A Search for Gamma-ray Burst Subgroups in the SWIFT and RHESSI Databases

A sample of 286 gamma-ray bursts (GRBs) detected by the Swift satellite and 358 GRBs detected by the RHESSI satellite are studied statistically. Previously published articles, based on the BATSE GRB Catalog, claimed the existence of an intermediate subgroup of GRBs with respect to duration. We use the statistical chi^2 test and the F-test to compare the number of GRB subgroups in our databases with the earlier BATSE results. Similarly to the BATSE database, the short and long subgroups are well detected in the Swift and RHESSI data. However, contrary to the BATSE data, we have not found a statistically significant intermediate subgroup in either Swift or RHESSI data.Comment: Published in Proceedings of the 2008 Nanjing Gamma-ray Burst Conferenc

On the Expressiveness of TPTL and MTL over \omega-Data Words

Metric Temporal Logic (MTL) and Timed Propositional Temporal Logic (TPTL) are prominent extensions of Linear Temporal Logic to specify properties about data languages. In this paper, we consider the class of data languages of non-monotonic data words over the natural numbers. We prove that, in this setting, TPTL is strictly more expressive than MTL. To this end, we introduce Ehrenfeucht-Fraisse (EF) games for MTL. Using EF games for MTL, we also prove that the MTL definability decision problem ("Given a TPTL-formula, is the language defined by this formula definable in MTL?") is undecidable. We also define EF games for TPTL, and we show the effect of various syntactic restrictions on the expressiveness of MTL and TPTL.Comment: In Proceedings AFL 2014, arXiv:1405.527

Estrogen transactivates EGFR via the sphingosine 1-phosphate receptor Edg-3: the role of sphingosine kinase-1

The transactivation of enhanced growth factor receptor (EGFR) by G protein–coupled receptor (GPCR) ligands is recognized as an important signaling mechanism in the regulation of complex biological processes, such as cancer development. Estrogen (E2), which is a steroid hormone that is intimately implicated in breast cancer, has also been suggested to function via EGFR transactivation. In this study, we demonstrate that E2-induced EGFR transactivation in human breast cancer cells is driven via a novel signaling system controlled by the lipid kinase sphingosine kinase-1 (SphK1). We show that E2 stimulates SphK1 activation and the release of sphingosine 1-phosphate (S1P), by which E2 is capable of activating the S1P receptor Edg-3, resulting in the EGFR transactivation in a matrix metalloprotease–dependent manner. Thus, these findings reveal a key role for SphK1 in the coupling of the signals between three membrane-spanning events induced by E2, S1P, and EGF. They also suggest a new signal transduction model across three individual ligand-receptor systems, i.e., “criss-cross” transactivation

Development of International Educational Systems by Competence Networking based on Project Management

AbstractThe globalization demands new kinds of concepts and models to ensure the provision of skilled labor by international educational systems based on advanced competence networking. The success depends on the professional use of the latest project management theory, methodology, and practice. Multinational multi-projects fail and are aborted. A reason for that could be the deficiency of project readiness. The project management approach should be integrated into other management subsystems such as information, knowledge, competence, network management etc. One of the most important challenges is to ensure the communication and information transfer for competence balancing and sharing. A successful and efficient cooperation is only possible under equivalent partners. It creates the necessary trust. Beginning with the presentation of the need for cooperation and the exchange of knowledge for global and fair growth, the relationship between education, competence development and applied project management will be explained for educational transfer systems. Subsequently, the application of the approach will be illustrated by the planning, designing, implementing, and further developing of a large-scale Sino-German cooperation in higher education. The success of the project and the sustainability will be guaranteed. The roll-out to other network partners on a national and international scale is in progress

Quantum oscillations revealing topological band in kagome metal ScV6Sn6

Compounds with kagome lattice structure are known to exhibit Dirac cones, flat bands, and van Hove singularities, which host numerous versatile quantum phenomena. Inspired by these intriguing properties, we investigate the temperature and magnetic field dependent electrical transports along with the theoretical calculations of ScV6Sn6, a nonmagnetic charge density wave (CDW) compound. At low temperatures, the compound exhibits Shubnikov-de Haas quantum oscillations, which help to design the Fermi surface (FS) topology. This analysis reveals the existence of several small FSs in the Brillouin zone, combined with a large FS. Among them, the FS possessing Dirac band is a non-trivial and generates a non-zero Berry phase. In addition, the compound also shows the anomalous Hall-like behaviour up to the CDW with the CDW phase, ScV6Sn6 presents a unique material example of the versatile HfFe6Ge6 family and provides various promising opportunities to explore the series further.Comment: Published version, 19 Pages, 5 figures with supplementar

Kinetics, SOA yields, and chemical composition of seconaary organic aerosol from beta-caryophyllene ozonolysis with and without nitrogen oxides between 213 and 313 K

beta-caryophyllene (BCP) is one of the most important sesquiterpenes (SQTs) in the atmosphere, with a large potential contribution to secondary organic aerosol (SOA) formation mainly from reactions with ozone (O-3) and nitrate radicals (NO3). In this work, we study the temperature dependence of the kinetics of BCP ozonolysis, SOA yields, and SOA chemical composition in the dark and in the absence and presence of nitrogen oxides including nitrate radicals (NO3). We cover a temperature range of 213-313 K, representative of tropospheric conditions. The oxidized components in both gas and particle phases were characterized on a molecular level by a chemical ionization mass spectrometer equipped with a filter inlet for gases and aerosols using iodide as the reagent ion (FIGAERO-iodide-CIMS). The batch mode experiments were conducted in the 84.5 m(3) aluminium simulation chamber AIDA at the Karlsruhe Institute of Technology (KIT). In the absence of nitrogen oxides, the temperature-dependent rate coefficient of the endocyclic double bond in BCP reacting with ozone between 243-313 K is negatively correlated with temperature, corresponding to the following Arrhenius equation: k = (1.6 +/- 0.4) x 10(-15) x exp((559 +/- 97)/ T). The SOA yields increase from 16 +/- 5 % to 37 +/- 11 %, with temperatures decreasing from 313 to 243 K at a total organic particle mass of 10 mu g m(-3). The variation in the ozonolysis temperature leads to a substantial impact on the abundance of individual organic molecules. In the absence of nitrogen oxides, monomers C14-15H22-24O3-7 (37.4 %), dimers C28-30H44-48O5-9 (53.7 %), and timers C41_44H62_6609_11 (8.6 %) are abundant in the particle phase at 213 K. At 313 K, we observed more oxidized monomers (mainly C14-15H22-24O6-9, 67.5 %) and dimers (mainly C27-29H42-44O9-11, 27.6 %), including highly oxidized molecules (HOMs; C14H22O7,9C15H22O7,9C15H24O7,9), which can be formed via hydrogen shift mechanisms, but no significant timers. In the presence of nitrogen oxides, the organonitrate fraction increased from 3 % at 213 K to 12 % and 49 % at 243 and 313 K, respectively. Most of the organonitrates were monomers with Cis skeletons and only one nitrate group. More highly oxygenated organonitrates were observed at higher temperatures, with their signal-weighted O : C atomic ratio increasing from 0.41 to 0.51 from 213 to 313 K. New dimeric and timeric organic species without nitrogen atoms (C-20, C-35) were formed in the presence of nitrogen oxides at 298-313 K, indicating potential new reaction pathways. Overall, our results show that increasing temperatures lead to a relatively small decrease in the rate coefficient of the endocyclic double bond in BCP reacting with ozone but to a strong decrease in SOA yields. In contrast, the formation of HOMs and organonitrates increases significantly with temperature.Peer reviewe