A Conceptual and Technological Framework for Building Collaborative Learning Environments

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Interaction Analysis Supporting Participants' Selfregulation in a Generic CSCL System

International audienceInteraction analysis can provide information directly to learners and teachers in order to assess and self-regulate their ongoing activity. Omega+ is a generic CSCL system that uses explicit models as parameters for flexibly supporting different kinds of collaborative applications. This paper describes Omega+ model-based generic approach for supporting participants' selfregulation through interaction analysis. Some quantitative and qualitative results obtained with the proposed approach are discussed

Deixis in synchronous CSCL systems. A collection of socio-technical patterns.

International audienceThere is a growing interest in synchronous CSCL systems that combine a communication space with a task space for supporting knowledge building by distributed or co-located small groups of learners. In that context, in which collaborative learning processes are scattered above two distinct spaces, deictic references to the objects in both spaces, the time of learners' actions, and the identity of participants are very important. This paper describes a structured collection of high-level patterns whose purpose is to catalog and document design knowledge about the mechanisms, resources and practices for deictic referencing

Foaming, emulsifying and rheological properties of extracts from a co-product of the Quorn fermentation process

Julien Lonchamp - ORCID: 0000-0001-7954-4745 https://orcid.org/0000-0001-7954-4745Item also deposited in University of Edinburgh repository, available at: https://www.research.ed.ac.uk/portal/en/publications/foaming-emulsifying-and-rheological-properties-of-extracts-from-a-coproduct-of-the-quorn-fermentation-process(c1316b1e-0940-4329-8b28-f010f4156548).htmlThis study assessed the functional profile (foaming, emulsifying and rheological properties), proteomic and metabolomic composition of a naturally foaming and currently unexploited co-product (centrate) from the Quorn fermentation process. Due to the low environmental footprint of this process the centrate is a potential source of sustainable functional ingredients for the food industry. A range of fractions were isolated from the centrate via successive ultrafiltration steps. The retentate 100 (R100) fraction, which was obtained following a 100 kDa ultrafiltration, displayed good foaming, emulsifying and rheological properties. R100 solutions and oil-in-water emulsions displayed high viscosity, while R100 solutions and hydrogels showed high viscoelasticity. R100 foams displayed high stability while oil-in-water R100 emulsions showed small and stable oil droplet size distributions. Large mycelial aggregates were reported in R100 solutions and gels, correlating with their high viscosity and viscoelasticity. A dense mycelial network was observed in R100 foams and contributing to their stability. In parallel tensiometry measurements highlighted the presence of interfacially active molecules in R100 which formed a rigid film stabilising the oil/water interface. A number of functional metabolites and proteins were identified in the centrate, including a cerato-platanin protein, cell membrane constituents (phospholipids, sterols, glycosphingolipids, sphingomyelins), cell wall constituents (chitin, chitosan, proteins), guanine and guanine-based nucleosides and nucleotides. This study highlighted the potential of functional extracts from the Quorn fermentation process as novel ingredients for the preparation of sustainable food products and the complex and specific nature of the centrate’s functional profile, with contributions reported for both mycelial structures and interfacially active molecules.This work was supported by the Engineering and Physical Sciences Research Council (Grant number EP/J501682/1 Foaming and Fat Replacer Ingredients).https://doi.org/10.1007/s00217-019-03287-z245pubpu

Functional fungal extracts from the Quorn fermentation co-product as novel partial egg white replacers

Replaced AM with VoR 2020-01-17The production of mycoprotein biomass by Marlow Foods for use in their meat alternative brand Quorn is a potential source of sustainable alternatives to functional ingredients of animal origin for the food industry. The conversion of this viscoelastic biomass into the Quorn meat-like texture relies on functional synergy with egg white (EW), effectively forming a fibre gel composite. In a previous study we reported that an extract (retentate 100 or R100) obtained from the Quorn fermentation co-product (centrate) via ultrafiltration displayed good foaming, emulsifying and rheological properties. This current study investigated if a possible similar synergy between EW and R100 could be exploited to partially replace EW as foaming and/or gelling ingredient. The large hyphal structures characteristic of R100 solutions were observed in EW-R100 mixtures, while EW-R100 gels showed dense networks of entangled hyphal aggregates and filaments. R100 foams prepared by frothing proved less stable than EW ones, however a 75/25 w/w EW-R100 mixture displayed a similar foam stability to EW. Simlarly R100 hydrogels proved less viscoelastic than EW ones, however the viscoelasticity of gels prepared with 50/50 w/w and 75/25 w/w EW-R100 proved similar to those of EW gels while 75/25 w/w EW-R100 gels displayed similar hardness to EW ones. Both results highlighted a functional synergy between the R100 material and EW proteins. In parallel tensiometry measurements highlighted the presence of surface-active material in EW-R100 mixtures contributing to their high foaming properties. These results highlighted the potential of functional extracts from the Quorn fermentation process for partial EW replacement as foaming and gelling agent, and the complex nature of the functional profile of EW-R100 mixtures, with contributions reported for both hyphal structures and surface-active material.This work was supported by the Engineering and Physical Sciences Research Council [grant number EP/J501682/1 Foaming and Fat Replacer Ingredients].https://doi.org/10.1007/s00217-019-03390-1246pubpu

