Alternative pre-mRNA splicing patterns can change an extracellular stimulus, but the signaling pathways leading to these changes are still poorly characterized. Here, we describe a ...tyrosine-phosphorylated nuclear protein, YT521-B, and show that it interacts with the nuclear transcriptosomal component scaffold attachment factor B, and the 68-kDa Src substrate associated during mitosis, Sam68. Northern blot analysis demonstrated ubiquitous expression, but detailed RNA in situ analysis revealed cell type specificity in the brain. YT521-B protein is localized in the nucleoplasm and concentrated in 5-20 large nuclear dots. Deletion analysis demonstrated that the formation of these dots depends on the presence of the amino-terminal glutamic acid-rich domain and the carboxyl-terminal glutamic acid/arginine-rich region. We show that the latter comprises an important protein-protein interaction domain. The Src family kinase p59(fyn)-mediated tyrosine phosphorylation of Sam68 negatively regulates its association with YT521-B, and overexpression of p59(fyn) dissolves nuclear dots containing YT521-B. In vivo splicing assays demonstrated that YT521-B modulates alternative splice site selection in a concentration-dependent manner. Together, our data indicate that YT521-B and Sam68 may be part of a signal transduction pathway that influences splice site selection.
Measurements and model developments with the objective to improve the quality and resolution of estimations of anthropogenic emissions are described. Measurement results on a chassis dynamometer were ...used to determine VOC profiles for exhaust gas emissions of passenger cars for different vehicle and fuel types and different driving modes. Further measurements resulted in emission factors and VOC profiles for lignite burning in residential stoves. Using remote sensing techniques benzene emission factors of gas stations and the efficiency of gasoline vapour recovery systems were measured.To improve the quality and the spatial and temporal resolution of emission data, emission models were improved or modified. This was done by elaborating and applying new methods for important emission source categories (e.g., solvent use, road traffic, small combustion) as well as including new data sources in the calculation routines (e.g. emission statements, land use data, import/export indices of solvents). Simultaneously considerable progress was made improving temporal and spatial allocation functions and VOC profiles. With these improvements a large number of anthropogenic emission data sets for 14 different grid projections in Germany and Europe have been generated. An emission scenario for Germany for 2010 suggests that considering air quality directives from the EU and Germany which are in force or in pipeline, German emissions of VOC and NO^sub x^ will decrease, but still exceed the national emission ceilings of the EU-NEC directive.PUBLICATION ABSTRACT
A Database for Volatile Organic Compounds Mannschreck, K; Bächmann, K; Becker, K H ...
Journal of atmospheric chemistry,
05/2002, Volume:
42, Issue:
1
Journal Article
Peer reviewed
The database for volatile organic compounds (VOC data base) was created with the aim of providing an overview of tropospheric hydrocarbon measurements. The data base contains 202 substances, for ...which atmospheric and useful kinetic data such as rate coefficients, photolysis frequencies, mixing ratios, emission data and ozone formation potentials are compiled from available literature. The database file can be downloaded without charge from http://www.physchem.uni-wuppertal.de/voc-database. Registered users will be informed about the appearance of updates.
A novel assay was developed which allows measuring the activity of protein tyrosine phosphatases (PTPases) downregulating the signaling activity of the receptors for platelet-derived growth factor ...(PDGF) or epidermal growth factor (EGF) in intact Swiss 3T3 cells and nerve growth factor (TrkA) in TrkA-overexpressing PC12 cells. The assay is based on the inhibition of the receptor tyrosine kinases by specific inhibitors which enter the cells rapidly and do not affect the activity of PTPases. Thereafter, the decay of phosphotyrosine in the autophosphorylated receptors is monitored by immunoblotting with anti-phosphotyrosine antibodies. The dephosphorylation kinetics of EGF receptors and PDGF receptors in Swiss 3T3 cells as measured with this assay were found to be strikingly different. EGF receptors are almost completely dephosphorylated after 2 min at room temperature, whereas PDGF receptors are dephosphorylated only by 50% after 5 min. These data agree with previous findings about receptor dephosphorylation kinetics in isolated Swiss 3T3 cell membranes employing conventional dephosphorylation assays. The novel assay will facilitate characterization of the hitherto not identified receptor-directed PTPases for PDGF receptors, EGF receptors, and TrkA. The assay principle is general and should be applicable to any PTPases and their substrates, provided specific inhibitors for the respective kinases are available. Furthermore, it can be applied to screen for regulator molecules of specific PTPases in their physiological environment.
