1,629 research outputs found
Why equality? On justifying liberal egalitarianism
The debate over the nature of egalitarianism has come to dominate political philosophy. As ever more sophisticated attempts are made to describe the principles of an egalitarian distribution or to specify the good or goods that should be distributed equally, little is said about the fundamental basis of equality. In virtue of what should people be regarded as equal? Egalitarians have tended to dismiss this question of fundamental equality. In the first part of the paper I will examine some of these strategies of marginalisation and assess whether the issue of fundamental equality matters. Jeremy Waldron has criticised this strategy of avoidance in his recent book God, Locke and equality. He argues that Locke's turn to a theistic grounding for fundamental equality provides a better approach to the problem than the approach taken by contemporary liberals such as John Rawls. I will examine Waldron's critique of Rawls and show that it is wanting. I will conclude by suggesting that Rawls's approach to the issue has a bearing on the way in which equality should be understood as a political value. This argument for the primacy of a political conception of egalitarianism has a bearing on the interconnection between core liberal values and the idea of the state that has been emphasised by Rawls, Dworkin and Nagel
Australia’s Murray-Darling Basin: A Century of Polycentric Experiments in Cross-Border Integration of Water Resources Management
We respond in this article to scholars having identified a theory-practice gap commonly afflicting applications of integrated water resources management (IWRM) internationally, and thus aneed for the concept to be recast according to evidence of how integration of fragmented watermanagement efforts actually occurs. The Murray-Darling Basin (MDB) is employed as a longitudinal case study for this purpose, focusing particularly on its cross-border integration challenges. We frame IWRM as the pursuit of coherent collective action by the multiple enterprises(public, private, civic and hybrid) typically constituting the polycentric public industry involvedin managing water resources. We look beyond approaches involving overt coordination to otherapproaches with potential to contribute towards such coherence. We find that Australiangovernments are no longer able to overtly coordinate the suite of interdependent enterprises relevant tothe success of water management efforts in the Basin. Their success in strengthening coherenceor integration in these efforts has come to depend increasingly on their ability to devise governancearrangements capable of catalysing (e.g., by fostering conditions supportive of fruitfulcompetitive rivalry or informal collaborations) the kinds of dynamics through which more of therequired integration of management efforts emerges on a self-organised basis
Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.
The São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity
Phenomenology of the Lense-Thirring effect in the Solar System
Recent years have seen increasing efforts to directly measure some aspects of
the general relativistic gravitomagnetic interaction in several astronomical
scenarios in the solar system. After briefly overviewing the concept of
gravitomagnetism from a theoretical point of view, we review the performed or
proposed attempts to detect the Lense-Thirring effect affecting the orbital
motions of natural and artificial bodies in the gravitational fields of the
Sun, Earth, Mars and Jupiter. In particular, we will focus on the evaluation of
the impact of several sources of systematic uncertainties of dynamical origin
to realistically elucidate the present and future perspectives in directly
measuring such an elusive relativistic effect.Comment: LaTex, 51 pages, 14 figures, 22 tables. Invited review, to appear in
Astrophysics and Space Science (ApSS). Some uncited references in the text
now correctly quoted. One reference added. A footnote adde
Generalized thermodynamics and Fokker-Planck equations. Applications to stellar dynamics, two-dimensional turbulence and Jupiter's great red spot
We introduce a new set of generalized Fokker-Planck equations that conserve
energy and mass and increase a generalized entropy until a maximum entropy
state is reached. The concept of generalized entropies is rigorously justified
for continuous Hamiltonian systems undergoing violent relaxation. Tsallis
entropies are just a special case of this generalized thermodynamics.
Application of these results to stellar dynamics, vortex dynamics and Jupiter's
great red spot are proposed. Our prime result is a novel relaxation equation
that should offer an easily implementable parametrization of geophysical
turbulence. This relaxation equation depends on a single key parameter related
to the skewness of the fine-grained vorticity distribution. Usual
parametrizations (including a single turbulent viscosity) correspond to the
infinite temperature limit of our model. They forget a fundamental systematic
drift that acts against diffusion as in Brownian theory. Our generalized
Fokker-Planck equations may have applications in other fields of physics such
as chemotaxis for bacterial populations. We propose the idea of a
classification of generalized entropies in classes of equivalence and provide
an aesthetic connexion between topics (vortices, stars, bacteries,...) which
were previously disconnected.Comment: Submitted to Phys. Rev.
