Atmospheric Halocarbon Measurements with a focus on East and South-East Asia

A large variety of halocarbon species are present in the atmosphere and can significantly impact stratospheric ozone depletion and/or global warming. Compound use has been phased out, reduced and replaced for some species under global control measures such as the Montreal and Kyoto Protocols. However, relatively long atmospheric lifetimes, imperfect substitutes and incomplete reductions in usage mean that global abundances of halocarbon species still require regular monitoring. This is especially true for the rapidly developing East and South-East Asian regions where widespread emissions have been repeatedly reported in recent years. To detect a variety of halocarbon mixing ratios, air samples are cryotrapped and analysed via gas chromatography couple with mass spectrometry (GC-MS). Highly sensitive and precise instrumentation widens this range further and the automation of the analysis system would improve and extend sample throughput. A semi-automated inlet system for a GC-MS set-up was constructed and cryotrapping with liquid nitrogen was tested successfully. In the atmosphere, anthropogenic emissions are the main source of many halocarbons, however methyl halides also have large natural sources including from cultivated crops like rice. Using genetically mapped and altered Arabidopsis thaliana and Physcomitrella patens, methyl halide emission rates were calculated. Differences found when compared to wild type plants indicated the potential for developing ‘ozone-safe’ crops through manipulation of the HOL-gene, which may particularly benefit Asian emissions. Three short-term sampling campaigns based in Taiwan assessed abundances of mainly anthropogenically-sourced halocarbons in East Asia. Backwards trajectory modelling was used to estimate potential source regions and both enhanced and close to background mixing ratios were observed for a range of species. Pollution events and interspecies correlations were found for many halocarbons with poorly understood sources such as CFC-113a and HCFC-133a. A further short-term campaign based in Bachok, Malaysia assessed long-range transport of ozone-depleting species to South-East Asia during the cold surge phenomenon of the winter monsoon, when rapid vertical transport may occur. Short-lived species were observed at significantly high abundances suggesting their potential impact on stratospheric ozone may have been previously underestimated

Reducing Intubation Time in Adult Cardiothoracic Surgery Patients: A Review of Data under the Direction of a Board Certified Critical Care Intensivist

Background: Prolonged intubation after cardiac surgery increases the risk of morbidity and mortality and lengthens hospital stays. Factors that influence the ability to extubate patients with speed and efficiency include the type of operation, the patient’s baseline physiological condition, and provider practice patterns. The purpose of this research was to prove that the change of practice patterns that followed the addition of an intensivist lessened extubation times in cardiac surgery patients. It was hypothesized that the interventions brought on by the introduction of an intensivist would greatly reduce the amount of time a patient is intubated while in the intensive care unit. Problem: Prolonged intubation times contributed to increased length of stay in the intensive care unit, increased morbidity and mortality rates. Method: Barriers of extubation were identified and a protocol was agreed upon by advanced practice providers along with RN’s. A comprehensive unit based safety initiative was designed and put into practice. From April 2020 to April 2021 data was collected where the cardiac intensive care unit was without an intensivist. Data was then collected from April 2021 to April 2022 when there was an intensivist on site. The data analyzed included the number of patient’s extubated under six hours out of the total number of cases. Cases included in the study consisted of CABG’s and Valves. Cases excluded from the study were aneurysm repairs and minimally assisted CABG’s where the patients came out of the OR extubated. Considerations included the elimination of Morphine/Versed, the introduction of Precedex and Propofol and more attention to the last paralytic/reversal agent out of the operating room. Results: Extubation in under six hours on the unit without an intensivist occurred in 116/571 patients (20.3%). With the introduction of an intensivist on the unit there was a total of 181/531 patients extubated in under six hours (34%). Conclusion: The number of early extubations increased with an intensivist in the intensive care unit.https://scholar.rochesterregional.org/nursingresearchday/1012/thumbnail.jp

Trends and emissions of six perfluorocarbons in the Northern Hemisphere and Southern Hemisphere

