Global spatially explicit yield gap time trends reveal regions at risk of future crop yield stagnation.

Yield gaps, here defined as the difference between actual and attainable yields, provide a framework for assessing opportunities to increase agricultural productivity. Previous global assessments, centred on a single year, were unable to identify temporal variation. Here we provide a spatially and temporally comprehensive analysis of yield gaps for ten major crops from 1975 to 2010.

Higher versus lower oxygenation targets in adult ICU patients: A rapid practice guideline.

The aim of this Intensive Care Medicine Rapid Practice Guideline (ICM-RPG) was to provide evidence-based clinical guidance about the use of higher versus lower oxygenation targets for adult patients in the intensive care unit (ICU). The guideline panel comprised 27 international panelists, including content experts, ICU clinicians, methodologists, and patient representatives. We adhered to the methodology for trustworthy clinical practice guidelines, including the use of the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the certainty of evidence, and used the Evidence-to-Decision framework to generate recommendations.

Accounting for herbaceous communities in process-based models will advance our understanding of "grassy" ecosystems.

Grassland and other herbaceous communities cover significant portions of Earth's terrestrial surface and provide many critical services, such as carbon sequestration, wildlife habitat, and food production. Forecasts of global change impacts on these services will require predictive tools, such as process-based dynamic vegetation models. Yet, model representation of herbaceous communities and ecosystems lags substantially behind that of tree communities and forests.

Stomatal behaviour moderates the water cost of CO acquisition for 21 boreal and temperate species under experimental climate change.

The linkage of stomatal behaviour with photosynthesis is critical to understanding water and carbon cycles under global change. The relationship of stomatal conductance (g ) and CO assimilation (A ) across a range of environmental contexts, as represented in the model parameter (g ), has served as a proxy of the marginal water cost of carbon acquisition. We use g to assess species differences in stomatal behaviour to a decade of open-air experimental climate change manipulations, asking whether generalisable patterns exist across species and climate contexts.

Enhanced light interception and light use efficiency explain overyielding in young tree communities.

Diverse plant communities are often more productive than mono-specific ones. Several possible mechanisms underlie this phenomenon but their relative importance remains unknown. Here we investigated whether light interception alone or in combination with light use efficiency (LUE) of dominant and subordinate species explained greater productivity of mixtures relative to monocultures (i.

Prospective, observational study of carbon dioxide gaps and free energy change and their association with fluid therapy following cardiac surgery.

Background Venoarterial carbon dioxide pressure (p CO ) and content (C CO ) differences, including the ratio to arteriovenous oxygen content difference (C O ), and free energy changes (-∆∆G ) may reflect tissue hypoperfusion. The associations with changes in cardiac output (CO) or oxygen consumption (VO ) following fluid bolus administration were investigated. Methods Single-centre, observational study of 89 adult post-operative cardiac surgical patients admitted to ICU.

The effect of systemic corticosteroids on the incidence of gastrointestinal bleeding in critically ill adults: a systematic review with meta-analysis.

Purpose: To assess the effect of systemic corticosteroids on the incidence of gastrointestinal bleeding in adult critically ill patients.

Methods: We systematically reviewed randomised clinical trials comparing systemic corticosteroids administered for more than 24 h with placebo/no treatment in adult critically ill patients. Trial selection, data abstraction and risk of bias assessments were performed in duplicate.

Peculiarly pleasant weather for US maize.

Continuation of historical trends in crop yield are critical to meeting the demands of a growing and more affluent world population. Climate change may compromise our ability to meet these demands, but estimates vary widely, highlighting the importance of understanding historical interactions between yield and climate trends. The relationship between temperature and yield is nuanced, involving differential yield outcomes to warm ([Formula: see text]C) and hot ([Formula: see text]C) temperatures and differing sensitivity across growth phases.

Low-dose corticosteroids for adult patients with septic shock: a systematic review with meta-analysis and trial sequential analysis.

Purpose: To assess the effect of low dose corticosteroids on outcomes in adults with septic shock.

Methods: We systematically reviewed randomised clinical trials (RCTs) comparing low-dose corticosteroids to placebo in adults with septic shock. Trial selection, data abstraction and risk of bias assessment were performed in duplicate.

