355 research outputs found
Distribution of amiodarone and desethylamiodarone in a patient with acute myocardial infarction after intravenous administration
The autopsy tissues concentration of amiodarone and desethylamiodarone of a man with acute myocardial infarction treated acutely with intravenous amiodarone is reported. Our data indicate that amiodarone is quickly distributed into all highly perfused tissues after intravenous administration with a high amiodarone/desethylamiodarone ratio. We also report here the autopsy case of a woman who died after 30 days of oral therapy with amiodarone. The increase in heart/plasma ratio of amiodarone and desethylamiodarone concentrations and the decrease in amiodarone/desethylamiodarone ratio after one month of therapy could explain the latency in the antiarrhythmic action of the drug
Atrial conduction delay as a possible arrhythmogenic mechanism in paroxysmal idiopathic atrial fibrillation
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Intuitionistc probability and the Bayesian objection to dogmatism
Given a few assumptions, the probability of a conjunction is raised, and the probability of its negation is lowered, by conditionalising upon one of the conjuncts. This simple result appears to bring Bayesian confirmation theory into tension with the prominent dogmatist view of perceptual justification – a tension often portrayed as a kind of ‘Bayesian objection’ to dogmatism. In a recent paper, David Jehle and Brian Weatherson observe that, while this crucial result holds within classical probability theory, it fails within intuitionistic probability theory. They conclude that the dogmatist who is willing to take intuitionistic logic seriously can make a convincing reply to the Bayesian objection. In this paper, I argue that this conclusion is premature – the Bayesian objection can survive the transition from classical to intuitionistic probability, albeit in a slightly altered form. I shall conclude with some general thoughts about what the Bayesian objection to dogmatism does and doesn’t show
Estimation of the incubation period and generation time of SARS-CoV-2 Alpha and Delta variants from contact tracing data
Quantitative information on epidemiological quantities such as the incubation period and generation time of SARS-CoV-2 variants is scarce. We analyzed a dataset collected during contact tracing activities in the province of Reggio Emilia, Italy, throughout 2021. We determined the distributions of the incubation period for the Alpha and Delta variants using information on negative PCR tests and the date of last exposure from 282 symptomatic cases. We estimated the distributions of the intrinsic generation time using a Bayesian inference approach applied to 9724 SARS-CoV-2 cases clustered in 3545 households where at least one secondary case was recorded. We estimated a mean incubation period of 4.9 days (95% credible intervals, CrI, 4.4-5.4) for Alpha and 4.5 days (95%CrI 4.0-5.0) for Delta. The intrinsic generation time was estimated to have a mean of 7.12 days (95% CrI 6.27-8.44) for Alpha and of 6.52 days (95%CrI 5.54-8.43) for Delta. The household serial interval was 2.43 days (95%CrI 2.29-2.58) for Alpha and 2.74 days (95%CrI 2.62-2.88) for Delta, and the estimated proportion of pre-symptomatic transmission was 48-51% for both variants. These results indicate limited differences in the incubation period and intrinsic generation time of SARS-CoV-2 variants Alpha and Delta compared to ancestral lineages
SARS-CoV-2 transmission patterns in educational settings during the Alpha wave in Reggio-Emilia, Italy
: Different monitoring and control policies have been implemented in schools to minimize the spread of SARS-CoV-2. Transmission in schools has been hard to quantify due to the large proportion of asymptomatic carriers in young individuals. We applied a Bayesian approach to reconstruct the transmission chains between 284 SARS-CoV-2 infections ascertained during 87 school outbreak investigations conducted between March and April 2021 in Italy. Under the policy of reactive quarantines, we found that 42.5% (95%CrI: 29.5-54.3%) of infections among school attendees were caused by school contacts. The mean number of secondary cases infected at school by a positive individual during in-person education was estimated to be 0.33 (95%CrI: 0.23-0.43), with marked heterogeneity across individuals. Specifically, we estimated that only 26.0% (95%CrI: 17.6-34.1%) of students and school personnel who tested positive during in-person education caused at least one secondary infection at school. Positive individuals who attended school for at least 6 days before being isolated or quarantined infected on average 0.49 (95%CrI: 0.14-0.83) secondary cases. Our findings provide quantitative insights on the contribution of school transmission to the spread of SARS-CoV-2 in young individuals. Identifying positive cases within 5 days after exposure to their infector could reduce onward transmission at school by at least 30%
Secondary organic aerosol formation from gasoline vehicle emissions in a new mobile environmental reaction chamber
We present a new mobile environmental reaction chamber for the simulation of the
atmospheric aging of different emissions sources without limitation from the instruments or
facilities available at any single site. Photochemistry is simulated using a set of 40 UV lights
(total power 4 KW). Characterisation of the emission spectrum of these lights shows that
atmospheric aging of emissions may be simulated over a range of temperatures (-7 to 25°C).
