Cosmic bulk viscosity through backreaction

We consider an effective viscous pressure as the result of a backreaction of inhomogeneities within Buchert's formalism. The use of an effective metric with a time-dependent curvature radius allows us to calculate the luminosity distance of the backreaction model. This quantity is different from its counterpart for a "conventional" spatially flat bulk viscous fluid universe. Both expressions are tested against the SNIa data of the Union2.1 sample with only marginally different results for the distance-redshift relation and in accordance with the $\Lambda$CDM model. Future observations are expected to be able to discriminate among these models on the basis of indirect measurements of the curvature evolution.Comment: 18 pages, 6 figures, comments and references added, accepted for publication in GR

Phenomenological model for symmetry breaking in chaotic system

We assume that the energy spectrum of a chaotic system undergoing symmetry breaking transitions can be represented as a superposition of independent level sequences, one increasing on the expense of the others. The relation between the fractional level densities of the sequences and the symmetry breaking interaction is deduced by comparing the asymptotic expression of the level-number variance with the corresponding expression obtained using the perturbation theory. This relation is supported by a comparison with previous numerical calculations. The predictions of the model for the nearest-neighbor-spacing distribution and the spectral rigidity are in agreement with the results of an acoustic resonance experiment.Comment: accepted for publication in Physical Review

Supporting direct care workers in dementia care: effects of a psycho-educational intervention

YesAn experimental study using a pre-posttest control group design was conducted to assess the effects of a person-centred care based psycho-educational intervention on direct care workers’ stress, burnout and job satisfaction. The intervention aimed to develop person-centred care competences and tools for stress management. Four aged care facilities were randomly assigned to a psycho-educational or an education-only intervention (control). Data were collected from fifty-six direct care workers (female, mean age 44.72±9.02) through measurements of burnout (Maslach Burnout Inventory), job satisfaction (Minnesota Satisfaction Questionnaire-short form) and stress (Perceived Stress Scale) and focus-group interviews. Results showed significant positive effects in emotional exhaustion (p=0.029) and positive but no significant effects in stress and job satisfaction. According to qualitative data, the experimental group perceived enhanced group cohesion, emotional management and self-care awareness. Psycho-educational interventions may contribute to reduce direct care workers’ burnout. Further work is needed to determine the extent of its benefits.Portuguese Foundation for Science and Technolog

Bioelectrochemical systems (BESs) towards conversion of carbon monoxide/syngas: A mini-review

Microbial conversion of carbon monoxide (CO)/syngas has been extensively investigated. The microbial conversion of CO/syngas offers numerous advantages over chemically catalyzed processes e.g. the specificity of the biocatalysts, the operation at ambient conditions and high conversion efficiencies. Bioelectrochemical systems (BESs) exploit the capacity of electrochemically active bacteria (EAB) to use insoluble electron acceptors or donors to produce electricity or added-value compounds. Electricity production from different organic sources in BESs has been broadly demonstrated, whereas electricity production from CO/syngas has been very little reported. Acetate oxidation by a consortium of carboxydotrophic and CO-tolerant EAB has been suggested to be the main pathway responsible for indirect electricity generation from CO/syngas. Although electricity production in BESs from several organic sources has been widely investigated, the interest on BESs research is currently moving to the production of added-value compounds by electro-fermentation (EF) processes. EF allows to modify redox balances by the use of electric circuits to fine tune metabolic pathways towards obtaining products with high economic value. Although EF has been widely studied, the potential of use CO-rich gas streams as substrate has been under explored. This review presents and discusses current advances on microbial conversion of CO/syngas in BESs.This study was supported by the Portuguese Foundation for Science and Technology (FCT), within the scope of the project “INNOVsyn - Innovative strategies for syngas fermentation” (POCI-01-0145-FEDER- 033177). This study was also supported by the FCT under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte oper-ation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Antibody Surface Coverage Drives Matrix Interference in Microfluidic Capillary Immunoassays

The performance of biosensors is often optimised in buffers, which brings inconsistencies during applications with biological samples. Current strategies for minimising sample (matrix) interference are complex to automate and miniaturise, involving e.g. sample dilution or recovery of serum/plasma. This study shows the first systematic study using hundreds of actual microfluidic immunoassay fluoropolymer strips to understand matrix interference in microflow systems. As many interfering factors are assay-specific, we have explored matrix interference for a range of enzymatic immunoassays, including a direct mIgG/anti-mIgG, a sandwich cancer biomarker PSA and a sandwich inflammatory cytokine IL-1β. Serum matrix interference was significantly affected by capillary antibody surface coverage, suggesting for the first time the main cause of serum matrix effect is low-affinity serum components (e.g. auto-antibodies) competing with high-affinity antigen for the immobilised antibody. Additional experiments carried out with different capillary diameters confirmed the importance of antibody surface coverage in managing matrix interference. Building on these findings we propose a novel analytical approach where antibody surface coverage and sample incubation times are key for eliminating and/or minimising serum matrix interference, consisting in bioassay optimization carried out in serum instead of buffer, without compromising the performance of the bioassay nor adding extra cost nor steps. This will help establishing a new route towards faster development of modern point-of-care tests and effective biosensors development

Planning a sustainable reverse logistics system: balancing costs with environmental and social concerns

The present work aims to support tactical and operational planning decisions of reverse logistics systems while considering economical, environmental and social objectives. In the literature, when addressing such systems economical aspects have been often used, while environmental concerns have been only recently emerging. The social component is the one less studied, and rarely the combination of the three concerns has been analyzed. This work address the three objectives and was motivated by the challenge of supporting decisions makers when managing a real case study of a recyclable waste collection system, where strategic decisions on the number and location of depots, vehicles and containers were taken beforehand. Tactical and operational decisions are studied involving the establishment of service areas for each depot and the definition and scheduling of collection routes for each vehicle. Such decisions should represent a compromise solution between the three objectives considered and support a sustainable reverse logistics plan. A multi-objective solution approach based on mixed-integer linear programming models is developed. Trade-offs between the objectives are discussed. Moreover the solutions obtained when each objective is tackled individually are compared between themselves and with the balanced solution.info:eu-repo/semantics/publishedVersio