Academic literature on the topic 'Life cycle symbiosis'

Industrial symbiosis networks conventionally provide economic and environmental benefits to participating industries. However, most studies have failed to quantify waste management solutions and identify network connections in addition to methodological variation of assessments. This study provides a comprehensive model to conduct sustainable study of industrial symbiosis, which includes identification of network connections, life cycle assessment of materials, economic assessment, and environmental performance using standard guidelines from the literature. Additionally, a case study of industrial symbiosis network from Sodankylä region of Finland is implemented. Results projected an estimated life cycle cost of €115.20 million. The symbiotic environment would save €6.42 million in waste management cost to the business participants in addition to the projected environmental impact of 0.95 million tonne of CO2, 339.80 tonne of CH4, and 18.20 tonne of N2O. The potential of further cost saving with presented optimal assessment in the current architecture is forecast at €0.63 million every year.

Abstract A review of the available literature concerning environmental impact assessment for industrial symbiosis has been carried out. The authors have recommended the use of life cycle assessment method for this purpose. It was stated that so far few studies presenting LCA results of industrial symbiosis have been published. Among the factors which contribute to the success of symbiotic exchange, the close location of collaborating companies has been often mentioned. This paper presents LCA results concerning the environmental impact of symbiotic gypsum transmission. Concepts of relative distance and critical distance for the case of industrial symbiosis were proposed and defined. Significant difference between critical distance obtained for particular endpoints were observed (3.5- 564 km). Application of Life Cycle Sustainability Triangle enabled the estimation of critical distance taking into account various impact categories. A sensitivity analysis indicated the relationship between critical distance and the means of transport which reflected the effect of scale. The critical distance determined for heavy trucks was 3.2 - 3.9 times longer than in case of lighter vehicles.

While the majority of symbiosis research is focused on bacteria, microbial eukaryotes play important roles in the microbiota and as pathogens, especially the incredibly diverse Fungi kingdom. The recent emergence of widespread pathogens in wildlife (bats, amphibians, snakes) and multidrug-resistant opportunists in human populations (Candida auris) has highlighted the importance of better understanding animal–fungus interactions. Regardless of their prominence there are few animal–fungus symbiosis models, but modern technological advances are allowing researchers to utilize novel organisms and systems. Here, I review a forgotten system of animal–fungus interactions: the beetle–fungus symbioses of Drugstore and Cigarette beetles with their symbiont Symbiotaphrina. As pioneering systems for the study of mutualistic symbioses, they were heavily researched between 1920 and 1970, but have received only sporadic attention in the past 40 years. Several features make them unique research organisms, including (1) the symbiont is both extracellular and intracellular during the life cycle of the host, and (2) both beetle and fungus can be cultured in isolation. Specifically, fungal symbionts intracellularly infect cells in the larval and adult beetle gut, while accessory glands in adult females harbor extracellular fungi. In this way, research on the microbiota, pathogenesis/infection, and mutualism can be performed. Furthermore, these beetles are economically important stored-product pests found worldwide. In addition to providing a historical perspective of the research undertaken and an overview of beetle biology and their symbiosis with Symbiotaphrina, I performed two analyses on publicly available genomic data. First, in a preliminary comparative genomic analysis of the fungal symbionts, I found striking differences in the pathways for the biosynthesis of two B vitamins important for the host beetle, thiamine and biotin. Second, I estimated the most recent common ancestor for Drugstore and Cigarette beetles at 8.8–13.5 Mya using sequence divergence (CO1 gene). Together, these analyses demonstrate that modern methods and data (genomics, transcriptomes, etc.) have great potential to transform these beetle–fungus systems into model systems again.

Most land plants engage in mutually beneficial interactions with arbuscular mycorrhizal (AM) fungi, the fungus providing phosphate and nitrogen in exchange for fixed carbon. During presymbiosis, both organisms communicate via oligosaccharides and butenolides. The requirement for a rice chitin receptor in symbiosis-induced lateral root development suggests that cell division programs operate in inner root tissues during both AM and nodule symbioses. Furthermore, the identification of transcription factors underpinning arbuscule development and degeneration reemphasized the plant's regulatory dominance in AM symbiosis. Finally, the finding that AM fungi, as lipid auxotrophs, depend on plant fatty acids (FAs) to complete their asexual life cycle revealed the basis for fungal biotrophy. Intriguingly, lipid metabolism is also central for asexual reproduction and interaction of the fungal sister clade, the Mucoromycotina, with endobacteria, indicative of an evolutionarily ancient role for lipids in fungal mutualism.

The Vibrio fischeri–Euprymna scolopes symbiosis has become a powerful model for the study of specificity, initiation, and maintenance between beneficial bacteria and their eukaryotic partner. In this invertebrate model system, the bacterial symbionts are acquired every generation from the surrounding seawater by newly hatched squid. These symbionts colonize a specialized internal structure called the light organ, which they inhabit for the remainder of the host’s lifetime. The V. fischeri population grows and ebbs following a diel cycle, with high cell densities at night producing bioluminescence that helps the host avoid predation during its nocturnal activities. Rhythmic timing of the growth of the symbionts and their production of bioluminescence only at night is critical for maintaining the symbiosis. V. fischeri symbionts detect their population densities through a behavior termed quorum-sensing, where they secrete and detect concentrations of autoinducer molecules at high cell density when nocturnal production of bioluminescence begins. In this review, we discuss events that lead up to the nocturnal acidification of the light organ and the cues used for pre-adaptive behaviors that both host and symbiont have evolved. This host–bacterium cross talk is used to coordinate networks of regulatory signals (such as quorum-sensing and bioluminescence) that eventually provide a unique yet stable environment for V. fischeri to thrive and be maintained throughout its life history as a successful partner in this dynamic symbiosis.

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente – Perfil Gestão e Sistemas Ambientais
Industrial symbiosis is an application of industrial ecology that consists of a collaborative approach between different industries and firms aimed at improving their environmental and economic performance involving the exchange of waste/byproducts as substitutes for raw materials. This collaboration is conditioned by the geographic proximity between industries and may face some information, economic, regulatory or motivational barriers. The main objective of this thesis was to develop a methodology to find and evaluate new potential exchanges in light of industrial symbiosis and to apply it to Sines oil refinery case study. The methodology was divided into four phases. The first phase is where, through the analysis of similar case studies, the potential new exchanges are uncovered.The second was made based on a literature review on the main barriers to industrial symbiosis development. This phase was developed to swiftly filter potential synergies that would face barriers to its development. The other two phases were only applied to the potential synergies that successfully passed the “filter”. Those phases consisted of an environmental evaluation through a LCA and a financial analysis. The application of the methodology showed two new potential synergetic possibilities for the Sines oil refinery. The results of the evaluation of those potential synergies were very promising both environmentally and financially. This research thus demonstrates the potential and benefits associated with the development of industrial symbiosis networks if the barriers to this development can be successfully surpassed.

