498 research outputs found
The wee country that roared : supporting Open Access in Scotland through institutional repositories
The 2019 CWTS Leiden statistics show 3 Scottish institutions in the Top 10 and 4 in the top 15 in Open Access. This presentation will focus on brief case studies of Scottish institutions and the growth of their institutional repository services as a demonstration of a wider national commitment to Open Access. It will also highlight Scotlandâs Open Access journey from 2004 to today through the experience and expertise of these institutions and the support of the Scottish Confederation of University and Research Libraries (SCURL). This journey will include the conditions of their local environments, key drivers and a mix of approaches for success, choice of platform(s) and the challenges, at an institutional level in embedding open repositories. These case studies taken together will demonstrate the drive to ensure Scotlandâs research is âOpen for Allâ and further enable the global impact for research undertaken in Scottish institutions
The wee country that rOAred : measuring, supporting and building trust in open access in Scotland through institutional repositories
The 2021 CWTS Leiden rankings show 24 UK institutions in the global Top 10 by percentage of Open Access publications and 25% of those institutions are in Scotland. This presentation will focus on the experience of some of these Scottish institutions and the growth of their institutional repository services as a demonstration of a wider national commitment to Open Access. It will also highlight the growth in Open Access demonstrated by the CWTS rankings and Scotland?s Open Access journey from 2004 to today. This will be done through brief case studies which showcase the experience and expertise of these institutions and the support of the Scottish Confederation of University and Research Libraries (SCURL). It will also highlight the opportunities for national collaboration at a Scottish and UK level set against the context of updated UK open access funder policy and a national assessment exercise (REF2021) which was committed to Open Access.PostprintPublisher PDFPeer reviewe
Analysis of change in patient-reported outcome measures with floor and ceiling effects using the multilevel Tobit model:a simulation study and an example from a National Joint Register using body mass index and the Oxford Hip Score
OBJECTIVES: This study has three objectives. (1) Investigate the association between body mass index (BMI) and the efficacy of primary hip replacement using a patient-reported outcome measure (PROMs) with a measurement floor and ceiling, (2) Explore the performance of different estimation methods to estimate change in PROMs score following surgery using a simulation study and real word data where data has measurement floors and ceilings and (3) Lastly, develop guidance for practising researchers on the analysis of PROMs in the presence of floor and ceiling effects. DESIGN: Simulation study and prospective national medical device register. SETTING: National Register of Joint Replacement and Medical Devices. METHODS: Using a Monte Carlo simulation study and data from a national joint replacement register (162â513 patients with pre- and post-surgery PROMs), we investigate simple approaches for the analysis of outcomes with floor and ceiling effects that are measured at two occasions: linear and Tobit regression (baseline adjusted analysis of covariance, change-score analysis, post-score analysis) in addition to linear and multilevel Tobit models. PRIMARY OUTCOME: The primary outcome of interest is change in PROMs from pre-surgery to 6 months post-surgery. RESULTS: Analysis of data with floor and ceiling effects with models that fail to account for these features induce substantial bias. Single-level Tobit models only correct for floor or ceiling effects when the exposure of interest is not associated with the baseline score. In observational data scenarios, only multilevel Tobit models are capable of providing unbiased inferences. CONCLUSIONS: Inferences from pre- post-studies that fail to account for floor and ceiling effects may induce spurious associations with substantial risk of bias. Multilevel Tobit models indicate the efficacy of total hip replacement is independent of BMI. Restricting access to total hip replacement based on a patients BMI can not be supported by the data
Mild sp2Carbon-Oxygen Bond Activation by an Isolable Ruthenium(II) bis(Dinitrogen) Complex: Experiment and Theory
The isolable ruthenium(II) bis(dinitrogen) complex [Ru(H)2(N2)2(PCy3)2] (1) reacts with aryl ethers (ArâOR, R = Me and Ar) containing a ketone directing group to effect sp2CâO bond activation at temperatures below 40 °C. DFT studies support a low-energy Ru(II)/Ru(IV) pathway for CâO bond activation: oxidative addition of the CâO bond to Ru(II) occurs in an asynchronous manner with RuâC bond formation preceding CâO bond breaking. Alternative pathways based on a Ru(0)/Ru(II) couple are competitive but less accessible due to the high energy of the Ru(0) precursors. Both experimentally and by DFT calculations, sp2CâH bond activation is shown to be more facile than sp2CâO bond activation. The kinetic preference for CâH bond activation over CâO activation is attributed to unfavorable approach of the CâO bond toward the metal in the selectivity determining step of the reaction pathway
