Magnetic anisotropies of late transition metal atomic clusters

We analyze the impact of the magnetic anisotropy on the geometric structure and magnetic ordering of small atomic clusters of palladium, iridium, platinum and gold, using Density Functional Theory. Our results highlight the absolute need to include self-consistently the spin orbit interaction in any simulation of the magnetic properties of small atomic clusters, and a complete lack of universality in the magnetic anisotropy of small-sized atomic clusters.Comment: 4 pages, 5 figures, 1 EPAPS fil

Decoherent time-dependent transport beyond the Landauer-B\"uttiker formulation: a quantum-drift alternative to quantum jumps

We present a model for decoherence in time-dependent transport. It boils down into a form of wave function that undergoes a smooth stochastic drift of the phase in a local basis, the Quantum Drift (QD) model. This drift is nothing else but a local energy fluctuation. Unlike Quantum Jumps (QJ) models, no jumps are present in the density as the evolution is unitary. As a first application, we address the transport through a resonant state $\left\vert 0\right\rangle$ that undergoes decoherence. We show the equivalence with the decoherent steady state transport in presence of a B\"{u}ttiker's voltage probe. In order to test the dynamics, we consider two many-spin systems whith a local energy fluctuation. A two-spin system is reduced to a two level system (TLS) that oscillates among $\left\vert 0\right\rangle$ $\equiv$ $\left\vert \uparrow \downarrow \right\rangle$ and $\left\vert 1\right\rangle \equiv$ $\left\vert \downarrow \uparrow \right\rangle$. We show that QD model recovers not only the exponential damping of the oscillations in the low perturbation regime, but also the non-trivial bifurcation of the damping rates at a critical point, i.e. the quantum dynamical phase transition. We also address the spin-wave like dynamics of local polarization in a spin chain. The QD average solution has about half the dispersion respect to the mean dynamics than QJ. By evaluating the Loschmidt Echo (LE), we find that the pure states $\left\vert 0\right\rangle$ and $\left\vert 1\right \rangle$ are quite robust against the local decoherence. In contrast, the LE, and hence coherence, decays faster when the system is in a superposition state. Because its simple implementation, the method is well suited to assess decoherent transport problems as well as to include decoherence in both one-body and many-body dynamics.Comment: 10 pages, 5 figure

New trends in industrial biocatalysis

The “manufacture and modification” of molecules in nature are catalyzed by enzymes with exquisite selectivity, unparalleled rate acceleration and under “mild” reaction conditions. Nowadays, enzyme-catalyzed synthesis is an attractive and eco-friendly alternative to the traditional multi-step and contaminating chemical processes

Biotechnological and biomedical applications of enzymes involved in the synthesis of nucleosides and nucleotides

Nucleic acid derivatives are involved in cell growth and replication, but they are also particularly important as building blocks for RNA and DNA synthesis. In nature, purine and pyrimidine nucleotides are synthesized through two distinct pathways, de novo and salvage pathways, both depending on 5-phospho-α-D-ribose 1-diphosphate (PRPP) as a key element [1,2]. In the de novo pathway, purine and pyrimidine nucleotides are synthesized from simple molecules such as glycine, glutamine, or aspartate. In contrast, the salvage pathway employs scavenged preformed endogenous or exogenous nucleobases to generate the corresponding nucleoside-50 -monophosphates (NMPs) [3]. Both metabolic routes, de novo and salvage pathways, lead to the synthesis of NMPs, which are subsequently phosphorylated to obtain the corresponding nucleoside-50 -di (NDPs) and triphosphates (NTPs). Moreover, all organisms also generate (20 -deoxy)nucleoside-50 -diphosphates (dNDPs) from NDPs [4], which will be converted to 20 -deoxyribonucleotides (dNTPs), as precursors for DNA synthesis. Additionally, nucleotide derivatives are involved in cell signaling (cyclic nucleotides, cNMPs or c-di-NMPs) [5] and a multitude of different biochemical processes, acting as cofactors (NADP+ ) or energy sources (ATP)

Professores em pedagogia hospitalar: uma revisão sistemática

Professores hospitalares enfrentam o desafio de incluir em contextos complexos com poucos antecedentes empíricos. Esta revisão sistemática (Sánchez-Meca, 2010) teve como objetivo analisar os estudos empíricos publicados entre 2000 e 2020 sobre a pedagogia em contextos hospitalares. Utilizando os lineamentos PRISMA, identificamos 363 artigos nas bases de dados; Web of Science, Scielo y Scopus, selecionando 11 sobre o critério de inclusão. Identificamos três categorias: tendências de estudo; dimensões de trabalho e características docentes; e desafios. Os resultados mostram a predominância no campo de estudos descritivos; focos teóricos de inclusão e direitos; e mulheres como docentes e investigadoras. As investigações enfatizam em aspectos emocionais, falta de orientação e dificuldades relacionais do trabalho docente. Concluímos que existe uma necessidade de fortalecer metodologicamente os estudos, aumentar a corresponsabilidade entre docente e equipe medica; e gerar politicas de formação especifica. Esses descobrimentos identificam avanços e desafios no campo, podendo orientar o seu desenvolvimento.Los/as docentes hospitalarios/as enfrentan el desafío de incluir en contextos complejos con pocos antecedentes empíricos. Esta revisión sistemática (Sánchez-Meca, 2010) tuvo por objetivo analizar los estudios empíricos publicados entre el 2000-2020 sobre docencia en pedagogía hospitalaria. Utilizando los lineamientos PRISMA, identificamos 363 artículos en las bases de datos Web of Science, Scielo y Scopus, seleccionando 11 bajo criterios de inclusión. Identificamos tres categorías transversales: tendencias de estudio; dimensiones del trabajo y características docentes; y desafíos. Los resultados muestran el predominio en el campo de: estudios descriptivos; enfoques teóricos de inclusión y derecho; y mujeres como docentes e investigadoras. Las investigaciones enfatizan en aspectos emocionales, la falta de orientaciones y dificultades relacionales del trabajo docente. Se concluye la necesidad de fortalecer metodológicamente los estudios, aumentar la corresponsabilidad docente-personal médico; y generar políticas y formación específica. Estos hallazgos identifican avances y desafíos en el campo pudiendo orientar su desarrollo.Hospital teachers face the challenge of working in complex contexts with few empirical references. This systematic review (Sánchez-Meca, 2010) aims to analyze empirical studies published between 2000-2020 related to teaching in hospital settings. Using the PRISMA guidelines, we identified 363 articles in the Web of Science, SciELO and Scopus databases; 11 studies were selected after the inclusion criteria were applied. We identified three areas of study: research trends; work dimensions and teacher characteristics; and challenges. We found a predominance of descriptive studies, theoretical frameworks of inclusion and civil rights, and female teachers and researchers. The analyzed studies emphasize emotional aspects, a lack of guidelines, and difficulties related to teachers' work. We conclude by signaling the need to strengthen the methodology of related studies, increase the joint responsibility of teachers and medical staff, and generate specific policies and preparation. These findings identify advances and challenges in the field that could guide its development

