It is increasingly being recognized that new applications for materials require functions and properties that are not achievable with monolithic materials. The combination of dissimilar materials for ...these new applications creates interfaces whose properties and processing need to be understood before they can be applied commercially. In the present review paper we try to emphasize the important role and challenges of ceramic/metal micro/nanocomposites in the new technologies. In this respect we will study and review the exotic effects of metal particles embedded into matrix ceramics due to the dissimilar properties of the components, percolation laws, and the nature of the interfaces. From an electromagnetic point of view we have underlined the enormous enhancement of permittivity in the proximity of the percolation threshold, associated with an induced soft mode similar to para-ferroelectric transition. From a mechanical standpoint, the synergic effect of nanometer size, clustering addressed by the percolation theory and ceramic/metal interface features produces an unexpected enhancement in the hardness of the composite giving rise to superhard materials.
Summary
RNA viruses have very compact genomes and so provide a unique opportunity to study how evolution works to optimize the use of very limited genomic information. A widespread viral strategy to ...solve this issue concerning the coding space relies on the expression of proteins with multiple functions. Members of the family Potyviridae, the most abundant group of RNA viruses in plants, offer several attractive examples of viral factors which play roles in diverse infection‐related pathways. The Helper Component Proteinase (HCPro) is an essential and well‐characterized multitasking protein for which at least three independent functions have been described: (i) viral plant‐to‐plant transmission; (ii) polyprotein maturation; and (iii) RNA silencing suppression. Moreover, multitudes of host factors have been found to interact with HCPro. Intriguingly, most of these partners have not been ascribed to any of the HCPro roles during the infectious cycle, supporting the idea that this protein might play even more roles than those already established. In this comprehensive review, we attempt to summarize our current knowledge about HCPro and its already attributed and putative novel roles, and to discuss the similarities and differences regarding this factor in members of this important viral family.
The pathological importance of mixed viral infections in plants might be underestimated except for a few well-characterized synergistic combinations in certain crops. Considering that the host ranges ...of many viruses often overlap and that most plant species can be infected by several unrelated viruses, it is not surprising to find more than one virus simultaneously in the same plant. Furthermore, dispersal of the majority of plant viruses relies on efficient transmission mechanisms mediated by vector organisms, mainly but not exclusively insects, which can contribute to the occurrence of multiple infections in the same plant. Recent work using different experimental approaches has shown that mixed viral infections can be remarkably frequent, up to the point that they could be considered the rule more than the exception. The purpose of this review is to describe the impact of multiple infections not only on the participating viruses themselves but also on their vectors and on the common host. From this standpoint, mixed infections arise as complex events that involve several cross-interacting players, and they consequently require a more general perspective than the analysis of single-virus/single-host approaches for a full understanding of their relevance.
The Cloud paradigm is at a critical point in which the existing energy-efficiency techniques are reaching a plateau, while the computing resources demand at Data Center facilities continues to ...increase exponentially. The main challenge in achieving a global energy efficiency strategy based on Artificial Intelligence is that we need massive amounts of data to feed the algorithms. This paper proposes a time-series data augmentation methodology based on synthetic scenario forecasting within the Data Center. For this purpose, we will implement a powerful generative algorithm: Generative Adversarial Networks (GANs). Specifically, our work combines the disciplines of GAN-based data augmentation and scenario forecasting, filling the gap in the generation of synthetic data in DCs. Furthermore, we propose a methodology to increase the variability and heterogeneity of the generated data by introducing on-demand anomalies without additional effort or expert knowledge. We also suggest the use of Kullback-Leibler Divergence and Mean Squared Error as new metrics in the validation of synthetic time series generation, as they provide a better overall comparison of multivariate data distributions. We validate our approach using real data collected in an operating Data Center, successfully generating synthetic data helpful for prediction and optimization models. Our research will help optimize the energy consumed in Data Centers, although the proposed methodology can be employed in any similar time-series-like problem.
A state‐of‐the‐art operando spectroscopic technique is applied to Co/TiO2 catalysts, which account for nearly half of the world's transportation fuels produced by Fischer–Tropsch catalysis. This ...allows determination of, at a spatial resolution of approximately 50 nm, the interdependence of formed hydrocarbon species in the inorganic catalyst. Observed trends show intra‐ and interparticular heterogeneities previously believed not to occur in particles under 200 μm. These heterogeneities are strongly dependent on changes in H2/CO ratio, but also on changes thereby induced on the Co and Ti valence states. We have captured the genesis of an active FTS particle over its propagation to steady‐state operation, in which microgradients lead to the gradual saturation of the Co/TiO2 catalyst surface with long chain hydrocarbons (i.e., organic film formation).
