Modified Korteweg-de Vries Hierachies in Multiple-Times Variables and the Solutions of Modified Boussinesq Equations

We study solitary-wave and kink-wave solutions of a modified Boussinesq equation through a multiple-time reductive perturbation method. We use appropriated modified Korteweg-de Vries hierarchies to eliminate secular producing terms in each order of the perturbative scheme. We show that the multiple-time variables needed to obtain a regular perturbative series are completely determined by the associated linear theory in the case of a solitary-wave solution, but requires the knowledge of each order of the perturbative series in the case of a kink-wave solution. These appropriate multiple-time variables allow us to show that the solitary-wave as well as the kink-wave solutions of the modified Botussinesq equation are actually respectively a solitary-wave and a kink-wave satisfying all the equations of suitable modified Korteweg-de Vries hierarchies.Comment: RevTex file, submitted to Proc. Roy. Soc. London

The Potassium abundance in the globular clusters NGC104, NGC6752 and NGC6809

We derived Potassium abundances in red giant branch stars in the Galactic globular clusters NGC104 (144 stars), NGC6752 (134 stars) and NGC6809 (151 stars) using high-resolution spectra collected with FLAMES at the ESO - Very Large Telescope. In the considered samples we do not find significant intrinsic spreads in [K/Fe] (confirming the previous findings by Carretta et al.), at variance with the cases of the massive clusters NGC2419 and NGC2808. Additionally, marginally significant [K/Fe]-[O/Fe] anti-correlations are found in NGC104 and NGC6809, and [K/Fe]-[Na/Fe] correlations are found in NGC104 and NGC6752. No evidence of [K/Fe]-[Mg/Fe] anti-correlation are found. The results of our analysis are consistent with a scenario in which the process leading to the multi-populations in globular clusters implies also enrichment in the K abundance, the amplitude of the associated [K/Fe] enhancement becoming measurable only in stars showing the most extreme effects of O and Mg depletion. Stars enhanced in [K/Fe] have been found so far only in clusters harbouring some Mg-poor stars, while the other globulars, without a Mg-poor sub-population, show small or null [K/Fe] spreads.Comment: 9 pages, 7 figures, 3 tables, accepted for publication in A&

Thermal rearrangements in the tetra-arylcyclopropene series

The literature provides many examples of thermal rearrangements of small-ring compounds to yield systems involving less bond-angle strain. In the arylcyclopropene series these involve, in many cases, fairly complex pathways, and only formalized mechanisms have been suggested

The Elements of the Neutrino Mass Matrix: Allowed Ranges and Implications of Texture Zeros

We study the range of the elements of the neutrino mass matrix m_nu in the charged lepton basis. Neutrino-less double beta decay is sensitive to the ee element of m_nu. We then analyze the phenomenological implications of single texture zeros. In particular, interesting predictions for the effective mass can be obtained, in the sense that typically only little cancellation due to the Majorana phases is expected. Some cases imply constraints on the atmospheric neutrino mixing angle.Comment: 21 pages, 7 figures. Minor corrections, matches version in PR

Reliability analysis of dynamic systems by translating temporal fault trees into Bayesian networks

Classical combinatorial fault trees can be used to assess combinations of failures but are unable to capture sequences of faults, which are important in complex dynamic systems. A number of proposed techniques extend fault tree analysis for dynamic systems. One of such technique, Pandora, introduces temporal gates to capture the sequencing of events and allows qualitative analysis of temporal fault trees. Pandora can be easily integrated in model-based design and analysis techniques. It is, therefore, useful to explore the possible avenues for quantitative analysis of Pandora temporal fault trees, and we identify Bayesian Networks as a possible framework for such analysis. We describe how Pandora fault trees can be translated to Bayesian Networks for dynamic dependability analysis and demonstrate the process on a simplified fuel system model. The conversion facilitates predictive reliability analysis of Pandora fault trees, but also opens the way for post-hoc diagnostic analysis of failures

Spectroscopic binaries among AGB stars from HERMES/Mercator: the case of V Hya

We report on our search for spectroscopic binaries among a sample of AGB stars. Observations were carried out in the framework of the monitoring of radial velocities of (candidate) binary stars performed at the Mercator 1.2m telescope, using the HERMES spectrograph. We found evidence for duplicity in UV Cam, TU Tau, BL Ori, VZ Per, T Dra, and V Hya. This short communication focus on V Hya, found to behave like RV Tau of the b subtype, which are binaries surrounded by a disc.Comment: Poster presented at IAU Symp. 343 "Why Galaxies Care About AGB Stars", Vienna, august 201

Selected Personality Constructs as Correlates of Personnel Appointment, Appraisal, and Mobility in Seventh-day Adventist Schools

