Developing points-based risk-scoring systems in the presence of competing risks.

Predicting the occurrence of an adverse event over time is an important issue in clinical medicine. Clinical prediction models and associated points-based risk-scoring systems are popular statistical methods for summarizing the relationship between a multivariable set of patient risk factors and the risk of the occurrence of an adverse event. Points-based risk-scoring systems are popular amongst physicians as they permit a rapid assessment of patient risk without the use of computers or other electronic devices. The use of such points-based risk-scoring systems facilitates evidence-based clinical decision making. There is a growing interest in cause-specific mortality and in non-fatal outcomes. However, when considering these types of outcomes, one must account for competing risks whose occurrence precludes the occurrence of the event of interest. We describe how points-based risk-scoring systems can be developed in the presence of competing events. We illustrate the application of these methods by developing risk-scoring systems for predicting cardiovascular mortality in patients hospitalized with acute myocardial infarction. Code in the R statistical programming language is provided for the implementation of the described methods. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd

Noiseless Linear Amplification and Loss-Tolerant Quantum Relay using Coherent State Superpositions

Noiseless linear amplification (NLA) is useful for a wide variety of quantum protocols. Here we propose a fully scalable amplifier which, for asymptotically large sizes, can perform perfect fidelity NLA on any quantum state. Given finite resources however, it is designed to perform perfect fidelity NLA on coherent states and their arbitrary superpositions. Our scheme is a generalisation of the multi-photon quantum scissor teleamplifier, which we implement using a coherent state superposition resource state. Furthermore, we prove our NLA is also a loss-tolerant relay for multi-ary phase-shift keyed coherent states. Finally, we demonstrate that our NLA is also useful for continuous-variable entanglement distillation, even with realistic experimental imperfections.Comment: 14 pages, 9 figure

Ideal Quantum Tele-amplification up to a Selected Energy Cut-off using Linear Optics

We introduce a linear optical technique that can implement ideal quantum tele-amplification up to the $n^\mathrm{th}$ Fock state, where $n$ can be any positive integer. Here tele-amplification consists of both quantum teleportation and noiseless linear amplification (NLA). This simple protocol consists of a beam-splitter and an $(n+1)$-splitter, with $n$ ancillary photons and detection of $n$ photons. For a given target fidelity, our technique improves success probability and physical resource costs by orders of magnitude over current alternative teleportation and NLA schemes. We show how this protocol can also be used as a loss-tolerant quantum relay for entanglement distribution and distillation.Comment: 6 pages (main) + 16 pages (supplementary), 5 figures (main) + 11 figures (supplementary). Main change is the addition of a new section describing how our scheme still works well given experimental imperfections + additional success probability paragrap

Saturating the Maximum Success Probability Bound for Noiseless Linear Amplification using Linear Optics

A noiseless linear amplifier (NLA) performs the highest quality amplification allowable under the rules of quantum physics. Unfortunately, these same rules conspire against us via the no-cloning theorem, which constrains NLA operations to the domain of probabilistic processes. Nevertheless, they are useful for a wide variety of quantum protocols, with numerous proposals assuming access to an optimal NLA device which performs with the maximum possible success probability. Here we propose the first linear optics NLA protocol which asymptotically achieves this success probability bound, by modifying the Knill-Laflamme-Milburn near-deterministic teleporter into an amplifier.Comment: 11 pages, 5 figures. Updated reference

Improving Continuous-variable Quantum Channels with Unitary Averaging

A significant hurdle for quantum information and processing using bosonic systems are stochastic phase errors, which are likely to occur as the photons propagate through a channel. We propose and demonstrate a scheme of passive, linear optical unitary averaging for protecting Gaussian channels. The scheme requires only linear optical elements and vacuum detectors, and protects against a loss of purity, squeezing and entanglement. We present numerical simulations and analytical formula, tailored for currently relevant parameters with low noise levels, where our approximations perform exceptionally well. We also show the asymptotic nature of the protocol, highlighting both current and future relevance.Comment: 6 pages, 7 figures, 1 tabl

