Maize 16-kD γ-zein forms very unusual disulfide-bonded polymers in the endoplasmic reticulum : implications for prolamin evolution

In the lumen of the endoplasmic reticulum (ER), prolamin storage proteins of cereal seeds form very large, ordered heteropolymers termed protein bodies (PBs), which are insoluble unless treated with alcohol or reducing agents. In maize PBs, 16-kD \u3b3-zein locates at the interface between a core of alcohol-soluble \u3b1-zeins and the outermost layer mainly composed of the reduced-soluble 27-kD \u3b3-zein. 16-kD \u3b3-zein originates from 27-kD \u3b3-zein upon whole-genome duplication and is mainly characterized by deletions in the N-terminal domain that eliminate most Pro-rich repeats and part of the Cys residues involved in inter-chain bonds. 27-kD \u3b3-zein also forms insoluble PBs when expressed in transgenic vegetative tissues. We show that in Arabidopsis leaves, 16-kD \u3b3-zein assembles into disulfide-linked polymers that fail to efficiently become insoluble. Instead of forming PBs, these polymers accumulate as very unusual threads that markedly enlarge the ER lumen, resembling amyloid-like fibers. Domain-swapping between the two \u3b3-zeins indicates that the N-terminal region of 16-kD \u3b3-zein has a dominant effect in preventing full insolubilization. Therefore, a newly evolved prolamin has lost the ability to form homotypic PBs, and has acquired a new function in the assembly of natural, heteropolymeric PBs

Plant cell culture technology in the cosmetics and food industries : current state and future trends

The production of drugs, cosmetics, and food which are derived from plant cell and tissue cultures has a long tradition. The emerging trend of manufacturing cosmetics and food products in a natural and sustainable manner has brought a new wave in plant cell culture technology over the past 10 years. More than 50 products based on extracts from plant cell cultures have made their way into the cosmetics industry during this time, whereby the majority is produced with plant cell suspension cultures. In addition, the first plant cell culture-based food supplement ingredients, such as Echigena Plus and Teoside 10, are now produced at production scale. In this mini review, we discuss the reasons for and the characteristics as well as the challenges of plant cell culture-based productions for the cosmetics and food industries. It focuses on the current state of the art in this field. In addition, two examples of the latest developments in plant cell culture-based food production are presented, that is, superfood which boosts health and food that can be produced in the lab or at home

The story of Wanderwolf: A contested tale on the re-emergence of 'new wilderness' in the Netherlands

In this chapter, the author studies what the particular wolf has come to signify culturally in the contemporary public imagination and understanding of the Dutch landscape. It suggests that the Wanderwolf 'wandered' into the production of a new landscape ideology, i.e., another genesis of the Dutch landscape, in which it fulfils a different kind, yet equally controversial, iconic role compared to those we know from West-European ethnological and folkloric traditions. The media commotion surrounding the sightings of the Wanderwolf should be seen in the context of a much larger interest and effort to 'rewild' Europe. The visions expressed by the enthusiasts on the apparent return of the wolf reflect strongly those which Cronon has critically analysed in his influential essay on the notion of wilderness. The wolf's adversaries spoke out equally during the Wanderwolf's appearance. As media announced during the Wanderwolf incident, the comeback of the wolf is no longer a fairy tale

Forgeabilité et microstructure d'un aluminiure de titane à base γ-TiAl déformé par torsion à chaud

Les aluminiures de titane γ-TiAl sont des matériaux prometteurs pour l'aéronautique du fait de leur faible densité et de leurs excellentes propriétés mécaniques en conditions extrêmes. Avec une densité beaucoup plus faible que celle des superalliages, une résistance à l'oxydation plus élevée que celle des alliages de titane, ils offrent d'excellentes propriétés entre 600°C et 800°C, avec un module d'Young qui varie très peu avec la température. De nombreuses études ont porté sur les relations microstructure / propriétés mécaniques mais peu sur les relations forgeabilité / microstructure. Cette forgeabilité est limitée par une faible ductilité jusqu'à 500°C. De plus, les gammes de mise en forme industrielles ne sont pas encore optimisées pour ces matériaux, en particulier les gammes de forgeage. On doit en effet bien maîtriser l'évolution de la microstructure, en relation avec les modes d'élaboration et les traitements thermomécaniques appliqués au matériau. C'est pourquoi une étude rhéologique et microstructurale d'un alliage γ-TiAl déformé au moyen de l'essai de torsion à chaud entre 1050°C et 1150°C est réalisée dans le cadre d'un développement d'aubes forgées pour moteurs aéronautiques. L'observation et l'analyse quantitative des microstructures sur les états déformés ont pour objectif de comprendre les évolutions microstructurales lors de déformations à chaud et de mieux appréhender les procédés de forgeage. Une loi de comportement est déterminée dans les gammes du procédé industriel et introduite dans un code de calcul de simulation par éléments finis pour optimiser les paramètres du procédé

Monitoring rock freezing and thawing by novel geoelectrical and acoustic techniques

Automated monitoring of freeze-thaw cycles and fracture propagation in mountain rockwalls is needed to provide early warning about rockfall hazards. Conventional geoelectrical methods such as electrical resistivity tomography (ERT) are limited by large and variable ohmic contact resistances, requiring galvanic coupling with metal electrodes inserted into holes drilled into rock, and which can be loosened by rock weathering. We report a novel experimental methodology that combined capacitive resistivity imaging (CRI), ERT, and microseismic event recording to monitor freeze-thaw of six blocks of hard and soft limestones under conditions simulating an active layer above permafrost and seasonally frozen rock in a nonpermafrost environment. Our results demonstrate that the CRI method is highly sensitive to freeze-thaw processes; it yields property information equivalent to that obtained with conventional ERT and offers a viable route for nongalvanic long-term geoelectrical monitoring, extending the benefits of the methodology to soft/hard rock environments. Contact impedances achieved with CRI are less affected by seasonal temperature changes, the aggregate state of the pore water (liquid or frozen), and the presence of low-porosity rock with high matrix resistivities than those achieved with ERT. Microseismic monitoring has the advantage over acoustic emissions that events were recorded in relevant field distances of meters to decameters from cracking events. For the first time we recorded about 1000 microcracking events and clustered them in four groups according to frequency and waveform. Compared to previous studies, mainly on ice-cracking in glaciers, the groups are attributed to single- or multiple-stage cracking events such as crack coalescence