Anthropogenic and natural CO2 fluxes on land constitute substantial CO2 emissions and removals but are usually not well distinguished in national greenhouse gas reporting. Instead, countries ...frequently combine natural and indirect human-induced CO2 fluxes on managed land in their reports, which diminishes their usefulness for designing policies consistent with climate mitigation targets. Here, we separate natural and land-use-related CO2 fluxes from national reports in eight countries using global models to improve the assessment of attribution of terrestrial CO2 fluxes to direct anthropogenic activities. In most investigated countries, the gap between model-based and report-based CO2 flux estimates is reduced if natural and indirect human-induced CO2 fluxes on managed land are considered. Further examinations show that remaining differences are linked to country-specific discrepancies between model-based and report-based estimates. Separating natural and land-use-related CO2 fluxes at national scales supports a fair burden sharing of climate mitigation across countries and facilitates the assessment of land-based mitigation ambitions.
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•Land-use flux estimates from models and reports can be reconciled at country level•Gaps between land-use flux estimates are reduced in the USA, Russia, China, and Brazil•Remaining discrepancies due to country-specific differences in methods/definitions•The reconciliation allows us to reassess countries’ land-based mitigation ambitions
Accurate and consistent estimates of greenhouse gas emissions are essential for climate mitigation. Yet, recent work has shown that estimates of land-use-related CO2 fluxes from global models and from country reports to the United Nation Framework Convention on Climate Change (UNFCCC) differ because of methodological and definitional discrepancies. This leads to partial double counting of the natural CO2 uptake by soil and vegetation, causing an overestimation of the remaining carbon budget to limit global warming to 1.5°C or 2°C. An adjustment to reconcile model- and report-based estimates has been established recently, achieving consistent estimates at global level.
In our study, we apply and evaluate this approach at the country level. We show that the adjustment is generally successful at country level as well and identify potential reasons for remaining differences. Our analysis allows the reassessment of countries’ land-based mitigation targets and supports a fair burden-sharing across countries.
Estimates of land-use-related CO2 fluxes from global models and national reports to the UNFCCC can differ due to methodological and definitional discrepancies. Previous works established an adjustment to reconcile both estimates, achieving consistency at the global level. We apply this approach to eight countries in 2001–2015, evaluate the performance of the approach at the country level, and identify potential reasons for remaining differences. The result shows that more consistent estimates of land-use-related CO2 fluxes at the country-level can improve the assessment of national land-based mitigation ambitions.
The fluorescence detection of ultra high energy cosmic rays requires a detailed knowledge of the fluorescence light emission from nitrogen molecules over a wide range of atmospheric parameters, ...corresponding to altitudes typical of the cosmic ray shower development in the atmosphere. We have studied the temperature and humidity dependence of the fluorescence light spectrum excited by MeV electrons in air. Results for the 313.6, 337.1, 353.7 and 391.4
nm bands are reported in this paper. We found that the temperature and humidity dependence of the quenching process changes the fluorescence yield by a sizeable amount (up to 20% for the temperature dependence in the 391.4
nm band) and its effect must be included for a precise estimation of the energy of ultra high energy cosmic rays.
The knowledge of the fluorescence emission as a function of atmospheric parameters is essential for the detection of extensive air showers with the fluorescence technique. In this paper, we summarize ...AIRFLY published measurements of the pressure dependence of the fluorescence yield. The spectral distribution of the fluorescent light between 280 and 429
nm has been measured with high resolution. Relative intensities of 34 spectral lines have been determined. The pressure dependence of 25 lines was measured in terms of quenching reference pressures
p
λ
′
in air. This set of AIRFLY measurements yields the most comprehensive parametrization of the pressure dependence of the fluorescent spectrum.
An investigation of kinetics of the helix to coil dark reaction of light adapted poly(spiropyran-L-glutamic acid) (PSLG) dissolved in hexafluoroisopropanol was performed. The reaction was associated ...with the spiropyran (SP) to merocyanine (MC) ring opening. The ring opening reaction monitored with UV/VIS spectroscopy showed first order kinetics. Chromophore and polypeptide backbone circular dichroism data fit to an expression consistent with a single intermediate series mechanism. By FTIR, we monitored the polypeptide alpha-helix amide I, the MC chromophore--C = C--stretch and the protonated unmodified carboxylate C = O stretch bands. During the first step of the series mechanism, changes in the hydrogen bonding of the unmodified carboxylate groups occurred, suggesting breakup of polypeptide aggregates. The second step of the proposed series mechanism was dominated by the helix to coil transition and the ring opening of SP to MC. The CD spectrum of MC in the dark adapted PSLG was red shifted and had a narrower bandwidth than the UV/VIS spectrum. The kinetic and spectroscopic data suggested that a fraction (population I) of the MC chromophores experienced optical activity induced by the chiral polypeptide environment, while the remainder of the MC chromophores (population II) were solvated and enantiomeric.
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