Woods-Saxon equivalent to a double folding potential

A Woods-Saxon equivalent to a double folding potential in the surface region is obtained for the heavy-ion scattering potential. The Woods-Saxon potential has fixed geometry and was applied as a bare potential in the analysis of experimental data of several systems. A new analytical formula for the position and height of the Coulomb barrier is presented, which reproduces the results obtained using double folding potentials. This simple formula has been applied to estimate the fusion cross section above the Coulomb barrier. A comparison with experimental data is presented

Experimental observation of fractional topological phases with photonic qudits

Geometrical and topological phases play a fundamental role in quantum theory. Geometric phases have been proposed as a tool for implementing unitary gates for quantum computation. A fractional topological phase has been recently discovered for bipartite systems. The dimension of the Hilbert space determines the topological phase of entangled qudits under local unitary operations. Here we investigate fractional topological phases acquired by photonic entangled qudits. Photon pairs prepared as spatial qudits are operated inside a Sagnac interferometer and the two-photon interference pattern reveals the topological phase as fringes shifts when local operations are performed. Dimensions $d = 2, 3$ and $4$ were tested, showing the expected theoretical values.Comment: 6 pages, 4 figure

Hermitian symmetric polynomials and CR complexity

Properties of Hermitian forms are used to investigate several natural questions from CR Geometry. To each Hermitian symmetric polynomial we assign a Hermitian form. We study how the signature pairs of two Hermitian forms behave under the polynomial product. We show, except for three trivial cases, that every signature pair can be obtained from the product of two indefinite forms. We provide several new applications to the complexity theory of rational mappings between hyperquadrics, including a stability result about the existence of non-trivial rational mappings from a sphere to a hyperquadric with a given signature pair.Comment: 19 pages, latex, fixed typos, to appear in Journal of Geometric Analysi

Analysis of polymorphic membrane protein expression in cultured cells Identifies PmpA and PmpH of Chlamydia psittaci as candidate factors in pathogenesis and immunity to infection

The polymorphic membrane protein (Pmp) paralogous families of Chlamydia trachomatis, Chlamydia pneumoniae and Chlamydia abortus are putative targets for Chlamydia vaccine development. To determine whether this is also the case for Pmp family members of C. psittaci, we analyzed transcription levels, protein production and localization of several Pmps of C. psittaci. Pmp expression profiles were characterized using quantitative real-time PCR (RT-qPCR), immunofluorescence (IF) and immuno-electron microscopy (IEM) under normal and stress conditions. We found that PmpA was highly produced in all inclusions as early as 12 hpi in all biological replicates. In addition, PmpA and PmpH appeared to be unusually accessible to antibody as determined by both immunofluorescence and immuno-electron microscopy. Our results suggest an important role for these Pmps in the pathogenesis of C. psittaci, and make them promising candidates in vaccine development

Spin-orbit coupling and intrinsic spin mixing in quantum dots

Spin-orbit coupling effects are studied in quantum dots in InSb, a narrow-gap material. Competition between different Rashba and Dresselhaus terms is shown to produce wholesale changes in the spectrum. The large (and negative) $g$-factor and the Rashba field produce states where spin is no longer a good quantum number and intrinsic flips occur at moderate magnetic fields. For dots with two electrons, a singlet-triplet mixing occurs in the ground state, with observable signatures in intraband FIR absorption, and possible importance in quantum computation.Comment: REVTEX4 text with 3 figures (high resolution figs available by request). Submitted to PR

Young Galaxy Candidates in the Hubble Frontier Fields - III. MACSJ0717.5+3745

In this paper we present the results of our search for and study of $z \gtrsim 6$ galaxy candidates behind the third Frontier Fields (FF) cluster, MACSJ0717.5+3745, and its parallel field, combining data from Hubble and Spitzer. We select 39 candidates using the Lyman Break technique, for which the clear non-detection in optical make the extreme mid-$z$ interlopers hypothesis unlikely. We also take benefit from $z \gtrsim 6$ samples selected using previous Frontier Fields datasets of Abell 2744 and MACS0416 to improve the constraints on the properties of very high-redshift objects. We compute the redshift and the physical properties, such emission lines properties, star formation rate, reddening, and stellar mass for all Frontier Fields objects from their spectral energy distribution using templates including nebular emission lines. We study the relationship between several physical properties and confirm the trend already observed in previous surveys for evolution of star formation rate with galaxy mass, and between the size and the UV luminosity of our candidates. The analysis of the evolution of the UV Luminosity Function with redshift seems more compatible with an evolution of density. Moreover, no robust $z\ge$8.5 object is selected behind the cluster field, and few $z$$\sim$9 candidates have been selected in the two previous datasets from this legacy survey, suggesting a strong evolution in the number density of galaxies between $z$$\sim$8 and 9. Thanks to the use of the lensing cluster, we study the evolution of the star formation rate density produced by galaxies with L$>$0.03L$^{\star}$, and confirm the strong decrease observed between $z$$\sim$8 and 9.Comment: 21 pages - Accepted for publication in ApJ - v2: small correction

Compression modulus of macroscopic fiber bundles

We study dense, disordered stacks of elastic macroscopic fibers. These stacks often exhibit non-linear elasticity, due to the coupling between the applied stress and the internal distribution of fiber contacts. We propose a theoretical model for the compression modulus of such systems, and illustrate our method by studying the conical shapes frequently observed at the extremities of ropes and other fiber structures. studying the conical shapes frequently observed at theextremities of ropes and other fiber structures

Demandas tecnológicas para o sistema produtivo da mandioca nas microrregiões de Altamira e Santarém, no estado do Pará.

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Zoneamento de riscos climáticos para a cultura do dendezeiro no Estado do Pará.

Este trabalho mostra os resultados preliminares do zoneamento de riscos climáticos para a cultura do dendezeiro no estado do Pará, maior produtor de óleo de palma do Brasil, onde se concentra mais de 80% da área plantada com dendezeiros no país. O estudo utilizou dois enfoques de zoneamento: o zoneamento agroclimático e o zoneamento de riscos climáticos. O zoneamento agroclimático constou de um refinamento de estudos anteriores para a definição das áreas com boa, moderada e restrita potencialidades para a cultura, utilizando informações de exigências de clima e de solo da cultura, e de dados climatológicos do estado. O zoneamento de riscos climáticos envolveu a identificação de zonas de riscos para as áreas, previamente, identificadas no zoneamento agroclimático. Essas áreas apresentam potencialidades boa e moderada para a cultura, e se concentram no pólo de produção de dendê no Pará. Usou-se modelo de balanço hídrico para período mensal e freqüência de 80% para efetuar simulações de balanço hídrico. Determinou-se níveis de riscos climáticos a partir de análise de déficits hídricos para a fase crítica da cultura com relação a deficiência de água, considerada como o período em que ocorre a diferenciação sexual do botão floral que influencia na quantidade de cachos. Os resultados obtidos foram espacializados utilizando-se o Sistema de Informações Geográficas. Os principais resultados obtidos foram: mapa de aptidão agroclimática do dendê para o estado do Pará, indicando as áreas classificadas como boa, moderada e restrita para a cultura, e a definição de quatro níveis de riscos climáticos no pólo dendezeiro: a) com leve ou nenhum risco climático; b) com pequeno risco climático; c) com moderado risco climático e d) com grande risco climático