The production of biofuels has increased in recent years, to reduce the dependence on fossil fuels and mitigate climate change. However, current production practices are heavily criticized on their environmental sustainability. Life cycle assessments have therefore been used in policies and academic studies to assess the systems; with divergent results. In the coming years however, biofuel production practices must improve to meet strict environmental sustainability policies. The aims of the research presented in this thesis, are to explore and analyze concepts from industrial symbiosis (IS) to improve the efficiency and environmental performance of biofuel production and identify possible material and energy exchanges between biofuel producers and external industries. An exploration of potential material and energy exchanges resulted in a diverse set of possible exchanges. Many exchanges were identified between biofuel producers to make use of each other’s by-products. There is also large potential for exchanges with external industries, e.g. with the food, energy and chemical producing industries. As such, the biofuel industry and external industries have possibilities for potential collaboration and environmental performance improvements, though implementation of the exchanges may be influenced by many conditions. In order to analyze if concepts from IS can provide benefits to firms of an IS network, an approach was created which outlines how quantifications of IS networks can be produced using life cycle assessment literature for guidelines and methodological considerations. The approach offers methods for quantifying the environmental performance for firms of the IS network and an approach to distribute impacts and credits for the exchanges between firm, to test the assumed benefits for the firms of the IS network. Life cycle assessment, and the approach from this thesis, have been used to quantify the environmental performance of IS networks by building scenarios based on an example from an IS network of biofuel producers in Sweden. From the analyses, it has been found that exchanges of material and energy may offer environmental performance improvements for the IS network and for firms of the network. However, the results are dependent upon the methodological considerations of the assessments, including the reference system, functional unit and allocation methods, in addition to important processes such as the agricultural inputs for the system and energy systems employed. By using industrial symbiosis concepts, biofuel producers have possibilities to improve the environmental performance. This is done by making use of by-products and waste and diversifying their products, promoting a transition toward biorefinery systems and a bio-based economy for regional environmental sustainability.
Produktionen av biobränslen har ökat de senaste åren, vilket är ett steg mot klimateffektivare lösningar i transportsektorn, men biodrivmedlen har ifrågasatts med hänvisning till tveksamheter kring deras miljö- och energiprestanda. Lifecykelanalyser har därför använts inom akademiska studier och för policy för att utvärdera systemen, dock utan samstämmiga resultat. Under de kommande åren måste därför praxis för produktion av biobränslen förbättras för att kunna möta de strikta kraven i hållbarhetskriterier för biobränslen. Syftet med forskningen som presenteras i den här doktorsavhandlingen är att utforska och analysera koncept från området Industriell symbios (IS) och därigenom identifiera förbättringar för ökad effektivitet och miljöprestanda för biobränsleproduktion. Vidare är syftet att identifiera möjliga material- och energiutbyten mellan biobränsleproducenter och externa industrier. Potentiella material- och energiutbyten undersöktes, vilket resulterade förslag på flera olika typer av potentiella utbyten. Undersökningen visar på en potential för att använda biprodukter i en biobränsleprocess som råvara till en annan biobränsleframställning. Vidare identifierades en stor potential för utbyten med externa industrier, som till exempel matproducenter samt industrier för energi och kemikalier. Det är tydligt att det finns möjligheter för biobränsleproducenter och externa industrier att samarbeta och därmed ge möjlighet till förbättringar i miljöprestandan, dock kan en implementering av dessa utbyten påverkas av många olika förutsättningar. Avhandlingen presenterar även ett tillvägagångssätt för att visa hur kvantifiering av miljöprestanda inom ett nätverk för IS kan genomföras genom att använda riktlinjer och metodavvägningar från litteratur för livscykelanalys.  Detta tillvägagångssätt kan användas för att analysera om koncept från IS kan leda till fördelar för företagen i ett IS-nätverk. Tillvägsgångssättet ger möjlighet att kvantifiera miljöprestandan för företagen i IS-nätverket och ger dessutom vägledning för hur miljöpåverkan från utbytena kan distribueras mellan de olika företagen. Metoden utvecklades för att bland annat undersöka de förmodade fördelarna från IS för varje enskild aktör. Livscykelanalys i kombination med tillvägagångssättet ovan har använts för att kvantifiera miljöprestandan för IS-nätverk genom att konstruera scenarier. Scenarierna har baserats på ett exempel från ett IS-nätverk av biobränsleprocenter i Sverige. Analyserna visar att utbyten av material- och energi kan ge förbättringar i miljöprestanda. Resultaten är dock beroende av vilka metodavvägningar som gjorts, till exempel val av referenssystem, funktionell enhet och allokeringsmetoder. Vidare spelar viktiga processer som inputs från jordbruk och val av energisystem stor roll för resultatet. Metodavvägningar för utväderingen influerar även miljöpåverkan samt hur den fördelas mellan företagen i IS-nätverket. Dessutom kan den lokala miljöpåverkan öka medan den globala påverkan minskar. Sammanfattningsvis kan biobränsleproducenter, genom att använda koncept från industriell symbios, ges möjlighet att förbättra sin miljöprestanda. Detta kan ske genom att använda biprodukter och avfall samt genom att diversifiera sina produkter som ett första steg mot en övergång mot bioraffinaderier och en mer biobaserad ekonomi för regional hållbarhet.

