Nanorod to quantum dot conversion in ZnO dispersions with co-surfactants

A chemically-induced nanorod to quantum dot transition is reported in ZnO. This transition is achieved using co-surfactants in a marginally polar solvent in chimie douce (soft chemical) conditions. This is different from the physical instability driven transitions reported so far in metal nanowires and polymers. We propose a suitable mechanism for the observed phenomenon.

Effectiveness of rescue antiretroviral therapy including intravenously administered zidovudine and foscarnet in a child with HIV-1 enteropathy.

Case Reports

STABILITY ANALYSIS WITH APPLICATIONS OF A TWO-DIMENSIONAL DYNAMICAL SYSTEM ARISING FROM A STOCHASTIC MODEL FOR AN ASSET MARKET

We analyze the stability properties of equilibrium solutions and periodicity of orbits in a two-dimensional dynamical system whose orbits mimic the evolution of the price of an asset and the excess demand for that asset. The construction of the system is grounded upon a heterogeneous interacting agent model for a single risky asset market. An advantage of this construction procedure is that the resulting dynamical system becomes a macroscopic market model which mirrors the market quantities and qualities that would typically be taken into account solely at the microscopic level of modeling. The system`s parameters correspond to: (a) the proportion of speculators in a market; (b) the traders` speculative trend; (c) the degree of heterogeneity of idiosyncratic evaluations of the market agents with respect to the asset`s fundamental value; and (d) the strength of the feedback of the population excess demand on the asset price update increment. This correspondence allows us to employ our results in order to infer plausible causes for the emergence of price and demand fluctuations in a real asset market. The employment of dynamical systems for studying evolution of stochastic models of socio-economic phenomena is quite usual in the area of heterogeneous interacting agent models. However, in the vast majority of the cases present in the literature, these dynamical systems are one-dimensional. Our work is among the few in the area that construct and study analytically a two-dimensional dynamical system and apply it for explanation of socio-economic phenomena.

Comparing non-stationary and irregularly spaced time series

In this paper, we present approximate distributions for the ratio of the cumulative wavelet periodograms considering stationary and non-stationary time series generated from independent Gaussian processes. We also adapt an existing procedure to use this statistic and its approximate distribution in order to test if two regularly or irregularly spaced time series are realizations of the same generating process. Simulation studies show good size and power properties for the test statistic. An application with financial microdata illustrates the test usefulness. We conclude advocating the use of these approximate distributions instead of the ones obtained through randomizations, mainly in the case of irregular time series. (C) 2012 Elsevier B.V. All rights reserved.

La invocación de los antepasados en "De divinatione" y "De natura deorum" de Cicerón. "Religio e identidad" romana a fines de la república

La invocación del ideal del mos maiorum, entendido como conjunto de virtudes o rasgos ejemplares de los romanos, ha sido estudiada repetidamente en los textos de Cicerón. Analiza el tópico en relación con la discusión en torno a la identidad romana en textos del siglo I a.C. y delimita tres empleos diferentes: uno al que define como típicamente aristocrático, referido a la ascendencia noble de un individuo en particular; un segundo uso que, en vez de individualizar, amalgama a todos los ancestros en un mismo conjunto y establece una continuidad entre pasado y presente; finalmente, una tercera modalidad que propone una ruptura total entre el mundo de los antepasados y el de los contemporáneos. En este trabajo indagaremos el funcionamiento de este tópico en De diuinatione y De natura deorum de Cicerón. Desde nuestro punto de vista, el ideal del mos maiorum no solamente involucra virtudes éticas y morales sino que también supone una especial actitud con respecto a los dioses y el culto que resulta central en la definición de la identidad romana.