Decision support system for hot spot detection

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Structural and regulatory analysis of quorum sensing in Rhizobium leguminosarum

In the present work, we have studied the role of quorum-sensing regulatory systems in Rhizobium-legume symbiosis. Competition assays suggest that inactivation of quorum sensing systems significantly affects the competitiveness of Rhizobium leguminosarum bv. viciae UPM791 (Rl UPM791) when compared to other strains. Structural analysis through HPLC / mass spectrometry revealed that the signals produced by Rl UPM791 correspond to: C6-HSL, C7-HSL, C8-HSL and 3OH-C14-HSL; also, small amounts of C4-HSL have been detected. We are also analyzing the complex regulation of AHL signal molecules. We have evidence indicating that an Rl UPM791 plasmid (pUPM791d) participates in a regulatory network acting on the chromosomal system cinRI. We are using concurrent strategies (sequencing of pUPM791d and random mutagenesis) to identify the mechanism responsible for the control of pUPM791d over AHL production in Rl UPM791

High level Decision Methodology for the Selection of a Fuel Cell Based Ower Distribution Architecture for an Aircraft Application

The selection of the right power distribution architecture for a given application has a tremendous impact on the overall system in terms of efficiency, cost, reliability, fault tolerance and size. Moreover, with the increasing number of power sources, storage elements, different supply voltages and strong requirements imposed at system level, the selection of the appropriate architecture becomes a nightmare for the system designer. The purpose of this paper is to describe a methodology for the selection of the most suitable architecture for a fuel cell based power distribution application. The methodology is based on the assessment of metric functions for all the components that can configure the architecture as a function of the electrical boundary conditions of each component

Caracterización del sistema de regulación por densidad poblacional (quorum sensing) en Rhizobium leguminosarum

En este trabajo se han caracterizado las AHLs sintetizadas por Rl UPM791 mediante un análisis estructural llevado a cabo con HPLC y espectrometría de masas. En función de los patrones de fragmentación y los iones moleculares característicos, se han identificado en el sobrenadante de cultivos de esta cepa, las siguientes moléculas: C6-HSL, C7-HSL y C8-HSL, sintetizadas por el sistema rhiRI, y 3-OH-C14-HSL, sintetizada por el sistema cromosómico cinRI. Asimismo, se ha podido detectar la presencia de C4-HSL en pequeñas cantidades. Por otro lado,s se ha estudiado el papel de los sistemas de regulación por QS en la simbiosis Rhizobium-leguminosa. Para ello, se han realizado ensayos de competitividad por la nodulación de la raíz de guisante por cepas de Rl UPM791 y 3841 productoras de AHLs, y cepas derivadas de las mismas, pero desprovistas de AHLs

Prognostic Value of the PROFUND Index for 30-Day Mortality in Acute Heart Failure

Background and Objectives: The prevalence and incidence of heart failure (HF) have been increasing in recent years as the population ages. These patients show a distinct profile of comorbidity, which makes their care more complex. In recent years, the PROFUND index, a specific tool for estimating the mortality rate at one year in pluripathology patients, has been developed. The aim of this study was to evaluate the prognostic value of the PROFUND index and of in-hospital and 30-day mortality after discharge of patients admitted for acute heart failure (AHF). Materials and Methods: A prospective multicenter longitudinal study was performed that included patients admitted with AHF and ≥2 comorbid conditions. Clinical, analytical, and prognostic variables were collected. The PROFUND index was collected in all patients and rates of in-hospital and 30-day mortality after discharge were analyzed. A bivariate analysis was performed with quantitative variables between patients who died and those who survived at the 30-day follow-up. A logistic regression analysis was performed with the variables that obtained statistical significance in the bivariate analysis between deceased and surviving subjects. Results: A total of 128 patients were included. Mean age was 80.5 +/− 9.98 years, and women represented 51.6%. The mean PROFUND index was 5.26 +/− 4.5. The mortality rate was 8.6% in-hospital and 20.3% at 30 days. Preserved left ventricular ejection fraction was found in 60.9%. In the sample studied, there were patients with a PROFUND score < 7 predominated (89 patients (70%) versus 39 patients (31%) with a PROFUND score ≥ 7). Thirteen patients (15%) with a PROFUND score < 7 died versus the 13 (33%) with a PROFUND score ≥ 7, p = 0.03. Twelve patients (15%) with a PROFUND score < 7 required readmission versus 12 patients (35%) with a PROFUND score ≥ 7, p = 0.02. The ROC curve of the PROFUND index for in-hospital mortality and 30-day follow-up in patients with AHF showed AUC 0.63, CI: 95% (0.508–0.764), p <0.033. Conclusions: The PROFUND index is a clinical tool that may be useful for predicting short-term mortality in elderly patients with AHF. Further studies with larger simple sizes are required to validate these results

