AFFINE INTERVAL EXCHANGE TRANSFORMATIONS WITH FLIPS AND WANDERING INTERVALS

There exist uniquely ergodic affine interval exchange transformations of [0,1] with flips which have wandering intervals and are such that the support of the invariant measure is a Cantor set.

Evaluation of alternative technical markers for the pelvic coordinate system

In this study, we evaluated alternative technical markers for the motion analysis of the pelvic segment. Thirteen subjects walked eight times while tri-dimensional kinematics were recorded for one stride of each trial. Five marker sets were evaluated, and we compared the tilt, obliquity, and rotation angles of the pelvis segment: (1) standard: markers at the anterior and posterior superior iliac spines (ASIS and PSIS); (2) markers at the PSIS and at the hip joint centers, HJCs (estimated by a functional method and described with clusters of markers at the thighs); (3) markers at the PSIS and HJCs (estimated by a predictive method and described with clusters of markers at the thighs); (4) markers at the PSIS and HJCs (estimated by a predictive method and described with skin-mounted markers at the thighs based on the Helen-Hayes marker set); (5) markers at the PSIS and at the iliac spines. Concerning the pelvic angles, evaluation of the alternative technical marker sets evinced that all marker sets demonstrated similar precision across trials (about 1 degrees) but different accuracies (ranging from 1 degrees to 3 degrees) in comparison to the standard marker set. We suggest that all the investigated marker sets are reliable alternatives to the standard pelvic marker set. (C) 2009 Elsevier Ltd. All rights reserved.

Bacterial communities and biogeochemical transformations of iron and sulfur in a high saltmarsh soil profile

Microbial community structure in saltmarsh soils is stratified by depth and availability of electron acceptors for respiration. However, the majority of the microbial species that are involved in the biogeochemical transformations of iron (Fe) and sulfur (S) in such environments are not known. Here we examined the structure of bacterial communities in a high saltmarsh soil profile and discuss their potential relationship with the geochemistry of Fe and S. Our data showed that the soil horizons Ag (oxic-suboxic), Bg (suboxic), Cri (anoxic with low concentration of pyrite Fe) and Cr-2 (anoxic with high concentrations of pyrite Fe) have distinct geochemical and microbiological characteristics. In general, total S concentration increased with depth and was correlated with the presence of pyrite Fe. Soluble + exchangable-Fe, pyrite Fe and acid volatile sulfide Fe concentrations also increased with depth, whereas ascorbate extractable-Fe concentrations decreased. The occurrence of reduced forms of Fe in the horizon Ag and oxidized Fe in horizon Cr-2 suggests that the typical redox zonation, common to several marine sediments, does not occur in the saltmarsh soil profile studied. Overall, the bacterial community structure in the horizon Ag and Cr-2 shared low levels of similarity, as compared to their adjacent horizons, Bg and Cr-1, respectively. The phylogenetic analyses of bacterial 16S rRNA gene sequences from clone libraries showed that the predominant phylotypes in horizon Ag were related to Alphaproteobacteria and Bacteroidetes. In contrast, the most abundant phylotypes in horizon Cr-2 were related to Deltaproteo-bacteria, Chloroflexi, Deferribacteres and Nitrospira. The high frequency of sequences with low levels of similarity to known bacterial species in horizons Ag and Cr-2 indicates that the bacterial communities in both horizons are dominated by novel bacterial species. (c) 2008 Elsevier Ltd. All rights reserved.

Chemokines and chemokine receptors coordinate the inflammatory immune response in human cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) includes different clinical manifestations displaying diverse intensities of dermal Inflammatory infiltrate Diffuse CL (DCL) cases are hyporesponsive and lesions show very few lymphocytes and a predominance of macrophages In contrast localized CL (LCL) cases are responsive to leishmanial antigen and lesions exhibit granulocytes and mononuclear cell infiltration in the early phases changing to a pattern with numerous lymphocytes and macrophages later in the lesion Therefore different chemokines may affect the predominance of cell infiltration in distinct clinical manifestations In lesions from LCL patients we examined by flow cytometry the presence of different chemokines and their receptors in T cells and we verified a higher expression of CXCR3 in the early stages of LCL (less than 30 days of infection) and a higher expression of CCR4 in the late stages of disease (more than 60 days of infection) We also observed a higher frequency of T cells producing IL-10 in the late stage of LCL Using immunohistochemistry we observed a higher expression of CCL7 CCL17 in lesions from late LCL as well as CCR4 suggesting a preferential recruitment of regulatory T cells in the late LCL Comparing lesions from LCL and DCL patients we observed a higher frequency of CCL7 in DCL lesions These results point out the Importance of the chemokines defining the different types of cells recruited to the site of the infection which could be related to the outcome of infection as well as the clinical form observed (C) 2010 American Society for Histocompatibility and Immunogenetics Published by Elsevier Inc All rights reserved