Observations of magnetic fields in the Milky Way and in nearby galaxies with a Square Kilometre Array
The role of magnetic fields in the dynamical evolution of galaxies and of the
interstellar medium (ISM) is not well understood, mainly because such fields
are difficult to directly observe. Radio astronomy provides the best tools to
measure magnetic fields: synchrotron radiation traces fields illuminated by
cosmic-ray electrons, while Faraday rotation and Zeeman splitting allow us to
detect fields in all kinds of astronomical plasmas, from lowest to highest
densities. Here we describe how fundamental new advances in studying magnetic
fields, both in our own Milky Way and in other nearby galaxies, can be made
through observations with the proposed Square Kilometre Array. Underpinning
much of what we propose is an all-sky survey of Faraday rotation, in which we
will accumulate tens of millions of rotation measure measurements toward
background radio sources. This will provide a unique database for studying
magnetic fields in individual Galactic supernova remnants and HII regions, for
characterizing the overall magnetic geometry of our Galaxy's disk and halo, and
for understanding the structure and evolution of magnetic fields in galaxies.
Also of considerable interest will be the mapping of diffuse polarized emission
from the Milky Way in many narrow bands over a wide frequency range. This will
allow us to carry out Faraday tomography of the Galaxy, yielding a
high-resolution three-dimensional picture of the magnetic field within a few
kpc of the Sun, and allowing us to understand its coupling to the other
components of the ISM. Finally, direct synchrotron imaging of a large number of
nearby galaxies, combined with Faraday rotation data, will allow us to
determine the magnetic field structure in these sources, and to test both the
dynamo and primordial field theories for field origin and amplification.Comment: 17 pages, 8 figures. To appear in "Science with the Square Kilometer
Array", eds. C. Carilli and S. Rawlings, New Astronomy Reviews (Elsevier:
Amsterdam); Typos corrected 26/10/200
Active Brownian Particles. From Individual to Collective Stochastic Dynamics
We review theoretical models of individual motility as well as collective
dynamics and pattern formation of active particles. We focus on simple models
of active dynamics with a particular emphasis on nonlinear and stochastic
dynamics of such self-propelled entities in the framework of statistical
mechanics. Examples of such active units in complex physico-chemical and
biological systems are chemically powered nano-rods, localized patterns in
reaction-diffusion system, motile cells or macroscopic animals. Based on the
description of individual motion of point-like active particles by stochastic
differential equations, we discuss different velocity-dependent friction
functions, the impact of various types of fluctuations and calculate
characteristic observables such as stationary velocity distributions or
diffusion coefficients. Finally, we consider not only the free and confined
individual active dynamics but also different types of interaction between
active particles. The resulting collective dynamical behavior of large
assemblies and aggregates of active units is discussed and an overview over
some recent results on spatiotemporal pattern formation in such systems is
given.Comment: 161 pages, Review, Eur Phys J Special-Topics, accepte
eta-prime photoproduction on the proton for photon energies from 1.527 to 2.227 GeV
Differential cross sections for the reaction gamma p -> eta-prime p have been
measured with the CLAS spectrometer and a tagged photon beam with energies from
1.527 to 2.227 GeV. The results reported here possess much greater accuracy
than previous measurements. Analyses of these data indicate for the first time
the coupling of the etaprime N channel to both the S_11(1535) and P_11(1710)
resonances, known to couple strongly to the eta N channel in photoproduction on
the proton, and the importance of j=3/2 resonances in the process.Comment: 6 pages, 3 figure
A Kinematically Complete Measurement of the Proton Structure Function F2 in the Resonance Region and Evaluation of Its Moments
We measured the inclusive electron-proton cross section in the nucleon
resonance region (W < 2.5 GeV) at momentum transfers Q**2 below 4.5 (GeV/c)**2
with the CLAS detector. The large acceptance of CLAS allowed for the first time
the measurement of the cross section in a large, contiguous two-dimensional
range of Q**2 and x, making it possible to perform an integration of the data
at fixed Q**2 over the whole significant x-interval. From these data we
extracted the structure function F2 and, by including other world data, we
studied the Q**2 evolution of its moments, Mn(Q**2), in order to estimate
higher twist contributions. The small statistical and systematic uncertainties
of the CLAS data allow a precise extraction of the higher twists and demand
significant improvements in theoretical predictions for a meaningful comparison
with new experimental results.Comment: revtex4 18 pp., 12 figure
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