Hot bubbles of planetary nebulae with hydrogen-deficient winds - II. Analytical approximations with application to BD+30∘^\circ3639

The first high-resolution X-ray spectroscopy of the planetary nebula BD+30$^\circ$3639 allowed to study X-ray emitting "hot bubbles" (HBs) of planetary nebulae in unprecedented detail. We investigate (i) how diagnostic line ratios are affected by the HB thermal structure and chemical profile, (ii) if the HB chemical composition of BD+30$^\circ$3639 is consistent with the H-poor (H for hydrogen) composition of the stellar photosphere, and (iii) if H-rich nebular matter has been added to this HB by evaporation. We apply an analytical, 1D model for wind-blown HBs with temperature and density profiles based on self-similar solutions including thermal conduction. We construct heat-conduction HBs with chemical stratification. The X-ray emission is computed using the CHIANTI code. Our HB models are used to re-analyse the high-resolution X-ray spectrum of BD+30$^\circ$3639. Our models reproduce the observed line ratios much better than plasmas with single electron temperatures. All the temperature- and abundance-sensitive line ratios are consistent with BD+30$^\circ$3639 X-ray observations for (i) an intervening column density of neutral H, $N_{\rm H} = 0.20_{-0.10}^{+0.05}\times\!10^{22}\rm\ cm^{-2}$, (ii) a characteristic HB X-ray temperature of ${T_{\rm X} = 1.8\pm 0.1~ }$MK together with (iii) a very high neon mass fraction of about 0.05, virtually as high as that of oxygen. For lower values of $N_{\rm H}$, we cannot exclude that the HB of BD+30$^\circ$3639 contains a small amount of evaporated (or mixed) H-rich nebular matter. Given the possible range of $N_{\rm H}$, the fraction of evaporated H-rich matter cannot exceed 3% of the HB mass. The diffuse X-ray emission from BD+30$^\circ$3639 can well be explained by models of wind-blown HBs with thermal conduction and a chemical composition equal to that of the H-poor and carbon-, oxygen-, and neon-rich stellar surface.Comment: 24 pages, 19 figures (col and b/w), 4 tables, accepted for publication in A&A, Fig. 18 adapted to accepted versio

Modeling the diffuse X-ray emission of Planetary Nebulae with different chemical composition

Based on time-dependent radiation-hydrodynamics simulations of the evolution of Planetary Nebulae (PNe), we have carried out a systematic parameter study to address the non-trivial question of how the diffuse X-ray emission of PNe with closed central cavities is expected to depend on the evolutionary state of the nebula, the mass of the central star, and the metallicity of stellar wind and circumstellar matter. We have also investigated how the model predictions depend on the treatment of thermal conduction at the interface between the central `hot bubble' and the `cool' inner nebula, and compare the results with recent X-ray observations. Our study includes models whose properties resemble the extreme case of PNe with Wolf-Rayet type central stars. Indeed, such models are found to produce the highest X-ray luminosities.Comment: 5 pages, 2 figures, to appear in proceedings of the IAU Symposium 283: "Planetary Nebulae: An Eye to the Future", Eds.: A. Manchado, L. Stanghellini and D. Schoenberne

The match between climate services demands and Earth System Models supplies

Earth System Models (ESM) are key ingredients of many of the climate services that are currently being developed and delivered. However, ESMs have more applications than the provision of climate services, and similarly many climate services use more sources of information than ESMs. This discussion paper elaborates on dilemmas that are evident at the interface between ESMs and climate services, in particular: (a) purposes of the models versus service development, (b) gap between the spatial and temporal scales of the models versus the scales needed in applications, and (c) Tailoring climate model results to real-world applications. A continued and broad-minded dialogue between the ESM developers and climate services providers’ communities is needed to improve both the optimal use and direction of ESM development and climate service development. We put forward considerations to improve this dialogue between the communities developing ESMs and climate services, in order to increase the mutual benefit that enhanced understanding of prospects and limitations of ESMs and climate services will bring.This work and its contributors (B. van den Hurk, C. Hewitt, J. Bessembinder, F. Doblas-Reyes, R. Döscher) were funded by the Horizon 2020 Framework Programme of the European Union: Project ref. 689029 (Climateurope project). The co-author and editor of the journal states that she was not involved in the review process of the paper.Peer ReviewedPostprint (published version

