396 research outputs found

    Sometimes, Money Does Grow On Trees: Data-Driven Demand Response with DR-Advisor

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    Real-time electricity pricing and demand response has become a clean, reliable and cost-effective way of mitigating peak demand on the electricity grid. We consider the problem of end-user demand response (DR) for large commercial buildings which involves predicting the demand response baseline, evaluating fixed DR strategies and synthesizing DR control actions for load curtailment in return for a financial reward. Using historical data from the building, we build a family of regression trees and learn data-driven models for predicting the power consumption of the building in real-time. We present a method called DR-Advisor called DR-Advisor, which acts as a recommender system for the building\u27s facilities manager and provides suitable control actions to meet the desired load curtailment while maintaining operations and maximizing the economic reward. We evaluate the performance of DR-Advisor for demand response using data from a real office building and a virtual test-bed

    Quality of life in survivors after cervical artery dissection

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    Background and purpose : Little data exists about longterm outcome, quality of life (QOL) and its predictors after spontaneous cervical artery dissections (sCAD). Methods : Clinical and radiological data of 114 patients with sCAD were collected prospectively. Six patients died within 3 months, the remaining 108 were contacted after a mean of 1498 days (range: 379-3455), 99 survivors (92 %) replied. QOL, assessed with the stroke-specific QOL scale (SSQOL), and functional abilities, measured with modified Rankin Scale (mRS) were compared, and predictors of QOL were analyzed. Subgroup analyses were performed for patients with ischemic stroke, those with isolated local symptoms or transient ischemic symptoms and those without significant disabilities (mRS 0-1) at follow-up. Results : Seventy-one of 99 patients (72 %) had no significant disability, but only 53 (54 %) reported a good QOL (SS-QOL ≥ 4). Compared to the self-rated premorbid QOL of all patients, SS-QOL was impaired after sCAD (p 0.5). High National Institute of Health Stroke Scale score on admission and higher age were independent predictors of impaired QOL (p < 0.05). Conclusion : QOL is impaired in almost half of long-term survivors after sCAD, even in patients with local or transient symptoms or without functional disability. Impairment of QOL is a surprisingly frequent long-term sequela after sCAD and deserves attention as an outcome measure in these patient

    Data Predictive Control for Peak Power Reduction

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    Decisions on how best to optimize today\u27s energy systems operations are becoming ever so complex and conflicting such that model-based predictive control algorithms must play a key role. However, learning dynamical models of energy consuming systems such as buildings, using grey/white box approaches is very cost and time prohibitive due to its complexity. This paper presents data-driven methods for making control-oriented model for peak power reduction in buildings. Specifically, a data predictive control with regression trees (DPCRT) algorithm, is presented. DPCRT is a finite receding horizon method, using which the building operator can optimally trade off peak power reduction against thermal comfort without having to learn white/grey box models of the systems dynamics. We evaluate the performance of our method using a DoE commercial reference virtual test-bed and show how it can be used for learning predictive models with 90% accuracy, and for achieving 8.6% reduction in peak power and costs

    Efficacy and safety of universal valganciclovir prophylaxis combined with a tacrolimus/mycophenolate-based regimen in kidney transplantation.

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    BACKGROUND: Immunosuppressive and antiviral prophylactic drugs are needed to prevent acute rejection and infection after transplantation. We assessed the efficacy and safety of the introduction of universal valganciclovir prophylaxis in combination with a tacrolimus/mycophenolate-based regimen in kidney transplantation at our centre. METHODS: We reviewed all consecutive patients who underwent kidney transplantation over a 5.5-year period. Patients transplanted from January 2000 to March 2003 (period 1) were compared to patients from April 2003 to July 2005 (period 2). In period 1 patients were treated with basiliximab, cyclosporine, steroids and mycophenolate (or azathioprine). Prophylaxis with valacyclovir was prescribed in cytomegalovirus (CMV) D+/R- patients, while any R+ patients were managed with a preemptive approach. In period 2, immunosuppression consisted of basiliximab or thymoglobulin induction, tacrolimus, steroids and mycophenolate. Three-month CMV prophylaxis with valganciclovir was used in all at-risk patients. RESULTS: Data analysis included 73 patients (period 1) and 70 (period 2). Acute rejection was more frequent in period 1 than in period 2 (42% vs 7%, p &lt;0.001). Overall, 30% of patients in period 1 were diagnosed with CMV infection/disease requiring antiviral treatment, compared with 11.4% in period 2 (p = 0.003). Late-onset CMV disease remained a problem in D+/R- patients in both periods. There was no difference in incidence of BK virus nephropathy, fungal infections, PTLD, graft loss or mortality. However, 4 cases (5.7%) of delayed transient asymptomatic agranulocytosis were observed in period 2. CONCLUSIONS: The present analysis indicates that the combined regimen introduced in period 2 improved clinical results with a significant decrease in acute rejection and in CMV infection/disease incidence. However, a unique syndrome of delayed transient agranulocytosis probably due to drug myelotoxicity was observed in a subset of patients

    DIFFUSE IDIOPATHIC SKELETAL HYPEROSTOSIS (DISH) OF THE SHOULDER: A CAUSE OF SHOULDER PAIN?