The wee country that rOAred : measuring, supporting and building trust in open access in Scotland through institutional repositories
The 2021 CWTS Leiden rankings show 24 UK institutions in the global Top 10 by percentage of Open Access publications and 25% of those institutions are in Scotland. i This presentation will focus on the experience of some of these Scottish institutions and the growth of their institutional repository services as a demonstration of a wider national commitment to Open Access. It will also highlight the growth in Open Access demonstrated by the CWTS rankings and Scotlandâs Open Access journey from 2004 to today. This will be done through brief case studies which showcase the experience and expertise of these institutions and the support of the Scottish Confederation of University and Research Libraries (SCURL). It will also highlight the opportunities for national collaboration at a Scottish and UK level set against the context of updated UK open access funder policy and a national assessment exercise (REF2021) which was committed to Open Access
Microclimate affects landscape level persistence in the British Lepidoptera
Microclimate has been known to drive variation in the distribution and abundance of insects for some time. Until recently however, quantification of microclimatic effects has been limited by computing constraints and the availability of fine-scale biological data. Here, we tested fine-scale patterns of persistence/extinction in butterflies and moths against two computed indices of microclimate derived from Digital Elevation Models: a summer solar index, representing fine-scale variation in temperature, and a topographic wetness index, representing fine-scale variation in moisture availability. We found evidence of microclimate effects on persistence in each of four 20 Ă 20 km British landscapes selected for study (the Brecks, the Broads, Dartmoor, and Exmoor). Broadly, local extinctions occurred more frequently in areas with higher minimum or maximum solar radiation input, while responses to wetness varied with landscape context. This negative response to solar radiation is consistent with a response to climatic warming, wherein grid squares with particularly high minimum or maximum insolation values provided an increasingly adverse microclimate as the climate warmed. The variable response to wetness in different landscapes may have reflected spatially variable trends in precipitation. We suggest that locations in the landscape featuring cooler minimum and/or maximum temperatures could act as refugia from climatic warming, and may therefore have a valuable role in adapting conservation to climatic change
Diet and bone mineral density study in postmenopausal women from the TwinsUK registry shows a negative association with a traditional English dietary pattern and a positive association with wine
Background: The effect of diet on bone mineral density (BMD) remains controversial, mainly because of difficulties in isolating dietary factors from the confounding influences of age, lifestyle, and genetic factors. Objective: The aim of this study was to use a novel method to examine the relation between BMD and diet. Design: A co-twin control study design with linear regression modeling was used to test for associations between BMD and habitual intakes of calcium, vitamin D, protein, and alcohol plus 5 previously identified dietary patterns in postmenopausal women from the TwinsUK registry. This approach exploited the unique matching of twins to provide an estimate of an association that was not confounded by age, genetic background, or shared lifestyle. Results: In >2000 postmenopausal women (BMD data on 1019, 1218, and 1232 twin pairs at the hip neck, hip, and spine, respectively), we observed a positive association between alcohol intake (from wine but not from beer or spirits) and spine BMD (P = 0.01) and a negative association with a traditional 20th-century English diet at the hip neck (P = 0.01). Both associations remained borderline significant after adjustment for mean twin-pair intakes (P = 0.04 and P = 0.055, respectively). Other dietary patterns and intakes of calcium, vitamin D, and protein were unrelated to BMD. Conclusion: Our results showed that diet has an independent but subtle effect on BMD; wine intake was positively associated with spine BMD, whereas a traditional (20th-century) English diet had a negative association with hip BMD
Phylogeography, Salinity Adaptations and Metabolic Potential of the Candidate Division KB1 Bacteria Based on a Partial Single Cell Genome
