Systemic analysis of production scenarios for bioethanol produced from ligno-cellulosic biomass [abstract]

Defining alternatives for non-renewable energy sources constitutes a priority to the development of our societies. One of these alternatives is biofuels production starting from energy crops, agricultural wastes, forest products or wastes. In this context, a "second generation" biofuels production, aiming at utilizing the whole plant, including ligno-cellulosic (hemicelluloses, cellulose, lignin) fractions (Ogier et al., 1999) that are not used for human food, would allow the reduction of the drawbacks of bioethanol production (Schoeling, 2007). However, numerous technical, economical, ethical and environmental questions are still pending. One of the aims of the BioEtha2 project, directed by the Walloon Agricultural Research Centre, is to define the position of bioethanol produced from ligno-cellulosic biomass among the different renewable energy alternatives that could be developed in Wallonia towards 2020. With this aim, and in order to answer the numerous questions in this field, the project aims at using tools and methods coming from the concept of "forecasting scenarios" (Sebillotte, 2002; Slegten et al., 2007; For-learn, 2008). This concept, based on a contemporary reality, aims to explore different possible scenarios for the future development of alternative sources of energy production. The principle is to evaluate, explore, possible futures of the studied problematic, through the establishment of possible evolution trajectories. We contribute to this prospective through a systemic approach (Vanloqueren, 2007) that allows lightening the existing interactions within the system "ligno-cellulosic biomass chain" without isolating it from its environment. We explain and sketch the two contexts needed to identify primary stakes. The global context includes inter-dependant and auto-regulating fields such as society, politics, technology and economy. These four fields influence each part of the "chain" with specific tools. However, the interest and possible action fields lay within the intermediary context representing the "resources" such as agriculture, forestry, "driving" elements such as mobility, mediation elements such as territories and environment and concurrent elements such as non-cellulosic biomass, the energy mix and the non-energy valorization

Placenta-Like Structure of the Aphid Endoparasitic Wasp Aphidius ervi: A Strategy of Optimal Resources Acquisition

Aphidius ervi (Hymenoptera: Braconidae) is an entomophagous parasitoid known to be an effective parasitoid of several aphid species of economic importance. A reduction of its production cost during mass rearing for inundative release is needed to improve its use in biological control of pests. In these contexts, a careful analysis of its entire development phases within its host is needed. This paper shows that this parasitoid has some characteristics in its embryological development rather complex and different from most other reported insects, which can be phylogenetically very close. First, its yolkless egg allows a high fecundity of the female but force them to hatch from the egg shell rapidly to the host hemocoel. An early cellularisation allowing a rapid differentiation of a serosa membrane seems to confirm this hypothesis. The serosa wraps the developing embryo until the first instar larva stage and invades the host tissues by microvilli projections and form a placenta like structure able to divert host resources and allowing nutrition and respiration of embryo. Such interspecific invasion, at the cellular level, recalls mammal's trophoblasts that anchors maternal uterine wall and underlines the high adaptation of A. ervi to develop in the host body

The Effects of Aphid Traits on Parasitoid Host Use and Specialist Advantage

Specialization is a central concept in ecology and one of the fundamental properties of parasitoids. Highly specialized parasitoids tend to be more efficient in host-use compared to generalized parasitoids, presumably owing to the trade-off between host range and hostuse efficiency. However, it remains unknown how parasitoid host specificity and host-use depends on host traits related to susceptibility to parasitoid attack. To address this question, we used data from a 13-year survey of interactions among 142 aphid and 75 parasitoid species in nine European countries. We found that only aphid traits related to local resource characteristics seem to influence the trade-off between host-range and efficiency: more specialized parasitoids had an apparent advantage (higher abundance on shared hosts) on aphids with sparse colonies, ant-attendance and without concealment, and this was more evident when host relatedness was included in calculation of parasitoid specificity. More traits influenced average assemblage specialization, which was highest in aphids that are monophagous, monoecious, large, highly mobile (easily drop from a plant), without myrmecophily, habitat specialists, inhabit non-agricultural habitats and have sparse colonies. Differences in aphid wax production did not influence parasitoid host specificity and host-use. Our study is the first step in identifying host traits important for aphid parasitoid host specificity and host-use and improves our understanding of bottom-up effects of aphid traits on aphid-parasitoid food web structure

Bilan et apports de différentes Analyses Sociales du Cycle de Vie menées dans le secteur des agro-industries

