Stratospheric ozone and Southern Hemisphere climate change:impacts and robustness in CMIP5 models

Stratospheric ozone depletion is thought to be the dominant cause of recent observed southern hemisphere (SH) circulation changes during austral summer, along with the consequential impacts on tropospheric climate conditions. Links between ozone depletion and the positive phase of the dominant mode of variability of the southern annular mode (SAM) have been found, which in turn are linked to changes in precipitation, atmospheric temperatures and winds. This dissertation investigates how well the models from the most recent Coupled Model Intercomparison Project (CMIP5) represent these changes and searches for consistencies and differences across the models. Comparisons are made with the reanalysis data set ERA-Interim. It is found that the magnitudes of the model trends vary dramatically across the CMIP5 ensemble, although between 1960-2000 all models have decreasing austral spring stratospheric ozone and November temperatures and increasing austral summer SAM trends. Across the CMIP5 models, the strength of the SAM trend is only loosely related to the strength of the stratospheric ozone trend, and this relationship does not always hold. There are changes in precipitation and surface temperatures that are significantly related to the SAM, with bands of increasing and decreasing trends across the SH, likely as a result of the poleward shift in storm tracks. However the magnitude and location of regional changes in surface climate that can be attributed to the SAM differ considerably across the models. For correlations of the SAM with both precipitation and surface temperatures, the models underestimate the correlation over southern Africa and are relatively good representations of Antarctica when compared to reanalysis data

The Effects of the Internal Control Opinion and Use of Audit Data Analytics on Perceptions of Audit Quality, Assurance, and Auditor Negligence

Advanced audit data analytics tools allow auditors to analyze the entire population of accessible client transactions. Though this approach has measurable benefits for audit efficiency and effectiveness, auditors caution that it does not incrementally increase the level of assurance they can provide relative to the fair presentation of the financial statements. We experimentally examine whether the audit testing methodology (audit data analytics versus traditional sampling) and the type of internal control (ICFR) opinion auditors issue (unqualified versus adverse) are signals of audit quality that affect jurors’ perceptions of auditor negligence after an audit failure. We predict and find that jurors’ perceptions of auditors’ personal control over the audit failure influence their assessment of negligence. We also find that when auditors issue an unqualified ICFR opinion, jurors make higher negligence assessments when auditors employ traditional statistical sampling techniques than when they employ audit data analytics. Lastly, we find that when auditors issue an adverse ICFR opinion, jurors attribute less blame to auditors and correspondingly more blame to management and the investor for an audit failure. Our study informs regulators, practitioners, and academics about the contextual effects of the ICFR opinion as well as the perceived assurance and potential litigation effects of using advanced technological tools in the audit

Teaching in groups in grade III.

Thesis (Ed.M.)--Boston University N.B.:Pages 28, 144 and 145 are missing from original thesis

ZAP: The role of routine surveillance data in understanding the geography and timing of Salmonella on UK pig farms.

The Zoonoses Action Plan (ZAP), at its inception m 2002, sought to reduce prevalence of Salmonella mfection 1n quality assured p1gs at slaughter by 25% within three years. Salmonella levels are monitored by Meat Juice ELISA tests on samples from individual pigs and aggregated to indicate farm-level Salmonella status. By combining the ZAP scheme and quality assurance scheme datasets we generated a large geographically referenced data set which allows us to investigate aspects of the spatial and temporal epidemiology of Salmonella on GB pig farms. We seek in this study to address two questions. First, is there evidence that Salmonella in GB pigs vanes seasonally? Secondly, do close farms tend to have similar levels of Salmonella? We suggest explanations for spatial and temporal effects where evidenced. Knowledge of seasons or GB regions which have atypically high Salmonella risk informs the design of control strategies

Radiocarbon releases from the 2011 Fukushima nuclear accident

Radiocarbon activities were measured in annual tree rings for the years 2009 to 2015 from Japanese cedar trees (Cryptomeria japonica) collected at six sites ranging from 2.5–38 km northwest and north of the Fukushima Dai-ichi nuclear power plant. The 14C specific activity varied from 280.4 Bq kg−1 C in 2010 to 226.0 Bq kg−1 C in 2015. The elevated 14C activities in the 2009 and 2010 rings confirmed 14C discharges during routine reactor operations, whereas those activities that were indistinguishable from background in 2012–2015 coincided with the permanent shutdown of the reactors after the accident in 2011. High-resolution 14C analysis of the 2011 ring indicated 14C releases during the Fukushima accident. The resulted 14C activity decreased with increasing distance from the plant. The maximum 14C activity released during the period of the accident was measured 42.4 Bq kg−1 C above the natural ambient 14C background. Our findings indicate that, unlike other Fukushima-derived radionuclides, the 14C released during the accident is indistinguishable from ambient background beyond the local environment (~30 km from the plant). Furthermore, the resulting dose to the local population from the excess 14C activities is negligible compared to the dose from natural/nuclear weapons sources

Presenting video recordings of newborn resuscitations in debriefings for teamwork training

Background: The Neonatal Resuscitation Program (NRP) and similar courses have been used to train clinicians. However, formal teamwork training was not included in these courses, and their effectiveness has been questioned. In adult resuscitation, debriefings using video recordings have improved outcomes, but recordings of neonatal resuscitation have been used primarily for research