Young consumers’ purchase behaviour of sustainably-labelled food products. What is the role of scepticism?

This paper aimed to investigate consumer scepticism towards third-party sustainability labels in the context of food products, evaluating its role in the formation of the customer’s buying behaviour. A covariance-based structural equation model (CB-SEM) was developed, and it included the customer’s socio-environmental concern, scepticism toward sustainability labels, reported use of the socio-environmental commitment declared by the producer, and purchase behaviour of sustainably-labelled food products. The model was tested on a sample of 311 Italian high-educated young consumers, a group of sustainability-conscious individuals. The findings highlight that purchase behaviour is positively influenced by two reciprocally-related variables: socio-environmental concern and the reported use of the socio-environmental commitment declared by the producer. While other studies have ascertained that scepticism is an antecedent of purchase behaviour, this study findings highlight it can also be considered a mediator of the relationships between purchase behaviour and other antecedents considered in this model. In addition to advancing the study on the role of scepticism in the formation of purchasing decisions for food products, drawing on signalling theory, this study provides insights for practitioners and policymakers, highlighting the absolute necessity to reassure consumers about the credibility of third-party sustainability labels and providing them with the instruments needed to distinguish the truth from the fluff in sustainability communication

Functional characterization of the type I toxin Lpt from Lactobacillus rhamnosus by fluorescence and atomic force microscopy

Lpt is a 29 amino acid long type I toxin identified in the plasmid DNA of wild Lactobacillus rhamnosus strains isolated from food. We previously reported that transcription of the encoding gene was upregulated under nutritional starvation conditions mimicking cheese ripening environment. The heterologous expression of the Lpt peptide in E. coli resulted in cell growth inhibition, nucleoid condensation and compromised integrity of the cell membrane. Fusion of the Lpt peptide with the fluorescent protein mCherry allowed to visualize the accumulation of the peptide into the membrane, while mutagenesis experiments showed that either the insertion of a negatively charged amino acid into the hydrophobic a-helix or deletion of the hydrophilic C-terminal region, leads to a non-toxic peptide. AFM imaging of Lpt expressing E. coli cells has revealed the presence of surface defects that are compatible with the loss of portions of the outer membrane bilayer. This observation provides support for the so-called "carpet" model, by which the Lpt peptide is supposed to destabilize the phospholipid packing through a detergent-like mechanism leading to the removal of small patches of bilayer through micellization

Strategies to investigate membrane damage, nucleoid condensation, and rnase activity of bacterial toxin–antitoxin systems

A large number of bacterial toxin–antitoxin (TA) systems have been identified so far and different experimental approaches have been explored to investigate their activity and regulation both in vivo and in vitro. Nonetheless, a common feature of these methods is represented by the difficulty in cell transformation, culturing, and stability of the transformants, due to the expression of highly toxic proteins. Recently, in dealing with the type I Lpt/RNAII and the type II YafQ/DinJ TA systems, we encountered several of these problems that urged us to optimize methodological strategies to study the phenotype of recombinant Escherichia coli host cells. In particular, we have found conditions to tightly repress toxin expression by combining the pET expression system with the E. coli C41(DE3) pLysS strain. To monitor the RNase activity of the YafQ toxin, we developed a fluorescence approach based on Thioflavin-T which fluoresces brightly when complexed with bacterial RNA. Fluorescence microscopy was also applied to reveal loss of membrane integrity associated with the activity of the type I toxin Lpt, by using DAPI and ethidium bromide to selectively stain cells with impaired membrane permeability. We further found that atomic force microscopy can readily be employed to characterize toxin-induced membrane damages

Everything and nothing: notes on the work of Antonio Dias from 1968 to 1971

This article analyses a group of works produced by Antonio Dias between 1968 and 1971 in which appear, for the first time, formal and thematic elements that will perform a central role in his subsequent research, especially in The Illustration of Art, a series developed from 1971 to 1978. We consider main aspects from this moment, as well as the way through which they are internalized in the work and the importance of the writings of Robert Smithson in this process. Finally, the last section of this text seeks to point how this elements appear in Dias’ subsequent work, in order to indicate its importance, as a productive operation, in his trajectory. Este artículo examina un conjunto de trabajos de Antonio Dias producidos entre 1968 y 1971 en lo cual es posible identificar las primeras reflexiones, temáticas y formales, de aspetos que han de desempeñar gran importancia en su producción posterior, sobretodo la serie The Illustration of Art, realizada entre 1971 y 1978. El texto aborda los principales temas de este período, la manera como son incorporados a lo trabajo y el rol de los escritos de Robert Smithson en el proceso. Finalmente, son mencionados como estos elementos aparecen en su obra posterior, así señalando su importancia, en su calidad de recurso productivo, en la obra de Antonio Dias.Este artigo analisa um conjunto de trabalhos de Antonio Dias, realizado entre 1968 e meados de 1971, no qual se veem as primeiras formulações, temáticas e formais, de aspectos que serão caros a grande parte de sua produção posterior, sobretudo à série The Illustration of Art, realizada a partir daquele último ano e até cerca de 1978. São abordados os principais temas desse período, o modo como são internalizados na obra e o papel desempenhado pelos escritos de Robert Smitshon nesse processo. Por fim, a última seção do texto busca mencionar como esses elementos aparecem na produção posterior, de modo a apontar sua importância, enquanto recurso produtivo, na obra de Antonio Dias

