1,441 research outputs found
The normative turn in European Union studies: legitimacy, identity and democracy
By raising fundamental questions about the methods and ultimate goals of European integration, Maastricht forced supporters and opponents alike to confront the legitimacy both of the Union and - as has become apparent with the crisis of the Santer Commission - of the institutional architecture put in place to steer it. The strategic-oriented action and normative argument avoided for so long by the main political actors, are inescapable when tackling this issue. Thus, national politicians and European authorities have self-consciously, though perhaps confusedly, been obliged to start discussing the future shape of what Jacques Delors once called ‘un object politique non-identifié.’ Academics, for their part, have discovered that the integration process depends not simply on functional efficiency and certain given economic and national interests, but also on people’s ideals and perceptions. Consequently, explanation and justification have proved less easily distinguishable than earlier positivistic and behaviouralist models assumed. Hence, the ‘normative turn’ in European studies. In this essay we wish to clarify certain aspects of the normative turn (section 1) and to explore some of the substantive issues that emerge from subjecting the European integration process to normative scrutiny (sections 2, 3 and 4). In the conclusion, we shall sketch the kind of normative politics we feel best suits the emerging European polity
Different transport regimes in a spatially-extended recirculating background
Passive scalar transport in a spatially-extended background of roll
convection is considered in the time-periodic regime. The latter arises due to
the even oscillatory instability of the cell lateral boundary, here accounted
for by sinusoidal oscillations of frequency . By varying the latter
parameter, the strength of anticorrelated regions of the velocity field can be
controled and the conditions under which either an enhancement or a reduction
of transport takes place can be created. Such two ubiquitous regimes are
triggered by a small-scale(random) velocity field superimposed to the
recirculating background. The crucial point is played by the dependence of
Lagrangian trajectories on the statistical properties of the small-scale
velocity field, e.g. its correlation time or its energy.Comment: 9 pages Latex; 5 figure
Interference phenomena in scalar transport induced by a noise finite correlation time
The role played on the scalar transport by a finite, not small, correlation
time, , for the noise velocity is investigated, both analytically and
numerically. For small 's a mechanism leading to enhancement of
transport has recently been identified and shown to be dominating for any type
of flow. For finite non-vanishing 's we recognize the existence of a
further mechanism associated with regions of anticorrelation of the Lagrangian
advecting velocity. Depending on the extension of the anticorrelated regions,
either an enhancement (corresponding to constructive interference) or a
depletion (corresponding to destructive interference) in the turbulent
transport now takes place.Comment: 8 pages, 3 figure
Constraining the true nature of an exotic binary in the core of NGC 6624
We report on the identification of the optical counterpart to Star1, the
exotic object serendipitously discovered by Deutsch et al. in the core of the
Galactic globular cluster NGC 6624. Star1 has been classified by Deutsch et al.
as either a quiescent Cataclysmic Variable or a low-mass X-ray binary. Deutsch
et al. proposed StarA as possible optical counterpart to this object. We used
high-resolution images obtained with the Hubble Space Telescope to perform a
variability analysis of the stars close to the nominal position of Star1. While
no variability was detected for StarA, we found another star, here named
COM_Star1, showing a clear sinusoidal light modulation with amplitude \Delta
m_F435W~0.7 mag and orbital period of P_orb~98 min. The shape of the light
curve is likely caused by strong irradiation by the primary heating one
hemisphere of the companion, thus suggesting a quite hot primary.Comment: Accepted for publication by ApJ Letters; 6 pages, 5 figure
Cation composition effects on oxide conductivity in the Zr_2Y_2O_7-Y_3NbO_7 system
Realistic, first-principles-based interatomic potentials have been used in
molecular dynamics simulations to study the effect of cation composition on the
ionic conductivity in the Zr2Y2O7-Y3NbO7 system and to link the dynamical
properties to the degree of lattice disorder. Across the composition range,
this system retains a disordered fluorite crystal structure and the vacancy
concentration is constant. The observed trends of decreasing conductivity and
increasing disorder with increasing Nb5+ content were reproduced in simulations
with the cations randomly assigned to positions on the cation sublattice. The
trends were traced to the influences of the cation charges and relative sizes
and their effect on vacancy ordering by carrying out additional calculations in
which, for example, the charges of the cations were equalised. The simulations
did not, however, reproduce all the observed properties, particularly for
Y3NbO7. Its conductivity was significantly overestimated and prominent diffuse
scattering features observed in small area electron diffraction studies were
not always reproduced. Consideration of these deficiencies led to a preliminary
attempt to characterise the consequence of partially ordering the cations on
their lattice, which significantly affects the propensity for vacancy ordering.
The extent and consequences of cation ordering seem to be much less pronounced
on the Zr2Y2O7 side of the composition range.Comment: 22 pages, 8 figures, submitted to Journal of Physics: Condensed
Matte
Spectral properties of quantum -body systems versus chaotic properties of their mean field approximations
We present numerical evidence that in a system of interacting bosons there
exists a correspondence between the spectral properties of the exact quantum
Hamiltonian and the dynamical chaos of the associated mean field evolution.
This correspondence, analogous to the usual quantum-classical correspondence,
is related to the formal parallel between the second quantization of the mean
field, which generates the exact dynamics of the quantum -body system, and
the first quantization of classical canonical coordinates. The limit of
infinite density and the thermodynamic limit are then briefly discussed.Comment: 15 pages RevTeX, 11 postscript figures included with psfig, uuencoded
gz-compressed .tar fil
The intergenic spacer region of the rDNA in Haplopappus gracilis (Nutt.) Gray
In this paper we provide further information on the genome organization of Haplopappus gracilis, one of the six angiosperms showing the lowest chromosome number, i.e. 2n=4, by determining the nucleotide sequence of the Intergenic Spacer region of the rRNA genes and its cytological localization on metaphase chromosomes. DNA sequence analysis reveals the occurring of a product of 4,382 bp in length, characterized by the presence of four blocks of different repeated sequences. Our analysis also evidenced putative promoter regions with three Transcription Initiation Sites for Polymerase I, as previously reported in Artemisia absinthium, belonging to the same Asteraceae family. A fluorescent in situ hybridization with the Intergenic Spacer probe indicates the presence of rDNA genes only in the satellited chromosomes of H. gracilis; besides differences in the signal intensity between homologous chromosomes were frequently observed, so suggesting, for these chromosome sites, the presence of a variable number of rDNA gene copies, even if a divergent chromatin organization in corresponding regions can not be ruled out
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Preventing a Thought from Coming to Mind Elicits Increased Right Frontal Beta Just as Stopping Action Does.
In the stop-signal task, an electrophysiological signature of action-stopping is increased early right frontal beta band power for successful vs. failed stop trials. Here we tested whether the requirement to stop an unwanted thought from coming to mind also elicits this signature. We recorded scalp EEG during a Think/No-Think task and a subsequent stop signal task in 42 participants. In the Think/No-Think task, participants first learned word pairs. In a second phase, they received the left-hand word as a reminder and were cued either to retrieve the associated right-hand word ("Think") or to stop retrieval ("No-Think"). At the end of each trial, participants reported whether they had experienced an intrusion of the associated memory. Finally, they received the left-hand reminder word and were asked to recall its associated target. Behaviorally, there was worse final recall for items in the No-Think condition, and decreased intrusions with practice for No-Think trials. For EEG, we reproduced increased early right frontal beta power for successful vs. failed action stopping. Critically, No-Think trials also elicited increased early right frontal beta power and this was stronger for trials without intrusion. These results suggest that preventing a thought from coming to mind also recruits fast prefrontal stopping
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