Giant Rashba splitting of quasi-1D surface states on Bi/InAs(110)-(2×\times1)

Electronic states on the Bi/InAs(110)-(2$\times$1) surface and its spin-polarized structure are revealed by angle-resolved photoelectron spectroscopy (ARPES), spin-resolved ARPES, and density-functional-theory calculation. The surface state showed quasi-one-dimensional (Q1D) dispersion and a nearly metallic character; the top of the hole-like surface band is just below the Fermi level. The size of the Rashba parameter ($\alpha_{\rm R}$) reached quite a large value ($\sim$5.5 eV\AA). The present result would provide a fertile playground for further studies of the exotic electronic phenomena in 1D or Q1D systems with the spin-split electronic states as well as for advanced spintronic devices.Comment: 8 pages (double column), 7 figures and 1 tabl

Oriental oculopalpebral dimensions: Quantitative comparison between Orientals from Japan and Brazil

Rodrigo U Takahagi1, Silvana A Schellini1, Carlos R Padovani1, Shinji Ideta2, Nobutada Katori2, Yasuhisa Nakamura21Department of Ophthalmology, Faculdade de Medicina de Botucatu, Botucatu, Sao Paulo State, Brazil; 2Department of Oculoplastic and Orbital Surgery, Hamamatsu Seirei General Hospital, Hamamatsu, Shizuoka-ken, JapanObjectives: Quantitative evaluation of palpebral dimensions of Japanese residents in Japan and Japanese descendant (Nikkeis) who live in Brazil, in order to define if environmental factors may influence these parameters.Methods: A prospective study evaluating 107 Nikkeis from Brazil and 114 Japanese residents in Japan, aged 20 years or older. Exclusion criteria were those with palpebral position alterations, prior palpebral surgery, and crossbreeding. Images were obtained with a digital camera, 30 cm from the frontal plane at pupil height, with the individual in a primary position and the eye trained on the camera lens. Images were transferred to computer and processed by the Scion Image program. Measurements were made of distance between medial canthi, distance between pupils (IPD), superior eyelid crease position, distance between the superior lid margin and corneal reflexes (MRD), horizontal width, height, area, and obliquity of the palpebral fissure. Data were analyzed using analysis of variance for a three factor model and respective multiple comparison tests.Results: Japanese residents and Nikkeis living in Brazil have similar measurements. Statistical differences were found for some age groups concerning distance between pupils, horizontal, and vertical fissures, palpebral fissure area, and obliquity with native Japanese presenting discretely higher measurements than Nikkeis.Conclusion: Environmental factors do not affect palpebral dimensions of Nikkeis living in Brazil.Keywords: eyelid dimensions, Japanese, Nikkeis, digital imag

Non-trivial surface states of samarium hexaboride at the (111) surface

The peculiar metallic electronic states observed in the Kondo insulator, samarium hexaboride (SmB$_6$), has stimulated considerable attention among those studying non-trivial electronic phenomena. However, experimental studies of these states have led to controversial conclusions mainly to the difficulty and inhomogeneity of the SmB$_6$ crystal surface. Here, we show the detailed electronic structure of SmB$_6$ with angle-resolved photoelectron spectroscopy measurements of the three-fold (111) surface where only two inequivalent time-reversal-invariant momenta (TRIM) exist. We observe the metallic two-dimensional state was dispersed across the bulk Kondo gap. Its helical in-plane spin polarisation around the surface TRIM suggests that SmB$_6$ is topologically non-trivial, according to the topological classification theory for weakly correlated systems. Based on these results, we propose a simple picture of the controversial topological classification of SmB$_6$.Comment: 34 pages, 4 figures for main text; 9 figures for supplementary materia

Feiras livres como alternativa de comercialização de produtos da agrofloresta.

Com a busca por alternativas comerciais socialmente justas como maneira de otimizar a comercialização de produtos provenientes de agricultura familiar, destaca se a venda direta através de feiras, livres, que permite acesso direto ao consumidor sem necessidade de intermediadores. O Grupo de Produtores Agroflorestais Gralha Azul, de Morretes-PR, iniciou plantios de agroflorestas agroecológicas em 2009, sendo formado, atualmente, por 12 famílias de agricultores. Há um ano, o Gralha Azul iniciou sua participação na Matinfeira, feira semanal de produtos da agricultura familiar em Matinhos, PR. Com o objetivo de caracterização dos produtos, produtores e do processo de comercialização, foram acompanhados e sistematizados em planilha a comercialização destes produtos em 22 feiras semanais, entre maio e dezembro de 2012. Onze produtores participaram da Matinfeira, comercializando entre 13 e 29 variedades de alimentos, e proporcionando uma renda que variou de R$101,00 a R$ 386,50, por semana. Mensalmente, as feiras permitiram uma receita bruta de R$ 141,17 por produtor familiar agroflorestal. Apesar desse baixo valor, há que se considerar que o mesmo reflete os primeiros seis meses de atuação do Grupo no processo de comercialização na feira (Matinfeira). A venda direta através desta feira livre mostra potencial como alternativa comercial socialmente justa para os produtores em transição agroecológica do Grupo Gralha Azul

Uncovering the Origins of Spiral Structure by Measuring Radial Variation in Pattern Speeds

Current theories of spiral and bar structure predict a variety of pattern speed behaviors, calling for detailed, direct measurement of the radial variation of pattern speeds. Our recently developed Radial Tremaine-Weinberg (TWR) method allows this goal to be achieved for the first time. Here we present TWR spiral pattern speed estimates for M101, IC 342, NGC 3938 and NGC 3344 in order to investigate whether spiral structure is steady or winding, whether spirals are described by multiple pattern speeds, and the relation between bar and spiral speeds. Where possible, we interpret our pattern speeds estimates according to the resonance radii associated with each (established with the disk angular rotation), and compare these to previous determinations. By analyzing the high-quality HI and CO data cubes available for these galaxies, we show that it is possible to determine directly multiple pattern speeds within these systems, and hence identify the characteristic signatures of the processes that drive the spiral structure. Even this small sample of galaxies reveals a surprisingly complex taxonomy, with the first direct evidence for the presence of resonant coupling of multiple patterns found in some systems, and the measurement of a simple single pattern speed in others. Overall, this study demonstrates that we are now in a position to uncover more of the apparently complex physics that lies behind spiral structure.Comment: 15 pages in emulateapj format, 12 figures, accepted for publication in Ap

Programmable models of growth and mutation of cancer-cell populations

In this paper we propose a systematic approach to construct mathematical models describing populations of cancer-cells at different stages of disease development. The methodology we propose is based on stochastic Concurrent Constraint Programming, a flexible stochastic modelling language. The methodology is tested on (and partially motivated by) the study of prostate cancer. In particular, we prove how our method is suitable to systematically reconstruct different mathematical models of prostate cancer growth - together with interactions with different kinds of hormone therapy - at different levels of refinement.Comment: In Proceedings CompMod 2011, arXiv:1109.104