Perfluorocarbons (PFCs) are potent greenhouse gases with global warming potentials up to several thousand times greater than CO2 on a 100-year time horizon. The lack of any significant sinks for PFCs means that they have long atmospheric lifetimes of the order of thousands of years. Anthropogenic production is thought to be the only source for most PFCs. Here we report an update on the global atmospheric abundances of the following PFCs, most of which have for the first time been analytically separated according to their isomers: c-octafluorobutane (c-C4F8), n-decafluorobutane (n-C4F10), n-dodecafluoropentane (n-C5F12), n-tetradecafluorohexane (n-C6F14), and n-hexadecafluoroheptane (n-C7F16). Additionally, we report the first data set on the atmospheric mixing ratios of perfluoro-2-methylpentane (i-C6F14). The existence and significance of PFC isomers have not been reported before, due to the analytical challenges of separating them. The time series spans a period from 1978 to the present. Several data sets are used to investigate temporal and spatial trends of these PFCs: time series of air samples collected at Cape Grim, Australia, from 1978 to the start of 2018; a time series of air samples collected between July 2015 and April 2017 at Tacolneston, UK; and intensive campaign-based sampling collections from Taiwan. Although the remote “background” Southern Hemispheric Cape Grim time series indicates that recent growth rates of most of these PFCs are lower than in the 1990s, we continue to see significantly increasing mixing ratios that are between 6 % and 27 % higher by the end of 2017 compared to abundances measured in 2010. Air samples from Tacolneston show a positive offset in PFC mixing ratios compared to the Southern Hemisphere baseline. The highest mixing ratios and variability are seen in air samples from Taiwan, which is therefore likely situated much closer to PFC sources, confirming predominantly Northern Hemispheric emissions for most PFCs. Even though these PFCs occur in the atmosphere at levels of parts per trillion molar or less, their total cumulative global emissions translate into 833 million metric tonnes of CO2 equivalent by the end of 2017, 23 % of which has been emitted since 2010. Almost two-thirds of the CO2 equivalent emissions within the last decade are attributable to c-C4F8, which currently also has the highest emission rates that continue to grow. Sources of all PFCs covered in this work remain poorly constrained and reported emissions in global databases do not account for the abundances found in the atmosphere

White Paper: Measuring Research Outputs Through Bibliometrics

The suggested citation for this white paper is: University of Waterloo Working Group on Bibliometrics, Winter 2016. White Paper: Measuring Research Outputs through Bibliometrics, Waterloo, Ontario: University of Waterloo.This White Paper provides a high-level review of issues relevant to understanding bibliometrics, and practical recommendations for how to appropriately use these measures. This is not a policy paper; instead, it defines and summarizes evidence that addresses appropriate use of bibliometric analysis at the University of Waterloo. Issues identified and recommendations will generally apply to other academic institutions. Understanding the types of bibliometric measures and their limitations makes it possible to identify both appropriate uses and crucial limitations of bibliometric analysis. Recommendations offered at the end of this paper provide a range of opportunities for how researchers and administrators at Waterloo and beyond can integrate bibliometric analysis into their practice

Abrupt reversal in emissions and atmospheric abundance of HCFC-133a (CF3CH2Cl)

Hydrochlorofluorocarbon HCFC-133a (CF3CH2Cl) is an anthropogenic compound whose consumption for emissive use is restricted under the Montreal Protocol. A recent study showed rapidly increasing atmospheric abundances and emissions. We report that, following this rise, the at- mospheric abundance and emissions have declined sharply in the past three years. We find a Northern Hemisphere HCFC-133a increase from 0.13 ppt (dry air mole fraction in parts-per-trillion) in 2000 to 0.50 ppt in 2012–mid-2013 followed by an abrupt reversal to 0.44 ppt by early 2015. Global emissions derived from these observations peaked at 3.1 kt in 2011, followed by a rapid decline of 0.5 kt yr−2 to 1.5 kt yr−1 in 2014. Sporadic HCFC-133a pollution events are detected in Europe from our high-resolution HCFC-133a records at three European stations, and in Asia from sam- ples collected in Taiwan. European emissions are estimated to be <0.1 kt yr−1 although emission hotspots were identi- fied in France

