Numerical Simulations Unveil Superradiant Coherence in a Lattice of Charged Quantum Oscillators

A system of ${N_{osc}}$ charged oscillators interacting with the electromagnetic field, spatially confined in a 3D lattice of sub-wavelength dimension, can condense into a superradiant coherent state if appropriate density and frequency conditions are met. In this state, the common frequency $\omega$ of the oscillators and the plasma frequency $\omega_p$ of the charges are combined into a frequency $\omega'=\sqrt{\omega^2+\omega_p^2}$ that is off-shell with respect to the wavelength of the photon modes involved, preventing them from propagating outside the material. Unlike other atomic cavity systems, the frequency $\omega$ in this case is not determined by the cavity itself but is defined by the periodic electrostatic potential that confines the charged particles in the lattice. Additionally, the electromagnetic modes involved have wave vectors distributed in all spatial directions, resulting in a significant increase in coupling. The analytical study of this system can be carried out in the limit of large ${N_{osc}}$ by searching for an approximation of the ground state via suitable coherent trial states. Alternatively, numerical simulations can be employed for smaller ${N_{osc}}$. In the numerical approach, it is possible to go beyond the Rotating Wave Approximation (RWA) and introduce a dissipation term for the photon modes. This dissipation term can account for the ohmic quench in a metal and also consider photon losses at the boundary of the material. By utilizing numerical solutions and Monte Carlo simulations, the presence of condensation has been confirmed, and an energy gap of a few electron volts (eV) per particle has been observed in typical metal crystals with protons bound to tetrahedral or octahedral sites.Comment: 20 pages, 6 figure

The Pomeron in QCD

In the framework of Anisotropic Chromodynamics, a non-perturbative realization of QCD, we develop the Low-Nussinov picture of the Pomeron. In this approach all the usual problems of low pT perturbative calculations (infrared divergence) are naturally absent. Thus, we are able to perform an ab initio calculation of the hadron-hadron total cross section. The result is a cross section of the same magnitude as indicated experimentally and approximately energy-independent (with a log^2 s growth). We further discuss the pT dependence of the hadron-hadron elastic-scattering cross section, which displays all the experimentally observed features.Comment: 8 pages (LaTeX, plus 4 postscript figures in a separate file), report number MITH 94/13 *** Replaced figures file with uuencoded, compressed, tarred version **

New Procedures to Make Active, Fractal-Like Surfaces on Thin pd Wires

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Dressed for Sex: Red as a Female Sexual Signal in Humans

Background: In many non-human primate species, a display of red by a female serves as a sexual signal to attract male conspecifics. Red is associated with sex and romance in humans, and women convey their sexual interest to men through a variety of verbal, postural, and behavioral means. In the present research, we investigate whether female red ornamentation in non-human primates has a human analog, whereby women use a behavioral display of red to signal their sexual interest to men. Methodology/Principal Findings: Three studies tested the hypothesis that women use red clothing to communicate sexual interest to men in profile pictures on dating websites. In Study 1, women who imagined being interested in casual sex were more likely to display red (but not other colors) on their anticipated web profile picture. In Study 2, women who indicated interest in casual sex were more likely to prominently display red (but not other colors) on their actual web profile picture. In Study 3, women on a website dedicated to facilitating casual sexual relationships were more likely to prominently exhibit red (but not other colors) than women on a website dedicated to facilitating marital relationships. Conclusions/Significance: These results establish a provocative parallel between women and non-human female primates in red signal coloration in the mating game. This research shows, for the first time, a functional use of color in women’s sexual self-presentation, and highlights the need to extend research on color beyond physics, physiology, and preference to psychological functioning

