Geochemical and helium isotopic variability within the Lau Basin

This research incorporates geochemical and helium isotopic analyses of Lau Basin volcanic glasses, along with helium isotopic analyses of water column hydrothermal plumes to better understand the processes that control the formation and evolution of this backarc basin. Lavas newly collected from the four southernmost segments of the Valu Fa Ridge (VFR) reveal gradients in element ratios such as Ba/Nb along axis over the 75 km length of the study area, and show an increase in arc-like geochemical signature to the south. Basalts from the VFR segments and the off-axis volcanoes are derived by 10–20% melting of a source that was previously melted 0.5–1.5% in association with arc volcanism. Melt fraction increases southwards along axis from ~10–15% and ranges up to 20% for the seamounts. 3He/4He ratios in glasses along the Eastern Lau Spreading Center (ELSC), from 20º–22º45’S, reveal an along-axis gradient. 3He/4He decreases from 9.6 RA in basalts at the Intermediate Lau Spreading Center-Eastern Lau Spreading Center transition, to 5.4 RA in low silica lavas at the southern end of the VFR. The decrease in the maximum 3He/4He towards the south is ascribed to mantle heterogeneity. The increased variability in 3He/4He along the VFR is due to processes occurring during prolonged residence of magma in the crust prior to eruption. Basalt 3He/4He values are similar to those measured from high-temperature vent fluids in the same region (Proskurowski et al., 2006). Neutrally buoyant plumes with detectable 3He anomalies (δ3He=65–70%) were present in all of the areas sampled, indicating an abundance of hydrothermal activity along the ELSC. Buoyant plumes with higher δ3He (100–225%) were sampled at two of the target areas. The δ3He anomalies revealed by the hydrocast profiles are ~200 m thick at each site. The depth of the neutrally buoyant hydrothermal plumes shallows from 2300–2600 m in the north to 1600–1800 m in the south. This change occurs in conjunction with the shallowing of the ELSC ridge axis, which is further enhanced by a transition in ridge morphology from axial valley to axial high at 20º 30’S. 3He/heat ratios of 1–2.8×10-17 mol J-1 are calculated for the neutrally buoyant plumes, while lower values of 0.8×10-17 mol J-1 are calculated for the buoyant plumes. These values are similar to those observed in vent fluids sampled from relatively mature hydrothermal systems along mid-ocean ridges (e.g., EPR at 21ºN, Cleft segment of the Juan de Fuca Ridge and TAG at 26ºN along the MAR), and about an order of magnitude less than values observed over young lava flows from recently perturbed magmatic systems.Keywords: Lau Basin, helium isotopes, backarc basin, geochemistr

Challenges and innovations in the economic evaluation of the risks of climate change

A large discrepancy exists between the dire impacts that most natural scientists project we could face from climate change and the modest estimates of damages calculated by mainstream economists. Economic assessments of climate change risks are intended to be comprehensive, covering the full range of physical impacts and their associated market and non-market costs, considering the greater vulnerability of poor people and the challenges of adaptation. Available estimates still fall significantly short of this goal, but alternative approaches that have been proposed attempt to address these gaps. This review seeks to provide a common basis for natural scientists, social scientists, and modellers to understand the research challenges involved in evaluating the economic risks of climate change. Focusing on the estimation processes embedded in economic integrated assessment models and the concerns raised in the literature, we summarise the frontiers of research relevant to improving quantitative damage estimates, representing the full complexity of the associated systems, and evaluating the impact of the various economic assumptions used to manage this complexity

Snacktivity™ to promote physical activity and reduce future risk of disease in the population: protocol for a feasibility randomised controlled trial and nested qualitative study

Background: Many people do not regularly participate in physical activity, which may negatively impact their health. Current physical activity guidelines are focused on promoting weekly accumulation of at least 150 min of moderate to vigorous intensity physical activity (MVPA). Whilst revised guidance now recognises the importance of making small changes to physical activity behaviour, guidance still focuses on adults needing to achieve at least 150 min of MVPA per week. An alternative ‘whole day’ approach that could motivate the public to be more physically active, is a concept called Snacktivity™. Instead of focusing on achieving 150 min per week of physical activity, for example 30 min of MVPA over 5 days, Snacktivity™ encourages the public to achieve this through small, but frequent, 2–5 min ‘snacks’ of MVPA throughout the whole day. Methods: The primary aim is to undertake a feasibility trial with nested qualitative interviews to assess the feasibility and acceptability of the Snacktivity™ intervention to inform the design of a subsequent phase III randomised trial. A two-arm randomised controlled feasibility trial aiming to recruit 80 inactive adults will be conducted. Recruitment will be from health and community settings and social media. Participants will be individually randomised (1:1 ratio) to receive either the Snacktivity™ intervention or usual care. The intervention will last 12 weeks with assessment of outcomes completed before and after the intervention in all participants. We are interested in whether the Snacktivity™ trial is appealing to participants (assessed by the recruitment rate) and if the Snacktivity™ intervention and trial methods are acceptable to participants (assessed by Snacktivity™/physical activity adherence and retention rates). The intervention will be delivered by health care providers within health care consultations or by researchers. Participants’ experiences of the trial and intervention, and health care providers’ views of delivering the intervention within health consultations will be explored. Discussion: The development of physical activity interventions that can be delivered at scale are needed. The findings from this study will inform the viability and design of a phase III trial to assess the effectiveness and cost-effectiveness of Snacktivity™ to increase physical activity. Trial registration: ISRCTN: 64851242

The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients

Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

Prediction of surgical site infections using spectrophotometry

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Perceptions Of Prospective Elementary Teachers Regarding Their Preparation In Health Education.

PhDTeacher educationUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/185670/2/6101751.pd

P047. Drain usage and associated complications in mastectomies and axillary clearance during the 2020 COVID-19 Pandemic

Supports Open AccessPublished version, accepted version (12 month embargo