Demographic limitation processes

20 páginas, 2 figuras, 1 tabla, 3 cuadros.-- Editor: Valladares, F.[ES]: Procesos de limitación demográfica. Este capítulo ofrece una revisión de los factores que afectan a la regeneración natural de la vegetación, considerando la serie de etapas demográficas que determinan la dinámica demográfica de una pobla- ción. Son muy escasos los estudios disponibles que analizan toda la serie de eventos concatenados entre la producción de flores y frutos y el establecimiento exitoso de una planta adulta reproductiva. También son escasos los trabajos que permiten establecer los efectos aplazados que tienen las interacciones con animales a lo largo del ciclo de regeneración. La aproximación que proponemos cuantifica las pérdidas de propágulos en cada etapa demográfica e identifica “cuellos de botella” del reclutamiento que pue- den colapsar la regeneración natural de una especie. Revisamos una serie de casos de estudio que ilustran diversos procesos de limitación demográfica. El uso de técnicas explícitamente demográficas es fundamental para comprender la evolución de las especies forestales Mediterráneas y para diseñar actuaciones de preservación de sus poblaciones y de su extraordinaria diversidad.[EN]: We review the main factors influencing recruitment limitation in Mediterranean woody species by considering the sequential stages that determine the demographic cycle. Very few studies examine the whole set of demographic stages, from flower production to the successful establishment of adult reproductive plants, and their influence on recruitment. There are also few studies exploring the delayed effects of animal interactions throughout the regeneration cycle, but the information on stage-specific effects is more detailed. We propose an approach that quantifies the propagule losses at each sequential demographic stage and identifies demographic bottlenecks that might collapse population growth. We review a series of case studies illustrating different limitation processes. The use of explicit demographic techniques is central to understand the evolution of Mediterranean woody species and to design sound, ecologically-based, conservation plans to preserve their extraordinary diversity.Juan Arroyo agradece la financiación otorgada a los proyectos 4474-91 (National Geographic Society), PB 91-0894, PB95-0551, 1FD97-0743-CO3-03, PB98-1144, BOS200307924-CO2-01 (MECD, MCyT). Los trabajos de Pedro Jordano han sido financiados con proyectos MECD y MCyT (1FD97-0743-CO3-01, PB 96-0857, BOS2000-1366-C02-01 y REN2003-00273), así como la Junta de Andalucía (PAI). Juan Luis García-Castaño estuvo financiado durante su período pre-doctoral con una beca FPU, AP96-27318040. El trabajo de Fernando Pulido ha sido parcialmente financiado por una beca FPI de la Junta de Extremadura y los proyectos regional IPR-0A050 y estatal BOS2002- 12222-E del Ministerio de Ciencia y Tecnología. Los trabajos de Patricio García-Fayos han sido financiados con proyectos MCyT (1FD97-0551), de la Generalitat Valenciana (02-046) y de la Institució Alfons el Magnánim (02-046)Peer reviewe

Zinc nitride thin films: Basic properties and applications

A. Redondo-Cubero, M. Gómez-Castaño, C. García Núñez, M. Domínguez, L. Vázquez, J. L. Pau , "Zinc nitride thin films: basic properties and applications", Oxide-based Materials and Devices VIII, Proc. SPIE 10105, 101051B (24 February 2017); doi: 10.1117/12.2253044. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibitedProceedings of VIII Oxide-based Materials and Devices Conference (San Francisco, California, United States)Zinc nitride films can be deposited by radio frequency magnetron sputtering using a Zn target at substrate temperatures lower than 250°C. This low deposition temperature makes the material compatible with flexible substrates. The asgrown layers present a black color, polycrystalline structures, large conductivities, and large visible light absorption. Different studies have reported about the severe oxidation of the layers in ambient conditions. Different compositional, structural and optical characterization techniques have shown that the films turn into ZnO polycrystalline layers, showing visible transparency and semi-insulating properties after total transformation. The oxidation rate is fairly constant as a function of time and depends on environmental parameters such as relative humidity or temperature. Taking advantage of those properties, potential applications of zinc nitride films in environmental sensing have been studied in the recent years. This work reviews the state-of-the-art of the zinc nitride technology and the development of several devices such as humidity indicators, thin film (photo)transistors and sweat monitoring sensors.This research is supported by the MINECO (CTQ2014-53334-C2-2-R) and Comunidad de Madrid (NANOAVANSENS ref. S2013/MIT-3029). ARC acknowledges Ramón y Cajal program (under contract number RYC-2015-18047

