Tidal pressurization of the ocean cavity near an Antarctic ice shelf grounding line

Mass loss from the Antarctic ice sheet is sensitive to conditions in ice shelf grounding zones, the transition between grounded and floating ice. To observe tidal dynamics in the grounding zone, we moored an ocean pressure sensor to Ross Ice Shelf, recording data for 54 days. In this region the ice shelf is brought out of hydrostatic equilibrium by the flexural rigidity of ice, yet we found that tidal pressure variations at a constant geopotential surface were similar within and outside of the grounding zone. This implies that the grounding zone ocean cavity was overpressurized at high tide and underpressurized at low tide by up to 10 kPa with respect to glaciostatic pressure at the ice shelf base. Phase lags between ocean pressure and vertical ice shelf motion were tens of minutes for diurnal and semidiurnal tides, an effect that has not been incorporated into ocean models of tidal currents below ice shelves. These tidal pressure variations may affect the production and export of meltwater in the subglacial environment and may increase basal crevasse heights in the grounding zone by several meters, according to linear elastic fracture mechanics. We find anomalously high tidal energy loss at the K1 constituent in the grounding zone and hypothesize that this could be explained by seawater injection into the subglacial environment at high tide or internal tide generation through interactions with topography. These observations lay the foundation for improved representation of the grounding zone and its tidal dynamics in ocean circulation models of sub–ice shelf cavities

Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone

Ocean‐driven melting of ice shelves is a primary mechanism for ice loss from Antarctica. However, due to the difficulty in accessing the sub‐ice shelf ocean cavity, the relationship between ice shelf melting and ocean conditions is poorly understood, particularly near the grounding zone, where the ice transitions from grounded to floating. We present the first borehole oceanographic observations from the grounding zone of the Ross Ice Shelf, Antarctica's largest ice shelf by area. Contrary to predictions that tidal currents near grounding zones mix the water column, we found that Ross Ice Shelf waters were vertically stratified. Current velocities at middepth in the ocean cavity did not change significantly over measurement periods at two different parts of the tidal cycle. The observed stratification resulted in low melt rates near this portion of the grounding zone, inferred from phase‐sensitive radar observations. These melt rates were generally <10 cm/year, which is lower than average for the Ross Ice Shelf (∼20 cm/year). Melt rates may be higher at portions of the grounding zone that experience higher subglacial discharge or stronger tidal mixing. Stratification in the cavity at the borehole site was prone to diffusive convection as a result of ice shelf melting. Since diffusive convection influences vertical heat and salt fluxes differently than shear‐driven turbulence, this process may affect ice shelf melting and merits further consideration in ocean models of sub‐ice shelf circulation

Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo

Ice surface albedo is a primary modulator of melt and runoff, yet our understanding of how reflectance varies over time across the Greenland Ice Sheet remains poor. This is due to a disconnect between point or transect scale albedo sampling and the coarser spatial, spectral and/or temporal resolutions of available satellite products. Here, we present time-series of bare-ice surface reflectance data that span a range of length scales, from the 500 m for Moderate Resolution Imaging Spectrometer’s MOD10A1 product, to 10 m for Sentinel-2 imagery, 0.1 m spot measurements from ground-based field spectrometry, and 2.5 cm from uncrewed aerial drone imagery. Our results reveal broad similarities in seasonal patterns in bare-ice reflectance, but further analysis identifies short-term dynamics in reflectance distribution that are unique to each dataset. Using these distributions, we demonstrate that areal mean reflectance is the primary control on local ablation rates, and that the spatial distribution of specific ice types and impurities is secondary. Given the rapid changes in mean reflectance observed in the datasets presented, we propose that albedo parameterizations can be improved by (i) quantitative assessment of the representativeness of time-averaged reflectance data products, and, (ii) using temporally-resolved functions to describe the variability in impurity distribution at daily time-scales. We conclude that the regional melt model performance may not be optimally improved by increased spatial resolution and the incorporation of sub-pixel heterogeneity, but instead, should focus on the temporal dynamics of bare-ice albedo

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Sustainable Urban Systems: Co-design and Framing for Transformation