Hydrocarbon carpet: The propagation of a Co/TiO2 catalyst system into steady‐state operation is studied by operando and in situ X‐ray nanospectroscopy. A joint understanding of inorganic and organic constituents of the catalyst, products, and reactants is achieved by mapping their respective spatiotemporal evolutions as a function of reaction time‐on‐stream.
Migraine is one of the most wide-spread neurological disorders, and its medical treatment represents a high percentage of the costs of health systems. In some patients, characteristic symptoms that ...precede the headache appear. However, they are nonspecific, and their prediction horizon is unknown and pretty variable; hence, these symptoms are almost useless for prediction, and they are not useful to advance the intake of drugs to be effective and neutralize the pain. To solve this problem, this paper sets up a realistic monitoring scenario where hemodynamic variables from real patients are monitored in ambulatory conditions with a wireless body sensor network (WBSN). The acquired data are used to evaluate the predictive capabilities and robustness against noise and failures in sensors of several modeling approaches. The obtained results encourage the development of per-patient models based on state-space models (N4SID) that are capable of providing average forecast windows of 47 min and a low rate of false positives.
Abstract In this article I analyse how transcontinental migrations, the various forms that these took (Paleolithic first settlement, conquest and colonialism, slavery, free mass movements, and ...mercantile diasporas), and the way these interacted in the receiving environments, shaped the historical formation of Latin America. The article shows how these interactions explain the key apparent contradictions of Latin America: that it is both the most racially diverse and the most culturally homogeneous region in the world; that it has the highest crime/homicide rates but also the lowest levels of civil and international wars, holocausts, and other forms of collective violence; and that it has the highest levels of social inequality in the world but also some of its historically most egalitarian areas.
Resumen En este artículo analizo cómo las migraciones transcontinentales, en las diversas formas que asumieron (el primer asentamiento paleolítico, conquista y colonialismo, esclavitud, movimientos de masa libres y diásporas mercantiles) y la manera como éstas interactuaron con los entornos receptores ha determinado la formación histórica de América Latina. El artículo muestra cómo estas interacciones explican las aparentes contradicciones de América Latina: el hecho de ser la región más diversa del mundo en términos raciales y, al mismo tiempo, aquella culturalmente más homogénea; la que exhibe las tasas más altas de criminalidad / homicidio, pero también los menores índices de guerras civiles e internacionales, holocaustos y otras formas de violencia colectiva; y la que muestra los más altos índices mundiales de desigualdad social, pero que incluye también algunas de las áreas históricamente más igualitarias en el mundo.
Resumo Este artigo analisa de que modo as migrações transcontinentais, nas várias formas que assumiram (o primeiro assentamento paleolítico, conquista e colonialismo, escravidão, movimentos de massa livres e diásporas mercantis) e a maneira como estas interagiam com os ambientes receptores moldou a formação histórica da América Latina. O artigo mostra como essas interações explicam as aparentes contradições da América Latina: o fato de ser a região mais diversa do mundo em termos raciais e, ao mesmo tempo, aquela culturalmente mais homogênea; a que exibe as mais altas taxas de criminalidade / homicídio, mas também os menores índices de guerras civis e internacionais, holocaustos e outras formas de violência coletiva; e a que mostra os níveis mais altos índices mundiais de desigualdade social, mas que incluiu também algumas das áreas historicamente mais igualitárias no mundo.
This paper documents and discusses the results of a study on the effects of oxidative and thermoreversible aging on the intermediate limiting phase angle temperatures for six Latin American asphalts. ...Materials were aged in the pressure aging vessel and investigated by infrared spectroscopy, modulated differential scanning calorimetry, and dynamic shear rheometry. It was found that the effects of irreversible/chemical and thermoreversible aging on rheological properties were of comparable weight. Hence, for future fatigue cracking performance grading, it is important to take the effects of both types of aging into consideration because the omission of thermoreversible effects will lead to inadequate control of cracking.
The chemical bulk reductive covalent functionalization of thin‐layer black phosphorus (BP) using BP intercalation compounds has been developed. Through effective reductive activation, covalent ...functionalization of the charged BP by reaction with organic alkyl halides is achieved. Functionalization was extensively demonstrated by means of several spectroscopic techniques and DFT calculations; the products showed higher functionalization degrees than those obtained by neutral routes.
The reductive covalent functionalization of thin‐layer black phosphorus (BP) proceeds via BP intercalation compounds. Following the reductive activation of BP, the resulting charged BP reacts with alkyl halides and undergoes covalent functionalization. The BP lattice shows unprecedented opening and a higher degree of functionalization than that obtained by neutral routes.
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