3,269 research outputs found

    Exemplary educational leadership : a reflective essay

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    Maybe now more than ever, the need for strong leadership in education is necessary. Unfortunately, leadership can be masked by many other titles: director, manager, boss, dictator. None are accurate descriptions of a leader. A leader takes on the appearance of servant, peer, guide, and mentor. By serving the staff and meeting their needs--physically, professionally, and emotionally--authority is developed so that managerial techniques which instill resentment are no longer effective,nor needed, and staff will feel comfortable working with you, for you, and along side you

    Quantum-coherent dynamics in photosynthetic charge separation revealed by wavelet analysis

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    Experimental/theoretical evidence for sustained vibration-assisted electronic (vibronic) coherence in the Photosystem II Reaction Center (PSII RC) indicates that photosynthetic solar-energy conversion might be optimized through the interplay of electronic and vibrational quantum dynamics. This evidence has been obtained by investigating the primary charge separation process in the PSII RC by two-dimensional electronic spectroscopy (2DES) and Redfield modeling of the experimental data. However, while conventional Fourier transform analysis of the 2DES data allows oscillatory signatures of vibronic coherence to be identified in the frequency domain in the form of static 2D frequency maps, the real-time evolution of the coherences is lost. Here we apply for the first time wavelet analysis to the PSII RC 2DES data to obtain time-resolved 2D frequency maps. These maps allow us to demonstrate that i) coherence between the excitons initiating the two different charge separation pathways is active for more than 500 fs, and ii) coherence between exciton and charge-transfer states, the reactant and product of the charge separation reaction, respectively, is active for at least 1 ps. These findings imply that the PSII RC employs coherence i) to sample competing electron transfer pathways, and ii) to perform directed, ultrafast and efficient electron transfer.Comment: Scientific reports 201

    Reflection on modern methods: Calculating a sample size for a repeatability sub-study to correct for measurement error in a single continuous exposure

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    Using a continuous exposure variable that is measured with random error in a univariable linear regression model leads to regression dilution bias: the observed association between the exposure and outcome is smaller than it would be if the true value of the exposure could be used. A repeatability sub-study, where a sample of study participants have their data measured again, can be used to correct for this bias. It is important to perform a sample size calculation for such a sub-study, to ensure that correction factors can be estimated with sufficient precision. We describe how a previously published method can be used to calculate the sample size from the anticipated size of the correction factor and its desired precision, and demonstrate this approach using the example of the cross-sectional studies conducted as part of the International Project on Cardiovascular Disease in Russia study. We also provide correction factors calculated from repeat data from the UK Biobank study, which can be used to help plan future repeatability studies

    Realising Value from Big Data Technology Adoption: Understanding the Role of Organisational Capabilities in the Affordance Actualization Process

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    The adoption of big data technologies presents organisations with many value creation opportunities that can transform and improve their business. Much of the research today focuses on big data value creation (what value big data technologies offer), whereas limited research focuses on big data value realisation (how big data value is realized). We aim to fill this research gap by addressing the following research question: how do organisations effectively realize value from the adoption of a new big data technology? We do so by adopting an affordance theory lens and empirically examine the adoption of smart meters (a big data technology) in the UK energy sector. We introduce the concept of actualization enablers, and our findings provide empirically grounded insights into the role of organisational capabilities and actualization enablers in the big data value realization process (affordance actualization). Furthermore, our findings provide important and relevant theoretical and managerial implications

    Histidine168 is crucial for ΔpH-dependent gating of the human voltage-gated proton channel, hHV1

