Estudi per desenvolupar una proposta per la remediació in situ d'aigües àcides de mina

Postprint (published version

Additive Pattern Databases for Decoupled Search

Abstraction heuristics are the state of the art in optimal classical planning as heuristic search. Despite their success for explicit-state search, though, abstraction heuristics are not available for decoupled state-space search, an orthogonal reduction technique that can lead to exponential savings by decomposing planning tasks. In this paper, we show how to compute pattern database (PDB) heuristics for decoupled states. The main challenge lies in how to additively employ multiple patterns, which is crucial for strong search guidance of the heuristics. We show that in the general case, for arbitrary collections of PDBs, computing the heuristic for a decoupled state is exponential in the number of leaf components of decoupled search. We derive several variants of decoupled PDB heuristics that allow to additively combine PDBs avoiding this blow-up and evaluate them empirically

Are competitiveness rankings and institutional measures helping emerging economies to improve?

Purpose – Based on the rankings of the global competitiveness index and the fragile states index, this paper aims to suggest alternative approaches to shed some light on the effectiveness of rankings in helping emerging economies improve their competitiveness from an institutional standpoint. Design/methodology/approach – The statistical analysis consisted of a two-stage analysis; the first stage consisted of constructing an updated Alternative Institutional Quality Index (AIQI), intending to design a comparative measure between dimensions over time. The second stage consisted of evidencing the structure of each of the observed dimensions' variance to evidence the existing changes or gaps of the AIQI and its components. We incorporated the Kruskas-Wallis (KW) model to test our results. Findings – This paper demonstrates that the analyzed countries generally maintain their competitive position, even though changes in their scores are reflected. This makes invisible the development and progress factors generated by the countries that are mainly found with low scores and only reflect stable structures that allow them to maintain their position. Practical implications – The paper contributes to the applicable measurement of competitiveness and its structural change over time. Originality/value – This paper proposed an alternative and simple methodology to assess the evolution of the competitiveness indicators; this methodology could be used to measure structural changes at different levels, which may be an input for the design and implementation of policies to foster competitiveness

Efficient Evaluation of Large Abstractions for Decoupled Search: Merge-and-Shrink and Symbolic Pattern Databases

Abstraction heuristics are a state-of-the-art technique to solve classical planning problems optimally. A common approach is to precompute many small abstractions and combine them admissibly using cost partitioning. Recent work has shown that this approach does not work out well when using such heuristics for decoupled state space search, where search nodes represent potentially large sets of states. This is due to the fact that admissibly combining the estimates of several heuristics without sacrificing accuracy is NP-hard for decoupled states. In this work we propose to use a single large abstraction instead. We focus on merge-and-shrink and symbolic pattern database heuristics, which are designed to produce such abstractions. For these heuristics, we prove that the evaluation of decoupled states is NP-hard in general, but we also identify conditions under which it is polynomial. We introduce algorithms for both the general and the polynomial case. Our experimental evaluation shows that single large abstraction heuristics lead to strong performance when the heuristic evaluation is polynomial

Mitochondrial DNA transfer through exosomes during immune synapsis primes antiviral innate immune response in dendritic cells

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha de lectura: 16-09-2019Las respuestas inmunitarias específicas frente a patógenos requieren de la interacción inicial de una célula T con una célula presentadora de antígeno (CPA), concretamente las células dendríticas (CD). El reconocimiento por parte de la célula T de un antígeno unido al complejo mayor de histocompatibilidad (CMH) conduce a la formación de una unión intercelular estable conocida como sinapsis inmune (SI). En las células T, la SI implica una importante redistribución del citoesqueleto y de los receptores asociados a membrana. También conlleva una polarización del tráfico intracelular y de los orgánulos secretores. La sinapsis inmune es una estructura adecuada para una comunicación intercelular eficiente. Durante este proceso las células T y las CD intercambian numerosas moléculas, incluyendo citoquinas, receptores de membrana aislados, moléculas de señalización y material genético. Las vesículas extracelulares (VE) son uno de los mecanismos que median la transferencia de información entre la célula T y las CD. Los cuerpos apoptóticos, los ectosomas y los exosomas son las principales vesículas extracelulares. Los exosomas se distinguen por su origen endocítico puesto que se forman por la invaginación de la membrana de los cuerpos multivesiculares (CMV) o endosomas tardíos. Cuando los CMV fusionan con la membrana liberan estas vesículas al medio. Los exosomas están particularmente enriquecidos en material genético; principalmente ARN, como los ARN pequeños y los ARN largos no codificantes, también se ha detectado presencia de ADN genómico. Esto los hace versátiles mediadores en la comunicación intercelular. No obstante, todavía queda mucho por explorar en los mecanismos de cómo el material genético contenido en los exosomas induce respuestas específicas en las células receptoras. En este trabajo hemos demostrado que las células T secretan VE cargadas de proteínas y ADN mitocondrial (ADNmt) que pueden ser transferidas a las CD a través de la sinapsis inmune. Evidenciamos que algunas proteínas de origen mitocondrial y el ADNmt se encuentran en los cuerpos multivesiculares y que el bloqueo de la secreción de exosomas altera la función y morfología mitocondrial, lo que sugiere que la liberación de contenido mitocondrial mediado por los exosomas contribuye a la homeostasis mitocondrial. También demostramos que tanto las proteínas mitocondriales como el ADNmt se transfieren durante la SI de forma unidireccional desde la célula T a la CPA y que esta transferencia pre-activa a las células dendríticas protegiéndolas en infecciones virales posteriores. En conclusión, los datos resultantes ilustran un nuevo mecanismo por el cual las células T promueven un estado de alerta en las células dendríticas promovido por la transferencia exosomal de ADN. Estos hallazgos aportan información relevante sobre cómo la comunicación recíproca entre las células del sistema inmune innato y del sistema inmune adaptativo facilita respuestas más eficaces frente a patógenos

Hand-developed creative prototyping. Methodological proposal and experimentation

The generation of original and innovative ideas is a challenge for any professional. There are several studies that demonstrate how the capacity to explore creativity is reduced until reaching educational levels where it is hardly experienced, and for this reason it is necessary to introduce it in the classroom to complement their academic training before their incorporation into the labour market. The use of new technologies implies in turn an abandonment of manual or craft skills, losing in this area a very relevant possibility of creative development. Most of the methods that are usually used to generate ideas are related to oral and written conceptualization, but manual ideation is practically not contemplated. This study proposes a methodology for generating ideas based on traditional ideation from the physical creation of models as part of the creative process. This methodology has been used with satisfactory results in 38 courses at the Industrial Organisation School (Spain), with 382 people between 18 and 30 years of age participating in the study, demonstrating that the development of creative skills obtained through this new approach can have a very significant impact on students' later career development.This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors

Generating Instructions at Different Levels of Abstraction

When generating technical instructions, it is often convenient to describe complex objects in the world at different levels of abstraction. A novice user might need an object explained piece by piece, while for an expert, talking about the complex object (e.g. a wall or railing) directly may be more succinct and efficient. We show how to generate building instructions at different levels of abstraction in Minecraft. We introduce the use of hierarchical planning to this end, a method from AI planning which can capture the structure of complex objects neatly. A crowdsourcing evaluation shows that the choice of abstraction level matters to users, and that an abstraction strategy which balances low-level and high-level object descriptions compares favorably to ones which don't.Comment: Accepted COLING 2020 long pape