Ranking Star-Shaped Valued Mappings with Respect to Shape Variability

The study of shapes is a difficult topic, but it is becoming more and more important as computer vision techniques are already crucial in many research fields. Concretely, the variability of shapes is the basis for many criteria of symptom definition in medical diagnosis. This article introduces a stochastic order to address the variability of star-shaped sets. The main properties of the order are analyzed. An example of an application to hypothesis testing in medical diagnosis is also provided. Namely, we study if there are significant differences between healthy and diseased corneal endothelia with respect to cell shapes by means of ocular images.     

Neuro-evolutionary approach applied for optimizing the PEMFC performance

A multi-objective optimization strategy, based on stacked neural network–genetic algorithm (SNN–GA) hybrid approach, was applied to study the C/PBI content on a high temperature PEMFC performance. The operating conditions of PEMFC were correlated with power density and electrochemical active surface area for electrodes. The structure of the stack was determined in an optimal form related to the contribution of individual neural networks, after applying an interpolation based procedure. Multi-objective optimization using SNN as model and GA as solving procedure provides optimal working conditions which lead to a high PEMFC performance. Simulation results were in agreement with experimental data, both for model validation and system optimization (the C/PBI content in the range of 17–21%).     

Zwitterionic‐Coated “Stealth” Nanoparticles for Biomedical Applications: Recent Advances in Countering Biomolecular Corona Formation and Uptake by the Mononuclear Phagocyte System

Nanoparticles represent highly promising platforms for the development of imaging and therapeutic agents, including those that can either be detected via more than one imaging technique (multi‐modal imaging agents) or used for both diagnosis and therapy (theranostics). A major obstacle to their medical application and translation to the clinic, however, is the fact that many accumulate in the liver and spleen as a result of opsonization and scavenging by the mononuclear phagocyte system. This focused review summarizes recent efforts to develop zwitterionic‐coatings to counter this issue and render nanoparticles more biocompatible. Such coatings have been found to greatly reduce the rate and/or extent of non‐specific adsorption of proteins and lipids to the nanoparticle surface, thereby inhibiting production of the “biomolecular corona” that is proposed to be a universal feature of nanoparticles within a biological environment. Additionally, in vivo studies have demonstrated that larger‐sized nanoparticles with a zwitterionic coating have extended circulatory lifetimes, while those with hydrodynamic diameters of ≤5 nm exhibit small‐molecule‐like pharmacokinetics, remaining sufficiently small to pass through the fenestrae and slit pores during glomerular filtration within the kidneys, and enabling efficient excretion via the urine. The larger particles represent ideal candidates for use as blood pool imaging agents, whilst the small ones provide a highly promising platform for the future development of theranostics with reduced side effect profiles and superior dose delivery and image contrast capabilities.     

Simplified EDF characterization method for WDM applications

Abstract

A new, simple EDF characterization method is presented. Departing from well-known equations, some approximations, applicable in WDM working conditions, are introduced. Thanks to them, the number of active parameters necessary to describe the EDF behaviour is sensibly reduced. Afterwards, a simple experiment to find such parameters is proposed. Finally, the characterization method is applied to an EDF and the parameters′ values obtained are used to predict gain results. A good agreement between these predictions and experimental data is observed.     

Characterization of a miniaturized liquid bridge for nL sample infusion: a comparative study of sample flush-out behavior using flow simulations and direct ESI-MS analysis

In this work we shed light on the microfluidics of a miniaturized liquid bridge that forms the central part of a so-called “capillary gap sampler,” a novel device for rapid and seamless injection of nanoliter sample volumes into an electrospray ionization mass spectrometer (ESI-MS). Parameters relevant for sample flush-out at the liquid bridge and in the spray capillary were identified by systematic variation of the capillary dimensions, the linear buffer flow rate (2.1–34 mm/s) and molecular weight of the analytes (0.5–30 kDa). We found that a reduction in capillary wall thickness by a factor of 1.6 significantly influences analyte peak shapes, leads to an inversion of the relationship between peak width and analyte molecular weight, and allows a fivefold decrease in peak width for large molecules down to 5 s. The results could be verified and explained by simulations, in which the presence of diffusion-controlled “dead zones” at the liquid bridge and dispersion in the spray tip that depend on analyte molecular weight were identified as key factors relevant for the sample flush-out process. The merging of simulations and experimental data gives useful hints toward the re-design of a spray tip as built-in ESI-MS interface for an optimized gap sampler performance.     

Ten Arguments Against the Proclaimed Amount of Dark Matter

According to the Standard cosmological model, our universe needs a significant amount of dark matter (DM), about six times that of the usual baryonic matter, besides an even larger amount of dark energy. But to date, both DMand dark energy have remained conceptually delusive, without concrete evidence based on direct physical measurements. In this survey paper, we present ten counterarguments showing that such a claimed amount of DMcan be a result of vast overestimation and does not conform to reality. Some of those counterarguments can be convincingly verified even by simple hand calculations.     

Metaheuristic optimization frameworks: a survey and benchmarking

This paper performs an unprecedented comparative study of Metaheuristic optimization frameworks. As criteria for comparison a set of 271 features grouped in 30 characteristics and 6 areas has been selected. These features include the different metaheuristic techniques covered, mechanisms for solution encoding, constraint handling, neighborhood specification, hybridization, parallel and distributed computation, software engineering best practices, documentation and user interface, etc. A metric has been defined for each feature so that the scores obtained by a framework are averaged within each group of features, leading to a final average score for each framework. Out of 33 frameworks ten have been selected from the literature using well-defined filtering criteria, and the results of the comparison are analyzed with the aim of identifying improvement areas and gaps in specific frameworks and the whole set. Generally speaking, a significant lack of support has been found for hyper-heuristics, and parallel and distributed computing capabilities. It is also desirable to have a wider implementation of some Software Engineering best practices. Finally, a wider support for some metaheuristics and hybridization capabilities is needed.     

Revision of ground albedo estimation in Heliosat scheme for deriving solar radiation from SEVIRI HRV channel of Meteosat satellite

Methodologies for computing ground albedo from geostationary satellite images are investigated within the framework of models for deriving solar radiation components from satellite information. A revision of Heliosat-3 approach for determining ground albedo and its implication in the cloud index estimation is done using two close pixels of quite different reflectivity in the Nile delta surroundings in Egypt. The analysis done has revealed that the way in which Heliosat-3 approaches the ground albedo and especially its dependence with the viewing angle is not very precise when dealing with high reflective sites. A simple method for fitting, individually for every pixel, the angular dependence and the ground albedo estimations is proposed here and applied to different points in the Mediterranean area. The results of the revised method show rather good estimations of ground albedo in every kind of terrain in terms of reflectivity. These results are translated to cloud index estimations and finally to surface solar irradiance and they show improvements in solar radiation estimation over high reflective pixels.     

A simple approach to estimate muscle forces and orthosis actuation in powered assisted walking of spinal cord-injured subjects

Simulation of walking in individuals with incomplete spinal cord injuries (SCI) wearing an active orthosis is a challenging problem from both the analytical and the computational points of view, due to the redundant nature of the simultaneous actuation of the two systems. The objective of this work is to quantify the contributions of muscles and active orthosis to the net joint torques, so as to assist the design of active orthoses for SCI. The functional innervated muscles of SCI patients were modeled as Hill-type actuators, while the idle muscles were represented by elastic and dissipative elements. The orthosis was included as a set of external torques added to the ankles, knees, and hips to obtain net joint torque patterns similar to those of normal unassisted walking. The muscle-orthosis redundant actuator problem was solved through a physiological static optimization approach, for which several cost functions and various sets of innervated muscles were compared.