Relation of study quality, concordance, take home message, funding, and impact in studies of influenza vaccines: systematic review

Objective To explore the relation between study concordance, take home message, funding, and dissemination of comparative studies assessing the effects of influenza vaccines

Beam test results of the irradiated Silicon Drift Detector for ALICE

The Silicon Drift Detectors will equip two of the six cylindrical layers of high precision position sensitive detectors in the ITS of the ALICE experiment at LHC. In this paper we report the beam test results of a SDD irradiated with 1 GeV electrons. The aim of this test was to verify the radiation tolerance of the device under an electron fluence equivalent to twice particle fluence expected during 10 years of ALICE operation.Comment: 6 pages,6 figures, to appear in the proceedings of International Workshop In high Multiplicity Environments (TIME'05), 3-7 October 2005, Zurich,Switzerlan

Functional characterization and transcriptional repression by Lacticaseibacillus paracasei DinJ-YafQ

DinJ-YafQ is a bacterial type II TA system formed by the toxin RNase YafQ and the antitoxin protein DinJ. The activity of YafQ and DinJ has been rigorously studied in Escherichia coli, but little has been reported about orthologous systems identified in different microorganisms. In this work, we report an in vitro and in vivo functional characterization of YafQ and DinJ identified in two different strains of Lacticaseibacillus paracasei and isolated as recombinant proteins. While DinJ is identical in both strains, the two YafQ orthologs differ only for the D72G substitution in the catalytic site. Both YafQ orthologs digest ribosomal RNA, albeit with different catalytic efficiencies, and their RNase activity is neutralized by DinJ. We further show that DinJ alone or in complex with YafQ can bind cooperatively to a 28-nt inverted repeat overlapping the -35 element of the TA operon promoter. Atomic force microscopy imaging of DinJ-YafQ in complex with DNA harboring the cognate site reveals the formation of different oligomeric states that prevent the binding of RNA polymerase to the promoter. A single amino acid substitution (R13A) within the RHH DNA-binding motif of DinJ is sufficient to abolish DinJ and DinJ-YafQ DNA binding in vitro. In vivo experiments confirm the negative regulation of the TA promoter by DinJ and DinJ-YafQ and unveil an unexpected high expression-related toxicity of the gfp reporter gene. A model for the binding of two YafQ-(DinJ)2-YafQ tetramers to the promoter inverted repeat showing the absence of protein-protein steric clash is also presented. KEY POINTS: • The RNase activity of L. paracasei YafQ toxin is neutralized by DinJ antitoxin. • DinJ and DinJ-YafQ bind to an inverted repeat to repress their own promoter. • The R13A mutation of DinJ abolishes DNA binding of both DinJ and DinJ-YafQ

Pressure pulsation in Kaplan turbines: Prototype-CFD comparison

Pressure pulsation phenomena in a large Kaplan turbine are investigated by means of numerical simulations (CFD) and prototype measurements in order to study the dynamic behavior of flow due to the blade passage and its interaction with other components of the turbine. Numerical simulations are performed with the commercial software Ansys CFX code, solving the incompressible Unsteady Reynolds-Averaged-Navier Stokes equations under a finite volume scheme. The computational domain involves the entire machine at prototype scale. Special care is taken in the discretization of the wicket gate overhang and runner blade gap. Prototype measurements are performed using pressure transducers at different locations among the wicket gate outlet and the draft tube inlet. Then, CFD results are compared with temporary signals of prototype measurements at identical locations to validate the numerical model. A detailed analysis was focused on the tip gap flow and the pressure field at the discharge ring. From a rotating reference frame perspective, it is found that the mean pressure fluctuates accordingly the wicket gate passage. Moreover, in prototype measurements the pressure frequency that reveals the presence of modulated cavitation at the discharge ring is distinguished, as also verified from the shape of erosion patches in concordance with the number of wicket gates

Pressure pulsation in Kaplan turbines: Prototype-CFD comparison

Abstract. Pressure pulsation phenomena in a large Kaplan turbine are investigated by means of numerical simulations (CFD) and prototype measurements in order to study the dynamic behavior of flow due to the blade passage and its interaction with other components of the turbine. Numerical simulations are performed with the commercial software Ansys CFX code, solving the incompressible Unsteady Reynolds-Averaged-Navier Stokes equations under a finite volume scheme. The computational domain involves the entire machine at prototype scale. Special care is taken in the discretization of the wicket gate overhang and runner blade gap. Prototype measurements are performed using pressure transducers at different locations among the wicket gate outlet and the draft tube inlet. Then, CFD results are compared with temporary signals of prototype measurements at identical locations to validate the numerical model. A detailed analysis was focused on the tip gap flow and the pressure field at the discharge ring. From a rotating reference frame perspective, it is found that the mean pressure fluctuates accordingly the wicket gate passage. Moreover, in prototype measurements the pressure frequency that reveals the presence of modulated cavitation at the discharge ring is distinguished, as also verified from the shape of erosion patches in concordance with the number of wicket gates