Mode of Peroxisome Proliferator-Activated Receptor gamma Activation by Luteolin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Death by apoptosis in salivary glands of females of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari : Ixodidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ultrastructure of oocytes of the Urostreptus atrobrunneus (Diplopoda, Spirostreptida, Spirostreptidae): A potential urban centers plague

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Muscle damage slows oxygen uptake kinetics during moderate-intensity exercise performed at high pedal rate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Moisture sorption isotherms of fresh and blanched pumpkin (Cucurbita moschata)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Superstrings in 2D backgrounds with R-R flux and new extremal black holes

The hybrid formalism is used to quantize the superstring compactified to two-dimensional target-space in a manifestly spacetime supersymmetric manner. A quantizable sigma model action is then constructed for the type II superstring in curved two-dimensional supergravity backgrounds which can include Ramond-Ramond flux. Such curved backgrounds include Calabi-Yau fourfold compactifications with Ramond-Ramond flux, and new extremal black hole solutions in two-dimensional dilaton supergravity theory. These black hole solutions are a natural generalization of the CGHS model and might be possible to describe using a supergroup version of the SL(2, R)/U(1) WZW model. We also study some dynamical aspects of the new black holes, such as formation and evaporation. (C) 2001 Published by Elsevier B.V. B.V.

Ten-dimensional supergravity constraints from the pure spinor formalism for the superstring

It has recently been shown that the ten-dimensional superstring can be quantized using the BRST operator Q = philambda(alpha)d(alpha), where lambda(alpha) is a pure spinor satisfying; lambdagamma(m)lambda = 0 and dalpha is the fermionic supersymmetric derivative. In this paper, the pure spinor version of superstring theory is formulated in a curved supergravity background and it is shown that nilpotency and holomorphicity of the pure spinor BRST operator imply the on-shell superspace constraints of the supergravity background. This is shown to lowest order in alpha' for the heterotic and Type II superstrings, thus providing a compact pure spinor version of the ten-dimensional superspace constraints for N = 1 Type IIA and Type IIB supergravities. Since quantization is straightforward using the pure spinor version of the superstring, it is expected that these methods can also be used to compute higher-order alpha' corrections to the ten-dimensional superspace constraints. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Quantization of the superstring in Ramond-Ramond backgrounds

Sigma model actions are constructed for the type II superstring compactified to four-and six-dimensional curved backgrounds which can contain non-vanishing Ramond-Ramond fields. These actions are N = 2 worldsheet superconformally invariant and can be covariantly quantized preserving manifest spacetime supersymmetry. They are constructed using a hybrid Version of superstring variables which combines features of the Ramond-Neveu-Schwarz and Green-Schwarz formalisms. For the AdS(2) x S-2 and AdS(3) x S-3 backgrounds, these actions differ from the classical Green-Schwarz actions by a crucial kinetic term for the fermions. Parts of this work have been done in collaborations with M Bershadsky, T Hauer, W Siegel, C Vafa, E Witten, S Zhukov and B Zwiebach.

One-loop superstring amplitude from integrals on pure spinors space

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Taming the b antighost with Ramond-Ramond flux

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hydrothermal rare earth elements mineralization in the Barra do Itapirapua carbonatite, southern Brazil: behaviour of selected trace elements and stable isotopes (C, O)

