Comment on "Anderson transition in disordered graphene"

We comment on a recent letter by Amini et al. (EPL 87, 37002 (2009)) concerning the existence of a mobility edge in disordered graphene.Comment: 3 pages, 3 figure

Survival probability in Generalized Rosenzweig-Porter random matrix ensemble

We study analytically and numerically the dynamics of the generalized Rosenzweig-Porter model, which is known to possess three distinct phases: ergodic, multifractal and localized phases. Our focus is on the survival probability $R(t)$, the probability of finding the initial state after time $t$. In particular, if the system is initially prepared in a highly-excited non-stationary state (wave packet) confined in space and containing a fixed fraction of all eigenstates, we show that $R(t)$ can be used as a dynamical indicator to distinguish these three phases. Three main aspects are identified in different phases. The ergodic phase is characterized by the standard power-law decay of $R(t)$ with periodic oscillations in time, surviving in the thermodynamic limit, with frequency equals to the energy bandwidth of the wave packet. In multifractal extended phase the survival probability shows an exponential decay but the decay rate vanishes in the thermodynamic limit in a non-trivial manner determined by the fractal dimension of wave functions. Localized phase is characterized by the saturation value of $R(t\to\infty)=k$, finite in the thermodynamic limit $N\rightarrow\infty$, which approaches $k=R(t\to 0)$ in this limit.Comment: 21 pages, 12 figures, 61 reference

Gonadal changes and serum steroid levels during the annual reproductive cycle of the pearl oyster Pinctada fucata Gould

The annual reproductive cycle of peal oyster Pinctada fucata was characteised by documenting gonadal development and changes in serum levels of estradiol-17b (E2), testosterone (T) and progesterone (P) in the wild bivalve caught in natural beds in the Persian Gulf throughout the year. Bivalve populations employed in this study spawn in June-July and November-December. The pearl oysters had group synchronous ovarian development with exogenous vitellogenesis during spring and summer for first spawning and during August-September for the second spawning. Serum E2 levels in the females increased rapidly from low values in May to peak in June and also in October coinciding with the time of spawning. Serum T levels in male and female exhibited a bimodal pattern. However in the male it increased during the early spermatogenesis. P was detected in both females and males. Its concentrations start to increase during the early gametogenesis and reaching to peak during the spawning season. The obtained results indicated that vitellogenesis and spermatogenesis in pearl oyster are not completed by the mi-summer and early winter

Focusing a fountain of neutral cesium atoms with an electrostatic lens triplet

An electrostatic lens with three focusing elements in an alternating-gradient configuration is used to focus a fountain of cesium atoms in their ground (strong-field-seeking) state. The lens electrodes are shaped to produce only sextupole plus dipole equipotentials which avoids adding the unnecessary nonlinear forces present in cylindrical lenses. Defocusing between lenses is greatly reduced by having all of the main electric fields point in the same direction and be of nearly equal magnitude. The addition of the third lens gave us better control of the focusing strength in the two transverse planes and allowed focusing of the beam to half the image size in both planes. The beam envelope was calculated for lens voltages selected to produced specific focusing properties. The calculations, starting from first principles, were compared with measured beam sizes and found to be in good agreement. Application to fountain experiments, atomic clocks, and focusing polar molecules in strong-field-seeking states is discussed.Comment: 8 pages 10 figure

The role of gated myocardial perfusion scintigraphy (GMPS) in myocarditis: A case report and review of the literature

Acute myocarditis is one of the most challenging diagnoses and treatments in cardiology. The acute viral myocarditis diagnosis is usually based on high suspicion, history taking, and physical examination. Likewise, the use of chest radiography, electrocardiography (ECG), and echocardiography is helpful in making a final diagnosis, but all are non-specific. In addition, in imaging query, magnetic resonance imaging (MRI) depicts some degree of cardiac inflammation in the course of myocarditis. Myocardial perfusion imaging (MPI) has also been shown to be useful in diagnosis, and this noninvasive technique diminishes the need for myocardial biopsy. The current study presents the diagnostic and prognostic role of MPI in a 25-year-old patient with suspected myocarditis. The patient underwent gated-technetium-99m-lablled, methoxyisobutyl isonitrile, single photon emission computed tomography (Gated 99mTc-MIBI SPECT) that showed nonheterogeneous absorption with remarkable decreased radiotracer uptake in the myocardium in both stress and rest phases. In addition, the gated mode demonstrated decreased wall motion and thickening of the myocardium with a sum motion score (SMS) of 28, a sum thickening score (STS) of 15, and a measured LVEF of 34%. The study concludes that 99mTC-MIBI SPECT imaging is a useful modality in the preparation of supplementary diagnostic and prognostic information in viral myocarditis. Copyright © 2011 Via Medica

A review on data stream classification

At this present time, the significance of data streams cannot be denied as many researchers have placed their focus on the research areas of databases, statistics, and computer science. In fact, data streams refer to some data points sequences that are found in order with the potential to be non-binding, which is generated from the process of generating information in a manner that is not stationary. As such the typical tasks of searching data have been linked to streams of data that are inclusive of clustering, classification, and repeated mining of pattern. This paper presents several data stream clustering approaches, which are based on density, besides attempting to comprehend the function of the related algorithms; both semi-supervised and active learning, along with reviews of a number of recent studies

Quantum communication between trapped ions through a dissipative environment

We study two trapped ions coupled to the axial phonon modes of a one-dimensional Coulomb crystal. This system is formally equivalent to the "two spin-boson" model. We propose a scheme to dynamically generate a maximally entangled state of two ions within a decoherence-free subspace. Here the phononic environment of the trapped ions, whatever its temperature and number of modes, serves as the entangling bus. The efficient production of the pure singlet state can be exploited to perform short-ranged quantum communication which is essential in building up a large-scale quantum computer.Comment: 4 pages, 2 figure