179^{179}Ta(n, γ) cross-section measurement and the astrophysical origin of the 180^{180}Ta isotope

$^{180m}$Ta is nature\u27s rarest (quasi) stable isotope and its astrophysical origin is an open question. A possible production site of this isotope is the slow neutron capture process in asymptotic giant branch stars, where it can be produced via neutron capture reactions on unstable $^{179}$Ta. We report a new measurement of the $^{179}$Ta(n,γ) $^{180}$Ta cross section at thermal-neutron energies via the activation technique. Our results for the thermal and resonance-integral cross sections are 952±57 and 2013±148 b, respectively. The thermal cross section is in good agreement with the only previous measurement [Phys. Rev. C 60, 025802 (1999)], while the resonance integral is different by a factor of ≈1.7. While neutron energies in this work are smaller than the energies in a stellar environment, our results may lead to improvements in theoretical predictions of the stellar cross section

Enterprise 2.0: Research challenges and opportunities

© Springer International Publishing Switzerland 2015. Blending Web 2.0 technologies with enterprise information systems is setting up the stage for a new generation of information systems that will help enterprises open up new communication channels with their stakeholders. Contrary to traditional enterprises with top-down command flow and bottom-up feedback flow, the same flows in Enterprise 2.0 cross all levels and in all directions bringing people together in the development of creative and innovative ideas. The power of Web 2.0 technologies stems from their ability to capture real-world phenomena such as collaboration, competition, and partnership that can be converted into useful and structured information sources from which enterprises can draw information about markets’ trends, consumers’ habits, suppliers’ strategies, etc. This paper discusses the research efforts that our international research group has put into the topic of Enterprise 2.0 (aka Social Enterprise). In particular, our research group advocates that existing practices for managing enterprise information systems need to be re-visited in a way that permits to capture social relations that arise inside and outside the enterprise, to establish guidelines and techniques to assist IT practitioners integrate social relations into their design, development, and maintenance efforts of these information systems, and last but not least to identify and tackle challenges that prevent capturing social relations

A characteristics framework for Semantic Information Systems Standards

Semantic Information Systems (IS) Standards play a critical role in the development of the networked economy. While their importance is undoubted by all stakeholders—such as businesses, policy makers, researchers, developers—the current state of research leaves a number of questions unaddressed. Terminological confusion exists around the notions of “business semantics”, “business-to-business interoperability”, and “interoperability standards” amongst others. And, moreover, a comprehensive understanding about the characteristics of Semantic IS Standards is missing. The paper addresses this gap in literature by developing a characteristics framework for Semantic IS Standards. Two case studies are used to check the applicability of the framework in a “real-life” context. The framework lays the foundation for future research in an important field of the IS discipline and supports practitioners in their efforts to analyze, compare, and evaluate Semantic IS Standard

Quick Ultra-VIolet Kilonova surveyor (QUVIK)

We present a near-UV space telescope on a ~70kg micro-satellite with a moderately fast repointing capability and a near real-time alert communication system that has been proposed in response to a call for an ambitious Czech national mission. The mission, which has recently been approved for Phase 0, A, and B1 study shall measure the brightness evolution of kilonovae, resulting from mergers of neutron stars in the near-UV band and thus it shall distinguish between different explosion scenarios. Between the observations of transient sources, the satellite shall perform observations of other targets of interest, a large part of which will be chosen in open competition.Comment: SPIE Astronomical Telescopes and Instrumentatio

Homocysteinylated Albumin Promotes Increased Monocyte-Endothelial Cell Adhesion and Up-Regulation of MCP1, Hsp60 and ADAM17

RATIONALE:The cardiovascular risk factor homocysteine is mainly bound to proteins in human plasma, and it has been hypothesized that homocysteinylated proteins are important mediators of the toxic effects of hyperhomocysteinemia. It has been recently demonstrated that homocysteinylated proteins are elevated in hemodialysis patients, a high cardiovascular risk population, and that homocysteinylated albumin shows altered properties. OBJECTIVE:Aim of this work was to investigate the effects of homocysteinylated albumin - the circulating form of this amino acid, utilized at the concentration present in uremia - on monocyte adhesion to a human endothelial cell culture monolayer and the relevant molecular changes induced at both cell levels. METHODS AND RESULTS:Treated endothelial cells showed a significant increase in monocyte adhesion. Endothelial cells showed after treatment a significant, specific and time-dependent increase in ICAM1 and VCAM1. Expression profiling and real time PCR, as well as protein analysis, showed an increase in the expression of genes encoding for chemokines/cytokines regulating the adhesion process and mediators of vascular remodeling (ADAM17, MCP1, and Hsp60). The mature form of ADAM17 was also increased as well as Tnf-α released in the cell medium. At monocyte level, treatment induced up-regulation of ICAM1, MCP1 and its receptor CCR2. CONCLUSIONS:Treatment with homocysteinylated albumin specifically increases monocyte adhesion to endothelial cells through up-regulation of effectors involved in vascular remodeling

