Signatures of the correlation hole in total and partial cross sections

In a complex scattering system with few open channels, say a quantum dot with leads, the correlation properties of the poles of the scattering matrix are most directly related to the internal dynamics of the system. We may ask how to extract these properties from an analysis of cross sections. In general this is very difficult, if we leave the domain of isolated resonances. We propose to consider the cross correlation function of two different elastic or total cross sections. For these we can show numerically and to some extent also analytically a significant dependence on the correlations between the scattering poles. The difference between uncorrelated and strongly correlated poles is clearly visible, even for strongly overlapping resonances.Comment: 25 pages, 13 Postscript figures, typos corrected and references adde

Female bed bugs (Cimex lectularius L) anticipate the immunological consequences of traumatic insemination via feeding cues

Not all encounters with pathogens are stochastic and insects can adjust their immune management in relation to cues associated with the likelihood of infection within a life cycle as well as across generations. In this study we show that female insects (bed bugs) up-regulate immune function in their copulatory organ in anticipation of mating by using feeding cues. Male bed bugs only mate with recently fed females and do so by traumatic insemination (TI). Consequently, there is a tight temporal correlation between female feeding and the likelihood of her being infected via TI. Females that received predictable access to food (and therefore predictable insemination and infection cycles) up-regulated induced immunity (generic antibacterial activity) in anticipation of feeding and mating. Females that received unpredictable (but the same mean periodicity) access to food did not. Females that anticipated mating-associated immune insult received measurable fitness benefits (survival and lifetime reproductive success) despite laying eggs at the same rate as females that were not able to predict these cycles. Given that mating is a time of increased likelihood of infection in many organisms, and is often associated with temporal cues such as courtship and/or feeding, we propose that anticipation of mating-associated infection in females may be more widespread than is currently evidenced

Quantum mechanical time-delay matrix in chaotic scattering

We calculate the probability distribution of the matrix Q = -i \hbar S^{-1} dS/dE for a chaotic system with scattering matrix S at energy E. The eigenvalues \tau_j of Q are the so-called proper delay times, introduced by E. P. Wigner and F. T. Smith to describe the time-dependence of a scattering process. The distribution of the inverse delay times turns out to be given by the Laguerre ensemble from random-matrix theory.Comment: 4 pages, RevTeX; to appear in Phys. Rev. Let

Dynamics of open quantum systems

The coupling between the states of a system and the continuum into which it is embedded, induces correlations that are especially large in the short time scale. These correlations cannot be calculated by using a statistical or perturbational approach. They are, however, involved in an approach describing structure and reaction aspects in a unified manner. Such a model is the SMEC (shell model embedded in the continuum). Some characteristic results obtained from SMEC as well as some aspects of the correlations induced by the coupling to the continuum are discussed.Comment: 16 pages, 5 figure

Quantum relaxation in open chaotic systems

Using the supersymmetry technique, we analytically derive the recent result of Casati, Maspero and Shepelyansky [cond-mat/9706103] according to which the quantum dynamics of open chaotic systems follows the classical decay up to a new quantum relaxation time scale $t_q\sim\sqrt{t_c t_H}$. This scale is larger than the classical escape time $t_c$ but still much smaller than the Heisenberg time $t_H$. For systems with orthogonal or unitary symmetry the quantum decay is slower than the classical one while for the symplectic case there is an intermediate regime in which the quantum decay is slightly faster.Comment: 4 pages Rev-Tex, one figure, important modifications in introduction and conlusion, four references added or modifie

Development and preliminary effectiveness of an innovative treatment for binge eating in racially diverse adolescent girls

Binge and loss of control (LOC) eating are significant concerns among many adolescents and are associated with poor physical, social, and psychological functioning. Black girls appear to be particularly vulnerable to binge and LOC eating. Yet, empirically validated, culturally sensitive treatments for these disordered eating behaviors are not well established. This investigation examined satisfaction, feasibility, and preliminary outcomes of a binge eating intervention for ethnically diverse adolescent girls

Time-resolved dynamics of electron wave packets in chaotic and regular quantum billiards with leads

We perform numerical studies of the wave packet propagation through open quantum billiards whose classical counterparts exhibit regular and chaotic dynamics. We show that for t less or similar to tau (tau being the Heisenberg time), the features in the transmitted and reflected currents are directly related to specific classical trajectories connecting the billiard leads. In contrast, the long-time asymptotics of the wave packet dynamics is qualitatively different for classical and quantum billiards. In particularly, the decay of the quantum system obeys a power law that depends on the number of decay channels, and is not sensitive to the nature of classical dynamics (chaotic or regular).Comment: 5 pages, 4 figure

Laryngeal tuberculosis presenting as a supraglottic carcinoma: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Laryngeal tuberculosis used to be a common complication in advanced pulmonary tuberculosis. However, it has become a rare occurrence in developed countries since the introduction of antituberculous agents. Moreover, the pattern of the disease has changed over the years. Nowadays, it more closely resembles a laryngeal carcinoma than any other laryngeal illness.</p> <p>Case presentation</p> <p>We describe the case of a 50-year-old Caucasian man who presented with the clinical picture of laryngeal cancer, but which turned out to be tuberculosis. We illustrate the difficulty of recognizing laryngeal tuberculosis both clinically and even with radiological examination.</p> <p>Conclusion</p> <p>Although laryngeal tuberculosis is uncommon, especially in developed countries, it still occurs and should be considered as a differential diagnosis in any laryngeal disease, in particular in the case of a laryngeal carcinoma.</p

Anti-cancer effects and mechanism of actions of aspirin analogues in the treatment of glioma cancer

INTRODUCTION: In the past 25 years only modest advancements in glioma treatment have been made, with patient prognosis and median survival time following diagnosis only increasing from 3 to 7 months. A substantial body of clinical and preclinical evidence has suggested a role for aspirin in the treatment of cancer with multiple mechanisms of action proposed including COX 2 inhibition, down regulation of EGFR expression, and NF-κB signaling affecting Bcl-2 expression. However, with serious side effects such as stroke and gastrointestinal bleeding, aspirin analogues with improved potency and side effect profiles are being developed. METHOD: Effects on cell viability following 24 hr incubation of four aspirin derivatives (PN508, 517, 526 and 529) were compared to cisplatin, aspirin and di-aspirin in four glioma cell lines (U87 MG, SVG P12, GOS – 3, and 1321N1), using the PrestoBlue assay, establishing IC50 and examining the time course of drug effects. RESULTS: All compounds were found to decrease cell viability in a concentration and time dependant manner. Significantly, the analogue PN517 (IC50 2mM) showed approximately a twofold increase in potency when compared to aspirin (3.7mM) and cisplatin (4.3mM) in U87 cells, with similar increased potency in SVG P12 cells. Other analogues demonstrated similar potency to aspirin and cisplatin. CONCLUSION: These results support the further development and characterization of novel NSAID derivatives for the treatment of glioma