The problem of quantum chaotic scattering with direct processes reduced to the one without

We show that the study of the statistical properties of the scattering matrix S for quantum chaotic scattering in the presence of direct processes (charaterized by a nonzero average S matrix ) can be reduced to the simpler case where direct processes are absent ( = 0). Our result is verified with a numerical simulation of the two-energy autocorrelation for two-dimensional S matrices. It is also used to extend Wigner's time delay distribution for one-dimensional S matrices, recently found for = 0, to the case not equal to zero; this extension is verified numerically. As a consequence of our result, future calculations can be restricted to the simpler case of no direct processes.Comment: 9 pages (Latex) and 1 EPS figure. Submitted to Europhysics Letters. The conjecture proposed in the previous version is proved; thus the present version contains a more satisfactory presentation of the proble

Desenvolvimento e aplicação biológica de nanossistemas contendo novos fotossensibilizantes derivados do benzo[a]fenoxazinio

Dissertação (mestrado)—Fundação Universidade de Brasília, Programa de Pós-Graduação em Biologia Animal, 2019.O presente trabalho teve como proposta desenvolver dois nanosistemas contendo fotossensibilizantes (FS) sintéticos do tipo benzo[a]fenoxazínio para serem utilizados em terapia fotodinâmica. Foram desenvolvidos um lipossoma e um nanocarreador lipídico nanoestruturado. Em seguida, foram associados a eles diferentes fotossensibilizantes conjugados com moléculas biológicas para direcionamento do fotossensibilizante ao tumor. O presente trabalho apresenta o desenvolvimento de nanossistemas de fabricação simples, com componentes já estabelecidos como pouco tóxicos, permitindo assim maior facilidade de produção e aplicabilidade na TFD. O trabalho analisou a atividade biológica dos sistemas desenvolvidos em diferentes tipos de linhagens celulares. Os lipossomas foram desenvolvidos pela técnica de hidratação de filme lipídico e os nanocarreadores lipídicos nanoestruturados pelo método de temperatura de inversão de fases. Os ensaios biológicos, in vitro, foram feitos pelo método 3,(4,5- dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT). Ao avaliar os nanosistemas desenvolvidos como possíveis fotossensibilizantes, notou-se que eles apresentaram boas características para ser utilizados em TFD. Possuem características fotofísicas que o habilitam como FS, além de apresentar capacidade de gerar ERO, baixa toxicidade no escuro e capacidade de reduzir a viabilidade de células tumorais in vitro, quando irradiado.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) e Fundação de Apoio à Pesquisa do Distrito Federal (FAP/DF).The present work had as proposal to develop two nanosystems containing synthetic benzo [a] phenoxazinium photosensitizers (FS) to be used in photodynamic therapy. A liposome and a nanostructured lipid nanocarrier have been developed. Subsequently, different photosensitizers conjugated with biological molecules were associated with them to direct the photosensitizer to the tumor. The present work presents the development of simple manufacturing nanosystems, with components already established as little toxic, thus allowing greater ease of production and applicability in PDT. The work analyzed the biological activity of the systems developed in different types of cell lines. Liposomes were developed by the lipid film hydration technique and nanostructured lipid nanocarriers by the phase inversion temperature method. Biological assays, in vitro, were done by the method 3, (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT). When evaluating the nanosystems developed as possible photosensitizers, it was observed that they presented good characteristics to be used in PDT. They have photophysical characteristics that enable it as FS, besides being able to generate ERO, low toxicity in the dark and ability to reduce the viability of tumor cells in vitro, when irradiated

A model of trust applied to the management ofinformation technology

This work presents a model of trust as it relates to the management of informationtechnology (IT). We comment on the definition of trust as applied to contemporarybusiness environments, and discuss the associated risks due to the complexity of modernglobalized relationships. This work focuses on IT management, emphasizing the necessityof aligning organizational strategies with a company’s activities as recent studies haveconcluded that organizations that exhibit “business-focused” IT management are subjectto less risk. In this context, our proposed model enables the evaluation of trust as itrelates to IT management, by means of metrics that are related to business factors. Afield application of this model demonstrates the relevance of measuring trust as a meansto mitigate business risks related to IT management