Intrinsically disordered chromatin protein NUPR1 binds to the enzyme PADI4

The nuclear protein 1 (NUPR1) is an intrinsically disordered protein involved in stress-mediated cellular conditions. Its paralogue nuclear protein 1-like (NUPR1L) is p53-regulated, and its expression down-regulates that of the NUPR1 gene. Peptidyl-arginine deiminase 4 (PADI4) is an isoform of a family of enzymes catalyzing arginine to citrulline conversion; it is also involved in stress-mediated cellular conditions. We characterized the interaction between NUPR1 and PADI4 in vitro, in silico, and in cellulo. The interaction of NUPR1 and PADI4 occurred with a dissociation constant of 18 ± 6 μM. The binding region of NUPR1, mapped by NMR, was a hydrophobic polypeptide patch surrounding the key residue Ala33, as pinpointed by: (i) computational results; and, (ii) site-directed mutagenesis of residues of NUPR1. The association between PADI4 and wild-type NUPR1 was also assessed in cellulo by using proximity ligation assays (PLAs) and immunofluorescence (IF), and it occurred mainly in the nucleus. Moreover, binding between NUPR1L and PADI4 also occurred in vitro with an affinity similar to that of NUPR1. Molecular modelling provided information on the binding hot spot for PADI4. This is an example of a disordered partner of PADI4, whereas its other known interacting proteins are well-folded. Altogether, our results suggest that the NUPR1/PADI4 complex could have crucial functions in modulating DNA-repair, favoring metastasis, or facilitating citrullination of other proteins

Evaluación del aprendizaje basado en problemas y examen final: diferencias en la percepción de justicia y el desarrollo de competencias [Problem-based learning assessment and final examination: differences in the perception of justice and the competencies development]

El examen es uno de los métodos de evaluación mayoritariamente utilizados en el contexto universitario. No obstante, su conexión con la capacidad para el afrontamiento y resolución de los problemas significativos de la vida profesional futura del alumnado ha sido cuestionada, y la evaluación del aprendizaje basado en problemas cobra cada vez más relevancia como alternativa al examen. Esta evaluación se centra en situaciones de aprendizaje de la vida real y puede suponer un beneficio tanto para el alumnado como para el marco de enseñanza actual, que demanda procesos de evaluación justos y que permitan al alumnado el desarrollo de competencias útiles para su desempeño laboral futuro. Con el objetivo de comprobar si la evaluación del aprendizaje basado en problemas supone una mejora de la percepción de justicia procedimental y la percepción del desarrollo de competencias del alumnado, 44 estudiantes universitarios fueron evaluados mediante ambos métodos y posteriormente cumplimentaron un cuestionario para su comparación. Los resultados pusieron de manifiesto los beneficios de la evaluación del aprendizaje basado en problemas. [The final examination is one of the assessment methods mostly used in the university context. However, their relatedness with the ability for coping and resolving significant problems of the future professional life of the students have been questioned, and problem-based learning assessment becomes increasingly relevant as an alternative to exam. This assessment is focused on real-life learning situations and may involve a benefit to both students and the current educational framework, which requires fair evaluation processes that allow students to develop useful competencies for their future work performance. In order to test if the problem-based learning system implies an improvement in the perception of procedural justice and in the perception of students' development of competences, 44 university students were evaluated by means of both methods and then completed a questionnaire to compare them. The results highlighted the benefits of the problem-based learning assessment.

