Scalar arguments of the mathematical functions defining molecular and turbulent transport of heat and mass in compressible fluids

The advection–diffusion equations defining control volume conservation laws in micrometeorological research are analysed to resolve discrepancies in their appropriate scalar variables for heat and mass transport. A scalar variable that is conserved during vertical motions enables the interpretation of turbulent mixing as ‘diffusion’. Gas-phase heat advection is shown to depend on gradients in the potential temperature (θ), not the temperature (T). Since conduction and radiation depend on T, advection–diffusion of heat depends on gradients of both θ and T. Conservation of θ (the first Law of Thermodynamics) requires including a pressure covariance term in the definition of the turbulent heat flux. Mass advection and diffusion are universally agreed to depend directly on gradients in the gas ‘concentration’ (c), a nonetheless ambiguous term. Depending upon author, c may be defined either as a dimensionless proportion or as a dimensional density, with non-trivial differences for the gas phase. Analyses of atmospheric law, scalar conservation and similarity theory demonstrate that mass advection–diffusion in gases depends on gradients, not in density but rather in a conserved proportion. Flux-tower researchers are encouraged to respect the meteorological tradition of writing conservation equations in terms of scalar variables that are conserved through simple air motions.The authors received funding support from Andalusian regional government project GEOCARBO (P08-RNM-3721), the National Institute for Agrarian Research and Technology (INIA; SUM2006–00010-00–00), the Spanish flux-tower network CARBORED-ES (Science Ministry project CGL2010- 22193-C04–02), and the European Commission collaborative project GHG Europe (FP7/2007-2013; grant agreement 244122)

Quantifying the overall added value of dynamical downscaling and the contribution from different spatial scales

This study evaluates the added value in the representation of surface climate variables from\ud an ensemble of regional climate model (RCM) simulations by comparing the relative skill of the RCM\ud simulations and their driving data over a wide range of RCM experimental setups and climate statistics.\ud The methodology is specifically designed to compare results across different variables and metrics, and it\ud incorporates a rigorous approach to separate the added value occurring at different spatial scales. Results\ud show that the RCMs’ added value strongly depends on the type of driving data, the climate variable, and the\ud region of interest but depends rather weakly on the choice of the statistical measure, the season, and the\ud RCM physical configuration. Decomposing climate statistics according to different spatial scales shows that\ud improvements are coming from the small scales when considering the representation of spatial patterns,\ud but from the large-scale contribution in the case of absolute values. Our results also show that a large part\ud of the added value can be attained using some simple postprocessing methods