Retinoic Acid and VEGF Delay Smooth Muscle Relative to Endothelial Differentiation to Coordinate Inner and Outer Coronary Vessel Wall Morphogenesis

Rationale: Major coronary vessels derive from the proepicardium, the cellular progenitor of the epicardium, coronary endothelium, and coronary smooth muscle cells (CoSMCs). CoSMCs are delayed in their differentiation relative to coronary endothelial cells (CoEs), such that CoSMCs mature only after CoEs have assembled into tubes. The mechanisms underlying this sequential CoE/CoSMC differentiation are unknown. Retinoic acid (RA) is crucial for vascular development and the main RA-synthesizing enzyme is progressively lost from epicardially derived cells as they differentiate into blood vessel types. In parallel, myocardial vascular endothelial growth factor (VEGF) expression also decreases along coronary vessel muscularization. Objective: We hypothesized that RA and VEGF act coordinately as physiological brakes to CoSMC differentiation. Methods and Results: In vitro assays (proepicardial cultures, cocultures, and RALDH2 [retinaldehyde dehydrogenase-2]/VEGF adenoviral overexpression) and in vivo inhibition of RA synthesis show that RA and VEGF act as repressors of CoSMC differentiation, whereas VEGF biases epicardially derived cell differentiation toward the endothelial phenotype. Conclusion: Experiments support a model in which early high levels of RA and VEGF prevent CoSMC differentiation from epicardially derived cells before RA and VEGF levels decline as an extensive endothelial network is established. We suggest this physiological delay guarantees the formation of a complex, hierarchical, tree of coronary vessels. (Circ Res. 2010;107:204-216.)

TRANSITIVE CIRCLE EXCHANGE TRANSFORMATIONS WITH FLIPS

We study the existence of transit we exchange transformations with flips defined on the unit circle S(1). We provide a complete answer to the question of whether there exists a transitive exchange transformation of S(1) defined on a subintervals and having f flips.

Exchange transformations reversing orientation

University of Sao Paulo (USP)

NONSTATIONARY MIXING AND THE UNIQUE ERGODICITY OF ADIC TRANSFORMATIONS

We define topological and measure-theoretic mixing for nonstationary dynamical systems and prove that for a nonstationary subshift of finite type, topological mixing implies the minimality of any adic transformation defined on the edge space, while if the Parry measure sequence is mixing, the adic transformation is uniquely ergodic. We also show this measure theoretic mixing is equivalent to weak ergodicity of the edge matrices in the sense of inhomogeneous Markov chain theory.

Synthesis, spectroscopic characterization and X-ray structures of five-coordinate diorganotin(IV) complexes containing 5-hydroxypyrazoline derivatives as ligands

Four new diorganotin(IV) complexes have been prepared from R(2)SnCl(2) (R = Me, Ph) with the ligands 5-hydroxy-3-metyl-5-phenyl-1-(S-benzildithiocarbazate)-pyrazoline (H(2)L(1)) and 5-hydroxy-3-methyl-5-phenyl-1-(2-thiophenecarboxylic)-pyrazoline (H(2)L(2)). The complexes were characterized by elemental analysis, IR. (1)H (13)C, (119)Sn NMR and Mossbauer spectroscopes The complexes [Me(2)SnL(1)], [Ph(2)SnL(1)] and [Me(2)SnL(2)] were also studied by single crystal X-ray diffraction and the results showed that the Sn(IV) central atom of the complexes adopts a distorted trigonal bipyramidal (TBP) geometry with the N atom of the ONX-tridentate (X = O and S) ligand and two organic groups occupying equatorial sites. The C-Sn-C angles for [Me(2)Sn(L(1))] and [Ph(2)Sn(L(1))] were calculated using a correlation between (119)Sn Mossbauer and X-ray crystallographic data based on the point-charge model Theoretical calculations were performed with the B3LYP density functional employing 3-21G(*) and DZVP all electron basis sets showing good agreement with experimental findings General and Sn(IV) specific IR harmonic frequency scale factors for both basis sets were obtained from comparison with selected experimental frequencies (C) 2010 Elsevier B V All rights reserved

Central chemoreceptors and neural mechanisms of cardiorespiratory control

The arterial partial pressure (P CO2) of carbon dioxide is virtually constant because of the close match between the metabolic production of this gas and its excretion via breathing. Blood gas homeostasis does not rely solely on changes in lung ventilation, but also to a considerable extent on circulatory adjustments that regulate the transport of CO2 from its sites of production to the lungs. The neural mechanisms that coordinate circulatory and ventilatory changes to achieve blood gas homeostasis are the subject of this review. Emphasis will be placed on the control of sympathetic outflow by central chemoreceptors. High levels of CO2 exert an excitatory effect on sympathetic outflow that is mediated by specialized chemoreceptors such as the neurons located in the retrotrapezoid region. In addition, high CO2 causes an aversive awareness in conscious animals, activating wake-promoting pathways such as the noradrenergic neurons. These neuronal groups, which may also be directly activated by brain acidification, have projections that contribute to the CO2-induced rise in breathing and sympathetic outflow. However, since the level of activity of the retrotrapezoid nucleus is regulated by converging inputs from wake-promoting systems, behavior-specific inputs from higher centers and by chemical drive, the main focus of the present manuscript is to review the contribution of central chemoreceptors to the control of autonomic and respiratory mechanisms.