Agriculture is one of the most carbon-intensive sectors in today’s world. With demand for food soaring to feed an ever-increasing population, many methods are employed to produce food, ranging from open-field to greenhouse systems. However, due to their large environmental footprint, urban agriculture methods such as soilless culture systems are increasingly becoming a preferred method for food production. A case study has been performed at Hollbium in Stockholm, Sweden for the purpose of evaluating potential environmental impacts of Hollbium Loop, a vertical hydroponic system used for food production. This is achieved by carrying out a stand-alone assessment of Hollbium Loop, to identify potential environmental hotspots over the product’s lifetime of 10 years. Furthermore, Hollbium Loop’s system is compared to the production of lettuce in a horizontal open-field, a greenhouse farming system and nutrient film technique located in Spain, to identify potential trade-offs. Attributional life cycle assessment (ALCA) has been employed as a methodology with an explicit focus on eight impact categories at a midpoint level. The results of the study indicate that hotspots of environmental impacts in Hollbium Loop’s life cycle are due to the use of an internal combustion engine vehicle for maintenance, production of electronic components and the consumption of electricity in the use phase. In contrast, the results from the comparative scenarios indicated that Hollbium Loop from a life cycle perspective had the highest impacts under all impact categories in relation to the other three systems of food production. When the distance for transportation within the maintenance phase is reduced to a reasonable figure, Hollbium Loop no longer had the highest impacts within global warming and fossil resource scarcity, showing that the distance traversed plays a key role in mitigating the impacts. Other aspects and assumptions are also analyzed further using a sensitivity analysis, which shows that there is scope for decreasing Hollbium Loop’s environmental footprint. It is therefore recommended that Hollbium puts its efforts into optimizing the distance and modes of transport utilized and increasing the outer frame thickness of the Loop to make it sturdy and robust. Finally, it is also advised to increase the Loop’s vertical length to increase the yield per cycle, thereby reducing the overall impacts per kilogram of lettuce produced.
Jordbruket är en av de mest kolintensiva sektorerna i dagens värld. Med en efterfrågan på livsmedel som stiger för att föda en ständigt ökande befolkning, används många metoder för att producera livsmedel. Dessa metoder omfattar allt från öppna fält till växthussystem. På grund av deras stora miljöpåverkan blir emellertid stadsnära jordbruksmetoder, såsom system för hydroponiska odlingar (odlingar utanför jorden) en alltmer föredragen metod för livsmedelsproduktion. En fallstudie har genomförts hos Hollbium i Stockholm, Sverige med syfte att genomföra en utvärdering av den potentiella miljöpåverkan för Hollbium Loop, ett vertikalt hydroponiskt system som används för livsmedelsproduktion. Detta uppnås genom att först utföra en fristående bedömning av Hollbium Loop och på så sätt identifiera potentiella riskområden under produktens livslängd på tio år. Dessutom jämförs Hollbium Loops system med produktionen av sallad i ett horisontellt öppet fält, ett växthusodlingssystem och en näringsfilmsteknik i Spanien för att identifiera potentiella avvägningar. Attributiv livscykelanalys (ALCA) har använts som metod med ett tydligt fokus på åtta karakteriseringsfaktorer för mittpunkt. Resultaten i studien indikerar att riskområden för miljöpåverkan i Hollbium Loops livscykel beror på en användning av fordon med förbränningsmotor i underhållsfasen, produktion av elektroniska komponenter och elförbrukning i användningsfasen. Däremot visade resultaten från de jämförande scenarierna att Hollbium Loop ur ett livscykelperspektiv har den högsta miljöpåverkan i alla påverkanskategorier i jämförelse med de tre andra systemen för livsmedelsproduktion. När avståndet för transport inom underhållsfasen reduceras till en rimlig nivå så hade Hollbium Loop inte längre den högsta påverkan inom global uppvärmning och knappa fossila resurser, vilket visar att det avståndet spelar en nyckelroll för att mildra effekterna. Andra aspekter och antaganden analyseras också vidare med hjälp av en känslighetsanalys, som således visar att det finns utrymme för att minska Hollbium Loops miljöavtryck. Det rekommenderas därför att Hollbium satsar på att optimera avståndet och de transportsätt som används, men att även öka tjockleken av den yttre ramen för att göra den stabil och robust. Slutligen rekommenderas det även att öka systemets vertikala längd för att öka avkastning och därmed minska de totala effekterna per kilo producerad sallad.

Les coccolithophores sont des microalgues calcifiées constituant un des principaux groupes phytoplanctoniques marins. Ces organismes restent cependant encore mal connus, du fait du peu d'espèces cultivées. Dans ce travail, les connaissances sur la biologie et l'écologie de ce groupe ont été approfondies à travers l'étude du cycle de vie et de ses implications écologiques pour quatre coccolithophores en culture : Coccolithus pelagicus, Calcidiscus leptoporus, Coronosphaera mediterranea et Emiliania huxleyi. Un cycle digénétique haplo-diplophasique hétéromorphe a d'abord été démontré par différentes techniques. Des expériences écophysiologiques sur des facteurs abiotiques (température, lumière, turbulence, nutriments) ont ensuite permis d'émettre des hypothèses sur l'influence du cycle digénétique sur l'écologie de ces espèces et d'établir un cycle écologique. Enfin, une étude préliminaire de la toxicité a été réalisée, démontrant la toxicité de cinq espèces côtières de coccolithophores.

Food systems are considered one of the most important anthropogenic activities contributing to climate change. On the other hand, climate change influences the conditions for growth with more frequent droughts and heatwaves. This contradiction poses a significant challenge to future food systems, which need not only become more sustainable, but also increase its production to feed a growing population, as stated in both the United Nations Sustainable Development Goals, and the Swedish action plan on food. This has given rise to alternative ways of producing food, such as urban farming and, in particular vertical hydroponic farming, where food is grown indoors in a controlled environment with artificial lighting and with a minimum use of water and without pesticides. In this study, a vertical hydroponic farm located in Stockholm, Sweden, is examined using life cycle assessment in terms of environmental sustainability. The farm, located in a basement space, works together with the building in a symbiotic network, where the farm provides the building with excess heat from the lighting, and in turn obtains carbon dioxide from an office floor. The findings from the study show that electricity is a major contributor to the environmental performance of the farm, along with the infrastructure employed. The impacts of water use in the farm, is very low, along with the impacts associated with the delivery of the crops; illustrating the advantages of producing food locally. By substituting the synthetic fertilizers employed to biofertilizers, and by substituting the plastic bag material to renewable material, reductions in greenhouse gases are possible. The symbiotic development between the farm and the building is shown very beneficial to the farm, highlighting the importance of synergies between actors in urban areas.
Livsmedelsindustrin anses vara en av de största antropogena drivkrafterna bakom klimatförändringarna. Å andra sidan så förändrar klimatförändringar i sig förutsättningarna för hållbar odling, med mer frekventa torrperioder, extrem värme och extrem nederbörd. Denna konträra situation ställer stora krav på framtidens livsmedelsindustri, som dessutom måste producera mer mat för att mätta en ökande befolkning; ett åtagande som står angivet både i FN:s globala mål och i den svenska Livsmedelsstrategin. Många forskare menar att dagens livsmedelsindustri inte kommer klara denna omställning, och att alternativa metoder för att producera mat behövs. Urban odling har föreslagits som en del av lösningen, och i synnerhet vertikal hydroponisk odling där grödor växer inomhus i en kontrollerad miljö med artificiell belysning, låg vattenanvändning och utan bekämpningsmedel. Den här studien undersökte en vertikal hydroponisk odling i Stockholm, och bedömde dess miljömässiga hållbarhet med hjälp av en livscykelanalys. Odlingen, som sker i en källarlokal, samarbetar med den omslutande byggnaden i en urban symbios, där odlingen förser byggnaden med spillvärme från belysningen, och får i sin tur koldioxid från en kontorslokal. Enligt resultat från studien bidrar elektriciteten till den största miljöpåverkan, men även infrastruktur har stor påverkan. Vattenanvändningen i odlingen är däremot väldigt låg, och miljöpåverkan från leveransen av varorna är mycket låg, vilket belyser fördelarna med att odla mat lokalt. Odlingen kan bland annat minska sin miljöpåverkan genom att byta ut det nuvarande konstgödslet till biogödsel och genom att byta ut plastpåsarnas material till förnybar plast. Symbiosen mellan odlingen och byggnaden visade sig vara väldigt gynnsam, vilket vidare belyser vikten av samspel mellan olika aktörer i den urbana miljön.

