3,104 research outputs found

    Does money matter in inflation forecasting?

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    This paper provides the most fully comprehensive evidence to date on whether or not monetary aggregates are valuable for forecasting US inflation in the early to mid 2000s. We explore a wide range of different definitions of money, including different methods of aggregation and different collections of included monetary assets. In our forecasting experiment we use two non-linear techniques, namely, recurrent neural networks and kernel recursive least squares regression - techniques that are new to macroeconomics. Recurrent neural networks operate with potentially unbounded input memory, while the kernel regression technique is a finite memory predictor. The two methodologies compete to find the best fitting US inflation forecasting models and are then compared to forecasts from a naive random walk model. The best models were non-linear autoregressive models based on kernel methods. Our findings do not provide much support for the usefulness of monetary aggregates in forecasting inflation.Forecasting ; Inflation (Finance) ; Monetary theory

    Pd/ZnO catalysts for direct CO2 hydrogenation to methanol

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    The direct hydrogenation of CO2 into methanol is crucial for providing a means of CO2 fixation and a way to store cleanly produced hydrogen in a more energy-dense and transportable form. Here we have prepared two series of Pd/ZnO catalysts, both by immobilisation of PVA-protected Pd colloids and by Pd impregnation of PdCl2 to investigate structure activity relationships for direct CO2 hydrogenation. Very different performances were found for the different preparation methods, and the Pd loading and pre-reduction of the catalysts were shown to be important factors for optimising methanol yield. The crucial factor for high methanol yield is the formation of a Pd–Zn alloy, either during the reaction itself, or better by high temperature pre-reduction. The formation of the alloy greatly reduces CO production by the reverse water gas shift reaction. The catalysts prepared by sol-immobilisation were relatively stable to thermal treatment. In contrast, the impregnated catalysts were much less thermally stable, due to the presence of remnant chloride on the surface of the catalyst, which was absent for the case of sol immobilisation preparation. The results illustrate the importance of controlling the PdZn particle size and its surface structure for the catalysts to achieve high methanol selectivity (60%, the rest being CO) and conversion (11%) at 250 °C and 20 bar. Selectivity for sol-immobilised catalysts decreases from 60% at 3 nm average diameter, to 20% at 7 nm

    Interventions for treating psoriatic arthritis (Review)

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    Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. This review is made available in accordance with Cochrane Database of Systematic Review's repositories policyBackground It has been estimated that arthritis occurs in 5‐7% of those with psoriasis. Relatively few clinical trials of treatment are available for psoriatic arthritis and data presentation in these trials is far from uniform making comparison difficult. Objectives To assess the effects of sulfasalazine, auranofin, etretinate, fumaric acid, IMI gold, azathioprine, efamol marine and methotrexate, in psoriatic arthritis. Search methods We searched MEDLINE up to February 2000, and Excerpta Medica (June 1974‐95). Search terms were psoriasis, arthritis, therapy and/or controlled trial. This was supplemented by manually searching bibliographies of previously published reviews, conference proceedings, contacting drug companies and referring to the Cochrane Clinical Trials Register. All languages were included in the initial search. Selection criteria All randomized trials comparing sulfasalazine, auranofin, etretinate, fumaric acid, IMI gold, azathioprine, and methotrexate, in psoriatic arthritis. Following a published a priori protocol, the main outcome measures included individual component variables derived from Outcome Measures in Rheumatology Clinical Trials (OMERACT). These include acute phase reactants, disability, pain, patient global assessment, physician global assessment, swollen joint count, tender joint count and radiographic changes of joints in any trial of one year or longer [Tugwell 1993], and the change in pooled disease index (DI). Only English trials were included in the review. Data collection and analysis Data were independently extracted from the published reports by two of the reviewers (MC, GJ). An independent blinded quality assessment was also performed. Main results Twenty randomized trials were identified of which thirteen were included in the quantitative analysis with data from 1022 subjects. Although all agents were better than placebo, parenteral high dose methotrexate (not included), sulfasalazine, azathioprine and etretinate were the agents that achieved statistical significance in a global index of disease activity (although it should be noted that only one component variable was available for azathioprine and only one trial was available for etretinate suggesting some caution is necessary in interpreting these results). Analysis of response in individual disease activity markers was more variable with considerable differences between different medications and responses. In all trials the placebo group improved over baseline (pooled improvement 0.39 DI units, 95% CI 0.26‐0.54). There was insufficient data to examine toxicity. Authors' conclusions Parenteral high dose methotrexate and sulfasalazine are the only two agents with well demonstrated published efficacy in psoriatic arthritis. The magnitude of the effect seen with azathioprine, etretinate, oral low dose methotrexate and perhaps colchicine suggests that they may be effective but that further multicentre clinical trials are required to establish their efficacy. Furthermore, the magnitude of the improvement observed in the placebo group strongly suggests that uncontrolled trials should not be used to guide management decisions in this condition

