86 research outputs found
The lifetime of nitrogen oxides in an isoprene-dominated forest
The lifetime of nitrogen oxides (NO_x) affects the concentration and distribution of NO_x and the spatial patterns of nitrogen deposition. Despite its importance, the lifetime of NO_x is poorly constrained in rural and remote continental regions. We use measurements from a site in central Alabama during the Southern Oxidant and Aerosol Study (SOAS) in summer 2013 to provide new insights into the chemistry of NO_x and NO_x reservoirs. We find that the lifetime of NO_x during the daytime is controlled primarily by the production and loss of alkyl and multifunctional nitrates (ΣANs). During SOAS, ΣAN production was rapid, averaging 90 ppt h^(−1) during the day, and occurred predominantly during isoprene oxidation. Analysis of the ΣAN and HNO_3 budgets indicate that ΣANs have an average lifetime of under 2 h, and that approximately 45 % of the ΣANs produced at this site are rapidly hydrolyzed to produce nitric acid. We find that ΣAN hydrolysis is the largest source of HNO_3 and the primary pathway to permanent removal of NO_x from the boundary layer in this location. Using these new constraints on the fate of ΣANs, we find that the NO_x lifetime is 11 ± 5 h under typical midday conditions. The lifetime is extended by storage of NO_x in temporary reservoirs, including acyl peroxy nitrates and ΣANs
Does discussion lead to opinion change within Political Science students? A pedagogical exercise of deliberative democracy
While the model of deliberative democracy gives a crucial role to dialog, empirical evidence has not yet established if discussion helps to reach a better understanding of political issues and, above all, if individuals are prepared to change their views. It is still unclear when the deliberative model, and more specifically discussion, could be usefully employed as a teaching tool, to improve students’ knowledge. This article presents an exercise performed within the Department of Political and Social Sciences at the LUISS University of Rome. Students were asked to discuss in the classroom the issues related to the course, and to cast a vote on selected issues before and after deliberation. Although our sample is not representative, we have gathered evidence from the same population on a rather large number of issues. Students changed their view in 24.6% of cases, and they agreed that discussion increased their understanding, while those with strong ex-ante views resulted more reluctant to change their opinions because of discussion. The analysis also showed the presence of individuals that are more likely to be permeable to discussion while others that are more likely to be impermeable
Development of a candidate reference material for adventitious virus detection in vaccine and biologicals manufacturing by deep sequencing.
Unbiased deep sequencing offers the potential for improved adventitious virus screening in vaccines and biotherapeutics. Successful implementation of such assays will require appropriate control materials to confirm assay performance and sensitivity.
A common reference material containing 25 target viruses was produced and 16 laboratories were invited to process it using their preferred adventitious virus detection assay.
Fifteen laboratories returned results, obtained using a wide range of wet-lab and informatics methods. Six of 25 target viruses were detected by all laboratories, with the remaining viruses detected by 4-14 laboratories. Six non-target viruses were detected by three or more laboratories.
The study demonstrated that a wide range of methods are currently used for adventitious virus detection screening in biological products by deep sequencing and that they can yield significantly different results. This underscores the need for common reference materials to ensure satisfactory assay performance and enable comparisons between laboratories
International Nonregimes: A Research Agenda1
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146934/1/j.1468-2486.2007.00672.x.pd
The lifetime of nitrogen oxides in an isoprene-dominated forest
The lifetime of nitrogen oxides (NO_x) affects the concentration and distribution of NO_x and the spatial patterns of nitrogen deposition. Despite its importance, the lifetime of NO_x is poorly constrained in rural and remote continental regions. We use measurements from a site in central Alabama during the Southern Oxidant and Aerosol Study (SOAS) in summer 2013 to provide new insights into the chemistry of NO_x and NO_x reservoirs. We find that the lifetime of NO_x during the daytime is controlled primarily by the production and loss of alkyl and multifunctional nitrates (ΣANs). During SOAS, ΣAN production was rapid, averaging 90 ppt h^(−1) during the day, and occurred predominantly during isoprene oxidation. Analysis of the ΣAN and HNO_3 budgets indicate that ΣANs have an average lifetime of under 2 h, and that approximately 45 % of the ΣANs produced at this site are rapidly hydrolyzed to produce nitric acid. We find that ΣAN hydrolysis is the largest source of HNO_3 and the primary pathway to permanent removal of NO_x from the boundary layer in this location. Using these new constraints on the fate of ΣANs, we find that the NO_x lifetime is 11 ± 5 h under typical midday conditions. The lifetime is extended by storage of NO_x in temporary reservoirs, including acyl peroxy nitrates and ΣANs
- …