Rapid urbanisation generates risks and opportunities for sustainable development. Urban policy and decision makers are challenged by the complexity of cities as social–ecological–technical systems. Consequently there is an increasing need for collaborative knowledge development that supports a whole-of-system view, and transformational change at multiple scales. Such holistic urban approaches are rare in practice. A co-design process involving researchers, practitioners and other stakeholders, has progressed such an approach in the Australian context, aiming to also contribute to international knowledge development and sharing. This process has generated three outputs: (1) a shared framework to support more systematic knowledge development and use, (2) identification of barriers that create a gap between stated urban goals and actual practice, and (3) identification of strategic focal areas to address this gap. Developing integrated strategies at broader urban scales is seen as the most pressing need. The knowledge framework adopts a systems perspective that incorporates the many urban trade-offs and synergies revealed by a systems view. Broader implications are drawn for policy and decision makers, for researchers and for a shared forward agenda

Service delivery and intervention intensity for phonology-based speech sound disorders

Background: When planning evidence-based intervention services for children with phonology-based speech sound disorders (SSD), speech and language therapists (SLTs) need to integrate research evidence regarding service delivery and intervention intensity within their clinical practice. However, relatively little is known about the optimal intensity of phonological interventions and whether SLTs’ services align with the research evidence.Aims: The aims are twofold. First, to review external evidence (i.e., empirical research evidence external to day-today clinical practice) regarding service delivery and intervention intensity for phonological interventions. Second,to investigate SLTs’ clinical practice with children with phonology-based SSD in Australia, focusing on service delivery and intensity. By considering these complementary sources of evidence, SLTs and researchers will be better placed to understand the state of the external evidence regarding the delivery of phonological interventions and appreciate the challenges facing SLTs in providing evidence-based services.Methods & Procedures: Two studies are presented. The first is a review of phonological intervention research published between 1979 and 2016. Details regarding service delivery and intervention intensity were extractedfrom the 199 papers that met inclusion criteria identified through a systematic search. The second study was an online survey of 288 SLTs working in Australia, focused on the service delivery and intensity of intervention provided in clinical practice.Main Contributions: There is a gap between the external evidence regarding service delivery and intervention intensity and the internal evidence from clinical practice. Most published intervention research has reported toprovide intervention two to three times per week in individual sessions delivered by an SLT in a university clinic, in sessions lasting 30–60 min comprising 100 production trials. SLTs reported providing services at intensities below that found in the literature. Further, they reported workplace, client and clinician factors that influenced the intensity of intervention they were able to provide to children with phonology-based SSD.Conclusions & Implications: Insufficient detail in the reporting of intervention intensity within published research coupled with service delivery constraints may affect the implementation of empirical evidence into everyday clinical practice. Research investigating innovative solutions to service delivery challenges is needed to provide SLTs with evidence that is relevant and feasible for clinical practice

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery

Recommendations to reduce inequalities for LGBT people facing advanced illness : ACCESSCare national qualitative interview study

This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (http://www.creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).BACKGROUND: Lesbian, gay, bisexual and/or trans (LGBT) people have higher risk of certain life-limiting illnesses and unmet needs in advanced illness and bereavement. ACCESSCare is the first national study to examine in depth the experiences of LGBT people facing advanced illness. AIM: To explore health-care experiences of LGBT people facing advanced illness to elicit views regarding sharing identity (sexual orientation/gender history), accessing services, discrimination/exclusion and best-practice examples. DESIGN: Semi-structured in-depth qualitative interviews analysed using thematic analysis. SETTING/PARTICIPANTS: In total, 40 LGBT people from across the United Kingdom facing advanced illness: cancer ( n = 21), non-cancer ( n = 16) and both a cancer and a non-cancer conditions ( n = 3). RESULTS: In total, five main themes emerged: (1) person-centred care needs that may require additional/different consideration for LGBT people (including different social support structures and additional legal concerns), (2) service level or interactional (created in the consultation) barriers/stressors (including heteronormative assumptions and homophobic/transphobic behaviours), (3) invisible barriers/stressors (including the historical context of pathology/criminalisation, fears and experiences of discrimination) and (4) service level or interactional facilitators (including acknowledging and including partners in critical discussions). These all shape (5) individuals' preferences for disclosing identity. Prior experiences of discrimination or violence, in response to disclosure, were carried into future care interactions and heightened with the frailty of advanced illness. CONCLUSION: Despite recent legislative change, experiences of discrimination and exclusion in health care persist for LGBT people. Ten recommendations, for health-care professionals and services/institutions, are made from the data. These are simple, low cost and offer potential gains in access to, and outcomes of, care for LGBT people.Peer reviewedFinal Published versio