On countings and enumerations of block-parallel automata networks

When we focus on finite dynamical systems from both the computability/complexity and the modelling standpoints, automata networks seem to be a particularly appropriate mathematical model on which theory shall be developed. In this paper, automata networks are finite collections of entities (the automata), each automaton having its own set of possible states, which interact with each other over discrete time, interactions being defined as local functions allowing the automata to change their state according to the states of their neighbourhoods. The studies on this model of computation have underlined the very importance of the way (i.e. the schedule) according to which the automata update their states, namely the update modes which can be deterministic, periodic, fair, or not. Indeed, a given network may admit numerous underlying dynamics, these latter depending highly on the update modes under which we let the former evolve. In this paper, we pay attention to a new kind of deterministic, periodic and fair update mode family introduced recently in a modelling framework, called the block-parallel update modes by duality with the well-known and studied block-sequential update modes. More precisely, in the general context of automata networks, this work aims at presenting what distinguish block-parallel update modes from block-sequential ones, and at counting and enumerating them: in absolute terms, by keeping only representatives leading to distinct dynamics, and by keeping only representatives giving rise to distinct isomorphic limit dynamics. Put together, this paper constitutes a first theoretical analysis of these update modes and their impact on automata networks dynamics

Assessing the Social Acceptability of New Technologies: Gaps and Tensions Between Science and Regulation

ArticleLes considérations éthiques concernant le développement de technologies font maintenant partie du champ de la bioéthique, concentrées en grande partie sur les interactions entre la science et le gouvernement pour établir le bien social. Depuis l’avènement des différentes formes de biotechnologies, l’analyse scientifique des risques a fait l’objet de diverses lignes de questionnement par rapport au rôle que la science quantitative joue dans la surveillance gouvernementale. Cela est d’autant plus important dans le débat actuel sur l’acceptabilité des nanotechnologies. Dans cet article, nous précisons d’abord les points forts et les limites de l’analyse scientifique de l’acceptabilité sociale des risques de la nanotechnologie. Ensuite, nous montrons les limites de l’adoption d’une approche empirique dans les sciences sociales et humaines pour prédire l’acceptabilité sociale d’une technologie. Nous soutenons que la reconnaissance des hypothèses sous-jacentes de ces deux approches quantitatives doit ouvrir une route à des approches plus réflexives par les sciences sociales et les sciences humaines.Ethical considerations regarding the development of technologies are now a standard part of the field of bioethics, focused in large part on the interactions between science and government in establishing the social good. Since the advent of different forms of biotechnology, scientific risk analysis has been subject to various lines of questioning relative to the role that quantitative science plays in government oversight. This is even more significant in the present debate on the acceptability of nanotechnology. In this article, we first specify the strengths and limitations of the scientific analysis of the social acceptability of risks in nanotechnology. Next, we demonstrate the limitations of taking an empirical approach in the social sciences and the humanities to predicting the social acceptability of a technology. We argue that recognizing the assumptions underlying these two quantitative approaches should open up a road to more reflective approaches by the social sciences and the humanities

Le Centre de découverte d’Aubeterre sur Dronne - Questionnements autour d’une « aventure partenariale » relative à la création d’un centre d’éducation à l’environnement

Les actions d’éducation relative à l’environnement (ERE) font de plus en plus fréquemment référence à l’intérêt de la mise en œuvre de démarches partenariales. Les discours des porteurs de projets insistent en effet sur l’importance de la mobilisation et de l’implication d’acteurs multiples, divers, de culture ou d’intérêts parfois contradictoires, qui s’accordent cependant pour poursuivre des objectifs partagés et mettre en commun leurs compétences, au service d’une action pour l’environneme..

Préparation et caractérisation de catalyseurs bimétalliques Re-Pd/TiO2 pour l'hydrogénation de l'acide succinique issu de la biomasse

L'objectif de ce travail est de mettre au point des catalyseurs bimétalliques Re-Pd/TiO2 actifs et suffisamment robustes en milieu hydrothermal pour hydrogéner sélectivement l'acide succinique (SUC) en 1,4-butanediol (BDO). Dans un premier temps, des catalyseurs monométalliques 2%Pd/TiO2 sont préparés et caractérisés par diverses techniques physico-chimiques. Les résultats montrent l'importance d'un certain nombre de paramètres sur les propriétés des catalyseurs et leurs performances catalytiques. Les catalyseurs à base de palladium sont très sélectifs en g-butyrolactone mais très peu en BDO. Différentes teneurs en rhénium sont ensuite déposées sur les catalyseurs 2%Pd/TiO2 (par imprégnation successive (IS) et par réduction catalytique (RC)). L'existence d'une interaction entre les deux métaux Pd-Re est mise en évidence par plusieurs techniques de caractérisation (chimisorption H2, réaction modèle de déshydrogénation du cyclohexane, RTP, XPS, MET-EDX). L'ajout de rhénium permet d'augmenter la vitesse de la réaction de transformation du SUC et améliore la sélectivité en BDO. Pour les catalyseurs préparés par IS, des quantités importantes de rhénium (3-4%) sont nécessaires pour avoir un effet optimum, alors que le dépôt par la méthode RC doit être limité à des teneurs plus faibles (< 1%). Néanmoins, les catalyseurs préparés par IS conduisent à une meilleure activité et sélectivité en BDO.The objective of this work is to synthesize bimetallic catalysts Re-Pd/TiO2 active and strong enough in hydrothermal environment to hydrogenate selectively the succinic acid (SUC) to 1,4-butanediol (BDO). At first, monometallic 2%Pd/TiO2 catalysts are prepared and characterized by various physico-chemical methods. The results show the importance of several parameters on the catalyst properties and catalytic performances. Palladium catalysts are very selective to g-butyrolactone but few to BDO. Various rhenium contents are then deposited on 2%Pd/TiO2 catalysts (by successive impregnation (SI) and catalytic reduction (CR)). The existence of an interaction between both Pd-Re metals is revealed using several techniques of characterization (H2 chemisorption, model reaction of cyclohexane dehydrogenation, TPR, XPS, TEM-EDX). Adding rhenium both allows enhancing the reaction rate of SUC transformation and improving the selectivity to BDO. For catalysts prepared by SI, important quantities of rhenium (3-4%) are needed for optimal effect, while the deposit must be limited to lower contents (< 1%) when using the CR method. Nevertheless, catalysts prepared by SI lead to better activity and selectivity to BDO.POITIERS-SCD-Bib. électronique (861949901) / SudocSudocFranceF

