Review of the Monitoring Programme: Baseline Measurement and Analysis of UK Ozone and UV

The Department for Environment, Food and Rural Affairs (Defra) and the Devolved Administrations (DA) continue to fund a long-running programme Baseline Measurement and Analysis of UK Ozone and UV to monitor column (effectively stratospheric) ozone and surface UV. The main driver for the monitoring programme is the 1985 Vienna Convention on the Protection of the Ozone Layer. The Convention obliges parties (including the UK) to undertake inter alia monitoring, data dissemination and information exchange activities. The current monitoring programme comprises: • measurements of column ozone at two sites in the UK (Lerwick and Reading) • spectrally-resolved UV measurements at one site (Reading) The ozone element of the monitoring programme was reviewed in 2002. Defra has commissioned this review of the programme to ensure that it continues to meet current and future policy and scientific requirements as well as international obligations. The Review The review was structured in terms of 7 questions, which addressed a range of strategic, technical and organisational aspects of the monitoring programme. 1. How does the monitoring programme help to meet the UK obligations under the Vienna Convention on the Protection of the Ozone Layer? 2. Are the data currently collected in the monitoring programme fit for purpose? If not, what measures could be employed to make the data fit for purpose? Are there any activities in the current monitoring programme which are no longer needed? 3. Are the current measurement techniques viable into the future (over a 5-20 year timescale), and what other techniques/instruments are available? 4. Are current methodologies for disseminating information sufficient? If other techniques/instruments are preferable, how (or indeed could) they be introduced whilst maintaining the continuity of the results? 5. Is the current monitoring programme cost effective? 6. Is the current monitoring programme structured for optimum delivery? 7. Should all or part of the programme be competitively tendered, or indeed should it be competitively tendered at all? Summary of Findings The key findings were 1. The current monitoring programme is working well but it has a low profile and impact 2. There are options to evolve the programme but these require further, more detailed evaluation

Peroxy radicals in the summer free troposphere: seasonality and potential for heterogeneous loss

The sum of peroxy radicals (HO2+ΣiRiO2) and supporting trace gases were measured on the Jungfraujoch (3580 m a.s.l.) during the late summer of 2005. The period was marked by extended times of heavy snow which led to reduction in the observed peroxy radicals during the snowy periods that was greater than the concomitant reduction in j(O1D). In the limit a first order loss rate of 0.0063 s−1 can be derived for the peroxy radical loss in the snowy conditions that could be potentially ascribed to a heterogenous loss process. On snow free days photolysis of HCHO is shown to be a significant peroxy radical source. The seasonal trends of the peroxy radical concentrations have been mapped from the winter to summer transition in line with previous experiments. Net ozone production in late summer at the Jungfraujoch was net neutral to marginally ozone destructive. A value of 28±4 pptv is calculated for the ozone compensation point for the snow free days.ISSN:1680-7375ISSN:1680-736

Ethanol Pharmacokinetics in Neonates Secondary to Medication Administration

Purpose: Ethanol serves as a solvent and microbial preservative in oral liquid medications and is the second most commonly used solvent in liquid medications following water. Despite widespread use of ethanol in liquid medications for neonates, the pharmacokinetics and toxicity of ethanol in young children are not well described. The aim of the current study is to quantify blood ethanol levels in neonates secondary to oral ethanol containing medications. Methods: Neonates who received either oral phenobarbital (15% ethanol) and/or oral dexamethasone (30% ethanol) per standard of care were eligible for enrollment. A maximum of 6 blood samples per patient (4.5 mL total) were taken over the study period. Blood samples were collected via heel stick at the time of clinical laboratory collections or following a specific collection for study purposes. In addition, blood samples were collected from neonates receiving sublingual buprenorphine (30% ethanol) for neonatal abstinence syndrome from a separate clinical study. Blood ethanol levels were measured using a validated headspace gas chromatography-mass spectrometry method utilizing micro-volume ( ̴100uL) plasma samples. The limit of detection and lower limit of quantification for the assay were 0.1 mg/L and 0.5 mg/L respectively. Results: A total of 39 plasma samples from 15 neonates who were on ethanol containing medications were collected over the study period. Four neonates were exposed to phenobarbital and/or dexamethasone, while eleven neonates were exposed to buprenorphine alone or in combination with phenobarbital. Patients were exposed to an average of 71.6 mg/kg (range 13.1 to 215 mg/kg) of ethanol after a single dose of an ethanol containing medication. Blood ethanol levels were detectable in 98% (38/39) of samples, quantifiable in 67% (26/39) of samples, and ranged from below detection to 85.4 mg/L. Ethanol was rapidly cleared and did not accumulate with current dosing regimens. Conclusion: Ethanol intake secondary to medication administration varied widely. Blood ethanol levels in neonates were low and ethanol was eliminated rapidly after a single dose of oral medications that contained a sizable fraction of ethanol.https://jdc.jefferson.edu/petposters/1000/thumbnail.jp

Air quality and climate change: designing new win-win policies for Europe

Anthropogenic activities are responsible for the emission of gaseous and particulate pollutants that modify atmospheric composition. Such changes are, in turn, responsible for the degradation of air quality at the regional/local scale as well as for changes of climate. Air pollution and climate change are two intimately connected environmental issues. However, these two environmental challenges are still viewed as separate issues, which are dealt with by different science communities and within different policy frameworks. Indeed, many mitigation options offer the possibility to both improve air quality and mitigate climate change but, at the same time, mitigation options that may provide benefits to one aspect, are worsening the situation in the other. Therefore, coordinated actions taking into account the air quality-climate linkages are required. These actions need to be based on strong scientific grounds, as recognised by the European Commission that in the past few years has promoted consultation processes among the science community, the policy makers and the relevant stakeholders. Here, the main fields in which such coordinated actions are needed are examined from a policy perspective

