Electrostatic Field Classifier for Deficient Data

This paper investigates the suitability of recently developed models based on the physical field phenomena for classification problems with incomplete datasets. An original approach to exploiting incomplete training data with missing features and labels, involving extensive use of electrostatic charge analogy, has been proposed. Classification of incomplete patterns has been investigated using a local dimensionality reduction technique, which aims at exploiting all available information rather than trying to estimate the missing values. The performance of all proposed methods has been tested on a number of benchmark datasets for a wide range of missing data scenarios and compared to the performance of some standard techniques. Several modifications of the original electrostatic field classifier aiming at improving speed and robustness in higher dimensional spaces are also discussed

X-ray Lighthouses of the High-Redshift Universe. II. Further Snapshot Observations of the Most Luminous z>4 Quasars with Chandra

We report on Chandra observations of a sample of 11 optically luminous (Mb<-28.5) quasars at z=3.96-4.55 selected from the Palomar Digital Sky Survey and the Automatic Plate Measuring Facility Survey. These are among the most luminous z>4 quasars known and hence represent ideal witnesses of the end of the "dark age ''. Nine quasars are detected by Chandra, with ~2-57 counts in the observed 0.5-8 keV band. These detections increase the number of X-ray detected AGN at z>4 to ~90; overall, Chandra has detected ~85% of the high-redshift quasars observed with snapshot (few kilosecond) observations. PSS 1506+5220, one of the two X-ray undetected quasars, displays a number of notable features in its rest-frame ultraviolet spectrum, the most prominent being broad, deep SiIV and CIV absorption lines. The average optical-to-X-ray spectral index for the present sample (=-1.88+/-0.05) is steeper than that typically found for z>4 quasars but consistent with the expected value from the known dependence of this spectral index on quasar luminosity. We present joint X-ray spectral fitting for a sample of 48 radio-quiet quasars in the redshift range 3.99-6.28 for which Chandra observations are available. The X-ray spectrum (~870 counts) is well parameterized by a power law with Gamma=1.93+0.10/-0.09 in the rest-frame ~2-40 keV band, and a tight upper limit of N_H~5x10^21 cm^-2 is obtained on any average intrinsic X-ray absorption. There is no indication of any significant evolution in the X-ray properties of quasars between redshifts zero and six, suggesting that the physical processes of accretion onto massive black holes have not changed over the bulk of cosmic time.Comment: 15 pages, 7 figures, accepted for publication in A

Generic, disease-specific and individualised approaches to measuring health-related quality of life among people with heart disease - a comparative analysis

Increasing emphasis is being placed on the evaluation of health-related quality of life. However, there is no consensus on the definition of this concept and as a result there are a plethora of existing measurement instruments. Head-to-head comparisons of the psychometric properties of existing instruments are necessary to facilitate evidence-based decisions about which instrument should be chosen for routine use. Therefore, an individualised instrument (the modified Patient Generated Index), a generic instrument (the Short Form 36) and a disease-specific instrument (the Quality of Life after Myocardial Infarction questionnaire) were administered to patients with ischaemic heart disease (n=117) and the evidence for the validity, reliability and sensitivity of each instrument was examined and compared. The modified Patient Generated Index compared favourably with the other instruments but none of the instruments examined provided sound evidence for sensitivity to change. Therefore, any recommendation for the use of the individualised approach in the routine collection of health-related quality of life data in clinical practice must be conditional upon the submission of further evidence to support the sensitivity of such instruments

Enhancing creative problem solving and creative self-efficacy: a preliminary study

