Modeling canopy-induced turbulence in the Earth system: a unified parameterization of turbulent exchange within plant canopies and the roughness sublayer (CLM-ml v0)

Land surface models used in climate models neglect the roughness sublayer and parameterize within-canopy turbulence in an ad hoc manner. We implemented a roughness sublayer turbulence parameterization in a multilayer canopy model (CLM-ml v0) to test if this theory provides a tractable parameterization extending from the ground through the canopy and the roughness sublayer. We compared the canopy model with the Community Land Model (CLM4.5) at seven forest, two grassland, and three cropland AmeriFlux sites over a range of canopy heights, leaf area indexes, and climates. CLM4.5 has pronounced biases during summer months at forest sites in midday latent heat flux, sensible heat flux, gross primary production, nighttime friction velocity, and the radiative temperature diurnal range. The new canopy model reduces these biases by introducing new physics. Advances in modeling stomatal conductance and canopy physiology beyond what is in CLM4.5 substantially improve model performance at the forest sites. The signature of the roughness sublayer is most evident in nighttime friction velocity and the diurnal cycle of radiative temperature, but is also seen in sensible heat flux. Within-canopy temperature profiles are markedly different compared with profiles obtained using Monin–Obukhov similarity theory, and the roughness sublayer produces cooler daytime and warmer nighttime temperatures. The herbaceous sites also show model improvements, but the improvements are related less systematically to the roughness sublayer parameterization in these canopies. The multilayer canopy with the roughness sublayer turbulence improves simulations compared with CLM4.5 while also advancing the theoretical basis for surface flux parameterizations

Short-Communication: Ingestion of a Nucleotide-Rich Mixed Meal Increases Serum Uric Acid Concentrations but Does Not Affect Postprandial Blood Glucose or Serum Insulin Responses in Young Adults

Circulating uric acid concentrations have been linked to various metabolic diseases. Consumption of large boluses of nucleotides increases serum uric acid concentrations. We investigated the effect of a nucleotide-rich mixed meal on postprandial circulating uric acid, glucose, and insulin responses. Ten healthy adults participated in a randomised, controlled, double-blind, crossover trial in which they consumed a mixed-meal containing either nucleotide-depleted mycoprotein (L-NU) or high-nucleotide mycoprotein (H-NU) on two separate visits. Blood samples were collected in the postabsorptive state and throughout a 24 h postprandial period, and were used to determine circulating uric acid, glucose, and insulin concentrations. Mixed meal ingestion had divergent effects on serum uric acid concentrations across conditions (time x condition interaction; P < 0.001), with L-NU decreasing transiently (from 45 to 240 min postprandially) by ~7% (from 279 ± 16 to 257 ± 14 µmol·L -1) and H-NU resulting in a ~12% increase (from 284 ± 13 to 319 ± 12 µmol·L -1 after 210 min), remaining elevated for 12 h and returning to baseline concentrations after 24 h. There were no differences between conditions in blood glucose or serum insulin responses, nor in indices of insulin sensitivity. The ingestion of a nucleotide-rich mixed-meal increases serum uric acid concentrations for ~12 h, but does not influence postprandial blood glucose or serum insulin concentrations

Field observations of canopy flows over complex terrain

The investigation of airflow over and within forests in complex terrain has been, until recently, limited to a handful of modelling and laboratory studies. Here, we present an observational dataset of airflow measurements inside and above a forest situated on a ridge on the Isle of Arran, Scotland. The spatial coverage of the observations all the way across the ridge makes this a unique dataset. Two case studies of across-ridge flow under near-neutral conditions are presented and compared with recent idealized two-dimensional modelling studies. Changes in the canopy profiles of both mean wind and turbulent quantities across the ridge are broadly consistent with these idealized studies. Flow separation over the lee slope is seen as a ubiquitous feature of the flow. The three-dimensional nature of the terrain and the heterogeneous forest canopy does however lead to significant variations in the flow separation across the ridge, particularly over the less steep western slope. Furthermore, strong directional shear with height in regions of flow separation has a significant impact on the Reynolds stress terms and other turbulent statistics. Also observed is a decrease in the variability of the wind speed over the summit and lee slope, which has not been seen in previous studies. This dataset should provide a valuable resource for validating models of canopy flow over real, complex terrain

Efficacy and tolerability of an endogenous metabolic modulator (AXA1125) in fatigue-predominant long COVID: a single-centre, double-blind, randomised controlled phase 2a pilot study