The Bura do Itapira pua carbonatite is located in southern Brazil and belongs to the Cretaceous Ponta Grossa alkaline-carbonatitic province related to the opening of the South Atlantic. The carbonatite complex is emplaced in Proterozoic granites and is mainly composed of plutonic magnesio- to ferrocarbonatite, with smaller amounts of subvolcanic magnesiocarbonatite. Hydrothermal alteration of the carbonatite has led to the formation of quartz, apatite, fluorite, rue earth fluorocarbonates, barite and sulfides in variable proportions. Trace element data, delta(13)C and delta(18)O are presented here, with the aim of better understanding the geochemical nature of hydrothermal alteration related to rare earth elements (REE) mineralization. The non-overprinted plutonic carbonatite shows the lowest REE contents, and its primitive carbon and oxygen stable isotopic composition places it in the field of primary igneous carbonatites. Two types of hydrothermally overprinted plutonic carbonatites can be distinguished based on secondary minerals and geochemical composition. Type I contains mainly quartz, rare earth fluorocarbonates and apatite as hydrothermal secondary minerals, and has steep chondrite normalized REE patterns, with Sigma(REE+Y) of up to 3 wt.% (i.e., two orders of magnitude higher than in fresh plutonic samples). In contrast, the Type II overprint contains apatite, fluorite and barite as dominant hydrothermal minerals, and is characterized by heavy REE enrichment relative to the fresh samples, with flat chondrite normalized REE patterns. Carbon and oxygen stable isotope ratios of Types I and II are elevated (delta(18)O + 8 to + 12 parts per thousand; delta(13)C - 6 to - 2 parts per thousand) relative to the fresh samples. Hydrothermally overprinted carbonatites exposed to weathering show even higher delta(18)O values (delta(18)O 13 to 25 parts per thousand) but no additional REE enrichment. The subvolcanic carbonatite has anomalously high delta(13)C of up to + 1 parts per thousand, which suggests crustal contamination through interaction with carbonate-bearing metasediments. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Peptides based on CcdB protein as novel inhibitors of bacterial topoisomerases

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OBSERVATIONS on ETCHED ENAMEL IN NON-ERUPTED DECIDUOUS MOLARS: A SCANNING ELECTRON MICROSCOPIC STUDY

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

População de plantas e espaçamento entre linhas do feijoeiro irrigado. I: comportamento morfológico das plantas

O experimento foi conduzido com o objetivo de avaliar variações no índice de área foliar, altura das plantas, número de nós, comprimento dos entrenós na haste principal e altura das vagens em relação à superfície do solo do feijoeiro irrigado e cultivado em diferentes populações de plantas e espaçamentos entre linhas de cultivo. O experimento foi conduzido no ano agrícola 1997/98, em área experimental do Departamento de Engenharia Rural da Universidade Federal de Santa Maria (UFSM), Santa Maria, RS. A cultivar de feijão preto BR-FEPAGRO 44 - Guapo brilhante, de crescimento indeterminado (tipo II), foi cultivada em três populações de plantas (175, 250 e 325 mil plantas há-1) e três espaçamentos entre linhas de cultivo (35, 50 e 65cm). Utilizou-se o delineamento experimental inteiramente casualizado, bifatorial, com quatro repetições. Irrigações por aspersão foram aplicadas quando a evapotranspiração máxima da cultura, estimada com base na evaporação do tanque classe A, indicava um valor acumulado de 25mm. Os resultados demonstraram que o aumento da população de plantas ocasionou aumento no índice de área foliar durante a fase de crescimento vegetativo da cultura, sendo que na fase reprodutiva, o índice de área foliar foi afetado pelo espaçamento entre as linhas de cultivo. A área foliar, a altura de plantas e o número de nós na haste principal aumentaram com a redução na população de plantas. A altura da extremidade da primeira vagem das plantas em relação ao solo apresentou comportamento quadrático com o aumento na população de plantas. Os diferentes espaçamentos e populações de plantas não afetaram o comprimento dos entrenós na haste principal das plantas.

Secretion of salivary glands of the Brazilian termite Serritermes serrifer Hagen&Bates (Isoptera: Serritermitidae)

The salivary glands of termites are composed of several secretory acini connected by ducts. These glands, in the Brazilian termite Serritermes serrifer, were examined through the electron microscope. The ultrastructure of worker salivary acinus revealed central ductule cells and four different types of cells. Cells of type I contain an abundance of electron-lucid vacuoles of various sizes which fuse to form enormous vacuolar structures that fill up most of the cell. Cells of type II are narrow cells in which the secretion is contained in small clear vacuoles of approximately equal diameter. Both of these cellular types have numerous Golgi bodies and rough endoplasmic reticulum. Type III or parietal cells have an apical plasma membrane deeply infolded and lined by microvilli. This type of cell is located in the acinar periphery and occurs in pairs. Cells of type IV are completely filled with electrondense secretion. The secretory granules can be small in some cells or large and similar to fingerprints in others. This is the first report of the occurrence of these spiral or concentric rings of dense material in the salivary gland of Isoptera.