Discriminately Decreasing Discriminability with Learned Image Filters

In machine learning and computer vision, input images are often filtered to increase data discriminability. In some situations, however, one may wish to purposely decrease discriminability of one classification task (a "distractor" task), while simultaneously preserving information relevant to another (the task-of-interest): For example, it may be important to mask the identity of persons contained in face images before submitting them to a crowdsourcing site (e.g., Mechanical Turk) when labeling them for certain facial attributes. Another example is inter-dataset generalization: when training on a dataset with a particular covariance structure among multiple attributes, it may be useful to suppress one attribute while preserving another so that a trained classifier does not learn spurious correlations between attributes. In this paper we present an algorithm that finds optimal filters to give high discriminability to one task while simultaneously giving low discriminability to a distractor task. We present results showing the effectiveness of the proposed technique on both simulated data and natural face images

Microbiology, antibiotic susceptibility, and bacteraemia associated factors in acute prostatitis

Introduction: The aim of the study was to analyze the characteristics of patients with acute prostatitis presenting to the Emergency Department, the microbiological findings, antibiotic susceptibility, and bacteraemia associated factors. Methods. Observational and cohort study with prospective follow-up including patients with acute prostatitis presenting to the Emergency Department from January-December 2012. Data were collected for demographic variables, comorbidities, microbiological findings, antibiotic treatment and outcome. Results: Two hundred and forty one episodes of acute prostatitis were included. Mean age was 62.9 ± 16 years, a history of prostate adenoma was reported in 54 cases (22.5%) and prior manipulation of the lower urinary tract in 40 (17%). Mean symptoms duration was 3.38 ± 4.04 days, voiding symptoms were present in 176 cases (73%) and fever in 154 (64%). Seventy patients (29%) were admitted to the hospital and 3 died. From 216 urine cultures, 128 were positive (59%) and 24 (17.6%) out of 136 blood cultures. Escherichia coli was the main pathogen (58.6% of urine cultures and 64% of blood cultures) with resistant strains to fluoroquinolones, cotrimoxazole and amoxicillin/clavulanic in 27.7%, 22.9% and 27.7% of cases respectively. In the univariate analysis, only chills were associated to bacteraemia (p=0.013). At 30-day follow-up, patients with bacteraemia returned more frequently to the Emergency Department (p=0.037) and were more often admitted to the hospital (p=0.003). Conclusions: Patients with acute prostatitis discharged from the Emergency Department need clinical follow-up and monitoring of microbiological findings in order to assure an adequate antibiotic treatment. Return to Emergency Department and admission to the hospital were significantly more frequent among patients with bacteraemia

Stability analysis of adaptive filters with regression vector nonlinearities

We present a unified framework to analyze the mean and mean-square stability of a large class of adaptive filters. We do this without obtaining a full transient model, allowing us to acquire sufficient conditions on the stability without assuming a given statistical distribution for the input regressors. We also apply the proposed framework to some popular adaptive filtering schemes, showing that in some cases the sufficient conditions derived are very tight and even necessary too.Fil: Rey Vega, Leonardo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Rey, Hernan. Universidad de Buenos Aires; ArgentinaFil: Benesty, Jacob. Centre Armand-frappier Santé Biotechnologie ; Institut National de Recherche Scientifique; . Université du Québec a Montreal; Canad

Emergency department direct discharge compared to short-stay unit admission for selected patients with acute heart failure: analysis of short-term outcomes

Insuficiència cardíaca; Serveis d'urgències mèdiques; MortalitatHeart failure; Emergency service, hospital; MortalityInsuficiencia cardíaca; Servicio hospitalario de urgencias; MortalidadShort stay unit (SSU) is an alternative to conventional hospitalization in patients with acute heart failure (AHF), but the prognosis is not known compared to direct discharge from the emergency department (ED). To determine whether direct discharge from the ED of patients diagnosed with AHF is associated with early adverse outcomes versus hospitalization in SSU. Endpoints, defined as 30-day all-cause mortality or post-discharge adverse events, were evaluated in patients diagnosed with AHF in 17 Spanish EDs with an SSU, and compared by ED discharge vs. SSU hospitalization. Endpoint risk was adjusted for baseline and AHF episode characteristics and in patients matched by propensity score (PS) for SSU hospitalization. Overall, 2358 patients were discharged home and 2003 were hospitalized in SSUs. Discharged patients were younger, more frequently men, with fewer comorbidities, had better baseline status, less infection, rapid atrial fibrillation and hypertensive emergency as the AHF trigger, and had a lower severity of AHF episode. While their 30-day mortality rate was lower than in patients hospitalized in SSU (4.4% vs. 8.1%, p < 0.001), 30-day post-discharge adverse events were similar (27.2% vs. 28.4%, p = 0.599). After adjustment, there were no differences in the 30-day risk of mortality of discharged patients (adjusted HR 0.846, 95% CI 0.637-1.107) or adverse events (1.035, 0.914-1.173). In 337 pairs of PS-matched patients, there were no differences in mortality or risk of adverse event between patients directly discharged or admitted to an SSU (0.753, 0.409-1.397; and 0.858, 0.645-1.142; respectively). Direct ED discharge of patients diagnosed with AHF provides similar outcomes compared to patients with similar characteristics and hospitalized in a SSU.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The author(s) disclosed receipt of the following fnancial support for the research, authorship, and/or publication of this article: This study was partially supported by grants from the Instituto de Salud Carlos III supported with funds from the Spanish Ministry of Health and FEDER (PI15/01019, PI18/00393) and Fundació La Marató de TV3 (2015/2510). The Emergencies: Processes and Pathologies research group of the IDIBAPS receives fnancial support from the Catalonian government for consolidated groups of investigation (GRC 2009/1385 and 2014/0313)