Caracterización del sistema de secreción de tipo VI en Rhizobium etli Mim1

La simbiosis rizobio-leguminosa es altamente específica. La translocación de proteínas denominadas efectores desde el citoplasma bacteriano a la célula vegetal es un elemento relacionado con dicha especificidad. Los efectores pueden ser translocados a través de diferentes sistemas de secreción. El análisis de genomas de rizobios ha permitido identificar en algunos la presencia de sistemas de secreción de tipo VI (T6SS). El T6SS tiene como componente principal una nanoestructura similar a las que utilizan los bacteriófagos1 para inyectar su ADN y que las bacterias usan para secretar proteínas. Los genes implicados en la formación de T6SS están agrupados y los que codifican para componentes estructurales del sistema presentan mayor grado de conservación entre rizobios y frente a otras bacterias en comparación a los genes que codifican para efectores y reguladores del sistema. En nuestro grupo se está estudiando el T6SS de Rhizobium etli bv mimosae Mim12 aislada de nódulos de Mimosa affinis y capaz de nodular además Phaseolus vulgaris y Leucaena leucocephala. La cepa Mim1 contiene una agrupación de 28 genes en el plásmido f no simbiótico, relacionados con la formación de un T6SS, presentando una organización similar a la descrita en Agrobacterium tumefaciens C583 que consiste en dos operones divergentes. Se ha descrito para varios microorganismos que cuando el T6SS está activo, las proteínas Hcp y VgrG que forman parte del aparato de secreción pueden detectarse en el medio extracelular3. Los genes que codifican proteínas estructurales en las dos bacterias presentan una gran similitud, así Hcp muestra un 94% de identidad entre ambas permitiendo que los anticuerpos que detectan Hcp de Agrobacterium3 también reaccionen con Hcp de Mim1. Utilizando anticuerpos contra Hcp de Agrobacterium se ha identificado esta proteína en el medio extracelular de cultivos de Mim1 en fase estacionaria y débilmente en fase exponencial. También se ha demostrado su presencia en nódulos de judía y en cultivos crecidos en presencia de exudados de L. leucocephala, P. vulgaris y Pisum sativum. Además, con el fin de conocer en qué condiciones se activa el T6SS de Mim1, se analizó una región de ADN presumiblemente promotora comprendida entre las dos agrupaciones de genes orientados de forma divergente de Mim1. Esta región se fusionó transcripcionalmente a un gen b-gal delator sin promotor del vector pMP220 en las dos posibles orientaciones, una de las orientaciones (P1) controlaría la expresión de genes como hcp y posibles efectores y la otra (P2) de otros genes estructurales. Los resultados mostraron que ambas orientaciones se expresaban a altas DO600 (0,8-1) aunque los valores de P1 fueron entre dos y tres veces superiores a los de P2. Sin embargo a bajas DO600 (0,1-0,2) la actividad de P1 ser redujo a la mitad y la de P2 a niveles del control sin promotor. Con el objetivo de conocer el papel del T6SS en simbiosis se han realizado 3 mutantes que afectan a genes estructurales del T6SS de Mim1, uno en el gen hcp, otro en tssM y el tercero es una deleción de todos los genes presumiblemente dependientes de P2. Se examinó el fenotipo producido en P. vulgaris y L. leucocephala y se observó que los tres mutantes produjeron nódulos blancos y plantas con un porte similar a plantas no inoculadas, con menor tamaño que las inoculadas con la cepa parental y con un color más amarillento. En este trabajo se ha mostrado por primera vez que la presencia de un T6SS en rizobios tiene un efecto beneficioso en la simbiosis con varios hospedadores. En estos momentos se esta trabajando en la caracterización de posibles efectores. Referencias. 1. Records AR. 2011 The type VI secretion system: a multipurpose delivery sustem with a phage-like machinery. Mol Plant Microbe Interact 24: 751-757. 2. Rogel MA et al. 2014. Genomic basis of symbiovar mimosae in Rhizobium etli. BMC Genomics 15: 575 3. Wu, HY et al. 2012. Acid-induced type VI secretion system is regulated by ExoR-ChvG/Chv

Characterization of type VI secretion systems (T6SS) of endosymbionts from mimosa or lupine

The T6SS is a nanosyringe that injects proteins into prokaryotic or eukaryotic cells, and it is encoded in the genomes of more than 25% of Gram-negative bacteria (1). We are studying the T6SS of Rhizobium etli Mim1 and Bradyrhizobium sp. LmicA16, symbionts of Phaseolus vulgaris/Leucaena leucocephala and Lupinus micranthus/Lupinus angustifolius/Spartium junceum, respectively. R. etli Mim1 contains a T6SS gene cluster organized in two divergent operons. When the T6SS is active, Hcp, a constituent of the secretory apparatus, can be detected in the extracellular medium (2). Hcp has been immunologically detected in the supernatant of Mim1 cultures. This protein was also detected in bean nodule extracts and in cultures grown in the presence of different legumes exudates. The putative divergent promoters located between the two T6SS gene clusters were analysed by ?- gal fusions. The results showed high levels of expression of the two promoters at high OD and low values at lower ODs. Mutants affected in structural genes induced white nodules with P. vulgaris and L. leucocephala. On the other hand, mutagenesis of T6SS structural genes from LmicA16 strain produced different symbiotic phenotypes. An LmicA16 tssC mutant showed reduced levels of nitrogen fixation on L. micranthus, whereas the same mutant induced the formation of few white, non-fixing nodules on L. angustifolius and S. junceum. (1) Ho et al. (2013) Cell Host Microbe 15:9-21. (2) Wu et al. (2012) PLoS Pathog. 8:1-18 Funded by grants BIO2013-43040-P (MINECO), CGL2011-26932 (MICINN) and AL16-PID-06 (UPM)

U.K. climate projections: Summer daytime and nighttime urban heat island changes in England’s major cities