The ability to improve creative problem solving (CPS) is considered to be an important resource in a variety of fields such as education (see Murdock, 2003) and business (see Thompson, 2003). Previous research suggests that interventions aimed at training people to improve their CPS skills can be effective, however it is not always clear what tools are being used and it is sometimes difficult to untangle the effect the different tools are having (see Vernon, Hocking, & Tyler, 2016, for a review). This study therefore aimed to utilise an empirically- based creativity toolkit in an 8 week training program aimed at enhancing students' CPS skills. The intervention group was comprised of 33 psychology students who signed up to undertake 8 weeks of CPS training and the control group (n = 9) were matched for contact time, undertaking 8 weeks of cognitive psychology lectures instead. In week 1 (Time 1) and week 8 (Time 2) all participants were assessed using two Unusual Uses Tasks (UUT) and a Creative Problem Solving (CPS) task and were also asked to fill out measures of creative self-efficacy. Analyses revealed that whilst the control group showed no improvement on any of the measures from Time 1 to Time 2, the intervention group showed a significant increase in both their creative self-efficacy and also their levels of creativity on both the UUT and CPS tasks. Whilst a follow- up study utilising a larger control group is ideally needed, these preliminary findings nonetheless support the use of this empirically based creativity toolkit for enhancing creativity problem solving skills

Biased tomography schemes: an objective approach

We report on an intrinsic relationship between the maximum-likelihood quantum-state estimation and the representation of the signal. A quantum analogy of the transfer function determines the space where the reconstruction should be done without the need for any ad hoc truncations of the Hilbert space. An illustration of this method is provided by a simple yet practically important tomography of an optical signal registered by realistic binary detectors.Comment: 4 pages, 3 figures, accepted in PR

SACOC: A spectral-based ACO clustering algorithm

The application of ACO-based algorithms in data mining is growing over the last few years and several supervised and unsupervised learning algorithms have been developed using this bio-inspired approach. Most recent works concerning unsupervised learning have been focused on clustering, where ACO-based techniques have showed a great potential. At the same time, new clustering techniques that seek the continuity of data, specially focused on spectral-based approaches in opposition to classical centroid-based approaches, have attracted an increasing research interest–an area still under study by ACO clustering techniques. This work presents a hybrid spectral-based ACO clustering algorithm inspired by the ACO Clustering (ACOC) algorithm. The proposed approach combines ACOC with the spectral Laplacian to generate a new search space for the algorithm in order to obtain more promising solutions. The new algorithm, called SACOC, has been compared against well-known algorithms (K-means and Spectral Clustering) and with ACOC. The experiments measure the accuracy of the algorithm for both synthetic datasets and real-world datasets extracted from the UCI Machine Learning Repository

Five-dimensional Nernst branes from special geometry

We construct Nernst brane solutions, that is black branes with zero entropy density in the extremal limit, of FI-gauged minimal five-dimensional supergravity coupled to an arbitrary number of vector multiplets. While the scalars take specific constant values and dynamically determine the value of the cosmological constant in terms of the FI-parameters, the metric takes the form of a boosted AdS Schwarzschild black brane. This metric can be brought to the Carter-Novotny-Horsky form that has previously been observed to occur in certain limits of boosted D3-branes. By dimensional reduction to four dimensions we recover the four-dimensional Nernst branes of arXiv:1501.07863 and show how the five-dimensional lift resolves all their UV singularities. The dynamics of the compactification circle, which expands both in the UV and in the IR, plays a crucial role. At asymptotic infinity, the curvature singularity of the four-dimensional metric and the run-away behaviour of the four-dimensional scalar combine in such a way that the lifted solution becomes asymptotic to AdS5. Moreover, the existence of a finite chemical potential in four dimensions is related to fact that the compactification circle has a finite minimal value. While it is not clear immediately how to embed our solutions into string theory, we argue that the same type of dictionary as proposed for boosted D3-branes should apply, although with a lower amount of supersymmetry.Comment: 59 pages, 1 figure. Revised version: references added, typos corrected. Final version, accepted by JHEP: two references adde

O Papel da Economia, da Segurança e da Aceitação do Líder do Partido na Previsão das Eleições Gerais de 2020 na Jamaica