Spatial analysis of access to and accessibility to surrounding train stations: a case study of accessibility for the elderly in Perth, Western Australia

Approximately one-fifth of Perth’s population is aged 60 or older. Projections suggest that this proportion will continue to increase as a result of the large number of children born after the World War II (1946–1964). Access to and accessibility around train stations for the aging population is and will become a more important issue as the elderly population continues to grow. The aim of the paper is to develop and apply anew measure of accessibility to train stations at a fine spatial scale, justified by the special circumstance of the elderly using a case study in Perth, Western Australia. Intercept surveys are used to collect data on factors affecting train station accessibility for patrons aged 60 years or older, at seven highly dispersed train stations. Overall accessibility is measured separately using a composite index based on three travel modes (walk-and-ride, park-and-ride and bus-and-ride). The results illustrate that key variables, such as distance from an origin to a station, walking or driving route directness, land-use diversity, service and facility quality, bus connection to train stations, all affect the accessibility to train stations for the elderly. This implies that improvements to these factors will improve accessibility for this population group

Tailor-made alkaliphilic and thermostable fungal laccases for industrial wood processing

Background: During the kraft process to obtain cellulosic pulp from wood, most of the lignin is removed by high‐ temperature alkaline cooking, released in the black liquors and usually incinerated for energy. However, kraft lignins are a valuable source of phenolic compounds that can be valorized in new bio‐based products. The aim of this work is to develop laccases capable of working under the extreme conditions of high temperature and pH, typical of the industrial conversion of wood into kraft pulp and fibreboard, in order to provide extremophilic biocatalysts for depoly‐ merising kraft lignin, and enzyme‐assisted technologies for kraft pulp and fibreboard production. Results: Through systematic enzyme engineering, combining enzyme‐directed evolution and rational design, we changed the optimal pH of the laccase for oxidation of lignin phenols from acidic to basic, enhanced the catalytic activity at alkaline pH and increased the thermal tolerance of the enzyme by accumulating up to eight mutations in the protein sequence. The extremophilic laccase variants show maximum activity at 70 °C and oxidize kraft lignin at pH 10. Their integration into industrial‐type processes saves energy and chemicals. As a pre‐bleaching stage, the enzymes promote kraft pulp bleachability and significantly reduce the need for chlorine dioxide compared to the industrial sequence. Their application in wood chips during fibreboard production, facilitates the defibering stage, with less energy required. Conclusions: A set of new alkaliphilic and thermophilic fungal laccases has been developed to operate under the extreme conditions of high temperature and pH typical of industrial wood conversion processes. For the first time basidiomycete laccases of high‐redox potential show activity on lignin‐derived phenols and polymeric lignin at pH 10. Considering the extreme conditions of current industrial processes for kraft pulp and fibreboard production, the new tailor‐made laccases constitute a step forward towards turning kraft pulp mills into biorefineries. Their use as biocata‐ lysts in the wood conversion sector is expected to support the development of more environmentally sound and efficient processes, and more sustainable products. Keywords: Laccase, Enzyme directed evolution, Extremophilic properties, Lignin, Kraft pulping, Fibreboard, Biorefiner

Extremozymes for wood-based building blocks: from pulp mill to board and insulation products – WoodZymes project

4 páginas.- 4 referencias.- Comunicación oral presentada en el 16th European Workshop on Lignocellulosics and Pulp (EWLP) Gothenburg, Sweden, June 28 – July 1, 2022Enzymes can substitute harsh and energy-demanding chemical treatments for production of bio-based building blocks and products from wood processing. However, their properties need to be adapted to the extreme operation conditions (such as high T and pH) commonly used by these industries. Here, we summarize the main results obtained during the WoodZymes European Project (www.woodzymes.eu), which aimed to provide tailor-made extremozymes and extremozyme-based processes never assayed before in wood biorefineries. Novel extremophilic enzymes active on kraft lignin (laccases) and xylan (xylanases) were developed and produced at pilot or industrial scales. The enzymatic fractionation of kraft lignins using the METNINTM lignin refining technology, and the extremozyme-aided delignification and bleaching of kraft pulps were demonstrated at pilot scale. The resulting lignin and hemicellulose derived compounds were chemically characterized and applied as components of phenol-(lignin)-formaldehyde resins for wood panels and of polyurethane foams, or as papermaking additives. The new extremozymes were also applied to improve some of the latter applications. The techno-economic and environmental assessment of the new materials and processes, developed in WoodZymes project, showed that extremozyme-based processes led to clear benefits in energy savings during the refining of pulp or wood fibres, enabled lower addition of harsh chemicals (e.g. ClO2 during pulp bleaching), and resulted in a lower carbon footprint of the new bio-based products by substitution of fossil-derived components.WoodZymes project was funded by the Bio-based Industries Joint Undertaking (BBI JU) under GA 792070. The BBI JU received support from the EU’s H2020 research and innovation programme and the Bio Based Industries ConsortiumN