Wigner localization in quantum dots from Kohn-Sham density functional theory without symmetry breaking

We address low-density two-dimensional circular quantum dots with spin-restricted Kohn-Sham density functional theory. By using an exchange-correlation functional that encodes the effects of the strongly-correlated regime (and that becomes exact in the limit of infinite correlation), we are able to reproduce characteristic phenomena such as the formation of ring structures in the electronic total density, preserving the fundamental circular symmetry of the system. The observation of this and other well-known effects in Wigner-localized quantum dots such as the flattening of the addition energy spectra, has until now only been within the scope of other, numerically more demanding theoretical approachesComment: 8 pages, 6 figure

Eros e Thanatos nella novella Loucura... di M\ue1rio de S\ue1-Carneiro

Il presente contributo sulle figure di Eros e Thanatos, Amore e Morte, nel racconto Loucura\u2026 della raccolta Princ\uedpio di M\ue1rio de S\ue1-Carneiro si inserisce in uno studio pi\uf9 ampio che ha per oggetto l\u2019analisi del rapporto Arte- Vita nella sua opera in prosa. Possiamo affermare che Amore e Morte sono due elementi centrali di questo rapporto, la comprensione del significato e del ruolo dei quali risulta per\uf2 possibile solo se inquadrati in un contesto tematico e interpretativo pi\uf9 complesso nel quale agiscono anche altri elementi. Tra questi, l\u2019Arte e la Malattia \u2013 la malattia dell\u2019anima che in S\ue1-Carneiro si identifica solitamente con la pazzia \u2013 elementi, tutti, che si riassumono nel quinto e fondamentale anello della sequenza: ossia la Vita, la vita con la V maiuscola, intesa come impulso che ispira e libera tutti gli altri. In Loucura\u2026 troviamo inoltre un\u2019altra tematica \u2013 funzionale, complementare e consequenziale agli altri motivi della concezione Arte-Vita del poeta \u2013 che \ue8 quella della Verg\ue4nglichkeit, ossia del trascorrere inesorabile del Tempo, che ha la precisa funzione di contribuire a innescare la deflagrazione della Malattia, gi\ue0 latente nel protagonista, accelerando cos\uec l\u2019inevitabile e inesorabile discesa dell\u2019uomo sacarneiriano verso la tragica fine della sua esistenza

A vanguarda florentina de Lacerba e Portugal Futurista: afinidades e diverg\ueancias/The Florentine Vanguard of Lacerba and Portugal Futurista: Affinities and Differences

O objetivo do artigo \ue9 evidenciar os elementos do futurismo italiano, em particular do futurismo florentino da revista Lacerba, encontrados, mutatis mutandis, em Portugal Futurista, que se pode considerar o manifesto propagandista mais completo do futurismo em Portugal. A revista portuguesa denota claramente um conhecimento profundo, por parte dos portugueses, do futurismo italiano, visto que os textos de Portugal Futurista foram realizados, em boa parte, por extrapola\ue7\ue3o e reelabora\ue7\ue3o de conte\ufados desenvolvidos sobretudo na revista Lacerba e, a partir dela, j\ue1 divulgados e conhecidos em todos os grandes pa\uedses europeus

Prolonged low flow reduces reactive hyperemia and augments low flow mediated constriction in the brachial artery independent of the menstrual cycle

