Ward Identities for the 2PI effective action in QED

We study the issue of symmetries and associated Ward-like identities in the context of two-particle-irreducible (2PI) functional techniques for abelian gauge theories. In the 2PI framework, the $n$-point proper vertices of the theory can be obtained in various different ways which, although equivalent in the exact theory, differ in general at finite approximation order. We derive generalized (2PI) Ward identities for these various $n$-point functions and show that such identities are exactly satisfied at any approximation order in 2PI QED. In particular, we show that 2PI-resummed vertex functions, i.e. field-derivatives of the so-called 2PI-resummed effective action, exactly satisfy standard Ward identities. We identify another set of $n$-point functions in the 2PI framework which exactly satisfy the standard Ward identities at any approximation order. These are obtained as field-derivatives of the two-point function \bcG^{-1}[\phi], which defines the extremum of the 2PI effective action. We point out that the latter is not constrained by the underlying symmetry. As a consequence, the well-known fact that the corresponding gauge-field polarization tensor is not transverse in momentum space for generic approximations does not constitute a violation of (2PI) Ward identities. More generally, our analysis demonstrates that approximation schemes based on 2PI functional techniques respect all the Ward identities associated with the underlying abelian gauge symmetry. Our results apply to arbitrary linearly realized global symmetries as well.Comment: 33 pages, 2 figure

The District Energy-Efficient Retrofitting of Torrelago (Laguna de Duero – Spain)

The urban growth is estimated to reach up the 66 % by 2050 and consequently the need of resources within the cities will increase significantly. This, combined with the 40 % of energy consumption and 36 % of CO2 emissions of the building sector, makes necessary to accelerate the transition towards more sustainable cities. The CITyFiED project contributes to this transition, aiming to develop an innovative and holistic methodological approach for energy-efficient district renovation and deliver three large scale demonstration cases in the cities of Lund (Sweden), Laguna de Duero (Spain) and Soma (Turkey). CITyFiED methodology consists of several phases that ease the decision-making tasks towards the district renovation, considering the energy efficiency as the main pillar and local authorities as clients. For the case of Torrelago district (Spain) the intervention consists of a set of energy conservative measures including the facąde retrofitting of 143.025 m2 of living space in 31 twelve-storey buildings; the renovation of the district heating network with a new biomass thermal plant; the integration of renewable energy sources, including a micro-cogeneration system, and the installation of individual smart meters. After the renovation action, one-year monitoring campaign is ongoing. The CITyFiED monitoring platform will collect information from the energy systems and deliver environmental, technical, economic and social key performance indicators by March 2019. At the end of the project the achievement of the predefined goals will be verified: Up to 36 % of energy saving and 3,429 tons-CO2/yr emissions saving covering the 59,4 % of the energy consumption with renewable sources.The research and results presented in this paper evolve from activities related to the CITyFiED project, which has received funding from the European Commission under the Grant Agreement no. 609129. This article is the result of cooperative research work of many experts from various countries and we would like to gratefully acknowledge the rest of the CITyFiED partners

2PI Effective Action and Evolution Equations of N = 4 super Yang-Mills

We employ nPI effective action techniques to study N = 4 super Yang-Mills, and write down the 2PI effective action of the theory. We also supply the evolution equations of two-point correlators within the theory.Comment: 16 pages, 6 figures. Figure 2 replaced, approximation scheme clarified, references adde

The role of noise and dissipation in the hadronization of the quark-gluon plasma

We discuss the role of noise and dissipation in the explosive spinodal decomposition scenario of hadron production during the chiral transition after a high-energy heavy ion collision. We use a Langevin description inspired by nonequilibrium field theory to perform real-time lattice simulations of the behavior of the chiral fields. Preliminary results for the interplay between additive and multiplicative noise terms, as well as for non-Markovian corrections, are also presented.Comment: 8 pages, invited talk at the Workshop on Quark Gluon Plasma Thermalization, Vienna, August 10-12, 200

