Optical characterisation of three reference Dobsons in the ATMOZ Project – verification of G. M. B. Dobson's original specifications

Laboratory investigations of optical characteristics of three standard Dobsons provide real wavelength settings and slit functions. These parameters were compared with the original values given in the manuals. The differences between real and nominal values are not too large, but their application will in any case improve the quality of the total ozone column measurements in the global network. This improvement was the main objective of the ATMOZ project funding these activities.This work has been supported by the European Metrology Research Programme (EMRP) within the joint research project EMRP ENV59 ATMOZ “Traceability for atmospheric total column ozone”. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union

South Pole Station ozonesondes: variability and trends in the springtime Antarctic ozone hole 1986–2021

Balloon-borne ozonesondes launched weekly from South Pole station (1986&ndash;2021) measure high vertical resolution profiles of ozone and temperature from surface to 30&ndash;35 km altitude. The launch frequency is increased in late winter before the onset of rapid stratospheric ozone loss in September. Ozone hole metrics show the yearly total column ozone and 14&ndash;21 km column ozone minimum values and September loss rates remain on an upward (less severe) trend since 2001. However, the data series also illustrate interannual variability, especially in the last three years (2019&ndash;2021). Here we show additional details of these three years by comparing minimum ozone profiles and the July&ndash;December 14&ndash;21 km column ozone time series. The 2019 anomalous vortex breakdown showed stratospheric temperatures began warming in early September leading to reduced ozone loss. The minimum total column ozone of 180 Dobson Units (DU) was observed on 24 September. This was followed by two stable and cold polar vortex years in 2020 and 2021 with total column ozone minimums at 104 DU (01 October) and 102 DU (07 October), respectively. These years also showed broad zero ozone (saturation loss) regions within the 14&ndash;21 km layer by the end of September which persisted into October. Validation of the ozonesonde observations is conducted through the ongoing comparison of total column ozone (TCO) measurements with the South Pole ground-based Dobson spectrophotometer. The ozonesondes show a constant positive offset of 2 &plusmn; 3 % (higher) than the Dobson following a thorough evaluation/homogenization of the ozonesonde record in 2018.</p

Characterization of Dobsons instruments within EMRP ATMOZ Project

Presentación realizada en: ATMOZ workshop at 11th RBCC-E, celebrado en El Arenosillo, Huelva, el 1 de junio de 2017

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

The employment implications of the United Kingdom's merchant fleet's decline

This paper examines the employment implications of the decline in the UK's merchant fleet, particularly over the past decade. Firstly, it is established that the number of UK officers and ratings fell in direct correspondence with the volume of shipping tonnage on the UK shipping register. Secondly, the impact of the transfer of UK owned tonnage to other flag registers is examined. It is further argued that the decline in seafarer numbers has made the task of projecting future trends more difficult, because the quality of information concerning their numbers has become less accurate. Lack of information about age profiles means that accurate forecasting has become extremely difficult. As their numbers decline, the problem of accuracy becomes more acute. These problems appear to have been exacerbated by the deregulation process.UK shipping labour UK seafarers decline

Employment characteristics of UK seafaring officers in 1999

Although UK deck and engineer officers numbers and age distribution are now well known, certain other aspects of this group of seafarers are not. This paper presents some new findings concerning their disposition across UK and non-UK companies, and provides a fresh estimate of the proportions of UK officers working at sea. The findings are based on a survey of members of National Union of Marine Aviation Shipping Transport. The evidence provides additional confirmation for the assumption that 90% of all officers are actively engaged at sea, and the numbers working for UK based companies are higher than previously thought. Policy implications are discussed.UK seafaring officers : Employment patterns

An analysis of the employment durations of UK seafaring officers 1999

This paper presents the results of an analysis of the duration of voyages undertaken by National Union of Marine Aviation Shipping Transport (NUMAST) deck and engineer officers during 1998-99. It provides a snapshot of the employment profile of the officers, and compares voyage patterns across Organisation Type, Company Nationality, Flag of Registry, and Ship Type. Analysis of the various cross-tabulations of employment duration appears to show that the key driver is ship type, which it is argued, is a proxy for different markets, which have different employment requirements for its seafarers. Further work is needed to determine the factors which help to explain the observed variations in voyage durations. The paper is completed with an analysis of the age profiles of NUMAST officers by Flag of Registry. It is shown that significant variations in age profiles exist, with those working under Open registers being slightly older than those in the UK or UK related registers.UK seafaring officers Employment Duration Organisation Type Company Nationality Flag of Registry Age profiles

Ozone Exposure of Macrophages Induces an Alveolar Epithelial Chemokine Response through IL-1α

Ozone is known to produce an acute influx of neutrophils, and alveolar epithelial cells can secrete chemokines and modulate inflammatory processes. However, direct exposure of alveolar epithelial cells and macrophages to ozone (O3) produces little chemokine response. To determine if cell–cell interactions might be responsible, we investigated the effect of alveolar macrophage–conditioned media after ozone exposure (MO3CM) on alveolar epithelial cell chemokine production. Serum-free media were conditioned by exposing a rat alveolar macrophage cell line NR8383 to ozone for 1 hour. Ozone stimulated secretion of IL-1α, IL-1β, and IL-18 from NR8383 cells, but there was no secretion of chemokines or TNF-α. Freshly isolated type II cells were cultured, so as to express the biological markers of type I cells, and these cells are referred to as type I–like cells. Type I–like cells were exposed to diluted MO3CM for 24 hours, and this conditioned medium stimulated secretion of cytokine-induced neutrophil chemattractant-1 (CXCL1) and monocyte chemoattractant protein-1 (CCL2). Secretion of these chemokines was inhibited by the IL-1 receptor antagonist. Although both recombinant IL-1α and IL-1β stimulated alveolar epithelial cells to secrete chemokines, recombinant IL-1α was 100-fold more potent than IL-1β. Furthermore, neutralizing anti-rat IL-1α antibodies inhibited the secretion of chemokines by alveolar epithelial cells, whereas neutralizing anti-rat IL-1β antibodies had no effect. These observations indicate that secretion of IL-1α from macrophages stimulates alveolar epithelial cells to secrete chemokines that can elicit an inflammatory response