89 research outputs found

    Momentum Trading Strategies in the UK Commodity Futures Market

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    Whilst the majority of evidence supports the superiority of the momentum technique in the stock market, this article tests the presence of short to medium term price continuation in the UK commodity futures market. The paper assesses the effectiveness of the momentum strategy using agricultural commodity futures contracts that are traded on the London International Financial Futures and Options Exchange (LIFFE) and the Baltic Futures Exchange (BFE) from 1990 to 2010. Furthermore, the paper aims to ascertain the underlying rationale that drive the momentum effect, providing a credible explanation where two central risk based explanations are assessed. Firstly static macroeconomic variables are considered using a simple unconditional multifactor model based on the equity, bond and commodity markets. Secondly, the time varying risks associated with these explanatory variables are considered through the addition of a market proxy that captures the time variation of all three indices. While the article identifies the significant performance of all 30 momentum strategies tested, the results indicate that the abnormal returns of momentum strategy are not limited to horizon periods ranging between 3 and 12 months, as the finance literature documents. Furthermore, the results show that the superior performance of the momentum strategy can be considered, to a certain degree, a compensation for the static and time varying risk factors analysed

    Momentum Trading Strategies in the UK Commodity Futures Market

    Get PDF
    Whilst the majority of evidence supports the superiority of the momentum technique in the stock market, this article tests the presence of short to medium term price continuation in the UK commodity futures market. The paper assesses the effectiveness of the momentum strategy using agricultural commodity futures contracts that are traded on the London International Financial Futures and Options Exchange (LIFFE) and the Baltic Futures Exchange (BFE) from 1990 to 2010. Furthermore, the paper aims to ascertain the underlying rationale that drive the momentum effect, providing a credible explanation where two central risk based explanations are assessed. Firstly static macroeconomic variables are considered using a simple unconditional multifactor model based on the equity, bond and commodity markets. Secondly, the time varying risks associated with these explanatory variables are considered through the addition of a market proxy that captures the time variation of all three indices. While the article identifies the significant performance of all 30 momentum strategies tested, the results indicate that the abnormal returns of momentum strategy are not limited to horizon periods ranging between 3 and 12 months, as the finance literature documents. Furthermore, the results show that the superior performance of the momentum strategy can be considered, to a certain degree, a compensation for the static and time varying risk factors analysed

    Plant Based Proteins: Sustainable Alternatives

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    Proteins can be procured from both plants and animals. Plant proteins are more preferable as the animal proteins may cause adverse health effects to human life. Proteins derived from plant sources are less expensive and hence are more cost effective. Quality of proteins relies on several factors and biological value is one such factor. Proteins with major essential amino acid are with high biological value. Every plant source is deficient in one or more essential amino acids so it is recommended to include multiple plant-based diets. Also proteins obtained from plant sources are less palatable so it is important to add flavor in order to make it more palatable. The quality and quantity of the proteins also depend on the techniques used for isolation and purification of proteins. Elucidation of the structure of proteins involves the use of techniques like nuclear magnetic resonance, X-ray crystallography and spectroscopy. Apart from the structural analysis the functioning of the protein could be determined by amino acid sequencing which could be performed using mass spectroscopy. Ultrasound assisted extraction, enzyme assisted protein extraction and electro activation method are few of the isolation and purification method which can be used in isolation and purification of these proteins. Owing to the vast availability of plant-based proteins it has various industrial applications like, plant based protein can be used as a dairy substitute, plant based meat analogue and its use as bioactive peptides which have been briefly discussed in the review

    Transition metal cooperative Lewis pairs using platinum(0) piphosphine Mmonocarbonyl complexes as Lewis bases

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    The platinum(0)-diphosphine complex [Pt(CO)(L1)] (3, where L1 = 1,2-C6H4(CH2PtBu2)2) and its diphosphinite analogue [Pt(CO)(L2)] (11, where L2 = 1,2-C6H4(OPtBu2)2) act as Lewis bases in conjunction with the main group Lewis acid B(C6F5)3 to form frustrated or cooperative Lewis pairs. These systems activate dihydrogen, ethene/carbon monoxide, and phenylacetylene, leading to products that depend on the exact ligand used. These subtle changes to ligand structure influence reactivity, most notably in hydrogen activation where a variety of dinuclear species of the type [(diphos)Pt(μ-H)3Pt(diphos)]+ or [(diphos)Pt(μ-H)(μ-CO)Pt(diphos)]+ are observed. Activation of ethene with the Lewis pair leads to a previously reported coupling product and the mechanism is probed. The basicity of [Pt(CO)(L)] is demonstrated by deprotonation of phenylacetylene. Preliminary studies with an analogous palladium complex [Pd(CO)(L1)] 33 suggests related chemistry may be exploited for this metal. These results provide further examples of cooperative Lewis pair behavior in which one of the components is based on a transition metal complex

    Initial Results from the LIGO Newtonian Calibrator

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    The precise calibration of the strain readout of the LIGO gravitational wave observatories is paramount to the accurate interpretation of gravitational wave events. This calibration is traditionally done by imparting a known force on the test masses of the observatory via radiation pressure. Here we describe the implementation of an alternative calibration scheme: the Newtonian Calibrator. This system uses a rotor consisting of both quadrupole and hexapole mass distributions to apply a time-varying gravitational force on one of the observatory's test masses. The force produced by this rotor can be predicted to <1%<1\% relative uncertainty and is well-resolved in the readout of the observatory. This system currently acts as a cross-check of the existing absolute calibration system