A photolysis rate of NO2, JNO2, of (8.0±0.7)×10-3 s-1 was determined at 25°C. We demonstrate
the utility of this new system by presenting results on the aging (OH=12×106 cm-3h) of
emissions from a modern (Euro 5) gasoline car operated during a driving cycle (New
European Driving Cycle, NEDC) on a chassis dynamometer in a vehicle test cell. Emissions
from the entire NEDC were sampled and aged in the chamber.
A thorough investigation of the composition of the gas
phase emissions suggests that the observed SOA is from previously unconsidered precursors
and processes. This large enhancement in PM mass from gasoline vehicle aerosol emissions
due to SOA formation, if it occurs across a wider range of gasoline vehicles, would have
significant implications for our understanding of the contribution of on-road gasoline vehicles
to ambient aerosols.JRC.F.8-Sustainable Transpor
Estimating the potential risk of transmission of arboviruses in the Americas and Europe: a modeling study
Two-stroke scooters are a dominant source of air pollution in many cities.
Fossil fuel-powered vehicles emit significant particulate matter, for example, black carbon and primary organic aerosol, and produce secondary organic aerosol. Here we quantify secondary organic aerosol production from two-stroke scooters. Cars and trucks, particularly diesel vehicles, are thought to be the main vehicular pollution sources. This needs re-thinking, as we show that elevated particulate matter levels can be a consequence of 'asymmetric pollution' from two-stroke scooters, vehicles that constitute a small fraction of the fleet, but can dominate urban vehicular pollution through organic aerosol and aromatic emission factors up to thousands of times higher than from other vehicle classes. Further, we demonstrate that oxidation processes producing secondary organic aerosol from vehicle exhaust also form potentially toxic 'reactive oxygen species'.This work was supported by the Swiss Federal Office for the Environment (FOEN), the Federal Roads Office (FEDRO), the Swiss National Science Foundation (Ambizione PZ00P2_131673, SAPMAV 200021_13016), the EU commission (FP7, COFUND: PSI-Fellow, grant agreement n.° 290605), the UK Natural Environment Research Council (NERC), the French Environment and Energy Management Agency (ADEME, Grant number 1162C00O2) and the Velux Foundation.This is the accepted manuscript version. The final version is available from http://www.nature.com/ncomms/2014/140513/ncomms4749/full/ncomms4749.html
Precision charging of microparticles in plasma via the Rayleigh instability for evaporating charged liquid droplets
In this paper we describe a novel method for delivering a precise, known amount of electric charge to a micron-sized solid target. Aerosolised microparticles passed through a plasma discharge will acquire significant electric charge. The fluid stability under evaporative stress is a key aspect that is core to the research. Initially stable charged aerosols subject to evaporation (i.e. a continually changing radius) may encounter the Rayleigh stability limit. This limit arises from the electrostatic and surface tension forces and determines the maximum charge a stable droplet can retain, as a function of radius. We demonstrate that even if the droplet charge is initially much less than the Rayleigh limit, the stability limit will be encountered as the droplet evaporates. The instability emission mechanism is strongly linked to the final charge deposited on the target, providing a mechanism that can be used to ensure a predictable charge deposit on a known encapsulated microparticle
Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 8
In this contribution, new data concerning algae, bryophytes, fungi, and lichens of the Italian flora are presented. It includes new records and confirmations for the algae genus Chara, the bryophyte genera Homalia, Mannia, and Tortella, the fungal genera Cortinarius, Russula, and Stereum, and the lichen genera Cetrelia, Cladonia, Enterographa, Graphis, Lecanora, Lepraria, Multiclavula, Mycomicrothelia, Parmelia, Peltigera, Pleopsidium, Psora, Scytinium, Umbilicaria, and Rhizocarpon
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