Ecologically Different Fungi Affect Arabidopsis Development: Contribution of Soluble and Volatile Compounds

<div><p>Plant growth and development can be influenced by mutualistic and non-mutualistic microorganisms. We investigated the ability of the ericoid endomycorrhizal fungus <i>Oidiodendron maius</i> to influence growth and development of the non-host plant <i>Arabidopsis thaliana</i>. Different experimental setups (non-compartmented and compartmented co-culture plates) were used to investigate the influence of both soluble and volatile fungal molecules on the plant phenotype. <i>O</i>. <i>maius</i> promoted growth of <i>A</i>. <i>thaliana</i> in all experimental setups. In addition, a peculiar clumped root phenotype, characterized by shortening of the primary root and by an increase of lateral root length and number, was observed in <i>A</i>. <i>thaliana</i> only in the non-compartmented plates, suggesting that soluble diffusible molecules are responsible for this root morphology. Fungal auxin does not seem to be involved in plant growth promotion and in the clumped root phenotype because co-cultivation with <i>O</i>. <i>maius</i> did not change auxin accumulation in plant tissues, as assessed in plants carrying the DR5::GUS reporter construct. In addition, no correlation between the amount of fungal auxin produced and the plant root phenotype was observed in an <i>O</i>. <i>maius</i> mutant unable to induce the clumped root phenotype in <i>A</i>. <i>thaliana</i>. Addition of active charcoal, a VOC absorbant, in the compartmented plates did not modify plant growth promotion, suggesting that VOCs are not involved in this phenomenon. The low VOCs emission measured for <i>O</i>. <i>maius</i> further corroborated this hypothesis. By contrast, the addition of CO₂ traps in the compartmented plates drastically reduced plant growth, suggesting involvement of fungal CO₂ in plant growth promotion. Other mycorrhizal fungi, as well as a saprotrophic and a pathogenic fungus, were also tested with the same experimental setups. In the non-compartmented plates, most fungi promoted <i>A</i>. <i>thaliana</i> growth and some could induce the clumped root phenotype. In the compartmented plate experiments, a general induction of plant growth was observed for most other fungi, especially those producing higher biomass, further strengthening the role of a nonspecific mechanism, such as CO₂ emission.</p></div

Individual-environment interactions in swimming: The smallest unit for analysing the emergence of coordination dynamics in performance?

Displacement in competitive swimming is highly dependent on fluid characteristics, since athletes use these properties to propel themselves. It is essential for sport scientists and practitioners to clearly identify the interactions that emerge between each individual swimmer and properties of an aquatic environment. Traditionally, the two protagonists in these interactions have been studied separately. Determining the impact of each swimmer’s movements on fluid flow, and vice versa, is a major challenge. Classic biomechanical research approaches have focused on swimmers’ actions, decomposing stroke characteristics for analysis, without exploring perturbations to fluid flows. Conversely, fluid mechanics research has sought to record fluid behaviours, isolated from the constraints of competitive swimming environments (e.g. analyses in two-dimensions, fluid flows passively studied on mannequins or robot effectors). With improvements in technology, however, recent investigations have focused on the emergent circular couplings between swimmers’ movements and fluid dynamics. Here, we provide insights into concepts and tools that can explain these on-going dynamical interactions in competitive swimming within the theoretical framework of ecological dynamics

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase&nbsp;1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation&nbsp;disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age&nbsp; 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score&nbsp; 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc&nbsp;= 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N&nbsp;= 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in&nbsp;Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in&nbsp;Asia&nbsp;and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Reactivity of a Molecular Magnesium Hydride Featuring a Terminal Magnesium-Hydrogen Bond

The reactivity of the molecular magnesium hydride [Mg­(Me₃TACD·Al^<i>i</i>Bu₃)­H] (<b>1</b>) featuring a terminal magnesium–hydrogen bond and an NNNN-type macrocyclic ligand, Me₃TACD ((Me₃TACD)H = Me₃[12]­aneN₄ = 1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane), can be grouped into protonolysis, oxidation, hydrometalation, (insertion), and hydride abstraction. Protonolysis of <b>1</b> with weak Brønsted acids HX such as terminal acetylenes, amines, silanols, and silanes gave the corresponding derivatives [Mg­(Me₃TACD·Al^<i>i</i>Bu₃)­X] (X = CCPh, <b>3</b>; HN­(3,5-Me₂-C₆H₃), <b>4</b>; OSiMe₃, <b>5</b>; OSiPh₃, <b>6</b>; Cl, <b>7</b>; Br, <b>8</b>). Single-crystal X-ray diffraction of anilide <b>4</b> showed a square-pyramidal coordination geometry for magnesium. No correlation with the p<i>K</i>_a values of the acids was detected. Oxidation of <b>1</b> with elemental iodine gave the iodide [Mg­(Me₃TACD·Al^<i>i</i>Bu₃)­I] (<b>9</b>), and oxidation with nitrous oxide afforded the μ-oxo-bridged compound [{Mg­(Me₃TACD·Al^<i>i</i>Bu₃)}₂(μ-O)] (<b>10</b>) with a linear Mg–O–Mg core, as characterized by single-crystal X-ray diffraction. The Mg–H bond reacted with benzaldehyde, benzophenone, fluorenone, and CO₂ under insertion but not with the olefins 1,1,2-triphenylethylene, <i>tert</i>-butylethylene, and cyclopentene. The unstable formate, prepared also by salt metathesis of iodide <b>9</b> with potassium formate, revealed κ<i>O</i>,κ<i>O</i>′ coordination in the solid state. Hydride abstraction with triphenylborane gave the ion pair [Mg­(Me₃TACD·Al^<i>i</i>Bu₃)­(thf)]­[HBPh₃] (<b>16</b>), which catalyzed the hydroboration of polar substrates by pinacolborane

Formation and Reactivity of a Molecular Magnesium Hydride with a Terminal Mg—H Bond

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