Representing glaciers in a regional climate model

A glacier parameterization scheme has been developed and implemented into the regional climate model REMO. The new scheme interactively simulates the mass balance as well as changes of the areal extent of glaciers on a subgrid scale. The temporal evolution and the general magnitude of the simulated glacier mass balance in the European Alps are in good accordance with observations for the period 1958-1980, but the strong mass loss towards the end of the twentieth century is systematically underestimated. The simulated decrease of glacier area in the Alps between 1958 and 2003 ranges from −17.1 to −23.6%. The results indicate that observed glacier mass balances can be approximately reproduced within a regional climate model based on simplified concepts of glacier-climate interaction. However, realistic results can only be achieved by explicitly accounting for the subgrid variability of atmospheric parameters within a climate model grid bo

El pez grande se come al chico: las consecuencias electorales de gobernar en las CC.AA. y municipios españoles

El artículo trata de verificar si el hecho de gobernar es electoralmente rentable o si, por el contrario, desgasta a los partidos gobernantes. El universo de análisis son las CC. AA. y los principales municipios españoles desde la recuperación de la democracia hasta la actualidad. El trabajo tiene tres conclusiones principales. En primer lugar, gobernar no constituye claramente ni una ventaja ni un problema para el titular del ejecutivo, pero sí una oportunidad para darse a conocer, contribuyendo así a reforzar la idea que son los gobiernos quienes ganan o pierden las elecciones. La primera legislatura municipal y autonómica presenta un patrón mucho más claro, donde el gobierno sí constituyó una gran ventaja electoral para quienes lo detentaron, en un contexto donde todo estaba por hacer y donde las bases sociales de los partidos estaban en buena medida por definir. Pero quizás el resultado más claro es que en los gobiernos de coalición es donde mayores transferencias electorales se producen y éstas funcionan casi siempre en el mismo sentido: a favor del principal socio de gobierno y en detrimento de los socios menores. El artículo incluye un anexo final comentando las hipótesis discutidas a la luz de los resultados de las elecciones municipales y autonómicas de 1999.Peer reviewe

Charakterisierung von tumorspezifischen humoralen Immunantworten gegen den immaturen Lamininrezeptor bei Patienten mit chronischer lymphatischer Leukämie

Patienten mit einer CLL können stark variierende Krankheitsverläufe aufweisen. Es wurde der Frage nachgegangen, inwieweit eine Kontrolle der Tumorzellen durch das Immunsystem zu diesen variablen Überlebenszeiten beitragen könnte. Im Speziellen wurde die humorale Immunantwort gegen von CLL-Zellen selektiv exprimierte immature Lamininrezeptor (iLR) analysiert. Dabei wurden Seren von 67 CLL-Pat. im ELISA untersucht. In 29 von 67 (43,3 %) Seren von CLL-Pat. ließen sich AK vom Typ IgG und IgM nachweisen, während lediglich 4 von 50 gesunden Spendern anti-iLR-AK aufwiesen. FACS-Analysen, Inhibitions-ELISA sowie Immunoblot-Untersuchungen bestätigen die Spezifität dieser AK. Die IgG-Subklassen-Analyse zeigt eine von IgG1- und IgG3-vermittelte Immunantwort. Setzt man die anti-iLR-Immunantwort mit der Dauer des PFS in Korrelation, zeigt sich ein signifikant längeres PFS bei Pat. mit messbaren anti-iLR-Titern. Diese Arbeit zeigt erstmalig einen möglichen Zusammenhang zwischen den unterschiedlichen klinischen Verlaufsformen bei der CLL und einer humoralen Immunantwort gegen den iL-Rezeptor

Agricultural land use weakens the relationship between biodiversity and ecosystem functioning

