The range of stereoscopic perception: influence of binocular summation,interocular differences in optical quality and halo perception

The study of the visual function and optical quality of the eye has become a fundamental aim in the characterization of visual performance, especially in binocular vision, as this is our natural state of visual perception and because of its importance in clinical applications. Interocular asymmetry affects visual performance, and therefore its effect on different visual functions and stereopsis is of interest. In this work, we analyse interocular differences in optical quality (higher order aberrations and Strehl ratio) on the maximum disparity (the total range of stereoscopic perception) under mesopic conditions. We also analyse the relationship between the maximum disparity and the visual-discrimination capacity (halo perception) or binocular summation. The results in normal observers show a deterioration of the range of stereoscopic perception with the interocular differences in optical quality and with a higher perception of halos. Regarding the binocular summation for the visual functions studied, a positive correlation with the maximum disparity is found.     

Electroconductive Biohybrid Collagen/Pristine Graphene Composite Biomaterials with Enhanced Biological Activity

Electroconductive substrates are emerging as promising functional materials for biomedical applications. Here, the development of biohybrids of collagen and pristine graphene that effectively harness both the biofunctionality of the protein component and the increased stiffness and enhanced electrical conductivity (matching native cardiac tissue) obtainable with pristine graphene is reported. As well as improving substrate physical properties, the addition of pristine graphene also enhances human cardiac fibroblast growth while simultaneously inhibiting bacterial attachment (Staphylococcus aureus). When embryonic‐stem‐cell‐derived cardiomyocytes (ESC‐CMs) are cultured on the substrates, biohybrids containing 32 wt% graphene significantly increase metabolic activity and cross‐striated sarcomeric structures, indicative of the improved substrate suitability. By then applying electrical stimulation to these conductive biohybrid substrates, an enhancement of the alignment and maturation of the ESC‐CMs is achieved. While this in vitro work has clearly shown the potential of these materials to be translated for cardiac applications, it is proposed that these graphene‐based biohybrid platforms have potential for a myriad of other applications—particularly in electrically sensitive tissues, such as neural and neural and musculoskeletal tissues.     

Engineering magnetic nanostructures with inverse hysteresis loops

Top-down lithography techniques allow the fabrication of nanostructured elements with novel spin configurations,which provide a new route to engineer and manipulate the magnetic response of sensors and electronic devices and understand the role of fundamental interactions in materials science.In this study, shallow nanostructure-pattemed thin films were designed to present inverse magnetization curves,i.e.,an anomalous magnetic mechanism characterized by a negative coercivity and negative remanence.This procedure involved a method for manipulating the spin configuration that yielded a negative coercivity after the patterning of a single material layer.Patterned NiFe thin films with trench depths between 15％-25％ of the total film thickness exhibited inverse hysteresis loops for a wide angular range of the applied field and the trench axis.A model based on two exchange-coupled subsystems accounts for the experimental results and thus predicts the conditions for the appearance of this magnetic behavior.The findings of the study not only advance our understanding of patterning effects and confined magnetic systems but also enable the local design and control of the magnetic response of thin materials with potential use in sensor engineering.     

An Evolutionary Solver for Pure Integer Linear Programming

In this paper we introduce an evolutionary algorithm for the solution of pure integer linear programs. All the variables of the problem are fixed by the evolutionary system. If they correspond to a feasible solution, their evaluation is determined directly by the objective function. If the variables correspond to an unfeasible solution, the evaluation is measured by the sum of infeasibilities, which can be determined by simple linear algebra manipulations. The algorithm proposed does not require the solution of continuous linear programs. We report results obtained for some standard benchmark problems, and compare them with those obtained by branch-and-bound. The performance of the evolutionary algorithm is promising. Good feasible solutions were generally obtained, and in some of the difficult benchmark tests it outperformed branch-and-bound.     

Integration of microfiltration and nanofiltration to promote textile effluent reuse

This study investigates the application of a hybrid microfiltration–nanofiltration (MF–NF) process for textile wastewater reclamation. Indigo blue dye was efficiently retained by an MF membrane, allowing its recovery from the concentrated stream. NF technology was successfully applied to polish textile effluent. The NF membrane was evaluated under different transmembrane pressure (8–15 bars), crossflow velocities (0.21–0.84 cm s^?1), pH (7–11), and feed temperature (20–40 °C). The best NF performance was provided at a pressure of 12 bar and a crossflow rate of 0.63 cm s^?1. The NF performance (in terms of COD, conductivity, colour, and nitrogen removal) was not influenced by pH; however, higher feed pH values resulted in increased membrane fouling. The principal cause of flux decline was due to concentration polarization. Membrane chemical cleaning was sufficient to regain the initial permeability. The NF permeate met the quality requirements for all water demands within the textile industry, while the NF concentrate could be used to wash equipment, print work screens, print paste containers, and floors. The total capital cost (CapEx) of the MF–NF system was estimated at 58,362.50 US dollars and the total operational cost (OpEx) at 0.31 US dollars per cubic metre of effluent.     

A framework for evaluating and improving requirements specifications based on the developers and testers perspective

Requirements Engineering - Requirements specifications are essential to properly communicate requirements among the software development team members. However, each role in the team has different...     

Effect of alkaline extraction on the structure of the protein of quinoa (Chenopodium quinoa Willd.) and its influence on film formation

It is important to produce hydrophobic edible protein films for use in foods. The aim of this study was to evaluate the effect of alkaline extraction of quinoa proteins (QP) on the structure and their film‐forming ability without plasticiser. QP were extracted between pH 8 to 12, and their structure was evaluated by PAGE‐SDS, size‐exclusion HPLC light scattering, fluorescence spectroscopy and SH and SS. Film was characterised by FTIR, SEM, tensile strength, barrier and colour. Structural changes of QP showing that alkalinisation over pH 10 produce significant denaturation/aggregation/dissociation structural changes in QP. pH 12 was the condition to form a film (film₁₂). FTIR showed hydrogen bonds and hydrophobic film interactions. Film₁₂ had 16.6 ± 3.8% elongation and 15.7 ± 1.1 MPa tensile strength, and water vapour permeability was 5.18 ± 0.38 g mm m^?2 day^?1 kPa^?1. Film₁₂ had a brownish colour. A high degree of denaturation/aggregation/dissociation of QP structure is required to form a film without plasticiser.     

Changes on the levels of serotonin precursors – tryptophan and 5-hydroxytryptophan – during roasting of Arabica and Robusta coffee

The levels of free and total tryptophan and of 5-hydroxytryptophan (5-HTP) were investigated in green and roasted grains and beverages of Coffea arabica L. (Arabica) and Coffea canephora Pierre var. robusta (Robusta). Grains were light, medium and dark roasted. Free and protein tryptophan were extracted before and after hydrolysis. The levels of tryptophan and 5-HTP were quantified simultaneously by ion-pair HPLC and fluorimetric detection after derivatisation with o-phthalaldehyde. Robusta green coffee had higher total and protein tryptophan, whereas Arabica had higher free tryptophan levels. 5-HTP was not detected in the samples before and after roasting. Free tryptophan was completely degraded during roasting. Roasting significantly affected protein tryptophan. The rate of loss was smaller in Arabica compared to Robusta at every roasting degree. A beverage prepared the Brazilian way with a medium-roasted coffee provided 1.4–2.5 mg tryptophan/50 ml cup.