A simple proof of the strong subadditivity inequality

Arguably the deepest fact known about the von Neumann entropy, the strong subadditivity inequality is a potent hammer in the quantum information theorist's toolkit. This short tutorial describes a simple proof of strong subadditivity due to Petz [Rep. on Math. Phys. 23 (1), 57-65 (1986)]. It assumes only knowledge of elementary linear algebra and quantum mechanics.

Optical Bloch equations and enhanced decay of Rabi oscillations in strong driving fields

Optical Bloch equations are widely used for describing dynamics in a system consisting molecules, electromagnetic waves, and a thermal bath. We analyze applicability of these equations to a single molecule imbedded in a solid matrix. Classical Bloch equations and the limits of their applicability are derived from more general master equations. Simple and intuitively appealing picture based on stochastic Bloch equations shows that at low temperatures, contrary to common believes, a strong driving field can not only suppress but can also increase decay rates of Rabi oscillations. A physical system where predicted effects can be observed experimentally is suggested. (c) 2005 Elsevier B.V. All rights reserved.

Restricted mating dispersal and strong breeding group structure in a mid-sized marsupial mammal (Petrogale penicillata)

Ecological genetic studies have demonstrated that spatial patterns of mating dispersal, the dispersal of gametes through mating behaviour, can facilitate inbreeding avoidance and strongly influence the structure of populations, particularly in highly philopatric species. Elements of breeding group dynamics, such as strong structuring and sex-biased dispersal among groups, can also minimize inbreeding and positively influence levels of genetic diversity within populations. Rock-wallabies are highly philopatric mid-sized mammals whose strong dependence on rocky terrain has resulted in series of discreet, small colonies in the landscape. Populations show no signs of inbreeding and maintain high levels of genetic diversity despite strong patterns of limited gene flow within and among colonies. We used this species to investigate the importance of mating dispersal and breeding group structure to inbreeding avoidance within a 'small' population. We examined the spatial patterns of mating dispersal, the extent of kinship within breeding groups, and the degree of relatedness among brush-tailed rock-wallaby breeding pairs within a colony in southeast Queensland. Parentage data revealed remarkably restricted mating dispersal and strong breeding group structuring for a mid-sized mammal. Breeding groups showed significant levels of female kinship with evidence of male dispersal among groups. We found no evidence for inbreeding avoidance through mate choice; however, anecdotal data suggest the importance of life history traits to inbreeding avoidance between first-degree relatives. We suggest that the restricted pattern of mating dispersal and strong breeding group structuring facilitates inbreeding avoidance within colonies. These results provide insight into the population structure and maintenance of genetic diversity within colonies of the threatened brush-tailed rock-wallaby.

Strong and weak lifespan extension: What is most feasible and likely?

Recent advances in biomedical science indicate that it may eventually be possible to intervene in the biological process of human ageing. This paper overviews the current state of the science of lifespan extension and promising future directions. It is uncertain whether 'strong' lifespan extension - the extension of human life beyond the maximum 122 years so far observed - will become a reality. It is more likely that cumulative effects of numerous scientific and biomedical advances in the treatment of common disease will produce 'weak' lifespan extension - the extension of average life expectancy. The practical application of molecular, genetic and nanomaterials research may also lead to advances in life expectancy. It is not too early to begin to consider the policy implications of either form of lifespan extension.

Strong electronic correlations in superconducting organic charge transfer salts

We review the role of strong electronic correlations in quasi-two-dimensional organic charge transfer salts such as (BEDT-TTF)(2)X, (BETS)(2)Y, and beta'-[Pd(dmit)(2)](2)Z. We begin by defining minimal models for these materials. It is necessary to identify two classes of material: the first class is strongly dimerized and is described by a half-filled Hubbard model; the second class is not strongly dimerized and is described by a quarter-filled extended Hubbard model. We argue that these models capture the essential physics of these materials. We explore the phase diagram of the half-filled quasi-two-dimensional organic charge transfer salts, focusing on the metallic and superconducting phases. We review work showing that the metallic phase, which has both Fermi liquid and 'bad metal' regimes, is described both quantitatively and qualitatively by dynamical mean field theory (DMFT). The phenomenology of the superconducting state is still a matter of contention. We critically review the experimental situation, focusing on the key experimental results that may distinguish between rival theories of superconductivity, particularly probes of the pairing symmetry and measurements of the superfluid stiffness. We then discuss some strongly correlated theories of superconductivity, in particular the resonating valence bond (RVB) theory of superconductivity. We conclude by discussing some of the major challenges currently facing the field. These include parameterizing minimal models, the evidence for a pseudogap from nuclear magnetic resonance (NMR) experiments, superconductors with low critical temperatures and extremely small superfluid stiffnesses, the possible spin- liquid states in kappa-(ET)(2)Cu-2(CN)(3) and beta'-[Pd(dmit)(2)](2)Z, and the need for high quality large single crystals.

