Non-Markovian Dynamics of Quantum Discord

We evaluate the quantum discord dynamics of two qubits in independent and common non-Markovian environments. We compare the dynamics of entanglement with that of quantum discord. For independent reservoirs the quantum discord vanishes only at discrete instants whereas the entanglement can disappear during a finite time interval. For a common reservoir, quantum discord and entanglement can behave very differently with sudden birth of the former but not of the latter. Furthermore, in this case the quantum discord dynamics presents sudden changes in the derivative of its time evolution which is evidenced by the presence of kinks in its behavior at discrete instants of time.Comment: 6 pages, 4 figure

Solitary practices or social connections? : a comparative study of fathering and health experiences among white and African-Caribbean working class men

This study addresses the following research question: what are the implications of African- Caribbean and White working class men's experiences within social connections (within families, friendships, communities and workplaces), for fathering and health experiences? The purposes of this study were to undertake a primary piece of intensive qualitative research, and also to analyse, critically, the study's findings, in order to identify implications for theory, policy, practice and research. This investigation was critical, interpretative and exploratory, informed by the principles of phenomenology and ethnography. Six African-Caribbean and seven White working class men were recruited, using purposive sampling, for two semi-structured individual interviews. This enabled the exploration of the interactive effects and processes of structure and agency, in relation to social class, gender, and ethnicity. The study did not find major differences between the experiences of these two groups of men, although the assets and constraints related to African-Caribbean men's experiences of ethnicity and racism within social connections were evident. Study findings, for both groups of men, indicated that social connectedness within families, communities and workplaces was highly valued, but social connections, material and structural factors also influenced the health of the men interviewed. Furthermore, findings indicated that men's experiences of social connectedness have limitations. Specifically, men's limited insights into the links between social connectedness and health, men's perceived limitations with their communication skills, their solitary methods of dealing with perceived vulnerability, but also the uncertainty associated with their identities as men were significant findings. Indeed, men's experiences of both solitary discourses and practices and social connectedness, regarding fathering and health, were associated with discourses about masculinities. Implications for existing theory, for example Connell's (1995) work regarding masculinities, and Putnam's (1995) work regarding `social capital', are identified. In addition, implications for research, policy and practice are examined, with specific reference to the opportunities for mental health promotion with working class men who are fathers

Fano resonances in plasmonic core-shell particles and the Purcell effect

Despite a long history, light scattering by particles with size comparable with the light wavelength still unveils surprising optical phenomena, and many of them are related to the Fano effect. Originally described in the context of atomic physics, the Fano resonance in light scattering arises from the interference between a narrow subradiant mode and a spectrally broad radiation line. Here, we present an overview of Fano resonances in coated spherical scatterers within the framework of the Lorenz-Mie theory. We briefly introduce the concept of conventional and unconventional Fano resonances in light scattering. These resonances are associated with the interference between electromagnetic modes excited in the particle with different or the same multipole moment, respectively. In addition, we investigate the modification of the spontaneous-emission rate of an optical emitter at the presence of a plasmonic nanoshell. This modification of decay rate due to electromagnetic environment is referred to as the Purcell effect. We analytically show that the Purcell factor related to a dipole emitter oriented orthogonal or tangential to the spherical surface can exhibit Fano or Lorentzian line shapes in the near field, respectively.Comment: 28 pages, 10 figures; invited book chapter to appear in "Fano Resonances in Optics and Microwaves: Physics and Application", Springer Series in Optical Sciences (2018), edited by E. O. Kamenetskii, A. Sadreev, and A. Miroshnichenk

Avaliação do estado nutricional de bananais em solos de várzea e terra firme do Amazonas.

O objetivo deste trabalho foi de relacionar, a partir da análise foliar, quais os nutrientes mais limitantes para bananicultura no Amazonas, tanto aquela cultivada na várzea, quanto em terra firme

Potencial alelopático de catequinas de Tachigali myrmecophyla (leguminosae).

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