AtChem (version 1), an open-source box model for the Master Chemical Mechanism

AtChem is an open-source zero-dimensional box model for atmospheric chemistry. Any general set of chemical reactions can be used with AtChem, but the model was designed specifically for use with the Master Chemical Mechanism (MCM, http://mcm.york.ac.uk/, last access: 16 January 2020). AtChem was initially developed within the EUROCHAMP project as a web application (AtChem-online, https://atchem.leeds.ac.uk/webapp/, last access: 16 January 2020) for modelling environmental chamber experiments; it was recently upgraded and further developed into a stand-alone offline version (AtChem2), which allows the user to run complex and long simulations, such as those needed for modelling of intensive field campaigns, as well as to perform batch model runs for sensitivity studies. AtChem is installed, set up and configured using semi-automated scripts and simple text configuration files, making it easy to use even for inexperienced users. A key feature of AtChem is that it can easily be constrained to observational data which may have different timescales, thus retaining all the information contained in the observations. Implementation of a continuous integration workflow, coupled with a comprehensive suite of tests and version control software, makes the AtChem code base robust, reliable and traceable. The AtChem2 code and documentation are available at https://github.com/AtChem/ (last access: 16 January 2020) under the open-source MIT License

Matched sizes of activating and inhibitory receptor/ligand pairs are required for optimal signal integration by human Natural Killer cells

It has been suggested that receptor-ligand complexes segregate or co-localise within immune synapses according to their size, and this is important for receptor signaling. Here, we set out to test the importance of receptor-ligand complex dimensions for immune surveillance of target cells by human Natural Killer (NK) cells. NK cell activation is regulated by integrating signals from activating receptors, such as NKG2D, and inhibitory receptors, such as KIR2DL1. Elongating the NKG2D ligand MICA reduced its ability to trigger NK cell activation. Conversely, elongation of KIR2DL1 ligand HLA-C reduced its ability to inhibit NK cells. Whereas normal-sized HLA-C was most effective at inhibiting activation by normal-length MICA, only elongated HLA-C could inhibit activation by elongated MICA. Moreover, HLA-C and MICA that were matched in size co-localised, whereas HLA-C and MICA that were different in size were segregated. These results demonstrate that receptor-ligand dimensions are important in NK cell recognition, and suggest that optimal integration of activating and inhibitory receptor signals requires the receptor-ligand complexes to have similar dimensions

Radical chemistry and ozone production at a UK coastal receptor site

OH, HO2, total and partially speciated RO2, and OH reactivity (kOH′) were measured during the July 2015 ICOZA (Integrated Chemistry of OZone in the Atmosphere) project that took place at a coastal site in north Norfolk, UK. Maximum measured daily OH, HO2 and total RO2 radical concentrations were in the range 2.6–17 × 106, 0.75–4.2 × 108 and 2.3–8.0 × 108 molec. cm−3, respectively. kOH′ ranged from 1.7 to 17.6 s−1, with a median value of 4.7 s−1. ICOZA data were split by wind direction to assess differences in the radical chemistry between air that had passed over the North Sea (NW–SE sectors) and that over major urban conurbations such as London (SW sector). A box model using the Master Chemical Mechanism (MCMv3.3.1) was in reasonable agreement with the OH measurements, but it overpredicted HO2 observations in NW–SE air in the afternoon by a factor of ∼ 2–3, although slightly better agreement was found for HO2 in SW air (factor of ∼ 1.4–2.0 underprediction). The box model severely underpredicted total RO2 observations in both NW–SE and SW air by factors of ∼ 8–9 on average. Measured radical and kOH′ levels and measurement–model ratios displayed strong dependences on NO mixing ratios, with the results suggesting that peroxy radical chemistry is not well understood under high-NOx conditions. The simultaneous measurement of OH, HO2, total RO2 and kOH′ was used to derive experimental (i.e. observationally determined) budgets for all radical species as well as total ROx (i.e. OH + HO2 + RO2). In NW–SE air, the ROx budget could be closed during the daytime within experimental uncertainty, but the rate of OH destruction exceeded the rate of OH production, and the rate of HO2 production greatly exceeded the rate of HO2 destruction, while the opposite was true for RO2. In SW air, the ROx budget analysis indicated missing daytime ROx sources, but the OH budget was balanced, and the same imbalances were found with the HO2 and RO2 budgets as in NW–SE air. For HO2 and RO2, the budget imbalances were most severe at high-NO mixing ratios, and the best agreement between HO2 and RO2 rates of production and destruction rates was found when the RO2 + NO rate coefficient was reduced by a factor of 5. A photostationary-steady-state (PSS) calculation underpredicted daytime OH in NW–SE air by ∼ 35 %, whereas agreement (∼ 15 %) was found within instrumental uncertainty (∼ 26 % at 2σ) in SW air. The rate of in situ ozone production (P(Ox)) was calculated from observations of ROx, NO and NO2 and compared to that calculated from MCM-modelled radical concentrations. The MCM-calculated P(Ox) significantly underpredicted the measurement-calculated P(Ox) in the morning, and the degree of underprediction was found to scale with NO.</p