Entourage: the immune microenvironment following follicular lymphoma

In follicular lymphoma, nonmalignant immune cells are important. Follicular lymphoma depends on CD4+ cells, but CD8+ cells counteract it. We hypothesized that the presence of follicular lymphoma is associated with higher CD4+ than CD8+ cell numbers in the tumor microenvironment but not in the immune system. Using flow cytometry, pre-treatment and follow-up CD4/CD8 ratios were estimated in the bone marrow, blood and lymph nodes of untreated follicular lymphoma patients in two independent data sets (N1=121; N2=166). The ratios were analyzed for their relation with bone marrow lymphoma involvement. Bone marrows were also investigated with immunohistochemistry. In either data set, the bone marrow CD4/CD8 ratios were higher in bone marrows involved with lymphoma (P=0.043 and 0.0002, respectively). The mean CD4/CD8 ratio was 1.0 in uninvolved and 1.4 in involved bone marrows. Also higher in involved bone marrows were CD4/CD56 and CD3CD25/CD3 ratios. No blood or lymph node ratios differed between bone marrow-negative and -positive patients. Sequential samples showed increased bone marrow CD4/CD8 ratios in all cases of progression to bone marrow involvement. Immunohistochemistry showed CD4+, CD57+, programmed death-1+, forkhead box protein 3+ and CD21+ cells accumulated inside the lymphoma infiltrates, whereas CD8+, CD56+ and CD68+ cells were outside the infiltrates. This study provides evidence in vivo that the microenvironment changes upon follicular lymphoma involvement

MANUALE DELLA CERTIFICAZIONE ENERGETICA DEGLI EDIFICI

Scritto da alcuni degli esperti italiani più qualificati, questo volume è un manuale essenziale per affrontare il tema più “caldo” del momento. L’adozione della direttiva europea 2002/91 ha portato in primo piano il tema dell’efficienza energetica degli edifici, mettendo in luce il pesante ritardo del nostro paese nell’adeguare la qualità dell’edilizia esistente e di nuova costruzione a parametri altrove già operanti. Nello stesso tempo si sono evidenziate anche le enormi opportunità connesse alla sfida della più grande trasformazione che il nostro settore edilizio abbia mai affrontato. Con gli obblighi previsti dai Dlgs 192/2005 e 311/2006 lo scenario si è definito e si entra nella fase della piena operatività; per rispondere alle nuove domande i professionisti devono quindi acquisire appieno la conoscenza delle norme e dei meccanismi procedurali che li rendono in grado di operare. Il tema della certificazione energetica degli edifici è illustrata sia attraverso casi studio locali sia attraverso l’analisi e spiegazione delle norme nazionali. Dal ruolo del certificatore ai sistemi di accreditamento, i nuovi compiti di tecnici e professionisti vengono delineati con chiarezza, così come i percorsi formativi necessari e i compiti di enti locali e amministrazione centrale. Ma la trattazione non si ferma qui, gli autori affrontano in due ampi capitoli le strategie di intervento sull’esistente e le tecniche di progettazione ecoefficiente per le nuove costruzioni

Contrast versus colour in aposematic signals

Conspicuousness is an important feature of warning coloration. One hypothesis for its function is that it increases signal efficacy by facilitating avoidance learning. An alternative, based on the handicap hypothesis, suggests that the degree of conspicuousness holds information directly about the quality of the prey, and that predators associate and learn about the conspicuousness of the coloration, and not the actual colour pattern. We studied the relative importance of signal contrast and the colours of signals for predator attention during discrimination. We used young chicks, Gallus gallus domesticus, as predators and small blue or red paper cones on either matching or contrasting paper backgrounds as stimuli associated with palatable or unpalatable chick crumbs. In four treatment groups, birds could use either cone and/or background colour, cone colour only, background colour only or cone-to-background contrast as cues for discrimination. Only birds in the contrast treatment failed to learn their discrimination task. Birds that had a choice between cone and background colour as cues used the cone colour and they learned the task faster than did birds that had to use background colour as a cue. The results suggest that birds primarily attend to the colours of signals and disregard contrast in discrimination tasks; they thus fail to support a handicap function of conspicuous aposematic coloration. © 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour