Highlights

Every year, a committee of experts sits down with a tough job to do: from among all ICREA publications, they must find a handful that stand out from all the others. This is indeed a challenge. The debates are sometimes heated and always difficult but, in the end, a shortlist of  the most outstanding publications of the year is produced. No prize is awarded, and the only additional acknowledge is the honour of being chosen and highlighted by ICREA. Each piece has something unique about it, whether it be a particularly elegant solution, the huge impact it has in the media or the sheer fascination it generates as a truly new idea. For whatever the reason, these are the best of the best and, as such, we are proud to share them here.

LIST OF SCIENTIFIC HIGHLIGHTS

Format: yyyy

  • New tools for designing your own enzyme  (2021)

    Osuna Oliveras, Sílvia (UdG)

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    New tools for designing your own enzyme 

    Enzymes are superb catalysts capable of accelerating the chemical reactions by as many as seventeen orders of magnitude. They achieve such impressive rate accelerations by decreasing the activation barriers of reactions, making them possible at lower temperatures and pressures. Apart from their high efficiency, enzymes are specific and selective, and operate under mild biological conditions. These features make enzyme-catalyzed processes an attractive alternative for chemical manufacturing. Still the application of enzymes in industry is quite limited, as most industrial processes lack a natural enzyme able to perform the desired transformations, to accommodate the non-natural substrate(s) of interest, and/or their low stability in non-optimal conditions.

    Enzyme design: Enzymes are typically engineered for catalytic activity, enantioselectivity, thermodynamic stability, substrate specificity, stability in non-aqueous solvents and co-solvents. Available enzyme design approaches can be classified into rational design, and Directed Evolution (DE). Multiple rational design strategies exist, but most of them focus on alterations in the active site pocket and the available channels for substrate binding or product release. This is in contrast with DE that introduces mutations all around the protein structure.

    How can distal activity-enhancing mutations be predicted? So far this has been highly challenging given the large number of possibilities to mutate. We have solved this challenge by accurately considering the enzyme ability to adopt multiple conformations key for their enzymatic function, and evaluating the most important positions involved in the conformational transitions. We demonstrated that by combining our new correlation-based tools with multiple sequence reconstruction (MSA) the prediction of distal activity-enhancing mutations can become within reach.

  • Synthesis of 2D porous crystalline materials in simulated microgravity (2021)

    Puigmartí Luis, Josep (UB)

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    Synthesis of 2D porous crystalline materials in simulated microgravity

    Crystallization studies conducted in space laboratories, which are costly and unaffordable for most research laboratories, showed the valuable effects of microgravity during the crystal growth process and the morphogenesis of materials. Now, a research study led by a scientific team of the University of Barcelona, has created an easy and efficient method to achieve experimentation conditions of microgravity on Earth that simulate those in space.

  • Device fingerprint of Magnetic Topological Matter (2021)

    Roche, Stephan (ICN2)

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    Device fingerprint of Magnetic Topological Matter

    Topological insulators are bulk insulator but with surface states which are particularly robust to disorder and crystalline imperfections, for time reversal symmetric systems. Additionally, the surface topological electronic states exhibit a peculiar spin texture as well as a so-called massless Dirac energy dispersion, which make them fascinating materials for fundamental research but also in view of spin-based technologies. Furthermore, when magnetically doped or in close contact with another magnetic material, the induced local breaking of time reversal symmetry leads to gapped surface states, and the formation of new edge states at the surface boundaries, carrying a single quantum channel. Magnetic topological insulators are currently investigated for their future use in resistance standardization (using the so-called quantum anomalous Hall effect), as well as for their use in future spintronic applications. A challenging problem is however to probe the intrinsic features of these nontrivial edge states,

    By elaborating a generic model of three-dimensional magnetically doped topological insulators embedded into a multiterminal device with ferromagnetic contacts near the top surface, and using nonlocal transport formalism, we found that the resistance measurements could give direct access to the local spin features of the chiral edge modes. Indeed, our simulations evidence that local spin polarization at the hinges inverts its sign between the top and bottom surfaces. At the opposite edge, the topological state with inverted spin polarization propagates in the reverse direction. As a result, a large resistance switch between forward and backward propagating states takes place, driven by the matching between the spin polarized hinges and the ferromagnetic contacts.

    This feature is general to the ferromagnetic, antiferromagnetic, and canted antiferromagnetic phases, and enables the design of spin-sensitive devices. Our theoretical prediction opens a way to confirm the formation of those topological edge states, an essential step before further controlling those states for a variety of applications.

