Quantum correlations between each qubit in a two-atom system and the environment in terms of interatomic distance

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Development of an open case-based decision-support system for diagnosis in oral pathology

Making diagnoses in oral pathology are often difficult and confusing in dental practice, especially for the lessexperienced dental student. One of the most promising areas in bioinformatics is computer-aided diagnosis, where a computer system is capable of imitating human reasoning ability and provides diagnoses with an accuracy approaching that of expert professionals. This type of system could be an alternative tool for assisting dental students to overcome the difficulties of the oral pathology learning process. This could allow students to define variables and information, important to improving the decision-making performance. However, no current open data management system has been integrated with an artificial intelligence system in a user-friendly environment. Such a system could also be used as an education tool to help students perform diagnoses. The aim of the present study was to develop and test an open case-based decisionsupport system.Methods: An open decision-support system based on Bayes' theorem connected to a relational database was developed using the C++ programming language. The software was tested in the computerisation of a surgical pathology service and in simulating the diagnosis of 43 known cases of oral bone disease. The simulation was performed after the system was initially filled with data from 401 cases of oral bone disease.Results: the system allowed the authors to construct and to manage a pathology database, and to simulate diagnoses using the variables from the database.Conclusion: Combining a relational database and an open decision-support system in the same user-friendly environment proved effective in simulating diagnoses based on information from an updated database.

Quantum and semiclassical Husimi distributions for a one-dimensional resonant system

We compare exact and semiclassical Husimi distributions for the single eigenstates of a one-dimensional resonant Hamiltonian. We find that both distributions concentrate near the unstable fixed points even when these points are made complex by suitably varying a parameter. © 1992 The American Physical Society.

Two definitions of the electric polarizability of a bound system in relativistic quantum theory

For the electric polarizability of a bound system in relativistic quantum theory, there are two definitions that have appeared in the literature. They differ depending on whether or not the vacuum background is included in the system. A recent confusion in this connection is clarified. © 1999 American Associations of Physics Teachers.

Sm-Nd system in total rock open versus closed isotopic composition in zones of high deformation

High strain shear zones of Brasiliano age, developed in Paleoproterozoic basement gneiss of the Caicó region, Borborema Province, NE Brazil, were associated with medium- to low-grade metamorphism and deformational processes that transformed porphyritic augen gneiss into muscovite quartzite, modifying their original mineralogy and chemical properties. During the last hydrothermal event mobility of major, minor and trace elements was great, whereas the pattern of Rare Earth Elements was not changed. We carried out a Sm-Nd isotopic study in these rocks in order to understand the behavior of Nd isotopes during mylonite generation. TDM model ages at around 2.6 Ga and εNd (t) values for both protolith and transformed rock suggest that the Nd isotopic system remained closed, recording the original source rock signature, despite undergoing two superposed metamorphic events. These new Sm-Nd results provide important information on the geologic evolution of basement rocks in the central Rio Grande do Norte Terrane of the Borborema Province, NE Brazil.

Sudden change of quantum discord for a system of two qubits

It is known that quantum discord might experience a sudden transition in its dynamics when calculated for certain Bell-diagonal states (BDS) that are in interaction with their surroundings. We examine this phenomenon, known as the sudden change of quantum discord, considering the case of two qubits independently interacting with dephasing reservoirs. We first demonstrate that, for a class of initial states which can be chosen arbitrarily close to BDS, the transition is in fact not sudden, although it might numerically appear so if not studied carefully. Then, we provide an extension of this discussion covering the X-shaped density matrices. Our findings suggest that the transition of quantum discord might be sudden only for an highly idealized zero-measure subset of states within the set of all possible initial conditions of two qubits. © 2013 American Physical Society.

Non-Markovianity through flow of information between a system and an environment

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Entropy effect in quantum computing and information: an open-source environment simulation

The technologies are rapidly developing, but some of them present in the computers, as for instance their processing capacity, are reaching their physical limits. It is up to quantum computation offer solutions to these limitations and issues that may arise. In the field of information security, encryption is of paramount importance, being then the development of quantum methods instead of the classics, given the computational power offered by quantum computing. In the quantum world, the physical states are interrelated, thus occurring phenomenon called entanglement. This study presents both a theoretical essay on the merits of quantum mechanics, computing, information, cryptography and quantum entropy, and some simulations, implementing in C language the effects of entropy of entanglement of photons in a data transmission, using Von Neumann entropy and Tsallis entropy.