Phosphorylation of a Myosin Motor by TgCDPK3 Facilitates Rapid Initiation of Motility during Toxoplasma gondii egress

Members of the family of calcium dependent protein kinases (CDPK's) are abundant in certain pathogenic parasites and absent in mammalian cells making them strong drug target candidates. In the obligate intracellular parasite Toxoplasma gondii TgCDPK3 is important for calcium dependent egress from the host cell. Nonetheless, the specific substrate through which TgCDPK3 exerts its function during egress remains unknown. To close this knowledge gap we applied the proximity-based protein interaction trap BioID and identified 13 proteins that are either near neighbors or direct interactors of TgCDPK3. Among these was Myosin A (TgMyoA), the unconventional motor protein greatly responsible for driving the gliding motility of this parasite, and whose phosphorylation at serine 21 by an unknown kinase was previously shown to be important for motility and egress. Through a non-biased peptide array approach we determined that TgCDPK3 can specifically phosphorylate serines 21 and 743 of TgMyoA in vitro. Complementation of the TgmyoA null mutant, which exhibits a delay in egress, with TgMyoA in which either S21 or S743 is mutated to alanine failed to rescue the egress defect. Similarly, phosphomimetic mutations in the motor protein overcome the need for TgCDPK3. Moreover, extracellular Tgcdpk3 mutant parasites have motility defects that are complemented by expression of S21+S743 phosphomimetic of TgMyoA. Thus, our studies establish that phosphorylation of TgMyoA by TgCDPK3 is responsible for initiation of motility and parasite egress from the host-cell and provides mechanistic insight into how this unique kinase regulates the lytic cycle of Toxoplasma gondii

El rol de las investigadoras en el sector de la construcción

Equal participation of women and men in industrial research is still a major challenge for the European Union. In most European countries, female graduates proportionately outnumber male graduates. However, scientific research and technological development remain male-dominated, especially in industry. Construction is one of the most important industrial sectors in terms of economic growth and employmet, but very little is known about the role of women in construction research and the factors that are hindering a more equal presence of women and men. As result of an extensive field work undertaken at European level, this paper offers a picture of the current situation of women in construction research that shows evidences of important inequalities. This work has allowed the development of recommendations for empowering women in construction research, addressing the opportunities for moving towards gender equality in this field. To invest in human capital for research is seen as an outstanding necessity within construction sector, and both women and men should fully develop their potential.La participación equitativa de mujeres y hombres en la investigación científica y el desarrollo tecnológico (I+D) es todavía un desafío por alcanzar en la Unión Europea. Las mujeres europeas siguen estando infra-representadas en este espacio, especialmente en los sectores industriales, a pesar de que en la mayoría de los países miembros la proporción de graduadas excede a la de graduados varones. Esta comunicación presenta cómo es la situación de las investigadoras en el sector de la construcción en Europa, centrando la atención en el papel que juegan en la I+D de este sector, su influencia, perspectivas de futuro, retos y oportunidades. Se presentan los principales resultados soportados por un extensivo trabajo de campo cofinanciado por la Comisión Europea, que muestran una situación de importante desigualdad. Este trabajo ha originado la propuesta de un conjunto de recomendaciones dirigidas a fortalecer la presencia femenina en el ámbito de la I+D en la construcción, e impulsar medios específicos que favorezcan la inhibición de las dificultades que encuentran las mujeres en su profesión científica. Más que nunca, en estos momentos de recesión económica, será necesario invertir en capital humano para la I+D, permitiendo que tanto las mujeres como los hombres puedan desplegar plenamente su potencial

Age-length keys availability for Atlantic bluefin tuna captured in the eastern management area

This paper analyzes the available direct ageing information in the last decade from Atlantic bluefin tuna caught in the eastern management area. To investigate differences among ALKs, a standard Von Bertalanffy growth function (VB) was fit to length at age data for each stratum. A deficient convergence of VB fitting to the asymptotic length due to the scarcity of old specimens was found for all available ALKs. After these analyses some records were identified as outliers (reading methodological issues) and removed from the data base.En prensa0,000