RELAÇÕES DE SUPORTE E BEM-ESTAR NO TRABALHO EM PESSOAS COM DEFICIÊNCIA

Desde tempos remotos é notória a busca da humanidade para entender e conquistar a felicidade, qualidade de vida, bem-estar e saúde na sua plenitude bio-psico-social. Assim, o objetivo geral deste estudo foi analisar as relações entre percepções de suporte (social, social no trabalho e organizacional) e bem-estar no trabalho (satisfação no trabalho, envolvimento com o trabalho e comprometimento organizacional afetivo) em trabalhadores com deficiência, pois são poucas as pesquisas sobre pessoas com deficiência (PCD). O propósito em abordar o trabalho é por ser um importante elemento de integração social e por constituir um símbolo de reconhecimento social, valorizando a capacidade de estreitar contatos e de estabelecer relações sociais. Deste estudo, participaram 44 trabalhadores com algum tipo de deficiência que atuam em cargos operacionais, técnicos e administrativos. Todos foram escolhidos por conveniência, sendo 24 (54,5%) do sexo masculino e 20 (45,5%) do sexo feminino, com idade entre 18 e 65 anos. Foi possível classificar as deficiências dos participantes em quatro categorias: deficiência nos membros superiores: 9 (20,5%) trabalhadores; deficiência nos membros inferiores: 11 (25%) trabalhadores; deficiência auditiva: 21 (47,7%) trabalhadores; deficiência visual: 3 (6,8%) trabalhadores. Para a coleta de dados foi utilizado questionário de auto-preenchimento, composto de seis escalas que avaliam satisfação no trabalho, envolvimento com o trabalho e comprometimento organizacional, além de suporte social, suportes social no trabalho e organizacional. Foram realizadas análises estatísticas descritivas, testadas diferenças entre médias, bem como calculados coeficientes de correlação entre variáveis. Os resultados apontam que em termos de satisfação no trabalho, não revelam discrepâncias entre estudos realizados com trabalhadores sem deficiências (considerados normais ). Também foi possível observar que as PCD declaram ter orgulho da empresa em que trabalham, além de estarem contentes, entusiasmadas, interessadas e animadas com a organização empregadora. O estudo revelou que as PCD obtêm de sua rede social, ajuda emocional que lhes proporciona sentimento de apoio frente às dificuldades ou carências afetivas, pois provavelmente entendam que podem contar com essa rede para comemorar realizações e sucessos, da mesma forma que receber carinho e consolo quando se frustram ou passam por algum momento triste. É possível afirmar que as PCD percebem que essa mesma rede seria capaz de lhes prover algum apoio prático, como receber informações acerca de sua saúde, talvez reabilitação, também informações para atualização profissional ou até acompanhamento do seu desenvolvimento, inclusive busca de novas oportunidades e desafios para crescimento pessoal e profissional. Os resultados desta pesquisa indicam que as PCD tendem a manter uma forte convicção de que a empresa em que trabalham preocupa-se com seu bem-estar e está disposta a oferecer ajuda diante uma necessidade. Demais resultados sinalizam que as PCD tendem a aumentar o seu vínculo com o trabalho vivenciando mais satisfação na medida em que também aumentam os suportes ofertados pela organização, pela rede social no contexto do trabalho e fora dele. A análise de todo o conteúdo confeccionado é a grande contribuição deste estudo, por ser considerado pioneiro nesta discussão, mas futuros estudos podem vir a confirmar tais resultados e corroborar com mais informações.(AU)

Affect networks:a structural analysis of the relationship between work ties and job-related affect

The relationship between organizational networks and employees' affect was examined in 2 organizations. In Study 1, social network analysis of work ties and job-related affect for 259 employees showed that affect converged within work interaction groups. Similarity of affect between employees depended on the presence of work ties and structural equivalence. Affect was also related to the size and density of employees' work networks. Study 2 used a 10-week diary study of 31 employees to examine a merger of 2 organizational divisions and found that negative changes in employees' affect were related to having fewer cross-divisional ties and to experiencing greater reductions in network density. The findings suggest that affect permeates through and is shaped by organizational networks.