Mud Loss Estimation using Machine Learning Approach

Lost circulation costs are a significant expense in drilling oil and gas wells. Drilling anywhere in the Rumaila field, one the world\u27s largest oilfields, requires penetrating the Dammam formation, which is notorious for lost circulation issues and thus a great source of information on lost circulation events. This paper presents a new, more precise model to predict lost circulation volumes, equivalent circulation density (ECD), and rate of penetration (ROP) in the Dammam formation. A larger data set, more systematic statistical approach, and a machine-learning algorithm have produced statistical models that give a better prediction of the lost circulation volumes, ECD, and ROP than the previous models for events. This paper presents the new model, validates the key elements impacting lost circulation in the Dammam formation, and compares the predicted outcomes to those from the older model. The work previously presented by Al-Hameedi et al. (http://www.onepetro.org, 2017a; http://www.AADE.org, 2017b) provided a platform for predicting the severity of lost circulation incidents in the Dammam formation. Using the new models, the predictions closely track actual field incidents of lost circulation. When new lost circulation events were compared with predictions from the old and new models, the new model presented a much tighter prediction of events. Three equations for optimizing operations were developed from these models focusing on the elements that have the highest degree of impact. The total flow area of the nozzles was determined to be a significant factor in the ROP model indicating that nozzle size should be chosen carefully to achieve optimal ROP. Good modeling of projected lost circulation events can assist in evaluating the effectiveness of new treatments for lost circulation. The Dammam formation is a significant source of lost circulation in a major oilfield and warrants evaluation of the effectiveness of lost circulation treatments. These techniques can be applied to other fields and formations to better understand the economic impact of lost circulation and evaluate the effectiveness of various lost circulation mitigation efforts

The ambivalent shadow of the pre-Wilsonian rise of international law

The generation of American international lawyers who founded the American Society of International Law in 1906 and nurtured the soil for what has been retrospectively called a “moralistic legalistic approach to international relations” remains little studied. A survey of the rise of international legal literature in the U.S. from the mid-19th century to the eve of the Great War serves as a backdrop to the examination of the boosting effect on international law of the Spanish American War in 1898. An examination of the Insular Cases before the US Supreme Court is then accompanied by the analysis of a number of influential factors behind the pre-war rise of international law in the U.S. The work concludes with an examination of the rise of natural law doctrines in international law during the interwar period and the critiques addressed.by the realist founders of the field of “international relations” to the “moralistic legalistic approach to international relation

The mechanism of differential neutralization of dengue serotype 3 strains by monoclonal antibody 8A1

While previous studies have demonstrated that envelope (E) glycoprotein variation between dengue viruses (DENV) genotypes can influence antibody neutralization potency, the mechanisms of variable neutralization remain incompletely understood. Here we characterize epitope antibody interactions of a DENV-3 EDIII binding mouse mAb 8A1 which displays highly variable neutralizing activity against DENV-3 genotypes. Using a DENV-3 reverse genetics platform, we characterize ability of 8A1 to bind and neutralize naturally occurring DENV-3 E genotypic variant viruses. Introduction of single and multiple amino acid mutations into the parental clone background demonstrates that mutations at positions 301 and 383 on EDIII are responsible for 8A1 differential neutralization phenotypes. ELISA and surface plasmon resonance (SPR) studies indicate differences in binding are responsible for the variable neutralization. Variability at position 301 primarily determined binding difference through influencing antibody-EDIII dissociation rate. Our findings are relevant to the many groups focusing on DENV EDIII as a vaccine target

The mechanism of differential neutralization of dengue serotype 3 strains by monoclonal antibody 8A1

While previous studies have demonstrated that envelope (E) glycoprotein variation between dengue viruses (DENV) genotypes can influence antibody neutralization potency, the mechanisms of variable neutralization remain incompletely understood. Here we characterize epitope antibody interactions of a DENV-3 EDIII binding mouse mAb 8A1 which displays highly variable neutralizing activity against DENV-3 genotypes. Using a DENV-3 reverse genetics platform, we characterize ability of 8A1 to bind and neutralize naturally occurring DENV-3 E genotypic variant viruses. Introduction of single and multiple amino acid mutations into the parental clone background demonstrates that mutations at positions 301 and 383 on EDIII are responsible for 8A1 differential neutralization phenotypes. ELISA and surface plasmon resonance (SPR) studies indicate differences in binding are responsible for the variable neutralization. Variability at position 301 primarily determined binding difference through influencing antibody-EDIII dissociation rate. Our findings are relevant to the many groups focusing on DENV EDIII as a vaccine target

Using Stars, Not Just ‘Reading’ Them:The roles and functions of film stars in mother-daughter relations

This article explores the various and important ways in which film stars can function within mother-daughter relations over the life-cycle of their relationship. Drawing on detailed qualitative material from an interdisciplinary audience study of mothers’ and daughters’ shared relations to film stars, it demonstrates how a significant shift can be identified with regard to the kinds of roles that stars play in dyadic relations as a daughter experiences various developmental and transitional phases to adulthood. Necessitating an alternative approach to those previously employed within Star and Celebrity Studies, the article takes a significant new perspective on the study of audiences for stars from the work of art anthropologist Alfred Gell (1998) and proposes a move away from semiotic, ‘textualist’ readings of stars towards an ‘action’-centred exploration of the ways in which films stars are used and function in social interactions over the life-cycle of personal relationships