This research is an attempt to create a comprehensive assessment framework for identifying and assessing potential improvement options of cement production systems. From an environmental systems analysis perspective, this study provides both an empirical account and a methodological approach for quantifying the CO2 footprint of a cement production system. An attributional Life Cycle Assessment (LCA) is performed to analyze the CO2 footprint of several products of a cement production system in Germany which consists of three dierent plants. Based on the results of the LCA study, six key performance indicators are dened as the basis for a simplied LCA model. This model is used to quantify the CO2 footprint of dierent versions of the cement production system. In order to identify potential improvement options, a framework for Multi-Criteria Assessment (MCA) is developed. The search and classication guideline of this framework is based on the concepts of Cleaner Production, Industrial Ecology, and Industrial Symbiosis. It allows systematic identication and classication of potential improvement options. In addition, it can be used for feasibility and applicability evaluation of dierent options. This MCA is applied both on a generic level, reecting the future landscape of the industry, and on a production organization level re ecting the most applicable possibilities for change. Based on this assessment a few appropriate futureoriented scenarios for the studied cement production system are constructed. The simplied LCA model is used to quantify the CO2 footprint of the production system for each scenario. By integrating Life Cycle Assessment and Multi-Criteria Assessment approaches, this study provides a comprehensive assessment method for identifying suitable industrial developments and quantifying the CO2 footprint improvements that might be achieved by their implementation. The results of this study emphasis, although by utilizing alternative fuels and more ecient production facility, it is possible to improve the CO2 footprint of clinker, radical improvements can be achieved on the portfolio level. Compared to Portland cement, very high reduction of CO2 footprint can be achieved if clinker is replaced with low carbon alternatives, such as Granulated Blast Furnace Slag (GBFS) which are the by-products of other  industrial production. Benchmarking a cement production system by its portfolio product is therefore a more reasonable approach, compared to focusing on the performance of its clinker production. This study showed that Industrial Symbiosis, that is, over the fence initiatives for material and energy exchanges and collaboration with nontraditional partners, are relevant to cement industry. However, the contingent nature of these strategies should always be noted, because the mere exercise of such activities may not lead to a more resource ecient production system. Therefore, in search for potential improvements, it is important to keep the search horizon as wide as possible, however, assess the potential improvements in each particular case. The comprehensive framework developed and applied in this research is an attempt in this direction.