2PI effective action for gauge theories: Renormalization

We discuss the application of two-particle-irreducible (2PI) functional techniques to gauge theories, focusing on the issue of non-perturbative renormalization. In particular, we show how to renormalize the photon and fermion propagators of QED obtained from a systematic loop expansion of the 2PI effective action. At any finite order, this implies introducing new counterterms as compared to the usual ones in perturbation theory. We show that these new counterterms are consistent with the 2PI Ward identities and are systematically of higher order than the approximation order, which guarantees the convergence of the approximation scheme. Our analysis can be applied to any theory with linearly realized gauge symmetry. This is for instance the case of QCD quantized in the background field gauge.Comment: 21 pages, 8 figures. Uses JHEP3.cl

Estimating albacore movement rates between the North Atlantic and the Mediterraneal from conventional tagging data

A tag attrition model is fit to albacore tag-recapture data in order to estimate albacore movement rates between the Atlantic and the Mediterranean. The estimated transfer rate from the Atlantic to the Mediterranean is not significantly different from zero, and the estimated annual transfer rate in the opposite direction, under the assumptions of the same catchability and reporting rates is 5,49%. Sensitivity tests to assumed reporting rates and relative catchabilities are performed, and observed lower recovery rates in the Mediterranean may suggest either a lower catchability or reporting rate in this area, that would give an even lower estimate of the transfer rate, which is also supported by information from later tag recaptures of fish tagged in the Mediterranean. The small impact of these transfer rates on stock assessment is discussed and a preliminary assessment of the amount of tagged fish needed in order to get accurate and precise estimates of these low transfer rates is also done by simulating different tagging scenarios.Un modèle de déperdition des marques est ajusté aux données de marquage-recapture du germon afin d’estimer les taux de déplacement du germon entre l’Atlantique et la Méditerranée. Le taux de transfert estimé de l’Atlantique à la Méditerranée n’est pas sensiblement différent de zéro, et le taux de transfert annuel estimé dans la direction opposée, en prenant comme postulat une capturabilité et des taux de soumission de données identiques, s’élève à 5,49%. On a réalisé des tests de sensibilité aux taux de soumission de données supposés et à la capturabilité relative. Les taux de récupération inférieurs observés en Méditerranée suggèrent éventuellement une capturabilité ou un taux de soumission de données plus faible dans cette zone, ce qui donnerait une estimation encore plus faible du taux de transfert. Cela est également appuyé par des informations provenant de récupérations tardives de marques de poissons marqués en Méditerranée. Le faible impact de ces taux de transfert sur l’évaluation du stock est discuté et une évaluation préliminaire du volume de poissons marqués nécessaire pour obtenir des estimations exactes et précises de ces faibles taux de transfert est également réalisée en simulant différents scénarios de marquage.Se ajusta un modelo de tasa de pérdida de marcas a los datos de marcado-recuperación de atún blanco con el fin de estimar las tasas de movimiento del atún blanco entre el Atlántico y el Mediterráneo. La tasa de transferencia estimada del Atlántico al Mediterráneo no se diferencia significativamente de cero, y la tasa de transferencia anual estimada en la dirección opuesta, bajo el supuesto de la misma tasa de capturabilidad y comunicación, es de 5,49%. Se realizaron pruebas de sensibilidad de las tasas de comunicación y capturabilidades relativas supuestas, y las tasas de recuperación inferiores observadas en el Mediterráneo pueden sugerir una tasa de capturabilidad o de comunicación más baja en esta zona, lo que proporcionaría una estimación aún más baja de transferencia, que se ve sustentada por la información de recuperaciones de marcas posteriores de peces marcados en el Mediterráneo. Se discute el bajo impacto de estas tasas de transferencia en la evaluación del stock y también se realiza una evaluación preliminar de la cantidad de peces marcados necesarios para obtener estimaciones precisas y exactas de estas bajas tasas de trasferencia mediante una simulación de diferentes escenarios de marcado