  • Climate is a structural driver of infectious diseases worldwide: From malaria in Ethiopia to the COVID-19 pandemic (2021)

    Rodó i López, Xavier (ISGlobal)

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    Climate is a structural driver of infectious diseases worldwide: From malaria in Ethiopia to the COVID-19 pandemic

    The slowdown in global warming that was observed at the end of last century was reflected by a concomittant decrease in malaria transmission in the Ethiopian highlands, underscoring the close connection between climate and health. For several years there has been a heated debate on the impact of global warming on malaria incidence. It is believed that the largest effect could occur in the highlands, where lower temperatures limit vector abundance, leading to intermittent and seasonal disease outbreaks. We see that malaria epidemiology in these areas is strongly under climate control at all scales (months, years and even decades), which settles once and for all the debate on whether climate change is affecting or not the dynamics of malaria in Africa.

    Similarly, by using a statistical method specifically designed to detect transitory associations and a mathematical model, we could show that climate played a strong role in modulating COVID-19 transmission during the first three pandemic waves in both hemispheres. COVID-19 behaves like a seasonal infection linked to low temperatures and humidity, much like seasonal influenza. We analysed the association to temperature and humidity in the initial phase of SARS-CoV-2 spread in 162 countries across five continents, before changes in human behaviour and public health policies were put into place. Using an epidemiological model, we showed that incorporating temperature into the transmission rate works better for predicting the rise and fall of the different waves, particularly the first and third ones in Europe. Our study also supports the considerable contribution of airborne SARS-CoV-2 transmission and the need to shift to measures that promote “air hygiene”. 

  • Decentralizing World Literature Through Data Science (2021)

    Roig Sanz, Diana (UOC)

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    Decentralizing World Literature Through Data Science

    In the last two decades, computational tools have been used in the humanities and the social sciences to study patterns of cultural change, both in the present and in the past, in a growing and interdisciplinary field. While the main goal has been to measure culture in an innovative way, it has evolved differently among the wide range of disciplines that study the human condition and at various university departments all over the world. This paper contributes to a better understanding of the potentials and pitfalls of using machine learning and artificial intelligence in the humanities and applies data science and digital tools to the study of translated literature and global translation flows. Specifically, it examines the opportunities and pitfalls of computationally analyzing large cultural data sets and describes how we can combine quantification, the statistical study of literary translations in an historical period, and data visualization on a large scale with qualitative methods. A general hypothesis is that one of the main possibilities offered by a Big Translation History approach (BTH) is to help decentralize translation and world literature, in a broad sense, by breaking with national historiographies. This might be particularly significant for researchers working on periods in which borders have changed, those dealing with translated literature in the diaspora, and those working on translations of regional literatures. This paper defines BTH as a conceptual and methodological tool that can be grounded on three fundamentals: (1) large scale research (geographical and chronological); (2) massive data, understood using a two-pronged approach involving both big data and little data, and drawing on a wide range of often heterogeneous and non-structured sources; and (3) the use of computational techniques as part of the research process and for the production of knowledge, rather than helping only with visualization.

  • Justification as Ignorance. An Essay in Epistemology (2021)

    Rosenkranz, Sven (UB)

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    Justification as Ignorance. An Essay in Epistemology

    Epistemic justification is justification to take the world to be a certain way. If one knows the world to be a certain way, one has justification for taking it to be that way. But, arguably, one may have such justification without knowing, and be justified in taking the world to be a certain way, although the world is not in fact that way: unlike knowledge, epistemic justification is non-factive. While one is not always in a position to know that one has knowledge if one does, one is arguably always in a position to know that one has epistemic justification if one does: epistemic justification is luminous. Traditionally, these features have been assumed to require that justification be a condition internal to the subject’s mind that is knowable by reflection alone. Justification as Ignorance offers an original account of epistemic justification as both non-factive and luminous, thereby vindicating core internalist intuitions, without yet construing justification as an internal condition. Rosenkranz conceives of justification, in its doxastic and propositional varieties, as a kind of epistemic possibility of knowing and of being in a position to know. His account contrasts with recently proposed alternatives that characterize justification in terms of the metaphysical possibility of knowing. Based on a suitable epistemic logic for knowledge, and for being in a position to know, Rosenkranz defends his conception of justification against well-known anti-luminosity arguments, shows that the account allows for fruitful applications and novel principled solutions to the lottery and preface paradoxes, and provides a metaphysics of justification and its varying degrees of strength.

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