Les écosystèmes hydrothermaux profonds hébergent des communautés présentant de fortes biomasses, issues de l’activité chimiotrophique des microorganismes, avec de nombreux exemples d’associations symbiotiques entre ces derniers et les organismes de la mégafaune dominante. La connaissance du cycle de vie de ces espèces, y compris de leurs symbiontes, et de la façon dont elles sont capables de disperser et de coloniser de nouveaux sites est incontournable pour la compréhension du fonctionnement des communautés hydrothermales.Dans cette étude, sont présentées de nombreuses avancées portant sur la distribution, la reproduction, la dispersion et le cycle de vie d’une espèce dominante des écosystèmes hydrothermaux de la dorsale Médio-Atlantique, la crevette alvinocarididé Rimicaris exoculata, et des espèces proches. Les outils méthodologiques utilisés incluent la description morphologique de larves, l’étude de la structure de populations et de leur état de reproduction, des approches moléculaires appliquées à l’identification des espèces via la reconstruction phylogénétique, la génétique populationnelle et l’étude de la diversité bactérienne. La plupart des observations et analyses ont été réalisées grâce aux prélèvements de la mission BICOSE qui s’est déroulée de janvier à février 2014 sur la dorsale Médio-Atlantique.L’analyse morphologique détaillée des premiers stades larvaires (zoé I) de quatre espèces d’Alvinocarididae (R.exoculata, Mirocaris fortunata, Nautilocaris saintlaurentae et Alvinocaris muricola), indique une combinaison de traits caractéristiques de cette famille et unique parmi les crevettes Caridés. Le premier stade larvaire lécithotrophe présente vraisemblablement une durée de développement prolongée, avec une transition vers la planctotrophie au cours des stades ultérieurs. La capture de ces larves près du fond suggère par ailleurs une dispersion bathypélagique. L’étude réalisée sur les populations de R. exoculata des champs hydrothermaux de TAG et Snake Pit met en évidence une ségrégation spatiale des sexes et des stades de vie. Les femelles, les sub-adultes et les juvéniles occupent la paroi des fumeurs actifs, tandis que les mâles se retrouvent majoritairement dispersés à la périphérie inactive des sites. L’identification de plusieurs cohortes d’individus, retrouvées au niveau des habitats des deux champs hydrothermaux indique par ailleurs un recrutement discontinu. Enfin, l’observation, pour la première fois, d’un grand nombre de femelles gravides sur les deux champs hydrothermaux, suggère une reproduction saisonnière, avec quelques différences mineures en terme de fécondité entre les populations des deux champs.Les embryons portés par les femelles jusqu’à l’éclosion des larves sont exposés aux fluides hydrothermaux. Nos résultats, encore partiels, d’analyses par clonage d’assemblages bactériens se développant sur les oeufs au cours de cette phase d’incubation indiquent une spécificité qui pourrait être le reflet d’une fonction symbiotique s’établissant à un stade précoce du cycle de vie de la crevette. La similarité de ces assemblages bactériens avec ceux colonisant le céphalothorax des crevettes adultes, suggère un possible rôle de détoxification et/ou de nutrition.Enfin la découverte, sur TAG, d’importantes « nurseries » de post-larves appartenant à R. chacei, espèce cohabitant avec R. exoculata mais relativement peu abondante, pose la question de l’origine de ce recrutement. Cette question s’inscrit également dans le débat taxonomique récurrent des délimitations d’espèces chez les Alvinocaridiés. Ainsi, de récents travaux de génétique suggèrent que R. chacei pourrait être identique à R. hybisae, une espèce des sites hydrothermaux de la Ride des Caïmans, qui paradoxalement, présente une écologie et un développement symbiotique beaucoup plus similaire à celui de R. exoculata que de R. chacei. Nos analyses de génétique populationnelle et une reconstruction phylogénétique réalisée avec plusieurs gènes […]
Deep-water hydrothermal vent host high-biomass communities based on chemoautotrophy supported by the metabolic activity of free-living and symbiotic bacteria associated to invertebrates, especially megafauna. Knowledge on the mechanisms of dispersal and the life cycle of vent species is essential to our understanding of the vent communities in terms of distribution, structure and temporal variation. In this study, I present some advances regarding the dispersal and life cycle of a dominant species of the Mid-Atlantic Ridge (MAR) vent ecosystems, the alvinocaridid shrimp Rimicaris exoculata, and other related species. The methodological approaches applied include morphological descriptions of larvae, analysis of population biology and reproduction, and molecular genetics for species identification, phylogenetic reconstructions, population genetics and bacterial diversity. Most observations and studies presented here were conducted on samples collected in January-February 2014, during the BICOSE cruise on the MAR.Based on the analysis of Zoea I larvae of four species (R. exoculata, Mirocaris fortunata, Nautilocaris saintlaurentae andAlvinocaris muricola), we conclude that the alvinocaridid first larval stage is lecitotrophic with extended development, allowing large dispersal without external food requirement. A bathypelagical larval dispersal and a shift to a planktotrophic stage during the larval period is proposed. In terms of population biology, collections performed at the TAG and Snake Pit vent fields show variations in the population structure among habitats, according to sex and life stage. Large aggregations of shrimps found close of the vent emission comprise mostly females and young individuals, whereas scattered adults found at the vent periphery were mostly males. Multiple cohorts were found in both vents fields, denoting a discontinuous recruitment. Brooding females were observed in significant numbers close to the vent emission, which contrasts with their constant lack in previous field studies and suggests a seasonal reproduction with a brooding period the winter season. In addition, differences in the reproductive effort were detected between vent fields, including egg number, egg size and proportion of aborted females. The egg surface of R. exoculata is colonized by episymbiotic bacteria. Cloning approaches show that the bacterial assemblages on eggs seem to be specific, suggesting their symbiotic role, and evolve according to the egg development. The bacterial assemblages on eggs and their variation during the embryonic development remind the episymbiotic communities found in the branchial chamber of adults, suggesting similar detoxification or nutrition role. In other Rimicaris species, questions about life cycle, vent connectivity and speciation have been raised recently. Genetic studies suggest that two species with contrasting distribution, morphology and ecology, R. hybisae and R. chacei, are the same species. This question is related also with the source of a massive recruitment of R. chacei found at TAG vent field, despite the low density of adults. Analysis of population genetics and phylogenetic reconstructions with multiple genes show that R. chacei and R. hybisae are separate lineages with recent or undergoing speciation. These species, as R. exoculata and other alvinocaridids, show a genetic population model associated with a migration pool. An extended larval period could contribute to the wide dispersal and high genetic flow between populations. Implications of these findings and perspectives of future research are discussed in terms of additional experiments and field sampling required to characterize the larval period of alvinocaridids, the variations of symbiosis of the different life stages and sexes inhabiting different habitats, the quantitative and functional characterization of the episymbiosis on eggs, and the evolutionary processes associated with the speciation in Rimicaris
Las emisiones hidrotermales profundas albergan comunidades de elevada biomasa basadas en quimioautotrofía, soportadas por la actividad metabólica de bacterias de vida libre y bacterias simbiontes asociadas a invertebrados marinos, especialmente megafauna. El conocimiento de los mecanismos de dispersión y el ciclo de vida de las especies de ambientes hidrotermales es escencial para comprender los procesos ecológicos de ambientes hidrotermales asociados a la distribución, la estructura comunitaria y la variación temporal. En este estudio, presento algunos avances relacionados a la dispersión y el ciclo de vida de una especie dominante de los sistemas de emision hidrotermal de la dorsal medioatlántica. La aproximaciones metodológicas aplicadas en este estudio incluyen el estudio de la morfología larvaria, el análisis de la biologia poblacional y de la reproducciôn, así como genética molecular con fines de identificación, reconstructión filogenética, genética de poblaciones y análisis de diversidad de bacterias. La mayoría de las observaciones y análisis presentados en el presente estudio fueron realizados con muestras colectadas en enero y febrero de 2014 durante el crucero oceanográfico BICOSE en la dorsal medioatlántica (campos TAG y Snake Pit). El análisis morfológico de la larva Zoea I de cuatro especies (R. exoculata, Mirocaris fortunata, Nautilocaris saintlaurentae y Alvinocaris muricola) permite concluir que el primer estadio larvario de la familia Alvinocarididae es lecitotrôfico con una duración del desarrollo extendida, permitiendo la dispersión a grandes distancias sin requerimiento de una fuente externa de nutrición. Se propone para estas especies una dispersión batipelágica y un cambio a un estadio planctotrófico durante el periodo larvario. En relación a la biología poblacional, fue observada una variación en la estructura poblacional entre hábitats en relación al sexo y el estado de desarrollo.Las agregaciones densas de camarones encontradas cerca de las emisiones hidrotermales están compuestas principales de hembras y juveniles, mientras la mayoría de adultos dispersos encontrados en la periferia de las chimeneas fueron machos. Varias cohortes de tallas fueron identificadas en ambas poblaciones, lo cual denota un reclutamiento discontinuo. Una gran cantidad de hembras ovígeras fueron observadas cerca de la emisión hidrotermal, lo cual contrasta con la casi completa ausencia de hembras ovígeras en muestreos previos y sugiere una reproducción estacional con incubación y desove durante el invierno. La superficie de los huevos de R.exoculata está colonizada por bacterias episimbiontes. Los análisis de clonación muestran que los ensambles bacterianos parecen ser específicos, lo cual sugiere una relación simbiótica. Además estos ensambles cambian en relación al desarrollo embrionario. Los ensambles de bacterias observados en los huevos son similares a las comunidades episimbiontes encontradas en la cámara branquial de los adultos, sugiriendo la ocurrencia de procesos de detoxificación o nutrición similares. En otras especies del género Rimicaris, interrogantes en relación al ciclo de vida, la conectividad entre sistemas hidrotermales y la especiación han surgido recientemente. Estudios genéticos sugieren que dos especies alopátricas y con diferencias en morfología y ecología, R. hybisae y R. chacei representan una especie única. Esta hipótesis se encuentra relacionada además con el origen de un reclutamiento masivo de R. chacei encontrado en el campo TAG, a pesar de la baja densidad de adultos. Análisis de genética poblacional y reconstrucciones filogenéticas utilizando varios genes muestran que R. chacei y R. hybisae son linajes separados producto de una especiación reciente o en proceso. Estas especies, al igual que R. exoculata y otros alvinocarídidos, muestran patrones de conectividad asociados al modelo de migración colectiva (migration pool). Implicaciones de estos hallazgos y perspectivas de futuras […]