Deep-sea hypersaline anoxic basins (DHABs) and other hypersaline environments contain abundant and diverse microbial life that has adapted to these extreme conditions. The bacterial Candidate Division KB1 represents one of several uncultured groups that has been consistently observed in hypersaline microbial diversity studies. Here we report the phylogeography of KB1, its phylogenetic relationships to Candidate Division OP1 Bacteria, and its potential metabolic and osmotic stress adaptations based on a partial single cell amplified genome (SAG) of KB1 from Orca Basin, the largest hypersaline seafloor brine basin in the Gulf of Mexico. Our results are consistent with the hypothesis â previously developed based on 14C incorporation experiments with mixed-species enrichments from Mediterranean seafloor brines - that KB1 has adapted its proteins to elevated intracellular salinity, but at the same time KB1 apparently imports glycine betaine; this compatible solute is potentially not limited to osmoregulation but could also serve as a carbon and energy source
Solid/Gas In Crystallo Reactivity of an Ir(I) Methylidene Complex
In crystallo stabilization of known, but solution unstable, methylidene complex [Ir(tBu-PONOP)(âCH2)][BArF4] allows single-crystal to single-crystal solid/gas reactivity associated with the {IrâCH2} group to be studied. Addition of H2 results in [Ir(tBu-PONOP)(H)2][BArF4]; exposure to CO forms iridium(I) carbonyl [Ir(tBu-PONOP)(CO)][BArF4], and reaction with NH3 gas results in the formation of methylamine complex [(tBu-PONOP)Ir(NH2Me)][BArF4] via an aminocarbene intermediate. Periodic density functional theory and electronic structure analyses confirm the IrâCH2 bond character but with a very low barrier to rotation around the IrâCH2 bond. Calculations show that addition of NH3 to the electrophilic alkylidene carbon gives an initial ammonium ylid intermediate. Stepwise NâH and CâH transfers then form the aminocarbene intermediate as a kinetic product from which two successive CâH couplings lead to the more stable methylamine product
Solid-state molecular organometallic chemistry. Single-crystal to single-crystal reactivity and catalysis with light hydrocarbon substrates
Single-crystal to single-crystal solid/gas reactivity and catalysis starting from the precursor sigma-alkane complex [Rh(Cy2PCH2CH2PCy2)(η2η2-NBA)][BArF4] (NBA = norbornane; ArF = 3,5-(CF3)2C6H3) is reported. By adding ethene, propene and 1-butene to this precursor in solid/gas reactions the resulting alkene complexes [Rh(Cy2PCH2CH2PCy2)(alkene)x][BArF4] are formed. The ethene (x = 2) complex, [Rh(Cy2PCH2CH2PCy2)(ethene)2][BArF4]-Oct, has been characterized in the solid-state (single-crystal X-ray diffraction) and by solution and solid-state NMR spectroscopy. Rapid, low temperature recrystallization using solution methods results in a different crystalline modification, [Rh(Cy2PCH2CH2PCy2)(ethene)2][BArF4]-Hex, that has a hexagonal microporous structure (P6322). The propene complex (x = 1) [Rh(Cy2PCH2CH2PCy2)(propene)][BArF4] is characterized as having a Ï-bound alkene with a supporting Îł-agostic RhâŻH3C interaction at low temperature by single-crystal X-ray diffraction, variable temperature solution and solid-state NMR spectroscopy, as well as periodic density functional theory (DFT) calculations. A fluxional process occurs in both the solid-state and solution that is proposed to proceed via a tautomeric allyl-hydride. Gas/solid catalytic isomerization of d3-propene, H2CCHCD3, using [Rh(Cy2PCH2CH2PCy2)(η2η2-NBA)][BArF4] scrambles the D-label into all possible positions of the propene, as shown by isotopic perturbation of equilibrium measurements for the agostic interaction. Periodic DFT calculations show a low barrier to H/D exchange (10.9 kcal mol-1, PBE-D3 level), and GIPAW chemical shift calculations guide the assignment of the experimental data. When synthesized using solution routes a bis-propene complex, [Rh(Cy2PCH2CH2PCy2)(propene)2][BArF4], is formed. [Rh(Cy2PCH2CH2PCy2)(butene)][BArF4] (x = 1) is characterized as having 2-butene bound as the cis-isomer and a single RhâŻH3C agostic interaction. In the solid-state two low-energy fluxional processes are proposed. The first is a simple libration of the 2-butene that exchanges the agostic interaction, and the second is a butene isomerization process that proceeds via an allyl-hydride intermediate with a low computed barrier of 14.5 kcal mol-1. [Rh(Cy2PCH2CH2PCy2)(η2η2-NBA)][BArF4] and the polymorphs of [Rh(Cy2PCH2CH2PCy2)(ethene)2][BArF4] are shown to be effective in solid-state molecular organometallic catalysis (SMOM-Cat) for the isomerization of 1-butene to a mixture of cis- and trans-2-butene at 298 K and 1 atm, and studies suggest that catalysis is likely dominated by surface-active species. [Rh(Cy2PCH2CH2PCy2)(η2η2-NBA)][BArF4] is also shown to catalyze the transfer dehydrogenation of butane to 2-butene at 298 K using ethene as the sacrificial acceptor
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