© 2013 Rakobowchuk et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Non-invasive forearm ischemia-reperfusion injury and low flow induced vascular dysfunction models provide methods to evaluate vascular function. The role of oestrogen, an endogenous anti-oxidant on recovery from ischemia-reperfusion injury has not been evaluated nor has the impact of prolonged low flow on vascular function been established. Eight healthy women (33610 yr) attended the lab during the follicular, ovulatory and mid-luteal phases of their menstrual cycles. After 30 minutes of rest, brachial artery vascular function was assessed by ultrasound measurements of diameter changes during 5 minutes of forearm ischemia and 3 minutes after. Subsequently, a 20-minute forearm ischemia period was completed. Further, vascular function assessments were completed 15, 30 and 45 minutes into recovery. Flow-mediated dilation, lowflow-mediated constriction, and reactive hyperaemia proximal to the area of ischemia were determined. Flow-mediated dilation was reduced at 15 minutes of recovery but recovered at 30 and 45 minutes (PRE: 7.161.0%, POST15:4.560.6%, POST30:5. 560.7% POST45:5.960.4%, p,0.01). Conversely, low-flow mediated constriction increased (PRE: 21.360.4%, POST15: 23.360.6%, POST30: 22.560.5% POST45: 21.560.12%, p,0.01). Reactive hyperaemia was reduced throughout recovery (p,0.05). Data were unaffected by menstrual phase. Prolonged low flow altered vascular function and may relate as much to increased vasoconstriction as with decreased vasodilation. Reductions in anterograde shear and greater retrograde shear likely modulate the brachial artery response, but the reduced total shear also plays an important role. The data suggest substantial alterations in vascular function proximal to areas of ischemia with potential clinical implications following reperfusion.British Heart Foundation (PG/08/060/25340),a Physiological Society summer studentship to SG, and a Wellcome Trust Vacation Studentship to EP

Density functional theory for strongly-correlated bosonic and fermionic ultracold dipolar and ionic gases

We introduce a density functional formalism to study the ground-state properties of strongly-correlated dipolar and ionic ultracold bosonic and fermionic gases, based on the self-consistent combination of the weak and the strong coupling limits. Contrary to conventional density functional approaches, our formalism does not require a previous calculation of the interacting homogeneous gas, and it is thus very suitable to treat systems with tunable long-range interactions. Due to its asymptotic exactness in the regime of strong correlation, the formalism works for systems in which standard mean-field theories fail.Comment: 5 pages, 2 figure

Pair densities at contact in the quantum electron gas

The value of the pair distribution function g(r) at contact (r = 0) in a quantum electron gas is determined by the scattering events between pairs of electrons with antiparallel spins. The theoretical results for g(0) as a function of the coupling strength r_s in the paramagnetic electron gas in dimensionality D=2 and 3, that have been obtained from the solution of the two-body scattering problem with a variety of effective scattering potentials embodying many-body effects, are compared with the results of many-body calculations in the ladder approximation and with quantum Monte Carlo data.Comment: 7 pages, 2 figure

Pair-distribution functions of the two-dimensional electron gas

Based on its known exact properties and a new set of extensive fixed-node reptation quantum Monte Carlo simulations (both with and without backflow correlations, which in this case turn out to yield negligible improvements), we propose a new analytical representation of (i) the spin-summed pair-distribution function and (ii) the spin-resolved potential energy of the ideal two-dimensional interacting electron gas for a wide range of electron densities and spin polarization, plus (iii) the spin-resolved pair-distribution function of the unpolarized gas. These formulae provide an accurate reference for quantities previously not available in analytic form, and may be relevant to semiconductor heterostructures, metal-insulator transitions and quantum dots both directly, in terms of phase diagram and spin susceptibility, and indirectly, as key ingredients for the construction of new two-dimensional spin density functionals, beyond the local approximation.Comment: 12 pages, 10 figures; misprints correcte

Passive seismology in southern Italy: the SAPTEX array

Abstract In this paper we describe the Southern APennines Tomography EXperiment (SAPTEX) temporary array deployed in southern Italy from June 2001 to December 2003. Five to twelve three-components seismic stations, all equipped with RefTek 72A07 digitizers in continuous mode recording and Lennartz 3D/5s sensors, were operating in the region during the three-year project. Many local, regional and teleseismic events have been recorded at 26 different recording sites, providing an invaluable data set for high-resolution seismological studies. Moreover, by the second half of 2002, two stations were installed in the Aeolian Islands with the main objective to record and better constrain the spatial distribution of the deep seismicity of the southern Tyrrhenian subduction zone. The preliminary analysis of the waveforms collected in the first two years includes phase identification and body wave arrival time estimation, local earthquakes (re)location and focal mechanisms computation, P -wave traveltime residuals, and resolution of crustal and upper mantle structure derived by teleseismic ray sampling