2,685 research outputs found
Virgo Early-Type Dwarfs in ALFALFA
Early-type dwarf galaxies dominate cluster populations, but their formation
and evolutionary histories are poorly understood. The ALFALFA (Arecibo Legacy
Fast ALFA) survey has completed observations of the Virgo Cluster in the
declination range of 6 - 16 degrees. Less than 2% of the early-type dwarf
population is detected, a significantly lower fraction than reported in
previous papers based on more limited samples. In contrast ~30 of the
irregular/BCD dwarf population is detected. The detected early-type galaxies
tend to be located in the outer regions of the cluster, with a concentration in
the direction of the M Cloud. Many show evidence for ongoing/recent star
formation. Galaxies such as these may be undergoing morphological transition
due to cluster environmental effects.Comment: 2 pages. To be published in proceedings of IAU Symposium 244: 'Dark
Galaxies and Lost Baryons', J. I. Davies & M. D. Disney. eds., Cambridge
University Pres
Aid for trade and the political economy of trade liberalization
The Aid for Trade (AfT) initiative has gained much popularity since its launch at the World Trade Organization's Ministerial Conference in 2005, and there are ongoing discussions on its effectiveness and potential to improve the integration of developing countries into the world economy. This paper contributes to the debate by analyzing AfT in a political economy context. We find that the delivery of AfT is a precondition for trade reform in developing countries, as well as for trade liberalization and trade-enhancing rule-making in regional and international forums. Accordingly, AfT may be a catalyst of trade reforms domestically and internationally. --Aid for Trade,Trade Liberalization,Trade Policy,Trade Reform
Model studies of Helmholtz resonances in rooms with windows and doorways
Numerical analysis of Helmholtz resonator system established between windows and open doors when subjected to sonic boom impulsive load
Veterinary treatment in organic husbandry
The organic farming regulations put emphasis on the preservation of animal health by prophylaxis in the agriculture. The No 5 of the regulation EC 1804/99 (EC organic regulation) Appendix I B defines the veterinary treatments in organic animal husbandry. The veterinarian can use any medicine, which is effective for the indication and the animal species. If possible, effective homeopathics, phytotherapeutics or the like should have priority.
Problems of implementing the EC organic regulation into the daily farm practice arise mostly from the doubling of the withdrawal period and the restriction of the numbers of treatments. The strict ban on prophylactic treatments is not mentioned any longer in the new regulation 834/2007, which shall apply as from 1st January 2009.
Clarification of the guidelines for animal treatments in organic farming seems to be useful for farmers, veterinarians and boards of control
The cultural shaping of compassion
In this chapter, we first review the existing literature on cross-cultural studies on compassion. While cultural similarities exist, we demonstrate cultural differences in the conception, experience, and expression of compassion. Then we present our own work on the cultural shaping of compassion by introducing Affect Valuation Theory ( e.g., Tsai, Knutson, & Fung, 2006), our theoretical framework. We show how the desire to avoid feeling negative partly explains cultural differences in conceptualizations and expressions of compassion. Specifically, the more people want to avoid feeling negative, the more they focus on the positive (e.g., comforting memories) than the negative (e.g., the pain of someone\u27s death) when responding to others\u27 suffering, and the more they regard responses as helpful that focus on the positive (vs. negative). Finally, we discuss implications of our work for counseling, health care, and public service settings, as well as for interventions that aim to promote compassion
Detection of Leptosphaeria maculans races on winter oilseed rape in different geographic regions of Germany and efficacy of monogenic resistance genes under varying temperatures
Final Published versio
Ram pressure stripping of disc galaxies: The role of the inclination angle
We present 3D hydrodynamical simulations of ram pressure stripping of massive
disc galaxies in clusters. Studies of galaxies that move face-on have predicted
that in such a geometry the galaxy can lose a substantial amount of its
interstellar medium. But only a small fraction of galaxies is moving face-on.
Therefore, in this work we focus on a systematic study of the effect of the
inclination angle between the direction of motion and the galaxy's rotation
axis.
In agreement with some previous works, we find that the inclination angle
does not play a major role for the mass loss as long as the galaxy is not
moving close to edge-on. We can predict this behaviour by extending Gunn &
Gott's estimate of the stripping radius, which is valid for face-on geometries,
to moderate inclinations.
The inclination plays a role as long as the ram pressure is comparable to
pressures in the galactic plane, which can span two orders of magnitude. For
very strong ram pressures, the disc will be stripped completely, and for very
weak ram pressures, mass loss is negligible independent of inclination. We show
that in non-edge-on geometries the stripping proceeds remarkably similar. A
major difference between different inclinations is the degree of asymmetry
introduced in the remaining gas disc.
We demonstrate that the tail of gas stripped from the galaxy does not
necessarily point in a direction opposite to the galaxy's direction of motion.
Therefore, the observation of a galaxy's gas tail may be misleading about the
galaxy's direction of motion.Comment: 14 pages, 14 figures, submitted to MNRAS. pdf version with high
resolution figures available at
http://www.faculty.iu-bremen.de/eroediger/PLOTLINKS/eroediger_rps.pd
Fisher-Wright model with deterministic seed bank and selection
Seed banks are a common characteristics to many plant species, which allow
storage of genetic diversity in the soil as dormant seeds for various periods
of time. We investigate an above-ground population following a Fisher-Wright
model with selection coupled with a deterministic seed bank assuming the length
of the seed bank is kept constant and the number of seeds is large. To assess
the combined impact of seed banks and selection on genetic diversity, we derive
a general diffusion model. The applied techniques outline a path of
approximating a stochastic delay differential equation by an appropriately
rescaled stochastic differential equation, which is a common issue in
statistical physics. We compute the equilibrium solution of the site-frequency
spectrum and derive the times to fixation of an allele with and without
selection. Finally, it is demonstrated that seed banks enhance the effect of
selection onto the site-frequency spectrum while slowing down the time until
the mutation-selection equilibrium is reached
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