Molecular simulation of partially denatured β-lactoglobulin

From Elsevier via Jisc Publications RouterHistory: accepted 2023-04-22, issued 2023-04-29Article version: AMPublication status: AcceptedFunder: Heriot-Watt University; FundRef: https://doi.org/10.13039/100009767Funder: Engineering & Physical Sciences Research Council; Grant(s): EP/J501682/1Julien Lonchamp - ORCID: 0000-0001-7954-4745 https://orcid.org/0000-0001-7954-4745The unfolding of β-lactoglobulin (β-lac) upon heating was comprehensively studied through molecular dynamics computer simulations. A β-lac molecule in the aqueous solution was firstly heated at 500 K for unfolding and then annealed at 300 K to collect stable conformations. There were five meta-stable conformations observed based on the Free Energy Landscape (FEL). The β-lac molecule was found to exhibit an open and extended conformation on heating followed by limited refolding upon cooling. The cysteine residues –SH121 and S–S66-160 in the most open conformation were located at the opposite ends of the β-lac molecule. This would favour the intermolecular –SH/S–S interchange reactions that are known to occur in β-lac as part of the inter-molecular aggregation process. Furthermore, the unfolding of the β-lac increased the hydrogen bond forming capacity between water molecules and the protein and between water molecules themselves. The interactions and the properties of the water molecules in the protein hydration shell also indicated that the hydration shell was stabilized by protein unfolding. However, it was found that the unfolding of β-lac increased diffusion of hydration water molecules, including those in the first hydration shell that interact more strongly with the protein. This may partly explain why unfolded proteins are more likely to aggregate even though there were more hydration water molecules protecting them. Such results provided more detailed information on the structure-functionality relationship of β-lac based on both the protein molecule and its hydration shell. This provides insight into how we can control the processing of proteins for desirable functional properties such as thickening and gelation, which are modified through protein-water interactions.inpressinpres

Electrostatic complexes of whey protein and pectin as foaming and emulsifying agents

Five types of electrostatic complex (macromolecular complexes, core-shell particles, and mixed homogeneous particles) were formed between whey protein (whey protein concentrate [WPC]) and pectin. By controlling the thermal treatment, composition, and order of mixing, it was possible to produce complexes that for the same biopolymer concentration gave differing functional properties. All protein-pectin complexes showed higher foaming ability and stability than native or heated WPC without pectin. Native WPC had higher emulsifying ability than protein-pectin complexes but exhibited the lowest emulsion stability. Ingredients based on such ideas might offer the food manufacturer greater control over food structure, stability, and organoleptic properties.sch_die20pub5156pubsup

Clostridium perfringensepsilon toxin H149A mutant as a platform for receptor binding studies

Clostridium perfringens epsilon toxin (Etx) is a pore-forming toxin responsible for a severe and rapidly fatal enterotoxemia of ruminants. The toxin is classified as a category B bioterrorism agent by the U.S. Government Centres for Disease Control and Prevention (CDC), making work with recombinant toxin difficult. To reduce the hazard posed by work with recombinant Etx, we have used a variant of Etx that contains a H149A mutation (Etx-H149A), previously reported to have reduced, but not abolished, toxicity. The three-dimensional structure of H149A prototoxin shows that the H149A mutation in domain III does not affect organisation of the putative receptor binding loops in domain I of the toxin. Surface exposed tyrosine residues in domain I of Etx-H149A (Y16, Y20, Y29, Y30, Y36 and Y196) were mutated to alanine and mutants Y30A and Y196A showed significantly reduced binding to MDCK.2 cells relative to Etx-H149A that correlated with their reduced cytotoxic activity. Thus, our study confirms the role of surface exposed tyrosine residues in domain I of Etx in binding to MDCK cells and the suitability of Etx-H149A for further receptor binding studies. In contrast, binding of all of the tyrosine mutants to ACHN cells was similar to that of Etx-H149A, suggesting that Etx can recognise different cell surface receptors. In support of this, the crystal structure of Etx-H149A identified a glycan (β-octyl-glucoside) binding site in domain III of Etx-H149A, which may be a second receptor binding site. These findings have important implications for developing strategies designed to neutralise toxin activity