Problem. Despite tentative postulations and explorations of the person/job interaction, the specific relationships between personality and occupational behavior are not clearly understood. In particular, the relationships between human temperament and various aspects of personnel administration in an educational setting are generally unknown. The purpose of this study was to profile the temperament traits of professional educators in the Seventh-day Adventist school system, grouped on the basis of occupationally relevant selection variables; and to investigate the role of personality as it relates to personnel appointment, appraisal, and mobility. Method. A demographic questionnaire and the Temperament Inventory were administered to 486 teachers, teacher/principals, principals, supervisors, and superintendents in nine local conference school systems of the Seventh-day Adventist Church. Phlegmatic, sanguine, choleric, and melancholy traits were profiled for selected subgroups and statistically compared using Cattell\u27s Coefficient of Pattern Similarity. Significant correlations were subjected to graphic comparisons as well. Results. Significant similarities and/or dissimilarities in personality emerged when profiles were contrasted on the bases of sex, professional position, perceived recruiter, preferred school size, rated competence, advancement status, and records of job stability. No significant results were observed when profiles were compared on the bases of geographic region, years of experience, assigned grade levels, assigned school size, and administrator/employee similarity. Conclusions. Analyses of the data prompted eighteen conclusions relative to the purpose for which the study was conducted. Each was generalized only to the population described for the study (i.e., K-10 Seventh-day Adventist educators of non-black conferences in North America). (1) Adventist educators collectively exhibit a choleric/phlegmatic personality. (2) Male and female educators collectively differ in personality. (3) The population is geographically and experientially heterogenous. (4) The population is highly mobile. (5) Teaching and non-teaching personnel differ significantly in personality. (6) Personality is significantly correlated with professional position. (7) No meaningful relationship exists between personality and years of experience. (8) No meaningful relationship exists between the personalities of educators and the personalities of the individuals responsible for hiring them. (9) The personalities of educators who strongly perceive that the Lord recruited them differ significantly from the personalities of individuals recruited by men. (10) No meaningful relationship exists between the personalities of teachers and the grade levels to which they are assigned. (11) No meaningful relationship exists between the personalities of educators and the size of school to which they are assigned. (12) The personalities of educators expressing a preference for one-teacher schools differ significantly from the personalities of educators preferring larger schools. (13) Demands for personnel in one-teacher schools clearly exceed the supply of teachers preferring such placement. (14) Personality is significantly correlated with levels of perceived competence. (15) No meaningful relationship exists between the personalities of educators judged most competent and the personalities of the supervisors passing judgment. (16) The personalities of female educators are significantly correlated with their opportunities for advancement. (17) No meaningful relationship exists between the personalities of educators selected for advancement and the personalities of administrators making the selections. (18) The personalities of highly stable educators differ significantly from the personalities of highly mobile educators

Structure of the closed Pol II transcription initiation complex and implications for promoter opening

Transcription is the first step of gene expression in all living cells. Regulatory mechanisms of transcription are fundamental for cell differentiation, organism development and adaption to environmental changes. One key event is transcription initiation. In eukaryotic cells RNA polymerase II (Pol II) transcribes messenger RNA and assembles with the general transcription factors (TF) -IIA, -IIB, -IID, -IIF, -IIE and -IIH on promoter DNA. DNA is opened and a 'transcription bubble' is formed that allows Pol II to synthesise a complementary copy of the genetic information. The molecular mechanisms of promoter assembly and opening remain poorly understood owing to the limited resolution of previous structural studies, the large size of the complex and the dynamics of the process. We report the cryo-electron microscopy structure of a closed transcription initiation complex containing Saccharomyces cerevisiae Pol II and the general transcription factors except TFIIH on double-stranded promoter DNA at 8.8 Angstrom resolution. Additionally, we show in a separate crystallographic study that the yeast-specific N-terminus of TFIIF subunit Tfg1 binds to the Pol II external 1 region. A high-resolution structure of the respective open complex at 3.6 Angstrom resolution containing a 15 nucleotide mismatch transcription bubble served for model building of the closed complex. The open complex structure reveals detailed information on the intricate interactions of the general transcription factors with each other, with Pol II and promoter DNA and it suggests a mechanism of DNA template strand loading into the Pol II active centre cleft. In the transition from closed to open complex formation we identify movements mainly in TFIIE. DNA opening occurs around the tip of the Pol II clamp and the TFIIE extended winged helix domain. In functional assays we show that the TFIIE extended winged helix domain and recruitment of TFIIE through its E-ribbon domain are important for transcription in vitro and in vivo. Moreover, we report that promoter opening can occur in the absence of the ATP-dependent factor TFIIH. Analysis of the closed complex data reveals that most of the particles (72 %) resemble the open complex structure and contain open promoter DNA. Based on our data we propose a general model how promoter opening can be achieved by the use of binding energy alone. Finally, our results underline the high structural conservation between the human and yeast transcription initiation systems