    An evidence-based approach to the use of telehealth in long-term health conditions: development of an intervention and evaluation through pragmatic randomised controlled trials in patients with depression or raised cardiovascular risk

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    Background: Health services internationally are exploring the potential of telehealth to support the management of the growing number of people with long-term conditions (LTCs). Aim: To develop, implement and evaluate new care programmes for patients with LTCs, focusing on two common LTCs as exemplars: depression or high cardiovascular disease (CVD) risk. Methods Development: We synthesised quantitative and qualitative evidence on the effectiveness of telehealth for LTCs, conducted a qualitative study based on interviews with patients and staff and undertook a postal survey to explore which patients are interested in different forms of telehealth. Based on these studies we developed a conceptual model [TElehealth in CHronic disease (TECH) model] as a framework for the development and evaluation of the Healthlines Service for patients with LTCs. Implementation: The Healthlines Service consisted of regular telephone calls to participants from health information advisors, supporting them to make behaviour change and to use tailored online resources. Advisors sought to optimise participants’ medication and to improve adherence. Evaluation: The Healthlines Service was evaluated with linked pragmatic randomised controlled trials comparing the Healthlines Service plus usual care with usual care alone, with nested process and economic evaluations. Participants were adults with depression or raised CVD risk recruited from 43 general practices in three areas of England. The primary outcome was response to treatment and the secondary outcomes included anxiety (depression trial), individual risk factors (CVD risk trial), self-management skills, medication adherence, perceptions of support, access to health care and satisfaction with treatment. Trial results Depression trial: In total, 609 participants were randomised and the retention rate was 86%. Response to treatment [Patient Health Questionnaire 9-items (PHQ-9) reduction of ≥ 5 points and score of < 10 after 4 months] was higher in the intervention group (27%, 68/255) than in the control group (19%, 50/270) [odds ratio 1.7, 95% confidence interval (CI) 1.1 to 2.5; p = 0.02]. Anxiety also improved. Intervention participants reported better access to health support, greater satisfaction with treatment and small improvements in self-management, but not improved medication adherence. CVD risk trial: In total, 641 participants were randomised and the retention rate was 91%. Response to treatment (maintenance of/reduction in QRISK®2 score after 12 months) was higher in the intervention group (50%, 148/295) than in the control group (43%, 124/291), which does not exclude a null effect (odds ratio 1.3, 95% CI 1.0 to 1.9; p = 0.08). The intervention was associated with small improvements in blood pressure and weight, but not smoking or cholesterol. Intervention participants were more likely to adhere to medication, reported better access to health support and greater satisfaction with treatment, but few improvements in self-management. The Healthlines Service was likely to be cost-effective for CVD risk, particularly if the benefits are sustained, but not for depression. The intervention was implemented largely as planned, although initial delays and later disruption to delivery because of the closure of NHS Direct may have adversely affected participant engagement. Conclusion: The Healthlines Service, designed using an evidence-based conceptual model, provided modest health benefits and participants valued the better access to care and extra support provided. This service was cost-effective for CVD risk but not depression. These findings of small benefits at extra cost are consistent with previous pragmatic research on the implementation of comprehensive telehealth programmes for LTCs

    COVID-19: Rapid antigen detection for SARS-CoV-2 by lateral flow assay: A national systematic evaluation of sensitivity and specificity for mass-testing

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    Background Lateral flow device (LFD) viral antigen immunoassays have been developed around the world as diagnostic tests for SARS-CoV-2 infection. They have been proposed to deliver an infrastructure-light, cost-economical solution giving results within half an hour. Methods LFDs were initially reviewed by a Department of Health and Social Care team, part of the UK government, from which 64 were selected for further evaluation from 1st August to 15th December 2020. Standardised laboratory evaluations, and for those that met the published criteria, field testing in the Falcon-C19 research study and UK pilots were performed (UK COVID-19 testing centres, hospital, schools, armed forces). Findings 4/64 LFDs so far have desirable performance characteristics (orient Gene, Deepblue, Abbott and Innova SARS-CoV-2 Antigen Rapid Qualitative Test). All these LFDs have a viral antigen detection of >90% at 100,000 RNA copies/ml. 8951 Innova LFD tests were performed with a kit failure rate of 5.6% (502/8951, 95% CI: 5.1–6.1), false positive rate of 0.32% (22/6954, 95% CI: 0.20–0.48). Viral antigen detection/sensitivity across the sampling cohort when performed by laboratory scientists was 78.8% (156/198, 95% CI 72.4–84.3). Interpretation Our results suggest LFDs have promising performance characteristics for mass population testing and can be used to identify infectious positive individuals. The Innova LFD shows good viral antigen detection/sensitivity with excellent specificity, although kit failure rates and the impact of training are potential issues. These results support the expanded evaluation of LFDs, and assessment of greater access to testing on COVID-19 transmission. Funding Department of Health and Social Care. University of Oxford. Public Health England Porton Down, Manchester University NHS Foundation Trust, National Institute of Health Research

    Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

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    Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

    Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

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    BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
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