A methodological approach for the analysis of ecosystem services from the local communities' perspective.

In this paper, we developed an innovative and plural methodology for a socio-cultural assessment of ecosystem services (ES). This methodology was performed using diverse and interdependent tools applied within the framework of ethnoecology and post-normal science, with the aim of identifying ES from the perspective of local communities that inhabit different socio-ecosystems, highlighting the relevance of Indigenous and Local Knowledge (ILK). As examples of how this methodology works, we analyzed a multiple case study performed in three peasant communities of the Dry Chaco eco-region, Argentina. We identified ES in all the categories and their fundamental contributions to the particular way of life in this area. The method is flexible enough to be used in other socio-ecosystems with different environmental and social features.

Thinking about a popular education in sciences? / Penser léducation populaire en sciences? / Pensando uma educação popular em ciências? / Pensando una educación popular en ¿ciencias?

Abstract In this article we reflect on Education in Natural Sciences, from our educational experiences with teachers in the public system, social movements and political organizations. These experiences serve as a base from which we can glimpse new paths, in a dialogue with a diversity of theoretical references from different disciplines and areas. We intend to continue thinking about a critical pedagogy in the natural and technological worlds with the objective of strengthening processes of social transformation.

Résumé Cet article aborde l'Éducation en sciences à partir de nos expériences éducatives auprès des professeurs de l'enseignement public, des mouvements sociaux et d'organisations politiques. Ces expériences nous ont servi de base pour déceler, en dialogue avec une diversité de références théoriques issues de différentes disciplines et d'espaces disctincts.de nouvelles voies de travail. Nous avons essayé de penser toujours à une pédagogie critique concernant les mondes sociaux, naturels et technologiques dont l'objectif est de renforcer les processus de transformation sociale.

Resumo Neste artigo refletimos sobre a Educação em Ciências a partir das nossas experiências educativas com professores do sistema público, movimentos sociais e organizações políticas. Essas experiências representam uma base da qual vislumbramos novos caminhos, ao dialogar com uma diversidade de referências teóricas de diferentes disciplinas e espaços. Tentamos continuar pensando em uma pedagogia crítica sobre os mundos sociais, naturais e tecnológicos cujo objetivo seja o fortalecimento de processos de transformação social.

Resumen En este artículo reflexionamos sobre la Educación en Ciencias a partir de nuestras experiencias educativas junto con docentes en el sistema público, movimientos sociales y organizaciones políticas. Estas experiencias nos sirven de suelo desde donde vislumbrar nuevos caminos en diálogo con una diversidad de referencias teóricas de distintas disciplinas y espacios. Buscamos seguir pensando una pedagogía crítica sobre los mundos sociales, naturales y tecnológicos que tenga como objetivo el fortalecimiento de procesos de transformación social.

Structured and Unstructured Binding of an Intrinsically Disordered Protein as Revealed by Atomistic Simulations.

Intrinsically disordered proteins (IDPs) are a set of proteins that lack a definite secondary structure in solution. IDPs can acquire tertiary structure when bound to their partners; therefore, the recognition process must also involve protein folding. The nature of the transition state (TS), structured or unstructured, determines the binding mechanism. The characterization of the TS has become a major challenge for experimental techniques and molecular simulations approaches since diffusion, recognition, and binding is coupled to folding. In this work we present atomistic molecular dynamics (MD) simulations that sample the free energy surface of the coupled folding and binding of the transcription factor c-myb to the cotranscription factor CREB binding protein (CBP). This process has been recently studied and became a model to study IDPs. Despite the plethora of available information, we still do not know how c-myb binds to CBP. We performed a set of atomistic biased MD simulations running a total of 15.6 µs. Our results show that c-myb folds very fast upon binding to CBP with no unique pathway for binding. The process can proceed through both structured or unstructured TS's with similar probabilities. This finding reconciles previous seemingly different experimental results. We also performed Go-type coarse-grained MD of several structured and unstructured models that indicate that coupled folding and binding follows a native contact mechanism. To the best of our knowledge, this is the first atomistic MD simulation that samples the free energy surface of the coupled folding and binding processes of IDPs.

Phosphorylation Regulates the Bound Structure of an Intrinsically Disordered Protein: The p53-TAZ2 Case.

Disordered regions and Intrinsically Disordered Proteins (IDPs) are involved in critical cellular processes and may acquire a stable three-dimensional structure only upon binding to their partners. IDPs may follow a folding-after-binding process, known as induced folding, or a folding-before-binding process, known as conformational selection. The transcription factor p53 is involved in the regulation of cellular events that arise upon stress or DNA damage. The p53 domain structure is composed of an N-terminal transactivation domain (p53TAD), a DNA Binding Domain and a tetramerization domain. The activity of TAD is tightly regulated by interactions with cofactors, inhibitors and phosphorylation. To initiate transcription, p53TAD binds to the TAZ2 domain of CBP, a co-transcription factor, and undergoes a folding and binding process, as revealed by the recent NMR structure of the complex. The activity of p53 is regulated by phosphorylation at multiple sites on the TAD domain and recent studies have shown that modifications at three residues affect the binding towards TAZ2. However, we still do not know how these phosphorylations affect the structure of the bound state and, therefore, how they regulate the p53 function. In this work, we have used computational simulations to understand how phosphorylation affects the structure of the p53TAD:TAZ2 complex and regulates the recognition mechanism. Phosphorylation has been proposed to enhance binding by direct interaction with the folded protein or by changing the unbound conformation of IDPs, for example by pre-folding the protein favoring the recognition mechanism. Here, we show an interesting turn in the p53 case: phosphorylation mainly affects the bound structure of p53TAD, highlighting the complexity of IDP protein-protein interactions. Our results are in agreement with previous experimental studies, allowing a clear picture of how p53 is regulated by phosphorylation and giving new insights into how post-translational modifications can regulate the function of IDPs.