Generation of Large-Scale Vorticity in a Homogeneous Turbulence with a Mean Velocity Shear

An effect of a mean velocity shear on a turbulence and on the effective force which is determined by the gradient of Reynolds stresses is studied. Generation of a mean vorticity in a homogeneous incompressible turbulent flow with an imposed mean velocity shear due to an excitation of a large-scale instability is found. The instability is caused by a combined effect of the large-scale shear motions (''skew-induced" deflection of equilibrium mean vorticity) and ''Reynolds stress-induced" generation of perturbations of mean vorticity. Spatial characteristics, such as the minimum size of the growing perturbations and the size of perturbations with the maximum growth rate, are determined. This instability and the dynamics of the mean vorticity are associated with the Prandtl's turbulent secondary flows. This instability is similar to the mean-field magnetic dynamo instability. Astrophysical applications of the obtained results are discussed.Comment: 8 pages, 3 figures, REVTEX4, submitted to Phys. Rev.

Atmospheric Heating and Wind Acceleration: Results for Cool Evolved Stars based on Proposed Processes

A chromosphere is a universal attribute of stars of spectral type later than ~F5. Evolved (K and M) giants and supergiants (including the zeta Aurigae binaries) show extended and highly turbulent chromospheres, which develop into slow massive winds. The associated continuous mass loss has a significant impact on stellar evolution, and thence on the chemical evolution of galaxies. Yet despite the fundamental importance of those winds in astrophysics, the question of their origin(s) remains unsolved. What sources heat a chromosphere? What is the role of the chromosphere in the formation of stellar winds? This chapter provides a review of the observational requirements and theoretical approaches for modeling chromospheric heating and the acceleration of winds in single cool, evolved stars and in eclipsing binary stars, including physical models that have recently been proposed. It describes the successes that have been achieved so far by invoking acoustic and MHD waves to provide a physical description of plasma heating and wind acceleration, and discusses the challenges that still remain.Comment: 46 pages, 9 figures, 1 table; modified and unedited manuscript; accepted version to appear in: Giants of Eclipse, eds. E. Griffin and T. Ake (Berlin: Springer

Geological controls on the geometry of incised-valley fills: Insights from a global dataset of late-Quaternary examples

Incised valleys that develop due to relative sea-level change are common features of continental shelves and coastal plains. Assessment of the factors that control the geometry of incised-valley fills has hitherto largely relied on conceptual, experimental or numerical models, else has been grounded on case studies of individual depositional systems. Here, a database-driven statistical analysis of 151 late-Quaternary incised-valley fills has been performed, the aim being to investigate the geological controls on their geometry. Results of this analysis have been interpreted with consideration of the role of different processes in determining the geometry of incised-valley fills through their effect on the degree and rate of river incision, and on river size and mobility. The studied incised-valley fills developed along active margins are thicker and wider, on average, than those along passive margins, suggesting that tectonic setting exerts a control on the geometry of incised-valley fills, likely through effects on relative sea-level change and river behaviour, and in relation to distinct characteristics of basin physiography, water discharge and modes of sediment delivery. Valley-fill geometry is positively correlated with the associated drainage-basin size, confirming the dominant role of water discharge. Climate is also inferred to exert a potential control on valley-fill dimensions, possibly through modulations of temperature, peak precipitation, vegetation and permafrost, which would in turn affect water discharge, rates of sediment supply and valley-margin stability. Shelves with slope breaks that are currently deeper than 120 m contain incised-valley fills that are thicker and wider, on average, than those hosted on shelves with breaks shallower than 120 m. No correlation exists between valley-fill thickness and present-day coastal-prism convexity, which is measured as the difference in gradient between lower coastal plains and inner shelves. These findings challenge some concepts embedded in sequence stratigraphic thinking, and have significant implications for analysis and improved understanding of source-to-sink sediment route-ways, and for attempting predictions of the occurrence and characteristics of hydrocarbon reservoirs

β-decay of odd-A Ti57 and V59

The β-decay of odd-A, neutron-rich Ti57 and V59 are studied. More precise β-decay half-lives of 98±5 and 97±2 ms are deduced for Ti57 and V59, respectively. In addition, β-delayed γ-ray spectroscopy is used to deduce β-decay branching ratios and establish the low-energy-level structures of the daughter nuclides. The new data for levels in V57 and Cr59 are compared with the results of shell-model calculations completed in the full pf model space. Both V57 and Cr59 show evidence of modest oblate deformation near the ground state