Mating system of a population of Myracrodruon urundeuva F.F. & M.F. Allemão using the fAFLP molecular marker

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fertilizer distribution mechanisms and side dress nitrogen fertilization in upland rice under no-tillage system

Algumas culturas têm pouca adaptação ao sistema plantio direto (SPD), em vista da alta compactação da camada superficial do solo. Nesse caso, o mecanismo utilizado na semeadora para a abertura dos sulcos para deposição do fertilizante pode ter grande importância no sentido de facilitar a penetração das raízes. Avaliouse a influência do mecanismo de distribuição de fertilizante e da adubação nitrogenada na cultura do arroz de terras altas (Oryza sativa) no sistema plantio direto. O experimento foi conduzido nos anos agrícolas 2001/2002 e 2002/2003, em Botucatu-SP, Brasil. O delineamento experimental foi em blocos casualizados, com parcelas subdivididas e quatro repetições. As parcelas foram constituídas por dois mecanismos de distribuição de fertilizantes (haste sulcadora e disco duplo). Nas subparcelas, quatro níveis de N foram aplicados em cobertura (0, 40, 80 e 120 kg ha-1). Avaliou-se a profundidade de abertura do sulco e de deposição das sementes, a população de plantas, a altura de plantas, o número de colmos e de panículas m-2, o número total de espiguetas por panícula, a fertilidade das espiguetas, a massa de 1.000 grãos, a matéria seca da parte aérea, a produtividade e o teor de N na folha bandeira. O sucesso no estabelecimento da cultura do arroz de terras altas no SPD nas regiões de inverno seco do Brasil está diretamente ligado ao mecanismo de distribuição das semeadoras-adubadoras. A haste sulcadora promoveu maior profundidade de deposição de sementes, conseqüentemente reduzindo o estande, o número de panículas por área e a produtividade. A aplicação de N em cobertura no arroz de terras altas em SPD proporciona maiores produtividades quando a semeadura é realizada com mecanismo de disco duplo.

Fos-like immunoreactivity in central nervous system of mice simultaneously exposed to the elevated plus-maze and nociception

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Photoinduced hole-transfer in semiconducting polymer/low-bandgap cyanine dye blends: evidence for unit charge separation quantum yield

Power-conversion efficiencies of organic heterojunction solar cells can be increased by using semiconducting donor-acceptor materials with complementary absorption spectra extending to the near-infrared region. Here, we used continuous wave fluorescence and absorption, as well as nanosecond transient absorption spectroscopy to study the initial charge transfer step for blends of a donor poly(p-phenylenevinylene) derivative and low-band gap cyanine dyes serving as electron acceptors. Electron transfer is the dominant relaxation process after photoexcitation of the donor. Hole transfer after cyanine photoexcitation occurs with an efficiency close to unity up to dye concentrations of similar to 30 wt%. Cyanines present an efficient self-quenching mechanism of their fluorescence, and for higher dye loadings in the blend, or pure cyanine films, this process effectively reduces the hole transfer. Comparison between dye emission in an inert polystyrene matrix and the donor matrix allowed us to separate the influence of self-quenching and charge transfer mechanisms. Favorable photovoltaic bilayer performance, including high open-circuit voltages of similar to 1 V confirmed the results from optical experiments. The characteristics of solar cells using different dyes also highlighted the need for balanced adjustment of the energy levels and their offsets at the heterojunction when using low-bandgap materials, and accentuated important effects of interface interactions and solid-state packing on charge generation and transport.

Mating system parameters at hierarchical levels of fruits, individuals and populations in the Brazilian insect-pollinated tropical tree, Tabebuia roseo-alba (Bignoniaceae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of seasonal variation on the central nervous system activity of Ocimum gratissimum L. essential oil

Ocimum gratissimum L. (Lamiaceae) and other species of the same genus are used as medicines to treat central nervous system (CNS) diseases, commonly encountered in warm regions of the world. The chemical composition of Ocimum gratissimum essential oil varies according to their chemotypes: timol, eugenol or geraniol. In this study, the essential oil type eugenol was extracted by hydrodistillation in each of the four seasons of the year. Activity upon CNS was evaluated in the open-field and rota-rod tests; sleeping time induced by sodium pentobarbital (PBS, 40 mg/kg, intraperitoneally, i.p.) and anticonvulsant activity against seizures induced by both pentylenetetrazole (PTZ; 85 mg/kg, s.c.) and maximal electroshock (MES, 50 mA, 0.11 s) were determined. Essential oils obtained in each season were effective in increasing the sleeping duration and a preparation obtained in Spring was able to protect animals against tonic seizures induced by electroshock. In each season, eugenol and 1,8-cineole were the most abundant compounds, and in Spring the essential oil presented the greatest relative percentage of sesquiterpenes, suggesting that these compounds could explain the differences observed in the biological activity in essential oils obtained in different seasons of the year. (c) 2005 Elsevier B.V.. All rights reserved.

Quantum states, thermodynamic limits, and entropy in M theory

We discuss the matching of the BPS part of the spectrum for a (super) membrane, which gives the possibility of getting the membrane's results via string calculations. In the small coupling limit of M theory the entropy of the system coincides with the standard entropy of type IIB string theory (including the logarithmic correction term). The thermodynamic behavior at a large coupling constant is computed by considering M theory on a manifold with a topology T-2 x R-9. We argue that the finite temperature partition functions (brane Laurent series for p not equal 1) associated with the BPS p-brane spectrum can be analytically continued to well-defined functionals. It means that a finite temperature can be introduced in brane theory, which behaves like finite temperature field theory. In the limit p --> 0 (point particle limit) it gives rise to the standard behavior of thermodynamic quantities.