A revised implicit equal-weights particle filter

Particle filters are fully non-linear data assimilation methods and as such are highly relevant. While the standard particle filter degenerates for high-dimensional systems, recent developments have opened the way for new particle filters that can be used in such systems. The implicit equal-weights particle filter (IEWPF) is an efficient approach which avoids filter degeneracy because it gives equal particle weights by construction. The method uses implicit sampling whereby auxiliary vectors drawn from a proposal distribution undergo a transformation before they are added to each particle. In the original formulation of the IEWPF, the proposal distribution has a gap causing all but one particle to have an inaccessible region in state space. We show that this leads to a systematic bias in the predictions and we modify the proposal distribution to eliminate the gap. We achieved this by using a two-stage proposal method, where a single variance parameter is tuned to obtain adequate statistical coverage properties of the predictive distribution. We discuss properties of the implicit mapping from an auxiliary random vector to the state vector, keeping in mind the aim of avoiding particle resampling. The revised filter is tested on linear and weakly nonlinear dynamical models in low-dimensional and moderately high-dimensional settings, demonstrating the suiccess of the new methodology in removing the bias

New tensegrity structures based on octagonal cells.

Tensegrity families are excellent sources of new tensegrity structures. A tensegrity family is a group of tensegrity structures that share a common connectivity pattern. The Octahedron, X‐Octahedron and Z‐Octahedron families are examples of them. The members of these families are constructed by assembling one‐bar elementary cells. Rhombic, X‐rhombic and Z‐shaped cells are used to construct the members of the Octahedron, X‐Octahedron and Z‐Octahedron families respectively. In a recent work, a new type of elementary cell was introduced: the octagonal cell. In this work, new tensegrity structures are obtained by assembling a new octagonal cell. The values of the force:length ratio of the members of the tensegrities that lead to an equilibrium configuration have been computed analytically. The stability of the resultant tensegrity structures has been analyzed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Author's reply to "comments on 'variable explicit regularization in affine projection algorithm: Robustness issues and optimal choice'"

Muralidhar et al. point out that when the VR-APA is applied in echo cancellation it will diverge during the presence of a near-end signal or a silence period. We provide an explanation for the behavior of the algorithm and show that a double-talk detector makes the VR-APA suitable for this application.Fil: Rey, Hernan Gonzalo. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rey Vega, Leonardo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Simulación Computacional para Aplicaciones Tecnológicas; ArgentinaFil: Benesty, Jacob. Centre Armand-frappier Santé Biotechnologie ; Institut National de Recherche Scientifique; . Université du Quàbec; CanadáFil: Tressens, Sara. Universidad de Buenos Aires; Argentin

Bayesian analysis of the ICAT·COVID randomized clinical trial

This communication provides new effect measures in the multiplicative scale from the ICAT·COVID randomized clinical trial, obtained through Bayesian statistics. These could not be calculated using the traditional frequentist statistics included in the original publication because the benefits of icatibant (a competitive antagonist of the bradykinin B2 receptors) on top of standard care in patients with COVID-19 pneumonia were such that there were no events in the active group.1 Additive effect measures (eg, risk differences) are the most appropriate measures for identifying the population groups that will benefit most from interventions in presence of interactions acting as effect modifiers.2 However, an aspect that multiplicative measures provide where additive effect measures cannot, is an indication of how many times interventions or exposures increase or decrease disease risk (eg, risk ratio, hazard ratio). Furthermore, multiplicative measures are more commonly used in epidemiology, and are more appropriate for outcome measures with strictly positive values, such as counts and the numerators of incidence rates

Four-Legs D-STATCOM for Current Balancing in Low-Voltage Distribution Grids

The fast deployment of distributed energy resources (DERs) is creating a series of challenges that should be addressed in the coming years. In particular, distribution grids are playing an increasingly important role in the electricity system. Moreover, the three-phase four-wire structure of this network contribute to the appearance of imbalances and a series of problems derived from them. In this context, distribution system operators (DSOs), as the main responsible for the distribution grid, must ensure the quality of supply to consumers. This paper takes advantage of a four-legs D-STATCOM to remove current imbalances in low-voltage power lines. A 35-kVA prototype has been developed and installed in an urban distribution grid. The effect of the D-STATCOM has been analyzed during its first month of operation, studying and measuring the advantages of providing DERs the ability to perform active balancing to the utility grid. The results show a reduction in current imbalances from 21 % to 0 % and neutral current from 10.3 A to 0.4 A. In addition, a 13 % decrease in cable losses has been estimated and a slight improvement in voltage unbalance factor can be noted