197,236 research outputs found
M. Maruani — Les mécomptes du chômage
No full textMeron Monique. M. Maruani — Les mécomptes du chômage. In: Population, 58ᵉ année, n°1, 2003. pp. 157-159
M. Maruani — Les mécomptes du chômage
No full textMeron Monique. M. Maruani — Les mécomptes du chômage. In: Population, 58ᵉ année, n°1, 2003. pp. 157-159
Meron ground states of quantum Hall droplets
Get PDFWe argue that topological meron excitations, which are in a strong coupling phase ͑bound in pairs͒ in infinite quantum Hall ferromagnets, become deconfined in finite-size quantum Hall systems. Although effectively for larger systems meron energy grows with the size of the system, when gyromagnetic ratio is small meron becomes the lowest-lying state of a quantum Hall droplet. This comes as a consequence of the many-body correlations built in the meron construction that minimize the interaction energy. We demonstrate this by using mean-field ansatzes for meron wave function. The ansatzes will enable us to consider much larger system sizes than in the previous work ͓A. Petković and M. V. Milovanović, Phys. Rev. Lett. 98, 066808 ͑2007͔͒, where fractionalization into merons was introduced
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An Analysis of the Mt. Meron Seismic Array
Get PDFWe have performed a quick analysis of the Mt. Meron seismic array to monitor regional seismic events in the Middle East. The Meron array is the only current array in the Levant and Arabian Peninsula and, as such, might be useful in contributing to event location, identification, and other analysis. Here, we provide a brief description of the array and a review of the travel time and array analysis done to assess its performance
The effect of prefrontal transcranial direct current stimulation on attention network function in healthy volunteers
Get PDFObjectives: The effect of acute transcranial direct current stimulation (tDCS) on cortical attention networks remains unclear. We examined the effect of 20 minutes of 2mA prefrontal dorsolateral prefrontal cortex (DLPFC) tDCS (bipolar balanced montage) on the efficiency of alerting, orienting and executive attention networks measured by the attention network test (ANT). Materials and Methods: A between-subjects stratified randomised design compared active tDCS vs. sham tDCS on attention network function in healthy young adults.Results: Executive attention was greater following active vs. sham stimulation (d= 0.76) in the absence of effects on alerting, orienting or global RT or error rates. Group differences were not moderated by state-mood. Conclusion(s): 20 minutes of active 2mA tDCS over left DLPFC is associated with greater executive attention in healthy humans.<br/
Modelling the survival of bacteria in drylands: the advantage of being dormant
No full textWe introduce a simple mathematical model for the description of
`dormancy', a survival strategy used by some bacterial populations that
are intermittently exposed to external stress. We focus on the case of
the cyanobacterial crust in drylands, exposed to severe water shortage,
and compare the fate of ideal populations that are, respectively,
capable or incapable of becoming dormant. The results of the simple
model introduced here indicate that under a constant, even though low,
supply of water the dormant strategy does not provide any benefit and it
can, instead, decrease the chances of survival of the population. The
situation is reversed for highly intermittent external stress, due to
the presence of prolonged periods of dry conditions intermingled with
short periods of intense precipitation. In this case, dormancy allows
for the survival of the population during the dry periods. In contrast,
bacteria that are incapable of turning into a dormant state cannot
overcome the difficult times. The model also rationalizes why dormant
bacteria, such as those composing the cyanobacterial crust in the
desert, are extremely sensitive to other disturbances, such as trampling
cattle
Thème 4. La mobilité des salariés de l'Etat. Discussion sur les communications de M. Méron, C. Agulhon et J. Pihan
No full textTerrier Christophe, Meron Monique, Faidutti Anne-Marie, Laget Michel. Thème 4. La mobilité des salariés de l'Etat. Discussion sur les communications de M. Méron, C. Agulhon et J. Pihan . In: Espace, populations, sociétés, 1988-3. La population face à l'emploi - Population and work opportunities. p. 554
Diversity of vegetation patterns and desertification
No full textA new model for vegetation patterns is introduced. The model reproduces
a wide range of patterns observed in water-limited regions, including
drifting bands, spots, and labyrinths. It predicts transitions from bare
soil at low precipitation to homogeneous vegetation at high
precipitation, through intermediate states of spot, stripe, and hole
patterns. It also predicts wide precipitation ranges where different
stable states coexist. Using these predictions we propose a novel
explanation of desertification phenomena and a new approach to
classifying aridity
CONTOURS OF CONSTANT SCATTERING ANGLE
No full textTraditionally, radiation-scattering experiments are conceived in terms of cylindrical geometry where the symmetry axis is the line between the source and the target. When the target becomes extended, as is the case in many real-life measurements, the analysis or the prediction of spectra becomes difficult. By definition of the axis of symmetry as being between the source and the detector, the extended target can be described in toroidal geometry with the surface of each toroid being a contour of constant scattering angle. With the scattering cross section constant over each contour, the calculation of total scattering intensities is greatly simplified. © 1988 The American Physical Society
The effect of focused attention and open monitoring meditation on attention network function in healthy volunteers
No full textMindfulness meditation techniques are increasingly popular both as a life-style choice and therapeutic adjunct for a range of mental and physical health conditions. However, little is known about the mechanisms through which mindfulness meditation and its constituent practices might produce positive change in cognition and emotion. Our study directly compared the effects of Focused Attention (FA) and Open-Monitoring (OM) meditation on alerting, orienting and executive attention network function in healthy individuals. Participants were randomized to three intervention groups: open-focused meditation, focused attention, and relaxation control. Participants completed an emotional variant of the Attention Network Test (ANT) at baseline and post-intervention. OM and FA practice improved executive attention, with no change observed in the relaxation control group. Improvements in executive attention occurred in the absence of change in subjective/self-report mood and cognitive function. Baseline levels of dispositional/trait mindfulness were positively correlated with executive control in the ANT at baseline. Our results suggest that mindfulness meditation might usefully target deficits in executive attention that characterise mood and anxiety disorders
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