Increasing resource efficiency by utilising secondary raw material is one of the key characteristics of a circular economy. Textile dust fibre, a waste generated from textile mechanical recycling has the prospect to be utilised as secondary raw material for producing novel material: textile paper suitable for packaging and other applications. A comparative Life Cycle Assessment (LCA) of carrier bags made from one ton of virgin paper, recycled paper and novel textile paper (~22584paper bags with grammage of 100 g/m2 and same dimensions for all 3 types of bags) showed that textile paper bag is more environmentally friendly in terms of carbon footprint. The largest environmental contributors were energy consumed in the pulping and paper making processes, followed by the use of adhesives and printing ink in the conversion process of paper to papercarrier bags. A comparative Techno-economic Assessment (TEA) was carried out for the operating cost of producing the three selected carrier bag types. The analysis conveyed that textile paper bags are more economically attractive, mainly due to the partial substitution of paper fibre with low-cost textile dust fibre. Furthermore, a simple tool was developed with an attempt to assess and compare materials suitability for the circular economy considering life cycle thinking and business perspectives. Assessment of textile paper using the Circular material assessment tool indicated that there is still scope for improvement on the following circularity characteristics of circular material: scarcity of raw material, local supply of resources, clean and non-toxic resources. Textile paper material scored high in the following circularity characteristics: secondary raw material, industrial symbiosis, recycling, resource efficiency in manufacturing and use. In the final step, the textile paper bag was eco-designed through the combined and iterative LCA and TEA approach with the aim to achieve improved scores as a circular material. In order to understand the overall sustainability advantages and trade-offs, further research is recommended on different textile dust fibre grades as well as textile paper performance based on mechanical properties. It is also recommended to investigate textile paper in other applications like one time fashion clothes, reusable paper bags as textile hangers etc.

The predominant nuclear fuel used globally at present is uranium which is a finite resource. Thorium has been identified as an alternative nuclear fuel source that can be utilized in almost all existing uranium–based reactors and can significantly help in conserving limited uranium reserves. Furthermore, the elimination of proliferation risks associated with thorium–based fuel cycles is a key reason for re–evaluating the possible utilization of thorium in high temperature reactors. In addition to the many advantages that thorium–based fuel has over uranium–based fuel, there are vast thorium resources in the earth's crust that up until the present have not been exploited optimally. This study focuses on determining the amount of uranium ore that can be saved using thorium as a nuclear fuel in HTR's. Four identical 200 MWth high temperature reactors are considered which make use of different fuel cycles. These fuel cycles range from the conventional uranium fuel cycle to a thorium–based fuel cycle in which no U–238 is present and have been simulated using the VSOP–A system of computer codes. This study also considers the effect that protactinium, an isotope that occurs in thorium–based fuel cycles, will have on the decay heat production in the case of a depressurized loss of coolant (DLOFC) accident.
Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2011.

Functionality of Cnidarian symbiosis with Symbiodiniaceae is fundamental to reef ecosystem success. Symbiodiniaceae cells have a complex life history, which, in hospite, is controlled by the host. In addition to the endosymbiotic lifestyle, they can exist free-living cells which diurnally alternate between a coccoid, vegetative night-time form to a day-time motile, flagellated cell. Their cell division cycle is gated by external light cues, and correlates with transitions in cell morphology. In contrast, endosymbiotic cells have an elongated G1 phase – demonstrating a de-coupling of cell cycle from 24-hour cycle in response to symbiosis. Furthermore, daughters of dividing endosymbiotic Symbiodiniaceae remain as coccoid cells, de-coupling morphological and cell division cycles. How this occurs remains unknown. The answer may lie in crystalline uric acid deposits, which are present only in motile, daytime cells, correlating with G1 and S phase. These store excess nitrogen and are quickly metabolized in low nitrogen availability. They also function as an eyespot. The influence of uric acid on the life cycle of free-living and endosymbiotic Symbiodiniaceae is unknown. In this study, I treated cultures of B. minutum with allopurinol, an inhibitor of uric acid synthesis. Flow cytometry showed that allopurinol the reduced growth rate and ratio of coccoid:motile cell cultures. RNA sequencing and differential gene expression analysis identified biological processes enriched in allopurinol treatment. I hypothesize that an intracellular lack of nitrogen imposed lack of uric acid crystals stimulates the General Amino Acid Control pathway. This represses translation, explaining the downregulation of ribosomal proteins, and upregulates amino acid and purine de novo biosynthesis pathways. Repression of translation may slow cellular growth and the G1 phase of the cell cycle, reducing number of cells meeting the size threshold for G1/S transition. Without uric acid deposits, cells may lack a functioning eyespot and not receive light cues which usually trigger morphological transitioning. This may suppress the motile morphology of free-living Symbiodiniaceae and cells in hospite even though the cell division cycle progresses, albeit more slowly. Genes involved in biosynthesis of flagella, thecal plates and the eyespot are upregulated, suggesting suppression of the motile form may act downstream of transcription.

Crustaceans are increasingly being used as model organisms in all fields of biology, including neurobiology, developmental biology, animal physiology, evolutionary ecology, biogeography, and resource management. Crustaceans have a very wide range of phenotypes and inhabit a diverse array of environments, ranging from the deep sea to high mountain lakes and even deserts. The evolution of their life histories has permitted crustaceans to successfully colonize this variety of habitats. Few other taxa exhibit such a variety of life histories and behavior. A comprehensive overview of their life histories is essential to the understanding of many aspects of their success in marine and terrestrial environments. This book provides a general overview of crustacean life histories. Crustaceans have particular life history adaptations that have permitted them to conquer all environments on earth. Crustacean life cycles have evolved to maximize fecundity, growth, and ageing, in a wide range of environmental conditions. Individual contributions contrast benefits and costs of different life histories including sexual versus asexual production, semelparity versus iteroparity, and planktonic larvae versus direct development. Important aspects of particular behaviors are presented (e.g. migrations, defense and territorial behaviors, anti-predator behavior, symbiosis).

AbstractThe combined use of Life Cycle Assessment and Data Envelopment Analysis (LCA + DEA) arises as a growing field of research when evaluating multiple similar entities under the umbrella of eco-efficiency and sustainability. This chapter revisits a set of four recent LCA + DEA articles within the tertiary sector to explore the novel advances offered regarding the application of the well-established five-step LCA + DEA method for enhanced sustainability benchmarking. These advances – which relate to the DEA stage of the framework – include the calculation of gradual benchmarks for continuous improvement, the period-oriented benchmarking of unidivisional or multidivisional entities, and the implementation of decision-makers’ preferences in the assessment. Overall, these advances further stress the suitability of using DEA to enhance the capabilities of LCA for the sustainability-oriented management of multiple similar entities.

