483 research outputs found

    Impact of The Daily Mile on children's physical and mental health, and educational attainment in primary schools: iMprOVE cohort study protocol

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    INTRODUCTION: School-based active mile initiatives such as The Daily Mile (TDM) are widely promoted to address shortfalls in meeting physical activity recommendations. The iMprOVE Study aims to examine the impact of TDM on children's physical and mental health and educational attainment throughout primary school. METHODS AND ANALYSIS: iMprOVE is a longitudinal quasi-experimental cohort study. We will send a survey to all state-funded primary schools in Greater London to identify participation in TDM. The survey responses will be used for non-random allocation to either the intervention group (Daily Mile schools) or to the control group (non-Daily Mile schools). We aim to recruit 3533 year 1 children (aged 5-6 years) from 77 primary schools and follow them up annually until the end of their primary school years. Data collection taking place at baseline (children in school year 1) and each primary school year thereafter includes device-based measures of moderate-to-vigorous physical activity (MVPA) and questionnaires to measure mental health (Strengths and Difficulties Questionnaire) and educational attainment (ratings from 'below expected' to 'above expected levels'). The primary outcome is the mean change in MVPA minutes from baseline to year 6 during the school day among the intervention group compared with controls. We will use multilevel linear regression models adjusting for sociodemographic data and participation in TDM. The study is powered to detect a 10% (5.5 min) difference between the intervention and control group which would be considered clinically significant. ETHICS AND DISSEMINATION: Ethics has been approved from Imperial College Research Ethics Committee, reference 20IC6127. Key findings will be disseminated to the public through research networks, social, print and media broadcasts, community engagement opportunities and schools. We will work with policy-makers for direct application and impact of our findings

    Exploring the Limits of Dative Boratrane Bonding: Iron as a Strong Lewis Base in Low-Valent Non-Heme Iron-Nitrosyl Complexes

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    We previously reported the synthesis and preliminary characterization of a unique series of low-spin (ls) {FeNO}⁸⁻¹⁰ complexes supported by an ambiphilic trisphosphineborane ligand, [Fe(TPB)(NO)]^(+/0/−). Herein, we use advanced spectroscopic techniques and density functional theory (DFT) calculations to extract detailed information as to how the bonding changes across the redox series. We find that, in spite of the highly reduced nature of these complexes, they feature an NO+ ligand throughout with strong Fe−NO π-backbonding and essentially closed-shell electronic structures of their FeNO units. This is enabled by an Fe−B interaction that is present throughout the series. In particular, the most reduced [Fe(TPB)(NO)]− complex, an example of a ls-{FeNO}¹⁰ species, features a true reverse dative Fe → B bond where the Fe center acts as a strong Lewis-base. Hence, this complex is in fact electronically similar to the ls-{FeNO}⁸ system, with two additional electrons “stored” on site in an Fe−B single bond. The outlier in this series is the ls-{FeNO}⁹ complex, due to spin polarization (quantified by pulse EPR spectroscopy), which weakens the Fe−NO bond. These data are further contextualized by comparison with a related N₂ complex, [Fe(TPB)(N₂)]⁻, which is a key intermediate in Fe(TPB)-catalyzed N₂ fixation. Our present study finds that the Fe → B interaction is key for storing the electrons needed to achieve a highly reduced state in these systems, and highlights the pitfalls associated with using geometric parameters to try to evaluate reverse dative interactions, a finding with broader implications to the study of transition metal complexes with boratrane and related ligands

    Exploring the Limits of Dative Boratrane Bonding: Iron as a Strong Lewis Base in Low-Valent Non-Heme Iron-Nitrosyl Complexes

    Get PDF
    We previously reported the synthesis and preliminary characterization of a unique series of low-spin (ls) {FeNO}⁸⁻¹⁰ complexes supported by an ambiphilic trisphosphineborane ligand, [Fe(TPB)(NO)]^(+/0/−). Herein, we use advanced spectroscopic techniques and density functional theory (DFT) calculations to extract detailed information as to how the bonding changes across the redox series. We find that, in spite of the highly reduced nature of these complexes, they feature an NO+ ligand throughout with strong Fe−NO π-backbonding and essentially closed-shell electronic structures of their FeNO units. This is enabled by an Fe−B interaction that is present throughout the series. In particular, the most reduced [Fe(TPB)(NO)]− complex, an example of a ls-{FeNO}¹⁰ species, features a true reverse dative Fe → B bond where the Fe center acts as a strong Lewis-base. Hence, this complex is in fact electronically similar to the ls-{FeNO}⁸ system, with two additional electrons “stored” on site in an Fe−B single bond. The outlier in this series is the ls-{FeNO}⁹ complex, due to spin polarization (quantified by pulse EPR spectroscopy), which weakens the Fe−NO bond. These data are further contextualized by comparison with a related N₂ complex, [Fe(TPB)(N₂)]⁻, which is a key intermediate in Fe(TPB)-catalyzed N₂ fixation. Our present study finds that the Fe → B interaction is key for storing the electrons needed to achieve a highly reduced state in these systems, and highlights the pitfalls associated with using geometric parameters to try to evaluate reverse dative interactions, a finding with broader implications to the study of transition metal complexes with boratrane and related ligands

