17,588 research outputs found

    Massive low surface brightness galaxies

    Get PDF
    A multi-wavelength study of an extreme type of galaxy which will assist us in our attempts to understand the formation and evolution of galaxies was completed. In particular, a subset of low surface brightness (bar-mu(sub B) is approximately greater than 25 mag arcsec(sup -2)), giant galaxies (LSBG's) which contain large amounts of atomic gas (M(HI) is approximately greater than 10(exp 10) solar mass), have blue optical diameters similar to those of giant spiral galaxies, but which do not seem to have prodigious amounts of ongoing star formation were observed. Our sample was drawn from the first and second Palomar Sky Surveys. This population of galaxies has been largely ignored because of selection effects which make it difficult to detect optically. The question of how these massive systems differ from the higher surface brightness 'normal' spiral galaxies is addressed. Using B and R surface photometry, in conjunction with H-alpha, HI, CO-12, and far-infrared data, an attempt is made to determine if these galaxies had an early epoch of star formation that has since faded, have ongoing star formation with an unusual interplanetary magnetic field (IMF), or are perhaps galaxies which have never efficiently formed stars due to a lack of molecular clouds

    Behavior at a Nesting Site and Prey of \u3ci\u3eCrabro Cribrellifer\u3c/i\u3e (Hymenoptera: Sphecidae)

    Get PDF
    In Michigan, Crabro cribrellifer tends to show nest clumping within a nest aggregation. Its nesting behavior is similar to that of other Crabro, and it preys on Neoitamus flavofemoratus (Diptera: Asilidae) on warm days in July. Miltogrammine flies Metopia campestris are active at the nesting site

    Organizational Citizenship and Teacher Evaluation: Using the T-TESS to Promote OCB and Improve Student Outcomes

    Get PDF
    Within the reach of institutional climate, organizational citizenship behavior (OCB) has received much attention in the business and psychological literature as a constructive mechanism designed to enhance group efficiency (Bateman & Organ, 1983; Organ, 1988; Podsakoff, Ahearn, & McKenzie, 1997). The essential definition indicates that organizational citizenship behavior refers to going beyond the requirements of one’s job with the understanding that taking such actions benefits the greater good (i.e., the company or school), with no expectation of reward or recognition for the action(s). Subsequent studies investigated OCB and its possible application in educational environs as a tool for improving school efficiency, climate, and student outcomes. The literature revealed that in schools where collectively high levels of faculty and administrator OCB existed, there have been improvements to school climate, school effectiveness, and student outcomes. In this paper, the researchers argue that the newly implemented teacher evaluation system used in the Texas public school system, the Texas Teacher Evaluation and Support System (T-TESS), may be leveraged as an effective planning and professional development tool to strategically and positively impact levels of OCB among the faculty, and by extension, to improve pedagogical practice, school climate, and increase student achievement

    Circular 109

    Get PDF
    Introduction -- Explanation of Plant Evaluation Tables -- Table 1. Weather records for the test years -- Table 2. All plant materials evaluated in 1996 -- Table 3. All plants that have been evaluated but did not survive the minimum number of test years -- Table 4. Plantings from 1996 that have not yet been evaluated for winter survival -- Table 5. Annual flowers evaluated in 1996 -- Appendix 1. Commercial Sources and Organizations -- Map of GB

    QCD sum rules in the effective heavy quark theory

    Get PDF
    We derive sum rules for the leptonic decay constant of a heavy-light meson in the effective heavy quark theory. We show that the summation of logarithms in the heavy quark mass by the renormalization group technique enhances considerably radiative corrections. Our result for the decay constant in the static limit agrees well with recent lattice calculations. Finite quark mass corrections are estimated

    Strengthening Resilience by thinking of Knowledge as a nutrient connecting the local person to global thinking: The case of Social Technology/Tecnologia Social

    Get PDF
    In this chapter, we describe the Knowledge as a Nutrient framework that emerged from these conversations. We describe how it relates to the Tecnologia Social policy approach to sustainability, developed in Brazil (Dagnino et al. 2004, Fundação Banco do Brasil 2009, Costa 2013), which is not well known in the anglophone world. Tecnologia Social was both inspired by and rooted in Paulo Freire’s pedagogical thinking (2000, Klix 2014).   We show how this framework has the potential to increase community resilience and adaptive capacity, not only for communities that face and must adapt to climate change but for all communities in the throes of complex social, ecological, economic and political transitions.This research was supported by the International Development Research Centre, grant number IDRC GRANT NO. 106002-00

    AFES Circular 127

    Get PDF

    The gas metallicity gradient and the star formation activity of disc galaxies

    Get PDF
    We study oxygen abundance profiles of the gaseous disc components in simulated galaxies in a hierarchical universe. We analyse the disc metallicity gradients in relation to the stellar masses and star formation rates of the simulated galaxies. We find a trend for galaxies with low stellar masses to have steeper metallicity gradients than galaxies with high stellar masses at z ~0. We also detect that the gas-phase metallicity slopes and the specific star formation rate (sSFR) of our simulated disc galaxies are consistent with recently reported observations at z ~0. Simulated galaxies with high stellar masses reproduce the observed relationship at all analysed redshifts and have an increasing contribution of discs with positive metallicity slopes with increasing redshift. Simulated galaxies with low stellar masses a have larger fraction of negative metallicity gradients with increasing redshift. Simulated galaxies with positive or very negative metallicity slopes exhibit disturbed morphologies and/or have a close neighbour. We analyse the evolution of the slope of the oxygen profile and sSFR for a gas-rich galaxy-galaxy encounter, finding that this kind of events could generate either positive and negative gas-phase oxygen profiles depending on their state of evolution. Our results support claims that the determination of reliable metallicity gradients as a function of redshift is a key piece of information to understand galaxy formation and set constrains on the subgrid physics.Comment: 12 pages, 8 figures, accepted MNRA
    corecore