Investigation of East Asian emissions of CFC-11 using atmospheric observations in Taiwan

Recent findings of an unexpected slowdown in the decline of CFC-11 mixing ratios in the atmosphere have led to the conclusion that global CFC-11 emissions have increased over the past decade and have been attributed in part to eastern China. This study independently assesses these findings by evaluating enhancements of CFC-11 mixing ratios in air samples collected in Taiwan between 2014 and 2018. Using the NAME (Numerical Atmospheric Modeling Environment) particle dispersion model, we find the likely source of the enhanced CFC-11 observed in Taiwan to be East China. Other halogenated trace gases were also measured, and there were positive interspecies correlations between CFC-11 and CHCl3, CCl4, HCFC-141b, HCFC-142b, CH2Cl2, and HCFC-22, indicating co-location of the emissions of these compounds. These correlations in combination with published emission estimates of CH2Cl2 and HCFC-22 from China, and of CHCl3 and CCl4 from eastern China, are used to estimate CFC-11 emissions. Within the uncertainties, these estimates do not differ for eastern China and the whole of China, so we combine them to derive a mean estimate that we term as being from "(eastern) China". For 2014-2018, we estimate an emission of 19 ± 5 Gg year-1 (gigagrams per year) of CFC-11 from (eastern) China, approximately one-quarter of global emissions. Comparing this to previously reported CFC-11 emissions estimated for earlier years, we estimate CFC-11 emissions from (eastern) China to have increased by 7 ± 5 Gg year-1 from the 2008-2011 average to the 2014-2018 average, which is 50 ± 40% of the estimated increase in global CFC-11 emissions and is consistent with the emission increases attributed to this region in an earlier study

Enhanced chlorinated very short-lived substances in South East Asia:Potential source regions and source types

Enhancements of the mixing ratios of short-lived halogenated gases were observed in air samples collected at Bachok Marine Research Station (BMRS), Peninsular Malaysia during Northern Hemisphere winters in 2013/2014 and 2015/2016. This study investigates the potential source regions and source types that influenced the variability in chlorinated very short-lived substances (Cl-VSLS) [dichloromethane, 1,2-dichloroethane, trichloromethane, tetrachloroethene] and methyl halides [methyl chloride and methyl bromide]. The UK Met Office’s Numerical Atmospheric Modelling Environment (NAME) dispersion model, was used for tracking the origin of air masses arriving at BMRS. For the purpose of identifying possible sources of these compounds, carbon monoxide (CO) emission data taken from the Representative Concentration Pathway 8.5 were used along with NAME footprints to calculate modelled CO mixing ratios. A correlation analysis between the mixing ratios of measured compounds and the modelled CO from various emission sectors was perform to assess the extent to which emission sectors might be related to the mixing ratios of halogenated gases. The results show that the events of higher mixing ratios were associated with air masses, especially from East China. During the 2013/2014 campaign, the modelled CO from industrial, solvents and agriculture (waste burning on fields) were significantly correlated with the mixing ratios of Cl-VSLS (R > 0.7) and methyl halides (R > 0.40). During the 2015/2016 campaign, the strength of these correlations reduced for Cl-VSLS (R > 0.5) and with no significant correlations for methyl halides. Instead, mixing ratios of methyl halides were correlated (R=0.4) with modelled CO from forest burning. This work provides evidence that East and South East Asia act as important sources of halogenated gases. This is of significant given the proximity of these regions to prevalent deep convection which can rapidly transport these halogen-containing gases into the stratosphere and impact the ozone layer

Fate of antibiotic resistance genes in dairy manure treated by anaerobic digestion and composting

The fate of antibiotic resistance genes in anaerobic digestion systems and composting systems is presented from a research review and on-farm study. Generally, higher temperature systems (thermophilic rather than mesophilic) are more capable of reducing AR genes, however other variables play a role and more research is needed. An example of the impact of solid-liquid separation of dairy manure followed by in-vessel rotary drum composting of the separated solids is described from an on-farm study that found significant reduction (greater than 60%) of each of the AR gene copies after the compost treatment.NIFA, USD