113 research outputs found

    Polling bias and undecided voter allocations: US Presidential elections, 2004 - 2016

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    Accounting for undecided and uncertain voters is a challenging issue for predicting election results from public opinion polls. Undecided voters typify the uncertainty of swing voters in polls but are often ignored or allocated to each candidate in a simple, deterministic manner. Historically this may have been adequate because the undecided were comparatively small enough to assume that they do not affect the relative proportions of the decided voters. However, in the presence of high numbers of undecided voters, these static rules may in fact bias election predictions from election poll authors and meta-poll analysts. In this paper, we examine the effect of undecided voters in the 2016 US presidential election to the previous three presidential elections. We show there were a relatively high number of undecided voters over the campaign and on election day, and that the allocation of undecided voters in this election was not consistent with two-party proportional (or even) allocations. We find evidence that static allocation regimes are inadequate for election prediction models and that probabilistic allocations may be superior. We also estimate the bias attributable to polling agencies, often referred to as "house effects".Comment: 32 pages, 9 figures, 6 table

    Testing and comparing conditional risk-return relationship with a new approach in the cross-sectional framework

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    This paper presents an innovative approach in examining the conditional relationship between beta and returns for stocks traded on S&P 500 for the period from July 2001 to June 2011. We challenge other competitive models with portfolios formed based on the book value per share and betas using monthly data. A novel approach for capturing time variation in betas whose pattern is treated as a function of market returns is developed and presented. The estimated coefficients of a nonlinear regression constitute the basis of creating a two factor model. Our results indicate that the proposed specification surpasses alternative models in explaining the cross‐section of returns. The implications of this study show that the proposed new risk factors that found to be significant both in time series and cross‐section analyses provide valuable information in better understanding the characteristics of returns, targeting the reinforcement of stock market efficiency, and the capital allocation procedure

    Quantum computing in optical microtraps based on the motional states of neutral atoms

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    We investigate quantum computation with neutral atoms in optical microtraps where the qubit is implemented in the motional states of the atoms, i.e., in the two lowest vibrational states of each trap. The quantum gate operation is performed by adiabatically approaching two traps and allowing tunneling and cold collisions to take place. We demonstrate the capability of this scheme to realize a square-root of swap gate, and address the problem of double occupation and excitation to other unwanted states. We expand the two-particle wavefunction in an orthonormal basis and analyze quantum correlations throughout the whole gate process. Fidelity of the gate operation is evaluated as a function of the degree of adiabaticity in moving the traps. Simulations are based on rubidium atoms in state-of-the-art optical microtraps with quantum gate realizations in the few tens of milliseconds duration range.Comment: 11 pages, 7 figures, for animations of the gate operation, see http://www.itp.uni-hannover.de/~eckert/na/index.htm

    Raccomandazioni per l’identificazione e la gestione dei risultati critici nei laboratori clinici

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    Critical results (also known as panic or alarm results) identify a laboratory test result associated with a serious risk for the patient's health, requiring immediate communication to the physician to establish appropriate therapeutic interventions. The adoption of an efficient procedure for the communication of critical values/results is crucial for clinical, ethical, organizational reasons, because it is a requirement for laboratory accreditiation and because of potential legal consequences related to the lack of notification of harmful laboratory results. In 2008, the Italian Society of Clinical Biochemistry and Laboratory Medicine (SIBioC) published its first consensus-based recommendation for the detection and management of critical values in clinical laboratories, with the aim to improve the implementation of standardized and universally accepted procedures, promoting an essential policy toward rational and efficient solutions to this issue. These new recommendations represent a complete review of the first document. Using the same consensus conference method between experts of scientific societies, the main aspects of clinical risk, patient safety and legal liability of health care workers were re-considered. The SIBioC and the Italian Society of Laboratory Medicine (SIPMeL), Intersociety Study Group on Standardization of extra-analytical variability of laboratory results, together with the Italian Society of Ergonomics and Human Factors (SIE) collaboration, issued the present join document

    Genetic instability in the tumor microenvironment: a new look at an old neighbor

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    Accelerated Partial Breast Irradiation (APBI): A review of available techniques

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    Breast conservation therapy (BCT) is the procedure of choice for the management of the early stage breast cancer. However, its utilization has not been maximized because of logistics issues associated with the protracted treatment involved with the radiation treatment. Accelerated Partial Breast Irradiation (APBI) is an approach that treats only the lumpectomy bed plus a 1-2 cm margin, rather than the whole breast. Hence because of the small volume of irradiation a higher dose can be delivered in a shorter period of time. There has been growing interest for APBI and various approaches have been developed under phase I-III clinical studies; these include multicatheter interstitial brachytherapy, balloon catheter brachytherapy, conformal external beam radiation therapy and intra-operative radiation therapy (IORT). Balloon-based brachytherapy approaches include Mammosite, Axxent electronic brachytherapy and Contura, Hybrid brachytherapy devices include SAVI and ClearPath. This paper reviews the different techniques, identifying the weaknesses and strength of each approach and proposes a direction for future research and development. It is evident that APBI will play a role in the management of a selected group of early breast cancer. However, the relative role of the different techniques is yet to be clearly identified
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