Implications of improved representations of plant respiration in a changing climate.

Land-atmosphere exchanges influence atmospheric CO. Emphasis has been on describing photosynthetic CO uptake, but less on respiration losses. New global datasets describe upper canopy dark respiration (R ) and temperature dependencies.

Microvascular reactivity, assessed by near-infrared spectroscopy and a vascular occlusion test, is associated with patient outcomes following cardiac surgery: A prospective observational study.

Background: Microvascular dysfunction in patients admitted to the ICU following cardiac surgery may be related to perioperative complications and increased resource utilisation even in the presence of acceptable systemic haemodynamic variables.

Objectives: To assess the relationship between microvascular impairment using peripheral near-infrared spectroscopy at ICU admission and 6 h postadmission and the duration of mechanical ventilatory support, length of stay in ICU and in hospital.

Design: Prospective, observational cohort study.

Fluid Responsiveness After CArdiac Surgery (FRACAS): A Prospective Observational Study Using Peripheral Near-Infrared Spectroscopy.

Objectives: To describe tissue oxygen saturation (StO) in response to a vascular occlusion test using thenar eminence and forearm near-infrared spectroscopy (NIRS) and the association with volume responsiveness after cardiac surgery.

Design: Single-center, prospective, observational cohort study.

Setting: Cardiothoracic intensive care unit.

Random Forests for Global and Regional Crop Yield Predictions.

Accurate predictions of crop yield are critical for developing effective agricultural and food policies at the regional and global scales. We evaluated a machine-learning method, Random Forests (RF), for its ability to predict crop yield responses to climate and biophysical variables at global and regional scales in wheat, maize, and potato in comparison with multiple linear regressions (MLR) serving as a benchmark. We used crop yield data from various sources and regions for model training and testing: 1) gridded global wheat grain yield, 2) maize grain yield from US counties over thirty years, and 3) potato tuber and maize silage yield from the northeastern seaboard region.

Exploiting multi-layered vector spaces for signal peptide detection.

Analysing and classifying sequences based on similarities and differences is a mathematical problem of escalating relevance and importance in many scientific disciplines. One of the primary challenges in applying machine learning algorithms to sequential data, such as biological sequences, is the extraction and representation of significant features from the data. To address this problem, we have recently developed a representation, entitled Multi-Layered Vector Spaces (MLVS), which is a simple mathematical model that maps sequences into a set of MLVS.

Asian archaeology. Comment on "Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 B.P. ".

Chen et al. (Reports, 16 January 2015, p. 248) argued that early Tibetan agriculturalists pushed the limits of farming up to 4000 meters above sea level.

Stalling the engine of resistance: targeting cancer metabolism to overcome therapeutic resistance.

Cancer cells are markedly different from normal cells with regards to how their metabolic pathways are used to fuel cellular growth and survival. Two basic metabolites that exemplify these differences through increased uptake and altered metabolic usage are glucose and glutamine. These molecules can be catabolized to manufacture many of the building blocks required for active cell growth and proliferation.

Structural basis of cooperative ligand binding by the glycine riboswitch.

The glycine riboswitch regulates gene expression through the cooperative recognition of its amino acid ligand by a tandem pair of aptamers. A 3.6 Å crystal structure of the tandem riboswitch from the glycine permease operon of Fusobacterium nucleatum reveals the glycine binding sites and an extensive network of interactions, largely mediated by asymmetric A-minor contacts, that serve to communicate ligand binding status between the aptamers.

Regiospecificity of the peptidyl tRNA ester within the ribosomal P site.

The ribosomal peptidyl transferase center is expected to be regiospecific with regard to its tRNA substrates, yet the ester linkages between the tRNA and the amino acid or peptide are susceptible to isomerization between the O2' and O3' hydroxyls of the terminal A76 ribose sugar. To establish which isomer of the P site tRNA ester is utilized by the ribosome, we prepared two nonisomerizable transition state inhibitors with either an A76 O2' or O3' linkage. Strong preferential binding to the O3' regioisomer indicates that the peptidyl transferase proceeds through a transition state with an O3'-linked peptide in the P-site.