79 resultados para SYMBIOSES
Resumo:
Contemporary cnidarian-algae symbioses are challenged by increasing CO2 concentrations (ocean warming and acidification) affecting organisms' biological performance. We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemone Anemonia viridis to investigate dietary shifts (autotrophy/heterotrophy) along a natural pCO2 gradient at the island of Vulcano, Italy. delta 13C values for both algal symbionts (Symbiodinium) and host tissue of A. viridis became significantly lighter with increasing seawater pCO2. Together with a decrease in the difference between delta 13C values of both fractions at the higher pCO2 sites, these results indicate there is a greater net autotrophic input to the A. viridis carbon budget under high pCO2 conditions. delta 15N values and C/N ratios did not change in Symbiodinium and host tissue along the pCO2 gradient. Additional physiological parameters revealed anemone protein and Symbiodinium chlorophyll a remained unaltered among sites. Symbiodinium density was similar among sites yet their mitotic index increased in anemones under elevated pCO2. Overall, our findings show that A. viridis is characterized by a higher autotrophic/heterotrophic ratio as pCO2 increases. The unique trophic flexibility of this species may give it a competitive advantage and enable its potential acclimation and ecological success in the future under increased ocean acidification.
Resumo:
Les services rendus par la nature sont ébranlés par les activités économiques humaines, ce qui invite l’économie à changer de paradigme. L’économie circulaire dont découle la symbiose industrielle, comporte des espoirs de transition. Dans le cadre de l’essai, c’est la symbiose qui dévoilera ses propres pistes de mutation, par son modèle d’affaires. Celui-ci permet de détecter et de créer de la valeur dans les entreprises. Il existe plusieurs angles pour dévoiler le modèle d’affaires, mais c’est la perspective du système d’activité qui est sélectionnée. L’objectif principal de l’essai est d’explorer cette perspective, en l’appliquant sur une symbiose industrielle québécoise, soit celle du Centre local de développement de Brome-Missisquoi. Cette perspective est systémique et s’avère pertinente dans le contexte d’une symbiose. Puisque le modèle d’affaires permet de constater comment s’organise la symbiose pour créer de la valeur, le premier sous objectif est d’analyser celle-ci. En découle une étude comparative soulevant ses facteurs de succès et d’entrave. Les expériences de symbioses sont multiples et différenciées, mais certaines constantes peuvent être dégagées. Puisque son développement prend du temps, la mobilisation des acteurs comporte des défis. L’analyse de la rentabilité de la symbiose et de sa gouvernance peut outiller les intervenants pour faciliter son déploiement. Les retombées de la symbiose industrielle de Brome-Missisquoi sont positives. Afin de maintenir l’intérêt des participants et d’impulser la symbiose vers la pérennité, des recommandations sont formulées. Il est recommandé d’augmenter la diversité de ses parties prenantes de la symbiose, encadré par une réflexion stratégique co construite. La résilience de la symbiose en sera renforcie. Il importe de revenir sur la vision des membres et de développer leur compréhension du concept. Enfin, il est recommandé d’améliorer l’ancrage de la symbiose sur son territoire, en se greffant aux organisations déjà existantes, mais actuellement absentes du membariat. Des témoignages soulèvent des changements de pratiques notables chez certaines parties prenantes, ce qui semble indiquer que les symbioses industrielles favorisent le changement de paradigme.
Resumo:
O presente relatório procura elucidar todo o processo que foi passado em contexto pré-escolar e 1º ciclo do ensino básico. Representa a simbiose entre a prática pedagógica e os pressupostos teóricos que sustentaram as metodologias e estratégias adotadas que funcionaram como alicerces fundamentais no processo de ensino e de aprendizagem. Ao longo do relatório, abordaram-se temáticas fulcrais que fundamentaram e destacaram a prática pedagógica em que foi necessário recolher informação recorrendo a instrumentos de observação e análise e utilizando uma metodologia de carater qualitativo. Para esta intervenção teve-se em conta a criança e aluno como intervenientes ativos de todo o processo de ensino/aprendizagem envolvendo a motivação para que a construção do conhecimento pudesse advir das crianças/alunos. Os princípios e intencionalidades orientadoras da prática pedagógica estão em constante confronto levando o profissional generalista a adotar uma postura reflexiva e construtiva no sentido de desenvolver a sua profissionalidade.ABSTRACT The existing report tries to clarify the whole process which refers to an experience lived in a Pre-schooler and Elementary School’s context. It represents the symbioses between pedagogical practice and theoretical assumptions that sustained methodologies and strategies adopted, which worked as fundamental foundations in the learning and teaching process. Along the report, it was approached key themes that sustain and highlight the pedagogical practice, in which it was necessary to collect information appealing to the observation and analysis instruments and using a quality character methodology. For this intervention, are taking in account, the child and student as active protagonists of the teaching/learning process, involving motivation, so that the knowledge can arise from them. The guiding principles and intentions of pedagogical practice are in constant confrontation, leading the generalist professional to adopt a reflective and constructive behavior towards developing their professionalism.
Resumo:
Rhizobia are important soil bacteria due to their ability to establish nitrogen-fixing symbioses with legume plants. In this dual lifestyle, as free-living bacteria or as plant symbiont, rhizobia are often exposed to different environmental stresses. The present chapter overviews the current knowledge on the heat shock response of rhizobia, highlighting how these large genome bacteria respond to heat from a transcriptional point of view. Response to heat shock in rhizobia involves genome wide changes in the transcriptome that may affect more than 30% of the genome and involve all replicons. In addition to the expected upregulation of genes already known to be involved in stress response (dnaK, groEL, ibpA, clpB), the reports on the heat shock response in rhizobia also showed particular aspects of stress response in these resourceful bacteria. The transcriptional response to heat in rhizobia includes the overexpression of a large number of genes involved in transcription and carbohydrate transport and metabolism. Additional studies are needed in order to better understand the transcriptional regulation of stress response in bacteria with large genomes.