mean aortic pressure both subtracted by central venous pressure). Subgroup of 152 patients included in randomised trials on the longitudinal effect of different arteriogenic protocols on CFI. INTERVENTIONS Collection of long-term follow-up information on clinical outcome. MAIN OUTCOME MEASURES All-cause mortality and major adverse cardiac events. RESULTS Cumulative 15-year survival rate was 48% in patients with CFI<0.25 and 65% in the group with CFI≥0.25 (p=0.0057). Cumulative 10-year survival rate was 75% in patients without arteriogenic therapy and 88% (p=0.0482) in the group with arteriogenic therapy and showing a significant increase in CFI at follow-up. By proportional hazard analysis, the following variables predicted increased all-cause mortality: age, low CFI, left ventricular end-diastolic pressure and number of vessels with CAD. CONCLUSIONS A well-functioning coronary collateral circulation independently predicts lowered mortality in patients with chronic CAD. This relation appears to be causal, because augmented collateral function by arteriogenic therapy is associated with prolonged survival.

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Hundreds of genetic variants in SCN5A, the gene coding for the pore-forming subunit of the cardiac sodium channel, Na(v) 1.5, have been described in patients with cardiac channelopathies as well as in individuals from control cohorts. The aim of this study was to characterize the biophysical properties of 2 naturally occurring Na(v) 1.5 variants, p.R689H and p.R689C, found in patients with cardiac arrhythmias and in control individuals. In addition, this study was motivated by the finding of the variant p.R689H in a family with sudden cardiac death (SCD) in children. When expressed in HEK293 cells, most of the sodium current (I(Na)) biophysical properties of both variants were indistinguishable from the wild-type (WT) channels. In both cases, however, an ∼2-fold increase of the tetrodotoxin-sensitive late I(Na) was observed. Action potential simulations and reconstruction of pseudo-ECGs demonstrated that such a subtle increase in the late I(Na) may prolong the QT interval in a nonlinear fashion. In conclusion, despite the fact that the causality link between p.R689H and the phenotype of the studied family cannot be demonstrated, this study supports the notion that subtle alterations of Na(v) 1.5 variants may increase the risk for cardiac arrhythmias.

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We examined the reciprocal prospective relations between self-esteem and work conditions and outcomes, including justice at work, support at work, work stressors, job satisfaction, job success, and counterproductive work behavior. Data came from two independent longitudinal studies, including five assessments over an 8-month period (N = 663, age 16–62 years) and three assessments over a 2-year period (N = 600, age 22–51 years), respectively. Across both studies, high self-esteem prospectively predicted better work conditions and outcomes, whereas nearly all of the reverse effects (i.e., work conditions and outcomes predicting self-esteem) were nonsignificant. The results held for both male and female participants. If future research supports the causality of the self-esteem effects, interventions aimed at improving self-esteem might be useful in increasing an individual’s well-being and success at work, which consequently might be beneficial for employers.

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Low self-esteem and depression are strongly related, but there is not yet consistent evidence on the nature of the relation. Whereas the vulnerability model states that low self-esteem contributes to depression, the scar model states that depression erodes self-esteem. Furthermore, it is unknown whether the models are specific for depression or whether they are also valid for anxiety. We evaluated the vulnerability and scar models of low self-esteem and depression, and low self-esteem and anxiety, by meta-analyzing the available longitudinal data (covering 77 studies on depression and 18 studies on anxiety). The mean age of the samples ranged from childhood to old age. In the analyses, we used a random-effects model and examined prospective effects between the variables, controlling for prior levels of the predicted variables. For depression, the findings supported the vulnerability model: The effect of self-esteem on depression (β = -.16) was significantly stronger than the effect of depression on self-esteem (β = -.08). In contrast, the effects between low self-esteem and anxiety were relatively balanced: Self-esteem predicted anxiety with β = -.10, and anxiety predicted self-esteem with β = -.08. Moderator analyses were conducted for the effect of low self-esteem on depression; these suggested that the effect is not significantly influenced by gender, age, measures of self-esteem and depression, or time lag between assessments. If future research supports the hypothesized causality of the vulnerability effect of low self-esteem on depression, interventions aimed at increasing self-esteem might be useful in reducing the risk of depression.