Background: ‘Long COVID’ describes persistent symptoms, commonly fatigue, lasting beyond 12 weeks following SARS-CoV-2 infection. Potential causes include reduced mitochondrial function and cellular bioenergetics. AXA1125 has previously increased β-oxidation and improved bioenergetics in preclinical models along with certain clinical conditions, and therefore may reduce fatigue associated with Long COVID. We aimed to assess the efficacy, safety and tolerability of AXA1125 in Long COVID. / Methods: Patients with fatigue dominant Long COVID were recruited in this single-centre, double-blind, randomised controlled phase 2a pilot study completed in the UK. Patients were randomly assigned (1:1) using an Interactive Response Technology to receive either AXA1125 or matching placebo in a clinical based setting. Each dose (33.9 g) of AXA1125 or placebo was administered orally in a liquid suspension twice daily for four weeks with a two week follow-up period. The primary endpoint was the mean change from baseline to day 28 in the phosphocreatine (PCr) recovery rate following moderate exercise, assessed by 31P-magnetic resonance spectroscopy (MRS). All patients were included in the intention to treat analysis. This trial was registered at ClinicalTrials.gov, NCT05152849. / Findings: Between December 15th 2021, and May 23th 2022, 60 participants were screened and 41 participants were randomised and included in the final analysis. Changes in skeletal muscle phosphocreatine recovery time constant (τPCr) and 6-min walk test (6MWT) did not significantly differ between treatment (n = 21) and placebo group (n = 20). However, treatment with AXA1125 was associated with significantly reduced day 28 Chalder Fatigue Questionnaire [CFQ-11] fatigue score when compared with placebo (least squares mean difference [LSMD] −4.30, 95% confidence interval (95% CI) −7.14, −1.47; P = 0.0039). Eleven (52.4%, AXA1125) and four (20.0%, placebo) patients reported treatment-emergent adverse events; none were serious, or led to treatment discontinuation. / Interpretation: Although treatment with AXA1125 did not improve the primary endpoint (τPCr-measure of mitochondrial respiration), when compared to placebo, there was a significant improvement in fatigue-based symptoms among patients living with Long COVID following a four week treatment period. Further multicentre studies are needed to validate our findings in a larger cohort of patients with fatigue-dominant Long COVID. / Funding: Axcella Therapeutics

Field evidence for the upwind velocity shift at the crest of low dunes

Wind topographically forced by hills and sand dunes accelerates on the upwind (stoss) slopes and reduces on the downwind (lee) slopes. This secondary wind regime, however, possesses a subtle effect, reported here for the first time from field measurements of near-surface wind velocity over a low dune: the wind velocity close to the surface reaches its maximum upwind of the crest. Our field-measured data show that this upwind phase shift of velocity with respect to topography is found to be in quantitative agreement with the prediction of hydrodynamical linear analysis for turbulent flows with first order closures. This effect, together with sand transport spatial relaxation, is at the origin of the mechanisms of dune initiation, instability and growth.Comment: 13 pages, 6 figures. Version accepted for publication in Boundary-Layer Meteorolog

The Early Years

Policy concentration on the early years is of vital importance for the wellbeing of children now and for their future health outcomes and life chances. Evidence-based research points to the need for a focus that is properly holistic and to precipitate intervention to promote a healthy diet, regular patterns of activity and rest and give children the best start in life. In 2005, The United Nations Committee on the Rights of the Child (General Comment No. 7) acknowledged the need for a fresh strategy, pinpointing research findings indicating that a failure to prioritise early years’ welfare exposes children to the ills of ‘malnutrition, disease, poverty, neglect, social exclusion and a range of other adversities.’ Professor Dame Sally Davies, Chief Medical Officer of the United Kingdom, considers that robust early years’ policies make both social and economic sense: ‘Too many children and young people do not have the start in life they need, leading to high costs for society, and too many affected lives’ (Forward to ‘The 1001 Critical Days’, June 16th 2014). This observation is significant because there remains much to do. In 2012, the NSPCC reviewed the United Kingdom policy scenario for babies and very young children and concluded that identifiable advances in maternity and early years’ provision did not detract from the fact that: ‘babies are still particularly vulnerable’ and ‘their rights are not always recognised or realised’. (‘All Babies Count – But what about their rights?’ Sally Knock and Lorriann Robinson, January 2012). Knock and Robinson highlight glaring gaps of support and provision – especially in maternity services whereby the fostering of a strong parent-child bond is invariably sacrificed to a concentration upon purely medical practicalities such as labour, birth and the immunisation programme. The All Party Group on a Fit and Healthy Childhood aims, in this report, to offer the incoming Government recommendations for an early years’ strategy that are credible, feasible and evidence-based and will enable the United Kingdom to set the standard in a crucial policy field both at home and abroad. In defining ‘early childhood’, we follow the example of The United Nations (2005) Convention on the Right of the Child by examining the period of 0-8 including, as it does, the vital transition phase from pre-school to primary school. We consider the antenatal period and maternal physical and mental health, methods of feeding the newborn, parental support services both hospital and home-based and infant nutrition and socioeconomic factors that may impact upon the health and wellbeing of young children. The report examines the optimum balance between sleep, rest and activity, the need for freely-chosen play, safeguarding measures and the importance of respecting cultural diversity in all early years’ settings. Above all, we analyse the relationship between young families and the professionals whose role it is to ensure that babies have the very best start in life, supported by parents who have confidence in the choices that they make and the advice that they are given. Just as new families require mentoring so that they can act in the best interests of their children, so the early years’ workforce needs training and continuous professional development to ensure that the advice given is of the highest possible quality and specifically tailored to the individual family. Early Years’ students from The University of Northampton (interviewed) explain what a positive difference their newly acquired knowledge has made to their performance in the settings and Government recognition of The Early Years as a developmental stage in its own right and the creation of the new posts of Early Years Teacher and Early Years Educator have been positive. Yet as the Ilkeston ‘Mums Group’ (interviewed) makes clear, there is still no guarantee of uniform excellence in the delivery of services nationwide and no assurance of continuity between, for example, advice on feeding from the midwife and the health visitor, or the emphasis put on freely-chosen play in an early years’ setting and a primary school. If young children are to thrive, we believe it is essential that there is a national consensus and political will behind multi-disciplinary working in the early years. We see the early years as a window of opportunity and make no apology for the fact that each section of this report is accompanied by many policy recommendations. It has not been possible to produce a uniform handful of ‘asks’, just as the early years itself is a rich, complex and multifarious developmental phase. However, neither do we consider it to be feasible to achieve everything that we recommend in the lifespan of a single Government. This is a two, even three term journey. However, if the nation’s families and the early years workforce are to embark upon it, the Government must be prepared to provide the resources; the Cabinet Minister for Children and Families, the commitment to multi-disciplinary co-operation to achieve an early years workforce that is truly ‘joined up’ and, above all, the finance to make well–intentioned aspiration a reality. In an age of austerity, by spending early, the later savings to education, health, social or criminal justice services will be immense. Investing in the children of today is not a gambl