Three econometric models were built between January and March 2020 to predict the September 3, 2020 General Election in Jamaica. These are the economics and security model (model1), the economics and security model with JLP leader acceptance (model 2), and the economics and security model with PNP leader acceptance (model 3). All three models accurately predicted a win for the Jamaica Labour Party. A Jack-knife resampling was performed for cross validation. These models show how the macro-economy, security concerns and party leader popularity influence election outcomes, with similar findings in the literature. However, there are peculiarities in the Anglophone Caribbean because the/nJamaican voters respond to economic and security concerns in different ways than the voters in the global north. For example, increases in the debt to GDP ratio and the homicide rate predicted a JLP win. This work should be replicated in the Caribbean and Latin America using panel data.Entre los meses de enero y marzo del 2020 se construyeron tres modelos econométricos para predecir los resultados de las elecciones generales del 3 de septiembre de 2020 en Jamaica. El Modelo 1 era un modelo de economía y seguridad; el Modelo 2 un modelo de economía y seguridad con los niveles de aceptación del líder del Partido Laborista de Jamaica (JLP, por sus siglas en inglés), y el Modelo 3 un modelo de economía y seguridad con los niveles de aceptación del líder del Partido Nacional del Pueblo (PNP). Los tres modelos acertaron al proyectar una victoria electoral para el JLP. Como validación cruzada de los datos, se utilizó el método "Jack-knife" para realizar un remuestreo. Estos modelos demuestran que, como ya venían señalando otros estudios, los resultados electorales se ven influidos tanto por la macroeconomía, como por los problemas de seguridad y la popularidad del líder del partido. Sin embargo, se debe tener en cuenta la idiosincrasia del Caribe anglófono, ya que los votantes jamaicanos no responden a los problemas económicos y de seguridad de la misma manera que los votantes del Norte global. Por ejemplo, el aumento tanto del coeficiente deuda/PIB como de la tasa de homicidios llevaron a la proyección de una victoria electoral del JLP. Se necesitaría replicar el presente estudio en el Caribe y Latinoamérica utilizando datos de panel.Para prever as eleições gerais do 3 de setembro de 2020 na Jamaica, três modelos econométricos foram elaborarados. Estes são: o modelo econômico e securitário (o modelo nr. 1), o modelo econômico e securitário com a aceitação do líder do JLP (o modelo nr. 2), e o modelo econômico e securitário com a aceitação do líder do PNP (o modelo nr. 3). Os três modelos previram corretamente a vitória do Partido Trabalhista da Jamaica (JLP). Para a validação cruzada, o método "Jack-knife" foi executado. Estes modelos, apoiados pelos achados semelhantes nos dados, indicam a medida em que a macroeconomia, as preocupações com segurança e a popularidade do líder do partido podem influenciar os resultados das eleições. Sem embargo, existem particularidades no Caribe anglófono devido ao fato do que os eleitores jamaicanos reagem às preocupações econômicas e securitárias de maneiras diferentes dos eleitores do hemisfério norte. Por exemplo, os aumentos da relação dívida/PIB e a taxa de homicídios previram uma vitória para o JLP. Este estudo deve ser reproduzido no Caribe e na América Latina com a aplicação de painel de dados

C1 inhibitor deficiency: 2014 United Kingdom consensus document

C1 inhibitor deficiency is a rare disorder manifesting with recurrent attacks of disabling and potentially life-threatening angioedema. Here we present an updated 2014 United Kingdom consensus document for the management of C1 inhibitor-deficient patients, representing a joint venture between the United Kingdom Primary Immunodeficiency Network and Hereditary Angioedema UK. To develop the consensus, we assembled a multi-disciplinary steering group of clinicians, nurses and a patient representative. This steering group first met in 2012, developing a total of 48 recommendations across 11 themes. The statements were distributed to relevant clinicians and a representative group of patients to be scored for agreement on a Likert scale. All 48 statements achieved a high degree of consensus, indicating strong alignment of opinion. The recommendations have evolved significantly since the 2005 document, with particularly notable developments including an improved evidence base to guide dosing and indications for acute treatment, greater emphasis on home therapy for acute attacks and a strong focus on service organisation. This article is protected by copyright. All rights reserved