The Welfare Cost of Macroeconomic Uncertainty in the Post-War Period

Lucas (1987) has shown the surprising result that the welfare cost of business cycles is quite small. Using standard assumptions on preferences and a fully-fledged econometric model we computed the welfare costs of macroeconomic uncertainty for the post-WWII era using the multivariate Beveridge-Nelson decomposition for trends and cycles, which considers not only business-cycle uncertainty but also uncertainty from the stochastic trend in consumption. The post-WWII period is relatively quiet, with the welfare costs of uncertainty being about 0.9% of per-capita consumption. Although changing the decomposition method changed substantially initial results, the welfare cost of uncertainty is qualitatively small in the post-WWII era - about $175.00 a year per-capita in the U.S. We also computed the marginal welfare cost of macroeconomic uncertainty using this same technique. It is about twice as large as the welfare cost -$350.00 a year per-capita.welfare costs of business cycles, Beveridge-Nelson decomposition

On the Welfare Costs of Business-Cycle Fluctuations and Economic-Growth Variation in the 20th Century

Lucas (1987) has shown a surprising result in business-cycle research: the welfare cost ofbusiness cycles are very small. Our paper has several original contributions. First, in computingwelfare costs, we propose a novel setup that separates the effects of uncertainty stemming frombusiness-cycle fluctuations and economic-growth variation. Second, we extend the sample from which to compute the moments of consumption: the whole of the literature chose primarily to work with post-WWII data. For this period, actual consumption is already a result of counter-cyclical policies, and is potentially smoother than what it otherwise have been in their absence. So, we employ also pre-WWII data. Third, we take an econometric approach and compute explicitly the asymptotic standard deviation of welfare costs using the Delta Method. Estimates of welfare costs show major differences for the pre-WWII and the post-WWII era. They can reach up to 15 times for reasonable parameter values -β=0.985, and ∅=5. For example, in the pre-WWII period (1901-1941), welfare cost estimates are 0.31% of consumption if we consider only permanent shocks and 0.61% of consumption if we consider only transitory shocks. In comparison, the post-WWII era is much quieter: welfare costs of economic growth are 0.11% and welfare costs of business cycles are 0.037% - the latter being very close to the estimate in Lucas (0.040%). Estimates of marginal welfare costs are roughly twice the size of the total welfare costs. For the pre-WWII era, marginal welfare costs of economic-growth and business- cycle fluctuations are respectively 0.63% and 1.17% of per-capita consumption. The same figures for the post-WWII era are, respectively, 0.21% and 0.07% of per-capita consumption.

Conductance distributions of 1D-disordered wires at finite temperature and bias voltage

We calculate the distribution of the conductance G in a one-dimensional disordered wire at finite temperature T and bias voltage V in a independent-electron picture and assuming full coherent transport. At high enough temperature and bias voltage, where several resonances of the system contribute to the conductance, the distribution P(G(T,V)) can be represented with good accuracy by autoconvolutions of the distribution of the conductance at zero temperature and zero bias voltage. The number of convolutions depends on T and V. In the regime of very low T and V, where only one resonance is relevant to G(T,V), the conductance distribution is analyzed by a resonant tunneling conductance model. Strong effects of finite T and V on the conductance distribution are observed and well described by our theoretical analysis, as we verify by performing a number of numerical simulations of a one-dimensional disordered wire at different temperatures, voltages, and lengths of the wire. Analytical estimates for the first moments of P(G(T,V)) at high temperature and bias voltage are also provided.Comment: 9 pages, 7 figures, Submitted to PR

Photonic heterostructures with Levy-type disorder: statistics of coherent transmission

We study the electromagnetic transmission $T$ through one-dimensional (1D) photonic heterostructures whose random layer thicknesses follow a long-tailed distribution --L\'evy-type distribution. Based on recent predictions made for 1D coherent transport with L\'evy-type disorder, we show numerically that for a system of length $L$ (i) the average $\propto L^\alpha$ for $0 \propto L$ for $1\le\alpha<2$, $\alpha$ being the exponent of the power-law decay of the layer-thickness probability distribution; and (ii) the transmission distribution $P(T)$ is independent of the angle of incidence and frequency of the electromagnetic wave, but it is fully determined by the values of $\alpha$ and $$.Comment: 4 pages, 4 figure