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    We recently identified a voltage-gated proton channel gene in the snail Helisoma trivolvis, HtHV1, and determined its electrophysiological properties. Consistent with early studies of proton currents in snail neurons, HtHV1 opens rapidly, but it unexpectedly exhibits uniquely defective sensitivity to intracellular pH (pHi). The H+ conductance (gH)-V relationship in the voltage-gated proton channel (HV1) from other species shifts 40 mV when either pHi or pHo (extracellular pH) is changed by 1 unit. This property, called ΔpH-dependent gating, is crucial to the functions of HV1 in many species and in numerous human tissues. The HtHV1 channel exhibits normal pHo dependence but anomalously weak pHi dependence. In this study, we show that a single point mutation in human hHV1—changing His168 to Gln168, the corresponding residue in HtHV1—compromises the pHi dependence of gating in the human channel so that it recapitulates the HtHV1 response. This location was previously identified as a contributor to the rapid gating kinetics of HV1 in Strongylocentrotus purpuratus. His168 mutation in human HV1 accelerates activation but accounts for only a fraction of the species difference. H168Q, H168S, or H168T mutants exhibit normal pHo dependence, but changing pHi shifts the gH-V relationship on average by /unit. Thus, His168 is critical to pHi sensing in hHV1. His168, located at the inner end of the pore on the S3 transmembrane helix, is the first residue identified in HV1 that significantly impairs pH sensing when mutated. Because pHo dependence remains intact, the selective erosion of pHi dependence supports the idea that there are distinct internal and external pH sensors. Although His168 may itself be a pHi sensor, the converse mutation, Q229H, does not normalize the pHi sensitivity of the HtHV1 channel. We hypothesize that the imidazole group of His168 interacts with nearby Phe165 or other parts of hHV1 to transduce pHi into shifts of voltage-dependent gating

    Crystal Structure of (E)-2-[(2- bromo-3-pyridyl)methylidene]-6-methoxy-3,4-dihydronaphthalen-1-one and 3-[(E)-(6- methoxy-3,4-dihydronaphth-2-oylidene)methyl]-1H-pyridin-2-one

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    The title compounds C17H14BrNO2, (I), and C17H15NO3, (II), were obtained from the reaction of 6-meth­oxy-3,4-di­hydro-2H-naphthalen-1-one and 2-bromo­nicotinaldehyde in ethanol. Compound (I) was the expected product and compound (II) was the oxidation product from air exposure. In the crystal structure of compound (I), there are no short contacts or hydrogen bonds. The structure does display [pi]-[pi] inter­actions between adjacent benzene rings and adjacent pyridyl rings. Compound (II) contains two independent mol­ecules, A and B, in the asymmetric unit; both are non-planar, the dihedral angles between the meth­oxy­benzene and 1H-pyridin-2-one mean planes being 35.07 (9)° in A and 35.28 (9)°in B. In each mol­ecule, the 1H-pyridin-2-one unit participates in inter­molecular N-H...O hydrogen bonding to another mol­ecule of the same type (A to A or B to B). The structure also displays [pi]-[pi] inter­actions between the pyridyl and the benzene rings of non-equivalent mol­ecules (viz., A to B and B to A)

    Evaluation of the incremental cost to the National Health Service of prescribing analogue insulin

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    Introduction Insulin analogues have become increasingly popular despite their greater cost compared with human insulin. The aim of this study was to calculate the incremental cost to the National Health Service (NHS) of prescribing analogue insulin preparations instead of their human insulin alternatives. Methods Open-source data from the four UK prescription pricing agencies from 2000 to 2009 were analysed. Cost was adjusted for inflation and reported in UK pounds at 2010 prices. Results Over the 10-year period, the NHS spent a total of £2732 million on insulin. The total annual cost increased from £156 million to £359 million, an increase of 130%. The annual cost of analogue insulin increased from £18.2 million (12% of total insulin cost) to £305 million (85% of total insulin cost), whereas the cost of human insulin decreased from £131 million (84% of total insulin cost) to £51 million (14% of total insulin cost). If it is assumed that all patients using insulin analogues could have received human insulin instead, the overall incremental cost of analogue insulin was £625 million. Conclusion Given the high marginal cost of analogue insulin, adherence to prescribing guidelines recommending the preferential use of human insulin would have resulted in considerable financial savings over the period
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