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    Shoulder pain is a common complaint and shoulder hyperostosis a frequent radiological condition. However, little is known about the association between the clinical and radiological findings. To evaluate the clinical relevance of shoulder hyperostosis we performed a controlled, blind study of 99 hospitalized probands with and without thoracospinal hyperostosis on lateral chest X-rays. The study included grading of the shoulder hyperostosis on the basis of three bilateral standard radiographs, assessing shoulder pain in a standardized way by an interviewer and recording extraskeletal causes of shoulder pain. The prevalence of shoulder hyperostosis was doubled in probands with thoracospinal hyperostosis compared to controls (X2= 5.90, F>0.025, n = 99). Shoulder hyperostosis, irrespective of thoracospinal hyperostosis, predisposed to shoulder pain (40% versus 18%, x2 = 4.06, F>0.05, n = 74). Shoulder hyperostosis in combination with thoracospinal hyperostosis (shoulder DISH) predisposed to shoulder pain to an even greater extent (46% versus 12%, x2 = 6.64, P>0.01, n = 47). We conclude that shoulder hyperostosis is a radiological finding of potential clinical relevanc

    Political institutions and debt crises

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    This paper shows that political institutions matter in explaining defaults on external and domestic debt obligations. We explore a large number of political and macroeconomic variables using a non-parametric technique to predict safety from default. The advantage of this technique is that it is able to identify patterns in the data that are not captured in standard probit analysis. We find that political factors matter, and do so in different ways for democratic and non-democratic regimes, and for domestic and external debt. In democracies, a parliamentary system or sufficient checks and balances almost guarantee the absence of default on external debt when economic fundamentals or liquidity are sufficiently strong. In dictatorships, high stability and tenure play a similar role for default on domestic debt

    Update of the Swiss guidelines on post-treatment Lyme disease syndrome.

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    Lyme borreliosis is caused by Borrelia burgdorferi sensu lato infection, which responds well to antibiotic therapy in the overwhelming majority of cases. However, despite adequate antibiotic treatment some patients report persisting symptoms which are commonly summarised as post-treatment Lyme disease syndrome (PTLDS). In 2005, the Swiss Society of Infectious Diseases published a case definition for PTLDS. We aimed to review the scientific literature with a special emphasis on the last 10 years, questioning whether the definitions from 2005 are still valid in the light of current knowledge. Furthermore, we describe the clinical history of infection with Borrelia burgdorferi sensu lato, the estimated prevalence of PTLDS, the possible pathogenesis of PTLDS, and treatment options with an emphasis on clinical studies. In summary, we were unable to find a scientific reason for modification of the PTLDS definitions published in 2005. Thus, the diagnostic criteria remain unchanged, namely documented clinical and laboratory evidence of previous infection with B. burgdorferi, a completed course of appropriate antibiotic therapy, symptoms including fatigue, arthralgia, myalgia, cognitive dysfunction or radicular pain persisting for &gt;6 months, a plausible timely association between documented B. burgdorferi infection and onset of symptoms (i.e., persistent or recurrent symptoms that began within 6 months of completion of a recommended antibiotic therapy for early or late Lyme borreliosis), and exclusion of other somatic or psychiatric causes of symptoms. The main therapeutic options remain cognitive behavioural therapy and low-impact aerobic exercise programmes. Growing and unequivocal evidence confirms that prolonged or repeated antibiotic therapy for PTLDS is not beneficial, but potentially harmful and therefore contraindicated. The Guidelines of the Swiss Society of Infectious Diseases offer an evidence based, diagnostic and therapeutic framework for physicians caring for patients suffering from presumptive PTLDS in Switzerland

    The Welfare Cost of Argentine Risk

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    In this paper we do a couple of things: discussing a way to measure the welfare cost of country risk, and measuring it for Argentina in the period 1875-2006. There are two conclusions: a) the welfare cost of Argentine risk has been huge: for example, in the period 1976-2006 it was around 20% of GDP, several times larger than the welfare cost of any conventional distortion; b) this cost would be wholly paid by labor. These fascinating results deserve further investigation

    Fiscal Deficit, Macro-Uncertainty, and Growth in Argentina

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    We analyze the relationship between fiscal deficit, macroeconomic uncertainty and growth for the period 1915-2006, and conclude that the deficit, possibly through the volatility in relative prices it generates, is a significant restriction on per-capita income growth in Argentina

    Crypto-currency bubbles: an application of the Phillips–Shi–Yu (2013) methodology on Mt. Gox bitcoin prices

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    The creation of bitcoin heralded the arrival of digital or crypto-currency and has been regarded as a phenomenon. Since its introduction, it has experienced a meteoric rise in price and rapid growth accompanied by huge volatility swings, and also attracted plenty of controversies which even involved law enforcement agencies. Hence, claims abound that bitcoin has been characterized by bubbles ready to burst any time (e.g. the recent collapse of bitcoin’s biggest exchange, Mt Gox). This has earned plenty of coverage in the media but surprisingly not in the academic literature. We therefore fill this knowledge gap. We conduct an econometric investigation of the existence of bubbles in the bitcoin market based on a recently developed technique that is robust in detecting bubbles – that of Phillips et al. (2013a). Over the period 2010–2014, we detected a number of short-lived bubbles; most importantly, we found three huge bubbles in the latter part of the period 2011–2013 lasting from 66 to 106 days, with the last and biggest one being the one that ‘broke the camel’s back’ – the demise of the Mt Gox exchange
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