1,175 research outputs found

    A new policy paradigm from the LSE Maryam Forum: 5. treat disinformation as a systemic risk to democracy

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    Disinformation has polarised democratic societies and threatens to make common, evidence-based debate impossible. Peter Pomerantsev (LSE and Johns Hopkins), Piroska Nagy-Mohácsi (LSE), Ben Grazda (LSE) and the LSE Maryam Forum Democracy and Disinformation Working Group suggest how to turn the tide. In the past, non-democracies were defined by censorship and control over media, while democracies guaranteed freedom ... Continue

    New aspects of the continuous phase transition in the scalar noise model (SNM) of collective motion

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    In this paper we present our detailed investigations on the nature of the phase transition in the scalar noise model (SNM) of collective motion. Our results confirm the original findings of Vicsek et al. [Phys. Rev. Lett. 75 (1995) 1226] that the disorder-order transition in the SNM is a continuous, second order phase transition for small particle velocities (v≤0.1v\leq 0.1). However, for large velocities (v≥0.3v\geq 0.3) we find a strong anisotropy in the particle diffusion in contrast with the isotropic diffusion for small velocities. The interplay between the anisotropic diffusion and the periodic boundary conditions leads to an artificial symmetry breaking of the solutions (directionally quantized density waves) and a consequent first order transition like behavior. Thus, it is not possible to draw any conclusion about the physical behavior in the large particle velocity regime of the SNM.Comment: 13 pages, 11 figure

    Computing generalized inverses using LU factorization of matrix product

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    An algorithm for computing {2, 3}, {2, 4}, {1, 2, 3}, {1, 2, 4} -inverses and the Moore-Penrose inverse of a given rational matrix A is established. Classes A(2, 3)s and A(2, 4)s are characterized in terms of matrix products (R*A)+R* and T*(AT*)+, where R and T are rational matrices with appropriate dimensions and corresponding rank. The proposed algorithm is based on these general representations and the Cholesky factorization of symmetric positive matrices. The algorithm is implemented in programming languages MATHEMATICA and DELPHI, and illustrated via examples. Numerical results of the algorithm, corresponding to the Moore-Penrose inverse, are compared with corresponding results obtained by several known methods for computing the Moore-Penrose inverse

    Time-Dependent Pseudo-Hermitian Hamiltonians Defining a Unitary Quantum System and Uniqueness of the Metric Operator

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    The quantum measurement axiom dictates that physical observables and in particular the Hamiltonian must be diagonalizable and have a real spectrum. For a time-independent Hamiltonian (with a discrete spectrum) these conditions ensure the existence of a positive-definite inner product that renders the Hamiltonian self-adjoint. Unlike for a time-independent Hamiltonian, this does not imply the unitarity of the Schroedinger time-evolution for a general time-dependent Hamiltonian. We give an additional necessary and sufficient condition for the unitarity of time-evolution. In particular, we obtain the general form of a two-level Hamiltonian that fulfils this condition. We show that this condition is geometrical in nature and that it implies the reality of the adiabatic geometric phases. We also address the problem of the uniqueness of the metric operator.Comment: 11 pages, published versio

    The L3Pilot Data Management Toolchain for a Level 3 Vehicle Automation Pilot

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    As industrial research in automated driving is rapidly advancing, it is of paramount importance to analyze field data from extensive road tests. This paper investigates the design and development of a toolchain to process and manage experimental data to answer a set of research questions about the evaluation of automated driving functions at various levels, from technical system functioning to overall impact assessment. We have faced this challenge in L3Pilot, the first comprehensive test of automated driving functions (ADFs) on public roads in Europe. L3Pilot is testing ADFs in vehicles made by 13 companies. The tested functions are mainly of Society of Automotive Engineers (SAE) automation level 3, some of them of level 4. In this context, the presented toolchain supports various confidentiality levels, and allows cross-vehicle owner seamless data management, with the efficient storage of data and their iterative processing with a variety of analysis and evaluation tools. Most of the toolchain modules have been developed to a prototype version in a desktop/cloud environment, exploiting state-of-the-art technology. This has allowed us to efficiently set up what could become a comprehensive edge-to-cloud reference architecture for managing data in automated vehicle tests. The project has been released as open source, the data format into which all vehicular signals, recorded in proprietary formats, were converted, in order to support efficient processing through multiple tools, scalability and data quality checking. We expect that this format should enhance research on automated driving testing, as it provides a shared framework for dealing with data from collection to analysis. We are confident that this format, and the information provided in this article, can represent a reference for the design of future architectures to implement in vehicles

    The IIP Examination: an Analysis of Group Performance 2009–2011

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    Developing a flexible automated continuous downstream processing system for research to clinical supply