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This article asks if voters' participation in federal elections is lower in the new Länder (East Germany) than in the old Länder (West Germany). It is assumed that voters in the new Länder are less convinced they can influence politics by voting. Using the perspective of cognitive psychology the article stresses differences in individual interpretations of the election context among citizens of both the new and old Länder. Furthermore, it is argued that the strength of the expected influence by voting depends on the structure and direction of individuals' beliefs in their competence and control as well as their belief in causality and self-efficacy. These beliefs may differ among voters in the new and old Länder. For empirical analysis, the article uses data from the German General Social Survey 1998.

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In species with indeterminate growth, age-related size variation of reproductive competitors within each sex is often high. This selects for divergence in reproductive tactics of same-sex competitors, particularly in males. Where alternative tactics are fixed for life, the causality of tactic choice is often unclear. In the African cichlid Lamprologus callipterus, large nest males collect and present empty snail shells to females that use these shells for egg deposition and brood care. Small dwarf males attempt to fertilize eggs by entering shells in which females are spawning. The bourgeois nest males exceed parasitic dwarf males in size by nearly two orders of magnitude, which is likely to result from greatly diverging growth patterns. Here, we ask whether growth patterns are heritable in this species, or whether and to which extent they are determined by environmental factors. Standardized breeding experiments using unrelated offspring and maternal half-sibs revealed highly divergent growth patterns of male young sired by nest or dwarf males, whereas the growth of female offspring of both male types did not differ. As expected, food had a significant modifying effect on growth, but neither the quantity of breeding substrate in the environment nor ambient temperature affected growth. None of the environmental factors tested influenced the choice of male life histories. We conclude that in L. callipterus growth rates of bourgeois and parasitic males are paternally inherited, and that male and female growth is phenotypically plastic to only a small degree.

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INTRODUCTION Herbal and dietary supplements are widely used as measures to improve and preserve health and well-being. Among the bestselling preparations are dietary supplement containing glucosamine and chondroitine sulfate taken to improve symptoms of osteoarthritis. METHODS AND RESULTS We here present a case of a male patient with biopsy-proven acute and severe autoimmune hepatitis subsequent to intake of a preparation containing glucosamine and chondroitine sulfate. Response to steroids was favorable and resulted in complete remission of the patient. Diagnostic work-up of the case revealed no other possible cause of liver injury, and causality assessment using the Roussel Uclaf Causality Assessment Method (RUCAM) resulted in a possible causal relationship between intake of glucosamine and chondroitine sulfate and the adverse hepatic reaction. CONCLUSION The present case recalls that products containing glucosamine and chondroitine sulfate can occasionally cause acute liver injury mimicking autoimmune hepatitis, and reminds of the potential dangers of compounds with poor efficacy and ill-defined safety records.

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Time is a basic dimension in psychology, underlying behavior and experience. Timing and time perception constitute implicit processes that are often inaccessible to the individual person. Research in this field has shown that timing is involved in many areas of clinical significance. In the projects presented here, we combine timing with seemingly different fields of research, such as psychopathology, perceptual grouping, and embodied cognition. Focusing on the time scale of the subjective present, we report findings from three different clinical studies: (1) We studied perceived causality in schizophrenia patients, finding that perceptual grouping (‘binding’, ‘Gestalt formation’), which leads to visual causality perceptions, did not distinguish between patients and healthy controls. Patients however did integrate context (provided by the temporal distribution of auditory context stimuli) less into perceptions, in significant contrast to controls. This is consistent with reports of higher inaccuracy in schizophrenia patients’ temporal processing. (2) In a project on auditory Gestalt perception we investigated auditory perceptual grouping in schizophrenia patients. The mean dwell time was positively related to how much patients were prone to auditory hallucinations. Dwell times of auditory Gestalts may be regarded as operationalizations of the subjective present; findings thus suggested that patients with hallucinations had a shorter present. (3) The movement correlations of interacting individuals were used to study the non-verbal synchrony between therapist and patient in psychotherapy sessions. We operationalized the duration of an embodied ‘social present’ by the statistical significance of such associations, finding a window of roughly 5.7 seconds in conversing dyads.We discuss that temporal scales of nowness may be modifiable, e.g., by mindfulness. This yields promising goals for future research on timing in the clinical context: psychotherapeutic techniques may alter binding processes, hence the subjective present of individuals, and may affect the social present in therapeutic interactions.