    Electronic Structures of an [Fe(NNR_2)]^(+/0/–) Redox Series: Ligand Noninnocence and Implications for Catalytic Nitrogen Fixation

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    The intermediacy of metal–NNH_2 complexes has been implicated in the catalytic cycles of several examples of transition-metal-mediated nitrogen (N_2) fixation. In this context, we have shown that triphosphine-supported Fe(N_2) complexes can be reduced and protonated at the distal N atom to yield Fe(NNH_2) complexes over an array of charge and oxidation states. Upon exposure to further H^+/e^– equivalents, these species either continue down a distal-type Chatt pathway to yield a terminal iron(IV) nitride or instead follow a distal-to-alternating pathway resulting in N–H bond formation at the proximal N atom. To understand the origin of this divergent selectivity, herein we synthesize and elucidate the electronic structures of a redox series of Fe(NNMe_2) complexes, which serve as spectroscopic models for their reactive protonated congeners. Using a combination of spectroscopies, in concert with density functional theory and correlated ab initio calculations, we evidence one-electron redox noninnocence of the “NNMe_2” moiety. Specifically, although two closed-shell configurations of the “NNR_2” ligand have been commonly considered in the literature—isodiazene and hydrazido(2−)—we provide evidence suggesting that, in their reduced forms, the present iron complexes are best viewed in terms of an open-shell [NNR_2]^•–ligand coupled antiferromagnetically to the Fe center. This one-electron redox noninnocence resembles that of the classically noninnocent ligand NO and may have mechanistic implications for selectivity in N_2 fixation activity

    A trigger-substrate model for smiling during an automated formative quiz: engagement is the substrate, not frustration

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    INTRODUCTION: Automated tutoring systems aim to respond to the learner’s cognitive state in order to maintain engagement. The end-user’s state might be inferred by interactive timings, bodily movements or facial expressions. Problematic computerized stimuli are known to cause smiling during periods of frustration. METHODS: Forty-four seated, healthy participants (age range 18-35, 18 male) used a handheld trackball to answer a computer-presented, formative, 3-way multiple choice geography quiz, with 9 questions, lasting a total of 175 seconds. Frontal facial videos (10 Hz) were collected with a webcam and processed for facial expressions by CrowdEmotion using a pattern recognition algorithm. Interactivity was recorded by a keystroke logger (Inputlog 5.2). Subjective responses were collected immediately after each quiz using a panel of visual analogue scales (VAS). RESULTS: Smiling was fie-fold enriched during the instantaneous feedback segments of the quiz, and this was correlated with VAS ratings for engagement but not with happiness or frustration. Nevertheless, smiling rate was significantly higher after wrong answers compared to correct ones, and frustration was correlated with the number of questions answered incorrectly. CONCLUSION: The apparent disconnect between the increased smiling during incorrect answers but the lack of correlation between VAS frustration and smiles suggests a trigger-substrate model where engagement is the permissive substrate, while the noises made by the quiz after wrong answers may be the trigger

    A standardized framing for reporting protein identifications in mzIdentML 1.2

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    Inferring which protein species have been detected in bottom-up proteomics experiments has been a challenging problem for which solutions have been maturing over the past decade. While many inference approaches now function well in isolation, comparing and reconciling the results generated across different tools remains difficult. It presently stands as one of the greatest barriers in collaborative efforts such as the Human Proteome Project and public repositories such as the PRoteomics IDEntifications (PRIDE) database. Here we present a framework for reporting protein identifications that seeks to improve capabilities for comparing results generated by different inference tools. This framework standardizes the terminology for describing protein identification results, associated with the HUPO-Proteomics Standards Initiative (PSI) mzIdentML standard, while still allowing for differing methodologies to reach that final state. It is proposed that developers of software for reporting identification results will adopt this terminology in their outputs. While the new terminology does not require any changes to the core mzIdentML model, it represents a significant change in practice, and, as such, the rules will be released via a new version of the mzIdentML specification (version 1.2) so that consumers of files are able to determine whether the new guidelines have been adopted by export software

    Breaking Up the C Complex Spliceosome Shows Stable Association of Proteins with the Lariat Intron Intermediate

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    Spliceosome assembly requires several structural rearrangements to position the components of the catalytic core. Many of these rearrangements involve successive strengthening and weakening of different RNA∶RNA and RNA∶proteins interactions within the complex. To gain insight into the organization of the catalytic core of the spliceosome arrested between the two steps of splicing chemistry (C complex), we investigated the effects of exposing C complex to low concentrations of urea. We find that in the presence of 3M urea C complex separates into at least three sub-complexes. One sub-complex contains the 5′exon, another contains the intron-lariat intermediate, and U2/U5/U6 snRNAs likely comprise a third sub-complex. We purified the intron-lariat intermediate sub-complex and identified several proteins, including U2 snRNP and PRP19 complex (NTC) components. The data from our study indicate that U2 snRNP proteins in C complex are more stably associated with the lariat-intron intermediate than the U2 snRNA. The results also suggest a set of candidate proteins that hold the lariat-intron intermediate together in C complex. This information is critical for further interpreting the complex architecture of the mammalian spliceosome
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