Pathergy Phenomenon.
Ontology highlight
ABSTRACT:
SUBMITTER: Ergun T
PROVIDER: S-EPMC8185024 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Can behavior be unconsciously primed via the activation of attitudes, stereotypes, or other concepts? A number of studies have suggested that such priming effects can occur, and a prominent illustration is the claim that individuals' accuracy in answering general knowledge questions can be influenced by activating intelligence-related concepts such as professor or soccer hooligan. In 9 experiments with 475 participants we employed the procedures used in these studies, as well as a number of variants of those procedures, in an attempt to obtain this intelligence priming effect. None of the experiments obtained the effect, although financial incentives did boost performance. A Bayesian analysis reveals considerable evidential support for the null hypothesis. The results conform to the pattern typically obtained in word priming experiments in which priming is very narrow in its generalization and unconscious (subliminal) influences, if they occur at all, are extremely short-lived. We encourage others to explore the circumstances in which this phenomenon might be obtained.
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Project description:Bus bunching is a perennial phenomenon that not only diminishes the efficiency of a bus system, but also prevents transit authorities from keeping buses on schedule. We present a physical theory of buses serving a loop of bus stops as a ring of coupled self-oscillators, analogous to the Kuramoto model. Sustained bunching is a repercussion of the process of phase synchronisation whereby the phases of the oscillators are locked to each other. This emerges when demand exceeds a critical threshold. Buses also bunch at low demand, albeit temporarily, due to frequency detuning arising from different human drivers' distinct natural speeds. We calculate the critical transition when complete phase locking (full synchronisation) occurs for the bus system, and posit the critical transition to completely no phase locking (zero synchronisation). The intermediate regime is the phase where clusters of partially phase locked buses exist. Intriguingly, these theoretical results are in close correspondence to real buses in a university's shuttle bus system.
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Project description:BackgroundMany different drugs have been suggested for the symptomatic treatment of primary Raynaud's phenomenon. Apart from calcium channel blockers, which are considered the drugs of choice, the evidence of the effects of alternative pharmacological treatments is limited. This is an update of a review first published in 2008.ObjectivesTo assess the effects of various drugs with vasodilator actions on primary Raynaud's phenomenon.Search methodsFor this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched 14 May 2012), CENTRAL (Issue 4, 2012) and clinical trials databases. We contacted one pharmaceutical company and one trial author for additional information. In addition, the reference lists of relevant studies were searched for additional citations. There were no language restrictions.Selection criteriaRandomised controlled trials evaluating the effects of oral formulations of any drug with vasodilator effects on subjective symptoms in primary Raynaud's phenomenon. Treatment with, or comparison with, calcium channel blockers was not assessed in this review.Data collection and analysisTwo members of the review team independently assessed the trials for inclusion and their quality and extracted the data. Data extraction included adverse events. We contacted trial authors for missing data.Main resultsEight studies involving 290 participants were included. Two trials examined the effects of captopril, the rest were single trials on single drugs. All comparisons were with placebo. The methodological quality of most trials was poor.Enalapril was associated with a small increase in the frequency of attacks per week (difference in means 0.8; 95% CI 0.43 to 1.17). The difference between the intervention groups on a subjective improvement score was non-significant. There was a significant effect of buflomedil on the frequency of attacks per week (weighted mean difference (WMD) -8.8; 95% CI -17.55 to -0.09), but there was no evidence of effect on the severity score. The proportion with fewer attacks was significantly higher on moxisylyte than on placebo (relative risk (RR) 4.33; 95% CI 1.36 to 13.81). For captopril, beraprost, dazoxiben and ketanserin there was no evidence of an effect on the frequency, severity or duration of attacks. Beraprost and moxisylyte gave significantly more adverse effects than placebo.Authors' conclusionsPoor methodological quality, small sample sizes and the limited data available resulted in low precision of the statistical results and limited value of the overall results .The overall results show that there is no evidence for an effect of vasodilator drugs on primary Raynaud's phenomenon.
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Project description:UnlabelledAmong the most fundamental questions in viral evolutionary biology are how fast viruses evolve and how evolutionary rates differ among viruses and fluctuate through time. Traditionally, viruses are loosely classed into two groups: slow-evolving DNA viruses and fast-evolving RNA viruses. As viral evolutionary rate estimates become more available, it appears that the rates are negatively correlated with the measurement timescales and that the boundary between the rates of DNA and RNA viruses might not be as clear as previously thought. In this study, we collected 396 viral evolutionary rate estimates across almost all viral genome types and replication strategies, and we examined their rate dynamics. We showed that the time-dependent rate phenomenon exists across multiple levels of viral taxonomy, from the Baltimore classification viral groups to genera. We also showed that, by taking the rate decay dynamics into account, a clear division between the rates of DNA and RNA viruses as well as reverse-transcribing viruses could be recovered. Surprisingly, despite large differences in their biology, our analyses suggested that the rate decay speed is independent of viral types and thus might be useful for better estimation of the evolutionary time scale of any virus. To illustrate this, we used our model to reestimate the evolutionary timescales of extant lentiviruses, which were previously suggested to be very young by standard phylogenetic analyses. Our analyses suggested that these viruses are millions of years old, in agreement with paleovirological evidence, and therefore, for the first time, reconciled molecular analyses of ancient and extant viruses.ImportanceThis work provides direct evidence that viral evolutionary rate estimates decay with their measurement timescales and that the rate decay speeds do not differ significantly among viruses despite the vast differences in their molecular features. After adjustment for the rate decay dynamics, the division between the rates of double-stranded DNA (dsDNA), single-stranded RNA (ssRNA), and ssDNA/reverse-transcribing viruses could be seen more clearly than before. Our results provide a guideline for further improvement of the molecular clock. As a demonstration of this, we used our model to reestimate the timescales of modern lentiviruses, which were previously thought to be very young, and concluded that they are millions of years old. This result matches the estimate from paleovirological analyses, thus bridging the gap between ancient and extant viral evolutionary studies.
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