    Development of an evidence-based regimen of prednisolone to treat giant cell arteritis - the Norwich regimen

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    We have reviewed the literature to form a bespoke regimen for daily oral prednisolone (DP) in GCA. Initial DP in clinical trials is 40-60 mg daily, but relapse rates are 67-92%. Cumulative prednisolone (CP) of 3.2 and 3.9 g (at 6 months) resulted in a relapse rate of 83 and 67%, respectively; and 3 and 3.9 g (at 12 months) resulted in 92 and 82% relapse, respectively. CP was 6.2-7.1 g in the first year. Mean DP was 18.8 mg at 3 months and 6.6-7.4 mg at 12 months. The duration of treatment with prednisolone for GCA was 22-26 months. The CP to achieve discontinuation was 6.5-12.1 g. Using these data, the Norwich regimen starts DP at 1 mg/kg/day of lean body mass, discontinuing over 100 weeks. For the average UK woman, initial DP is 45 mg daily, reaching 21 mg daily by 12 weeks and 6 mg daily by 52 weeks. The CP for the average UK woman would be 6.5 g at 52 weeks and 7.4 g to discontinuation

    Identification of single-site gold catalysis in acetylene hydrochlorination

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    There remains considerable debate over the active form of gold under operating conditions of a recently validated gold catalyst for acetylene hydrochlorination. We have performed an in situ x-ray absorption fine structure study of gold/carbon (Au/C) catalysts under acetylene hydrochlorination reaction conditions and show that highly active catalysts comprise single-site cationic Au entities whose activity correlates with the ratio of Au(I):Au(III) present. We demonstrate that these Au/C catalysts are supported analogs of single-site homogeneous Au catalysts and propose a mechanism, supported by computational modeling, based on a redox couple of Au(I)-Au(III) species. View Full Tex

    Public involvement in an aggregate and individual participant data meta-analysis of mindfulness-based programmes for mental health promotion

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    Background: Involving the public in evidence synthesis research is challenging due to the highly analytic nature of the projects, so it is important that involvement processes are documented, reflected upon, and shared to devise best practices. There is a literature gap on the involvement of the public in individual participant data meta-analyses, particularly in public health projects. We aimed to document and reflect on our collective experiences of involving and being involved as public stakeholders at all stages of a systematic review and individual participant data meta-analysis project. Methods: We formed a stakeholder group made of four members of the public at the beginning of our evidence synthesis project comprising a systematic review, an aggregate data meta-analysis, and an individual participant data meta-analysis of mindfulness-based programmes for mental health promotion in non-clinical adults. Following each group meeting, members and participating researchers completed written reflections; one group member collected and collated these. At the end of the project, a reflective writing workshop was held before all members completed their final reflections. Everyone completed an adapted, open-ended questionnaire which asked about what did and did not work well, the overall experience, what could be improved, and the felt impact the stakeholder group had on the research. Results: Overall, the stakeholders and researchers reported a positive experience of working together. Positives from the stakeholders’ point of view included learning new skills, experiencing research, and making new friends. For the researchers, stakeholders helped them focus on what matters to the public and were reinvigorating research partners. The challenges stakeholders experienced included having long gaps between meetings and feeling overwhelmed. The researchers found it challenging to strike the balance between asking stakeholders to be involved and for them to learn research-related skills without overburdening them and making sure that the learning was engaging. When looking back at their experience, stakeholders described seeing their impact on the project in hindsight but that this was not felt while the project was being carried out. Conclusion: Successfully involving the public in complex evidence synthesis projects is possible and valuable from the points of view of the researchers and the stakeholders. However, it requires a significant time, skill, and resource investment that needs to be factored in from project inception. Further guidance and stakeholder training materials would be helpful. Specific suggestions are provided

    Photonic Quantum Logic with Narrowband Light from Single Atoms

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    Increasing control of single photons enables new applications of photonic quantum-enhanced technology and further experimental exploration of fundamental quantum phenomena. Here, we demonstrate quantum logic using narrow linewidth photons that are produced under nearly perfect quantum control from a single ^87Rb atom strongly coupled to a high-finesse cavity. We use a controlled- NOT gate integrated into a photonic chip to entangle these photons, and we observe non-classical correlations between events separated by periods exceeding the travel time across the chip by three orders of magnitude. This enables quantum technology that will use the properties of both narrowband single photon sources and integrated quantum photonics, such as networked quantum computing, narrow linewidth quantum enhanced sensing and atomic memories.Comment: 5 pates, 3 figure
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