A simple deterministic self-organized critical system

We introduce a new continuous cellular automaton that presents self-organized criticality. It is one-dimensional, totally deterministic, without any kind of embedded randomness, not even in the initial conditions. This system is in the same universality class as the Oslo rice pile system, boundary driven interface depinning and the train model for earthquakes. Although the system is chaotic, in the thermodynamic limit chaos occurs only in a microscopic level.Comment: System slightly modified. New results on Liapunov exponents. Submitted for publication (8 pages

AN ECONOMIC ANALYSIS OF THE RELATIONSHIP OF POVERTY AND INCOME INEQUALITY IN RURAL WEST VIRGINIA

Ordinary and two-stage least square regressions were used to examine the major determinants of poverty and income inequality with cross-sectional data of 38 rural counties of West Virginia. The empirical findings confirm the possibility of simultaneity between poverty and income inequality and poverty level is the main determinant of increased levels of income inequality. The proportions of population in welfare, population of age 65 or older, female-headed households, people unemployed, and the level of inequality contributed to increased poverty levels. The proportion of employment shares in finance, insurance and real estate, and per capita income contributed to reduced poverty levels. But, per capita income, the proportion of human capital stock, and the proportion of employment shares in manufacturing contributed to reduced income inequality.Food Security and Poverty,

Ohmic and step noise from a single trapping center hybridized with a Fermi sea

We show that single electron tunneling devices such as the Cooper-pair box or double quantum dot can be sensitive to the zero-point fluctuation of a single trapping center hybridized with a Fermi sea. If the trap energy level is close to the Fermi sea and has line-width \gamma > k_B T, its noise spectrum has an Ohmic Johnson-Nyquist form, whereas for \gamma < k_B T the noise has a Lorentzian form expected from the semiclassical limit. Trap levels above the Fermi level are shown to lead to steps in the noise spectrum that can be used to probe their energetics, allowing the identification of individual trapping centers coupled to the device.Comment: Revised version to appear in Phys. Rev. Let

Chaos and Synchronized Chaos in an Earthquake Model

We show that chaos is present in the symmetric two-block Burridge-Knopoff model for earthquakes. This is in contrast with previous numerical studies, but in agreement with experimental results. In this system, we have found a rich dynamical behavior with an unusual route to chaos. In the three-block system, we see the appearance of synchronized chaos, showing that this concept can have potential applications in the field of seismology.Comment: To appear in Physical Review Letters (13 pages, 6 figures

Variation of nitric oxide levels in imported Plasmodium falciparum malaria episodes

Nitric oxide (NO) has been recognized during the past two decades as one of the most versatile players in the immune system. Even though the molecular mechanisms responsible by the naturally acquiredimmunity against malaria are still to be clarified, the production of NO seems to play an important role as a marker for the severity of the disease. In this study we assess the level of nitric oxide in the serumof subjects exposed to malarial settings but who have not become clinically infected by plasmodia parasites. We conclude that NO is in fact a marker of clinical infections but cannot be used as an indicator of the disease’s severity

Análise da situação da ATEPA (Assistência Técnica e Extensão Pesqueira e Aquícola) no Tocantins: perspectivas e entraves.

O presente estudo tem como objetivo geral analisar a situação dos serviços de ATEPA (Assistência Técnica e Extensão Pesqueira e Aquícola) no Tocantins e, especificamente, mapear e caracterizar as empresas prestadoras de ATEPA; e caracterizar o perfil dos extensionistas que atuam no setor pesqueiro. O estudo tem caráter exploratório-descritivo utilizando-se de fontes primárias, com o apoio da técnica de entrevista semi-estruturada, além de fontes secundárias.Organizado por: Sílvio Ricardo Maurano; AQUACIÊNCIA 2012

Qubit coherence control in a nuclear spin bath

Coherent dynamics of localized spins in semiconductors is limited by spectral diffusion arising from dipolar fluctuation of lattice nuclear spins. Here we extend the semiclassical theory of spectral diffusion for nuclear spins I=1/2 to the high nuclear spins relevant to the III-V materials and show that applying successive qubit pi-rotations at a rate approximately proportional to the nuclear spin quantum number squared (I^2) provides an efficient method for coherence enhancement. Hence robust coherent manipulation in the large spin environments characteristic of the III-V compounds is possible without resorting to nuclear spin polarization, provided that the pi-pulses can be generated at intervals scaling as I^{-2}

Efeito de diferentes solventes orgânicos sobre a viabilidade do pólen de jerivá (Syagrus romanzoffiana S. CHAM).

EVINCI. Resumo