An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

Beta-delayed γ-ray studies of φf7/2 - νpf shell nuclei

We have utilized the selective process of β decay to populate low-energy excited states in the neutron-rich 22Ti, 23V, 24Cr, and 25Mn nuclei. The goal was to systematically track the monopole shift of the νf5/2 single-particle level with increased occupancy of the φf7/2 orbital.The β-decay properties of the parent nuclides, along with the low-energy structure of the daughters, are presented and compared with the results of shell model calculations employing the GXPF1 interaction

Creating the cultures of the future: cultural strategy, policy and institutions in Gramsci. Part one: Gramsci and cultural policy studies: some methodological reflections

Gramsci’s writings have rarely been discussed and used systematically by scholars in cultural policy studies, despite the fact that in cultural studies, from which the field emerged, Gramsci has been a major source of theoretical concepts. Cultural policy studies were, in fact, theorised as an anti-Gramscian project between the late 1980s and the early 1990s, when a group of scholars based in Australia advocated a major political and theoretical reorientation of cultural studies away from hegemony theory and radical politicisation, and towards reformist-technocratic engagement with the policy concerns of contemporary government and business. Their criticism of the ‘Gramscian tradition’ as inadequate for the study of cultural policy and institutions has remained largely unexamined in any detail for almost twenty years and seems to have had a significant role in the subsequent neglect of Gramsci’s contribution in this area of study. This essay, consisting of three parts, is an attempt to challenge such criticism and to provide an analysis of Gramsci’s writings, with the aim of proposing a more systematic contribution of his work to the theoretical development of cultural policy studies. In Part One, I question the use of the notion of ‘Gramscian tradition’ made by its critics and challenge the claim that it was inadequate for the study of cultural policy and institutions. In parts Two and Three, I consider Gramsci’s specific writings on questions of cultural strategy, policy and institutions, which have so far been overlooked by scholars, arguing that they provide further analytical insights to those offered by his more general concepts. More specifically, in Part Two, I consider Gramsci’s pre-prison writings and political practice in relation to questions of cultural strategy and institutions. I argue that the analysis of these early texts, which were written in the years in which Gramsci was active in party organisation and leadership, is fundamental not only for understanding the nature of Gramsci’s early and continued involvement with questions of cultural strategy and institutions, but also as a key for deciphering and interpreting cultural policy themes that he later developed in the prison notebooks, and which originated in earlier debates. Finally, in Part Three, I carry out a detailed analysis of Gramsci’s prison notes on questions of cultural strategy, policy and institutions, which enrich the theoretical underpinnings for critical frameworks of analysis as well as for radical practices of cultural strategy, cultural policy-making and cultural organisation. I then answer the question of whether Gramsci’s insights amount to a theory of cultural policy

Effect of Ficus hispida L. on normal and dexamethasone suppressed wound healing

Ethanolic extract of roots of Ficus hispida was investigated in normal and dexamethasone depressed healing conditions, using incision, excision and dead space wound models in albino rats. The root extract of Ficus hispida has shown the maximum breaking strength compared to control group. The rate of epithelialization and wound contraction in excision model was better as compared to control groups. There was significant increase in granulation tissue weight and hydroxyproline content in dead space model compared to control group. The antihealing effect of dexamethasone was also reverted by the administration of ethanolic extract of Ficus hispida in all the wound models .The results indicated that the root extract of Ficus hispida has a significant wound healing activity and also promotes healing in dexamethasone depressed healing conditions.O extrato etanólico de raízes de Ficus hispida foi ensaiado em ratos albinos normais e em condições de cicatrização deprimida por dexametasona, utilizando modelos de ferida por incisão, excisão e de espaço morto. O extrato da raiz de Ficus hispida mostrou a força máxima de tensão comparativamente ao grupo controle. A velocidade de epitelização e de contração da ferida no modelo de excisão foi melhor do que a dos grupos controles. Houve aumento significativo no peso do tecido de granulação e no conteúdo de hidroxiprolina no modelo de espaço morto comparativamente ao grupo controle. O efeito anticicatrizante da dexametasona foi, também, revertido pela administração do extrato etanólico de Ficus hispida em todos os modelos de feridas. Os resultados indicaram que o extrato de Ficus hispida tem atividade cicatrizante em feridas e, também, promove a cicatrização em condições de depressão de cicatrização pela dexametasona