Although many ciliates are free-living, more than 140 families of ciliates (Alveolata, Ciliophora) include symbiotic species of animals. Symbiosis, defined as an interaction between two species, is analyzed in this chapter to show a wide diversity of symbiotic systems in ciliates (epibiosis, commensalism, mutualism, and parasitism), providing some data about ciliate strategies showing their success as symbionts. Some species are free-living as well symbionts, facultative symbionts, and obligate symbionts. Analysis of reconstructions of ancestral state evidence that the parasitism arose numerous times and independently among the lineages of ciliates. At least three evolutionary routes can be traced: (1) transition from free-living to mutualism and parasitism, (2) transition from free-living to parasitism, and (3) regression from parasitism to free-living. The evolution of the symbiosis in ciliates demonstrates a higher diversification rate concerning free-living ciliates. The analysis of the evolution of the life cycles complexity, exploring molecular data of the phases of the ciliate cycle in their hosts is also essential. We propose new approaches for an integrative study of symbiotic ciliates.

Since 2002, the University of the Basque Country has supported several teaching experiences related to the so-called Life Cycle Thinking and Ecodesign in collaboration with local and regional public institutions and private companies. The implementation of a Master’s Degree entitled ‘Circular Economy: Business Application’ constitutes a milestone in the framework of these teaching experiences. From the very moment the European Green Deal was approved and, subsequently, before the state and regional strategies were launched, thanks to our prior experience, we have been able to offer the postgraduate course required by our administration and companies. The courses have been specifically designed to provide education for Circular Economy for new graduates as well as professionals with backgrounds as varied as product manufacturing engineering, environmental engineering, business administration or economics. It aims to become a European reference in its goal of promoting Circular Economy, life cycle thinking, ecodesign, industrial symbiosis and sustainable development and, at the same time, support the transition to circular economy in our region. As a result, in just two years the master’s degree has led to the creation within our university of a knowledge hub in Circular Economy, which hosts more than 20 research groups.

In the subphylum Crustacea, species from most major clades have independently evolved symbiotic relationships with a wide variety of invertebrate and vertebrate hosts. Herein, we review the life cycle disparity in symbiotic crustaceans. Relatively simple life cycles with direct or abbreviated development can be found among symbiotic decapods, mysids, and amphipods. Compared to their closest free-living relatives, no major life cycle modifications were detected in these clades as well as in most symbiotic cirripeds. In contrast, symbiotic isopods, copepods, and tantulocarids exhibit complex life cycles with major differences compared to their closest free-living relatives. Key modifications in these clades include the presence of larval stages well endowed for dispersal and host infestation, and the use of up to 2 different host species with dissimilar ecologies throughout their ontogeny. Phylogenetic inertia and restrictions imposed by the body plan of some clades appear to be most relevant in determining life cycle modifications (or the lack thereof) from the “typical” ground pattern. Furthermore, the life cycle ground pattern is likely either constraining or favoring the adoption of a symbiotic lifestyle in some crustacean clades (e.g., in the Thecostraca).

In this paper the decision situation of an automobile manufacturer (OEM), which alternative powertrains to promote, is presented by discussing the three planning levels technology, product and product portfolio planning, the interdependencies between the levels as well as the necessity to integrate a life-cycle perspective. Based on this, a concept for the life-cycle-oriented symbiosis of technology, product and product portfolio planning is developed. The concept consists of three planning modules each incorporating a life-cycle perspective: technology planning, product planning and product portfolio planning. Within each module, technologies, products and the resulting portfolio are analyzed, evaluated and selected according to the company objective(s). Referring to the developed concept, existing approaches to support the implementation and open challenges are discussed.

Thinking conceptually on what is tangible results in ideas that feed cycles of thought. This incremental continuum gives rise to a reflection on the current crisis of temporal dispersion.Creativity can be continuously stimulated through life-long learning. When exploring societal active methodologies within teaching and learning processes, Design is an interdisciplinary subject aided by: Artificial Intelligence in rethinking the positioning that humans conquered as conscious beings, but which underestimates nature and fails to recognize its dependency on other species; User-centered Psychotherapy and Spatial Interaction towards strategies for emotions and mind impulses which correspond to societal behaviors; Social Sciences in the context of Landscapes and Territorial Dynamics; Bionics and Mimetics reformulating technology through Nature as a model; Human Factors Engineering in the investigation of the cognitive system in the adequacy of physical and digital agents. It is projected consolidate the design of the procedural spiral in the design orientation of a methodology for the Design that leads the memory in anticipation to the retroactive effect of the knowledge that will operationalize responsible creative contents, aiming at the expansion of a remembrance against the forgetfulness of the human being to care Mother Earth.The intention to develop and validate this societal active methodology started from a model (4Xself) elaborated in the context of the PhD that, with the guidance of the respective Practical Assignments Guide, intends to guide a Symbiosis Proto-Methodology. This model was applied in 2019/20 and 2020/21 with students, and preliminary conclusions have already been reached in the scope of SPIRAL project. This project aligns with the 4th SDG on education, specifically target goal 4.7, as we aim to contribute to the SDGs defined by the UN in a transversal way with the methodology. We aspire to achieve acceptance of concepts and practices that integrate the research questions: How to create and implement a Symbiosis methodology that promotes interdisciplinary, sustainable, and ethically committed design processes? How can this methodology consolidate its meaning as a catalyst and aggregator system for acting in the Design process, guaranteeing the benefit of the agents involved?The expected outcomes of this project result from exploring different media channels to disseminate and implement Symbiosis’s proto-methodology whose expertise promote the crossing of knowledge in the respective areas and interactive practices in education, training in companies, in entrepreneurship and professionalization, ensuring the following principles: be transversal to the values and mission of the methodology for a more qualitative strategy in teaching; supporting a transition to information glocalization; reflect on Education as a learning channel for all; encourage a shared responsibility among everyone involved in the design process guaranteeing code of conduct; develop an operational methodology with and for society through Co-design and Participatory Design to better qualify individuals in society and this as a social collectively; improving training methodologies in education through interdisciplinarity and participatory learning; be enrolled in the ECO triangulation in which the Social, Economic and Ecological aspects are marked out between the poles Perception/Production and Nature/Culture in the domains of Design, Art, Science and Engineering

Sundarbans as the primary coastal defense of Bangladesh against various natural disaster encounters recurrent homelessness due to these calamities, resulting in cutting down forests for housing materials from the only nearby resource. The traditional vernacular practice and socio-cultural studies show a symbiotic relationship between the forest and inhabitants, but the ecological imbalance created by climate change made life difficult for them, whose livelihood solely depends on the forest as well. The inability to reuse the building materials any disaster causes an ever-increasing cycle of carbon footprint. Regarding these, the non-experimental research aims to build such a homestead prototype that creates an adaptable solution. The existing building practices consist of non-reusable materials, poor structural integrity, and lack of sustainable approaches, thus unfit to withstand the increasing disasters and calamities. The approach discussed here utilizes plastic waste, drums, bamboo for disaster adaptability, structural flexibility, rainwater harvesting, solar, and biogas energy for a sustainable lifestyle. So, the goal is to provide a sustainable solution for the economically challenged population. This prototype creates an adaptive strategy for mitigating the disastrous events in Sundarbans to promote resilience and sustainability.

