Hamilton-Jacobi approach for first order actions and theories with higher derivatives

In this work, we analyze systems described by Lagrangians with higher order derivatives in the context of the Hamilton-Jacobi formalism for first order actions. Two different approaches are studied here: the first one is analogous to the description of theories with higher derivatives in the hamiltonian formalism according to [D.M. Gitman, S.L. Lyakhovich, I.V. Tyutin, Soviet Phys. J. 26 (1983) 730; D.M. Gitman, I.V. Tyutin, Quantization of Fields with Constraints, Springer-Verlag, New York, Berlin, 1990] the second treats the case where degenerate coordinate are present, in an analogy to reference [D.M. Gitman, I.V. Tyutin, Nucl. Phys. B 630 (2002) 509]. Several examples are analyzed where a comparison between both approaches is made. (C) 2007 Elsevier B.V. All rights reserved.

Ultrastructural morphology and morphometry of the normal corneal endothelium of adult crossbred pig

O endotélio corneal é uma monocamada de células poligonais. A integridade e saúde dessa camada são essenciais para a manutenção da transparência corneal normal. Este estudo reportou pela primeira vez, de forma detalhada, a morfologia ultra-estrutural e a morfometria do endotélio corneal de suínos adultos mestiços à microscopia eletrônica de varredura (MEV). A superfície endothelial corneal apresentou um padrão regular de células poligonais, com predomínio da forma hexagonal e de bordas celulares nítidas. O núcleo foi observado como protuberância arredondada no centro da célula. Também foram observados os cílios (2-4) em apenas algumas células da região periférica da córnea, as aberturas das vesículas pinocitóticas na proximidade dos cílios, as microvilosidades, as varas da borda e as bordas celulares em formato de zigzag. A área celular média foi significativamente maior (P<0,05) no centro da córnea do que na periferia, com um coeficiente de variação menor no centro da córnea. A densidade celular média foi significativamente maior na periferia (P<0,05) e 43,9% maior que os dados reportados por outros autores na microscopia especular, o que demonstra o efeito da retração celular durante o processamento das amostras. O valor médio do número de lados das células (pleomorfismo) foi de 5,9, o que evidencia um predomínio do formato hexagonal. A percentagem de células hexagonais foi significativamente maior no centro (P<0,001). Os parâmetros obtidos nesta pesquisa servirão de base para estudos futuros sobre o efeito de medicamentos, cirurgias intracamerulares ou soluções para armazenamento de córneas para transplantes no endotélio corneal do suíno.

Comparison of caffeine-induced locomotor activity between adolescent and adult rats

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

Intraspecific Variation of Biological Activities in Venoms from Wild and Captive Bothrops jararaca

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

Photo-electrochemical investigation of anodic oxide films on cast Ti-Mo alloys I. Anodic behaviour and effect of alloy composition

The anodic behaviour of cast Ti-Mo alloys, having different Mo contents (6-20 wt.%), was investigated in acidic and neutral aerated aqueous solutions. All sample showed a valve-metal behaviour, owing to formation and thickening of barrier-type anodic oxides displaying interference colours Growth kinetics. of passive films is influenced by both anodizing electrolyte and composition of the starting alloy. This last parameter was found to change also the solid-state properties of the films, explored by photoelectrochemical and impedance spectroscopy experiments. Thicker films (U(f) = 8 V/MSE) grown on alloys richer in Mo showed more resistive character and a photocurrent sign inversion under negative bias, that revealed an insulating character, whereas corresponding films grown on alloys with lower Mo content, as well as thinner films, behaved as n-type semiconductors. Results are discussed in terms of formation of a mixed Ti-Mo oxide phase. (C) 2008 Elsevier Ltd. All rights reserved

A comparative-analysis of glycosaminoglycans from human umbilical arteries in normal subjects and in pathological conditions affecting pregnancy

BACKGROUND: Vascular cells express different phenotypes in adult and fetal vessels, and the extracellular matrix they synthesize should reflect these differences. Alterations of vascular proteoglycan/glycosaminoglycan is verified in disorders such as hypertension and diabetes, and when occurring during pregnancy, they bring about structural changes to fetal vessels that often lead to impaired fetus growth. Yet there is little data about the extracellular matrix of an important human fetal vessel, the umbilical artery.EXPERIMENTAL DESIGN: This study involved the biochemical characterization of the extracellular matrix of normal umbilical arteries, umbilical arteries from complicated pregnancies (maternal hypertension and diabetes and intrauterine growth retardation syndrome), and, for purpose of comparison, normal adult arteries (aorta and iliac and pulmonary arteries). Although the collagen types I:III ratio was determined in some cases, emphasis was placed on analysis of glycosaminoglycans.RESULTS: Normal umbilical arteries differ from normal adult arteries in that they contain greater concentrations of hyaluronic acid and lesser concentrations of heparan sulfate and chondroitin 4-and 6-sulfate. The umbilical artery also differs from adult arteries in the disaccharide composition of its chondroitin and heparan sulfates and in the molecular weight of this latter glycosaminoglycan. The glycosaminoglycan distribution in umbilical arteries derived from complicated pregnancies is roughly similar to that of controls. However, total glycosaminoglycan and collagen were significantly reduced, and the collagen I:III ratio was increased in the umbilical arteries from hypertension-complicated pregnancies.CONCLUSIONS: the glycosaminoglycan composition of the normal umbilical artery, a fully differentiated tissue, differs in many aspects from that of normal adult arteries. of the cases of complicated pregnancies studied, the extracellular matrix of umbilical arteries was altered only in maternal hypertension. The changes, notably a mild fibrosis, were not very pronounced and should not impair hemodynamic properties of the vessel.