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    Continuous manufacturing has gained a lot of attention over the last 10-15 years for numerous reasons such as the potential for higher efficiencies, reduced cost of goods, and improved product quality. However, the adoption of these technologies has been slow due to concerns over operating these processes in a GMP manufacturing environment. Some of these concerns relate to the operation of multiple continuous unit operations in an integrated process sequence. This presentation will highlight these concerns and show how these issues were addressed by developing an overarching automated and modular platform which can be easily reconfigured for processing most products. The developed automation platform is the result of a project funded by Innovate UK that brings together a number of biopharmaceutical companies including Allergan, AstraZeneca, Fujifilm Diosynth Biotechnologies and GSK to identify and address these issues. One objective of the project is to develop a flexible automated biologics downstream process consisting of multiple unit operations that can be rapidly reconfigured for manufacturing different products. To that end the process has been design with modularity in mind with each module having common inputs and outputs. The automation software has also been developed in a way that most typical downstream processes can be implemented in the system with little to no software updates. The ability to rapidly reconfigure the process has been demonstrated by using the system to produce three products with different process sequences. Another issue that inhibits the adoption of continuous technologies is the concern over simultaneously operating multiple unit operations. This presentation will detail how the automation software was developed to control both the key unit operations such as chromatography and filtration steps but also intermediate operations such as feed conditioning and viral inactivation steps. The automated system reduces the complexity of downstream processes, which can have in excess of eleven unit operations, to a single user-friendly interface. Implementing this control platform enables a single operator to control the entire process. This presentation will also detail how the automation strategy has been developed to enable a single operator to deal with start-up/shutdown, perturbations in the process and mid-process equipment turnover. It will highlight the challenges that have been faced when developing this system and how these have been overcome. The aim of this project was to improve efficiency by reducing processing time when compared to the current batch process and this was demonstrated by testing the system with three different products (a MAb and a MAb fusion protein). Furthermore, this presentation with show data from the production of three products that demonstrates comparability between the continuous process and the original batch processes. It will then detail how this was used to demonstrate the production of a large-scale clinical batch run

    Treatment response and remission in a double-blind, randomized, head-to-head study of lisdexamfetamine dimesylate and atomoxetine in children and adolescents with attention-deficit hyperactivity disorder

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    The Author(s) 2014. This article is published with open access at Springerlink.com Objectives A secondary objective of this head-to-head study of lisdexamfetamine dimesylate (LDX) and ato-moxetine (ATX) was to assess treatment response rates in children and adolescents with attention-deficit hyperactiv-ity disorder (ADHD) and an inadequate response to methylphenidate (MPH). The primary efficacy and safety outcomes of the study, SPD489-317 (ClinicalTrials.gov NCT01106430), have been published previously. Methods In this 9-week, double-blind, active-controlled study, patients aged 6–17 years with a previous inadequate response to MPH were randomized (1:1) to dose-optimized LDX (30, 50 or 70 mg/day) or ATX (patients \70 kg: 0.5–1.2 mg/kg/day, not to exceed 1.4 mg/kg/day; patients C70 kg: 40, 80 or 100 mg/day). Treatment response was a secondary efficacy outcome and was predefined as a reduction from baseline in ADHD Rating Scale IV (ADHD-RS-IV) total score of at least 25, 30 or 50 %. Sustained response was predefined as a reduction from baseline in ADHD-RS-IV total score (C25, C30 or C50 %) or a Clinical Global Impressions (CGI)–Improvement (CGI–I) score of 1 or 2 throughout weeks 4–9. CGI– Severity (CGI–S) scores were also assessed, as an indicator of remission. Results A total of 267 patients were enrolled (LDX, n = 133; ATX, n = 134) and 200 completed the study (LDX, n = 99; ATX, n = 101). By week 9, significantly (p \ 0.01) greater proportions of patients receiving LDX than ATX met the response criteria of a reduction from baseline in ADHD-RS-IV total score of at least 25 % (90.5 vs. 76.7 %), 30 % (88.1 vs. 73.7 %) or 50 % (73.0 vs. 50.4 %). Sustained response rates were also signifi-cantly (p \ 0.05) higher among LDX-treated patient

    Preconception insulin resistance and neonatal birth weight in women with obesity:role of bile acids

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    Research question: Does maternal preconception insulin resistance affect neonatal birth weight among women with obesity? Is insulin resistance associated with circulating bile acids? Do bile acids influence the association between maternal preconception insulin resistance and neonatal birth weight? Design: An exploratory post-hoc analysis of the LIFEstyle randomized controlled trial comparing lifestyle intervention with conventional infertility treatment in women with a BMI of ≥29 kg/m2. Fasting blood samples were collected at randomization and after 3 and 6 months in 469 women. Insulin resistance was quantified using the homeostasis model assessment of insulin resistance (HOMA-IR). Bile acid sub-species were determined by liquid chromatography with tandem mass spectrometry. Singletons were included (n = 238). Birth weight Z-scores were adjusted for age, offspring gender and parity. Multilevel analysis and linear regressions were used. Results: A total of 913 pairs of simultaneous preconception HOMA-IR (median [Q25; Q75]: 2.96 [2.07; 4.16]) and total bile acid measurements (1.79 [1.10; 2.94]) µmol/l were taken. Preconception HOMA-IR was positively associated with total bile acids (adjusted B 0.15; 95% CI 0.09 to 0.22; P < 0.001) and all bile acid sub-species. At the last measurement before pregnancy, HOMA-IR (2.71 [1.91; 3.74]) was positively related to birth weight Z-score (mean ± SD 0.4 ± 1.1; adjusted B 0.08; 95% CI 0.01 to 0.14; P = 0.03). None of the preconception bile acids measured were associated with birth weight. Conclusion: Maternal preconception insulin resistance is an important determinant of neonatal birth weight in women with obesity, whereas preconception bile acids are not
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