A novel synthetic approach to tyrosine dimers based on pterin photosensitization

[EN] Oxidative damage to proteins leads to a variety of modifications that are markers of pathogenesis. One of the most important modifications is the dityrosine (Tyr(2)) cross-link, resulting from an oxidative covalent bond between two tyrosines (Tyr). An optimized methodology for preparation of pure Tyr(2) is important to investigate in detail its physicochemical properties and reactivity. Pterin (Ptr), the parent and unsubstituted compound of oxidized pterins, is able to photosensitize the cross-linking of free tyrosine (Tyr) and tyrosine residues of peptides and proteins through a photoinduced electron transfer mechanism. We have optimized a simple, one-step photocatalyzed formation of Tyr(2), using Ptr as photocatalyst. Our procedure is carried out in aqueous solutions under UV-A radiation for few minutes. The purification of Tyr(2) is performed by reverse-phase chromatography. The obtained highly pure solution is used to fully characterize the Tyr(2) (exact mass and H-1, H-1-H-1 COSY; DEPT; HSQC and HMBC NMR experiments) and to deeper study its fluorescence properties. (C) 2017 Elsevier Ltd. All rights reserved.The present work was partially supported by Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET; Grant PIP 0304), Agencia de Promocion Cientifica y Tecnologica (ANPCyT; Grants PICT 2012-0508), and Universidad Nacional de La Plata (UNLP; Grant X586 and X712). L.O.R. and C.C. thanks CONICET for doctoral research fellowships. Funding from the Programa CSIC de Cooperacion Cientifica para el Desarrollo (iCOOPLight project ref 20105CD0017) is gratefully acknowledged. A.H.T. and M.L.D are research members of CONICET. The authors thank Dr. Mariana Vignoni (INIFTA, CONICET) and Nathalie Martins-Froment of the Service Commun de Spectrometrie de Masse (FR2599), Universite de Toulouse III (Paul Sabatier) for their crucial contributions in mass spectrometry measurements.Reid, LO.; Castaño, C.; Dantola, ML.; Lhiaubet ., VL.; Miranda Alonso, MÁ.; Marín García, ML.; Thomas, AH. (2017). A novel synthetic approach to tyrosine dimers based on pterin photosensitization. Dyes and Pigments. 147:67-74. https://doi.org/10.1016/j.dyepig.2017.07.058S677414

SEOM clinical guidelines for the treatment of head and neck cancer (2020)

Head and neck cancers (HNC) are defined as malignant tumours located in the upper aerodigestive tract and represents 5% of oncologic cases in adults in Spain. More than 90% of these tumours have squamous histology. In an effort to incorporate evidence obtained since 2017 publication, the Spanish Society of Medical Oncology (SEOM) presents an update of the squamous cell HNC diagnosis and treatment guideline. Most relevant diagnostic and therapeutic changes from the last guideline have been updated: introduction of sentinel node biopsy in early oral/oropharyngeal cancer treated with surgery, concomitant radiotherapy with weekly cisplatin 40 mg/m2 in the adjuvant setting, new approaches for HPV-related oropharyngeal cancer and new treatments with immune-checkpoint inhibitors in recurrent/metastatic disease

Azonia derivatives of the γ-carboline system. A new class of DNA intercalators

1-Methyl-γ-carboline derivatives were transformed into the corresponding N-aminoazinium salts, which were condensed with 1,2-dicarbonyl compounds (Westphal reaction) to afford azonia derivatives with a bridgehead quaternary nitrogen atom. Some of them show DNA intercalating properties.Instituto de Qulmica Computaciona

Pyrrolodiazines. 4. Structure and chemistry of 3,4-dihydropyrrolo[1,2-a]pyrazine

The structure of 3,4-dihydropyrrolo[1,2-a]pyrazine and its N-protonated form is studied by ab initio calculations. Examples of the reactivity of this poorly studied system are presented in which it is shown that the imino moiety does not react with dienes but does undergo inter- and intramolecular 1,3-dipolar cycloadditions by reaction of azomethine ylides of this bicyclic system with suitable dipolarophiles.Ministerio de Educación y CienciaCentro de Computación de Galixia (CESGA

Elucidating dynamic behavior of synthetic supramolecular polymers in water by hydrogen/deuterium exchange mass spectrometry

A comprehensive understanding of the structure, self-assembly mechanism, and dynamics of one-dimensional supramolecular polymers in water is essential for their application as biomaterials. Although a plethora of techniques are available to study the first two properties, there is a paucity in possibilities to study dynamic exchange of monomers between supramolecular polymers in solution. We recently introduced hydrogen/deuterium exchange mass spectrometry (HDX-MS) to characterize the dynamic nature of synthetic supramolecular polymers with only a minimal perturbation of the chemical structure. To further expand the application of this powerful technique some essential experimental aspects have been reaffirmed and the technique has been applied to a diverse library of assemblies. HDX-MS is widely applicable if there are exchangeable hydrogen atoms protected from direct contact with the solvent and if the monomer concentration is sufficiently high to ensure the presence of supramolecular polymers during dilution. In addition, we demonstrate that the kinetic behavior as probed by HDX-MS is influenced by the internal order within the supramolecular polymers and by the self-assembly mechanism.MINECO, Spain, Grant/Award Number: IJCI-2015-252389; Marie Curie FP7 SASSYPOL ITN program, Grant/Award Number: 607602; European Research Council, Grant/Award Number: 788618; Dutch Ministry of Education, Culture and Science, Grant/Award Number: 024.001.03