Positive Hopf plumbed links with maximal signature

This thesis has six chapters. In Chapters 1 and 2, we give the definitions and examples of the main links under study in this thesis: positive braids links, checkerboard graph links, and basket links. In Chapter 2, we also define the signature function of a link and compute it for the cases of three and four positive Hopf bands plumbed together. In particular, we investigate the behavior of the signature function when the intersection of the core curves of these Hopf bands goes to infinity. In Chapter 3, we define special types of moves for checkerboard graphs and use them to prove that a checkerboard graph link with maximal signature is isotopic to one of the links realized by the simply laced Dinkin diagrams (ADE diagrams). In Chapter 4, we also characterize checkerboard graphs whose corresponding link is of the ADE type and use this to show that there is a linear time algorithm to find these links from a checkerboard graph. In Chapter 5, we study the connection between checkerboard graph links and basket links. In Chapter 6, we prove that a basket link made with positive Hopf bands and symmetrized Seifert form congruent to the Cartan matrix of the simply laced Dynkin diagram A is isotopic to a two-strand torus link. We also provide some examples of fake A links

Clustering of syntactic and discursive information for the dynamic adaptation of Language Models

Presentamos una estrategia de agrupamiento de elementos de diálogo, de tipo semántico y discursivo. Empleando Latent Semantic Analysis (LSA) agru- pamos los diferentes elementos de acuerdo a un criterio de distancia basado en correlación. Tras seleccionar un conjunto de grupos que forman una partición del espacio semántico o discursivo considerado, entrenamos unos modelos de lenguaje estocásticos (LM) asociados a cada modelo. Dichos modelos se emplearán en la adaptación dinámica del modelo de lenguaje empleado por el reconocedor de habla incluido en un sistema de diálogo. Mediante el empleo de información de diálogo (las probabilidades a posteriori que el gestor de diálogo asigna a cada elemento de diálogo en cada turno), estimamos los pesos de interpolación correspondientes a cada LM. Los experimentos iniciales muestran una reducción de la tasa de error de palabra al emplear la información obtenida a partir de una frase para reestimar la misma frase

Subtitling practice as a task for motivation enhancement and oral comprehension improvement in the acquisition of english as a second language and its viability in a learning unit

This research studies the effects of subtitling practice as a task to improve oral comprehension and enhance students´ motivation. The task is included in a learning unit specifically designed for secondary students in the Spanish education system to find out their preferences and to test the feasibility of the integration of the task as a regular activity in language learning. Subtitling brings into the classroom the motivational component of ICTs, multimedia, and the use of authentic materials while it simulates real-life tasks in the classroom and promotes active and autonomous learning. Listening in second language teaching is a skill which has been neglected over the years and is still not dealt with in a motivating way in the classroom. Besides, there is great amount of research carried out on the effects of watching captioned videos in the acquisition of language skills, but the area of subtitle production as an effective educational tool is still unexplored. The findings show a tendency among students to consider subtitling the most motivating activity. The integration of subtitling in a learning unit intends to cater for all students´ needs and learning styles and to keep a balance among the treatment of all the skills. The outcome of the study enhances the need for further research to find conclusive results on the improvement of oral comprehension, gives clues for the improvement of the learning unit and provides suggestions for further research on the effective use of subtitling practice as an educational tool

Detection of mecC-Methicillin-resistant Staphylococcus aureus isolates in river water : a potential role for water in the environmental dissemination

Methicillin-resistant Staphylococcus aureus (MRSA) is a public health concern due to limited treatment options. The recent description of a mecA homologue, mecC in human and cattle, led to studies to detect this new variant in human and other animal species. Detection of mecC in wild boar and fallow deer in a Spanish game estate led us to further investigate the presence of mecC-MRSA at this location. Samples from cattle, wild animals, workers and river water were tested. A further three mecC-MRSA isolates were obtained from river water. Molecular characterization (multilocus sequence typing and spa typing) and antimicrobial susceptibility testing (broth microdilution) showed that isolates were similar to those detected in wild animals. Whole genome sequencing confirmed that the isolates from the river water and wild animals in the same geographic area were all closely related isolates of ST425 mecC-MRSA. The presence of mecC-MRSA in the river water highlights the potential role of water in the dissemination of mecC-MRSA