Assessment and contributions of different Social Life Cycle Assessments performed in the agribusiness sector. Introduction. Consumers are attaching increasing importance to the sustainability of the products they purchase. The agribusiness sector is well aware of this trend and is making efforts to guarantee product sustainability. Literature. Social Life Cycle Assessment (S-LCA) is a widely used methodology (like others in this field, such as ISO 26000 and SA 8000) for evaluating the social impact of the activities involved in the life cycle of a product. The S-LCA guidelines were published in 2009 and therefore the framework for this methodology is not yet well established. Nevertheless, some S-LCA studies have been completed and have contributed to the development of the methodology. The objective of this paper is to give feedback to the agribusiness sector and researchers regarding prospects for future use of Social Life Cycle Assessment in the agribusiness sector. Papers selected for this literature review have been chosen on the basis of Scopus's query from 2000 to the present day. Scopus's query contains analyses of major international conferences. The case studies in the agribusiness sector that are reviewed in this paper highlight the usefulness of a social hotspots database, the need for stakeholder involvement in S-LCA implementation, the link between S-LCA and its regional context, and the benefits of developing causal links between indicators and impact categories, such as working conditions and governance. Conclusions. Further methodological investigation needs to be conducted in order to standardize this new methodology. Its ability to provide an overview of assessment of socioeconomic impacts makes it a good choice for evaluating the aspect of social impact as part of sustainability studies

Dike-break induced flowa: a simplified model

peer reviewedA simplified model for the prediction of the steady-state outflowthrough a breach in an inland dike is presented. It consists in the application of the mass and momentum conservation principles to a macroscopic control volume. A proper definition of the shape of the control volume enables to take the main characteristics of the flow into account and thus to compensate for the extreme simplification of the spatial representation of the model. At the breach, a relation derived from the shallow-water equations is used to determine the direction of the flow. Developments have been guided by numerical simulations and results have been compared to experimental data. Both the accuracy and the domain of validity of the simplified model are found satisfactory

Etat des lieux des flux céréaliers en Wallonie selon différentes filières d'utilisation

Survey on cereal resources in Wallonia according to their different uses. Survey on cereal resources in Wallonia according to their different uses. More than 60% of the arable cropped area in Wallonia is dedicated to cereals. Cereal chains were initially aimed at ensuring food security but are now progressively oriented towards new non-food uses. Walloon cereal chains are now having to face up to new global challenges: to ensure the competitiveness and sustainability of vegetal and animal chains, to match society's expectations and to meet the biomass needs for energy uses and bio-based products. Within this framework, this research aims to evaluate the environmental and socio-economic sustainability of future scenarios of current and potential food and non-food uses for Walloon cereals. This paper, the first in a series of two, presents the current picture of Walloon cereal crops and their uses. Various steps are analyzed: production, collection, wholesale and processing. Four main uses characterize cereal processing: the so-called "4Fs", representing Food (human food uses), Feed (animal feed uses), Fuel (energy uses) and Fiber (material uses). Data collected from stakeholders in the Walloon cereal chain enabled us to assess cereal flows for the "4Fs", drawing a qualitative and a quantitative picture of Walloon cereal resources including the key elements of the cereal chains. This approach serves as a basis for a prospective exercise, described in a companion paper, which develops potential uses for Walloon cereal resources at the 2030 horizon

Portrait et durabilité de différentes voies de valorisations des ressources céréalières wallonnes. Résultats extraits du projet ALT-4-CER

Cet article a pour but de communiquer de manière succincte les résultats du projet ALT-4-CER, financé par le Centre wallon de Recherches agronomiques (CRA-W) sur base des fonds de la loi de défiscalisation des institutions de recherches Moerman. Ce projet s'est déroulé de mars 2011 à juillet 2015. Le projet comportait les objectifs suivants : (1) dresser un portrait des utilisations actuelles des céréales wallonnes ; (2) élaborer des scénarios originaux d'évaluations possibles de l'utilisation des céréales wallonnes en concertation avec le secteur wallon ; (3) évaluer, sur base d'analyses du cycle de vie (ACV), les impacts environnementaux (et socio-économiques, disponibles mais non repris dans cet article) de la production et la transformation des céréales wallonnes selon des exemples de filières de valorisation. L'article présente des informations, extraites des résultats du projet, sur le portrait en 2010 de la valorisation des céréales wallonnes et sur l'estimation de l'impact environnemental de la production de céréales en Wallonie. Il se limite à donner les conclusions et messages-clés de l'étude sur la construction de scénarios possibles d'évolution de l'utilisation des céréales wallonnes d'une part et, d'autre part, sur l'utilisation des céréales pour la production d'énergie