Modelling Canopy Flows over Complex Terrain

Recent studies of flow over forested hills have been motivated by a number of important applications including understanding CO22 and other gaseous fluxes over forests in complex terrain, predicting wind damage to trees, and modelling wind energy potential at forested sites. Current modelling studies have focussed almost exclusively on highly idealized, and usually fully forested, hills. Here, we present model results for a site on the Isle of Arran, Scotland with complex terrain and heterogeneous forest canopy. The model uses an explicit representation of the canopy and a 1.5-order turbulence closure for flow within and above the canopy. The validity of the closure scheme is assessed using turbulence data from a field experiment before comparing predictions of the full model with field observations. For near-neutral stability, the results compare well with the observations, showing that such a relatively simple canopy model can accurately reproduce the flow patterns observed over complex terrain and realistic, variable forest cover, while at the same time remaining computationally feasible for real case studies. The model allows closer examination of the flow separation observed over complex forested terrain. Comparisons with model simulations using a roughness length parametrization show significant differences, particularly with respect to flow separation, highlighting the need to explicitly model the forest canopy if detailed predictions of near-surface flow around forests are required

Systematic review of safety checklists for use by medical care teams in acute hospital settings - limited evidence of effectiveness

<p>Abstract</p> <p>Background</p> <p>Patient safety is a fundamental component of good quality health care. Checklists have been proposed as a method of improving patient safety. This systematic review, asked "In acute hospital settings, would the use of safety checklists applied by medical care teams, compared to not using checklists, improve patient safety?"</p> <p>Methods</p> <p>We searched the Cochrane Library, MEDLINE, CINAHL, and EMBASE for randomised controlled trials published in English before September 2009. Studies were selected and appraised by two reviewers independently in consultation with colleagues, using inclusion, exclusion and appraisal criteria established a priori.</p> <p>Results</p> <p>Nine cohort studies with historical controls studies from four hospital care settings were included-intensive care unit, emergency department, surgery, and acute care. The studies used a variety of designs of safety checklists, and implemented them in different ways, however most incorporated an educational component to teach the staff how to use the checklist. The studies assessed outcomes occurring a few weeks to a maximum of 12 months post-implementation, and these outcomes were diverse.</p> <p>The studies were generally of low to moderate quality and of low levels of evidence, with all but one of the studies containing a high risk of bias.</p> <p>The results of these studies suggest some improvements in patient safety arising from use of safety checklists, but these were not consistent across all studies or for all outcomes. Some studies showed no difference in outcomes between checklist use and standard care without a checklist. Due to the variations in setting, checklist design, educational training given, and outcomes measured, it was unfeasible to accurately summarise any trends across all studies.</p> <p>Conclusions</p> <p>The included studies suggest some benefits of using safety checklists to improve protocol adherence and patient safety, but due to the risk of bias in these studies, their results should be interpreted with caution. More high quality and studies, are needed to enable confident conclusions about the effectiveness of safety checklists in acute hospital settings.</p