Leaf litter decomposition is a significant ecosystem process for streams' energy provisioning, while species-specific decomposition rates often form a continuum from slow to fast decomposing species allowing for resources' availability to stream consumers over a longer time period after leaf fall. Leaf litter mixtures in streams typically comprise leaf species varying in their traits, allowing for litter diversity effects on decomposition. At the same time, agricultural land use, habitat characteristics, water quality and invertebrate composition modulate leaf litter decomposition. To identify leaf litter diversity effects and disentangle the roles of agricultural intensity, habitat characteristics, water quality and invertebrate composition for leaf litter processing in streams, we quantified leaf litter decomposition of three leaf species covering a gradient from slow to fast decomposing species, tested either individually or as a three-species mixture. The study was conducted over 21 days across 18 streams with a gradient of agricultural intensity (percent agricultural land use) in their catchments. We found leaf litter diversity effects in terms of complementarity under low to intermediate agricultural intensity, given that slow decomposing leaf species decomposed almost twice as fast in the three-species mixture compared to the observations on individual leaf species. This leaf litter diversity effect decreased with increasing agricultural intensity, suggesting that agriculture weakens the biodiversity-ecosystem functioning relationship. However, pathways by which agriculture affected decomposition differed between single-species and mixed-species scenarios. For the single-species scenario, negative effects of agriculture appeared to be mediated through effects on the proportion of sensitive detritivore species and altered habitat characteristics. For the mixed-species scenario, altered water quality negatively affected the proportion of sensitive detritivore species, in turn reducing the diversity effect on functioning. Our results suggest that the weakened biodiversity-ecosystem functioning relationship under increasing agricultural intensity might be a significant factor threatening carbon cycling and food web integrity in streams

Galectin-3 interacts with components of the nuclear ribonucleoprotein complex

Differentially spliced mRNAs following galectin‐3 depletion. (PDF 122 kb

Trafficking pathways of Cx49-GFP in living mammalian cells

In the present study we examined the trafficking pathways of connexin49 (Cx49) fused to green fluorescent protein (GFP) in polar and non-polar cell lines. The Cx49 gene was isolated from ovine lens by RT-PCR. Cx49 cDNA was fused to GFP and the hybrid cDNA was transfected into several cell lines. After transfection of Cx49-GFP cDNA into HeLa cells, it was shown using the double whole-cell patch-clamp technique that the expressed fusion protein was still able to form conducting gap junction channels. Synthesis, assembly, and turnover of the Cx49-GFP hybrid protein were investigated using a pulse-chase protocol. A major 78-kDa protein band corresponding to Cx49-GFP could be detected with a turnover of 16-20 h and a half-life time of 10 h. The trafficking pathways of Cx49-GFP were monitored by confocal laser microscopy. Fusion proteins were localized in subcellular compartments, including the endoplasmic reticulum (ER), the ER-Golgi intermediate compartment, the Golgi apparatus, and the trans-Golgi network, as well as vesicles traveling towards the plasma membrane. Time-dependent sequential localization of Cx49-GFP in the ER and then the Golgi apparatus supports the notion of a slow turnover of Cx49-GFP compared to other connexins analyzed so far. Gap junction plaques resembling the usual punctuate distribution pattern could be demonstrated for COS-1 and MDCK cells. Basolateral distribution of Cx49-GFP was observed in polar MDCK cells, indicating specific sorting behavior of Cx49 in polarized cells. Together, this report describes the first characterization of biosynthesis and trafficking of lens Cx49.Fritz Thyssen-Stiftun

Triggering and characterisation of realistic internal short circuits in lithium-ion pouch cells: a new approach using precise needle penetration

The internal short circuit (ISC) in lithium-ion batteries is a serious problem because it is probably the most common cause of a thermal runaway (TR) that still presents many open questions although it has been intensively investigated. Therefore this article focuses on the generation and characterisation of the local single-layer ISC, which is particularly relevant in practice application. A new, very promising method of precise needle penetration made it possible to generate the most safety-critical short-circuit type, the contact between the Al-Collector and the graphite active material of the anode reliable, demonstrated on a 10 Ah Graphite/NMC pouch cell. The special efforts in achieving high reproducibility as well as the detailed analysis of the initiated internal short-circuit conditions led to more reliable and meaningful results. A comprehensive approach to characterisation has been made by detailed measurement of the dynamic short-circuit evolution and a subsequent post-characterisation, which included the application of different electrochemical measurement techniques as well as a post-abuse analysis. It was shown that the cells demonstrated a very individual and difficult-to-predict behaviour, which is a major challenge for early failure detection and risk assessment of cells with an existing or former ISC. On the one hand, it is found that despite high local temperatures of over 1260 ◦C and significant damage to the cell-internal structure, the cell did not develop a TR even with further cycling. On the other hand, it was observed that the TR occurs spontaneously without any previous abnormalities. Based on the overall test results, it was shown that at the high state of charge (SOC = 100 %) even small, dynamically developing voltage drops must be classified as safety-critical for the cell. For reliable and early failure detection, the first voltage drops of the ISC must already be detected