Labeled EF-Tus for rapid kinetic studies of pretranslocation complex formation

The universally conserved translation elongation factor EF-Tu delivers aminoacyl(aa)-tRNA in the form of an aa-tRNA·EF-Tu·GTP ternary complex (TC) to the ribosome where it binds to the cognate mRNA codon within the ribosomal A-site, leading to formation of a pretranslocation (PRE) complex. Here we describe preparation of QSY9 and Cy5 derivatives of the variant E348C-EF-Tu that are functional in translation elongation. Together with fluorophore derivatives of aa-tRNA and of ribosomal protein L11, located within the GTPase associated center (GAC), these labeled EF-Tus allow development of two new FRET assays that permit the dynamics of distance changes between EF-Tu and both L11 (Tu-L11 assay) and aa-tRNA (Tu-tRNA assay) to be determined during the decoding process. We use these assays to examine: (i) the relative rates of EF-Tu movement away from the GAC and from aa-tRNA during decoding, (ii) the effects of the misreading-inducing antibiotics streptomycin and paromomycin on tRNA selection at the A-site, and (iii) how strengthening the binding of aa-tRNA to EF-Tu affects the rate of EF-Tu movement away from L11 on the ribosome. These FRET assays have the potential to be adapted for high throughput screening of ribosomal antibiotics

Pleiotropic Roles of a Ribosomal Protein in Dictyostelium discoideum

The cell cycle phase at starvation influences post-starvation differentiation and morphogenesis in Dictyostelium discoideum. We found that when expressed in Saccharomyces cerevisiae, a D. discoideum cDNA that encodes the ribosomal protein S4 (DdS4) rescues mutations in the cell cycle genes cdc24, cdc42 and bem1. The products of these genes affect morphogenesis in yeast via a coordinated moulding of the cytoskeleton during bud site selection. D. discoideum cells that over- or under-expressed DdS4 did not show detectable changes in protein synthesis but displayed similar developmental aberrations whose intensity was graded with the extent of over- or under-expression. This suggested that DdS4 might influence morphogenesis via a stoichiometric effect – specifically, by taking part in a multimeric complex similar to the one involving Cdc24p, Cdc42p and Bem1p in yeast. In support of the hypothesis, the S. cerevisiae proteins Cdc24p, Cdc42p and Bem1p as well as their D. discoideum cognates could be co-precipitated with antibodies to DdS4. Computational analysis and mutational studies explained these findings: a C-terminal domain of DdS4 is the functional equivalent of an SH3 domain in the yeast scaffold protein Bem1p that is central to constructing the bud site selection complex. Thus in addition to being part of the ribosome, DdS4 has a second function, also as part of a multi-protein complex. We speculate that the existence of the second role can act as a safeguard against perturbations to ribosome function caused by spontaneous variations in DdS4 levels

Some features of the south-west monsoon rainfall of Cochin and Minicoy

Several characteristics of (he south-west monsoon rainfall of the low latitude stations of Cochin (coastal) and Minicoy (island) have been studied using the hyetograms of these stations for the ten year period 1973-1982. Both stations exhibit diurnal variations of rainfall with maximum activity in the post-midnight hours and minimum in the afternoon hours. The amplitude of the diurnal variation increases for rain events of increasing intensities. The integrated duration of the seasonal rainfall is about 250 h at Cochin and 110 h al Minicoy. Half the total rain from heavy falls is received in a fifth of the total duration; half the total duration accounts for only a fifth of the total rain from light falls.The association between cumulative percentage rainfall (x) and cumulative percentage rain duration (y) is found to be of the form x = ay exp (byc) where a, b and c are empirical constants. The average rain intensity varies from about I mm/h to 25 mm/h along this rainfall curve. An equation of the same form also gives a satisfactory representation of the variation of cumulative percentages of rain amount/rain-duration/rain hours with rain events of increasing amounts