Nonparametric Frequency Response Identification for Dc-Dc Converters Based on Spectral Analysis with Automatic Determination of the Perturbation Amplitude

Digital control for high switching frequency converter enables new features on DC-DC power conversion for a minimum cost. Frequency response identification is one such enabled functionality used in auto tunning, measurement of components to assess the converter’s state of health, or system stability monitoring. High accuracy, flexibility to operate in open or closed loop, and minimum impact in the converter’s regular operation are the frequency response identification system’s goals. We propose in this paper a nonparametric identification system addressing these main goals. First, it can autoadjust the perturbation size to reduce the perturbation’s impact on the converter’s output quantities. Second, as it is based on spectral analysis, it is suitable for open and closed-loop operation. Third, we demonstrate the identification system’s high accuracy, achieving a very low difference between the experimental measurements and the discrete model used as reference

Analysis and Sizing of Power Distribution Architectures Applied to Fuel Cell Based Vehicles

The fuel cell based vehicles powertrain is an extensive system that comprises a fuel cell (FC) as the primary energy source, a set of power converters both unidirectional and bidirectional and batteries or supercapacitors as secondary energy sources. Its design is a complex task that affects the mass, volume, cost, efficiency and fuel economy of the vehicle. This paper describes a graphic and straightforward sizing of the secondary energy sources needed to fulfil the vehicle load requirements, as well as the set of equations related to the mass, cost and volume of each one of the power distribution subsystems. Moreover, this paper analysis ten different power distribution architectures to conclude which is the most suitable secondary energy source, the minimum sizing, cost, volume and weight, depending on the amount of power delivered by the fuel cell. Also, a 1.6 kW fuel cell based architecture is implemented and testing. The experimental results confirm the proposed methodology

Influence of the Main Design Factors on the Optimal Fuel Cell-Based Powertrain Sizing

The design of the optimal power distribution system (PDS or powertrain) for fuel cell-based vehicles is a complex task due to PDS comprising one or more power converters, several types of secondary energy sources, a fuel cell, several control loops, and protections, among others. The optimized powertrain design tries to minimize the mass, volume, and cost, and also to improve system efficiency, fuel economy (both hydrogen and electricity), and vehicle autonomy. This paper analyzes the influence of four different factors that deeply affect the optimal powertrain design, in particular: the minimum power delivered by the fuel cell, the storage of the recovered energy from the regenerative braking periods, the battery technology, and the maximum battery state-of-charge variation. The analysis of these factors is carried out over a set of 9 different fuel cell-based architectures applied to a light vehicle, and a 10th architecture corresponding to a pure electric vehicle. This analysis provides the knowledge of how these design factors affect the mass, volume, and cost of the optimal power distribution architectures, and how they can be considered in the design

Black-box model, identification technique and frequency analysis for PEM fuel cell with overshooted transient response

Fuel cells are one of the most promising energy sources, especially for onboard applications. However, fuel cells present several drawbacks, such as slow dynamic response, load-dependent voltage, and unidirectional power flow, which cause an inappropriate vehicle operation. So, secondary energy sources and power converters must be implemented in order to satisfy fast changes in the current load and to store the energy delivered by the load if regenerative braking is intended. Taking into account the number and nature of the power converters, loads, secondary energy sources, and the possibilities for the control strategies, the design of a power distribution architecture based on fuel cells for transport applications is a complex task. In order to address these architectures, modeling and simulation design tools at system level are essential. This paper proposes a complete fuel cell black-box model which reproduces the behavior of a commercial fuel cell with overshooted transient response. The identification technique applied to parameterize the model components, based on manufacturer\u27s datasheets and a test based on load steps, is explained thoroughly. In addition, if only the fuel cell frequency response and manufacturer\u27s datasheet are available, an alternative parameterization methodology based on the fuel cell frequency response is presented. The fuel cell black-box model is validated experimentally using a commercial proton exchange membrane fuel cell. Two different parameterizations are carried out with the aim of verifying the robustness of both the fuel cell model and the proposed identification methodology. © 1986-2012 IEEE