Biomass production and chemical composition of essential oil of Piper callosum as affected by spacing in Manaus, Amazonas State, Brazil

The family Piperaceae contains nearly 2000 species, most of them distributed in two genera, Piper and Peperomia. In Brazil circa 170 Piper species are found, mainly in tropical areas Their use ranges from flavoring and culinary to raw material for pharmaceutical and cosmetic industry. One of these species, Piper callosum, is used in folk medicine in the Amazon area. The objective of this study was to evaluate the production of biomass (aerial parts) as well as yield and composition of the essential oil from the leaves, according to different spacing between cultivated plants at Embrapa Western Amazon, in Manaus, State of Amazonas, Brazil. The experimental design was randomized blocks, with four treatments and seven replicates with six plants. Biomass production was inversely proportional to the spatial arrangements, with the greatest biomass production (1034.93 kg/ha) in the shortest spacing (E1), although no statistical difference was verified between E3 and E4. The same response was observed for the production of essential oil. The chemical composition of the oil was not affected by spacing, and major compounds found were safrole (59.1%), beta-pinene (8.3%), alpha-pinene (6.5%), methyl eugenol (6.3%) and 1,8-cineole (4.1).

Distribution, composition and seasonality of aquatic birds in the Nhecolandia sub-region of South Pantanal, Brazil

Despite remarkable significance of Pantanal for the conservation of aquatic birds, the status of their populations, the spatiotemporal patterns of distribution and habitat use and structure of communities are little known. Thus, we studied three aquatic environments (Negro river, bays and salines) from 2007 to 2009 in the Nhecolandia Pantanal to verify the distribution and composition of aquatic birds and also if there is significant seasonal influence on these aspects. We adopted the transect method (288 hours of sampling) and recorded 135 species (7.834 individuals). The Negro river showed the highest diversity, while the salines the lowest. The similarity of aquatic bird communities was higher between bays and salines, followed by Negro river and bays and lower between salines and Negro river. The equidistribution is more variable in the salines and more stable in the Negro river. The environments strongly differ from each other in aquatic bird composition in space (habitat use and distribution) and time (seasonal water fluctuations). The diversity of bird community in the dry season varies significantly in the salines, followed by the bays and more stable in the Negro river. The Negro river, regardless of large annual amplitude of flow, is more seasonally stable since its riparian vegetation is continuous (not isolated) and constant. These aspects provide better conditions to stay all year, contributing to decrease the seasonal nomadic tendencies of aquatic birds. Finally, all these data provide strong arguments to the preservation of all phytophysiognomies in the Nhecolandia sub-region of Pantanal, but with special attention to the salines widely used by many flocks of aquatic birds (mainly in the dry season) and migrant and/or rare species restricted to this habitat.

Mycorrhization alters foliar soluble amino acid composition and influences tolerance to Pb in Calopogonium mucunoides

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cross-sensitization between testosterone and cocaine in adolescent and adult rats

Cocaine and anabolic-androgenic steroids are substances commonly co-abused. The use of anabolic steroids and cocaine has increased among adolescents. However, few studies investigated the consequences of the interaction between anabolic-androgenic steroids in animals' model of adolescence. We examined the effects of acute and repeated testosterone administration on cocaine-induced locomotor activity in adult and adolescent rats. Rats received ten once-daily subcutaneous (s.c.) injections of testosterone (10mg/kg) or vehicle. Three days after the last testosterone or vehicle injections rats received an intraperitoneal (i.p.) challenge injection of either saline or cocaine (10mg/kg). A different subset of rats was treated with a single injection of testosterone (10mg/kg) or vehicle and three days later was challenged with cocaine (10mg/kg, i.p.) or saline. Immediately after cocaine or saline injections the locomotor activity was recorded during forty minutes. Our results demonstrated that repeated testosterone induced locomotor sensitization to cocaine in adolescent but not adult rats.

Intrauterine exposure to bisphenol A promotes different effects in both neonatal and adult prostate of male and female gerbils (Meriones unguiculatus)

Substances that mimic endogenous hormones may alter the cell signaling that govern prostate development and predispose it to developing lesions in adult and senile life. Bisphenol A is able to mimic estrogens, and studies have demonstrated that low levels of exposure to this compound have caused alterations during prostate development. The aim of this study was to describe the prostate development in both male and female neonatal gerbils in normal conditions and under exposure to BPA during intrauterine life, and also to analyze whether the effects of intrauterine exposure to BPA remain in adulthood. Morphological, stereological, three-dimensional reconstruction, and immunohistochemical methods were employed. The results demonstrated that in 1-day-old normal gerbils, the female paraurethral glands and the male ventral lobe are morphologically similar, although its tissue components-epithelial buds (EB), periurethral mesenchyme (PeM), paraurethral mesenchyme (PaM) or ventral mesenchymal pad (VMP), and smooth muscle (SM)-have presented different immunolabeling pattern for androgen receptor (AR), and for proliferating cell nuclear antigen (PCNA). Moreover, we observed a differential response of male and female prostate to intrauterine BPA exposure. In 1-day-old males, the intrauterine exposure to BPA caused a decrease of AR-positive cells in the PeM and SM, and a decrease of the proliferative status in the EB. In contrast, no morphological alterations were observed in ventral prostate of adult males. In 1-day-old females, BPA exposure promoted an increase of estrogen receptor alpha (ERα) positive cells in PeM and PaM, a decrease of AR-positive cells in EB and PeM, besides a reduction of cell proliferation in EB. Additionally, the adult female prostate of BPA-exposed animals presented an increase of AR- and PCNA-positive cells. These results suggest that the prostate of female gerbils were more susceptible to the intrauterine BPA effects, since they became more proliferative in adult life. © 2015 Wiley Periodicals, Inc. Environ Toxicol, 2015.