Entre a corte e a revolução: a atuação de um "negociante" na América sede do Império português

O artigo discute a trajetória de Manuel Luís da Veiga que, como comerciante em Portugal (seu território natal), investiu na instalação de uma fábrica em Pernambuco após a chegada da família real no Rio de Janeiro, tendo em vista as transformações que à época se processavam no Império português. O foco da análise centra-se no campo das sociabilidades políticas, com destaque para a atuação de Veiga na corte carioca e sua produção literária sobre economia política, entendendo-as como duas dimensões indissociáveis de sua prática social. Defende-se aqui que sua trajetória ilumina um mundo em profunda mudança nos seus paradigmas, impossível de ser sintetizado pelo estabelecimento de um padrão preciso de distinção entre o que era antigo e o que era novidade no início dos oitocentos.

Transmissão psíquica transgeracional e construção de subjetividade: relato de uma psicoterapia psicanalítica vincular

O presente artigo tem como objetivo refletir acerca do conceito de transmissão psíquica entre gerações, especificamente de uma modalidade - a transmissão psíquica transgeracional - e sua influência na construção das subjetividades individuais e dos vínculos familiares, enfatizando-se aqui o vínculo mãe-filha como gerador de sintomas na criança e conflitos no âmbito familiar, através de um relato clínico de uma psicoterapia psicanalítica vincular, segundo os referenciais de Eiguer (2006) e Berenstein e Puget (1997, 2005). A apresentação do caso clínico permite discutir, ainda, a relação entre a transmissão psíquica transgeracional e o estabelecimento da “maternagem”, bem como os resultados obtidos ao longo de todo o processo psicoterápico. A finalidade desse espaço terapêutico familiar é a de propiciar transformações frente ao legado geracional, promovendo o surgimento de uma subjetividade nova, impulsionadora de vida.

Casamento contemporâneo: revisão de literatura acerca da opção por não ter filhos

Em meio às diversas transformações sofridas pelo casamento e pela família ao longo da história, várias configurações familiares convivem na contemporaneidade: nuclear, monoparental, homoparental, recomposta, entre outras possibilidades. Nesse contexto, aumenta, em vários países, e mais recentemente no Brasil, o número de casais que escolhem não ter filhos. O objetivo deste trabalho foi realizar uma revisão bibliográfica sobre o tema, incluindo publicações nacionais e internacionais. A busca foi feita em bases de dados (Web of Science, PsycINFO, Medline, SciELO, Lilacs, Psicodoc, BVS-Psi, Dedalus), e foram levantados artigos completos em periódicos indexados e resumos de teses e dissertações produzidas nos últimos dez anos. Os resultados coletados abordam diversas facetas do fenômeno da escolha contemporânea por não ter filhos: motivações declaradas, associação entre esse tipo de escolha e a situação profissional, relação com fatores de história de vida e família de origem, satisfação de vida e conjugal, preconceito e estereótipos negativos.

As vivências: questões de tradução, sentidos e fontes epistemológicas no legado de Vigotski

O objetivo deste artigo é abordar a questão das vivências na perspectiva de L.S. Vigotski, tratando de suas fontes epistemológicas, de suas raízes na língua russa e de seus sentidos específicos, priorizando "A Tragédia do Hamlet, Príncipe da Dinamarca" (1916) e os textos pedológicos dos anos 1930, com destaque para "A questão do meio na pedologia". Destacam-se as transformações das ideias do autor sobre vivências e sua contribuição metodológica à  análise da relação indivíduo-meio no desenvolvimento humano, articulada aos conceitos de consciência e sistema.

Uma perspectiva computacional sobre catálise enzimática

Enzymes are extremely efficient catalysts. Here, part of the mechanisms proposed to explain this catalytic power will be compared to quantitative experimental results and computer simulations. Influence of the enzymatic environment over species along the reaction coordinate will be analysed. Concepts of transition state stabilisation and reactant destabilisation will be confronted. Divided site model and near-attack conformation hypotheses will also be discussed. Molecular interactions such as covalent catalysis, general acid-base catalysis, electrostatics, entropic effects, steric hindrance, quantum and dynamical effects will also be analysed as sources of catalysis. Reaction mechanisms, in particular that catalysed by protein tyrosine phosphatases, illustrate the concepts.