In the United Kingdom, where 90% of residents are projected to live in urban areas by 2050, projecting changes in urban heat islands (UHIs) is essential to municipal adaptation. Increased summer temperatures are linked to increased mortality. Using the new regional U.K. Climate Projections, UKCP18-regional, we estimate the 1981–2079 trends in summer urban and rural near-surface air temperatures and in UHI intensities during day and at night in the 10 most populous built-up areas in England. Summer temperatures increase by 0.45°–0.81°C per decade under RCP8.5, depending on the time of day and location. Nighttime temperatures increase more in urban than rural areas, enhancing the nighttime UHI by 0.01°–0.05°C per decade in all cities. When these upward UHI signals emerge from 2008–18 variability, positive summer nighttime UHI intensities of up to 1.8°C are projected in most cities. However, we can prevent most of these upward nighttime UHI signals from emerging by stabilizing climate to the Paris Agreement target of 2°C above preindustrial levels. In contrast, daytime UHI intensities decrease in nine cities, at rates between −0.004° and −0.05°C per decade, indicating a trend toward a reduced daytime UHI effect. These changes reflect different feedbacks over urban and rural areas and are specific to UKCP18-regional. Future research is important to better understand the drivers of these UHI intensity changes

Labour and social security law in Spain in 2015

El informe ha sido elaborado por la Sección Juvenil de la Asociación Española de Derecho del Trabajo y Seguridad SocialEste Informe deja constancia de los cambios normativos más relevantes y de las tendencias judiciales más paradigmáticas del ordenamiento laboral en 2015. En él se observa el imparable dinamismo del Derecho del Trabajo y de la Seguridad Social en España. El documento, consciente de tal mutabilidad, recoge una minuciosa selección de cuestiones esenciales, a juicio de las personas que abordan cada una de las materias, de las que son especialistas; los autores y las autoras, que forman parte de la Sección Juvenil de la Asociación Española de Derecho del Trabajo y de la Seguridad Social, se adscriben a los grupos temáticos por afinidad con sus principales líneas de investigación y su labor docente universitaria. En síntesis, en el Informe “El Derecho del Trabajo y de la Seguridad Social en España en 2015” se puede encontrar información muy útil para los profesionales del iuslaboralismo en materia de derechos fundamentales inespecíficos, contratación laboral y empleo, vicisitudes del contrato de trabajo, derechos colectivos, igualdad y corresponsabilidad, Seguridad Social o prevención de riesgos laborales.This report has as aim leaving a record of the most relevant normative changes and the most paradigmatic judicial trends in Labour Law in 2015. One can easily observe the unstoppable dynamismof Labour and Social Security Law in Spain. The document, conscious of that mutability, collects a thorough selection of key issues, according to the judgement of the authors, all of them specialists and all of them members of the Young Scholars’ Section of the Spanish Association for Labour and Social Security Law. They are part of thematic groups, linked to their main research lines and their teaching task. Summing up, in this report “Labour and Social Security Law in Spain in 2015”, one can easily find useful information for labour lawyers in subjects such as unspecific fundamental rights, work contracts and employment, issues of the labour relationship, collective rights, equality and co-responsibility, Social Security or occupational risk prevention

Proyecciones de cambio climático de alta resolución sobre la Penínula Ibérica mediante un modelo de mesoscala

Tesis Univ. Granada. Departamento de Física Aplicada. Leída el 7 de octubre de 201

Mechanisms for Extreme Precipitation Changes in a Tropical Archipelago

International audienceThe Maritime Continent is one of the most challenging regions for atmospheric models. Processes that modulate deep convection are poorly represented in models, which affects their ability to simulate precipitation features accurately. Thus, future projections of precipitation over the region are prone to large uncertainties. One of the key players in modeling tropical precipitation is the convective representation, and hence convection-permitting experiments have contributed to improve aspects of precipitation in models. This improvement creates opportunities to explore the physical processes that govern rainfall in the Maritime Continent, as well as their role in a warming climate. Here, we examine the response to climate change of models with explicit and parameterized convection and how that reflects in precipitation changes. We focus on the intensification of spatial contrasts as precursors of changes in mean and extreme precipitation in the tropical archipelago. Our results show that the broad picture is similar in both model setups, where islands will undergo an increase in mean and extreme precipitation in a warmer climate and the ocean will see less rain. However, the magnitude and spatial structure of such changes, as well as the projection of rainfall percentiles, are different across model experiments. We suggest that while the primary effect of climate change is thermodynamical and it is similarly reproduced by both model configurations, dynamical effects are represented quite differently in explicit and parameterized convection experiments. In this study, we link such differences to horizontal and vertical spatial contrasts and how convective representations translate them into precipitation changes

Numerical simulation "Numerical simulation of atmospheric Lamb waves generated by the 2022 Hunga-Tonga volcanic eruption"

Numerical simulation results for the atmospheric Lamb waves generated by the Hunga-Tonga volcano explosion on January 15th 2022.Peer reviewe