At present, the 125 GWe of nuclear power in the European Union produce about 3000 tons of spent fuel annually, containing about 25 tons of plutonium, 2.5 tons of minor actinides (MA) and about 100 tons of fission products, of which 3.1 tons are long-lived fission products. Actual reprocessing of LWR fuel and a first recycling as mixed plutonium and depleted uranium oxide fuel (MOX) in LWR already contribute to a significant reduction of waste volumes and radiotoxicity. However HTRs have some characteristics which make them particularly attractive: intrinsic safety, cost-effectiveness, reduced thermal pollution, capability of increasing energy availability (with the use of Pu-Th cycle) and of minimizing actinides radiotoxicity and volume of actinides. In this paper particularly the last item is investigated. Symbiotic fuel cycles of LWR and HTR can reach much better waste minimization performances. It happens because of the specific features of HTRs cores that leads to an ultra-high burnup and, last but not least, the ability to accommodate a wide variety of mixtures of fissile and fertile materials without any significant modification of the core design. This property is due to a decoupling between the parameters of cooling geometry and of neutronic optimization. In our calculations we considered a pebble-bed HTR using a Pu-based fuel (deriving from reprocessing of classical LWR fuel and/or weapons grade plutonium) at the maximum technological discharge burnup. As results, we find, at EOL (End Of Life), a relatively small amounts of residual Pu and MA produced in terms of quantities and of radiotoxicities. Furthermore we used in our calculations a different type of fuel based on a mixture of Pu and Th to try to optimize the previous results and to increase energy availability. Calculations have been done using MCNP-based burnup codes, capable of treating 3-D complex geometry and ultra-high burnup.

A tree may be the earliest multifunctional structure, and wood is the oldest known engineering material. Yet, trees have no place in engineering education. If we view a tree from merely a mechanical or civil engineering perspective, engineering mechanics can be learned from the tree’s example. Trees have survived by adapting to the most difficult circumstances: heavy winds, rains, floods, droughts, earthquakes, mammal damage, human intervention, etc. The root system must be strong and flexible enough to support the tree’s entire structure from varying load conditions and to provide food storage and nutrient transfer. The stem system provides structural support for the tree’s above-the-ground parts and transfers water and nutrients from the roots through the network of thick-walled cells to other parts of the tree. Leaves produce food and form the surface area surrounding the tree. Leaves come in a variety of shapes and sizes. The tree’s crown, comprising branches, leaves, and reproductive elements, help the tree to catch more sunlight. It moves upward and outward to expose more of its leaves to direct sunlight for photosynthesis while maintaining physical balance on the earth. A tree’s lifecycle can span hundreds of years, despite its vulnerability to constantly changing loads throughout the day and throughout its life. In monsoon and windy seasons, trees endure extremely difficult fatigue-loading. Various parts of the tree and its stem are subjected to combined loading conditions: tension, compression, shear, bending, and torsion. Trees develop and adapt stress management strategies by adjusting their shapes to the type or level of stress they endure: they add more mass where more strength is needed, allows material to easily break off (or physiologically inactive) from locations where it is not necessary, design optimum shapes, and create variable notch radii for reducing stress concentration. But a tree is much more than a structural member. It provides food and shelter for wildlife. It absorbs atmospheric carbon dioxide and produces oxygen. It lowers air temperature and facilitates the water cycle. Structural analysis of a tree can benefit engineering students and practicing engineers alike. Furthermore, a deeper understanding of trees can help us to create multifunctional designs that are in a symbiotic relationship with other members in the system. In short, studying tree mechanics can help us to become better engineers. This paper presents our efforts to integrate trees into engineering curricula to teach mechanics ranging from equilibrium study to stress analysis. Students of statics, dynamics, the strength of materials, stress analysis, material science, design, etc., can benefit from learning about trees. This approach enables students to understand the complexities of real-world living systems, appreciate the genius of nature’s design, and develop methods for creating sustainable designs.

This proposal is focused on examination of two plant interactions: parasitic with Orobanche, and symbiosis with arbuscular mycorrhiza fungi (AMF), and the involvement of a newly define plant hormones, strigolactones (SLs), in these plant interactions. In addition to strigolactones role in regulation of above-ground plant architecture, they are also known to be secreted from roots, and to be a signal for seed germination of the parasitic plants Orobanche. Moreover, secreted strigolactones were recognized as inducers of AMFhyphae branching. The present work was aimed at Generation of RNAi mutants of both tomato and Medicago, targeting multiple genes that may be involved in strigolactone production, carotenoid biosynthesis pathway, Pi signaling or other metabolic pathways, and hence affect AMF colonization and/or Orobanche resistance. Following the newly formed and existing RNAi mutants were examined for AMF colonization and Orobanche resistance. At the first phase of this project Orobanche seed germination assays and AMF colonization were examined in intact plants. These assays were shown to be effective and resulted with enhancement of Orobanche seed germination and AMF colonization in WT tomato plants, whereas roots of strigolactones impaired lines did not result with Orobanche seed germination and mycorrhiza colonization. Unexpectedly, root organ cultures (ROC) that were produced from the same wild type (WT) and mutant lines did not induce the Orobanche seed germination and AMFhyphal branching. This implies that under in vitro conditions ROC cultures are missing an important component for induction of Orobanche seed germination and AMFhyphal branching. In another line of experiments we have tested transgenic lines of Medicagotruncatula for AMFhuyphal branching and Orobanche seed germination assays. These lines included lines silenced for a GRAS transcription factor (RNAi 1845), an NBS-LRR type resistance gene (RNAi 1847), a kinase (RNAi 2403) and a protein of unknown function (RNAi 2417). In all cases, five independent transgenic root lines showed altered AMFphenotypes with reduced or aberrant colonization patterns. Following, we transformed tomato plants with the M. truncatulaTC 127050 PhosphoinositidekinaseRNAi construct. Transgenic lines that contained GUS constructs were used as control. All transgenic lines showed reduced level of Orobanche seed germination, masking any strigoalctones-specific effect. The research demonstrated that SLs production may not be examined in ROC –based bioassays. It was shown by the 3 independent assays employed in this project that none of the recognized characters of SLs may be reflected in these bioassays. However, when the whole plant root exudates were examined, SLs activity in root exudates was demonstrated. Hence, it can be concluded that the presence of an intact shoot, and possibly, shoot factors, may be necessary for production of SLs in roots. Another point of interest that rises from these results is that the presence of SLs is not necessary for AMF completion of life cycle. Hence, it may be concluded that SLs are important for AMFhyphal branching, before symbiosis, but not essential for AMF colonization and life cycle completion under ROC system conditions.